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