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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /drivers/staging/iio/Documentation
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/staging/iio/Documentation')
-rw-r--r--drivers/staging/iio/Documentation/inkernel.txt58
-rw-r--r--drivers/staging/iio/Documentation/sysfs-bus-iio-adc-ad7280a21
-rw-r--r--drivers/staging/iio/Documentation/sysfs-bus-iio-dds96
3 files changed, 175 insertions, 0 deletions
diff --git a/drivers/staging/iio/Documentation/inkernel.txt b/drivers/staging/iio/Documentation/inkernel.txt
new file mode 100644
index 0000000000..ab528409bb
--- /dev/null
+++ b/drivers/staging/iio/Documentation/inkernel.txt
@@ -0,0 +1,58 @@
+Industrial I/O Subsystem in kernel consumers.
+
+The IIO subsystem can act as a layer under other elements of the kernel
+providing a means of obtaining ADC type readings or of driving DAC type
+signals. The functionality supported will grow as use cases arise.
+
+Describing the channel mapping (iio/machine.h)
+
+Channel associations are described using:
+
+struct iio_map {
+ const char *adc_channel_label;
+ const char *consumer_dev_name;
+ const char *consumer_channel;
+};
+
+adc_channel_label identifies the channel on the IIO device by being
+matched against the datasheet_name field of the iio_chan_spec.
+
+consumer_dev_name allows identification of the consumer device.
+This are then used to find the channel mapping from the consumer device (see
+below).
+
+Finally consumer_channel is a string identifying the channel to the consumer.
+(Perhaps 'battery_voltage' or similar).
+
+An array of these structures is then passed to the IIO driver.
+
+Supporting in kernel interfaces in the driver (driver.h)
+
+The driver must provide datasheet_name values for its channels and
+must pass the iio_map structures and a pointer to its own iio_dev structure
+ on to the core via a call to iio_map_array_register. On removal,
+iio_map_array_unregister reverses this process.
+
+The result of this is that the IIO core now has all the information needed
+to associate a given channel with the consumer requesting it.
+
+Acting as an IIO consumer (consumer.h)
+
+The consumer first has to obtain an iio_channel structure from the core
+by calling iio_channel_get(). The correct channel is identified by:
+
+* matching dev or dev_name against consumer_dev and consumer_dev_name
+* matching consumer_channel against consumer_channel in the map
+
+There are then a number of functions that can be used to get information
+about this channel such as it's current reading.
+
+e.g.
+iio_read_channel_raw() - get a reading
+iio_get_channel_type() - get the type of channel
+
+There is also provision for retrieving all of the channels associated
+with a given consumer. This is useful for generic drivers such as
+iio_hwmon where the number and naming of channels is not known by the
+consumer driver. To do this, use iio_channel_get_all.
+
diff --git a/drivers/staging/iio/Documentation/sysfs-bus-iio-adc-ad7280a b/drivers/staging/iio/Documentation/sysfs-bus-iio-adc-ad7280a
new file mode 100644
index 0000000000..863d385671
--- /dev/null
+++ b/drivers/staging/iio/Documentation/sysfs-bus-iio-adc-ad7280a
@@ -0,0 +1,21 @@
+What: /sys/bus/iio/devices/deviceX/inY-inZ_balance_switch_en
+KernelVersion: 3.0.0
+Contact: linux-iio@vger.kernel.org
+Description:
+ Writing 1 enables the cell balance output switch corresponding
+ to input Y. Writing 0 disables it. If the inY-inZ_balance_timer
+ is set to a none zero value, the corresponding switch will
+ enable for the programmed amount of time, before it
+ automatically disables.
+
+What: /sys/bus/iio/devices/deviceX/inY-inZ_balance_timer
+KernelVersion: 3.0.0
+Contact: linux-iio@vger.kernel.org
+Description:
+ The inY-inZ_balance_timer file allows the user to program
+ individual times for each cell balance output. The AD7280A
+ allows the user to set the timer to a value from 0 minutes to
+ 36.9 minutes. The resolution of the timer is 71.5 sec.
+ The value written is the on-time in milliseconds. When the
+ timer value is set 0, the timer is disabled. The cell balance
+ outputs are controlled only by inY-inZ_balance_switch_en.
diff --git a/drivers/staging/iio/Documentation/sysfs-bus-iio-dds b/drivers/staging/iio/Documentation/sysfs-bus-iio-dds
new file mode 100644
index 0000000000..ee8c509c67
--- /dev/null
+++ b/drivers/staging/iio/Documentation/sysfs-bus-iio-dds
@@ -0,0 +1,96 @@
+
+What: /sys/bus/iio/devices/.../out_altvoltageX_frequencyY
+KernelVersion: 2.6.37
+Contact: linux-iio@vger.kernel.org
+Description:
+ Stores frequency into tuning word Y.
+ There will be more than one out_altvoltageX_frequencyY file,
+ which allows for pin controlled FSK Frequency Shift Keying
+ (out_altvoltageX_pincontrol_frequency_en is active) or the user
+ can control the desired active tuning word by writing Y to the
+ out_altvoltageX_frequencysymbol file.
+
+What: /sys/bus/iio/devices/.../out_altvoltageX_frequencyY_scale
+KernelVersion: 2.6.37
+Contact: linux-iio@vger.kernel.org
+Description:
+ Scale to be applied to out_altvoltageX_frequencyY in order to
+ obtain the desired value in Hz. If shared across all frequency
+ registers Y is not present. It is also possible X is not present
+ if shared across all channels.
+
+What: /sys/bus/iio/devices/.../out_altvoltageX_frequencysymbol
+KernelVersion: 2.6.37
+Contact: linux-iio@vger.kernel.org
+Description:
+ Specifies the active output frequency tuning word. The value
+ corresponds to the Y in out_altvoltageX_frequencyY.
+ To exit this mode the user can write
+ out_altvoltageX_pincontrol_frequency_en or
+ out_altvoltageX_out_enable file.
+
+What: /sys/bus/iio/devices/.../out_altvoltageX_phaseY
+KernelVersion: 2.6.37
+Contact: linux-iio@vger.kernel.org
+Description:
+ Stores phase into Y.
+ There will be more than one out_altvoltageX_phaseY file, which
+ allows for pin controlled PSK Phase Shift Keying
+ (out_altvoltageX_pincontrol_phase_en is active) or the user can
+ control the desired phase Y which is added to the phase
+ accumulator output by writing Y to the phase_en file.
+
+What: /sys/bus/iio/devices/.../out_altvoltageX_phaseY_scale
+KernelVersion: 2.6.37
+Contact: linux-iio@vger.kernel.org
+Description:
+ Scale to be applied to out_altvoltageX_phaseY in order to obtain
+ the desired value in rad. If shared across all phase registers
+ Y is not present. It is also possible X is not present if
+ shared across all channels.
+
+What: /sys/bus/iio/devices/.../out_altvoltageX_phasesymbol
+KernelVersion: 2.6.37
+Contact: linux-iio@vger.kernel.org
+Description:
+ Specifies the active phase Y which is added to the phase
+ accumulator output. The value corresponds to the Y in
+ out_altvoltageX_phaseY. To exit this mode the user can write
+ out_altvoltageX_pincontrol_phase_en or disable file.
+
+What: /sys/bus/iio/devices/.../out_altvoltageX_pincontrol_en
+What: /sys/bus/iio/devices/.../out_altvoltageX_pincontrol_frequency_en
+What: /sys/bus/iio/devices/.../out_altvoltageX_pincontrol_phase_en
+KernelVersion: 2.6.37
+Contact: linux-iio@vger.kernel.org
+Description:
+ out_altvoltageX_pincontrol_en: Both, the active frequency and
+ phase is controlled by the respective phase and frequency
+ control inputs. In case the device in features independent
+ controls, then there are dedicated files
+ (out_altvoltageX_pincontrol_frequency_en,
+ out_altvoltageX_pincontrol_phase_en).
+
+What: /sys/bus/iio/devices/.../out_altvoltageX_out_enable
+What: /sys/bus/iio/devices/.../out_altvoltageX_outY_enable
+KernelVersion: 2.6.37
+Contact: linux-iio@vger.kernel.org
+Description:
+ out_altvoltageX_outY_enable controls signal generation on
+ output Y of channel X. Y may be suppressed if all channels are
+ controlled together.
+
+What: /sys/bus/iio/devices/.../out_altvoltageX_outY_wavetype
+KernelVersion: 2.6.37
+Contact: linux-iio@vger.kernel.org
+Description:
+ Specifies the output waveform.
+ (sine, triangle, ramp, square, ...)
+ For a list of available output waveform options read
+ available_output_modes.
+
+What: /sys/bus/iio/devices/.../out_altvoltageX_outY_wavetype_available
+KernelVersion: 2.6.37
+Contact: linux-iio@vger.kernel.org
+Description:
+ Lists all available output waveform options.