xref: /linux/drivers/leds/trigger/ledtrig-netdev.c (revision 021bc4b9)
1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright 2017 Ben Whitten <ben.whitten@gmail.com>
3 // Copyright 2007 Oliver Jowett <oliver@opencloud.com>
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 <rpurdie@openedhand.com>
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 	/*
252 	 * Take RTNL lock before trigger_data lock to prevent potential
253 	 * deadlock with netdev notifier registration.
254 	 */
255 	rtnl_lock();
256 	mutex_lock(&trigger_data->lock);
257 
258 	if (trigger_data->net_dev) {
259 		dev_put(trigger_data->net_dev);
260 		trigger_data->net_dev = NULL;
261 	}
262 
263 	memcpy(trigger_data->device_name, name, size);
264 	trigger_data->device_name[size] = 0;
265 	if (size > 0 && trigger_data->device_name[size - 1] == '\n')
266 		trigger_data->device_name[size - 1] = 0;
267 
268 	if (trigger_data->device_name[0] != 0)
269 		trigger_data->net_dev =
270 		    dev_get_by_name(&init_net, trigger_data->device_name);
271 
272 	trigger_data->carrier_link_up = false;
273 	trigger_data->link_speed = SPEED_UNKNOWN;
274 	trigger_data->duplex = DUPLEX_UNKNOWN;
275 	if (trigger_data->net_dev)
276 		get_device_state(trigger_data);
277 
278 	trigger_data->last_activity = 0;
279 
280 	set_baseline_state(trigger_data);
281 	mutex_unlock(&trigger_data->lock);
282 	rtnl_unlock();
283 
284 	return 0;
285 }
286 
287 static ssize_t device_name_store(struct device *dev,
288 				 struct device_attribute *attr, const char *buf,
289 				 size_t size)
290 {
291 	struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
292 	int ret;
293 
294 	ret = set_device_name(trigger_data, buf, size);
295 
296 	if (ret < 0)
297 		return ret;
298 	return size;
299 }
300 
301 static DEVICE_ATTR_RW(device_name);
302 
303 static ssize_t netdev_led_attr_show(struct device *dev, char *buf,
304 				    enum led_trigger_netdev_modes attr)
305 {
306 	struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
307 	int bit;
308 
309 	switch (attr) {
310 	case TRIGGER_NETDEV_LINK:
311 	case TRIGGER_NETDEV_LINK_10:
312 	case TRIGGER_NETDEV_LINK_100:
313 	case TRIGGER_NETDEV_LINK_1000:
314 	case TRIGGER_NETDEV_LINK_2500:
315 	case TRIGGER_NETDEV_LINK_5000:
316 	case TRIGGER_NETDEV_LINK_10000:
317 	case TRIGGER_NETDEV_HALF_DUPLEX:
318 	case TRIGGER_NETDEV_FULL_DUPLEX:
319 	case TRIGGER_NETDEV_TX:
320 	case TRIGGER_NETDEV_RX:
321 		bit = attr;
322 		break;
323 	default:
324 		return -EINVAL;
325 	}
326 
327 	return sprintf(buf, "%u\n", test_bit(bit, &trigger_data->mode));
328 }
329 
330 static ssize_t netdev_led_attr_store(struct device *dev, const char *buf,
331 				     size_t size, enum led_trigger_netdev_modes attr)
332 {
333 	struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
334 	struct led_classdev *led_cdev = trigger_data->led_cdev;
335 	unsigned long state, mode = trigger_data->mode;
336 	int ret;
337 	int bit;
338 
339 	ret = kstrtoul(buf, 0, &state);
340 	if (ret)
341 		return ret;
342 
343 	switch (attr) {
344 	case TRIGGER_NETDEV_LINK:
345 	case TRIGGER_NETDEV_LINK_10:
346 	case TRIGGER_NETDEV_LINK_100:
347 	case TRIGGER_NETDEV_LINK_1000:
348 	case TRIGGER_NETDEV_LINK_2500:
349 	case TRIGGER_NETDEV_LINK_5000:
350 	case TRIGGER_NETDEV_LINK_10000:
351 	case TRIGGER_NETDEV_HALF_DUPLEX:
352 	case TRIGGER_NETDEV_FULL_DUPLEX:
353 	case TRIGGER_NETDEV_TX:
354 	case TRIGGER_NETDEV_RX:
355 		bit = attr;
356 		break;
357 	default:
358 		return -EINVAL;
359 	}
360 
361 	if (state)
362 		set_bit(bit, &mode);
363 	else
364 		clear_bit(bit, &mode);
365 
366 	if (test_bit(TRIGGER_NETDEV_LINK, &mode) &&
367 	    (test_bit(TRIGGER_NETDEV_LINK_10, &mode) ||
368 	     test_bit(TRIGGER_NETDEV_LINK_100, &mode) ||
369 	     test_bit(TRIGGER_NETDEV_LINK_1000, &mode) ||
370 	     test_bit(TRIGGER_NETDEV_LINK_2500, &mode) ||
371 	     test_bit(TRIGGER_NETDEV_LINK_5000, &mode) ||
372 	     test_bit(TRIGGER_NETDEV_LINK_10000, &mode)))
373 		return -EINVAL;
374 
375 	cancel_delayed_work_sync(&trigger_data->work);
376 
377 	trigger_data->mode = mode;
378 	trigger_data->hw_control = can_hw_control(trigger_data);
379 
380 	if (!led_cdev->brightness_set && !led_cdev->brightness_set_blocking &&
381 	    !trigger_data->hw_control)
382 		return -EOPNOTSUPP;
383 
384 	set_baseline_state(trigger_data);
385 
386 	return size;
387 }
388 
389 #define DEFINE_NETDEV_TRIGGER(trigger_name, trigger) \
390 	static ssize_t trigger_name##_show(struct device *dev, \
391 		struct device_attribute *attr, char *buf) \
392 	{ \
393 		return netdev_led_attr_show(dev, buf, trigger); \
394 	} \
395 	static ssize_t trigger_name##_store(struct device *dev, \
396 		struct device_attribute *attr, const char *buf, size_t size) \
397 	{ \
398 		return netdev_led_attr_store(dev, buf, size, trigger); \
399 	} \
400 	static DEVICE_ATTR_RW(trigger_name)
401 
402 DEFINE_NETDEV_TRIGGER(link, TRIGGER_NETDEV_LINK);
403 DEFINE_NETDEV_TRIGGER(link_10, TRIGGER_NETDEV_LINK_10);
404 DEFINE_NETDEV_TRIGGER(link_100, TRIGGER_NETDEV_LINK_100);
405 DEFINE_NETDEV_TRIGGER(link_1000, TRIGGER_NETDEV_LINK_1000);
406 DEFINE_NETDEV_TRIGGER(link_2500, TRIGGER_NETDEV_LINK_2500);
407 DEFINE_NETDEV_TRIGGER(link_5000, TRIGGER_NETDEV_LINK_5000);
408 DEFINE_NETDEV_TRIGGER(link_10000, TRIGGER_NETDEV_LINK_10000);
409 DEFINE_NETDEV_TRIGGER(half_duplex, TRIGGER_NETDEV_HALF_DUPLEX);
410 DEFINE_NETDEV_TRIGGER(full_duplex, TRIGGER_NETDEV_FULL_DUPLEX);
411 DEFINE_NETDEV_TRIGGER(tx, TRIGGER_NETDEV_TX);
412 DEFINE_NETDEV_TRIGGER(rx, TRIGGER_NETDEV_RX);
413 
414 static ssize_t interval_show(struct device *dev,
415 			     struct device_attribute *attr, char *buf)
416 {
417 	struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
418 
419 	return sprintf(buf, "%u\n",
420 		       jiffies_to_msecs(atomic_read(&trigger_data->interval)));
421 }
422 
423 static ssize_t interval_store(struct device *dev,
424 			      struct device_attribute *attr, const char *buf,
425 			      size_t size)
426 {
427 	struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
428 	unsigned long value;
429 	int ret;
430 
431 	if (trigger_data->hw_control)
432 		return -EINVAL;
433 
434 	ret = kstrtoul(buf, 0, &value);
435 	if (ret)
436 		return ret;
437 
438 	/* impose some basic bounds on the timer interval */
439 	if (value >= 5 && value <= 10000) {
440 		cancel_delayed_work_sync(&trigger_data->work);
441 
442 		atomic_set(&trigger_data->interval, msecs_to_jiffies(value));
443 		set_baseline_state(trigger_data);	/* resets timer */
444 	}
445 
446 	return size;
447 }
448 
449 static DEVICE_ATTR_RW(interval);
450 
451 static ssize_t offloaded_show(struct device *dev,
452 			      struct device_attribute *attr, char *buf)
453 {
454 	struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
455 
456 	return sprintf(buf, "%d\n", trigger_data->hw_control);
457 }
458 
459 static DEVICE_ATTR_RO(offloaded);
460 
461 static struct attribute *netdev_trig_attrs[] = {
462 	&dev_attr_device_name.attr,
463 	&dev_attr_link.attr,
464 	&dev_attr_link_10.attr,
465 	&dev_attr_link_100.attr,
466 	&dev_attr_link_1000.attr,
467 	&dev_attr_link_2500.attr,
468 	&dev_attr_link_5000.attr,
469 	&dev_attr_link_10000.attr,
470 	&dev_attr_full_duplex.attr,
471 	&dev_attr_half_duplex.attr,
472 	&dev_attr_rx.attr,
473 	&dev_attr_tx.attr,
474 	&dev_attr_interval.attr,
475 	&dev_attr_offloaded.attr,
476 	NULL
477 };
478 ATTRIBUTE_GROUPS(netdev_trig);
479 
480 static int netdev_trig_notify(struct notifier_block *nb,
481 			      unsigned long evt, void *dv)
482 {
483 	struct net_device *dev =
484 		netdev_notifier_info_to_dev((struct netdev_notifier_info *)dv);
485 	struct led_netdev_data *trigger_data =
486 		container_of(nb, struct led_netdev_data, notifier);
487 
488 	if (evt != NETDEV_UP && evt != NETDEV_DOWN && evt != NETDEV_CHANGE
489 	    && evt != NETDEV_REGISTER && evt != NETDEV_UNREGISTER
490 	    && evt != NETDEV_CHANGENAME)
491 		return NOTIFY_DONE;
492 
493 	if (!(dev == trigger_data->net_dev ||
494 	      (evt == NETDEV_CHANGENAME && !strcmp(dev->name, trigger_data->device_name)) ||
495 	      (evt == NETDEV_REGISTER && !strcmp(dev->name, trigger_data->device_name))))
496 		return NOTIFY_DONE;
497 
498 	cancel_delayed_work_sync(&trigger_data->work);
499 
500 	mutex_lock(&trigger_data->lock);
501 
502 	trigger_data->carrier_link_up = false;
503 	trigger_data->link_speed = SPEED_UNKNOWN;
504 	trigger_data->duplex = DUPLEX_UNKNOWN;
505 	switch (evt) {
506 	case NETDEV_CHANGENAME:
507 		get_device_state(trigger_data);
508 		fallthrough;
509 	case NETDEV_REGISTER:
510 		dev_put(trigger_data->net_dev);
511 		dev_hold(dev);
512 		trigger_data->net_dev = dev;
513 		break;
514 	case NETDEV_UNREGISTER:
515 		dev_put(trigger_data->net_dev);
516 		trigger_data->net_dev = NULL;
517 		break;
518 	case NETDEV_UP:
519 	case NETDEV_CHANGE:
520 		get_device_state(trigger_data);
521 		break;
522 	}
523 
524 	set_baseline_state(trigger_data);
525 
526 	mutex_unlock(&trigger_data->lock);
527 
528 	return NOTIFY_DONE;
529 }
530 
531 /* here's the real work! */
532 static void netdev_trig_work(struct work_struct *work)
533 {
534 	struct led_netdev_data *trigger_data =
535 		container_of(work, struct led_netdev_data, work.work);
536 	struct rtnl_link_stats64 *dev_stats;
537 	unsigned int new_activity;
538 	struct rtnl_link_stats64 temp;
539 	unsigned long interval;
540 	int invert;
541 
542 	/* If we dont have a device, insure we are off */
543 	if (!trigger_data->net_dev) {
544 		led_set_brightness(trigger_data->led_cdev, LED_OFF);
545 		return;
546 	}
547 
548 	/* If we are not looking for RX/TX then return  */
549 	if (!test_bit(TRIGGER_NETDEV_TX, &trigger_data->mode) &&
550 	    !test_bit(TRIGGER_NETDEV_RX, &trigger_data->mode))
551 		return;
552 
553 	dev_stats = dev_get_stats(trigger_data->net_dev, &temp);
554 	new_activity =
555 	    (test_bit(TRIGGER_NETDEV_TX, &trigger_data->mode) ?
556 		dev_stats->tx_packets : 0) +
557 	    (test_bit(TRIGGER_NETDEV_RX, &trigger_data->mode) ?
558 		dev_stats->rx_packets : 0);
559 
560 	if (trigger_data->last_activity != new_activity) {
561 		led_stop_software_blink(trigger_data->led_cdev);
562 
563 		invert = test_bit(TRIGGER_NETDEV_LINK, &trigger_data->mode) ||
564 			 test_bit(TRIGGER_NETDEV_LINK_10, &trigger_data->mode) ||
565 			 test_bit(TRIGGER_NETDEV_LINK_100, &trigger_data->mode) ||
566 			 test_bit(TRIGGER_NETDEV_LINK_1000, &trigger_data->mode) ||
567 			 test_bit(TRIGGER_NETDEV_LINK_2500, &trigger_data->mode) ||
568 			 test_bit(TRIGGER_NETDEV_LINK_5000, &trigger_data->mode) ||
569 			 test_bit(TRIGGER_NETDEV_LINK_10000, &trigger_data->mode) ||
570 			 test_bit(TRIGGER_NETDEV_HALF_DUPLEX, &trigger_data->mode) ||
571 			 test_bit(TRIGGER_NETDEV_FULL_DUPLEX, &trigger_data->mode);
572 		interval = jiffies_to_msecs(
573 				atomic_read(&trigger_data->interval));
574 		/* base state is ON (link present) */
575 		led_blink_set_oneshot(trigger_data->led_cdev,
576 				      &interval,
577 				      &interval,
578 				      invert);
579 		trigger_data->last_activity = new_activity;
580 	}
581 
582 	schedule_delayed_work(&trigger_data->work,
583 			(atomic_read(&trigger_data->interval)*2));
584 }
585 
586 static int netdev_trig_activate(struct led_classdev *led_cdev)
587 {
588 	struct led_netdev_data *trigger_data;
589 	unsigned long mode = 0;
590 	struct device *dev;
591 	int rc;
592 
593 	trigger_data = kzalloc(sizeof(struct led_netdev_data), GFP_KERNEL);
594 	if (!trigger_data)
595 		return -ENOMEM;
596 
597 	mutex_init(&trigger_data->lock);
598 
599 	trigger_data->notifier.notifier_call = netdev_trig_notify;
600 	trigger_data->notifier.priority = 10;
601 
602 	INIT_DELAYED_WORK(&trigger_data->work, netdev_trig_work);
603 
604 	trigger_data->led_cdev = led_cdev;
605 	trigger_data->net_dev = NULL;
606 	trigger_data->device_name[0] = 0;
607 
608 	trigger_data->mode = 0;
609 	atomic_set(&trigger_data->interval, msecs_to_jiffies(NETDEV_LED_DEFAULT_INTERVAL));
610 	trigger_data->last_activity = 0;
611 
612 	/* Check if hw control is active by default on the LED.
613 	 * Init already enabled mode in hw control.
614 	 */
615 	if (supports_hw_control(led_cdev)) {
616 		dev = led_cdev->hw_control_get_device(led_cdev);
617 		if (dev) {
618 			const char *name = dev_name(dev);
619 
620 			set_device_name(trigger_data, name, strlen(name));
621 			trigger_data->hw_control = true;
622 
623 			rc = led_cdev->hw_control_get(led_cdev, &mode);
624 			if (!rc)
625 				trigger_data->mode = mode;
626 		}
627 	}
628 
629 	led_set_trigger_data(led_cdev, trigger_data);
630 
631 	rc = register_netdevice_notifier(&trigger_data->notifier);
632 	if (rc)
633 		kfree(trigger_data);
634 
635 	return rc;
636 }
637 
638 static void netdev_trig_deactivate(struct led_classdev *led_cdev)
639 {
640 	struct led_netdev_data *trigger_data = led_get_trigger_data(led_cdev);
641 
642 	unregister_netdevice_notifier(&trigger_data->notifier);
643 
644 	cancel_delayed_work_sync(&trigger_data->work);
645 
646 	led_set_brightness(led_cdev, LED_OFF);
647 
648 	dev_put(trigger_data->net_dev);
649 
650 	kfree(trigger_data);
651 }
652 
653 static struct led_trigger netdev_led_trigger = {
654 	.name = "netdev",
655 	.activate = netdev_trig_activate,
656 	.deactivate = netdev_trig_deactivate,
657 	.groups = netdev_trig_groups,
658 };
659 
660 module_led_trigger(netdev_led_trigger);
661 
662 MODULE_AUTHOR("Ben Whitten <ben.whitten@gmail.com>");
663 MODULE_AUTHOR("Oliver Jowett <oliver@opencloud.com>");
664 MODULE_DESCRIPTION("Netdev LED trigger");
665 MODULE_LICENSE("GPL v2");
666