1/* 2 * LED Class Core 3 * 4 * Copyright (C) 2005 John Lenz <lenz@cs.wisc.edu> 5 * Copyright (C) 2005-2007 Richard Purdie <rpurdie@openedhand.com> 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License version 2 as 9 * published by the Free Software Foundation. 10 */ 11 12#include <linux/module.h> 13#include <linux/kernel.h> 14#include <linux/init.h> 15#include <linux/list.h> 16#include <linux/spinlock.h> 17#include <linux/device.h> 18#include <linux/sysdev.h> 19#include <linux/timer.h> 20#include <linux/err.h> 21#include <linux/ctype.h> 22#include <linux/leds.h> 23#include "leds.h" 24 25static struct class *leds_class; 26 27static void led_update_brightness(struct led_classdev *led_cdev) 28{ 29 if (led_cdev->brightness_get) 30 led_cdev->brightness = led_cdev->brightness_get(led_cdev); 31} 32 33static ssize_t led_brightness_show(struct device *dev, 34 struct device_attribute *attr, char *buf) 35{ 36 struct led_classdev *led_cdev = dev_get_drvdata(dev); 37 38 /* no lock needed for this */ 39 led_update_brightness(led_cdev); 40 41 return sprintf(buf, "%u\n", led_cdev->brightness); 42} 43 44static ssize_t led_brightness_store(struct device *dev, 45 struct device_attribute *attr, const char *buf, size_t size) 46{ 47 struct led_classdev *led_cdev = dev_get_drvdata(dev); 48 ssize_t ret = -EINVAL; 49 char *after; 50 unsigned long state = simple_strtoul(buf, &after, 10); 51 size_t count = after - buf; 52 53 if (isspace(*after)) 54 count++; 55 56 if (count == size) { 57 ret = count; 58 59 if (state == LED_OFF) 60 led_trigger_remove(led_cdev); 61 led_set_brightness(led_cdev, state); 62 } 63 64 return ret; 65} 66 67static ssize_t led_max_brightness_show(struct device *dev, 68 struct device_attribute *attr, char *buf) 69{ 70 struct led_classdev *led_cdev = dev_get_drvdata(dev); 71 72 return sprintf(buf, "%u\n", led_cdev->max_brightness); 73} 74 75static struct device_attribute led_class_attrs[] = { 76 __ATTR(brightness, 0644, led_brightness_show, led_brightness_store), 77 __ATTR(max_brightness, 0444, led_max_brightness_show, NULL), 78#ifdef CONFIG_LEDS_TRIGGERS 79 __ATTR(trigger, 0644, led_trigger_show, led_trigger_store), 80#endif 81 __ATTR_NULL, 82}; 83 84/** 85 * led_classdev_suspend - suspend an led_classdev. 86 * @led_cdev: the led_classdev to suspend. 87 */ 88void led_classdev_suspend(struct led_classdev *led_cdev) 89{ 90 led_cdev->flags |= LED_SUSPENDED; 91 led_cdev->brightness_set(led_cdev, 0); 92} 93EXPORT_SYMBOL_GPL(led_classdev_suspend); 94 95/** 96 * led_classdev_resume - resume an led_classdev. 97 * @led_cdev: the led_classdev to resume. 98 */ 99void led_classdev_resume(struct led_classdev *led_cdev) 100{ 101 led_cdev->brightness_set(led_cdev, led_cdev->brightness); 102 led_cdev->flags &= ~LED_SUSPENDED; 103} 104EXPORT_SYMBOL_GPL(led_classdev_resume); 105 106static int led_suspend(struct device *dev, pm_message_t state) 107{ 108 struct led_classdev *led_cdev = dev_get_drvdata(dev); 109 110 if (led_cdev->flags & LED_CORE_SUSPENDRESUME) 111 led_classdev_suspend(led_cdev); 112 113 return 0; 114} 115 116static int led_resume(struct device *dev) 117{ 118 struct led_classdev *led_cdev = dev_get_drvdata(dev); 119 120 if (led_cdev->flags & LED_CORE_SUSPENDRESUME) 121 led_classdev_resume(led_cdev); 122 123 return 0; 124} 125 126/** 127 * led_classdev_register - register a new object of led_classdev class. 128 * @parent: The device to register. 129 * @led_cdev: the led_classdev structure for this device. 130 */ 131int led_classdev_register(struct device *parent, struct led_classdev *led_cdev) 132{ 133 led_cdev->dev = device_create(leds_class, parent, 0, led_cdev, 134 "%s", led_cdev->name); 135 if (IS_ERR(led_cdev->dev)) 136 return PTR_ERR(led_cdev->dev); 137 138#ifdef CONFIG_LEDS_TRIGGERS 139 init_rwsem(&led_cdev->trigger_lock); 140#endif 141 /* add to the list of leds */ 142 down_write(&leds_list_lock); 143 list_add_tail(&led_cdev->node, &leds_list); 144 up_write(&leds_list_lock); 145 146 if (!led_cdev->max_brightness) 147 led_cdev->max_brightness = LED_FULL; 148 149 led_update_brightness(led_cdev); 150 151#ifdef CONFIG_LEDS_TRIGGERS 152 led_trigger_set_default(led_cdev); 153#endif 154 155 printk(KERN_DEBUG "Registered led device: %s\n", 156 led_cdev->name); 157 158 return 0; 159} 160 161EXPORT_SYMBOL_GPL(led_classdev_register); 162 163/** 164 * led_classdev_unregister - unregisters a object of led_properties class. 165 * @led_cdev: the led device to unregister 166 * 167 * Unregisters a previously registered via led_classdev_register object. 168 */ 169void led_classdev_unregister(struct led_classdev *led_cdev) 170{ 171#ifdef CONFIG_LEDS_TRIGGERS 172 down_write(&led_cdev->trigger_lock); 173 if (led_cdev->trigger) 174 led_trigger_set(led_cdev, NULL); 175 up_write(&led_cdev->trigger_lock); 176#endif 177 178 device_unregister(led_cdev->dev); 179 180 down_write(&leds_list_lock); 181 list_del(&led_cdev->node); 182 up_write(&leds_list_lock); 183} 184EXPORT_SYMBOL_GPL(led_classdev_unregister); 185 186static int __init leds_init(void) 187{ 188 leds_class = class_create(THIS_MODULE, "leds"); 189 if (IS_ERR(leds_class)) 190 return PTR_ERR(leds_class); 191 leds_class->suspend = led_suspend; 192 leds_class->resume = led_resume; 193 leds_class->dev_attrs = led_class_attrs; 194 return 0; 195} 196 197static void __exit leds_exit(void) 198{ 199 class_destroy(leds_class); 200} 201 202subsys_initcall(leds_init); 203module_exit(leds_exit); 204 205MODULE_AUTHOR("John Lenz, Richard Purdie"); 206MODULE_LICENSE("GPL"); 207MODULE_DESCRIPTION("LED Class Interface"); 208