leds: class: Add flag to avoid automatic renaming of LED devices

Add a mechanism for drivers to opt-out of the automatic device renaming
on conflicts.
Those drivers will provide their own conflict resolution.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://lore.kernel.org/r/20240526-cros_ec-kbd-led-framework-v3-2-ee577415a521@weissschuh.netSigned-off-by: Lee Jones <lee@kernel.org>

drivers/leds/led-class.c

@@ -503,6 +503,8 @@ int led_classdev_register_ext(struct device *parent,
 	ret = led_classdev_next_name(proposed_name, final_name, sizeof(final_name));
 	if (ret < 0)
 		return ret;
+	else if (ret && led_cdev->flags & LED_REJECT_NAME_CONFLICT)
+		return -EEXIST;
 	else if (ret)
 		dev_warn(parent, "Led %s renamed to %s due to name collision\n",
 			 proposed_name, final_name);

include/linux/leds.h

@@ -107,6 +107,7 @@ struct led_classdev {
 #define LED_BRIGHT_HW_CHANGED	BIT(21)
 #define LED_RETAIN_AT_SHUTDOWN	BIT(22)
 #define LED_INIT_DEFAULT_TRIGGER BIT(23)
+#define LED_REJECT_NAME_CONFLICT BIT(24)
 
 	/* set_brightness_work / blink_timer flags, atomic, private. */
 	unsigned long		work_flags;