xref: /linux/drivers/leds/trigger/ledtrig-netdev.c (revision 1c5b72e60c56f17a54f627bde290bd2bf214ce16)
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/linkmode.h>
22 #include <linux/list.h>
23 #include <linux/module.h>
24 #include <linux/netdevice.h>
25 #include <linux/mutex.h>
26 #include <linux/phy.h>
27 #include <linux/rtnetlink.h>
28 #include <linux/timer.h>
29 #include "../leds.h"
30 
31 #define NETDEV_LED_DEFAULT_INTERVAL	50
32 
33 /*
34  * Configurable sysfs attributes:
35  *
36  * device_name - network device name to monitor
37  * interval - duration of LED blink, in milliseconds
38  * link -  LED's normal state reflects whether the link is up
39  *         (has carrier) or not
40  * tx -  LED blinks on transmitted data
41  * rx -  LED blinks on receive data
42  *
43  * Note: If the user selects a mode that is not supported by hw, default
44  * behavior is to fall back to software control of the LED. However not every
45  * hw supports software control. LED callbacks brightness_set() and
46  * brightness_set_blocking() are NULL in this case. hw_control_is_supported()
47  * should use available means supported by hw to inform the user that selected
48  * mode isn't supported by hw. This could be switching off the LED or any
49  * hw blink mode. If software control fallback isn't possible, we return
50  * -EOPNOTSUPP to the user, but still store the selected mode. This is needed
51  * in case an intermediate unsupported mode is necessary to switch from one
52  * supported mode to another.
53  */
54 
55 struct led_netdev_data {
56 	struct mutex lock;
57 
58 	struct delayed_work work;
59 	struct notifier_block notifier;
60 
61 	struct led_classdev *led_cdev;
62 	struct net_device *net_dev;
63 
64 	char device_name[IFNAMSIZ];
65 	atomic_t interval;
66 	unsigned int last_activity;
67 
68 	unsigned long mode;
69 	int link_speed;
70 	__ETHTOOL_DECLARE_LINK_MODE_MASK(supported_link_modes);
71 	u8 duplex;
72 
73 	bool carrier_link_up;
74 	bool hw_control;
75 };
76 
77 static const struct attribute_group netdev_trig_link_speed_attrs_group;
78 
79 static void set_baseline_state(struct led_netdev_data *trigger_data)
80 {
81 	int current_brightness;
82 	struct led_classdev *led_cdev = trigger_data->led_cdev;
83 
84 	/* Already validated, hw control is possible with the requested mode */
85 	if (trigger_data->hw_control) {
86 		led_cdev->hw_control_set(led_cdev, trigger_data->mode);
87 
88 		return;
89 	}
90 
91 	current_brightness = led_cdev->brightness;
92 	if (current_brightness)
93 		led_cdev->blink_brightness = current_brightness;
94 	if (!led_cdev->blink_brightness)
95 		led_cdev->blink_brightness = led_cdev->max_brightness;
96 
97 	if (!trigger_data->carrier_link_up) {
98 		led_set_brightness(led_cdev, LED_OFF);
99 	} else {
100 		bool blink_on = false;
101 
102 		if (test_bit(TRIGGER_NETDEV_LINK, &trigger_data->mode))
103 			blink_on = true;
104 
105 		if (test_bit(TRIGGER_NETDEV_LINK_10, &trigger_data->mode) &&
106 		    trigger_data->link_speed == SPEED_10)
107 			blink_on = true;
108 
109 		if (test_bit(TRIGGER_NETDEV_LINK_100, &trigger_data->mode) &&
110 		    trigger_data->link_speed == SPEED_100)
111 			blink_on = true;
112 
113 		if (test_bit(TRIGGER_NETDEV_LINK_1000, &trigger_data->mode) &&
114 		    trigger_data->link_speed == SPEED_1000)
115 			blink_on = true;
116 
117 		if (test_bit(TRIGGER_NETDEV_LINK_2500, &trigger_data->mode) &&
118 		    trigger_data->link_speed == SPEED_2500)
119 			blink_on = true;
120 
121 		if (test_bit(TRIGGER_NETDEV_LINK_5000, &trigger_data->mode) &&
122 		    trigger_data->link_speed == SPEED_5000)
123 			blink_on = true;
124 
125 		if (test_bit(TRIGGER_NETDEV_LINK_10000, &trigger_data->mode) &&
126 		    trigger_data->link_speed == SPEED_10000)
127 			blink_on = true;
128 
129 		if (test_bit(TRIGGER_NETDEV_HALF_DUPLEX, &trigger_data->mode) &&
130 		    trigger_data->duplex == DUPLEX_HALF)
131 			blink_on = true;
132 
133 		if (test_bit(TRIGGER_NETDEV_FULL_DUPLEX, &trigger_data->mode) &&
134 		    trigger_data->duplex == DUPLEX_FULL)
135 			blink_on = true;
136 
137 		if (blink_on)
138 			led_set_brightness(led_cdev,
139 					   led_cdev->blink_brightness);
140 		else
141 			led_set_brightness(led_cdev, LED_OFF);
142 
143 		/* If we are looking for RX/TX start periodically
144 		 * checking stats
145 		 */
146 		if (test_bit(TRIGGER_NETDEV_TX, &trigger_data->mode) ||
147 		    test_bit(TRIGGER_NETDEV_RX, &trigger_data->mode))
148 			schedule_delayed_work(&trigger_data->work, 0);
149 	}
150 }
151 
152 static bool supports_hw_control(struct led_classdev *led_cdev)
153 {
154 	if (!led_cdev->hw_control_get || !led_cdev->hw_control_set ||
155 	    !led_cdev->hw_control_is_supported)
156 		return false;
157 
158 	return !strcmp(led_cdev->hw_control_trigger, led_cdev->trigger->name);
159 }
160 
161 /*
162  * Validate the configured netdev is the same as the one associated with
163  * the LED driver in hw control.
164  */
165 static bool validate_net_dev(struct led_classdev *led_cdev,
166 			     struct net_device *net_dev)
167 {
168 	struct device *dev = led_cdev->hw_control_get_device(led_cdev);
169 	struct net_device *ndev;
170 
171 	if (!dev)
172 		return false;
173 
174 	ndev = to_net_dev(dev);
175 
176 	return ndev == net_dev;
177 }
178 
179 static bool can_hw_control(struct led_netdev_data *trigger_data)
180 {
181 	unsigned long default_interval = msecs_to_jiffies(NETDEV_LED_DEFAULT_INTERVAL);
182 	unsigned int interval = atomic_read(&trigger_data->interval);
183 	struct led_classdev *led_cdev = trigger_data->led_cdev;
184 	int ret;
185 
186 	if (!supports_hw_control(led_cdev))
187 		return false;
188 
189 	/*
190 	 * Interval must be set to the default
191 	 * value. Any different value is rejected if in hw
192 	 * control.
193 	 */
194 	if (interval != default_interval)
195 		return false;
196 
197 	/*
198 	 * net_dev must be set with hw control, otherwise no
199 	 * blinking can be happening and there is nothing to
200 	 * offloaded. Additionally, for hw control to be
201 	 * valid, the configured netdev must be the same as
202 	 * netdev associated to the LED.
203 	 */
204 	if (!validate_net_dev(led_cdev, trigger_data->net_dev))
205 		return false;
206 
207 	/* Check if the requested mode is supported */
208 	ret = led_cdev->hw_control_is_supported(led_cdev, trigger_data->mode);
209 	/* Fall back to software blinking if not supported */
210 	if (ret == -EOPNOTSUPP)
211 		return false;
212 	if (ret) {
213 		dev_warn(led_cdev->dev,
214 			 "Current mode check failed with error %d\n", ret);
215 		return false;
216 	}
217 
218 	return true;
219 }
220 
221 static void get_device_state(struct led_netdev_data *trigger_data)
222 {
223 	struct ethtool_link_ksettings cmd;
224 
225 	trigger_data->carrier_link_up = netif_carrier_ok(trigger_data->net_dev);
226 
227 	if (__ethtool_get_link_ksettings(trigger_data->net_dev, &cmd))
228 		return;
229 
230 	if (trigger_data->carrier_link_up) {
231 		trigger_data->link_speed = cmd.base.speed;
232 		trigger_data->duplex = cmd.base.duplex;
233 	}
234 
235 	/*
236 	 * Have a local copy of the link speed supported to avoid rtnl lock every time
237 	 * modes are refreshed on any change event
238 	 */
239 	linkmode_copy(trigger_data->supported_link_modes, cmd.link_modes.supported);
240 }
241 
242 static ssize_t device_name_show(struct device *dev,
243 				struct device_attribute *attr, char *buf)
244 {
245 	struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
246 	ssize_t len;
247 
248 	mutex_lock(&trigger_data->lock);
249 	len = sprintf(buf, "%s\n", trigger_data->device_name);
250 	mutex_unlock(&trigger_data->lock);
251 
252 	return len;
253 }
254 
255 static int set_device_name(struct led_netdev_data *trigger_data,
256 			   const char *name, size_t size)
257 {
258 	if (size >= IFNAMSIZ)
259 		return -EINVAL;
260 
261 	cancel_delayed_work_sync(&trigger_data->work);
262 
263 	/*
264 	 * Take RTNL lock before trigger_data lock to prevent potential
265 	 * deadlock with netdev notifier registration.
266 	 */
267 	rtnl_lock();
268 	mutex_lock(&trigger_data->lock);
269 
270 	if (trigger_data->net_dev) {
271 		dev_put(trigger_data->net_dev);
272 		trigger_data->net_dev = NULL;
273 	}
274 
275 	memcpy(trigger_data->device_name, name, size);
276 	trigger_data->device_name[size] = 0;
277 	if (size > 0 && trigger_data->device_name[size - 1] == '\n')
278 		trigger_data->device_name[size - 1] = 0;
279 
280 	if (trigger_data->device_name[0] != 0)
281 		trigger_data->net_dev =
282 		    dev_get_by_name(&init_net, trigger_data->device_name);
283 
284 	trigger_data->carrier_link_up = false;
285 	trigger_data->link_speed = SPEED_UNKNOWN;
286 	trigger_data->duplex = DUPLEX_UNKNOWN;
287 	if (trigger_data->net_dev)
288 		get_device_state(trigger_data);
289 
290 	trigger_data->last_activity = 0;
291 
292 	/* Skip if we're called from netdev_trig_activate() and hw_control is true */
293 	if (!trigger_data->hw_control || led_get_trigger_data(trigger_data->led_cdev))
294 		set_baseline_state(trigger_data);
295 
296 	mutex_unlock(&trigger_data->lock);
297 	rtnl_unlock();
298 
299 	return 0;
300 }
301 
302 static ssize_t device_name_store(struct device *dev,
303 				 struct device_attribute *attr, const char *buf,
304 				 size_t size)
305 {
306 	struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
307 	int ret;
308 
309 	ret = set_device_name(trigger_data, buf, size);
310 
311 	if (ret < 0)
312 		return ret;
313 
314 	/* Refresh link_speed visibility */
315 	sysfs_update_group(&dev->kobj, &netdev_trig_link_speed_attrs_group);
316 
317 	return size;
318 }
319 
320 static DEVICE_ATTR_RW(device_name);
321 
322 static ssize_t netdev_led_attr_show(struct device *dev, char *buf,
323 				    enum led_trigger_netdev_modes attr)
324 {
325 	struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
326 	int bit;
327 
328 	switch (attr) {
329 	case TRIGGER_NETDEV_LINK:
330 	case TRIGGER_NETDEV_LINK_10:
331 	case TRIGGER_NETDEV_LINK_100:
332 	case TRIGGER_NETDEV_LINK_1000:
333 	case TRIGGER_NETDEV_LINK_2500:
334 	case TRIGGER_NETDEV_LINK_5000:
335 	case TRIGGER_NETDEV_LINK_10000:
336 	case TRIGGER_NETDEV_HALF_DUPLEX:
337 	case TRIGGER_NETDEV_FULL_DUPLEX:
338 	case TRIGGER_NETDEV_TX:
339 	case TRIGGER_NETDEV_RX:
340 		bit = attr;
341 		break;
342 	default:
343 		return -EINVAL;
344 	}
345 
346 	return sprintf(buf, "%u\n", test_bit(bit, &trigger_data->mode));
347 }
348 
349 static ssize_t netdev_led_attr_store(struct device *dev, const char *buf,
350 				     size_t size, enum led_trigger_netdev_modes attr)
351 {
352 	struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
353 	struct led_classdev *led_cdev = trigger_data->led_cdev;
354 	unsigned long state, mode = trigger_data->mode;
355 	int ret;
356 	int bit;
357 
358 	ret = kstrtoul(buf, 0, &state);
359 	if (ret)
360 		return ret;
361 
362 	switch (attr) {
363 	case TRIGGER_NETDEV_LINK:
364 	case TRIGGER_NETDEV_LINK_10:
365 	case TRIGGER_NETDEV_LINK_100:
366 	case TRIGGER_NETDEV_LINK_1000:
367 	case TRIGGER_NETDEV_LINK_2500:
368 	case TRIGGER_NETDEV_LINK_5000:
369 	case TRIGGER_NETDEV_LINK_10000:
370 	case TRIGGER_NETDEV_HALF_DUPLEX:
371 	case TRIGGER_NETDEV_FULL_DUPLEX:
372 	case TRIGGER_NETDEV_TX:
373 	case TRIGGER_NETDEV_RX:
374 		bit = attr;
375 		break;
376 	default:
377 		return -EINVAL;
378 	}
379 
380 	if (state)
381 		set_bit(bit, &mode);
382 	else
383 		clear_bit(bit, &mode);
384 
385 	if (test_bit(TRIGGER_NETDEV_LINK, &mode) &&
386 	    (test_bit(TRIGGER_NETDEV_LINK_10, &mode) ||
387 	     test_bit(TRIGGER_NETDEV_LINK_100, &mode) ||
388 	     test_bit(TRIGGER_NETDEV_LINK_1000, &mode) ||
389 	     test_bit(TRIGGER_NETDEV_LINK_2500, &mode) ||
390 	     test_bit(TRIGGER_NETDEV_LINK_5000, &mode) ||
391 	     test_bit(TRIGGER_NETDEV_LINK_10000, &mode)))
392 		return -EINVAL;
393 
394 	cancel_delayed_work_sync(&trigger_data->work);
395 
396 	trigger_data->mode = mode;
397 	trigger_data->hw_control = can_hw_control(trigger_data);
398 
399 	if (!led_cdev->brightness_set && !led_cdev->brightness_set_blocking &&
400 	    !trigger_data->hw_control)
401 		return -EOPNOTSUPP;
402 
403 	set_baseline_state(trigger_data);
404 
405 	return size;
406 }
407 
408 #define DEFINE_NETDEV_TRIGGER(trigger_name, trigger) \
409 	static ssize_t trigger_name##_show(struct device *dev, \
410 		struct device_attribute *attr, char *buf) \
411 	{ \
412 		return netdev_led_attr_show(dev, buf, trigger); \
413 	} \
414 	static ssize_t trigger_name##_store(struct device *dev, \
415 		struct device_attribute *attr, const char *buf, size_t size) \
416 	{ \
417 		return netdev_led_attr_store(dev, buf, size, trigger); \
418 	} \
419 	static DEVICE_ATTR_RW(trigger_name)
420 
421 DEFINE_NETDEV_TRIGGER(link, TRIGGER_NETDEV_LINK);
422 DEFINE_NETDEV_TRIGGER(link_10, TRIGGER_NETDEV_LINK_10);
423 DEFINE_NETDEV_TRIGGER(link_100, TRIGGER_NETDEV_LINK_100);
424 DEFINE_NETDEV_TRIGGER(link_1000, TRIGGER_NETDEV_LINK_1000);
425 DEFINE_NETDEV_TRIGGER(link_2500, TRIGGER_NETDEV_LINK_2500);
426 DEFINE_NETDEV_TRIGGER(link_5000, TRIGGER_NETDEV_LINK_5000);
427 DEFINE_NETDEV_TRIGGER(link_10000, TRIGGER_NETDEV_LINK_10000);
428 DEFINE_NETDEV_TRIGGER(half_duplex, TRIGGER_NETDEV_HALF_DUPLEX);
429 DEFINE_NETDEV_TRIGGER(full_duplex, TRIGGER_NETDEV_FULL_DUPLEX);
430 DEFINE_NETDEV_TRIGGER(tx, TRIGGER_NETDEV_TX);
431 DEFINE_NETDEV_TRIGGER(rx, TRIGGER_NETDEV_RX);
432 
433 static ssize_t interval_show(struct device *dev,
434 			     struct device_attribute *attr, char *buf)
435 {
436 	struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
437 
438 	return sprintf(buf, "%u\n",
439 		       jiffies_to_msecs(atomic_read(&trigger_data->interval)));
440 }
441 
442 static ssize_t interval_store(struct device *dev,
443 			      struct device_attribute *attr, const char *buf,
444 			      size_t size)
445 {
446 	struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
447 	unsigned long value;
448 	int ret;
449 
450 	if (trigger_data->hw_control)
451 		return -EINVAL;
452 
453 	ret = kstrtoul(buf, 0, &value);
454 	if (ret)
455 		return ret;
456 
457 	/* impose some basic bounds on the timer interval */
458 	if (value >= 5 && value <= 10000) {
459 		cancel_delayed_work_sync(&trigger_data->work);
460 
461 		atomic_set(&trigger_data->interval, msecs_to_jiffies(value));
462 		set_baseline_state(trigger_data);	/* resets timer */
463 	}
464 
465 	return size;
466 }
467 
468 static DEVICE_ATTR_RW(interval);
469 
470 static ssize_t offloaded_show(struct device *dev,
471 			      struct device_attribute *attr, char *buf)
472 {
473 	struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
474 
475 	return sprintf(buf, "%d\n", trigger_data->hw_control);
476 }
477 
478 static DEVICE_ATTR_RO(offloaded);
479 
480 #define CHECK_LINK_MODE_ATTR(link_speed) \
481 	do { \
482 		if (attr == &dev_attr_link_##link_speed.attr && \
483 		    link_ksettings.base.speed == SPEED_##link_speed) \
484 			return attr->mode; \
485 	} while (0)
486 
487 static umode_t netdev_trig_link_speed_visible(struct kobject *kobj,
488 					      struct attribute *attr, int n)
489 {
490 	struct device *dev = kobj_to_dev(kobj);
491 	struct led_netdev_data *trigger_data;
492 	unsigned long *supported_link_modes;
493 	u32 mode;
494 
495 	trigger_data = led_trigger_get_drvdata(dev);
496 	supported_link_modes = trigger_data->supported_link_modes;
497 
498 	/*
499 	 * Search in the supported link mode mask a matching supported mode.
500 	 * Stop at the first matching entry as we care only to check if a particular
501 	 * speed is supported and not the kind.
502 	 */
503 	for_each_set_bit(mode, supported_link_modes, __ETHTOOL_LINK_MODE_MASK_NBITS) {
504 		struct ethtool_link_ksettings link_ksettings;
505 
506 		ethtool_params_from_link_mode(&link_ksettings, mode);
507 
508 		CHECK_LINK_MODE_ATTR(10);
509 		CHECK_LINK_MODE_ATTR(100);
510 		CHECK_LINK_MODE_ATTR(1000);
511 		CHECK_LINK_MODE_ATTR(2500);
512 		CHECK_LINK_MODE_ATTR(5000);
513 		CHECK_LINK_MODE_ATTR(10000);
514 	}
515 
516 	return 0;
517 }
518 
519 static struct attribute *netdev_trig_link_speed_attrs[] = {
520 	&dev_attr_link_10.attr,
521 	&dev_attr_link_100.attr,
522 	&dev_attr_link_1000.attr,
523 	&dev_attr_link_2500.attr,
524 	&dev_attr_link_5000.attr,
525 	&dev_attr_link_10000.attr,
526 	NULL
527 };
528 
529 static const struct attribute_group netdev_trig_link_speed_attrs_group = {
530 	.attrs = netdev_trig_link_speed_attrs,
531 	.is_visible = netdev_trig_link_speed_visible,
532 };
533 
534 static struct attribute *netdev_trig_attrs[] = {
535 	&dev_attr_device_name.attr,
536 	&dev_attr_link.attr,
537 	&dev_attr_full_duplex.attr,
538 	&dev_attr_half_duplex.attr,
539 	&dev_attr_rx.attr,
540 	&dev_attr_tx.attr,
541 	&dev_attr_interval.attr,
542 	&dev_attr_offloaded.attr,
543 	NULL
544 };
545 
546 static const struct attribute_group netdev_trig_attrs_group = {
547 	.attrs = netdev_trig_attrs,
548 };
549 
550 static const struct attribute_group *netdev_trig_groups[] = {
551 	&netdev_trig_attrs_group,
552 	&netdev_trig_link_speed_attrs_group,
553 	NULL,
554 };
555 
556 static int netdev_trig_notify(struct notifier_block *nb,
557 			      unsigned long evt, void *dv)
558 {
559 	struct net_device *dev =
560 		netdev_notifier_info_to_dev((struct netdev_notifier_info *)dv);
561 	struct led_netdev_data *trigger_data =
562 		container_of(nb, struct led_netdev_data, notifier);
563 	struct led_classdev *led_cdev = trigger_data->led_cdev;
564 
565 	if (evt != NETDEV_UP && evt != NETDEV_DOWN && evt != NETDEV_CHANGE
566 	    && evt != NETDEV_REGISTER && evt != NETDEV_UNREGISTER
567 	    && evt != NETDEV_CHANGENAME)
568 		return NOTIFY_DONE;
569 
570 	if (!(dev == trigger_data->net_dev ||
571 	      (evt == NETDEV_CHANGENAME && !strcmp(dev->name, trigger_data->device_name)) ||
572 	      (evt == NETDEV_REGISTER && !strcmp(dev->name, trigger_data->device_name))))
573 		return NOTIFY_DONE;
574 
575 	cancel_delayed_work_sync(&trigger_data->work);
576 
577 	mutex_lock(&trigger_data->lock);
578 
579 	trigger_data->carrier_link_up = false;
580 	trigger_data->link_speed = SPEED_UNKNOWN;
581 	trigger_data->duplex = DUPLEX_UNKNOWN;
582 	switch (evt) {
583 	case NETDEV_CHANGENAME:
584 		get_device_state(trigger_data);
585 		fallthrough;
586 	case NETDEV_REGISTER:
587 		dev_put(trigger_data->net_dev);
588 		dev_hold(dev);
589 		trigger_data->net_dev = dev;
590 		break;
591 	case NETDEV_UNREGISTER:
592 		dev_put(trigger_data->net_dev);
593 		trigger_data->net_dev = NULL;
594 		break;
595 	case NETDEV_UP:
596 	case NETDEV_CHANGE:
597 		get_device_state(trigger_data);
598 		/* Refresh link_speed visibility */
599 		if (evt == NETDEV_CHANGE)
600 			sysfs_update_group(&led_cdev->dev->kobj,
601 					   &netdev_trig_link_speed_attrs_group);
602 		break;
603 	}
604 
605 	set_baseline_state(trigger_data);
606 
607 	mutex_unlock(&trigger_data->lock);
608 
609 	return NOTIFY_DONE;
610 }
611 
612 /* here's the real work! */
613 static void netdev_trig_work(struct work_struct *work)
614 {
615 	struct led_netdev_data *trigger_data =
616 		container_of(work, struct led_netdev_data, work.work);
617 	struct rtnl_link_stats64 *dev_stats;
618 	unsigned int new_activity;
619 	struct rtnl_link_stats64 temp;
620 	unsigned long interval;
621 	int invert;
622 
623 	/* If we dont have a device, insure we are off */
624 	if (!trigger_data->net_dev) {
625 		led_set_brightness(trigger_data->led_cdev, LED_OFF);
626 		return;
627 	}
628 
629 	/* If we are not looking for RX/TX then return  */
630 	if (!test_bit(TRIGGER_NETDEV_TX, &trigger_data->mode) &&
631 	    !test_bit(TRIGGER_NETDEV_RX, &trigger_data->mode))
632 		return;
633 
634 	dev_stats = dev_get_stats(trigger_data->net_dev, &temp);
635 	new_activity =
636 	    (test_bit(TRIGGER_NETDEV_TX, &trigger_data->mode) ?
637 		dev_stats->tx_packets : 0) +
638 	    (test_bit(TRIGGER_NETDEV_RX, &trigger_data->mode) ?
639 		dev_stats->rx_packets : 0);
640 
641 	if (trigger_data->last_activity != new_activity) {
642 		led_stop_software_blink(trigger_data->led_cdev);
643 
644 		invert = test_bit(TRIGGER_NETDEV_LINK, &trigger_data->mode) ||
645 			 test_bit(TRIGGER_NETDEV_LINK_10, &trigger_data->mode) ||
646 			 test_bit(TRIGGER_NETDEV_LINK_100, &trigger_data->mode) ||
647 			 test_bit(TRIGGER_NETDEV_LINK_1000, &trigger_data->mode) ||
648 			 test_bit(TRIGGER_NETDEV_LINK_2500, &trigger_data->mode) ||
649 			 test_bit(TRIGGER_NETDEV_LINK_5000, &trigger_data->mode) ||
650 			 test_bit(TRIGGER_NETDEV_LINK_10000, &trigger_data->mode) ||
651 			 test_bit(TRIGGER_NETDEV_HALF_DUPLEX, &trigger_data->mode) ||
652 			 test_bit(TRIGGER_NETDEV_FULL_DUPLEX, &trigger_data->mode);
653 		interval = jiffies_to_msecs(
654 				atomic_read(&trigger_data->interval));
655 		/* base state is ON (link present) */
656 		led_blink_set_oneshot(trigger_data->led_cdev,
657 				      &interval,
658 				      &interval,
659 				      invert);
660 		trigger_data->last_activity = new_activity;
661 	}
662 
663 	schedule_delayed_work(&trigger_data->work,
664 			(atomic_read(&trigger_data->interval)*2));
665 }
666 
667 static int netdev_trig_activate(struct led_classdev *led_cdev)
668 {
669 	struct led_netdev_data *trigger_data;
670 	unsigned long mode = 0;
671 	struct device *dev;
672 	int rc;
673 
674 	trigger_data = kzalloc(sizeof(struct led_netdev_data), GFP_KERNEL);
675 	if (!trigger_data)
676 		return -ENOMEM;
677 
678 	mutex_init(&trigger_data->lock);
679 
680 	trigger_data->notifier.notifier_call = netdev_trig_notify;
681 	trigger_data->notifier.priority = 10;
682 
683 	INIT_DELAYED_WORK(&trigger_data->work, netdev_trig_work);
684 
685 	trigger_data->led_cdev = led_cdev;
686 	trigger_data->net_dev = NULL;
687 	trigger_data->device_name[0] = 0;
688 
689 	trigger_data->mode = 0;
690 	atomic_set(&trigger_data->interval, msecs_to_jiffies(NETDEV_LED_DEFAULT_INTERVAL));
691 	trigger_data->last_activity = 0;
692 
693 	/* Check if hw control is active by default on the LED.
694 	 * Init already enabled mode in hw control.
695 	 */
696 	if (supports_hw_control(led_cdev)) {
697 		dev = led_cdev->hw_control_get_device(led_cdev);
698 		if (dev) {
699 			const char *name = dev_name(dev);
700 
701 			trigger_data->hw_control = true;
702 			set_device_name(trigger_data, name, strlen(name));
703 
704 			rc = led_cdev->hw_control_get(led_cdev, &mode);
705 			if (!rc)
706 				trigger_data->mode = mode;
707 		}
708 	}
709 
710 	led_set_trigger_data(led_cdev, trigger_data);
711 
712 	rc = register_netdevice_notifier(&trigger_data->notifier);
713 	if (rc)
714 		kfree(trigger_data);
715 
716 	return rc;
717 }
718 
719 static void netdev_trig_deactivate(struct led_classdev *led_cdev)
720 {
721 	struct led_netdev_data *trigger_data = led_get_trigger_data(led_cdev);
722 
723 	unregister_netdevice_notifier(&trigger_data->notifier);
724 
725 	cancel_delayed_work_sync(&trigger_data->work);
726 
727 	led_set_brightness(led_cdev, LED_OFF);
728 
729 	dev_put(trigger_data->net_dev);
730 
731 	kfree(trigger_data);
732 }
733 
734 static struct led_trigger netdev_led_trigger = {
735 	.name = "netdev",
736 	.activate = netdev_trig_activate,
737 	.deactivate = netdev_trig_deactivate,
738 	.groups = netdev_trig_groups,
739 };
740 
741 module_led_trigger(netdev_led_trigger);
742 
743 MODULE_AUTHOR("Ben Whitten <ben.whitten@gmail.com>");
744 MODULE_AUTHOR("Oliver Jowett <oliver@opencloud.com>");
745 MODULE_DESCRIPTION("Netdev LED trigger");
746 MODULE_LICENSE("GPL v2");
747 MODULE_ALIAS("ledtrig:netdev");
748