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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 #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 #include <linux/pm.h>
  18
  19 #include <asm/system.h>
  20 #include <asm/ebus.h>
  21 #include <asm/isa.h>
  22 #include <asm/auxio.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 static void __iomem *power_reg;
  34
  35 static DECLARE_WAIT_QUEUE_HEAD(powerd_wait);
  36 static int button_pressed;
  37
  38 static irqreturn_t power_handler(int irq, void *dev_id, struct pt_regs *regs)
  39 {
  40         if (button_pressed == 0) {
  41                 button_pressed = 1;
  42                 wake_up(&powerd_wait);
  43         }
  44
  45         /* FIXME: Check registers for status... */
  46         return IRQ_HANDLED;
  47 }
  48 #endif /* CONFIG_PCI */
  49
  50 extern void machine_halt(void);
  51 extern void machine_alt_power_off(void);
  52 static void (*poweroff_method)(void) = machine_alt_power_off;
  53
  54 void machine_power_off(void)
  55 {
  56         if (!serial_console || scons_pwroff) {
  57 #ifdef CONFIG_PCI
  58                 if (power_reg) {
  59                         /* Both register bits seem to have the
  60                          * same effect, so until I figure out
  61                          * what the difference is...
  62                          */
  63                         writel(AUXIO_PCIO_CPWR_OFF | AUXIO_PCIO_SPWR_OFF, power_reg);
  64                 } else
  65 #endif /* CONFIG_PCI */
  66                         if (poweroff_method != NULL) {
  67                                 poweroff_method();
  68                                 /* not reached */
  69                         }
  70         }
  71         machine_halt();
  72 }
  73
  74 void (*pm_power_off)(void) = machine_power_off;
  75 EXPORT_SYMBOL(pm_power_off);
  76
  77 #ifdef CONFIG_PCI
  78 static int powerd(void *__unused)
  79 {
  80         static char *envp[] = { "HOME=/", "TERM=linux", "PATH=/sbin:/usr/sbin:/bin:/usr/bin", NULL };
  81         char *argv[] = { "/sbin/shutdown", "-h", "now", NULL };
  82         DECLARE_WAITQUEUE(wait, current);
  83
  84         daemonize("powerd");
  85
  86         add_wait_queue(&powerd_wait, &wait);
  87 again:
  88         for (;;) {
  89                 set_task_state(current, TASK_INTERRUPTIBLE);
  90                 if (button_pressed)
  91                         break;
  92                 flush_signals(current);
  93                 schedule();
  94         }
  95         __set_current_state(TASK_RUNNING);
  96         remove_wait_queue(&powerd_wait, &wait);
  97
  98         /* Ok, down we go... */
  99         button_pressed = 0;
 100         if (execve("/sbin/shutdown", argv, envp) < 0) {
 101                 printk("powerd: shutdown execution failed\n");
 102                 add_wait_queue(&powerd_wait, &wait);
 103                 goto again;
 104         }
 105         return 0;
 106 }
 107
 108 static int __init has_button_interrupt(unsigned int irq, int prom_node)
 109 {
 110         if (irq == PCI_IRQ_NONE)
 111                 return 0;
 112         if (!prom_node_has_property(prom_node, "button"))
 113                 return 0;
 114
 115         return 1;
 116 }
 117
 118 static int __init power_probe_ebus(struct resource **resp, unsigned int *irq_p, int *prom_node_p)
 119 {
 120         struct linux_ebus *ebus;
 121         struct linux_ebus_device *edev;
 122
 123         for_each_ebus(ebus) {
 124                 for_each_ebusdev(edev, ebus) {
 125                         if (!strcmp(edev->prom_name, "power")) {
 126                                 *resp = &edev->resource[0];
 127                                 *irq_p = edev->irqs[0];
 128                                 *prom_node_p = edev->prom_node;
 129                                 return 0;
 130                         }
 131                 }
 132         }
 133         return -ENODEV;
 134 }
 135
 136 static int __init power_probe_isa(struct resource **resp, unsigned int *irq_p, int *prom_node_p)
 137 {
 138         struct sparc_isa_bridge *isa_bus;
 139         struct sparc_isa_device *isa_dev;
 140
 141         for_each_isa(isa_bus) {
 142                 for_each_isadev(isa_dev, isa_bus) {
 143                         if (!strcmp(isa_dev->prom_name, "power")) {
 144                                 *resp = &isa_dev->resource;
 145                                 *irq_p = isa_dev->irq;
 146                                 *prom_node_p = isa_dev->prom_node;
 147                                 return 0;
 148                         }
 149                 }
 150         }
 151         return -ENODEV;
 152 }
 153
 154 void __init power_init(void)
 155 {
 156         struct resource *res = NULL;
 157         unsigned int irq;
 158         int prom_node;
 159         static int invoked;
 160
 161         if (invoked)
 162                 return;
 163         invoked = 1;
 164
 165         if (!power_probe_ebus(&res, &irq, &prom_node))
 166                 goto found;
 167
 168         if (!power_probe_isa(&res, &irq, &prom_node))
 169                 goto found;
 170
 171         return;
 172
 173 found:
 174         power_reg = ioremap(res->start, 0x4);
 175         printk("power: Control reg at %p ... ", power_reg);
 176         poweroff_method = machine_halt;  /* able to use the standard halt */
 177         if (has_button_interrupt(irq, prom_node)) {
 178                 if (kernel_thread(powerd, NULL, CLONE_FS) < 0) {
 179                         printk("Failed to start power daemon.\n");
 180                         return;
 181                 }
 182                 printk("powerd running.\n");
 183
 184                 if (request_irq(irq,
 185                                 power_handler, SA_SHIRQ, "power", NULL) < 0)
 186                         printk("power: Error, cannot register IRQ handler.\n");
 187         } else {
 188                 printk("not using powerd.\n");
 189         }
 190 }
 191 #endif /* CONFIG_PCI */