arch/arm/mach-at91/leds.c

   1 /*
   2  * LED driver for Atmel AT91-based boards.
   3  *
   4  *  Copyright (C) SAN People (Pty) Ltd
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the License, or (at your option) any later version.
  10 */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/module.h>
  14 #include <linux/init.h>
  15
  16 #include <asm/mach-types.h>
  17 #include <asm/leds.h>
  18 #include <asm/arch/board.h>
  19 #include <asm/arch/gpio.h>
  20
  21
  22 static inline void at91_led_on(unsigned int led)
  23 {
  24         at91_set_gpio_value(led, 0);
  25 }
  26
  27 static inline void at91_led_off(unsigned int led)
  28 {
  29         at91_set_gpio_value(led, 1);
  30 }
  31
  32 static inline void at91_led_toggle(unsigned int led)
  33 {
  34         unsigned long is_off = at91_get_gpio_value(led);
  35         if (is_off)
  36                 at91_led_on(led);
  37         else
  38                 at91_led_off(led);
  39 }
  40
  41
  42 /*
  43  * Handle LED events.
  44  */
  45 static void at91_leds_event(led_event_t evt)
  46 {
  47         unsigned long flags;
  48
  49         local_irq_save(flags);
  50
  51         switch(evt) {
  52         case led_start:         /* System startup */
  53                 at91_led_on(at91_leds_cpu);
  54                 break;
  55
  56         case led_stop:          /* System stop / suspend */
  57                 at91_led_off(at91_leds_cpu);
  58                 break;
  59
  60 #ifdef CONFIG_LEDS_TIMER
  61         case led_timer:         /* Every 50 timer ticks */
  62                 at91_led_toggle(at91_leds_timer);
  63                 break;
  64 #endif
  65
  66 #ifdef CONFIG_LEDS_CPU
  67         case led_idle_start:    /* Entering idle state */
  68                 at91_led_off(at91_leds_cpu);
  69                 break;
  70
  71         case led_idle_end:      /* Exit idle state */
  72                 at91_led_on(at91_leds_cpu);
  73                 break;
  74 #endif
  75
  76         default:
  77                 break;
  78         }
  79
  80         local_irq_restore(flags);
  81 }
  82
  83
  84 static int __init leds_init(void)
  85 {
  86         if (!at91_leds_timer || !at91_leds_cpu)
  87                 return -ENODEV;
  88
  89         leds_event = at91_leds_event;
  90
  91         leds_event(led_start);
  92         return 0;
  93 }
  94
  95 __initcall(leds_init);