hwmon: Add documentation for SQ24860

Document the supported sysfs attributes for the Silergy SQ24860 PMBus
hwmon driver.

Signed-off-by: Ziming Zhu <ziming.zhu@silergycorp.com>
Link: https://lore.kernel.org/r/20260612030304.5165-4-zmzhu0630@163.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Documentation/hwmon/index.rst

@@ -253,6 +253,7 @@ Hardware Monitoring Kernel Drivers
    smsc47m1
    sparx5-temp
    spd5118
+   sq24860
    stpddc60
    surface_fan
    sy7636a-hwmon

Documentation/hwmon/sq24860.rst

@@ -0,0 +1,96 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+Kernel driver sq24860
+=====================
+
+Supported chips:
+
+  * Silergy SQ24860
+
+    Prefix: 'sq24860'
+
+Author:
+
+	Ziming Zhu <ziming.zhu@silergycorp.com>
+
+Description
+------------
+
+This driver implements support for the Silergy SQ24860 eFuse. The device is an
+integrated circuit protection and power management device with a PMBus
+interface.
+
+The device supports direct format for reading input voltage, output voltage,
+auxiliary voltage, input current, input power, and temperature.
+
+The current and power measurement scale depends on the resistor connected
+between the IMON pin and ground. The resistor value can be configured with the
+``silergy,rimon-micro-ohms`` device tree property. See
+``Documentation/devicetree/bindings/hwmon/pmbus/silergy,sq24860.yaml`` for details.
+
+Due to the specificities of the chip, all history reset attributes are tied
+together. Resetting the history of one sensor resets the history of all sensors.
+
+Sysfs entries
+-------------
+
+The following attributes are supported. Limits are read-write; all other
+attributes are read-only.
+
+======================= ======================================================
+in1_label               "vin"
+in1_input               Measured input voltage.
+in1_average             Average measured input voltage.
+in1_min                 Minimum input voltage limit.
+in1_lcrit               Critical low input voltage limit.
+in1_max                 Maximum input voltage limit.
+in1_crit                Critical high input voltage limit.
+in1_min_alarm           Input voltage low warning alarm.
+in1_lcrit_alarm         Input voltage low fault alarm.
+in1_max_alarm           Input voltage high warning alarm.
+in1_crit_alarm          Input voltage high fault alarm.
+in1_highest             Historical maximum input voltage.
+in1_lowest              Historical minimum input voltage.
+in1_reset_history       Write any value to reset history.
+
+in2_label               "vmon"
+in2_input               Measured auxiliary input voltage.
+
+in3_label               "vout1"
+in3_input               Measured output voltage.
+in3_average             Average measured output voltage.
+in3_min                 Minimum output voltage limit.
+in3_min_alarm           Output voltage low alarm.
+in3_lowest              Historical minimum output voltage.
+in3_reset_history       Write any value to reset history.
+
+curr1_label             "iin"
+curr1_input             Measured input current.
+curr1_average           Average measured input current.
+curr1_max               Maximum input current warning limit.
+curr1_crit              Critical input over-current fault limit.
+curr1_max_alarm         Input current warning alarm.
+curr1_crit_alarm        Input over-current fault alarm.
+curr1_highest           Historical maximum input current.
+curr1_reset_history     Write any value to reset history.
+
+power1_label            "pin"
+power1_input            Measured input power.
+power1_average          Average measured input power.
+power1_max              Maximum input power warning limit.
+power1_alarm            Input power warning alarm.
+power1_input_highest    Historical maximum input power.
+power1_reset_history    Write any value to reset history.
+
+temp1_input             Measured temperature.
+temp1_average           Average measured temperature.
+temp1_max               Maximum temperature warning limit.
+temp1_crit              Critical temperature fault limit.
+temp1_max_alarm         Temperature warning alarm.
+temp1_crit_alarm        Temperature fault alarm.
+temp1_highest           Historical maximum temperature.
+temp1_reset_history     Write any value to reset history.
+
+samples                 Number of samples used for average values.
+======================= ======================================================
+