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 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 33 static 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 44 static 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 (*after && 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 67 static DEVICE_ATTR(brightness, 0644, led_brightness_show, led_brightness_store); 68 #ifdef CONFIG_LEDS_TRIGGERS 69 static DEVICE_ATTR(trigger, 0644, led_trigger_show, led_trigger_store); 70 #endif 71 72 /** 73 * led_classdev_suspend - suspend an led_classdev. 74 * @led_cdev: the led_classdev to suspend. 75 */ 76 void led_classdev_suspend(struct led_classdev *led_cdev) 77 { 78 led_cdev->flags |= LED_SUSPENDED; 79 led_cdev->brightness_set(led_cdev, 0); 80 } 81 EXPORT_SYMBOL_GPL(led_classdev_suspend); 82 83 /** 84 * led_classdev_resume - resume an led_classdev. 85 * @led_cdev: the led_classdev to resume. 86 */ 87 void led_classdev_resume(struct led_classdev *led_cdev) 88 { 89 led_cdev->brightness_set(led_cdev, led_cdev->brightness); 90 led_cdev->flags &= ~LED_SUSPENDED; 91 } 92 EXPORT_SYMBOL_GPL(led_classdev_resume); 93 94 static int led_suspend(struct device *dev, pm_message_t state) 95 { 96 struct led_classdev *led_cdev = dev_get_drvdata(dev); 97 98 if (led_cdev->flags & LED_CORE_SUSPENDRESUME) 99 led_classdev_suspend(led_cdev); 100 101 return 0; 102 } 103 104 static int led_resume(struct device *dev) 105 { 106 struct led_classdev *led_cdev = dev_get_drvdata(dev); 107 108 if (led_cdev->flags & LED_CORE_SUSPENDRESUME) 109 led_classdev_resume(led_cdev); 110 111 return 0; 112 } 113 114 /** 115 * led_classdev_register - register a new object of led_classdev class. 116 * @parent: The device to register. 117 * @led_cdev: the led_classdev structure for this device. 118 */ 119 int led_classdev_register(struct device *parent, struct led_classdev *led_cdev) 120 { 121 int rc; 122 123 led_cdev->dev = device_create(leds_class, parent, 0, led_cdev, 124 "%s", led_cdev->name); 125 if (IS_ERR(led_cdev->dev)) 126 return PTR_ERR(led_cdev->dev); 127 128 /* register the attributes */ 129 rc = device_create_file(led_cdev->dev, &dev_attr_brightness); 130 if (rc) 131 goto err_out; 132 133 #ifdef CONFIG_LEDS_TRIGGERS 134 init_rwsem(&led_cdev->trigger_lock); 135 #endif 136 /* add to the list of leds */ 137 down_write(&leds_list_lock); 138 list_add_tail(&led_cdev->node, &leds_list); 139 up_write(&leds_list_lock); 140 141 led_update_brightness(led_cdev); 142 143 #ifdef CONFIG_LEDS_TRIGGERS 144 rc = device_create_file(led_cdev->dev, &dev_attr_trigger); 145 if (rc) 146 goto err_out_led_list; 147 148 led_trigger_set_default(led_cdev); 149 #endif 150 151 printk(KERN_INFO "Registered led device: %s\n", 152 led_cdev->name); 153 154 return 0; 155 156 #ifdef CONFIG_LEDS_TRIGGERS 157 err_out_led_list: 158 device_remove_file(led_cdev->dev, &dev_attr_brightness); 159 list_del(&led_cdev->node); 160 #endif 161 err_out: 162 device_unregister(led_cdev->dev); 163 return rc; 164 } 165 EXPORT_SYMBOL_GPL(led_classdev_register); 166 167 /** 168 * led_classdev_unregister - unregisters a object of led_properties class. 169 * @led_cdev: the led device to unregister 170 * 171 * Unregisters a previously registered via led_classdev_register object. 172 */ 173 void led_classdev_unregister(struct led_classdev *led_cdev) 174 { 175 device_remove_file(led_cdev->dev, &dev_attr_brightness); 176 #ifdef CONFIG_LEDS_TRIGGERS 177 device_remove_file(led_cdev->dev, &dev_attr_trigger); 178 down_write(&led_cdev->trigger_lock); 179 if (led_cdev->trigger) 180 led_trigger_set(led_cdev, NULL); 181 up_write(&led_cdev->trigger_lock); 182 #endif 183 184 device_unregister(led_cdev->dev); 185 186 down_write(&leds_list_lock); 187 list_del(&led_cdev->node); 188 up_write(&leds_list_lock); 189 } 190 EXPORT_SYMBOL_GPL(led_classdev_unregister); 191 192 static int __init leds_init(void) 193 { 194 leds_class = class_create(THIS_MODULE, "leds"); 195 if (IS_ERR(leds_class)) 196 return PTR_ERR(leds_class); 197 leds_class->suspend = led_suspend; 198 leds_class->resume = led_resume; 199 return 0; 200 } 201 202 static void __exit leds_exit(void) 203 { 204 class_destroy(leds_class); 205 } 206 207 subsys_initcall(leds_init); 208 module_exit(leds_exit); 209 210 MODULE_AUTHOR("John Lenz, Richard Purdie"); 211 MODULE_LICENSE("GPL"); 212 MODULE_DESCRIPTION("LED Class Interface"); 213