1 /*
2 * LED support code, ripped out of arch/arm/kernel/time.c
3 *
4 * Copyright (C) 1994-2001 Russell King
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10 #include <linux/export.h>
11 #include <linux/init.h>
12 #include <linux/device.h>
13 #include <linux/syscore_ops.h>
14 #include <linux/string.h>
15
16 #include <asm/leds.h>
17
dummy_leds_event(led_event_t evt)18 static void dummy_leds_event(led_event_t evt)
19 {
20 }
21
22 void (*leds_event)(led_event_t) = dummy_leds_event;
23
24 struct leds_evt_name {
25 const char name[8];
26 int on;
27 int off;
28 };
29
30 static const struct leds_evt_name evt_names[] = {
31 { "amber", led_amber_on, led_amber_off },
32 { "blue", led_blue_on, led_blue_off },
33 { "green", led_green_on, led_green_off },
34 { "red", led_red_on, led_red_off },
35 };
36
leds_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t size)37 static ssize_t leds_store(struct device *dev,
38 struct device_attribute *attr,
39 const char *buf, size_t size)
40 {
41 int ret = -EINVAL, len = strcspn(buf, " ");
42
43 if (len > 0 && buf[len] == '\0')
44 len--;
45
46 if (strncmp(buf, "claim", len) == 0) {
47 leds_event(led_claim);
48 ret = size;
49 } else if (strncmp(buf, "release", len) == 0) {
50 leds_event(led_release);
51 ret = size;
52 } else {
53 int i;
54
55 for (i = 0; i < ARRAY_SIZE(evt_names); i++) {
56 if (strlen(evt_names[i].name) != len ||
57 strncmp(buf, evt_names[i].name, len) != 0)
58 continue;
59 if (strncmp(buf+len, " on", 3) == 0) {
60 leds_event(evt_names[i].on);
61 ret = size;
62 } else if (strncmp(buf+len, " off", 4) == 0) {
63 leds_event(evt_names[i].off);
64 ret = size;
65 }
66 break;
67 }
68 }
69 return ret;
70 }
71
72 static DEVICE_ATTR(event, 0200, NULL, leds_store);
73
74 static struct bus_type leds_subsys = {
75 .name = "leds",
76 .dev_name = "leds",
77 };
78
79 static struct device leds_device = {
80 .id = 0,
81 .bus = &leds_subsys,
82 };
83
leds_suspend(void)84 static int leds_suspend(void)
85 {
86 leds_event(led_stop);
87 return 0;
88 }
89
leds_resume(void)90 static void leds_resume(void)
91 {
92 leds_event(led_start);
93 }
94
leds_shutdown(void)95 static void leds_shutdown(void)
96 {
97 leds_event(led_halted);
98 }
99
100 static struct syscore_ops leds_syscore_ops = {
101 .shutdown = leds_shutdown,
102 .suspend = leds_suspend,
103 .resume = leds_resume,
104 };
105
leds_init(void)106 static int __init leds_init(void)
107 {
108 int ret;
109 ret = subsys_system_register(&leds_subsys, NULL);
110 if (ret == 0)
111 ret = device_register(&leds_device);
112 if (ret == 0)
113 ret = device_create_file(&leds_device, &dev_attr_event);
114 if (ret == 0)
115 register_syscore_ops(&leds_syscore_ops);
116 return ret;
117 }
118
119 device_initcall(leds_init);
120
121 EXPORT_SYMBOL(leds_event);
122