[PATCH v6 0/2] hwmon: add GPD devices sensor driver

[PATCH v6 0/2] hwmon: add GPD devices sensor driver

[Cryolitia PukNgae via B4 Relay]

Sensors driver for GPD Handhelds that expose fan reading and control via
hwmon sysfs.

Shenzhen GPD Technology Co., Ltd. manufactures a series of handheld
devices. This driver implements these functions through x86 port-mapped IO.

Tested-by: Marcin Strągowski <marcin@stragowski.com>
Tested-by: someone5678 <someone5678.dev@gmail.com>
Tested-by: Justin Weiss <justin@justinweiss.com>
Tested-by: Antheas Kapenekakis <lkml@antheas.dev>
Tested-by: command_block <mtf@ik.me>

Signed-off-by: Cryolitia PukNgae <Cryolitia@gmail.com>

---
Changes in v6:
- fix: nullptr and label followed by a declaration
- cleanup: clean up code and rename some function
- format code
- dmi: add 2025 new GPD devices
- Link to v5: https://lore.kernel.org/r/20250211-gpd_fan-v5-0-608f4255f0e1@gmail.com

Changes in v5:
- Rebase on kernel 6.13
- Remove all value-cache related code
- Clean up code
- Link to v4: https://lore.kernel.org/r/20240718-gpd_fan-v4-0-116e5431a9fe@gmail.com

Changes in v4:
- Apply suggest by Krzysztof Kozlowski, thanks!
- Link to v3: https://lore.kernel.org/r/20240717-gpd_fan-v3-0-8d7efb1263b7@gmail.com

Changes in v3:
- Re-arrange code, thanks to Krzysztof Kozlowski, Guenter Roeck, Yao Zi!
- Link to v2: https://lore.kernel.org/r/20240717-gpd_fan-v2-0-f7b7e6b9f21b@gmail.com

Changes in v2:
- Improved documentation, thanks to Randy Dunlap!
- Link to v1: https://lore.kernel.org/r/20240716-gpd_fan-v1-0-34051dd71a06@gmail.com

---
Cryolitia PukNgae (2):
      hwmon: add GPD devices sensor driver
      hwmon: document: add gpd-fan

 Documentation/hwmon/gpd-fan.rst |  71 +++++
 Documentation/hwmon/index.rst   |   1 +
 MAINTAINERS                     |   7 +
 drivers/hwmon/Kconfig           |  10 +
 drivers/hwmon/Makefile          |   1 +
 drivers/hwmon/gpd-fan.c         | 681 ++++++++++++++++++++++++++++++++++++++++
 6 files changed, 771 insertions(+)
---
base-commit: ffd294d346d185b70e28b1a28abe367bbfe53c04
change-id: 20240716-gpd_fan-57f30923c884

Best regards,
-- 
Cryolitia PukNgae <Cryolitia@gmail.com>

[PATCH v6 1/2] hwmon: add GPD devices sensor driver

[Cryolitia PukNgae via B4 Relay]

From: Cryolitia PukNgae <Cryolitia@gmail.com>

Sensors driver for GPD Handhelds that expose fan reading and control via
hwmon sysfs.

Shenzhen GPD Technology Co., Ltd. manufactures a series of handheld
devices. This driver implements these functions through x86 port-mapped IO.

Signed-off-by: Cryolitia PukNgae <Cryolitia@gmail.com>
---
 MAINTAINERS             |   6 +
 drivers/hwmon/Kconfig   |  10 +
 drivers/hwmon/Makefile  |   1 +
 drivers/hwmon/gpd-fan.c | 681 ++++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 698 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 0fa7c5728f1e64d031f4a47b6fce1db484ce0fc2..777ba74ccb07ccc0840c3cd34e7b4d98d726f964 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9762,6 +9762,12 @@ F:	drivers/phy/samsung/phy-gs101-ufs.c
 F:	include/dt-bindings/clock/google,gs101.h
 K:	[gG]oogle.?[tT]ensor
 
+GPD FAN DRIVER
+M:	Cryolitia PukNgae <Cryolitia@gmail.com>
+L:	linux-hwmon@vger.kernel.org
+S:	Maintained
+F:	drivers/hwmon/gpd-fan.c
+
 GPD POCKET FAN DRIVER
 M:	Hans de Goede <hdegoede@redhat.com>
 L:	platform-driver-x86@vger.kernel.org
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index dd376602f3f19c6f258651afeffbe1bb5d9b6b72..974b341c0bdaba147370de59f510140c0c937913 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -729,6 +729,16 @@ config SENSORS_GL520SM
 	  This driver can also be built as a module. If so, the module
 	  will be called gl520sm.
 
+config SENSORS_GPD
+	tristate "GPD handhelds"
+	depends on X86
+	help
+	  If you say yes here you get support for fan readings and
+	  control over GPD handheld devices.
+
+	  Can also be built as a module. In that case it will be
+	  called gpd-fan.
+
 config SENSORS_G760A
 	tristate "GMT G760A"
 	depends on I2C
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index b827b92f2a7844418f3f3b6434a63b744b52c33d..cd512c19caa9737a2926a3d4860f65b65cd013c3 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -87,6 +87,7 @@ 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
+obj-$(CONFIG_SENSORS_GPD)	+= gpd-fan.o
 obj-$(CONFIG_SENSORS_GPIO_FAN)	+= gpio-fan.o
 obj-$(CONFIG_SENSORS_GXP_FAN_CTRL) += gxp-fan-ctrl.o
 obj-$(CONFIG_SENSORS_HIH6130)	+= hih6130.o
diff --git a/drivers/hwmon/gpd-fan.c b/drivers/hwmon/gpd-fan.c
new file mode 100644
index 0000000000000000000000000000000000000000..782c9981d5357b11faad4e6cd75242828e667f95
--- /dev/null
+++ b/drivers/hwmon/gpd-fan.c
@@ -0,0 +1,681 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+/* Platform driver for GPD devices that expose fan control via hwmon sysfs.
+ *
+ * Fan control is provided via pwm interface in the range [0-255].
+ * Each model has a different range in the EC, the written value is scaled to
+ * accommodate for that.
+ *
+ * Based on this repo:
+ * https://github.com/Cryolitia/gpd-fan-driver
+ *
+ * Copyright (c) 2024 Cryolitia PukNgae
+ */
+
+#include <linux/acpi.h>
+#include <linux/dmi.h>
+#include <linux/hwmon.h>
+#include <linux/ioport.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+#define DRIVER_NAME "gpdfan"
+#define GPD_PWM_CTR_OFFSET 0x1841
+
+static char *gpd_fan_board = "";
+module_param(gpd_fan_board, charp, 0444);
+
+// EC read/write locker
+// Should never access EC at the same time, otherwise system down.
+static DEFINE_MUTEX(gpd_fan_lock);
+
+enum gpd_board {
+	win_mini,
+	win4_6800u,
+	win_max_2,
+};
+
+enum FAN_PWM_ENABLE {
+	DISABLE		= 0,
+	MANUAL		= 1,
+	AUTOMATIC	= 2,
+};
+
+static struct {
+	enum FAN_PWM_ENABLE pwm_enable;
+	u8 pwm_value;
+
+	const struct gpd_fan_drvdata *drvdata;
+} gpd_driver_priv;
+
+struct gpd_fan_drvdata {
+	const char *board_name; /* Board name for module param comparison */
+	const enum gpd_board board;
+
+	const u8 addr_port;
+	const u8 data_port;
+	const u16 manual_control_enable;
+	const u16 rpm_read;
+	const u16 pwm_write;
+	const u16 pwm_max;
+};
+
+static struct gpd_fan_drvdata gpd_win_mini_drvdata = {
+	.board_name		= "win_mini",
+	.board			= win_mini,
+
+	.addr_port		= 0x4E,
+	.data_port		= 0x4F,
+	.manual_control_enable	= 0x047A,
+	.rpm_read		= 0x0478,
+	.pwm_write		= 0x047A,
+	.pwm_max		= 244,
+};
+
+static struct gpd_fan_drvdata gpd_win4_drvdata = {
+	.board_name		= "win4",
+	.board			= win4_6800u,
+
+	.addr_port		= 0x2E,
+	.data_port		= 0x2F,
+	.manual_control_enable	= 0xC311,
+	.rpm_read		= 0xC880,
+	.pwm_write		= 0xC311,
+	.pwm_max		= 127,
+};
+
+static struct gpd_fan_drvdata gpd_wm2_drvdata = {
+	.board_name		= "wm2",
+	.board			= win_max_2,
+
+	.addr_port		= 0x4E,
+	.data_port		= 0x4F,
+	.manual_control_enable	= 0x0275,
+	.rpm_read		= 0x0218,
+	.pwm_write		= 0x1809,
+	.pwm_max		= 184,
+};
+
+static const struct dmi_system_id dmi_table[] = {
+	{
+		// GPD Win Mini
+		// GPD Win Mini with AMD Ryzen 8840U
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "GPD"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "G1617-01")
+		},
+		.driver_data = &gpd_win_mini_drvdata,
+	},
+	{
+		// GPD Win Mini
+		// GPD Win Mini with AMD Ryzen HX370
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "GPD"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "G1617-02")
+		},
+		.driver_data = &gpd_win_mini_drvdata,
+	},
+	{
+		// GPD Win Mini
+		// GPD Win Mini with AMD Ryzen HX370
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "GPD"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "G1617-02-L")
+		},
+		.driver_data = &gpd_win_mini_drvdata,
+	},
+	{
+		// GPD Win 4 with AMD Ryzen 6800U
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "GPD"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "G1618-04"),
+			DMI_MATCH(DMI_BOARD_VERSION, "Default string"),
+		},
+		.driver_data = &gpd_win4_drvdata,
+	},
+	{
+		// GPD Win 4 with Ryzen 7840U
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "GPD"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "G1618-04"),
+			DMI_MATCH(DMI_BOARD_VERSION, "Ver. 1.0"),
+		},
+		// Since 7840U, win4 uses the same drvdata as wm2
+		.driver_data = &gpd_wm2_drvdata,
+	},
+	{
+		// GPD Win 4 with Ryzen 7840U (another)
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "GPD"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "G1618-04"),
+			DMI_MATCH(DMI_BOARD_VERSION, "Ver.1.0"),
+		},
+		.driver_data = &gpd_wm2_drvdata,
+	},
+	{
+		// GPD Win Max 2 with Ryzen 6800U
+		// GPD Win Max 2 2023 with Ryzen 7840U
+		// GPD Win Max 2 2024 with Ryzen 8840U
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "GPD"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "G1619-04"),
+		},
+		.driver_data = &gpd_wm2_drvdata,
+	},
+	{
+		// GPD Win Max 2 with AMD Ryzen HX370
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "GPD"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "G1619-05"),
+		},
+		.driver_data = &gpd_wm2_drvdata,
+	},
+	{
+		// GPD Pocket 4
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "GPD"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "G1628-04"),
+		},
+		.driver_data = &gpd_win_mini_drvdata,
+	},
+	{
+		// GPD Pocket 4 (another)
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "GPD"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "G1628-04-L"),
+		},
+		.driver_data = &gpd_win_mini_drvdata,
+	},
+	{}
+};
+
+static const struct gpd_fan_drvdata *gpd_module_drvdata[] = {
+	&gpd_win_mini_drvdata, &gpd_win4_drvdata, &gpd_wm2_drvdata, NULL
+};
+
+/* Helper functions to handle EC read/write */
+static int gpd_ecram_read(const struct gpd_fan_drvdata *drvdata, u16 offset,
+			  u8 *val)
+{
+	int ret;
+	u16 addr_port = drvdata->addr_port;
+	u16 data_port = drvdata->data_port;
+
+	ret = mutex_lock_interruptible(&gpd_fan_lock);
+
+	if (ret)
+		return ret;
+
+	outb(0x2E, addr_port);
+	outb(0x11, data_port);
+	outb(0x2F, addr_port);
+	outb((u8)((offset >> 8) & 0xFF), data_port);
+
+	outb(0x2E, addr_port);
+	outb(0x10, data_port);
+	outb(0x2F, addr_port);
+	outb((u8)(offset & 0xFF), data_port);
+
+	outb(0x2E, addr_port);
+	outb(0x12, data_port);
+	outb(0x2F, addr_port);
+	*val = inb(data_port);
+
+	mutex_unlock(&gpd_fan_lock);
+	return 0;
+}
+
+static int gpd_ecram_write(const struct gpd_fan_drvdata *drvdata, u16 offset,
+			   u8 value)
+{
+	int ret;
+	u16 addr_port = drvdata->addr_port;
+	u16 data_port = drvdata->data_port;
+
+	ret = mutex_lock_interruptible(&gpd_fan_lock);
+
+	if (ret)
+		return ret;
+
+	outb(0x2E, addr_port);
+	outb(0x11, data_port);
+	outb(0x2F, addr_port);
+	outb((u8)((offset >> 8) & 0xFF), data_port);
+
+	outb(0x2E, addr_port);
+	outb(0x10, data_port);
+	outb(0x2F, addr_port);
+	outb((u8)(offset & 0xFF), data_port);
+
+	outb(0x2E, addr_port);
+	outb(0x12, data_port);
+	outb(0x2F, addr_port);
+	outb(value, data_port);
+
+	mutex_unlock(&gpd_fan_lock);
+	return 0;
+}
+
+static int gpd_generic_read_rpm(void)
+{
+	u8 high, low;
+	int ret;
+	const struct gpd_fan_drvdata *const drvdata = gpd_driver_priv.drvdata;
+
+	ret = gpd_ecram_read(drvdata, drvdata->rpm_read, &high);
+	if (ret)
+		return ret;
+
+	ret = gpd_ecram_read(drvdata, drvdata->rpm_read + 1, &low);
+	if (ret)
+		return ret;
+
+	return (u16)high << 8 | low;
+}
+
+static int gpd_win4_read_rpm(void)
+{
+	const struct gpd_fan_drvdata *const drvdata = gpd_driver_priv.drvdata;
+	u8 pwm_ctr_reg;
+	int ret;
+
+	gpd_ecram_read(drvdata, GPD_PWM_CTR_OFFSET, &pwm_ctr_reg);
+
+	if (pwm_ctr_reg != 0x7F)
+		gpd_ecram_write(drvdata, GPD_PWM_CTR_OFFSET, 0x7F);
+
+	ret = gpd_generic_read_rpm();
+
+	if (ret < 0)
+		return ret;
+
+	if (ret == 0) {
+		// re-init EC
+		u8 chip_id;
+
+		gpd_ecram_read(drvdata, 0x2000, &chip_id);
+		if (chip_id == 0x55) {
+			u8 chip_ver;
+
+			if (gpd_ecram_read(drvdata, 0x1060, &chip_ver))
+				gpd_ecram_write(drvdata, 0x1060,
+						chip_ver | 0x80);
+		}
+	}
+
+	return ret;
+}
+
+static int gpd_wm2_read_rpm(void)
+{
+	const struct gpd_fan_drvdata *const drvdata = gpd_driver_priv.drvdata;
+
+	for (u16 pwm_ctr_offset = GPD_PWM_CTR_OFFSET;
+	     pwm_ctr_offset <= GPD_PWM_CTR_OFFSET + 2; pwm_ctr_offset++) {
+		u8 PWMCTR;
+
+		gpd_ecram_read(drvdata, pwm_ctr_offset, &PWMCTR);
+
+		if (PWMCTR != 0xB8)
+			gpd_ecram_write(drvdata, pwm_ctr_offset, 0xB8);
+	}
+
+	return gpd_generic_read_rpm();
+}
+
+// Read value for fan1_input
+static int gpd_read_rpm(void)
+{
+	switch (gpd_driver_priv.drvdata->board) {
+	case win_mini:
+		return gpd_generic_read_rpm();
+	case win4_6800u:
+		return gpd_win4_read_rpm();
+	case win_max_2:
+		return gpd_wm2_read_rpm();
+	}
+
+	return 0;
+}
+
+static int gpd_wm2_read_pwm(void)
+{
+	const struct gpd_fan_drvdata *const drvdata = gpd_driver_priv.drvdata;
+	u8 var;
+	int ret = gpd_ecram_read(drvdata, drvdata->pwm_write, &var);
+
+	if (ret < 0)
+		return ret;
+
+	return var * 255 / drvdata->pwm_max;
+}
+
+// Read value for pwm1
+static int gpd_read_pwm(void)
+{
+	switch (gpd_driver_priv.drvdata->board) {
+	case win_mini:
+	case win4_6800u:
+		return gpd_driver_priv.pwm_value;
+	case win_max_2:
+		return gpd_wm2_read_pwm();
+	}
+	return 0;
+}
+
+static int gpd_generic_write_pwm(u8 val)
+{
+	const struct gpd_fan_drvdata *const drvdata = gpd_driver_priv.drvdata;
+	u8 pwm_reg;
+
+	// PWM value's range in EC is 1 - pwm_max, cast 0 - 255 to it.
+	pwm_reg = val * (drvdata->pwm_max - 1) / 255 + 1;
+	return gpd_ecram_write(drvdata, drvdata->pwm_write, pwm_reg);
+}
+
+static int gpd_win_mini_write_pwm(u8 val)
+{
+	if (gpd_driver_priv.pwm_enable == MANUAL)
+		return gpd_generic_write_pwm(val);
+	else
+		return -EPERM;
+}
+
+static int gpd_wm2_write_pwm(u8 val)
+{
+	if (gpd_driver_priv.pwm_enable != DISABLE)
+		return gpd_generic_write_pwm(val);
+	else
+		return -EPERM;
+}
+
+// Write value for pwm1
+static int gpd_write_pwm(u8 val)
+{
+	switch (gpd_driver_priv.drvdata->board) {
+	case win_mini:
+		return gpd_win_mini_write_pwm(val);
+	case win4_6800u:
+		return gpd_generic_write_pwm(val);
+	case win_max_2:
+		return gpd_wm2_write_pwm(val);
+	}
+
+	return 0;
+}
+
+static int gpd_win_mini_set_pwm_enable(enum FAN_PWM_ENABLE pwm_enable)
+{
+	const struct gpd_fan_drvdata *drvdata;
+
+	switch (pwm_enable) {
+	case DISABLE:
+		return gpd_generic_write_pwm(255);
+	case MANUAL:
+		return gpd_generic_write_pwm(gpd_driver_priv.pwm_value);
+	case AUTOMATIC:
+		drvdata = gpd_driver_priv.drvdata;
+		return gpd_ecram_write(drvdata, drvdata->pwm_write, 0);
+	}
+
+	return 0;
+}
+
+static int gpd_wm2_set_pwm_enable(enum FAN_PWM_ENABLE enable)
+{
+	const struct gpd_fan_drvdata *const drvdata = gpd_driver_priv.drvdata;
+	int ret;
+
+	switch (enable) {
+	case DISABLE: {
+		ret = gpd_generic_write_pwm(255);
+
+		if (ret)
+			return ret;
+
+		return gpd_ecram_write(drvdata, drvdata->manual_control_enable,
+				       1);
+	}
+	case MANUAL: {
+		ret = gpd_generic_write_pwm(gpd_driver_priv.pwm_value);
+
+		if (ret)
+			return ret;
+
+		return gpd_ecram_write(drvdata, drvdata->manual_control_enable,
+				       1);
+	}
+	case AUTOMATIC: {
+		ret = gpd_ecram_write(drvdata, drvdata->manual_control_enable,
+				      0);
+
+		return ret;
+	}
+	}
+
+	return 0;
+}
+
+// Write value for pwm1_enable
+static int gpd_set_pwm_enable(enum FAN_PWM_ENABLE enable)
+{
+	switch (gpd_driver_priv.drvdata->board) {
+	case win_mini:
+	case win4_6800u:
+		return gpd_win_mini_set_pwm_enable(enable);
+	case win_max_2:
+		return gpd_wm2_set_pwm_enable(enable);
+	}
+
+	return 0;
+}
+
+static umode_t gpd_fan_hwmon_is_visible(__always_unused const void *drvdata,
+					enum hwmon_sensor_types type, u32 attr,
+					__always_unused int channel)
+{
+	if (type == hwmon_fan && attr == hwmon_fan_input) {
+		return 0444;
+	} else if (type == hwmon_pwm) {
+		switch (attr) {
+		case hwmon_pwm_enable:
+		case hwmon_pwm_input:
+			return 0644;
+		default:
+			return 0;
+		}
+	}
+	return 0;
+}
+
+static int gpd_fan_hwmon_read(__always_unused struct device *dev,
+			      enum hwmon_sensor_types type, u32 attr,
+			      __always_unused int channel, long *val)
+{
+	if (type == hwmon_fan) {
+		if (attr == hwmon_fan_input) {
+			int ret = gpd_read_rpm();
+
+			if (ret < 0)
+				return ret;
+
+			*val = ret;
+			return 0;
+		}
+		return -EOPNOTSUPP;
+	} else if (type == hwmon_pwm) {
+		int ret;
+
+		switch (attr) {
+		case hwmon_pwm_enable:
+			*val = gpd_driver_priv.pwm_enable;
+			return 0;
+		case hwmon_pwm_input:
+			ret = gpd_read_pwm();
+
+			if (ret < 0)
+				return ret;
+
+			*val = ret;
+			return 0;
+		default:
+			return -EOPNOTSUPP;
+		}
+	}
+
+	return -EOPNOTSUPP;
+}
+
+static int gpd_fan_hwmon_write(__always_unused struct device *dev,
+			       enum hwmon_sensor_types type, u32 attr,
+			       __always_unused int channel, long val)
+{
+	u8 var;
+
+	if (type == hwmon_pwm) {
+		switch (attr) {
+		case hwmon_pwm_enable:
+			if (!in_range(val, 0, 3))
+				return -EINVAL;
+
+			gpd_driver_priv.pwm_enable = val;
+
+			return gpd_set_pwm_enable(gpd_driver_priv.pwm_enable);
+		case hwmon_pwm_input:
+			var = clamp_val(val, 0, 255);
+
+			gpd_driver_priv.pwm_value = var;
+
+			return gpd_write_pwm(var);
+		default:
+			return -EOPNOTSUPP;
+		}
+	}
+
+	return -EOPNOTSUPP;
+}
+
+static const struct hwmon_ops gpd_fan_ops = {
+	.is_visible = gpd_fan_hwmon_is_visible,
+	.read = gpd_fan_hwmon_read,
+	.write = gpd_fan_hwmon_write,
+};
+
+static const struct hwmon_channel_info *gpd_fan_hwmon_channel_info[] = {
+	HWMON_CHANNEL_INFO(fan, HWMON_F_INPUT),
+	HWMON_CHANNEL_INFO(pwm, HWMON_PWM_INPUT | HWMON_PWM_ENABLE),
+	NULL
+};
+
+static struct hwmon_chip_info gpd_fan_chip_info = {
+	.ops = &gpd_fan_ops,
+	.info = gpd_fan_hwmon_channel_info
+};
+
+static int gpd_fan_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	const struct resource *res;
+	const struct device *hwdev;
+	const struct resource *region;
+
+	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
+	if (IS_ERR(res))
+		return dev_err_probe(dev, PTR_ERR(res),
+				     "Failed to get platform resource\n");
+
+	region = devm_request_region(dev, res->start,
+				     resource_size(res), DRIVER_NAME);
+	if (IS_ERR(region))
+		return dev_err_probe(dev, PTR_ERR(region),
+				     "Failed to request region\n");
+
+	hwdev = devm_hwmon_device_register_with_info(dev,
+						     DRIVER_NAME,
+						     NULL,
+						     &gpd_fan_chip_info,
+						     NULL);
+	if (IS_ERR(hwdev))
+		return dev_err_probe(dev, PTR_ERR(region),
+				     "Failed to register hwmon device\n");
+
+	return 0;
+}
+
+static void gpd_fan_remove(__always_unused struct platform_device *pdev)
+{
+	gpd_driver_priv.pwm_enable = AUTOMATIC;
+	gpd_set_pwm_enable(AUTOMATIC);
+}
+
+static struct platform_driver gpd_fan_driver = {
+	.probe = gpd_fan_probe,
+	.remove = gpd_fan_remove,
+	.driver = {
+		.name = KBUILD_MODNAME,
+	},
+};
+
+static struct platform_device *gpd_fan_platform_device;
+
+static int __init gpd_fan_init(void)
+{
+	const struct gpd_fan_drvdata *match = NULL;
+
+	for (const struct gpd_fan_drvdata **p = gpd_module_drvdata; *p; p++) {
+		if (strcmp(gpd_fan_board, (*p)->board_name) == 0) {
+			match = *p;
+			break;
+		}
+	}
+
+	if (!match) {
+		const struct dmi_system_id *dmi_match =
+			dmi_first_match(dmi_table);
+		if (dmi_match)
+			match = dmi_match->driver_data;
+	}
+
+	if (!match)
+		return -ENODEV;
+
+	gpd_driver_priv.pwm_enable = AUTOMATIC;
+	gpd_driver_priv.pwm_value = 255;
+	gpd_driver_priv.drvdata = match;
+
+	struct resource gpd_fan_resources[] = {
+		{
+			.start = match->addr_port,
+			.end = match->data_port,
+			.flags = IORESOURCE_IO,
+		},
+	};
+
+	gpd_fan_platform_device = platform_create_bundle(&gpd_fan_driver,
+							 gpd_fan_probe,
+							 gpd_fan_resources,
+							 1, NULL, 0);
+
+	if (IS_ERR(gpd_fan_platform_device)) {
+		pr_warn("Failed to create platform device\n");
+		return PTR_ERR(gpd_fan_platform_device);
+	}
+
+	return 0;
+}
+
+static void __exit gpd_fan_exit(void)
+{
+	platform_device_unregister(gpd_fan_platform_device);
+	platform_driver_unregister(&gpd_fan_driver);
+}
+
+MODULE_DEVICE_TABLE(dmi, dmi_table);
+
+module_init(gpd_fan_init);
+module_exit(gpd_fan_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Cryolitia PukNgae <Cryolitia@gmail.com>");
+MODULE_DESCRIPTION("GPD Devices fan control driver");

-- 
2.48.1

Re: [PATCH v6 1/2] hwmon: add GPD devices sensor driver

[Antheas Kapenekakis]

On Thu, 13 Mar 2025 at 21:10, Cryolitia PukNgae via B4 Relay
<devnull+Cryolitia.gmail.com@kernel.org> wrote:
>
> From: Cryolitia PukNgae <Cryolitia@gmail.com>
>
> Sensors driver for GPD Handhelds that expose fan reading and control via
> hwmon sysfs.
>
> Shenzhen GPD Technology Co., Ltd. manufactures a series of handheld
> devices. This driver implements these functions through x86 port-mapped IO.
>
> Signed-off-by: Cryolitia PukNgae <Cryolitia@gmail.com>
> ---
>  MAINTAINERS             |   6 +
>  drivers/hwmon/Kconfig   |  10 +
>  drivers/hwmon/Makefile  |   1 +
>  drivers/hwmon/gpd-fan.c | 681 ++++++++++++++++++++++++++++++++++++++++++++++++
>  4 files changed, 698 insertions(+)
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 0fa7c5728f1e64d031f4a47b6fce1db484ce0fc2..777ba74ccb07ccc0840c3cd34e7b4d98d726f964 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -9762,6 +9762,12 @@ F:       drivers/phy/samsung/phy-gs101-ufs.c
>  F:     include/dt-bindings/clock/google,gs101.h
>  K:     [gG]oogle.?[tT]ensor
>
> +GPD FAN DRIVER
> +M:     Cryolitia PukNgae <Cryolitia@gmail.com>
> +L:     linux-hwmon@vger.kernel.org
> +S:     Maintained
> +F:     drivers/hwmon/gpd-fan.c

A problem we had with oxp sensors is that once OneXPlayer expanded
their EC to include e.g., battery capacity limits, it was no longer
appropriate for it to reside in hwmon. I expect GPD to do the same
sometime in the near future. If that is the case, should we
futureproof the driver by moving it to platform-x86 right away?

> +
>  GPD POCKET FAN DRIVER
>  M:     Hans de Goede <hdegoede@redhat.com>
>  L:     platform-driver-x86@vger.kernel.org
> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
> index dd376602f3f19c6f258651afeffbe1bb5d9b6b72..974b341c0bdaba147370de59f510140c0c937913 100644
> --- a/drivers/hwmon/Kconfig
> +++ b/drivers/hwmon/Kconfig
> @@ -729,6 +729,16 @@ config SENSORS_GL520SM
>           This driver can also be built as a module. If so, the module
>           will be called gl520sm.
>
> +config SENSORS_GPD
> +       tristate "GPD handhelds"
> +       depends on X86
> +       help
> +         If you say yes here you get support for fan readings and
> +         control over GPD handheld devices.
> +
> +         Can also be built as a module. In that case it will be
> +         called gpd-fan.
> +
>  config SENSORS_G760A
>         tristate "GMT G760A"
>         depends on I2C
> diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
> index b827b92f2a7844418f3f3b6434a63b744b52c33d..cd512c19caa9737a2926a3d4860f65b65cd013c3 100644
> --- a/drivers/hwmon/Makefile
> +++ b/drivers/hwmon/Makefile
> @@ -87,6 +87,7 @@ 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
> +obj-$(CONFIG_SENSORS_GPD)      += gpd-fan.o
>  obj-$(CONFIG_SENSORS_GPIO_FAN) += gpio-fan.o
>  obj-$(CONFIG_SENSORS_GXP_FAN_CTRL) += gxp-fan-ctrl.o
>  obj-$(CONFIG_SENSORS_HIH6130)  += hih6130.o
> diff --git a/drivers/hwmon/gpd-fan.c b/drivers/hwmon/gpd-fan.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..782c9981d5357b11faad4e6cd75242828e667f95
> --- /dev/null
> +++ b/drivers/hwmon/gpd-fan.c
> @@ -0,0 +1,681 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +
> +/* Platform driver for GPD devices that expose fan control via hwmon sysfs.
> + *
> + * Fan control is provided via pwm interface in the range [0-255].
> + * Each model has a different range in the EC, the written value is scaled to
> + * accommodate for that.
> + *
> + * Based on this repo:
> + * https://github.com/Cryolitia/gpd-fan-driver

Perhaps the github link will date this. I would remove it.

> + *
> + * Copyright (c) 2024 Cryolitia PukNgae
> + */
> +
> +#include <linux/acpi.h>
> +#include <linux/dmi.h>
> +#include <linux/hwmon.h>
> +#include <linux/ioport.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +
> +#define DRIVER_NAME "gpdfan"
> +#define GPD_PWM_CTR_OFFSET 0x1841
> +
> +static char *gpd_fan_board = "";
> +module_param(gpd_fan_board, charp, 0444);
> +
> +// EC read/write locker
> +// Should never access EC at the same time, otherwise system down.

These two comments could use some rewording. E.g., Prevent access to
the EC at the same time to avoid system instability.

> +static DEFINE_MUTEX(gpd_fan_lock);
> +
> +enum gpd_board {
> +       win_mini,
> +       win4_6800u,
> +       win_max_2,
> +};
> +
> +enum FAN_PWM_ENABLE {
> +       DISABLE         = 0,
> +       MANUAL          = 1,
> +       AUTOMATIC       = 2,
> +};
> +
> +static struct {
> +       enum FAN_PWM_ENABLE pwm_enable;
> +       u8 pwm_value;
> +
> +       const struct gpd_fan_drvdata *drvdata;
> +} gpd_driver_priv;
> +
> +struct gpd_fan_drvdata {
> +       const char *board_name; /* Board name for module param comparison */
> +       const enum gpd_board board;
> +
> +       const u8 addr_port;
> +       const u8 data_port;
> +       const u16 manual_control_enable;
> +       const u16 rpm_read;
> +       const u16 pwm_write;
> +       const u16 pwm_max;
> +};
> +
> +static struct gpd_fan_drvdata gpd_win_mini_drvdata = {
> +       .board_name             = "win_mini",
> +       .board                  = win_mini,
> +
> +       .addr_port              = 0x4E,
> +       .data_port              = 0x4F,
> +       .manual_control_enable  = 0x047A,
> +       .rpm_read               = 0x0478,
> +       .pwm_write              = 0x047A,
> +       .pwm_max                = 244,
> +};
> +
> +static struct gpd_fan_drvdata gpd_win4_drvdata = {
> +       .board_name             = "win4",
> +       .board                  = win4_6800u,
> +
> +       .addr_port              = 0x2E,
> +       .data_port              = 0x2F,
> +       .manual_control_enable  = 0xC311,
> +       .rpm_read               = 0xC880,
> +       .pwm_write              = 0xC311,
> +       .pwm_max                = 127,
> +};
> +
> +static struct gpd_fan_drvdata gpd_wm2_drvdata = {
> +       .board_name             = "wm2",
> +       .board                  = win_max_2,
> +
> +       .addr_port              = 0x4E,
> +       .data_port              = 0x4F,
> +       .manual_control_enable  = 0x0275,
> +       .rpm_read               = 0x0218,
> +       .pwm_write              = 0x1809,
> +       .pwm_max                = 184,
> +};
> +
> +static const struct dmi_system_id dmi_table[] = {
> +       {
> +               // GPD Win Mini
> +               // GPD Win Mini with AMD Ryzen 8840U
> +               .matches = {
> +                       DMI_MATCH(DMI_SYS_VENDOR, "GPD"),
> +                       DMI_MATCH(DMI_PRODUCT_NAME, "G1617-01")
> +               },
> +               .driver_data = &gpd_win_mini_drvdata,
> +       },
> +       {
> +               // GPD Win Mini
> +               // GPD Win Mini with AMD Ryzen HX370
> +               .matches = {
> +                       DMI_MATCH(DMI_SYS_VENDOR, "GPD"),
> +                       DMI_MATCH(DMI_PRODUCT_NAME, "G1617-02")
> +               },
> +               .driver_data = &gpd_win_mini_drvdata,
> +       },
> +       {
> +               // GPD Win Mini
> +               // GPD Win Mini with AMD Ryzen HX370
> +               .matches = {
> +                       DMI_MATCH(DMI_SYS_VENDOR, "GPD"),
> +                       DMI_MATCH(DMI_PRODUCT_NAME, "G1617-02-L")
> +               },
> +               .driver_data = &gpd_win_mini_drvdata,
> +       },
> +       {
> +               // GPD Win 4 with AMD Ryzen 6800U
> +               .matches = {
> +                       DMI_MATCH(DMI_SYS_VENDOR, "GPD"),
> +                       DMI_MATCH(DMI_PRODUCT_NAME, "G1618-04"),
> +                       DMI_MATCH(DMI_BOARD_VERSION, "Default string"),
> +               },
> +               .driver_data = &gpd_win4_drvdata,
> +       },
> +       {
> +               // GPD Win 4 with Ryzen 7840U
> +               .matches = {
> +                       DMI_MATCH(DMI_SYS_VENDOR, "GPD"),
> +                       DMI_MATCH(DMI_PRODUCT_NAME, "G1618-04"),
> +                       DMI_MATCH(DMI_BOARD_VERSION, "Ver. 1.0"),
> +               },
> +               // Since 7840U, win4 uses the same drvdata as wm2
> +               .driver_data = &gpd_wm2_drvdata,
> +       },
> +       {
> +               // GPD Win 4 with Ryzen 7840U (another)
> +               .matches = {
> +                       DMI_MATCH(DMI_SYS_VENDOR, "GPD"),
> +                       DMI_MATCH(DMI_PRODUCT_NAME, "G1618-04"),
> +                       DMI_MATCH(DMI_BOARD_VERSION, "Ver.1.0"),
> +               },
> +               .driver_data = &gpd_wm2_drvdata,
> +       },
> +       {
> +               // GPD Win Max 2 with Ryzen 6800U
> +               // GPD Win Max 2 2023 with Ryzen 7840U
> +               // GPD Win Max 2 2024 with Ryzen 8840U
> +               .matches = {
> +                       DMI_MATCH(DMI_SYS_VENDOR, "GPD"),
> +                       DMI_MATCH(DMI_PRODUCT_NAME, "G1619-04"),
> +               },
> +               .driver_data = &gpd_wm2_drvdata,
> +       },
> +       {
> +               // GPD Win Max 2 with AMD Ryzen HX370
> +               .matches = {
> +                       DMI_MATCH(DMI_SYS_VENDOR, "GPD"),
> +                       DMI_MATCH(DMI_PRODUCT_NAME, "G1619-05"),
> +               },
> +               .driver_data = &gpd_wm2_drvdata,
> +       },
> +       {
> +               // GPD Pocket 4
> +               .matches = {
> +                       DMI_MATCH(DMI_SYS_VENDOR, "GPD"),
> +                       DMI_MATCH(DMI_PRODUCT_NAME, "G1628-04"),
> +               },
> +               .driver_data = &gpd_win_mini_drvdata,
> +       },
> +       {
> +               // GPD Pocket 4 (another)
> +               .matches = {
> +                       DMI_MATCH(DMI_SYS_VENDOR, "GPD"),
> +                       DMI_MATCH(DMI_PRODUCT_NAME, "G1628-04-L"),
> +               },
> +               .driver_data = &gpd_win_mini_drvdata,
> +       },
> +       {}
> +};
> +
> +static const struct gpd_fan_drvdata *gpd_module_drvdata[] = {
> +       &gpd_win_mini_drvdata, &gpd_win4_drvdata, &gpd_wm2_drvdata, NULL
> +};
> +
> +/* Helper functions to handle EC read/write */
> +static int gpd_ecram_read(const struct gpd_fan_drvdata *drvdata, u16 offset,
> +                         u8 *val)
> +{
> +       int ret;
> +       u16 addr_port = drvdata->addr_port;
> +       u16 data_port = drvdata->data_port;
> +
> +       ret = mutex_lock_interruptible(&gpd_fan_lock);
> +
> +       if (ret)
> +               return ret;
> +
> +       outb(0x2E, addr_port);
> +       outb(0x11, data_port);
> +       outb(0x2F, addr_port);
> +       outb((u8)((offset >> 8) & 0xFF), data_port);
> +
> +       outb(0x2E, addr_port);
> +       outb(0x10, data_port);
> +       outb(0x2F, addr_port);
> +       outb((u8)(offset & 0xFF), data_port);
> +
> +       outb(0x2E, addr_port);
> +       outb(0x12, data_port);
> +       outb(0x2F, addr_port);
> +       *val = inb(data_port);
> +
> +       mutex_unlock(&gpd_fan_lock);
> +       return 0;
> +}

One concern I had with this driver while using it is that ACPI might
have access to this EC. If that is the case, then this mutex is not
exclusive and that could cause some instability. You can reference
oxp-sensors for an ACPI lock.

Although, if I am being honest, the lock in oxp-sensors is probably
duplicative because ec_read already holds a mutex. In your case, you
do not use ec_read so it is not.

> +
> +static int gpd_ecram_write(const struct gpd_fan_drvdata *drvdata, u16 offset,
> +                          u8 value)
> +{
> +       int ret;
> +       u16 addr_port = drvdata->addr_port;
> +       u16 data_port = drvdata->data_port;
> +
> +       ret = mutex_lock_interruptible(&gpd_fan_lock);
> +
> +       if (ret)
> +               return ret;
> +
> +       outb(0x2E, addr_port);
> +       outb(0x11, data_port);
> +       outb(0x2F, addr_port);
> +       outb((u8)((offset >> 8) & 0xFF), data_port);
> +
> +       outb(0x2E, addr_port);
> +       outb(0x10, data_port);
> +       outb(0x2F, addr_port);
> +       outb((u8)(offset & 0xFF), data_port);
> +
> +       outb(0x2E, addr_port);
> +       outb(0x12, data_port);
> +       outb(0x2F, addr_port);
> +       outb(value, data_port);
> +
> +       mutex_unlock(&gpd_fan_lock);
> +       return 0;
> +}
> +
> +static int gpd_generic_read_rpm(void)
> +{
> +       u8 high, low;
> +       int ret;
> +       const struct gpd_fan_drvdata *const drvdata = gpd_driver_priv.drvdata;
> +
> +       ret = gpd_ecram_read(drvdata, drvdata->rpm_read, &high);
> +       if (ret)
> +               return ret;
> +
> +       ret = gpd_ecram_read(drvdata, drvdata->rpm_read + 1, &low);
> +       if (ret)
> +               return ret;
> +
> +       return (u16)high << 8 | low;
> +}
> +
> +static int gpd_win4_read_rpm(void)
> +{
> +       const struct gpd_fan_drvdata *const drvdata = gpd_driver_priv.drvdata;
> +       u8 pwm_ctr_reg;
> +       int ret;
> +
> +       gpd_ecram_read(drvdata, GPD_PWM_CTR_OFFSET, &pwm_ctr_reg);
> +
> +       if (pwm_ctr_reg != 0x7F)
> +               gpd_ecram_write(drvdata, GPD_PWM_CTR_OFFSET, 0x7F);
> +
> +       ret = gpd_generic_read_rpm();
> +
> +       if (ret < 0)
> +               return ret;
> +
> +       if (ret == 0) {
> +               // re-init EC
> +               u8 chip_id;
> +
> +               gpd_ecram_read(drvdata, 0x2000, &chip_id);
> +               if (chip_id == 0x55) {
> +                       u8 chip_ver;
> +
> +                       if (gpd_ecram_read(drvdata, 0x1060, &chip_ver))
> +                               gpd_ecram_write(drvdata, 0x1060,
> +                                               chip_ver | 0x80);
> +               }
> +       }
> +
> +       return ret;
> +}
> +
> +static int gpd_wm2_read_rpm(void)
> +{
> +       const struct gpd_fan_drvdata *const drvdata = gpd_driver_priv.drvdata;
> +
> +       for (u16 pwm_ctr_offset = GPD_PWM_CTR_OFFSET;
> +            pwm_ctr_offset <= GPD_PWM_CTR_OFFSET + 2; pwm_ctr_offset++) {
> +               u8 PWMCTR;
> +
> +               gpd_ecram_read(drvdata, pwm_ctr_offset, &PWMCTR);
> +
> +               if (PWMCTR != 0xB8)
> +                       gpd_ecram_write(drvdata, pwm_ctr_offset, 0xB8);
> +       }
> +
> +       return gpd_generic_read_rpm();
> +}
> +
> +// Read value for fan1_input
> +static int gpd_read_rpm(void)
> +{
> +       switch (gpd_driver_priv.drvdata->board) {
> +       case win_mini:
> +               return gpd_generic_read_rpm();
> +       case win4_6800u:
> +               return gpd_win4_read_rpm();
> +       case win_max_2:
> +               return gpd_wm2_read_rpm();
> +       }
> +
> +       return 0;
> +}
> +
> +static int gpd_wm2_read_pwm(void)
> +{
> +       const struct gpd_fan_drvdata *const drvdata = gpd_driver_priv.drvdata;
> +       u8 var;
> +       int ret = gpd_ecram_read(drvdata, drvdata->pwm_write, &var);
> +
> +       if (ret < 0)
> +               return ret;
> +
> +       return var * 255 / drvdata->pwm_max;
> +}
> +
> +// Read value for pwm1
> +static int gpd_read_pwm(void)
> +{
> +       switch (gpd_driver_priv.drvdata->board) {
> +       case win_mini:
> +       case win4_6800u:
> +               return gpd_driver_priv.pwm_value;
> +       case win_max_2:
> +               return gpd_wm2_read_pwm();
> +       }
> +       return 0;
> +}
> +
> +static int gpd_generic_write_pwm(u8 val)
> +{
> +       const struct gpd_fan_drvdata *const drvdata = gpd_driver_priv.drvdata;
> +       u8 pwm_reg;
> +
> +       // PWM value's range in EC is 1 - pwm_max, cast 0 - 255 to it.
> +       pwm_reg = val * (drvdata->pwm_max - 1) / 255 + 1;
> +       return gpd_ecram_write(drvdata, drvdata->pwm_write, pwm_reg);
> +}
> +
> +static int gpd_win_mini_write_pwm(u8 val)
> +{
> +       if (gpd_driver_priv.pwm_enable == MANUAL)
> +               return gpd_generic_write_pwm(val);
> +       else
> +               return -EPERM;
> +}
> +
> +static int gpd_wm2_write_pwm(u8 val)
> +{
> +       if (gpd_driver_priv.pwm_enable != DISABLE)
> +               return gpd_generic_write_pwm(val);
> +       else
> +               return -EPERM;
> +}
> +
> +// Write value for pwm1
> +static int gpd_write_pwm(u8 val)
> +{
> +       switch (gpd_driver_priv.drvdata->board) {
> +       case win_mini:
> +               return gpd_win_mini_write_pwm(val);
> +       case win4_6800u:
> +               return gpd_generic_write_pwm(val);
> +       case win_max_2:
> +               return gpd_wm2_write_pwm(val);
> +       }
> +
> +       return 0;
> +}
> +
> +static int gpd_win_mini_set_pwm_enable(enum FAN_PWM_ENABLE pwm_enable)
> +{
> +       const struct gpd_fan_drvdata *drvdata;
> +
> +       switch (pwm_enable) {
> +       case DISABLE:
> +               return gpd_generic_write_pwm(255);
> +       case MANUAL:
> +               return gpd_generic_write_pwm(gpd_driver_priv.pwm_value);
> +       case AUTOMATIC:
> +               drvdata = gpd_driver_priv.drvdata;
> +               return gpd_ecram_write(drvdata, drvdata->pwm_write, 0);
> +       }
> +
> +       return 0;
> +}
> +
> +static int gpd_wm2_set_pwm_enable(enum FAN_PWM_ENABLE enable)
> +{
> +       const struct gpd_fan_drvdata *const drvdata = gpd_driver_priv.drvdata;
> +       int ret;
> +
> +       switch (enable) {
> +       case DISABLE: {
> +               ret = gpd_generic_write_pwm(255);
> +
> +               if (ret)
> +                       return ret;
> +
> +               return gpd_ecram_write(drvdata, drvdata->manual_control_enable,
> +                                      1);
> +       }
> +       case MANUAL: {
> +               ret = gpd_generic_write_pwm(gpd_driver_priv.pwm_value);
> +
> +               if (ret)
> +                       return ret;
> +
> +               return gpd_ecram_write(drvdata, drvdata->manual_control_enable,
> +                                      1);
> +       }
> +       case AUTOMATIC: {
> +               ret = gpd_ecram_write(drvdata, drvdata->manual_control_enable,
> +                                     0);
> +
> +               return ret;
> +       }
> +       }
> +
> +       return 0;
> +}
> +
> +// Write value for pwm1_enable
> +static int gpd_set_pwm_enable(enum FAN_PWM_ENABLE enable)
> +{
> +       switch (gpd_driver_priv.drvdata->board) {
> +       case win_mini:
> +       case win4_6800u:
> +               return gpd_win_mini_set_pwm_enable(enable);
> +       case win_max_2:
> +               return gpd_wm2_set_pwm_enable(enable);
> +       }
> +
> +       return 0;
> +}
> +
> +static umode_t gpd_fan_hwmon_is_visible(__always_unused const void *drvdata,
> +                                       enum hwmon_sensor_types type, u32 attr,
> +                                       __always_unused int channel)
> +{
> +       if (type == hwmon_fan && attr == hwmon_fan_input) {
> +               return 0444;
> +       } else if (type == hwmon_pwm) {
> +               switch (attr) {
> +               case hwmon_pwm_enable:
> +               case hwmon_pwm_input:
> +                       return 0644;
> +               default:
> +                       return 0;
> +               }
> +       }
> +       return 0;
> +}
> +
> +static int gpd_fan_hwmon_read(__always_unused struct device *dev,
> +                             enum hwmon_sensor_types type, u32 attr,
> +                             __always_unused int channel, long *val)
> +{
> +       if (type == hwmon_fan) {
> +               if (attr == hwmon_fan_input) {
> +                       int ret = gpd_read_rpm();
> +
> +                       if (ret < 0)
> +                               return ret;
> +
> +                       *val = ret;
> +                       return 0;
> +               }
> +               return -EOPNOTSUPP;
> +       } else if (type == hwmon_pwm) {
> +               int ret;
> +
> +               switch (attr) {
> +               case hwmon_pwm_enable:
> +                       *val = gpd_driver_priv.pwm_enable;
> +                       return 0;
> +               case hwmon_pwm_input:
> +                       ret = gpd_read_pwm();
> +
> +                       if (ret < 0)
> +                               return ret;
> +
> +                       *val = ret;
> +                       return 0;
> +               default:
> +                       return -EOPNOTSUPP;
> +               }
> +       }
> +
> +       return -EOPNOTSUPP;
> +}
> +
> +static int gpd_fan_hwmon_write(__always_unused struct device *dev,
> +                              enum hwmon_sensor_types type, u32 attr,
> +                              __always_unused int channel, long val)
> +{
> +       u8 var;
> +
> +       if (type == hwmon_pwm) {
> +               switch (attr) {
> +               case hwmon_pwm_enable:
> +                       if (!in_range(val, 0, 3))
> +                               return -EINVAL;
> +
> +                       gpd_driver_priv.pwm_enable = val;
> +
> +                       return gpd_set_pwm_enable(gpd_driver_priv.pwm_enable);
> +               case hwmon_pwm_input:
> +                       var = clamp_val(val, 0, 255);
> +
> +                       gpd_driver_priv.pwm_value = var;
> +
> +                       return gpd_write_pwm(var);
> +               default:
> +                       return -EOPNOTSUPP;
> +               }
> +       }
> +
> +       return -EOPNOTSUPP;
> +}
> +
> +static const struct hwmon_ops gpd_fan_ops = {
> +       .is_visible = gpd_fan_hwmon_is_visible,
> +       .read = gpd_fan_hwmon_read,
> +       .write = gpd_fan_hwmon_write,
> +};
> +
> +static const struct hwmon_channel_info *gpd_fan_hwmon_channel_info[] = {
> +       HWMON_CHANNEL_INFO(fan, HWMON_F_INPUT),
> +       HWMON_CHANNEL_INFO(pwm, HWMON_PWM_INPUT | HWMON_PWM_ENABLE),
> +       NULL
> +};
> +
> +static struct hwmon_chip_info gpd_fan_chip_info = {
> +       .ops = &gpd_fan_ops,
> +       .info = gpd_fan_hwmon_channel_info
> +};
> +
> +static int gpd_fan_probe(struct platform_device *pdev)
> +{
> +       struct device *dev = &pdev->dev;
> +       const struct resource *res;
> +       const struct device *hwdev;
> +       const struct resource *region;
> +
> +       res = platform_get_resource(pdev, IORESOURCE_IO, 0);
> +       if (IS_ERR(res))
> +               return dev_err_probe(dev, PTR_ERR(res),
> +                                    "Failed to get platform resource\n");
> +
> +       region = devm_request_region(dev, res->start,
> +                                    resource_size(res), DRIVER_NAME);
> +       if (IS_ERR(region))
> +               return dev_err_probe(dev, PTR_ERR(region),
> +                                    "Failed to request region\n");
> +
> +       hwdev = devm_hwmon_device_register_with_info(dev,
> +                                                    DRIVER_NAME,
> +                                                    NULL,
> +                                                    &gpd_fan_chip_info,
> +                                                    NULL);
> +       if (IS_ERR(hwdev))
> +               return dev_err_probe(dev, PTR_ERR(region),
> +                                    "Failed to register hwmon device\n");
> +
> +       return 0;
> +}
> +
> +static void gpd_fan_remove(__always_unused struct platform_device *pdev)
> +{
> +       gpd_driver_priv.pwm_enable = AUTOMATIC;
> +       gpd_set_pwm_enable(AUTOMATIC);
> +}
> +
> +static struct platform_driver gpd_fan_driver = {
> +       .probe = gpd_fan_probe,
> +       .remove = gpd_fan_remove,
> +       .driver = {
> +               .name = KBUILD_MODNAME,
> +       },
> +};
> +
> +static struct platform_device *gpd_fan_platform_device;
> +
> +static int __init gpd_fan_init(void)
> +{
> +       const struct gpd_fan_drvdata *match = NULL;
> +
> +       for (const struct gpd_fan_drvdata **p = gpd_module_drvdata; *p; p++) {
> +               if (strcmp(gpd_fan_board, (*p)->board_name) == 0) {
> +                       match = *p;
> +                       break;
> +               }
> +       }
> +
> +       if (!match) {
> +               const struct dmi_system_id *dmi_match =
> +                       dmi_first_match(dmi_table);
> +               if (dmi_match)
> +                       match = dmi_match->driver_data;
> +       }
> +
> +       if (!match)
> +               return -ENODEV;
> +
> +       gpd_driver_priv.pwm_enable = AUTOMATIC;
> +       gpd_driver_priv.pwm_value = 255;
> +       gpd_driver_priv.drvdata = match;
> +
> +       struct resource gpd_fan_resources[] = {
> +               {
> +                       .start = match->addr_port,
> +                       .end = match->data_port,
> +                       .flags = IORESOURCE_IO,
> +               },
> +       };
> +
> +       gpd_fan_platform_device = platform_create_bundle(&gpd_fan_driver,
> +                                                        gpd_fan_probe,
> +                                                        gpd_fan_resources,
> +                                                        1, NULL, 0);
> +
> +       if (IS_ERR(gpd_fan_platform_device)) {
> +               pr_warn("Failed to create platform device\n");
> +               return PTR_ERR(gpd_fan_platform_device);
> +       }
> +
> +       return 0;
> +}
> +
> +static void __exit gpd_fan_exit(void)
> +{
> +       platform_device_unregister(gpd_fan_platform_device);
> +       platform_driver_unregister(&gpd_fan_driver);
> +}
> +
> +MODULE_DEVICE_TABLE(dmi, dmi_table);
> +
> +module_init(gpd_fan_init);
> +module_exit(gpd_fan_exit);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_AUTHOR("Cryolitia PukNgae <Cryolitia@gmail.com>");
> +MODULE_DESCRIPTION("GPD Devices fan control driver");
>
> --
> 2.48.1
>
>

I will try to swap from the dkms variant to this series soon.

Best,
Antheas

Re: [PATCH v6 1/2] hwmon: add GPD devices sensor driver

[Guenter Roeck]

On 3/13/25 13:58, Antheas Kapenekakis wrote:
> On Thu, 13 Mar 2025 at 21:10, Cryolitia PukNgae via B4 Relay
> <devnull+Cryolitia.gmail.com@kernel.org> wrote:
>>
>> From: Cryolitia PukNgae <Cryolitia@gmail.com>
>>
>> Sensors driver for GPD Handhelds that expose fan reading and control via
>> hwmon sysfs.
>>
>> Shenzhen GPD Technology Co., Ltd. manufactures a series of handheld
>> devices. This driver implements these functions through x86 port-mapped IO.
>>
>> Signed-off-by: Cryolitia PukNgae <Cryolitia@gmail.com>
>> ---
>>   MAINTAINERS             |   6 +
>>   drivers/hwmon/Kconfig   |  10 +
>>   drivers/hwmon/Makefile  |   1 +
>>   drivers/hwmon/gpd-fan.c | 681 ++++++++++++++++++++++++++++++++++++++++++++++++
>>   4 files changed, 698 insertions(+)
>>
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index 0fa7c5728f1e64d031f4a47b6fce1db484ce0fc2..777ba74ccb07ccc0840c3cd34e7b4d98d726f964 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -9762,6 +9762,12 @@ F:       drivers/phy/samsung/phy-gs101-ufs.c
>>   F:     include/dt-bindings/clock/google,gs101.h
>>   K:     [gG]oogle.?[tT]ensor
>>
>> +GPD FAN DRIVER
>> +M:     Cryolitia PukNgae <Cryolitia@gmail.com>
>> +L:     linux-hwmon@vger.kernel.org
>> +S:     Maintained
>> +F:     drivers/hwmon/gpd-fan.c
> 
> A problem we had with oxp sensors is that once OneXPlayer expanded
> their EC to include e.g., battery capacity limits, it was no longer
> appropriate for it to reside in hwmon. I expect GPD to do the same
> sometime in the near future. If that is the case, should we
> futureproof the driver by moving it to platform-x86 right away?
> 

My problem with platform drivers, especially with x86 platform drivers,
including the OneXPlayer driver, is that the developers responsible for
those drivers refrain from implementing the client drivers as auxiliary
drivers but instead like to bundle everything into a non-subsystem
directory. I have always wondered why that is the case. My best guess
is that it is to limit and/or avoid subsystem maintainer oversight.
Does that work out for you ?

Not objecting, I am just curious.

Guenter

Re: [PATCH v6 1/2] hwmon: add GPD devices sensor driver

[Antheas Kapenekakis]

On Thu, 17 Jul 2025 at 04:32, Guenter Roeck <linux@roeck-us.net> wrote:
>
> On 3/13/25 13:58, Antheas Kapenekakis wrote:
> > On Thu, 13 Mar 2025 at 21:10, Cryolitia PukNgae via B4 Relay
> > <devnull+Cryolitia.gmail.com@kernel.org> wrote:
> >>
> >> From: Cryolitia PukNgae <Cryolitia@gmail.com>
> >>
> >> Sensors driver for GPD Handhelds that expose fan reading and control via
> >> hwmon sysfs.
> >>
> >> Shenzhen GPD Technology Co., Ltd. manufactures a series of handheld
> >> devices. This driver implements these functions through x86 port-mapped IO.
> >>
> >> Signed-off-by: Cryolitia PukNgae <Cryolitia@gmail.com>
> >> ---
> >>   MAINTAINERS             |   6 +
> >>   drivers/hwmon/Kconfig   |  10 +
> >>   drivers/hwmon/Makefile  |   1 +
> >>   drivers/hwmon/gpd-fan.c | 681 ++++++++++++++++++++++++++++++++++++++++++++++++
> >>   4 files changed, 698 insertions(+)
> >>
> >> diff --git a/MAINTAINERS b/MAINTAINERS
> >> index 0fa7c5728f1e64d031f4a47b6fce1db484ce0fc2..777ba74ccb07ccc0840c3cd34e7b4d98d726f964 100644
> >> --- a/MAINTAINERS
> >> +++ b/MAINTAINERS
> >> @@ -9762,6 +9762,12 @@ F:       drivers/phy/samsung/phy-gs101-ufs.c
> >>   F:     include/dt-bindings/clock/google,gs101.h
> >>   K:     [gG]oogle.?[tT]ensor
> >>
> >> +GPD FAN DRIVER
> >> +M:     Cryolitia PukNgae <Cryolitia@gmail.com>
> >> +L:     linux-hwmon@vger.kernel.org
> >> +S:     Maintained
> >> +F:     drivers/hwmon/gpd-fan.c
> >
> > A problem we had with oxp sensors is that once OneXPlayer expanded
> > their EC to include e.g., battery capacity limits, it was no longer
> > appropriate for it to reside in hwmon. I expect GPD to do the same
> > sometime in the near future. If that is the case, should we
> > futureproof the driver by moving it to platform-x86 right away?
> >
>
> My problem with platform drivers, especially with x86 platform drivers,
> including the OneXPlayer driver, is that the developers responsible for
> those drivers refrain from implementing the client drivers as auxiliary
> drivers but instead like to bundle everything into a non-subsystem
> directory. I have always wondered why that is the case. My best guess
> is that it is to limit and/or avoid subsystem maintainer oversight.
> Does that work out for you ?

Particularly for simple ECs such as OneXPlayer and GPD boards I think
keeping all the addresses in the same file makes sense. E.g., I just
sent a Fixes for the OneXPlayer G1 AMD variant and it was one commit
instead of 2 or 3. At least for me it was practical, I did not
consider having a lesser oversight as a benefit when making that
choice.

But I do understand the concern.

Antheas

> Not objecting, I am just curious.
>
> Guenter
>
>

Re: [PATCH v6 1/2] hwmon: add GPD devices sensor driver

[Cryolitia]

Thank you for raising this valid concern. We've closely monitored GPD's
development plans and currently see no indication of EC functionality
expansion beyond thermal sensors in the foreseeable future. Given this
observation, we believe placing the driver in hwmon remains appropriate
for now.

That said, we fully respect your maintainer perspective on
future-proofing. If you feel strongly that platform/x86 would be a safer
long-term home despite the current scope, we're happy to move the driver
there immediately. We're committed to finding the most sustainable
solution for upstream.

------
Apologies for mistakenly replying to Antheas Kapenekakis instead of the 
mailing list.

I am Cryolitia <cryolitia@gmail.com> that previously sending the patch. 
Due to work, I changed my email address. GPG can verify it's the same 
person: 
https://keyserver.ubuntu.com/pks/lookup?op=vindex&search=0x84dd0c0130a54df7
------

在 2025/7/19 00:38, Antheas Kapenekakis 写道:
> On Thu, 17 Jul 2025 at 04:32, Guenter Roeck <linux@roeck-us.net> wrote:
>>
>> On 3/13/25 13:58, Antheas Kapenekakis wrote:
>>> On Thu, 13 Mar 2025 at 21:10, Cryolitia PukNgae via B4 Relay
>>> <devnull+Cryolitia.gmail.com@kernel.org> wrote:
>>>>
>>>> From: Cryolitia PukNgae <Cryolitia@gmail.com>
>>>>
>>>> Sensors driver for GPD Handhelds that expose fan reading and control via
>>>> hwmon sysfs.
>>>>
>>>> Shenzhen GPD Technology Co., Ltd. manufactures a series of handheld
>>>> devices. This driver implements these functions through x86 port-mapped IO.
>>>>
>>>> Signed-off-by: Cryolitia PukNgae <Cryolitia@gmail.com>
>>>> ---
>>>>    MAINTAINERS             |   6 +
>>>>    drivers/hwmon/Kconfig   |  10 +
>>>>    drivers/hwmon/Makefile  |   1 +
>>>>    drivers/hwmon/gpd-fan.c | 681 ++++++++++++++++++++++++++++++++++++++++++++++++
>>>>    4 files changed, 698 insertions(+)
>>>>
>>>> diff --git a/MAINTAINERS b/MAINTAINERS
>>>> index 0fa7c5728f1e64d031f4a47b6fce1db484ce0fc2..777ba74ccb07ccc0840c3cd34e7b4d98d726f964 100644
>>>> --- a/MAINTAINERS
>>>> +++ b/MAINTAINERS
>>>> @@ -9762,6 +9762,12 @@ F:       drivers/phy/samsung/phy-gs101-ufs.c
>>>>    F:     include/dt-bindings/clock/google,gs101.h
>>>>    K:     [gG]oogle.?[tT]ensor
>>>>
>>>> +GPD FAN DRIVER
>>>> +M:     Cryolitia PukNgae <Cryolitia@gmail.com>
>>>> +L:     linux-hwmon@vger.kernel.org
>>>> +S:     Maintained
>>>> +F:     drivers/hwmon/gpd-fan.c
>>>
>>> A problem we had with oxp sensors is that once OneXPlayer expanded
>>> their EC to include e.g., battery capacity limits, it was no longer
>>> appropriate for it to reside in hwmon. I expect GPD to do the same
>>> sometime in the near future. If that is the case, should we
>>> futureproof the driver by moving it to platform-x86 right away?
>>>
>>
>> My problem with platform drivers, especially with x86 platform drivers,
>> including the OneXPlayer driver, is that the developers responsible for
>> those drivers refrain from implementing the client drivers as auxiliary
>> drivers but instead like to bundle everything into a non-subsystem
>> directory. I have always wondered why that is the case. My best guess
>> is that it is to limit and/or avoid subsystem maintainer oversight.
>> Does that work out for you ?
> 
> Particularly for simple ECs such as OneXPlayer and GPD boards I think
> keeping all the addresses in the same file makes sense. E.g., I just
> sent a Fixes for the OneXPlayer G1 AMD variant and it was one commit
> instead of 2 or 3. At least for me it was practical, I did not
> consider having a lesser oversight as a benefit when making that
> choice.
> 
> But I do understand the concern.
> 
> Antheas
> 
>> Not objecting, I am just curious.
>>
>> Guenter
>>
>>
> 

Re: [PATCH v6 1/2] hwmon: add GPD devices sensor driver

[Guenter Roeck]

On 7/30/25 02:24, Cryolitia wrote:
> Thank you for raising this valid concern. We've closely monitored GPD's
> development plans and currently see no indication of EC functionality
> expansion beyond thermal sensors in the foreseeable future. Given this
> observation, we believe placing the driver in hwmon remains appropriate
> for now.
> 
> That said, we fully respect your maintainer perspective on
> future-proofing. If you feel strongly that platform/x86 would be a safer
> long-term home despite the current scope, we're happy to move the driver
> there immediately. We're committed to finding the most sustainable
> solution for upstream.
> 

As hwmon maintainer, I feel strongly (since you used the word) that moving
the driver (or any hwmon driver, for that matter) out of hwmon space would
be a bad idea, but I won't prevent you from doing it either. It means less
work for me, after all.

Guenter

Re: [PATCH v6 1/2] hwmon: add GPD devices sensor driver

[Cryolitia PukNgae]

Personally, I'd prefer to maintain this small driver in the hwmon
subsystem until we need to write drivers for the same EC with more
diverse subsystem functionality. We can then discuss and learn how to
evolve it. I personally don't think that's going to happen in the near
future.

So, could we continue reviewing the current patch series? Where are we 
stuck?

在 2025/7/31 01:26, Guenter Roeck 写道:
> On 7/30/25 02:24, Cryolitia wrote:
>> Thank you for raising this valid concern. We've closely monitored GPD's
>> development plans and currently see no indication of EC functionality
>> expansion beyond thermal sensors in the foreseeable future. Given this
>> observation, we believe placing the driver in hwmon remains appropriate
>> for now.
>>
>> That said, we fully respect your maintainer perspective on
>> future-proofing. If you feel strongly that platform/x86 would be a safer
>> long-term home despite the current scope, we're happy to move the driver
>> there immediately. We're committed to finding the most sustainable
>> solution for upstream.
>>
> 
> As hwmon maintainer, I feel strongly (since you used the word) that moving
> the driver (or any hwmon driver, for that matter) out of hwmon space would
> be a bad idea, but I won't prevent you from doing it either. It means less
> work for me, after all.
> 
> Guenter
> 
> 

Re: [PATCH v6 1/2] hwmon: add GPD devices sensor driver

[Antheas Kapenekakis]

On Thu, 31 Jul 2025 at 05:30, Cryolitia PukNgae <liziyao@uniontech.com> wrote:
>
> Personally, I'd prefer to maintain this small driver in the hwmon
> subsystem until we need to write drivers for the same EC with more
> diverse subsystem functionality. We can then discuss and learn how to
> evolve it. I personally don't think that's going to happen in the near
> future.
>
> So, could we continue reviewing the current patch series? Where are we
> stuck?

Either is fine by me. The move is simply a rename anyway. My reasoning
was it will take a bit of back and forth to get approved and charge
limiting is a standard feature now on all manufacturers except GPD, so
I expect them to add it soon. But since it is a rename, it is not a
blocker for reviewing in any case.

If you want more comments I think you should send a new current
version so it can be reviewed again. It has been a while since the
previous one.

Antheas

> 在 2025/7/31 01:26, Guenter Roeck 写道:
> > On 7/30/25 02:24, Cryolitia wrote:
> >> Thank you for raising this valid concern. We've closely monitored GPD's
> >> development plans and currently see no indication of EC functionality
> >> expansion beyond thermal sensors in the foreseeable future. Given this
> >> observation, we believe placing the driver in hwmon remains appropriate
> >> for now.
> >>
> >> That said, we fully respect your maintainer perspective on
> >> future-proofing. If you feel strongly that platform/x86 would be a safer
> >> long-term home despite the current scope, we're happy to move the driver
> >> there immediately. We're committed to finding the most sustainable
> >> solution for upstream.
> >>
> >
> > As hwmon maintainer, I feel strongly (since you used the word) that moving
> > the driver (or any hwmon driver, for that matter) out of hwmon space would
> > be a bad idea, but I won't prevent you from doing it either. It means less
> > work for me, after all.
> >
> > Guenter
> >
> >
>
>

Re: [PATCH v6 1/2] hwmon: add GPD devices sensor driver

[Guenter Roeck]

On 7/31/25 01:13, Antheas Kapenekakis wrote:
> On Thu, 31 Jul 2025 at 05:30, Cryolitia PukNgae <liziyao@uniontech.com> wrote:
>>
>> Personally, I'd prefer to maintain this small driver in the hwmon
>> subsystem until we need to write drivers for the same EC with more
>> diverse subsystem functionality. We can then discuss and learn how to
>> evolve it. I personally don't think that's going to happen in the near
>> future.
>>
>> So, could we continue reviewing the current patch series? Where are we
>> stuck?
> 
> Either is fine by me. The move is simply a rename anyway. My reasoning
> was it will take a bit of back and forth to get approved and charge
> limiting is a standard feature now on all manufacturers except GPD, so
> I expect them to add it soon. But since it is a rename, it is not a
> blocker for reviewing in any case.
> 

It is moving code from one maintainer domain to another. That is like moving
from one country to another. It is not "just" a rename.

Guenter

Re: [PATCH v6 1/2] hwmon: add GPD devices sensor driver

[Cryolitia PukNgae]

On 31/07/2025 16.13, Antheas Kapenekakis wrote:
> On Thu, 31 Jul 2025 at 05:30, Cryolitia PukNgae <liziyao@uniontech.com> wrote:
>>
>> Personally, I'd prefer to maintain this small driver in the hwmon
>> subsystem until we need to write drivers for the same EC with more
>> diverse subsystem functionality. We can then discuss and learn how to
>> evolve it. I personally don't think that's going to happen in the near
>> future.
>>
>> So, could we continue reviewing the current patch series? Where are we
>> stuck?
> 
> Either is fine by me. The move is simply a rename anyway. My reasoning
> was it will take a bit of back and forth to get approved and charge
> limiting is a standard feature now on all manufacturers except GPD, so
> I expect them to add it soon. But since it is a rename, it is not a
> blocker for reviewing in any case.
> 
> If you want more comments I think you should send a new current
> version so it can be reviewed again. It has been a while since the
> previous one.

I have sent the 7th version two weeks ago. I would like to hear your 
comments if you have a free time to take a look at it. Thx a lot.

> Antheas
> 
>> 在 2025/7/31 01:26, Guenter Roeck 写道:
>>> On 7/30/25 02:24, Cryolitia wrote:
>>>> Thank you for raising this valid concern. We've closely monitored GPD's
>>>> development plans and currently see no indication of EC functionality
>>>> expansion beyond thermal sensors in the foreseeable future. Given this
>>>> observation, we believe placing the driver in hwmon remains appropriate
>>>> for now.
>>>>
>>>> That said, we fully respect your maintainer perspective on
>>>> future-proofing. If you feel strongly that platform/x86 would be a safer
>>>> long-term home despite the current scope, we're happy to move the driver
>>>> there immediately. We're committed to finding the most sustainable
>>>> solution for upstream.
>>>>
>>>
>>> As hwmon maintainer, I feel strongly (since you used the word) that moving
>>> the driver (or any hwmon driver, for that matter) out of hwmon space would
>>> be a bad idea, but I won't prevent you from doing it either. It means less
>>> work for me, after all.
>>>
>>> Guenter
>>>

Best regards,
Cryolitia

[PATCH v6 2/2] hwmon: document: add gpd-fan

[Cryolitia PukNgae via B4 Relay]

From: Cryolitia PukNgae <Cryolitia@gmail.com>

Add GPD fan driver document

Signed-off-by: Cryolitia PukNgae <Cryolitia@gmail.com>
---
 Documentation/hwmon/gpd-fan.rst | 71 +++++++++++++++++++++++++++++++++++++++++
 Documentation/hwmon/index.rst   |  1 +
 MAINTAINERS                     |  1 +
 3 files changed, 73 insertions(+)

diff --git a/Documentation/hwmon/gpd-fan.rst b/Documentation/hwmon/gpd-fan.rst
new file mode 100644
index 0000000000000000000000000000000000000000..55059d1dfc5c6a1219c88c1c4c3c4c776fa79cdb
--- /dev/null
+++ b/Documentation/hwmon/gpd-fan.rst
@@ -0,0 +1,71 @@
+.. 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 Mini (HX370)
+ - GPD Pocket 4
+ - GPD Duo
+ - GPD Win Max 2 (6800U)
+ - GPD Win Max 2 2023 (7840U)
+ - GPD Win Max 2 2024 (8840U)
+ - GPD Win Max 2 2025 (HX370)
+ - GPD Win 4 (6800U)
+ - GPD Win 4 (7840U)
+
+Module parameters
+-----------------
+
+gpd_fan_board
+  Force specific which module quirk should be used.
+  Use it like "gpd_fan_board=wm2".
+
+   - wm2
+       - GPD Win 4 (7840U)
+       - GPD Win Max 2 (6800U)
+       - GPD Win Max 2 2023 (7840U)
+       - GPD Win Max 2 2024 (8840U)
+       - GPD Win Max 2 2025 (HX370)
+   - win4
+       - GPD Win 4 (6800U)
+   - win_mini
+       - GPD Win Mini (7840U)
+       - GPD Win Mini (8840U)
+       - GPD Win Mini (HX370)
+       - GPD Pocket 4
+       - GPD Duo
+
+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 55f1111594b2e9ada4a881e5d4d8884f33256d1f..d5c7cd0cfdeb7059b6cd83050ae98aa7cb1334e6 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 777ba74ccb07ccc0840c3cd34e7b4d98d726f964..20faebeae981e4b7619fb10331c50525d98db944 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9766,6 +9766,7 @@ 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

-- 
2.48.1