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   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/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  */
  30 int scons_pwroff = 1;
  31
  32 #ifdef CONFIG_PCI
  33 #include <linux/pci.h>
  34 static void __iomem *power_reg;
  35
  36 static DECLARE_WAIT_QUEUE_HEAD(powerd_wait);
  37 static int button_pressed;
  38
  39 static 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         /* FIXME: Check registers for status... */
  47         return IRQ_HANDLED;
  48 }
  49 #endif /* CONFIG_PCI */
  50
  51 extern void machine_halt(void);
  52 extern void machine_alt_power_off(void);
  53 static void (*poweroff_method)(void) = machine_alt_power_off;
  54
  55 void machine_power_off(void)
  56 {
  57         sstate_poweroff();
  58         if (!serial_console || scons_pwroff) {
  59 #ifdef CONFIG_PCI
  60                 if (power_reg) {
  61                         /* Both register bits seem to have the
  62                          * same effect, so until I figure out
  63                          * what the difference is...
  64                          */
  65                         writel(AUXIO_PCIO_CPWR_OFF | AUXIO_PCIO_SPWR_OFF, power_reg);
  66                 } else
  67 #endif /* CONFIG_PCI */
  68                         if (poweroff_method != NULL) {
  69                                 poweroff_method();
  70                                 /* not reached */
  71                         }
  72         }
  73         machine_halt();
  74 }
  75
  76 void (*pm_power_off)(void) = machine_power_off;
  77 EXPORT_SYMBOL(pm_power_off);
  78
  79 #ifdef CONFIG_PCI
  80 static int powerd(void *__unused)
  81 {
  82         static char *envp[] = { "HOME=/", "TERM=linux", "PATH=/sbin:/usr/sbin:/bin:/usr/bin", NULL };
  83         char *argv[] = { "/sbin/shutdown", "-h", "now", NULL };
  84         DECLARE_WAITQUEUE(wait, current);
  85
  86         daemonize("powerd");
  87
  88         add_wait_queue(&powerd_wait, &wait);
  89 again:
  90         for (;;) {
  91                 set_task_state(current, TASK_INTERRUPTIBLE);
  92                 if (button_pressed)
  93                         break;
  94                 flush_signals(current);
  95                 schedule();
  96         }
  97         __set_current_state(TASK_RUNNING);
  98         remove_wait_queue(&powerd_wait, &wait);
  99
 100         /* Ok, down we go... */
 101         button_pressed = 0;
 102         if (kernel_execve("/sbin/shutdown", argv, envp) < 0) {
 103                 printk("powerd: shutdown execution failed\n");
 104                 add_wait_queue(&powerd_wait, &wait);
 105                 goto again;
 106         }
 107         return 0;
 108 }
 109
 110 static int __init has_button_interrupt(unsigned int irq, struct device_node *dp)
 111 {
 112         if (irq == PCI_IRQ_NONE)
 113                 return 0;
 114         if (!of_find_property(dp, "button", NULL))
 115                 return 0;
 116
 117         return 1;
 118 }
 119
 120 static int __devinit power_probe(struct of_device *op, const struct of_device_id *match)
 121 {
 122         struct resource *res = &op->resource[0];
 123         unsigned int irq= op->irqs[0];
 124
 125         power_reg = of_ioremap(res, 0, 0x4, "power");
 126
 127         printk("%s: Control reg at %lx ... ",
 128                op->node->name, res->start);
 129
 130         poweroff_method = machine_halt;  /* able to use the standard halt */
 131
 132         if (has_button_interrupt(irq, op->node)) {
 133                 if (kernel_thread(powerd, NULL, CLONE_FS) < 0) {
 134                         printk("Failed to start power daemon.\n");
 135                         return 0;
 136                 }
 137                 printk("powerd running.\n");
 138
 139                 if (request_irq(irq,
 140                                 power_handler, 0, "power", NULL) < 0)
 141                         printk("power: Error, cannot register IRQ handler.\n");
 142         } else {
 143                 printk("not using powerd.\n");
 144         }
 145
 146         return 0;
 147 }
 148
 149 static struct of_device_id power_match[] = {
 150         {
 151                 .name = "power",
 152         },
 153         {},
 154 };
 155
 156 static struct of_platform_driver power_driver = {
 157         .name           = "power",
 158         .match_table    = power_match,
 159         .probe          = power_probe,
 160 };
 161
 162 void __init power_init(void)
 163 {
 164         of_register_driver(&power_driver, &of_bus_type);
 165         return;
 166 }
 167 #endif /* CONFIG_PCI */