1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright 2017 Ben Whitten <ben.whitten@gmail.com>
3 // Copyright 2007 Oliver Jowett <oliver@opencloud.com>
5 // LED Kernel Netdev Trigger
7 // Toggles the LED to reflect the link and traffic state of a named net device
9 // Derived from ledtrig-timer.c which is:
10 // Copyright 2005-2006 Openedhand Ltd.
11 // Author: Richard Purdie <rpurdie@openedhand.com>
13 #include <linux/atomic.h>
14 #include <linux/ctype.h>
15 #include <linux/device.h>
16 #include <linux/ethtool.h>
17 #include <linux/init.h>
18 #include <linux/jiffies.h>
19 #include <linux/kernel.h>
20 #include <linux/leds.h>
21 #include <linux/list.h>
22 #include <linux/module.h>
23 #include <linux/netdevice.h>
24 #include <linux/mutex.h>
25 #include <linux/rtnetlink.h>
26 #include <linux/timer.h>
29 #define NETDEV_LED_DEFAULT_INTERVAL 50
32 * Configurable sysfs attributes:
34 * device_name - network device name to monitor
35 * interval - duration of LED blink, in milliseconds
36 * link - LED's normal state reflects whether the link is up
37 * (has carrier) or not
38 * tx - LED blinks on transmitted data
39 * rx - LED blinks on receive data
43 struct led_netdev_data
{
46 struct delayed_work work
;
47 struct notifier_block notifier
;
49 struct led_classdev
*led_cdev
;
50 struct net_device
*net_dev
;
52 char device_name
[IFNAMSIZ
];
54 unsigned int last_activity
;
64 static void set_baseline_state(struct led_netdev_data
*trigger_data
)
66 int current_brightness
;
67 struct led_classdev
*led_cdev
= trigger_data
->led_cdev
;
69 /* Already validated, hw control is possible with the requested mode */
70 if (trigger_data
->hw_control
) {
71 led_cdev
->hw_control_set(led_cdev
, trigger_data
->mode
);
76 current_brightness
= led_cdev
->brightness
;
77 if (current_brightness
)
78 led_cdev
->blink_brightness
= current_brightness
;
79 if (!led_cdev
->blink_brightness
)
80 led_cdev
->blink_brightness
= led_cdev
->max_brightness
;
82 if (!trigger_data
->carrier_link_up
) {
83 led_set_brightness(led_cdev
, LED_OFF
);
85 bool blink_on
= false;
87 if (test_bit(TRIGGER_NETDEV_LINK
, &trigger_data
->mode
))
90 if (test_bit(TRIGGER_NETDEV_LINK_10
, &trigger_data
->mode
) &&
91 trigger_data
->link_speed
== SPEED_10
)
94 if (test_bit(TRIGGER_NETDEV_LINK_100
, &trigger_data
->mode
) &&
95 trigger_data
->link_speed
== SPEED_100
)
98 if (test_bit(TRIGGER_NETDEV_LINK_1000
, &trigger_data
->mode
) &&
99 trigger_data
->link_speed
== SPEED_1000
)
102 if (test_bit(TRIGGER_NETDEV_HALF_DUPLEX
, &trigger_data
->mode
) &&
103 trigger_data
->duplex
== DUPLEX_HALF
)
106 if (test_bit(TRIGGER_NETDEV_FULL_DUPLEX
, &trigger_data
->mode
) &&
107 trigger_data
->duplex
== DUPLEX_FULL
)
111 led_set_brightness(led_cdev
,
112 led_cdev
->blink_brightness
);
114 led_set_brightness(led_cdev
, LED_OFF
);
116 /* If we are looking for RX/TX start periodically
119 if (test_bit(TRIGGER_NETDEV_TX
, &trigger_data
->mode
) ||
120 test_bit(TRIGGER_NETDEV_RX
, &trigger_data
->mode
))
121 schedule_delayed_work(&trigger_data
->work
, 0);
125 static bool supports_hw_control(struct led_classdev
*led_cdev
)
127 if (!led_cdev
->hw_control_get
|| !led_cdev
->hw_control_set
||
128 !led_cdev
->hw_control_is_supported
)
131 return !strcmp(led_cdev
->hw_control_trigger
, led_cdev
->trigger
->name
);
135 * Validate the configured netdev is the same as the one associated with
136 * the LED driver in hw control.
138 static bool validate_net_dev(struct led_classdev
*led_cdev
,
139 struct net_device
*net_dev
)
141 struct device
*dev
= led_cdev
->hw_control_get_device(led_cdev
);
142 struct net_device
*ndev
;
147 ndev
= to_net_dev(dev
);
149 return ndev
== net_dev
;
152 static bool can_hw_control(struct led_netdev_data
*trigger_data
)
154 unsigned long default_interval
= msecs_to_jiffies(NETDEV_LED_DEFAULT_INTERVAL
);
155 unsigned int interval
= atomic_read(&trigger_data
->interval
);
156 struct led_classdev
*led_cdev
= trigger_data
->led_cdev
;
159 if (!supports_hw_control(led_cdev
))
163 * Interval must be set to the default
164 * value. Any different value is rejected if in hw
167 if (interval
!= default_interval
)
171 * net_dev must be set with hw control, otherwise no
172 * blinking can be happening and there is nothing to
173 * offloaded. Additionally, for hw control to be
174 * valid, the configured netdev must be the same as
175 * netdev associated to the LED.
177 if (!validate_net_dev(led_cdev
, trigger_data
->net_dev
))
180 /* Check if the requested mode is supported */
181 ret
= led_cdev
->hw_control_is_supported(led_cdev
, trigger_data
->mode
);
182 /* Fall back to software blinking if not supported */
183 if (ret
== -EOPNOTSUPP
)
186 dev_warn(led_cdev
->dev
,
187 "Current mode check failed with error %d\n", ret
);
194 static void get_device_state(struct led_netdev_data
*trigger_data
)
196 struct ethtool_link_ksettings cmd
;
198 trigger_data
->carrier_link_up
= netif_carrier_ok(trigger_data
->net_dev
);
199 if (!trigger_data
->carrier_link_up
)
202 if (!__ethtool_get_link_ksettings(trigger_data
->net_dev
, &cmd
)) {
203 trigger_data
->link_speed
= cmd
.base
.speed
;
204 trigger_data
->duplex
= cmd
.base
.duplex
;
208 static ssize_t
device_name_show(struct device
*dev
,
209 struct device_attribute
*attr
, char *buf
)
211 struct led_netdev_data
*trigger_data
= led_trigger_get_drvdata(dev
);
214 mutex_lock(&trigger_data
->lock
);
215 len
= sprintf(buf
, "%s\n", trigger_data
->device_name
);
216 mutex_unlock(&trigger_data
->lock
);
221 static int set_device_name(struct led_netdev_data
*trigger_data
,
222 const char *name
, size_t size
)
224 if (size
>= IFNAMSIZ
)
227 cancel_delayed_work_sync(&trigger_data
->work
);
230 * Take RTNL lock before trigger_data lock to prevent potential
231 * deadlock with netdev notifier registration.
234 mutex_lock(&trigger_data
->lock
);
236 if (trigger_data
->net_dev
) {
237 dev_put(trigger_data
->net_dev
);
238 trigger_data
->net_dev
= NULL
;
241 memcpy(trigger_data
->device_name
, name
, size
);
242 trigger_data
->device_name
[size
] = 0;
243 if (size
> 0 && trigger_data
->device_name
[size
- 1] == '\n')
244 trigger_data
->device_name
[size
- 1] = 0;
246 if (trigger_data
->device_name
[0] != 0)
247 trigger_data
->net_dev
=
248 dev_get_by_name(&init_net
, trigger_data
->device_name
);
250 trigger_data
->carrier_link_up
= false;
251 trigger_data
->link_speed
= SPEED_UNKNOWN
;
252 trigger_data
->duplex
= DUPLEX_UNKNOWN
;
253 if (trigger_data
->net_dev
)
254 get_device_state(trigger_data
);
256 trigger_data
->last_activity
= 0;
258 set_baseline_state(trigger_data
);
259 mutex_unlock(&trigger_data
->lock
);
265 static ssize_t
device_name_store(struct device
*dev
,
266 struct device_attribute
*attr
, const char *buf
,
269 struct led_netdev_data
*trigger_data
= led_trigger_get_drvdata(dev
);
272 ret
= set_device_name(trigger_data
, buf
, size
);
279 static DEVICE_ATTR_RW(device_name
);
281 static ssize_t
netdev_led_attr_show(struct device
*dev
, char *buf
,
282 enum led_trigger_netdev_modes attr
)
284 struct led_netdev_data
*trigger_data
= led_trigger_get_drvdata(dev
);
288 case TRIGGER_NETDEV_LINK
:
289 case TRIGGER_NETDEV_LINK_10
:
290 case TRIGGER_NETDEV_LINK_100
:
291 case TRIGGER_NETDEV_LINK_1000
:
292 case TRIGGER_NETDEV_HALF_DUPLEX
:
293 case TRIGGER_NETDEV_FULL_DUPLEX
:
294 case TRIGGER_NETDEV_TX
:
295 case TRIGGER_NETDEV_RX
:
302 return sprintf(buf
, "%u\n", test_bit(bit
, &trigger_data
->mode
));
305 static ssize_t
netdev_led_attr_store(struct device
*dev
, const char *buf
,
306 size_t size
, enum led_trigger_netdev_modes attr
)
308 struct led_netdev_data
*trigger_data
= led_trigger_get_drvdata(dev
);
309 unsigned long state
, mode
= trigger_data
->mode
;
313 ret
= kstrtoul(buf
, 0, &state
);
318 case TRIGGER_NETDEV_LINK
:
319 case TRIGGER_NETDEV_LINK_10
:
320 case TRIGGER_NETDEV_LINK_100
:
321 case TRIGGER_NETDEV_LINK_1000
:
322 case TRIGGER_NETDEV_HALF_DUPLEX
:
323 case TRIGGER_NETDEV_FULL_DUPLEX
:
324 case TRIGGER_NETDEV_TX
:
325 case TRIGGER_NETDEV_RX
:
335 clear_bit(bit
, &mode
);
337 if (test_bit(TRIGGER_NETDEV_LINK
, &mode
) &&
338 (test_bit(TRIGGER_NETDEV_LINK_10
, &mode
) ||
339 test_bit(TRIGGER_NETDEV_LINK_100
, &mode
) ||
340 test_bit(TRIGGER_NETDEV_LINK_1000
, &mode
)))
343 cancel_delayed_work_sync(&trigger_data
->work
);
345 trigger_data
->mode
= mode
;
346 trigger_data
->hw_control
= can_hw_control(trigger_data
);
348 set_baseline_state(trigger_data
);
353 #define DEFINE_NETDEV_TRIGGER(trigger_name, trigger) \
354 static ssize_t trigger_name##_show(struct device *dev, \
355 struct device_attribute *attr, char *buf) \
357 return netdev_led_attr_show(dev, buf, trigger); \
359 static ssize_t trigger_name##_store(struct device *dev, \
360 struct device_attribute *attr, const char *buf, size_t size) \
362 return netdev_led_attr_store(dev, buf, size, trigger); \
364 static DEVICE_ATTR_RW(trigger_name)
366 DEFINE_NETDEV_TRIGGER(link
, TRIGGER_NETDEV_LINK
);
367 DEFINE_NETDEV_TRIGGER(link_10
, TRIGGER_NETDEV_LINK_10
);
368 DEFINE_NETDEV_TRIGGER(link_100
, TRIGGER_NETDEV_LINK_100
);
369 DEFINE_NETDEV_TRIGGER(link_1000
, TRIGGER_NETDEV_LINK_1000
);
370 DEFINE_NETDEV_TRIGGER(half_duplex
, TRIGGER_NETDEV_HALF_DUPLEX
);
371 DEFINE_NETDEV_TRIGGER(full_duplex
, TRIGGER_NETDEV_FULL_DUPLEX
);
372 DEFINE_NETDEV_TRIGGER(tx
, TRIGGER_NETDEV_TX
);
373 DEFINE_NETDEV_TRIGGER(rx
, TRIGGER_NETDEV_RX
);
375 static ssize_t
interval_show(struct device
*dev
,
376 struct device_attribute
*attr
, char *buf
)
378 struct led_netdev_data
*trigger_data
= led_trigger_get_drvdata(dev
);
380 return sprintf(buf
, "%u\n",
381 jiffies_to_msecs(atomic_read(&trigger_data
->interval
)));
384 static ssize_t
interval_store(struct device
*dev
,
385 struct device_attribute
*attr
, const char *buf
,
388 struct led_netdev_data
*trigger_data
= led_trigger_get_drvdata(dev
);
392 if (trigger_data
->hw_control
)
395 ret
= kstrtoul(buf
, 0, &value
);
399 /* impose some basic bounds on the timer interval */
400 if (value
>= 5 && value
<= 10000) {
401 cancel_delayed_work_sync(&trigger_data
->work
);
403 atomic_set(&trigger_data
->interval
, msecs_to_jiffies(value
));
404 set_baseline_state(trigger_data
); /* resets timer */
410 static DEVICE_ATTR_RW(interval
);
412 static ssize_t
offloaded_show(struct device
*dev
,
413 struct device_attribute
*attr
, char *buf
)
415 struct led_netdev_data
*trigger_data
= led_trigger_get_drvdata(dev
);
417 return sprintf(buf
, "%d\n", trigger_data
->hw_control
);
420 static DEVICE_ATTR_RO(offloaded
);
422 static struct attribute
*netdev_trig_attrs
[] = {
423 &dev_attr_device_name
.attr
,
425 &dev_attr_link_10
.attr
,
426 &dev_attr_link_100
.attr
,
427 &dev_attr_link_1000
.attr
,
428 &dev_attr_full_duplex
.attr
,
429 &dev_attr_half_duplex
.attr
,
432 &dev_attr_interval
.attr
,
433 &dev_attr_offloaded
.attr
,
436 ATTRIBUTE_GROUPS(netdev_trig
);
438 static int netdev_trig_notify(struct notifier_block
*nb
,
439 unsigned long evt
, void *dv
)
441 struct net_device
*dev
=
442 netdev_notifier_info_to_dev((struct netdev_notifier_info
*)dv
);
443 struct led_netdev_data
*trigger_data
=
444 container_of(nb
, struct led_netdev_data
, notifier
);
446 if (evt
!= NETDEV_UP
&& evt
!= NETDEV_DOWN
&& evt
!= NETDEV_CHANGE
447 && evt
!= NETDEV_REGISTER
&& evt
!= NETDEV_UNREGISTER
448 && evt
!= NETDEV_CHANGENAME
)
451 if (!(dev
== trigger_data
->net_dev
||
452 (evt
== NETDEV_CHANGENAME
&& !strcmp(dev
->name
, trigger_data
->device_name
)) ||
453 (evt
== NETDEV_REGISTER
&& !strcmp(dev
->name
, trigger_data
->device_name
))))
456 cancel_delayed_work_sync(&trigger_data
->work
);
458 mutex_lock(&trigger_data
->lock
);
460 trigger_data
->carrier_link_up
= false;
461 trigger_data
->link_speed
= SPEED_UNKNOWN
;
462 trigger_data
->duplex
= DUPLEX_UNKNOWN
;
464 case NETDEV_CHANGENAME
:
465 get_device_state(trigger_data
);
467 case NETDEV_REGISTER
:
468 dev_put(trigger_data
->net_dev
);
470 trigger_data
->net_dev
= dev
;
472 case NETDEV_UNREGISTER
:
473 dev_put(trigger_data
->net_dev
);
474 trigger_data
->net_dev
= NULL
;
478 get_device_state(trigger_data
);
482 set_baseline_state(trigger_data
);
484 mutex_unlock(&trigger_data
->lock
);
489 /* here's the real work! */
490 static void netdev_trig_work(struct work_struct
*work
)
492 struct led_netdev_data
*trigger_data
=
493 container_of(work
, struct led_netdev_data
, work
.work
);
494 struct rtnl_link_stats64
*dev_stats
;
495 unsigned int new_activity
;
496 struct rtnl_link_stats64 temp
;
497 unsigned long interval
;
500 /* If we dont have a device, insure we are off */
501 if (!trigger_data
->net_dev
) {
502 led_set_brightness(trigger_data
->led_cdev
, LED_OFF
);
506 /* If we are not looking for RX/TX then return */
507 if (!test_bit(TRIGGER_NETDEV_TX
, &trigger_data
->mode
) &&
508 !test_bit(TRIGGER_NETDEV_RX
, &trigger_data
->mode
))
511 dev_stats
= dev_get_stats(trigger_data
->net_dev
, &temp
);
513 (test_bit(TRIGGER_NETDEV_TX
, &trigger_data
->mode
) ?
514 dev_stats
->tx_packets
: 0) +
515 (test_bit(TRIGGER_NETDEV_RX
, &trigger_data
->mode
) ?
516 dev_stats
->rx_packets
: 0);
518 if (trigger_data
->last_activity
!= new_activity
) {
519 led_stop_software_blink(trigger_data
->led_cdev
);
521 invert
= test_bit(TRIGGER_NETDEV_LINK
, &trigger_data
->mode
) ||
522 test_bit(TRIGGER_NETDEV_LINK_10
, &trigger_data
->mode
) ||
523 test_bit(TRIGGER_NETDEV_LINK_100
, &trigger_data
->mode
) ||
524 test_bit(TRIGGER_NETDEV_LINK_1000
, &trigger_data
->mode
) ||
525 test_bit(TRIGGER_NETDEV_HALF_DUPLEX
, &trigger_data
->mode
) ||
526 test_bit(TRIGGER_NETDEV_FULL_DUPLEX
, &trigger_data
->mode
);
527 interval
= jiffies_to_msecs(
528 atomic_read(&trigger_data
->interval
));
529 /* base state is ON (link present) */
530 led_blink_set_oneshot(trigger_data
->led_cdev
,
534 trigger_data
->last_activity
= new_activity
;
537 schedule_delayed_work(&trigger_data
->work
,
538 (atomic_read(&trigger_data
->interval
)*2));
541 static int netdev_trig_activate(struct led_classdev
*led_cdev
)
543 struct led_netdev_data
*trigger_data
;
544 unsigned long mode
= 0;
548 trigger_data
= kzalloc(sizeof(struct led_netdev_data
), GFP_KERNEL
);
552 mutex_init(&trigger_data
->lock
);
554 trigger_data
->notifier
.notifier_call
= netdev_trig_notify
;
555 trigger_data
->notifier
.priority
= 10;
557 INIT_DELAYED_WORK(&trigger_data
->work
, netdev_trig_work
);
559 trigger_data
->led_cdev
= led_cdev
;
560 trigger_data
->net_dev
= NULL
;
561 trigger_data
->device_name
[0] = 0;
563 trigger_data
->mode
= 0;
564 atomic_set(&trigger_data
->interval
, msecs_to_jiffies(NETDEV_LED_DEFAULT_INTERVAL
));
565 trigger_data
->last_activity
= 0;
567 /* Check if hw control is active by default on the LED.
568 * Init already enabled mode in hw control.
570 if (supports_hw_control(led_cdev
)) {
571 dev
= led_cdev
->hw_control_get_device(led_cdev
);
573 const char *name
= dev_name(dev
);
575 set_device_name(trigger_data
, name
, strlen(name
));
576 trigger_data
->hw_control
= true;
578 rc
= led_cdev
->hw_control_get(led_cdev
, &mode
);
580 trigger_data
->mode
= mode
;
584 led_set_trigger_data(led_cdev
, trigger_data
);
586 rc
= register_netdevice_notifier(&trigger_data
->notifier
);
593 static void netdev_trig_deactivate(struct led_classdev
*led_cdev
)
595 struct led_netdev_data
*trigger_data
= led_get_trigger_data(led_cdev
);
597 unregister_netdevice_notifier(&trigger_data
->notifier
);
599 cancel_delayed_work_sync(&trigger_data
->work
);
601 led_set_brightness(led_cdev
, LED_OFF
);
603 dev_put(trigger_data
->net_dev
);
608 static struct led_trigger netdev_led_trigger
= {
610 .activate
= netdev_trig_activate
,
611 .deactivate
= netdev_trig_deactivate
,
612 .groups
= netdev_trig_groups
,
615 module_led_trigger(netdev_led_trigger
);
617 MODULE_AUTHOR("Ben Whitten <ben.whitten@gmail.com>");
618 MODULE_AUTHOR("Oliver Jowett <oliver@opencloud.com>");
619 MODULE_DESCRIPTION("Netdev LED trigger");
620 MODULE_LICENSE("GPL v2");