diff options
Diffstat (limited to 'kernel/drivers/leds/led-triggers.c')
| -rw-r--r-- | kernel/drivers/leds/led-triggers.c | 342 |
1 files changed, 342 insertions, 0 deletions
diff --git a/kernel/drivers/leds/led-triggers.c b/kernel/drivers/leds/led-triggers.c new file mode 100644 index 000000000..e8b1120f4 --- /dev/null +++ b/kernel/drivers/leds/led-triggers.c @@ -0,0 +1,342 @@ +/* + * LED Triggers Core + * + * Copyright 2005-2007 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/module.h> +#include <linux/kernel.h> +#include <linux/list.h> +#include <linux/spinlock.h> +#include <linux/device.h> +#include <linux/timer.h> +#include <linux/rwsem.h> +#include <linux/leds.h> +#include <linux/slab.h> +#include "leds.h" + +/* + * Nests outside led_cdev->trigger_lock + */ +static DECLARE_RWSEM(triggers_list_lock); +static LIST_HEAD(trigger_list); + + /* Used by LED Class */ + +ssize_t led_trigger_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct led_classdev *led_cdev = dev_get_drvdata(dev); + char trigger_name[TRIG_NAME_MAX]; + struct led_trigger *trig; + size_t len; + int ret = count; + + mutex_lock(&led_cdev->led_access); + + if (led_sysfs_is_disabled(led_cdev)) { + ret = -EBUSY; + goto unlock; + } + + 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")) { + led_trigger_remove(led_cdev); + goto unlock; + } + + down_read(&triggers_list_lock); + list_for_each_entry(trig, &trigger_list, next_trig) { + if (!strcmp(trigger_name, trig->name)) { + down_write(&led_cdev->trigger_lock); + led_trigger_set(led_cdev, trig); + up_write(&led_cdev->trigger_lock); + + up_read(&triggers_list_lock); + goto unlock; + } + } + up_read(&triggers_list_lock); + +unlock: + mutex_unlock(&led_cdev->led_access); + return ret; +} +EXPORT_SYMBOL_GPL(led_trigger_store); + +ssize_t led_trigger_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct led_classdev *led_cdev = dev_get_drvdata(dev); + struct led_trigger *trig; + int len = 0; + + down_read(&triggers_list_lock); + down_read(&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); + } + up_read(&led_cdev->trigger_lock); + up_read(&triggers_list_lock); + + len += sprintf(len+buf, "\n"); + return len; +} +EXPORT_SYMBOL_GPL(led_trigger_show); + +/* Caller must ensure led_cdev->trigger_lock held */ +void led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trig) +{ + unsigned long flags; + char *event = NULL; + char *envp[2]; + const char *name; + + name = trig ? trig->name : "none"; + event = kasprintf(GFP_KERNEL, "TRIGGER=%s", name); + + /* 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); + cancel_work_sync(&led_cdev->set_brightness_work); + led_stop_software_blink(led_cdev); + if (led_cdev->trigger->deactivate) + led_cdev->trigger->deactivate(led_cdev); + led_cdev->trigger = NULL; + led_set_brightness(led_cdev, LED_OFF); + } + if (trig) { + write_lock_irqsave(&trig->leddev_list_lock, flags); + list_add_tail(&led_cdev->trig_list, &trig->led_cdevs); + write_unlock_irqrestore(&trig->leddev_list_lock, flags); + led_cdev->trigger = trig; + if (trig->activate) + trig->activate(led_cdev); + } + + if (event) { + envp[0] = event; + envp[1] = NULL; + kobject_uevent_env(&led_cdev->dev->kobj, KOBJ_CHANGE, envp); + kfree(event); + } +} +EXPORT_SYMBOL_GPL(led_trigger_set); + +void led_trigger_remove(struct led_classdev *led_cdev) +{ + down_write(&led_cdev->trigger_lock); + led_trigger_set(led_cdev, NULL); + up_write(&led_cdev->trigger_lock); +} +EXPORT_SYMBOL_GPL(led_trigger_remove); + +void led_trigger_set_default(struct led_classdev *led_cdev) +{ + struct led_trigger *trig; + + if (!led_cdev->default_trigger) + return; + + down_read(&triggers_list_lock); + down_write(&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); + } + up_write(&led_cdev->trigger_lock); + up_read(&triggers_list_lock); +} +EXPORT_SYMBOL_GPL(led_trigger_set_default); + +void led_trigger_rename_static(const char *name, struct led_trigger *trig) +{ + /* new name must be on a temporary string to prevent races */ + BUG_ON(name == trig->name); + + down_write(&triggers_list_lock); + /* this assumes that trig->name was originaly allocated to + * non constant storage */ + strcpy((char *)trig->name, name); + up_write(&triggers_list_lock); +} +EXPORT_SYMBOL_GPL(led_trigger_rename_static); + +/* LED Trigger Interface */ + +int led_trigger_register(struct led_trigger *trig) +{ + struct led_classdev *led_cdev; + struct led_trigger *_trig; + + rwlock_init(&trig->leddev_list_lock); + INIT_LIST_HEAD(&trig->led_cdevs); + + down_write(&triggers_list_lock); + /* Make sure the trigger's name isn't already in use */ + list_for_each_entry(_trig, &trigger_list, next_trig) { + if (!strcmp(_trig->name, trig->name)) { + up_write(&triggers_list_lock); + return -EEXIST; + } + } + /* Add to the list of led triggers */ + list_add_tail(&trig->next_trig, &trigger_list); + up_write(&triggers_list_lock); + + /* Register with any LEDs that have this as a default trigger */ + down_read(&leds_list_lock); + list_for_each_entry(led_cdev, &leds_list, node) { + down_write(&led_cdev->trigger_lock); + if (!led_cdev->trigger && led_cdev->default_trigger && + !strcmp(led_cdev->default_trigger, trig->name)) + led_trigger_set(led_cdev, trig); + up_write(&led_cdev->trigger_lock); + } + up_read(&leds_list_lock); + + return 0; +} +EXPORT_SYMBOL_GPL(led_trigger_register); + +void led_trigger_unregister(struct led_trigger *trig) +{ + struct led_classdev *led_cdev; + + if (list_empty_careful(&trig->next_trig)) + return; + + /* Remove from the list of led triggers */ + down_write(&triggers_list_lock); + list_del_init(&trig->next_trig); + up_write(&triggers_list_lock); + + /* Remove anyone actively using this trigger */ + down_read(&leds_list_lock); + list_for_each_entry(led_cdev, &leds_list, node) { + down_write(&led_cdev->trigger_lock); + if (led_cdev->trigger == trig) + led_trigger_set(led_cdev, NULL); + up_write(&led_cdev->trigger_lock); + } + up_read(&leds_list_lock); +} +EXPORT_SYMBOL_GPL(led_trigger_unregister); + +/* Simple LED Tigger Interface */ + +void led_trigger_event(struct led_trigger *trig, + enum led_brightness brightness) +{ + struct led_classdev *led_cdev; + + if (!trig) + return; + + read_lock(&trig->leddev_list_lock); + list_for_each_entry(led_cdev, &trig->led_cdevs, trig_list) + led_set_brightness(led_cdev, brightness); + read_unlock(&trig->leddev_list_lock); +} +EXPORT_SYMBOL_GPL(led_trigger_event); + +static void led_trigger_blink_setup(struct led_trigger *trig, + unsigned long *delay_on, + unsigned long *delay_off, + int oneshot, + int invert) +{ + struct led_classdev *led_cdev; + + if (!trig) + return; + + read_lock(&trig->leddev_list_lock); + list_for_each_entry(led_cdev, &trig->led_cdevs, trig_list) { + if (oneshot) + led_blink_set_oneshot(led_cdev, delay_on, delay_off, + invert); + else + led_blink_set(led_cdev, delay_on, delay_off); + } + read_unlock(&trig->leddev_list_lock); +} + +void led_trigger_blink(struct led_trigger *trig, + unsigned long *delay_on, + unsigned long *delay_off) +{ + led_trigger_blink_setup(trig, delay_on, delay_off, 0, 0); +} +EXPORT_SYMBOL_GPL(led_trigger_blink); + +void led_trigger_blink_oneshot(struct led_trigger *trig, + unsigned long *delay_on, + unsigned long *delay_off, + int invert) +{ + led_trigger_blink_setup(trig, delay_on, delay_off, 1, invert); +} +EXPORT_SYMBOL_GPL(led_trigger_blink_oneshot); + +void led_trigger_register_simple(const char *name, struct led_trigger **tp) +{ + struct led_trigger *trig; + int err; + + trig = kzalloc(sizeof(struct led_trigger), GFP_KERNEL); + + if (trig) { + trig->name = name; + err = led_trigger_register(trig); + if (err < 0) { + kfree(trig); + trig = NULL; + pr_warn("LED trigger %s failed to register (%d)\n", + name, err); + } + } else { + pr_warn("LED trigger %s failed to register (no memory)\n", + name); + } + *tp = trig; +} +EXPORT_SYMBOL_GPL(led_trigger_register_simple); + +void led_trigger_unregister_simple(struct led_trigger *trig) +{ + if (trig) + led_trigger_unregister(trig); + kfree(trig); +} +EXPORT_SYMBOL_GPL(led_trigger_unregister_simple); + +MODULE_AUTHOR("Richard Purdie"); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("LED Triggers Core"); |