summaryrefslogtreecommitdiff
path: root/target/linux/generic-2.6/files/drivers/leds/ledtrig-netdev.c
blob: 285d0f795c829922eb958aad205002237347dcbf (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
/*
 * LED Kernel Netdev Trigger
 *
 * Toggles the LED to reflect the link and traffic state of a named net device
 *
 * Copyright 2007 Oliver Jowett <oliver@opencloud.com>
 *
 * Derived from ledtrig-timer.c which is:
 *  Copyright 2005-2006 Openedhand Ltd.
 *  Author: Richard Purdie <rpurdie@openedhand.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 */

#include <linux/module.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/spinlock.h>
#include <linux/device.h>
#include <linux/sysdev.h>
#include <linux/netdevice.h>
#include <linux/timer.h>
#include <linux/ctype.h>
#include <linux/leds.h>
#include "leds.h"

/*
 * Configurable sysfs attributes:
 *
 * device_name - network device name to monitor
 *
 * interval - duration of LED blink, in milliseconds
 *
 * mode - either "none" (LED is off) or a space separated list of one or more of:
 *   link: LED's normal state reflects whether the link is up (has carrier) or not
 *   tx:   LED blinks on transmitted data
 *   rx:   LED blinks on receive data
 * 
 * Some suggestions:
 *
 *  Simple link status LED:
 *  $ echo netdev >someled/trigger
 *  $ echo eth0 >someled/device_name
 *  $ echo link >someled/mode
 *
 *  Ethernet-style link/activity LED:
 *  $ echo netdev >someled/trigger
 *  $ echo eth0 >someled/device_name
 *  $ echo "link tx rx" >someled/mode
 *
 *  Modem-style tx/rx LEDs:
 *  $ echo netdev >led1/trigger
 *  $ echo ppp0 >led1/device_name
 *  $ echo tx >led1/mode
 *  $ echo netdev >led2/trigger
 *  $ echo ppp0 >led2/device_name
 *  $ echo rx >led2/mode
 *
 */

#define MODE_LINK 1
#define MODE_TX   2
#define MODE_RX   4

struct led_netdev_data {
	rwlock_t lock;
	
	struct timer_list timer;
	struct notifier_block notifier;	
	
	struct led_classdev *led_cdev;
	struct net_device *net_dev;
	
	char device_name[IFNAMSIZ];
	unsigned interval;
	unsigned mode;
	unsigned link_up;
	unsigned last_activity;
};

static void set_baseline_state(struct led_netdev_data *trigger_data)
{  
	if ((trigger_data->mode & MODE_LINK) != 0 && trigger_data->link_up)
		led_set_brightness(trigger_data->led_cdev, LED_FULL);
	else
		led_set_brightness(trigger_data->led_cdev, LED_OFF);
	
	if ((trigger_data->mode & (MODE_TX | MODE_RX)) != 0 && trigger_data->link_up)
		mod_timer(&trigger_data->timer, jiffies + trigger_data->interval);
	else
		del_timer(&trigger_data->timer);    
}  

static ssize_t led_device_name_show(struct device *dev,
				    struct device_attribute *attr, char *buf)
{
	struct led_classdev *led_cdev = dev_get_drvdata(dev);
	struct led_netdev_data *trigger_data = led_cdev->trigger_data;
	
	read_lock(&trigger_data->lock);
	sprintf(buf, "%s\n", trigger_data->device_name);
	read_unlock(&trigger_data->lock);
	
	return strlen(buf) + 1;
}
  
static ssize_t led_device_name_store(struct device *dev, 
				     struct device_attribute *attr, const char *buf, size_t size)
{
	struct led_classdev *led_cdev = dev_get_drvdata(dev);
	struct led_netdev_data *trigger_data = led_cdev->trigger_data;
	
	if (size < 0 || size >= IFNAMSIZ)
		return -EINVAL;
	
	write_lock(&trigger_data->lock);

	strcpy(trigger_data->device_name, buf);
	if (size > 0 && trigger_data->device_name[size-1] == '\n')
		trigger_data->device_name[size-1] = 0;
	
	if (trigger_data->device_name[0] != 0) {
		/* check for existing device to update from */
		trigger_data->net_dev = dev_get_by_name(trigger_data->device_name);
		if (trigger_data->net_dev != NULL)
			trigger_data->link_up = (dev_get_flags(trigger_data->net_dev) & IFF_LOWER_UP) != 0;
		set_baseline_state(trigger_data); /* updates LEDs, may start timers */
	}
	
	write_unlock(&trigger_data->lock);	
	return size;
}

static DEVICE_ATTR(device_name, 0644, led_device_name_show, led_device_name_store);

static ssize_t led_mode_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
{
	struct led_classdev *led_cdev = dev_get_drvdata(dev);
	struct led_netdev_data *trigger_data = led_cdev->trigger_data;
	
	read_lock(&trigger_data->lock);
	
	if (trigger_data->mode == 0) {
		strcpy(buf, "none\n");
	} else {
		if (trigger_data->mode & MODE_LINK) 
			strcat(buf, "link ");
		if (trigger_data->mode & MODE_TX)
			strcat(buf, "tx ");
		if (trigger_data->mode & MODE_RX)
			strcat(buf, "rx ");
		strcat(buf, "\n");
	}
	
	read_unlock(&trigger_data->lock);	

	return strlen(buf)+1;
}

static ssize_t led_mode_store(struct device *dev, 
			      struct device_attribute *attr, const char *buf, size_t size)
{
	struct led_classdev *led_cdev = dev_get_drvdata(dev);
	struct led_netdev_data *trigger_data = led_cdev->trigger_data;	
	char copybuf[1024];
	int new_mode = -1;
	char *p, *token;

	/* take a copy since we don't want to trash the inbound buffer when using strsep */
	strncpy(copybuf, buf, sizeof(copybuf));
	copybuf[1023] = 0;
	p = copybuf;
	
	while ((token = strsep(&p, " \t\n")) != NULL) {
		if (!*token)
			continue;
		
		if (new_mode == -1)
			new_mode = 0;
		
		if (!strcmp(token, "none"))
			new_mode = 0;
		else if (!strcmp(token, "tx"))
			new_mode |= MODE_TX;
		else if (!strcmp(token, "rx"))
			new_mode |= MODE_RX;
		else if (!strcmp(token, "link"))
			new_mode |= MODE_LINK;
		else
			return -EINVAL;
	}
	
	if (new_mode == -1)
		return -EINVAL;
	
	write_lock(&trigger_data->lock);	
	trigger_data->mode = new_mode;  
	set_baseline_state(trigger_data);
	write_unlock(&trigger_data->lock);
	
	return size;
}

static DEVICE_ATTR(mode, 0644, led_mode_show, led_mode_store);

static ssize_t led_interval_show(struct device *dev, 
				 struct device_attribute *attr, char *buf)
{
	struct led_classdev *led_cdev = dev_get_drvdata(dev);
	struct led_netdev_data *trigger_data = led_cdev->trigger_data;
	
	read_lock(&trigger_data->lock);
	sprintf(buf, "%u\n", jiffies_to_msecs(trigger_data->interval));
	read_unlock(&trigger_data->lock);
	
	return strlen(buf) + 1;
}

static ssize_t led_interval_store(struct device *dev, 
				  struct device_attribute *attr, const char *buf, size_t size)
{
	struct led_classdev *led_cdev = dev_get_drvdata(dev);
	struct led_netdev_data *trigger_data = led_cdev->trigger_data;
	int ret = -EINVAL;
	char *after;
	unsigned long value = simple_strtoul(buf, &after, 10);
	size_t count = after - buf;

	if (*after && isspace(*after))
		count++;

	/* impose some basic bounds on the timer interval */
	if (count == size && value >= 5 && value <= 10000) {
		write_lock(&trigger_data->lock);
		trigger_data->interval = msecs_to_jiffies(value);
		set_baseline_state(trigger_data); // resets timer
		write_unlock(&trigger_data->lock);
		ret = count;
	}
	
	return ret;
}

static DEVICE_ATTR(interval, 0644, led_interval_show, led_interval_store);

static int netdev_trig_notify(struct notifier_block *nb,
			      unsigned long evt,
			      void *dv)
{
	struct net_device *dev = dv;
	struct led_netdev_data *trigger_data = container_of(nb, struct led_netdev_data, notifier);
	
	if (evt != NETDEV_UP && evt != NETDEV_DOWN && evt != NETDEV_CHANGE && evt != NETDEV_REGISTER && evt != NETDEV_UNREGISTER)
		return NOTIFY_DONE;
	
	write_lock(&trigger_data->lock);

	if (strcmp(dev->name, trigger_data->device_name))
		goto done;
	
	if (evt == NETDEV_REGISTER) {
		if (trigger_data->net_dev != NULL)
			dev_put(trigger_data->net_dev);
		dev_hold(dev);
		trigger_data->net_dev = dev;
		trigger_data->link_up = 0;
		goto done;
	}
	
	if (evt == NETDEV_UNREGISTER && trigger_data->net_dev != NULL) {
		dev_put(trigger_data->net_dev);
		trigger_data->net_dev = NULL;
		goto done;
	}
	
	/* UP / DOWN / CHANGE */
	
	trigger_data->link_up = (evt != NETDEV_DOWN && netif_carrier_ok(dev));
	set_baseline_state(trigger_data);

done:
	write_unlock(&trigger_data->lock);  
	return NOTIFY_DONE;
}

/* here's the real work! */
static void netdev_trig_timer(unsigned long arg)
{
	struct led_netdev_data *trigger_data = (struct led_netdev_data *)arg;
	struct net_device_stats *dev_stats;
	unsigned new_activity;
	
	write_lock(&trigger_data->lock);
    
	if (!trigger_data->link_up || !trigger_data->net_dev || (trigger_data->mode & (MODE_TX | MODE_RX)) == 0) {
		/* we don't need to do timer work, just reflect link state. */
		led_set_brightness(trigger_data->led_cdev, ((trigger_data->mode & MODE_LINK) != 0 && trigger_data->link_up) ? LED_FULL : LED_OFF);
		goto no_restart;
	}
	
	dev_stats = trigger_data->net_dev->get_stats(trigger_data->net_dev);
	new_activity =
		((trigger_data->mode & MODE_TX) ? dev_stats->tx_packets : 0) +
		((trigger_data->mode & MODE_RX) ? dev_stats->rx_packets : 0);
      
	if (trigger_data->mode & MODE_LINK) {
		/* base state is ON (link present) */
		/* if there's no link, we don't get this far and the LED is off */
		
		/* OFF -> ON always */
		/* ON -> OFF on activity */
		if (trigger_data->led_cdev->brightness == LED_OFF) {
			led_set_brightness(trigger_data->led_cdev, LED_FULL);
		} else if (trigger_data->last_activity != new_activity) {
			led_set_brightness(trigger_data->led_cdev, LED_OFF);
		}
	} else {
		/* base state is OFF */
		/* ON -> OFF always */
		/* OFF -> ON on activity */
		if (trigger_data->led_cdev->brightness == LED_FULL) {
			led_set_brightness(trigger_data->led_cdev, LED_OFF);
		} else if (trigger_data->last_activity != new_activity) {
			led_set_brightness(trigger_data->led_cdev, LED_FULL);
		}
	}
	
	trigger_data->last_activity = new_activity;
	mod_timer(&trigger_data->timer, jiffies + trigger_data->interval);

no_restart:
	write_unlock(&trigger_data->lock);
}

static void netdev_trig_activate(struct led_classdev *led_cdev)
{
	struct led_netdev_data *trigger_data;
	int rc;

	trigger_data = kzalloc(sizeof(struct led_netdev_data), GFP_KERNEL);
	if (!trigger_data)
		return;

	rwlock_init(&trigger_data->lock);

	trigger_data->notifier.notifier_call = netdev_trig_notify;
	trigger_data->notifier.priority = 10;

	setup_timer(&trigger_data->timer, netdev_trig_timer, (unsigned long) trigger_data);

	trigger_data->led_cdev = led_cdev;
	trigger_data->net_dev = NULL;
	trigger_data->device_name[0] = 0;
	
	trigger_data->mode = 0;
	trigger_data->interval = msecs_to_jiffies(50);
	trigger_data->link_up = 0;
	trigger_data->last_activity = 0;
	
	led_cdev->trigger_data = trigger_data;

	rc = device_create_file(led_cdev->dev, &dev_attr_device_name);
	if (rc)
		goto err_out;
	rc = device_create_file(led_cdev->dev, &dev_attr_mode);
	if (rc)
		goto err_out_device_name;
	rc = device_create_file(led_cdev->dev, &dev_attr_interval);
	if (rc)
		goto err_out_mode;

	register_netdevice_notifier(&trigger_data->notifier);	
	return;

err_out_mode:
	device_remove_file(led_cdev->dev, &dev_attr_mode);
err_out_device_name:
	device_remove_file(led_cdev->dev, &dev_attr_device_name);
err_out:
	led_cdev->trigger_data = NULL;
	kfree(trigger_data);
}

static void netdev_trig_deactivate(struct led_classdev *led_cdev)
{
	struct led_netdev_data *trigger_data = led_cdev->trigger_data;

	if (trigger_data) {	  
		unregister_netdevice_notifier(&trigger_data->notifier);

		device_remove_file(led_cdev->dev, &dev_attr_device_name);
		device_remove_file(led_cdev->dev, &dev_attr_mode);
		device_remove_file(led_cdev->dev, &dev_attr_interval);

		write_lock(&trigger_data->lock);
		
		if (trigger_data->net_dev) {
			dev_put(trigger_data->net_dev);
			trigger_data->net_dev = NULL;
		}
		
		write_unlock(&trigger_data->lock);

		del_timer_sync(&trigger_data->timer);

		kfree(trigger_data);
	}
}

static struct led_trigger netdev_led_trigger = {
	.name     = "netdev",
	.activate = netdev_trig_activate,
	.deactivate = netdev_trig_deactivate,
};

static int __init netdev_trig_init(void)
{
	return led_trigger_register(&netdev_led_trigger);
}

static void __exit netdev_trig_exit(void)
{
	led_trigger_unregister(&netdev_led_trigger);
}

module_init(netdev_trig_init);
module_exit(netdev_trig_exit);

MODULE_AUTHOR("Oliver Jowett <oliver@opencloud.com>");
MODULE_DESCRIPTION("Netdev LED trigger");
MODULE_LICENSE("GPL");