diff options
author | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2016-09-11 04:34:46 -0300 |
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committer | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2016-09-11 04:34:46 -0300 |
commit | 863981e96738983919de841ec669e157e6bdaeb0 (patch) | |
tree | d6d89a12e7eb8017837c057935a2271290907f76 /drivers/leds/trigger/ledtrig-panic.c | |
parent | 8dec7c70575785729a6a9e6719a955e9c545bcab (diff) |
Linux-libre 4.7.1-gnupck-4.7.1-gnu
Diffstat (limited to 'drivers/leds/trigger/ledtrig-panic.c')
-rw-r--r-- | drivers/leds/trigger/ledtrig-panic.c | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/drivers/leds/trigger/ledtrig-panic.c b/drivers/leds/trigger/ledtrig-panic.c new file mode 100644 index 000000000..d735526b9 --- /dev/null +++ b/drivers/leds/trigger/ledtrig-panic.c @@ -0,0 +1,77 @@ +/* + * Kernel Panic LED Trigger + * + * Copyright 2016 Ezequiel Garcia <ezequiel@vanguardiasur.com.ar> + * + * 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. + * + */ + +#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); |