| 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/ctype.h> |
| 13 | #include <linux/device.h> |
| 14 | #include <linux/err.h> |
| 15 | #include <linux/init.h> |
| 16 | #include <linux/kernel.h> |
| 17 | #include <linux/leds.h> |
| 18 | #include <linux/list.h> |
| 19 | #include <linux/module.h> |
| 20 | #include <linux/slab.h> |
| 21 | #include <linux/spinlock.h> |
| 22 | #include <linux/timer.h> |
| 23 | #include "leds.h" |
| 24 | |
| 25 | static struct class *leds_class; |
| 26 | |
| 27 | static ssize_t brightness_show(struct device *dev, |
| 28 | struct device_attribute *attr, char *buf) |
| 29 | { |
| 30 | struct led_classdev *led_cdev = dev_get_drvdata(dev); |
| 31 | |
| 32 | /* no lock needed for this */ |
| 33 | led_update_brightness(led_cdev); |
| 34 | |
| 35 | return sprintf(buf, "%u\n", led_cdev->brightness); |
| 36 | } |
| 37 | |
| 38 | static ssize_t brightness_store(struct device *dev, |
| 39 | struct device_attribute *attr, const char *buf, size_t size) |
| 40 | { |
| 41 | struct led_classdev *led_cdev = dev_get_drvdata(dev); |
| 42 | unsigned long state; |
| 43 | ssize_t ret; |
| 44 | |
| 45 | mutex_lock(&led_cdev->led_access); |
| 46 | |
| 47 | if (led_sysfs_is_disabled(led_cdev)) { |
| 48 | ret = -EBUSY; |
| 49 | goto unlock; |
| 50 | } |
| 51 | |
| 52 | ret = kstrtoul(buf, 10, &state); |
| 53 | if (ret) |
| 54 | goto unlock; |
| 55 | |
| 56 | if (state == LED_OFF) |
| 57 | led_trigger_remove(led_cdev); |
| 58 | led_set_brightness(led_cdev, state); |
| 59 | |
| 60 | ret = size; |
| 61 | unlock: |
| 62 | mutex_unlock(&led_cdev->led_access); |
| 63 | return ret; |
| 64 | } |
| 65 | static DEVICE_ATTR_RW(brightness); |
| 66 | |
| 67 | static ssize_t 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 | static DEVICE_ATTR_RO(max_brightness); |
| 75 | |
| 76 | #ifdef CONFIG_LEDS_TRIGGERS |
| 77 | static DEVICE_ATTR(trigger, 0644, led_trigger_show, led_trigger_store); |
| 78 | static struct attribute *led_trigger_attrs[] = { |
| 79 | &dev_attr_trigger.attr, |
| 80 | NULL, |
| 81 | }; |
| 82 | static const struct attribute_group led_trigger_group = { |
| 83 | .attrs = led_trigger_attrs, |
| 84 | }; |
| 85 | #endif |
| 86 | |
| 87 | static struct attribute *led_class_attrs[] = { |
| 88 | &dev_attr_brightness.attr, |
| 89 | &dev_attr_max_brightness.attr, |
| 90 | NULL, |
| 91 | }; |
| 92 | |
| 93 | static const struct attribute_group led_group = { |
| 94 | .attrs = led_class_attrs, |
| 95 | }; |
| 96 | |
| 97 | static const struct attribute_group *led_groups[] = { |
| 98 | &led_group, |
| 99 | #ifdef CONFIG_LEDS_TRIGGERS |
| 100 | &led_trigger_group, |
| 101 | #endif |
| 102 | NULL, |
| 103 | }; |
| 104 | |
| 105 | /** |
| 106 | * led_classdev_suspend - suspend an led_classdev. |
| 107 | * @led_cdev: the led_classdev to suspend. |
| 108 | */ |
| 109 | void led_classdev_suspend(struct led_classdev *led_cdev) |
| 110 | { |
| 111 | led_cdev->flags |= LED_SUSPENDED; |
| 112 | led_set_brightness_nopm(led_cdev, 0); |
| 113 | } |
| 114 | EXPORT_SYMBOL_GPL(led_classdev_suspend); |
| 115 | |
| 116 | /** |
| 117 | * led_classdev_resume - resume an led_classdev. |
| 118 | * @led_cdev: the led_classdev to resume. |
| 119 | */ |
| 120 | void led_classdev_resume(struct led_classdev *led_cdev) |
| 121 | { |
| 122 | led_set_brightness_nopm(led_cdev, led_cdev->brightness); |
| 123 | |
| 124 | if (led_cdev->flash_resume) |
| 125 | led_cdev->flash_resume(led_cdev); |
| 126 | |
| 127 | led_cdev->flags &= ~LED_SUSPENDED; |
| 128 | } |
| 129 | EXPORT_SYMBOL_GPL(led_classdev_resume); |
| 130 | |
| 131 | #ifdef CONFIG_PM_SLEEP |
| 132 | static int led_suspend(struct device *dev) |
| 133 | { |
| 134 | struct led_classdev *led_cdev = dev_get_drvdata(dev); |
| 135 | |
| 136 | if (led_cdev->flags & LED_CORE_SUSPENDRESUME) |
| 137 | led_classdev_suspend(led_cdev); |
| 138 | |
| 139 | return 0; |
| 140 | } |
| 141 | |
| 142 | static int led_resume(struct device *dev) |
| 143 | { |
| 144 | struct led_classdev *led_cdev = dev_get_drvdata(dev); |
| 145 | |
| 146 | if (led_cdev->flags & LED_CORE_SUSPENDRESUME) |
| 147 | led_classdev_resume(led_cdev); |
| 148 | |
| 149 | return 0; |
| 150 | } |
| 151 | #endif |
| 152 | |
| 153 | static SIMPLE_DEV_PM_OPS(leds_class_dev_pm_ops, led_suspend, led_resume); |
| 154 | |
| 155 | static int match_name(struct device *dev, const void *data) |
| 156 | { |
| 157 | if (!dev_name(dev)) |
| 158 | return 0; |
| 159 | return !strcmp(dev_name(dev), (char *)data); |
| 160 | } |
| 161 | |
| 162 | static int led_classdev_next_name(const char *init_name, char *name, |
| 163 | size_t len) |
| 164 | { |
| 165 | unsigned int i = 0; |
| 166 | int ret = 0; |
| 167 | struct device *dev; |
| 168 | |
| 169 | strlcpy(name, init_name, len); |
| 170 | |
| 171 | while ((ret < len) && |
| 172 | (dev = class_find_device(leds_class, NULL, name, match_name))) { |
| 173 | put_device(dev); |
| 174 | ret = snprintf(name, len, "%s_%u", init_name, ++i); |
| 175 | } |
| 176 | |
| 177 | if (ret >= len) |
| 178 | return -ENOMEM; |
| 179 | |
| 180 | return i; |
| 181 | } |
| 182 | |
| 183 | /** |
| 184 | * led_classdev_register - register a new object of led_classdev class. |
| 185 | * @parent: The device to register. |
| 186 | * @led_cdev: the led_classdev structure for this device. |
| 187 | */ |
| 188 | int led_classdev_register(struct device *parent, struct led_classdev *led_cdev) |
| 189 | { |
| 190 | char name[64]; |
| 191 | int ret; |
| 192 | |
| 193 | ret = led_classdev_next_name(led_cdev->name, name, sizeof(name)); |
| 194 | if (ret < 0) |
| 195 | return ret; |
| 196 | |
| 197 | led_cdev->dev = device_create_with_groups(leds_class, parent, 0, |
| 198 | led_cdev, led_cdev->groups, "%s", name); |
| 199 | if (IS_ERR(led_cdev->dev)) |
| 200 | return PTR_ERR(led_cdev->dev); |
| 201 | |
| 202 | if (ret) |
| 203 | dev_warn(parent, "Led %s renamed to %s due to name collision", |
| 204 | led_cdev->name, dev_name(led_cdev->dev)); |
| 205 | |
| 206 | #ifdef CONFIG_LEDS_TRIGGERS |
| 207 | init_rwsem(&led_cdev->trigger_lock); |
| 208 | #endif |
| 209 | mutex_init(&led_cdev->led_access); |
| 210 | /* add to the list of leds */ |
| 211 | down_write(&leds_list_lock); |
| 212 | list_add_tail(&led_cdev->node, &leds_list); |
| 213 | up_write(&leds_list_lock); |
| 214 | |
| 215 | if (!led_cdev->max_brightness) |
| 216 | led_cdev->max_brightness = LED_FULL; |
| 217 | |
| 218 | led_update_brightness(led_cdev); |
| 219 | |
| 220 | led_init_core(led_cdev); |
| 221 | |
| 222 | #ifdef CONFIG_LEDS_TRIGGERS |
| 223 | led_trigger_set_default(led_cdev); |
| 224 | #endif |
| 225 | |
| 226 | dev_dbg(parent, "Registered led device: %s\n", |
| 227 | led_cdev->name); |
| 228 | |
| 229 | return 0; |
| 230 | } |
| 231 | EXPORT_SYMBOL_GPL(led_classdev_register); |
| 232 | |
| 233 | /** |
| 234 | * led_classdev_unregister - unregisters a object of led_properties class. |
| 235 | * @led_cdev: the led device to unregister |
| 236 | * |
| 237 | * Unregisters a previously registered via led_classdev_register object. |
| 238 | */ |
| 239 | void led_classdev_unregister(struct led_classdev *led_cdev) |
| 240 | { |
| 241 | #ifdef CONFIG_LEDS_TRIGGERS |
| 242 | down_write(&led_cdev->trigger_lock); |
| 243 | if (led_cdev->trigger) |
| 244 | led_trigger_set(led_cdev, NULL); |
| 245 | up_write(&led_cdev->trigger_lock); |
| 246 | #endif |
| 247 | |
| 248 | /* Stop blinking */ |
| 249 | led_stop_software_blink(led_cdev); |
| 250 | |
| 251 | led_set_brightness(led_cdev, LED_OFF); |
| 252 | |
| 253 | flush_work(&led_cdev->set_brightness_work); |
| 254 | |
| 255 | device_unregister(led_cdev->dev); |
| 256 | |
| 257 | down_write(&leds_list_lock); |
| 258 | list_del(&led_cdev->node); |
| 259 | up_write(&leds_list_lock); |
| 260 | |
| 261 | mutex_destroy(&led_cdev->led_access); |
| 262 | } |
| 263 | EXPORT_SYMBOL_GPL(led_classdev_unregister); |
| 264 | |
| 265 | static void devm_led_classdev_release(struct device *dev, void *res) |
| 266 | { |
| 267 | led_classdev_unregister(*(struct led_classdev **)res); |
| 268 | } |
| 269 | |
| 270 | /** |
| 271 | * devm_led_classdev_register - resource managed led_classdev_register() |
| 272 | * @parent: The device to register. |
| 273 | * @led_cdev: the led_classdev structure for this device. |
| 274 | */ |
| 275 | int devm_led_classdev_register(struct device *parent, |
| 276 | struct led_classdev *led_cdev) |
| 277 | { |
| 278 | struct led_classdev **dr; |
| 279 | int rc; |
| 280 | |
| 281 | dr = devres_alloc(devm_led_classdev_release, sizeof(*dr), GFP_KERNEL); |
| 282 | if (!dr) |
| 283 | return -ENOMEM; |
| 284 | |
| 285 | rc = led_classdev_register(parent, led_cdev); |
| 286 | if (rc) { |
| 287 | devres_free(dr); |
| 288 | return rc; |
| 289 | } |
| 290 | |
| 291 | *dr = led_cdev; |
| 292 | devres_add(parent, dr); |
| 293 | |
| 294 | return 0; |
| 295 | } |
| 296 | EXPORT_SYMBOL_GPL(devm_led_classdev_register); |
| 297 | |
| 298 | static int devm_led_classdev_match(struct device *dev, void *res, void *data) |
| 299 | { |
| 300 | struct led_cdev **p = res; |
| 301 | |
| 302 | if (WARN_ON(!p || !*p)) |
| 303 | return 0; |
| 304 | |
| 305 | return *p == data; |
| 306 | } |
| 307 | |
| 308 | /** |
| 309 | * devm_led_classdev_unregister() - resource managed led_classdev_unregister() |
| 310 | * @parent: The device to unregister. |
| 311 | * @led_cdev: the led_classdev structure for this device. |
| 312 | */ |
| 313 | void devm_led_classdev_unregister(struct device *dev, |
| 314 | struct led_classdev *led_cdev) |
| 315 | { |
| 316 | WARN_ON(devres_release(dev, |
| 317 | devm_led_classdev_release, |
| 318 | devm_led_classdev_match, led_cdev)); |
| 319 | } |
| 320 | EXPORT_SYMBOL_GPL(devm_led_classdev_unregister); |
| 321 | |
| 322 | static int __init leds_init(void) |
| 323 | { |
| 324 | leds_class = class_create(THIS_MODULE, "leds"); |
| 325 | if (IS_ERR(leds_class)) |
| 326 | return PTR_ERR(leds_class); |
| 327 | leds_class->pm = &leds_class_dev_pm_ops; |
| 328 | leds_class->dev_groups = led_groups; |
| 329 | return 0; |
| 330 | } |
| 331 | |
| 332 | static void __exit leds_exit(void) |
| 333 | { |
| 334 | class_destroy(leds_class); |
| 335 | } |
| 336 | |
| 337 | subsys_initcall(leds_init); |
| 338 | module_exit(leds_exit); |
| 339 | |
| 340 | MODULE_AUTHOR("John Lenz, Richard Purdie"); |
| 341 | MODULE_LICENSE("GPL"); |
| 342 | MODULE_DESCRIPTION("LED Class Interface"); |