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
28static 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
38static 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
47static 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
78static 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
87module_init(nslu2_power_init);
88module_exit(nslu2_power_exit);
89
90MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
91MODULE_DESCRIPTION("NSLU2 Power/Reset driver");
92MODULE_LICENSE("GPL");
93