hwmon: (gpd-fan) add support for Micro PC 2

GPD Micro PC 2 is a mobile productivity device with 7-inch screen and
abundant ports.[1]

Link: https://www.gpd.hk/gpdmicropc2345345345 #1
Co-developed-by: kylon <3252255+kylon@users.noreply.github.com>
Signed-off-by: kylon <3252255+kylon@users.noreply.github.com>
Tested-by: kylon <3252255+kylon@users.noreply.github.com>
Link: https://github.com/Cryolitia/gpd-fan-driver/pull/23
Signed-off-by: Cryolitia PukNgae <cryolitia@uniontech.com>
Link: https://lore.kernel.org/r/20251222-mpc2-v1-1-695d8d351cc1@uniontech.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Documentation/hwmon/gpd-fan.rst

@@ -28,6 +28,7 @@ Currently the driver supports the following handhelds:
  - GPD Win Max 2 2025 (HX370)
  - GPD Win 4 (6800U)
  - GPD Win 4 (7840U)
+ - GPD Micro PC 2
 
 Module parameters
 -----------------
@@ -50,6 +51,8 @@ gpd_fan_board
        - GPD Win Mini (HX370)
        - GPD Pocket 4
        - GPD Duo
+   - mpc2
+       - GPD Micro PC 2
 
 Sysfs entries
 -------------

drivers/hwmon/gpd-fan.c

@@ -31,6 +31,7 @@ enum gpd_board {
 	win4_6800u,
 	win_max_2,
 	duo,
+	mpc2,
 };
 
 enum FAN_PWM_ENABLE {
@@ -106,6 +107,18 @@ static struct gpd_fan_drvdata gpd_wm2_drvdata = {
 	.pwm_max		= 184,
 };
 
+static struct gpd_fan_drvdata gpd_mpc2_drvdata = {
+	.board_name		= "mpc2",
+	.board			= mpc2,
+
+	.addr_port		= 0x4E,
+	.data_port		= 0x4F,
+	.manual_control_enable	= 0x047A,
+	.rpm_read		= 0x0476,
+	.pwm_write		= 0x047A,
+	.pwm_max		= 244,
+};
+
 static const struct dmi_system_id dmi_table[] = {
 	{
 		// GPD Win Mini
@@ -212,11 +225,19 @@ static const struct dmi_system_id dmi_table[] = {
 		},
 		.driver_data = &gpd_win_mini_drvdata,
 	},
+	{
+		// GPD Micro PC 2
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "GPD"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "G1688-08"),
+		},
+		.driver_data = &gpd_mpc2_drvdata,
+	},
 	{}
 };
 
 static const struct gpd_fan_drvdata *gpd_module_drvdata[] = {
-	&gpd_win_mini_drvdata, &gpd_win4_drvdata, &gpd_wm2_drvdata, NULL
+	&gpd_win_mini_drvdata, &gpd_win4_drvdata, &gpd_wm2_drvdata, &gpd_mpc2_drvdata, NULL
 };
 
 // Helper functions to handle EC read/write
@@ -295,6 +316,7 @@ static int gpd_read_rpm(void)
 	case win4_6800u:
 	case win_mini:
 	case duo:
+	case mpc2:
 		return gpd_generic_read_rpm();
 	case win_max_2:
 		return gpd_wm2_read_rpm();
@@ -321,6 +343,7 @@ static int gpd_read_pwm(void)
 	case win_mini:
 	case duo:
 	case win4_6800u:
+	case mpc2:
 		switch (gpd_driver_priv.pwm_enable) {
 		case DISABLE:
 			return 255;
@@ -376,6 +399,7 @@ static int gpd_write_pwm(u8 val)
 	case win_mini:
 	case win4_6800u:
 	case win_max_2:
+	case mpc2:
 		gpd_generic_write_pwm(val);
 		break;
 	}
@@ -443,6 +467,7 @@ static void gpd_set_pwm_enable(enum FAN_PWM_ENABLE enable)
 	switch (gpd_driver_priv.drvdata->board) {
 	case win_mini:
 	case win4_6800u:
+	case mpc2:
 		gpd_win_mini_set_pwm_enable(enable);
 		break;
 	case duo: