[PATCH 1/5] asus-wmi: Add basic support for TUF laptop keyboard RGB

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

Adds support for TUF laptop RGB control via the multicolor LED API.

As this is the base essentials for adjusting the RGB, it sets the
default mode of the keyboard to static. This overwrites the booted
state of the keyboard.

Signed-off-by: Luke D. Jones <luke@ljones.dev>
---
 drivers/platform/x86/asus-wmi.c            | 89 ++++++++++++++++++++++
 include/linux/platform_data/x86/asus-wmi.h |  3 +
 2 files changed, 92 insertions(+)

diff --git a/drivers/platform/x86/asus-wmi.c b/drivers/platform/x86/asus-wmi.c
index 0e7fbed8a50d..33384e3321bb 100644
--- a/drivers/platform/x86/asus-wmi.c
+++ b/drivers/platform/x86/asus-wmi.c
@@ -25,6 +25,7 @@
 #include <linux/input/sparse-keymap.h>
 #include <linux/kernel.h>
 #include <linux/leds.h>
+#include <linux/led-class-multicolor.h>
 #include <linux/module.h>
 #include <linux/pci.h>
 #include <linux/pci_hotplug.h>
@@ -190,6 +191,11 @@ struct fan_curve_data {
 	u8 percents[FAN_CURVE_POINTS];
 };
 
+struct keyboard_rgb_led {
+	struct led_classdev_mc dev;
+	struct mc_subled subled_info[3]; /* r g b */
+};
+
 struct asus_wmi {
 	int dsts_id;
 	int spec;
@@ -234,6 +240,9 @@ struct asus_wmi {
 	bool dgpu_disable_available;
 	bool dgpu_disable;
 
+	bool keyboard_rgb_mode_available;
+	struct keyboard_rgb_led keyboard_rgb_mode;
+
 	bool throttle_thermal_policy_available;
 	u8 throttle_thermal_policy_mode;
 
@@ -1028,6 +1037,35 @@ static enum led_brightness lightbar_led_get(struct led_classdev *led_cdev)
 	return result & ASUS_WMI_DSTS_LIGHTBAR_MASK;
 }
 
+static int tuf_rgb_brightness_set(struct led_classdev *cdev,
+	enum led_brightness brightness)
+{
+	u8 r, g, b;
+	int err;
+	u32 ret;
+
+	struct led_classdev_mc *mc_cdev = lcdev_to_mccdev(cdev);
+
+	led_mc_calc_color_components(mc_cdev, brightness);
+	r = mc_cdev->subled_info[0].brightness;
+	g = mc_cdev->subled_info[1].brightness;
+	b = mc_cdev->subled_info[2].brightness;
+
+	/* Writing out requires some defaults. This will overwrite boot mode */
+	err = asus_wmi_evaluate_method3(ASUS_WMI_METHODID_DEVS, ASUS_WMI_DEVID_TUF_RGB_MODE,
+			1 | 0 | (r << 16) | (g << 24), (b) | 0, &ret);
+	if (err) {
+		pr_err("Unable to set TUF RGB data?\n");
+		return err;
+	}
+	return 0;
+}
+
+static enum led_brightness tuf_rgb_brightness_get(struct led_classdev *cdev)
+{
+	return cdev->brightness;
+}
+
 static void asus_wmi_led_exit(struct asus_wmi *asus)
 {
 	led_classdev_unregister(&asus->kbd_led);
@@ -1105,6 +1143,57 @@ static int asus_wmi_led_init(struct asus_wmi *asus)
 					   &asus->lightbar_led);
 	}
 
+	if (asus_wmi_dev_is_present(asus, ASUS_WMI_DEVID_TUF_RGB_MODE)) {
+		struct led_classdev_mc *mc_cdev;
+		struct mc_subled *mc_led_info;
+		u8 brightness = 127;
+
+		mc_cdev = &asus->keyboard_rgb_mode.dev;
+
+		/*
+		 * asus::kbd_backlight still controls a base 3-level backlight and when
+		 * it is on 0, the RGB is not visible at all. RGB should be treated as
+		 * an additional step.
+		 */
+		mc_cdev->led_cdev.name = "asus::multicolour::kbd_backlight";
+		mc_cdev->led_cdev.flags = LED_CORE_SUSPENDRESUME | LED_RETAIN_AT_SHUTDOWN;
+		mc_cdev->led_cdev.brightness_set_blocking = tuf_rgb_brightness_set;
+		mc_cdev->led_cdev.brightness_get = tuf_rgb_brightness_get;
+
+		/* Let the multicolour LED own the info */
+		mc_led_info = devm_kmalloc_array(
+			&asus->platform_device->dev,
+			3,
+			sizeof(*mc_led_info),
+			GFP_KERNEL | __GFP_ZERO);
+
+		if (!mc_led_info)
+			return -ENOMEM;
+
+		mc_led_info[0].color_index = LED_COLOR_ID_RED;
+		mc_led_info[1].color_index = LED_COLOR_ID_GREEN;
+		mc_led_info[2].color_index = LED_COLOR_ID_BLUE;
+
+		/*
+		 * It's not possible to get last set data from device so set defaults
+		 * to make it safe for a user to change either RGB or modes. We don't
+		 * write these defaults to the device because they will overwrite a
+		 * users last saved boot setting (in NVRAM).
+		 */
+		mc_cdev->led_cdev.brightness = brightness;
+		mc_cdev->led_cdev.max_brightness = brightness;
+		mc_led_info[0].intensity = brightness;
+		mc_led_info[0].brightness = mc_cdev->led_cdev.brightness;
+		mc_led_info[1].brightness = mc_cdev->led_cdev.brightness;
+		mc_led_info[2].brightness = mc_cdev->led_cdev.brightness;
+		led_mc_calc_color_components(mc_cdev, brightness);
+
+		mc_cdev->subled_info = mc_led_info;
+		mc_cdev->num_colors = 3;
+
+		rv = led_classdev_multicolor_register(&asus->platform_device->dev, mc_cdev);
+	}
+
 error:
 	if (rv)
 		asus_wmi_led_exit(asus);
diff --git a/include/linux/platform_data/x86/asus-wmi.h b/include/linux/platform_data/x86/asus-wmi.h
index a571b47ff362..d63c9945a17d 100644
--- a/include/linux/platform_data/x86/asus-wmi.h
+++ b/include/linux/platform_data/x86/asus-wmi.h
@@ -98,6 +98,9 @@
 /* dgpu on/off */
 #define ASUS_WMI_DEVID_DGPU		0x00090020
 
+/* TUF laptop RGB control */
+#define ASUS_WMI_DEVID_TUF_RGB_MODE	0x00100056
+
 /* DSTS masks */
 #define ASUS_WMI_DSTS_STATUS_BIT	0x00000001
 #define ASUS_WMI_DSTS_UNKNOWN_BIT	0x00000002
-- 
2.37.1