2 * LED Kernel Netdev Trigger
4 * Toggles the LED to reflect the link and traffic state of a named net device
6 * Copyright 2007 Oliver Jowett <oliver@opencloud.com>
8 * Derived from ledtrig-timer.c which is:
9 * Copyright 2005-2006 Openedhand Ltd.
10 * Author: Richard Purdie <rpurdie@openedhand.com>
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License version 2 as
14 * published by the Free Software Foundation.
18 #include <linux/module.h>
19 #include <linux/jiffies.h>
20 #include <linux/kernel.h>
21 #include <linux/init.h>
22 #include <linux/list.h>
23 #include <linux/spinlock.h>
24 #include <linux/device.h>
25 #include <linux/netdevice.h>
26 #include <linux/timer.h>
27 #include <linux/ctype.h>
28 #include <linux/leds.h>
33 * Configurable sysfs attributes:
35 * device_name - network device name to monitor
37 * interval - duration of LED blink, in milliseconds
39 * mode - either "none" (LED is off) or a space separated list of one or more of:
40 * link: LED's normal state reflects whether the link is up (has carrier) or not
41 * tx: LED blinks on transmitted data
42 * rx: LED blinks on receive data
46 * Simple link status LED:
47 * $ echo netdev >someled/trigger
48 * $ echo eth0 >someled/device_name
49 * $ echo link >someled/mode
51 * Ethernet-style link/activity LED:
52 * $ echo netdev >someled/trigger
53 * $ echo eth0 >someled/device_name
54 * $ echo "link tx rx" >someled/mode
56 * Modem-style tx/rx LEDs:
57 * $ echo netdev >led1/trigger
58 * $ echo ppp0 >led1/device_name
59 * $ echo tx >led1/mode
60 * $ echo netdev >led2/trigger
61 * $ echo ppp0 >led2/device_name
62 * $ echo rx >led2/mode
70 struct led_netdev_data {
73 struct delayed_work work;
74 struct notifier_block notifier;
76 struct led_classdev *led_cdev;
77 struct net_device *net_dev;
79 char device_name[IFNAMSIZ];
83 unsigned last_activity;
86 static void set_baseline_state(struct led_netdev_data *trigger_data)
88 if ((trigger_data->mode & MODE_LINK) != 0 && trigger_data->link_up)
89 led_set_brightness(trigger_data->led_cdev, LED_FULL);
91 led_set_brightness(trigger_data->led_cdev, LED_OFF);
93 if ((trigger_data->mode & (MODE_TX | MODE_RX)) != 0 && trigger_data->link_up)
94 schedule_delayed_work(&trigger_data->work, trigger_data->interval);
97 static ssize_t led_device_name_show(struct device *dev,
98 struct device_attribute *attr, char *buf)
100 struct led_classdev *led_cdev = dev_get_drvdata(dev);
101 struct led_netdev_data *trigger_data = led_cdev->trigger_data;
103 spin_lock_bh(&trigger_data->lock);
104 sprintf(buf, "%s\n", trigger_data->device_name);
105 spin_unlock_bh(&trigger_data->lock);
107 return strlen(buf) + 1;
110 static ssize_t led_device_name_store(struct device *dev,
111 struct device_attribute *attr, const char *buf, size_t size)
113 struct led_classdev *led_cdev = dev_get_drvdata(dev);
114 struct led_netdev_data *trigger_data = led_cdev->trigger_data;
116 if (size < 0 || size >= IFNAMSIZ)
119 cancel_delayed_work_sync(&trigger_data->work);
121 spin_lock_bh(&trigger_data->lock);
123 strcpy(trigger_data->device_name, buf);
124 if (size > 0 && trigger_data->device_name[size-1] == '\n')
125 trigger_data->device_name[size-1] = 0;
126 trigger_data->link_up = 0;
127 trigger_data->last_activity = 0;
129 if (trigger_data->device_name[0] != 0) {
130 /* check for existing device to update from */
131 trigger_data->net_dev = dev_get_by_name(&init_net, trigger_data->device_name);
132 if (trigger_data->net_dev != NULL)
133 trigger_data->link_up = (dev_get_flags(trigger_data->net_dev) & IFF_LOWER_UP) != 0;
136 set_baseline_state(trigger_data);
137 spin_unlock_bh(&trigger_data->lock);
142 static DEVICE_ATTR(device_name, 0644, led_device_name_show, led_device_name_store);
144 static ssize_t led_mode_show(struct device *dev,
145 struct device_attribute *attr, char *buf)
147 struct led_classdev *led_cdev = dev_get_drvdata(dev);
148 struct led_netdev_data *trigger_data = led_cdev->trigger_data;
150 spin_lock_bh(&trigger_data->lock);
152 if (trigger_data->mode == 0) {
153 strcpy(buf, "none\n");
155 if (trigger_data->mode & MODE_LINK)
156 strcat(buf, "link ");
157 if (trigger_data->mode & MODE_TX)
159 if (trigger_data->mode & MODE_RX)
164 spin_unlock_bh(&trigger_data->lock);
166 return strlen(buf)+1;
169 static ssize_t led_mode_store(struct device *dev,
170 struct device_attribute *attr, const char *buf, size_t size)
172 struct led_classdev *led_cdev = dev_get_drvdata(dev);
173 struct led_netdev_data *trigger_data = led_cdev->trigger_data;
178 /* take a copy since we don't want to trash the inbound buffer when using strsep */
179 strncpy(copybuf, buf, sizeof(copybuf));
180 copybuf[sizeof(copybuf) - 1] = 0;
183 while ((token = strsep(&p, " \t\n")) != NULL) {
190 if (!strcmp(token, "none"))
192 else if (!strcmp(token, "tx"))
194 else if (!strcmp(token, "rx"))
196 else if (!strcmp(token, "link"))
197 new_mode |= MODE_LINK;
205 cancel_delayed_work_sync(&trigger_data->work);
207 spin_lock_bh(&trigger_data->lock);
208 trigger_data->mode = new_mode;
209 set_baseline_state(trigger_data);
210 spin_unlock_bh(&trigger_data->lock);
215 static DEVICE_ATTR(mode, 0644, led_mode_show, led_mode_store);
217 static ssize_t led_interval_show(struct device *dev,
218 struct device_attribute *attr, char *buf)
220 struct led_classdev *led_cdev = dev_get_drvdata(dev);
221 struct led_netdev_data *trigger_data = led_cdev->trigger_data;
223 spin_lock_bh(&trigger_data->lock);
224 sprintf(buf, "%u\n", jiffies_to_msecs(trigger_data->interval));
225 spin_unlock_bh(&trigger_data->lock);
227 return strlen(buf) + 1;
230 static ssize_t led_interval_store(struct device *dev,
231 struct device_attribute *attr, const char *buf, size_t size)
233 struct led_classdev *led_cdev = dev_get_drvdata(dev);
234 struct led_netdev_data *trigger_data = led_cdev->trigger_data;
237 unsigned long value = simple_strtoul(buf, &after, 10);
238 size_t count = after - buf;
243 /* impose some basic bounds on the timer interval */
244 if (count == size && value >= 5 && value <= 10000) {
245 cancel_delayed_work_sync(&trigger_data->work);
247 spin_lock_bh(&trigger_data->lock);
248 trigger_data->interval = msecs_to_jiffies(value);
249 set_baseline_state(trigger_data); /* resets timer */
250 spin_unlock_bh(&trigger_data->lock);
258 static DEVICE_ATTR(interval, 0644, led_interval_show, led_interval_store);
260 static int netdev_trig_notify(struct notifier_block *nb,
264 struct net_device *dev = netdev_notifier_info_to_dev((struct netdev_notifier_info *) dv);
265 struct led_netdev_data *trigger_data = container_of(nb, struct led_netdev_data, notifier);
267 if (evt != NETDEV_UP && evt != NETDEV_DOWN && evt != NETDEV_CHANGE && evt != NETDEV_REGISTER && evt != NETDEV_UNREGISTER && evt != NETDEV_CHANGENAME)
270 if (strcmp(dev->name, trigger_data->device_name))
273 cancel_delayed_work_sync(&trigger_data->work);
275 spin_lock_bh(&trigger_data->lock);
277 if (evt == NETDEV_REGISTER || evt == NETDEV_CHANGENAME) {
278 if (trigger_data->net_dev != NULL)
279 dev_put(trigger_data->net_dev);
282 trigger_data->net_dev = dev;
283 trigger_data->link_up = 0;
287 if (evt == NETDEV_UNREGISTER && trigger_data->net_dev != NULL) {
288 dev_put(trigger_data->net_dev);
289 trigger_data->net_dev = NULL;
293 /* UP / DOWN / CHANGE */
295 trigger_data->link_up = (evt != NETDEV_DOWN && netif_carrier_ok(dev));
296 set_baseline_state(trigger_data);
299 spin_unlock_bh(&trigger_data->lock);
303 /* here's the real work! */
304 static void netdev_trig_work(struct work_struct *work)
306 struct led_netdev_data *trigger_data = container_of(work, struct led_netdev_data, work.work);
307 struct rtnl_link_stats64 *dev_stats;
308 unsigned new_activity;
309 struct rtnl_link_stats64 temp;
311 if (!trigger_data->link_up || !trigger_data->net_dev || (trigger_data->mode & (MODE_TX | MODE_RX)) == 0) {
312 /* we don't need to do timer work, just reflect link state. */
313 led_set_brightness(trigger_data->led_cdev, ((trigger_data->mode & MODE_LINK) != 0 && trigger_data->link_up) ? LED_FULL : LED_OFF);
317 dev_stats = dev_get_stats(trigger_data->net_dev, &temp);
319 ((trigger_data->mode & MODE_TX) ? dev_stats->tx_packets : 0) +
320 ((trigger_data->mode & MODE_RX) ? dev_stats->rx_packets : 0);
322 if (trigger_data->mode & MODE_LINK) {
323 /* base state is ON (link present) */
324 /* if there's no link, we don't get this far and the LED is off */
326 /* OFF -> ON always */
327 /* ON -> OFF on activity */
328 if (trigger_data->led_cdev->brightness == LED_OFF) {
329 led_set_brightness(trigger_data->led_cdev, LED_FULL);
330 } else if (trigger_data->last_activity != new_activity) {
331 led_set_brightness(trigger_data->led_cdev, LED_OFF);
334 /* base state is OFF */
335 /* ON -> OFF always */
336 /* OFF -> ON on activity */
337 if (trigger_data->led_cdev->brightness == LED_FULL) {
338 led_set_brightness(trigger_data->led_cdev, LED_OFF);
339 } else if (trigger_data->last_activity != new_activity) {
340 led_set_brightness(trigger_data->led_cdev, LED_FULL);
344 trigger_data->last_activity = new_activity;
345 schedule_delayed_work(&trigger_data->work, trigger_data->interval);
348 static void netdev_trig_activate(struct led_classdev *led_cdev)
350 struct led_netdev_data *trigger_data;
353 trigger_data = kzalloc(sizeof(struct led_netdev_data), GFP_KERNEL);
357 spin_lock_init(&trigger_data->lock);
359 trigger_data->notifier.notifier_call = netdev_trig_notify;
360 trigger_data->notifier.priority = 10;
362 INIT_DELAYED_WORK(&trigger_data->work, netdev_trig_work);
364 trigger_data->led_cdev = led_cdev;
365 trigger_data->net_dev = NULL;
366 trigger_data->device_name[0] = 0;
368 trigger_data->mode = 0;
369 trigger_data->interval = msecs_to_jiffies(50);
370 trigger_data->link_up = 0;
371 trigger_data->last_activity = 0;
373 led_cdev->trigger_data = trigger_data;
375 rc = device_create_file(led_cdev->dev, &dev_attr_device_name);
378 rc = device_create_file(led_cdev->dev, &dev_attr_mode);
380 goto err_out_device_name;
381 rc = device_create_file(led_cdev->dev, &dev_attr_interval);
385 register_netdevice_notifier(&trigger_data->notifier);
389 device_remove_file(led_cdev->dev, &dev_attr_mode);
391 device_remove_file(led_cdev->dev, &dev_attr_device_name);
393 led_cdev->trigger_data = NULL;
397 static void netdev_trig_deactivate(struct led_classdev *led_cdev)
399 struct led_netdev_data *trigger_data = led_cdev->trigger_data;
402 unregister_netdevice_notifier(&trigger_data->notifier);
404 device_remove_file(led_cdev->dev, &dev_attr_device_name);
405 device_remove_file(led_cdev->dev, &dev_attr_mode);
406 device_remove_file(led_cdev->dev, &dev_attr_interval);
408 cancel_delayed_work_sync(&trigger_data->work);
410 spin_lock_bh(&trigger_data->lock);
412 if (trigger_data->net_dev) {
413 dev_put(trigger_data->net_dev);
414 trigger_data->net_dev = NULL;
417 spin_unlock_bh(&trigger_data->lock);
423 static struct led_trigger netdev_led_trigger = {
425 .activate = netdev_trig_activate,
426 .deactivate = netdev_trig_deactivate,
429 static int __init netdev_trig_init(void)
431 return led_trigger_register(&netdev_led_trigger);
434 static void __exit netdev_trig_exit(void)
436 led_trigger_unregister(&netdev_led_trigger);
439 module_init(netdev_trig_init);
440 module_exit(netdev_trig_exit);
442 MODULE_AUTHOR("Oliver Jowett <oliver@opencloud.com>");
443 MODULE_DESCRIPTION("Netdev LED trigger");
444 MODULE_LICENSE("GPL");