drivers/leds/trigger/ledtrig-netdev.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 // Copyright 2017 Ben Whitten <[email protected]>
   3 // Copyright 2007 Oliver Jowett <[email protected]>
   4 //
   5 // LED Kernel Netdev Trigger
   6 //
   7 // Toggles the LED to reflect the link and traffic state of a named net device
   8 //
   9 // Derived from ledtrig-timer.c which is:
  10 //  Copyright 2005-2006 Openedhand Ltd.
  11 //  Author: Richard Purdie <[email protected]>
  12
  13 #include <linux/atomic.h>
  14 #include <linux/ctype.h>
  15 #include <linux/device.h>
  16 #include <linux/ethtool.h>
  17 #include <linux/init.h>
  18 #include <linux/jiffies.h>
  19 #include <linux/kernel.h>
  20 #include <linux/leds.h>
  21 #include <linux/list.h>
  22 #include <linux/module.h>
  23 #include <linux/netdevice.h>
  24 #include <linux/mutex.h>
  25 #include <linux/rtnetlink.h>
  26 #include <linux/timer.h>
  27 #include "../leds.h"
  28
  29 #define NETDEV_LED_DEFAULT_INTERVAL     50
  30
  31 /*
  32  * Configurable sysfs attributes:
  33  *
  34  * device_name - network device name to monitor
  35  * interval - duration of LED blink, in milliseconds
  36  * link -  LED's normal state reflects whether the link is up
  37  *         (has carrier) or not
  38  * tx -  LED blinks on transmitted data
  39  * rx -  LED blinks on receive data
  40  *
  41  * Note: If the user selects a mode that is not supported by hw, default
  42  * behavior is to fall back to software control of the LED. However not every
  43  * hw supports software control. LED callbacks brightness_set() and
  44  * brightness_set_blocking() are NULL in this case. hw_control_is_supported()
  45  * should use available means supported by hw to inform the user that selected
  46  * mode isn't supported by hw. This could be switching off the LED or any
  47  * hw blink mode. If software control fallback isn't possible, we return
  48  * -EOPNOTSUPP to the user, but still store the selected mode. This is needed
  49  * in case an intermediate unsupported mode is necessary to switch from one
  50  * supported mode to another.
  51  */
  52
  53 struct led_netdev_data {
  54         struct mutex lock;
  55
  56         struct delayed_work work;
  57         struct notifier_block notifier;
  58
  59         struct led_classdev *led_cdev;
  60         struct net_device *net_dev;
  61
  62         char device_name[IFNAMSIZ];
  63         atomic_t interval;
  64         unsigned int last_activity;
  65
  66         unsigned long mode;
  67         int link_speed;
  68         u8 duplex;
  69
  70         bool carrier_link_up;
  71         bool hw_control;
  72 };
  73
  74 static void set_baseline_state(struct led_netdev_data *trigger_data)
  75 {
  76         int current_brightness;
  77         struct led_classdev *led_cdev = trigger_data->led_cdev;
  78
  79         /* Already validated, hw control is possible with the requested mode */
  80         if (trigger_data->hw_control) {
  81                 led_cdev->hw_control_set(led_cdev, trigger_data->mode);
  82
  83                 return;
  84         }
  85
  86         current_brightness = led_cdev->brightness;
  87         if (current_brightness)
  88                 led_cdev->blink_brightness = current_brightness;
  89         if (!led_cdev->blink_brightness)
  90                 led_cdev->blink_brightness = led_cdev->max_brightness;
  91
  92         if (!trigger_data->carrier_link_up) {
  93                 led_set_brightness(led_cdev, LED_OFF);
  94         } else {
  95                 bool blink_on = false;
  96
  97                 if (test_bit(TRIGGER_NETDEV_LINK, &trigger_data->mode))
  98                         blink_on = true;
  99
 100                 if (test_bit(TRIGGER_NETDEV_LINK_10, &trigger_data->mode) &&
 101                     trigger_data->link_speed == SPEED_10)
 102                         blink_on = true;
 103
 104                 if (test_bit(TRIGGER_NETDEV_LINK_100, &trigger_data->mode) &&
 105                     trigger_data->link_speed == SPEED_100)
 106                         blink_on = true;
 107
 108                 if (test_bit(TRIGGER_NETDEV_LINK_1000, &trigger_data->mode) &&
 109                     trigger_data->link_speed == SPEED_1000)
 110                         blink_on = true;
 111
 112                 if (test_bit(TRIGGER_NETDEV_LINK_2500, &trigger_data->mode) &&
 113                     trigger_data->link_speed == SPEED_2500)
 114                         blink_on = true;
 115
 116                 if (test_bit(TRIGGER_NETDEV_LINK_5000, &trigger_data->mode) &&
 117                     trigger_data->link_speed == SPEED_5000)
 118                         blink_on = true;
 119
 120                 if (test_bit(TRIGGER_NETDEV_LINK_10000, &trigger_data->mode) &&
 121                     trigger_data->link_speed == SPEED_10000)
 122                         blink_on = true;
 123
 124                 if (test_bit(TRIGGER_NETDEV_HALF_DUPLEX, &trigger_data->mode) &&
 125                     trigger_data->duplex == DUPLEX_HALF)
 126                         blink_on = true;
 127
 128                 if (test_bit(TRIGGER_NETDEV_FULL_DUPLEX, &trigger_data->mode) &&
 129                     trigger_data->duplex == DUPLEX_FULL)
 130                         blink_on = true;
 131
 132                 if (blink_on)
 133                         led_set_brightness(led_cdev,
 134                                            led_cdev->blink_brightness);
 135                 else
 136                         led_set_brightness(led_cdev, LED_OFF);
 137
 138                 /* If we are looking for RX/TX start periodically
 139                  * checking stats
 140                  */
 141                 if (test_bit(TRIGGER_NETDEV_TX, &trigger_data->mode) ||
 142                     test_bit(TRIGGER_NETDEV_RX, &trigger_data->mode))
 143                         schedule_delayed_work(&trigger_data->work, 0);
 144         }
 145 }
 146
 147 static bool supports_hw_control(struct led_classdev *led_cdev)
 148 {
 149         if (!led_cdev->hw_control_get || !led_cdev->hw_control_set ||
 150             !led_cdev->hw_control_is_supported)
 151                 return false;
 152
 153         return !strcmp(led_cdev->hw_control_trigger, led_cdev->trigger->name);
 154 }
 155
 156 /*
 157  * Validate the configured netdev is the same as the one associated with
 158  * the LED driver in hw control.
 159  */
 160 static bool validate_net_dev(struct led_classdev *led_cdev,
 161                              struct net_device *net_dev)
 162 {
 163         struct device *dev = led_cdev->hw_control_get_device(led_cdev);
 164         struct net_device *ndev;
 165
 166         if (!dev)
 167                 return false;
 168
 169         ndev = to_net_dev(dev);
 170
 171         return ndev == net_dev;
 172 }
 173
 174 static bool can_hw_control(struct led_netdev_data *trigger_data)
 175 {
 176         unsigned long default_interval = msecs_to_jiffies(NETDEV_LED_DEFAULT_INTERVAL);
 177         unsigned int interval = atomic_read(&trigger_data->interval);
 178         struct led_classdev *led_cdev = trigger_data->led_cdev;
 179         int ret;
 180
 181         if (!supports_hw_control(led_cdev))
 182                 return false;
 183
 184         /*
 185          * Interval must be set to the default
 186          * value. Any different value is rejected if in hw
 187          * control.
 188          */
 189         if (interval != default_interval)
 190                 return false;
 191
 192         /*
 193          * net_dev must be set with hw control, otherwise no
 194          * blinking can be happening and there is nothing to
 195          * offloaded. Additionally, for hw control to be
 196          * valid, the configured netdev must be the same as
 197          * netdev associated to the LED.
 198          */
 199         if (!validate_net_dev(led_cdev, trigger_data->net_dev))
 200                 return false;
 201
 202         /* Check if the requested mode is supported */
 203         ret = led_cdev->hw_control_is_supported(led_cdev, trigger_data->mode);
 204         /* Fall back to software blinking if not supported */
 205         if (ret == -EOPNOTSUPP)
 206                 return false;
 207         if (ret) {
 208                 dev_warn(led_cdev->dev,
 209                          "Current mode check failed with error %d\n", ret);
 210                 return false;
 211         }
 212
 213         return true;
 214 }
 215
 216 static void get_device_state(struct led_netdev_data *trigger_data)
 217 {
 218         struct ethtool_link_ksettings cmd;
 219
 220         trigger_data->carrier_link_up = netif_carrier_ok(trigger_data->net_dev);
 221         if (!trigger_data->carrier_link_up)
 222                 return;
 223
 224         if (!__ethtool_get_link_ksettings(trigger_data->net_dev, &cmd)) {
 225                 trigger_data->link_speed = cmd.base.speed;
 226                 trigger_data->duplex = cmd.base.duplex;
 227         }
 228 }
 229
 230 static ssize_t device_name_show(struct device *dev,
 231                                 struct device_attribute *attr, char *buf)
 232 {
 233         struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
 234         ssize_t len;
 235
 236         mutex_lock(&trigger_data->lock);
 237         len = sprintf(buf, "%s\n", trigger_data->device_name);
 238         mutex_unlock(&trigger_data->lock);
 239
 240         return len;
 241 }
 242
 243 static int set_device_name(struct led_netdev_data *trigger_data,
 244                            const char *name, size_t size)
 245 {
 246         if (size >= IFNAMSIZ)
 247                 return -EINVAL;
 248
 249         cancel_delayed_work_sync(&trigger_data->work);
 250
 251         mutex_lock(&trigger_data->lock);
 252
 253         if (trigger_data->net_dev) {
 254                 dev_put(trigger_data->net_dev);
 255                 trigger_data->net_dev = NULL;
 256         }
 257
 258         memcpy(trigger_data->device_name, name, size);
 259         trigger_data->device_name[size] = 0;
 260         if (size > 0 && trigger_data->device_name[size - 1] == '\n')
 261                 trigger_data->device_name[size - 1] = 0;
 262
 263         if (trigger_data->device_name[0] != 0)
 264                 trigger_data->net_dev =
 265                     dev_get_by_name(&init_net, trigger_data->device_name);
 266
 267         trigger_data->carrier_link_up = false;
 268         trigger_data->link_speed = SPEED_UNKNOWN;
 269         trigger_data->duplex = DUPLEX_UNKNOWN;
 270         if (trigger_data->net_dev != NULL) {
 271                 rtnl_lock();
 272                 get_device_state(trigger_data);
 273                 rtnl_unlock();
 274         }
 275
 276         trigger_data->last_activity = 0;
 277
 278         set_baseline_state(trigger_data);
 279         mutex_unlock(&trigger_data->lock);
 280
 281         return 0;
 282 }
 283
 284 static ssize_t device_name_store(struct device *dev,
 285                                  struct device_attribute *attr, const char *buf,
 286                                  size_t size)
 287 {
 288         struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
 289         int ret;
 290
 291         ret = set_device_name(trigger_data, buf, size);
 292
 293         if (ret < 0)
 294                 return ret;
 295         return size;
 296 }
 297
 298 static DEVICE_ATTR_RW(device_name);
 299
 300 static ssize_t netdev_led_attr_show(struct device *dev, char *buf,
 301                                     enum led_trigger_netdev_modes attr)
 302 {
 303         struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
 304         int bit;
 305
 306         switch (attr) {
 307         case TRIGGER_NETDEV_LINK:
 308         case TRIGGER_NETDEV_LINK_10:
 309         case TRIGGER_NETDEV_LINK_100:
 310         case TRIGGER_NETDEV_LINK_1000:
 311         case TRIGGER_NETDEV_LINK_2500:
 312         case TRIGGER_NETDEV_LINK_5000:
 313         case TRIGGER_NETDEV_LINK_10000:
 314         case TRIGGER_NETDEV_HALF_DUPLEX:
 315         case TRIGGER_NETDEV_FULL_DUPLEX:
 316         case TRIGGER_NETDEV_TX:
 317         case TRIGGER_NETDEV_RX:
 318                 bit = attr;
 319                 break;
 320         default:
 321                 return -EINVAL;
 322         }
 323
 324         return sprintf(buf, "%u\n", test_bit(bit, &trigger_data->mode));
 325 }
 326
 327 static ssize_t netdev_led_attr_store(struct device *dev, const char *buf,
 328                                      size_t size, enum led_trigger_netdev_modes attr)
 329 {
 330         struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
 331         struct led_classdev *led_cdev = trigger_data->led_cdev;
 332         unsigned long state, mode = trigger_data->mode;
 333         int ret;
 334         int bit;
 335
 336         ret = kstrtoul(buf, 0, &state);
 337         if (ret)
 338                 return ret;
 339
 340         switch (attr) {
 341         case TRIGGER_NETDEV_LINK:
 342         case TRIGGER_NETDEV_LINK_10:
 343         case TRIGGER_NETDEV_LINK_100:
 344         case TRIGGER_NETDEV_LINK_1000:
 345         case TRIGGER_NETDEV_LINK_2500:
 346         case TRIGGER_NETDEV_LINK_5000:
 347         case TRIGGER_NETDEV_LINK_10000:
 348         case TRIGGER_NETDEV_HALF_DUPLEX:
 349         case TRIGGER_NETDEV_FULL_DUPLEX:
 350         case TRIGGER_NETDEV_TX:
 351         case TRIGGER_NETDEV_RX:
 352                 bit = attr;
 353                 break;
 354         default:
 355                 return -EINVAL;
 356         }
 357
 358         if (state)
 359                 set_bit(bit, &mode);
 360         else
 361                 clear_bit(bit, &mode);
 362
 363         if (test_bit(TRIGGER_NETDEV_LINK, &mode) &&
 364             (test_bit(TRIGGER_NETDEV_LINK_10, &mode) ||
 365              test_bit(TRIGGER_NETDEV_LINK_100, &mode) ||
 366              test_bit(TRIGGER_NETDEV_LINK_1000, &mode) ||
 367              test_bit(TRIGGER_NETDEV_LINK_2500, &mode) ||
 368              test_bit(TRIGGER_NETDEV_LINK_5000, &mode) ||
 369              test_bit(TRIGGER_NETDEV_LINK_10000, &mode)))
 370                 return -EINVAL;
 371
 372         cancel_delayed_work_sync(&trigger_data->work);
 373
 374         trigger_data->mode = mode;
 375         trigger_data->hw_control = can_hw_control(trigger_data);
 376
 377         if (!led_cdev->brightness_set && !led_cdev->brightness_set_blocking &&
 378             !trigger_data->hw_control)
 379                 return -EOPNOTSUPP;
 380
 381         set_baseline_state(trigger_data);
 382
 383         return size;
 384 }
 385
 386 #define DEFINE_NETDEV_TRIGGER(trigger_name, trigger) \
 387         static ssize_t trigger_name##_show(struct device *dev, \
 388                 struct device_attribute *attr, char *buf) \
 389         { \
 390                 return netdev_led_attr_show(dev, buf, trigger); \
 391         } \
 392         static ssize_t trigger_name##_store(struct device *dev, \
 393                 struct device_attribute *attr, const char *buf, size_t size) \
 394         { \
 395                 return netdev_led_attr_store(dev, buf, size, trigger); \
 396         } \
 397         static DEVICE_ATTR_RW(trigger_name)
 398
 399 DEFINE_NETDEV_TRIGGER(link, TRIGGER_NETDEV_LINK);
 400 DEFINE_NETDEV_TRIGGER(link_10, TRIGGER_NETDEV_LINK_10);
 401 DEFINE_NETDEV_TRIGGER(link_100, TRIGGER_NETDEV_LINK_100);
 402 DEFINE_NETDEV_TRIGGER(link_1000, TRIGGER_NETDEV_LINK_1000);
 403 DEFINE_NETDEV_TRIGGER(link_2500, TRIGGER_NETDEV_LINK_2500);
 404 DEFINE_NETDEV_TRIGGER(link_5000, TRIGGER_NETDEV_LINK_5000);
 405 DEFINE_NETDEV_TRIGGER(link_10000, TRIGGER_NETDEV_LINK_10000);
 406 DEFINE_NETDEV_TRIGGER(half_duplex, TRIGGER_NETDEV_HALF_DUPLEX);
 407 DEFINE_NETDEV_TRIGGER(full_duplex, TRIGGER_NETDEV_FULL_DUPLEX);
 408 DEFINE_NETDEV_TRIGGER(tx, TRIGGER_NETDEV_TX);
 409 DEFINE_NETDEV_TRIGGER(rx, TRIGGER_NETDEV_RX);
 410
 411 static ssize_t interval_show(struct device *dev,
 412                              struct device_attribute *attr, char *buf)
 413 {
 414         struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
 415
 416         return sprintf(buf, "%u\n",
 417                        jiffies_to_msecs(atomic_read(&trigger_data->interval)));
 418 }
 419
 420 static ssize_t interval_store(struct device *dev,
 421                               struct device_attribute *attr, const char *buf,
 422                               size_t size)
 423 {
 424         struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
 425         unsigned long value;
 426         int ret;
 427
 428         if (trigger_data->hw_control)
 429                 return -EINVAL;
 430
 431         ret = kstrtoul(buf, 0, &value);
 432         if (ret)
 433                 return ret;
 434
 435         /* impose some basic bounds on the timer interval */
 436         if (value >= 5 && value <= 10000) {
 437                 cancel_delayed_work_sync(&trigger_data->work);
 438
 439                 atomic_set(&trigger_data->interval, msecs_to_jiffies(value));
 440                 set_baseline_state(trigger_data);       /* resets timer */
 441         }
 442
 443         return size;
 444 }
 445
 446 static DEVICE_ATTR_RW(interval);
 447
 448 static ssize_t offloaded_show(struct device *dev,
 449                               struct device_attribute *attr, char *buf)
 450 {
 451         struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
 452
 453         return sprintf(buf, "%d\n", trigger_data->hw_control);
 454 }
 455
 456 static DEVICE_ATTR_RO(offloaded);
 457
 458 static struct attribute *netdev_trig_attrs[] = {
 459         &dev_attr_device_name.attr,
 460         &dev_attr_link.attr,
 461         &dev_attr_link_10.attr,
 462         &dev_attr_link_100.attr,
 463         &dev_attr_link_1000.attr,
 464         &dev_attr_link_2500.attr,
 465         &dev_attr_link_5000.attr,
 466         &dev_attr_link_10000.attr,
 467         &dev_attr_full_duplex.attr,
 468         &dev_attr_half_duplex.attr,
 469         &dev_attr_rx.attr,
 470         &dev_attr_tx.attr,
 471         &dev_attr_interval.attr,
 472         &dev_attr_offloaded.attr,
 473         NULL
 474 };
 475 ATTRIBUTE_GROUPS(netdev_trig);
 476
 477 static int netdev_trig_notify(struct notifier_block *nb,
 478                               unsigned long evt, void *dv)
 479 {
 480         struct net_device *dev =
 481                 netdev_notifier_info_to_dev((struct netdev_notifier_info *)dv);
 482         struct led_netdev_data *trigger_data =
 483                 container_of(nb, struct led_netdev_data, notifier);
 484
 485         if (evt != NETDEV_UP && evt != NETDEV_DOWN && evt != NETDEV_CHANGE
 486             && evt != NETDEV_REGISTER && evt != NETDEV_UNREGISTER
 487             && evt != NETDEV_CHANGENAME)
 488                 return NOTIFY_DONE;
 489
 490         if (!(dev == trigger_data->net_dev ||
 491               (evt == NETDEV_CHANGENAME && !strcmp(dev->name, trigger_data->device_name)) ||
 492               (evt == NETDEV_REGISTER && !strcmp(dev->name, trigger_data->device_name))))
 493                 return NOTIFY_DONE;
 494
 495         cancel_delayed_work_sync(&trigger_data->work);
 496
 497         mutex_lock(&trigger_data->lock);
 498
 499         trigger_data->carrier_link_up = false;
 500         trigger_data->link_speed = SPEED_UNKNOWN;
 501         trigger_data->duplex = DUPLEX_UNKNOWN;
 502         switch (evt) {
 503         case NETDEV_CHANGENAME:
 504                 get_device_state(trigger_data);
 505                 fallthrough;
 506         case NETDEV_REGISTER:
 507                 dev_put(trigger_data->net_dev);
 508                 dev_hold(dev);
 509                 trigger_data->net_dev = dev;
 510                 break;
 511         case NETDEV_UNREGISTER:
 512                 dev_put(trigger_data->net_dev);
 513                 trigger_data->net_dev = NULL;
 514                 break;
 515         case NETDEV_UP:
 516         case NETDEV_CHANGE:
 517                 get_device_state(trigger_data);
 518                 break;
 519         }
 520
 521         set_baseline_state(trigger_data);
 522
 523         mutex_unlock(&trigger_data->lock);
 524
 525         return NOTIFY_DONE;
 526 }
 527
 528 /* here's the real work! */
 529 static void netdev_trig_work(struct work_struct *work)
 530 {
 531         struct led_netdev_data *trigger_data =
 532                 container_of(work, struct led_netdev_data, work.work);
 533         struct rtnl_link_stats64 *dev_stats;
 534         unsigned int new_activity;
 535         struct rtnl_link_stats64 temp;
 536         unsigned long interval;
 537         int invert;
 538
 539         /* If we dont have a device, insure we are off */
 540         if (!trigger_data->net_dev) {
 541                 led_set_brightness(trigger_data->led_cdev, LED_OFF);
 542                 return;
 543         }
 544
 545         /* If we are not looking for RX/TX then return  */
 546         if (!test_bit(TRIGGER_NETDEV_TX, &trigger_data->mode) &&
 547             !test_bit(TRIGGER_NETDEV_RX, &trigger_data->mode))
 548                 return;
 549
 550         dev_stats = dev_get_stats(trigger_data->net_dev, &temp);
 551         new_activity =
 552             (test_bit(TRIGGER_NETDEV_TX, &trigger_data->mode) ?
 553                 dev_stats->tx_packets : 0) +
 554             (test_bit(TRIGGER_NETDEV_RX, &trigger_data->mode) ?
 555                 dev_stats->rx_packets : 0);
 556
 557         if (trigger_data->last_activity != new_activity) {
 558                 led_stop_software_blink(trigger_data->led_cdev);
 559
 560                 invert = test_bit(TRIGGER_NETDEV_LINK, &trigger_data->mode) ||
 561                          test_bit(TRIGGER_NETDEV_LINK_10, &trigger_data->mode) ||
 562                          test_bit(TRIGGER_NETDEV_LINK_100, &trigger_data->mode) ||
 563                          test_bit(TRIGGER_NETDEV_LINK_1000, &trigger_data->mode) ||
 564                          test_bit(TRIGGER_NETDEV_LINK_2500, &trigger_data->mode) ||
 565                          test_bit(TRIGGER_NETDEV_LINK_5000, &trigger_data->mode) ||
 566                          test_bit(TRIGGER_NETDEV_LINK_10000, &trigger_data->mode) ||
 567                          test_bit(TRIGGER_NETDEV_HALF_DUPLEX, &trigger_data->mode) ||
 568                          test_bit(TRIGGER_NETDEV_FULL_DUPLEX, &trigger_data->mode);
 569                 interval = jiffies_to_msecs(
 570                                 atomic_read(&trigger_data->interval));
 571                 /* base state is ON (link present) */
 572                 led_blink_set_oneshot(trigger_data->led_cdev,
 573                                       &interval,
 574                                       &interval,
 575                                       invert);
 576                 trigger_data->last_activity = new_activity;
 577         }
 578
 579         schedule_delayed_work(&trigger_data->work,
 580                         (atomic_read(&trigger_data->interval)*2));
 581 }
 582
 583 static int netdev_trig_activate(struct led_classdev *led_cdev)
 584 {
 585         struct led_netdev_data *trigger_data;
 586         unsigned long mode = 0;
 587         struct device *dev;
 588         int rc;
 589
 590         trigger_data = kzalloc(sizeof(struct led_netdev_data), GFP_KERNEL);
 591         if (!trigger_data)
 592                 return -ENOMEM;
 593
 594         mutex_init(&trigger_data->lock);
 595
 596         trigger_data->notifier.notifier_call = netdev_trig_notify;
 597         trigger_data->notifier.priority = 10;
 598
 599         INIT_DELAYED_WORK(&trigger_data->work, netdev_trig_work);
 600
 601         trigger_data->led_cdev = led_cdev;
 602         trigger_data->net_dev = NULL;
 603         trigger_data->device_name[0] = 0;
 604
 605         trigger_data->mode = 0;
 606         atomic_set(&trigger_data->interval, msecs_to_jiffies(NETDEV_LED_DEFAULT_INTERVAL));
 607         trigger_data->last_activity = 0;
 608
 609         /* Check if hw control is active by default on the LED.
 610          * Init already enabled mode in hw control.
 611          */
 612         if (supports_hw_control(led_cdev)) {
 613                 dev = led_cdev->hw_control_get_device(led_cdev);
 614                 if (dev) {
 615                         const char *name = dev_name(dev);
 616
 617                         set_device_name(trigger_data, name, strlen(name));
 618                         trigger_data->hw_control = true;
 619
 620                         rc = led_cdev->hw_control_get(led_cdev, &mode);
 621                         if (!rc)
 622                                 trigger_data->mode = mode;
 623                 }
 624         }
 625
 626         led_set_trigger_data(led_cdev, trigger_data);
 627
 628         rc = register_netdevice_notifier(&trigger_data->notifier);
 629         if (rc)
 630                 kfree(trigger_data);
 631
 632         return rc;
 633 }
 634
 635 static void netdev_trig_deactivate(struct led_classdev *led_cdev)
 636 {
 637         struct led_netdev_data *trigger_data = led_get_trigger_data(led_cdev);
 638
 639         unregister_netdevice_notifier(&trigger_data->notifier);
 640
 641         cancel_delayed_work_sync(&trigger_data->work);
 642
 643         led_set_brightness(led_cdev, LED_OFF);
 644
 645         dev_put(trigger_data->net_dev);
 646
 647         kfree(trigger_data);
 648 }
 649
 650 static struct led_trigger netdev_led_trigger = {
 651         .name = "netdev",
 652         .activate = netdev_trig_activate,
 653         .deactivate = netdev_trig_deactivate,
 654         .groups = netdev_trig_groups,
 655 };
 656
 657 module_led_trigger(netdev_led_trigger);
 658
 659 MODULE_AUTHOR("Ben Whitten <[email protected]>");
 660 MODULE_AUTHOR("Oliver Jowett <[email protected]>");
 661 MODULE_DESCRIPTION("Netdev LED trigger");
 662 MODULE_LICENSE("GPL v2");