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