[PATCH v4 2/2] hwmon: document: add gpd-fan

[Cryolitia PukNgae via B4 Relay <devnull+Cryolitia.gmail.com@kernel.org>]

From: Cryolitia PukNgae <Cryolitia@gmail.com>

Add GPD fan driver document

Signed-off-by: Cryolitia PukNgae <Cryolitia@gmail.com>
---
 Documentation/hwmon/gpd-fan.rst | 63 +++++++++++++++++++++++++++++++++++++++++
 Documentation/hwmon/index.rst   |  1 +
 MAINTAINERS                     |  1 +
 3 files changed, 65 insertions(+)

diff --git a/Documentation/hwmon/gpd-fan.rst b/Documentation/hwmon/gpd-fan.rst
new file mode 100644
index 000000000000..68189cdc5b45
--- /dev/null
+++ b/Documentation/hwmon/gpd-fan.rst
@@ -0,0 +1,63 @@
+.. SPDX-License-Identifier: GPL-2.0-or-later
+
+Kernel driver gpd-fan
+=========================
+
+Author:
+    - Cryolitia PukNgae <Cryolitia@gmail.com>
+
+Description
+------------
+
+Handheld devices from Shenzhen GPD Technology Co., Ltd. provide fan readings and fan control through
+their embedded controllers.
+
+Supported devices
+-----------------
+
+Currently the driver supports the following handhelds:
+
+ - GPD Win Mini (7840U)
+ - GPD Win Mini (8840U)
+ - GPD Win Max 2
+ - GPD Win Max 2 2023 (7840U)
+ - GPD Win Max 2 2024 (8840U)
+ - GPD Win 4 (6800U)
+ - GPD Win 4 (7840U)
+
+Module parameters
+-----------------
+
+gpd_fan_model
+  Force specific which module quirk should be used.
+  Use it like "gpd_fan_model=wm2".
+
+   - wm2
+       - GPD Win 4 (7840U)
+       - GPD Win Max 2 (6800U)
+       - GPD Win Max 2 2023 (7840U)
+       - GPD Win Max 2 2024 (8840U)
+   - win4
+       - GPD Win 4 (6800U)
+   - win_mini
+       - GPD Win Mini (7840U)
+       - GPD Win Mini (8840U)
+
+Sysfs entries
+-------------
+
+The following attributes are supported:
+
+fan1_input
+  Read Only. Reads current fan RPM.
+
+pwm1_enable
+  Read/Write. Enable manual fan control. Write "0" to disable control and run at
+  full speed. Write "1" to set to manual, write "2" to let the EC control decide
+  fan speed. Read this attribute to see current status.
+
+pwm1
+  Read/Write. Read this attribute to see current duty cycle in the range [0-255].
+  When pwm1_enable is set to "1" (manual) write any value in the range [0-255]
+  to set fan speed.
+
diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst
index 913c11390a45..97add26f53b7 100644
--- a/Documentation/hwmon/index.rst
+++ b/Documentation/hwmon/index.rst
@@ -80,6 +80,7 @@ Hardware Monitoring Kernel Drivers
    gigabyte_waterforce
    gsc-hwmon
    gl518sm
+   gpd-fan
    gxp-fan-ctrl
    hih6130
    hp-wmi-sensors
diff --git a/MAINTAINERS b/MAINTAINERS
index 9ced72cec42b..5079b5bfe4b1 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9376,6 +9376,7 @@ GPD FAN DRIVER
 M:	Cryolitia PukNgae <Cryolitia@gmail.com>
 L:	linux-hwmon@vger.kernel.org
 S:	Maintained
+F:	Documentation/hwmon/gpd-fan.rst
 F:	drivers/hwmon/gpd-fan.c
 
 GPD POCKET FAN DRIVER

-- 
2.45.2