1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright 2017 Ben Whitten <ben.whitten@gmail.com>
3 // Copyright 2007 Oliver Jowett <oliver@opencloud.com>
5 // LED Kernel Netdev Trigger
7 // Toggles the LED to reflect the link and traffic state of a named net device
9 // Derived from ledtrig-timer.c which is:
10 // Copyright 2005-2006 Openedhand Ltd.
11 // Author: Richard Purdie <rpurdie@openedhand.com>
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>
29 #define NETDEV_LED_DEFAULT_INTERVAL 50
32 * Configurable sysfs attributes:
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
43 struct led_netdev_data {
46 struct delayed_work work;
47 struct notifier_block notifier;
49 struct led_classdev *led_cdev;
50 struct net_device *net_dev;
52 char device_name[IFNAMSIZ];
54 unsigned int last_activity;
64 static void set_baseline_state(struct led_netdev_data *trigger_data)
66 int current_brightness;
67 struct led_classdev *led_cdev = trigger_data->led_cdev;
69 /* Already validated, hw control is possible with the requested mode */
70 if (trigger_data->hw_control) {
71 led_cdev->hw_control_set(led_cdev, trigger_data->mode);
76 current_brightness = led_cdev->brightness;
77 if (current_brightness)
78 led_cdev->blink_brightness = current_brightness;
79 if (!led_cdev->blink_brightness)
80 led_cdev->blink_brightness = led_cdev->max_brightness;
82 if (!trigger_data->carrier_link_up) {
83 led_set_brightness(led_cdev, LED_OFF);
85 bool blink_on = false;
87 if (test_bit(TRIGGER_NETDEV_LINK, &trigger_data->mode))
90 if (test_bit(TRIGGER_NETDEV_LINK_10, &trigger_data->mode) &&
91 trigger_data->link_speed == SPEED_10)
94 if (test_bit(TRIGGER_NETDEV_LINK_100, &trigger_data->mode) &&
95 trigger_data->link_speed == SPEED_100)
98 if (test_bit(TRIGGER_NETDEV_LINK_1000, &trigger_data->mode) &&
99 trigger_data->link_speed == SPEED_1000)
102 if (test_bit(TRIGGER_NETDEV_HALF_DUPLEX, &trigger_data->mode) &&
103 trigger_data->duplex == DUPLEX_HALF)
106 if (test_bit(TRIGGER_NETDEV_FULL_DUPLEX, &trigger_data->mode) &&
107 trigger_data->duplex == DUPLEX_FULL)
111 led_set_brightness(led_cdev,
112 led_cdev->blink_brightness);
114 led_set_brightness(led_cdev, LED_OFF);
116 /* If we are looking for RX/TX start periodically
119 if (test_bit(TRIGGER_NETDEV_TX, &trigger_data->mode) ||
120 test_bit(TRIGGER_NETDEV_RX, &trigger_data->mode))
121 schedule_delayed_work(&trigger_data->work, 0);
125 static bool supports_hw_control(struct led_classdev *led_cdev)
127 if (!led_cdev->hw_control_get || !led_cdev->hw_control_set ||
128 !led_cdev->hw_control_is_supported)
131 return !strcmp(led_cdev->hw_control_trigger, led_cdev->trigger->name);
135 * Validate the configured netdev is the same as the one associated with
136 * the LED driver in hw control.
138 static bool validate_net_dev(struct led_classdev *led_cdev,
139 struct net_device *net_dev)
141 struct device *dev = led_cdev->hw_control_get_device(led_cdev);
142 struct net_device *ndev;
147 ndev = to_net_dev(dev);
149 return ndev == net_dev;
152 static bool can_hw_control(struct led_netdev_data *trigger_data)
154 unsigned long default_interval = msecs_to_jiffies(NETDEV_LED_DEFAULT_INTERVAL);
155 unsigned int interval = atomic_read(&trigger_data->interval);
156 struct led_classdev *led_cdev = trigger_data->led_cdev;
159 if (!supports_hw_control(led_cdev))
163 * Interval must be set to the default
164 * value. Any different value is rejected if in hw
167 if (interval != default_interval)
171 * net_dev must be set with hw control, otherwise no
172 * blinking can be happening and there is nothing to
173 * offloaded. Additionally, for hw control to be
174 * valid, the configured netdev must be the same as
175 * netdev associated to the LED.
177 if (!validate_net_dev(led_cdev, trigger_data->net_dev))
180 /* Check if the requested mode is supported */
181 ret = led_cdev->hw_control_is_supported(led_cdev, trigger_data->mode);
182 /* Fall back to software blinking if not supported */
183 if (ret == -EOPNOTSUPP)
186 dev_warn(led_cdev->dev,
187 "Current mode check failed with error %d\n", ret);
194 static void get_device_state(struct led_netdev_data *trigger_data)
196 struct ethtool_link_ksettings cmd;
198 trigger_data->carrier_link_up = netif_carrier_ok(trigger_data->net_dev);
199 if (!trigger_data->carrier_link_up)
202 if (!__ethtool_get_link_ksettings(trigger_data->net_dev, &cmd)) {
203 trigger_data->link_speed = cmd.base.speed;
204 trigger_data->duplex = cmd.base.duplex;
208 static ssize_t device_name_show(struct device *dev,
209 struct device_attribute *attr, char *buf)
211 struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
214 mutex_lock(&trigger_data->lock);
215 len = sprintf(buf, "%s\n", trigger_data->device_name);
216 mutex_unlock(&trigger_data->lock);
221 static int set_device_name(struct led_netdev_data *trigger_data,
222 const char *name, size_t size)
224 cancel_delayed_work_sync(&trigger_data->work);
226 mutex_lock(&trigger_data->lock);
228 if (trigger_data->net_dev) {
229 dev_put(trigger_data->net_dev);
230 trigger_data->net_dev = NULL;
233 memcpy(trigger_data->device_name, name, size);
234 trigger_data->device_name[size] = 0;
235 if (size > 0 && trigger_data->device_name[size - 1] == '\n')
236 trigger_data->device_name[size - 1] = 0;
238 if (trigger_data->device_name[0] != 0)
239 trigger_data->net_dev =
240 dev_get_by_name(&init_net, trigger_data->device_name);
242 trigger_data->carrier_link_up = false;
243 trigger_data->link_speed = SPEED_UNKNOWN;
244 trigger_data->duplex = DUPLEX_UNKNOWN;
245 if (trigger_data->net_dev != NULL) {
247 get_device_state(trigger_data);
251 trigger_data->last_activity = 0;
253 set_baseline_state(trigger_data);
254 mutex_unlock(&trigger_data->lock);
259 static ssize_t device_name_store(struct device *dev,
260 struct device_attribute *attr, const char *buf,
263 struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
266 if (size >= IFNAMSIZ)
269 ret = set_device_name(trigger_data, buf, size);
276 static DEVICE_ATTR_RW(device_name);
278 static ssize_t netdev_led_attr_show(struct device *dev, char *buf,
279 enum led_trigger_netdev_modes attr)
281 struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
285 case TRIGGER_NETDEV_LINK:
286 case TRIGGER_NETDEV_LINK_10:
287 case TRIGGER_NETDEV_LINK_100:
288 case TRIGGER_NETDEV_LINK_1000:
289 case TRIGGER_NETDEV_HALF_DUPLEX:
290 case TRIGGER_NETDEV_FULL_DUPLEX:
291 case TRIGGER_NETDEV_TX:
292 case TRIGGER_NETDEV_RX:
299 return sprintf(buf, "%u\n", test_bit(bit, &trigger_data->mode));
302 static ssize_t netdev_led_attr_store(struct device *dev, const char *buf,
303 size_t size, enum led_trigger_netdev_modes attr)
305 struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
306 unsigned long state, mode = trigger_data->mode;
310 ret = kstrtoul(buf, 0, &state);
315 case TRIGGER_NETDEV_LINK:
316 case TRIGGER_NETDEV_LINK_10:
317 case TRIGGER_NETDEV_LINK_100:
318 case TRIGGER_NETDEV_LINK_1000:
319 case TRIGGER_NETDEV_HALF_DUPLEX:
320 case TRIGGER_NETDEV_FULL_DUPLEX:
321 case TRIGGER_NETDEV_TX:
322 case TRIGGER_NETDEV_RX:
332 clear_bit(bit, &mode);
334 if (test_bit(TRIGGER_NETDEV_LINK, &mode) &&
335 (test_bit(TRIGGER_NETDEV_LINK_10, &mode) ||
336 test_bit(TRIGGER_NETDEV_LINK_100, &mode) ||
337 test_bit(TRIGGER_NETDEV_LINK_1000, &mode)))
340 cancel_delayed_work_sync(&trigger_data->work);
342 trigger_data->mode = mode;
343 trigger_data->hw_control = can_hw_control(trigger_data);
345 set_baseline_state(trigger_data);
350 #define DEFINE_NETDEV_TRIGGER(trigger_name, trigger) \
351 static ssize_t trigger_name##_show(struct device *dev, \
352 struct device_attribute *attr, char *buf) \
354 return netdev_led_attr_show(dev, buf, trigger); \
356 static ssize_t trigger_name##_store(struct device *dev, \
357 struct device_attribute *attr, const char *buf, size_t size) \
359 return netdev_led_attr_store(dev, buf, size, trigger); \
361 static DEVICE_ATTR_RW(trigger_name)
363 DEFINE_NETDEV_TRIGGER(link, TRIGGER_NETDEV_LINK);
364 DEFINE_NETDEV_TRIGGER(link_10, TRIGGER_NETDEV_LINK_10);
365 DEFINE_NETDEV_TRIGGER(link_100, TRIGGER_NETDEV_LINK_100);
366 DEFINE_NETDEV_TRIGGER(link_1000, TRIGGER_NETDEV_LINK_1000);
367 DEFINE_NETDEV_TRIGGER(half_duplex, TRIGGER_NETDEV_HALF_DUPLEX);
368 DEFINE_NETDEV_TRIGGER(full_duplex, TRIGGER_NETDEV_FULL_DUPLEX);
369 DEFINE_NETDEV_TRIGGER(tx, TRIGGER_NETDEV_TX);
370 DEFINE_NETDEV_TRIGGER(rx, TRIGGER_NETDEV_RX);
372 static ssize_t interval_show(struct device *dev,
373 struct device_attribute *attr, char *buf)
375 struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
377 return sprintf(buf, "%u\n",
378 jiffies_to_msecs(atomic_read(&trigger_data->interval)));
381 static ssize_t interval_store(struct device *dev,
382 struct device_attribute *attr, const char *buf,
385 struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
389 if (trigger_data->hw_control)
392 ret = kstrtoul(buf, 0, &value);
396 /* impose some basic bounds on the timer interval */
397 if (value >= 5 && value <= 10000) {
398 cancel_delayed_work_sync(&trigger_data->work);
400 atomic_set(&trigger_data->interval, msecs_to_jiffies(value));
401 set_baseline_state(trigger_data); /* resets timer */
407 static DEVICE_ATTR_RW(interval);
409 static ssize_t offloaded_show(struct device *dev,
410 struct device_attribute *attr, char *buf)
412 struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
414 return sprintf(buf, "%d\n", trigger_data->hw_control);
417 static DEVICE_ATTR_RO(offloaded);
419 static struct attribute *netdev_trig_attrs[] = {
420 &dev_attr_device_name.attr,
422 &dev_attr_link_10.attr,
423 &dev_attr_link_100.attr,
424 &dev_attr_link_1000.attr,
425 &dev_attr_full_duplex.attr,
426 &dev_attr_half_duplex.attr,
429 &dev_attr_interval.attr,
430 &dev_attr_offloaded.attr,
433 ATTRIBUTE_GROUPS(netdev_trig);
435 static int netdev_trig_notify(struct notifier_block *nb,
436 unsigned long evt, void *dv)
438 struct net_device *dev =
439 netdev_notifier_info_to_dev((struct netdev_notifier_info *)dv);
440 struct led_netdev_data *trigger_data =
441 container_of(nb, struct led_netdev_data, notifier);
443 if (evt != NETDEV_UP && evt != NETDEV_DOWN && evt != NETDEV_CHANGE
444 && evt != NETDEV_REGISTER && evt != NETDEV_UNREGISTER
445 && evt != NETDEV_CHANGENAME)
448 if (!(dev == trigger_data->net_dev ||
449 (evt == NETDEV_CHANGENAME && !strcmp(dev->name, trigger_data->device_name)) ||
450 (evt == NETDEV_REGISTER && !strcmp(dev->name, trigger_data->device_name))))
453 cancel_delayed_work_sync(&trigger_data->work);
455 mutex_lock(&trigger_data->lock);
457 trigger_data->carrier_link_up = false;
458 trigger_data->link_speed = SPEED_UNKNOWN;
459 trigger_data->duplex = DUPLEX_UNKNOWN;
461 case NETDEV_CHANGENAME:
462 get_device_state(trigger_data);
464 case NETDEV_REGISTER:
465 dev_put(trigger_data->net_dev);
467 trigger_data->net_dev = dev;
469 case NETDEV_UNREGISTER:
470 dev_put(trigger_data->net_dev);
471 trigger_data->net_dev = NULL;
475 get_device_state(trigger_data);
479 set_baseline_state(trigger_data);
481 mutex_unlock(&trigger_data->lock);
486 /* here's the real work! */
487 static void netdev_trig_work(struct work_struct *work)
489 struct led_netdev_data *trigger_data =
490 container_of(work, struct led_netdev_data, work.work);
491 struct rtnl_link_stats64 *dev_stats;
492 unsigned int new_activity;
493 struct rtnl_link_stats64 temp;
494 unsigned long interval;
497 /* If we dont have a device, insure we are off */
498 if (!trigger_data->net_dev) {
499 led_set_brightness(trigger_data->led_cdev, LED_OFF);
503 /* If we are not looking for RX/TX then return */
504 if (!test_bit(TRIGGER_NETDEV_TX, &trigger_data->mode) &&
505 !test_bit(TRIGGER_NETDEV_RX, &trigger_data->mode))
508 dev_stats = dev_get_stats(trigger_data->net_dev, &temp);
510 (test_bit(TRIGGER_NETDEV_TX, &trigger_data->mode) ?
511 dev_stats->tx_packets : 0) +
512 (test_bit(TRIGGER_NETDEV_RX, &trigger_data->mode) ?
513 dev_stats->rx_packets : 0);
515 if (trigger_data->last_activity != new_activity) {
516 led_stop_software_blink(trigger_data->led_cdev);
518 invert = test_bit(TRIGGER_NETDEV_LINK, &trigger_data->mode) ||
519 test_bit(TRIGGER_NETDEV_LINK_10, &trigger_data->mode) ||
520 test_bit(TRIGGER_NETDEV_LINK_100, &trigger_data->mode) ||
521 test_bit(TRIGGER_NETDEV_LINK_1000, &trigger_data->mode) ||
522 test_bit(TRIGGER_NETDEV_HALF_DUPLEX, &trigger_data->mode) ||
523 test_bit(TRIGGER_NETDEV_FULL_DUPLEX, &trigger_data->mode);
524 interval = jiffies_to_msecs(
525 atomic_read(&trigger_data->interval));
526 /* base state is ON (link present) */
527 led_blink_set_oneshot(trigger_data->led_cdev,
531 trigger_data->last_activity = new_activity;
534 schedule_delayed_work(&trigger_data->work,
535 (atomic_read(&trigger_data->interval)*2));
538 static int netdev_trig_activate(struct led_classdev *led_cdev)
540 struct led_netdev_data *trigger_data;
541 unsigned long mode = 0;
545 trigger_data = kzalloc(sizeof(struct led_netdev_data), GFP_KERNEL);
549 mutex_init(&trigger_data->lock);
551 trigger_data->notifier.notifier_call = netdev_trig_notify;
552 trigger_data->notifier.priority = 10;
554 INIT_DELAYED_WORK(&trigger_data->work, netdev_trig_work);
556 trigger_data->led_cdev = led_cdev;
557 trigger_data->net_dev = NULL;
558 trigger_data->device_name[0] = 0;
560 trigger_data->mode = 0;
561 atomic_set(&trigger_data->interval, msecs_to_jiffies(NETDEV_LED_DEFAULT_INTERVAL));
562 trigger_data->last_activity = 0;
564 /* Check if hw control is active by default on the LED.
565 * Init already enabled mode in hw control.
567 if (supports_hw_control(led_cdev)) {
568 dev = led_cdev->hw_control_get_device(led_cdev);
570 const char *name = dev_name(dev);
572 set_device_name(trigger_data, name, strlen(name));
573 trigger_data->hw_control = true;
575 rc = led_cdev->hw_control_get(led_cdev, &mode);
577 trigger_data->mode = mode;
581 led_set_trigger_data(led_cdev, trigger_data);
583 rc = register_netdevice_notifier(&trigger_data->notifier);
590 static void netdev_trig_deactivate(struct led_classdev *led_cdev)
592 struct led_netdev_data *trigger_data = led_get_trigger_data(led_cdev);
594 unregister_netdevice_notifier(&trigger_data->notifier);
596 cancel_delayed_work_sync(&trigger_data->work);
598 led_set_brightness(led_cdev, LED_OFF);
600 dev_put(trigger_data->net_dev);
605 static struct led_trigger netdev_led_trigger = {
607 .activate = netdev_trig_activate,
608 .deactivate = netdev_trig_deactivate,
609 .groups = netdev_trig_groups,
612 static int __init netdev_trig_init(void)
614 return led_trigger_register(&netdev_led_trigger);
617 static void __exit netdev_trig_exit(void)
619 led_trigger_unregister(&netdev_led_trigger);
622 module_init(netdev_trig_init);
623 module_exit(netdev_trig_exit);
625 MODULE_AUTHOR("Ben Whitten <ben.whitten@gmail.com>");
626 MODULE_AUTHOR("Oliver Jowett <oliver@opencloud.com>");
627 MODULE_DESCRIPTION("Netdev LED trigger");
628 MODULE_LICENSE("GPL v2");