xref: /kernel/linux/linux-5.10/drivers/net/can/led.c (revision 8c2ecf20)
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright 2012, Fabio Baltieri <fabio.baltieri@gmail.com>
4 * Copyright 2012, Kurt Van Dijck <kurt.van.dijck@eia.be>
5 */
6
7#include <linux/module.h>
8#include <linux/device.h>
9#include <linux/kernel.h>
10#include <linux/slab.h>
11#include <linux/netdevice.h>
12#include <linux/can/dev.h>
13
14#include <linux/can/led.h>
15
16static unsigned long led_delay = 50;
17module_param(led_delay, ulong, 0644);
18MODULE_PARM_DESC(led_delay,
19		"blink delay time for activity leds (msecs, default: 50).");
20
21/* Trigger a LED event in response to a CAN device event */
22void can_led_event(struct net_device *netdev, enum can_led_event event)
23{
24	struct can_priv *priv = netdev_priv(netdev);
25
26	switch (event) {
27	case CAN_LED_EVENT_OPEN:
28		led_trigger_event(priv->tx_led_trig, LED_FULL);
29		led_trigger_event(priv->rx_led_trig, LED_FULL);
30		led_trigger_event(priv->rxtx_led_trig, LED_FULL);
31		break;
32	case CAN_LED_EVENT_STOP:
33		led_trigger_event(priv->tx_led_trig, LED_OFF);
34		led_trigger_event(priv->rx_led_trig, LED_OFF);
35		led_trigger_event(priv->rxtx_led_trig, LED_OFF);
36		break;
37	case CAN_LED_EVENT_TX:
38		if (led_delay) {
39			led_trigger_blink_oneshot(priv->tx_led_trig,
40						  &led_delay, &led_delay, 1);
41			led_trigger_blink_oneshot(priv->rxtx_led_trig,
42						  &led_delay, &led_delay, 1);
43		}
44		break;
45	case CAN_LED_EVENT_RX:
46		if (led_delay) {
47			led_trigger_blink_oneshot(priv->rx_led_trig,
48						  &led_delay, &led_delay, 1);
49			led_trigger_blink_oneshot(priv->rxtx_led_trig,
50						  &led_delay, &led_delay, 1);
51		}
52		break;
53	}
54}
55EXPORT_SYMBOL_GPL(can_led_event);
56
57static void can_led_release(struct device *gendev, void *res)
58{
59	struct can_priv *priv = netdev_priv(to_net_dev(gendev));
60
61	led_trigger_unregister_simple(priv->tx_led_trig);
62	led_trigger_unregister_simple(priv->rx_led_trig);
63	led_trigger_unregister_simple(priv->rxtx_led_trig);
64}
65
66/* Register CAN LED triggers for a CAN device
67 *
68 * This is normally called from a driver's probe function
69 */
70void devm_can_led_init(struct net_device *netdev)
71{
72	struct can_priv *priv = netdev_priv(netdev);
73	void *res;
74
75	res = devres_alloc(can_led_release, 0, GFP_KERNEL);
76	if (!res) {
77		netdev_err(netdev, "cannot register LED triggers\n");
78		return;
79	}
80
81	snprintf(priv->tx_led_trig_name, sizeof(priv->tx_led_trig_name),
82		 "%s-tx", netdev->name);
83	snprintf(priv->rx_led_trig_name, sizeof(priv->rx_led_trig_name),
84		 "%s-rx", netdev->name);
85	snprintf(priv->rxtx_led_trig_name, sizeof(priv->rxtx_led_trig_name),
86		 "%s-rxtx", netdev->name);
87
88	led_trigger_register_simple(priv->tx_led_trig_name,
89				    &priv->tx_led_trig);
90	led_trigger_register_simple(priv->rx_led_trig_name,
91				    &priv->rx_led_trig);
92	led_trigger_register_simple(priv->rxtx_led_trig_name,
93				    &priv->rxtx_led_trig);
94
95	devres_add(&netdev->dev, res);
96}
97EXPORT_SYMBOL_GPL(devm_can_led_init);
98
99/* NETDEV rename notifier to rename the associated led triggers too */
100static int can_led_notifier(struct notifier_block *nb, unsigned long msg,
101			    void *ptr)
102{
103	struct net_device *netdev = netdev_notifier_info_to_dev(ptr);
104	struct can_priv *priv = safe_candev_priv(netdev);
105	char name[CAN_LED_NAME_SZ];
106
107	if (!priv)
108		return NOTIFY_DONE;
109
110	if (!priv->tx_led_trig || !priv->rx_led_trig || !priv->rxtx_led_trig)
111		return NOTIFY_DONE;
112
113	if (msg == NETDEV_CHANGENAME) {
114		snprintf(name, sizeof(name), "%s-tx", netdev->name);
115		led_trigger_rename_static(name, priv->tx_led_trig);
116
117		snprintf(name, sizeof(name), "%s-rx", netdev->name);
118		led_trigger_rename_static(name, priv->rx_led_trig);
119
120		snprintf(name, sizeof(name), "%s-rxtx", netdev->name);
121		led_trigger_rename_static(name, priv->rxtx_led_trig);
122	}
123
124	return NOTIFY_DONE;
125}
126
127/* notifier block for netdevice event */
128static struct notifier_block can_netdev_notifier __read_mostly = {
129	.notifier_call = can_led_notifier,
130};
131
132int __init can_led_notifier_init(void)
133{
134	return register_netdevice_notifier(&can_netdev_notifier);
135}
136
137void __exit can_led_notifier_exit(void)
138{
139	unregister_netdevice_notifier(&can_netdev_notifier);
140}
141