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 25 static struct class *leds_class; 26 27 static ssize_t led_brightness_show(struct device *dev, 28 struct device_attribute *attr, char *buf) 29 { 30 struct led_classdev *led_cdev = dev_get_drvdata(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 device *dev, 41 struct device_attribute *attr, const char *buf, size_t size) 42 { 43 struct led_classdev *led_cdev = dev_get_drvdata(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 DEVICE_ATTR(brightness, 0644, led_brightness_show, led_brightness_store); 61 #ifdef CONFIG_LEDS_TRIGGERS 62 static DEVICE_ATTR(trigger, 0644, led_trigger_show, led_trigger_store); 63 #endif 64 65 /** 66 * led_classdev_suspend - suspend an led_classdev. 67 * @led_cdev: the led_classdev to suspend. 68 */ 69 void led_classdev_suspend(struct led_classdev *led_cdev) 70 { 71 led_cdev->flags |= LED_SUSPENDED; 72 led_cdev->brightness_set(led_cdev, 0); 73 } 74 EXPORT_SYMBOL_GPL(led_classdev_suspend); 75 76 /** 77 * led_classdev_resume - resume an led_classdev. 78 * @led_cdev: the led_classdev to resume. 79 */ 80 void led_classdev_resume(struct led_classdev *led_cdev) 81 { 82 led_cdev->brightness_set(led_cdev, led_cdev->brightness); 83 led_cdev->flags &= ~LED_SUSPENDED; 84 } 85 EXPORT_SYMBOL_GPL(led_classdev_resume); 86 87 /** 88 * led_classdev_register - register a new object of led_classdev class. 89 * @dev: The device to register. 90 * @led_cdev: the led_classdev structure for this device. 91 */ 92 int led_classdev_register(struct device *parent, struct led_classdev *led_cdev) 93 { 94 int rc; 95 96 led_cdev->dev = device_create(leds_class, parent, 0, "%s", 97 led_cdev->name); 98 if (unlikely(IS_ERR(led_cdev->dev))) 99 return PTR_ERR(led_cdev->dev); 100 101 dev_set_drvdata(led_cdev->dev, led_cdev); 102 103 /* register the attributes */ 104 rc = device_create_file(led_cdev->dev, &dev_attr_brightness); 105 if (rc) 106 goto err_out; 107 108 /* add to the list of leds */ 109 down_write(&leds_list_lock); 110 list_add_tail(&led_cdev->node, &leds_list); 111 up_write(&leds_list_lock); 112 113 #ifdef CONFIG_LEDS_TRIGGERS 114 init_rwsem(&led_cdev->trigger_lock); 115 116 rc = device_create_file(led_cdev->dev, &dev_attr_trigger); 117 if (rc) 118 goto err_out_led_list; 119 120 led_trigger_set_default(led_cdev); 121 #endif 122 123 printk(KERN_INFO "Registered led device: %s\n", 124 led_cdev->name); 125 126 return 0; 127 128 #ifdef CONFIG_LEDS_TRIGGERS 129 err_out_led_list: 130 device_remove_file(led_cdev->dev, &dev_attr_brightness); 131 list_del(&led_cdev->node); 132 #endif 133 err_out: 134 device_unregister(led_cdev->dev); 135 return rc; 136 } 137 EXPORT_SYMBOL_GPL(led_classdev_register); 138 139 /** 140 * led_classdev_unregister - unregisters a object of led_properties class. 141 * @led_cdev: the led device to unregister 142 * 143 * Unregisters a previously registered via led_classdev_register object. 144 */ 145 void led_classdev_unregister(struct led_classdev *led_cdev) 146 { 147 device_remove_file(led_cdev->dev, &dev_attr_brightness); 148 #ifdef CONFIG_LEDS_TRIGGERS 149 device_remove_file(led_cdev->dev, &dev_attr_trigger); 150 down_write(&led_cdev->trigger_lock); 151 if (led_cdev->trigger) 152 led_trigger_set(led_cdev, NULL); 153 up_write(&led_cdev->trigger_lock); 154 #endif 155 156 device_unregister(led_cdev->dev); 157 158 down_write(&leds_list_lock); 159 list_del(&led_cdev->node); 160 up_write(&leds_list_lock); 161 } 162 EXPORT_SYMBOL_GPL(led_classdev_unregister); 163 164 static int __init leds_init(void) 165 { 166 leds_class = class_create(THIS_MODULE, "leds"); 167 if (IS_ERR(leds_class)) 168 return PTR_ERR(leds_class); 169 return 0; 170 } 171 172 static void __exit leds_exit(void) 173 { 174 class_destroy(leds_class); 175 } 176 177 subsys_initcall(leds_init); 178 module_exit(leds_exit); 179 180 MODULE_AUTHOR("John Lenz, Richard Purdie"); 181 MODULE_LICENSE("GPL"); 182 MODULE_DESCRIPTION("LED Class Interface"); 183