/* * LED Class Core * * Copyright (C) 2005 John Lenz <lenz@cs.wisc.edu> * Copyright (C) 2005-2007 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/ctype.h> #include <linux/device.h> #include <linux/err.h> #include <linux/init.h> #include <linux/kernel.h> #include <linux/leds.h> #include <linux/list.h> #include <linux/module.h> #include <linux/slab.h> #include <linux/spinlock.h> #include <linux/timer.h> #include "leds.h" static struct class *leds_class; static ssize_t brightness_show(struct device *dev, struct device_attribute *attr, char *buf) { struct led_classdev *led_cdev = dev_get_drvdata(dev); /* no lock needed for this */ led_update_brightness(led_cdev); return sprintf(buf, "%u\n", led_cdev->brightness); } static ssize_t brightness_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t size) { struct led_classdev *led_cdev = dev_get_drvdata(dev); unsigned long state; ssize_t ret; mutex_lock(&led_cdev->led_access); if (led_sysfs_is_disabled(led_cdev)) { ret = -EBUSY; goto unlock; } ret = kstrtoul(buf, 10, &state); if (ret) goto unlock; if (state == LED_OFF) led_trigger_remove(led_cdev); led_set_brightness(led_cdev, state); ret = size; unlock: mutex_unlock(&led_cdev->led_access); return ret; } static DEVICE_ATTR_RW(brightness); static ssize_t max_brightness_show(struct device *dev, struct device_attribute *attr, char *buf) { struct led_classdev *led_cdev = dev_get_drvdata(dev); return sprintf(buf, "%u\n", led_cdev->max_brightness); } static DEVICE_ATTR_RO(max_brightness); #ifdef CONFIG_LEDS_TRIGGERS static DEVICE_ATTR(trigger, 0644, led_trigger_show, led_trigger_store); static struct attribute *led_trigger_attrs[] = { &dev_attr_trigger.attr, NULL, }; static const struct attribute_group led_trigger_group = { .attrs = led_trigger_attrs, }; #endif static struct attribute *led_class_attrs[] = { &dev_attr_brightness.attr, &dev_attr_max_brightness.attr, NULL, }; static const struct attribute_group led_group = { .attrs = led_class_attrs, }; static const struct attribute_group *led_groups[] = { &led_group, #ifdef CONFIG_LEDS_TRIGGERS &led_trigger_group, #endif NULL, }; static void led_timer_function(unsigned long data) { struct led_classdev *led_cdev = (void *)data; unsigned long brightness; unsigned long delay; if (!led_cdev->blink_delay_on || !led_cdev->blink_delay_off) { led_set_brightness_async(led_cdev, LED_OFF); return; } if (led_cdev->flags & LED_BLINK_ONESHOT_STOP) { led_cdev->flags &= ~LED_BLINK_ONESHOT_STOP; return; } brightness = led_get_brightness(led_cdev); if (!brightness) { /* Time to switch the LED on. */ if (led_cdev->delayed_set_value) { led_cdev->blink_brightness = led_cdev->delayed_set_value; led_cdev->delayed_set_value = 0; } brightness = led_cdev->blink_brightness; delay = led_cdev->blink_delay_on; } else { /* Store the current brightness value to be able * to restore it when the delay_off period is over. */ led_cdev->blink_brightness = brightness; brightness = LED_OFF; delay = led_cdev->blink_delay_off; } led_set_brightness_async(led_cdev, brightness); /* Return in next iteration if led is in one-shot mode and we are in * the final blink state so that the led is toggled each delay_on + * delay_off milliseconds in worst case. */ if (led_cdev->flags & LED_BLINK_ONESHOT) { if (led_cdev->flags & LED_BLINK_INVERT) { if (brightness) led_cdev->flags |= LED_BLINK_ONESHOT_STOP; } else { if (!brightness) led_cdev->flags |= LED_BLINK_ONESHOT_STOP; } } mod_timer(&led_cdev->blink_timer, jiffies + msecs_to_jiffies(delay)); } static void set_brightness_delayed(struct work_struct *ws) { struct led_classdev *led_cdev = container_of(ws, struct led_classdev, set_brightness_work); led_stop_software_blink(led_cdev); led_set_brightness_async(led_cdev, led_cdev->delayed_set_value); } /** * led_classdev_suspend - suspend an led_classdev. * @led_cdev: the led_classdev to suspend. */ void led_classdev_suspend(struct led_classdev *led_cdev) { led_cdev->flags |= LED_SUSPENDED; led_cdev->brightness_set(led_cdev, 0); } EXPORT_SYMBOL_GPL(led_classdev_suspend); /** * led_classdev_resume - resume an led_classdev. * @led_cdev: the led_classdev to resume. */ void led_classdev_resume(struct led_classdev *led_cdev) { led_cdev->brightness_set(led_cdev, led_cdev->brightness); if (led_cdev->flash_resume) led_cdev->flash_resume(led_cdev); led_cdev->flags &= ~LED_SUSPENDED; } EXPORT_SYMBOL_GPL(led_classdev_resume); #ifdef CONFIG_PM_SLEEP static int led_suspend(struct device *dev) { struct led_classdev *led_cdev = dev_get_drvdata(dev); if (led_cdev->flags & LED_CORE_SUSPENDRESUME) led_classdev_suspend(led_cdev); return 0; } static int led_resume(struct device *dev) { struct led_classdev *led_cdev = dev_get_drvdata(dev); if (led_cdev->flags & LED_CORE_SUSPENDRESUME) led_classdev_resume(led_cdev); return 0; } #endif static SIMPLE_DEV_PM_OPS(leds_class_dev_pm_ops, led_suspend, led_resume); static int match_name(struct device *dev, const void *data) { if (!dev_name(dev)) return 0; return !strcmp(dev_name(dev), (char *)data); } static int led_classdev_next_name(const char *init_name, char *name, size_t len) { unsigned int i = 0; int ret = 0; strlcpy(name, init_name, len); while (class_find_device(leds_class, NULL, name, match_name) && (ret < len)) ret = snprintf(name, len, "%s_%u", init_name, ++i); if (ret >= len) return -ENOMEM; return i; } /** * led_classdev_register - register a new object of led_classdev class. * @parent: The device to register. * @led_cdev: the led_classdev structure for this device. */ int led_classdev_register(struct device *parent, struct led_classdev *led_cdev) { char name[64]; int ret; ret = led_classdev_next_name(led_cdev->name, name, sizeof(name)); if (ret < 0) return ret; led_cdev->dev = device_create_with_groups(leds_class, parent, 0, led_cdev, led_cdev->groups, "%s", name); if (IS_ERR(led_cdev->dev)) return PTR_ERR(led_cdev->dev); if (ret) dev_warn(parent, "Led %s renamed to %s due to name collision", led_cdev->name, dev_name(led_cdev->dev)); #ifdef CONFIG_LEDS_TRIGGERS init_rwsem(&led_cdev->trigger_lock); #endif mutex_init(&led_cdev->led_access); /* add to the list of leds */ down_write(&leds_list_lock); list_add_tail(&led_cdev->node, &leds_list); up_write(&leds_list_lock); if (!led_cdev->max_brightness) led_cdev->max_brightness = LED_FULL; led_cdev->flags |= SET_BRIGHTNESS_ASYNC; led_update_brightness(led_cdev); INIT_WORK(&led_cdev->set_brightness_work, set_brightness_delayed); setup_timer(&led_cdev->blink_timer, led_timer_function, (unsigned long)led_cdev); #ifdef CONFIG_LEDS_TRIGGERS led_trigger_set_default(led_cdev); #endif dev_dbg(parent, "Registered led device: %s\n", led_cdev->name); return 0; } EXPORT_SYMBOL_GPL(led_classdev_register); /** * led_classdev_unregister - unregisters a object of led_properties class. * @led_cdev: the led device to unregister * * Unregisters a previously registered via led_classdev_register object. */ void led_classdev_unregister(struct led_classdev *led_cdev) { #ifdef CONFIG_LEDS_TRIGGERS down_write(&led_cdev->trigger_lock); if (led_cdev->trigger) led_trigger_set(led_cdev, NULL); up_write(&led_cdev->trigger_lock); #endif cancel_work_sync(&led_cdev->set_brightness_work); /* Stop blinking */ led_stop_software_blink(led_cdev); led_set_brightness(led_cdev, LED_OFF); device_unregister(led_cdev->dev); down_write(&leds_list_lock); list_del(&led_cdev->node); up_write(&leds_list_lock); mutex_destroy(&led_cdev->led_access); } EXPORT_SYMBOL_GPL(led_classdev_unregister); static void devm_led_classdev_release(struct device *dev, void *res) { led_classdev_unregister(*(struct led_classdev **)res); } /** * devm_led_classdev_register - resource managed led_classdev_register() * @parent: The device to register. * @led_cdev: the led_classdev structure for this device. */ int devm_led_classdev_register(struct device *parent, struct led_classdev *led_cdev) { struct led_classdev **dr; int rc; dr = devres_alloc(devm_led_classdev_release, sizeof(*dr), GFP_KERNEL); if (!dr) return -ENOMEM; rc = led_classdev_register(parent, led_cdev); if (rc) { devres_free(dr); return rc; } *dr = led_cdev; devres_add(parent, dr); return 0; } EXPORT_SYMBOL_GPL(devm_led_classdev_register); static int devm_led_classdev_match(struct device *dev, void *res, void *data) { struct led_cdev **p = res; if (WARN_ON(!p || !*p)) return 0; return *p == data; } /** * devm_led_classdev_unregister() - resource managed led_classdev_unregister() * @parent: The device to unregister. * @led_cdev: the led_classdev structure for this device. */ void devm_led_classdev_unregister(struct device *dev, struct led_classdev *led_cdev) { WARN_ON(devres_release(dev, devm_led_classdev_release, devm_led_classdev_match, led_cdev)); } EXPORT_SYMBOL_GPL(devm_led_classdev_unregister); static int __init leds_init(void) { leds_class = class_create(THIS_MODULE, "leds"); if (IS_ERR(leds_class)) return PTR_ERR(leds_class); leds_class->pm = &leds_class_dev_pm_ops; leds_class->dev_groups = led_groups; return 0; } static void __exit leds_exit(void) { class_destroy(leds_class); } subsys_initcall(leds_init); module_exit(leds_exit); MODULE_AUTHOR("John Lenz, Richard Purdie"); MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("LED Class Interface");