arch/arm/kernel/leds.c

   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/module.h>
  11 #include <linux/init.h>
  12 #include <linux/sysdev.h>
  13 #include <linux/syscore_ops.h>
  14
  15 #include <asm/leds.h>
  16
  17 static void dummy_leds_event(led_event_t evt)
  18 {
  19 }
  20
  21 void (*leds_event)(led_event_t) = dummy_leds_event;
  22
  23 struct leds_evt_name {
  24         const char      name[8];
  25         int             on;
  26         int             off;
  27 };
  28
  29 static const struct leds_evt_name evt_names[] = {
  30         { "amber", led_amber_on, led_amber_off },
  31         { "blue",  led_blue_on,  led_blue_off  },
  32         { "green", led_green_on, led_green_off },
  33         { "red",   led_red_on,   led_red_off   },
  34 };
  35
  36 static ssize_t leds_store(struct sys_device *dev,
  37                         struct sysdev_attribute *attr,
  38                         const char *buf, size_t size)
  39 {
  40         int ret = -EINVAL, len = strcspn(buf, " ");
  41
  42         if (len > 0 && buf[len] == '\0')
  43                 len--;
  44
  45         if (strncmp(buf, "claim", len) == 0) {
  46                 leds_event(led_claim);
  47                 ret = size;
  48         } else if (strncmp(buf, "release", len) == 0) {
  49                 leds_event(led_release);
  50                 ret = size;
  51         } else {
  52                 int i;
  53
  54                 for (i = 0; i < ARRAY_SIZE(evt_names); i++) {
  55                         if (strlen(evt_names[i].name) != len ||
  56                             strncmp(buf, evt_names[i].name, len) != 0)
  57                                 continue;
  58                         if (strncmp(buf+len, " on", 3) == 0) {
  59                                 leds_event(evt_names[i].on);
  60                                 ret = size;
  61                         } else if (strncmp(buf+len, " off", 4) == 0) {
  62                                 leds_event(evt_names[i].off);
  63                                 ret = size;
  64                         }
  65                         break;
  66                 }
  67         }
  68         return ret;
  69 }
  70
  71 static SYSDEV_ATTR(event, 0200, NULL, leds_store);
  72
  73 static struct sysdev_class leds_sysclass = {
  74         .name           = "leds",
  75 };
  76
  77 static struct sys_device leds_device = {
  78         .id             = 0,
  79         .cls            = &leds_sysclass,
  80 };
  81
  82 static int leds_suspend(void)
  83 {
  84         leds_event(led_stop);
  85         return 0;
  86 }
  87
  88 static void leds_resume(void)
  89 {
  90         leds_event(led_start);
  91 }
  92
  93 static void leds_shutdown(void)
  94 {
  95         leds_event(led_halted);
  96 }
  97
  98 static struct syscore_ops leds_syscore_ops = {
  99         .shutdown       = leds_shutdown,
 100         .suspend        = leds_suspend,
 101         .resume         = leds_resume,
 102 };
 103
 104 static int __init leds_init(void)
 105 {
 106         int ret;
 107         ret = sysdev_class_register(&leds_sysclass);
 108         if (ret == 0)
 109                 ret = sysdev_register(&leds_device);
 110         if (ret == 0)
 111                 ret = sysdev_create_file(&leds_device, &attr_event);
 112         if (ret == 0)
 113                 register_syscore_ops(&leds_syscore_ops);
 114         return ret;
 115 }
 116
 117 device_initcall(leds_init);
 118
 119 EXPORT_SYMBOL(leds_event);