[PATCH 10/11] HID: asus: add basic RGB support

[Antheas Kapenekakis <lkml@antheas.dev>]

Adds basic RGB support to hid-asus through multi-index. The interface
works quite well, but has not gone through much stability testing.
Applied on demand, if userspace does not touch the RGB sysfs, not
even initialization is done. Ensuring compatibility with existing
userspace programs.

Signed-off-by: Antheas Kapenekakis <lkml@antheas.dev>
---
 drivers/hid/hid-asus.c | 169 +++++++++++++++++++++++++++++++++++++----
 1 file changed, 155 insertions(+), 14 deletions(-)

diff --git a/drivers/hid/hid-asus.c b/drivers/hid/hid-asus.c
index 546603f5193c7..5e87923b35520 100644
--- a/drivers/hid/hid-asus.c
+++ b/drivers/hid/hid-asus.c
@@ -30,6 +30,7 @@
 #include <linux/input/mt.h>
 #include <linux/usb.h> /* For to_usb_interface for T100 touchpad intf check */
 #include <linux/power_supply.h>
+#include <linux/led-class-multicolor.h>
 #include <linux/leds.h>
 
 #include "hid-ids.h"
@@ -85,6 +86,7 @@ MODULE_DESCRIPTION("Asus HID Keyboard and TouchPad");
 #define QUIRK_ROG_NKEY_KEYBOARD		BIT(11)
 #define QUIRK_ROG_CLAYMORE_II_KEYBOARD BIT(12)
 #define QUIRK_HANDLE_GENERIC		BIT(13)
+#define QUIRK_ROG_NKEY_RGB		BIT(14)
 
 #define I2C_KEYBOARD_QUIRKS			(QUIRK_FIX_NOTEBOOK_REPORT | \
 						 QUIRK_NO_INIT_REPORTS | \
@@ -97,9 +99,15 @@ MODULE_DESCRIPTION("Asus HID Keyboard and TouchPad");
 
 struct asus_kbd_leds {
 	struct asus_brt_listener listener;
+	struct led_classdev_mc mc_led;
+	struct mc_subled subled_info[3];
 	struct hid_device *hdev;
 	struct work_struct work;
 	unsigned int brightness;
+	uint8_t rgb_colors[3];
+	bool rgb_init;
+	bool rgb_set;
+	bool rgb_registered;
 	spinlock_t lock;
 	bool removed;
 };
@@ -505,23 +513,67 @@ static void asus_schedule_work(struct asus_kbd_leds *led)
 	spin_unlock_irqrestore(&led->lock, flags);
 }
 
-static void asus_kbd_backlight_set(struct asus_brt_listener *listener,
+static void do_asus_kbd_backlight_set(struct asus_kbd_leds *led, int brightness)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&led->lock, flags);
+	led->brightness = brightness;
+	spin_unlock_irqrestore(&led->lock, flags);
+
+	asus_schedule_work(led);
+}
+
+static void asus_kbd_listener_set(struct asus_brt_listener *listener,
 				   int brightness)
 {
 	struct asus_kbd_leds *led = container_of(listener, struct asus_kbd_leds,
 						 listener);
+	do_asus_kbd_backlight_set(led, brightness);
+	if (led->rgb_registered) {
+		led->mc_led.led_cdev.brightness = brightness;
+		led_classdev_notify_brightness_hw_changed(&led->mc_led.led_cdev,
+							  brightness);
+	}
+}
+
+static void asus_kbd_brightness_set(struct led_classdev *led_cdev,
+				    enum led_brightness brightness)
+{
+	struct led_classdev_mc *mc_cdev = lcdev_to_mccdev(led_cdev);
+	struct asus_kbd_leds *led = container_of(mc_cdev, struct asus_kbd_leds,
+						 mc_led);
 	unsigned long flags;
 
 	spin_lock_irqsave(&led->lock, flags);
-	led->brightness = brightness;
+	led->rgb_colors[0] = mc_cdev->subled_info[0].intensity;
+	led->rgb_colors[1] = mc_cdev->subled_info[1].intensity;
+	led->rgb_colors[2] = mc_cdev->subled_info[2].intensity;
+	led->rgb_set = true;
 	spin_unlock_irqrestore(&led->lock, flags);
 
-	asus_schedule_work(led);
+	do_asus_kbd_backlight_set(led, brightness);
+}
+
+static enum led_brightness asus_kbd_brightness_get(struct led_classdev *led_cdev)
+{
+	struct led_classdev_mc *mc_led;
+	struct asus_kbd_leds *led;
+	enum led_brightness brightness;
+	unsigned long flags;
+
+	mc_led = lcdev_to_mccdev(led_cdev);
+	led = container_of(mc_led, struct asus_kbd_leds, mc_led);
+
+	spin_lock_irqsave(&led->lock, flags);
+	brightness = led->brightness;
+	spin_unlock_irqrestore(&led->lock, flags);
+
+	return brightness;
 }
 
-static void asus_kbd_backlight_work(struct work_struct *work)
+static void asus_kbd_backlight_work(struct asus_kbd_leds *led)
 {
-	struct asus_kbd_leds *led = container_of(work, struct asus_kbd_leds, work);
 	u8 buf[] = { FEATURE_KBD_REPORT_ID, 0xba, 0xc5, 0xc4, 0x00 };
 	int ret;
 	unsigned long flags;
@@ -535,10 +587,69 @@ static void asus_kbd_backlight_work(struct work_struct *work)
 		hid_err(led->hdev, "Asus failed to set keyboard backlight: %d\n", ret);
 }
 
+static void asus_kbd_rgb_work(struct asus_kbd_leds *led)
+{
+	u8 rgb_buf[][7] = {
+		{ FEATURE_KBD_LED_REPORT_ID1, 0xB3 }, /* set mode */
+		{ FEATURE_KBD_LED_REPORT_ID1, 0xB5 }, /* apply mode */
+		{ FEATURE_KBD_LED_REPORT_ID1, 0xB4 }, /* save to mem */
+	};
+	unsigned long flags;
+	uint8_t colors[3];
+	bool rgb_init, rgb_set;
+	int ret;
+
+	spin_lock_irqsave(&led->lock, flags);
+	rgb_init = led->rgb_init;
+	rgb_set = led->rgb_set;
+	led->rgb_set = false;
+	colors[0] = led->rgb_colors[0];
+	colors[1] = led->rgb_colors[1];
+	colors[2] = led->rgb_colors[2];
+	spin_unlock_irqrestore(&led->lock, flags);
+
+	if (!rgb_set)
+		return;
+
+	if (rgb_init) {
+		ret = asus_kbd_init(led->hdev, FEATURE_KBD_LED_REPORT_ID1);
+		if (ret < 0) {
+			hid_err(led->hdev, "Asus failed to init RGB: %d\n", ret);
+			return;
+		}
+		spin_lock_irqsave(&led->lock, flags);
+		led->rgb_init = false;
+		spin_unlock_irqrestore(&led->lock, flags);
+	}
+
+	/* Protocol is: 54b3 zone (0=all) mode (0=solid) RGB */
+	rgb_buf[0][4] = colors[0];
+	rgb_buf[0][5] = colors[1];
+	rgb_buf[0][6] = colors[2];
+
+	for (size_t i = 0; i < ARRAY_SIZE(rgb_buf); i++) {
+		ret = asus_kbd_set_report(led->hdev, rgb_buf[i], sizeof(rgb_buf[i]));
+		if (ret < 0) {
+			hid_err(led->hdev, "Asus failed to set RGB: %d\n", ret);
+			return;
+		}
+	}
+}
+
+static void asus_kbd_work(struct work_struct *work)
+{
+	struct asus_kbd_leds *led = container_of(work, struct asus_kbd_leds,
+						 work);
+	asus_kbd_backlight_work(led);
+	asus_kbd_rgb_work(led);
+}
+
 static int asus_kbd_register_leds(struct hid_device *hdev)
 {
 	struct asus_drvdata *drvdata = hid_get_drvdata(hdev);
 	unsigned char kbd_func;
+	struct asus_kbd_leds *leds;
+	bool no_led;
 	int ret;
 
 	ret = asus_kbd_init(hdev, FEATURE_KBD_REPORT_ID);
@@ -566,21 +677,51 @@ static int asus_kbd_register_leds(struct hid_device *hdev)
 	if (!drvdata->kbd_backlight)
 		return -ENOMEM;
 
-	drvdata->kbd_backlight->removed = false;
-	drvdata->kbd_backlight->brightness = 0;
-	drvdata->kbd_backlight->hdev = hdev;
-	drvdata->kbd_backlight->listener.notify = asus_kbd_backlight_set;
-	INIT_WORK(&drvdata->kbd_backlight->work, asus_kbd_backlight_work);
+	leds = drvdata->kbd_backlight;
+	leds->removed = false;
+	leds->brightness = 3;
+	leds->hdev = hdev;
+	leds->listener.notify = asus_kbd_listener_set;
+
+	leds->rgb_colors[0] = 0;
+	leds->rgb_colors[1] = 0;
+	leds->rgb_colors[2] = 0;
+	leds->rgb_init = true;
+	leds->rgb_set = false;
+	leds->mc_led.led_cdev.name = devm_kasprintf(&hdev->dev, GFP_KERNEL,
+					"asus-%s-led",
+					strlen(hdev->uniq) ?
+					hdev->uniq : dev_name(&hdev->dev));
+	leds->mc_led.led_cdev.flags = LED_BRIGHT_HW_CHANGED;
+	leds->mc_led.led_cdev.max_brightness = 3,
+	leds->mc_led.led_cdev.brightness_set = asus_kbd_brightness_set,
+	leds->mc_led.led_cdev.brightness_get = asus_kbd_brightness_get,
+	leds->mc_led.subled_info = leds->subled_info,
+	leds->mc_led.num_colors = ARRAY_SIZE(leds->subled_info),
+	leds->subled_info[0].color_index = LED_COLOR_ID_RED;
+	leds->subled_info[1].color_index = LED_COLOR_ID_GREEN;
+	leds->subled_info[2].color_index = LED_COLOR_ID_BLUE;
+
+	INIT_WORK(&drvdata->kbd_backlight->work, asus_kbd_work);
 	spin_lock_init(&drvdata->kbd_backlight->lock);
 
 	ret = asus_brt_register_listener(&drvdata->kbd_backlight->listener);
+	no_led = !!ret;
+
+	if (drvdata->quirks & QUIRK_ROG_NKEY_RGB) {
+		ret = devm_led_classdev_multicolor_register(
+			&hdev->dev, &leds->mc_led);
+		if (!ret)
+			leds->rgb_registered = true;
+		no_led &= !!ret;
+	}
 
-	if (ret < 0) {
+	if (no_led) {
 		/* No need to have this still around */
 		devm_kfree(&hdev->dev, drvdata->kbd_backlight);
 	}
 
-	return ret;
+	return no_led ? -ENODEV : 0;
 }
 
 /*
@@ -1305,7 +1446,7 @@ static const struct hid_device_id asus_devices[] = {
 	  QUIRK_USE_KBD_BACKLIGHT | QUIRK_ROG_NKEY_KEYBOARD },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_ASUSTEK,
 	    USB_DEVICE_ID_ASUSTEK_ROG_Z13_LIGHTBAR),
-	  QUIRK_USE_KBD_BACKLIGHT | QUIRK_ROG_NKEY_KEYBOARD },
+	  QUIRK_USE_KBD_BACKLIGHT | QUIRK_ROG_NKEY_KEYBOARD | QUIRK_ROG_NKEY_RGB },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_ASUSTEK,
 	    USB_DEVICE_ID_ASUSTEK_ROG_NKEY_ALLY),
 	  QUIRK_USE_KBD_BACKLIGHT | QUIRK_ROG_NKEY_KEYBOARD },
@@ -1334,7 +1475,7 @@ static const struct hid_device_id asus_devices[] = {
 	 */
 	{ HID_DEVICE(BUS_USB, HID_GROUP_GENERIC,
 		USB_VENDOR_ID_ASUSTEK, USB_DEVICE_ID_ASUSTEK_ROG_Z13_FOLIO),
-	  QUIRK_USE_KBD_BACKLIGHT | QUIRK_ROG_NKEY_KEYBOARD },
+	  QUIRK_USE_KBD_BACKLIGHT | QUIRK_ROG_NKEY_KEYBOARD | QUIRK_ROG_NKEY_RGB },
 	{ HID_DEVICE(BUS_USB, HID_GROUP_GENERIC,
 		USB_VENDOR_ID_ASUSTEK, USB_DEVICE_ID_ASUSTEK_T101HA_KEYBOARD) },
 	{ }
-- 
2.48.1