1/* $Id: power.c,v 1.1.1.1 2007/08/03 18:52:18 Exp $
2 * power.c: Power management driver.
3 *
4 * Copyright (C) 1999 David S. Miller (davem@redhat.com)
5 */
6
7#include <linux/kernel.h>
8#include <linux/module.h>
9#include <linux/init.h>
10#include <linux/sched.h>
11#include <linux/signal.h>
12#include <linux/delay.h>
13#include <linux/interrupt.h>
14#include <linux/pm.h>
15#include <linux/syscalls.h>
16
17#include <asm/system.h>
18#include <asm/auxio.h>
19#include <asm/prom.h>
20#include <asm/of_device.h>
21#include <asm/io.h>
22#include <asm/sstate.h>
23
24#include <linux/unistd.h>
25
26/*
27 * sysctl - toggle power-off restriction for serial console
28 * systems in machine_power_off()
29 */
30int scons_pwroff = 1;
31
32#ifdef CONFIG_PCI
33#include <linux/pci.h>
34static void __iomem *power_reg;
35
36static DECLARE_WAIT_QUEUE_HEAD(powerd_wait);
37static int button_pressed;
38
39static irqreturn_t power_handler(int irq, void *dev_id)
40{
41	if (button_pressed == 0) {
42		button_pressed = 1;
43		wake_up(&powerd_wait);
44	}
45
46	return IRQ_HANDLED;
47}
48#endif /* CONFIG_PCI */
49
50extern void machine_halt(void);
51extern void machine_alt_power_off(void);
52static void (*poweroff_method)(void) = machine_alt_power_off;
53
54void machine_power_off(void)
55{
56	sstate_poweroff();
57	if (!serial_console || scons_pwroff) {
58#ifdef CONFIG_PCI
59		if (power_reg) {
60			/* Both register bits seem to have the
61			 * same effect, so until I figure out
62			 * what the difference is...
63			 */
64			writel(AUXIO_PCIO_CPWR_OFF | AUXIO_PCIO_SPWR_OFF, power_reg);
65		} else
66#endif /* CONFIG_PCI */
67			if (poweroff_method != NULL) {
68				poweroff_method();
69				/* not reached */
70			}
71	}
72	machine_halt();
73}
74
75void (*pm_power_off)(void) = machine_power_off;
76EXPORT_SYMBOL(pm_power_off);
77
78#ifdef CONFIG_PCI
79static int powerd(void *__unused)
80{
81	static char *envp[] = { "HOME=/", "TERM=linux", "PATH=/sbin:/usr/sbin:/bin:/usr/bin", NULL };
82	char *argv[] = { "/sbin/shutdown", "-h", "now", NULL };
83	DECLARE_WAITQUEUE(wait, current);
84
85	daemonize("powerd");
86
87	add_wait_queue(&powerd_wait, &wait);
88again:
89	for (;;) {
90		set_task_state(current, TASK_INTERRUPTIBLE);
91		if (button_pressed)
92			break;
93		flush_signals(current);
94		schedule();
95	}
96	__set_current_state(TASK_RUNNING);
97	remove_wait_queue(&powerd_wait, &wait);
98
99	/* Ok, down we go... */
100	button_pressed = 0;
101	if (kernel_execve("/sbin/shutdown", argv, envp) < 0) {
102		printk("powerd: shutdown execution failed\n");
103		add_wait_queue(&powerd_wait, &wait);
104		goto again;
105	}
106	return 0;
107}
108
109static int __init has_button_interrupt(unsigned int irq, struct device_node *dp)
110{
111	if (irq == PCI_IRQ_NONE)
112		return 0;
113	if (!of_find_property(dp, "button", NULL))
114		return 0;
115
116	return 1;
117}
118
119static int __devinit power_probe(struct of_device *op, const struct of_device_id *match)
120{
121	struct resource *res = &op->resource[0];
122	unsigned int irq= op->irqs[0];
123
124	power_reg = of_ioremap(res, 0, 0x4, "power");
125
126	printk("%s: Control reg at %lx ... ",
127	       op->node->name, res->start);
128
129	poweroff_method = machine_halt;  /* able to use the standard halt */
130
131	if (has_button_interrupt(irq, op->node)) {
132		if (kernel_thread(powerd, NULL, CLONE_FS) < 0) {
133			printk("Failed to start power daemon.\n");
134			return 0;
135		}
136		printk("powerd running.\n");
137
138		if (request_irq(irq,
139				power_handler, 0, "power", NULL) < 0)
140			printk("power: Error, cannot register IRQ handler.\n");
141	} else {
142		printk("not using powerd.\n");
143	}
144
145	return 0;
146}
147
148static struct of_device_id power_match[] = {
149	{
150		.name = "power",
151	},
152	{},
153};
154
155static struct of_platform_driver power_driver = {
156	.name		= "power",
157	.match_table	= power_match,
158	.probe		= power_probe,
159};
160
161void __init power_init(void)
162{
163	of_register_driver(&power_driver, &of_bus_type);
164	return;
165}
166#endif /* CONFIG_PCI */
167