drivers/leds/led-class.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * LED Class Core
   4  *
   5  * Copyright (C) 2005 John Lenz <[email protected]>
   6  * Copyright (C) 2005-2007 Richard Purdie <[email protected]>
   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 ssize_t brightness_show(struct device *dev,
  29                 struct device_attribute *attr, char *buf)
  30 {
  31         struct led_classdev *led_cdev = dev_get_drvdata(dev);
  32
  33         /* no lock needed for this */
  34         led_update_brightness(led_cdev);
  35
  36         return sprintf(buf, "%u\n", led_cdev->brightness);
  37 }
  38
  39 static ssize_t brightness_store(struct device *dev,
  40                 struct device_attribute *attr, const char *buf, size_t size)
  41 {
  42         struct led_classdev *led_cdev = dev_get_drvdata(dev);
  43         unsigned long state;
  44         ssize_t ret;
  45
  46         mutex_lock(&led_cdev->led_access);
  47
  48         if (led_sysfs_is_disabled(led_cdev)) {
  49                 ret = -EBUSY;
  50                 goto unlock;
  51         }
  52
  53         ret = kstrtoul(buf, 10, &state);
  54         if (ret)
  55                 goto unlock;
  56
  57         if (state == LED_OFF)
  58                 led_trigger_remove(led_cdev);
  59         led_set_brightness(led_cdev, state);
  60         flush_work(&led_cdev->set_brightness_work);
  61
  62         ret = size;
  63 unlock:
  64         mutex_unlock(&led_cdev->led_access);
  65         return ret;
  66 }
  67 static DEVICE_ATTR_RW(brightness);
  68
  69 static ssize_t max_brightness_show(struct device *dev,
  70                 struct device_attribute *attr, char *buf)
  71 {
  72         struct led_classdev *led_cdev = dev_get_drvdata(dev);
  73
  74         return sprintf(buf, "%u\n", led_cdev->max_brightness);
  75 }
  76 static DEVICE_ATTR_RO(max_brightness);
  77
  78 static ssize_t color_show(struct device *dev,
  79                 struct device_attribute *attr, char *buf)
  80 {
  81         const char *color_text = "invalid";
  82         struct led_classdev *led_cdev = dev_get_drvdata(dev);
  83
  84         if (led_cdev->color < LED_COLOR_ID_MAX)
  85                 color_text = led_colors[led_cdev->color];
  86
  87         return sysfs_emit(buf, "%s\n", color_text);
  88 }
  89 static DEVICE_ATTR_RO(color);
  90
  91 #ifdef CONFIG_LEDS_TRIGGERS
  92 static BIN_ATTR(trigger, 0644, led_trigger_read, led_trigger_write, 0);
  93 static struct bin_attribute *led_trigger_bin_attrs[] = {
  94         &bin_attr_trigger,
  95         NULL,
  96 };
  97 static const struct attribute_group led_trigger_group = {
  98         .bin_attrs = led_trigger_bin_attrs,
  99 };
 100 #endif
 101
 102 static struct attribute *led_class_attrs[] = {
 103         &dev_attr_brightness.attr,
 104         &dev_attr_max_brightness.attr,
 105         &dev_attr_color.attr,
 106         NULL,
 107 };
 108
 109 static const struct attribute_group led_group = {
 110         .attrs = led_class_attrs,
 111 };
 112
 113 static const struct attribute_group *led_groups[] = {
 114         &led_group,
 115 #ifdef CONFIG_LEDS_TRIGGERS
 116         &led_trigger_group,
 117 #endif
 118         NULL,
 119 };
 120
 121 #ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
 122 static ssize_t brightness_hw_changed_show(struct device *dev,
 123                 struct device_attribute *attr, char *buf)
 124 {
 125         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 126
 127         if (led_cdev->brightness_hw_changed == -1)
 128                 return -ENODATA;
 129
 130         return sprintf(buf, "%u\n", led_cdev->brightness_hw_changed);
 131 }
 132
 133 static DEVICE_ATTR_RO(brightness_hw_changed);
 134
 135 static int led_add_brightness_hw_changed(struct led_classdev *led_cdev)
 136 {
 137         struct device *dev = led_cdev->dev;
 138         int ret;
 139
 140         ret = device_create_file(dev, &dev_attr_brightness_hw_changed);
 141         if (ret) {
 142                 dev_err(dev, "Error creating brightness_hw_changed\n");
 143                 return ret;
 144         }
 145
 146         led_cdev->brightness_hw_changed_kn =
 147                 sysfs_get_dirent(dev->kobj.sd, "brightness_hw_changed");
 148         if (!led_cdev->brightness_hw_changed_kn) {
 149                 dev_err(dev, "Error getting brightness_hw_changed kn\n");
 150                 device_remove_file(dev, &dev_attr_brightness_hw_changed);
 151                 return -ENXIO;
 152         }
 153
 154         return 0;
 155 }
 156
 157 static void led_remove_brightness_hw_changed(struct led_classdev *led_cdev)
 158 {
 159         sysfs_put(led_cdev->brightness_hw_changed_kn);
 160         device_remove_file(led_cdev->dev, &dev_attr_brightness_hw_changed);
 161 }
 162
 163 void led_classdev_notify_brightness_hw_changed(struct led_classdev *led_cdev, unsigned int brightness)
 164 {
 165         if (WARN_ON(!led_cdev->brightness_hw_changed_kn))
 166                 return;
 167
 168         led_cdev->brightness_hw_changed = brightness;
 169         sysfs_notify_dirent(led_cdev->brightness_hw_changed_kn);
 170 }
 171 EXPORT_SYMBOL_GPL(led_classdev_notify_brightness_hw_changed);
 172 #else
 173 static int led_add_brightness_hw_changed(struct led_classdev *led_cdev)
 174 {
 175         return 0;
 176 }
 177 static void led_remove_brightness_hw_changed(struct led_classdev *led_cdev)
 178 {
 179 }
 180 #endif
 181
 182 /**
 183  * led_classdev_suspend - suspend an led_classdev.
 184  * @led_cdev: the led_classdev to suspend.
 185  */
 186 void led_classdev_suspend(struct led_classdev *led_cdev)
 187 {
 188         led_cdev->flags |= LED_SUSPENDED;
 189         led_set_brightness_nopm(led_cdev, 0);
 190         flush_work(&led_cdev->set_brightness_work);
 191 }
 192 EXPORT_SYMBOL_GPL(led_classdev_suspend);
 193
 194 /**
 195  * led_classdev_resume - resume an led_classdev.
 196  * @led_cdev: the led_classdev to resume.
 197  */
 198 void led_classdev_resume(struct led_classdev *led_cdev)
 199 {
 200         led_set_brightness_nopm(led_cdev, led_cdev->brightness);
 201
 202         if (led_cdev->flash_resume)
 203                 led_cdev->flash_resume(led_cdev);
 204
 205         led_cdev->flags &= ~LED_SUSPENDED;
 206 }
 207 EXPORT_SYMBOL_GPL(led_classdev_resume);
 208
 209 #ifdef CONFIG_PM_SLEEP
 210 static int led_suspend(struct device *dev)
 211 {
 212         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 213
 214         if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
 215                 led_classdev_suspend(led_cdev);
 216
 217         return 0;
 218 }
 219
 220 static int led_resume(struct device *dev)
 221 {
 222         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 223
 224         if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
 225                 led_classdev_resume(led_cdev);
 226
 227         return 0;
 228 }
 229 #endif
 230
 231 static SIMPLE_DEV_PM_OPS(leds_class_dev_pm_ops, led_suspend, led_resume);
 232
 233 static struct led_classdev *led_module_get(struct device *led_dev)
 234 {
 235         struct led_classdev *led_cdev;
 236
 237         if (!led_dev)
 238                 return ERR_PTR(-EPROBE_DEFER);
 239
 240         led_cdev = dev_get_drvdata(led_dev);
 241
 242         if (!try_module_get(led_cdev->dev->parent->driver->owner)) {
 243                 put_device(led_cdev->dev);
 244                 return ERR_PTR(-ENODEV);
 245         }
 246
 247         return led_cdev;
 248 }
 249
 250 static const struct class leds_class = {
 251         .name = "leds",
 252         .dev_groups = led_groups,
 253         .pm = &leds_class_dev_pm_ops,
 254 };
 255
 256 /**
 257  * of_led_get() - request a LED device via the LED framework
 258  * @np: device node to get the LED device from
 259  * @index: the index of the LED
 260  *
 261  * Returns the LED device parsed from the phandle specified in the "leds"
 262  * property of a device tree node or a negative error-code on failure.
 263  */
 264 struct led_classdev *of_led_get(struct device_node *np, int index)
 265 {
 266         struct device *led_dev;
 267         struct device_node *led_node;
 268
 269         led_node = of_parse_phandle(np, "leds", index);
 270         if (!led_node)
 271                 return ERR_PTR(-ENOENT);
 272
 273         led_dev = class_find_device_by_of_node(&leds_class, led_node);
 274         of_node_put(led_node);
 275         put_device(led_dev);
 276
 277         return led_module_get(led_dev);
 278 }
 279 EXPORT_SYMBOL_GPL(of_led_get);
 280
 281 /**
 282  * led_put() - release a LED device
 283  * @led_cdev: LED device
 284  */
 285 void led_put(struct led_classdev *led_cdev)
 286 {
 287         module_put(led_cdev->dev->parent->driver->owner);
 288         put_device(led_cdev->dev);
 289 }
 290 EXPORT_SYMBOL_GPL(led_put);
 291
 292 static void devm_led_release(struct device *dev, void *res)
 293 {
 294         struct led_classdev **p = res;
 295
 296         led_put(*p);
 297 }
 298
 299 static struct led_classdev *__devm_led_get(struct device *dev, struct led_classdev *led)
 300 {
 301         struct led_classdev **dr;
 302
 303         dr = devres_alloc(devm_led_release, sizeof(struct led_classdev *), GFP_KERNEL);
 304         if (!dr) {
 305                 led_put(led);
 306                 return ERR_PTR(-ENOMEM);
 307         }
 308
 309         *dr = led;
 310         devres_add(dev, dr);
 311
 312         return led;
 313 }
 314
 315 /**
 316  * devm_of_led_get - Resource-managed request of a LED device
 317  * @dev:        LED consumer
 318  * @index:      index of the LED to obtain in the consumer
 319  *
 320  * The device node of the device is parse to find the request LED device.
 321  * The LED device returned from this function is automatically released
 322  * on driver detach.
 323  *
 324  * @return a pointer to a LED device or ERR_PTR(errno) on failure.
 325  */
 326 struct led_classdev *__must_check devm_of_led_get(struct device *dev,
 327                                                   int index)
 328 {
 329         struct led_classdev *led;
 330
 331         if (!dev)
 332                 return ERR_PTR(-EINVAL);
 333
 334         led = of_led_get(dev->of_node, index);
 335         if (IS_ERR(led))
 336                 return led;
 337
 338         return __devm_led_get(dev, led);
 339 }
 340 EXPORT_SYMBOL_GPL(devm_of_led_get);
 341
 342 /**
 343  * led_get() - request a LED device via the LED framework
 344  * @dev: device for which to get the LED device
 345  * @con_id: name of the LED from the device's point of view
 346  *
 347  * @return a pointer to a LED device or ERR_PTR(errno) on failure.
 348  */
 349 struct led_classdev *led_get(struct device *dev, char *con_id)
 350 {
 351         struct led_lookup_data *lookup;
 352         const char *provider = NULL;
 353         struct device *led_dev;
 354
 355         mutex_lock(&leds_lookup_lock);
 356         list_for_each_entry(lookup, &leds_lookup_list, list) {
 357                 if (!strcmp(lookup->dev_id, dev_name(dev)) &&
 358                     !strcmp(lookup->con_id, con_id)) {
 359                         provider = kstrdup_const(lookup->provider, GFP_KERNEL);
 360                         break;
 361                 }
 362         }
 363         mutex_unlock(&leds_lookup_lock);
 364
 365         if (!provider)
 366                 return ERR_PTR(-ENOENT);
 367
 368         led_dev = class_find_device_by_name(&leds_class, provider);
 369         kfree_const(provider);
 370
 371         return led_module_get(led_dev);
 372 }
 373 EXPORT_SYMBOL_GPL(led_get);
 374
 375 /**
 376  * devm_led_get() - request a LED device via the LED framework
 377  * @dev: device for which to get the LED device
 378  * @con_id: name of the LED from the device's point of view
 379  *
 380  * The LED device returned from this function is automatically released
 381  * on driver detach.
 382  *
 383  * @return a pointer to a LED device or ERR_PTR(errno) on failure.
 384  */
 385 struct led_classdev *devm_led_get(struct device *dev, char *con_id)
 386 {
 387         struct led_classdev *led;
 388
 389         led = led_get(dev, con_id);
 390         if (IS_ERR(led))
 391                 return led;
 392
 393         return __devm_led_get(dev, led);
 394 }
 395 EXPORT_SYMBOL_GPL(devm_led_get);
 396
 397 /**
 398  * led_add_lookup() - Add a LED lookup table entry
 399  * @led_lookup: the lookup table entry to add
 400  *
 401  * Add a LED lookup table entry. On systems without devicetree the lookup table
 402  * is used by led_get() to find LEDs.
 403  */
 404 void led_add_lookup(struct led_lookup_data *led_lookup)
 405 {
 406         mutex_lock(&leds_lookup_lock);
 407         list_add_tail(&led_lookup->list, &leds_lookup_list);
 408         mutex_unlock(&leds_lookup_lock);
 409 }
 410 EXPORT_SYMBOL_GPL(led_add_lookup);
 411
 412 /**
 413  * led_remove_lookup() - Remove a LED lookup table entry
 414  * @led_lookup: the lookup table entry to remove
 415  */
 416 void led_remove_lookup(struct led_lookup_data *led_lookup)
 417 {
 418         mutex_lock(&leds_lookup_lock);
 419         list_del(&led_lookup->list);
 420         mutex_unlock(&leds_lookup_lock);
 421 }
 422 EXPORT_SYMBOL_GPL(led_remove_lookup);
 423
 424 /**
 425  * devm_of_led_get_optional - Resource-managed request of an optional LED device
 426  * @dev:        LED consumer
 427  * @index:      index of the LED to obtain in the consumer
 428  *
 429  * The device node of the device is parsed to find the requested LED device.
 430  * The LED device returned from this function is automatically released
 431  * on driver detach.
 432  *
 433  * @return a pointer to a LED device, ERR_PTR(errno) on failure and NULL if the
 434  * led was not found.
 435  */
 436 struct led_classdev *__must_check devm_of_led_get_optional(struct device *dev,
 437                                                         int index)
 438 {
 439         struct led_classdev *led;
 440
 441         led = devm_of_led_get(dev, index);
 442         if (IS_ERR(led) && PTR_ERR(led) == -ENOENT)
 443                 return NULL;
 444
 445         return led;
 446 }
 447 EXPORT_SYMBOL_GPL(devm_of_led_get_optional);
 448
 449 static int led_classdev_next_name(const char *init_name, char *name,
 450                                   size_t len)
 451 {
 452         unsigned int i = 0;
 453         int ret = 0;
 454         struct device *dev;
 455
 456         strscpy(name, init_name, len);
 457
 458         while ((ret < len) &&
 459                (dev = class_find_device_by_name(&leds_class, name))) {
 460                 put_device(dev);
 461                 ret = snprintf(name, len, "%s_%u", init_name, ++i);
 462         }
 463
 464         if (ret >= len)
 465                 return -ENOMEM;
 466
 467         return i;
 468 }
 469
 470 /**
 471  * led_classdev_register_ext - register a new object of led_classdev class
 472  *                             with init data.
 473  *
 474  * @parent: parent of LED device
 475  * @led_cdev: the led_classdev structure for this device.
 476  * @init_data: LED class device initialization data
 477  */
 478 int led_classdev_register_ext(struct device *parent,
 479                               struct led_classdev *led_cdev,
 480                               struct led_init_data *init_data)
 481 {
 482         char composed_name[LED_MAX_NAME_SIZE];
 483         char final_name[LED_MAX_NAME_SIZE];
 484         const char *proposed_name = composed_name;
 485         int ret;
 486
 487         if (init_data) {
 488                 if (init_data->devname_mandatory && !init_data->devicename) {
 489                         dev_err(parent, "Mandatory device name is missing");
 490                         return -EINVAL;
 491                 }
 492                 ret = led_compose_name(parent, init_data, composed_name);
 493                 if (ret < 0)
 494                         return ret;
 495
 496                 if (init_data->fwnode) {
 497                         fwnode_property_read_string(init_data->fwnode,
 498                                 "linux,default-trigger",
 499                                 &led_cdev->default_trigger);
 500
 501                         if (fwnode_property_present(init_data->fwnode,
 502                                                     "retain-state-shutdown"))
 503                                 led_cdev->flags |= LED_RETAIN_AT_SHUTDOWN;
 504
 505                         fwnode_property_read_u32(init_data->fwnode,
 506                                 "max-brightness",
 507                                 &led_cdev->max_brightness);
 508
 509                         if (fwnode_property_present(init_data->fwnode, "color"))
 510                                 fwnode_property_read_u32(init_data->fwnode, "color",
 511                                                          &led_cdev->color);
 512                 }
 513         } else {
 514                 proposed_name = led_cdev->name;
 515         }
 516
 517         ret = led_classdev_next_name(proposed_name, final_name, sizeof(final_name));
 518         if (ret < 0)
 519                 return ret;
 520
 521         if (led_cdev->color >= LED_COLOR_ID_MAX)
 522                 dev_warn(parent, "LED %s color identifier out of range\n", final_name);
 523
 524         mutex_init(&led_cdev->led_access);
 525         mutex_lock(&led_cdev->led_access);
 526         led_cdev->dev = device_create_with_groups(&leds_class, parent, 0,
 527                                                   led_cdev, led_cdev->groups, "%s", final_name);
 528         if (IS_ERR(led_cdev->dev)) {
 529                 mutex_unlock(&led_cdev->led_access);
 530                 return PTR_ERR(led_cdev->dev);
 531         }
 532         if (init_data && init_data->fwnode)
 533                 device_set_node(led_cdev->dev, init_data->fwnode);
 534
 535         if (ret)
 536                 dev_warn(parent, "Led %s renamed to %s due to name collision",
 537                                 proposed_name, dev_name(led_cdev->dev));
 538
 539         if (led_cdev->flags & LED_BRIGHT_HW_CHANGED) {
 540                 ret = led_add_brightness_hw_changed(led_cdev);
 541                 if (ret) {
 542                         device_unregister(led_cdev->dev);
 543                         led_cdev->dev = NULL;
 544                         mutex_unlock(&led_cdev->led_access);
 545                         return ret;
 546                 }
 547         }
 548
 549         led_cdev->work_flags = 0;
 550 #ifdef CONFIG_LEDS_TRIGGERS
 551         init_rwsem(&led_cdev->trigger_lock);
 552 #endif
 553 #ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
 554         led_cdev->brightness_hw_changed = -1;
 555 #endif
 556         /* add to the list of leds */
 557         down_write(&leds_list_lock);
 558         list_add_tail(&led_cdev->node, &leds_list);
 559         up_write(&leds_list_lock);
 560
 561         if (!led_cdev->max_brightness)
 562                 led_cdev->max_brightness = LED_FULL;
 563
 564         led_update_brightness(led_cdev);
 565
 566         led_init_core(led_cdev);
 567
 568 #ifdef CONFIG_LEDS_TRIGGERS
 569         led_trigger_set_default(led_cdev);
 570 #endif
 571
 572         mutex_unlock(&led_cdev->led_access);
 573
 574         dev_dbg(parent, "Registered led device: %s\n",
 575                         led_cdev->name);
 576
 577         return 0;
 578 }
 579 EXPORT_SYMBOL_GPL(led_classdev_register_ext);
 580
 581 /**
 582  * led_classdev_unregister - unregisters a object of led_properties class.
 583  * @led_cdev: the led device to unregister
 584  *
 585  * Unregisters a previously registered via led_classdev_register object.
 586  */
 587 void led_classdev_unregister(struct led_classdev *led_cdev)
 588 {
 589         if (IS_ERR_OR_NULL(led_cdev->dev))
 590                 return;
 591
 592 #ifdef CONFIG_LEDS_TRIGGERS
 593         down_write(&led_cdev->trigger_lock);
 594         if (led_cdev->trigger)
 595                 led_trigger_set(led_cdev, NULL);
 596         up_write(&led_cdev->trigger_lock);
 597 #endif
 598
 599         led_cdev->flags |= LED_UNREGISTERING;
 600
 601         /* Stop blinking */
 602         led_stop_software_blink(led_cdev);
 603
 604         if (!(led_cdev->flags & LED_RETAIN_AT_SHUTDOWN))
 605                 led_set_brightness(led_cdev, LED_OFF);
 606
 607         flush_work(&led_cdev->set_brightness_work);
 608
 609         if (led_cdev->flags & LED_BRIGHT_HW_CHANGED)
 610                 led_remove_brightness_hw_changed(led_cdev);
 611
 612         device_unregister(led_cdev->dev);
 613
 614         down_write(&leds_list_lock);
 615         list_del(&led_cdev->node);
 616         up_write(&leds_list_lock);
 617
 618         mutex_destroy(&led_cdev->led_access);
 619 }
 620 EXPORT_SYMBOL_GPL(led_classdev_unregister);
 621
 622 static void devm_led_classdev_release(struct device *dev, void *res)
 623 {
 624         led_classdev_unregister(*(struct led_classdev **)res);
 625 }
 626
 627 /**
 628  * devm_led_classdev_register_ext - resource managed led_classdev_register_ext()
 629  *
 630  * @parent: parent of LED device
 631  * @led_cdev: the led_classdev structure for this device.
 632  * @init_data: LED class device initialization data
 633  */
 634 int devm_led_classdev_register_ext(struct device *parent,
 635                                    struct led_classdev *led_cdev,
 636                                    struct led_init_data *init_data)
 637 {
 638         struct led_classdev **dr;
 639         int rc;
 640
 641         dr = devres_alloc(devm_led_classdev_release, sizeof(*dr), GFP_KERNEL);
 642         if (!dr)
 643                 return -ENOMEM;
 644
 645         rc = led_classdev_register_ext(parent, led_cdev, init_data);
 646         if (rc) {
 647                 devres_free(dr);
 648                 return rc;
 649         }
 650
 651         *dr = led_cdev;
 652         devres_add(parent, dr);
 653
 654         return 0;
 655 }
 656 EXPORT_SYMBOL_GPL(devm_led_classdev_register_ext);
 657
 658 static int devm_led_classdev_match(struct device *dev, void *res, void *data)
 659 {
 660         struct led_classdev **p = res;
 661
 662         if (WARN_ON(!p || !*p))
 663                 return 0;
 664
 665         return *p == data;
 666 }
 667
 668 /**
 669  * devm_led_classdev_unregister() - resource managed led_classdev_unregister()
 670  * @dev: The device to unregister.
 671  * @led_cdev: the led_classdev structure for this device.
 672  */
 673 void devm_led_classdev_unregister(struct device *dev,
 674                                   struct led_classdev *led_cdev)
 675 {
 676         WARN_ON(devres_release(dev,
 677                                devm_led_classdev_release,
 678                                devm_led_classdev_match, led_cdev));
 679 }
 680 EXPORT_SYMBOL_GPL(devm_led_classdev_unregister);
 681
 682 static int __init leds_init(void)
 683 {
 684         return class_register(&leds_class);
 685 }
 686
 687 static void __exit leds_exit(void)
 688 {
 689         class_unregister(&leds_class);
 690 }
 691
 692 subsys_initcall(leds_init);
 693 module_exit(leds_exit);
 694
 695 MODULE_AUTHOR("John Lenz, Richard Purdie");
 696 MODULE_LICENSE("GPL");
 697 MODULE_DESCRIPTION("LED Class Interface");