HID: nintendo: add home led support

This patch adds the ability to set the intensity level of the home
button's LED.

Signed-off-by: Daniel J. Ogorchock <djogorchock@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/hid-nintendo.c

@@ -199,7 +199,8 @@ static const char * const joycon_player_led_names[] = {
 struct joycon_ctlr {
 	struct hid_device *hdev;
 	struct input_dev *input;
-	struct led_classdev leds[JC_NUM_LEDS];
+	struct led_classdev leds[JC_NUM_LEDS]; /* player leds */
+	struct led_classdev home_led;
 	enum joycon_ctlr_state ctlr_state;
 	spinlock_t lock;
 
@@ -733,8 +734,42 @@ static int joycon_player_led_brightness_set(struct led_classdev *led,
 	return ret;
 }
 
+static int joycon_home_led_brightness_set(struct led_classdev *led,
+					  enum led_brightness brightness)
+{
+	struct device *dev = led->dev->parent;
+	struct hid_device *hdev = to_hid_device(dev);
+	struct joycon_ctlr *ctlr;
+	struct joycon_subcmd_request *req;
+	u8 buffer[sizeof(*req) + 5] = { 0 };
+	u8 *data;
+	int ret;
+
+	ctlr = hid_get_drvdata(hdev);
+	if (!ctlr) {
+		hid_err(hdev, "No controller data\n");
+		return -ENODEV;
+	}
+
+	req = (struct joycon_subcmd_request *)buffer;
+	req->subcmd_id = JC_SUBCMD_SET_HOME_LIGHT;
+	data = req->data;
+	data[0] = 0x01;
+	data[1] = brightness << 4;
+	data[2] = brightness | (brightness << 4);
+	data[3] = 0x11;
+	data[4] = 0x11;
+
+	hid_dbg(hdev, "setting home led brightness\n");
+	mutex_lock(&ctlr->output_mutex);
+	ret = joycon_send_subcmd(ctlr, req, 5);
+	mutex_unlock(&ctlr->output_mutex);
+
+	return ret;
+}
+
 static DEFINE_MUTEX(joycon_input_num_mutex);
-static int joycon_player_leds_create(struct joycon_ctlr *ctlr)
+static int joycon_leds_create(struct joycon_ctlr *ctlr)
 {
 	struct hid_device *hdev = ctlr->hdev;
 	struct device *dev = &hdev->dev;
@@ -773,14 +808,43 @@ static int joycon_player_leds_create(struct joycon_ctlr *ctlr)
 		ret = devm_led_classdev_register(&hdev->dev, led);
 		if (ret) {
 			hid_err(hdev, "Failed registering %s LED\n", led->name);
-			break;
+			return ret;
 		}
 	}
 
 	if (++input_num > 4)
 		input_num = 1;
 	mutex_unlock(&joycon_input_num_mutex);
 
+	/* configure the home LED */
+	if (ctlr->hdev->product != USB_DEVICE_ID_NINTENDO_JOYCONL) {
+		name = devm_kasprintf(dev, GFP_KERNEL, "%s:%s:%s",
+				      d_name,
+				      "blue",
+				      LED_FUNCTION_PLAYER5);
+		if (!name)
+			return -ENOMEM;
+
+		led = &ctlr->home_led;
+		led->name = name;
+		led->brightness = 0;
+		led->max_brightness = 0xF;
+		led->brightness_set_blocking = joycon_home_led_brightness_set;
+		led->flags = LED_CORE_SUSPENDRESUME | LED_HW_PLUGGABLE;
+		ret = devm_led_classdev_register(&hdev->dev, led);
+		if (ret) {
+			hid_err(hdev, "Failed registering home led\n");
+			return ret;
+		}
+		/* Set the home LED to 0 as default state */
+		ret = joycon_home_led_brightness_set(led, 0);
+		if (ret) {
+			hid_err(hdev, "Failed to set home LED dflt; ret=%d\n",
+									ret);
+			return ret;
+		}
+	}
+
 	return 0;
 }
 
@@ -1027,7 +1091,7 @@ static int nintendo_hid_probe(struct hid_device *hdev,
 	mutex_unlock(&ctlr->output_mutex);
 
 	/* Initialize the leds */
-	ret = joycon_player_leds_create(ctlr);
+	ret = joycon_leds_create(ctlr);
 	if (ret) {
 		hid_err(hdev, "Failed to create leds; ret=%d\n", ret);
 		goto err_close;