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
>= 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");