Adding upstream version 5.10.209.upstream/5.10.209

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
author: Daniel Baumann <daniel.baumann@progress-linux.org> 2024-04-27 10:05:51 +0000
committer: Daniel Baumann <daniel.baumann@progress-linux.org> 2024-04-27 10:05:51 +0000
commit: 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch)
tree: a94efe259b9009378be6d90eb30d2b019d95c194 /Documentation/driver-api/media
parent: Initial commit. (diff)
download: linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.tar.xz
linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.zip
53 files changed, 11178 insertions, 0 deletions
diff --git a/Documentation/driver-api/media/camera-sensor.rst b/Documentation/driver-api/media/camera-sensor.rst
new file mode 100644
index 000000000..4d1ae12b9
--- /dev/null
+++ b/Documentation/driver-api/media/camera-sensor.rst
@@ -0,0 +1,134 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+Writing camera sensor drivers
+=============================
+
+CSI-2
+-----
+
+Please see what is written on :ref:`MIPI_CSI_2`.
+
+Handling clocks
+---------------
+
+Camera sensors have an internal clock tree including a PLL and a number of
+divisors. The clock tree is generally configured by the driver based on a few
+input parameters that are specific to the hardware:: the external clock frequency
+and the link frequency. The two parameters generally are obtained from system
+firmware. No other frequencies should be used in any circumstances.
+
+The reason why the clock frequencies are so important is that the clock signals
+come out of the SoC, and in many cases a specific frequency is designed to be
+used in the system. Using another frequency may cause harmful effects
+elsewhere. Therefore only the pre-determined frequencies are configurable by the
+user.
+
+Frame size
+----------
+
+There are two distinct ways to configure the frame size produced by camera
+sensors.
+
+Freely configurable camera sensor drivers
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Freely configurable camera sensor drivers expose the device's internal
+processing pipeline as one or more sub-devices with different cropping and
+scaling configurations. The output size of the device is the result of a series
+of cropping and scaling operations from the device's pixel array's size.
+
+An example of such a driver is the smiapp driver (see drivers/media/i2c/smiapp).
+
+Register list based drivers
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Register list based drivers generally, instead of able to configure the device
+they control based on user requests, are limited to a number of preset
+configurations that combine a number of different parameters that on hardware
+level are independent. How a driver picks such configuration is based on the
+format set on a source pad at the end of the device's internal pipeline.
+
+Most sensor drivers are implemented this way, see e.g.
+drivers/media/i2c/imx319.c for an example.
+
+Frame interval configuration
+----------------------------
+
+There are two different methods for obtaining possibilities for different frame
+intervals as well as configuring the frame interval. Which one to implement
+depends on the type of the device.
+
+Raw camera sensors
+~~~~~~~~~~~~~~~~~~
+
+Instead of a high level parameter such as frame interval, the frame interval is
+a result of the configuration of a number of camera sensor implementation
+specific parameters. Luckily, these parameters tend to be the same for more or
+less all modern raw camera sensors.
+
+The frame interval is calculated using the following equation::
+
+	frame interval = (analogue crop width + horizontal blanking) *
+			 (analogue crop height + vertical blanking) / pixel rate
+
+The formula is bus independent and is applicable for raw timing parameters on
+large variety of devices beyond camera sensors. Devices that have no analogue
+crop, use the full source image size, i.e. pixel array size.
+
+Horizontal and vertical blanking are specified by ``V4L2_CID_HBLANK`` and
+``V4L2_CID_VBLANK``, respectively. The unit of these controls are lines. The
+pixel rate is specified by ``V4L2_CID_PIXEL_RATE`` in the same sub-device. The
+unit of that control is Hz.
+
+Register list based drivers need to implement read-only sub-device nodes for the
+purpose. Devices that are not register list based need these to configure the
+device's internal processing pipeline.
+
+The first entity in the linear pipeline is the pixel array. The pixel array may
+be followed by other entities that are there to allow configuring binning,
+skipping, scaling or digital crop :ref:`v4l2-subdev-selections`.
+
+USB cameras etc. devices
+~~~~~~~~~~~~~~~~~~~~~~~~
+
+USB video class hardware, as well as many cameras offering a similar higher
+level interface natively, generally use the concept of frame interval (or frame
+rate) on device level in firmware or hardware. This means lower level controls
+implemented by raw cameras may not be used on uAPI (or even kAPI) to control the
+frame interval on these devices.
+
+Power management
+----------------
+
+Always use runtime PM to manage the power states of your device. Camera sensor
+drivers are in no way special in this respect: they are responsible for
+controlling the power state of the device they otherwise control as well. In
+general, the device must be powered on at least when its registers are being
+accessed and when it is streaming.
+
+Existing camera sensor drivers may rely on the old
+:c:type:`v4l2_subdev_core_ops`->s_power() callback for bridge or ISP drivers to
+manage their power state. This is however **deprecated**. If you feel you need
+to begin calling an s_power from an ISP or a bridge driver, instead please add
+runtime PM support to the sensor driver you are using. Likewise, new drivers
+should not use s_power.
+
+Please see examples in e.g. ``drivers/media/i2c/ov8856.c`` and
+``drivers/media/i2c/smiapp/smiapp-core.c``. The two drivers work in both ACPI
+and DT based systems.
+
+Control framework
+~~~~~~~~~~~~~~~~~
+
+``v4l2_ctrl_handler_setup()`` function may not be used in the device's runtime
+PM ``runtime_resume`` callback, as it has no way to figure out the power state
+of the device. This is because the power state of the device is only changed
+after the power state transition has taken place. The ``s_ctrl`` callback can be
+used to obtain device's power state after the power state transition:
+
+.. c:function::
+	int pm_runtime_get_if_in_use(struct device *dev);
+
+The function returns a non-zero value if it succeeded getting the power count or
+runtime PM was disabled, in either of which cases the driver may proceed to
+access the device.
diff --git a/Documentation/driver-api/media/cec-core.rst b/Documentation/driver-api/media/cec-core.rst
new file mode 100644
index 000000000..bc42982ac
--- /dev/null
+++ b/Documentation/driver-api/media/cec-core.rst
@@ -0,0 +1,464 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+CEC Kernel Support
+==================
+
+The CEC framework provides a unified kernel interface for use with HDMI CEC
+hardware. It is designed to handle a multiple types of hardware (receivers,
+transmitters, USB dongles). The framework also gives the option to decide
+what to do in the kernel driver and what should be handled by userspace
+applications. In addition it integrates the remote control passthrough
+feature into the kernel's remote control framework.
+
+
+The CEC Protocol
+----------------
+
+The CEC protocol enables consumer electronic devices to communicate with each
+other through the HDMI connection. The protocol uses logical addresses in the
+communication. The logical address is strictly connected with the functionality
+provided by the device. The TV acting as the communication hub is always
+assigned address 0. The physical address is determined by the physical
+connection between devices.
+
+The CEC framework described here is up to date with the CEC 2.0 specification.
+It is documented in the HDMI 1.4 specification with the new 2.0 bits documented
+in the HDMI 2.0 specification. But for most of the features the freely available
+HDMI 1.3a specification is sufficient:
+
+http://www.microprocessor.org/HDMISpecification13a.pdf
+
+
+CEC Adapter Interface
+---------------------
+
+The struct cec_adapter represents the CEC adapter hardware. It is created by
+calling cec_allocate_adapter() and deleted by calling cec_delete_adapter():
+
+.. c:function::
+   struct cec_adapter *cec_allocate_adapter(const struct cec_adap_ops *ops, \
+					    void *priv, const char *name, \
+					    u32 caps, u8 available_las);
+
+.. c:function::
+   void cec_delete_adapter(struct cec_adapter *adap);
+
+To create an adapter you need to pass the following information:
+
+ops:
+	adapter operations which are called by the CEC framework and that you
+	have to implement.
+
+priv:
+	will be stored in adap->priv and can be used by the adapter ops.
+	Use cec_get_drvdata(adap) to get the priv pointer.
+
+name:
+	the name of the CEC adapter. Note: this name will be copied.
+
+caps:
+	capabilities of the CEC adapter. These capabilities determine the
+	capabilities of the hardware and which parts are to be handled
+	by userspace and which parts are handled by kernelspace. The
+	capabilities are returned by CEC_ADAP_G_CAPS.
+
+available_las:
+	the number of simultaneous logical addresses that this
+	adapter can handle. Must be 1 <= available_las <= CEC_MAX_LOG_ADDRS.
+
+To obtain the priv pointer use this helper function:
+
+.. c:function::
+	void *cec_get_drvdata(const struct cec_adapter *adap);
+
+To register the /dev/cecX device node and the remote control device (if
+CEC_CAP_RC is set) you call:
+
+.. c:function::
+	int cec_register_adapter(struct cec_adapter *adap, \
+				 struct device *parent);
+
+where parent is the parent device.
+
+To unregister the devices call:
+
+.. c:function::
+	void cec_unregister_adapter(struct cec_adapter *adap);
+
+Note: if cec_register_adapter() fails, then call cec_delete_adapter() to
+clean up. But if cec_register_adapter() succeeded, then only call
+cec_unregister_adapter() to clean up, never cec_delete_adapter(). The
+unregister function will delete the adapter automatically once the last user
+of that /dev/cecX device has closed its file handle.
+
+
+Implementing the Low-Level CEC Adapter
+--------------------------------------
+
+The following low-level adapter operations have to be implemented in
+your driver:
+
+.. c:struct:: cec_adap_ops
+
+.. code-block:: none
+
+	struct cec_adap_ops
+	{
+		/* Low-level callbacks */
+		int (*adap_enable)(struct cec_adapter *adap, bool enable);
+		int (*adap_monitor_all_enable)(struct cec_adapter *adap, bool enable);
+		int (*adap_monitor_pin_enable)(struct cec_adapter *adap, bool enable);
+		int (*adap_log_addr)(struct cec_adapter *adap, u8 logical_addr);
+		int (*adap_transmit)(struct cec_adapter *adap, u8 attempts,
+				      u32 signal_free_time, struct cec_msg *msg);
+		void (*adap_status)(struct cec_adapter *adap, struct seq_file *file);
+		void (*adap_free)(struct cec_adapter *adap);
+
+		/* Error injection callbacks */
+		...
+
+		/* High-level callbacks */
+		...
+	};
+
+The seven low-level ops deal with various aspects of controlling the CEC adapter
+hardware:
+
+
+To enable/disable the hardware::
+
+	int (*adap_enable)(struct cec_adapter *adap, bool enable);
+
+This callback enables or disables the CEC hardware. Enabling the CEC hardware
+means powering it up in a state where no logical addresses are claimed. This
+op assumes that the physical address (adap->phys_addr) is valid when enable is
+true and will not change while the CEC adapter remains enabled. The initial
+state of the CEC adapter after calling cec_allocate_adapter() is disabled.
+
+Note that adap_enable must return 0 if enable is false.
+
+
+To enable/disable the 'monitor all' mode::
+
+	int (*adap_monitor_all_enable)(struct cec_adapter *adap, bool enable);
+
+If enabled, then the adapter should be put in a mode to also monitor messages
+that not for us. Not all hardware supports this and this function is only
+called if the CEC_CAP_MONITOR_ALL capability is set. This callback is optional
+(some hardware may always be in 'monitor all' mode).
+
+Note that adap_monitor_all_enable must return 0 if enable is false.
+
+
+To enable/disable the 'monitor pin' mode::
+
+	int (*adap_monitor_pin_enable)(struct cec_adapter *adap, bool enable);
+
+If enabled, then the adapter should be put in a mode to also monitor CEC pin
+changes. Not all hardware supports this and this function is only called if
+the CEC_CAP_MONITOR_PIN capability is set. This callback is optional
+(some hardware may always be in 'monitor pin' mode).
+
+Note that adap_monitor_pin_enable must return 0 if enable is false.
+
+
+To program a new logical address::
+
+	int (*adap_log_addr)(struct cec_adapter *adap, u8 logical_addr);
+
+If logical_addr == CEC_LOG_ADDR_INVALID then all programmed logical addresses
+are to be erased. Otherwise the given logical address should be programmed.
+If the maximum number of available logical addresses is exceeded, then it
+should return -ENXIO. Once a logical address is programmed the CEC hardware
+can receive directed messages to that address.
+
+Note that adap_log_addr must return 0 if logical_addr is CEC_LOG_ADDR_INVALID.
+
+
+To transmit a new message::
+
+	int (*adap_transmit)(struct cec_adapter *adap, u8 attempts,
+			     u32 signal_free_time, struct cec_msg *msg);
+
+This transmits a new message. The attempts argument is the suggested number of
+attempts for the transmit.
+
+The signal_free_time is the number of data bit periods that the adapter should
+wait when the line is free before attempting to send a message. This value
+depends on whether this transmit is a retry, a message from a new initiator or
+a new message for the same initiator. Most hardware will handle this
+automatically, but in some cases this information is needed.
+
+The CEC_FREE_TIME_TO_USEC macro can be used to convert signal_free_time to
+microseconds (one data bit period is 2.4 ms).
+
+
+To log the current CEC hardware status::
+
+	void (*adap_status)(struct cec_adapter *adap, struct seq_file *file);
+
+This optional callback can be used to show the status of the CEC hardware.
+The status is available through debugfs: cat /sys/kernel/debug/cec/cecX/status
+
+To free any resources when the adapter is deleted::
+
+	void (*adap_free)(struct cec_adapter *adap);
+
+This optional callback can be used to free any resources that might have been
+allocated by the driver. It's called from cec_delete_adapter.
+
+
+Your adapter driver will also have to react to events (typically interrupt
+driven) by calling into the framework in the following situations:
+
+When a transmit finished (successfully or otherwise)::
+
+	void cec_transmit_done(struct cec_adapter *adap, u8 status,
+			       u8 arb_lost_cnt,  u8 nack_cnt, u8 low_drive_cnt,
+			       u8 error_cnt);
+
+or::
+
+	void cec_transmit_attempt_done(struct cec_adapter *adap, u8 status);
+
+The status can be one of:
+
+CEC_TX_STATUS_OK:
+	the transmit was successful.
+
+CEC_TX_STATUS_ARB_LOST:
+	arbitration was lost: another CEC initiator
+	took control of the CEC line and you lost the arbitration.
+
+CEC_TX_STATUS_NACK:
+	the message was nacked (for a directed message) or
+	acked (for a broadcast message). A retransmission is needed.
+
+CEC_TX_STATUS_LOW_DRIVE:
+	low drive was detected on the CEC bus. This indicates that
+	a follower detected an error on the bus and requested a
+	retransmission.
+
+CEC_TX_STATUS_ERROR:
+	some unspecified error occurred: this can be one of ARB_LOST
+	or LOW_DRIVE if the hardware cannot differentiate or something
+	else entirely. Some hardware only supports OK and FAIL as the
+	result of a transmit, i.e. there is no way to differentiate
+	between the different possible errors. In that case map FAIL
+	to CEC_TX_STATUS_NACK and not to CEC_TX_STATUS_ERROR.
+
+CEC_TX_STATUS_MAX_RETRIES:
+	could not transmit the message after trying multiple times.
+	Should only be set by the driver if it has hardware support for
+	retrying messages. If set, then the framework assumes that it
+	doesn't have to make another attempt to transmit the message
+	since the hardware did that already.
+
+The hardware must be able to differentiate between OK, NACK and 'something
+else'.
+
+The \*_cnt arguments are the number of error conditions that were seen.
+This may be 0 if no information is available. Drivers that do not support
+hardware retry can just set the counter corresponding to the transmit error
+to 1, if the hardware does support retry then either set these counters to
+0 if the hardware provides no feedback of which errors occurred and how many
+times, or fill in the correct values as reported by the hardware.
+
+Be aware that calling these functions can immediately start a new transmit
+if there is one pending in the queue. So make sure that the hardware is in
+a state where new transmits can be started *before* calling these functions.
+
+The cec_transmit_attempt_done() function is a helper for cases where the
+hardware never retries, so the transmit is always for just a single
+attempt. It will call cec_transmit_done() in turn, filling in 1 for the
+count argument corresponding to the status. Or all 0 if the status was OK.
+
+When a CEC message was received:
+
+.. c:function::
+	void cec_received_msg(struct cec_adapter *adap, struct cec_msg *msg);
+
+Speaks for itself.
+
+Implementing the interrupt handler
+----------------------------------
+
+Typically the CEC hardware provides interrupts that signal when a transmit
+finished and whether it was successful or not, and it provides and interrupt
+when a CEC message was received.
+
+The CEC driver should always process the transmit interrupts first before
+handling the receive interrupt. The framework expects to see the cec_transmit_done
+call before the cec_received_msg call, otherwise it can get confused if the
+received message was in reply to the transmitted message.
+
+Optional: Implementing Error Injection Support
+----------------------------------------------
+
+If the CEC adapter supports Error Injection functionality, then that can
+be exposed through the Error Injection callbacks:
+
+.. code-block:: none
+
+	struct cec_adap_ops {
+		/* Low-level callbacks */
+		...
+
+		/* Error injection callbacks */
+		int (*error_inj_show)(struct cec_adapter *adap, struct seq_file *sf);
+		bool (*error_inj_parse_line)(struct cec_adapter *adap, char *line);
+
+		/* High-level CEC message callback */
+		...
+	};
+
+If both callbacks are set, then an ``error-inj`` file will appear in debugfs.
+The basic syntax is as follows:
+
+Leading spaces/tabs are ignored. If the next character is a ``#`` or the end of the
+line was reached, then the whole line is ignored. Otherwise a command is expected.
+
+This basic parsing is done in the CEC Framework. It is up to the driver to decide
+what commands to implement. The only requirement is that the command ``clear`` without
+any arguments must be implemented and that it will remove all current error injection
+commands.
+
+This ensures that you can always do ``echo clear >error-inj`` to clear any error
+injections without having to know the details of the driver-specific commands.
+
+Note that the output of ``error-inj`` shall be valid as input to ``error-inj``.
+So this must work:
+
+.. code-block:: none
+
+	$ cat error-inj >einj.txt
+	$ cat einj.txt >error-inj
+
+The first callback is called when this file is read and it should show the
+the current error injection state::
+
+	int (*error_inj_show)(struct cec_adapter *adap, struct seq_file *sf);
+
+It is recommended that it starts with a comment block with basic usage
+information. It returns 0 for success and an error otherwise.
+
+The second callback will parse commands written to the ``error-inj`` file::
+
+	bool (*error_inj_parse_line)(struct cec_adapter *adap, char *line);
+
+The ``line`` argument points to the start of the command. Any leading
+spaces or tabs have already been skipped. It is a single line only (so there
+are no embedded newlines) and it is 0-terminated. The callback is free to
+modify the contents of the buffer. It is only called for lines containing a
+command, so this callback is never called for empty lines or comment lines.
+
+Return true if the command was valid or false if there were syntax errors.
+
+Implementing the High-Level CEC Adapter
+---------------------------------------
+
+The low-level operations drive the hardware, the high-level operations are
+CEC protocol driven. The following high-level callbacks are available:
+
+.. code-block:: none
+
+	struct cec_adap_ops {
+		/* Low-level callbacks */
+		...
+
+		/* Error injection callbacks */
+		...
+
+		/* High-level CEC message callback */
+		int (*received)(struct cec_adapter *adap, struct cec_msg *msg);
+	};
+
+The received() callback allows the driver to optionally handle a newly
+received CEC message::
+
+	int (*received)(struct cec_adapter *adap, struct cec_msg *msg);
+
+If the driver wants to process a CEC message, then it can implement this
+callback. If it doesn't want to handle this message, then it should return
+-ENOMSG, otherwise the CEC framework assumes it processed this message and
+it will not do anything with it.
+
+
+CEC framework functions
+-----------------------
+
+CEC Adapter drivers can call the following CEC framework functions:
+
+.. c:function::
+   int cec_transmit_msg(struct cec_adapter *adap, struct cec_msg *msg, \
+			bool block);
+
+Transmit a CEC message. If block is true, then wait until the message has been
+transmitted, otherwise just queue it and return.
+
+.. c:function::
+   void cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr, bool block);
+
+Change the physical address. This function will set adap->phys_addr and
+send an event if it has changed. If cec_s_log_addrs() has been called and
+the physical address has become valid, then the CEC framework will start
+claiming the logical addresses. If block is true, then this function won't
+return until this process has finished.
+
+When the physical address is set to a valid value the CEC adapter will
+be enabled (see the adap_enable op). When it is set to CEC_PHYS_ADDR_INVALID,
+then the CEC adapter will be disabled. If you change a valid physical address
+to another valid physical address, then this function will first set the
+address to CEC_PHYS_ADDR_INVALID before enabling the new physical address.
+
+.. c:function::
+   void cec_s_phys_addr_from_edid(struct cec_adapter *adap, \
+				  const struct edid *edid);
+
+A helper function that extracts the physical address from the edid struct
+and calls cec_s_phys_addr() with that address, or CEC_PHYS_ADDR_INVALID
+if the EDID did not contain a physical address or edid was a NULL pointer.
+
+.. c:function::
+	int cec_s_log_addrs(struct cec_adapter *adap, \
+			    struct cec_log_addrs *log_addrs, bool block);
+
+Claim the CEC logical addresses. Should never be called if CEC_CAP_LOG_ADDRS
+is set. If block is true, then wait until the logical addresses have been
+claimed, otherwise just queue it and return. To unconfigure all logical
+addresses call this function with log_addrs set to NULL or with
+log_addrs->num_log_addrs set to 0. The block argument is ignored when
+unconfiguring. This function will just return if the physical address is
+invalid. Once the physical address becomes valid, then the framework will
+attempt to claim these logical addresses.
+
+CEC Pin framework
+-----------------
+
+Most CEC hardware operates on full CEC messages where the software provides
+the message and the hardware handles the low-level CEC protocol. But some
+hardware only drives the CEC pin and software has to handle the low-level
+CEC protocol. The CEC pin framework was created to handle such devices.
+
+Note that due to the close-to-realtime requirements it can never be guaranteed
+to work 100%. This framework uses highres timers internally, but if a
+timer goes off too late by more than 300 microseconds wrong results can
+occur. In reality it appears to be fairly reliable.
+
+One advantage of this low-level implementation is that it can be used as
+a cheap CEC analyser, especially if interrupts can be used to detect
+CEC pin transitions from low to high or vice versa.
+
+.. kernel-doc:: include/media/cec-pin.h
+
+CEC Notifier framework
+----------------------
+
+Most drm HDMI implementations have an integrated CEC implementation and no
+notifier support is needed. But some have independent CEC implementations
+that have their own driver. This could be an IP block for an SoC or a
+completely separate chip that deals with the CEC pin. For those cases a
+drm driver can install a notifier and use the notifier to inform the
+CEC driver about changes in the physical address.
+
+.. kernel-doc:: include/media/cec-notifier.h
diff --git a/Documentation/driver-api/media/csi2.rst b/Documentation/driver-api/media/csi2.rst
new file mode 100644
index 000000000..e1b838014
--- /dev/null
+++ b/Documentation/driver-api/media/csi2.rst
@@ -0,0 +1,93 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+.. _MIPI_CSI_2:
+
+MIPI CSI-2
+==========
+
+CSI-2 is a data bus intended for transferring images from cameras to
+the host SoC. It is defined by the `MIPI alliance`_.
+
+.. _`MIPI alliance`: http://www.mipi.org/
+
+Media bus formats
+-----------------
+
+See :ref:`v4l2-mbus-pixelcode` for details on which media bus formats should
+be used for CSI-2 interfaces.
+
+Transmitter drivers
+-------------------
+
+CSI-2 transmitter, such as a sensor or a TV tuner, drivers need to
+provide the CSI-2 receiver with information on the CSI-2 bus
+configuration. These include the V4L2_CID_LINK_FREQ and
+V4L2_CID_PIXEL_RATE controls and
+(:c:type:`v4l2_subdev_video_ops`->s_stream() callback). These
+interface elements must be present on the sub-device represents the
+CSI-2 transmitter.
+
+The V4L2_CID_LINK_FREQ control is used to tell the receiver driver the
+frequency (and not the symbol rate) of the link. The
+V4L2_CID_PIXEL_RATE is may be used by the receiver to obtain the pixel
+rate the transmitter uses. The
+:c:type:`v4l2_subdev_video_ops`->s_stream() callback provides an
+ability to start and stop the stream.
+
+The value of the V4L2_CID_PIXEL_RATE is calculated as follows::
+
+	pixel_rate = link_freq * 2 * nr_of_lanes / bits_per_sample
+
+where
+
+.. list-table:: variables in pixel rate calculation
+   :header-rows: 1
+
+   * - variable or constant
+     - description
+   * - link_freq
+     - The value of the V4L2_CID_LINK_FREQ integer64 menu item.
+   * - nr_of_lanes
+     - Number of data lanes used on the CSI-2 link. This can
+       be obtained from the OF endpoint configuration.
+   * - 2
+     - Two bits are transferred per clock cycle per lane.
+   * - bits_per_sample
+     - Number of bits per sample.
+
+The transmitter drivers must, if possible, configure the CSI-2
+transmitter to *LP-11 mode* whenever the transmitter is powered on but
+not active, and maintain *LP-11 mode* until stream on. Only at stream
+on should the transmitter activate the clock on the clock lane and
+transition to *HS mode*.
+
+Some transmitters do this automatically but some have to be explicitly
+programmed to do so, and some are unable to do so altogether due to
+hardware constraints.
+
+Stopping the transmitter
+^^^^^^^^^^^^^^^^^^^^^^^^
+
+A transmitter stops sending the stream of images as a result of
+calling the ``.s_stream()`` callback. Some transmitters may stop the
+stream at a frame boundary whereas others stop immediately,
+effectively leaving the current frame unfinished. The receiver driver
+should not make assumptions either way, but function properly in both
+cases.
+
+Receiver drivers
+----------------
+
+Before the receiver driver may enable the CSI-2 transmitter by using
+the :c:type:`v4l2_subdev_video_ops`->s_stream(), it must have powered
+the transmitter up by using the
+:c:type:`v4l2_subdev_core_ops`->s_power() callback. This may take
+place either indirectly by using :c:func:`v4l2_pipeline_pm_get` or
+directly.
+
+Formats
+-------
+
+The media bus pixel codes document parallel formats. Should the pixel data be
+transported over a serial bus, the media bus pixel code that describes a
+parallel format that transfers a sample on a single clock cycle is used.
diff --git a/Documentation/driver-api/media/drivers/bttv-devel.rst b/Documentation/driver-api/media/drivers/bttv-devel.rst
new file mode 100644
index 000000000..c9aa8b95a
--- /dev/null
+++ b/Documentation/driver-api/media/drivers/bttv-devel.rst
@@ -0,0 +1,116 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+The bttv driver
+===============
+
+bttv and sound mini howto
+-------------------------
+
+There are a lot of different bt848/849/878/879 based boards available.
+Making video work often is not a big deal, because this is handled
+completely by the bt8xx chip, which is common on all boards.  But
+sound is handled in slightly different ways on each board.
+
+To handle the grabber boards correctly, there is a array tvcards[] in
+bttv-cards.c, which holds the information required for each board.
+Sound will work only, if the correct entry is used (for video it often
+makes no difference).  The bttv driver prints a line to the kernel
+log, telling which card type is used.  Like this one::
+
+	bttv0: model: BT848(Hauppauge old) [autodetected]
+
+You should verify this is correct.  If it isn't, you have to pass the
+correct board type as insmod argument, ``insmod bttv card=2`` for
+example.  The file :doc:`/admin-guide/media/bttv-cardlist` has a list
+of valid arguments for card.
+
+If your card isn't listed there, you might check the source code for
+new entries which are not listed yet.  If there isn't one for your
+card, you can check if one of the existing entries does work for you
+(just trial and error...).
+
+Some boards have an extra processor for sound to do stereo decoding
+and other nice features.  The msp34xx chips are used by Hauppauge for
+example.  If your board has one, you might have to load a helper
+module like ``msp3400`` to make sound work.  If there isn't one for the
+chip used on your board:  Bad luck.  Start writing a new one.  Well,
+you might want to check the video4linux mailing list archive first...
+
+Of course you need a correctly installed soundcard unless you have the
+speakers connected directly to the grabber board.  Hint: check the
+mixer settings too.  ALSA for example has everything muted by default.
+
+
+How sound works in detail
+~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Still doesn't work?  Looks like some driver hacking is required.
+Below is a do-it-yourself description for you.
+
+The bt8xx chips have 32 general purpose pins, and registers to control
+these pins.  One register is the output enable register
+(``BT848_GPIO_OUT_EN``), it says which pins are actively driven by the
+bt848 chip.  Another one is the data register (``BT848_GPIO_DATA``), where
+you can get/set the status if these pins.  They can be used for input
+and output.
+
+Most grabber board vendors use these pins to control an external chip
+which does the sound routing.  But every board is a little different.
+These pins are also used by some companies to drive remote control
+receiver chips.  Some boards use the i2c bus instead of the gpio pins
+to connect the mux chip.
+
+As mentioned above, there is a array which holds the required
+information for each known board.  You basically have to create a new
+line for your board.  The important fields are these two::
+
+  struct tvcard
+  {
+	[ ... ]
+	u32 gpiomask;
+	u32 audiomux[6]; /* Tuner, Radio, external, internal, mute, stereo */
+  };
+
+gpiomask specifies which pins are used to control the audio mux chip.
+The corresponding bits in the output enable register
+(``BT848_GPIO_OUT_EN``) will be set as these pins must be driven by the
+bt848 chip.
+
+The ``audiomux[]`` array holds the data values for the different inputs
+(i.e. which pins must be high/low for tuner/mute/...).  This will be
+written to the data register (``BT848_GPIO_DATA``) to switch the audio
+mux.
+
+
+What you have to do is figure out the correct values for gpiomask and
+the audiomux array.  If you have Windows and the drivers four your
+card installed, you might to check out if you can read these registers
+values used by the windows driver.  A tool to do this is available
+from http://btwincap.sourceforge.net/download.html.
+
+You might also dig around in the ``*.ini`` files of the Windows applications.
+You can have a look at the board to see which of the gpio pins are
+connected at all and then start trial-and-error ...
+
+
+Starting with release 0.7.41 bttv has a number of insmod options to
+make the gpio debugging easier:
+
+	=================	==============================================
+	bttv_gpio=0/1		enable/disable gpio debug messages
+	gpiomask=n		set the gpiomask value
+	audiomux=i,j,...	set the values of the audiomux array
+	audioall=a		set the values of the audiomux array (one
+				value for all array elements, useful to check
+				out which effect the particular value has).
+	=================	==============================================
+
+The messages printed with ``bttv_gpio=1`` look like this::
+
+	bttv0: gpio: en=00000027, out=00000024 in=00ffffd8 [audio: off]
+
+	en  =	output _en_able register (BT848_GPIO_OUT_EN)
+	out =	_out_put bits of the data register (BT848_GPIO_DATA),
+		i.e. BT848_GPIO_DATA & BT848_GPIO_OUT_EN
+	in  = 	_in_put bits of the data register,
+		i.e. BT848_GPIO_DATA & ~BT848_GPIO_OUT_EN
diff --git a/Documentation/driver-api/media/drivers/contributors.rst b/Documentation/driver-api/media/drivers/contributors.rst
new file mode 100644
index 000000000..f23b6e6fa
--- /dev/null
+++ b/Documentation/driver-api/media/drivers/contributors.rst
@@ -0,0 +1,131 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+Contributors
+============
+
+.. note::
+
+   This documentation is outdated. There are several other DVB contributors
+   that aren't listed below.
+
+Thanks go to the following people for patches and contributions:
+
+- Michael Hunold <m.hunold@gmx.de>
+
+  - for the initial saa7146 driver and its recent overhaul
+
+- Christian Theiss
+
+  - for his work on the initial Linux DVB driver
+
+- Marcus Metzler <mocm@metzlerbros.de> and
+  Ralph Metzler <rjkm@metzlerbros.de>
+
+  - for their continuing work on the DVB driver
+
+- Michael Holzt <kju@debian.org>
+
+  - for his contributions to the dvb-net driver
+
+- Diego Picciani <d.picciani@novacomp.it>
+
+  - for CyberLogin for Linux which allows logging onto EON
+    (in case you are wondering where CyberLogin is, EON changed its login
+    procedure and CyberLogin is no longer used.)
+
+- Martin Schaller <martin@smurf.franken.de>
+
+  - for patching the cable card decoder driver
+
+- Klaus Schmidinger <Klaus.Schmidinger@cadsoft.de>
+
+  - for various fixes regarding tuning, OSD and CI stuff and his work on VDR
+
+- Steve Brown <sbrown@cortland.com>
+
+  - for his AFC kernel thread
+
+- Christoph Martin <martin@uni-mainz.de>
+
+  - for his LIRC infrared handler
+
+- Andreas Oberritter <obi@linuxtv.org>,
+  Dennis Noermann <dennis.noermann@noernet.de>,
+  Felix Domke <tmbinc@elitedvb.net>,
+  Florian Schirmer <jolt@tuxbox.org>,
+  Ronny Strutz <3des@elitedvb.de>,
+  Wolfram Joost <dbox2@frokaschwei.de>
+  and all the other dbox2 people
+
+  - for many bugfixes in the generic DVB Core, frontend drivers and
+    their work on the dbox2 port of the DVB driver
+
+- Oliver Endriss <o.endriss@gmx.de>
+
+  - for many bugfixes
+
+- Andrew de Quincey <adq_dvb@lidskialf.net>
+
+  - for the tda1004x frontend driver, and various bugfixes
+
+- Peter Schildmann <peter.schildmann@web.de>
+
+  - for the driver for the Technisat SkyStar2 PCI DVB card
+
+- Vadim Catana <skystar@moldova.cc>,
+  Roberto Ragusa <r.ragusa@libero.it> and
+  Augusto Cardoso <augusto@carhil.net>
+
+  - for all the work for the FlexCopII chipset by B2C2,Inc.
+
+- Davor Emard <emard@softhome.net>
+
+  - for his work on the budget drivers, the demux code,
+    the module unloading problems, ...
+
+- Hans-Frieder Vogt <hfvogt@arcor.de>
+
+  - for his work on calculating and checking the crc's for the
+    TechnoTrend/Hauppauge DEC driver firmware
+
+- Michael Dreher <michael@5dot1.de> and
+  Andreas 'randy' Weinberger
+
+  - for the support of the Fujitsu-Siemens Activy budget DVB-S
+
+- Kenneth Aafløy <ke-aa@frisurf.no>
+
+  - for adding support for Typhoon DVB-S budget card
+
+- Ernst Peinlich <e.peinlich@inode.at>
+
+  - for tuning/DiSEqC support for the DEC 3000-s
+
+- Peter Beutner <p.beutner@gmx.net>
+
+  - for the IR code for the ttusb-dec driver
+
+- Wilson Michaels <wilsonmichaels@earthlink.net>
+
+  - for the lgdt330x frontend driver, and various bugfixes
+
+- Michael Krufky <mkrufky@linuxtv.org>
+
+  - for maintaining v4l/dvb inter-tree dependencies
+
+- Taylor Jacob <rtjacob@earthlink.net>
+
+  - for the nxt2002 frontend driver
+
+- Jean-Francois Thibert <jeanfrancois@sagetv.com>
+
+  - for the nxt2004 frontend driver
+
+- Kirk Lapray <kirk.lapray@gmail.com>
+
+  - for the or51211 and or51132 frontend drivers, and
+    for merging the nxt2002 and nxt2004 modules into a
+    single nxt200x frontend driver.
+
+(If you think you should be in this list, but you are not, drop a
+line to the DVB mailing list)
diff --git a/Documentation/driver-api/media/drivers/cpia2_devel.rst b/Documentation/driver-api/media/drivers/cpia2_devel.rst
new file mode 100644
index 000000000..decaa4768
--- /dev/null
+++ b/Documentation/driver-api/media/drivers/cpia2_devel.rst
@@ -0,0 +1,56 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+The cpia2 driver
+================
+
+Authors: Peter Pregler <Peter_Pregler@email.com>,
+Scott J. Bertin <scottbertin@yahoo.com>, and
+Jarl Totland <Jarl.Totland@bdc.no> for the original cpia driver, which
+this one was modelled from.
+
+
+Notes to developers
+~~~~~~~~~~~~~~~~~~~
+
+   - This is a driver version stripped of the 2.4 back compatibility
+     and old MJPEG ioctl API. See cpia2.sf.net for 2.4 support.
+
+Programmer's overview of cpia2 driver
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Cpia2 is the second generation video coprocessor from VLSI Vision Ltd (now a
+division of ST Microelectronics).  There are two versions.  The first is the
+STV0672, which is capable of up to 30 frames per second (fps) in frame sizes
+up to CIF, and 15 fps for VGA frames.  The STV0676 is an improved version,
+which can handle up to 30 fps VGA.  Both coprocessors can be attached to two
+CMOS sensors - the vvl6410 CIF sensor and the vvl6500 VGA sensor.  These will
+be referred to as the 410 and the 500 sensors, or the CIF and VGA sensors.
+
+The two chipsets operate almost identically.  The core is an 8051 processor,
+running two different versions of firmware.  The 672 runs the VP4 video
+processor code, the 676 runs VP5.  There are a few differences in register
+mappings for the two chips.  In these cases, the symbols defined in the
+header files are marked with VP4 or VP5 as part of the symbol name.
+
+The cameras appear externally as three sets of registers. Setting register
+values is the only way to control the camera.  Some settings are
+interdependant, such as the sequence required to power up the camera. I will
+try to make note of all of these cases.
+
+The register sets are called blocks.  Block 0 is the system block.  This
+section is always powered on when the camera is plugged in.  It contains
+registers that control housekeeping functions such as powering up the video
+processor.  The video processor is the VP block.  These registers control
+how the video from the sensor is processed.  Examples are timing registers,
+user mode (vga, qvga), scaling, cropping, framerates, and so on.  The last
+block is the video compressor (VC).  The video stream sent from the camera is
+compressed as Motion JPEG (JPEGA).  The VC controls all of the compression
+parameters.  Looking at the file cpia2_registers.h, you can get a full view
+of these registers and the possible values for most of them.
+
+One or more registers can be set or read by sending a usb control message to
+the camera.  There are three modes for this.  Block mode requests a number
+of contiguous registers.  Random mode reads or writes random registers with
+a tuple structure containing address/value pairs.  The repeat mode is only
+used by VP4 to load a firmware patch.  It contains a starting address and
+a sequence of bytes to be written into a gpio port.
diff --git a/Documentation/driver-api/media/drivers/cx2341x-devel.rst b/Documentation/driver-api/media/drivers/cx2341x-devel.rst
new file mode 100644
index 000000000..97699df6e
--- /dev/null
+++ b/Documentation/driver-api/media/drivers/cx2341x-devel.rst
@@ -0,0 +1,3685 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+The cx2341x driver
+==================
+
+Memory at cx2341x chips
+-----------------------
+
+This section describes the cx2341x memory map and documents some of the
+register space.
+
+.. note:: the memory long words are little-endian ('intel format').
+
+.. warning::
+
+	This information was figured out from searching through the memory
+	and registers, this information may not be correct and is certainly
+	not complete, and was not derived from anything more than searching
+	through the memory space with commands like:
+
+	.. code-block:: none
+
+		ivtvctl -O min=0x02000000,max=0x020000ff
+
+	So take this as is, I'm always searching for more stuff, it's a large
+	register space :-).
+
+Memory Map
+~~~~~~~~~~
+
+The cx2341x exposes its entire 64M memory space to the PCI host via the PCI BAR0
+(Base Address Register 0). The addresses here are offsets relative to the
+address held in BAR0.
+
+.. code-block:: none
+
+	0x00000000-0x00ffffff Encoder memory space
+	0x00000000-0x0003ffff Encode.rom
+	???-???         MPEG buffer(s)
+	???-???         Raw video capture buffer(s)
+	???-???         Raw audio capture buffer(s)
+	???-???         Display buffers (6 or 9)
+
+	0x01000000-0x01ffffff Decoder memory space
+	0x01000000-0x0103ffff Decode.rom
+	???-???         MPEG buffers(s)
+	0x0114b000-0x0115afff Audio.rom (deprecated?)
+
+	0x02000000-0x0200ffff Register Space
+
+Registers
+~~~~~~~~~
+
+The registers occupy the 64k space starting at the 0x02000000 offset from BAR0.
+All of these registers are 32 bits wide.
+
+.. code-block:: none
+
+	DMA Registers 0x000-0xff:
+
+	0x00 - Control:
+		0=reset/cancel, 1=read, 2=write, 4=stop
+	0x04 - DMA status:
+		1=read busy, 2=write busy, 4=read error, 8=write error, 16=link list error
+	0x08 - pci DMA pointer for read link list
+	0x0c - pci DMA pointer for write link list
+	0x10 - read/write DMA enable:
+		1=read enable, 2=write enable
+	0x14 - always 0xffffffff, if set any lower instability occurs, 0x00 crashes
+	0x18 - ??
+	0x1c - always 0x20 or 32, smaller values slow down DMA transactions
+	0x20 - always value of 0x780a010a
+	0x24-0x3c - usually just random values???
+	0x40 - Interrupt status
+	0x44 - Write a bit here and shows up in Interrupt status 0x40
+	0x48 - Interrupt Mask
+	0x4C - always value of 0xfffdffff,
+		if changed to 0xffffffff DMA write interrupts break.
+	0x50 - always 0xffffffff
+	0x54 - always 0xffffffff (0x4c, 0x50, 0x54 seem like interrupt masks, are
+		3 processors on chip, Java ones, VPU, SPU, APU, maybe these are the
+		interrupt masks???).
+	0x60-0x7C - random values
+	0x80 - first write linked list reg, for Encoder Memory addr
+	0x84 - first write linked list reg, for pci memory addr
+	0x88 - first write linked list reg, for length of buffer in memory addr
+		(|0x80000000 or this for last link)
+	0x8c-0xdc - rest of write linked list reg, 8 sets of 3 total, DMA goes here
+		from linked list addr in reg 0x0c, firmware must push through or
+		something.
+	0xe0 - first (and only) read linked list reg, for pci memory addr
+	0xe4 - first (and only) read linked list reg, for Decoder memory addr
+	0xe8 - first (and only) read linked list reg, for length of buffer
+	0xec-0xff - Nothing seems to be in these registers, 0xec-f4 are 0x00000000.
+
+Memory locations for Encoder Buffers 0x700-0x7ff:
+
+These registers show offsets of memory locations pertaining to each
+buffer area used for encoding, have to shift them by <<1 first.
+
+- 0x07F8: Encoder SDRAM refresh
+- 0x07FC: Encoder SDRAM pre-charge
+
+Memory locations for Decoder Buffers 0x800-0x8ff:
+
+These registers show offsets of memory locations pertaining to each
+buffer area used for decoding, have to shift them by <<1 first.
+
+- 0x08F8: Decoder SDRAM refresh
+- 0x08FC: Decoder SDRAM pre-charge
+
+Other memory locations:
+
+- 0x2800: Video Display Module control
+- 0x2D00: AO (audio output?) control
+- 0x2D24: Bytes Flushed
+- 0x7000: LSB I2C write clock bit (inverted)
+- 0x7004: LSB I2C write data bit (inverted)
+- 0x7008: LSB I2C read clock bit
+- 0x700c: LSB I2C read data bit
+- 0x9008: GPIO get input state
+- 0x900c: GPIO set output state
+- 0x9020: GPIO direction (Bit7 (GPIO 0..7) - 0:input, 1:output)
+- 0x9050: SPU control
+- 0x9054: Reset HW blocks
+- 0x9058: VPU control
+- 0xA018: Bit6: interrupt pending?
+- 0xA064: APU command
+
+
+Interrupt Status Register
+~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The definition of the bits in the interrupt status register 0x0040, and the
+interrupt mask 0x0048. If a bit is cleared in the mask, then we want our ISR to
+execute.
+
+- bit 31 Encoder Start Capture
+- bit 30 Encoder EOS
+- bit 29 Encoder VBI capture
+- bit 28 Encoder Video Input Module reset event
+- bit 27 Encoder DMA complete
+- bit 24 Decoder audio mode change detection event (through event notification)
+- bit 22 Decoder data request
+- bit 20 Decoder DMA complete
+- bit 19 Decoder VBI re-insertion
+- bit 18 Decoder DMA err (linked-list bad)
+
+Missing documentation
+---------------------
+
+- Encoder API post(?)
+- Decoder API post(?)
+- Decoder VTRACE event
+
+
+The cx2341x firmware upload
+---------------------------
+
+This document describes how to upload the cx2341x firmware to the card.
+
+How to find
+~~~~~~~~~~~
+
+See the web pages of the various projects that uses this chip for information
+on how to obtain the firmware.
+
+The firmware stored in a Windows driver can be detected as follows:
+
+- Each firmware image is 256k bytes.
+- The 1st 32-bit word of the Encoder image is 0x0000da7
+- The 1st 32-bit word of the Decoder image is 0x00003a7
+- The 2nd 32-bit word of both images is 0xaa55bb66
+
+How to load
+~~~~~~~~~~~
+
+- Issue the FWapi command to stop the encoder if it is running. Wait for the
+  command to complete.
+- Issue the FWapi command to stop the decoder if it is running. Wait for the
+  command to complete.
+- Issue the I2C command to the digitizer to stop emitting VSYNC events.
+- Issue the FWapi command to halt the encoder's firmware.
+- Sleep for 10ms.
+- Issue the FWapi command to halt the decoder's firmware.
+- Sleep for 10ms.
+- Write 0x00000000 to register 0x2800 to stop the Video Display Module.
+- Write 0x00000005 to register 0x2D00 to stop the AO (audio output?).
+- Write 0x00000000 to register 0xA064 to ping? the APU.
+- Write 0xFFFFFFFE to register 0x9058 to stop the VPU.
+- Write 0xFFFFFFFF to register 0x9054 to reset the HW blocks.
+- Write 0x00000001 to register 0x9050 to stop the SPU.
+- Sleep for 10ms.
+- Write 0x0000001A to register 0x07FC to init the Encoder SDRAM's pre-charge.
+- Write 0x80000640 to register 0x07F8 to init the Encoder SDRAM's refresh to 1us.
+- Write 0x0000001A to register 0x08FC to init the Decoder SDRAM's pre-charge.
+- Write 0x80000640 to register 0x08F8 to init the Decoder SDRAM's refresh to 1us.
+- Sleep for 512ms. (600ms is recommended)
+- Transfer the encoder's firmware image to offset 0 in Encoder memory space.
+- Transfer the decoder's firmware image to offset 0 in Decoder memory space.
+- Use a read-modify-write operation to Clear bit 0 of register 0x9050 to
+  re-enable the SPU.
+- Sleep for 1 second.
+- Use a read-modify-write operation to Clear bits 3 and 0 of register 0x9058
+  to re-enable the VPU.
+- Sleep for 1 second.
+- Issue status API commands to both firmware images to verify.
+
+
+How to call the firmware API
+----------------------------
+
+The preferred calling convention is known as the firmware mailbox. The
+mailboxes are basically a fixed length array that serves as the call-stack.
+
+Firmware mailboxes can be located by searching the encoder and decoder memory
+for a 16 byte signature. That signature will be located on a 256-byte boundary.
+
+Signature:
+
+.. code-block:: none
+
+	0x78, 0x56, 0x34, 0x12, 0x12, 0x78, 0x56, 0x34,
+	0x34, 0x12, 0x78, 0x56, 0x56, 0x34, 0x12, 0x78
+
+The firmware implements 20 mailboxes of 20 32-bit words. The first 10 are
+reserved for API calls. The second 10 are used by the firmware for event
+notification.
+
+  ====== =================
+  Index  Name
+  ====== =================
+  0      Flags
+  1      Command
+  2      Return value
+  3      Timeout
+  4-19   Parameter/Result
+  ====== =================
+
+
+The flags are defined in the following table. The direction is from the
+perspective of the firmware.
+
+  ==== ========== ============================================
+  Bit  Direction  Purpose
+  ==== ========== ============================================
+  2    O          Firmware has processed the command.
+  1    I          Driver has finished setting the parameters.
+  0    I          Driver is using this mailbox.
+  ==== ========== ============================================
+
+The command is a 32-bit enumerator. The API specifics may be found in this
+chapter.
+
+The return value is a 32-bit enumerator. Only two values are currently defined:
+
+- 0=success
+- -1=command undefined.
+
+There are 16 parameters/results 32-bit fields. The driver populates these fields
+with values for all the parameters required by the call. The driver overwrites
+these fields with result values returned by the call.
+
+The timeout value protects the card from a hung driver thread. If the driver
+doesn't handle the completed call within the timeout specified, the firmware
+will reset that mailbox.
+
+To make an API call, the driver iterates over each mailbox looking for the
+first one available (bit 0 has been cleared). The driver sets that bit, fills
+in the command enumerator, the timeout value and any required parameters. The
+driver then sets the parameter ready bit (bit 1). The firmware scans the
+mailboxes for pending commands, processes them, sets the result code, populates
+the result value array with that call's return values and sets the call
+complete bit (bit 2). Once bit 2 is set, the driver should retrieve the results
+and clear all the flags. If the driver does not perform this task within the
+time set in the timeout register, the firmware will reset that mailbox.
+
+Event notifications are sent from the firmware to the host. The host tells the
+firmware which events it is interested in via an API call. That call tells the
+firmware which notification mailbox to use. The firmware signals the host via
+an interrupt. Only the 16 Results fields are used, the Flags, Command, Return
+value and Timeout words are not used.
+
+
+OSD firmware API description
+----------------------------
+
+.. note:: this API is part of the decoder firmware, so it's cx23415 only.
+
+
+
+CX2341X_OSD_GET_FRAMEBUFFER
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 65/0x41
+
+Description
+^^^^^^^^^^^
+
+Return base and length of contiguous OSD memory.
+
+Result[0]
+^^^^^^^^^
+
+OSD base address
+
+Result[1]
+^^^^^^^^^
+
+OSD length
+
+
+
+CX2341X_OSD_GET_PIXEL_FORMAT
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 66/0x42
+
+Description
+^^^^^^^^^^^
+
+Query OSD format
+
+Result[0]
+^^^^^^^^^
+
+0=8bit index
+1=16bit RGB 5:6:5
+2=16bit ARGB 1:5:5:5
+3=16bit ARGB 1:4:4:4
+4=32bit ARGB 8:8:8:8
+
+
+
+CX2341X_OSD_SET_PIXEL_FORMAT
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 67/0x43
+
+Description
+^^^^^^^^^^^
+
+Assign pixel format
+
+Param[0]
+^^^^^^^^
+
+- 0=8bit index
+- 1=16bit RGB 5:6:5
+- 2=16bit ARGB 1:5:5:5
+- 3=16bit ARGB 1:4:4:4
+- 4=32bit ARGB 8:8:8:8
+
+
+
+CX2341X_OSD_GET_STATE
+~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 68/0x44
+
+Description
+^^^^^^^^^^^
+
+Query OSD state
+
+Result[0]
+^^^^^^^^^
+
+- Bit  0   0=off, 1=on
+- Bits 1:2 alpha control
+- Bits 3:5 pixel format
+
+
+
+CX2341X_OSD_SET_STATE
+~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 69/0x45
+
+Description
+^^^^^^^^^^^
+
+OSD switch
+
+Param[0]
+^^^^^^^^
+
+0=off, 1=on
+
+
+
+CX2341X_OSD_GET_OSD_COORDS
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 70/0x46
+
+Description
+^^^^^^^^^^^
+
+Retrieve coordinates of OSD area blended with video
+
+Result[0]
+^^^^^^^^^
+
+OSD buffer address
+
+Result[1]
+^^^^^^^^^
+
+Stride in pixels
+
+Result[2]
+^^^^^^^^^
+
+Lines in OSD buffer
+
+Result[3]
+^^^^^^^^^
+
+Horizontal offset in buffer
+
+Result[4]
+^^^^^^^^^
+
+Vertical offset in buffer
+
+
+
+CX2341X_OSD_SET_OSD_COORDS
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 71/0x47
+
+Description
+^^^^^^^^^^^
+
+Assign the coordinates of the OSD area to blend with video
+
+Param[0]
+^^^^^^^^
+
+buffer address
+
+Param[1]
+^^^^^^^^
+
+buffer stride in pixels
+
+Param[2]
+^^^^^^^^
+
+lines in buffer
+
+Param[3]
+^^^^^^^^
+
+horizontal offset
+
+Param[4]
+^^^^^^^^
+
+vertical offset
+
+
+
+CX2341X_OSD_GET_SCREEN_COORDS
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 72/0x48
+
+Description
+^^^^^^^^^^^
+
+Retrieve OSD screen area coordinates
+
+Result[0]
+^^^^^^^^^
+
+top left horizontal offset
+
+Result[1]
+^^^^^^^^^
+
+top left vertical offset
+
+Result[2]
+^^^^^^^^^
+
+bottom right horizontal offset
+
+Result[3]
+^^^^^^^^^
+
+bottom right vertical offset
+
+
+
+CX2341X_OSD_SET_SCREEN_COORDS
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 73/0x49
+
+Description
+^^^^^^^^^^^
+
+Assign the coordinates of the screen area to blend with video
+
+Param[0]
+^^^^^^^^
+
+top left horizontal offset
+
+Param[1]
+^^^^^^^^
+
+top left vertical offset
+
+Param[2]
+^^^^^^^^
+
+bottom left horizontal offset
+
+Param[3]
+^^^^^^^^
+
+bottom left vertical offset
+
+
+
+CX2341X_OSD_GET_GLOBAL_ALPHA
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 74/0x4A
+
+Description
+^^^^^^^^^^^
+
+Retrieve OSD global alpha
+
+Result[0]
+^^^^^^^^^
+
+global alpha: 0=off, 1=on
+
+Result[1]
+^^^^^^^^^
+
+bits 0:7 global alpha
+
+
+
+CX2341X_OSD_SET_GLOBAL_ALPHA
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 75/0x4B
+
+Description
+^^^^^^^^^^^
+
+Update global alpha
+
+Param[0]
+^^^^^^^^
+
+global alpha: 0=off, 1=on
+
+Param[1]
+^^^^^^^^
+
+global alpha (8 bits)
+
+Param[2]
+^^^^^^^^
+
+local alpha: 0=on, 1=off
+
+
+
+CX2341X_OSD_SET_BLEND_COORDS
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 78/0x4C
+
+Description
+^^^^^^^^^^^
+
+Move start of blending area within display buffer
+
+Param[0]
+^^^^^^^^
+
+horizontal offset in buffer
+
+Param[1]
+^^^^^^^^
+
+vertical offset in buffer
+
+
+
+CX2341X_OSD_GET_FLICKER_STATE
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 79/0x4F
+
+Description
+^^^^^^^^^^^
+
+Retrieve flicker reduction module state
+
+Result[0]
+^^^^^^^^^
+
+flicker state: 0=off, 1=on
+
+
+
+CX2341X_OSD_SET_FLICKER_STATE
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 80/0x50
+
+Description
+^^^^^^^^^^^
+
+Set flicker reduction module state
+
+Param[0]
+^^^^^^^^
+
+State: 0=off, 1=on
+
+
+
+CX2341X_OSD_BLT_COPY
+~~~~~~~~~~~~~~~~~~~~
+
+Enum: 82/0x52
+
+Description
+^^^^^^^^^^^
+
+BLT copy
+
+Param[0]
+^^^^^^^^
+
+.. code-block:: none
+
+	'0000'  zero
+	'0001' ~destination AND ~source
+	'0010' ~destination AND  source
+	'0011' ~destination
+	'0100'  destination AND ~source
+	'0101'                  ~source
+	'0110'  destination XOR  source
+	'0111' ~destination OR  ~source
+	'1000' ~destination AND ~source
+	'1001'  destination XNOR source
+	'1010'                   source
+	'1011' ~destination OR   source
+	'1100'  destination
+	'1101'  destination OR  ~source
+	'1110'  destination OR   source
+	'1111'  one
+
+
+Param[1]
+^^^^^^^^
+
+Resulting alpha blending
+
+- '01' source_alpha
+- '10' destination_alpha
+- '11' source_alpha*destination_alpha+1
+  (zero if both source and destination alpha are zero)
+
+Param[2]
+^^^^^^^^
+
+.. code-block:: none
+
+	'00' output_pixel = source_pixel
+
+	'01' if source_alpha=0:
+		 output_pixel = destination_pixel
+	     if 256 > source_alpha > 1:
+		 output_pixel = ((source_alpha + 1)*source_pixel +
+				 (255 - source_alpha)*destination_pixel)/256
+
+	'10' if destination_alpha=0:
+		 output_pixel = source_pixel
+	      if 255 > destination_alpha > 0:
+		 output_pixel = ((255 - destination_alpha)*source_pixel +
+				 (destination_alpha + 1)*destination_pixel)/256
+
+	'11' if source_alpha=0:
+		 source_temp = 0
+	     if source_alpha=255:
+		 source_temp = source_pixel*256
+	     if 255 > source_alpha > 0:
+		 source_temp = source_pixel*(source_alpha + 1)
+	     if destination_alpha=0:
+		 destination_temp = 0
+	     if destination_alpha=255:
+		 destination_temp = destination_pixel*256
+	     if 255 > destination_alpha > 0:
+		 destination_temp = destination_pixel*(destination_alpha + 1)
+	     output_pixel = (source_temp + destination_temp)/256
+
+Param[3]
+^^^^^^^^
+
+width
+
+Param[4]
+^^^^^^^^
+
+height
+
+Param[5]
+^^^^^^^^
+
+destination pixel mask
+
+Param[6]
+^^^^^^^^
+
+destination rectangle start address
+
+Param[7]
+^^^^^^^^
+
+destination stride in dwords
+
+Param[8]
+^^^^^^^^
+
+source stride in dwords
+
+Param[9]
+^^^^^^^^
+
+source rectangle start address
+
+
+
+CX2341X_OSD_BLT_FILL
+~~~~~~~~~~~~~~~~~~~~
+
+Enum: 83/0x53
+
+Description
+^^^^^^^^^^^
+
+BLT fill color
+
+Param[0]
+^^^^^^^^
+
+Same as Param[0] on API 0x52
+
+Param[1]
+^^^^^^^^
+
+Same as Param[1] on API 0x52
+
+Param[2]
+^^^^^^^^
+
+Same as Param[2] on API 0x52
+
+Param[3]
+^^^^^^^^
+
+width
+
+Param[4]
+^^^^^^^^
+
+height
+
+Param[5]
+^^^^^^^^
+
+destination pixel mask
+
+Param[6]
+^^^^^^^^
+
+destination rectangle start address
+
+Param[7]
+^^^^^^^^
+
+destination stride in dwords
+
+Param[8]
+^^^^^^^^
+
+color fill value
+
+
+
+CX2341X_OSD_BLT_TEXT
+~~~~~~~~~~~~~~~~~~~~
+
+Enum: 84/0x54
+
+Description
+^^^^^^^^^^^
+
+BLT for 8 bit alpha text source
+
+Param[0]
+^^^^^^^^
+
+Same as Param[0] on API 0x52
+
+Param[1]
+^^^^^^^^
+
+Same as Param[1] on API 0x52
+
+Param[2]
+^^^^^^^^
+
+Same as Param[2] on API 0x52
+
+Param[3]
+^^^^^^^^
+
+width
+
+Param[4]
+^^^^^^^^
+
+height
+
+Param[5]
+^^^^^^^^
+
+destination pixel mask
+
+Param[6]
+^^^^^^^^
+
+destination rectangle start address
+
+Param[7]
+^^^^^^^^
+
+destination stride in dwords
+
+Param[8]
+^^^^^^^^
+
+source stride in dwords
+
+Param[9]
+^^^^^^^^
+
+source rectangle start address
+
+Param[10]
+^^^^^^^^^
+
+color fill value
+
+
+
+CX2341X_OSD_SET_FRAMEBUFFER_WINDOW
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 86/0x56
+
+Description
+^^^^^^^^^^^
+
+Positions the main output window on the screen. The coordinates must be
+such that the entire window fits on the screen.
+
+Param[0]
+^^^^^^^^
+
+window width
+
+Param[1]
+^^^^^^^^
+
+window height
+
+Param[2]
+^^^^^^^^
+
+top left window corner horizontal offset
+
+Param[3]
+^^^^^^^^
+
+top left window corner vertical offset
+
+
+
+CX2341X_OSD_SET_CHROMA_KEY
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 96/0x60
+
+Description
+^^^^^^^^^^^
+
+Chroma key switch and color
+
+Param[0]
+^^^^^^^^
+
+state: 0=off, 1=on
+
+Param[1]
+^^^^^^^^
+
+color
+
+
+
+CX2341X_OSD_GET_ALPHA_CONTENT_INDEX
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 97/0x61
+
+Description
+^^^^^^^^^^^
+
+Retrieve alpha content index
+
+Result[0]
+^^^^^^^^^
+
+alpha content index, Range 0:15
+
+
+
+CX2341X_OSD_SET_ALPHA_CONTENT_INDEX
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 98/0x62
+
+Description
+^^^^^^^^^^^
+
+Assign alpha content index
+
+Param[0]
+^^^^^^^^
+
+alpha content index, range 0:15
+
+
+Encoder firmware API description
+--------------------------------
+
+CX2341X_ENC_PING_FW
+~~~~~~~~~~~~~~~~~~~
+
+Enum: 128/0x80
+
+Description
+^^^^^^^^^^^
+
+Does nothing. Can be used to check if the firmware is responding.
+
+
+
+CX2341X_ENC_START_CAPTURE
+~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 129/0x81
+
+Description
+^^^^^^^^^^^
+
+Commences the capture of video, audio and/or VBI data. All encoding
+parameters must be initialized prior to this API call. Captures frames
+continuously or until a predefined number of frames have been captured.
+
+Param[0]
+^^^^^^^^
+
+Capture stream type:
+
+	- 0=MPEG
+	- 1=Raw
+	- 2=Raw passthrough
+	- 3=VBI
+
+
+Param[1]
+^^^^^^^^
+
+Bitmask:
+
+	- Bit 0 when set, captures YUV
+	- Bit 1 when set, captures PCM audio
+	- Bit 2 when set, captures VBI (same as param[0]=3)
+	- Bit 3 when set, the capture destination is the decoder
+	  (same as param[0]=2)
+	- Bit 4 when set, the capture destination is the host
+
+.. note:: this parameter is only meaningful for RAW capture type.
+
+
+
+CX2341X_ENC_STOP_CAPTURE
+~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 130/0x82
+
+Description
+^^^^^^^^^^^
+
+Ends a capture in progress
+
+Param[0]
+^^^^^^^^
+
+- 0=stop at end of GOP (generates IRQ)
+- 1=stop immediate (no IRQ)
+
+Param[1]
+^^^^^^^^
+
+Stream type to stop, see param[0] of API 0x81
+
+Param[2]
+^^^^^^^^
+
+Subtype, see param[1] of API 0x81
+
+
+
+CX2341X_ENC_SET_AUDIO_ID
+~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 137/0x89
+
+Description
+^^^^^^^^^^^
+
+Assigns the transport stream ID of the encoded audio stream
+
+Param[0]
+^^^^^^^^
+
+Audio Stream ID
+
+
+
+CX2341X_ENC_SET_VIDEO_ID
+~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 139/0x8B
+
+Description
+^^^^^^^^^^^
+
+Set video transport stream ID
+
+Param[0]
+^^^^^^^^
+
+Video stream ID
+
+
+
+CX2341X_ENC_SET_PCR_ID
+~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 141/0x8D
+
+Description
+^^^^^^^^^^^
+
+Assigns the transport stream ID for PCR packets
+
+Param[0]
+^^^^^^^^
+
+PCR Stream ID
+
+
+
+CX2341X_ENC_SET_FRAME_RATE
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 143/0x8F
+
+Description
+^^^^^^^^^^^
+
+Set video frames per second. Change occurs at start of new GOP.
+
+Param[0]
+^^^^^^^^
+
+- 0=30fps
+- 1=25fps
+
+
+
+CX2341X_ENC_SET_FRAME_SIZE
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 145/0x91
+
+Description
+^^^^^^^^^^^
+
+Select video stream encoding resolution.
+
+Param[0]
+^^^^^^^^
+
+Height in lines. Default 480
+
+Param[1]
+^^^^^^^^
+
+Width in pixels. Default 720
+
+
+
+CX2341X_ENC_SET_BIT_RATE
+~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 149/0x95
+
+Description
+^^^^^^^^^^^
+
+Assign average video stream bitrate.
+
+Param[0]
+^^^^^^^^
+
+0=variable bitrate, 1=constant bitrate
+
+Param[1]
+^^^^^^^^
+
+bitrate in bits per second
+
+Param[2]
+^^^^^^^^
+
+peak bitrate in bits per second, divided by 400
+
+Param[3]
+^^^^^^^^
+
+Mux bitrate in bits per second, divided by 400. May be 0 (default).
+
+Param[4]
+^^^^^^^^
+
+Rate Control VBR Padding
+
+Param[5]
+^^^^^^^^
+
+VBV Buffer used by encoder
+
+.. note::
+
+	#) Param\[3\] and Param\[4\] seem to be always 0
+	#) Param\[5\] doesn't seem to be used.
+
+
+
+CX2341X_ENC_SET_GOP_PROPERTIES
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 151/0x97
+
+Description
+^^^^^^^^^^^
+
+Setup the GOP structure
+
+Param[0]
+^^^^^^^^
+
+GOP size (maximum is 34)
+
+Param[1]
+^^^^^^^^
+
+Number of B frames between the I and P frame, plus 1.
+For example: IBBPBBPBBPBB --> GOP size: 12, number of B frames: 2+1 = 3
+
+.. note::
+
+	GOP size must be a multiple of (B-frames + 1).
+
+
+
+CX2341X_ENC_SET_ASPECT_RATIO
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 153/0x99
+
+Description
+^^^^^^^^^^^
+
+Sets the encoding aspect ratio. Changes in the aspect ratio take effect
+at the start of the next GOP.
+
+Param[0]
+^^^^^^^^
+
+- '0000' forbidden
+- '0001' 1:1 square
+- '0010' 4:3
+- '0011' 16:9
+- '0100' 2.21:1
+- '0101' to '1111' reserved
+
+
+
+CX2341X_ENC_SET_DNR_FILTER_MODE
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 155/0x9B
+
+Description
+^^^^^^^^^^^
+
+Assign Dynamic Noise Reduction operating mode
+
+Param[0]
+^^^^^^^^
+
+Bit0: Spatial filter, set=auto, clear=manual
+Bit1: Temporal filter, set=auto, clear=manual
+
+Param[1]
+^^^^^^^^
+
+Median filter:
+
+- 0=Disabled
+- 1=Horizontal
+- 2=Vertical
+- 3=Horiz/Vert
+- 4=Diagonal
+
+
+
+CX2341X_ENC_SET_DNR_FILTER_PROPS
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 157/0x9D
+
+Description
+^^^^^^^^^^^
+
+These Dynamic Noise Reduction filter values are only meaningful when
+the respective filter is set to "manual" (See API 0x9B)
+
+Param[0]
+^^^^^^^^
+
+Spatial filter: default 0, range 0:15
+
+Param[1]
+^^^^^^^^
+
+Temporal filter: default 0, range 0:31
+
+
+
+CX2341X_ENC_SET_CORING_LEVELS
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 159/0x9F
+
+Description
+^^^^^^^^^^^
+
+Assign Dynamic Noise Reduction median filter properties.
+
+Param[0]
+^^^^^^^^
+
+Threshold above which the luminance median filter is enabled.
+Default: 0, range 0:255
+
+Param[1]
+^^^^^^^^
+
+Threshold below which the luminance median filter is enabled.
+Default: 255, range 0:255
+
+Param[2]
+^^^^^^^^
+
+Threshold above which the chrominance median filter is enabled.
+Default: 0, range 0:255
+
+Param[3]
+^^^^^^^^
+
+Threshold below which the chrominance median filter is enabled.
+Default: 255, range 0:255
+
+
+
+CX2341X_ENC_SET_SPATIAL_FILTER_TYPE
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 161/0xA1
+
+Description
+^^^^^^^^^^^
+
+Assign spatial prefilter parameters
+
+Param[0]
+^^^^^^^^
+
+Luminance filter
+
+- 0=Off
+- 1=1D Horizontal
+- 2=1D Vertical
+- 3=2D H/V Separable (default)
+- 4=2D Symmetric non-separable
+
+Param[1]
+^^^^^^^^
+
+Chrominance filter
+
+- 0=Off
+- 1=1D Horizontal (default)
+
+
+
+CX2341X_ENC_SET_VBI_LINE
+~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 183/0xB7
+
+Description
+^^^^^^^^^^^
+
+Selects VBI line number.
+
+Param[0]
+^^^^^^^^
+
+- Bits 0:4 	line number
+- Bit  31		0=top_field, 1=bottom_field
+- Bits 0:31 	all set specifies "all lines"
+
+Param[1]
+^^^^^^^^
+
+VBI line information features: 0=disabled, 1=enabled
+
+Param[2]
+^^^^^^^^
+
+Slicing: 0=None, 1=Closed Caption
+Almost certainly not implemented. Set to 0.
+
+Param[3]
+^^^^^^^^
+
+Luminance samples in this line.
+Almost certainly not implemented. Set to 0.
+
+Param[4]
+^^^^^^^^
+
+Chrominance samples in this line
+Almost certainly not implemented. Set to 0.
+
+
+
+CX2341X_ENC_SET_STREAM_TYPE
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 185/0xB9
+
+Description
+^^^^^^^^^^^
+
+Assign stream type
+
+.. note::
+
+	Transport stream is not working in recent firmwares.
+	And in older firmwares the timestamps in the TS seem to be
+	unreliable.
+
+Param[0]
+^^^^^^^^
+
+- 0=Program stream
+- 1=Transport stream
+- 2=MPEG1 stream
+- 3=PES A/V stream
+- 5=PES Video stream
+- 7=PES Audio stream
+- 10=DVD stream
+- 11=VCD stream
+- 12=SVCD stream
+- 13=DVD_S1 stream
+- 14=DVD_S2 stream
+
+
+
+CX2341X_ENC_SET_OUTPUT_PORT
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 187/0xBB
+
+Description
+^^^^^^^^^^^
+
+Assign stream output port. Normally 0 when the data is copied through
+the PCI bus (DMA), and 1 when the data is streamed to another chip
+(pvrusb and cx88-blackbird).
+
+Param[0]
+^^^^^^^^
+
+- 0=Memory (default)
+- 1=Streaming
+- 2=Serial
+
+Param[1]
+^^^^^^^^
+
+Unknown, but leaving this to 0 seems to work best. Indications are that
+this might have to do with USB support, although passing anything but 0
+only breaks things.
+
+
+
+CX2341X_ENC_SET_AUDIO_PROPERTIES
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 189/0xBD
+
+Description
+^^^^^^^^^^^
+
+Set audio stream properties, may be called while encoding is in progress.
+
+.. note::
+
+	All bitfields are consistent with ISO11172 documentation except
+	bits 2:3 which ISO docs define as:
+
+	- '11' Layer I
+	- '10' Layer II
+	- '01' Layer III
+	- '00' Undefined
+
+	This discrepancy may indicate a possible error in the documentation.
+	Testing indicated that only Layer II is actually working, and that
+	the minimum bitrate should be 192 kbps.
+
+Param[0]
+^^^^^^^^
+
+Bitmask:
+
+.. code-block:: none
+
+	   0:1  '00' 44.1Khz
+		'01' 48Khz
+		'10' 32Khz
+		'11' reserved
+
+	   2:3  '01'=Layer I
+		'10'=Layer II
+
+	   4:7  Bitrate:
+		     Index | Layer I     | Layer II
+		     ------+-------------+------------
+		    '0000' | free format | free format
+		    '0001' |  32 kbit/s  |  32 kbit/s
+		    '0010' |  64 kbit/s  |  48 kbit/s
+		    '0011' |  96 kbit/s  |  56 kbit/s
+		    '0100' | 128 kbit/s  |  64 kbit/s
+		    '0101' | 160 kbit/s  |  80 kbit/s
+		    '0110' | 192 kbit/s  |  96 kbit/s
+		    '0111' | 224 kbit/s  | 112 kbit/s
+		    '1000' | 256 kbit/s  | 128 kbit/s
+		    '1001' | 288 kbit/s  | 160 kbit/s
+		    '1010' | 320 kbit/s  | 192 kbit/s
+		    '1011' | 352 kbit/s  | 224 kbit/s
+		    '1100' | 384 kbit/s  | 256 kbit/s
+		    '1101' | 416 kbit/s  | 320 kbit/s
+		    '1110' | 448 kbit/s  | 384 kbit/s
+
+		.. note::
+
+			For Layer II, not all combinations of total bitrate
+			and mode are allowed. See ISO11172-3 3-Annex B,
+			Table 3-B.2
+
+	   8:9  '00'=Stereo
+		'01'=JointStereo
+		'10'=Dual
+		'11'=Mono
+
+		.. note::
+
+			The cx23415 cannot decode Joint Stereo properly.
+
+	  10:11 Mode Extension used in joint_stereo mode.
+		In Layer I and II they indicate which subbands are in
+		intensity_stereo. All other subbands are coded in stereo.
+		    '00' subbands 4-31 in intensity_stereo, bound==4
+		    '01' subbands 8-31 in intensity_stereo, bound==8
+		    '10' subbands 12-31 in intensity_stereo, bound==12
+		    '11' subbands 16-31 in intensity_stereo, bound==16
+
+	  12:13 Emphasis:
+		    '00' None
+		    '01' 50/15uS
+		    '10' reserved
+		    '11' CCITT J.17
+
+	  14 	CRC:
+		    '0' off
+		    '1' on
+
+	  15    Copyright:
+		    '0' off
+		    '1' on
+
+	  16    Generation:
+		    '0' copy
+		    '1' original
+
+
+
+CX2341X_ENC_HALT_FW
+~~~~~~~~~~~~~~~~~~~
+
+Enum: 195/0xC3
+
+Description
+^^^^^^^^^^^
+
+The firmware is halted and no further API calls are serviced until the
+firmware is uploaded again.
+
+
+
+CX2341X_ENC_GET_VERSION
+~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 196/0xC4
+
+Description
+^^^^^^^^^^^
+
+Returns the version of the encoder firmware.
+
+Result[0]
+^^^^^^^^^
+
+Version bitmask:
+- Bits  0:15 build
+- Bits 16:23 minor
+- Bits 24:31 major
+
+
+
+CX2341X_ENC_SET_GOP_CLOSURE
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 197/0xC5
+
+Description
+^^^^^^^^^^^
+
+Assigns the GOP open/close property.
+
+Param[0]
+^^^^^^^^
+
+- 0=Open
+- 1=Closed
+
+
+
+CX2341X_ENC_GET_SEQ_END
+~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 198/0xC6
+
+Description
+^^^^^^^^^^^
+
+Obtains the sequence end code of the encoder's buffer. When a capture
+is started a number of interrupts are still generated, the last of
+which will have Result[0] set to 1 and Result[1] will contain the size
+of the buffer.
+
+Result[0]
+^^^^^^^^^
+
+State of the transfer (1 if last buffer)
+
+Result[1]
+^^^^^^^^^
+
+If Result[0] is 1, this contains the size of the last buffer, undefined
+otherwise.
+
+
+
+CX2341X_ENC_SET_PGM_INDEX_INFO
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 199/0xC7
+
+Description
+^^^^^^^^^^^
+
+Sets the Program Index Information.
+The information is stored as follows:
+
+.. code-block:: c
+
+	struct info {
+		u32 length;		// Length of this frame
+		u32 offset_low;		// Offset in the file of the
+		u32 offset_high;	// start of this frame
+		u32 mask1;		// Bits 0-2 are the type mask:
+					// 1=I, 2=P, 4=B
+					// 0=End of Program Index, other fields
+					//   are invalid.
+		u32 pts;		// The PTS of the frame
+		u32 mask2;		// Bit 0 is bit 32 of the pts.
+	};
+	u32 table_ptr;
+	struct info index[400];
+
+The table_ptr is the encoder memory address in the table were
+*new* entries will be written.
+
+.. note:: This is a ringbuffer, so the table_ptr will wraparound.
+
+Param[0]
+^^^^^^^^
+
+Picture Mask:
+- 0=No index capture
+- 1=I frames
+- 3=I,P frames
+- 7=I,P,B frames
+
+(Seems to be ignored, it always indexes I, P and B frames)
+
+Param[1]
+^^^^^^^^
+
+Elements requested (up to 400)
+
+Result[0]
+^^^^^^^^^
+
+Offset in the encoder memory of the start of the table.
+
+Result[1]
+^^^^^^^^^
+
+Number of allocated elements up to a maximum of Param[1]
+
+
+
+CX2341X_ENC_SET_VBI_CONFIG
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 200/0xC8
+
+Description
+^^^^^^^^^^^
+
+Configure VBI settings
+
+Param[0]
+^^^^^^^^
+
+Bitmap:
+
+.. code-block:: none
+
+	    0    Mode '0' Sliced, '1' Raw
+	    1:3  Insertion:
+		     '000' insert in extension & user data
+		     '001' insert in private packets
+		     '010' separate stream and user data
+		     '111' separate stream and private data
+	    8:15 Stream ID (normally 0xBD)
+
+Param[1]
+^^^^^^^^
+
+Frames per interrupt (max 8). Only valid in raw mode.
+
+Param[2]
+^^^^^^^^
+
+Total raw VBI frames. Only valid in raw mode.
+
+Param[3]
+^^^^^^^^
+
+Start codes
+
+Param[4]
+^^^^^^^^
+
+Stop codes
+
+Param[5]
+^^^^^^^^
+
+Lines per frame
+
+Param[6]
+^^^^^^^^
+
+Byte per line
+
+Result[0]
+^^^^^^^^^
+
+Observed frames per interrupt in raw mode only. Rage 1 to Param[1]
+
+Result[1]
+^^^^^^^^^
+
+Observed number of frames in raw mode. Range 1 to Param[2]
+
+Result[2]
+^^^^^^^^^
+
+Memory offset to start or raw VBI data
+
+
+
+CX2341X_ENC_SET_DMA_BLOCK_SIZE
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 201/0xC9
+
+Description
+^^^^^^^^^^^
+
+Set DMA transfer block size
+
+Param[0]
+^^^^^^^^
+
+DMA transfer block size in bytes or frames. When unit is bytes,
+supported block sizes are 2^7, 2^8 and 2^9 bytes.
+
+Param[1]
+^^^^^^^^
+
+Unit: 0=bytes, 1=frames
+
+
+
+CX2341X_ENC_GET_PREV_DMA_INFO_MB_10
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 202/0xCA
+
+Description
+^^^^^^^^^^^
+
+Returns information on the previous DMA transfer in conjunction with
+bit 27 of the interrupt mask. Uses mailbox 10.
+
+Result[0]
+^^^^^^^^^
+
+Type of stream
+
+Result[1]
+^^^^^^^^^
+
+Address Offset
+
+Result[2]
+^^^^^^^^^
+
+Maximum size of transfer
+
+
+
+CX2341X_ENC_GET_PREV_DMA_INFO_MB_9
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 203/0xCB
+
+Description
+^^^^^^^^^^^
+
+Returns information on the previous DMA transfer in conjunction with
+bit 27 or 18 of the interrupt mask. Uses mailbox 9.
+
+Result[0]
+^^^^^^^^^
+
+Status bits:
+- 0   read completed
+- 1   write completed
+- 2   DMA read error
+- 3   DMA write error
+- 4   Scatter-Gather array error
+
+Result[1]
+^^^^^^^^^
+
+DMA type
+
+Result[2]
+^^^^^^^^^
+
+Presentation Time Stamp bits 0..31
+
+Result[3]
+^^^^^^^^^
+
+Presentation Time Stamp bit 32
+
+
+
+CX2341X_ENC_SCHED_DMA_TO_HOST
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 204/0xCC
+
+Description
+^^^^^^^^^^^
+
+Setup DMA to host operation
+
+Param[0]
+^^^^^^^^
+
+Memory address of link list
+
+Param[1]
+^^^^^^^^
+
+Length of link list (wtf: what units ???)
+
+Param[2]
+^^^^^^^^
+
+DMA type (0=MPEG)
+
+
+
+CX2341X_ENC_INITIALIZE_INPUT
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 205/0xCD
+
+Description
+^^^^^^^^^^^
+
+Initializes the video input
+
+
+
+CX2341X_ENC_SET_FRAME_DROP_RATE
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 208/0xD0
+
+Description
+^^^^^^^^^^^
+
+For each frame captured, skip specified number of frames.
+
+Param[0]
+^^^^^^^^
+
+Number of frames to skip
+
+
+
+CX2341X_ENC_PAUSE_ENCODER
+~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 210/0xD2
+
+Description
+^^^^^^^^^^^
+
+During a pause condition, all frames are dropped instead of being encoded.
+
+Param[0]
+^^^^^^^^
+
+- 0=Pause encoding
+- 1=Continue encoding
+
+
+
+CX2341X_ENC_REFRESH_INPUT
+~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 211/0xD3
+
+Description
+^^^^^^^^^^^
+
+Refreshes the video input
+
+
+
+CX2341X_ENC_SET_COPYRIGHT
+~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 212/0xD4
+
+Description
+^^^^^^^^^^^
+
+Sets stream copyright property
+
+Param[0]
+^^^^^^^^
+
+
+- 0=Stream is not copyrighted
+- 1=Stream is copyrighted
+
+
+
+CX2341X_ENC_SET_EVENT_NOTIFICATION
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 213/0xD5
+
+Description
+^^^^^^^^^^^
+
+Setup firmware to notify the host about a particular event. Host must
+unmask the interrupt bit.
+
+Param[0]
+^^^^^^^^
+
+Event (0=refresh encoder input)
+
+Param[1]
+^^^^^^^^
+
+Notification 0=disabled 1=enabled
+
+Param[2]
+^^^^^^^^
+
+Interrupt bit
+
+Param[3]
+^^^^^^^^
+
+Mailbox slot, -1 if no mailbox required.
+
+
+
+CX2341X_ENC_SET_NUM_VSYNC_LINES
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 214/0xD6
+
+Description
+^^^^^^^^^^^
+
+Depending on the analog video decoder used, this assigns the number
+of lines for field 1 and 2.
+
+Param[0]
+^^^^^^^^
+
+Field 1 number of lines:
+- 0x00EF for SAA7114
+- 0x00F0 for SAA7115
+- 0x0105 for Micronas
+
+Param[1]
+^^^^^^^^
+
+Field 2 number of lines:
+- 0x00EF for SAA7114
+- 0x00F0 for SAA7115
+- 0x0106 for Micronas
+
+
+
+CX2341X_ENC_SET_PLACEHOLDER
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 215/0xD7
+
+Description
+^^^^^^^^^^^
+
+Provides a mechanism of inserting custom user data in the MPEG stream.
+
+Param[0]
+^^^^^^^^
+
+- 0=extension & user data
+- 1=private packet with stream ID 0xBD
+
+Param[1]
+^^^^^^^^
+
+Rate at which to insert data, in units of frames (for private packet)
+or GOPs (for ext. & user data)
+
+Param[2]
+^^^^^^^^
+
+Number of data DWORDs (below) to insert
+
+Param[3]
+^^^^^^^^
+
+Custom data 0
+
+Param[4]
+^^^^^^^^
+
+Custom data 1
+
+Param[5]
+^^^^^^^^
+
+Custom data 2
+
+Param[6]
+^^^^^^^^
+
+Custom data 3
+
+Param[7]
+^^^^^^^^
+
+Custom data 4
+
+Param[8]
+^^^^^^^^
+
+Custom data 5
+
+Param[9]
+^^^^^^^^
+
+Custom data 6
+
+Param[10]
+^^^^^^^^^
+
+Custom data 7
+
+Param[11]
+^^^^^^^^^
+
+Custom data 8
+
+
+
+CX2341X_ENC_MUTE_VIDEO
+~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 217/0xD9
+
+Description
+^^^^^^^^^^^
+
+Video muting
+
+Param[0]
+^^^^^^^^
+
+Bit usage:
+
+.. code-block:: none
+
+	 0    	'0'=video not muted
+		'1'=video muted, creates frames with the YUV color defined below
+	 1:7  	Unused
+	 8:15 	V chrominance information
+	16:23 	U chrominance information
+	24:31 	Y luminance information
+
+
+
+CX2341X_ENC_MUTE_AUDIO
+~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 218/0xDA
+
+Description
+^^^^^^^^^^^
+
+Audio muting
+
+Param[0]
+^^^^^^^^
+
+- 0=audio not muted
+- 1=audio muted (produces silent mpeg audio stream)
+
+
+
+CX2341X_ENC_SET_VERT_CROP_LINE
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 219/0xDB
+
+Description
+^^^^^^^^^^^
+
+Something to do with 'Vertical Crop Line'
+
+Param[0]
+^^^^^^^^
+
+If saa7114 and raw VBI capture and 60 Hz, then set to 10001.
+Else 0.
+
+
+
+CX2341X_ENC_MISC
+~~~~~~~~~~~~~~~~
+
+Enum: 220/0xDC
+
+Description
+^^^^^^^^^^^
+
+Miscellaneous actions. Not known for 100% what it does. It's really a
+sort of ioctl call. The first parameter is a command number, the second
+the value.
+
+Param[0]
+^^^^^^^^
+
+Command number:
+
+.. code-block:: none
+
+	 1=set initial SCR value when starting encoding (works).
+	 2=set quality mode (apparently some test setting).
+	 3=setup advanced VIM protection handling.
+	   Always 1 for the cx23416 and 0 for cx23415.
+	 4=generate DVD compatible PTS timestamps
+	 5=USB flush mode
+	 6=something to do with the quantization matrix
+	 7=set navigation pack insertion for DVD: adds 0xbf (private stream 2)
+	   packets to the MPEG. The size of these packets is 2048 bytes (including
+	   the header of 6 bytes: 0x000001bf + length). The payload is zeroed and
+	   it is up to the application to fill them in. These packets are apparently
+	   inserted every four frames.
+	 8=enable scene change detection (seems to be a failure)
+	 9=set history parameters of the video input module
+	10=set input field order of VIM
+	11=set quantization matrix
+	12=reset audio interface after channel change or input switch (has no argument).
+	   Needed for the cx2584x, not needed for the mspx4xx, but it doesn't seem to
+	   do any harm calling it regardless.
+	13=set audio volume delay
+	14=set audio delay
+
+
+Param[1]
+^^^^^^^^
+
+Command value.
+
+Decoder firmware API description
+--------------------------------
+
+.. note:: this API is part of the decoder firmware, so it's cx23415 only.
+
+
+
+CX2341X_DEC_PING_FW
+~~~~~~~~~~~~~~~~~~~
+
+Enum: 0/0x00
+
+Description
+^^^^^^^^^^^
+
+This API call does nothing. It may be used to check if the firmware
+is responding.
+
+
+
+CX2341X_DEC_START_PLAYBACK
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 1/0x01
+
+Description
+^^^^^^^^^^^
+
+Begin or resume playback.
+
+Param[0]
+^^^^^^^^
+
+0 based frame number in GOP to begin playback from.
+
+Param[1]
+^^^^^^^^
+
+Specifies the number of muted audio frames to play before normal
+audio resumes. (This is not implemented in the firmware, leave at 0)
+
+
+
+CX2341X_DEC_STOP_PLAYBACK
+~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 2/0x02
+
+Description
+^^^^^^^^^^^
+
+Ends playback and clears all decoder buffers. If PTS is not zero,
+playback stops at specified PTS.
+
+Param[0]
+^^^^^^^^
+
+Display 0=last frame, 1=black
+
+.. note::
+
+	this takes effect immediately, so if you want to wait for a PTS,
+	then use '0', otherwise the screen goes to black at once.
+	You can call this later (even if there is no playback) with a 1 value
+	to set the screen to black.
+
+Param[1]
+^^^^^^^^
+
+PTS low
+
+Param[2]
+^^^^^^^^
+
+PTS high
+
+
+
+CX2341X_DEC_SET_PLAYBACK_SPEED
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 3/0x03
+
+Description
+^^^^^^^^^^^
+
+Playback stream at speed other than normal. There are two modes of
+operation:
+
+	- Smooth: host transfers entire stream and firmware drops unused
+	  frames.
+	- Coarse: host drops frames based on indexing as required to achieve
+	  desired speed.
+
+Param[0]
+^^^^^^^^
+
+.. code-block:: none
+
+	Bitmap:
+	    0:7  0 normal
+		 1 fast only "1.5 times"
+		 n nX fast, 1/nX slow
+	    30   Framedrop:
+		     '0' during 1.5 times play, every other B frame is dropped
+		     '1' during 1.5 times play, stream is unchanged (bitrate
+			 must not exceed 8mbps)
+	    31   Speed:
+		     '0' slow
+		     '1' fast
+
+.. note::
+
+	n is limited to 2. Anything higher does not result in
+	faster playback. Instead the host should start dropping frames.
+
+Param[1]
+^^^^^^^^
+
+Direction: 0=forward, 1=reverse
+
+.. note::
+
+	to make reverse playback work you have to write full GOPs in
+	reverse order.
+
+Param[2]
+^^^^^^^^
+
+.. code-block:: none
+
+	Picture mask:
+	    1=I frames
+	    3=I, P frames
+	    7=I, P, B frames
+
+Param[3]
+^^^^^^^^
+
+B frames per GOP (for reverse play only)
+
+.. note::
+
+	for reverse playback the Picture Mask should be set to I or I, P.
+	Adding B frames to the mask will result in corrupt video. This field
+	has to be set to the correct value in order to keep the timing correct.
+
+Param[4]
+^^^^^^^^
+
+Mute audio: 0=disable, 1=enable
+
+Param[5]
+^^^^^^^^
+
+Display 0=frame, 1=field
+
+Param[6]
+^^^^^^^^
+
+Specifies the number of muted audio frames to play before normal audio
+resumes. (Not implemented in the firmware, leave at 0)
+
+
+
+CX2341X_DEC_STEP_VIDEO
+~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 5/0x05
+
+Description
+^^^^^^^^^^^
+
+Each call to this API steps the playback to the next unit defined below
+in the current playback direction.
+
+Param[0]
+^^^^^^^^
+
+0=frame, 1=top field, 2=bottom field
+
+
+
+CX2341X_DEC_SET_DMA_BLOCK_SIZE
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 8/0x08
+
+Description
+^^^^^^^^^^^
+
+Set DMA transfer block size. Counterpart to API 0xC9
+
+Param[0]
+^^^^^^^^
+
+DMA transfer block size in bytes. A different size may be specified
+when issuing the DMA transfer command.
+
+
+
+CX2341X_DEC_GET_XFER_INFO
+~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 9/0x09
+
+Description
+^^^^^^^^^^^
+
+This API call may be used to detect an end of stream condition.
+
+Result[0]
+^^^^^^^^^
+
+Stream type
+
+Result[1]
+^^^^^^^^^
+
+Address offset
+
+Result[2]
+^^^^^^^^^
+
+Maximum bytes to transfer
+
+Result[3]
+^^^^^^^^^
+
+Buffer fullness
+
+
+
+CX2341X_DEC_GET_DMA_STATUS
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 10/0x0A
+
+Description
+^^^^^^^^^^^
+
+Status of the last DMA transfer
+
+Result[0]
+^^^^^^^^^
+
+Bit 1 set means transfer complete
+Bit 2 set means DMA error
+Bit 3 set means linked list error
+
+Result[1]
+^^^^^^^^^
+
+DMA type: 0=MPEG, 1=OSD, 2=YUV
+
+
+
+CX2341X_DEC_SCHED_DMA_FROM_HOST
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 11/0x0B
+
+Description
+^^^^^^^^^^^
+
+Setup DMA from host operation. Counterpart to API 0xCC
+
+Param[0]
+^^^^^^^^
+
+Memory address of link list
+
+Param[1]
+^^^^^^^^
+
+Total # of bytes to transfer
+
+Param[2]
+^^^^^^^^
+
+DMA type (0=MPEG, 1=OSD, 2=YUV)
+
+
+
+CX2341X_DEC_PAUSE_PLAYBACK
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 13/0x0D
+
+Description
+^^^^^^^^^^^
+
+Freeze playback immediately. In this mode, when internal buffers are
+full, no more data will be accepted and data request IRQs will be
+masked.
+
+Param[0]
+^^^^^^^^
+
+Display: 0=last frame, 1=black
+
+
+
+CX2341X_DEC_HALT_FW
+~~~~~~~~~~~~~~~~~~~
+
+Enum: 14/0x0E
+
+Description
+^^^^^^^^^^^
+
+The firmware is halted and no further API calls are serviced until
+the firmware is uploaded again.
+
+
+
+CX2341X_DEC_SET_STANDARD
+~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 16/0x10
+
+Description
+^^^^^^^^^^^
+
+Selects display standard
+
+Param[0]
+^^^^^^^^
+
+0=NTSC, 1=PAL
+
+
+
+CX2341X_DEC_GET_VERSION
+~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 17/0x11
+
+Description
+^^^^^^^^^^^
+
+Returns decoder firmware version information
+
+Result[0]
+^^^^^^^^^
+
+Version bitmask:
+	- Bits  0:15 build
+	- Bits 16:23 minor
+	- Bits 24:31 major
+
+
+
+CX2341X_DEC_SET_STREAM_INPUT
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 20/0x14
+
+Description
+^^^^^^^^^^^
+
+Select decoder stream input port
+
+Param[0]
+^^^^^^^^
+
+0=memory (default), 1=streaming
+
+
+
+CX2341X_DEC_GET_TIMING_INFO
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 21/0x15
+
+Description
+^^^^^^^^^^^
+
+Returns timing information from start of playback
+
+Result[0]
+^^^^^^^^^
+
+Frame count by decode order
+
+Result[1]
+^^^^^^^^^
+
+Video PTS bits 0:31 by display order
+
+Result[2]
+^^^^^^^^^
+
+Video PTS bit 32 by display order
+
+Result[3]
+^^^^^^^^^
+
+SCR bits 0:31 by display order
+
+Result[4]
+^^^^^^^^^
+
+SCR bit 32 by display order
+
+
+
+CX2341X_DEC_SET_AUDIO_MODE
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 22/0x16
+
+Description
+^^^^^^^^^^^
+
+Select audio mode
+
+Param[0]
+^^^^^^^^
+
+Dual mono mode action
+	0=Stereo, 1=Left, 2=Right, 3=Mono, 4=Swap, -1=Unchanged
+
+Param[1]
+^^^^^^^^
+
+Stereo mode action:
+	0=Stereo, 1=Left, 2=Right, 3=Mono, 4=Swap, -1=Unchanged
+
+
+
+CX2341X_DEC_SET_EVENT_NOTIFICATION
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 23/0x17
+
+Description
+^^^^^^^^^^^
+
+Setup firmware to notify the host about a particular event.
+Counterpart to API 0xD5
+
+Param[0]
+^^^^^^^^
+
+Event:
+	- 0=Audio mode change between mono, (joint) stereo and dual channel.
+	- 3=Decoder started
+	- 4=Unknown: goes off 10-15 times per second while decoding.
+	- 5=Some sync event: goes off once per frame.
+
+Param[1]
+^^^^^^^^
+
+Notification 0=disabled, 1=enabled
+
+Param[2]
+^^^^^^^^
+
+Interrupt bit
+
+Param[3]
+^^^^^^^^
+
+Mailbox slot, -1 if no mailbox required.
+
+
+
+CX2341X_DEC_SET_DISPLAY_BUFFERS
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 24/0x18
+
+Description
+^^^^^^^^^^^
+
+Number of display buffers. To decode all frames in reverse playback you
+must use nine buffers.
+
+Param[0]
+^^^^^^^^
+
+0=six buffers, 1=nine buffers
+
+
+
+CX2341X_DEC_EXTRACT_VBI
+~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 25/0x19
+
+Description
+^^^^^^^^^^^
+
+Extracts VBI data
+
+Param[0]
+^^^^^^^^
+
+0=extract from extension & user data, 1=extract from private packets
+
+Result[0]
+^^^^^^^^^
+
+VBI table location
+
+Result[1]
+^^^^^^^^^
+
+VBI table size
+
+
+
+CX2341X_DEC_SET_DECODER_SOURCE
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 26/0x1A
+
+Description
+^^^^^^^^^^^
+
+Selects decoder source. Ensure that the parameters passed to this
+API match the encoder settings.
+
+Param[0]
+^^^^^^^^
+
+Mode: 0=MPEG from host, 1=YUV from encoder, 2=YUV from host
+
+Param[1]
+^^^^^^^^
+
+YUV picture width
+
+Param[2]
+^^^^^^^^
+
+YUV picture height
+
+Param[3]
+^^^^^^^^
+
+Bitmap: see Param[0] of API 0xBD
+
+
+
+CX2341X_DEC_SET_PREBUFFERING
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Enum: 30/0x1E
+
+Description
+^^^^^^^^^^^
+
+Decoder prebuffering, when enabled up to 128KB are buffered for
+streams <8mpbs or 640KB for streams >8mbps
+
+Param[0]
+^^^^^^^^
+
+0=off, 1=on
+
+PVR350 Video decoder registers 0x02002800 -> 0x02002B00
+-------------------------------------------------------
+
+Author: Ian Armstrong <ian@iarmst.demon.co.uk>
+
+Version: v0.4
+
+Date: 12 March 2007
+
+
+This list has been worked out through trial and error. There will be mistakes
+and omissions. Some registers have no obvious effect so it's hard to say what
+they do, while others interact with each other, or require a certain load
+sequence. Horizontal filter setup is one example, with six registers working
+in unison and requiring a certain load sequence to correctly configure. The
+indexed colour palette is much easier to set at just two registers, but again
+it requires a certain load sequence.
+
+Some registers are fussy about what they are set to. Load in a bad value & the
+decoder will fail. A firmware reload will often recover, but sometimes a reset
+is required. For registers containing size information, setting them to 0 is
+generally a bad idea. For other control registers i.e. 2878, you'll only find
+out what values are bad when it hangs.
+
+.. code-block:: none
+
+	--------------------------------------------------------------------------------
+	2800
+	bit 0
+		Decoder enable
+		0 = disable
+		1 = enable
+	--------------------------------------------------------------------------------
+	2804
+	bits 0:31
+		Decoder horizontal Y alias register 1
+	---------------
+	2808
+	bits 0:31
+		Decoder horizontal Y alias register 2
+	---------------
+	280C
+	bits 0:31
+		Decoder horizontal Y alias register 3
+	---------------
+	2810
+	bits 0:31
+		Decoder horizontal Y alias register 4
+	---------------
+	2814
+	bits 0:31
+		Decoder horizontal Y alias register 5
+	---------------
+	2818
+	bits 0:31
+		Decoder horizontal Y alias trigger
+
+	These six registers control the horizontal aliasing filter for the Y plane.
+	The first five registers must all be loaded before accessing the trigger
+	(2818), as this register actually clocks the data through for the first
+	five.
+
+	To correctly program set the filter, this whole procedure must be done 16
+	times. The actual register contents are copied from a lookup-table in the
+	firmware which contains 4 different filter settings.
+
+	--------------------------------------------------------------------------------
+	281C
+	bits 0:31
+		Decoder horizontal UV alias register 1
+	---------------
+	2820
+	bits 0:31
+		Decoder horizontal UV alias register 2
+	---------------
+	2824
+	bits 0:31
+		Decoder horizontal UV alias register 3
+	---------------
+	2828
+	bits 0:31
+		Decoder horizontal UV alias register 4
+	---------------
+	282C
+	bits 0:31
+		Decoder horizontal UV alias register 5
+	---------------
+	2830
+	bits 0:31
+		Decoder horizontal UV alias trigger
+
+	These six registers control the horizontal aliasing for the UV plane.
+	Operation is the same as the Y filter, with 2830 being the trigger
+	register.
+
+	--------------------------------------------------------------------------------
+	2834
+	bits 0:15
+		Decoder Y source width in pixels
+
+	bits 16:31
+		Decoder Y destination width in pixels
+	---------------
+	2838
+	bits 0:15
+		Decoder UV source width in pixels
+
+	bits 16:31
+		Decoder UV destination width in pixels
+
+	NOTE: For both registers, the resulting image must be fully visible on
+	screen. If the image exceeds the right edge both the source and destination
+	size must be adjusted to reflect the visible portion. For the source width,
+	you must take into account the scaling when calculating the new value.
+	--------------------------------------------------------------------------------
+
+	283C
+	bits 0:31
+		Decoder Y horizontal scaling
+			Normally = Reg 2854 >> 2
+	---------------
+	2840
+	bits 0:31
+		Decoder ?? unknown - horizontal scaling
+		Usually 0x00080514
+	---------------
+	2844
+	bits 0:31
+		Decoder UV horizontal scaling
+		Normally = Reg 2854 >> 2
+	---------------
+	2848
+	bits 0:31
+		Decoder ?? unknown - horizontal scaling
+		Usually 0x00100514
+	---------------
+	284C
+	bits 0:31
+		Decoder ?? unknown - Y plane
+		Usually 0x00200020
+	---------------
+	2850
+	bits 0:31
+		Decoder ?? unknown - UV plane
+		Usually 0x00200020
+	---------------
+	2854
+	bits 0:31
+		Decoder 'master' value for horizontal scaling
+	---------------
+	2858
+	bits 0:31
+		Decoder ?? unknown
+		Usually 0
+	---------------
+	285C
+	bits 0:31
+		Decoder ?? unknown
+		Normally = Reg 2854 >> 1
+	---------------
+	2860
+	bits 0:31
+		Decoder ?? unknown
+		Usually 0
+	---------------
+	2864
+	bits 0:31
+		Decoder ?? unknown
+		Normally = Reg 2854 >> 1
+	---------------
+	2868
+	bits 0:31
+		Decoder ?? unknown
+		Usually 0
+
+	Most of these registers either control horizontal scaling, or appear linked
+	to it in some way. Register 2854 contains the 'master' value & the other
+	registers can be calculated from that one. You must also remember to
+	correctly set the divider in Reg 2874.
+
+	To enlarge:
+		Reg 2854 = (source_width * 0x00200000) / destination_width
+		Reg 2874 = No divide
+
+	To reduce from full size down to half size:
+		Reg 2854 = (source_width/2 * 0x00200000) / destination width
+		Reg 2874 = Divide by 2
+
+	To reduce from half size down to quarter size:
+		Reg 2854 = (source_width/4 * 0x00200000) / destination width
+		Reg 2874 = Divide by 4
+
+	The result is always rounded up.
+
+	--------------------------------------------------------------------------------
+	286C
+	bits 0:15
+		Decoder horizontal Y buffer offset
+
+	bits 15:31
+		Decoder horizontal UV buffer offset
+
+	Offset into the video image buffer. If the offset is gradually incremented,
+	the on screen image will move left & wrap around higher up on the right.
+
+	--------------------------------------------------------------------------------
+	2870
+	bits 0:15
+		Decoder horizontal Y output offset
+
+	bits 16:31
+		Decoder horizontal UV output offset
+
+	Offsets the actual video output. Controls output alignment of the Y & UV
+	planes. The higher the value, the greater the shift to the left. Use
+	reg 2890 to move the image right.
+
+	--------------------------------------------------------------------------------
+	2874
+	bits 0:1
+		Decoder horizontal Y output size divider
+		00 = No divide
+		01 = Divide by 2
+		10 = Divide by 3
+
+	bits 4:5
+		Decoder horizontal UV output size divider
+		00 = No divide
+		01 = Divide by 2
+		10 = Divide by 3
+
+	bit 8
+		Decoder ?? unknown
+		0 = Normal
+		1 = Affects video output levels
+
+	bit 16
+		Decoder ?? unknown
+		0 = Normal
+		1 = Disable horizontal filter
+
+	--------------------------------------------------------------------------------
+	2878
+	bit 0
+		?? unknown
+
+	bit 1
+		osd on/off
+		0 = osd off
+		1 = osd on
+
+	bit 2
+		Decoder + osd video timing
+		0 = NTSC
+		1 = PAL
+
+	bits 3:4
+		?? unknown
+
+	bit 5
+		Decoder + osd
+		Swaps upper & lower fields
+
+	--------------------------------------------------------------------------------
+	287C
+	bits 0:10
+		Decoder & osd ?? unknown
+		Moves entire screen horizontally. Starts at 0x005 with the screen
+		shifted heavily to the right. Incrementing in steps of 0x004 will
+		gradually shift the screen to the left.
+
+	bits 11:31
+		?? unknown
+
+	Normally contents are 0x00101111 (NTSC) or 0x1010111d (PAL)
+
+	--------------------------------------------------------------------------------
+	2880  --------    ?? unknown
+	2884  --------    ?? unknown
+	--------------------------------------------------------------------------------
+	2888
+	bit 0
+		Decoder + osd ?? unknown
+		0 = Normal
+		1 = Misaligned fields (Correctable through 289C & 28A4)
+
+	bit 4
+		?? unknown
+
+	bit 8
+		?? unknown
+
+	Warning: Bad values will require a firmware reload to recover.
+			Known to be bad are 0x000,0x011,0x100,0x111
+	--------------------------------------------------------------------------------
+	288C
+	bits 0:15
+		osd ?? unknown
+		Appears to affect the osd position stability. The higher the value the
+		more unstable it becomes. Decoder output remains stable.
+
+	bits 16:31
+		osd ?? unknown
+		Same as bits 0:15
+
+	--------------------------------------------------------------------------------
+	2890
+	bits 0:11
+		Decoder output horizontal offset.
+
+	Horizontal offset moves the video image right. A small left shift is
+	possible, but it's better to use reg 2870 for that due to its greater
+	range.
+
+	NOTE: Video corruption will occur if video window is shifted off the right
+	edge. To avoid this read the notes for 2834 & 2838.
+	--------------------------------------------------------------------------------
+	2894
+	bits 0:23
+		Decoder output video surround colour.
+
+	Contains the colour (in yuv) used to fill the screen when the video is
+	running in a window.
+	--------------------------------------------------------------------------------
+	2898
+	bits 0:23
+		Decoder video window colour
+		Contains the colour (in yuv) used to fill the video window when the
+		video is turned off.
+
+	bit 24
+		Decoder video output
+		0 = Video on
+		1 = Video off
+
+	bit 28
+		Decoder plane order
+		0 = Y,UV
+		1 = UV,Y
+
+	bit 29
+		Decoder second plane byte order
+		0 = Normal (UV)
+		1 = Swapped (VU)
+
+	In normal usage, the first plane is Y & the second plane is UV. Though the
+	order of the planes can be swapped, only the byte order of the second plane
+	can be swapped. This isn't much use for the Y plane, but can be useful for
+	the UV plane.
+
+	--------------------------------------------------------------------------------
+	289C
+	bits 0:15
+		Decoder vertical field offset 1
+
+	bits 16:31
+		Decoder vertical field offset 2
+
+	Controls field output vertical alignment. The higher the number, the lower
+	the image on screen. Known starting values are 0x011E0017 (NTSC) &
+	0x01500017 (PAL)
+	--------------------------------------------------------------------------------
+	28A0
+	bits 0:15
+		Decoder & osd width in pixels
+
+	bits 16:31
+		Decoder & osd height in pixels
+
+	All output from the decoder & osd are disabled beyond this area. Decoder
+	output will simply go black outside of this region. If the osd tries to
+	exceed this area it will become corrupt.
+	--------------------------------------------------------------------------------
+	28A4
+	bits 0:11
+		osd left shift.
+
+	Has a range of 0x770->0x7FF. With the exception of 0, any value outside of
+	this range corrupts the osd.
+	--------------------------------------------------------------------------------
+	28A8
+	bits 0:15
+		osd vertical field offset 1
+
+	bits 16:31
+		osd vertical field offset 2
+
+	Controls field output vertical alignment. The higher the number, the lower
+	the image on screen. Known starting values are 0x011E0017 (NTSC) &
+	0x01500017 (PAL)
+	--------------------------------------------------------------------------------
+	28AC  --------    ?? unknown
+	|
+	V
+	28BC  --------    ?? unknown
+	--------------------------------------------------------------------------------
+	28C0
+	bit 0
+		Current output field
+		0 = first field
+		1 = second field
+
+	bits 16:31
+		Current scanline
+		The scanline counts from the top line of the first field
+		through to the last line of the second field.
+	--------------------------------------------------------------------------------
+	28C4  --------    ?? unknown
+	|
+	V
+	28F8  --------    ?? unknown
+	--------------------------------------------------------------------------------
+	28FC
+	bit 0
+		?? unknown
+		0 = Normal
+		1 = Breaks decoder & osd output
+	--------------------------------------------------------------------------------
+	2900
+	bits 0:31
+		Decoder vertical Y alias register 1
+	---------------
+	2904
+	bits 0:31
+		Decoder vertical Y alias register 2
+	---------------
+	2908
+	bits 0:31
+		Decoder vertical Y alias trigger
+
+	These three registers control the vertical aliasing filter for the Y plane.
+	Operation is similar to the horizontal Y filter (2804). The only real
+	difference is that there are only two registers to set before accessing
+	the trigger register (2908). As for the horizontal filter, the values are
+	taken from a lookup table in the firmware, and the procedure must be
+	repeated 16 times to fully program the filter.
+	--------------------------------------------------------------------------------
+	290C
+	bits 0:31
+		Decoder vertical UV alias register 1
+	---------------
+	2910
+	bits 0:31
+		Decoder vertical UV alias register 2
+	---------------
+	2914
+	bits 0:31
+		Decoder vertical UV alias trigger
+
+	These three registers control the vertical aliasing filter for the UV
+	plane. Operation is the same as the Y filter, with 2914 being the trigger.
+	--------------------------------------------------------------------------------
+	2918
+	bits 0:15
+		Decoder Y source height in pixels
+
+	bits 16:31
+		Decoder Y destination height in pixels
+	---------------
+	291C
+	bits 0:15
+		Decoder UV source height in pixels divided by 2
+
+	bits 16:31
+		Decoder UV destination height in pixels
+
+	NOTE: For both registers, the resulting image must be fully visible on
+	screen. If the image exceeds the bottom edge both the source and
+	destination size must be adjusted to reflect the visible portion. For the
+	source height, you must take into account the scaling when calculating the
+	new value.
+	--------------------------------------------------------------------------------
+	2920
+	bits 0:31
+		Decoder Y vertical scaling
+		Normally = Reg 2930 >> 2
+	---------------
+	2924
+	bits 0:31
+		Decoder Y vertical scaling
+		Normally = Reg 2920 + 0x514
+	---------------
+	2928
+	bits 0:31
+		Decoder UV vertical scaling
+		When enlarging = Reg 2930 >> 2
+		When reducing = Reg 2930 >> 3
+	---------------
+	292C
+	bits 0:31
+		Decoder UV vertical scaling
+		Normally = Reg 2928 + 0x514
+	---------------
+	2930
+	bits 0:31
+		Decoder 'master' value for vertical scaling
+	---------------
+	2934
+	bits 0:31
+		Decoder ?? unknown - Y vertical scaling
+	---------------
+	2938
+	bits 0:31
+		Decoder Y vertical scaling
+		Normally = Reg 2930
+	---------------
+	293C
+	bits 0:31
+		Decoder ?? unknown - Y vertical scaling
+	---------------
+	2940
+	bits 0:31
+		Decoder UV vertical scaling
+		When enlarging = Reg 2930 >> 1
+		When reducing = Reg 2930
+	---------------
+	2944
+	bits 0:31
+		Decoder ?? unknown - UV vertical scaling
+	---------------
+	2948
+	bits 0:31
+		Decoder UV vertical scaling
+		Normally = Reg 2940
+	---------------
+	294C
+	bits 0:31
+		Decoder ?? unknown - UV vertical scaling
+
+	Most of these registers either control vertical scaling, or appear linked
+	to it in some way. Register 2930 contains the 'master' value & all other
+	registers can be calculated from that one. You must also remember to
+	correctly set the divider in Reg 296C
+
+	To enlarge:
+		Reg 2930 = (source_height * 0x00200000) / destination_height
+		Reg 296C = No divide
+
+	To reduce from full size down to half size:
+		Reg 2930 = (source_height/2 * 0x00200000) / destination height
+		Reg 296C = Divide by 2
+
+	To reduce from half down to quarter.
+		Reg 2930 = (source_height/4 * 0x00200000) / destination height
+		Reg 296C = Divide by 4
+
+	--------------------------------------------------------------------------------
+	2950
+	bits 0:15
+		Decoder Y line index into display buffer, first field
+
+	bits 16:31
+		Decoder Y vertical line skip, first field
+	--------------------------------------------------------------------------------
+	2954
+	bits 0:15
+		Decoder Y line index into display buffer, second field
+
+	bits 16:31
+		Decoder Y vertical line skip, second field
+	--------------------------------------------------------------------------------
+	2958
+	bits 0:15
+		Decoder UV line index into display buffer, first field
+
+	bits 16:31
+		Decoder UV vertical line skip, first field
+	--------------------------------------------------------------------------------
+	295C
+	bits 0:15
+		Decoder UV line index into display buffer, second field
+
+	bits 16:31
+		Decoder UV vertical line skip, second field
+	--------------------------------------------------------------------------------
+	2960
+	bits 0:15
+		Decoder destination height minus 1
+
+	bits 16:31
+		Decoder destination height divided by 2
+	--------------------------------------------------------------------------------
+	2964
+	bits 0:15
+		Decoder Y vertical offset, second field
+
+	bits 16:31
+		Decoder Y vertical offset, first field
+
+	These two registers shift the Y plane up. The higher the number, the
+	greater the shift.
+	--------------------------------------------------------------------------------
+	2968
+	bits 0:15
+		Decoder UV vertical offset, second field
+
+	bits 16:31
+		Decoder UV vertical offset, first field
+
+	These two registers shift the UV plane up. The higher the number, the
+	greater the shift.
+	--------------------------------------------------------------------------------
+	296C
+	bits 0:1
+		Decoder vertical Y output size divider
+		00 = No divide
+		01 = Divide by 2
+		10 = Divide by 4
+
+	bits 8:9
+		Decoder vertical UV output size divider
+		00 = No divide
+		01 = Divide by 2
+		10 = Divide by 4
+	--------------------------------------------------------------------------------
+	2970
+	bit 0
+		Decoder ?? unknown
+		0 = Normal
+		1 = Affect video output levels
+
+	bit 16
+		Decoder ?? unknown
+		0 = Normal
+		1 = Disable vertical filter
+
+	--------------------------------------------------------------------------------
+	2974  --------   ?? unknown
+	|
+	V
+	29EF  --------   ?? unknown
+	--------------------------------------------------------------------------------
+	2A00
+	bits 0:2
+		osd colour mode
+		000 = 8 bit indexed
+		001 = 16 bit (565)
+		010 = 15 bit (555)
+		011 = 12 bit (444)
+		100 = 32 bit (8888)
+
+	bits 4:5
+		osd display bpp
+		01 = 8 bit
+		10 = 16 bit
+		11 = 32 bit
+
+	bit 8
+		osd global alpha
+		0 = Off
+		1 = On
+
+	bit 9
+		osd local alpha
+		0 = Off
+		1 = On
+
+	bit 10
+		osd colour key
+		0 = Off
+		1 = On
+
+	bit 11
+		osd ?? unknown
+		Must be 1
+
+	bit 13
+		osd colour space
+		0 = ARGB
+		1 = AYVU
+
+	bits 16:31
+		osd ?? unknown
+		Must be 0x001B (some kind of buffer pointer ?)
+
+	When the bits-per-pixel is set to 8, the colour mode is ignored and
+	assumed to be 8 bit indexed. For 16 & 32 bits-per-pixel the colour depth
+	is honoured, and when using a colour depth that requires fewer bytes than
+	allocated the extra bytes are used as padding. So for a 32 bpp with 8 bit
+	index colour, there are 3 padding bytes per pixel. It's also possible to
+	select 16bpp with a 32 bit colour mode. This results in the pixel width
+	being doubled, but the color key will not work as expected in this mode.
+
+	Colour key is as it suggests. You designate a colour which will become
+	completely transparent. When using 565, 555 or 444 colour modes, the
+	colour key is always 16 bits wide. The colour to key on is set in Reg 2A18.
+
+	Local alpha works differently depending on the colour mode. For 32bpp & 8
+	bit indexed, local alpha is a per-pixel 256 step transparency, with 0 being
+	transparent and 255 being solid. For the 16bpp modes 555 & 444, the unused
+	bit(s) act as a simple transparency switch, with 0 being solid & 1 being
+	fully transparent. There is no local alpha support for 16bit 565.
+
+	Global alpha is a 256 step transparency that applies to the entire osd,
+	with 0 being transparent & 255 being solid.
+
+	It's possible to combine colour key, local alpha & global alpha.
+	--------------------------------------------------------------------------------
+	2A04
+	bits 0:15
+		osd x coord for left edge
+
+	bits 16:31
+		osd y coord for top edge
+	---------------
+	2A08
+	bits 0:15
+		osd x coord for right edge
+
+	bits 16:31
+		osd y coord for bottom edge
+
+	For both registers, (0,0) = top left corner of the display area. These
+	registers do not control the osd size, only where it's positioned & how
+	much is visible. The visible osd area cannot exceed the right edge of the
+	display, otherwise the osd will become corrupt. See reg 2A10 for
+	setting osd width.
+	--------------------------------------------------------------------------------
+	2A0C
+	bits 0:31
+		osd buffer index
+
+	An index into the osd buffer. Slowly incrementing this moves the osd left,
+	wrapping around onto the right edge
+	--------------------------------------------------------------------------------
+	2A10
+	bits 0:11
+		osd buffer 32 bit word width
+
+	Contains the width of the osd measured in 32 bit words. This means that all
+	colour modes are restricted to a byte width which is divisible by 4.
+	--------------------------------------------------------------------------------
+	2A14
+	bits 0:15
+		osd height in pixels
+
+	bits 16:32
+		osd line index into buffer
+		osd will start displaying from this line.
+	--------------------------------------------------------------------------------
+	2A18
+	bits 0:31
+		osd colour key
+
+	Contains the colour value which will be transparent.
+	--------------------------------------------------------------------------------
+	2A1C
+	bits 0:7
+		osd global alpha
+
+	Contains the global alpha value (equiv ivtvfbctl --alpha XX)
+	--------------------------------------------------------------------------------
+	2A20  --------    ?? unknown
+	|
+	V
+	2A2C  --------    ?? unknown
+	--------------------------------------------------------------------------------
+	2A30
+	bits 0:7
+		osd colour to change in indexed palette
+	---------------
+	2A34
+	bits 0:31
+		osd colour for indexed palette
+
+	To set the new palette, first load the index of the colour to change into
+	2A30, then load the new colour into 2A34. The full palette is 256 colours,
+	so the index range is 0x00-0xFF
+	--------------------------------------------------------------------------------
+	2A38  --------    ?? unknown
+	2A3C  --------    ?? unknown
+	--------------------------------------------------------------------------------
+	2A40
+	bits 0:31
+		osd ?? unknown
+
+	Affects overall brightness, wrapping around to black
+	--------------------------------------------------------------------------------
+	2A44
+	bits 0:31
+		osd ?? unknown
+
+	Green tint
+	--------------------------------------------------------------------------------
+	2A48
+	bits 0:31
+		osd ?? unknown
+
+	Red tint
+	--------------------------------------------------------------------------------
+	2A4C
+	bits 0:31
+		osd ?? unknown
+
+	Affects overall brightness, wrapping around to black
+	--------------------------------------------------------------------------------
+	2A50
+	bits 0:31
+		osd ?? unknown
+
+	Colour shift
+	--------------------------------------------------------------------------------
+	2A54
+	bits 0:31
+		osd ?? unknown
+
+	Colour shift
+	--------------------------------------------------------------------------------
+	2A58  --------    ?? unknown
+	|
+	V
+	2AFC  --------    ?? unknown
+	--------------------------------------------------------------------------------
+	2B00
+	bit 0
+		osd filter control
+		0 = filter off
+		1 = filter on
+
+	bits 1:4
+		osd ?? unknown
+
+	--------------------------------------------------------------------------------
+
+The cx231xx DMA engine
+----------------------
+
+
+This page describes the structures and procedures used by the cx2341x DMA
+engine.
+
+Introduction
+~~~~~~~~~~~~
+
+The cx2341x PCI interface is busmaster capable. This means it has a DMA
+engine to efficiently transfer large volumes of data between the card and main
+memory without requiring help from a CPU. Like most hardware, it must operate
+on contiguous physical memory. This is difficult to come by in large quantities
+on virtual memory machines.
+
+Therefore, it also supports a technique called "scatter-gather". The card can
+transfer multiple buffers in one operation. Instead of allocating one large
+contiguous buffer, the driver can allocate several smaller buffers.
+
+In practice, I've seen the average transfer to be roughly 80K, but transfers
+above 128K were not uncommon, particularly at startup. The 128K figure is
+important, because that is the largest block that the kernel can normally
+allocate. Even still, 128K blocks are hard to come by, so the driver writer is
+urged to choose a smaller block size and learn the scatter-gather technique.
+
+Mailbox #10 is reserved for DMA transfer information.
+
+Note: the hardware expects little-endian data ('intel format').
+
+Flow
+~~~~
+
+This section describes, in general, the order of events when handling DMA
+transfers. Detailed information follows this section.
+
+- The card raises the Encoder interrupt.
+- The driver reads the transfer type, offset and size from Mailbox #10.
+- The driver constructs the scatter-gather array from enough free dma buffers
+  to cover the size.
+- The driver schedules the DMA transfer via the ScheduleDMAtoHost API call.
+- The card raises the DMA Complete interrupt.
+- The driver checks the DMA status register for any errors.
+- The driver post-processes the newly transferred buffers.
+
+NOTE! It is possible that the Encoder and DMA Complete interrupts get raised
+simultaneously. (End of the last, start of the next, etc.)
+
+Mailbox #10
+~~~~~~~~~~~
+
+The Flags, Command, Return Value and Timeout fields are ignored.
+
+- Name:       Mailbox #10
+- Results[0]: Type: 0: MPEG.
+- Results[1]: Offset: The position relative to the card's memory space.
+- Results[2]: Size: The exact number of bytes to transfer.
+
+My speculation is that since the StartCapture API has a capture type of "RAW"
+available, that the type field will have other values that correspond to YUV
+and PCM data.
+
+Scatter-Gather Array
+~~~~~~~~~~~~~~~~~~~~
+
+The scatter-gather array is a contiguously allocated block of memory that
+tells the card the source and destination of each data-block to transfer.
+Card "addresses" are derived from the offset supplied by Mailbox #10. Host
+addresses are the physical memory location of the target DMA buffer.
+
+Each S-G array element is a struct of three 32-bit words. The first word is
+the source address, the second is the destination address. Both take up the
+entire 32 bits. The lowest 18 bits of the third word is the transfer byte
+count. The high-bit of the third word is the "last" flag. The last-flag tells
+the card to raise the DMA_DONE interrupt. From hard personal experience, if
+you forget to set this bit, the card will still "work" but the stream will
+most likely get corrupted.
+
+The transfer count must be a multiple of 256. Therefore, the driver will need
+to track how much data in the target buffer is valid and deal with it
+accordingly.
+
+Array Element:
+
+- 32-bit Source Address
+- 32-bit Destination Address
+- 14-bit reserved (high bit is the last flag)
+- 18-bit byte count
+
+DMA Transfer Status
+~~~~~~~~~~~~~~~~~~~
+
+Register 0x0004 holds the DMA Transfer Status:
+
+- bit 0:   read completed
+- bit 1:   write completed
+- bit 2:   DMA read error
+- bit 3:   DMA write error
+- bit 4:   Scatter-Gather array error
diff --git a/Documentation/driver-api/media/drivers/cx88-devel.rst b/Documentation/driver-api/media/drivers/cx88-devel.rst
new file mode 100644
index 000000000..cfe7c03f4
--- /dev/null
+++ b/Documentation/driver-api/media/drivers/cx88-devel.rst
@@ -0,0 +1,113 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+The cx88 driver
+===============
+
+Author:  Gerd Hoffmann
+
+Documentation missing at the cx88 datasheet
+-------------------------------------------
+
+MO_OUTPUT_FORMAT (0x310164)
+
+.. code-block:: none
+
+  Previous default from DScaler: 0x1c1f0008
+  Digit 8: 31-28
+  28: PREVREMOD = 1
+
+  Digit 7: 27-24 (0xc = 12 = b1100 )
+  27: COMBALT = 1
+  26: PAL_INV_PHASE
+    (DScaler apparently set this to 1, resulted in sucky picture)
+
+  Digits 6,5: 23-16
+  25-16: COMB_RANGE = 0x1f [default] (9 bits -> max 512)
+
+  Digit 4: 15-12
+  15: DISIFX = 0
+  14: INVCBF = 0
+  13: DISADAPT = 0
+  12: NARROWADAPT = 0
+
+  Digit 3: 11-8
+  11: FORCE2H
+  10: FORCEREMD
+  9: NCHROMAEN
+  8: NREMODEN
+
+  Digit 2: 7-4
+  7-6: YCORE
+  5-4: CCORE
+
+  Digit 1: 3-0
+  3: RANGE = 1
+  2: HACTEXT
+  1: HSFMT
+
+0x47 is the sync byte for MPEG-2 transport stream packets.
+Datasheet incorrectly states to use 47 decimal. 188 is the length.
+All DVB compliant frontends output packets with this start code.
+
+Hauppauge WinTV cx88 IR information
+-----------------------------------
+
+The controls for the mux are GPIO [0,1] for source, and GPIO 2 for muting.
+
+====== ======== =================================================
+GPIO0  GPIO1
+====== ======== =================================================
+  0        0    TV Audio
+  1        0    FM radio
+  0        1    Line-In
+  1        1    Mono tuner bypass or CD passthru (tuner specific)
+====== ======== =================================================
+
+GPIO 16(I believe) is tied to the IR port (if present).
+
+
+From the data sheet:
+
+- Register 24'h20004  PCI Interrupt Status
+
+ - bit [18]  IR_SMP_INT Set when 32 input samples have been collected over
+ - gpio[16] pin into GP_SAMPLE register.
+
+What's missing from the data sheet:
+
+- Setup 4KHz sampling rate (roughly 2x oversampled; good enough for our RC5
+  compat remote)
+- set register 0x35C050 to  0xa80a80
+- enable sampling
+- set register 0x35C054 to 0x5
+- enable the IRQ bit 18 in the interrupt mask register (and
+  provide for a handler)
+
+GP_SAMPLE register is at 0x35C058
+
+Bits are then right shifted into the GP_SAMPLE register at the specified
+rate; you get an interrupt when a full DWORD is received.
+You need to recover the actual RC5 bits out of the (oversampled) IR sensor
+bits. (Hint: look for the 0/1and 1/0 crossings of the RC5 bi-phase data)  An
+actual raw RC5 code will span 2-3 DWORDS, depending on the actual alignment.
+
+I'm pretty sure when no IR signal is present the receiver is always in a
+marking state(1); but stray light, etc can cause intermittent noise values
+as well.  Remember, this is a free running sample of the IR receiver state
+over time, so don't assume any sample starts at any particular place.
+
+Additional info
+~~~~~~~~~~~~~~~
+
+This data sheet (google search) seems to have a lovely description of the
+RC5 basics:
+http://www.atmel.com/dyn/resources/prod_documents/doc2817.pdf
+
+This document has more data:
+http://www.nenya.be/beor/electronics/rc5.htm
+
+This document has a  how to decode a bi-phase data stream:
+http://www.ee.washington.edu/circuit_archive/text/ir_decode.txt
+
+This document has still more info:
+http://www.xs4all.nl/~sbp/knowledge/ir/rc5.htm
diff --git a/Documentation/driver-api/media/drivers/davinci-vpbe-devel.rst b/Documentation/driver-api/media/drivers/davinci-vpbe-devel.rst
new file mode 100644
index 000000000..f0961672e
--- /dev/null
+++ b/Documentation/driver-api/media/drivers/davinci-vpbe-devel.rst
@@ -0,0 +1,39 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+The VPBE V4L2 driver design
+===========================
+
+File partitioning
+-----------------
+
+ V4L2 display device driver
+         drivers/media/platform/davinci/vpbe_display.c
+         drivers/media/platform/davinci/vpbe_display.h
+
+ VPBE display controller
+         drivers/media/platform/davinci/vpbe.c
+         drivers/media/platform/davinci/vpbe.h
+
+ VPBE venc sub device driver
+         drivers/media/platform/davinci/vpbe_venc.c
+         drivers/media/platform/davinci/vpbe_venc.h
+         drivers/media/platform/davinci/vpbe_venc_regs.h
+
+ VPBE osd driver
+         drivers/media/platform/davinci/vpbe_osd.c
+         drivers/media/platform/davinci/vpbe_osd.h
+         drivers/media/platform/davinci/vpbe_osd_regs.h
+
+To be done
+----------
+
+vpbe display controller
+    - Add support for external encoders.
+    - add support for selecting external encoder as default at probe time.
+
+vpbe venc sub device
+    - add timings for supporting ths8200
+    - add support for LogicPD LCD.
+
+FB drivers
+    - Add support for fbdev drivers.- Ready and part of subsequent patches.
diff --git a/Documentation/driver-api/media/drivers/dvb-usb.rst b/Documentation/driver-api/media/drivers/dvb-usb.rst
new file mode 100644
index 000000000..b2d5d9e62
--- /dev/null
+++ b/Documentation/driver-api/media/drivers/dvb-usb.rst
@@ -0,0 +1,357 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+Idea behind the dvb-usb-framework
+=================================
+
+.. note::
+
+   #) This documentation is outdated. Please check at the DVB wiki
+      at https://linuxtv.org/wiki for more updated info.
+
+   #) **deprecated:** Newer DVB USB drivers should use the dvb-usb-v2 framework.
+
+In March 2005 I got the new Twinhan USB2.0 DVB-T device. They provided specs
+and a firmware.
+
+Quite keen I wanted to put the driver (with some quirks of course) into dibusb.
+After reading some specs and doing some USB snooping, it realized, that the
+dibusb-driver would be a complete mess afterwards. So I decided to do it in a
+different way: With the help of a dvb-usb-framework.
+
+The framework provides generic functions (mostly kernel API calls), such as:
+
+- Transport Stream URB handling in conjunction with dvb-demux-feed-control
+  (bulk and isoc are supported)
+- registering the device for the DVB-API
+- registering an I2C-adapter if applicable
+- remote-control/input-device handling
+- firmware requesting and loading (currently just for the Cypress USB
+  controllers)
+- other functions/methods which can be shared by several drivers (such as
+  functions for bulk-control-commands)
+- TODO: a I2C-chunker. It creates device-specific chunks of register-accesses
+  depending on length of a register and the number of values that can be
+  multi-written and multi-read.
+
+The source code of the particular DVB USB devices does just the communication
+with the device via the bus. The connection between the DVB-API-functionality
+is done via callbacks, assigned in a static device-description (struct
+dvb_usb_device) each device-driver has to have.
+
+For an example have a look in drivers/media/usb/dvb-usb/vp7045*.
+
+Objective is to migrate all the usb-devices (dibusb, cinergyT2, maybe the
+ttusb; flexcop-usb already benefits from the generic flexcop-device) to use
+the dvb-usb-lib.
+
+TODO: dynamic enabling and disabling of the pid-filter in regard to number of
+feeds requested.
+
+Supported devices
+-----------------
+
+See the LinuxTV DVB Wiki at https://linuxtv.org for a complete list of
+cards/drivers/firmwares:
+https://linuxtv.org/wiki/index.php/DVB_USB
+
+0. History & News:
+
+  2005-06-30
+
+  - added support for WideView WT-220U (Thanks to Steve Chang)
+
+  2005-05-30
+
+  - added basic isochronous support to the dvb-usb-framework
+  - added support for Conexant Hybrid reference design and Nebula
+	       DigiTV USB
+
+  2005-04-17
+
+  - all dibusb devices ported to make use of the dvb-usb-framework
+
+  2005-04-02
+
+  - re-enabled and improved remote control code.
+
+  2005-03-31
+
+  - ported the Yakumo/Hama/Typhoon DVB-T USB2.0 device to dvb-usb.
+
+  2005-03-30
+
+  - first commit of the dvb-usb-module based on the dibusb-source.
+    First device is a new driver for the
+    TwinhanDTV Alpha / MagicBox II USB2.0-only DVB-T device.
+  - (change from dvb-dibusb to dvb-usb)
+
+  2005-03-28
+
+  - added support for the AVerMedia AverTV DVB-T USB2.0 device
+    (Thanks to Glen Harris and Jiun-Kuei Jung, AVerMedia)
+
+  2005-03-14
+
+  - added support for the Typhoon/Yakumo/HAMA DVB-T mobile USB2.0
+
+  2005-02-11
+
+  - added support for the KWorld/ADSTech Instant DVB-T USB2.0.
+    Thanks a lot to Joachim von Caron
+
+  2005-02-02
+  - added support for the Hauppauge Win-TV Nova-T USB2
+
+  2005-01-31
+  - distorted streaming is gone for USB1.1 devices
+
+  2005-01-13
+
+  - moved the mirrored pid_filter_table back to dvb-dibusb
+    first almost working version for HanfTek UMT-010
+    found out, that Yakumo/HAMA/Typhoon are predecessors of the HanfTek UMT-010
+
+  2005-01-10
+
+  - refactoring completed, now everything is very delightful
+
+  - tuner quirks for some weird devices (Artec T1 AN2235 device has sometimes a
+    Panasonic Tuner assembled). Tunerprobing implemented.
+    Thanks a lot to Gunnar Wittich.
+
+  2004-12-29
+
+  - after several days of struggling around bug of no returning URBs fixed.
+
+  2004-12-26
+
+  - refactored the dibusb-driver, split into separate files
+  - i2c-probing enabled
+
+  2004-12-06
+
+  - possibility for demod i2c-address probing
+  - new usb IDs (Compro, Artec)
+
+  2004-11-23
+
+  - merged changes from DiB3000MC_ver2.1
+  - revised the debugging
+  - possibility to deliver the complete TS for USB2.0
+
+  2004-11-21
+
+  - first working version of the dib3000mc/p frontend driver.
+
+  2004-11-12
+
+  - added additional remote control keys. Thanks to Uwe Hanke.
+
+  2004-11-07
+
+  - added remote control support. Thanks to David Matthews.
+
+  2004-11-05
+
+  - added support for a new devices (Grandtec/Avermedia/Artec)
+  - merged my changes (for dib3000mb/dibusb) to the FE_REFACTORING, because it became HEAD
+  - moved transfer control (pid filter, fifo control) from usb driver to frontend, it seems
+    better settled there (added xfer_ops-struct)
+  - created a common files for frontends (mc/p/mb)
+
+  2004-09-28
+
+  - added support for a new device (Unknown, vendor ID is Hyper-Paltek)
+
+  2004-09-20
+
+  - added support for a new device (Compro DVB-U2000), thanks
+    to Amaury Demol for reporting
+  - changed usb TS transfer method (several urbs, stopping transfer
+    before setting a new pid)
+
+  2004-09-13
+
+  - added support for a new device (Artec T1 USB TVBOX), thanks
+    to Christian Motschke for reporting
+
+  2004-09-05
+
+  - released the dibusb device and dib3000mb-frontend driver
+    (old news for vp7041.c)
+
+  2004-07-15
+
+  - found out, by accident, that the device has a TUA6010XS for PLL
+
+  2004-07-12
+
+  - figured out, that the driver should also work with the
+    CTS Portable (Chinese Television System)
+
+  2004-07-08
+
+  - firmware-extraction-2.422-problem solved, driver is now working
+    properly with firmware extracted from 2.422
+  - #if for 2.6.4 (dvb), compile issue
+  - changed firmware handling, see vp7041.txt sec 1.1
+
+  2004-07-02
+
+  - some tuner modifications, v0.1, cleanups, first public
+
+  2004-06-28
+
+  - now using the dvb_dmx_swfilter_packets, everything runs fine now
+
+  2004-06-27
+
+  - able to watch and switching channels (pre-alpha)
+  - no section filtering yet
+
+  2004-06-06
+
+  - first TS received, but kernel oops :/
+
+  2004-05-14
+
+  - firmware loader is working
+
+  2004-05-11
+
+  - start writing the driver
+
+How to use?
+-----------
+
+Firmware
+~~~~~~~~
+
+Most of the USB drivers need to download a firmware to the device before start
+working.
+
+Have a look at the Wikipage for the DVB-USB-drivers to find out, which firmware
+you need for your device:
+
+https://linuxtv.org/wiki/index.php/DVB_USB
+
+Compiling
+~~~~~~~~~
+
+Since the driver is in the linux kernel, activating the driver in
+your favorite config-environment should sufficient. I recommend
+to compile the driver as module. Hotplug does the rest.
+
+If you use dvb-kernel enter the build-2.6 directory run 'make' and 'insmod.sh
+load' afterwards.
+
+Loading the drivers
+~~~~~~~~~~~~~~~~~~~
+
+Hotplug is able to load the driver, when it is needed (because you plugged
+in the device).
+
+If you want to enable debug output, you have to load the driver manually and
+from within the dvb-kernel cvs repository.
+
+first have a look, which debug level are available:
+
+.. code-block:: none
+
+	# modinfo dvb-usb
+	# modinfo dvb-usb-vp7045
+
+	etc.
+
+.. code-block:: none
+
+	modprobe dvb-usb debug=<level>
+	modprobe dvb-usb-vp7045 debug=<level>
+	etc.
+
+should do the trick.
+
+When the driver is loaded successfully, the firmware file was in
+the right place and the device is connected, the "Power"-LED should be
+turned on.
+
+At this point you should be able to start a dvb-capable application. I'm use
+(t|s)zap, mplayer and dvbscan to test the basics. VDR-xine provides the
+long-term test scenario.
+
+Known problems and bugs
+-----------------------
+
+- Don't remove the USB device while running an DVB application, your system
+  will go crazy or die most likely.
+
+Adding support for devices
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+TODO
+
+USB1.1 Bandwidth limitation
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+A lot of the currently supported devices are USB1.1 and thus they have a
+maximum bandwidth of about 5-6 MBit/s when connected to a USB2.0 hub.
+This is not enough for receiving the complete transport stream of a
+DVB-T channel (which is about 16 MBit/s). Normally this is not a
+problem, if you only want to watch TV (this does not apply for HDTV),
+but watching a channel while recording another channel on the same
+frequency simply does not work very well. This applies to all USB1.1
+DVB-T devices, not just the dvb-usb-devices)
+
+The bug, where the TS is distorted by a heavy usage of the device is gone
+definitely. All dvb-usb-devices I was using (Twinhan, Kworld, DiBcom) are
+working like charm now with VDR. Sometimes I even was able to record a channel
+and watch another one.
+
+Comments
+~~~~~~~~
+
+Patches, comments and suggestions are very very welcome.
+
+3. Acknowledgements
+-------------------
+
+   Amaury Demol (Amaury.Demol@parrot.com) and Francois Kanounnikoff from DiBcom for
+   providing specs, code and help, on which the dvb-dibusb, dib3000mb and
+   dib3000mc are based.
+
+   David Matthews for identifying a new device type (Artec T1 with AN2235)
+   and for extending dibusb with remote control event handling. Thank you.
+
+   Alex Woods for frequently answering question about usb and dvb
+   stuff, a big thank you.
+
+   Bernd Wagner for helping with huge bug reports and discussions.
+
+   Gunnar Wittich and Joachim von Caron for their trust for providing
+   root-shells on their machines to implement support for new devices.
+
+   Allan Third and Michael Hutchinson for their help to write the Nebula
+   digitv-driver.
+
+   Glen Harris for bringing up, that there is a new dibusb-device and Jiun-Kuei
+   Jung from AVerMedia who kindly provided a special firmware to get the device
+   up and running in Linux.
+
+   Jennifer Chen, Jeff and Jack from Twinhan for kindly supporting by
+   writing the vp7045-driver.
+
+   Steve Chang from WideView for providing information for new devices and
+   firmware files.
+
+   Michael Paxton for submitting remote control keymaps.
+
+   Some guys on the linux-dvb mailing list for encouraging me.
+
+   Peter Schildmann >peter.schildmann-nospam-at-web.de< for his
+   user-level firmware loader, which saves a lot of time
+   (when writing the vp7041 driver)
+
+   Ulf Hermenau for helping me out with traditional chinese.
+
+   André Smoktun and Christian Frömmel for supporting me with
+   hardware and listening to my problems very patiently.
diff --git a/Documentation/driver-api/media/drivers/fimc-devel.rst b/Documentation/driver-api/media/drivers/fimc-devel.rst
new file mode 100644
index 000000000..956e3a990
--- /dev/null
+++ b/Documentation/driver-api/media/drivers/fimc-devel.rst
@@ -0,0 +1,33 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+.. include:: <isonum.txt>
+
+The Samsung S5P/EXYNOS4 FIMC driver
+===================================
+
+Copyright |copy| 2012 - 2013 Samsung Electronics Co., Ltd.
+
+Files partitioning
+------------------
+
+- media device driver
+
+  drivers/media/platform/exynos4-is/media-dev.[ch]
+
+- camera capture video device driver
+
+  drivers/media/platform/exynos4-is/fimc-capture.c
+
+- MIPI-CSI2 receiver subdev
+
+  drivers/media/platform/exynos4-is/mipi-csis.[ch]
+
+- video post-processor (mem-to-mem)
+
+  drivers/media/platform/exynos4-is/fimc-core.c
+
+- common files
+
+  drivers/media/platform/exynos4-is/fimc-core.h
+  drivers/media/platform/exynos4-is/fimc-reg.h
+  drivers/media/platform/exynos4-is/regs-fimc.h
diff --git a/Documentation/driver-api/media/drivers/frontends.rst b/Documentation/driver-api/media/drivers/frontends.rst
new file mode 100644
index 000000000..7b8336ece
--- /dev/null
+++ b/Documentation/driver-api/media/drivers/frontends.rst
@@ -0,0 +1,32 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+****************
+Frontend drivers
+****************
+
+Frontend attach headers
+***********************
+
+.. Keep it on alphabetic order
+
+.. kernel-doc:: drivers/media/dvb-frontends/a8293.h
+.. kernel-doc:: drivers/media/dvb-frontends/af9013.h
+.. kernel-doc:: drivers/media/dvb-frontends/ascot2e.h
+.. kernel-doc:: drivers/media/dvb-frontends/cxd2820r.h
+.. kernel-doc:: drivers/media/dvb-frontends/drxk.h
+.. kernel-doc:: drivers/media/dvb-frontends/dvb-pll.h
+.. kernel-doc:: drivers/media/dvb-frontends/helene.h
+.. kernel-doc:: drivers/media/dvb-frontends/horus3a.h
+.. kernel-doc:: drivers/media/dvb-frontends/ix2505v.h
+.. kernel-doc:: drivers/media/dvb-frontends/m88ds3103.h
+.. kernel-doc:: drivers/media/dvb-frontends/mb86a20s.h
+.. kernel-doc:: drivers/media/dvb-frontends/mn88472.h
+.. kernel-doc:: drivers/media/dvb-frontends/rtl2830.h
+.. kernel-doc:: drivers/media/dvb-frontends/rtl2832.h
+.. kernel-doc:: drivers/media/dvb-frontends/rtl2832_sdr.h
+.. kernel-doc:: drivers/media/dvb-frontends/stb6000.h
+.. kernel-doc:: drivers/media/dvb-frontends/tda10071.h
+.. kernel-doc:: drivers/media/dvb-frontends/tda826x.h
+.. kernel-doc:: drivers/media/dvb-frontends/zd1301_demod.h
+.. kernel-doc:: drivers/media/dvb-frontends/zl10036.h
+
diff --git a/Documentation/driver-api/media/drivers/index.rst b/Documentation/driver-api/media/drivers/index.rst
new file mode 100644
index 000000000..eb7011782
--- /dev/null
+++ b/Documentation/driver-api/media/drivers/index.rst
@@ -0,0 +1,40 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+.. include:: <isonum.txt>
+
+===================================
+Media driver-specific documentation
+===================================
+
+Video4Linux (V4L) drivers
+=========================
+
+.. toctree::
+	:maxdepth: 5
+
+	bttv-devel
+	cpia2_devel
+	cx2341x-devel
+	cx88-devel
+	davinci-vpbe-devel
+	fimc-devel
+	pvrusb2
+	pxa_camera
+	radiotrack
+	saa7134-devel
+	sh_mobile_ceu_camera
+	tuners
+	vimc-devel
+	zoran
+
+
+Digital TV drivers
+==================
+
+.. toctree::
+	:maxdepth: 5
+
+	dvb-usb
+	frontends
+	vidtv
+	contributors
diff --git a/Documentation/driver-api/media/drivers/pvrusb2.rst b/Documentation/driver-api/media/drivers/pvrusb2.rst
new file mode 100644
index 000000000..cbd9359c2
--- /dev/null
+++ b/Documentation/driver-api/media/drivers/pvrusb2.rst
@@ -0,0 +1,202 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+The pvrusb2 driver
+==================
+
+Author: Mike Isely <isely@pobox.com>
+
+Background
+----------
+
+This driver is intended for the "Hauppauge WinTV PVR USB 2.0", which
+is a USB 2.0 hosted TV Tuner.  This driver is a work in progress.
+Its history started with the reverse-engineering effort by Björn
+Danielsson <pvrusb2@dax.nu> whose web page can be found here:
+http://pvrusb2.dax.nu/
+
+From there Aurelien Alleaume <slts@free.fr> began an effort to
+create a video4linux compatible driver.  I began with Aurelien's
+last known snapshot and evolved the driver to the state it is in
+here.
+
+More information on this driver can be found at:
+https://www.isely.net/pvrusb2.html
+
+
+This driver has a strong separation of layers.  They are very
+roughly:
+
+1. Low level wire-protocol implementation with the device.
+
+2. I2C adaptor implementation and corresponding I2C client drivers
+   implemented elsewhere in V4L.
+
+3. High level hardware driver implementation which coordinates all
+   activities that ensure correct operation of the device.
+
+4. A "context" layer which manages instancing of driver, setup,
+   tear-down, arbitration, and interaction with high level
+   interfaces appropriately as devices are hotplugged in the
+   system.
+
+5. High level interfaces which glue the driver to various published
+   Linux APIs (V4L, sysfs, maybe DVB in the future).
+
+The most important shearing layer is between the top 2 layers.  A
+lot of work went into the driver to ensure that any kind of
+conceivable API can be laid on top of the core driver.  (Yes, the
+driver internally leverages V4L to do its work but that really has
+nothing to do with the API published by the driver to the outside
+world.)  The architecture allows for different APIs to
+simultaneously access the driver.  I have a strong sense of fairness
+about APIs and also feel that it is a good design principle to keep
+implementation and interface isolated from each other.  Thus while
+right now the V4L high level interface is the most complete, the
+sysfs high level interface will work equally well for similar
+functions, and there's no reason I see right now why it shouldn't be
+possible to produce a DVB high level interface that can sit right
+alongside V4L.
+
+Building
+--------
+
+To build these modules essentially amounts to just running "Make",
+but you need the kernel source tree nearby and you will likely also
+want to set a few controlling environment variables first in order
+to link things up with that source tree.  Please see the Makefile
+here for comments that explain how to do that.
+
+Source file list / functional overview
+--------------------------------------
+
+(Note: The term "module" used below generally refers to loosely
+defined functional units within the pvrusb2 driver and bears no
+relation to the Linux kernel's concept of a loadable module.)
+
+pvrusb2-audio.[ch] - This is glue logic that resides between this
+    driver and the msp3400.ko I2C client driver (which is found
+    elsewhere in V4L).
+
+pvrusb2-context.[ch] - This module implements the context for an
+    instance of the driver.  Everything else eventually ties back to
+    or is otherwise instanced within the data structures implemented
+    here.  Hotplugging is ultimately coordinated here.  All high level
+    interfaces tie into the driver through this module.  This module
+    helps arbitrate each interface's access to the actual driver core,
+    and is designed to allow concurrent access through multiple
+    instances of multiple interfaces (thus you can for example change
+    the tuner's frequency through sysfs while simultaneously streaming
+    video through V4L out to an instance of mplayer).
+
+pvrusb2-debug.h - This header defines a printk() wrapper and a mask
+    of debugging bit definitions for the various kinds of debug
+    messages that can be enabled within the driver.
+
+pvrusb2-debugifc.[ch] - This module implements a crude command line
+    oriented debug interface into the driver.  Aside from being part
+    of the process for implementing manual firmware extraction (see
+    the pvrusb2 web site mentioned earlier), probably I'm the only one
+    who has ever used this.  It is mainly a debugging aid.
+
+pvrusb2-eeprom.[ch] - This is glue logic that resides between this
+    driver the tveeprom.ko module, which is itself implemented
+    elsewhere in V4L.
+
+pvrusb2-encoder.[ch] - This module implements all protocol needed to
+    interact with the Conexant mpeg2 encoder chip within the pvrusb2
+    device.  It is a crude echo of corresponding logic in ivtv,
+    however the design goals (strict isolation) and physical layer
+    (proxy through USB instead of PCI) are enough different that this
+    implementation had to be completely different.
+
+pvrusb2-hdw-internal.h - This header defines the core data structure
+    in the driver used to track ALL internal state related to control
+    of the hardware.  Nobody outside of the core hardware-handling
+    modules should have any business using this header.  All external
+    access to the driver should be through one of the high level
+    interfaces (e.g. V4L, sysfs, etc), and in fact even those high
+    level interfaces are restricted to the API defined in
+    pvrusb2-hdw.h and NOT this header.
+
+pvrusb2-hdw.h - This header defines the full internal API for
+    controlling the hardware.  High level interfaces (e.g. V4L, sysfs)
+    will work through here.
+
+pvrusb2-hdw.c - This module implements all the various bits of logic
+    that handle overall control of a specific pvrusb2 device.
+    (Policy, instantiation, and arbitration of pvrusb2 devices fall
+    within the jurisdiction of pvrusb-context not here).
+
+pvrusb2-i2c-chips-\*.c - These modules implement the glue logic to
+    tie together and configure various I2C modules as they attach to
+    the I2C bus.  There are two versions of this file.  The "v4l2"
+    version is intended to be used in-tree alongside V4L, where we
+    implement just the logic that makes sense for a pure V4L
+    environment.  The "all" version is intended for use outside of
+    V4L, where we might encounter other possibly "challenging" modules
+    from ivtv or older kernel snapshots (or even the support modules
+    in the standalone snapshot).
+
+pvrusb2-i2c-cmd-v4l1.[ch] - This module implements generic V4L1
+    compatible commands to the I2C modules.  It is here where state
+    changes inside the pvrusb2 driver are translated into V4L1
+    commands that are in turn send to the various I2C modules.
+
+pvrusb2-i2c-cmd-v4l2.[ch] - This module implements generic V4L2
+    compatible commands to the I2C modules.  It is here where state
+    changes inside the pvrusb2 driver are translated into V4L2
+    commands that are in turn send to the various I2C modules.
+
+pvrusb2-i2c-core.[ch] - This module provides an implementation of a
+    kernel-friendly I2C adaptor driver, through which other external
+    I2C client drivers (e.g. msp3400, tuner, lirc) may connect and
+    operate corresponding chips within the pvrusb2 device.  It is
+    through here that other V4L modules can reach into this driver to
+    operate specific pieces (and those modules are in turn driven by
+    glue logic which is coordinated by pvrusb2-hdw, doled out by
+    pvrusb2-context, and then ultimately made available to users
+    through one of the high level interfaces).
+
+pvrusb2-io.[ch] - This module implements a very low level ring of
+    transfer buffers, required in order to stream data from the
+    device.  This module is *very* low level.  It only operates the
+    buffers and makes no attempt to define any policy or mechanism for
+    how such buffers might be used.
+
+pvrusb2-ioread.[ch] - This module layers on top of pvrusb2-io.[ch]
+    to provide a streaming API usable by a read() system call style of
+    I/O.  Right now this is the only layer on top of pvrusb2-io.[ch],
+    however the underlying architecture here was intended to allow for
+    other styles of I/O to be implemented with additional modules, like
+    mmap()'ed buffers or something even more exotic.
+
+pvrusb2-main.c - This is the top level of the driver.  Module level
+    and USB core entry points are here.  This is our "main".
+
+pvrusb2-sysfs.[ch] - This is the high level interface which ties the
+    pvrusb2 driver into sysfs.  Through this interface you can do
+    everything with the driver except actually stream data.
+
+pvrusb2-tuner.[ch] - This is glue logic that resides between this
+    driver and the tuner.ko I2C client driver (which is found
+    elsewhere in V4L).
+
+pvrusb2-util.h - This header defines some common macros used
+    throughout the driver.  These macros are not really specific to
+    the driver, but they had to go somewhere.
+
+pvrusb2-v4l2.[ch] - This is the high level interface which ties the
+    pvrusb2 driver into video4linux.  It is through here that V4L
+    applications can open and operate the driver in the usual V4L
+    ways.  Note that **ALL** V4L functionality is published only
+    through here and nowhere else.
+
+pvrusb2-video-\*.[ch] - This is glue logic that resides between this
+    driver and the saa711x.ko I2C client driver (which is found
+    elsewhere in V4L).  Note that saa711x.ko used to be known as
+    saa7115.ko in ivtv.  There are two versions of this; one is
+    selected depending on the particular saa711[5x].ko that is found.
+
+pvrusb2.h - This header contains compile time tunable parameters
+    (and at the moment the driver has very little that needs to be
+    tuned).
diff --git a/Documentation/driver-api/media/drivers/pxa_camera.rst b/Documentation/driver-api/media/drivers/pxa_camera.rst
new file mode 100644
index 000000000..ee1bd96b6
--- /dev/null
+++ b/Documentation/driver-api/media/drivers/pxa_camera.rst
@@ -0,0 +1,194 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+PXA-Camera Host Driver
+======================
+
+Author: Robert Jarzmik <robert.jarzmik@free.fr>
+
+Constraints
+-----------
+
+a) Image size for YUV422P format
+   All YUV422P images are enforced to have width x height % 16 = 0.
+   This is due to DMA constraints, which transfers only planes of 8 byte
+   multiples.
+
+
+Global video workflow
+---------------------
+
+a) QCI stopped
+   Initially, the QCI interface is stopped.
+   When a buffer is queued (pxa_videobuf_ops->buf_queue), the QCI starts.
+
+b) QCI started
+   More buffers can be queued while the QCI is started without halting the
+   capture.  The new buffers are "appended" at the tail of the DMA chain, and
+   smoothly captured one frame after the other.
+
+   Once a buffer is filled in the QCI interface, it is marked as "DONE" and
+   removed from the active buffers list. It can be then requeud or dequeued by
+   userland application.
+
+   Once the last buffer is filled in, the QCI interface stops.
+
+c) Capture global finite state machine schema
+
+.. code-block:: none
+
+	+----+                             +---+  +----+
+	| DQ |                             | Q |  | DQ |
+	|    v                             |   v  |    v
+	+-----------+                     +------------------------+
+	|   STOP    |                     | Wait for capture start |
+	+-----------+         Q           +------------------------+
+	+-> | QCI: stop | ------------------> | QCI: run               | <------------+
+	|   | DMA: stop |                     | DMA: stop              |              |
+	|   +-----------+             +-----> +------------------------+              |
+	|                            /                            |                   |
+	|                           /             +---+  +----+   |                   |
+	|capture list empty        /              | Q |  | DQ |   | QCI Irq EOF       |
+	|                         /               |   v  |    v   v                   |
+	|   +--------------------+             +----------------------+               |
+	|   | DMA hotlink missed |             |    Capture running   |               |
+	|   +--------------------+             +----------------------+               |
+	|   | QCI: run           |     +-----> | QCI: run             | <-+           |
+	|   | DMA: stop          |    /        | DMA: run             |   |           |
+	|   +--------------------+   /         +----------------------+   | Other     |
+	|     ^                     /DMA still            |               | channels  |
+	|     | capture list       /  running             | DMA Irq End   | not       |
+	|     | not empty         /                       |               | finished  |
+	|     |                  /                        v               | yet       |
+	|   +----------------------+           +----------------------+   |           |
+	|   |  Videobuf released   |           |  Channel completed   |   |           |
+	|   +----------------------+           +----------------------+   |           |
+	+-- | QCI: run             |           | QCI: run             | --+           |
+	| DMA: run             |           | DMA: run             |               |
+	+----------------------+           +----------------------+               |
+		^                      /           |                           |
+		|          no overrun /            | overrun                   |
+		|                    /             v                           |
+	+--------------------+         /   +----------------------+               |
+	|  Frame completed   |        /    |     Frame overran    |               |
+	+--------------------+ <-----+     +----------------------+ restart frame |
+	| QCI: run           |             | QCI: stop            | --------------+
+	| DMA: run           |             | DMA: stop            |
+	+--------------------+             +----------------------+
+
+	Legend: - each box is a FSM state
+		- each arrow is the condition to transition to another state
+		- an arrow with a comment is a mandatory transition (no condition)
+		- arrow "Q" means : a buffer was enqueued
+		- arrow "DQ" means : a buffer was dequeued
+		- "QCI: stop" means the QCI interface is not enabled
+		- "DMA: stop" means all 3 DMA channels are stopped
+		- "DMA: run" means at least 1 DMA channel is still running
+
+DMA usage
+---------
+
+a) DMA flow
+     - first buffer queued for capture
+       Once a first buffer is queued for capture, the QCI is started, but data
+       transfer is not started. On "End Of Frame" interrupt, the irq handler
+       starts the DMA chain.
+     - capture of one videobuffer
+       The DMA chain starts transferring data into videobuffer RAM pages.
+       When all pages are transferred, the DMA irq is raised on "ENDINTR" status
+     - finishing one videobuffer
+       The DMA irq handler marks the videobuffer as "done", and removes it from
+       the active running queue
+       Meanwhile, the next videobuffer (if there is one), is transferred by DMA
+     - finishing the last videobuffer
+       On the DMA irq of the last videobuffer, the QCI is stopped.
+
+b) DMA prepared buffer will have this structure
+
+.. code-block:: none
+
+     +------------+-----+---------------+-----------------+
+     | desc-sg[0] | ... | desc-sg[last] | finisher/linker |
+     +------------+-----+---------------+-----------------+
+
+This structure is pointed by dma->sg_cpu.
+The descriptors are used as follows:
+
+- desc-sg[i]: i-th descriptor, transferring the i-th sg
+  element to the video buffer scatter gather
+- finisher: has ddadr=DADDR_STOP, dcmd=ENDIRQEN
+- linker: has ddadr= desc-sg[0] of next video buffer, dcmd=0
+
+For the next schema, let's assume d0=desc-sg[0] .. dN=desc-sg[N],
+"f" stands for finisher and "l" for linker.
+A typical running chain is :
+
+.. code-block:: none
+
+         Videobuffer 1         Videobuffer 2
+     +---------+----+---+  +----+----+----+---+
+     | d0 | .. | dN | l |  | d0 | .. | dN | f |
+     +---------+----+-|-+  ^----+----+----+---+
+                      |    |
+                      +----+
+
+After the chaining is finished, the chain looks like :
+
+.. code-block:: none
+
+         Videobuffer 1         Videobuffer 2         Videobuffer 3
+     +---------+----+---+  +----+----+----+---+  +----+----+----+---+
+     | d0 | .. | dN | l |  | d0 | .. | dN | l |  | d0 | .. | dN | f |
+     +---------+----+-|-+  ^----+----+----+-|-+  ^----+----+----+---+
+                      |    |                |    |
+                      +----+                +----+
+                                           new_link
+
+c) DMA hot chaining timeslice issue
+
+As DMA chaining is done while DMA _is_ running, the linking may be done
+while the DMA jumps from one Videobuffer to another. On the schema, that
+would be a problem if the following sequence is encountered :
+
+- DMA chain is Videobuffer1 + Videobuffer2
+- pxa_videobuf_queue() is called to queue Videobuffer3
+- DMA controller finishes Videobuffer2, and DMA stops
+
+.. code-block:: none
+
+      =>
+         Videobuffer 1         Videobuffer 2
+     +---------+----+---+  +----+----+----+---+
+     | d0 | .. | dN | l |  | d0 | .. | dN | f |
+     +---------+----+-|-+  ^----+----+----+-^-+
+                      |    |                |
+                      +----+                +-- DMA DDADR loads DDADR_STOP
+
+- pxa_dma_add_tail_buf() is called, the Videobuffer2 "finisher" is
+  replaced by a "linker" to Videobuffer3 (creation of new_link)
+- pxa_videobuf_queue() finishes
+- the DMA irq handler is called, which terminates Videobuffer2
+- Videobuffer3 capture is not scheduled on DMA chain (as it stopped !!!)
+
+.. code-block:: none
+
+         Videobuffer 1         Videobuffer 2         Videobuffer 3
+     +---------+----+---+  +----+----+----+---+  +----+----+----+---+
+     | d0 | .. | dN | l |  | d0 | .. | dN | l |  | d0 | .. | dN | f |
+     +---------+----+-|-+  ^----+----+----+-|-+  ^----+----+----+---+
+                      |    |                |    |
+                      +----+                +----+
+                                           new_link
+                                          DMA DDADR still is DDADR_STOP
+
+- pxa_camera_check_link_miss() is called
+  This checks if the DMA is finished and a buffer is still on the
+  pcdev->capture list. If that's the case, the capture will be restarted,
+  and Videobuffer3 is scheduled on DMA chain.
+- the DMA irq handler finishes
+
+.. note::
+
+     If DMA stops just after pxa_camera_check_link_miss() reads DDADR()
+     value, we have the guarantee that the DMA irq handler will be called back
+     when the DMA will finish the buffer, and pxa_camera_check_link_miss() will
+     be called again, to reschedule Videobuffer3.
diff --git a/Documentation/driver-api/media/drivers/radiotrack.rst b/Documentation/driver-api/media/drivers/radiotrack.rst
new file mode 100644
index 000000000..a85cb6205
--- /dev/null
+++ b/Documentation/driver-api/media/drivers/radiotrack.rst
@@ -0,0 +1,168 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+The Radiotrack radio driver
+===========================
+
+Author: Stephen M. Benoit <benoits@servicepro.com>
+
+Date:  Dec 14, 1996
+
+ACKNOWLEDGMENTS
+----------------
+
+This document was made based on 'C' code for Linux from Gideon le Grange
+(legrang@active.co.za or legrang@cs.sun.ac.za) in 1994, and elaborations from
+Frans Brinkman (brinkman@esd.nl) in 1996.  The results reported here are from
+experiments that the author performed on his own setup, so your mileage may
+vary... I make no guarantees, claims or warranties to the suitability or
+validity of this information.  No other documentation on the AIMS
+Lab (http://www.aimslab.com/) RadioTrack card was made available to the
+author.  This document is offered in the hopes that it might help users who
+want to use the RadioTrack card in an environment other than MS Windows.
+
+WHY THIS DOCUMENT?
+------------------
+
+I have a RadioTrack card from back when I ran an MS-Windows platform.  After
+converting to Linux, I found Gideon le Grange's command-line software for
+running the card, and found that it was good!  Frans Brinkman made a
+comfortable X-windows interface, and added a scanning feature.  For hack
+value, I wanted to see if the tuner could be tuned beyond the usual FM radio
+broadcast band, so I could pick up the audio carriers from North American
+broadcast TV channels, situated just below and above the 87.0-109.0 MHz range.
+I did not get much success, but I learned about programming ioports under
+Linux and gained some insights about the hardware design used for the card.
+
+So, without further delay, here are the details.
+
+
+PHYSICAL DESCRIPTION
+--------------------
+
+The RadioTrack card is an ISA 8-bit FM radio card.  The radio frequency (RF)
+input is simply an antenna lead, and the output is a power audio signal
+available through a miniature phone plug.  Its RF frequencies of operation are
+more or less limited from 87.0 to 109.0 MHz (the commercial FM broadcast
+band).  Although the registers can be programmed to request frequencies beyond
+these limits, experiments did not give promising results.  The variable
+frequency oscillator (VFO) that demodulates the intermediate frequency (IF)
+signal probably has a small range of useful frequencies, and wraps around or
+gets clipped beyond the limits mentioned above.
+
+
+CONTROLLING THE CARD WITH IOPORT
+--------------------------------
+
+The RadioTrack (base) ioport is configurable for 0x30c or 0x20c.  Only one
+ioport seems to be involved.  The ioport decoding circuitry must be pretty
+simple, as individual ioport bits are directly matched to specific functions
+(or blocks) of the radio card.  This way, many functions can be changed in
+parallel with one write to the ioport.  The only feedback available through
+the ioports appears to be the "Stereo Detect" bit.
+
+The bits of the ioport are arranged as follows:
+
+.. code-block:: none
+
+	MSb                                                         LSb
+	+------+------+------+--------+--------+-------+---------+--------+
+	| VolA | VolB | ???? | Stereo | Radio  | TuneA | TuneB   | Tune   |
+	|  (+) |  (-) |      | Detect | Audio  | (bit) | (latch) | Update |
+	|      |      |      | Enable | Enable |       |         | Enable |
+	+------+------+------+--------+--------+-------+---------+--------+
+
+
+====  ====  =================================
+VolA  VolB  Description
+====  ====  =================================
+0	 0  audio mute
+0	 1  volume +    (some delay required)
+1	 0  volume -    (some delay required)
+1	 1  stay at present volume
+====  ====  =================================
+
+====================	===========
+Stereo Detect Enable	Description
+====================	===========
+0			No Detect
+1			Detect
+====================	===========
+
+Results available by reading ioport >60 msec after last port write.
+
+  0xff ==> no stereo detected,  0xfd ==> stereo detected.
+
+=============================	=============================
+Radio to Audio (path) Enable	Description
+=============================	=============================
+0				Disable path (silence)
+1				Enable path  (audio produced)
+=============================	=============================
+
+=====  =====  ==================
+TuneA  TuneB  Description
+=====  =====  ==================
+0	0     "zero" bit phase 1
+0	1     "zero" bit phase 2
+1	0     "one" bit phase 1
+1	1     "one" bit phase 2
+=====  =====  ==================
+
+
+24-bit code, where bits = (freq*40) + 10486188.
+The Most Significant 11 bits must be 1010 xxxx 0x0 to be valid.
+The bits are shifted in LSb first.
+
+==================	===========================
+Tune Update Enable	Description
+==================	===========================
+0			Tuner held constant
+1			Tuner updating in progress
+==================	===========================
+
+
+PROGRAMMING EXAMPLES
+--------------------
+
+.. code-block:: none
+
+	Default:        BASE <-- 0xc8  (current volume, no stereo detect,
+					radio enable, tuner adjust disable)
+
+	Card Off:	BASE <-- 0x00  (audio mute, no stereo detect,
+					radio disable, tuner adjust disable)
+
+	Card On:	BASE <-- 0x00  (see "Card Off", clears any unfinished business)
+			BASE <-- 0xc8  (see "Default")
+
+	Volume Down:    BASE <-- 0x48  (volume down, no stereo detect,
+					radio enable, tuner adjust disable)
+			wait 10 msec
+			BASE <-- 0xc8  (see "Default")
+
+	Volume Up:      BASE <-- 0x88  (volume up, no stereo detect,
+					radio enable, tuner adjust disable)
+			wait 10 msec
+			BASE <-- 0xc8  (see "Default")
+
+	Check Stereo:   BASE <-- 0xd8  (current volume, stereo detect,
+					radio enable, tuner adjust disable)
+			wait 100 msec
+			x <-- BASE     (read ioport)
+			BASE <-- 0xc8  (see "Default")
+
+			x=0xff ==> "not stereo", x=0xfd ==> "stereo detected"
+
+	Set Frequency:  code = (freq*40) + 10486188
+			foreach of the 24 bits in code,
+			(from Least to Most Significant):
+			to write a "zero" bit,
+			BASE <-- 0x01  (audio mute, no stereo detect, radio
+					disable, "zero" bit phase 1, tuner adjust)
+			BASE <-- 0x03  (audio mute, no stereo detect, radio
+					disable, "zero" bit phase 2, tuner adjust)
+			to write a "one" bit,
+			BASE <-- 0x05  (audio mute, no stereo detect, radio
+					disable, "one" bit phase 1, tuner adjust)
+			BASE <-- 0x07  (audio mute, no stereo detect, radio
+					disable, "one" bit phase 2, tuner adjust)
diff --git a/Documentation/driver-api/media/drivers/saa7134-devel.rst b/Documentation/driver-api/media/drivers/saa7134-devel.rst
new file mode 100644
index 000000000..167fd729b
--- /dev/null
+++ b/Documentation/driver-api/media/drivers/saa7134-devel.rst
@@ -0,0 +1,67 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+The saa7134 driver
+==================
+
+Author Gerd Hoffmann
+
+
+Card Variations:
+----------------
+
+Cards can use either of these two crystals (xtal):
+
+- 32.11 MHz -> .audio_clock=0x187de7
+- 24.576MHz -> .audio_clock=0x200000 (xtal * .audio_clock = 51539600)
+
+Some details about 30/34/35:
+
+- saa7130 - low-price chip, doesn't have mute, that is why all those
+  cards should have .mute field defined in their tuner structure.
+
+- saa7134 - usual chip
+
+- saa7133/35 - saa7135 is probably a marketing decision, since all those
+  chips identifies itself as 33 on pci.
+
+LifeView GPIOs
+--------------
+
+This section was authored by: Peter Missel <peter.missel@onlinehome.de>
+
+- LifeView FlyTV Platinum FM (LR214WF)
+
+    - GP27    MDT2005 PB4 pin 10
+    - GP26    MDT2005 PB3 pin 9
+    - GP25    MDT2005 PB2 pin 8
+    - GP23    MDT2005 PB1 pin 7
+    - GP22    MDT2005 PB0 pin 6
+    - GP21    MDT2005 PB5 pin 11
+    - GP20    MDT2005 PB6 pin 12
+    - GP19    MDT2005 PB7 pin 13
+    - nc      MDT2005 PA3 pin 2
+    - Remote  MDT2005 PA2 pin 1
+    - GP18    MDT2005 PA1 pin 18
+    - nc      MDT2005 PA0 pin 17 strap low
+    - GP17    Strap "GP7"=High
+    - GP16    Strap "GP6"=High
+
+	- 0=Radio 1=TV
+	- Drives SA630D ENCH1 and HEF4052 A1 pinsto do FM radio through
+	  SIF input
+
+    - GP15    nc
+    - GP14    nc
+    - GP13    nc
+    - GP12    Strap "GP5" = High
+    - GP11    Strap "GP4" = High
+    - GP10    Strap "GP3" = High
+    - GP09    Strap "GP2" = Low
+    - GP08    Strap "GP1" = Low
+    - GP07.00 nc
+
+Credits
+-------
+
+andrew.stevens@philips.com + werner.leeb@philips.com for providing
+saa7134 hardware specs and sample board.
diff --git a/Documentation/driver-api/media/drivers/sh_mobile_ceu_camera.rst b/Documentation/driver-api/media/drivers/sh_mobile_ceu_camera.rst
new file mode 100644
index 000000000..822fcb836
--- /dev/null
+++ b/Documentation/driver-api/media/drivers/sh_mobile_ceu_camera.rst
@@ -0,0 +1,142 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+Cropping and Scaling algorithm, used in the sh_mobile_ceu_camera driver
+=======================================================================
+
+Author: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
+
+Terminology
+-----------
+
+sensor scales: horizontal and vertical scales, configured by the sensor driver
+host scales: -"- host driver
+combined scales: sensor_scale * host_scale
+
+
+Generic scaling / cropping scheme
+---------------------------------
+
+.. code-block:: none
+
+	-1--
+	|
+	-2-- -\
+	|      --\
+	|         --\
+	+-5-- .      -- -3-- -\
+	|      `...            -\
+	|          `... -4-- .   - -7..
+	|                     `.
+	|                       `. .6--
+	|
+	|                        . .6'-
+	|                      .´
+	|           ... -4'- .´
+	|       ...´             - -7'.
+	+-5'- .´               -/
+	|            -- -3'- -/
+	|         --/
+	|      --/
+	-2'- -/
+	|
+	|
+	-1'-
+
+In the above chart minuses and slashes represent "real" data amounts, points and
+accents represent "useful" data, basically, CEU scaled and cropped output,
+mapped back onto the client's source plane.
+
+Such a configuration can be produced by user requests:
+
+S_CROP(left / top = (5) - (1), width / height = (5') - (5))
+S_FMT(width / height = (6') - (6))
+
+Here:
+
+(1) to (1') - whole max width or height
+(1) to (2)  - sensor cropped left or top
+(2) to (2') - sensor cropped width or height
+(3) to (3') - sensor scale
+(3) to (4)  - CEU cropped left or top
+(4) to (4') - CEU cropped width or height
+(5) to (5') - reverse sensor scale applied to CEU cropped width or height
+(2) to (5)  - reverse sensor scale applied to CEU cropped left or top
+(6) to (6') - CEU scale - user window
+
+
+S_FMT
+-----
+
+Do not touch input rectangle - it is already optimal.
+
+1. Calculate current sensor scales:
+
+	scale_s = ((2') - (2)) / ((3') - (3))
+
+2. Calculate "effective" input crop (sensor subwindow) - CEU crop scaled back at
+current sensor scales onto input window - this is user S_CROP:
+
+	width_u = (5') - (5) = ((4') - (4)) * scale_s
+
+3. Calculate new combined scales from "effective" input window to requested user
+window:
+
+	scale_comb = width_u / ((6') - (6))
+
+4. Calculate sensor output window by applying combined scales to real input
+window:
+
+	width_s_out = ((7') - (7)) = ((2') - (2)) / scale_comb
+
+5. Apply iterative sensor S_FMT for sensor output window.
+
+	subdev->video_ops->s_fmt(.width = width_s_out)
+
+6. Retrieve sensor output window (g_fmt)
+
+7. Calculate new sensor scales:
+
+	scale_s_new = ((3')_new - (3)_new) / ((2') - (2))
+
+8. Calculate new CEU crop - apply sensor scales to previously calculated
+"effective" crop:
+
+	width_ceu = (4')_new - (4)_new = width_u / scale_s_new
+	left_ceu = (4)_new - (3)_new = ((5) - (2)) / scale_s_new
+
+9. Use CEU cropping to crop to the new window:
+
+	ceu_crop(.width = width_ceu, .left = left_ceu)
+
+10. Use CEU scaling to scale to the requested user window:
+
+	scale_ceu = width_ceu / width
+
+
+S_CROP
+------
+
+The :ref:`V4L2 crop API <crop-scale>` says:
+
+"...specification does not define an origin or units. However by convention
+drivers should horizontally count unscaled samples relative to 0H."
+
+We choose to follow the advise and interpret cropping units as client input
+pixels.
+
+Cropping is performed in the following 6 steps:
+
+1. Request exactly user rectangle from the sensor.
+
+2. If smaller - iterate until a larger one is obtained. Result: sensor cropped
+   to 2 : 2', target crop 5 : 5', current output format 6' - 6.
+
+3. In the previous step the sensor has tried to preserve its output frame as
+   good as possible, but it could have changed. Retrieve it again.
+
+4. Sensor scaled to 3 : 3'. Sensor's scale is (2' - 2) / (3' - 3). Calculate
+   intermediate window: 4' - 4 = (5' - 5) * (3' - 3) / (2' - 2)
+
+5. Calculate and apply host scale = (6' - 6) / (4' - 4)
+
+6. Calculate and apply host crop: 6 - 7 = (5 - 2) * (6' - 6) / (5' - 5)
diff --git a/Documentation/driver-api/media/drivers/tuners.rst b/Documentation/driver-api/media/drivers/tuners.rst
new file mode 100644
index 000000000..d7924141c
--- /dev/null
+++ b/Documentation/driver-api/media/drivers/tuners.rst
@@ -0,0 +1,133 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+Tuner drivers
+=============
+
+Simple tuner Programming
+------------------------
+
+There are some flavors of Tuner programming APIs.
+These differ mainly by the bandswitch byte.
+
+- L= LG_API       (VHF_LO=0x01, VHF_HI=0x02, UHF=0x08, radio=0x04)
+- P= PHILIPS_API  (VHF_LO=0xA0, VHF_HI=0x90, UHF=0x30, radio=0x04)
+- T= TEMIC_API    (VHF_LO=0x02, VHF_HI=0x04, UHF=0x01)
+- A= ALPS_API     (VHF_LO=0x14, VHF_HI=0x12, UHF=0x11)
+- M= PHILIPS_MK3  (VHF_LO=0x01, VHF_HI=0x02, UHF=0x04, radio=0x19)
+
+Tuner Manufacturers
+-------------------
+
+- Samsung Tuner identification: (e.g. TCPM9091PD27)
+
+.. code-block:: none
+
+ TCP [ABCJLMNQ] 90[89][125] [DP] [ACD] 27 [ABCD]
+ [ABCJLMNQ]:
+   A= BG+DK
+   B= BG
+   C= I+DK
+   J= NTSC-Japan
+   L= Secam LL
+   M= BG+I+DK
+   N= NTSC
+   Q= BG+I+DK+LL
+ [89]: ?
+ [125]:
+   2: No FM
+   5: With FM
+ [DP]:
+   D= NTSC
+   P= PAL
+ [ACD]:
+   A= F-connector
+   C= Phono connector
+   D= Din Jack
+ [ABCD]:
+   3-wire/I2C tuning, 2-band/3-band
+
+These Tuners are PHILIPS_API compatible.
+
+Philips Tuner identification: (e.g. FM1216MF)
+
+.. code-block:: none
+
+  F[IRMQ]12[1345]6{MF|ME|MP}
+  F[IRMQ]:
+   FI12x6: Tuner Series
+   FR12x6: Tuner + Radio IF
+   FM12x6: Tuner + FM
+   FQ12x6: special
+   FMR12x6: special
+   TD15xx: Digital Tuner ATSC
+  12[1345]6:
+   1216: PAL BG
+   1236: NTSC
+   1246: PAL I
+   1256: Pal DK
+  {MF|ME|MP}
+   MF: BG LL w/ Secam (Multi France)
+   ME: BG DK I LL   (Multi Europe)
+   MP: BG DK I      (Multi PAL)
+   MR: BG DK M (?)
+   MG: BG DKI M (?)
+  MK2 series PHILIPS_API, most tuners are compatible to this one !
+  MK3 series introduced in 2002 w/ PHILIPS_MK3_API
+
+Temic Tuner identification: (.e.g 4006FH5)
+
+.. code-block:: none
+
+   4[01][0136][269]F[HYNR]5
+    40x2: Tuner (5V/33V), TEMIC_API.
+    40x6: Tuner 5V
+    41xx: Tuner compact
+    40x9: Tuner+FM compact
+   [0136]
+    xx0x: PAL BG
+    xx1x: Pal DK, Secam LL
+    xx3x: NTSC
+    xx6x: PAL I
+   F[HYNR]5
+    FH5: Pal BG
+    FY5: others
+    FN5: multistandard
+    FR5: w/ FM radio
+   3X xxxx: order number with specific connector
+  Note: Only 40x2 series has TEMIC_API, all newer tuners have PHILIPS_API.
+
+LG Innotek Tuner:
+
+- TPI8NSR11 : NTSC J/M    (TPI8NSR01 w/FM)  (P,210/497)
+- TPI8PSB11 : PAL B/G     (TPI8PSB01 w/FM)  (P,170/450)
+- TAPC-I701 : PAL I       (TAPC-I001 w/FM)  (P,170/450)
+- TPI8PSB12 : PAL D/K+B/G (TPI8PSB02 w/FM)  (P,170/450)
+- TAPC-H701P: NTSC_JP     (TAPC-H001P w/FM) (L,170/450)
+- TAPC-G701P: PAL B/G     (TAPC-G001P w/FM) (L,170/450)
+- TAPC-W701P: PAL I       (TAPC-W001P w/FM) (L,170/450)
+- TAPC-Q703P: PAL D/K     (TAPC-Q001P w/FM) (L,170/450)
+- TAPC-Q704P: PAL D/K+I   (L,170/450)
+- TAPC-G702P: PAL D/K+B/G (L,170/450)
+
+- TADC-H002F: NTSC (L,175/410?; 2-B, C-W+11, W+12-69)
+- TADC-M201D: PAL D/K+B/G+I (L,143/425)  (sound control at I2C address 0xc8)
+- TADC-T003F: NTSC Taiwan  (L,175/410?; 2-B, C-W+11, W+12-69)
+
+Suffix:
+  - P= Standard phono female socket
+  - D= IEC female socket
+  - F= F-connector
+
+Other Tuners:
+
+- TCL2002MB-1 : PAL BG + DK       =TUNER_LG_PAL_NEW_TAPC
+- TCL2002MB-1F: PAL BG + DK w/FM  =PHILIPS_PAL
+- TCL2002MI-2 : PAL I		= ??
+
+ALPS Tuners:
+
+- Most are LG_API compatible
+- TSCH6 has ALPS_API (TSCH5 ?)
+- TSBE1 has extra API 05,02,08 Control_byte=0xCB Source:[#f1]_
+
+.. [#f1] conexant100029b-PCI-Decoder-ApplicationNote.pdf
diff --git a/Documentation/driver-api/media/drivers/vidtv.rst b/Documentation/driver-api/media/drivers/vidtv.rst
new file mode 100644
index 000000000..673bdff91
--- /dev/null
+++ b/Documentation/driver-api/media/drivers/vidtv.rst
@@ -0,0 +1,513 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+================================
+vidtv: Virtual Digital TV driver
+================================
+
+Author: Daniel W. S. Almeida <dwlsalmeida@gmail.com>, June 2020.
+
+Background
+----------
+
+Vidtv is a virtual DVB driver that aims to serve as a reference for driver
+writers by serving as a template. It also validates the existing media DVB
+APIs, thus helping userspace application writers.
+
+Currently, it consists of:
+
+- A fake tuner driver, which will report a bad signal quality if the chosen
+  frequency is too far away from a table of valid frequencies for a
+  particular delivery system.
+
+- A fake demod driver, which will constantly poll the fake signal quality
+  returned by the tuner, simulating a device that can lose/reacquire a lock
+  on the signal depending on the CNR levels.
+
+- A fake bridge driver, which is the module responsible for modprobing the
+  fake tuner and demod modules and implementing the demux logic. This module
+  takes parameters at initialization that will dictate how the simulation
+  behaves.
+
+- Code reponsible for encoding a valid MPEG Transport Stream, which is then
+  passed to the bridge driver. This fake stream contains some hardcoded content.
+  For now, we have a single, audio-only channel containing a single MPEG
+  Elementary Stream, which in turn contains a SMPTE 302m encoded sine-wave.
+  Note that this particular encoder was chosen because it is the easiest
+  way to encode PCM audio data in a MPEG Transport Stream.
+
+Building vidtv
+--------------
+vidtv is a test driver and thus is **not** enabled by default when
+compiling the kernel.
+
+In order to enable compilation of vidtv:
+
+- Enable **DVB_TEST_DRIVERS**, then
+- Enable **DVB_VIDTV**
+
+When compiled as a module, expect the following .ko files:
+
+- dvb_vidtv_tuner.ko
+
+- dvb_vidtv_demod.ko
+
+- dvb_vidtv_bridge.ko
+
+Running vidtv
+-------------
+When compiled as a module, run::
+
+	modprobe vidtv
+
+That's it! The bridge driver will initialize the tuner and demod drivers as
+part of its own initialization.
+
+By default, it will accept the following frequencies:
+
+	- 474 MHz for DVB-T/T2/C;
+	- 11,362 GHz for DVB-S/S2.
+
+For satellite systems, the driver simulates an universal extended
+LNBf, with frequencies at Ku-Band, ranging from 10.7 GHz to 12.75 GHz.
+
+You can optionally define some command-line arguments to vidtv.
+
+Command-line arguments to vidtv
+-------------------------------
+Below is a list of all arguments that can be supplied to vidtv:
+
+drop_tslock_prob_on_low_snr
+	Probability of losing the TS lock if the signal quality is bad.
+	This probability be used by the fake demodulator driver to
+	eventually return a status of 0 when the signal quality is not
+	good.
+
+recover_tslock_prob_on_good_snr:
+	Probability recovering the TS lock when the signal improves. This
+	probability be used by the fake demodulator driver to eventually
+	return a status of 0x1f when/if the signal quality improves.
+
+mock_power_up_delay_msec
+	Simulate a power up delay.  Default: 0.
+
+mock_tune_delay_msec
+	Simulate a tune delay.  Default 0.
+
+vidtv_valid_dvb_t_freqs
+	Valid DVB-T frequencies to simulate, in Hz.
+
+vidtv_valid_dvb_c_freqs
+	Valid DVB-C frequencies to simulate, in Hz.
+
+vidtv_valid_dvb_s_freqs
+	Valid DVB-S/S2 frequencies to simulate at Ku-Band, in kHz.
+
+max_frequency_shift_hz,
+	Maximum shift in HZ allowed when tuning in a channel.
+
+si_period_msec
+	How often to send SI packets.  Default: 40ms.
+
+pcr_period_msec
+	How often to send PCR packets.  Default: 40ms.
+
+mux_rate_kbytes_sec
+	Attempt to maintain this bit rate by inserting TS null packets, if
+	necessary.  Default: 4096.
+
+pcr_pid,
+	PCR PID for all channels.  Default: 0x200.
+
+mux_buf_sz_pkts,
+	Size for the mux buffer in multiples of 188 bytes.
+
+vidtv internal structure
+------------------------
+The kernel modules are split in the following way:
+
+vidtv_tuner.[ch]
+	Implements a fake tuner DVB driver.
+
+vidtv_demod.[ch]
+	Implements a fake demodulator DVB driver.
+
+vidtv_bridge.[ch]
+	Implements a bridge driver.
+
+The MPEG related code is split in the following way:
+
+vidtv_ts.[ch]
+	Code to work with MPEG TS packets, such as TS headers, adaptation
+	fields, PCR packets and NULL packets.
+
+vidtv_psi.[ch]
+	This is the PSI generator.  PSI packets contain general information
+	about a MPEG Transport Stream.  A PSI generator is needed so
+	userspace apps can retrieve information about the Transport Stream
+	and eventually tune into a (dummy) channel.
+
+	Because the generator is implemented in a separate file, it can be
+	reused elsewhere in the media subsystem.
+
+	Currently vidtv supports working with 5 PSI tables: PAT, PMT,
+	SDT, NIT and EIT.
+
+	The specification for PAT and PMT can be found in *ISO 13818-1:
+	Systems*, while the specification for the SDT, NIT, EIT can be found in *ETSI
+	EN 300 468: Specification for Service Information (SI) in DVB
+	systems*.
+
+	It isn't strictly necessary, but using a real TS file helps when
+	debugging PSI tables. Vidtv currently tries to replicate the PSI
+	structure found in this file: `TS1Globo.ts
+	<https://tsduck.io/streams/brazil-isdb-tb/TS1globo.ts>`_.
+
+	A good way to visualize the structure of streams is by using
+	`DVBInspector <https://sourceforge.net/projects/dvbinspector/>`_.
+
+vidtv_pes.[ch]
+	Implements the PES logic to convert encoder data into MPEG TS
+	packets. These can then be fed into a TS multiplexer and eventually
+	into userspace.
+
+vidtv_encoder.h
+	An interface for vidtv encoders. New encoders can be added to this
+	driver by implementing the calls in this file.
+
+vidtv_s302m.[ch]
+	Implements a S302M encoder to make it possible to insert PCM audio
+	data in the generated MPEG Transport Stream. The relevant
+	specification is available online as *SMPTE 302M-2007: Television -
+	Mapping of AES3 Data into MPEG-2 Transport Stream*.
+
+
+	The resulting MPEG Elementary Stream is conveyed in a private
+	stream with a S302M registration descriptor attached.
+
+	This shall enable passing an audio signal into userspace so it can
+	be decoded and played by media software. The corresponding decoder
+	in ffmpeg is located in 'libavcodec/s302m.c' and is experimental.
+
+vidtv_channel.[ch]
+	Implements a 'channel' abstraction.
+
+	When vidtv boots, it will create some hardcoded channels:
+
+	#. Their services will be concatenated to populate the SDT.
+
+	#. Their programs will be concatenated to populate the PAT
+
+	#. Their events will be concatenated to populate the EIT
+
+	#. For each program in the PAT, a PMT section will be created
+
+	#. The PMT section for a channel will be assigned its streams.
+
+	#. Every stream will have its corresponding encoder polled in a
+	   loop to produce TS packets.
+	   These packets may be interleaved by the muxer and then delivered
+	   to the bridge.
+
+vidtv_mux.[ch]
+	Implements a MPEG TS mux, loosely based on the ffmpeg
+	implementation in "libavcodec/mpegtsenc.c"
+
+	The muxer runs a loop which is responsible for:
+
+	#. Keeping track of the amount of time elapsed since the last
+	   iteration.
+
+	#. Polling encoders in order to fetch 'elapsed_time' worth of data.
+
+	#. Inserting PSI and/or PCR packets, if needed.
+
+	#. Padding the resulting stream with NULL packets if
+	   necessary in order to maintain the chosen bit rate.
+
+	#. Delivering the resulting TS packets to the bridge
+	   driver so it can pass them to the demux.
+
+Testing vidtv with v4l-utils
+----------------------------
+
+Using the tools in v4l-utils is a great way to test and inspect the output of
+vidtv. It is hosted here: `v4l-utils Documentation
+<https://linuxtv.org/wiki/index.php/V4l-utils>`_.
+
+From its webpage::
+
+	The v4l-utils are a series of packages for handling media devices.
+
+	It is hosted at http://git.linuxtv.org/v4l-utils.git, and packaged
+	on most distributions.
+
+	It provides a series of libraries and utilities to be used to
+	control several aspect of the media boards.
+
+
+Start by installing v4l-utils and then modprobing vidtv::
+
+	modprobe dvb_vidtv_bridge
+
+If the driver is OK, it should load and its probing code will run. This will
+pull in the tuner and demod drivers.
+
+Using dvb-fe-tool
+~~~~~~~~~~~~~~~~~
+
+The first step to check whether the demod loaded successfully is to run::
+
+	$ dvb-fe-tool
+	Device Dummy demod for DVB-T/T2/C/S/S2 (/dev/dvb/adapter0/frontend0) capabilities:
+	    CAN_FEC_1_2
+	    CAN_FEC_2_3
+	    CAN_FEC_3_4
+	    CAN_FEC_4_5
+	    CAN_FEC_5_6
+	    CAN_FEC_6_7
+	    CAN_FEC_7_8
+	    CAN_FEC_8_9
+	    CAN_FEC_AUTO
+	    CAN_GUARD_INTERVAL_AUTO
+	    CAN_HIERARCHY_AUTO
+	    CAN_INVERSION_AUTO
+	    CAN_QAM_16
+	    CAN_QAM_32
+	    CAN_QAM_64
+	    CAN_QAM_128
+	    CAN_QAM_256
+	    CAN_QAM_AUTO
+	    CAN_QPSK
+	    CAN_TRANSMISSION_MODE_AUTO
+	DVB API Version 5.11, Current v5 delivery system: DVBC/ANNEX_A
+	Supported delivery systems:
+	    DVBT
+	    DVBT2
+	    [DVBC/ANNEX_A]
+	    DVBS
+	    DVBS2
+	Frequency range for the current standard:
+	From:            51.0 MHz
+	To:              2.15 GHz
+	Step:            62.5 kHz
+	Tolerance:       29.5 MHz
+	Symbol rate ranges for the current standard:
+	From:            1.00 MBauds
+	To:              45.0 MBauds
+
+This should return what is currently set up at the demod struct, i.e.::
+
+	static const struct dvb_frontend_ops vidtv_demod_ops = {
+		.delsys = {
+			SYS_DVBT,
+			SYS_DVBT2,
+			SYS_DVBC_ANNEX_A,
+			SYS_DVBS,
+			SYS_DVBS2,
+		},
+
+		.info = {
+			.name                   = "Dummy demod for DVB-T/T2/C/S/S2",
+			.frequency_min_hz       = 51 * MHz,
+			.frequency_max_hz       = 2150 * MHz,
+			.frequency_stepsize_hz  = 62500,
+			.frequency_tolerance_hz = 29500 * kHz,
+			.symbol_rate_min        = 1000000,
+			.symbol_rate_max        = 45000000,
+
+			.caps = FE_CAN_FEC_1_2 |
+				FE_CAN_FEC_2_3 |
+				FE_CAN_FEC_3_4 |
+				FE_CAN_FEC_4_5 |
+				FE_CAN_FEC_5_6 |
+				FE_CAN_FEC_6_7 |
+				FE_CAN_FEC_7_8 |
+				FE_CAN_FEC_8_9 |
+				FE_CAN_QAM_16 |
+				FE_CAN_QAM_64 |
+				FE_CAN_QAM_32 |
+				FE_CAN_QAM_128 |
+				FE_CAN_QAM_256 |
+				FE_CAN_QAM_AUTO |
+				FE_CAN_QPSK |
+				FE_CAN_FEC_AUTO |
+				FE_CAN_INVERSION_AUTO |
+				FE_CAN_TRANSMISSION_MODE_AUTO |
+				FE_CAN_GUARD_INTERVAL_AUTO |
+				FE_CAN_HIERARCHY_AUTO,
+		}
+
+		....
+
+For more information on dvb-fe-tools check its online documentation here:
+`dvb-fe-tool Documentation
+<https://www.linuxtv.org/wiki/index.php/Dvb-fe-tool>`_.
+
+Using dvb-scan
+~~~~~~~~~~~~~~
+
+In order to tune into a channel and read the PSI tables, we can use dvb-scan.
+
+For this, one should provide a configuration file known as a 'scan file',
+here's an example::
+
+	[Channel]
+	FREQUENCY = 474000000
+	MODULATION = QAM/AUTO
+	SYMBOL_RATE = 6940000
+	INNER_FEC = AUTO
+	DELIVERY_SYSTEM = DVBC/ANNEX_A
+
+.. note::
+	The parameters depend on the video standard you're testing.
+
+.. note::
+	Vidtv is a fake driver and does not validate much of the information
+	in the scan file. Just specifying 'FREQUENCY' and 'DELIVERY_SYSTEM'
+	should be enough for DVB-T/DVB-T2. For DVB-S/DVB-C however, you
+	should also provide 'SYMBOL_RATE'.
+
+You can browse scan tables online here: `dvb-scan-tables
+<https://git.linuxtv.org/dtv-scan-tables.git>`_.
+
+Assuming this channel is named 'channel.conf', you can then run::
+
+	$ dvbv5-scan channel.conf
+	dvbv5-scan ~/vidtv.conf
+	ERROR    command BANDWIDTH_HZ (5) not found during retrieve
+	Cannot calc frequency shift. Either bandwidth/symbol-rate is unavailable (yet).
+	Scanning frequency #1 330000000
+	    (0x00) Signal= -68.00dBm
+	Scanning frequency #2 474000000
+	Lock   (0x1f) Signal= -34.45dBm C/N= 33.74dB UCB= 0
+	Service Beethoven, provider LinuxTV.org: digital television
+
+For more information on dvb-scan, check its documentation online here:
+`dvb-scan Documentation <https://www.linuxtv.org/wiki/index.php/Dvbscan>`_.
+
+Using dvb-zap
+~~~~~~~~~~~~~
+
+dvbv5-zap is a command line tool that can be used to record MPEG-TS to disk. The
+typical use is to tune into a channel and put it into record mode. The example
+below - which is taken from the documentation - illustrates that\ [1]_::
+
+	$ dvbv5-zap -c dvb_channel.conf "beethoven" -o music.ts -P -t 10
+	using demux 'dvb0.demux0'
+	reading channels from file 'dvb_channel.conf'
+	tuning to 474000000 Hz
+	pass all PID's to TS
+	dvb_set_pesfilter 8192
+	dvb_dev_set_bufsize: buffer set to 6160384
+	Lock   (0x1f) Quality= Good Signal= -34.66dBm C/N= 33.41dB UCB= 0 postBER= 0 preBER= 1.05x10^-3 PER= 0
+	Lock   (0x1f) Quality= Good Signal= -34.57dBm C/N= 33.46dB UCB= 0 postBER= 0 preBER= 1.05x10^-3 PER= 0
+	Record to file 'music.ts' started
+	received 24587768 bytes (2401 Kbytes/sec)
+	Lock   (0x1f) Quality= Good Signal= -34.42dBm C/N= 33.89dB UCB= 0 postBER= 0 preBER= 2.44x10^-3 PER= 0
+
+.. [1] In this example, it records 10 seconds with all program ID's stored
+       at the music.ts file.
+
+
+The channel can be watched by playing the contents of the stream with some
+player that  recognizes the MPEG-TS format, such as ``mplayer`` or ``vlc``.
+
+By playing the contents of the stream one can visually inspect the workings of
+vidtv, e.g., to play a recorded TS file with::
+
+	$ mplayer music.ts
+
+or, alternatively, running this command on one terminal::
+
+	$ dvbv5-zap -c dvb_channel.conf "beethoven" -P -r &
+
+And, on a second terminal, playing the contents from DVR interface with::
+
+	$ mplayer /dev/dvb/adapter0/dvr0
+
+For more information on dvb-zap check its online documentation here:
+`dvb-zap Documentation
+<https://www.linuxtv.org/wiki/index.php/Dvbv5-zap>`_.
+See also: `zap <https://www.linuxtv.org/wiki/index.php/Zap>`_.
+
+
+What can still be improved in vidtv
+-----------------------------------
+
+Add *debugfs* integration
+~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Although frontend drivers provide DVBv5 statistics via the .read_status
+call, a nice addition would be to make additional statistics available to
+userspace via debugfs, which is a simple-to-use, RAM-based filesystem
+specifically designed for debug purposes.
+
+The logic for this would be implemented on a separate file so as not to
+pollute the frontend driver.  These statistics are driver-specific and can
+be useful during tests.
+
+The Siano driver is one example of a driver using
+debugfs to convey driver-specific statistics to userspace and it can be
+used as a reference.
+
+This should be further enabled and disabled via a Kconfig
+option for convenience.
+
+Add a way to test video
+~~~~~~~~~~~~~~~~~~~~~~~
+
+Currently, vidtv can only encode PCM audio. It would be great to implement
+a barebones version of MPEG-2 video encoding so we can also test video. The
+first place to look into is *ISO 13818-2: Information technology — Generic
+coding of moving pictures and associated audio information — Part 2: Video*,
+which covers the encoding of compressed video in MPEG Transport Streams.
+
+This might optionally use the Video4Linux2 Test Pattern Generator, v4l2-tpg,
+which resides at::
+
+	drivers/media/common/v4l2-tpg/
+
+
+Add white noise simulation
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The vidtv tuner already has code to identify whether the chosen frequency
+is too far away from a table of valid frequencies. For now, this means that
+the demodulator can eventually lose the lock on the signal, since the tuner will
+report a bad signal quality.
+
+A nice addition is to simulate some noise when the signal quality is bad by:
+
+- Randomly dropping some TS packets. This will trigger a continuity error if the
+  continuity counter is updated but the packet is not passed on to the demux.
+
+- Updating the error statistics accordingly (e.g. BER, etc).
+
+- Simulating some noise in the encoded data.
+
+Functions and structs used within vidtv
+---------------------------------------
+
+.. kernel-doc:: drivers/media/test-drivers/vidtv/vidtv_bridge.h
+
+.. kernel-doc:: drivers/media/test-drivers/vidtv/vidtv_channel.h
+
+.. kernel-doc:: drivers/media/test-drivers/vidtv/vidtv_demod.h
+
+.. kernel-doc:: drivers/media/test-drivers/vidtv/vidtv_encoder.h
+
+.. kernel-doc:: drivers/media/test-drivers/vidtv/vidtv_mux.h
+
+.. kernel-doc:: drivers/media/test-drivers/vidtv/vidtv_pes.h
+
+.. kernel-doc:: drivers/media/test-drivers/vidtv/vidtv_psi.h
+
+.. kernel-doc:: drivers/media/test-drivers/vidtv/vidtv_s302m.h
+
+.. kernel-doc:: drivers/media/test-drivers/vidtv/vidtv_ts.h
+
+.. kernel-doc:: drivers/media/test-drivers/vidtv/vidtv_tuner.h
+
+.. kernel-doc:: drivers/media/test-drivers/vidtv/vidtv_common.c
+
+.. kernel-doc:: drivers/media/test-drivers/vidtv/vidtv_tuner.c
diff --git a/Documentation/driver-api/media/drivers/vimc-devel.rst b/Documentation/driver-api/media/drivers/vimc-devel.rst
new file mode 100644
index 000000000..9e984f914
--- /dev/null
+++ b/Documentation/driver-api/media/drivers/vimc-devel.rst
@@ -0,0 +1,15 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+The Virtual Media Controller Driver (vimc)
+==========================================
+
+Source code documentation
+-------------------------
+
+vimc-streamer
+~~~~~~~~~~~~~
+
+.. kernel-doc:: drivers/media/test-drivers/vimc/vimc-streamer.h
+   :internal:
+
+.. kernel-doc:: drivers/media/test-drivers/vimc/vimc-streamer.c
diff --git a/Documentation/driver-api/media/drivers/zoran.rst b/Documentation/driver-api/media/drivers/zoran.rst
new file mode 100644
index 000000000..83cbae9ce
--- /dev/null
+++ b/Documentation/driver-api/media/drivers/zoran.rst
@@ -0,0 +1,575 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+The Zoran driver
+================
+
+unified zoran driver (zr360x7, zoran, buz, dc10(+), dc30(+), lml33)
+
+website: http://mjpeg.sourceforge.net/driver-zoran/
+
+
+Frequently Asked Questions
+--------------------------
+
+What cards are supported
+------------------------
+
+Iomega Buz, Linux Media Labs LML33/LML33R10, Pinnacle/Miro
+DC10/DC10+/DC30/DC30+ and related boards (available under various names).
+
+Iomega Buz
+~~~~~~~~~~
+
+* Zoran zr36067 PCI controller
+* Zoran zr36060 MJPEG codec
+* Philips saa7111 TV decoder
+* Philips saa7185 TV encoder
+
+Drivers to use: videodev, i2c-core, i2c-algo-bit,
+videocodec, saa7111, saa7185, zr36060, zr36067
+
+Inputs/outputs: Composite and S-video
+
+Norms: PAL, SECAM (720x576 @ 25 fps), NTSC (720x480 @ 29.97 fps)
+
+Card number: 7
+
+AverMedia 6 Eyes AVS6EYES
+~~~~~~~~~~~~~~~~~~~~~~~~~
+
+* Zoran zr36067 PCI controller
+* Zoran zr36060 MJPEG codec
+* Samsung ks0127 TV decoder
+* Conexant bt866  TV encoder
+
+Drivers to use: videodev, i2c-core, i2c-algo-bit,
+videocodec, ks0127, bt866, zr36060, zr36067
+
+Inputs/outputs:
+	Six physical inputs. 1-6 are composite,
+	1-2, 3-4, 5-6 doubles as S-video,
+	1-3 triples as component.
+	One composite output.
+
+Norms: PAL, SECAM (720x576 @ 25 fps), NTSC (720x480 @ 29.97 fps)
+
+Card number: 8
+
+.. note::
+
+   Not autodetected, card=8 is necessary.
+
+Linux Media Labs LML33
+~~~~~~~~~~~~~~~~~~~~~~
+
+* Zoran zr36067 PCI controller
+* Zoran zr36060 MJPEG codec
+* Brooktree bt819 TV decoder
+* Brooktree bt856 TV encoder
+
+Drivers to use: videodev, i2c-core, i2c-algo-bit,
+videocodec, bt819, bt856, zr36060, zr36067
+
+Inputs/outputs: Composite and S-video
+
+Norms: PAL (720x576 @ 25 fps), NTSC (720x480 @ 29.97 fps)
+
+Card number: 5
+
+Linux Media Labs LML33R10
+~~~~~~~~~~~~~~~~~~~~~~~~~
+
+* Zoran zr36067 PCI controller
+* Zoran zr36060 MJPEG codec
+* Philips saa7114 TV decoder
+* Analog Devices adv7170 TV encoder
+
+Drivers to use: videodev, i2c-core, i2c-algo-bit,
+videocodec, saa7114, adv7170, zr36060, zr36067
+
+Inputs/outputs: Composite and S-video
+
+Norms: PAL (720x576 @ 25 fps), NTSC (720x480 @ 29.97 fps)
+
+Card number: 6
+
+Pinnacle/Miro DC10(new)
+~~~~~~~~~~~~~~~~~~~~~~~
+
+* Zoran zr36057 PCI controller
+* Zoran zr36060 MJPEG codec
+* Philips saa7110a TV decoder
+* Analog Devices adv7176 TV encoder
+
+Drivers to use: videodev, i2c-core, i2c-algo-bit,
+videocodec, saa7110, adv7175, zr36060, zr36067
+
+Inputs/outputs: Composite, S-video and Internal
+
+Norms: PAL, SECAM (768x576 @ 25 fps), NTSC (640x480 @ 29.97 fps)
+
+Card number: 1
+
+Pinnacle/Miro DC10+
+~~~~~~~~~~~~~~~~~~~
+
+* Zoran zr36067 PCI controller
+* Zoran zr36060 MJPEG codec
+* Philips saa7110a TV decoder
+* Analog Devices adv7176 TV encoder
+
+Drivers to use: videodev, i2c-core, i2c-algo-bit,
+videocodec, saa7110, adv7175, zr36060, zr36067
+
+Inputs/outputs: Composite, S-video and Internal
+
+Norms: PAL, SECAM (768x576 @ 25 fps), NTSC (640x480 @ 29.97 fps)
+
+Card number: 2
+
+Pinnacle/Miro DC10(old)
+~~~~~~~~~~~~~~~~~~~~~~~
+
+* Zoran zr36057 PCI controller
+* Zoran zr36050 MJPEG codec
+* Zoran zr36016 Video Front End or Fuji md0211 Video Front End (clone?)
+* Micronas vpx3220a TV decoder
+* mse3000 TV encoder or Analog Devices adv7176 TV encoder
+
+Drivers to use: videodev, i2c-core, i2c-algo-bit,
+videocodec, vpx3220, mse3000/adv7175, zr36050, zr36016, zr36067
+
+Inputs/outputs: Composite, S-video and Internal
+
+Norms: PAL, SECAM (768x576 @ 25 fps), NTSC (640x480 @ 29.97 fps)
+
+Card number: 0
+
+Pinnacle/Miro DC30
+~~~~~~~~~~~~~~~~~~
+
+* Zoran zr36057 PCI controller
+* Zoran zr36050 MJPEG codec
+* Zoran zr36016 Video Front End
+* Micronas vpx3225d/vpx3220a/vpx3216b TV decoder
+* Analog Devices adv7176 TV encoder
+
+Drivers to use: videodev, i2c-core, i2c-algo-bit,
+videocodec, vpx3220/vpx3224, adv7175, zr36050, zr36016, zr36067
+
+Inputs/outputs: Composite, S-video and Internal
+
+Norms: PAL, SECAM (768x576 @ 25 fps), NTSC (640x480 @ 29.97 fps)
+
+Card number: 3
+
+Pinnacle/Miro DC30+
+~~~~~~~~~~~~~~~~~~~
+
+* Zoran zr36067 PCI controller
+* Zoran zr36050 MJPEG codec
+* Zoran zr36016 Video Front End
+* Micronas vpx3225d/vpx3220a/vpx3216b TV decoder
+* Analog Devices adv7176 TV encoder
+
+Drivers to use: videodev, i2c-core, i2c-algo-bit,
+videocodec, vpx3220/vpx3224, adv7175, zr36050, zr36015, zr36067
+
+Inputs/outputs: Composite, S-video and Internal
+
+Norms: PAL, SECAM (768x576 @ 25 fps), NTSC (640x480 @ 29.97 fps)
+
+Card number: 4
+
+.. note::
+
+   #) No module for the mse3000 is available yet
+   #) No module for the vpx3224 is available yet
+
+1.1 What the TV decoder can do an what not
+------------------------------------------
+
+The best know TV standards are NTSC/PAL/SECAM. but for decoding a frame that
+information is not enough. There are several formats of the TV standards.
+And not every TV decoder is able to handle every format. Also the every
+combination is supported by the driver. There are currently 11 different
+tv broadcast formats all aver the world.
+
+The CCIR defines parameters needed for broadcasting the signal.
+The CCIR has defined different standards: A,B,D,E,F,G,D,H,I,K,K1,L,M,N,...
+The CCIR says not much about the colorsystem used !!!
+And talking about a colorsystem says not to much about how it is broadcast.
+
+The CCIR standards A,E,F are not used any more.
+
+When you speak about NTSC, you usually mean the standard: CCIR - M using
+the NTSC colorsystem which is used in the USA, Japan, Mexico, Canada
+and a few others.
+
+When you talk about PAL, you usually mean: CCIR - B/G using the PAL
+colorsystem which is used in many Countries.
+
+When you talk about SECAM, you mean: CCIR - L using the SECAM Colorsystem
+which is used in France, and a few others.
+
+There the other version of SECAM, CCIR - D/K is used in Bulgaria, China,
+Slovakai, Hungary, Korea (Rep.), Poland, Rumania and a others.
+
+The CCIR - H uses the PAL colorsystem (sometimes SECAM) and is used in
+Egypt, Libya, Sri Lanka, Syrain Arab. Rep.
+
+The CCIR - I uses the PAL colorsystem, and is used in Great Britain, Hong Kong,
+Ireland, Nigeria, South Africa.
+
+The CCIR - N uses the PAL colorsystem and PAL frame size but the NTSC framerate,
+and is used in Argentinia, Uruguay, an a few others
+
+We do not talk about how the audio is broadcast !
+
+A rather good sites about the TV standards are:
+http://www.sony.jp/support/
+http://info.electronicwerkstatt.de/bereiche/fernsehtechnik/frequenzen_und_normen/Fernsehnormen/
+and http://www.cabl.com/restaurant/channel.html
+
+Other weird things around: NTSC 4.43 is a modificated NTSC, which is mainly
+used in PAL VCR's that are able to play back NTSC. PAL 60 seems to be the same
+as NTSC 4.43 . The Datasheets also talk about NTSC 44, It seems as if it would
+be the same as NTSC 4.43.
+NTSC Combs seems to be a decoder mode where the decoder uses a comb filter
+to split coma and luma instead of a Delay line.
+
+But I did not defiantly find out what NTSC Comb is.
+
+Philips saa7111 TV decoder
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+- was introduced in 1997, is used in the BUZ and
+- can handle: PAL B/G/H/I, PAL N, PAL M, NTSC M, NTSC N, NTSC 4.43 and SECAM
+
+Philips saa7110a TV decoder
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+- was introduced in 1995, is used in the Pinnacle/Miro DC10(new), DC10+ and
+- can handle: PAL B/G, NTSC M and SECAM
+
+Philips saa7114 TV decoder
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+- was introduced in 2000, is used in the LML33R10 and
+- can handle: PAL B/G/D/H/I/N, PAL N, PAL M, NTSC M, NTSC 4.43 and SECAM
+
+Brooktree bt819 TV decoder
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+- was introduced in 1996, and is used in the LML33 and
+- can handle: PAL B/D/G/H/I, NTSC M
+
+Micronas vpx3220a TV decoder
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+- was introduced in 1996, is used in the DC30 and DC30+ and
+- can handle: PAL B/G/H/I, PAL N, PAL M, NTSC M, NTSC 44, PAL 60, SECAM,NTSC Comb
+
+Samsung ks0127 TV decoder
+~~~~~~~~~~~~~~~~~~~~~~~~~
+
+- is used in the AVS6EYES card and
+- can handle: NTSC-M/N/44, PAL-M/N/B/G/H/I/D/K/L and SECAM
+
+
+What the TV encoder can do an what not
+--------------------------------------
+
+The TV encoder is doing the "same" as the decoder, but in the other direction.
+You feed them digital data and the generate a Composite or SVHS signal.
+For information about the colorsystems and TV norm take a look in the
+TV decoder section.
+
+Philips saa7185 TV Encoder
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+- was introduced in 1996, is used in the BUZ
+- can generate: PAL B/G, NTSC M
+
+Brooktree bt856 TV Encoder
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+- was introduced in 1994, is used in the LML33
+- can generate: PAL B/D/G/H/I/N, PAL M, NTSC M, PAL-N (Argentina)
+
+Analog Devices adv7170 TV Encoder
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+- was introduced in 2000, is used in the LML300R10
+- can generate: PAL B/D/G/H/I/N, PAL M, NTSC M, PAL 60
+
+Analog Devices adv7175 TV Encoder
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+- was introduced in 1996, is used in the DC10, DC10+, DC10 old, DC30, DC30+
+- can generate: PAL B/D/G/H/I/N, PAL M, NTSC M
+
+ITT mse3000 TV encoder
+~~~~~~~~~~~~~~~~~~~~~~
+
+- was introduced in 1991, is used in the DC10 old
+- can generate: PAL , NTSC , SECAM
+
+Conexant bt866 TV encoder
+~~~~~~~~~~~~~~~~~~~~~~~~~
+
+- is used in AVS6EYES, and
+- can generate: NTSC/PAL, PALM, PALN
+
+The adv717x, should be able to produce PAL N. But you find nothing PAL N
+specific in the registers. Seem that you have to reuse a other standard
+to generate PAL N, maybe it would work if you use the PAL M settings.
+
+How do I get this damn thing to work
+------------------------------------
+
+Load zr36067.o. If it can't autodetect your card, use the card=X insmod
+option with X being the card number as given in the previous section.
+To have more than one card, use card=X1[,X2[,X3,[X4[..]]]]
+
+To automate this, add the following to your /etc/modprobe.d/zoran.conf:
+
+options zr36067 card=X1[,X2[,X3[,X4[..]]]]
+alias char-major-81-0 zr36067
+
+One thing to keep in mind is that this doesn't load zr36067.o itself yet. It
+just automates loading. If you start using xawtv, the device won't load on
+some systems, since you're trying to load modules as a user, which is not
+allowed ("permission denied"). A quick workaround is to add 'Load "v4l"' to
+XF86Config-4 when you use X by default, or to run 'v4l-conf -c <device>' in
+one of your startup scripts (normally rc.local) if you don't use X. Both
+make sure that the modules are loaded on startup, under the root account.
+
+What mainboard should I use (or why doesn't my card work)
+---------------------------------------------------------
+
+
+<insert lousy disclaimer here>. In short: good=SiS/Intel, bad=VIA.
+
+Experience tells us that people with a Buz, on average, have more problems
+than users with a DC10+/LML33. Also, it tells us that people owning a VIA-
+based mainboard (ktXXX, MVP3) have more problems than users with a mainboard
+based on a different chipset. Here's some notes from Andrew Stevens:
+
+Here's my experience of using LML33 and Buz on various motherboards:
+
+- VIA MVP3
+	- Forget it. Pointless. Doesn't work.
+- Intel 430FX (Pentium 200)
+	- LML33 perfect, Buz tolerable (3 or 4 frames dropped per movie)
+- Intel 440BX (early stepping)
+	- LML33 tolerable. Buz starting to get annoying (6-10 frames/hour)
+- Intel 440BX (late stepping)
+	- Buz tolerable, LML3 almost perfect (occasional single frame drops)
+- SiS735
+	- LML33 perfect, Buz tolerable.
+- VIA KT133(*)
+	- LML33 starting to get annoying, Buz poor enough that I have up.
+
+- Both 440BX boards were dual CPU versions.
+
+Bernhard Praschinger later added:
+
+- AMD 751
+	- Buz perfect-tolerable
+- AMD 760
+	- Buz perfect-tolerable
+
+In general, people on the user mailinglist won't give you much of a chance
+if you have a VIA-based motherboard. They may be cheap, but sometimes, you'd
+rather want to spend some more money on better boards. In general, VIA
+mainboard's IDE/PCI performance will also suck badly compared to others.
+You'll noticed the DC10+/DC30+ aren't mentioned anywhere in the overview.
+Basically, you can assume that if the Buz works, the LML33 will work too. If
+the LML33 works, the DC10+/DC30+ will work too. They're most tolerant to
+different mainboard chipsets from all of the supported cards.
+
+If you experience timeouts during capture, buy a better mainboard or lower
+the quality/buffersize during capture (see 'Concerning buffer sizes, quality,
+output size etc.'). If it hangs, there's little we can do as of now. Check
+your IRQs and make sure the card has its own interrupts.
+
+Programming interface
+---------------------
+
+This driver conforms to video4linux2. Support for V4L1 and for the custom
+zoran ioctls has been removed in kernel 2.6.38.
+
+For programming example, please, look at lavrec.c and lavplay.c code in
+the MJPEG-tools (http://mjpeg.sf.net/).
+
+Additional notes for software developers:
+
+   The driver returns maxwidth and maxheight parameters according to
+   the current TV standard (norm). Therefore, the software which
+   communicates with the driver and "asks" for these parameters should
+   first set the correct norm. Well, it seems logically correct: TV
+   standard is "more constant" for current country than geometry
+   settings of a variety of TV capture cards which may work in ITU or
+   square pixel format.
+
+Applications
+------------
+
+Applications known to work with this driver:
+
+TV viewing:
+
+* xawtv
+* kwintv
+* probably any TV application that supports video4linux or video4linux2.
+
+MJPEG capture/playback:
+
+* mjpegtools/lavtools (or Linux Video Studio)
+* gstreamer
+* mplayer
+
+General raw capture:
+
+* xawtv
+* gstreamer
+* probably any application that supports video4linux or video4linux2
+
+Video editing:
+
+* Cinelerra
+* MainActor
+* mjpegtools (or Linux Video Studio)
+
+
+Concerning buffer sizes, quality, output size etc.
+--------------------------------------------------
+
+
+The zr36060 can do 1:2 JPEG compression. This is really the theoretical
+maximum that the chipset can reach. The driver can, however, limit compression
+to a maximum (size) of 1:4. The reason for this is that some cards (e.g. Buz)
+can't handle 1:2 compression without stopping capture after only a few minutes.
+With 1:4, it'll mostly work. If you have a Buz, use 'low_bitrate=1' to go into
+1:4 max. compression mode.
+
+100% JPEG quality is thus 1:2 compression in practice. So for a full PAL frame
+(size 720x576). The JPEG fields are stored in YUY2 format, so the size of the
+fields are 720x288x16/2 bits/field (2 fields/frame) = 207360 bytes/field x 2 =
+414720 bytes/frame (add some more bytes for headers and DHT (huffman)/DQT
+(quantization) tables, and you'll get to something like 512kB per frame for
+1:2 compression. For 1:4 compression, you'd have frames of half this size.
+
+Some additional explanation by Martin Samuelsson, which also explains the
+importance of buffer sizes:
+--
+> Hmm, I do not think it is really that way. With the current (downloaded
+> at 18:00 Monday) driver I get that output sizes for 10 sec:
+> -q 50 -b 128 : 24.283.332 Bytes
+> -q 50 -b 256 : 48.442.368
+> -q 25 -b 128 : 24.655.992
+> -q 25 -b 256 : 25.859.820
+
+I woke up, and can't go to sleep again. I'll kill some time explaining why
+this doesn't look strange to me.
+
+Let's do some math using a width of 704 pixels. I'm not sure whether the Buz
+actually use that number or not, but that's not too important right now.
+
+704x288 pixels, one field, is 202752 pixels. Divided by 64 pixels per block;
+3168 blocks per field. Each pixel consist of two bytes; 128 bytes per block;
+1024 bits per block. 100% in the new driver mean 1:2 compression; the maximum
+output becomes 512 bits per block. Actually 510, but 512 is simpler to use
+for calculations.
+
+Let's say that we specify d1q50. We thus want 256 bits per block; times 3168
+becomes 811008 bits; 101376 bytes per field. We're talking raw bits and bytes
+here, so we don't need to do any fancy corrections for bits-per-pixel or such
+things. 101376 bytes per field.
+
+d1 video contains two fields per frame. Those sum up to 202752 bytes per
+frame, and one of those frames goes into each buffer.
+
+But wait a second! -b128 gives 128kB buffers! It's not possible to cram
+202752 bytes of JPEG data into 128kB!
+
+This is what the driver notice and automatically compensate for in your
+examples. Let's do some math using this information:
+
+128kB is 131072 bytes. In this buffer, we want to store two fields, which
+leaves 65536 bytes for each field. Using 3168 blocks per field, we get
+20.68686868... available bytes per block; 165 bits. We can't allow the
+request for 256 bits per block when there's only 165 bits available! The -q50
+option is silently overridden, and the -b128 option takes precedence, leaving
+us with the equivalence of -q32.
+
+This gives us a data rate of 165 bits per block, which, times 3168, sums up
+to 65340 bytes per field, out of the allowed 65536. The current driver has
+another level of rate limiting; it won't accept -q values that fill more than
+6/8 of the specified buffers. (I'm not sure why. "Playing it safe" seem to be
+a safe bet. Personally, I think I would have lowered requested-bits-per-block
+by one, or something like that.) We can't use 165 bits per block, but have to
+lower it again, to 6/8 of the available buffer space: We end up with 124 bits
+per block, the equivalence of -q24. With 128kB buffers, you can't use greater
+than -q24 at -d1. (And PAL, and 704 pixels width...)
+
+The third example is limited to -q24 through the same process. The second
+example, using very similar calculations, is limited to -q48. The only
+example that actually grab at the specified -q value is the last one, which
+is clearly visible, looking at the file size.
+--
+
+Conclusion: the quality of the resulting movie depends on buffer size, quality,
+whether or not you use 'low_bitrate=1' as insmod option for the zr36060.c
+module to do 1:4 instead of 1:2 compression, etc.
+
+If you experience timeouts, lowering the quality/buffersize or using
+'low_bitrate=1 as insmod option for zr36060.o might actually help, as is
+proven by the Buz.
+
+It hangs/crashes/fails/whatevers! Help!
+---------------------------------------
+
+Make sure that the card has its own interrupts (see /proc/interrupts), check
+the output of dmesg at high verbosity (load zr36067.o with debug=2,
+load all other modules with debug=1). Check that your mainboard is favorable
+(see question 2) and if not, test the card in another computer. Also see the
+notes given in question 3 and try lowering quality/buffersize/capturesize
+if recording fails after a period of time.
+
+If all this doesn't help, give a clear description of the problem including
+detailed hardware information (memory+brand, mainboard+chipset+brand, which
+MJPEG card, processor, other PCI cards that might be of interest), give the
+system PnP information (/proc/interrupts, /proc/dma, /proc/devices), and give
+the kernel version, driver version, glibc version, gcc version and any other
+information that might possibly be of interest. Also provide the dmesg output
+at high verbosity. See 'Contacting' on how to contact the developers.
+
+Maintainers/Contacting
+----------------------
+
+Previous maintainers/developers of this driver are
+- Laurent Pinchart <laurent.pinchart@skynet.be>
+- Ronald Bultje rbultje@ronald.bitfreak.net
+- Serguei Miridonov <mirsev@cicese.mx>
+- Wolfgang Scherr <scherr@net4you.net>
+- Dave Perks <dperks@ibm.net>
+- Rainer Johanni <Rainer@Johanni.de>
+
+Driver's License
+----------------
+
+    This driver is distributed under the terms of the General Public License.
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+See http://www.gnu.org/ for more information.
diff --git a/Documentation/driver-api/media/dtv-ca.rst b/Documentation/driver-api/media/dtv-ca.rst
new file mode 100644
index 000000000..8a09862b4
--- /dev/null
+++ b/Documentation/driver-api/media/dtv-ca.rst
@@ -0,0 +1,6 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+Digital TV Conditional Access kABI
+----------------------------------
+
+.. kernel-doc:: include/media/dvb_ca_en50221.h
diff --git a/Documentation/driver-api/media/dtv-common.rst b/Documentation/driver-api/media/dtv-common.rst
new file mode 100644
index 000000000..f8b2c4dc8
--- /dev/null
+++ b/Documentation/driver-api/media/dtv-common.rst
@@ -0,0 +1,62 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+Digital TV Common functions
+---------------------------
+
+Math functions
+~~~~~~~~~~~~~~
+
+Provide some commonly-used math functions, usually required in order to
+estimate signal strength and signal to noise measurements in dB.
+
+.. kernel-doc:: include/media/dvb_math.h
+
+
+DVB devices
+~~~~~~~~~~~
+
+Those functions are responsible for handling the DVB device nodes.
+
+.. kernel-doc:: include/media/dvbdev.h
+
+Digital TV Ring buffer
+~~~~~~~~~~~~~~~~~~~~~~
+
+Those routines implement ring buffers used to handle digital TV data and
+copy it from/to userspace.
+
+.. note::
+
+  1) For performance reasons read and write routines don't check buffer sizes
+     and/or number of bytes free/available. This has to be done before these
+     routines are called. For example:
+
+   .. code-block:: c
+
+        /* write @buflen: bytes */
+        free = dvb_ringbuffer_free(rbuf);
+        if (free >= buflen)
+                count = dvb_ringbuffer_write(rbuf, buffer, buflen);
+        else
+                /* do something */
+
+        /* read min. 1000, max. @bufsize: bytes */
+        avail = dvb_ringbuffer_avail(rbuf);
+        if (avail >= 1000)
+                count = dvb_ringbuffer_read(rbuf, buffer, min(avail, bufsize));
+        else
+                /* do something */
+
+  2) If there is exactly one reader and one writer, there is no need
+     to lock read or write operations.
+     Two or more readers must be locked against each other.
+     Flushing the buffer counts as a read operation.
+     Resetting the buffer counts as a read and write operation.
+     Two or more writers must be locked against each other.
+
+.. kernel-doc:: include/media/dvb_ringbuffer.h
+
+Digital TV VB2 handler
+~~~~~~~~~~~~~~~~~~~~~~
+
+.. kernel-doc:: include/media/dvb_vb2.h
diff --git a/Documentation/driver-api/media/dtv-core.rst b/Documentation/driver-api/media/dtv-core.rst
new file mode 100644
index 000000000..82c5b85ed
--- /dev/null
+++ b/Documentation/driver-api/media/dtv-core.rst
@@ -0,0 +1,39 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+Digital TV (DVB) devices
+------------------------
+
+Digital TV devices are implemented by several different drivers:
+
+- A bridge driver that is responsible to talk with the bus where the other
+  devices are connected (PCI, USB, SPI), bind to the other drivers and
+  implement the digital demux logic (either in software or in hardware);
+
+- Frontend drivers that are usually implemented as two separate drivers:
+
+  - A tuner driver that implements the logic which commands the part of
+    the hardware responsible for tuning into a digital TV transponder or
+    physical channel. The output of a tuner is usually a baseband or
+    Intermediate Frequency (IF) signal;
+
+  - A demodulator driver (a.k.a "demod") that implements the logic which
+    commands the digital TV decoding hardware. The output of a demod is
+    a digital stream, with multiple audio, video and data channels typically
+    multiplexed using MPEG Transport Stream [#f1]_.
+
+On most hardware, the frontend drivers talk with the bridge driver using an
+I2C bus.
+
+.. [#f1] Some standards use TCP/IP for multiplexing data, like DVB-H (an
+   abandoned standard, not used anymore) and ATSC version 3.0 current
+   proposals. Currently, the DVB subsystem doesn't implement those standards.
+
+
+.. toctree::
+    :maxdepth: 1
+
+    dtv-common
+    dtv-frontend
+    dtv-demux
+    dtv-ca
+    dtv-net
diff --git a/Documentation/driver-api/media/dtv-demux.rst b/Documentation/driver-api/media/dtv-demux.rst
new file mode 100644
index 000000000..c0ae5dec5
--- /dev/null
+++ b/Documentation/driver-api/media/dtv-demux.rst
@@ -0,0 +1,84 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+Digital TV Demux kABI
+---------------------
+
+Digital TV Demux
+~~~~~~~~~~~~~~~~
+
+The Kernel Digital TV Demux kABI defines a driver-internal interface for
+registering low-level, hardware specific driver to a hardware independent
+demux layer. It is only of interest for Digital TV device driver writers.
+The header file for this kABI is named ``demux.h`` and located in
+``include/media``.
+
+The demux kABI should be implemented for each demux in the system. It is
+used to select the TS source of a demux and to manage the demux resources.
+When the demux client allocates a resource via the demux kABI, it receives
+a pointer to the kABI of that resource.
+
+Each demux receives its TS input from a DVB front-end or from memory, as
+set via this demux kABI. In a system with more than one front-end, the kABI
+can be used to select one of the DVB front-ends as a TS source for a demux,
+unless this is fixed in the HW platform.
+
+The demux kABI only controls front-ends regarding to their connections with
+demuxes; the kABI used to set the other front-end parameters, such as
+tuning, are devined via the Digital TV Frontend kABI.
+
+The functions that implement the abstract interface demux should be defined
+static or module private and registered to the Demux core for external
+access. It is not necessary to implement every function in the struct
+:c:type:`dmx_demux`. For example, a demux interface might support Section filtering,
+but not PES filtering. The kABI client is expected to check the value of any
+function pointer before calling the function: the value of ``NULL`` means
+that the function is not available.
+
+Whenever the functions of the demux API modify shared data, the
+possibilities of lost update and race condition problems should be
+addressed, e.g. by protecting parts of code with mutexes.
+
+Note that functions called from a bottom half context must not sleep.
+Even a simple memory allocation without using ``GFP_ATOMIC`` can result in a
+kernel thread being put to sleep if swapping is needed. For example, the
+Linux Kernel calls the functions of a network device interface from a
+bottom half context. Thus, if a demux kABI function is called from network
+device code, the function must not sleep.
+
+Demux Callback API
+~~~~~~~~~~~~~~~~~~
+
+This kernel-space API comprises the callback functions that deliver filtered
+data to the demux client. Unlike the other DVB kABIs, these functions are
+provided by the client and called from the demux code.
+
+The function pointers of this abstract interface are not packed into a
+structure as in the other demux APIs, because the callback functions are
+registered and used independent of each other. As an example, it is possible
+for the API client to provide several callback functions for receiving TS
+packets and no callbacks for PES packets or sections.
+
+The functions that implement the callback API need not be re-entrant: when
+a demux driver calls one of these functions, the driver is not allowed to
+call the function again before the original call returns. If a callback is
+triggered by a hardware interrupt, it is recommended to use the Linux
+bottom half mechanism or start a tasklet instead of making the callback
+function call directly from a hardware interrupt.
+
+This mechanism is implemented by :c:func:`dmx_ts_cb()` and :c:func:`dmx_section_cb()`
+callbacks.
+
+Digital TV Demux device registration functions and data structures
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+.. kernel-doc:: include/media/dmxdev.h
+
+High-level Digital TV demux interface
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+.. kernel-doc:: include/media/dvb_demux.h
+
+Driver-internal low-level hardware specific driver demux interface
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+.. kernel-doc:: include/media/demux.h
diff --git a/Documentation/driver-api/media/dtv-frontend.rst b/Documentation/driver-api/media/dtv-frontend.rst
new file mode 100644
index 000000000..91f77fe58
--- /dev/null
+++ b/Documentation/driver-api/media/dtv-frontend.rst
@@ -0,0 +1,445 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+Digital TV Frontend kABI
+------------------------
+
+Digital TV Frontend
+~~~~~~~~~~~~~~~~~~~
+
+The Digital TV Frontend kABI defines a driver-internal interface for
+registering low-level, hardware specific driver to a hardware independent
+frontend layer. It is only of interest for Digital TV device driver writers.
+The header file for this API is named ``dvb_frontend.h`` and located in
+``include/media/``.
+
+Demodulator driver
+^^^^^^^^^^^^^^^^^^
+
+The demodulator driver is responsible for talking with the decoding part of the
+hardware. Such driver should implement :c:type:`dvb_frontend_ops`, which
+tells what type of digital TV standards are supported, and points to a
+series of functions that allow the DVB core to command the hardware via
+the code under ``include/media/dvb_frontend.c``.
+
+A typical example of such struct in a driver ``foo`` is::
+
+	static struct dvb_frontend_ops foo_ops = {
+		.delsys = { SYS_DVBT, SYS_DVBT2, SYS_DVBC_ANNEX_A },
+		.info = {
+			.name	= "foo DVB-T/T2/C driver",
+			.caps = FE_CAN_FEC_1_2 |
+				FE_CAN_FEC_2_3 |
+				FE_CAN_FEC_3_4 |
+				FE_CAN_FEC_5_6 |
+				FE_CAN_FEC_7_8 |
+				FE_CAN_FEC_AUTO |
+				FE_CAN_QPSK |
+				FE_CAN_QAM_16 |
+				FE_CAN_QAM_32 |
+				FE_CAN_QAM_64 |
+				FE_CAN_QAM_128 |
+				FE_CAN_QAM_256 |
+				FE_CAN_QAM_AUTO |
+				FE_CAN_TRANSMISSION_MODE_AUTO |
+				FE_CAN_GUARD_INTERVAL_AUTO |
+				FE_CAN_HIERARCHY_AUTO |
+				FE_CAN_MUTE_TS |
+				FE_CAN_2G_MODULATION,
+			.frequency_min = 42000000, /* Hz */
+			.frequency_max = 1002000000, /* Hz */
+			.symbol_rate_min = 870000,
+			.symbol_rate_max = 11700000
+		},
+		.init = foo_init,
+		.sleep = foo_sleep,
+		.release = foo_release,
+		.set_frontend = foo_set_frontend,
+		.get_frontend = foo_get_frontend,
+		.read_status = foo_get_status_and_stats,
+		.tune = foo_tune,
+		.i2c_gate_ctrl = foo_i2c_gate_ctrl,
+		.get_frontend_algo = foo_get_algo,
+	};
+
+A typical example of such struct in a driver ``bar`` meant to be used on
+Satellite TV reception is::
+
+	static const struct dvb_frontend_ops bar_ops = {
+		.delsys = { SYS_DVBS, SYS_DVBS2 },
+		.info = {
+			.name		= "Bar DVB-S/S2 demodulator",
+			.frequency_min	= 500000, /* KHz */
+			.frequency_max	= 2500000, /* KHz */
+			.frequency_stepsize	= 0,
+			.symbol_rate_min = 1000000,
+			.symbol_rate_max = 45000000,
+			.symbol_rate_tolerance = 500,
+			.caps = FE_CAN_INVERSION_AUTO |
+				FE_CAN_FEC_AUTO |
+				FE_CAN_QPSK,
+		},
+		.init = bar_init,
+		.sleep = bar_sleep,
+		.release = bar_release,
+		.set_frontend = bar_set_frontend,
+		.get_frontend = bar_get_frontend,
+		.read_status = bar_get_status_and_stats,
+		.i2c_gate_ctrl = bar_i2c_gate_ctrl,
+		.get_frontend_algo = bar_get_algo,
+		.tune = bar_tune,
+
+		/* Satellite-specific */
+		.diseqc_send_master_cmd = bar_send_diseqc_msg,
+		.diseqc_send_burst = bar_send_burst,
+		.set_tone = bar_set_tone,
+		.set_voltage = bar_set_voltage,
+	};
+
+.. note::
+
+   #) For satellite digital TV standards (DVB-S, DVB-S2, ISDB-S), the
+      frequencies are specified in kHz, while, for terrestrial and cable
+      standards, they're specified in Hz. Due to that, if the same frontend
+      supports both types, you'll need to have two separate
+      :c:type:`dvb_frontend_ops` structures, one for each standard.
+   #) The ``.i2c_gate_ctrl`` field is present only when the hardware has
+      allows controlling an I2C gate (either directly of via some GPIO pin),
+      in order to remove the tuner from the I2C bus after a channel is
+      tuned.
+   #) All new drivers should implement the
+      :ref:`DVBv5 statistics <dvbv5_stats>` via ``.read_status``.
+      Yet, there are a number of callbacks meant to get statistics for
+      signal strength, S/N and UCB. Those are there to provide backward
+      compatibility with legacy applications that don't support the DVBv5
+      API. Implementing those callbacks are optional. Those callbacks may be
+      removed in the future, after we have all existing drivers supporting
+      DVBv5 stats.
+   #) Other callbacks are required for satellite TV standards, in order to
+      control LNBf and DiSEqC: ``.diseqc_send_master_cmd``,
+      ``.diseqc_send_burst``, ``.set_tone``, ``.set_voltage``.
+
+.. |delta|   unicode:: U+00394
+
+The ``include/media/dvb_frontend.c`` has a kernel thread which is
+responsible for tuning the device. It supports multiple algorithms to
+detect a channel, as defined at enum :c:func:`dvbfe_algo`.
+
+The algorithm to be used is obtained via ``.get_frontend_algo``. If the driver
+doesn't fill its field at struct dvb_frontend_ops, it will default to
+``DVBFE_ALGO_SW``, meaning that the dvb-core will do a zigzag when tuning,
+e. g. it will try first to use the specified center frequency ``f``,
+then, it will do ``f`` + |delta|, ``f`` - |delta|, ``f`` + 2 x |delta|,
+``f`` - 2 x |delta| and so on.
+
+If the hardware has internally a some sort of zigzag algorithm, you should
+define a ``.get_frontend_algo`` function that would return ``DVBFE_ALGO_HW``.
+
+.. note::
+
+   The core frontend support also supports
+   a third type (``DVBFE_ALGO_CUSTOM``), in order to allow the driver to
+   define its own hardware-assisted algorithm. Very few hardware need to
+   use it nowadays. Using ``DVBFE_ALGO_CUSTOM`` require to provide other
+   function callbacks at struct dvb_frontend_ops.
+
+Attaching frontend driver to the bridge driver
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Before using the Digital TV frontend core, the bridge driver should attach
+the frontend demod, tuner and SEC devices and call
+:c:func:`dvb_register_frontend()`,
+in order to register the new frontend at the subsystem. At device
+detach/removal, the bridge driver should call
+:c:func:`dvb_unregister_frontend()` to
+remove the frontend from the core and then :c:func:`dvb_frontend_detach()`
+to free the memory allocated by the frontend drivers.
+
+The drivers should also call :c:func:`dvb_frontend_suspend()` as part of
+their handler for the :c:type:`device_driver`.\ ``suspend()``, and
+:c:func:`dvb_frontend_resume()` as
+part of their handler for :c:type:`device_driver`.\ ``resume()``.
+
+A few other optional functions are provided to handle some special cases.
+
+.. _dvbv5_stats:
+
+Digital TV Frontend statistics
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Introduction
+^^^^^^^^^^^^
+
+Digital TV frontends provide a range of
+:ref:`statistics <frontend-stat-properties>` meant to help tuning the device
+and measuring the quality of service.
+
+For each statistics measurement, the driver should set the type of scale used,
+or ``FE_SCALE_NOT_AVAILABLE`` if the statistics is not available on a given
+time. Drivers should also provide the number of statistics for each type.
+that's usually 1 for most video standards [#f2]_.
+
+Drivers should initialize each statistic counters with length and
+scale at its init code. For example, if the frontend provides signal
+strength, it should have, on its init code::
+
+	struct dtv_frontend_properties *c = &state->fe.dtv_property_cache;
+
+	c->strength.len = 1;
+	c->strength.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
+
+And, when the statistics got updated, set the scale::
+
+	c->strength.stat[0].scale = FE_SCALE_DECIBEL;
+	c->strength.stat[0].uvalue = strength;
+
+.. [#f2] For ISDB-T, it may provide both a global statistics and a per-layer
+   set of statistics. On such cases, len should be equal to 4. The first
+   value corresponds to the global stat; the other ones to each layer, e. g.:
+
+   - c->cnr.stat[0] for global S/N carrier ratio,
+   - c->cnr.stat[1] for Layer A S/N carrier ratio,
+   - c->cnr.stat[2] for layer B S/N carrier ratio,
+   - c->cnr.stat[3] for layer C S/N carrier ratio.
+
+.. note:: Please prefer to use ``FE_SCALE_DECIBEL`` instead of
+   ``FE_SCALE_RELATIVE`` for signal strength and CNR measurements.
+
+Groups of statistics
+^^^^^^^^^^^^^^^^^^^^
+
+There are several groups of statistics currently supported:
+
+Signal strength (:ref:`DTV-STAT-SIGNAL-STRENGTH`)
+  - Measures the signal strength level at the analog part of the tuner or
+    demod.
+
+  - Typically obtained from the gain applied to the tuner and/or frontend
+    in order to detect the carrier. When no carrier is detected, the gain is
+    at the maximum value (so, strength is on its minimal).
+
+  - As the gain is visible through the set of registers that adjust the gain,
+    typically, this statistics is always available [#f3]_.
+
+  - Drivers should try to make it available all the times, as these statistics
+    can be used when adjusting an antenna position and to check for troubles
+    at the cabling.
+
+  .. [#f3] On a few devices, the gain keeps floating if there is no carrier.
+     On such devices, strength report should check first if carrier is
+     detected at the tuner (``FE_HAS_CARRIER``, see :c:type:`fe_status`),
+     and otherwise return the lowest possible value.
+
+Carrier Signal to Noise ratio (:ref:`DTV-STAT-CNR`)
+  - Signal to Noise ratio for the main carrier.
+
+  - Signal to Noise measurement depends on the device. On some hardware, it is
+    available when the main carrier is detected. On those hardware, CNR
+    measurement usually comes from the tuner (e. g. after ``FE_HAS_CARRIER``,
+    see :c:type:`fe_status`).
+
+    On other devices, it requires inner FEC decoding,
+    as the frontend measures it indirectly from other parameters (e. g. after
+    ``FE_HAS_VITERBI``, see :c:type:`fe_status`).
+
+    Having it available after inner FEC is more common.
+
+Bit counts post-FEC (:ref:`DTV-STAT-POST-ERROR-BIT-COUNT` and :ref:`DTV-STAT-POST-TOTAL-BIT-COUNT`)
+  - Those counters measure the number of bits and bit errors errors after
+    the forward error correction (FEC) on the inner coding block
+    (after Viterbi, LDPC or other inner code).
+
+  - Due to its nature, those statistics depend on full coding lock
+    (e. g. after ``FE_HAS_SYNC`` or after ``FE_HAS_LOCK``,
+    see :c:type:`fe_status`).
+
+Bit counts pre-FEC (:ref:`DTV-STAT-PRE-ERROR-BIT-COUNT` and :ref:`DTV-STAT-PRE-TOTAL-BIT-COUNT`)
+  - Those counters measure the number of bits and bit errors errors before
+    the forward error correction (FEC) on the inner coding block
+    (before Viterbi, LDPC or other inner code).
+
+  - Not all frontends provide this kind of statistics.
+
+  - Due to its nature, those statistics depend on inner coding lock (e. g.
+    after ``FE_HAS_VITERBI``, see :c:type:`fe_status`).
+
+Block counts (:ref:`DTV-STAT-ERROR-BLOCK-COUNT` and :ref:`DTV-STAT-TOTAL-BLOCK-COUNT`)
+  - Those counters measure the number of blocks and block errors errors after
+    the forward error correction (FEC) on the inner coding block
+    (before Viterbi, LDPC or other inner code).
+
+  - Due to its nature, those statistics depend on full coding lock
+    (e. g. after ``FE_HAS_SYNC`` or after
+    ``FE_HAS_LOCK``, see :c:type:`fe_status`).
+
+.. note:: All counters should be monotonically increased as they're
+   collected from the hardware.
+
+A typical example of the logic that handle status and statistics is::
+
+	static int foo_get_status_and_stats(struct dvb_frontend *fe)
+	{
+		struct foo_state *state = fe->demodulator_priv;
+		struct dtv_frontend_properties *c = &fe->dtv_property_cache;
+
+		int rc;
+		enum fe_status *status;
+
+		/* Both status and strength are always available */
+		rc = foo_read_status(fe, &status);
+		if (rc < 0)
+			return rc;
+
+		rc = foo_read_strength(fe);
+		if (rc < 0)
+			return rc;
+
+		/* Check if CNR is available */
+		if (!(fe->status & FE_HAS_CARRIER))
+			return 0;
+
+		rc = foo_read_cnr(fe);
+		if (rc < 0)
+			return rc;
+
+		/* Check if pre-BER stats are available */
+		if (!(fe->status & FE_HAS_VITERBI))
+			return 0;
+
+		rc = foo_get_pre_ber(fe);
+		if (rc < 0)
+			return rc;
+
+		/* Check if post-BER stats are available */
+		if (!(fe->status & FE_HAS_SYNC))
+			return 0;
+
+		rc = foo_get_post_ber(fe);
+		if (rc < 0)
+			return rc;
+	}
+
+	static const struct dvb_frontend_ops ops = {
+		/* ... */
+		.read_status = foo_get_status_and_stats,
+	};
+
+Statistics collection
+^^^^^^^^^^^^^^^^^^^^^
+
+On almost all frontend hardware, the bit and byte counts are stored by
+the hardware after a certain amount of time or after the total bit/block
+counter reaches a certain value (usually programmable), for example, on
+every 1000 ms or after receiving 1,000,000 bits.
+
+So, if you read the registers too soon, you'll end by reading the same
+value as in the previous reading, causing the monotonic value to be
+incremented too often.
+
+Drivers should take the responsibility to avoid too often reads. That
+can be done using two approaches:
+
+if the driver have a bit that indicates when a collected data is ready
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+Driver should check such bit before making the statistics available.
+
+An example of such behavior can be found at this code snippet (adapted
+from mb86a20s driver's logic)::
+
+	static int foo_get_pre_ber(struct dvb_frontend *fe)
+	{
+		struct foo_state *state = fe->demodulator_priv;
+		struct dtv_frontend_properties *c = &fe->dtv_property_cache;
+		int rc, bit_error;
+
+		/* Check if the BER measures are already available */
+		rc = foo_read_u8(state, 0x54);
+		if (rc < 0)
+			return rc;
+
+		if (!rc)
+			return 0;
+
+		/* Read Bit Error Count */
+		bit_error = foo_read_u32(state, 0x55);
+		if (bit_error < 0)
+			return bit_error;
+
+		/* Read Total Bit Count */
+		rc = foo_read_u32(state, 0x51);
+		if (rc < 0)
+			return rc;
+
+		c->pre_bit_error.stat[0].scale = FE_SCALE_COUNTER;
+		c->pre_bit_error.stat[0].uvalue += bit_error;
+		c->pre_bit_count.stat[0].scale = FE_SCALE_COUNTER;
+		c->pre_bit_count.stat[0].uvalue += rc;
+
+		return 0;
+	}
+
+If the driver doesn't provide a statistics available check bit
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+A few devices, however, may not provide a way to check if the stats are
+available (or the way to check it is unknown). They may not even provide
+a way to directly read the total number of bits or blocks.
+
+On those devices, the driver need to ensure that it won't be reading from
+the register too often and/or estimate the total number of bits/blocks.
+
+On such drivers, a typical routine to get statistics would be like
+(adapted from dib8000 driver's logic)::
+
+	struct foo_state {
+		/* ... */
+
+		unsigned long per_jiffies_stats;
+	}
+
+	static int foo_get_pre_ber(struct dvb_frontend *fe)
+	{
+		struct foo_state *state = fe->demodulator_priv;
+		struct dtv_frontend_properties *c = &fe->dtv_property_cache;
+		int rc, bit_error;
+		u64 bits;
+
+		/* Check if time for stats was elapsed */
+		if (!time_after(jiffies, state->per_jiffies_stats))
+			return 0;
+
+		/* Next stat should be collected in 1000 ms */
+		state->per_jiffies_stats = jiffies + msecs_to_jiffies(1000);
+
+		/* Read Bit Error Count */
+		bit_error = foo_read_u32(state, 0x55);
+		if (bit_error < 0)
+			return bit_error;
+
+		/*
+		 * On this particular frontend, there's no register that
+		 * would provide the number of bits per 1000ms sample. So,
+		 * some function would calculate it based on DTV properties
+		 */
+		bits = get_number_of_bits_per_1000ms(fe);
+
+		c->pre_bit_error.stat[0].scale = FE_SCALE_COUNTER;
+		c->pre_bit_error.stat[0].uvalue += bit_error;
+		c->pre_bit_count.stat[0].scale = FE_SCALE_COUNTER;
+		c->pre_bit_count.stat[0].uvalue += bits;
+
+		return 0;
+	}
+
+Please notice that, on both cases, we're getting the statistics using the
+:c:type:`dvb_frontend_ops` ``.read_status`` callback. The rationale is that
+the frontend core will automatically call this function periodically
+(usually, 3 times per second, when the frontend is locked).
+
+That warrants that we won't miss to collect a counter and increment the
+monotonic stats at the right time.
+
+Digital TV Frontend functions and types
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+.. kernel-doc:: include/media/dvb_frontend.h
diff --git a/Documentation/driver-api/media/dtv-net.rst b/Documentation/driver-api/media/dtv-net.rst
new file mode 100644
index 000000000..deb6bffe9
--- /dev/null
+++ b/Documentation/driver-api/media/dtv-net.rst
@@ -0,0 +1,6 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+Digital TV Network kABI
+-----------------------
+
+.. kernel-doc:: include/media/dvb_net.h
diff --git a/Documentation/driver-api/media/index.rst b/Documentation/driver-api/media/index.rst
new file mode 100644
index 000000000..c14069245
--- /dev/null
+++ b/Documentation/driver-api/media/index.rst
@@ -0,0 +1,55 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+.. include:: <isonum.txt>
+
+===================================
+Media subsystem kernel internal API
+===================================
+
+This section contains usage information about media subsystem and
+its supported drivers.
+
+Please see:
+
+- :doc:`/admin-guide/media/index`
+    for usage information about media subsystem and supported drivers;
+
+- :doc:`/userspace-api/media/index`
+     for the userspace APIs used on media devices.
+
+
+.. only:: html
+
+   .. class:: toc-title
+
+        Table of Contents
+
+.. toctree::
+    :maxdepth: 5
+    :numbered:
+
+    v4l2-core
+    dtv-core
+    rc-core
+    mc-core
+    cec-core
+    csi2
+    camera-sensor
+
+    drivers/index
+
+**Copyright** |copy| 2009-2020 : LinuxTV Developers
+
+::
+
+  This documentation is free software; you can redistribute it and/or modify it
+  under the terms of the GNU General Public License as published by the Free
+  Software Foundation; either version 2 of the License, or (at your option) any
+  later version.
+
+  This program is distributed in the hope that it will be useful, but WITHOUT
+  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+  FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+  more details.
+
+  For more details see the file COPYING in the source distribution of Linux.
diff --git a/Documentation/driver-api/media/mc-core.rst b/Documentation/driver-api/media/mc-core.rst
new file mode 100644
index 000000000..57b5bbba9
--- /dev/null
+++ b/Documentation/driver-api/media/mc-core.rst
@@ -0,0 +1,309 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+Media Controller devices
+------------------------
+
+Media Controller
+~~~~~~~~~~~~~~~~
+
+The media controller userspace API is documented in
+:ref:`the Media Controller uAPI book <media_controller>`. This document focus
+on the kernel-side implementation of the media framework.
+
+Abstract media device model
+^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Discovering a device internal topology, and configuring it at runtime, is one
+of the goals of the media framework. To achieve this, hardware devices are
+modelled as an oriented graph of building blocks called entities connected
+through pads.
+
+An entity is a basic media hardware building block. It can correspond to
+a large variety of logical blocks such as physical hardware devices
+(CMOS sensor for instance), logical hardware devices (a building block
+in a System-on-Chip image processing pipeline), DMA channels or physical
+connectors.
+
+A pad is a connection endpoint through which an entity can interact with
+other entities. Data (not restricted to video) produced by an entity
+flows from the entity's output to one or more entity inputs. Pads should
+not be confused with physical pins at chip boundaries.
+
+A link is a point-to-point oriented connection between two pads, either
+on the same entity or on different entities. Data flows from a source
+pad to a sink pad.
+
+Media device
+^^^^^^^^^^^^
+
+A media device is represented by a struct media_device
+instance, defined in ``include/media/media-device.h``.
+Allocation of the structure is handled by the media device driver, usually by
+embedding the :c:type:`media_device` instance in a larger driver-specific
+structure.
+
+Drivers register media device instances by calling
+:c:func:`__media_device_register()` via the macro ``media_device_register()``
+and unregistered by calling :c:func:`media_device_unregister()`.
+
+Entities
+^^^^^^^^
+
+Entities are represented by a struct media_entity
+instance, defined in ``include/media/media-entity.h``. The structure is usually
+embedded into a higher-level structure, such as
+:c:type:`v4l2_subdev` or :c:type:`video_device`
+instances, although drivers can allocate entities directly.
+
+Drivers initialize entity pads by calling
+:c:func:`media_entity_pads_init()`.
+
+Drivers register entities with a media device by calling
+:c:func:`media_device_register_entity()`
+and unregistered by calling
+:c:func:`media_device_unregister_entity()`.
+
+Interfaces
+^^^^^^^^^^
+
+Interfaces are represented by a
+struct media_interface instance, defined in
+``include/media/media-entity.h``. Currently, only one type of interface is
+defined: a device node. Such interfaces are represented by a
+struct media_intf_devnode.
+
+Drivers initialize and create device node interfaces by calling
+:c:func:`media_devnode_create()`
+and remove them by calling:
+:c:func:`media_devnode_remove()`.
+
+Pads
+^^^^
+Pads are represented by a struct media_pad instance,
+defined in ``include/media/media-entity.h``. Each entity stores its pads in
+a pads array managed by the entity driver. Drivers usually embed the array in
+a driver-specific structure.
+
+Pads are identified by their entity and their 0-based index in the pads
+array.
+
+Both information are stored in the struct media_pad,
+making the struct media_pad pointer the canonical way
+to store and pass link references.
+
+Pads have flags that describe the pad capabilities and state.
+
+``MEDIA_PAD_FL_SINK`` indicates that the pad supports sinking data.
+``MEDIA_PAD_FL_SOURCE`` indicates that the pad supports sourcing data.
+
+.. note::
+
+  One and only one of ``MEDIA_PAD_FL_SINK`` or ``MEDIA_PAD_FL_SOURCE`` must
+  be set for each pad.
+
+Links
+^^^^^
+
+Links are represented by a struct media_link instance,
+defined in ``include/media/media-entity.h``. There are two types of links:
+
+**1. pad to pad links**:
+
+Associate two entities via their PADs. Each entity has a list that points
+to all links originating at or targeting any of its pads.
+A given link is thus stored twice, once in the source entity and once in
+the target entity.
+
+Drivers create pad to pad links by calling:
+:c:func:`media_create_pad_link()` and remove with
+:c:func:`media_entity_remove_links()`.
+
+**2. interface to entity links**:
+
+Associate one interface to a Link.
+
+Drivers create interface to entity links by calling:
+:c:func:`media_create_intf_link()` and remove with
+:c:func:`media_remove_intf_links()`.
+
+.. note::
+
+   Links can only be created after having both ends already created.
+
+Links have flags that describe the link capabilities and state. The
+valid values are described at :c:func:`media_create_pad_link()` and
+:c:func:`media_create_intf_link()`.
+
+Graph traversal
+^^^^^^^^^^^^^^^
+
+The media framework provides APIs to iterate over entities in a graph.
+
+To iterate over all entities belonging to a media device, drivers can use
+the media_device_for_each_entity macro, defined in
+``include/media/media-device.h``.
+
+..  code-block:: c
+
+    struct media_entity *entity;
+
+    media_device_for_each_entity(entity, mdev) {
+    // entity will point to each entity in turn
+    ...
+    }
+
+Drivers might also need to iterate over all entities in a graph that can be
+reached only through enabled links starting at a given entity. The media
+framework provides a depth-first graph traversal API for that purpose.
+
+.. note::
+
+   Graphs with cycles (whether directed or undirected) are **NOT**
+   supported by the graph traversal API. To prevent infinite loops, the graph
+   traversal code limits the maximum depth to ``MEDIA_ENTITY_ENUM_MAX_DEPTH``,
+   currently defined as 16.
+
+Drivers initiate a graph traversal by calling
+:c:func:`media_graph_walk_start()`
+
+The graph structure, provided by the caller, is initialized to start graph
+traversal at the given entity.
+
+Drivers can then retrieve the next entity by calling
+:c:func:`media_graph_walk_next()`
+
+When the graph traversal is complete the function will return ``NULL``.
+
+Graph traversal can be interrupted at any moment. No cleanup function call
+is required and the graph structure can be freed normally.
+
+Helper functions can be used to find a link between two given pads, or a pad
+connected to another pad through an enabled link
+:c:func:`media_entity_find_link()` and
+:c:func:`media_entity_remote_pad()`.
+
+Use count and power handling
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Due to the wide differences between drivers regarding power management
+needs, the media controller does not implement power management. However,
+the struct media_entity includes a ``use_count``
+field that media drivers
+can use to track the number of users of every entity for power management
+needs.
+
+The :c:type:`media_entity<media_entity>`.\ ``use_count`` field is owned by
+media drivers and must not be
+touched by entity drivers. Access to the field must be protected by the
+:c:type:`media_device`.\ ``graph_mutex`` lock.
+
+Links setup
+^^^^^^^^^^^
+
+Link properties can be modified at runtime by calling
+:c:func:`media_entity_setup_link()`.
+
+Pipelines and media streams
+^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+When starting streaming, drivers must notify all entities in the pipeline to
+prevent link states from being modified during streaming by calling
+:c:func:`media_pipeline_start()`.
+
+The function will mark all entities connected to the given entity through
+enabled links, either directly or indirectly, as streaming.
+
+The struct media_pipeline instance pointed to by
+the pipe argument will be stored in every entity in the pipeline.
+Drivers should embed the struct media_pipeline
+in higher-level pipeline structures and can then access the
+pipeline through the struct media_entity
+pipe field.
+
+Calls to :c:func:`media_pipeline_start()` can be nested.
+The pipeline pointer must be identical for all nested calls to the function.
+
+:c:func:`media_pipeline_start()` may return an error. In that case,
+it will clean up any of the changes it did by itself.
+
+When stopping the stream, drivers must notify the entities with
+:c:func:`media_pipeline_stop()`.
+
+If multiple calls to :c:func:`media_pipeline_start()` have been
+made the same number of :c:func:`media_pipeline_stop()` calls
+are required to stop streaming.
+The :c:type:`media_entity`.\ ``pipe`` field is reset to ``NULL`` on the last
+nested stop call.
+
+Link configuration will fail with ``-EBUSY`` by default if either end of the
+link is a streaming entity. Links that can be modified while streaming must
+be marked with the ``MEDIA_LNK_FL_DYNAMIC`` flag.
+
+If other operations need to be disallowed on streaming entities (such as
+changing entities configuration parameters) drivers can explicitly check the
+media_entity stream_count field to find out if an entity is streaming. This
+operation must be done with the media_device graph_mutex held.
+
+Link validation
+^^^^^^^^^^^^^^^
+
+Link validation is performed by :c:func:`media_pipeline_start()`
+for any entity which has sink pads in the pipeline. The
+:c:type:`media_entity`.\ ``link_validate()`` callback is used for that
+purpose. In ``link_validate()`` callback, entity driver should check
+that the properties of the source pad of the connected entity and its own
+sink pad match. It is up to the type of the entity (and in the end, the
+properties of the hardware) what matching actually means.
+
+Subsystems should facilitate link validation by providing subsystem specific
+helper functions to provide easy access for commonly needed information, and
+in the end provide a way to use driver-specific callbacks.
+
+Media Controller Device Allocator API
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+When the media device belongs to more than one driver, the shared media
+device is allocated with the shared struct device as the key for look ups.
+
+The shared media device should stay in registered state until the last
+driver unregisters it. In addition, the media device should be released when
+all the references are released. Each driver gets a reference to the media
+device during probe, when it allocates the media device. If media device is
+already allocated, the allocate API bumps up the refcount and returns the
+existing media device. The driver puts the reference back in its disconnect
+routine when it calls :c:func:`media_device_delete()`.
+
+The media device is unregistered and cleaned up from the kref put handler to
+ensure that the media device stays in registered state until the last driver
+unregisters the media device.
+
+**Driver Usage**
+
+Drivers should use the appropriate media-core routines to manage the shared
+media device life-time handling the two states:
+1. allocate -> register -> delete
+2. get reference to already registered device -> delete
+
+call :c:func:`media_device_delete()` routine to make sure the shared media
+device delete is handled correctly.
+
+**driver probe:**
+Call :c:func:`media_device_usb_allocate()` to allocate or get a reference
+Call :c:func:`media_device_register()`, if media devnode isn't registered
+
+**driver disconnect:**
+Call :c:func:`media_device_delete()` to free the media_device. Freeing is
+handled by the kref put handler.
+
+API Definitions
+^^^^^^^^^^^^^^^
+
+.. kernel-doc:: include/media/media-device.h
+
+.. kernel-doc:: include/media/media-devnode.h
+
+.. kernel-doc:: include/media/media-entity.h
+
+.. kernel-doc:: include/media/media-request.h
+
+.. kernel-doc:: include/media/media-dev-allocator.h
diff --git a/Documentation/driver-api/media/rc-core.rst b/Documentation/driver-api/media/rc-core.rst
new file mode 100644
index 000000000..53f5e643b
--- /dev/null
+++ b/Documentation/driver-api/media/rc-core.rst
@@ -0,0 +1,88 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+Remote Controller devices
+-------------------------
+
+Remote Controller core
+~~~~~~~~~~~~~~~~~~~~~~
+
+The remote controller core implements infrastructure to receive and send
+remote controller keyboard keystrokes and mouse events.
+
+Every time a key is pressed on a remote controller, a scan code is produced.
+Also, on most hardware, keeping a key pressed for more than a few dozens of
+milliseconds produce a repeat key event. That's somewhat similar to what
+a normal keyboard or mouse is handled internally on Linux\ [#f1]_. So, the
+remote controller core is implemented on the top of the linux input/evdev
+interface.
+
+.. [#f1]
+
+   The main difference is that, on keyboard events, the keyboard controller
+   produces one event for a key press and another one for key release. On
+   infrared-based remote controllers, there's no key release event. Instead,
+   an extra code is produced to indicate key repeats.
+
+However, most of the remote controllers use infrared (IR) to transmit signals.
+As there are several protocols used to modulate infrared signals, one
+important part of the core is dedicated to adjust the driver and the core
+system to support the infrared protocol used by the emitter.
+
+The infrared transmission is done by blinking a infrared emitter using a
+carrier. The carrier can be switched on or off by the IR transmitter
+hardware. When the carrier is switched on, it is called *PULSE*.
+When the carrier is switched off, it is called *SPACE*.
+
+In other words, a typical IR transmission can be viewed as a sequence of
+*PULSE* and *SPACE* events, each with a given duration.
+
+The carrier parameters (frequency, duty cycle) and the intervals for
+*PULSE* and *SPACE* events depend on the protocol.
+For example, the NEC protocol uses a carrier of 38kHz, and transmissions
+start with a 9ms *PULSE* and a 4.5ms SPACE. It then transmits 16 bits of
+scan code, being 8 bits for address (usually it is a fixed number for a
+given remote controller), followed by 8 bits of code. A bit "1" is modulated
+with 560µs *PULSE* followed by 1690µs *SPACE* and a bit "0"  is modulated
+with 560µs *PULSE* followed by 560µs *SPACE*.
+
+At receiver, a simple low-pass filter can be used to convert the received
+signal in a sequence of *PULSE/SPACE* events, filtering out the carrier
+frequency. Due to that, the receiver doesn't care about the carrier's
+actual frequency parameters: all it has to do is to measure the amount
+of time it receives *PULSE/SPACE* events.
+So, a simple IR receiver hardware will just provide a sequence of timings
+for those events to the Kernel. The drivers for hardware with such kind of
+receivers are identified by  ``RC_DRIVER_IR_RAW``, as defined by
+:c:type:`rc_driver_type`\ [#f2]_. Other hardware come with a
+microcontroller that decode the *PULSE/SPACE* sequence and return scan
+codes to the Kernel. Such kind of receivers are identified
+by ``RC_DRIVER_SCANCODE``.
+
+.. [#f2]
+
+   The RC core also supports devices that have just IR emitters,
+   without any receivers. Right now, all such devices work only in
+   raw TX mode. Such kind of hardware is identified as
+   ``RC_DRIVER_IR_RAW_TX``.
+
+When the RC core receives events produced by ``RC_DRIVER_IR_RAW`` IR
+receivers, it needs to decode the IR protocol, in order to obtain the
+corresponding scan code. The protocols supported by the RC core are
+defined at enum :c:type:`rc_proto`.
+
+When the RC code receives a scan code (either directly, by a driver
+of the type ``RC_DRIVER_SCANCODE``, or via its IR decoders), it needs
+to convert into a Linux input event code. This is done via a mapping
+table.
+
+The Kernel has support for mapping tables available on most media
+devices. It also supports loading a table in runtime, via some
+sysfs nodes. See the :ref:`RC userspace API <Remote_controllers_Intro>`
+for more details.
+
+Remote controller data structures and functions
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+.. kernel-doc:: include/media/rc-core.h
+
+.. kernel-doc:: include/media/rc-map.h
diff --git a/Documentation/driver-api/media/v4l2-async.rst b/Documentation/driver-api/media/v4l2-async.rst
new file mode 100644
index 000000000..3422330b3
--- /dev/null
+++ b/Documentation/driver-api/media/v4l2-async.rst
@@ -0,0 +1,5 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+V4L2 async kAPI
+^^^^^^^^^^^^^^^
+.. kernel-doc:: include/media/v4l2-async.h
diff --git a/Documentation/driver-api/media/v4l2-clocks.rst b/Documentation/driver-api/media/v4l2-clocks.rst
new file mode 100644
index 000000000..5c22eecab
--- /dev/null
+++ b/Documentation/driver-api/media/v4l2-clocks.rst
@@ -0,0 +1,31 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+V4L2 clocks
+-----------
+
+.. attention::
+
+	This is a temporary API and it shall be replaced by the generic
+	clock API, when the latter becomes widely available.
+
+Many subdevices, like camera sensors, TV decoders and encoders, need a clock
+signal to be supplied by the system. Often this clock is supplied by the
+respective bridge device. The Linux kernel provides a Common Clock Framework for
+this purpose. However, it is not (yet) available on all architectures. Besides,
+the nature of the multi-functional (clock, data + synchronisation, I2C control)
+connection of subdevices to the system might impose special requirements on the
+clock API usage. E.g. V4L2 has to support clock provider driver unregistration
+while a subdevice driver is holding a reference to the clock. For these reasons
+a V4L2 clock helper API has been developed and is provided to bridge and
+subdevice drivers.
+
+The API consists of two parts: two functions to register and unregister a V4L2
+clock source: v4l2_clk_register() and v4l2_clk_unregister() and calls to control
+a clock object, similar to the respective generic clock API calls:
+v4l2_clk_get(), v4l2_clk_put(), v4l2_clk_enable(), v4l2_clk_disable(),
+v4l2_clk_get_rate(), and v4l2_clk_set_rate(). Clock suppliers have to provide
+clock operations that will be called when clock users invoke respective API
+methods.
+
+It is expected that once the CCF becomes available on all relevant
+architectures this API will be removed.
diff --git a/Documentation/driver-api/media/v4l2-common.rst b/Documentation/driver-api/media/v4l2-common.rst
new file mode 100644
index 000000000..b1e70eb56
--- /dev/null
+++ b/Documentation/driver-api/media/v4l2-common.rst
@@ -0,0 +1,8 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+V4L2 common functions and data structures
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+.. kernel-doc:: include/media/v4l2-common.h
+
+.. kernel-doc:: include/media/v4l2-ioctl.h
diff --git a/Documentation/driver-api/media/v4l2-controls.rst b/Documentation/driver-api/media/v4l2-controls.rst
new file mode 100644
index 000000000..77f42ea3b
--- /dev/null
+++ b/Documentation/driver-api/media/v4l2-controls.rst
@@ -0,0 +1,823 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+V4L2 Controls
+=============
+
+Introduction
+------------
+
+The V4L2 control API seems simple enough, but quickly becomes very hard to
+implement correctly in drivers. But much of the code needed to handle controls
+is actually not driver specific and can be moved to the V4L core framework.
+
+After all, the only part that a driver developer is interested in is:
+
+1) How do I add a control?
+2) How do I set the control's value? (i.e. s_ctrl)
+
+And occasionally:
+
+3) How do I get the control's value? (i.e. g_volatile_ctrl)
+4) How do I validate the user's proposed control value? (i.e. try_ctrl)
+
+All the rest is something that can be done centrally.
+
+The control framework was created in order to implement all the rules of the
+V4L2 specification with respect to controls in a central place. And to make
+life as easy as possible for the driver developer.
+
+Note that the control framework relies on the presence of a struct
+:c:type:`v4l2_device` for V4L2 drivers and struct v4l2_subdev for
+sub-device drivers.
+
+
+Objects in the framework
+------------------------
+
+There are two main objects:
+
+The :c:type:`v4l2_ctrl` object describes the control properties and keeps
+track of the control's value (both the current value and the proposed new
+value).
+
+:c:type:`v4l2_ctrl_handler` is the object that keeps track of controls. It
+maintains a list of v4l2_ctrl objects that it owns and another list of
+references to controls, possibly to controls owned by other handlers.
+
+
+Basic usage for V4L2 and sub-device drivers
+-------------------------------------------
+
+1) Prepare the driver:
+
+.. code-block:: c
+
+	#include <media/v4l2-ctrls.h>
+
+1.1) Add the handler to your driver's top-level struct:
+
+For V4L2 drivers:
+
+.. code-block:: c
+
+	struct foo_dev {
+		...
+		struct v4l2_device v4l2_dev;
+		...
+		struct v4l2_ctrl_handler ctrl_handler;
+		...
+	};
+
+For sub-device drivers:
+
+.. code-block:: c
+
+	struct foo_dev {
+		...
+		struct v4l2_subdev sd;
+		...
+		struct v4l2_ctrl_handler ctrl_handler;
+		...
+	};
+
+1.2) Initialize the handler:
+
+.. code-block:: c
+
+	v4l2_ctrl_handler_init(&foo->ctrl_handler, nr_of_controls);
+
+The second argument is a hint telling the function how many controls this
+handler is expected to handle. It will allocate a hashtable based on this
+information. It is a hint only.
+
+1.3) Hook the control handler into the driver:
+
+For V4L2 drivers:
+
+.. code-block:: c
+
+	foo->v4l2_dev.ctrl_handler = &foo->ctrl_handler;
+
+For sub-device drivers:
+
+.. code-block:: c
+
+	foo->sd.ctrl_handler = &foo->ctrl_handler;
+
+1.4) Clean up the handler at the end:
+
+.. code-block:: c
+
+	v4l2_ctrl_handler_free(&foo->ctrl_handler);
+
+
+2) Add controls:
+
+You add non-menu controls by calling :c:func:`v4l2_ctrl_new_std`:
+
+.. code-block:: c
+
+	struct v4l2_ctrl *v4l2_ctrl_new_std(struct v4l2_ctrl_handler *hdl,
+			const struct v4l2_ctrl_ops *ops,
+			u32 id, s32 min, s32 max, u32 step, s32 def);
+
+Menu and integer menu controls are added by calling
+:c:func:`v4l2_ctrl_new_std_menu`:
+
+.. code-block:: c
+
+	struct v4l2_ctrl *v4l2_ctrl_new_std_menu(struct v4l2_ctrl_handler *hdl,
+			const struct v4l2_ctrl_ops *ops,
+			u32 id, s32 max, s32 skip_mask, s32 def);
+
+Menu controls with a driver specific menu are added by calling
+:c:func:`v4l2_ctrl_new_std_menu_items`:
+
+.. code-block:: c
+
+       struct v4l2_ctrl *v4l2_ctrl_new_std_menu_items(
+                       struct v4l2_ctrl_handler *hdl,
+                       const struct v4l2_ctrl_ops *ops, u32 id, s32 max,
+                       s32 skip_mask, s32 def, const char * const *qmenu);
+
+Standard compound controls can be added by calling
+:c:func:`v4l2_ctrl_new_std_compound`:
+
+.. code-block:: c
+
+       struct v4l2_ctrl *v4l2_ctrl_new_std_compound(struct v4l2_ctrl_handler *hdl,
+                       const struct v4l2_ctrl_ops *ops, u32 id,
+                       const union v4l2_ctrl_ptr p_def);
+
+Integer menu controls with a driver specific menu can be added by calling
+:c:func:`v4l2_ctrl_new_int_menu`:
+
+.. code-block:: c
+
+	struct v4l2_ctrl *v4l2_ctrl_new_int_menu(struct v4l2_ctrl_handler *hdl,
+			const struct v4l2_ctrl_ops *ops,
+			u32 id, s32 max, s32 def, const s64 *qmenu_int);
+
+These functions are typically called right after the
+:c:func:`v4l2_ctrl_handler_init`:
+
+.. code-block:: c
+
+	static const s64 exp_bias_qmenu[] = {
+	       -2, -1, 0, 1, 2
+	};
+	static const char * const test_pattern[] = {
+		"Disabled",
+		"Vertical Bars",
+		"Solid Black",
+		"Solid White",
+	};
+
+	v4l2_ctrl_handler_init(&foo->ctrl_handler, nr_of_controls);
+	v4l2_ctrl_new_std(&foo->ctrl_handler, &foo_ctrl_ops,
+			V4L2_CID_BRIGHTNESS, 0, 255, 1, 128);
+	v4l2_ctrl_new_std(&foo->ctrl_handler, &foo_ctrl_ops,
+			V4L2_CID_CONTRAST, 0, 255, 1, 128);
+	v4l2_ctrl_new_std_menu(&foo->ctrl_handler, &foo_ctrl_ops,
+			V4L2_CID_POWER_LINE_FREQUENCY,
+			V4L2_CID_POWER_LINE_FREQUENCY_60HZ, 0,
+			V4L2_CID_POWER_LINE_FREQUENCY_DISABLED);
+	v4l2_ctrl_new_int_menu(&foo->ctrl_handler, &foo_ctrl_ops,
+			V4L2_CID_EXPOSURE_BIAS,
+			ARRAY_SIZE(exp_bias_qmenu) - 1,
+			ARRAY_SIZE(exp_bias_qmenu) / 2 - 1,
+			exp_bias_qmenu);
+	v4l2_ctrl_new_std_menu_items(&foo->ctrl_handler, &foo_ctrl_ops,
+			V4L2_CID_TEST_PATTERN, ARRAY_SIZE(test_pattern) - 1, 0,
+			0, test_pattern);
+	...
+	if (foo->ctrl_handler.error) {
+		int err = foo->ctrl_handler.error;
+
+		v4l2_ctrl_handler_free(&foo->ctrl_handler);
+		return err;
+	}
+
+The :c:func:`v4l2_ctrl_new_std` function returns the v4l2_ctrl pointer to
+the new control, but if you do not need to access the pointer outside the
+control ops, then there is no need to store it.
+
+The :c:func:`v4l2_ctrl_new_std` function will fill in most fields based on
+the control ID except for the min, max, step and default values. These are
+passed in the last four arguments. These values are driver specific while
+control attributes like type, name, flags are all global. The control's
+current value will be set to the default value.
+
+The :c:func:`v4l2_ctrl_new_std_menu` function is very similar but it is
+used for menu controls. There is no min argument since that is always 0 for
+menu controls, and instead of a step there is a skip_mask argument: if bit
+X is 1, then menu item X is skipped.
+
+The :c:func:`v4l2_ctrl_new_int_menu` function creates a new standard
+integer menu control with driver-specific items in the menu. It differs
+from v4l2_ctrl_new_std_menu in that it doesn't have the mask argument and
+takes as the last argument an array of signed 64-bit integers that form an
+exact menu item list.
+
+The :c:func:`v4l2_ctrl_new_std_menu_items` function is very similar to
+v4l2_ctrl_new_std_menu but takes an extra parameter qmenu, which is the
+driver specific menu for an otherwise standard menu control. A good example
+for this control is the test pattern control for capture/display/sensors
+devices that have the capability to generate test patterns. These test
+patterns are hardware specific, so the contents of the menu will vary from
+device to device.
+
+Note that if something fails, the function will return NULL or an error and
+set ctrl_handler->error to the error code. If ctrl_handler->error was already
+set, then it will just return and do nothing. This is also true for
+v4l2_ctrl_handler_init if it cannot allocate the internal data structure.
+
+This makes it easy to init the handler and just add all controls and only check
+the error code at the end. Saves a lot of repetitive error checking.
+
+It is recommended to add controls in ascending control ID order: it will be
+a bit faster that way.
+
+3) Optionally force initial control setup:
+
+.. code-block:: c
+
+	v4l2_ctrl_handler_setup(&foo->ctrl_handler);
+
+This will call s_ctrl for all controls unconditionally. Effectively this
+initializes the hardware to the default control values. It is recommended
+that you do this as this ensures that both the internal data structures and
+the hardware are in sync.
+
+4) Finally: implement the :c:type:`v4l2_ctrl_ops`
+
+.. code-block:: c
+
+	static const struct v4l2_ctrl_ops foo_ctrl_ops = {
+		.s_ctrl = foo_s_ctrl,
+	};
+
+Usually all you need is s_ctrl:
+
+.. code-block:: c
+
+	static int foo_s_ctrl(struct v4l2_ctrl *ctrl)
+	{
+		struct foo *state = container_of(ctrl->handler, struct foo, ctrl_handler);
+
+		switch (ctrl->id) {
+		case V4L2_CID_BRIGHTNESS:
+			write_reg(0x123, ctrl->val);
+			break;
+		case V4L2_CID_CONTRAST:
+			write_reg(0x456, ctrl->val);
+			break;
+		}
+		return 0;
+	}
+
+The control ops are called with the v4l2_ctrl pointer as argument.
+The new control value has already been validated, so all you need to do is
+to actually update the hardware registers.
+
+You're done! And this is sufficient for most of the drivers we have. No need
+to do any validation of control values, or implement QUERYCTRL, QUERY_EXT_CTRL
+and QUERYMENU. And G/S_CTRL as well as G/TRY/S_EXT_CTRLS are automatically supported.
+
+
+.. note::
+
+   The remainder sections deal with more advanced controls topics and scenarios.
+   In practice the basic usage as described above is sufficient for most drivers.
+
+
+Inheriting Sub-device Controls
+------------------------------
+
+When a sub-device is registered with a V4L2 driver by calling
+v4l2_device_register_subdev() and the ctrl_handler fields of both v4l2_subdev
+and v4l2_device are set, then the controls of the subdev will become
+automatically available in the V4L2 driver as well. If the subdev driver
+contains controls that already exist in the V4L2 driver, then those will be
+skipped (so a V4L2 driver can always override a subdev control).
+
+What happens here is that v4l2_device_register_subdev() calls
+v4l2_ctrl_add_handler() adding the controls of the subdev to the controls
+of v4l2_device.
+
+
+Accessing Control Values
+------------------------
+
+The following union is used inside the control framework to access control
+values:
+
+.. code-block:: c
+
+	union v4l2_ctrl_ptr {
+		s32 *p_s32;
+		s64 *p_s64;
+		char *p_char;
+		void *p;
+	};
+
+The v4l2_ctrl struct contains these fields that can be used to access both
+current and new values:
+
+.. code-block:: c
+
+	s32 val;
+	struct {
+		s32 val;
+	} cur;
+
+
+	union v4l2_ctrl_ptr p_new;
+	union v4l2_ctrl_ptr p_cur;
+
+If the control has a simple s32 type type, then:
+
+.. code-block:: c
+
+	&ctrl->val == ctrl->p_new.p_s32
+	&ctrl->cur.val == ctrl->p_cur.p_s32
+
+For all other types use ctrl->p_cur.p<something>. Basically the val
+and cur.val fields can be considered an alias since these are used so often.
+
+Within the control ops you can freely use these. The val and cur.val speak for
+themselves. The p_char pointers point to character buffers of length
+ctrl->maximum + 1, and are always 0-terminated.
+
+Unless the control is marked volatile the p_cur field points to the the
+current cached control value. When you create a new control this value is made
+identical to the default value. After calling v4l2_ctrl_handler_setup() this
+value is passed to the hardware. It is generally a good idea to call this
+function.
+
+Whenever a new value is set that new value is automatically cached. This means
+that most drivers do not need to implement the g_volatile_ctrl() op. The
+exception is for controls that return a volatile register such as a signal
+strength read-out that changes continuously. In that case you will need to
+implement g_volatile_ctrl like this:
+
+.. code-block:: c
+
+	static int foo_g_volatile_ctrl(struct v4l2_ctrl *ctrl)
+	{
+		switch (ctrl->id) {
+		case V4L2_CID_BRIGHTNESS:
+			ctrl->val = read_reg(0x123);
+			break;
+		}
+	}
+
+Note that you use the 'new value' union as well in g_volatile_ctrl. In general
+controls that need to implement g_volatile_ctrl are read-only controls. If they
+are not, a V4L2_EVENT_CTRL_CH_VALUE will not be generated when the control
+changes.
+
+To mark a control as volatile you have to set V4L2_CTRL_FLAG_VOLATILE:
+
+.. code-block:: c
+
+	ctrl = v4l2_ctrl_new_std(&sd->ctrl_handler, ...);
+	if (ctrl)
+		ctrl->flags |= V4L2_CTRL_FLAG_VOLATILE;
+
+For try/s_ctrl the new values (i.e. as passed by the user) are filled in and
+you can modify them in try_ctrl or set them in s_ctrl. The 'cur' union
+contains the current value, which you can use (but not change!) as well.
+
+If s_ctrl returns 0 (OK), then the control framework will copy the new final
+values to the 'cur' union.
+
+While in g_volatile/s/try_ctrl you can access the value of all controls owned
+by the same handler since the handler's lock is held. If you need to access
+the value of controls owned by other handlers, then you have to be very careful
+not to introduce deadlocks.
+
+Outside of the control ops you have to go through to helper functions to get
+or set a single control value safely in your driver:
+
+.. code-block:: c
+
+	s32 v4l2_ctrl_g_ctrl(struct v4l2_ctrl *ctrl);
+	int v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val);
+
+These functions go through the control framework just as VIDIOC_G/S_CTRL ioctls
+do. Don't use these inside the control ops g_volatile/s/try_ctrl, though, that
+will result in a deadlock since these helpers lock the handler as well.
+
+You can also take the handler lock yourself:
+
+.. code-block:: c
+
+	mutex_lock(&state->ctrl_handler.lock);
+	pr_info("String value is '%s'\n", ctrl1->p_cur.p_char);
+	pr_info("Integer value is '%s'\n", ctrl2->cur.val);
+	mutex_unlock(&state->ctrl_handler.lock);
+
+
+Menu Controls
+-------------
+
+The v4l2_ctrl struct contains this union:
+
+.. code-block:: c
+
+	union {
+		u32 step;
+		u32 menu_skip_mask;
+	};
+
+For menu controls menu_skip_mask is used. What it does is that it allows you
+to easily exclude certain menu items. This is used in the VIDIOC_QUERYMENU
+implementation where you can return -EINVAL if a certain menu item is not
+present. Note that VIDIOC_QUERYCTRL always returns a step value of 1 for
+menu controls.
+
+A good example is the MPEG Audio Layer II Bitrate menu control where the
+menu is a list of standardized possible bitrates. But in practice hardware
+implementations will only support a subset of those. By setting the skip
+mask you can tell the framework which menu items should be skipped. Setting
+it to 0 means that all menu items are supported.
+
+You set this mask either through the v4l2_ctrl_config struct for a custom
+control, or by calling v4l2_ctrl_new_std_menu().
+
+
+Custom Controls
+---------------
+
+Driver specific controls can be created using v4l2_ctrl_new_custom():
+
+.. code-block:: c
+
+	static const struct v4l2_ctrl_config ctrl_filter = {
+		.ops = &ctrl_custom_ops,
+		.id = V4L2_CID_MPEG_CX2341X_VIDEO_SPATIAL_FILTER,
+		.name = "Spatial Filter",
+		.type = V4L2_CTRL_TYPE_INTEGER,
+		.flags = V4L2_CTRL_FLAG_SLIDER,
+		.max = 15,
+		.step = 1,
+	};
+
+	ctrl = v4l2_ctrl_new_custom(&foo->ctrl_handler, &ctrl_filter, NULL);
+
+The last argument is the priv pointer which can be set to driver-specific
+private data.
+
+The v4l2_ctrl_config struct also has a field to set the is_private flag.
+
+If the name field is not set, then the framework will assume this is a standard
+control and will fill in the name, type and flags fields accordingly.
+
+
+Active and Grabbed Controls
+---------------------------
+
+If you get more complex relationships between controls, then you may have to
+activate and deactivate controls. For example, if the Chroma AGC control is
+on, then the Chroma Gain control is inactive. That is, you may set it, but
+the value will not be used by the hardware as long as the automatic gain
+control is on. Typically user interfaces can disable such input fields.
+
+You can set the 'active' status using v4l2_ctrl_activate(). By default all
+controls are active. Note that the framework does not check for this flag.
+It is meant purely for GUIs. The function is typically called from within
+s_ctrl.
+
+The other flag is the 'grabbed' flag. A grabbed control means that you cannot
+change it because it is in use by some resource. Typical examples are MPEG
+bitrate controls that cannot be changed while capturing is in progress.
+
+If a control is set to 'grabbed' using v4l2_ctrl_grab(), then the framework
+will return -EBUSY if an attempt is made to set this control. The
+v4l2_ctrl_grab() function is typically called from the driver when it
+starts or stops streaming.
+
+
+Control Clusters
+----------------
+
+By default all controls are independent from the others. But in more
+complex scenarios you can get dependencies from one control to another.
+In that case you need to 'cluster' them:
+
+.. code-block:: c
+
+	struct foo {
+		struct v4l2_ctrl_handler ctrl_handler;
+	#define AUDIO_CL_VOLUME (0)
+	#define AUDIO_CL_MUTE   (1)
+		struct v4l2_ctrl *audio_cluster[2];
+		...
+	};
+
+	state->audio_cluster[AUDIO_CL_VOLUME] =
+		v4l2_ctrl_new_std(&state->ctrl_handler, ...);
+	state->audio_cluster[AUDIO_CL_MUTE] =
+		v4l2_ctrl_new_std(&state->ctrl_handler, ...);
+	v4l2_ctrl_cluster(ARRAY_SIZE(state->audio_cluster), state->audio_cluster);
+
+From now on whenever one or more of the controls belonging to the same
+cluster is set (or 'gotten', or 'tried'), only the control ops of the first
+control ('volume' in this example) is called. You effectively create a new
+composite control. Similar to how a 'struct' works in C.
+
+So when s_ctrl is called with V4L2_CID_AUDIO_VOLUME as argument, you should set
+all two controls belonging to the audio_cluster:
+
+.. code-block:: c
+
+	static int foo_s_ctrl(struct v4l2_ctrl *ctrl)
+	{
+		struct foo *state = container_of(ctrl->handler, struct foo, ctrl_handler);
+
+		switch (ctrl->id) {
+		case V4L2_CID_AUDIO_VOLUME: {
+			struct v4l2_ctrl *mute = ctrl->cluster[AUDIO_CL_MUTE];
+
+			write_reg(0x123, mute->val ? 0 : ctrl->val);
+			break;
+		}
+		case V4L2_CID_CONTRAST:
+			write_reg(0x456, ctrl->val);
+			break;
+		}
+		return 0;
+	}
+
+In the example above the following are equivalent for the VOLUME case:
+
+.. code-block:: c
+
+	ctrl == ctrl->cluster[AUDIO_CL_VOLUME] == state->audio_cluster[AUDIO_CL_VOLUME]
+	ctrl->cluster[AUDIO_CL_MUTE] == state->audio_cluster[AUDIO_CL_MUTE]
+
+In practice using cluster arrays like this becomes very tiresome. So instead
+the following equivalent method is used:
+
+.. code-block:: c
+
+	struct {
+		/* audio cluster */
+		struct v4l2_ctrl *volume;
+		struct v4l2_ctrl *mute;
+	};
+
+The anonymous struct is used to clearly 'cluster' these two control pointers,
+but it serves no other purpose. The effect is the same as creating an
+array with two control pointers. So you can just do:
+
+.. code-block:: c
+
+	state->volume = v4l2_ctrl_new_std(&state->ctrl_handler, ...);
+	state->mute = v4l2_ctrl_new_std(&state->ctrl_handler, ...);
+	v4l2_ctrl_cluster(2, &state->volume);
+
+And in foo_s_ctrl you can use these pointers directly: state->mute->val.
+
+Note that controls in a cluster may be NULL. For example, if for some
+reason mute was never added (because the hardware doesn't support that
+particular feature), then mute will be NULL. So in that case we have a
+cluster of 2 controls, of which only 1 is actually instantiated. The
+only restriction is that the first control of the cluster must always be
+present, since that is the 'master' control of the cluster. The master
+control is the one that identifies the cluster and that provides the
+pointer to the v4l2_ctrl_ops struct that is used for that cluster.
+
+Obviously, all controls in the cluster array must be initialized to either
+a valid control or to NULL.
+
+In rare cases you might want to know which controls of a cluster actually
+were set explicitly by the user. For this you can check the 'is_new' flag of
+each control. For example, in the case of a volume/mute cluster the 'is_new'
+flag of the mute control would be set if the user called VIDIOC_S_CTRL for
+mute only. If the user would call VIDIOC_S_EXT_CTRLS for both mute and volume
+controls, then the 'is_new' flag would be 1 for both controls.
+
+The 'is_new' flag is always 1 when called from v4l2_ctrl_handler_setup().
+
+
+Handling autogain/gain-type Controls with Auto Clusters
+-------------------------------------------------------
+
+A common type of control cluster is one that handles 'auto-foo/foo'-type
+controls. Typical examples are autogain/gain, autoexposure/exposure,
+autowhitebalance/red balance/blue balance. In all cases you have one control
+that determines whether another control is handled automatically by the hardware,
+or whether it is under manual control from the user.
+
+If the cluster is in automatic mode, then the manual controls should be
+marked inactive and volatile. When the volatile controls are read the
+g_volatile_ctrl operation should return the value that the hardware's automatic
+mode set up automatically.
+
+If the cluster is put in manual mode, then the manual controls should become
+active again and the volatile flag is cleared (so g_volatile_ctrl is no longer
+called while in manual mode). In addition just before switching to manual mode
+the current values as determined by the auto mode are copied as the new manual
+values.
+
+Finally the V4L2_CTRL_FLAG_UPDATE should be set for the auto control since
+changing that control affects the control flags of the manual controls.
+
+In order to simplify this a special variation of v4l2_ctrl_cluster was
+introduced:
+
+.. code-block:: c
+
+	void v4l2_ctrl_auto_cluster(unsigned ncontrols, struct v4l2_ctrl **controls,
+				    u8 manual_val, bool set_volatile);
+
+The first two arguments are identical to v4l2_ctrl_cluster. The third argument
+tells the framework which value switches the cluster into manual mode. The
+last argument will optionally set V4L2_CTRL_FLAG_VOLATILE for the non-auto controls.
+If it is false, then the manual controls are never volatile. You would typically
+use that if the hardware does not give you the option to read back to values as
+determined by the auto mode (e.g. if autogain is on, the hardware doesn't allow
+you to obtain the current gain value).
+
+The first control of the cluster is assumed to be the 'auto' control.
+
+Using this function will ensure that you don't need to handle all the complex
+flag and volatile handling.
+
+
+VIDIOC_LOG_STATUS Support
+-------------------------
+
+This ioctl allow you to dump the current status of a driver to the kernel log.
+The v4l2_ctrl_handler_log_status(ctrl_handler, prefix) can be used to dump the
+value of the controls owned by the given handler to the log. You can supply a
+prefix as well. If the prefix didn't end with a space, then ': ' will be added
+for you.
+
+
+Different Handlers for Different Video Nodes
+--------------------------------------------
+
+Usually the V4L2 driver has just one control handler that is global for
+all video nodes. But you can also specify different control handlers for
+different video nodes. You can do that by manually setting the ctrl_handler
+field of struct video_device.
+
+That is no problem if there are no subdevs involved but if there are, then
+you need to block the automatic merging of subdev controls to the global
+control handler. You do that by simply setting the ctrl_handler field in
+struct v4l2_device to NULL. Now v4l2_device_register_subdev() will no longer
+merge subdev controls.
+
+After each subdev was added, you will then have to call v4l2_ctrl_add_handler
+manually to add the subdev's control handler (sd->ctrl_handler) to the desired
+control handler. This control handler may be specific to the video_device or
+for a subset of video_device's. For example: the radio device nodes only have
+audio controls, while the video and vbi device nodes share the same control
+handler for the audio and video controls.
+
+If you want to have one handler (e.g. for a radio device node) have a subset
+of another handler (e.g. for a video device node), then you should first add
+the controls to the first handler, add the other controls to the second
+handler and finally add the first handler to the second. For example:
+
+.. code-block:: c
+
+	v4l2_ctrl_new_std(&radio_ctrl_handler, &radio_ops, V4L2_CID_AUDIO_VOLUME, ...);
+	v4l2_ctrl_new_std(&radio_ctrl_handler, &radio_ops, V4L2_CID_AUDIO_MUTE, ...);
+	v4l2_ctrl_new_std(&video_ctrl_handler, &video_ops, V4L2_CID_BRIGHTNESS, ...);
+	v4l2_ctrl_new_std(&video_ctrl_handler, &video_ops, V4L2_CID_CONTRAST, ...);
+	v4l2_ctrl_add_handler(&video_ctrl_handler, &radio_ctrl_handler, NULL);
+
+The last argument to v4l2_ctrl_add_handler() is a filter function that allows
+you to filter which controls will be added. Set it to NULL if you want to add
+all controls.
+
+Or you can add specific controls to a handler:
+
+.. code-block:: c
+
+	volume = v4l2_ctrl_new_std(&video_ctrl_handler, &ops, V4L2_CID_AUDIO_VOLUME, ...);
+	v4l2_ctrl_new_std(&video_ctrl_handler, &ops, V4L2_CID_BRIGHTNESS, ...);
+	v4l2_ctrl_new_std(&video_ctrl_handler, &ops, V4L2_CID_CONTRAST, ...);
+
+What you should not do is make two identical controls for two handlers.
+For example:
+
+.. code-block:: c
+
+	v4l2_ctrl_new_std(&radio_ctrl_handler, &radio_ops, V4L2_CID_AUDIO_MUTE, ...);
+	v4l2_ctrl_new_std(&video_ctrl_handler, &video_ops, V4L2_CID_AUDIO_MUTE, ...);
+
+This would be bad since muting the radio would not change the video mute
+control. The rule is to have one control for each hardware 'knob' that you
+can twiddle.
+
+
+Finding Controls
+----------------
+
+Normally you have created the controls yourself and you can store the struct
+v4l2_ctrl pointer into your own struct.
+
+But sometimes you need to find a control from another handler that you do
+not own. For example, if you have to find a volume control from a subdev.
+
+You can do that by calling v4l2_ctrl_find:
+
+.. code-block:: c
+
+	struct v4l2_ctrl *volume;
+
+	volume = v4l2_ctrl_find(sd->ctrl_handler, V4L2_CID_AUDIO_VOLUME);
+
+Since v4l2_ctrl_find will lock the handler you have to be careful where you
+use it. For example, this is not a good idea:
+
+.. code-block:: c
+
+	struct v4l2_ctrl_handler ctrl_handler;
+
+	v4l2_ctrl_new_std(&ctrl_handler, &video_ops, V4L2_CID_BRIGHTNESS, ...);
+	v4l2_ctrl_new_std(&ctrl_handler, &video_ops, V4L2_CID_CONTRAST, ...);
+
+...and in video_ops.s_ctrl:
+
+.. code-block:: c
+
+	case V4L2_CID_BRIGHTNESS:
+		contrast = v4l2_find_ctrl(&ctrl_handler, V4L2_CID_CONTRAST);
+		...
+
+When s_ctrl is called by the framework the ctrl_handler.lock is already taken, so
+attempting to find another control from the same handler will deadlock.
+
+It is recommended not to use this function from inside the control ops.
+
+
+Preventing Controls inheritance
+-------------------------------
+
+When one control handler is added to another using v4l2_ctrl_add_handler, then
+by default all controls from one are merged to the other. But a subdev might
+have low-level controls that make sense for some advanced embedded system, but
+not when it is used in consumer-level hardware. In that case you want to keep
+those low-level controls local to the subdev. You can do this by simply
+setting the 'is_private' flag of the control to 1:
+
+.. code-block:: c
+
+	static const struct v4l2_ctrl_config ctrl_private = {
+		.ops = &ctrl_custom_ops,
+		.id = V4L2_CID_...,
+		.name = "Some Private Control",
+		.type = V4L2_CTRL_TYPE_INTEGER,
+		.max = 15,
+		.step = 1,
+		.is_private = 1,
+	};
+
+	ctrl = v4l2_ctrl_new_custom(&foo->ctrl_handler, &ctrl_private, NULL);
+
+These controls will now be skipped when v4l2_ctrl_add_handler is called.
+
+
+V4L2_CTRL_TYPE_CTRL_CLASS Controls
+----------------------------------
+
+Controls of this type can be used by GUIs to get the name of the control class.
+A fully featured GUI can make a dialog with multiple tabs with each tab
+containing the controls belonging to a particular control class. The name of
+each tab can be found by querying a special control with ID <control class | 1>.
+
+Drivers do not have to care about this. The framework will automatically add
+a control of this type whenever the first control belonging to a new control
+class is added.
+
+
+Adding Notify Callbacks
+-----------------------
+
+Sometimes the platform or bridge driver needs to be notified when a control
+from a sub-device driver changes. You can set a notify callback by calling
+this function:
+
+.. code-block:: c
+
+	void v4l2_ctrl_notify(struct v4l2_ctrl *ctrl,
+		void (*notify)(struct v4l2_ctrl *ctrl, void *priv), void *priv);
+
+Whenever the give control changes value the notify callback will be called
+with a pointer to the control and the priv pointer that was passed with
+v4l2_ctrl_notify. Note that the control's handler lock is held when the
+notify function is called.
+
+There can be only one notify function per control handler. Any attempt
+to set another notify function will cause a WARN_ON.
+
+v4l2_ctrl functions and data structures
+---------------------------------------
+
+.. kernel-doc:: include/media/v4l2-ctrls.h
diff --git a/Documentation/driver-api/media/v4l2-core.rst b/Documentation/driver-api/media/v4l2-core.rst
new file mode 100644
index 000000000..0dcad7a23
--- /dev/null
+++ b/Documentation/driver-api/media/v4l2-core.rst
@@ -0,0 +1,29 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+Video4Linux devices
+-------------------
+
+.. toctree::
+    :maxdepth: 1
+
+    v4l2-intro
+    v4l2-dev
+    v4l2-device
+    v4l2-fh
+    v4l2-subdev
+    v4l2-event
+    v4l2-controls
+    v4l2-videobuf
+    v4l2-videobuf2
+    v4l2-clocks
+    v4l2-dv-timings
+    v4l2-flash-led-class
+    v4l2-mc
+    v4l2-mediabus
+    v4l2-mem2mem
+    v4l2-async
+    v4l2-fwnode
+    v4l2-rect
+    v4l2-tuner
+    v4l2-common
+    v4l2-tveeprom
diff --git a/Documentation/driver-api/media/v4l2-dev.rst b/Documentation/driver-api/media/v4l2-dev.rst
new file mode 100644
index 000000000..666330af3
--- /dev/null
+++ b/Documentation/driver-api/media/v4l2-dev.rst
@@ -0,0 +1,375 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+Video device' s internal representation
+=======================================
+
+The actual device nodes in the ``/dev`` directory are created using the
+:c:type:`video_device` struct (``v4l2-dev.h``). This struct can either be
+allocated dynamically or embedded in a larger struct.
+
+To allocate it dynamically use :c:func:`video_device_alloc`:
+
+.. code-block:: c
+
+	struct video_device *vdev = video_device_alloc();
+
+	if (vdev == NULL)
+		return -ENOMEM;
+
+	vdev->release = video_device_release;
+
+If you embed it in a larger struct, then you must set the ``release()``
+callback to your own function:
+
+.. code-block:: c
+
+	struct video_device *vdev = &my_vdev->vdev;
+
+	vdev->release = my_vdev_release;
+
+The ``release()`` callback must be set and it is called when the last user
+of the video device exits.
+
+The default :c:func:`video_device_release` callback currently
+just calls ``kfree`` to free the allocated memory.
+
+There is also a :c:func:`video_device_release_empty` function that does
+nothing (is empty) and should be used if the struct is embedded and there
+is nothing to do when it is released.
+
+You should also set these fields of :c:type:`video_device`:
+
+- :c:type:`video_device`->v4l2_dev: must be set to the :c:type:`v4l2_device`
+  parent device.
+
+- :c:type:`video_device`->name: set to something descriptive and unique.
+
+- :c:type:`video_device`->vfl_dir: set this to ``VFL_DIR_RX`` for capture
+  devices (``VFL_DIR_RX`` has value 0, so this is normally already the
+  default), set to ``VFL_DIR_TX`` for output devices and ``VFL_DIR_M2M`` for mem2mem (codec) devices.
+
+- :c:type:`video_device`->fops: set to the :c:type:`v4l2_file_operations`
+  struct.
+
+- :c:type:`video_device`->ioctl_ops: if you use the :c:type:`v4l2_ioctl_ops`
+  to simplify ioctl maintenance (highly recommended to use this and it might
+  become compulsory in the future!), then set this to your
+  :c:type:`v4l2_ioctl_ops` struct. The :c:type:`video_device`->vfl_type and
+  :c:type:`video_device`->vfl_dir fields are used to disable ops that do not
+  match the type/dir combination. E.g. VBI ops are disabled for non-VBI nodes,
+  and output ops  are disabled for a capture device. This makes it possible to
+  provide just one :c:type:`v4l2_ioctl_ops` struct for both vbi and
+  video nodes.
+
+- :c:type:`video_device`->lock: leave to ``NULL`` if you want to do all the
+  locking  in the driver. Otherwise you give it a pointer to a struct
+  ``mutex_lock`` and before the :c:type:`video_device`->unlocked_ioctl
+  file operation is called this lock will be taken by the core and released
+  afterwards. See the next section for more details.
+
+- :c:type:`video_device`->queue: a pointer to the struct vb2_queue
+  associated with this device node.
+  If queue is not ``NULL``, and queue->lock is not ``NULL``, then queue->lock
+  is used for the queuing ioctls (``VIDIOC_REQBUFS``, ``CREATE_BUFS``,
+  ``QBUF``, ``DQBUF``,  ``QUERYBUF``, ``PREPARE_BUF``, ``STREAMON`` and
+  ``STREAMOFF``) instead of the lock above.
+  That way the :ref:`vb2 <vb2_framework>` queuing framework does not have
+  to wait for other ioctls.   This queue pointer is also used by the
+  :ref:`vb2 <vb2_framework>` helper functions to check for
+  queuing ownership (i.e. is the filehandle calling it allowed to do the
+  operation).
+
+- :c:type:`video_device`->prio: keeps track of the priorities. Used to
+  implement ``VIDIOC_G_PRIORITY`` and ``VIDIOC_S_PRIORITY``.
+  If left to ``NULL``, then it will use the struct v4l2_prio_state
+  in :c:type:`v4l2_device`. If you want to have a separate priority state per
+  (group of) device node(s),   then you can point it to your own struct
+  :c:type:`v4l2_prio_state`.
+
+- :c:type:`video_device`->dev_parent: you only set this if v4l2_device was
+  registered with ``NULL`` as the parent ``device`` struct. This only happens
+  in cases where one hardware device has multiple PCI devices that all share
+  the same :c:type:`v4l2_device` core.
+
+  The cx88 driver is an example of this: one core :c:type:`v4l2_device` struct,
+  but   it is used by both a raw video PCI device (cx8800) and a MPEG PCI device
+  (cx8802). Since the :c:type:`v4l2_device` cannot be associated with two PCI
+  devices at the same time it is setup without a parent device. But when the
+  struct video_device is initialized you **do** know which parent
+  PCI device to use and so you set ``dev_device`` to the correct PCI device.
+
+If you use :c:type:`v4l2_ioctl_ops`, then you should set
+:c:type:`video_device`->unlocked_ioctl to :c:func:`video_ioctl2` in your
+:c:type:`v4l2_file_operations` struct.
+
+In some cases you want to tell the core that a function you had specified in
+your :c:type:`v4l2_ioctl_ops` should be ignored. You can mark such ioctls by
+calling this function before :c:func:`video_register_device` is called:
+
+	:c:func:`v4l2_disable_ioctl <v4l2_disable_ioctl>`
+	(:c:type:`vdev <video_device>`, cmd).
+
+This tends to be needed if based on external factors (e.g. which card is
+being used) you want to turns off certain features in :c:type:`v4l2_ioctl_ops`
+without having to make a new struct.
+
+The :c:type:`v4l2_file_operations` struct is a subset of file_operations.
+The main difference is that the inode argument is omitted since it is never
+used.
+
+If integration with the media framework is needed, you must initialize the
+:c:type:`media_entity` struct embedded in the :c:type:`video_device` struct
+(entity field) by calling :c:func:`media_entity_pads_init`:
+
+.. code-block:: c
+
+	struct media_pad *pad = &my_vdev->pad;
+	int err;
+
+	err = media_entity_pads_init(&vdev->entity, 1, pad);
+
+The pads array must have been previously initialized. There is no need to
+manually set the struct media_entity type and name fields.
+
+A reference to the entity will be automatically acquired/released when the
+video device is opened/closed.
+
+ioctls and locking
+------------------
+
+The V4L core provides optional locking services. The main service is the
+lock field in struct video_device, which is a pointer to a mutex.
+If you set this pointer, then that will be used by unlocked_ioctl to
+serialize all ioctls.
+
+If you are using the :ref:`videobuf2 framework <vb2_framework>`, then there
+is a second lock that you can set: :c:type:`video_device`->queue->lock. If
+set, then this lock will be used instead of :c:type:`video_device`->lock
+to serialize all queuing ioctls (see the previous section
+for the full list of those ioctls).
+
+The advantage of using a different lock for the queuing ioctls is that for some
+drivers (particularly USB drivers) certain commands such as setting controls
+can take a long time, so you want to use a separate lock for the buffer queuing
+ioctls. That way your ``VIDIOC_DQBUF`` doesn't stall because the driver is busy
+changing the e.g. exposure of the webcam.
+
+Of course, you can always do all the locking yourself by leaving both lock
+pointers at ``NULL``.
+
+If you use the old :ref:`videobuf framework <vb_framework>` then you must
+pass the :c:type:`video_device`->lock to the videobuf queue initialize
+function: if videobuf has to wait for a frame to arrive, then it will
+temporarily unlock the lock and relock it afterwards. If your driver also
+waits in the code, then you should do the same to allow other
+processes to access the device node while the first process is waiting for
+something.
+
+In the case of :ref:`videobuf2 <vb2_framework>` you will need to implement the
+``wait_prepare()`` and ``wait_finish()`` callbacks to unlock/lock if applicable.
+If you use the ``queue->lock`` pointer, then you can use the helper functions
+:c:func:`vb2_ops_wait_prepare` and :c:func:`vb2_ops_wait_finish`.
+
+The implementation of a hotplug disconnect should also take the lock from
+:c:type:`video_device` before calling v4l2_device_disconnect. If you are also
+using :c:type:`video_device`->queue->lock, then you have to first lock
+:c:type:`video_device`->queue->lock followed by :c:type:`video_device`->lock.
+That way you can be sure no ioctl is running when you call
+:c:func:`v4l2_device_disconnect`.
+
+Video device registration
+-------------------------
+
+Next you register the video device with :c:func:`video_register_device`.
+This will create the character device for you.
+
+.. code-block:: c
+
+	err = video_register_device(vdev, VFL_TYPE_VIDEO, -1);
+	if (err) {
+		video_device_release(vdev); /* or kfree(my_vdev); */
+		return err;
+	}
+
+If the :c:type:`v4l2_device` parent device has a not ``NULL`` mdev field,
+the video device entity will be automatically registered with the media
+device.
+
+Which device is registered depends on the type argument. The following
+types exist:
+
+========================== ====================	 ==============================
+:c:type:`vfl_devnode_type` Device name		 Usage
+========================== ====================	 ==============================
+``VFL_TYPE_VIDEO``         ``/dev/videoX``       for video input/output devices
+``VFL_TYPE_VBI``           ``/dev/vbiX``         for vertical blank data (i.e.
+						 closed captions, teletext)
+``VFL_TYPE_RADIO``         ``/dev/radioX``       for radio tuners
+``VFL_TYPE_SUBDEV``        ``/dev/v4l-subdevX``  for V4L2 subdevices
+``VFL_TYPE_SDR``           ``/dev/swradioX``     for Software Defined Radio
+						 (SDR) tuners
+``VFL_TYPE_TOUCH``         ``/dev/v4l-touchX``   for touch sensors
+========================== ====================	 ==============================
+
+The last argument gives you a certain amount of control over the device
+device node number used (i.e. the X in ``videoX``). Normally you will pass -1
+to let the v4l2 framework pick the first free number. But sometimes users
+want to select a specific node number. It is common that drivers allow
+the user to select a specific device node number through a driver module
+option. That number is then passed to this function and video_register_device
+will attempt to select that device node number. If that number was already
+in use, then the next free device node number will be selected and it
+will send a warning to the kernel log.
+
+Another use-case is if a driver creates many devices. In that case it can
+be useful to place different video devices in separate ranges. For example,
+video capture devices start at 0, video output devices start at 16.
+So you can use the last argument to specify a minimum device node number
+and the v4l2 framework will try to pick the first free number that is equal
+or higher to what you passed. If that fails, then it will just pick the
+first free number.
+
+Since in this case you do not care about a warning about not being able
+to select the specified device node number, you can call the function
+:c:func:`video_register_device_no_warn` instead.
+
+Whenever a device node is created some attributes are also created for you.
+If you look in ``/sys/class/video4linux`` you see the devices. Go into e.g.
+``video0`` and you will see 'name', 'dev_debug' and 'index' attributes. The
+'name' attribute is the 'name' field of the video_device struct. The
+'dev_debug' attribute can be used to enable core debugging. See the next
+section for more detailed information on this.
+
+The 'index' attribute is the index of the device node: for each call to
+:c:func:`video_register_device()` the index is just increased by 1. The
+first video device node you register always starts with index 0.
+
+Users can setup udev rules that utilize the index attribute to make fancy
+device names (e.g. '``mpegX``' for MPEG video capture device nodes).
+
+After the device was successfully registered, then you can use these fields:
+
+- :c:type:`video_device`->vfl_type: the device type passed to
+  :c:func:`video_register_device`.
+- :c:type:`video_device`->minor: the assigned device minor number.
+- :c:type:`video_device`->num: the device node number (i.e. the X in
+  ``videoX``).
+- :c:type:`video_device`->index: the device index number.
+
+If the registration failed, then you need to call
+:c:func:`video_device_release` to free the allocated :c:type:`video_device`
+struct, or free your own struct if the :c:type:`video_device` was embedded in
+it. The ``vdev->release()`` callback will never be called if the registration
+failed, nor should you ever attempt to unregister the device if the
+registration failed.
+
+video device debugging
+----------------------
+
+The 'dev_debug' attribute that is created for each video, vbi, radio or swradio
+device in ``/sys/class/video4linux/<devX>/`` allows you to enable logging of
+file operations.
+
+It is a bitmask and the following bits can be set:
+
+.. tabularcolumns:: |p{5ex}|L|
+
+===== ================================================================
+Mask  Description
+===== ================================================================
+0x01  Log the ioctl name and error code. VIDIOC_(D)QBUF ioctls are
+      only logged if bit 0x08 is also set.
+0x02  Log the ioctl name arguments and error code. VIDIOC_(D)QBUF
+      ioctls are
+      only logged if bit 0x08 is also set.
+0x04  Log the file operations open, release, read, write, mmap and
+      get_unmapped_area. The read and write operations are only
+      logged if bit 0x08 is also set.
+0x08  Log the read and write file operations and the VIDIOC_QBUF and
+      VIDIOC_DQBUF ioctls.
+0x10  Log the poll file operation.
+0x20  Log error and messages in the control operations.
+===== ================================================================
+
+Video device cleanup
+--------------------
+
+When the video device nodes have to be removed, either during the unload
+of the driver or because the USB device was disconnected, then you should
+unregister them with:
+
+	:c:func:`video_unregister_device`
+	(:c:type:`vdev <video_device>`);
+
+This will remove the device nodes from sysfs (causing udev to remove them
+from ``/dev``).
+
+After :c:func:`video_unregister_device` returns no new opens can be done.
+However, in the case of USB devices some application might still have one of
+these device nodes open. So after the unregister all file operations (except
+release, of course) will return an error as well.
+
+When the last user of the video device node exits, then the ``vdev->release()``
+callback is called and you can do the final cleanup there.
+
+Don't forget to cleanup the media entity associated with the video device if
+it has been initialized:
+
+	:c:func:`media_entity_cleanup <media_entity_cleanup>`
+	(&vdev->entity);
+
+This can be done from the release callback.
+
+
+helper functions
+----------------
+
+There are a few useful helper functions:
+
+- file and :c:type:`video_device` private data
+
+You can set/get driver private data in the video_device struct using:
+
+	:c:func:`video_get_drvdata <video_get_drvdata>`
+	(:c:type:`vdev <video_device>`);
+
+	:c:func:`video_set_drvdata <video_set_drvdata>`
+	(:c:type:`vdev <video_device>`);
+
+Note that you can safely call :c:func:`video_set_drvdata` before calling
+:c:func:`video_register_device`.
+
+And this function:
+
+	:c:func:`video_devdata <video_devdata>`
+	(struct file \*file);
+
+returns the video_device belonging to the file struct.
+
+The :c:func:`video_devdata` function combines :c:func:`video_get_drvdata`
+with :c:func:`video_devdata`:
+
+	:c:func:`video_drvdata <video_drvdata>`
+	(struct file \*file);
+
+You can go from a :c:type:`video_device` struct to the v4l2_device struct using:
+
+.. code-block:: c
+
+	struct v4l2_device *v4l2_dev = vdev->v4l2_dev;
+
+- Device node name
+
+The :c:type:`video_device` node kernel name can be retrieved using:
+
+	:c:func:`video_device_node_name <video_device_node_name>`
+	(:c:type:`vdev <video_device>`);
+
+The name is used as a hint by userspace tools such as udev. The function
+should be used where possible instead of accessing the video_device::num and
+video_device::minor fields.
+
+video_device functions and data structures
+------------------------------------------
+
+.. kernel-doc:: include/media/v4l2-dev.h
diff --git a/Documentation/driver-api/media/v4l2-device.rst b/Documentation/driver-api/media/v4l2-device.rst
new file mode 100644
index 000000000..7bd9c45f5
--- /dev/null
+++ b/Documentation/driver-api/media/v4l2-device.rst
@@ -0,0 +1,146 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+V4L2 device instance
+--------------------
+
+Each device instance is represented by a struct v4l2_device.
+Very simple devices can just allocate this struct, but most of the time you
+would embed this struct inside a larger struct.
+
+You must register the device instance by calling:
+
+	:c:func:`v4l2_device_register <v4l2_device_register>`
+	(dev, :c:type:`v4l2_dev <v4l2_device>`).
+
+Registration will initialize the :c:type:`v4l2_device` struct. If the
+dev->driver_data field is ``NULL``, it will be linked to
+:c:type:`v4l2_dev <v4l2_device>` argument.
+
+Drivers that want integration with the media device framework need to set
+dev->driver_data manually to point to the driver-specific device structure
+that embed the struct v4l2_device instance. This is achieved by a
+``dev_set_drvdata()`` call before registering the V4L2 device instance.
+They must also set the struct v4l2_device mdev field to point to a
+properly initialized and registered :c:type:`media_device` instance.
+
+If :c:type:`v4l2_dev <v4l2_device>`\ ->name is empty then it will be set to a
+value derived from dev (driver name followed by the bus_id, to be precise).
+If you set it up before  calling :c:func:`v4l2_device_register` then it will
+be untouched. If dev is ``NULL``, then you **must** setup
+:c:type:`v4l2_dev <v4l2_device>`\ ->name before calling
+:c:func:`v4l2_device_register`.
+
+You can use :c:func:`v4l2_device_set_name` to set the name based on a driver
+name and a driver-global atomic_t instance. This will generate names like
+``ivtv0``, ``ivtv1``, etc. If the name ends with a digit, then it will insert
+a dash: ``cx18-0``, ``cx18-1``, etc. This function returns the instance number.
+
+The first ``dev`` argument is normally the ``struct device`` pointer of a
+``pci_dev``, ``usb_interface`` or ``platform_device``. It is rare for dev to
+be ``NULL``, but it happens with ISA devices or when one device creates
+multiple PCI devices, thus making it impossible to associate
+:c:type:`v4l2_dev <v4l2_device>` with a particular parent.
+
+You can also supply a ``notify()`` callback that can be called by sub-devices
+to notify you of events. Whether you need to set this depends on the
+sub-device. Any notifications a sub-device supports must be defined in a header
+in ``include/media/subdevice.h``.
+
+V4L2 devices are unregistered by calling:
+
+	:c:func:`v4l2_device_unregister`
+	(:c:type:`v4l2_dev <v4l2_device>`).
+
+If the dev->driver_data field points to :c:type:`v4l2_dev <v4l2_device>`,
+it will be reset to ``NULL``. Unregistering will also automatically unregister
+all subdevs from the device.
+
+If you have a hotpluggable device (e.g. a USB device), then when a disconnect
+happens the parent device becomes invalid. Since :c:type:`v4l2_device` has a
+pointer to that parent device it has to be cleared as well to mark that the
+parent is gone. To do this call:
+
+	:c:func:`v4l2_device_disconnect`
+	(:c:type:`v4l2_dev <v4l2_device>`).
+
+This does *not* unregister the subdevs, so you still need to call the
+:c:func:`v4l2_device_unregister` function for that. If your driver is not
+hotpluggable, then there is no need to call :c:func:`v4l2_device_disconnect`.
+
+Sometimes you need to iterate over all devices registered by a specific
+driver. This is usually the case if multiple device drivers use the same
+hardware. E.g. the ivtvfb driver is a framebuffer driver that uses the ivtv
+hardware. The same is true for alsa drivers for example.
+
+You can iterate over all registered devices as follows:
+
+.. code-block:: c
+
+	static int callback(struct device *dev, void *p)
+	{
+		struct v4l2_device *v4l2_dev = dev_get_drvdata(dev);
+
+		/* test if this device was inited */
+		if (v4l2_dev == NULL)
+			return 0;
+		...
+		return 0;
+	}
+
+	int iterate(void *p)
+	{
+		struct device_driver *drv;
+		int err;
+
+		/* Find driver 'ivtv' on the PCI bus.
+		pci_bus_type is a global. For USB buses use usb_bus_type. */
+		drv = driver_find("ivtv", &pci_bus_type);
+		/* iterate over all ivtv device instances */
+		err = driver_for_each_device(drv, NULL, p, callback);
+		put_driver(drv);
+		return err;
+	}
+
+Sometimes you need to keep a running counter of the device instance. This is
+commonly used to map a device instance to an index of a module option array.
+
+The recommended approach is as follows:
+
+.. code-block:: c
+
+	static atomic_t drv_instance = ATOMIC_INIT(0);
+
+	static int drv_probe(struct pci_dev *pdev, const struct pci_device_id *pci_id)
+	{
+		...
+		state->instance = atomic_inc_return(&drv_instance) - 1;
+	}
+
+If you have multiple device nodes then it can be difficult to know when it is
+safe to unregister :c:type:`v4l2_device` for hotpluggable devices. For this
+purpose :c:type:`v4l2_device` has refcounting support. The refcount is
+increased whenever :c:func:`video_register_device` is called and it is
+decreased whenever that device node is released. When the refcount reaches
+zero, then the :c:type:`v4l2_device` release() callback is called. You can
+do your final cleanup there.
+
+If other device nodes (e.g. ALSA) are created, then you can increase and
+decrease the refcount manually as well by calling:
+
+	:c:func:`v4l2_device_get`
+	(:c:type:`v4l2_dev <v4l2_device>`).
+
+or:
+
+	:c:func:`v4l2_device_put`
+	(:c:type:`v4l2_dev <v4l2_device>`).
+
+Since the initial refcount is 1 you also need to call
+:c:func:`v4l2_device_put` in the ``disconnect()`` callback (for USB devices)
+or in the ``remove()`` callback (for e.g. PCI devices), otherwise the refcount
+will never reach 0.
+
+v4l2_device functions and data structures
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+.. kernel-doc:: include/media/v4l2-device.h
diff --git a/Documentation/driver-api/media/v4l2-dv-timings.rst b/Documentation/driver-api/media/v4l2-dv-timings.rst
new file mode 100644
index 000000000..b178f9315
--- /dev/null
+++ b/Documentation/driver-api/media/v4l2-dv-timings.rst
@@ -0,0 +1,6 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+V4L2 DV Timings functions
+^^^^^^^^^^^^^^^^^^^^^^^^^
+
+.. kernel-doc:: include/media/v4l2-dv-timings.h
diff --git a/Documentation/driver-api/media/v4l2-event.rst b/Documentation/driver-api/media/v4l2-event.rst
new file mode 100644
index 000000000..5b8254eba
--- /dev/null
+++ b/Documentation/driver-api/media/v4l2-event.rst
@@ -0,0 +1,181 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+V4L2 events
+-----------
+
+The V4L2 events provide a generic way to pass events to user space.
+The driver must use :c:type:`v4l2_fh` to be able to support V4L2 events.
+
+Events are subscribed per-filehandle. An event specification consists of a
+``type`` and is optionally associated with an object identified through the
+``id`` field. If unused, then the ``id`` is 0. So an event is uniquely
+identified by the ``(type, id)`` tuple.
+
+The :c:type:`v4l2_fh` struct has a list of subscribed events on its
+``subscribed`` field.
+
+When the user subscribes to an event, a :c:type:`v4l2_subscribed_event`
+struct is added to :c:type:`v4l2_fh`\ ``.subscribed``, one for every
+subscribed event.
+
+Each :c:type:`v4l2_subscribed_event` struct ends with a
+:c:type:`v4l2_kevent` ringbuffer, with the size given by the caller
+of :c:func:`v4l2_event_subscribe`. This ringbuffer is used to store any events
+raised by the driver.
+
+So every ``(type, ID)`` event tuple will have its own
+:c:type:`v4l2_kevent` ringbuffer. This guarantees that if a driver is
+generating lots of events of one type in a short time, then that will
+not overwrite events of another type.
+
+But if you get more events of one type than the size of the
+:c:type:`v4l2_kevent` ringbuffer, then the oldest event will be dropped
+and the new one added.
+
+The :c:type:`v4l2_kevent` struct links into the ``available``
+list of the :c:type:`v4l2_fh` struct so :ref:`VIDIOC_DQEVENT` will
+know which event to dequeue first.
+
+Finally, if the event subscription is associated with a particular object
+such as a V4L2 control, then that object needs to know about that as well
+so that an event can be raised by that object. So the ``node`` field can
+be used to link the :c:type:`v4l2_subscribed_event` struct into a list of
+such objects.
+
+So to summarize:
+
+- struct v4l2_fh has two lists: one of the ``subscribed`` events,
+  and one of the ``available`` events.
+
+- struct v4l2_subscribed_event has a ringbuffer of raised
+  (pending) events of that particular type.
+
+- If struct v4l2_subscribed_event is associated with a specific
+  object, then that object will have an internal list of
+  struct v4l2_subscribed_event so it knows who subscribed an
+  event to that object.
+
+Furthermore, the internal struct v4l2_subscribed_event has
+``merge()`` and ``replace()`` callbacks which drivers can set. These
+callbacks are called when a new event is raised and there is no more room.
+
+The ``replace()`` callback allows you to replace the payload of the old event
+with that of the new event, merging any relevant data from the old payload
+into the new payload that replaces it. It is called when this event type has
+a ringbuffer with size is one, i.e. only one event can be stored in the
+ringbuffer.
+
+The ``merge()`` callback allows you to merge the oldest event payload into
+that of the second-oldest event payload. It is called when
+the ringbuffer has size is greater than one.
+
+This way no status information is lost, just the intermediate steps leading
+up to that state.
+
+A good example of these ``replace``/``merge`` callbacks is in v4l2-event.c:
+``ctrls_replace()`` and ``ctrls_merge()`` callbacks for the control event.
+
+.. note::
+	these callbacks can be called from interrupt context, so they must
+	be fast.
+
+In order to queue events to video device, drivers should call:
+
+	:c:func:`v4l2_event_queue <v4l2_event_queue>`
+	(:c:type:`vdev <video_device>`, :c:type:`ev <v4l2_event>`)
+
+The driver's only responsibility is to fill in the type and the data fields.
+The other fields will be filled in by V4L2.
+
+Event subscription
+~~~~~~~~~~~~~~~~~~
+
+Subscribing to an event is via:
+
+	:c:func:`v4l2_event_subscribe <v4l2_event_subscribe>`
+	(:c:type:`fh <v4l2_fh>`, :c:type:`sub <v4l2_event_subscription>` ,
+	elems, :c:type:`ops <v4l2_subscribed_event_ops>`)
+
+
+This function is used to implement :c:type:`video_device`->
+:c:type:`ioctl_ops <v4l2_ioctl_ops>`-> ``vidioc_subscribe_event``,
+but the driver must check first if the driver is able to produce events
+with specified event id, and then should call
+:c:func:`v4l2_event_subscribe` to subscribe the event.
+
+The elems argument is the size of the event queue for this event. If it is 0,
+then the framework will fill in a default value (this depends on the event
+type).
+
+The ops argument allows the driver to specify a number of callbacks:
+
+.. tabularcolumns:: |p{1.5cm}|p{16.0cm}|
+
+======== ==============================================================
+Callback Description
+======== ==============================================================
+add      called when a new listener gets added (subscribing to the same
+	 event twice will only cause this callback to get called once)
+del      called when a listener stops listening
+replace  replace event 'old' with event 'new'.
+merge    merge event 'old' into event 'new'.
+======== ==============================================================
+
+All 4 callbacks are optional, if you don't want to specify any callbacks
+the ops argument itself maybe ``NULL``.
+
+Unsubscribing an event
+~~~~~~~~~~~~~~~~~~~~~~
+
+Unsubscribing to an event is via:
+
+	:c:func:`v4l2_event_unsubscribe <v4l2_event_unsubscribe>`
+	(:c:type:`fh <v4l2_fh>`, :c:type:`sub <v4l2_event_subscription>`)
+
+This function is used to implement :c:type:`video_device`->
+:c:type:`ioctl_ops <v4l2_ioctl_ops>`-> ``vidioc_unsubscribe_event``.
+A driver may call :c:func:`v4l2_event_unsubscribe` directly unless it
+wants to be involved in unsubscription process.
+
+The special type ``V4L2_EVENT_ALL`` may be used to unsubscribe all events. The
+drivers may want to handle this in a special way.
+
+Check if there's a pending event
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Checking if there's a pending event is via:
+
+	:c:func:`v4l2_event_pending <v4l2_event_pending>`
+	(:c:type:`fh <v4l2_fh>`)
+
+
+This function returns the number of pending events. Useful when implementing
+poll.
+
+How events work
+~~~~~~~~~~~~~~~
+
+Events are delivered to user space through the poll system call. The driver
+can use :c:type:`v4l2_fh`->wait (a wait_queue_head_t) as the argument for
+``poll_wait()``.
+
+There are standard and private events. New standard events must use the
+smallest available event type. The drivers must allocate their events from
+their own class starting from class base. Class base is
+``V4L2_EVENT_PRIVATE_START`` + n * 1000 where n is the lowest available number.
+The first event type in the class is reserved for future use, so the first
+available event type is 'class base + 1'.
+
+An example on how the V4L2 events may be used can be found in the OMAP
+3 ISP driver (``drivers/media/platform/omap3isp``).
+
+A subdev can directly send an event to the :c:type:`v4l2_device` notify
+function with ``V4L2_DEVICE_NOTIFY_EVENT``. This allows the bridge to map
+the subdev that sends the event to the video node(s) associated with the
+subdev that need to be informed about such an event.
+
+V4L2 event functions and data structures
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+.. kernel-doc:: include/media/v4l2-event.h
+
diff --git a/Documentation/driver-api/media/v4l2-fh.rst b/Documentation/driver-api/media/v4l2-fh.rst
new file mode 100644
index 000000000..3eeaa8da0
--- /dev/null
+++ b/Documentation/driver-api/media/v4l2-fh.rst
@@ -0,0 +1,141 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+V4L2 File handlers
+------------------
+
+struct v4l2_fh provides a way to easily keep file handle specific
+data that is used by the V4L2 framework.
+
+.. attention::
+	New drivers must use struct v4l2_fh
+	since it is also used to implement priority handling
+	(:ref:`VIDIOC_G_PRIORITY`).
+
+The users of :c:type:`v4l2_fh` (in the V4L2 framework, not the driver) know
+whether a driver uses :c:type:`v4l2_fh` as its ``file->private_data`` pointer
+by testing the ``V4L2_FL_USES_V4L2_FH`` bit in :c:type:`video_device`->flags.
+This bit is set whenever :c:func:`v4l2_fh_init` is called.
+
+struct v4l2_fh is allocated as a part of the driver's own file handle
+structure and ``file->private_data`` is set to it in the driver's ``open()``
+function by the driver.
+
+In many cases the struct v4l2_fh will be embedded in a larger
+structure. In that case you should call:
+
+#) :c:func:`v4l2_fh_init` and :c:func:`v4l2_fh_add` in ``open()``
+#) :c:func:`v4l2_fh_del` and :c:func:`v4l2_fh_exit` in ``release()``
+
+Drivers can extract their own file handle structure by using the container_of
+macro.
+
+Example:
+
+.. code-block:: c
+
+	struct my_fh {
+		int blah;
+		struct v4l2_fh fh;
+	};
+
+	...
+
+	int my_open(struct file *file)
+	{
+		struct my_fh *my_fh;
+		struct video_device *vfd;
+		int ret;
+
+		...
+
+		my_fh = kzalloc(sizeof(*my_fh), GFP_KERNEL);
+
+		...
+
+		v4l2_fh_init(&my_fh->fh, vfd);
+
+		...
+
+		file->private_data = &my_fh->fh;
+		v4l2_fh_add(&my_fh->fh);
+		return 0;
+	}
+
+	int my_release(struct file *file)
+	{
+		struct v4l2_fh *fh = file->private_data;
+		struct my_fh *my_fh = container_of(fh, struct my_fh, fh);
+
+		...
+		v4l2_fh_del(&my_fh->fh);
+		v4l2_fh_exit(&my_fh->fh);
+		kfree(my_fh);
+		return 0;
+	}
+
+Below is a short description of the :c:type:`v4l2_fh` functions used:
+
+:c:func:`v4l2_fh_init <v4l2_fh_init>`
+(:c:type:`fh <v4l2_fh>`, :c:type:`vdev <video_device>`)
+
+
+- Initialise the file handle. This **MUST** be performed in the driver's
+  :c:type:`v4l2_file_operations`->open() handler.
+
+
+:c:func:`v4l2_fh_add <v4l2_fh_add>`
+(:c:type:`fh <v4l2_fh>`)
+
+- Add a :c:type:`v4l2_fh` to :c:type:`video_device` file handle list.
+  Must be called once the file handle is completely initialized.
+
+:c:func:`v4l2_fh_del <v4l2_fh_del>`
+(:c:type:`fh <v4l2_fh>`)
+
+- Unassociate the file handle from :c:type:`video_device`. The file handle
+  exit function may now be called.
+
+:c:func:`v4l2_fh_exit <v4l2_fh_exit>`
+(:c:type:`fh <v4l2_fh>`)
+
+- Uninitialise the file handle. After uninitialisation the :c:type:`v4l2_fh`
+  memory can be freed.
+
+
+If struct v4l2_fh is not embedded, then you can use these helper functions:
+
+:c:func:`v4l2_fh_open <v4l2_fh_open>`
+(struct file \*filp)
+
+- This allocates a struct v4l2_fh, initializes it and adds it to
+  the struct video_device associated with the file struct.
+
+:c:func:`v4l2_fh_release <v4l2_fh_release>`
+(struct file \*filp)
+
+- This deletes it from the struct video_device associated with the
+  file struct, uninitialised the :c:type:`v4l2_fh` and frees it.
+
+These two functions can be plugged into the v4l2_file_operation's ``open()``
+and ``release()`` ops.
+
+Several drivers need to do something when the first file handle is opened and
+when the last file handle closes. Two helper functions were added to check
+whether the :c:type:`v4l2_fh` struct is the only open filehandle of the
+associated device node:
+
+:c:func:`v4l2_fh_is_singular <v4l2_fh_is_singular>`
+(:c:type:`fh <v4l2_fh>`)
+
+-  Returns 1 if the file handle is the only open file handle, else 0.
+
+:c:func:`v4l2_fh_is_singular_file <v4l2_fh_is_singular_file>`
+(struct file \*filp)
+
+- Same, but it calls v4l2_fh_is_singular with filp->private_data.
+
+
+V4L2 fh functions and data structures
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+.. kernel-doc:: include/media/v4l2-fh.h
diff --git a/Documentation/driver-api/media/v4l2-flash-led-class.rst b/Documentation/driver-api/media/v4l2-flash-led-class.rst
new file mode 100644
index 000000000..2aa6bed9b
--- /dev/null
+++ b/Documentation/driver-api/media/v4l2-flash-led-class.rst
@@ -0,0 +1,6 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+V4L2 flash functions and data structures
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+.. kernel-doc:: include/media/v4l2-flash-led-class.h
diff --git a/Documentation/driver-api/media/v4l2-fwnode.rst b/Documentation/driver-api/media/v4l2-fwnode.rst
new file mode 100644
index 000000000..e313b6cdd
--- /dev/null
+++ b/Documentation/driver-api/media/v4l2-fwnode.rst
@@ -0,0 +1,5 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+V4L2 fwnode kAPI
+^^^^^^^^^^^^^^^^
+.. kernel-doc:: include/media/v4l2-fwnode.h
diff --git a/Documentation/driver-api/media/v4l2-intro.rst b/Documentation/driver-api/media/v4l2-intro.rst
new file mode 100644
index 000000000..4d54fa9d7
--- /dev/null
+++ b/Documentation/driver-api/media/v4l2-intro.rst
@@ -0,0 +1,76 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+Introduction
+------------
+
+The V4L2 drivers tend to be very complex due to the complexity of the
+hardware: most devices have multiple ICs, export multiple device nodes in
+/dev, and create also non-V4L2 devices such as DVB, ALSA, FB, I2C and input
+(IR) devices.
+
+Especially the fact that V4L2 drivers have to setup supporting ICs to
+do audio/video muxing/encoding/decoding makes it more complex than most.
+Usually these ICs are connected to the main bridge driver through one or
+more I2C buses, but other buses can also be used. Such devices are
+called 'sub-devices'.
+
+For a long time the framework was limited to the video_device struct for
+creating V4L device nodes and video_buf for handling the video buffers
+(note that this document does not discuss the video_buf framework).
+
+This meant that all drivers had to do the setup of device instances and
+connecting to sub-devices themselves. Some of this is quite complicated
+to do right and many drivers never did do it correctly.
+
+There is also a lot of common code that could never be refactored due to
+the lack of a framework.
+
+So this framework sets up the basic building blocks that all drivers
+need and this same framework should make it much easier to refactor
+common code into utility functions shared by all drivers.
+
+A good example to look at as a reference is the v4l2-pci-skeleton.c
+source that is available in samples/v4l/. It is a skeleton driver for
+a PCI capture card, and demonstrates how to use the V4L2 driver
+framework. It can be used as a template for real PCI video capture driver.
+
+Structure of a V4L driver
+-------------------------
+
+All drivers have the following structure:
+
+1) A struct for each device instance containing the device state.
+
+2) A way of initializing and commanding sub-devices (if any).
+
+3) Creating V4L2 device nodes (/dev/videoX, /dev/vbiX and /dev/radioX)
+   and keeping track of device-node specific data.
+
+4) Filehandle-specific structs containing per-filehandle data;
+
+5) video buffer handling.
+
+This is a rough schematic of how it all relates:
+
+.. code-block:: none
+
+    device instances
+      |
+      +-sub-device instances
+      |
+      \-V4L2 device nodes
+	  |
+	  \-filehandle instances
+
+
+Structure of the V4L2 framework
+-------------------------------
+
+The framework closely resembles the driver structure: it has a v4l2_device
+struct for the device instance data, a v4l2_subdev struct to refer to
+sub-device instances, the video_device struct stores V4L2 device node data
+and the v4l2_fh struct keeps track of filehandle instances.
+
+The V4L2 framework also optionally integrates with the media framework. If a
+driver sets the struct v4l2_device mdev field, sub-devices and video nodes
+will automatically appear in the media framework as entities.
diff --git a/Documentation/driver-api/media/v4l2-mc.rst b/Documentation/driver-api/media/v4l2-mc.rst
new file mode 100644
index 000000000..0c352ac58
--- /dev/null
+++ b/Documentation/driver-api/media/v4l2-mc.rst
@@ -0,0 +1,6 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+V4L2 Media Controller functions and data structures
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+.. kernel-doc:: include/media/v4l2-mc.h
diff --git a/Documentation/driver-api/media/v4l2-mediabus.rst b/Documentation/driver-api/media/v4l2-mediabus.rst
new file mode 100644
index 000000000..1f2254cba
--- /dev/null
+++ b/Documentation/driver-api/media/v4l2-mediabus.rst
@@ -0,0 +1,6 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+V4L2 Media Bus functions and data structures
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+.. kernel-doc:: include/media/v4l2-mediabus.h
diff --git a/Documentation/driver-api/media/v4l2-mem2mem.rst b/Documentation/driver-api/media/v4l2-mem2mem.rst
new file mode 100644
index 000000000..a43b31cc8
--- /dev/null
+++ b/Documentation/driver-api/media/v4l2-mem2mem.rst
@@ -0,0 +1,6 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+V4L2 Memory to Memory functions and data structures
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+.. kernel-doc:: include/media/v4l2-mem2mem.h
diff --git a/Documentation/driver-api/media/v4l2-rect.rst b/Documentation/driver-api/media/v4l2-rect.rst
new file mode 100644
index 000000000..fc315cd84
--- /dev/null
+++ b/Documentation/driver-api/media/v4l2-rect.rst
@@ -0,0 +1,6 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+V4L2 rect helper functions
+^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+.. kernel-doc:: include/media/v4l2-rect.h
diff --git a/Documentation/driver-api/media/v4l2-subdev.rst b/Documentation/driver-api/media/v4l2-subdev.rst
new file mode 100644
index 000000000..bb5b1a7cd
--- /dev/null
+++ b/Documentation/driver-api/media/v4l2-subdev.rst
@@ -0,0 +1,497 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+V4L2 sub-devices
+----------------
+
+Many drivers need to communicate with sub-devices. These devices can do all
+sort of tasks, but most commonly they handle audio and/or video muxing,
+encoding or decoding. For webcams common sub-devices are sensors and camera
+controllers.
+
+Usually these are I2C devices, but not necessarily. In order to provide the
+driver with a consistent interface to these sub-devices the
+:c:type:`v4l2_subdev` struct (v4l2-subdev.h) was created.
+
+Each sub-device driver must have a :c:type:`v4l2_subdev` struct. This struct
+can be stand-alone for simple sub-devices or it might be embedded in a larger
+struct if more state information needs to be stored. Usually there is a
+low-level device struct (e.g. ``i2c_client``) that contains the device data as
+setup by the kernel. It is recommended to store that pointer in the private
+data of :c:type:`v4l2_subdev` using :c:func:`v4l2_set_subdevdata`. That makes
+it easy to go from a :c:type:`v4l2_subdev` to the actual low-level bus-specific
+device data.
+
+You also need a way to go from the low-level struct to :c:type:`v4l2_subdev`.
+For the common i2c_client struct the i2c_set_clientdata() call is used to store
+a :c:type:`v4l2_subdev` pointer, for other buses you may have to use other
+methods.
+
+Bridges might also need to store per-subdev private data, such as a pointer to
+bridge-specific per-subdev private data. The :c:type:`v4l2_subdev` structure
+provides host private data for that purpose that can be accessed with
+:c:func:`v4l2_get_subdev_hostdata` and :c:func:`v4l2_set_subdev_hostdata`.
+
+From the bridge driver perspective, you load the sub-device module and somehow
+obtain the :c:type:`v4l2_subdev` pointer. For i2c devices this is easy: you call
+``i2c_get_clientdata()``. For other buses something similar needs to be done.
+Helper functions exist for sub-devices on an I2C bus that do most of this
+tricky work for you.
+
+Each :c:type:`v4l2_subdev` contains function pointers that sub-device drivers
+can implement (or leave ``NULL`` if it is not applicable). Since sub-devices can
+do so many different things and you do not want to end up with a huge ops struct
+of which only a handful of ops are commonly implemented, the function pointers
+are sorted according to category and each category has its own ops struct.
+
+The top-level ops struct contains pointers to the category ops structs, which
+may be NULL if the subdev driver does not support anything from that category.
+
+It looks like this:
+
+.. code-block:: c
+
+	struct v4l2_subdev_core_ops {
+		int (*log_status)(struct v4l2_subdev *sd);
+		int (*init)(struct v4l2_subdev *sd, u32 val);
+		...
+	};
+
+	struct v4l2_subdev_tuner_ops {
+		...
+	};
+
+	struct v4l2_subdev_audio_ops {
+		...
+	};
+
+	struct v4l2_subdev_video_ops {
+		...
+	};
+
+	struct v4l2_subdev_pad_ops {
+		...
+	};
+
+	struct v4l2_subdev_ops {
+		const struct v4l2_subdev_core_ops  *core;
+		const struct v4l2_subdev_tuner_ops *tuner;
+		const struct v4l2_subdev_audio_ops *audio;
+		const struct v4l2_subdev_video_ops *video;
+		const struct v4l2_subdev_pad_ops *video;
+	};
+
+The core ops are common to all subdevs, the other categories are implemented
+depending on the sub-device. E.g. a video device is unlikely to support the
+audio ops and vice versa.
+
+This setup limits the number of function pointers while still making it easy
+to add new ops and categories.
+
+A sub-device driver initializes the :c:type:`v4l2_subdev` struct using:
+
+	:c:func:`v4l2_subdev_init <v4l2_subdev_init>`
+	(:c:type:`sd <v4l2_subdev>`, &\ :c:type:`ops <v4l2_subdev_ops>`).
+
+
+Afterwards you need to initialize :c:type:`sd <v4l2_subdev>`->name with a
+unique name and set the module owner. This is done for you if you use the
+i2c helper functions.
+
+If integration with the media framework is needed, you must initialize the
+:c:type:`media_entity` struct embedded in the :c:type:`v4l2_subdev` struct
+(entity field) by calling :c:func:`media_entity_pads_init`, if the entity has
+pads:
+
+.. code-block:: c
+
+	struct media_pad *pads = &my_sd->pads;
+	int err;
+
+	err = media_entity_pads_init(&sd->entity, npads, pads);
+
+The pads array must have been previously initialized. There is no need to
+manually set the struct media_entity function and name fields, but the
+revision field must be initialized if needed.
+
+A reference to the entity will be automatically acquired/released when the
+subdev device node (if any) is opened/closed.
+
+Don't forget to cleanup the media entity before the sub-device is destroyed:
+
+.. code-block:: c
+
+	media_entity_cleanup(&sd->entity);
+
+If the subdev driver intends to process video and integrate with the media
+framework, it must implement format related functionality using
+:c:type:`v4l2_subdev_pad_ops` instead of :c:type:`v4l2_subdev_video_ops`.
+
+In that case, the subdev driver may set the link_validate field to provide
+its own link validation function. The link validation function is called for
+every link in the pipeline where both of the ends of the links are V4L2
+sub-devices. The driver is still responsible for validating the correctness
+of the format configuration between sub-devices and video nodes.
+
+If link_validate op is not set, the default function
+:c:func:`v4l2_subdev_link_validate_default` is used instead. This function
+ensures that width, height and the media bus pixel code are equal on both source
+and sink of the link. Subdev drivers are also free to use this function to
+perform the checks mentioned above in addition to their own checks.
+
+Subdev registration
+~~~~~~~~~~~~~~~~~~~
+
+There are currently two ways to register subdevices with the V4L2 core. The
+first (traditional) possibility is to have subdevices registered by bridge
+drivers. This can be done when the bridge driver has the complete information
+about subdevices connected to it and knows exactly when to register them. This
+is typically the case for internal subdevices, like video data processing units
+within SoCs or complex PCI(e) boards, camera sensors in USB cameras or connected
+to SoCs, which pass information about them to bridge drivers, usually in their
+platform data.
+
+There are however also situations where subdevices have to be registered
+asynchronously to bridge devices. An example of such a configuration is a Device
+Tree based system where information about subdevices is made available to the
+system independently from the bridge devices, e.g. when subdevices are defined
+in DT as I2C device nodes. The API used in this second case is described further
+below.
+
+Using one or the other registration method only affects the probing process, the
+run-time bridge-subdevice interaction is in both cases the same.
+
+In the **synchronous** case a device (bridge) driver needs to register the
+:c:type:`v4l2_subdev` with the v4l2_device:
+
+	:c:func:`v4l2_device_register_subdev <v4l2_device_register_subdev>`
+	(:c:type:`v4l2_dev <v4l2_device>`, :c:type:`sd <v4l2_subdev>`).
+
+This can fail if the subdev module disappeared before it could be registered.
+After this function was called successfully the subdev->dev field points to
+the :c:type:`v4l2_device`.
+
+If the v4l2_device parent device has a non-NULL mdev field, the sub-device
+entity will be automatically registered with the media device.
+
+You can unregister a sub-device using:
+
+	:c:func:`v4l2_device_unregister_subdev <v4l2_device_unregister_subdev>`
+	(:c:type:`sd <v4l2_subdev>`).
+
+
+Afterwards the subdev module can be unloaded and
+:c:type:`sd <v4l2_subdev>`->dev == ``NULL``.
+
+In the **asynchronous** case subdevice probing can be invoked independently of
+the bridge driver availability. The subdevice driver then has to verify whether
+all the requirements for a successful probing are satisfied. This can include a
+check for a master clock availability. If any of the conditions aren't satisfied
+the driver might decide to return ``-EPROBE_DEFER`` to request further reprobing
+attempts. Once all conditions are met the subdevice shall be registered using
+the :c:func:`v4l2_async_register_subdev` function. Unregistration is
+performed using the :c:func:`v4l2_async_unregister_subdev` call. Subdevices
+registered this way are stored in a global list of subdevices, ready to be
+picked up by bridge drivers.
+
+Bridge drivers in turn have to register a notifier object. This is
+performed using the :c:func:`v4l2_async_notifier_register` call. To
+unregister the notifier the driver has to call
+:c:func:`v4l2_async_notifier_unregister`. The former of the two functions
+takes two arguments: a pointer to struct :c:type:`v4l2_device` and a
+pointer to struct :c:type:`v4l2_async_notifier`.
+
+Before registering the notifier, bridge drivers must do two things:
+first, the notifier must be initialized using the
+:c:func:`v4l2_async_notifier_init`. Second, bridge drivers can then
+begin to form a list of subdevice descriptors that the bridge device
+needs for its operation. Subdevice descriptors are added to the notifier
+using the :c:func:`v4l2_async_notifier_add_subdev` call. This function
+takes two arguments: a pointer to struct :c:type:`v4l2_async_notifier`,
+and a pointer to the subdevice descripter, which is of type struct
+:c:type:`v4l2_async_subdev`.
+
+The V4L2 core will then use these descriptors to match asynchronously
+registered subdevices to them. If a match is detected the ``.bound()``
+notifier callback is called. After all subdevices have been located the
+.complete() callback is called. When a subdevice is removed from the
+system the .unbind() method is called. All three callbacks are optional.
+
+Calling subdev operations
+~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The advantage of using :c:type:`v4l2_subdev` is that it is a generic struct and
+does not contain any knowledge about the underlying hardware. So a driver might
+contain several subdevs that use an I2C bus, but also a subdev that is
+controlled through GPIO pins. This distinction is only relevant when setting
+up the device, but once the subdev is registered it is completely transparent.
+
+Once te subdev has been registered you can call an ops function either
+directly:
+
+.. code-block:: c
+
+	err = sd->ops->core->g_std(sd, &norm);
+
+but it is better and easier to use this macro:
+
+.. code-block:: c
+
+	err = v4l2_subdev_call(sd, core, g_std, &norm);
+
+The macro will do the right ``NULL`` pointer checks and returns ``-ENODEV``
+if :c:type:`sd <v4l2_subdev>` is ``NULL``, ``-ENOIOCTLCMD`` if either
+:c:type:`sd <v4l2_subdev>`->core or :c:type:`sd <v4l2_subdev>`->core->g_std is ``NULL``, or the actual result of the
+:c:type:`sd <v4l2_subdev>`->ops->core->g_std ops.
+
+It is also possible to call all or a subset of the sub-devices:
+
+.. code-block:: c
+
+	v4l2_device_call_all(v4l2_dev, 0, core, g_std, &norm);
+
+Any subdev that does not support this ops is skipped and error results are
+ignored. If you want to check for errors use this:
+
+.. code-block:: c
+
+	err = v4l2_device_call_until_err(v4l2_dev, 0, core, g_std, &norm);
+
+Any error except ``-ENOIOCTLCMD`` will exit the loop with that error. If no
+errors (except ``-ENOIOCTLCMD``) occurred, then 0 is returned.
+
+The second argument to both calls is a group ID. If 0, then all subdevs are
+called. If non-zero, then only those whose group ID match that value will
+be called. Before a bridge driver registers a subdev it can set
+:c:type:`sd <v4l2_subdev>`->grp_id to whatever value it wants (it's 0 by
+default). This value is owned by the bridge driver and the sub-device driver
+will never modify or use it.
+
+The group ID gives the bridge driver more control how callbacks are called.
+For example, there may be multiple audio chips on a board, each capable of
+changing the volume. But usually only one will actually be used when the
+user want to change the volume. You can set the group ID for that subdev to
+e.g. AUDIO_CONTROLLER and specify that as the group ID value when calling
+``v4l2_device_call_all()``. That ensures that it will only go to the subdev
+that needs it.
+
+If the sub-device needs to notify its v4l2_device parent of an event, then
+it can call ``v4l2_subdev_notify(sd, notification, arg)``. This macro checks
+whether there is a ``notify()`` callback defined and returns ``-ENODEV`` if not.
+Otherwise the result of the ``notify()`` call is returned.
+
+V4L2 sub-device userspace API
+-----------------------------
+
+Bridge drivers traditionally expose one or multiple video nodes to userspace,
+and control subdevices through the :c:type:`v4l2_subdev_ops` operations in
+response to video node operations. This hides the complexity of the underlying
+hardware from applications. For complex devices, finer-grained control of the
+device than what the video nodes offer may be required. In those cases, bridge
+drivers that implement :ref:`the media controller API <media_controller>` may
+opt for making the subdevice operations directly accessible from userpace.
+
+Device nodes named ``v4l-subdev``\ *X* can be created in ``/dev`` to access
+sub-devices directly. If a sub-device supports direct userspace configuration
+it must set the ``V4L2_SUBDEV_FL_HAS_DEVNODE`` flag before being registered.
+
+After registering sub-devices, the :c:type:`v4l2_device` driver can create
+device nodes for all registered sub-devices marked with
+``V4L2_SUBDEV_FL_HAS_DEVNODE`` by calling
+:c:func:`v4l2_device_register_subdev_nodes`. Those device nodes will be
+automatically removed when sub-devices are unregistered.
+
+The device node handles a subset of the V4L2 API.
+
+``VIDIOC_QUERYCTRL``,
+``VIDIOC_QUERYMENU``,
+``VIDIOC_G_CTRL``,
+``VIDIOC_S_CTRL``,
+``VIDIOC_G_EXT_CTRLS``,
+``VIDIOC_S_EXT_CTRLS`` and
+``VIDIOC_TRY_EXT_CTRLS``:
+
+	The controls ioctls are identical to the ones defined in V4L2. They
+	behave identically, with the only exception that they deal only with
+	controls implemented in the sub-device. Depending on the driver, those
+	controls can be also be accessed through one (or several) V4L2 device
+	nodes.
+
+``VIDIOC_DQEVENT``,
+``VIDIOC_SUBSCRIBE_EVENT`` and
+``VIDIOC_UNSUBSCRIBE_EVENT``
+
+	The events ioctls are identical to the ones defined in V4L2. They
+	behave identically, with the only exception that they deal only with
+	events generated by the sub-device. Depending on the driver, those
+	events can also be reported by one (or several) V4L2 device nodes.
+
+	Sub-device drivers that want to use events need to set the
+	``V4L2_SUBDEV_FL_HAS_EVENTS`` :c:type:`v4l2_subdev`.flags before registering
+	the sub-device. After registration events can be queued as usual on the
+	:c:type:`v4l2_subdev`.devnode device node.
+
+	To properly support events, the ``poll()`` file operation is also
+	implemented.
+
+Private ioctls
+
+	All ioctls not in the above list are passed directly to the sub-device
+	driver through the core::ioctl operation.
+
+Read-only sub-device userspace API
+----------------------------------
+
+Bridge drivers that control their connected subdevices through direct calls to
+the kernel API realized by :c:type:`v4l2_subdev_ops` structure do not usually
+want userspace to be able to change the same parameters through the subdevice
+device node and thus do not usually register any.
+
+It is sometimes useful to report to userspace the current subdevice
+configuration through a read-only API, that does not permit applications to
+change to the device parameters but allows interfacing to the subdevice device
+node to inspect them.
+
+For instance, to implement cameras based on computational photography, userspace
+needs to know the detailed camera sensor configuration (in terms of skipping,
+binning, cropping and scaling) for each supported output resolution. To support
+such use cases, bridge drivers may expose the subdevice operations to userspace
+through a read-only API.
+
+To create a read-only device node for all the subdevices registered with the
+``V4L2_SUBDEV_FL_HAS_DEVNODE`` set, the :c:type:`v4l2_device` driver should call
+:c:func:`v4l2_device_register_ro_subdev_nodes`.
+
+Access to the following ioctls for userspace applications is restricted on
+sub-device device nodes registered with
+:c:func:`v4l2_device_register_ro_subdev_nodes`.
+
+``VIDIOC_SUBDEV_S_FMT``,
+``VIDIOC_SUBDEV_S_CROP``,
+``VIDIOC_SUBDEV_S_SELECTION``:
+
+	These ioctls are only allowed on a read-only subdevice device node
+	for the :ref:`V4L2_SUBDEV_FORMAT_TRY <v4l2-subdev-format-whence>`
+	formats and selection rectangles.
+
+``VIDIOC_SUBDEV_S_FRAME_INTERVAL``,
+``VIDIOC_SUBDEV_S_DV_TIMINGS``,
+``VIDIOC_SUBDEV_S_STD``:
+
+	These ioctls are not allowed on a read-only subdevice node.
+
+In case the ioctl is not allowed, or the format to modify is set to
+``V4L2_SUBDEV_FORMAT_ACTIVE``, the core returns a negative error code and
+the errno variable is set to ``-EPERM``.
+
+I2C sub-device drivers
+----------------------
+
+Since these drivers are so common, special helper functions are available to
+ease the use of these drivers (``v4l2-common.h``).
+
+The recommended method of adding :c:type:`v4l2_subdev` support to an I2C driver
+is to embed the :c:type:`v4l2_subdev` struct into the state struct that is
+created for each I2C device instance. Very simple devices have no state
+struct and in that case you can just create a :c:type:`v4l2_subdev` directly.
+
+A typical state struct would look like this (where 'chipname' is replaced by
+the name of the chip):
+
+.. code-block:: c
+
+	struct chipname_state {
+		struct v4l2_subdev sd;
+		...  /* additional state fields */
+	};
+
+Initialize the :c:type:`v4l2_subdev` struct as follows:
+
+.. code-block:: c
+
+	v4l2_i2c_subdev_init(&state->sd, client, subdev_ops);
+
+This function will fill in all the fields of :c:type:`v4l2_subdev` ensure that
+the :c:type:`v4l2_subdev` and i2c_client both point to one another.
+
+You should also add a helper inline function to go from a :c:type:`v4l2_subdev`
+pointer to a chipname_state struct:
+
+.. code-block:: c
+
+	static inline struct chipname_state *to_state(struct v4l2_subdev *sd)
+	{
+		return container_of(sd, struct chipname_state, sd);
+	}
+
+Use this to go from the :c:type:`v4l2_subdev` struct to the ``i2c_client``
+struct:
+
+.. code-block:: c
+
+	struct i2c_client *client = v4l2_get_subdevdata(sd);
+
+And this to go from an ``i2c_client`` to a :c:type:`v4l2_subdev` struct:
+
+.. code-block:: c
+
+	struct v4l2_subdev *sd = i2c_get_clientdata(client);
+
+Make sure to call
+:c:func:`v4l2_device_unregister_subdev`\ (:c:type:`sd <v4l2_subdev>`)
+when the ``remove()`` callback is called. This will unregister the sub-device
+from the bridge driver. It is safe to call this even if the sub-device was
+never registered.
+
+You need to do this because when the bridge driver destroys the i2c adapter
+the ``remove()`` callbacks are called of the i2c devices on that adapter.
+After that the corresponding v4l2_subdev structures are invalid, so they
+have to be unregistered first. Calling
+:c:func:`v4l2_device_unregister_subdev`\ (:c:type:`sd <v4l2_subdev>`)
+from the ``remove()`` callback ensures that this is always done correctly.
+
+
+The bridge driver also has some helper functions it can use:
+
+.. code-block:: c
+
+	struct v4l2_subdev *sd = v4l2_i2c_new_subdev(v4l2_dev, adapter,
+					"module_foo", "chipid", 0x36, NULL);
+
+This loads the given module (can be ``NULL`` if no module needs to be loaded)
+and calls :c:func:`i2c_new_client_device` with the given ``i2c_adapter`` and
+chip/address arguments. If all goes well, then it registers the subdev with
+the v4l2_device.
+
+You can also use the last argument of :c:func:`v4l2_i2c_new_subdev` to pass
+an array of possible I2C addresses that it should probe. These probe addresses
+are only used if the previous argument is 0. A non-zero argument means that you
+know the exact i2c address so in that case no probing will take place.
+
+Both functions return ``NULL`` if something went wrong.
+
+Note that the chipid you pass to :c:func:`v4l2_i2c_new_subdev` is usually
+the same as the module name. It allows you to specify a chip variant, e.g.
+"saa7114" or "saa7115". In general though the i2c driver autodetects this.
+The use of chipid is something that needs to be looked at more closely at a
+later date. It differs between i2c drivers and as such can be confusing.
+To see which chip variants are supported you can look in the i2c driver code
+for the i2c_device_id table. This lists all the possibilities.
+
+There are one more helper function:
+
+:c:func:`v4l2_i2c_new_subdev_board` uses an :c:type:`i2c_board_info` struct
+which is passed to the i2c driver and replaces the irq, platform_data and addr
+arguments.
+
+If the subdev supports the s_config core ops, then that op is called with
+the irq and platform_data arguments after the subdev was setup.
+
+The :c:func:`v4l2_i2c_new_subdev` function will call
+:c:func:`v4l2_i2c_new_subdev_board`, internally filling a
+:c:type:`i2c_board_info` structure using the ``client_type`` and the
+``addr`` to fill it.
+
+V4L2 sub-device functions and data structures
+---------------------------------------------
+
+.. kernel-doc:: include/media/v4l2-subdev.h
diff --git a/Documentation/driver-api/media/v4l2-tuner.rst b/Documentation/driver-api/media/v4l2-tuner.rst
new file mode 100644
index 000000000..e6caa3321
--- /dev/null
+++ b/Documentation/driver-api/media/v4l2-tuner.rst
@@ -0,0 +1,8 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+Tuner functions and data structures
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+.. kernel-doc:: include/media/tuner.h
+
+.. kernel-doc:: include/media/tuner-types.h
diff --git a/Documentation/driver-api/media/v4l2-tveeprom.rst b/Documentation/driver-api/media/v4l2-tveeprom.rst
new file mode 100644
index 000000000..43fb391ed
--- /dev/null
+++ b/Documentation/driver-api/media/v4l2-tveeprom.rst
@@ -0,0 +1,6 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+Hauppauge TV EEPROM functions and data structures
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+.. kernel-doc:: include/media/tveeprom.h
diff --git a/Documentation/driver-api/media/v4l2-videobuf.rst b/Documentation/driver-api/media/v4l2-videobuf.rst
new file mode 100644
index 000000000..4b1d84eef
--- /dev/null
+++ b/Documentation/driver-api/media/v4l2-videobuf.rst
@@ -0,0 +1,403 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+.. _vb_framework:
+
+Videobuf Framework
+==================
+
+Author: Jonathan Corbet <corbet@lwn.net>
+
+Current as of 2.6.33
+
+.. note::
+
+   The videobuf framework was deprecated in favor of videobuf2. Shouldn't
+   be used on new drivers.
+
+Introduction
+------------
+
+The videobuf layer functions as a sort of glue layer between a V4L2 driver
+and user space.  It handles the allocation and management of buffers for
+the storage of video frames.  There is a set of functions which can be used
+to implement many of the standard POSIX I/O system calls, including read(),
+poll(), and, happily, mmap().  Another set of functions can be used to
+implement the bulk of the V4L2 ioctl() calls related to streaming I/O,
+including buffer allocation, queueing and dequeueing, and streaming
+control.  Using videobuf imposes a few design decisions on the driver
+author, but the payback comes in the form of reduced code in the driver and
+a consistent implementation of the V4L2 user-space API.
+
+Buffer types
+------------
+
+Not all video devices use the same kind of buffers.  In fact, there are (at
+least) three common variations:
+
+ - Buffers which are scattered in both the physical and (kernel) virtual
+   address spaces.  (Almost) all user-space buffers are like this, but it
+   makes great sense to allocate kernel-space buffers this way as well when
+   it is possible.  Unfortunately, it is not always possible; working with
+   this kind of buffer normally requires hardware which can do
+   scatter/gather DMA operations.
+
+ - Buffers which are physically scattered, but which are virtually
+   contiguous; buffers allocated with vmalloc(), in other words.  These
+   buffers are just as hard to use for DMA operations, but they can be
+   useful in situations where DMA is not available but virtually-contiguous
+   buffers are convenient.
+
+ - Buffers which are physically contiguous.  Allocation of this kind of
+   buffer can be unreliable on fragmented systems, but simpler DMA
+   controllers cannot deal with anything else.
+
+Videobuf can work with all three types of buffers, but the driver author
+must pick one at the outset and design the driver around that decision.
+
+[It's worth noting that there's a fourth kind of buffer: "overlay" buffers
+which are located within the system's video memory.  The overlay
+functionality is considered to be deprecated for most use, but it still
+shows up occasionally in system-on-chip drivers where the performance
+benefits merit the use of this technique.  Overlay buffers can be handled
+as a form of scattered buffer, but there are very few implementations in
+the kernel and a description of this technique is currently beyond the
+scope of this document.]
+
+Data structures, callbacks, and initialization
+----------------------------------------------
+
+Depending on which type of buffers are being used, the driver should
+include one of the following files:
+
+.. code-block:: none
+
+    <media/videobuf-dma-sg.h>		/* Physically scattered */
+    <media/videobuf-vmalloc.h>		/* vmalloc() buffers	*/
+    <media/videobuf-dma-contig.h>	/* Physically contiguous */
+
+The driver's data structure describing a V4L2 device should include a
+struct videobuf_queue instance for the management of the buffer queue,
+along with a list_head for the queue of available buffers.  There will also
+need to be an interrupt-safe spinlock which is used to protect (at least)
+the queue.
+
+The next step is to write four simple callbacks to help videobuf deal with
+the management of buffers:
+
+.. code-block:: none
+
+    struct videobuf_queue_ops {
+	int (*buf_setup)(struct videobuf_queue *q,
+			 unsigned int *count, unsigned int *size);
+	int (*buf_prepare)(struct videobuf_queue *q,
+			   struct videobuf_buffer *vb,
+			   enum v4l2_field field);
+	void (*buf_queue)(struct videobuf_queue *q,
+			  struct videobuf_buffer *vb);
+	void (*buf_release)(struct videobuf_queue *q,
+			    struct videobuf_buffer *vb);
+    };
+
+buf_setup() is called early in the I/O process, when streaming is being
+initiated; its purpose is to tell videobuf about the I/O stream.  The count
+parameter will be a suggested number of buffers to use; the driver should
+check it for rationality and adjust it if need be.  As a practical rule, a
+minimum of two buffers are needed for proper streaming, and there is
+usually a maximum (which cannot exceed 32) which makes sense for each
+device.  The size parameter should be set to the expected (maximum) size
+for each frame of data.
+
+Each buffer (in the form of a struct videobuf_buffer pointer) will be
+passed to buf_prepare(), which should set the buffer's size, width, height,
+and field fields properly.  If the buffer's state field is
+VIDEOBUF_NEEDS_INIT, the driver should pass it to:
+
+.. code-block:: none
+
+    int videobuf_iolock(struct videobuf_queue* q, struct videobuf_buffer *vb,
+			struct v4l2_framebuffer *fbuf);
+
+Among other things, this call will usually allocate memory for the buffer.
+Finally, the buf_prepare() function should set the buffer's state to
+VIDEOBUF_PREPARED.
+
+When a buffer is queued for I/O, it is passed to buf_queue(), which should
+put it onto the driver's list of available buffers and set its state to
+VIDEOBUF_QUEUED.  Note that this function is called with the queue spinlock
+held; if it tries to acquire it as well things will come to a screeching
+halt.  Yes, this is the voice of experience.  Note also that videobuf may
+wait on the first buffer in the queue; placing other buffers in front of it
+could again gum up the works.  So use list_add_tail() to enqueue buffers.
+
+Finally, buf_release() is called when a buffer is no longer intended to be
+used.  The driver should ensure that there is no I/O active on the buffer,
+then pass it to the appropriate free routine(s):
+
+.. code-block:: none
+
+    /* Scatter/gather drivers */
+    int videobuf_dma_unmap(struct videobuf_queue *q,
+			   struct videobuf_dmabuf *dma);
+    int videobuf_dma_free(struct videobuf_dmabuf *dma);
+
+    /* vmalloc drivers */
+    void videobuf_vmalloc_free (struct videobuf_buffer *buf);
+
+    /* Contiguous drivers */
+    void videobuf_dma_contig_free(struct videobuf_queue *q,
+				  struct videobuf_buffer *buf);
+
+One way to ensure that a buffer is no longer under I/O is to pass it to:
+
+.. code-block:: none
+
+    int videobuf_waiton(struct videobuf_buffer *vb, int non_blocking, int intr);
+
+Here, vb is the buffer, non_blocking indicates whether non-blocking I/O
+should be used (it should be zero in the buf_release() case), and intr
+controls whether an interruptible wait is used.
+
+File operations
+---------------
+
+At this point, much of the work is done; much of the rest is slipping
+videobuf calls into the implementation of the other driver callbacks.  The
+first step is in the open() function, which must initialize the
+videobuf queue.  The function to use depends on the type of buffer used:
+
+.. code-block:: none
+
+    void videobuf_queue_sg_init(struct videobuf_queue *q,
+				struct videobuf_queue_ops *ops,
+				struct device *dev,
+				spinlock_t *irqlock,
+				enum v4l2_buf_type type,
+				enum v4l2_field field,
+				unsigned int msize,
+				void *priv);
+
+    void videobuf_queue_vmalloc_init(struct videobuf_queue *q,
+				struct videobuf_queue_ops *ops,
+				struct device *dev,
+				spinlock_t *irqlock,
+				enum v4l2_buf_type type,
+				enum v4l2_field field,
+				unsigned int msize,
+				void *priv);
+
+    void videobuf_queue_dma_contig_init(struct videobuf_queue *q,
+				       struct videobuf_queue_ops *ops,
+				       struct device *dev,
+				       spinlock_t *irqlock,
+				       enum v4l2_buf_type type,
+				       enum v4l2_field field,
+				       unsigned int msize,
+				       void *priv);
+
+In each case, the parameters are the same: q is the queue structure for the
+device, ops is the set of callbacks as described above, dev is the device
+structure for this video device, irqlock is an interrupt-safe spinlock to
+protect access to the data structures, type is the buffer type used by the
+device (cameras will use V4L2_BUF_TYPE_VIDEO_CAPTURE, for example), field
+describes which field is being captured (often V4L2_FIELD_NONE for
+progressive devices), msize is the size of any containing structure used
+around struct videobuf_buffer, and priv is a private data pointer which
+shows up in the priv_data field of struct videobuf_queue.  Note that these
+are void functions which, evidently, are immune to failure.
+
+V4L2 capture drivers can be written to support either of two APIs: the
+read() system call and the rather more complicated streaming mechanism.  As
+a general rule, it is necessary to support both to ensure that all
+applications have a chance of working with the device.  Videobuf makes it
+easy to do that with the same code.  To implement read(), the driver need
+only make a call to one of:
+
+.. code-block:: none
+
+    ssize_t videobuf_read_one(struct videobuf_queue *q,
+			      char __user *data, size_t count,
+			      loff_t *ppos, int nonblocking);
+
+    ssize_t videobuf_read_stream(struct videobuf_queue *q,
+				 char __user *data, size_t count,
+				 loff_t *ppos, int vbihack, int nonblocking);
+
+Either one of these functions will read frame data into data, returning the
+amount actually read; the difference is that videobuf_read_one() will only
+read a single frame, while videobuf_read_stream() will read multiple frames
+if they are needed to satisfy the count requested by the application.  A
+typical driver read() implementation will start the capture engine, call
+one of the above functions, then stop the engine before returning (though a
+smarter implementation might leave the engine running for a little while in
+anticipation of another read() call happening in the near future).
+
+The poll() function can usually be implemented with a direct call to:
+
+.. code-block:: none
+
+    unsigned int videobuf_poll_stream(struct file *file,
+				      struct videobuf_queue *q,
+				      poll_table *wait);
+
+Note that the actual wait queue eventually used will be the one associated
+with the first available buffer.
+
+When streaming I/O is done to kernel-space buffers, the driver must support
+the mmap() system call to enable user space to access the data.  In many
+V4L2 drivers, the often-complex mmap() implementation simplifies to a
+single call to:
+
+.. code-block:: none
+
+    int videobuf_mmap_mapper(struct videobuf_queue *q,
+			     struct vm_area_struct *vma);
+
+Everything else is handled by the videobuf code.
+
+The release() function requires two separate videobuf calls:
+
+.. code-block:: none
+
+    void videobuf_stop(struct videobuf_queue *q);
+    int videobuf_mmap_free(struct videobuf_queue *q);
+
+The call to videobuf_stop() terminates any I/O in progress - though it is
+still up to the driver to stop the capture engine.  The call to
+videobuf_mmap_free() will ensure that all buffers have been unmapped; if
+so, they will all be passed to the buf_release() callback.  If buffers
+remain mapped, videobuf_mmap_free() returns an error code instead.  The
+purpose is clearly to cause the closing of the file descriptor to fail if
+buffers are still mapped, but every driver in the 2.6.32 kernel cheerfully
+ignores its return value.
+
+ioctl() operations
+------------------
+
+The V4L2 API includes a very long list of driver callbacks to respond to
+the many ioctl() commands made available to user space.  A number of these
+- those associated with streaming I/O - turn almost directly into videobuf
+calls.  The relevant helper functions are:
+
+.. code-block:: none
+
+    int videobuf_reqbufs(struct videobuf_queue *q,
+			 struct v4l2_requestbuffers *req);
+    int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b);
+    int videobuf_qbuf(struct videobuf_queue *q, struct v4l2_buffer *b);
+    int videobuf_dqbuf(struct videobuf_queue *q, struct v4l2_buffer *b,
+		       int nonblocking);
+    int videobuf_streamon(struct videobuf_queue *q);
+    int videobuf_streamoff(struct videobuf_queue *q);
+
+So, for example, a VIDIOC_REQBUFS call turns into a call to the driver's
+vidioc_reqbufs() callback which, in turn, usually only needs to locate the
+proper struct videobuf_queue pointer and pass it to videobuf_reqbufs().
+These support functions can replace a great deal of buffer management
+boilerplate in a lot of V4L2 drivers.
+
+The vidioc_streamon() and vidioc_streamoff() functions will be a bit more
+complex, of course, since they will also need to deal with starting and
+stopping the capture engine.
+
+Buffer allocation
+-----------------
+
+Thus far, we have talked about buffers, but have not looked at how they are
+allocated.  The scatter/gather case is the most complex on this front.  For
+allocation, the driver can leave buffer allocation entirely up to the
+videobuf layer; in this case, buffers will be allocated as anonymous
+user-space pages and will be very scattered indeed.  If the application is
+using user-space buffers, no allocation is needed; the videobuf layer will
+take care of calling get_user_pages() and filling in the scatterlist array.
+
+If the driver needs to do its own memory allocation, it should be done in
+the vidioc_reqbufs() function, *after* calling videobuf_reqbufs().  The
+first step is a call to:
+
+.. code-block:: none
+
+    struct videobuf_dmabuf *videobuf_to_dma(struct videobuf_buffer *buf);
+
+The returned videobuf_dmabuf structure (defined in
+<media/videobuf-dma-sg.h>) includes a couple of relevant fields:
+
+.. code-block:: none
+
+    struct scatterlist  *sglist;
+    int                 sglen;
+
+The driver must allocate an appropriately-sized scatterlist array and
+populate it with pointers to the pieces of the allocated buffer; sglen
+should be set to the length of the array.
+
+Drivers using the vmalloc() method need not (and cannot) concern themselves
+with buffer allocation at all; videobuf will handle those details.  The
+same is normally true of contiguous-DMA drivers as well; videobuf will
+allocate the buffers (with dma_alloc_coherent()) when it sees fit.  That
+means that these drivers may be trying to do high-order allocations at any
+time, an operation which is not always guaranteed to work.  Some drivers
+play tricks by allocating DMA space at system boot time; videobuf does not
+currently play well with those drivers.
+
+As of 2.6.31, contiguous-DMA drivers can work with a user-supplied buffer,
+as long as that buffer is physically contiguous.  Normal user-space
+allocations will not meet that criterion, but buffers obtained from other
+kernel drivers, or those contained within huge pages, will work with these
+drivers.
+
+Filling the buffers
+-------------------
+
+The final part of a videobuf implementation has no direct callback - it's
+the portion of the code which actually puts frame data into the buffers,
+usually in response to interrupts from the device.  For all types of
+drivers, this process works approximately as follows:
+
+ - Obtain the next available buffer and make sure that somebody is actually
+   waiting for it.
+
+ - Get a pointer to the memory and put video data there.
+
+ - Mark the buffer as done and wake up the process waiting for it.
+
+Step (1) above is done by looking at the driver-managed list_head structure
+- the one which is filled in the buf_queue() callback.  Because starting
+the engine and enqueueing buffers are done in separate steps, it's possible
+for the engine to be running without any buffers available - in the
+vmalloc() case especially.  So the driver should be prepared for the list
+to be empty.  It is equally possible that nobody is yet interested in the
+buffer; the driver should not remove it from the list or fill it until a
+process is waiting on it.  That test can be done by examining the buffer's
+done field (a wait_queue_head_t structure) with waitqueue_active().
+
+A buffer's state should be set to VIDEOBUF_ACTIVE before being mapped for
+DMA; that ensures that the videobuf layer will not try to do anything with
+it while the device is transferring data.
+
+For scatter/gather drivers, the needed memory pointers will be found in the
+scatterlist structure described above.  Drivers using the vmalloc() method
+can get a memory pointer with:
+
+.. code-block:: none
+
+    void *videobuf_to_vmalloc(struct videobuf_buffer *buf);
+
+For contiguous DMA drivers, the function to use is:
+
+.. code-block:: none
+
+    dma_addr_t videobuf_to_dma_contig(struct videobuf_buffer *buf);
+
+The contiguous DMA API goes out of its way to hide the kernel-space address
+of the DMA buffer from drivers.
+
+The final step is to set the size field of the relevant videobuf_buffer
+structure to the actual size of the captured image, set state to
+VIDEOBUF_DONE, then call wake_up() on the done queue.  At this point, the
+buffer is owned by the videobuf layer and the driver should not touch it
+again.
+
+Developers who are interested in more information can go into the relevant
+header files; there are a few low-level functions declared there which have
+not been talked about here.  Note also that all of these calls are exported
+GPL-only, so they will not be available to non-GPL kernel modules.
diff --git a/Documentation/driver-api/media/v4l2-videobuf2.rst b/Documentation/driver-api/media/v4l2-videobuf2.rst
new file mode 100644
index 000000000..1044f64ff
--- /dev/null
+++ b/Documentation/driver-api/media/v4l2-videobuf2.rst
@@ -0,0 +1,12 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+.. _vb2_framework:
+
+V4L2 videobuf2 functions and data structures
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+.. kernel-doc:: include/media/videobuf2-core.h
+
+.. kernel-doc:: include/media/videobuf2-v4l2.h
+
+.. kernel-doc:: include/media/videobuf2-memops.h
author	Daniel Baumann <daniel.baumann@progress-linux.org>	2024-04-27 10:05:51 +0000
committer	Daniel Baumann <daniel.baumann@progress-linux.org>	2024-04-27 10:05:51 +0000
commit	5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch)
tree	a94efe259b9009378be6d90eb30d2b019d95c194 /Documentation/driver-api/media
parent	Initial commit. (diff)
download	linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.tar.xz linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.zip