[PATCH v3 5/8] docs: iio: ad4052: Add offload support documentation

[Jorge Marques]

Explain the AD4052 support for the SPI Engine Offload.

Signed-off-by: Jorge Marques <jorge.marques@xxxxxxxxxx>
---
 Documentation/iio/ad4052.rst | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/Documentation/iio/ad4052.rst b/Documentation/iio/ad4052.rst
index 25e55eb72e167bd2b2195ba789b45ce402869b0f..2ad1c7712766118b03c48929d1f2b7670d5f8d41 100644
--- a/Documentation/iio/ad4052.rst
+++ b/Documentation/iio/ad4052.rst
@@ -49,6 +49,12 @@ The ADC contains only one channel with following attributes:
    * - ``in_voltage_oversampling_ratio_available``
      - List of available oversampling values. Value 1 disable the burst
        averaging mode.
+   * - ``in_voltage_sampling_frequency``
+     - Set the sampling frequency, only present if SPI Offload is being used.
+
+If `gp1` interrupt is not set, the driver will not wait for the data ready
+assertion, and will result in reading a sample before it's ready, particularly
+in oversampling mode.
 
 Also contain the following device attributes:
 
@@ -69,3 +75,21 @@ 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.
+
+SPI offload support
+===================
+
+To be able to achieve the maximum sample rate, the driver can be used with the
+`AXI SPI Engine`_ to provide SPI offload support.
+
+.. _AXI SPI Engine: http://analogdevicesinc.github.io/hdl/projects/ad4052_ardz/index.html
+
+When SPI offload is being used, additional attributes are present:
+
+.. list-table:: Additional attributes
+   :header-rows: 1
+
+   * - Attribute
+     - Description
+   * - ``in_voltage_sampling_frequency``
+     - Set the sampling frequency.

-- 
2.49.0