[PATCH v2 2/2] asus-wmi: Support the GPU fan on TUF laptops

[Luke D. Jones]

Add support for TUF laptops which have the ability to control
the GPU fan. This will show as a second fan in hwmon, and has
the ability to run as boost (fullspeed), or auto.

Signed-off-by: Luke D. Jones <luke@xxxxxxxxxx>
---
 drivers/platform/x86/asus-wmi.c            | 71 ++++++++++++++++++++++
 include/linux/platform_data/x86/asus-wmi.h |  1 +
 2 files changed, 72 insertions(+)

diff --git a/drivers/platform/x86/asus-wmi.c b/drivers/platform/x86/asus-wmi.c
index ea45e10302f7..d05684194f2d 100644
--- a/drivers/platform/x86/asus-wmi.c
+++ b/drivers/platform/x86/asus-wmi.c
@@ -226,7 +226,9 @@ struct asus_wmi {
 	u32 tablet_switch_dev_id;
 
 	enum fan_type fan_type;
+	enum fan_type gpu_fan_type;
 	int fan_pwm_mode;
+	int gpu_fan_pwm_mode;
 	int agfn_pwm;
 
 	bool fan_boost_mode_available;
@@ -1861,6 +1863,18 @@ static int asus_fan_set_auto(struct asus_wmi *asus)
 		return -ENXIO;
 	}
 
+	/*
+	 * Modern models like the G713 also have GPU fan control (this is not AGFN)
+	 */
+	if (asus->gpu_fan_type == FAN_TYPE_SPEC83) {
+		status = asus_wmi_set_devstate(ASUS_WMI_DEVID_GPU_FAN_CTRL,
+					       0, &retval);
+		if (status)
+			return status;
+
+		if (retval != 1)
+			return -EIO;
+	}
 
 	return 0;
 }
@@ -2063,9 +2077,57 @@ static ssize_t asus_hwmon_temp1(struct device *dev,
 		       deci_kelvin_to_millicelsius(value & 0xFFFF));
 }
 
+/* GPU fan on modern ROG laptops */
+static ssize_t pwm2_enable_show(struct device *dev,
+				struct device_attribute *attr,
+				char *buf)
+{
+	struct asus_wmi *asus = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%d\n", asus->gpu_fan_pwm_mode);
+}
+
+static ssize_t pwm2_enable_store(struct device *dev,
+				 struct device_attribute *attr,
+				 const char *buf, size_t count)
+{
+	struct asus_wmi *asus = dev_get_drvdata(dev);
+	int state;
+	int value;
+	int ret;
+	u32 retval;
+
+	ret = kstrtouint(buf, 10, &state);
+	if (ret)
+		return ret;
+
+	switch (state) { /* standard documented hwmon values */
+	case ASUS_FAN_CTRL_FULLSPEED:
+		value = 1;
+		break;
+	case ASUS_FAN_CTRL_AUTO:
+		value = 0;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	ret = asus_wmi_set_devstate(ASUS_WMI_DEVID_GPU_FAN_CTRL,
+				    value, &retval);
+	if (ret)
+		return ret;
+
+	if (retval != 1)
+		return -EIO;
+
+	asus->gpu_fan_pwm_mode = state;
+	return count;
+}
+
 /* Fan1 */
 static DEVICE_ATTR_RW(pwm1);
 static DEVICE_ATTR_RW(pwm1_enable);
+static DEVICE_ATTR_RW(pwm2_enable);
 static DEVICE_ATTR_RO(fan1_input);
 static DEVICE_ATTR_RO(fan1_label);
 
@@ -2075,6 +2137,7 @@ static DEVICE_ATTR(temp1_input, S_IRUGO, asus_hwmon_temp1, NULL);
 static struct attribute *hwmon_attributes[] = {
 	&dev_attr_pwm1.attr,
 	&dev_attr_pwm1_enable.attr,
+	&dev_attr_pwm2_enable.attr,
 	&dev_attr_fan1_input.attr,
 	&dev_attr_fan1_label.attr,
 
@@ -2097,6 +2160,9 @@ static umode_t asus_hwmon_sysfs_is_visible(struct kobject *kobj,
 	    || attr == &dev_attr_pwm1_enable.attr) {
 		if (asus->fan_type == FAN_TYPE_NONE)
 			return 0;
+	} else if (attr == &dev_attr_pwm2_enable.attr) {
+		if (asus->gpu_fan_type == FAN_TYPE_NONE)
+			return 0;
 	} else if (attr == &dev_attr_temp1_input.attr) {
 		int err = asus_wmi_get_devstate(asus,
 						ASUS_WMI_DEVID_THERMAL_CTRL,
@@ -2139,6 +2205,7 @@ static int asus_wmi_hwmon_init(struct asus_wmi *asus)
 
 static int asus_wmi_fan_init(struct asus_wmi *asus)
 {
+	asus->gpu_fan_type = FAN_TYPE_NONE;
 	asus->fan_type = FAN_TYPE_NONE;
 	asus->agfn_pwm = -1;
 
@@ -2147,6 +2214,10 @@ static int asus_wmi_fan_init(struct asus_wmi *asus)
 	else if (asus_wmi_has_agfn_fan(asus))
 		asus->fan_type = FAN_TYPE_AGFN;
 
+	/*  Modern models like G713 also have GPU fan control */
+	if (asus_wmi_dev_is_present(asus, ASUS_WMI_DEVID_GPU_FAN_CTRL))
+		asus->gpu_fan_type = FAN_TYPE_SPEC83;
+
 	if (asus->fan_type == FAN_TYPE_NONE)
 		return -ENODEV;
 
diff --git a/include/linux/platform_data/x86/asus-wmi.h b/include/linux/platform_data/x86/asus-wmi.h
index 7dd580fdc61c..28234dc9fa6a 100644
--- a/include/linux/platform_data/x86/asus-wmi.h
+++ b/include/linux/platform_data/x86/asus-wmi.h
@@ -79,6 +79,7 @@
 #define ASUS_WMI_DEVID_THERMAL_CTRL	0x00110011
 #define ASUS_WMI_DEVID_FAN_CTRL		0x00110012 /* deprecated */
 #define ASUS_WMI_DEVID_CPU_FAN_CTRL	0x00110013
+#define ASUS_WMI_DEVID_GPU_FAN_CTRL	0x00110014
 #define ASUS_WMI_DEVID_CPU_FAN_CURVE	0x00110024
 #define ASUS_WMI_DEVID_GPU_FAN_CURVE	0x00110025
 
-- 
2.37.2