arch/sparc64/kernel/power.c

   1 /* power.c: Power management driver.
   2  *
   3  * Copyright (C) 1999, 2007 David S. Miller (davem@davemloft.net)
   4  */
   5
   6 #include <linux/kernel.h>
   7 #include <linux/module.h>
   8 #include <linux/init.h>
   9 #include <linux/sched.h>
  10 #include <linux/signal.h>
  11 #include <linux/delay.h>
  12 #include <linux/interrupt.h>
  13 #include <linux/pm.h>
  14 #include <linux/syscalls.h>
  15 #include <linux/reboot.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 #include <asm/reboot.h>
  24
  25 #include <linux/unistd.h>
  26
  27 /*
  28  * sysctl - toggle power-off restriction for serial console
  29  * systems in machine_power_off()
  30  */
  31 int scons_pwroff = 1;
  32
  33 static void __iomem *power_reg;
  34
  35 static irqreturn_t power_handler(int irq, void *dev_id)
  36 {
  37         orderly_poweroff(true);
  38
  39         /* FIXME: Check registers for status... */
  40         return IRQ_HANDLED;
  41 }
  42
  43 static void (*poweroff_method)(void) = machine_alt_power_off;
  44
  45 void machine_power_off(void)
  46 {
  47         sstate_poweroff();
  48         if (strcmp(of_console_device->type, "serial") || scons_pwroff) {
  49                 if (power_reg) {
  50                         /* Both register bits seem to have the
  51                          * same effect, so until I figure out
  52                          * what the difference is...
  53                          */
  54                         writel(AUXIO_PCIO_CPWR_OFF | AUXIO_PCIO_SPWR_OFF, power_reg);
  55                 } else {
  56                         if (poweroff_method != NULL) {
  57                                 poweroff_method();
  58                                 /* not reached */
  59                         }
  60                 }
  61         }
  62         machine_halt();
  63 }
  64
  65 void (*pm_power_off)(void) = machine_power_off;
  66 EXPORT_SYMBOL(pm_power_off);
  67
  68 static int __init has_button_interrupt(unsigned int irq, struct device_node *dp)
  69 {
  70         if (irq == 0xffffffff)
  71                 return 0;
  72         if (!of_find_property(dp, "button", NULL))
  73                 return 0;
  74
  75         return 1;
  76 }
  77
  78 static int __devinit power_probe(struct of_device *op, const struct of_device_id *match)
  79 {
  80         struct resource *res = &op->resource[0];
  81         unsigned int irq= op->irqs[0];
  82
  83         power_reg = of_ioremap(res, 0, 0x4, "power");
  84
  85         printk(KERN_INFO "%s: Control reg at %lx\n",
  86                op->node->name, res->start);
  87
  88         poweroff_method = machine_halt;  /* able to use the standard halt */
  89
  90         if (has_button_interrupt(irq, op->node)) {
  91                 if (request_irq(irq,
  92                                 power_handler, 0, "power", NULL) < 0)
  93                         printk(KERN_ERR "power: Cannot setup IRQ handler.\n");
  94         }
  95
  96         return 0;
  97 }
  98
  99 static struct of_device_id power_match[] = {
 100         {
 101                 .name = "power",
 102         },
 103         {},
 104 };
 105
 106 static struct of_platform_driver power_driver = {
 107         .match_table    = power_match,
 108         .probe          = power_probe,
 109         .driver         = {
 110                 .name   = "power",
 111         },
 112 };
 113
 114 void __init power_init(void)
 115 {
 116         of_register_driver(&power_driver, &of_platform_bus_type);
 117         return;
 118 }