arch/arm/mach-ixp4xx/nslu2-power.c

   1 /*
   2  * arch/arm/mach-ixp4xx/nslu2-power.c
   3  *
   4  * NSLU2 Power/Reset driver
   5  *
   6  * Copyright (C) 2005 Tower Technologies
   7  *
   8  * based on nslu2-io.c
   9  *  Copyright (C) 2004 Karen Spearel
  10  *
  11  * Author: Alessandro Zummo <a.zummo@towertech.it>
  12  * Maintainers: http://www.nslu2-linux.org/
  13  *
  14  * This program is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License version 2 as
  16  * published by the Free Software Foundation.
  17  *
  18  */
  19
  20 #include <linux/module.h>
  21 #include <linux/reboot.h>
  22 #include <linux/irq.h>
  23 #include <linux/interrupt.h>
  24 #include <linux/reboot.h>
  25
  26 #include <asm/mach-types.h>
  27
  28 static irqreturn_t nslu2_power_handler(int irq, void *dev_id)
  29 {
  30         /* Signal init to do the ctrlaltdel action, this will bypass init if
  31          * it hasn't started and do a kernel_restart.
  32          */
  33         ctrl_alt_del();
  34
  35         return IRQ_HANDLED;
  36 }
  37
  38 static irqreturn_t nslu2_reset_handler(int irq, void *dev_id)
  39 {
  40         /* This is the paper-clip reset, it shuts the machine down directly.
  41          */
  42         machine_power_off();
  43
  44         return IRQ_HANDLED;
  45 }
  46
  47 static int __init nslu2_power_init(void)
  48 {
  49         if (!(machine_is_nslu2()))
  50                 return 0;
  51
  52         *IXP4XX_GPIO_GPISR = 0x20400000;        /* read the 2 irqs to clr */
  53
  54         set_irq_type(NSLU2_RB_IRQ, IRQT_LOW);
  55         set_irq_type(NSLU2_PB_IRQ, IRQT_HIGH);
  56
  57         if (request_irq(NSLU2_RB_IRQ, &nslu2_reset_handler,
  58                 IRQF_DISABLED, "NSLU2 reset button", NULL) < 0) {
  59
  60                 printk(KERN_DEBUG "Reset Button IRQ %d not available\n",
  61                         NSLU2_RB_IRQ);
  62
  63                 return -EIO;
  64         }
  65
  66         if (request_irq(NSLU2_PB_IRQ, &nslu2_power_handler,
  67                 IRQF_DISABLED, "NSLU2 power button", NULL) < 0) {
  68
  69                 printk(KERN_DEBUG "Power Button IRQ %d not available\n",
  70                         NSLU2_PB_IRQ);
  71
  72                 return -EIO;
  73         }
  74
  75         return 0;
  76 }
  77
  78 static void __exit nslu2_power_exit(void)
  79 {
  80         if (!(machine_is_nslu2()))
  81                 return;
  82
  83         free_irq(NSLU2_RB_IRQ, NULL);
  84         free_irq(NSLU2_PB_IRQ, NULL);
  85 }
  86
  87 module_init(nslu2_power_init);
  88 module_exit(nslu2_power_exit);
  89
  90 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
  91 MODULE_DESCRIPTION("NSLU2 Power/Reset driver");
  92 MODULE_LICENSE("GPL");