[PATCH v3 5/5] docs: iio: ad7380: add alert support

[Julien Stephan <jstephan@baylibre.com>]

Add a section for alert support, explaining how user can use iio events
attributes to enable alert and set thresholds.

Signed-off-by: Julien Stephan <jstephan@baylibre.com>
---
 Documentation/iio/ad7380.rst | 32 +++++++++++++++++++++++++++++++-
 1 file changed, 31 insertions(+), 1 deletion(-)

diff --git a/Documentation/iio/ad7380.rst b/Documentation/iio/ad7380.rst
index c46127700e14ca9ec3cac0bd5776b6702f2659e2..9b4407eeaf1d4309c06c64071ed08b4ac80944d2 100644
--- a/Documentation/iio/ad7380.rst
+++ b/Documentation/iio/ad7380.rst
@@ -92,6 +92,37 @@ must restart iiod using the following command:
 
 	root:~# systemctl restart iiod
 
+Alert
+-----
+
+When configured in 1 SDO line mode (see `SPI wiring modes`_), the SDOB or the
+SDOD line (respectively for the 2 or 4 channels variants) can act as an alert
+pin.
+
+At the end of a conversion the low-active alert pin gets asserted if the
+conversion result exceeds the alert high limit or falls below the alert low
+limit. It is cleared, on a falling edge of CS. The alert pin is common to all
+channels.
+
+User can enable alert using the regular iio events attribute:
+
+.. code-block:: bash
+
+	events/thresh_either_en
+
+The high and low thresholds are common to all channels and can also be set using
+regular iio events attributes:
+
+.. code-block:: bash
+
+	events/in_thresh_falling_value
+	events/in_thresh_rising_value
+
+If debugfs is enabled anc configured, user can read the ALERT register to
+determine the faulty channel and direction.
+
+In most use cases, user will hardwire the alert pin to trigger a shutdown.
+
 Channel selection and sequencer (single-end chips only)
 -------------------------------------------------------
 
@@ -144,7 +175,6 @@ Unimplemented features
 - Rolling average oversampling
 - Power down mode
 - CRC indication
-- Alert
 
 
 Device buffers

-- 
2.47.1