/* $Id: power.c,v 1.9.2.1 2001/12/11 01:57:49 davem Exp $ * power.c: Power management driver. * * Copyright (C) 1999 David S. Miller (davem@redhat.com) */#include <linux/config.h>#include <linux/kernel.h>#include <linux/init.h>#include <linux/sched.h>#include <linux/signal.h>#include <linux/delay.h>#include <asm/ebus.h>#include <asm/auxio.h>#define __KERNEL_SYSCALLS__#include <linux/unistd.h>/* * sysctl - toggle power-off restriction for serial console  * systems in machine_power_off() */int scons_pwroff = 1; #ifdef CONFIG_PCIstatic unsigned long power_reg = 0UL;static DECLARE_WAIT_QUEUE_HEAD(powerd_wait);static int button_pressed;static void power_handler(int irq, void *dev_id, struct pt_regs *regs){	if (button_pressed == 0) {		wake_up(&powerd_wait);		button_pressed = 1;	}}#endif /* CONFIG_PCI */extern void machine_halt(void);extern void machine_alt_power_off(void);static void (*poweroff_method)(void) = machine_alt_power_off;extern int serial_console;void machine_power_off(void){	if (!serial_console || scons_pwroff) {#ifdef CONFIG_PCI		if (power_reg != 0UL) {			/* Both register bits seem to have the			 * same effect, so until I figure out			 * what the difference is...			 */			writel(AUXIO_PCIO_CPWR_OFF | AUXIO_PCIO_SPWR_OFF, power_reg);		} else#endif /* CONFIG_PCI */			if (poweroff_method != NULL) {				poweroff_method();				/* not reached */			}	}	machine_halt();}#ifdef CONFIG_PCIstatic int powerd(void *__unused){	static char *envp[] = { "HOME=/", "TERM=linux", "PATH=/sbin:/usr/sbin:/bin:/usr/bin", NULL };	char *argv[] = { "/sbin/shutdown", "-h", "now", NULL };	daemonize();	sprintf(current->comm, "powerd");again:	while (button_pressed == 0) {		spin_lock_irq(&current->sigmask_lock);		flush_signals(current);		spin_unlock_irq(&current->sigmask_lock);		interruptible_sleep_on(&powerd_wait);	}	/* Ok, down we go... */	if (execve("/sbin/shutdown", argv, envp) < 0) {		printk("powerd: shutdown execution failed\n");		button_pressed = 0;		goto again;	}	return 0;}static int __init has_button_interrupt(struct linux_ebus_device *edev){	if (edev->irqs[0] == PCI_IRQ_NONE)		return 0;	if (!prom_node_has_property(edev->prom_node, "button"))		return 0;	return 1;}void __init power_init(void){	struct linux_ebus *ebus;	struct linux_ebus_device *edev;	static int invoked;	if (invoked)		return;	invoked = 1;	for_each_ebus(ebus) {		for_each_ebusdev(edev, ebus) {			if (!strcmp(edev->prom_name, "power"))				goto found;		}	}	return;found:	power_reg = (unsigned long)ioremap(edev->resource[0].start, 0x4);	printk("power: Control reg at %016lx ... ", power_reg);	poweroff_method = machine_halt; /* able to use the standard poweroff */	if (has_button_interrupt(edev)) {		if (kernel_thread(powerd, 0, CLONE_FS) < 0) {			printk("Failed to start power daemon.\n");			return;		}		printk("powerd running.\n");		if (request_irq(edev->irqs[0],				power_handler, SA_SHIRQ, "power",				(void *) power_reg) < 0)			printk("power: Error, cannot register IRQ handler.\n");	} else {		printk("not using powerd.\n");	}}#endif /* CONFIG_PCI */