/arch/sparc64/kernel/power.c

  1/* $Id: power.c,v 1.10 2001/12/11 01:57:16 davem Exp $
  2 * power.c: Power management driver.
  3 *
  4 * Copyright (C) 1999 David S. Miller (davem@redhat.com)
  5 */
  6
  7#include <linux/config.h>
  8#include <linux/kernel.h>
  9#include <linux/module.h>
 10#include <linux/init.h>
 11#include <linux/sched.h>
 12#include <linux/signal.h>
 13#include <linux/delay.h>
 14#include <linux/interrupt.h>
 15
 16#include <asm/system.h>
 17#include <asm/ebus.h>
 18#include <asm/auxio.h>
 19
 20#define __KERNEL_SYSCALLS__
 21#include <linux/unistd.h>
 22
 23/*
 24 * sysctl - toggle power-off restriction for serial console 
 25 * systems in machine_power_off()
 26 */
 27int scons_pwroff = 1; 
 28
 29#ifdef CONFIG_PCI
 30static void __iomem *power_reg;
 31
 32static DECLARE_WAIT_QUEUE_HEAD(powerd_wait);
 33static int button_pressed;
 34
 35static irqreturn_t power_handler(int irq, void *dev_id, struct pt_regs *regs)
 36{
 37	if (button_pressed == 0) {
 38		button_pressed = 1;
 39		wake_up(&powerd_wait);
 40	}
 41
 42	/* FIXME: Check registers for status... */
 43	return IRQ_HANDLED;
 44}
 45#endif /* CONFIG_PCI */
 46
 47extern void machine_halt(void);
 48extern void machine_alt_power_off(void);
 49static void (*poweroff_method)(void) = machine_alt_power_off;
 50
 51void machine_power_off(void)
 52{
 53	if (!serial_console || scons_pwroff) {
 54#ifdef CONFIG_PCI
 55		if (power_reg) {
 56			/* Both register bits seem to have the
 57			 * same effect, so until I figure out
 58			 * what the difference is...
 59			 */
 60			writel(AUXIO_PCIO_CPWR_OFF | AUXIO_PCIO_SPWR_OFF, power_reg);
 61		} else
 62#endif /* CONFIG_PCI */
 63			if (poweroff_method != NULL) {
 64				poweroff_method();
 65				/* not reached */
 66			}
 67	}
 68	machine_halt();
 69}
 70
 71EXPORT_SYMBOL(machine_power_off);
 72
 73#ifdef CONFIG_PCI
 74static int powerd(void *__unused)
 75{
 76	static char *envp[] = { "HOME=/", "TERM=linux", "PATH=/sbin:/usr/sbin:/bin:/usr/bin", NULL };
 77	char *argv[] = { "/sbin/shutdown", "-h", "now", NULL };
 78	DECLARE_WAITQUEUE(wait, current);
 79
 80	daemonize("powerd");
 81
 82	add_wait_queue(&powerd_wait, &wait);
 83again:
 84	for (;;) {
 85		set_task_state(current, TASK_INTERRUPTIBLE);
 86		if (button_pressed)
 87			break;
 88		flush_signals(current);
 89		schedule();
 90	}
 91	__set_current_state(TASK_RUNNING);
 92	remove_wait_queue(&powerd_wait, &wait);
 93
 94	/* Ok, down we go... */
 95	button_pressed = 0;
 96	if (execve("/sbin/shutdown", argv, envp) < 0) {
 97		printk("powerd: shutdown execution failed\n");
 98		add_wait_queue(&powerd_wait, &wait);
 99		goto again;
100	}
101	return 0;
102}
103
104static int __init has_button_interrupt(struct linux_ebus_device *edev)
105{
106	if (edev->irqs[0] == PCI_IRQ_NONE)
107		return 0;
108	if (!prom_node_has_property(edev->prom_node, "button"))
109		return 0;
110
111	return 1;
112}
113
114void __init power_init(void)
115{
116	struct linux_ebus *ebus;
117	struct linux_ebus_device *edev;
118	static int invoked;
119
120	if (invoked)
121		return;
122	invoked = 1;
123
124	for_each_ebus(ebus) {
125		for_each_ebusdev(edev, ebus) {
126			if (!strcmp(edev->prom_name, "power"))
127				goto found;
128		}
129	}
130	return;
131
132found:
133	power_reg = ioremap(edev->resource[0].start, 0x4);
134	printk("power: Control reg at %p ... ", power_reg);
135	poweroff_method = machine_halt;  /* able to use the standard halt */
136	if (has_button_interrupt(edev)) {
137		if (kernel_thread(powerd, NULL, CLONE_FS) < 0) {
138			printk("Failed to start power daemon.\n");
139			return;
140		}
141		printk("powerd running.\n");
142
143		if (request_irq(edev->irqs[0],
144				power_handler, SA_SHIRQ, "power", NULL) < 0)
145			printk("power: Error, cannot register IRQ handler.\n");
146	} else {
147		printk("not using powerd.\n");
148	}
149}
150#endif /* CONFIG_PCI */