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 #define __KERNEL_SYSCALLS__
   8
   9 #include <linux/kernel.h>
  10 #include <linux/module.h>
  11 #include <linux/init.h>
  12 #include <linux/sched.h>
  13 #include <linux/signal.h>
  14 #include <linux/delay.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/pm.h>
  17
  18 #include <asm/system.h>
  19 #include <asm/auxio.h>
  20 #include <asm/prom.h>
  21 #include <asm/of_device.h>
  22 #include <asm/io.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, struct pt_regs *regs)
  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         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
  75 void (*pm_power_off)(void) = machine_power_off;
  76 EXPORT_SYMBOL(pm_power_off);
  77
  78 #ifdef CONFIG_PCI
  79 static 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);
  88 again:
  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 (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
 109 static 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
 119 static 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
 148 static struct of_device_id power_match[] = {
 149         {
 150                 .name = "power",
 151         },
 152         {},
 153 };
 154
 155 static struct of_platform_driver power_driver = {
 156         .name           = "power",
 157         .match_table    = power_match,
 158         .probe          = power_probe,
 159 };
 160
 161 void __init power_init(void)
 162 {
 163         of_register_driver(&power_driver, &of_bus_type);
 164         return;
 165 }
 166 #endif /* CONFIG_PCI */