target/linux/generic-2.6/files/drivers/leds/ledtrig-netdev.c

   1 /*
   2  * LED Kernel Netdev Trigger
   3  *
   4  * Toggles the LED to reflect the link and traffic state of a named net device
   5  *
   6  * Copyright 2007 Oliver Jowett <oliver@opencloud.com>
   7  *
   8  * Derived from ledtrig-timer.c which is:
   9  *  Copyright 2005-2006 Openedhand Ltd.
  10  *  Author: Richard Purdie <rpurdie@openedhand.com>
  11  *
  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.
  15  *
  16  */
  17
  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/sysdev.h>
  26 #include <linux/netdevice.h>
  27 #include <linux/timer.h>
  28 #include <linux/ctype.h>
  29 #include <linux/leds.h>
  30 #include "leds.h"
  31
  32 /*
  33  * Configurable sysfs attributes:
  34  *
  35  * device_name - network device name to monitor
  36  *
  37  * interval - duration of LED blink, in milliseconds
  38  *
  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
  43  *
  44  * Some suggestions:
  45  *
  46  *  Simple link status LED:
  47  *  $ echo netdev >someled/trigger
  48  *  $ echo eth0 >someled/device_name
  49  *  $ echo link >someled/mode
  50  *
  51  *  Ethernet-style link/activity LED:
  52  *  $ echo netdev >someled/trigger
  53  *  $ echo eth0 >someled/device_name
  54  *  $ echo "link tx rx" >someled/mode
  55  *
  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
  63  *
  64  */
  65
  66 #define MODE_LINK 1
  67 #define MODE_TX   2
  68 #define MODE_RX   4
  69
  70 struct led_netdev_data {
  71         rwlock_t lock;
  72
  73         struct timer_list timer;
  74         struct notifier_block notifier;
  75
  76         struct led_classdev *led_cdev;
  77         struct net_device *net_dev;
  78
  79         char device_name[IFNAMSIZ];
  80         unsigned interval;
  81         unsigned mode;
  82         unsigned link_up;
  83         unsigned last_activity;
  84 };
  85
  86 static void set_baseline_state(struct led_netdev_data *trigger_data)
  87 {
  88         if ((trigger_data->mode & MODE_LINK) != 0 && trigger_data->link_up)
  89                 led_set_brightness(trigger_data->led_cdev, LED_FULL);
  90         else
  91                 led_set_brightness(trigger_data->led_cdev, LED_OFF);
  92
  93         if ((trigger_data->mode & (MODE_TX | MODE_RX)) != 0 && trigger_data->link_up)
  94                 mod_timer(&trigger_data->timer, jiffies + trigger_data->interval);
  95         else
  96                 del_timer(&trigger_data->timer);
  97 }
  98
  99 static ssize_t led_device_name_show(struct device *dev,
 100                                     struct device_attribute *attr, char *buf)
 101 {
 102         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 103         struct led_netdev_data *trigger_data = led_cdev->trigger_data;
 104
 105         read_lock(&trigger_data->lock);
 106         sprintf(buf, "%s\n", trigger_data->device_name);
 107         read_unlock(&trigger_data->lock);
 108
 109         return strlen(buf) + 1;
 110 }
 111
 112 static ssize_t led_device_name_store(struct device *dev,
 113                                      struct device_attribute *attr, const char *buf, size_t size)
 114 {
 115         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 116         struct led_netdev_data *trigger_data = led_cdev->trigger_data;
 117
 118         if (size < 0 || size >= IFNAMSIZ)
 119                 return -EINVAL;
 120
 121         write_lock(&trigger_data->lock);
 122
 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
 127         if (trigger_data->device_name[0] != 0) {
 128                 /* check for existing device to update from */
 129                 trigger_data->net_dev = dev_get_by_name(trigger_data->device_name);
 130                 if (trigger_data->net_dev != NULL)
 131                         trigger_data->link_up = (dev_get_flags(trigger_data->net_dev) & IFF_LOWER_UP) != 0;
 132                 set_baseline_state(trigger_data); /* updates LEDs, may start timers */
 133         }
 134
 135         write_unlock(&trigger_data->lock);
 136         return size;
 137 }
 138
 139 static DEVICE_ATTR(device_name, 0644, led_device_name_show, led_device_name_store);
 140
 141 static ssize_t led_mode_show(struct device *dev,
 142                              struct device_attribute *attr, char *buf)
 143 {
 144         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 145         struct led_netdev_data *trigger_data = led_cdev->trigger_data;
 146
 147         read_lock(&trigger_data->lock);
 148
 149         if (trigger_data->mode == 0) {
 150                 strcpy(buf, "none\n");
 151         } else {
 152                 if (trigger_data->mode & MODE_LINK)
 153                         strcat(buf, "link ");
 154                 if (trigger_data->mode & MODE_TX)
 155                         strcat(buf, "tx ");
 156                 if (trigger_data->mode & MODE_RX)
 157                         strcat(buf, "rx ");
 158                 strcat(buf, "\n");
 159         }
 160
 161         read_unlock(&trigger_data->lock);
 162
 163         return strlen(buf)+1;
 164 }
 165
 166 static ssize_t led_mode_store(struct device *dev,
 167                               struct device_attribute *attr, const char *buf, size_t size)
 168 {
 169         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 170         struct led_netdev_data *trigger_data = led_cdev->trigger_data;
 171         char copybuf[1024];
 172         int new_mode = -1;
 173         char *p, *token;
 174
 175         /* take a copy since we don't want to trash the inbound buffer when using strsep */
 176         strncpy(copybuf, buf, sizeof(copybuf));
 177         copybuf[1023] = 0;
 178         p = copybuf;
 179
 180         while ((token = strsep(&p, " \t\n")) != NULL) {
 181                 if (!*token)
 182                         continue;
 183
 184                 if (new_mode == -1)
 185                         new_mode = 0;
 186
 187                 if (!strcmp(token, "none"))
 188                         new_mode = 0;
 189                 else if (!strcmp(token, "tx"))
 190                         new_mode |= MODE_TX;
 191                 else if (!strcmp(token, "rx"))
 192                         new_mode |= MODE_RX;
 193                 else if (!strcmp(token, "link"))
 194                         new_mode |= MODE_LINK;
 195                 else
 196                         return -EINVAL;
 197         }
 198
 199         if (new_mode == -1)
 200                 return -EINVAL;
 201
 202         write_lock(&trigger_data->lock);
 203         trigger_data->mode = new_mode;
 204         set_baseline_state(trigger_data);
 205         write_unlock(&trigger_data->lock);
 206
 207         return size;
 208 }
 209
 210 static DEVICE_ATTR(mode, 0644, led_mode_show, led_mode_store);
 211
 212 static ssize_t led_interval_show(struct device *dev,
 213                                  struct device_attribute *attr, char *buf)
 214 {
 215         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 216         struct led_netdev_data *trigger_data = led_cdev->trigger_data;
 217
 218         read_lock(&trigger_data->lock);
 219         sprintf(buf, "%u\n", jiffies_to_msecs(trigger_data->interval));
 220         read_unlock(&trigger_data->lock);
 221
 222         return strlen(buf) + 1;
 223 }
 224
 225 static ssize_t led_interval_store(struct device *dev,
 226                                   struct device_attribute *attr, const char *buf, size_t size)
 227 {
 228         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 229         struct led_netdev_data *trigger_data = led_cdev->trigger_data;
 230         int ret = -EINVAL;
 231         char *after;
 232         unsigned long value = simple_strtoul(buf, &after, 10);
 233         size_t count = after - buf;
 234
 235         if (*after && isspace(*after))
 236                 count++;
 237
 238         /* impose some basic bounds on the timer interval */
 239         if (count == size && value >= 5 && value <= 10000) {
 240                 write_lock(&trigger_data->lock);
 241                 trigger_data->interval = msecs_to_jiffies(value);
 242                 set_baseline_state(trigger_data); // resets timer
 243                 write_unlock(&trigger_data->lock);
 244                 ret = count;
 245         }
 246
 247         return ret;
 248 }
 249
 250 static DEVICE_ATTR(interval, 0644, led_interval_show, led_interval_store);
 251
 252 static int netdev_trig_notify(struct notifier_block *nb,
 253                               unsigned long evt,
 254                               void *dv)
 255 {
 256         struct net_device *dev = dv;
 257         struct led_netdev_data *trigger_data = container_of(nb, struct led_netdev_data, notifier);
 258
 259         if (evt != NETDEV_UP && evt != NETDEV_DOWN && evt != NETDEV_CHANGE && evt != NETDEV_REGISTER && evt != NETDEV_UNREGISTER)
 260                 return NOTIFY_DONE;
 261
 262         write_lock(&trigger_data->lock);
 263
 264         if (strcmp(dev->name, trigger_data->device_name))
 265                 goto done;
 266
 267         if (evt == NETDEV_REGISTER) {
 268                 if (trigger_data->net_dev != NULL)
 269                         dev_put(trigger_data->net_dev);
 270                 dev_hold(dev);
 271                 trigger_data->net_dev = dev;
 272                 trigger_data->link_up = 0;
 273                 goto done;
 274         }
 275
 276         if (evt == NETDEV_UNREGISTER && trigger_data->net_dev != NULL) {
 277                 dev_put(trigger_data->net_dev);
 278                 trigger_data->net_dev = NULL;
 279                 goto done;
 280         }
 281
 282         /* UP / DOWN / CHANGE */
 283
 284         trigger_data->link_up = (evt != NETDEV_DOWN && netif_carrier_ok(dev));
 285         set_baseline_state(trigger_data);
 286
 287 done:
 288         write_unlock(&trigger_data->lock);
 289         return NOTIFY_DONE;
 290 }
 291
 292 /* here's the real work! */
 293 static void netdev_trig_timer(unsigned long arg)
 294 {
 295         struct led_netdev_data *trigger_data = (struct led_netdev_data *)arg;
 296         struct net_device_stats *dev_stats;
 297         unsigned new_activity;
 298
 299         write_lock(&trigger_data->lock);
 300
 301         if (!trigger_data->link_up || !trigger_data->net_dev || (trigger_data->mode & (MODE_TX | MODE_RX)) == 0) {
 302                 /* we don't need to do timer work, just reflect link state. */
 303                 led_set_brightness(trigger_data->led_cdev, ((trigger_data->mode & MODE_LINK) != 0 && trigger_data->link_up) ? LED_FULL : LED_OFF);
 304                 goto no_restart;
 305         }
 306
 307         dev_stats = trigger_data->net_dev->get_stats(trigger_data->net_dev);
 308         new_activity =
 309                 ((trigger_data->mode & MODE_TX) ? dev_stats->tx_packets : 0) +
 310                 ((trigger_data->mode & MODE_RX) ? dev_stats->rx_packets : 0);
 311
 312         if (trigger_data->mode & MODE_LINK) {
 313                 /* base state is ON (link present) */
 314                 /* if there's no link, we don't get this far and the LED is off */
 315
 316                 /* OFF -> ON always */
 317                 /* ON -> OFF on activity */
 318                 if (trigger_data->led_cdev->brightness == LED_OFF) {
 319                         led_set_brightness(trigger_data->led_cdev, LED_FULL);
 320                 } else if (trigger_data->last_activity != new_activity) {
 321                         led_set_brightness(trigger_data->led_cdev, LED_OFF);
 322                 }
 323         } else {
 324                 /* base state is OFF */
 325                 /* ON -> OFF always */
 326                 /* OFF -> ON on activity */
 327                 if (trigger_data->led_cdev->brightness == LED_FULL) {
 328                         led_set_brightness(trigger_data->led_cdev, LED_OFF);
 329                 } else if (trigger_data->last_activity != new_activity) {
 330                         led_set_brightness(trigger_data->led_cdev, LED_FULL);
 331                 }
 332         }
 333
 334         trigger_data->last_activity = new_activity;
 335         mod_timer(&trigger_data->timer, jiffies + trigger_data->interval);
 336
 337 no_restart:
 338         write_unlock(&trigger_data->lock);
 339 }
 340
 341 static void netdev_trig_activate(struct led_classdev *led_cdev)
 342 {
 343         struct led_netdev_data *trigger_data;
 344         int rc;
 345
 346         trigger_data = kzalloc(sizeof(struct led_netdev_data), GFP_KERNEL);
 347         if (!trigger_data)
 348                 return;
 349
 350         rwlock_init(&trigger_data->lock);
 351
 352         trigger_data->notifier.notifier_call = netdev_trig_notify;
 353         trigger_data->notifier.priority = 10;
 354
 355         setup_timer(&trigger_data->timer, netdev_trig_timer, (unsigned long) trigger_data);
 356
 357         trigger_data->led_cdev = led_cdev;
 358         trigger_data->net_dev = NULL;
 359         trigger_data->device_name[0] = 0;
 360
 361         trigger_data->mode = 0;
 362         trigger_data->interval = msecs_to_jiffies(50);
 363         trigger_data->link_up = 0;
 364         trigger_data->last_activity = 0;
 365
 366         led_cdev->trigger_data = trigger_data;
 367
 368         rc = device_create_file(led_cdev->dev, &dev_attr_device_name);
 369         if (rc)
 370                 goto err_out;
 371         rc = device_create_file(led_cdev->dev, &dev_attr_mode);
 372         if (rc)
 373                 goto err_out_device_name;
 374         rc = device_create_file(led_cdev->dev, &dev_attr_interval);
 375         if (rc)
 376                 goto err_out_mode;
 377
 378         register_netdevice_notifier(&trigger_data->notifier);
 379         return;
 380
 381 err_out_mode:
 382         device_remove_file(led_cdev->dev, &dev_attr_mode);
 383 err_out_device_name:
 384         device_remove_file(led_cdev->dev, &dev_attr_device_name);
 385 err_out:
 386         led_cdev->trigger_data = NULL;
 387         kfree(trigger_data);
 388 }
 389
 390 static void netdev_trig_deactivate(struct led_classdev *led_cdev)
 391 {
 392         struct led_netdev_data *trigger_data = led_cdev->trigger_data;
 393
 394         if (trigger_data) {
 395                 unregister_netdevice_notifier(&trigger_data->notifier);
 396
 397                 device_remove_file(led_cdev->dev, &dev_attr_device_name);
 398                 device_remove_file(led_cdev->dev, &dev_attr_mode);
 399                 device_remove_file(led_cdev->dev, &dev_attr_interval);
 400
 401                 write_lock(&trigger_data->lock);
 402
 403                 if (trigger_data->net_dev) {
 404                         dev_put(trigger_data->net_dev);
 405                         trigger_data->net_dev = NULL;
 406                 }
 407
 408                 write_unlock(&trigger_data->lock);
 409
 410                 del_timer_sync(&trigger_data->timer);
 411
 412                 kfree(trigger_data);
 413         }
 414 }
 415
 416 static struct led_trigger netdev_led_trigger = {
 417         .name     = "netdev",
 418         .activate = netdev_trig_activate,
 419         .deactivate = netdev_trig_deactivate,
 420 };
 421
 422 static int __init netdev_trig_init(void)
 423 {
 424         return led_trigger_register(&netdev_led_trigger);
 425 }
 426
 427 static void __exit netdev_trig_exit(void)
 428 {
 429         led_trigger_unregister(&netdev_led_trigger);
 430 }
 431
 432 module_init(netdev_trig_init);
 433 module_exit(netdev_trig_exit);
 434
 435 MODULE_AUTHOR("Oliver Jowett <oliver@opencloud.com>");
 436 MODULE_DESCRIPTION("Netdev LED trigger");
 437 MODULE_LICENSE("GPL");