1 /* 2 * LED Class Core 3 * 4 * Copyright (C) 2005 John Lenz <lenz@cs.wisc.edu> 5 * Copyright (C) 2005-2006 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/config.h> 13 #include <linux/module.h> 14 #include <linux/kernel.h> 15 #include <linux/init.h> 16 #include <linux/list.h> 17 #include <linux/spinlock.h> 18 #include <linux/device.h> 19 #include <linux/sysdev.h> 20 #include <linux/timer.h> 21 #include <linux/err.h> 22 #include <linux/leds.h> 23 #include "leds.h" 24 25 static struct class *leds_class; 26 27 static ssize_t led_brightness_show(struct class_device *dev, char *buf) 28 { 29 struct led_classdev *led_cdev = class_get_devdata(dev); 30 ssize_t ret = 0; 31 32 /* no lock needed for this */ 33 sprintf(buf, "%u\n", led_cdev->brightness); 34 ret = strlen(buf) + 1; 35 36 return ret; 37 } 38 39 static ssize_t led_brightness_store(struct class_device *dev, 40 const char *buf, size_t size) 41 { 42 struct led_classdev *led_cdev = class_get_devdata(dev); 43 ssize_t ret = -EINVAL; 44 char *after; 45 unsigned long state = simple_strtoul(buf, &after, 10); 46 47 if (after - buf > 0) { 48 ret = after - buf; 49 led_set_brightness(led_cdev, state); 50 } 51 52 return ret; 53 } 54 55 static CLASS_DEVICE_ATTR(brightness, 0644, led_brightness_show, 56 led_brightness_store); 57 #ifdef CONFIG_LEDS_TRIGGERS 58 static CLASS_DEVICE_ATTR(trigger, 0644, led_trigger_show, led_trigger_store); 59 #endif 60 61 /** 62 * led_classdev_suspend - suspend an led_classdev. 63 * @led_cdev: the led_classdev to suspend. 64 */ 65 void led_classdev_suspend(struct led_classdev *led_cdev) 66 { 67 led_cdev->flags |= LED_SUSPENDED; 68 led_cdev->brightness_set(led_cdev, 0); 69 } 70 EXPORT_SYMBOL_GPL(led_classdev_suspend); 71 72 /** 73 * led_classdev_resume - resume an led_classdev. 74 * @led_cdev: the led_classdev to resume. 75 */ 76 void led_classdev_resume(struct led_classdev *led_cdev) 77 { 78 led_cdev->brightness_set(led_cdev, led_cdev->brightness); 79 led_cdev->flags &= ~LED_SUSPENDED; 80 } 81 EXPORT_SYMBOL_GPL(led_classdev_resume); 82 83 /** 84 * led_classdev_register - register a new object of led_classdev class. 85 * @dev: The device to register. 86 * @led_cdev: the led_classdev structure for this device. 87 */ 88 int led_classdev_register(struct device *parent, struct led_classdev *led_cdev) 89 { 90 led_cdev->class_dev = class_device_create(leds_class, NULL, 0, 91 parent, "%s", led_cdev->name); 92 if (unlikely(IS_ERR(led_cdev->class_dev))) 93 return PTR_ERR(led_cdev->class_dev); 94 95 class_set_devdata(led_cdev->class_dev, led_cdev); 96 97 /* register the attributes */ 98 class_device_create_file(led_cdev->class_dev, 99 &class_device_attr_brightness); 100 101 /* add to the list of leds */ 102 write_lock(&leds_list_lock); 103 list_add_tail(&led_cdev->node, &leds_list); 104 write_unlock(&leds_list_lock); 105 106 #ifdef CONFIG_LEDS_TRIGGERS 107 rwlock_init(&led_cdev->trigger_lock); 108 109 led_trigger_set_default(led_cdev); 110 111 class_device_create_file(led_cdev->class_dev, 112 &class_device_attr_trigger); 113 #endif 114 115 printk(KERN_INFO "Registered led device: %s\n", 116 led_cdev->class_dev->class_id); 117 118 return 0; 119 } 120 EXPORT_SYMBOL_GPL(led_classdev_register); 121 122 /** 123 * led_classdev_unregister - unregisters a object of led_properties class. 124 * @led_cdev: the led device to unreigister 125 * 126 * Unregisters a previously registered via led_classdev_register object. 127 */ 128 void led_classdev_unregister(struct led_classdev *led_cdev) 129 { 130 class_device_remove_file(led_cdev->class_dev, 131 &class_device_attr_brightness); 132 #ifdef CONFIG_LEDS_TRIGGERS 133 class_device_remove_file(led_cdev->class_dev, 134 &class_device_attr_trigger); 135 write_lock(&led_cdev->trigger_lock); 136 if (led_cdev->trigger) 137 led_trigger_set(led_cdev, NULL); 138 write_unlock(&led_cdev->trigger_lock); 139 #endif 140 141 class_device_unregister(led_cdev->class_dev); 142 143 write_lock(&leds_list_lock); 144 list_del(&led_cdev->node); 145 write_unlock(&leds_list_lock); 146 } 147 EXPORT_SYMBOL_GPL(led_classdev_unregister); 148 149 static int __init leds_init(void) 150 { 151 leds_class = class_create(THIS_MODULE, "leds"); 152 if (IS_ERR(leds_class)) 153 return PTR_ERR(leds_class); 154 return 0; 155 } 156 157 static void __exit leds_exit(void) 158 { 159 class_destroy(leds_class); 160 } 161 162 subsys_initcall(leds_init); 163 module_exit(leds_exit); 164 165 MODULE_AUTHOR("John Lenz, Richard Purdie"); 166 MODULE_LICENSE("GPL"); 167 MODULE_DESCRIPTION("LED Class Interface"); 168