| 1 | // SPDX-License-Identifier: GPL-2.0-only |
| 2 | /* |
| 3 | * LED Class Core |
| 4 | * |
| 5 | * Copyright (C) 2005 John Lenz <lenz@cs.wisc.edu> |
| 6 | * Copyright (C) 2005-2007 Richard Purdie <rpurdie@openedhand.com> |
| 7 | */ |
| 8 | |
| 9 | #include <linux/ctype.h> |
| 10 | #include <linux/device.h> |
| 11 | #include <linux/err.h> |
| 12 | #include <linux/init.h> |
| 13 | #include <linux/kernel.h> |
| 14 | #include <linux/leds.h> |
| 15 | #include <linux/list.h> |
| 16 | #include <linux/module.h> |
| 17 | #include <linux/property.h> |
| 18 | #include <linux/slab.h> |
| 19 | #include <linux/spinlock.h> |
| 20 | #include <linux/timer.h> |
| 21 | #include <uapi/linux/uleds.h> |
| 22 | #include <linux/of.h> |
| 23 | #include "leds.h" |
| 24 | |
| 25 | static DEFINE_MUTEX(leds_lookup_lock); |
| 26 | static LIST_HEAD(leds_lookup_list); |
| 27 | |
| 28 | static struct workqueue_struct *leds_wq; |
| 29 | |
| 30 | static ssize_t brightness_show(struct device *dev, |
| 31 | struct device_attribute *attr, char *buf) |
| 32 | { |
| 33 | struct led_classdev *led_cdev = dev_get_drvdata(dev); |
| 34 | unsigned int brightness; |
| 35 | |
| 36 | mutex_lock(&led_cdev->led_access); |
| 37 | led_update_brightness(led_cdev); |
| 38 | brightness = led_cdev->brightness; |
| 39 | mutex_unlock(&led_cdev->led_access); |
| 40 | |
| 41 | return sprintf(buf, "%u\n", brightness); |
| 42 | } |
| 43 | |
| 44 | static ssize_t 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 | unsigned long state; |
| 49 | ssize_t ret; |
| 50 | |
| 51 | mutex_lock(&led_cdev->led_access); |
| 52 | |
| 53 | if (led_sysfs_is_disabled(led_cdev)) { |
| 54 | ret = -EBUSY; |
| 55 | goto unlock; |
| 56 | } |
| 57 | |
| 58 | ret = kstrtoul(buf, 10, &state); |
| 59 | if (ret) |
| 60 | goto unlock; |
| 61 | |
| 62 | if (state == LED_OFF) |
| 63 | led_trigger_remove(led_cdev); |
| 64 | led_set_brightness(led_cdev, state); |
| 65 | |
| 66 | ret = size; |
| 67 | unlock: |
| 68 | mutex_unlock(&led_cdev->led_access); |
| 69 | return ret; |
| 70 | } |
| 71 | static DEVICE_ATTR_RW(brightness); |
| 72 | |
| 73 | static ssize_t max_brightness_show(struct device *dev, |
| 74 | struct device_attribute *attr, char *buf) |
| 75 | { |
| 76 | struct led_classdev *led_cdev = dev_get_drvdata(dev); |
| 77 | unsigned int max_brightness; |
| 78 | |
| 79 | mutex_lock(&led_cdev->led_access); |
| 80 | max_brightness = led_cdev->max_brightness; |
| 81 | mutex_unlock(&led_cdev->led_access); |
| 82 | |
| 83 | return sprintf(buf, "%u\n", max_brightness); |
| 84 | } |
| 85 | static DEVICE_ATTR_RO(max_brightness); |
| 86 | |
| 87 | #ifdef CONFIG_LEDS_TRIGGERS |
| 88 | static const BIN_ATTR(trigger, 0644, led_trigger_read, led_trigger_write, 0); |
| 89 | static const struct bin_attribute *const led_trigger_bin_attrs[] = { |
| 90 | &bin_attr_trigger, |
| 91 | NULL, |
| 92 | }; |
| 93 | static const struct attribute_group led_trigger_group = { |
| 94 | .bin_attrs_new = led_trigger_bin_attrs, |
| 95 | }; |
| 96 | #endif |
| 97 | |
| 98 | static struct attribute *led_class_attrs[] = { |
| 99 | &dev_attr_brightness.attr, |
| 100 | &dev_attr_max_brightness.attr, |
| 101 | NULL, |
| 102 | }; |
| 103 | |
| 104 | static const struct attribute_group led_group = { |
| 105 | .attrs = led_class_attrs, |
| 106 | }; |
| 107 | |
| 108 | static const struct attribute_group *led_groups[] = { |
| 109 | &led_group, |
| 110 | #ifdef CONFIG_LEDS_TRIGGERS |
| 111 | &led_trigger_group, |
| 112 | #endif |
| 113 | NULL, |
| 114 | }; |
| 115 | |
| 116 | #ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED |
| 117 | static ssize_t brightness_hw_changed_show(struct device *dev, |
| 118 | struct device_attribute *attr, char *buf) |
| 119 | { |
| 120 | struct led_classdev *led_cdev = dev_get_drvdata(dev); |
| 121 | |
| 122 | if (led_cdev->brightness_hw_changed == -1) |
| 123 | return -ENODATA; |
| 124 | |
| 125 | return sprintf(buf, "%u\n", led_cdev->brightness_hw_changed); |
| 126 | } |
| 127 | |
| 128 | static DEVICE_ATTR_RO(brightness_hw_changed); |
| 129 | |
| 130 | static int led_add_brightness_hw_changed(struct led_classdev *led_cdev) |
| 131 | { |
| 132 | struct device *dev = led_cdev->dev; |
| 133 | int ret; |
| 134 | |
| 135 | ret = device_create_file(dev, &dev_attr_brightness_hw_changed); |
| 136 | if (ret) { |
| 137 | dev_err(dev, "Error creating brightness_hw_changed\n"); |
| 138 | return ret; |
| 139 | } |
| 140 | |
| 141 | led_cdev->brightness_hw_changed_kn = |
| 142 | sysfs_get_dirent(dev->kobj.sd, "brightness_hw_changed"); |
| 143 | if (!led_cdev->brightness_hw_changed_kn) { |
| 144 | dev_err(dev, "Error getting brightness_hw_changed kn\n"); |
| 145 | device_remove_file(dev, &dev_attr_brightness_hw_changed); |
| 146 | return -ENXIO; |
| 147 | } |
| 148 | |
| 149 | return 0; |
| 150 | } |
| 151 | |
| 152 | static void led_remove_brightness_hw_changed(struct led_classdev *led_cdev) |
| 153 | { |
| 154 | sysfs_put(led_cdev->brightness_hw_changed_kn); |
| 155 | device_remove_file(led_cdev->dev, &dev_attr_brightness_hw_changed); |
| 156 | } |
| 157 | |
| 158 | void led_classdev_notify_brightness_hw_changed(struct led_classdev *led_cdev, unsigned int brightness) |
| 159 | { |
| 160 | if (WARN_ON(!led_cdev->brightness_hw_changed_kn)) |
| 161 | return; |
| 162 | |
| 163 | led_cdev->brightness_hw_changed = brightness; |
| 164 | sysfs_notify_dirent(led_cdev->brightness_hw_changed_kn); |
| 165 | } |
| 166 | EXPORT_SYMBOL_GPL(led_classdev_notify_brightness_hw_changed); |
| 167 | #else |
| 168 | static int led_add_brightness_hw_changed(struct led_classdev *led_cdev) |
| 169 | { |
| 170 | return 0; |
| 171 | } |
| 172 | static void led_remove_brightness_hw_changed(struct led_classdev *led_cdev) |
| 173 | { |
| 174 | } |
| 175 | #endif |
| 176 | |
| 177 | /** |
| 178 | * led_classdev_suspend - suspend an led_classdev. |
| 179 | * @led_cdev: the led_classdev to suspend. |
| 180 | */ |
| 181 | void led_classdev_suspend(struct led_classdev *led_cdev) |
| 182 | { |
| 183 | led_cdev->flags |= LED_SUSPENDED; |
| 184 | led_set_brightness_nopm(led_cdev, 0); |
| 185 | flush_work(&led_cdev->set_brightness_work); |
| 186 | } |
| 187 | EXPORT_SYMBOL_GPL(led_classdev_suspend); |
| 188 | |
| 189 | /** |
| 190 | * led_classdev_resume - resume an led_classdev. |
| 191 | * @led_cdev: the led_classdev to resume. |
| 192 | */ |
| 193 | void led_classdev_resume(struct led_classdev *led_cdev) |
| 194 | { |
| 195 | led_set_brightness_nopm(led_cdev, led_cdev->brightness); |
| 196 | |
| 197 | if (led_cdev->flash_resume) |
| 198 | led_cdev->flash_resume(led_cdev); |
| 199 | |
| 200 | led_cdev->flags &= ~LED_SUSPENDED; |
| 201 | } |
| 202 | EXPORT_SYMBOL_GPL(led_classdev_resume); |
| 203 | |
| 204 | #ifdef CONFIG_PM_SLEEP |
| 205 | static int led_suspend(struct device *dev) |
| 206 | { |
| 207 | struct led_classdev *led_cdev = dev_get_drvdata(dev); |
| 208 | |
| 209 | if (led_cdev->flags & LED_CORE_SUSPENDRESUME) |
| 210 | led_classdev_suspend(led_cdev); |
| 211 | |
| 212 | return 0; |
| 213 | } |
| 214 | |
| 215 | static int led_resume(struct device *dev) |
| 216 | { |
| 217 | struct led_classdev *led_cdev = dev_get_drvdata(dev); |
| 218 | |
| 219 | if (led_cdev->flags & LED_CORE_SUSPENDRESUME) |
| 220 | led_classdev_resume(led_cdev); |
| 221 | |
| 222 | return 0; |
| 223 | } |
| 224 | #endif |
| 225 | |
| 226 | static SIMPLE_DEV_PM_OPS(leds_class_dev_pm_ops, led_suspend, led_resume); |
| 227 | |
| 228 | static struct led_classdev *led_module_get(struct device *led_dev) |
| 229 | { |
| 230 | struct led_classdev *led_cdev; |
| 231 | |
| 232 | if (!led_dev) |
| 233 | return ERR_PTR(-EPROBE_DEFER); |
| 234 | |
| 235 | led_cdev = dev_get_drvdata(led_dev); |
| 236 | |
| 237 | if (!try_module_get(led_cdev->dev->parent->driver->owner)) { |
| 238 | put_device(led_cdev->dev); |
| 239 | return ERR_PTR(-ENODEV); |
| 240 | } |
| 241 | |
| 242 | return led_cdev; |
| 243 | } |
| 244 | |
| 245 | static const struct class leds_class = { |
| 246 | .name = "leds", |
| 247 | .dev_groups = led_groups, |
| 248 | .pm = &leds_class_dev_pm_ops, |
| 249 | }; |
| 250 | |
| 251 | /** |
| 252 | * of_led_get() - request a LED device via the LED framework |
| 253 | * @np: device node to get the LED device from |
| 254 | * @index: the index of the LED |
| 255 | * |
| 256 | * Returns the LED device parsed from the phandle specified in the "leds" |
| 257 | * property of a device tree node or a negative error-code on failure. |
| 258 | */ |
| 259 | struct led_classdev *of_led_get(struct device_node *np, int index) |
| 260 | { |
| 261 | struct device *led_dev; |
| 262 | struct device_node *led_node; |
| 263 | |
| 264 | led_node = of_parse_phandle(np, "leds", index); |
| 265 | if (!led_node) |
| 266 | return ERR_PTR(-ENOENT); |
| 267 | |
| 268 | led_dev = class_find_device_by_of_node(&leds_class, led_node); |
| 269 | of_node_put(led_node); |
| 270 | |
| 271 | return led_module_get(led_dev); |
| 272 | } |
| 273 | EXPORT_SYMBOL_GPL(of_led_get); |
| 274 | |
| 275 | /** |
| 276 | * led_put() - release a LED device |
| 277 | * @led_cdev: LED device |
| 278 | */ |
| 279 | void led_put(struct led_classdev *led_cdev) |
| 280 | { |
| 281 | module_put(led_cdev->dev->parent->driver->owner); |
| 282 | put_device(led_cdev->dev); |
| 283 | } |
| 284 | EXPORT_SYMBOL_GPL(led_put); |
| 285 | |
| 286 | static void devm_led_release(struct device *dev, void *res) |
| 287 | { |
| 288 | struct led_classdev **p = res; |
| 289 | |
| 290 | led_put(*p); |
| 291 | } |
| 292 | |
| 293 | static struct led_classdev *__devm_led_get(struct device *dev, struct led_classdev *led) |
| 294 | { |
| 295 | struct led_classdev **dr; |
| 296 | |
| 297 | dr = devres_alloc(devm_led_release, sizeof(struct led_classdev *), GFP_KERNEL); |
| 298 | if (!dr) { |
| 299 | led_put(led); |
| 300 | return ERR_PTR(-ENOMEM); |
| 301 | } |
| 302 | |
| 303 | *dr = led; |
| 304 | devres_add(dev, dr); |
| 305 | |
| 306 | return led; |
| 307 | } |
| 308 | |
| 309 | /** |
| 310 | * devm_of_led_get - Resource-managed request of a LED device |
| 311 | * @dev: LED consumer |
| 312 | * @index: index of the LED to obtain in the consumer |
| 313 | * |
| 314 | * The device node of the device is parse to find the request LED device. |
| 315 | * The LED device returned from this function is automatically released |
| 316 | * on driver detach. |
| 317 | * |
| 318 | * @return a pointer to a LED device or ERR_PTR(errno) on failure. |
| 319 | */ |
| 320 | struct led_classdev *__must_check devm_of_led_get(struct device *dev, |
| 321 | int index) |
| 322 | { |
| 323 | struct led_classdev *led; |
| 324 | |
| 325 | if (!dev) |
| 326 | return ERR_PTR(-EINVAL); |
| 327 | |
| 328 | led = of_led_get(dev->of_node, index); |
| 329 | if (IS_ERR(led)) |
| 330 | return led; |
| 331 | |
| 332 | return __devm_led_get(dev, led); |
| 333 | } |
| 334 | EXPORT_SYMBOL_GPL(devm_of_led_get); |
| 335 | |
| 336 | /** |
| 337 | * led_get() - request a LED device via the LED framework |
| 338 | * @dev: device for which to get the LED device |
| 339 | * @con_id: name of the LED from the device's point of view |
| 340 | * |
| 341 | * @return a pointer to a LED device or ERR_PTR(errno) on failure. |
| 342 | */ |
| 343 | struct led_classdev *led_get(struct device *dev, char *con_id) |
| 344 | { |
| 345 | struct led_lookup_data *lookup; |
| 346 | const char *provider = NULL; |
| 347 | struct device *led_dev; |
| 348 | |
| 349 | mutex_lock(&leds_lookup_lock); |
| 350 | list_for_each_entry(lookup, &leds_lookup_list, list) { |
| 351 | if (!strcmp(lookup->dev_id, dev_name(dev)) && |
| 352 | !strcmp(lookup->con_id, con_id)) { |
| 353 | provider = kstrdup_const(lookup->provider, GFP_KERNEL); |
| 354 | break; |
| 355 | } |
| 356 | } |
| 357 | mutex_unlock(&leds_lookup_lock); |
| 358 | |
| 359 | if (!provider) |
| 360 | return ERR_PTR(-ENOENT); |
| 361 | |
| 362 | led_dev = class_find_device_by_name(&leds_class, provider); |
| 363 | kfree_const(provider); |
| 364 | |
| 365 | return led_module_get(led_dev); |
| 366 | } |
| 367 | EXPORT_SYMBOL_GPL(led_get); |
| 368 | |
| 369 | /** |
| 370 | * devm_led_get() - request a LED device via the LED framework |
| 371 | * @dev: device for which to get the LED device |
| 372 | * @con_id: name of the LED from the device's point of view |
| 373 | * |
| 374 | * The LED device returned from this function is automatically released |
| 375 | * on driver detach. |
| 376 | * |
| 377 | * @return a pointer to a LED device or ERR_PTR(errno) on failure. |
| 378 | */ |
| 379 | struct led_classdev *devm_led_get(struct device *dev, char *con_id) |
| 380 | { |
| 381 | struct led_classdev *led; |
| 382 | |
| 383 | led = led_get(dev, con_id); |
| 384 | if (IS_ERR(led)) |
| 385 | return led; |
| 386 | |
| 387 | return __devm_led_get(dev, led); |
| 388 | } |
| 389 | EXPORT_SYMBOL_GPL(devm_led_get); |
| 390 | |
| 391 | /** |
| 392 | * led_add_lookup() - Add a LED lookup table entry |
| 393 | * @led_lookup: the lookup table entry to add |
| 394 | * |
| 395 | * Add a LED lookup table entry. On systems without devicetree the lookup table |
| 396 | * is used by led_get() to find LEDs. |
| 397 | */ |
| 398 | void led_add_lookup(struct led_lookup_data *led_lookup) |
| 399 | { |
| 400 | mutex_lock(&leds_lookup_lock); |
| 401 | list_add_tail(&led_lookup->list, &leds_lookup_list); |
| 402 | mutex_unlock(&leds_lookup_lock); |
| 403 | } |
| 404 | EXPORT_SYMBOL_GPL(led_add_lookup); |
| 405 | |
| 406 | /** |
| 407 | * led_remove_lookup() - Remove a LED lookup table entry |
| 408 | * @led_lookup: the lookup table entry to remove |
| 409 | */ |
| 410 | void led_remove_lookup(struct led_lookup_data *led_lookup) |
| 411 | { |
| 412 | mutex_lock(&leds_lookup_lock); |
| 413 | list_del(&led_lookup->list); |
| 414 | mutex_unlock(&leds_lookup_lock); |
| 415 | } |
| 416 | EXPORT_SYMBOL_GPL(led_remove_lookup); |
| 417 | |
| 418 | /** |
| 419 | * devm_of_led_get_optional - Resource-managed request of an optional LED device |
| 420 | * @dev: LED consumer |
| 421 | * @index: index of the LED to obtain in the consumer |
| 422 | * |
| 423 | * The device node of the device is parsed to find the requested LED device. |
| 424 | * The LED device returned from this function is automatically released |
| 425 | * on driver detach. |
| 426 | * |
| 427 | * @return a pointer to a LED device, ERR_PTR(errno) on failure and NULL if the |
| 428 | * led was not found. |
| 429 | */ |
| 430 | struct led_classdev *__must_check devm_of_led_get_optional(struct device *dev, |
| 431 | int index) |
| 432 | { |
| 433 | struct led_classdev *led; |
| 434 | |
| 435 | led = devm_of_led_get(dev, index); |
| 436 | if (IS_ERR(led) && PTR_ERR(led) == -ENOENT) |
| 437 | return NULL; |
| 438 | |
| 439 | return led; |
| 440 | } |
| 441 | EXPORT_SYMBOL_GPL(devm_of_led_get_optional); |
| 442 | |
| 443 | static int led_classdev_next_name(const char *init_name, char *name, |
| 444 | size_t len) |
| 445 | { |
| 446 | unsigned int i = 0; |
| 447 | int ret = 0; |
| 448 | struct device *dev; |
| 449 | |
| 450 | strscpy(name, init_name, len); |
| 451 | |
| 452 | while ((ret < len) && |
| 453 | (dev = class_find_device_by_name(&leds_class, name))) { |
| 454 | put_device(dev); |
| 455 | ret = snprintf(name, len, "%s_%u", init_name, ++i); |
| 456 | } |
| 457 | |
| 458 | if (ret >= len) |
| 459 | return -ENOMEM; |
| 460 | |
| 461 | return i; |
| 462 | } |
| 463 | |
| 464 | /** |
| 465 | * led_classdev_register_ext - register a new object of led_classdev class |
| 466 | * with init data. |
| 467 | * |
| 468 | * @parent: parent of LED device |
| 469 | * @led_cdev: the led_classdev structure for this device. |
| 470 | * @init_data: LED class device initialization data |
| 471 | */ |
| 472 | int led_classdev_register_ext(struct device *parent, |
| 473 | struct led_classdev *led_cdev, |
| 474 | struct led_init_data *init_data) |
| 475 | { |
| 476 | char composed_name[LED_MAX_NAME_SIZE]; |
| 477 | char final_name[LED_MAX_NAME_SIZE]; |
| 478 | const char *proposed_name = composed_name; |
| 479 | int ret; |
| 480 | |
| 481 | if (init_data) { |
| 482 | if (init_data->devname_mandatory && !init_data->devicename) { |
| 483 | dev_err(parent, "Mandatory device name is missing"); |
| 484 | return -EINVAL; |
| 485 | } |
| 486 | ret = led_compose_name(parent, init_data, composed_name); |
| 487 | if (ret < 0) |
| 488 | return ret; |
| 489 | |
| 490 | if (init_data->fwnode) { |
| 491 | fwnode_property_read_string(init_data->fwnode, |
| 492 | "linux,default-trigger", |
| 493 | &led_cdev->default_trigger); |
| 494 | |
| 495 | if (fwnode_property_present(init_data->fwnode, |
| 496 | "retain-state-shutdown")) |
| 497 | led_cdev->flags |= LED_RETAIN_AT_SHUTDOWN; |
| 498 | |
| 499 | fwnode_property_read_u32(init_data->fwnode, |
| 500 | "max-brightness", |
| 501 | &led_cdev->max_brightness); |
| 502 | |
| 503 | if (fwnode_property_present(init_data->fwnode, "color")) |
| 504 | fwnode_property_read_u32(init_data->fwnode, "color", |
| 505 | &led_cdev->color); |
| 506 | } |
| 507 | } else { |
| 508 | proposed_name = led_cdev->name; |
| 509 | } |
| 510 | |
| 511 | ret = led_classdev_next_name(proposed_name, final_name, sizeof(final_name)); |
| 512 | if (ret < 0) |
| 513 | return ret; |
| 514 | else if (ret && led_cdev->flags & LED_REJECT_NAME_CONFLICT) |
| 515 | return -EEXIST; |
| 516 | else if (ret) |
| 517 | dev_warn(parent, "Led %s renamed to %s due to name collision\n", |
| 518 | proposed_name, final_name); |
| 519 | |
| 520 | if (led_cdev->color >= LED_COLOR_ID_MAX) |
| 521 | dev_warn(parent, "LED %s color identifier out of range\n", final_name); |
| 522 | |
| 523 | mutex_init(&led_cdev->led_access); |
| 524 | mutex_lock(&led_cdev->led_access); |
| 525 | led_cdev->dev = device_create_with_groups(&leds_class, parent, 0, |
| 526 | led_cdev, led_cdev->groups, "%s", final_name); |
| 527 | if (IS_ERR(led_cdev->dev)) { |
| 528 | mutex_unlock(&led_cdev->led_access); |
| 529 | return PTR_ERR(led_cdev->dev); |
| 530 | } |
| 531 | if (init_data && init_data->fwnode) |
| 532 | device_set_node(led_cdev->dev, init_data->fwnode); |
| 533 | |
| 534 | if (led_cdev->flags & LED_BRIGHT_HW_CHANGED) { |
| 535 | ret = led_add_brightness_hw_changed(led_cdev); |
| 536 | if (ret) { |
| 537 | device_unregister(led_cdev->dev); |
| 538 | led_cdev->dev = NULL; |
| 539 | mutex_unlock(&led_cdev->led_access); |
| 540 | return ret; |
| 541 | } |
| 542 | } |
| 543 | |
| 544 | led_cdev->work_flags = 0; |
| 545 | #ifdef CONFIG_LEDS_TRIGGERS |
| 546 | init_rwsem(&led_cdev->trigger_lock); |
| 547 | #endif |
| 548 | #ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED |
| 549 | led_cdev->brightness_hw_changed = -1; |
| 550 | #endif |
| 551 | /* add to the list of leds */ |
| 552 | down_write(&leds_list_lock); |
| 553 | list_add_tail(&led_cdev->node, &leds_list); |
| 554 | up_write(&leds_list_lock); |
| 555 | |
| 556 | if (!led_cdev->max_brightness) |
| 557 | led_cdev->max_brightness = LED_FULL; |
| 558 | |
| 559 | led_update_brightness(led_cdev); |
| 560 | |
| 561 | led_cdev->wq = leds_wq; |
| 562 | |
| 563 | led_init_core(led_cdev); |
| 564 | |
| 565 | #ifdef CONFIG_LEDS_TRIGGERS |
| 566 | led_trigger_set_default(led_cdev); |
| 567 | #endif |
| 568 | |
| 569 | mutex_unlock(&led_cdev->led_access); |
| 570 | |
| 571 | dev_dbg(parent, "Registered led device: %s\n", |
| 572 | led_cdev->name); |
| 573 | |
| 574 | return 0; |
| 575 | } |
| 576 | EXPORT_SYMBOL_GPL(led_classdev_register_ext); |
| 577 | |
| 578 | /** |
| 579 | * led_classdev_unregister - unregisters a object of led_properties class. |
| 580 | * @led_cdev: the led device to unregister |
| 581 | * |
| 582 | * Unregisters a previously registered via led_classdev_register object. |
| 583 | */ |
| 584 | void led_classdev_unregister(struct led_classdev *led_cdev) |
| 585 | { |
| 586 | if (IS_ERR_OR_NULL(led_cdev->dev)) |
| 587 | return; |
| 588 | |
| 589 | #ifdef CONFIG_LEDS_TRIGGERS |
| 590 | down_write(&led_cdev->trigger_lock); |
| 591 | if (led_cdev->trigger) |
| 592 | led_trigger_set(led_cdev, NULL); |
| 593 | up_write(&led_cdev->trigger_lock); |
| 594 | #endif |
| 595 | |
| 596 | led_cdev->flags |= LED_UNREGISTERING; |
| 597 | |
| 598 | /* Stop blinking */ |
| 599 | led_stop_software_blink(led_cdev); |
| 600 | |
| 601 | if (!(led_cdev->flags & LED_RETAIN_AT_SHUTDOWN)) |
| 602 | led_set_brightness(led_cdev, LED_OFF); |
| 603 | |
| 604 | flush_work(&led_cdev->set_brightness_work); |
| 605 | |
| 606 | if (led_cdev->flags & LED_BRIGHT_HW_CHANGED) |
| 607 | led_remove_brightness_hw_changed(led_cdev); |
| 608 | |
| 609 | device_unregister(led_cdev->dev); |
| 610 | |
| 611 | down_write(&leds_list_lock); |
| 612 | list_del(&led_cdev->node); |
| 613 | up_write(&leds_list_lock); |
| 614 | |
| 615 | mutex_destroy(&led_cdev->led_access); |
| 616 | } |
| 617 | EXPORT_SYMBOL_GPL(led_classdev_unregister); |
| 618 | |
| 619 | static void devm_led_classdev_release(struct device *dev, void *res) |
| 620 | { |
| 621 | led_classdev_unregister(*(struct led_classdev **)res); |
| 622 | } |
| 623 | |
| 624 | /** |
| 625 | * devm_led_classdev_register_ext - resource managed led_classdev_register_ext() |
| 626 | * |
| 627 | * @parent: parent of LED device |
| 628 | * @led_cdev: the led_classdev structure for this device. |
| 629 | * @init_data: LED class device initialization data |
| 630 | */ |
| 631 | int devm_led_classdev_register_ext(struct device *parent, |
| 632 | struct led_classdev *led_cdev, |
| 633 | struct led_init_data *init_data) |
| 634 | { |
| 635 | struct led_classdev **dr; |
| 636 | int rc; |
| 637 | |
| 638 | dr = devres_alloc(devm_led_classdev_release, sizeof(*dr), GFP_KERNEL); |
| 639 | if (!dr) |
| 640 | return -ENOMEM; |
| 641 | |
| 642 | rc = led_classdev_register_ext(parent, led_cdev, init_data); |
| 643 | if (rc) { |
| 644 | devres_free(dr); |
| 645 | return rc; |
| 646 | } |
| 647 | |
| 648 | *dr = led_cdev; |
| 649 | devres_add(parent, dr); |
| 650 | |
| 651 | return 0; |
| 652 | } |
| 653 | EXPORT_SYMBOL_GPL(devm_led_classdev_register_ext); |
| 654 | |
| 655 | static int devm_led_classdev_match(struct device *dev, void *res, void *data) |
| 656 | { |
| 657 | struct led_classdev **p = res; |
| 658 | |
| 659 | if (WARN_ON(!p || !*p)) |
| 660 | return 0; |
| 661 | |
| 662 | return *p == data; |
| 663 | } |
| 664 | |
| 665 | /** |
| 666 | * devm_led_classdev_unregister() - resource managed led_classdev_unregister() |
| 667 | * @dev: The device to unregister. |
| 668 | * @led_cdev: the led_classdev structure for this device. |
| 669 | */ |
| 670 | void devm_led_classdev_unregister(struct device *dev, |
| 671 | struct led_classdev *led_cdev) |
| 672 | { |
| 673 | WARN_ON(devres_release(dev, |
| 674 | devm_led_classdev_release, |
| 675 | devm_led_classdev_match, led_cdev)); |
| 676 | } |
| 677 | EXPORT_SYMBOL_GPL(devm_led_classdev_unregister); |
| 678 | |
| 679 | static int __init leds_init(void) |
| 680 | { |
| 681 | leds_wq = alloc_ordered_workqueue("leds", 0); |
| 682 | if (!leds_wq) { |
| 683 | pr_err("Failed to create LEDs ordered workqueue\n"); |
| 684 | return -ENOMEM; |
| 685 | } |
| 686 | |
| 687 | return class_register(&leds_class); |
| 688 | } |
| 689 | |
| 690 | static void __exit leds_exit(void) |
| 691 | { |
| 692 | class_unregister(&leds_class); |
| 693 | destroy_workqueue(leds_wq); |
| 694 | } |
| 695 | |
| 696 | subsys_initcall(leds_init); |
| 697 | module_exit(leds_exit); |
| 698 | |
| 699 | MODULE_AUTHOR("John Lenz, Richard Purdie"); |
| 700 | MODULE_LICENSE("GPL"); |
| 701 | MODULE_DESCRIPTION("LED Class Interface"); |