Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 195 insertions, 0 deletions

diff --git a/Documentation/media/uapi/v4l/vidioc-g-modulator.rst b/Documentation/media/uapi/v4l/vidioc-g-modulator.rst
new file mode 100644
index 000000000..a47b6a15c
--- /dev/null
+++ b/Documentation/media/uapi/v4l/vidioc-g-modulator.rst
@@ -0,0 +1,195 @@
+.. -*- coding: utf-8; mode: rst -*-
+
+.. _VIDIOC_G_MODULATOR:
+
+********************************************
+ioctl VIDIOC_G_MODULATOR, VIDIOC_S_MODULATOR
+********************************************
+
+Name
+====
+
+VIDIOC_G_MODULATOR - VIDIOC_S_MODULATOR - Get or set modulator attributes
+
+
+Synopsis
+========
+
+.. c:function:: int ioctl( int fd, VIDIOC_G_MODULATOR, struct v4l2_modulator *argp )
+    :name: VIDIOC_G_MODULATOR
+
+.. c:function:: int ioctl( int fd, VIDIOC_S_MODULATOR, const struct v4l2_modulator *argp )
+    :name: VIDIOC_S_MODULATOR
+
+
+Arguments
+=========
+
+``fd``
+    File descriptor returned by :ref:`open() <func-open>`.
+
+``argp``
+    Pointer to struct :c:type:`v4l2_modulator`.
+
+
+Description
+===========
+
+To query the attributes of a modulator applications initialize the
+``index`` field and zero out the ``reserved`` array of a struct
+:c:type:`v4l2_modulator` and call the
+:ref:`VIDIOC_G_MODULATOR <VIDIOC_G_MODULATOR>` ioctl with a pointer to this structure. Drivers
+fill the rest of the structure or return an ``EINVAL`` error code when the
+index is out of bounds. To enumerate all modulators applications shall
+begin at index zero, incrementing by one until the driver returns
+EINVAL.
+
+Modulators have two writable properties, an audio modulation set and the
+radio frequency. To change the modulated audio subprograms, applications
+initialize the ``index`` and ``txsubchans`` fields and the ``reserved``
+array and call the :ref:`VIDIOC_S_MODULATOR <VIDIOC_G_MODULATOR>` ioctl. Drivers may choose a
+different audio modulation if the request cannot be satisfied. However
+this is a write-only ioctl, it does not return the actual audio
+modulation selected.
+
+:ref:`SDR <sdr>` specific modulator types are ``V4L2_TUNER_SDR`` and
+``V4L2_TUNER_RF``. For SDR devices ``txsubchans`` field must be
+initialized to zero. The term 'modulator' means SDR transmitter in this
+context.
+
+To change the radio frequency the
+:ref:`VIDIOC_S_FREQUENCY <VIDIOC_G_FREQUENCY>` ioctl is available.
+
+
+.. tabularcolumns:: |p{2.9cm}|p{2.9cm}|p{5.8cm}|p{2.9cm}|p{3.0cm}|
+
+.. c:type:: v4l2_modulator
+
+.. flat-table:: struct v4l2_modulator
+    :header-rows:  0
+    :stub-columns: 0
+    :widths:       1 1 2 1 1
+
+    * - __u32
+      - ``index``
+      - Identifies the modulator, set by the application.
+    * - __u8
+      - ``name``\ [32]
+      - Name of the modulator, a NUL-terminated ASCII string.
+
+	This information is intended for the user.
+    * - __u32
+      - ``capability``
+      - Modulator capability flags. No flags are defined for this field,
+	the tuner flags in struct :c:type:`v4l2_tuner` are
+	used accordingly. The audio flags indicate the ability to encode
+	audio subprograms. They will *not* change for example with the
+	current video standard.
+    * - __u32
+      - ``rangelow``
+      - The lowest tunable frequency in units of 62.5 KHz, or if the
+	``capability`` flag ``V4L2_TUNER_CAP_LOW`` is set, in units of
+	62.5 Hz, or if the ``capability`` flag ``V4L2_TUNER_CAP_1HZ`` is
+	set, in units of 1 Hz.
+    * - __u32
+      - ``rangehigh``
+      - The highest tunable frequency in units of 62.5 KHz, or if the
+	``capability`` flag ``V4L2_TUNER_CAP_LOW`` is set, in units of
+	62.5 Hz, or if the ``capability`` flag ``V4L2_TUNER_CAP_1HZ`` is
+	set, in units of 1 Hz.
+    * - __u32
+      - ``txsubchans``
+      - With this field applications can determine how audio sub-carriers
+	shall be modulated. It contains a set of flags as defined in
+	:ref:`modulator-txsubchans`.
+
+	.. note::
+
+	   The tuner ``rxsubchans`` flags  are reused, but the
+	   semantics are different. Video output devices
+	   are assumed to have an analog or PCM audio input with 1-3
+	   channels. The ``txsubchans`` flags select one or more channels
+	   for modulation, together with some audio subprogram indicator,
+	   for example, a stereo pilot tone.
+    * - __u32
+      - ``type``
+      - :cspan:`2` Type of the modulator, see :c:type:`v4l2_tuner_type`.
+    * - __u32
+      - ``reserved``\ [3]
+      - Reserved for future extensions.
+
+	Drivers and applications must set the array to zero.
+
+
+
+.. tabularcolumns:: |p{6.6cm}|p{2.2cm}|p{8.7cm}|
+
+.. _modulator-txsubchans:
+
+.. flat-table:: Modulator Audio Transmission Flags
+    :header-rows:  0
+    :stub-columns: 0
+    :widths:       3 1 4
+
+    * - ``V4L2_TUNER_SUB_MONO``
+      - 0x0001
+      - Modulate channel 1 as mono audio, when the input has more
+	channels, a down-mix of channel 1 and 2. This flag does not
+	combine with ``V4L2_TUNER_SUB_STEREO`` or
+	``V4L2_TUNER_SUB_LANG1``.
+    * - ``V4L2_TUNER_SUB_STEREO``
+      - 0x0002
+      - Modulate channel 1 and 2 as left and right channel of a stereo
+	audio signal. When the input has only one channel or two channels
+	and ``V4L2_TUNER_SUB_SAP`` is also set, channel 1 is encoded as
+	left and right channel. This flag does not combine with
+	``V4L2_TUNER_SUB_MONO`` or ``V4L2_TUNER_SUB_LANG1``. When the
+	driver does not support stereo audio it shall fall back to mono.
+    * - ``V4L2_TUNER_SUB_LANG1``
+      - 0x0008
+      - Modulate channel 1 and 2 as primary and secondary language of a
+	bilingual audio signal. When the input has only one channel it is
+	used for both languages. It is not possible to encode the primary
+	or secondary language only. This flag does not combine with
+	``V4L2_TUNER_SUB_MONO``, ``V4L2_TUNER_SUB_STEREO`` or
+	``V4L2_TUNER_SUB_SAP``. If the hardware does not support the
+	respective audio matrix, or the current video standard does not
+	permit bilingual audio the :ref:`VIDIOC_S_MODULATOR <VIDIOC_G_MODULATOR>` ioctl shall
+	return an ``EINVAL`` error code and the driver shall fall back to mono
+	or stereo mode.
+    * - ``V4L2_TUNER_SUB_LANG2``
+      - 0x0004
+      - Same effect as ``V4L2_TUNER_SUB_SAP``.
+    * - ``V4L2_TUNER_SUB_SAP``
+      - 0x0004
+      - When combined with ``V4L2_TUNER_SUB_MONO`` the first channel is
+	encoded as mono audio, the last channel as Second Audio Program.
+	When the input has only one channel it is used for both audio
+	tracks. When the input has three channels the mono track is a
+	down-mix of channel 1 and 2. When combined with
+	``V4L2_TUNER_SUB_STEREO`` channel 1 and 2 are encoded as left and
+	right stereo audio, channel 3 as Second Audio Program. When the
+	input has only two channels, the first is encoded as left and
+	right channel and the second as SAP. When the input has only one
+	channel it is used for all audio tracks. It is not possible to
+	encode a Second Audio Program only. This flag must combine with
+	``V4L2_TUNER_SUB_MONO`` or ``V4L2_TUNER_SUB_STEREO``. If the
+	hardware does not support the respective audio matrix, or the
+	current video standard does not permit SAP the
+	:ref:`VIDIOC_S_MODULATOR <VIDIOC_G_MODULATOR>` ioctl shall return an ``EINVAL`` error code and
+	driver shall fall back to mono or stereo mode.
+    * - ``V4L2_TUNER_SUB_RDS``
+      - 0x0010
+      - Enable the RDS encoder for a radio FM transmitter.
+
+
+Return Value
+============
+
+On success 0 is returned, on error -1 and the ``errno`` variable is set
+appropriately. The generic error codes are described at the
+:ref:`Generic Error Codes <gen-errors>` chapter.
+
+EINVAL
+    The struct :c:type:`v4l2_modulator` ``index`` is
+    out of bounds.