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 (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 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 75 static DEVICE_ATTR(brightness, 0644, led_brightness_show, led_brightness_store); 76 static DEVICE_ATTR(max_brightness, 0444, led_max_brightness_show, NULL); 77 #ifdef CONFIG_LEDS_TRIGGERS 78 static DEVICE_ATTR(trigger, 0644, led_trigger_show, led_trigger_store); 79 #endif 80 81 /** 82 * led_classdev_suspend - suspend an led_classdev. 83 * @led_cdev: the led_classdev to suspend. 84 */ 85 void led_classdev_suspend(struct led_classdev *led_cdev) 86 { 87 led_cdev->flags |= LED_SUSPENDED; 88 led_cdev->brightness_set(led_cdev, 0); 89 } 90 EXPORT_SYMBOL_GPL(led_classdev_suspend); 91 92 /** 93 * led_classdev_resume - resume an led_classdev. 94 * @led_cdev: the led_classdev to resume. 95 */ 96 void led_classdev_resume(struct led_classdev *led_cdev) 97 { 98 led_cdev->brightness_set(led_cdev, led_cdev->brightness); 99 led_cdev->flags &= ~LED_SUSPENDED; 100 } 101 EXPORT_SYMBOL_GPL(led_classdev_resume); 102 103 static int led_suspend(struct device *dev, pm_message_t state) 104 { 105 struct led_classdev *led_cdev = dev_get_drvdata(dev); 106 107 if (led_cdev->flags & LED_CORE_SUSPENDRESUME) 108 led_classdev_suspend(led_cdev); 109 110 return 0; 111 } 112 113 static int led_resume(struct device *dev) 114 { 115 struct led_classdev *led_cdev = dev_get_drvdata(dev); 116 117 if (led_cdev->flags & LED_CORE_SUSPENDRESUME) 118 led_classdev_resume(led_cdev); 119 120 return 0; 121 } 122 123 /** 124 * led_classdev_register - register a new object of led_classdev class. 125 * @parent: The device to register. 126 * @led_cdev: the led_classdev structure for this device. 127 */ 128 int led_classdev_register(struct device *parent, struct led_classdev *led_cdev) 129 { 130 int rc; 131 132 led_cdev->dev = device_create(leds_class, parent, 0, led_cdev, 133 "%s", led_cdev->name); 134 if (IS_ERR(led_cdev->dev)) 135 return PTR_ERR(led_cdev->dev); 136 137 /* register the attributes */ 138 rc = device_create_file(led_cdev->dev, &dev_attr_brightness); 139 if (rc) 140 goto err_out; 141 142 #ifdef CONFIG_LEDS_TRIGGERS 143 init_rwsem(&led_cdev->trigger_lock); 144 #endif 145 /* add to the list of leds */ 146 down_write(&leds_list_lock); 147 list_add_tail(&led_cdev->node, &leds_list); 148 up_write(&leds_list_lock); 149 150 if (!led_cdev->max_brightness) 151 led_cdev->max_brightness = LED_FULL; 152 153 rc = device_create_file(led_cdev->dev, &dev_attr_max_brightness); 154 if (rc) 155 goto err_out_attr_max; 156 157 led_update_brightness(led_cdev); 158 159 #ifdef CONFIG_LEDS_TRIGGERS 160 rc = device_create_file(led_cdev->dev, &dev_attr_trigger); 161 if (rc) 162 goto err_out_led_list; 163 164 led_trigger_set_default(led_cdev); 165 #endif 166 167 printk(KERN_INFO "Registered led device: %s\n", 168 led_cdev->name); 169 170 return 0; 171 172 #ifdef CONFIG_LEDS_TRIGGERS 173 err_out_led_list: 174 device_remove_file(led_cdev->dev, &dev_attr_max_brightness); 175 #endif 176 err_out_attr_max: 177 device_remove_file(led_cdev->dev, &dev_attr_brightness); 178 list_del(&led_cdev->node); 179 err_out: 180 device_unregister(led_cdev->dev); 181 return rc; 182 } 183 EXPORT_SYMBOL_GPL(led_classdev_register); 184 185 /** 186 * led_classdev_unregister - unregisters a object of led_properties class. 187 * @led_cdev: the led device to unregister 188 * 189 * Unregisters a previously registered via led_classdev_register object. 190 */ 191 void led_classdev_unregister(struct led_classdev *led_cdev) 192 { 193 device_remove_file(led_cdev->dev, &dev_attr_max_brightness); 194 device_remove_file(led_cdev->dev, &dev_attr_brightness); 195 #ifdef CONFIG_LEDS_TRIGGERS 196 device_remove_file(led_cdev->dev, &dev_attr_trigger); 197 down_write(&led_cdev->trigger_lock); 198 if (led_cdev->trigger) 199 led_trigger_set(led_cdev, NULL); 200 up_write(&led_cdev->trigger_lock); 201 #endif 202 203 device_unregister(led_cdev->dev); 204 205 down_write(&leds_list_lock); 206 list_del(&led_cdev->node); 207 up_write(&leds_list_lock); 208 } 209 EXPORT_SYMBOL_GPL(led_classdev_unregister); 210 211 static int __init leds_init(void) 212 { 213 leds_class = class_create(THIS_MODULE, "leds"); 214 if (IS_ERR(leds_class)) 215 return PTR_ERR(leds_class); 216 leds_class->suspend = led_suspend; 217 leds_class->resume = led_resume; 218 return 0; 219 } 220 221 static void __exit leds_exit(void) 222 { 223 class_destroy(leds_class); 224 } 225 226 subsys_initcall(leds_init); 227 module_exit(leds_exit); 228 229 MODULE_AUTHOR("John Lenz, Richard Purdie"); 230 MODULE_LICENSE("GPL"); 231 MODULE_DESCRIPTION("LED Class Interface"); 232