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/ctype.h> 23 #include <linux/leds.h> 24 #include "leds.h" 25 26 static struct class *leds_class; 27 28 static ssize_t led_brightness_show(struct class_device *dev, char *buf) 29 { 30 struct led_classdev *led_cdev = class_get_devdata(dev); 31 ssize_t ret = 0; 32 33 /* no lock needed for this */ 34 sprintf(buf, "%u\n", led_cdev->brightness); 35 ret = strlen(buf) + 1; 36 37 return ret; 38 } 39 40 static ssize_t led_brightness_store(struct class_device *dev, 41 const char *buf, size_t size) 42 { 43 struct led_classdev *led_cdev = class_get_devdata(dev); 44 ssize_t ret = -EINVAL; 45 char *after; 46 unsigned long state = simple_strtoul(buf, &after, 10); 47 size_t count = after - buf; 48 49 if (*after && isspace(*after)) 50 count++; 51 52 if (count == size) { 53 ret = count; 54 led_set_brightness(led_cdev, state); 55 } 56 57 return ret; 58 } 59 60 static CLASS_DEVICE_ATTR(brightness, 0644, led_brightness_show, 61 led_brightness_store); 62 #ifdef CONFIG_LEDS_TRIGGERS 63 static CLASS_DEVICE_ATTR(trigger, 0644, led_trigger_show, led_trigger_store); 64 #endif 65 66 /** 67 * led_classdev_suspend - suspend an led_classdev. 68 * @led_cdev: the led_classdev to suspend. 69 */ 70 void led_classdev_suspend(struct led_classdev *led_cdev) 71 { 72 led_cdev->flags |= LED_SUSPENDED; 73 led_cdev->brightness_set(led_cdev, 0); 74 } 75 EXPORT_SYMBOL_GPL(led_classdev_suspend); 76 77 /** 78 * led_classdev_resume - resume an led_classdev. 79 * @led_cdev: the led_classdev to resume. 80 */ 81 void led_classdev_resume(struct led_classdev *led_cdev) 82 { 83 led_cdev->brightness_set(led_cdev, led_cdev->brightness); 84 led_cdev->flags &= ~LED_SUSPENDED; 85 } 86 EXPORT_SYMBOL_GPL(led_classdev_resume); 87 88 /** 89 * led_classdev_register - register a new object of led_classdev class. 90 * @dev: The device to register. 91 * @led_cdev: the led_classdev structure for this device. 92 */ 93 int led_classdev_register(struct device *parent, struct led_classdev *led_cdev) 94 { 95 led_cdev->class_dev = class_device_create(leds_class, NULL, 0, 96 parent, "%s", led_cdev->name); 97 if (unlikely(IS_ERR(led_cdev->class_dev))) 98 return PTR_ERR(led_cdev->class_dev); 99 100 class_set_devdata(led_cdev->class_dev, led_cdev); 101 102 /* register the attributes */ 103 class_device_create_file(led_cdev->class_dev, 104 &class_device_attr_brightness); 105 106 /* add to the list of leds */ 107 write_lock(&leds_list_lock); 108 list_add_tail(&led_cdev->node, &leds_list); 109 write_unlock(&leds_list_lock); 110 111 #ifdef CONFIG_LEDS_TRIGGERS 112 rwlock_init(&led_cdev->trigger_lock); 113 114 led_trigger_set_default(led_cdev); 115 116 class_device_create_file(led_cdev->class_dev, 117 &class_device_attr_trigger); 118 #endif 119 120 printk(KERN_INFO "Registered led device: %s\n", 121 led_cdev->class_dev->class_id); 122 123 return 0; 124 } 125 EXPORT_SYMBOL_GPL(led_classdev_register); 126 127 /** 128 * led_classdev_unregister - unregisters a object of led_properties class. 129 * @led_cdev: the led device to unreigister 130 * 131 * Unregisters a previously registered via led_classdev_register object. 132 */ 133 void led_classdev_unregister(struct led_classdev *led_cdev) 134 { 135 class_device_remove_file(led_cdev->class_dev, 136 &class_device_attr_brightness); 137 #ifdef CONFIG_LEDS_TRIGGERS 138 class_device_remove_file(led_cdev->class_dev, 139 &class_device_attr_trigger); 140 write_lock(&led_cdev->trigger_lock); 141 if (led_cdev->trigger) 142 led_trigger_set(led_cdev, NULL); 143 write_unlock(&led_cdev->trigger_lock); 144 #endif 145 146 class_device_unregister(led_cdev->class_dev); 147 148 write_lock(&leds_list_lock); 149 list_del(&led_cdev->node); 150 write_unlock(&leds_list_lock); 151 } 152 EXPORT_SYMBOL_GPL(led_classdev_unregister); 153 154 static int __init leds_init(void) 155 { 156 leds_class = class_create(THIS_MODULE, "leds"); 157 if (IS_ERR(leds_class)) 158 return PTR_ERR(leds_class); 159 return 0; 160 } 161 162 static void __exit leds_exit(void) 163 { 164 class_destroy(leds_class); 165 } 166 167 subsys_initcall(leds_init); 168 module_exit(leds_exit); 169 170 MODULE_AUTHOR("John Lenz, Richard Purdie"); 171 MODULE_LICENSE("GPL"); 172 MODULE_DESCRIPTION("LED Class Interface"); 173