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  */
  27 int scons_pwroff = 1;
  28
  29 #ifdef CONFIG_PCI
  30 static void __iomem *power_reg;
  31
  32 static DECLARE_WAIT_QUEUE_HEAD(powerd_wait);
  33 static int button_pressed;
  34
  35 static 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
  47 extern void machine_halt(void);
  48 extern void machine_alt_power_off(void);
  49 static void (*poweroff_method)(void) = machine_alt_power_off;
  50
  51 void 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
  71 EXPORT_SYMBOL(machine_power_off);
  72
  73 #ifdef CONFIG_PCI
  74 static 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);
  83 again:
  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
 104 static 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
 114 void __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
 132 found:
 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 */