[PATCH 2/2] asus-wmi: Add support for keyboard rgb backlights

[Abhijeet V <abhijeetviswa@gmail.com>]

Uses the led multicolor classdev to change the rgb values.
The WMI function expects other settings in addition to the rgb values.
This patch assumes some defaults to get the base rgb functionality
working.

Signed-off-by: Abhijeet V <abhijeetviswa@gmail.com>
---
 drivers/platform/x86/asus-wmi.c            | 137 +++++++++++++++++++++
 include/linux/platform_data/x86/asus-wmi.h |   2 +
 2 files changed, 139 insertions(+)

diff --git a/drivers/platform/x86/asus-wmi.c b/drivers/platform/x86/asus-wmi.c
index 117fbcb303d3..f8e92021399c 100644
--- a/drivers/platform/x86/asus-wmi.c
+++ b/drivers/platform/x86/asus-wmi.c
@@ -193,6 +193,12 @@ struct fan_curve_data {
 	u8 percents[FAN_CURVE_POINTS];
 };
 
+struct asus_kbd_rgb {
+	u8 red;
+	u8 green;
+	u8 blue;
+};
+
 struct asus_wmi {
 	int dsts_id;
 	int spec;
@@ -217,6 +223,8 @@ struct asus_wmi {
 	struct led_classdev_mc kbd_led_mc;
 	int kbd_led_wk;
 	struct mc_subled subled_info[ASUS_KBD_SUBLED_COUNT];
+	struct asus_kbd_rgb kbd_rgb;
+	bool kbd_rgb_available;
 
 	struct asus_rfkill wlan;
 	struct asus_rfkill bluetooth;
@@ -914,6 +922,114 @@ static void kbd_led_brightness_wmi_write(struct asus_wmi *asus, int value)
 	asus_wmi_set_devstate(ASUS_WMI_DEVID_KBD_BACKLIGHT, ctrl_param, NULL);
 }
 
+static int kbd_led_rgb_wmi_write(struct asus_wmi *asus)
+{
+	int err;
+	u32 retval;
+	u8 red;
+	u8 green;
+	u8 blue;
+	u8 speed_byte;
+	u8 mode_byte;
+	u8 speed;
+	u8 mode;
+	u8 flags;
+	u8 persistent;
+
+	speed = 0; // Sane default
+	switch (speed) {
+	case 0:
+	default:
+		speed_byte = 0xe1; // slow
+		speed = 0;
+		break;
+	case 1:
+		speed_byte = 0xeb; // medium
+		break;
+	case 2:
+		speed_byte = 0xf5; // fast
+		break;
+	}
+
+	mode = 0; // Sane default
+	switch (mode) {
+	case 0:
+	default:
+		mode_byte = 0x00; // static color
+		mode = 0;
+		break;
+	case 1:
+		mode_byte = 0x01; // breathing
+		break;
+	case 2:
+		mode_byte = 0x02; // color cycle
+		break;
+	case 3:
+		mode_byte = 0x0a; // strobing
+		break;
+	}
+
+	red = clamp_val(asus->kbd_led_mc.subled_info[0].intensity, 0, 255);
+	green = clamp_val(asus->kbd_led_mc.subled_info[1].intensity, 0, 255);
+	blue = clamp_val(asus->kbd_led_mc.subled_info[2].intensity, 0, 255);
+
+	/*
+	 * 00 - Reset on boot
+	 * 01 - Persist across boot
+	 */
+	persistent = 1; // Sane defaults
+
+	err = asus_wmi_evaluate_method3(ASUS_WMI_METHODID_DEVS,
+		ASUS_WMI_DEVID_KBD_RGB,
+		(persistent ? 0xb4 : 0xb3) |
+		(mode_byte << 8) |
+		(red << 16) |
+		(green << 24),
+		(blue) |
+		(speed_byte << 8), &retval);
+	if (err) {
+		pr_warn("RGB keyboard device 1, write error: %d\n", err);
+		return err;
+	}
+
+	if (retval != 1) {
+		pr_warn("RGB keyboard device 1, write error (retval): %x\n",
+				retval);
+		return -EIO;
+	}
+
+	/*
+	 * Enable: 02 - on boot (until module load) | 08 - awake | 20 - sleep
+	 * (2a or ff to enable everything)
+	 *
+	 * Logically 80 would be shutdown, but no visible effects of this option
+	 * were observed so far
+	 */
+	flags = 0xff;
+
+	err = asus_wmi_evaluate_method3(ASUS_WMI_METHODID_DEVS,
+		ASUS_WMI_DEVID_KBD_RGB2,
+		(0xbd) |
+		(flags << 16) |
+		(persistent ? 0x0100 : 0x0000), 0, &retval);
+	if (err) {
+		pr_warn("RGB keyboard device 2, write error: %d\n", err);
+		return err;
+	}
+
+	if (retval != 1) {
+		pr_warn("RGB keyboard device 2, write error (retval): %x\n",
+				retval);
+		return -EIO;
+	}
+
+	asus->kbd_rgb.red = red;
+	asus->kbd_rgb.green = green;
+	asus->kbd_rgb.blue = blue;
+
+	return 0;
+}
+
 static void kbd_led_brightness_set(struct led_classdev *led_cdev,
 		enum led_brightness value)
 {
@@ -928,6 +1044,18 @@ static void kbd_led_brightness_set(struct led_classdev *led_cdev,
 	asus = container_of(led_cdev_mc, struct asus_wmi, kbd_led_mc);
 
 	kbd_led_brightness_wmi_write(asus, value);
+
+	/* Check and set if rgb available */
+	if (!asus->kbd_rgb_available)
+		return;
+
+	if (asus->kbd_rgb.red == asus->subled_info[LED_COLOR_ID_RED].intensity &&
+			asus->kbd_rgb.green == asus->subled_info[LED_COLOR_ID_GREEN].intensity &&
+			asus->kbd_rgb.blue == asus->subled_info[LED_COLOR_ID_BLUE].intensity) {
+		return;
+	}
+
+	kbd_led_rgb_wmi_write(asus);
 }
 
 static void kbd_led_set_brightness_by_hw(struct asus_wmi *asus,
@@ -959,6 +1087,7 @@ int kbd_led_classdev_init(struct asus_wmi *asus, int brightness)
 {
 	int rv;
 
+	asus->kbd_rgb_available = true;
 	asus->kbd_led_wk = brightness;
 	asus->kbd_led_mc.led_cdev.name = "asus::kbd_backlight";
 	asus->kbd_led_mc.led_cdev.flags = LED_BRIGHT_HW_CHANGED;
@@ -966,6 +1095,14 @@ int kbd_led_classdev_init(struct asus_wmi *asus, int brightness)
 	asus->kbd_led_mc.led_cdev.brightness_get = kbd_led_brightness_get;
 	asus->kbd_led_mc.led_cdev.max_brightness = 3;
 
+	asus->subled_info[0].color_index = LED_COLOR_ID_RED;
+	asus->subled_info[0].channel = 0;
+	asus->subled_info[1].color_index = LED_COLOR_ID_GREEN;
+	asus->subled_info[1].channel = 1;
+	asus->subled_info[2].color_index = LED_COLOR_ID_BLUE;
+	asus->subled_info[2].channel = 2;
+	asus->kbd_led_mc.subled_info = asus->subled_info;
+
 	asus->kbd_led_mc.num_colors = ASUS_KBD_SUBLED_COUNT;
 
 	rv = led_classdev_multicolor_register(&asus->platform_device->dev,
diff --git a/include/linux/platform_data/x86/asus-wmi.h b/include/linux/platform_data/x86/asus-wmi.h
index a571b47ff362..a20ca3787e9f 100644
--- a/include/linux/platform_data/x86/asus-wmi.h
+++ b/include/linux/platform_data/x86/asus-wmi.h
@@ -59,6 +59,8 @@
 #define ASUS_WMI_DEVID_LIGHTBAR		0x00050025
 #define ASUS_WMI_DEVID_FAN_BOOST_MODE	0x00110018
 #define ASUS_WMI_DEVID_THROTTLE_THERMAL_POLICY 0x00120075
+#define ASUS_WMI_DEVID_KBD_RGB		0x00100056
+#define ASUS_WMI_DEVID_KBD_RGB2		0x00100057
 
 /* Misc */
 #define ASUS_WMI_DEVID_PANEL_OD		0x00050019
-- 
2.35.1