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/export.h>
  11 #include <linux/init.h>
  12 #include <linux/sysdev.h>
  13 #include <linux/syscore_ops.h>
  14 #include <linux/string.h>
  15
  16 #include <asm/leds.h>
  17
  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
  37 static ssize_t leds_store(struct sys_device *dev,
  38                         struct sysdev_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 SYSDEV_ATTR(event, 0200, NULL, leds_store);
  73
  74 static struct sysdev_class leds_sysclass = {
  75         .name           = "leds",
  76 };
  77
  78 static struct sys_device leds_device = {
  79         .id             = 0,
  80         .cls            = &leds_sysclass,
  81 };
  82
  83 static int leds_suspend(void)
  84 {
  85         leds_event(led_stop);
  86         return 0;
  87 }
  88
  89 static void leds_resume(void)
  90 {
  91         leds_event(led_start);
  92 }
  93
  94 static void leds_shutdown(void)
  95 {
  96         leds_event(led_halted);
  97 }
  98
  99 static struct syscore_ops leds_syscore_ops = {
 100         .shutdown       = leds_shutdown,
 101         .suspend        = leds_suspend,
 102         .resume         = leds_resume,
 103 };
 104
 105 static int __init leds_init(void)
 106 {
 107         int ret;
 108         ret = sysdev_class_register(&leds_sysclass);
 109         if (ret == 0)
 110                 ret = sysdev_register(&leds_device);
 111         if (ret == 0)
 112                 ret = sysdev_create_file(&leds_device, &attr_event);
 113         if (ret == 0)
 114                 register_syscore_ops(&leds_syscore_ops);
 115         return ret;
 116 }
 117
 118 device_initcall(leds_init);
 119
 120 EXPORT_SYMBOL(leds_event);