[PATCH] Documentation/hwmon: Document hwmon_notify_event()

The hwmon core provides hwmon_notify_event() for drivers to report events
such as alarm or fault conditions to userspace via sysfs notifications
and uevents, as well as to the thermal subsystem for temperature sensors.
However, this function is not documented in the hwmon kernel API guide.

Add the function prototype and description of hwmon_notify_event() to
Documentation/hwmon/hwmon-kernel-api.rst.

Cc: Kalesh AP <[email protected]>
Fixes: 1597b374af222 ("hwmon: Add notification support")
Signed-off-by: Guenter Roeck <[email protected]>
---
 Documentation/hwmon/hwmon-kernel-api.rst | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/Documentation/hwmon/hwmon-kernel-api.rst b/Documentation/hwmon/hwmon-kernel-api.rst
index 9fcde32a140d..c3eb433a78f6 100644
--- a/Documentation/hwmon/hwmon-kernel-api.rst
+++ b/Documentation/hwmon/hwmon-kernel-api.rst
@@ -42,6 +42,9 @@ register/unregister functions::
 
   char *devm_hwmon_sanitize_name(struct device *dev, const char *name);
 
+  int hwmon_notify_event(struct device *dev, enum hwmon_sensor_types type,
+			 u32 attr, int channel);
+
   void hwmon_lock(struct device *dev);
   void hwmon_unlock(struct device *dev);
 
@@ -90,6 +93,18 @@ implemented in the driver, or debugfs functions, hwmon_lock() and hwmon_unlock()
 can be used to ensure that calls to those functions are serialized. Those
 functions also support guard() and scoped_guard() variants.
 
+Drivers can call hwmon_notify_event() to notify userspace and the thermal
+subsystem when a hardware monitoring event (such as an alarm or a fault
+condition) occurs or clears. The parameters are the hwmon device, the sensor
+type, the attribute identifier associated with the event (such as
+hwmon_temp_max_alarm or hwmon_fan_fault), and the sensor channel number.
+hwmon_notify_event() generates a sysfs event (calling sysfs_notify()) and a
+udev event with the attribute name passed in the NAME environment property
+(e.g., "NAME=temp1_max_alarm"). If the event is for a temperature sensor and
+the sensor is attached to a thermal zone, it also notifies the thermal
+subsystem to update the thermal zone. hwmon_notify_event() returns 0 on
+success or a negative error code on failure.
+
 Using devm_hwmon_device_register_with_info()
 --------------------------------------------
 
-- 
2.45.2