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/config.h>
  10 #include <linux/kernel.h>
  11 #include <linux/module.h>
  12 #include <linux/init.h>
  13 #include <linux/sched.h>
  14 #include <linux/signal.h>
  15 #include <linux/delay.h>
  16 #include <linux/interrupt.h>
  17
  18 #include <asm/system.h>
  19 #include <asm/ebus.h>
  20 #include <asm/isa.h>
  21 #include <asm/auxio.h>
  22
  23 #include <linux/unistd.h>
  24
  25 /*
  26  * sysctl - toggle power-off restriction for serial console
  27  * systems in machine_power_off()
  28  */
  29 int scons_pwroff = 1;
  30
  31 #ifdef CONFIG_PCI
  32 static void __iomem *power_reg;
  33
  34 static DECLARE_WAIT_QUEUE_HEAD(powerd_wait);
  35 static int button_pressed;
  36
  37 static irqreturn_t power_handler(int irq, void *dev_id, struct pt_regs *regs)
  38 {
  39         if (button_pressed == 0) {
  40                 button_pressed = 1;
  41                 wake_up(&powerd_wait);
  42         }
  43
  44         /* FIXME: Check registers for status... */
  45         return IRQ_HANDLED;
  46 }
  47 #endif /* CONFIG_PCI */
  48
  49 extern void machine_halt(void);
  50 extern void machine_alt_power_off(void);
  51 static void (*poweroff_method)(void) = machine_alt_power_off;
  52
  53 void machine_power_off(void)
  54 {
  55         if (!serial_console || scons_pwroff) {
  56 #ifdef CONFIG_PCI
  57                 if (power_reg) {
  58                         /* Both register bits seem to have the
  59                          * same effect, so until I figure out
  60                          * what the difference is...
  61                          */
  62                         writel(AUXIO_PCIO_CPWR_OFF | AUXIO_PCIO_SPWR_OFF, power_reg);
  63                 } else
  64 #endif /* CONFIG_PCI */
  65                         if (poweroff_method != NULL) {
  66                                 poweroff_method();
  67                                 /* not reached */
  68                         }
  69         }
  70         machine_halt();
  71 }
  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(unsigned int irq, int prom_node)
 105 {
 106         if (irq == PCI_IRQ_NONE)
 107                 return 0;
 108         if (!prom_node_has_property(prom_node, "button"))
 109                 return 0;
 110
 111         return 1;
 112 }
 113
 114 static int __init power_probe_ebus(struct resource **resp, unsigned int *irq_p, int *prom_node_p)
 115 {
 116         struct linux_ebus *ebus;
 117         struct linux_ebus_device *edev;
 118
 119         for_each_ebus(ebus) {
 120                 for_each_ebusdev(edev, ebus) {
 121                         if (!strcmp(edev->prom_name, "power")) {
 122                                 *resp = &edev->resource[0];
 123                                 *irq_p = edev->irqs[0];
 124                                 *prom_node_p = edev->prom_node;
 125                                 return 0;
 126                         }
 127                 }
 128         }
 129         return -ENODEV;
 130 }
 131
 132 static int __init power_probe_isa(struct resource **resp, unsigned int *irq_p, int *prom_node_p)
 133 {
 134         struct sparc_isa_bridge *isa_bus;
 135         struct sparc_isa_device *isa_dev;
 136
 137         for_each_isa(isa_bus) {
 138                 for_each_isadev(isa_dev, isa_bus) {
 139                         if (!strcmp(isa_dev->prom_name, "power")) {
 140                                 *resp = &isa_dev->resource;
 141                                 *irq_p = isa_dev->irq;
 142                                 *prom_node_p = isa_dev->prom_node;
 143                                 return 0;
 144                         }
 145                 }
 146         }
 147         return -ENODEV;
 148 }
 149
 150 void __init power_init(void)
 151 {
 152         struct resource *res = NULL;
 153         unsigned int irq;
 154         int prom_node;
 155         static int invoked;
 156
 157         if (invoked)
 158                 return;
 159         invoked = 1;
 160
 161         if (!power_probe_ebus(&res, &irq, &prom_node))
 162                 goto found;
 163
 164         if (!power_probe_isa(&res, &irq, &prom_node))
 165                 goto found;
 166
 167         return;
 168
 169 found:
 170         power_reg = ioremap(res->start, 0x4);
 171         printk("power: Control reg at %p ... ", power_reg);
 172         poweroff_method = machine_halt;  /* able to use the standard halt */
 173         if (has_button_interrupt(irq, prom_node)) {
 174                 if (kernel_thread(powerd, NULL, CLONE_FS) < 0) {
 175                         printk("Failed to start power daemon.\n");
 176                         return;
 177                 }
 178                 printk("powerd running.\n");
 179
 180                 if (request_irq(irq,
 181                                 power_handler, SA_SHIRQ, "power", NULL) < 0)
 182                         printk("power: Error, cannot register IRQ handler.\n");
 183         } else {
 184                 printk("not using powerd.\n");
 185         }
 186 }
 187 #endif /* CONFIG_PCI */