diff options
Diffstat (limited to 'drivers/leds/led-triggers.c')
| -rw-r--r-- | drivers/leds/led-triggers.c | 239 |
1 files changed, 239 insertions, 0 deletions
diff --git a/drivers/leds/led-triggers.c b/drivers/leds/led-triggers.c new file mode 100644 index 00000000000000..5e2cd8be1191b9 --- /dev/null +++ b/drivers/leds/led-triggers.c @@ -0,0 +1,239 @@ +/* + * LED Triggers Core + * + * Copyright 2005-2006 Openedhand Ltd. + * + * Author: Richard Purdie <rpurdie@openedhand.com> + * + * 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/config.h> +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/list.h> +#include <linux/spinlock.h> +#include <linux/device.h> +#include <linux/sysdev.h> +#include <linux/timer.h> +#include <linux/leds.h> +#include "leds.h" + +/* + * Nests outside led_cdev->trigger_lock + */ +static rwlock_t triggers_list_lock = RW_LOCK_UNLOCKED; +static LIST_HEAD(trigger_list); + +ssize_t led_trigger_store(struct class_device *dev, const char *buf, + size_t count) +{ + struct led_classdev *led_cdev = class_get_devdata(dev); + char trigger_name[TRIG_NAME_MAX]; + struct led_trigger *trig; + size_t len; + + trigger_name[sizeof(trigger_name) - 1] = '\0'; + strncpy(trigger_name, buf, sizeof(trigger_name) - 1); + len = strlen(trigger_name); + + if (len && trigger_name[len - 1] == '\n') + trigger_name[len - 1] = '\0'; + + if (!strcmp(trigger_name, "none")) { + write_lock(&led_cdev->trigger_lock); + led_trigger_set(led_cdev, NULL); + write_unlock(&led_cdev->trigger_lock); + return count; + } + + read_lock(&triggers_list_lock); + list_for_each_entry(trig, &trigger_list, next_trig) { + if (!strcmp(trigger_name, trig->name)) { + write_lock(&led_cdev->trigger_lock); + led_trigger_set(led_cdev, trig); + write_unlock(&led_cdev->trigger_lock); + + read_unlock(&triggers_list_lock); + return count; + } + } + read_unlock(&triggers_list_lock); + + return -EINVAL; +} + + +ssize_t led_trigger_show(struct class_device *dev, char *buf) +{ + struct led_classdev *led_cdev = class_get_devdata(dev); + struct led_trigger *trig; + int len = 0; + + read_lock(&triggers_list_lock); + read_lock(&led_cdev->trigger_lock); + + if (!led_cdev->trigger) + len += sprintf(buf+len, "[none] "); + else + len += sprintf(buf+len, "none "); + + list_for_each_entry(trig, &trigger_list, next_trig) { + if (led_cdev->trigger && !strcmp(led_cdev->trigger->name, + trig->name)) + len += sprintf(buf+len, "[%s] ", trig->name); + else + len += sprintf(buf+len, "%s ", trig->name); + } + read_unlock(&led_cdev->trigger_lock); + read_unlock(&triggers_list_lock); + + len += sprintf(len+buf, "\n"); + return len; +} + +void led_trigger_event(struct led_trigger *trigger, + enum led_brightness brightness) +{ + struct list_head *entry; + + if (!trigger) + return; + + read_lock(&trigger->leddev_list_lock); + list_for_each(entry, &trigger->led_cdevs) { + struct led_classdev *led_cdev; + + led_cdev = list_entry(entry, struct led_classdev, trig_list); + led_set_brightness(led_cdev, brightness); + } + read_unlock(&trigger->leddev_list_lock); +} + +/* Caller must ensure led_cdev->trigger_lock held */ +void led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trigger) +{ + unsigned long flags; + + /* Remove any existing trigger */ + if (led_cdev->trigger) { + write_lock_irqsave(&led_cdev->trigger->leddev_list_lock, flags); + list_del(&led_cdev->trig_list); + write_unlock_irqrestore(&led_cdev->trigger->leddev_list_lock, flags); + if (led_cdev->trigger->deactivate) + led_cdev->trigger->deactivate(led_cdev); + } + if (trigger) { + write_lock_irqsave(&trigger->leddev_list_lock, flags); + list_add_tail(&led_cdev->trig_list, &trigger->led_cdevs); + write_unlock_irqrestore(&trigger->leddev_list_lock, flags); + if (trigger->activate) + trigger->activate(led_cdev); + } + led_cdev->trigger = trigger; +} + +void led_trigger_set_default(struct led_classdev *led_cdev) +{ + struct led_trigger *trig; + + if (!led_cdev->default_trigger) + return; + + read_lock(&triggers_list_lock); + write_lock(&led_cdev->trigger_lock); + list_for_each_entry(trig, &trigger_list, next_trig) { + if (!strcmp(led_cdev->default_trigger, trig->name)) + led_trigger_set(led_cdev, trig); + } + write_unlock(&led_cdev->trigger_lock); + read_unlock(&triggers_list_lock); +} + +int led_trigger_register(struct led_trigger *trigger) +{ + struct led_classdev *led_cdev; + + rwlock_init(&trigger->leddev_list_lock); + INIT_LIST_HEAD(&trigger->led_cdevs); + + /* Add to the list of led triggers */ + write_lock(&triggers_list_lock); + list_add_tail(&trigger->next_trig, &trigger_list); + write_unlock(&triggers_list_lock); + + /* Register with any LEDs that have this as a default trigger */ + read_lock(&leds_list_lock); + list_for_each_entry(led_cdev, &leds_list, node) { + write_lock(&led_cdev->trigger_lock); + if (!led_cdev->trigger && led_cdev->default_trigger && + !strcmp(led_cdev->default_trigger, trigger->name)) + led_trigger_set(led_cdev, trigger); + write_unlock(&led_cdev->trigger_lock); + } + read_unlock(&leds_list_lock); + + return 0; +} + +void led_trigger_register_simple(const char *name, struct led_trigger **tp) +{ + struct led_trigger *trigger; + + trigger = kzalloc(sizeof(struct led_trigger), GFP_KERNEL); + + if (trigger) { + trigger->name = name; + led_trigger_register(trigger); + } + *tp = trigger; +} + +void led_trigger_unregister(struct led_trigger *trigger) +{ + struct led_classdev *led_cdev; + + /* Remove from the list of led triggers */ + write_lock(&triggers_list_lock); + list_del(&trigger->next_trig); + write_unlock(&triggers_list_lock); + + /* Remove anyone actively using this trigger */ + read_lock(&leds_list_lock); + list_for_each_entry(led_cdev, &leds_list, node) { + write_lock(&led_cdev->trigger_lock); + if (led_cdev->trigger == trigger) + led_trigger_set(led_cdev, NULL); + write_unlock(&led_cdev->trigger_lock); + } + read_unlock(&leds_list_lock); +} + +void led_trigger_unregister_simple(struct led_trigger *trigger) +{ + led_trigger_unregister(trigger); + kfree(trigger); +} + +/* Used by LED Class */ +EXPORT_SYMBOL_GPL(led_trigger_set); +EXPORT_SYMBOL_GPL(led_trigger_set_default); +EXPORT_SYMBOL_GPL(led_trigger_show); +EXPORT_SYMBOL_GPL(led_trigger_store); + +/* LED Trigger Interface */ +EXPORT_SYMBOL_GPL(led_trigger_register); +EXPORT_SYMBOL_GPL(led_trigger_unregister); + +/* Simple LED Tigger Interface */ +EXPORT_SYMBOL_GPL(led_trigger_register_simple); +EXPORT_SYMBOL_GPL(led_trigger_unregister_simple); +EXPORT_SYMBOL_GPL(led_trigger_event); + +MODULE_AUTHOR("Richard Purdie"); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("LED Triggers Core"); |