leds:panic: Added off state to panic indicator

Added an optional off state to the panic trigger of the Kernel.
This state can be used to disable other LEDs during a panic condition.

BCS 746-001091

drivers/leds/leds-gpio.c

@@ -103,6 +103,8 @@ static int create_gpio_led(const struct gpio_led *template,
 		led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
 	if (template->panic_indicator)
 		led_dat->cdev.flags |= LED_PANIC_INDICATOR;
+	else if (template->panic_indicator_off)
+		led_dat->cdev.flags |= LED_PANIC_INDICATOR_OFF;
 	if (template->retain_state_shutdown)
 		led_dat->cdev.flags |= LED_RETAIN_AT_SHUTDOWN;
 
@@ -169,6 +171,8 @@ static struct gpio_leds_priv *gpio_leds_create(struct platform_device *pdev)
 			led.retain_state_shutdown = 1;
 		if (fwnode_property_present(child, "panic-indicator"))
 			led.panic_indicator = 1;
+		else if (fwnode_property_present(child, "panic-indicator-off"))
+			led.panic_indicator_off = 1;
 
 		ret = create_gpio_led(&led, led_dat, dev, child, NULL);
 		if (ret < 0) {

drivers/leds/trigger/ledtrig-panic.c

@@ -12,19 +12,25 @@
 #include <linux/leds.h>
 #include "../leds.h"
 
-static struct led_trigger *trigger;
+enum led_panic_type {
+	OFF,
+	BLINK,
+	PANIC_TYPE_COUNT,
+};
+
+static struct led_trigger *trigger[PANIC_TYPE_COUNT];
 
 /*
  * This is called in a special context by the atomic panic
  * notifier. This means the trigger can be changed without
  * worrying about locking.
  */
-static void led_trigger_set_panic(struct led_classdev *led_cdev)
+static void led_trigger_set_panic(struct led_classdev *led_cdev, const char *type)
 {
 	struct led_trigger *trig;
 
 	list_for_each_entry(trig, &trigger_list, next_trig) {
-		if (strcmp("panic", trig->name))
+		if (strcmp(type, trig->name))
 			continue;
 		if (led_cdev->trigger)
 			list_del(&led_cdev->trig_list);
@@ -47,8 +53,11 @@ static int led_trigger_panic_notifier(struct notifier_block *nb,
 	struct led_classdev *led_cdev;
 
 	list_for_each_entry(led_cdev, &leds_list, node)
-		if (led_cdev->flags & LED_PANIC_INDICATOR)
-			led_trigger_set_panic(led_cdev);
+		if (led_cdev->flags & LED_PANIC_INDICATOR_OFF)
+			led_trigger_set_panic(led_cdev, "panic_off");
+		else if (led_cdev->flags & LED_PANIC_INDICATOR)
+			led_trigger_set_panic(led_cdev, "panic");
+
 	return NOTIFY_DONE;
 }
 
@@ -56,9 +65,10 @@ static struct notifier_block led_trigger_panic_nb = {
 	.notifier_call = led_trigger_panic_notifier,
 };
 
-static long led_panic_blink(int state)
+static long led_panic_activity(int state)
 {
-	led_trigger_event(trigger, state ? LED_FULL : LED_OFF);
+	led_trigger_event(trigger[OFF], LED_OFF);
+	led_trigger_event(trigger[BLINK], state ? LED_FULL : LED_OFF);
 	return 0;
 }
 
@@ -67,8 +77,9 @@ static int __init ledtrig_panic_init(void)
 	atomic_notifier_chain_register(&panic_notifier_list,
 				       &led_trigger_panic_nb);
 
-	led_trigger_register_simple("panic", &trigger);
-	panic_blink = led_panic_blink;
+	led_trigger_register_simple("panic_off", &trigger[OFF]);
+	led_trigger_register_simple("panic", &trigger[BLINK]);
+	panic_blink = led_panic_activity;
 	return 0;
 }
 device_initcall(ledtrig_panic_init);

include/linux/leds.h

@@ -85,6 +85,7 @@ 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_PANIC_INDICATOR_OFF	BIT(24)
 
 	/* set_brightness_work / blink_timer flags, atomic, private. */
 	unsigned long		work_flags;
@@ -521,6 +522,7 @@ struct gpio_led {
 	unsigned	active_low : 1;
 	unsigned	retain_state_suspended : 1;
 	unsigned	panic_indicator : 1;
+	unsigned	panic_indicator_off : 1;
 	unsigned	default_state : 2;
 	unsigned	retain_state_shutdown : 1;
 	/* default_state should be one of LEDS_GPIO_DEFSTATE_(ON|OFF|KEEP) */