docs: hwmon: htu31: document debugfs serial_number

Document the debugfs serial_number file exposed by the htu31 driver.

The driver creates a debugfs entry for the sensor serial number, but
the documentation currently only describes the sysfs interface.

Signed-off-by: Chen-Shi-Hong <eric039eric@gmail.com>
Link: https://lore.kernel.org/r/20260517125320.2196-1-eric039eric@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/Documentation/hwmon/htu31.rst b/Documentation/hwmon/htu31.rst
index ccde84264643d72b8f53381a86be79bb59fe184b..9ab774dcf65deacbc20f963575682146c3babcb1 100644 (file)
--- a/Documentation/hwmon/htu31.rst
+++ b/Documentation/hwmon/htu31.rst
@@ -35,3 +35,10 @@ temp1_input:        temperature input
 humidity1_input:    humidity input
 heater_enable:      heater control
 =================== =================
+
+debugfs-Interface
+-----------------
+
+=================== =========================================
+serial_number:      unique serial number of the sensor
+=================== =========================================