linux/drivers/leds/trigger/ledtrig-panic.c
Thomas Gleixner d2912cb15b treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500
Based on 2 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-19 17:09:55 +02:00

74 lines
1.7 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Kernel Panic LED Trigger
*
* Copyright 2016 Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/notifier.h>
#include <linux/leds.h>
#include "../leds.h"
static struct led_trigger *trigger;
/*
* 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)
{
struct led_trigger *trig;
list_for_each_entry(trig, &trigger_list, next_trig) {
if (strcmp("panic", trig->name))
continue;
if (led_cdev->trigger)
list_del(&led_cdev->trig_list);
list_add_tail(&led_cdev->trig_list, &trig->led_cdevs);
/* Avoid the delayed blink path */
led_cdev->blink_delay_on = 0;
led_cdev->blink_delay_off = 0;
led_cdev->trigger = trig;
if (trig->activate)
trig->activate(led_cdev);
break;
}
}
static int led_trigger_panic_notifier(struct notifier_block *nb,
unsigned long code, void *unused)
{
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);
return NOTIFY_DONE;
}
static struct notifier_block led_trigger_panic_nb = {
.notifier_call = led_trigger_panic_notifier,
};
static long led_panic_blink(int state)
{
led_trigger_event(trigger, state ? LED_FULL : LED_OFF);
return 0;
}
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;
return 0;
}
device_initcall(ledtrig_panic_init);