[PATCH v3 3/8] docs: iio: New docs for ad4052 driver

[Jorge Marques <jorge.marques@analog.com>]

This adds a new page to document how to use the ad4052 ADC driver.

Signed-off-by: Jorge Marques <jorge.marques@analog.com>
---
 Documentation/iio/ad4052.rst | 71 ++++++++++++++++++++++++++++++++++++++++++++
 Documentation/iio/index.rst  |  1 +
 MAINTAINERS                  |  1 +
 3 files changed, 73 insertions(+)

diff --git a/Documentation/iio/ad4052.rst b/Documentation/iio/ad4052.rst
new file mode 100644
index 0000000000000000000000000000000000000000..25e55eb72e167bd2b2195ba789b45ce402869b0f
--- /dev/null
+++ b/Documentation/iio/ad4052.rst
@@ -0,0 +1,71 @@
+.. SPDX-License-Identifier: GPL-2.0-only
+
+=============
+AD4052 driver
+=============
+
+ADC driver for Analog Devices Inc. AD4052 and similar devices. The module name
+is ``ad4052``.
+
+Supported devices
+=================
+
+The following chips are supported by this driver:
+
+* `AD4050 <https://www.analog.com/AD4050>`_
+* `AD4052 <https://www.analog.com/AD4052>`_
+* `AD4056 <https://www.analog.com/AD4056>`_
+* `AD4058 <https://www.analog.com/AD4058>`_
+
+Wiring modes
+============
+
+The ADC uses SPI 4-wire mode, and contain two programmable GPIOs and a CNV pin.
+
+The CNV pin is exposed as the ``cnv-gpios`` and triggers an ADC conversion. GP1
+is ADC conversion ready signal and GP0 Threshold event interrupt, both exposed
+as interrupts.
+
+Omit ``cnv-gpios`` and tie CNV and CS together to use the rising edge of the CS
+as the CNV signal.
+
+Device attributes
+=================
+
+The ADC contains only one channel with following attributes:
+
+.. list-table:: Channel attributes
+   :header-rows: 1
+
+   * - Attribute
+     - Description
+   * - ``in_voltage_calibscale``
+     - Scale factor to multiply the raw value.
+   * - ``in_voltage_raw``
+     - Raw ADC voltage value
+   * - ``in_voltage_oversampling_ratio``
+     - Enable the device's burst averaging mode to over sample using the
+       internal sample rate.
+   * - ``in_voltage_oversampling_ratio_available``
+     - List of available oversampling values. Value 1 disable the burst
+       averaging mode.
+
+Also contain the following device attributes:
+
+.. list-table:: Device attributes
+   :header-rows: 1
+
+   * - Attribute
+     - Description
+   * - ``oversamling_frequency``
+     - Frequency used in the burst averaging mode, sets the device internal
+       sample rate when the mode is activated.
+   * - ``oversampling_frequency_available``
+     - List of available sample rates.
+
+Low-power mode
+==============
+
+The device enters low-power mode on idle to save power. Enabling an event puts
+the device out of the low-power since the ADC autonomously samples to assert
+the event condition.
diff --git a/Documentation/iio/index.rst b/Documentation/iio/index.rst
index 2d6afc5a8ed54a90cd8d5723f0dc5212b8593d16..ef03022b8a6374c14d7b1b2e51e5c487e1d37df9 100644
--- a/Documentation/iio/index.rst
+++ b/Documentation/iio/index.rst
@@ -22,6 +22,7 @@ Industrial I/O Kernel Drivers
    ad3552r
    ad4000
    ad4030
+   ad4052
    ad4695
    ad7191
    ad7380
diff --git a/MAINTAINERS b/MAINTAINERS
index d000c7de7ff9eba390f87593bc2b1847f966f48b..32afd568b68e45616c291d689a35ab905d421cd1 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1342,6 +1342,7 @@ M:	Jorge Marques <jorge.marques@analog.com>
 S:	Supported
 W:	https://ez.analog.com/linux-software-drivers
 F:	Documentation/devicetree/bindings/iio/adc/adi,ad4052.yaml
+F:	Documentation/iio/ad4052.rst
 
 ANALOG DEVICES INC AD4080 DRIVER
 M:	Antoniu Miclaus <antoniu.miclaus@analog.com>

-- 
2.49.0