drivers/leds/trigger/ledtrig-netdev.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 // Copyright 2017 Ben Whitten <[email protected]>
   3 // Copyright 2007 Oliver Jowett <[email protected]>
   4 //
   5 // LED Kernel Netdev Trigger
   6 //
   7 // Toggles the LED to reflect the link and traffic state of a named net device
   8 //
   9 // Derived from ledtrig-timer.c which is:
  10 //  Copyright 2005-2006 Openedhand Ltd.
  11 //  Author: Richard Purdie <[email protected]>
  12
  13 #include <linux/atomic.h>
  14 #include <linux/ctype.h>
  15 #include <linux/device.h>
  16 #include <linux/init.h>
  17 #include <linux/jiffies.h>
  18 #include <linux/kernel.h>
  19 #include <linux/leds.h>
  20 #include <linux/list.h>
  21 #include <linux/module.h>
  22 #include <linux/netdevice.h>
  23 #include <linux/spinlock.h>
  24 #include <linux/timer.h>
  25 #include "../leds.h"
  26
  27 /*
  28  * Configurable sysfs attributes:
  29  *
  30  * device_name - network device name to monitor
  31  * interval - duration of LED blink, in milliseconds
  32  * link -  LED's normal state reflects whether the link is up
  33  *         (has carrier) or not
  34  * tx -  LED blinks on transmitted data
  35  * rx -  LED blinks on receive data
  36  *
  37  */
  38
  39 struct led_netdev_data {
  40         spinlock_t lock;
  41
  42         struct delayed_work work;
  43         struct notifier_block notifier;
  44
  45         struct led_classdev *led_cdev;
  46         struct net_device *net_dev;
  47
  48         char device_name[IFNAMSIZ];
  49         atomic_t interval;
  50         unsigned int last_activity;
  51
  52         unsigned long mode;
  53 #define NETDEV_LED_LINK 0
  54 #define NETDEV_LED_TX   1
  55 #define NETDEV_LED_RX   2
  56 #define NETDEV_LED_MODE_LINKUP  3
  57 };
  58
  59 enum netdev_led_attr {
  60         NETDEV_ATTR_LINK,
  61         NETDEV_ATTR_TX,
  62         NETDEV_ATTR_RX
  63 };
  64
  65 static void set_baseline_state(struct led_netdev_data *trigger_data)
  66 {
  67         int current_brightness;
  68         struct led_classdev *led_cdev = trigger_data->led_cdev;
  69
  70         current_brightness = led_cdev->brightness;
  71         if (current_brightness)
  72                 led_cdev->blink_brightness = current_brightness;
  73         if (!led_cdev->blink_brightness)
  74                 led_cdev->blink_brightness = led_cdev->max_brightness;
  75
  76         if (!test_bit(NETDEV_LED_MODE_LINKUP, &trigger_data->mode))
  77                 led_set_brightness(led_cdev, LED_OFF);
  78         else {
  79                 if (test_bit(NETDEV_LED_LINK, &trigger_data->mode))
  80                         led_set_brightness(led_cdev,
  81                                            led_cdev->blink_brightness);
  82                 else
  83                         led_set_brightness(led_cdev, LED_OFF);
  84
  85                 /* If we are looking for RX/TX start periodically
  86                  * checking stats
  87                  */
  88                 if (test_bit(NETDEV_LED_TX, &trigger_data->mode) ||
  89                     test_bit(NETDEV_LED_RX, &trigger_data->mode))
  90                         schedule_delayed_work(&trigger_data->work, 0);
  91         }
  92 }
  93
  94 static ssize_t device_name_show(struct device *dev,
  95                                 struct device_attribute *attr, char *buf)
  96 {
  97         struct led_classdev *led_cdev = dev_get_drvdata(dev);
  98         struct led_netdev_data *trigger_data = led_cdev->trigger_data;
  99         ssize_t len;
 100
 101         spin_lock_bh(&trigger_data->lock);
 102         len = sprintf(buf, "%s\n", trigger_data->device_name);
 103         spin_unlock_bh(&trigger_data->lock);
 104
 105         return len;
 106 }
 107
 108 static ssize_t device_name_store(struct device *dev,
 109                                  struct device_attribute *attr, const char *buf,
 110                                  size_t size)
 111 {
 112         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 113         struct led_netdev_data *trigger_data = led_cdev->trigger_data;
 114
 115         if (size >= IFNAMSIZ)
 116                 return -EINVAL;
 117
 118         cancel_delayed_work_sync(&trigger_data->work);
 119
 120         spin_lock_bh(&trigger_data->lock);
 121
 122         if (trigger_data->net_dev) {
 123                 dev_put(trigger_data->net_dev);
 124                 trigger_data->net_dev = NULL;
 125         }
 126
 127         strncpy(trigger_data->device_name, buf, size);
 128         if (size > 0 && trigger_data->device_name[size - 1] == '\n')
 129                 trigger_data->device_name[size - 1] = 0;
 130
 131         if (trigger_data->device_name[0] != 0)
 132                 trigger_data->net_dev =
 133                     dev_get_by_name(&init_net, trigger_data->device_name);
 134
 135         clear_bit(NETDEV_LED_MODE_LINKUP, &trigger_data->mode);
 136         if (trigger_data->net_dev != NULL)
 137                 if (netif_carrier_ok(trigger_data->net_dev))
 138                         set_bit(NETDEV_LED_MODE_LINKUP, &trigger_data->mode);
 139
 140         trigger_data->last_activity = 0;
 141
 142         set_baseline_state(trigger_data);
 143         spin_unlock_bh(&trigger_data->lock);
 144
 145         return size;
 146 }
 147
 148 static DEVICE_ATTR_RW(device_name);
 149
 150 static ssize_t netdev_led_attr_show(struct device *dev, char *buf,
 151         enum netdev_led_attr attr)
 152 {
 153         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 154         struct led_netdev_data *trigger_data = led_cdev->trigger_data;
 155         int bit;
 156
 157         switch (attr) {
 158         case NETDEV_ATTR_LINK:
 159                 bit = NETDEV_LED_LINK;
 160                 break;
 161         case NETDEV_ATTR_TX:
 162                 bit = NETDEV_LED_TX;
 163                 break;
 164         case NETDEV_ATTR_RX:
 165                 bit = NETDEV_LED_RX;
 166                 break;
 167         default:
 168                 return -EINVAL;
 169         }
 170
 171         return sprintf(buf, "%u\n", test_bit(bit, &trigger_data->mode));
 172 }
 173
 174 static ssize_t netdev_led_attr_store(struct device *dev, const char *buf,
 175         size_t size, enum netdev_led_attr attr)
 176 {
 177         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 178         struct led_netdev_data *trigger_data = led_cdev->trigger_data;
 179         unsigned long state;
 180         int ret;
 181         int bit;
 182
 183         ret = kstrtoul(buf, 0, &state);
 184         if (ret)
 185                 return ret;
 186
 187         switch (attr) {
 188         case NETDEV_ATTR_LINK:
 189                 bit = NETDEV_LED_LINK;
 190                 break;
 191         case NETDEV_ATTR_TX:
 192                 bit = NETDEV_LED_TX;
 193                 break;
 194         case NETDEV_ATTR_RX:
 195                 bit = NETDEV_LED_RX;
 196                 break;
 197         default:
 198                 return -EINVAL;
 199         }
 200
 201         cancel_delayed_work_sync(&trigger_data->work);
 202
 203         if (state)
 204                 set_bit(bit, &trigger_data->mode);
 205         else
 206                 clear_bit(bit, &trigger_data->mode);
 207
 208         set_baseline_state(trigger_data);
 209
 210         return size;
 211 }
 212
 213 static ssize_t link_show(struct device *dev,
 214         struct device_attribute *attr, char *buf)
 215 {
 216         return netdev_led_attr_show(dev, buf, NETDEV_ATTR_LINK);
 217 }
 218
 219 static ssize_t link_store(struct device *dev,
 220         struct device_attribute *attr, const char *buf, size_t size)
 221 {
 222         return netdev_led_attr_store(dev, buf, size, NETDEV_ATTR_LINK);
 223 }
 224
 225 static DEVICE_ATTR_RW(link);
 226
 227 static ssize_t tx_show(struct device *dev,
 228         struct device_attribute *attr, char *buf)
 229 {
 230         return netdev_led_attr_show(dev, buf, NETDEV_ATTR_TX);
 231 }
 232
 233 static ssize_t tx_store(struct device *dev,
 234         struct device_attribute *attr, const char *buf, size_t size)
 235 {
 236         return netdev_led_attr_store(dev, buf, size, NETDEV_ATTR_TX);
 237 }
 238
 239 static DEVICE_ATTR_RW(tx);
 240
 241 static ssize_t rx_show(struct device *dev,
 242         struct device_attribute *attr, char *buf)
 243 {
 244         return netdev_led_attr_show(dev, buf, NETDEV_ATTR_RX);
 245 }
 246
 247 static ssize_t rx_store(struct device *dev,
 248         struct device_attribute *attr, const char *buf, size_t size)
 249 {
 250         return netdev_led_attr_store(dev, buf, size, NETDEV_ATTR_RX);
 251 }
 252
 253 static DEVICE_ATTR_RW(rx);
 254
 255 static ssize_t interval_show(struct device *dev,
 256                              struct device_attribute *attr, char *buf)
 257 {
 258         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 259         struct led_netdev_data *trigger_data = led_cdev->trigger_data;
 260
 261         return sprintf(buf, "%u\n",
 262                        jiffies_to_msecs(atomic_read(&trigger_data->interval)));
 263 }
 264
 265 static ssize_t interval_store(struct device *dev,
 266                               struct device_attribute *attr, const char *buf,
 267                               size_t size)
 268 {
 269         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 270         struct led_netdev_data *trigger_data = led_cdev->trigger_data;
 271         unsigned long value;
 272         int ret;
 273
 274         ret = kstrtoul(buf, 0, &value);
 275         if (ret)
 276                 return ret;
 277
 278         /* impose some basic bounds on the timer interval */
 279         if (value >= 5 && value <= 10000) {
 280                 cancel_delayed_work_sync(&trigger_data->work);
 281
 282                 atomic_set(&trigger_data->interval, msecs_to_jiffies(value));
 283                 set_baseline_state(trigger_data);       /* resets timer */
 284         }
 285
 286         return size;
 287 }
 288
 289 static DEVICE_ATTR_RW(interval);
 290
 291 static int netdev_trig_notify(struct notifier_block *nb,
 292                               unsigned long evt, void *dv)
 293 {
 294         struct net_device *dev =
 295                 netdev_notifier_info_to_dev((struct netdev_notifier_info *)dv);
 296         struct led_netdev_data *trigger_data = container_of(nb,
 297                                                             struct
 298                                                             led_netdev_data,
 299                                                             notifier);
 300
 301         if (evt != NETDEV_UP && evt != NETDEV_DOWN && evt != NETDEV_CHANGE
 302             && evt != NETDEV_REGISTER && evt != NETDEV_UNREGISTER
 303             && evt != NETDEV_CHANGENAME)
 304                 return NOTIFY_DONE;
 305
 306         if (strcmp(dev->name, trigger_data->device_name))
 307                 return NOTIFY_DONE;
 308
 309         cancel_delayed_work_sync(&trigger_data->work);
 310
 311         spin_lock_bh(&trigger_data->lock);
 312
 313         clear_bit(NETDEV_LED_MODE_LINKUP, &trigger_data->mode);
 314         switch (evt) {
 315         case NETDEV_REGISTER:
 316                 if (trigger_data->net_dev)
 317                         dev_put(trigger_data->net_dev);
 318                 dev_hold(dev);
 319                 trigger_data->net_dev = dev;
 320                 break;
 321         case NETDEV_CHANGENAME:
 322         case NETDEV_UNREGISTER:
 323                 if (trigger_data->net_dev) {
 324                         dev_put(trigger_data->net_dev);
 325                         trigger_data->net_dev = NULL;
 326                 }
 327                 break;
 328         case NETDEV_UP:
 329         case NETDEV_CHANGE:
 330                 if (netif_carrier_ok(dev))
 331                         set_bit(NETDEV_LED_MODE_LINKUP, &trigger_data->mode);
 332                 break;
 333         }
 334
 335         set_baseline_state(trigger_data);
 336
 337         spin_unlock_bh(&trigger_data->lock);
 338
 339         return NOTIFY_DONE;
 340 }
 341
 342 /* here's the real work! */
 343 static void netdev_trig_work(struct work_struct *work)
 344 {
 345         struct led_netdev_data *trigger_data = container_of(work,
 346                                                             struct
 347                                                             led_netdev_data,
 348                                                             work.work);
 349         struct rtnl_link_stats64 *dev_stats;
 350         unsigned int new_activity;
 351         struct rtnl_link_stats64 temp;
 352         unsigned long interval;
 353         int invert;
 354
 355         /* If we dont have a device, insure we are off */
 356         if (!trigger_data->net_dev) {
 357                 led_set_brightness(trigger_data->led_cdev, LED_OFF);
 358                 return;
 359         }
 360
 361         /* If we are not looking for RX/TX then return  */
 362         if (!test_bit(NETDEV_LED_TX, &trigger_data->mode) &&
 363             !test_bit(NETDEV_LED_RX, &trigger_data->mode))
 364                 return;
 365
 366         dev_stats = dev_get_stats(trigger_data->net_dev, &temp);
 367         new_activity =
 368             (test_bit(NETDEV_LED_TX, &trigger_data->mode) ?
 369                 dev_stats->tx_packets : 0) +
 370             (test_bit(NETDEV_LED_RX, &trigger_data->mode) ?
 371                 dev_stats->rx_packets : 0);
 372
 373         if (trigger_data->last_activity != new_activity) {
 374                 led_stop_software_blink(trigger_data->led_cdev);
 375
 376                 invert = test_bit(NETDEV_LED_LINK, &trigger_data->mode);
 377                 interval = jiffies_to_msecs(
 378                                 atomic_read(&trigger_data->interval));
 379                 /* base state is ON (link present) */
 380                 led_blink_set_oneshot(trigger_data->led_cdev,
 381                                       &interval,
 382                                       &interval,
 383                                       invert);
 384                 trigger_data->last_activity = new_activity;
 385         }
 386
 387         schedule_delayed_work(&trigger_data->work,
 388                         (atomic_read(&trigger_data->interval)*2));
 389 }
 390
 391 static void netdev_trig_activate(struct led_classdev *led_cdev)
 392 {
 393         struct led_netdev_data *trigger_data;
 394         int rc;
 395
 396         trigger_data = kzalloc(sizeof(struct led_netdev_data), GFP_KERNEL);
 397         if (!trigger_data)
 398                 return;
 399
 400         spin_lock_init(&trigger_data->lock);
 401
 402         trigger_data->notifier.notifier_call = netdev_trig_notify;
 403         trigger_data->notifier.priority = 10;
 404
 405         INIT_DELAYED_WORK(&trigger_data->work, netdev_trig_work);
 406
 407         trigger_data->led_cdev = led_cdev;
 408         trigger_data->net_dev = NULL;
 409         trigger_data->device_name[0] = 0;
 410
 411         trigger_data->mode = 0;
 412         atomic_set(&trigger_data->interval, msecs_to_jiffies(50));
 413         trigger_data->last_activity = 0;
 414
 415         led_cdev->trigger_data = trigger_data;
 416
 417         rc = device_create_file(led_cdev->dev, &dev_attr_device_name);
 418         if (rc)
 419                 goto err_out;
 420         rc = device_create_file(led_cdev->dev, &dev_attr_link);
 421         if (rc)
 422                 goto err_out_device_name;
 423         rc = device_create_file(led_cdev->dev, &dev_attr_rx);
 424         if (rc)
 425                 goto err_out_link;
 426         rc = device_create_file(led_cdev->dev, &dev_attr_tx);
 427         if (rc)
 428                 goto err_out_rx;
 429         rc = device_create_file(led_cdev->dev, &dev_attr_interval);
 430         if (rc)
 431                 goto err_out_tx;
 432         rc = register_netdevice_notifier(&trigger_data->notifier);
 433         if (rc)
 434                 goto err_out_interval;
 435         return;
 436
 437 err_out_interval:
 438         device_remove_file(led_cdev->dev, &dev_attr_interval);
 439 err_out_tx:
 440         device_remove_file(led_cdev->dev, &dev_attr_tx);
 441 err_out_rx:
 442         device_remove_file(led_cdev->dev, &dev_attr_rx);
 443 err_out_link:
 444         device_remove_file(led_cdev->dev, &dev_attr_link);
 445 err_out_device_name:
 446         device_remove_file(led_cdev->dev, &dev_attr_device_name);
 447 err_out:
 448         led_cdev->trigger_data = NULL;
 449         kfree(trigger_data);
 450 }
 451
 452 static void netdev_trig_deactivate(struct led_classdev *led_cdev)
 453 {
 454         struct led_netdev_data *trigger_data = led_cdev->trigger_data;
 455
 456         if (trigger_data) {
 457                 unregister_netdevice_notifier(&trigger_data->notifier);
 458
 459                 device_remove_file(led_cdev->dev, &dev_attr_device_name);
 460                 device_remove_file(led_cdev->dev, &dev_attr_link);
 461                 device_remove_file(led_cdev->dev, &dev_attr_rx);
 462                 device_remove_file(led_cdev->dev, &dev_attr_tx);
 463                 device_remove_file(led_cdev->dev, &dev_attr_interval);
 464
 465                 cancel_delayed_work_sync(&trigger_data->work);
 466
 467                 if (trigger_data->net_dev)
 468                         dev_put(trigger_data->net_dev);
 469
 470                 kfree(trigger_data);
 471         }
 472 }
 473
 474 static struct led_trigger netdev_led_trigger = {
 475         .name = "netdev",
 476         .activate = netdev_trig_activate,
 477         .deactivate = netdev_trig_deactivate,
 478 };
 479
 480 static int __init netdev_trig_init(void)
 481 {
 482         return led_trigger_register(&netdev_led_trigger);
 483 }
 484
 485 static void __exit netdev_trig_exit(void)
 486 {
 487         led_trigger_unregister(&netdev_led_trigger);
 488 }
 489
 490 module_init(netdev_trig_init);
 491 module_exit(netdev_trig_exit);
 492
 493 MODULE_AUTHOR("Ben Whitten <[email protected]>");
 494 MODULE_AUTHOR("Oliver Jowett <[email protected]>");
 495 MODULE_DESCRIPTION("Netdev LED trigger");
 496 MODULE_LICENSE("GPL v2");