hwmon: Add driver for Gigabyte AORUS Waterforce AIO coolers

This driver exposes hardware sensors of the Gigabyte AORUS Waterforce
all-in-one CPU liquid coolers, which communicate through a proprietary
USB HID protocol. Report offsets were initially discovered in [1] and
confirmed by me on a Waterforce X240 by observing the sent reports from
the official software.

Available sensors are pump and fan speed in RPM, as well as coolant
temperature. Also available through debugfs is the firmware version.

Attaching a fan is optional and allows it to be controlled from the
device. If it's not connected, the fan-related sensors will report
zeroes.

The addressable RGB LEDs and LCD screen are not supported in this
driver and should be controlled through userspace tools.

[1]: https://github.com/liquidctl/liquidctl/issues/167Signed-off-by: Aleksa Savic <savicaleksa83@gmail.com>
Link: https://lore.kernel.org/r/20231207122402.107032-1-savicaleksa83@gmail.comSigned-off-by: Guenter Roeck <linux@roeck-us.net>

Documentation/hwmon/gigabyte_waterforce.rst

+.. SPDX-License-Identifier: GPL-2.0-or-later
+
+Kernel driver gigabyte_waterforce
+=================================
+
+Supported devices:
+
+* Gigabyte AORUS WATERFORCE X240
+* Gigabyte AORUS WATERFORCE X280
+* Gigabyte AORUS WATERFORCE X360
+
+Author: Aleksa Savic
+
+Description
+-----------
+
+This driver enables hardware monitoring support for the listed Gigabyte Waterforce
+all-in-one CPU liquid coolers. Available sensors are pump and fan speed in RPM, as
+well as coolant temperature. Also available through debugfs is the firmware version.
+
+Attaching a fan is optional and allows it to be controlled from the device. If
+it's not connected, the fan-related sensors will report zeroes.
+
+The addressable RGB LEDs and LCD screen are not supported in this driver and should
+be controlled through userspace tools.
+
+Usage notes
+-----------
+
+As these are USB HIDs, the driver can be loaded automatically by the kernel and
+supports hot swapping.
+
+Sysfs entries
+-------------
+
+=========== =============================================
+fan1_input  Fan speed (in rpm)
+fan2_input  Pump speed (in rpm)
+temp1_input Coolant temperature (in millidegrees Celsius)
+=========== =============================================
+
+Debugfs entries
+---------------
+
+================ =======================
+firmware_version Device firmware version
+================ =======================

Documentation/hwmon/index.rst

@@ -73,6 +73,7 @@ Hardware Monitoring Kernel Drivers
    ftsteutates
    g760a
    g762
+   gigabyte_waterforce
    gsc-hwmon
    gl518sm
    gxp-fan-ctrl

MAINTAINERS

@@ -8916,6 +8916,13 @@ F:	Documentation/filesystems/gfs2*
 F:	fs/gfs2/
 F:	include/uapi/linux/gfs2_ondisk.h
 
+GIGABYTE WATERFORCE SENSOR DRIVER
+M:	Aleksa Savic <savicaleksa83@gmail.com>
+L:	linux-hwmon@vger.kernel.org
+S:	Maintained
+F:	Documentation/hwmon/gigabyte_waterforce.rst
+F:	drivers/hwmon/gigabyte_waterforce.c
+
 GIGABYTE WMI DRIVER
 M:	Thomas Weißschuh <thomas@weissschuh.net>
 L:	platform-driver-x86@vger.kernel.org

drivers/hwmon/Kconfig

@@ -664,6 +664,16 @@ config SENSORS_FTSTEUTATES
 	  This driver can also be built as a module. If so, the module
 	  will be called ftsteutates.
 
+config SENSORS_GIGABYTE_WATERFORCE
+	tristate "Gigabyte Waterforce X240/X280/X360 AIO CPU coolers"
+	depends on USB_HID
+	help
+	  If you say yes here you get support for hardware monitoring for the
+	  Gigabyte Waterforce X240/X280/X360 all-in-one CPU liquid coolers.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called gigabyte_waterforce.
+
 config SENSORS_GL518SM
 	tristate "Genesys Logic GL518SM"
 	depends on I2C

drivers/hwmon/Makefile

@@ -80,6 +80,7 @@ obj-$(CONFIG_SENSORS_FSCHMD)	+= fschmd.o
 obj-$(CONFIG_SENSORS_FTSTEUTATES) += ftsteutates.o
 obj-$(CONFIG_SENSORS_G760A)	+= g760a.o
 obj-$(CONFIG_SENSORS_G762)	+= g762.o
+obj-$(CONFIG_SENSORS_GIGABYTE_WATERFORCE) += gigabyte_waterforce.o
 obj-$(CONFIG_SENSORS_GL518SM)	+= gl518sm.o
 obj-$(CONFIG_SENSORS_GL520SM)	+= gl520sm.o
 obj-$(CONFIG_SENSORS_GSC)	+= gsc-hwmon.o