HID: nintendo: add player led support

This patch adds led_classdev functionality to the switch controller
driver. It adds support for the 4 player LEDs. The Home Button LED still
needs to be supported on the pro controllers and right joy-con.
Signed-off-by: Daniel J. Ogorchock <djogorchock@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/Kconfig

@@ -734,6 +734,8 @@ config HID_MULTITOUCH
 config HID_NINTENDO
 	tristate "Nintendo Joy-Con and Pro Controller support"
 	depends on HID
+	depends on NEW_LEDS
+	depends on LEDS_CLASS
 	help
 	Adds support for the Nintendo Switch Joy-Cons and Pro Controller.
 	All controllers support bluetooth, and the Pro Controller also supports

drivers/hid/hid-nintendo.c

@@ -25,6 +25,7 @@
 #include <linux/device.h>
 #include <linux/hid.h>
 #include <linux/input.h>
+#include <linux/leds.h>
 #include <linux/module.h>
 #include <linux/spinlock.h>
 
@@ -184,10 +185,19 @@ struct joycon_input_report {
 
 #define JC_MAX_RESP_SIZE	(sizeof(struct joycon_input_report) + 35)
 
+static const char * const joycon_player_led_names[] = {
+	LED_FUNCTION_PLAYER1,
+	LED_FUNCTION_PLAYER2,
+	LED_FUNCTION_PLAYER3,
+	LED_FUNCTION_PLAYER4,
+};
+#define JC_NUM_LEDS		ARRAY_SIZE(joycon_player_led_names)
+
 /* Each physical controller is associated with a joycon_ctlr struct */
 struct joycon_ctlr {
 	struct hid_device *hdev;
 	struct input_dev *input;
+	struct led_classdev leds[JC_NUM_LEDS];
 	enum joycon_ctlr_state ctlr_state;
 
 	/* The following members are used for synchronous sends/receives */
@@ -553,11 +563,9 @@ static const unsigned int joycon_dpad_inputs_jc[] = {
 	BTN_DPAD_UP, BTN_DPAD_DOWN, BTN_DPAD_LEFT, BTN_DPAD_RIGHT,
 };
 
-static DEFINE_MUTEX(joycon_input_num_mutex);
 static int joycon_input_create(struct joycon_ctlr *ctlr)
 {
 	struct hid_device *hdev;
-	static int input_num = 1;
 	const char *name;
 	int ret;
 	int i;
@@ -643,6 +651,59 @@ static int joycon_input_create(struct joycon_ctlr *ctlr)
 	if (ret)
 		return ret;
 
+	return 0;
+}
+
+static int joycon_player_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;
+	int val = 0;
+	int i;
+	int ret;
+	int num;
+
+	ctlr = hid_get_drvdata(hdev);
+	if (!ctlr) {
+		hid_err(hdev, "No controller data\n");
+		return -ENODEV;
+	}
+
+	/* determine which player led this is */
+	for (num = 0; num < JC_NUM_LEDS; num++) {
+		if (&ctlr->leds[num] == led)
+			break;
+	}
+	if (num >= JC_NUM_LEDS)
+		return -EINVAL;
+
+	mutex_lock(&ctlr->output_mutex);
+	for (i = 0; i < JC_NUM_LEDS; i++) {
+		if (i == num)
+			val |= brightness << i;
+		else
+			val |= ctlr->leds[i].brightness << i;
+	}
+	ret = joycon_set_player_leds(ctlr, 0, val);
+	mutex_unlock(&ctlr->output_mutex);
+
+	return ret;
+}
+
+static DEFINE_MUTEX(joycon_input_num_mutex);
+static int joycon_player_leds_create(struct joycon_ctlr *ctlr)
+{
+	struct hid_device *hdev = ctlr->hdev;
+	struct device *dev = &hdev->dev;
+	const char *d_name = dev_name(dev);
+	struct led_classdev *led;
+	char *name;
+	int ret = 0;
+	int i;
+	static int input_num = 1;
+
 	/* Set the default controller player leds based on controller number */
 	mutex_lock(&joycon_input_num_mutex);
 	mutex_lock(&ctlr->output_mutex);
@@ -650,6 +711,31 @@ static int joycon_input_create(struct joycon_ctlr *ctlr)
 	if (ret)
 		hid_warn(ctlr->hdev, "Failed to set leds; ret=%d\n", ret);
 	mutex_unlock(&ctlr->output_mutex);
+
+	/* configure the player LEDs */
+	for (i = 0; i < JC_NUM_LEDS; i++) {
+		name = devm_kasprintf(dev, GFP_KERNEL, "%s:%s:%s",
+				      d_name,
+				      "green",
+				      joycon_player_led_names[i]);
+		if (!name)
+			return -ENOMEM;
+
+		led = &ctlr->leds[i];
+		led->name = name;
+		led->brightness = ((i + 1) <= input_num) ? 1 : 0;
+		led->max_brightness = 1;
+		led->brightness_set_blocking =
+					joycon_player_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 %s LED\n", led->name);
+			break;
+		}
+	}
+
 	if (++input_num > 4)
 		input_num = 1;
 	mutex_unlock(&joycon_input_num_mutex);
@@ -813,6 +899,13 @@ static int nintendo_hid_probe(struct hid_device *hdev,
 
 	mutex_unlock(&ctlr->output_mutex);
 
+	/* Initialize the leds */
+	ret = joycon_player_leds_create(ctlr);
+	if (ret) {
+		hid_err(hdev, "Failed to create leds; ret=%d\n", ret);
+		goto err_close;
+	}
+
 	ret = joycon_input_create(ctlr);
 	if (ret) {
 		hid_err(hdev, "Failed to create input device; ret=%d\n", ret);