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
  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 static void __iomem *power_reg;
  33
  34 static irqreturn_t power_handler(int irq, void *dev_id)
  35 {
  36         orderly_poweroff(true);
  37
  38         /* FIXME: Check registers for status... */
  39         return IRQ_HANDLED;
  40 }
  41
  42 extern void machine_halt(void);
  43 extern void machine_alt_power_off(void);
  44 static void (*poweroff_method)(void) = machine_alt_power_off;
  45
  46 void machine_power_off(void)
  47 {
  48         sstate_poweroff();
  49         if (!serial_console || scons_pwroff) {
  50                 if (power_reg) {
  51                         /* Both register bits seem to have the
  52                          * same effect, so until I figure out
  53                          * what the difference is...
  54                          */
  55                         writel(AUXIO_PCIO_CPWR_OFF | AUXIO_PCIO_SPWR_OFF, power_reg);
  56                 } else {
  57                         if (poweroff_method != NULL) {
  58                                 poweroff_method();
  59                                 /* not reached */
  60                         }
  61                 }
  62         }
  63         machine_halt();
  64 }
  65
  66 void (*pm_power_off)(void) = machine_power_off;
  67 EXPORT_SYMBOL(pm_power_off);
  68
  69 static int __init has_button_interrupt(unsigned int irq, struct device_node *dp)
  70 {
  71         if (irq == 0xffffffff)
  72                 return 0;
  73         if (!of_find_property(dp, "button", NULL))
  74                 return 0;
  75
  76         return 1;
  77 }
  78
  79 static int __devinit power_probe(struct of_device *op, const struct of_device_id *match)
  80 {
  81         struct resource *res = &op->resource[0];
  82         unsigned int irq= op->irqs[0];
  83
  84         power_reg = of_ioremap(res, 0, 0x4, "power");
  85
  86         printk(KERN_INFO "%s: Control reg at %lx\n",
  87                op->node->name, res->start);
  88
  89         poweroff_method = machine_halt;  /* able to use the standard halt */
  90
  91         if (has_button_interrupt(irq, op->node)) {
  92                 if (request_irq(irq,
  93                                 power_handler, 0, "power", NULL) < 0)
  94                         printk(KERN_ERR "power: Cannot setup IRQ handler.\n");
  95         }
  96
  97         return 0;
  98 }
  99
 100 static struct of_device_id power_match[] = {
 101         {
 102                 .name = "power",
 103         },
 104         {},
 105 };
 106
 107 static struct of_platform_driver power_driver = {
 108         .name           = "power",
 109         .match_table    = power_match,
 110         .probe          = power_probe,
 111 };
 112
 113 void __init power_init(void)
 114 {
 115         of_register_driver(&power_driver, &of_platform_bus_type);
 116         return;
 117 }