/* * 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/module.h> #include <linux/kernel.h> #include <linux/init.h> #include <linux/list.h> #include <linux/spinlock.h> #include <linux/device.h> #include <linux/timer.h> #include <linux/err.h> #include <linux/ctype.h> #include <linux/leds.h> #include "leds.h" static struct class *leds_class; static void led_update_brightness(struct led_classdev *led_cdev) { if (led_cdev->brightness_get) led_cdev->brightness = led_cdev->brightness_get(led_cdev); } static ssize_t led_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 led_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 = -EINVAL; ret = kstrtoul(buf, 10, &state); if (ret) return ret; if (state == LED_OFF) led_trigger_remove(led_cdev); led_set_brightness(led_cdev, state); return size; } static ssize_t led_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 struct device_attribute led_class_attrs[] = { __ATTR(brightness, 0644, led_brightness_show, led_brightness_store), __ATTR(max_brightness, 0444, led_max_brightness_show, NULL), #ifdef CONFIG_LEDS_TRIGGERS __ATTR(trigger, 0644, led_trigger_show, led_trigger_store), #endif __ATTR_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(led_cdev, LED_OFF); return; } brightness = led_get_brightness(led_cdev); if (!brightness) { /* Time to switch the LED on. */ 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(led_cdev, brightness); mod_timer(&led_cdev->blink_timer, jiffies + msecs_to_jiffies(delay)); } /** * 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); led_cdev->flags &= ~LED_SUSPENDED; } EXPORT_SYMBOL_GPL(led_classdev_resume); static int led_suspend(struct device *dev, pm_message_t state) { 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; } /** * 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) { led_cdev->dev = device_create(leds_class, parent, 0, led_cdev, "%s", led_cdev->name); if (IS_ERR(led_cdev->dev)) return PTR_ERR(led_cdev->dev); #ifdef CONFIG_LEDS_TRIGGERS init_rwsem(&led_cdev->trigger_lock); #endif /* 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_update_brightness(led_cdev); init_timer(&led_cdev->blink_timer); led_cdev->blink_timer.function = led_timer_function; led_cdev->blink_timer.data = (unsigned long)led_cdev; #ifdef CONFIG_LEDS_TRIGGERS led_trigger_set_default(led_cdev); #endif printk(KERN_DEBUG "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 /* Stop blinking */ led_brightness_set(led_cdev, LED_OFF); device_unregister(led_cdev->dev); down_write(&leds_list_lock); list_del(&led_cdev->node); up_write(&leds_list_lock); } EXPORT_SYMBOL_GPL(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->suspend = led_suspend; leds_class->resume = led_resume; leds_class->dev_attrs = led_class_attrs; 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");