[PATCH v4 5/5] docs: iio: ad7380: add alert support

Julien Stephan
2025-01-08T12:49:49Z

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

Reviewed-by: David Lechner <dlechner@baylibre.com>
Signed-off-by: Julien Stephan <jstephan@baylibre.com>
---
Documentation/iio/ad7380.rst | 33 ++++++++++++++++++++++++++++++++-
1 file changed, 32 insertions(+), 1 deletion(-)

diff --git a/Documentation/iio/ad7380.rst b/Documentation/iio/ad7380.rst
index c46127700e14ca9ec3cac0bd5776b6702f2659e2..cff688bcc2d9601a9faf42d5e9c217486639ca66 100644
--- a/Documentation/iio/ad7380.rst
+++ b/Documentation/iio/ad7380.rst
@@ -92,6 +92,38 @@ must restart iiod using the following command:

root:~# systemctl restart iiod

+Alert
+-----
+
+2 channels variants of the ad738x family, can use the SDOB line as an alert pin
+when configured in 1 SDO line mode. 4 channels variants, can use SDOD as an
+alert pin when configured in 1 or 2 SDO line(s) mode, although only 1 SDO line
+mode is currently supported by the driver (see `SPI wiring modes`_).
+
+At the end of a conversion the active-low 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 available, 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 +176,6 @@ Unimplemented features
- Rolling average oversampling
- Power down mode
- CRC indication
-- Alert

Device buffers

--
2.47.1