[PATCH v4 3/3] docs: iio: Add adxl372 documentation

[<alexandru.tachici@analog.com>]

From: Alexandru Tachici <alexandru.tachici@analog.com>

Add documentation for adxl372 3-axis accelerometer.

Signed-off-by: Alexandru Tachici <alexandru.tachici@analog.com>
---
 Documentation/iio/adxl372.rst | 46 +++++++++++++++++++++++++++++++++++
 Documentation/iio/index.rst   |  1 +
 2 files changed, 47 insertions(+)
 create mode 100644 Documentation/iio/adxl372.rst

diff --git a/Documentation/iio/adxl372.rst b/Documentation/iio/adxl372.rst
new file mode 100644
index 000000000000..f8fe5f438400
--- /dev/null
+++ b/Documentation/iio/adxl372.rst
@@ -0,0 +1,46 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+Kernel driver adxl372
+=====================
+
+Supported chips:
+  * Analog Devices ADXL372
+    Prefix: 'adxl372'
+    Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/ADXL372.pdf
+
+Author: Stefan Popa <stefan.popa@analog.com>
+
+
+Description
+-----------
+
+The ADXL372 is an ultralow power, 3-axis, ±200 g MEMS accelerometer
+that consumes 22 μA at a 3200 Hz output data rate (ODR).
+
+The ADXL372 provides 12-bit output data at 100 mg/LSB scale factor.
+
+Using the FIFO Buffer
+---------------------
+
+The ADXL372 includes a deep, 512 sample FIFO buffer.
+The 512 FIFO samples can be allotted in several ways, such as the following:
+
+    170 sample sets of concurrent 3-axis data
+    256 sample sets of concurrent 2-axis data (see scan_elements/in_accel_*_en)
+    512 sample sets of single-axis data
+    170 sets of impact event peak (x, y, z)
+
+By default when using the buffer adxl372 will store all
+acceleration data. To store only the peak acceleration data, the user must
+select the peak data trigger: adxl372-dev0-peak
+
+The user can set the thresholds for each axis for activity and inactivity in:
+- events/in_accel_*_thresh_rising_value
+- events/in_accel_*_thresh_falling_value
+
+An inactivity/activity event is detected when acceleration in all enabled
+axes remains below/above a specified threshold for a specified time. The user
+can set these timings in:
+- events/thresh_falling_period
+- events/thresh_rising_period
+
diff --git a/Documentation/iio/index.rst b/Documentation/iio/index.rst
index 58b7a4ebac51..3d0acb1eef86 100644
--- a/Documentation/iio/index.rst
+++ b/Documentation/iio/index.rst
@@ -10,3 +10,4 @@ Industrial I/O
    iio_configfs
 
    ep93xx_adc
+   adxl372.rst
-- 
2.20.1