[PATCH 2/5] asus-wmi: Add support for TUF laptop keyboard RGB mode control

["Luke D. Jones" <luke@ljones.dev>]

Adds support for TUF laptop RGB mode control.

Two paths are added:
- /sys/devices/platform/asus-nb-wmi/kernel_rgb_mode
- /sys/devices/platform/asus-nb-wmi/kernel_rgb_mode_index

Signed-off-by: Luke D. Jones <luke@ljones.dev>
---
 drivers/platform/x86/asus-wmi.c | 86 +++++++++++++++++++++++++++++++++
 1 file changed, 86 insertions(+)

diff --git a/drivers/platform/x86/asus-wmi.c b/drivers/platform/x86/asus-wmi.c
index 33384e3321bb..9e6b83d8dd75 100644
--- a/drivers/platform/x86/asus-wmi.c
+++ b/drivers/platform/x86/asus-wmi.c
@@ -118,6 +118,9 @@ static const char * const ashs_ids[] = { "ATK4001", "ATK4002", NULL };
 
 static int throttle_thermal_policy_write(struct asus_wmi *);
 
+static int tuf_rgb_brightness_set(struct led_classdev *cdev,
+							enum led_brightness brightness);
+
 static bool ashs_present(void)
 {
 	int i = 0;
@@ -194,6 +197,9 @@ struct fan_curve_data {
 struct keyboard_rgb_led {
 	struct led_classdev_mc dev;
 	struct mc_subled subled_info[3]; /* r g b */
+	u8 save;
+	u8 mode;
+	u8 speed;
 };
 
 struct asus_wmi {
@@ -743,6 +749,72 @@ static ssize_t egpu_enable_store(struct device *dev,
 
 static DEVICE_ATTR_RW(egpu_enable);
 
+/* TUF Laptop Keyboard RGB Modes **********************************************/
+static int keyboard_rgb_mode_check_present(struct asus_wmi *asus)
+{
+	u32 result;
+	int err;
+
+	asus->keyboard_rgb_mode_available = false;
+
+	err = asus_wmi_get_devstate(asus, ASUS_WMI_DEVID_TUF_RGB_MODE, &result);
+	if (err) {
+		if (err == -ENODEV)
+			return 0;
+		return err;
+	}
+
+	if (result & ASUS_WMI_DSTS_PRESENCE_BIT) {
+		asus->keyboard_rgb_mode_available = true;
+	}
+
+	return 0;
+}
+
+static ssize_t keyboard_rgb_mode_store(struct device *device,
+				 struct device_attribute *attr,
+				 const char *buf, size_t count)
+{
+	u8 save, mode, speed;
+	int err;
+
+	struct asus_wmi *asus = dev_get_drvdata(device);
+	struct led_classdev *cdev = &asus->keyboard_rgb_mode.dev.led_cdev;
+
+	if (sscanf(buf, "%hhd %hhd %hhd", &save, &mode, &speed) != 3)
+		return -EINVAL;
+
+	asus->keyboard_rgb_mode.save = save > 0 ? 1 : 0;
+
+	/* These are the known usable modes across all TUF/ROG */
+	asus->keyboard_rgb_mode.mode = mode < 12 && mode != 9 ? mode : 0x0a;
+
+	if (speed == 0)
+		asus->keyboard_rgb_mode.speed = 0xe1;
+	else if (speed == 1)
+		asus->keyboard_rgb_mode.speed = 0xeb;
+	else if (speed == 2)
+		asus->keyboard_rgb_mode.speed = 0xf5;
+	else
+		asus->keyboard_rgb_mode.speed = 0xeb;
+
+	err = tuf_rgb_brightness_set(cdev, cdev->brightness);
+	if (err)
+		return err;
+	return 0;
+}
+
+static DEVICE_ATTR_WO(keyboard_rgb_mode);
+
+static ssize_t keyboard_rgb_mode_index_show(struct device *device,
+						 struct device_attribute *attr,
+						 char *buf)
+{
+	return sysfs_emit(buf, "%s\n", "save mode speed\n");
+}
+
+static DEVICE_ATTR_RO(keyboard_rgb_mode_index);
+
 /* Battery ********************************************************************/
 
 /* The battery maximum charging percentage */
@@ -1180,6 +1252,9 @@ static int asus_wmi_led_init(struct asus_wmi *asus)
 		 * write these defaults to the device because they will overwrite a
 		 * users last saved boot setting (in NVRAM).
 		 */
+		asus->keyboard_rgb_mode.save = 1;
+		asus->keyboard_rgb_mode.mode = 0;
+		asus->keyboard_rgb_mode.speed = 1;
 		mc_cdev->led_cdev.brightness = brightness;
 		mc_cdev->led_cdev.max_brightness = brightness;
 		mc_led_info[0].intensity = brightness;
@@ -3347,6 +3422,8 @@ static struct attribute *platform_attributes[] = {
 	&dev_attr_touchpad.attr,
 	&dev_attr_egpu_enable.attr,
 	&dev_attr_dgpu_disable.attr,
+	&dev_attr_keyboard_rgb_mode.attr,
+	&dev_attr_keyboard_rgb_mode_index.attr,
 	&dev_attr_lid_resume.attr,
 	&dev_attr_als_enable.attr,
 	&dev_attr_fan_boost_mode.attr,
@@ -3377,6 +3454,10 @@ static umode_t asus_sysfs_is_visible(struct kobject *kobj,
 		ok = asus->egpu_enable_available;
 	else if (attr == &dev_attr_dgpu_disable.attr)
 		ok = asus->dgpu_disable_available;
+	else if (attr == &dev_attr_keyboard_rgb_mode.attr)
+		ok = asus->keyboard_rgb_mode_available;
+	else if (attr == &dev_attr_keyboard_rgb_mode_index.attr)
+		ok = asus->keyboard_rgb_mode_available;
 	else if (attr == &dev_attr_fan_boost_mode.attr)
 		ok = asus->fan_boost_mode_available;
 	else if (attr == &dev_attr_throttle_thermal_policy.attr)
@@ -3646,6 +3727,10 @@ static int asus_wmi_add(struct platform_device *pdev)
 	if (err)
 		goto fail_dgpu_disable;
 
+	err = keyboard_rgb_mode_check_present(asus);
+	if (err)
+		goto fail_keyboard_rgb_mode;
+
 	err = fan_boost_mode_check_present(asus);
 	if (err)
 		goto fail_fan_boost_mode;
@@ -3760,6 +3845,7 @@ static int asus_wmi_add(struct platform_device *pdev)
 fail_fan_boost_mode:
 fail_egpu_enable:
 fail_dgpu_disable:
+fail_keyboard_rgb_mode:
 fail_platform:
 fail_panel_od:
 	kfree(asus);
-- 
2.37.1