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
  25 #include <asm/mach-types.h>
  26
  27 static irqreturn_t nslu2_power_handler(int irq, void *dev_id)
  28 {
  29         /* Signal init to do the ctrlaltdel action, this will bypass init if
  30          * it hasn't started and do a kernel_restart.
  31          */
  32         ctrl_alt_del();
  33
  34         return IRQ_HANDLED;
  35 }
  36
  37 static irqreturn_t nslu2_reset_handler(int irq, void *dev_id)
  38 {
  39         /* This is the paper-clip reset, it shuts the machine down directly.
  40          */
  41         machine_power_off();
  42
  43         return IRQ_HANDLED;
  44 }
  45
  46 static int __init nslu2_power_init(void)
  47 {
  48         if (!(machine_is_nslu2()))
  49                 return 0;
  50
  51         *IXP4XX_GPIO_GPISR = 0x20400000;        /* read the 2 irqs to clr */
  52
  53         set_irq_type(NSLU2_RB_IRQ, IRQT_LOW);
  54         set_irq_type(NSLU2_PB_IRQ, IRQT_HIGH);
  55
  56         if (request_irq(NSLU2_RB_IRQ, &nslu2_reset_handler,
  57                 IRQF_DISABLED, "NSLU2 reset button", NULL) < 0) {
  58
  59                 printk(KERN_DEBUG "Reset Button IRQ %d not available\n",
  60                         NSLU2_RB_IRQ);
  61
  62                 return -EIO;
  63         }
  64
  65         if (request_irq(NSLU2_PB_IRQ, &nslu2_power_handler,
  66                 IRQF_DISABLED, "NSLU2 power button", NULL) < 0) {
  67
  68                 printk(KERN_DEBUG "Power Button IRQ %d not available\n",
  69                         NSLU2_PB_IRQ);
  70
  71                 return -EIO;
  72         }
  73
  74         return 0;
  75 }
  76
  77 static void __exit nslu2_power_exit(void)
  78 {
  79         if (!(machine_is_nslu2()))
  80                 return;
  81
  82         free_irq(NSLU2_RB_IRQ, NULL);
  83         free_irq(NSLU2_PB_IRQ, NULL);
  84 }
  85
  86 module_init(nslu2_power_init);
  87 module_exit(nslu2_power_exit);
  88
  89 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
  90 MODULE_DESCRIPTION("NSLU2 Power/Reset driver");
  91 MODULE_LICENSE("GPL");