arch/sparc64/kernel/power.c

   1 /* power.c: Power management driver.
   2  *
   3  * Copyright (C) 1999, 2007, 2008 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/interrupt.h>
  10 #include <linux/pm.h>
  11 #include <linux/reboot.h>
  12 #include <linux/of_device.h>
  13
  14 #include <asm/auxio.h>
  15 #include <asm/prom.h>
  16 #include <asm/io.h>
  17 #include <asm/sstate.h>
  18 #include <asm/reboot.h>
  19
  20 /*
  21  * sysctl - toggle power-off restriction for serial console
  22  * systems in machine_power_off()
  23  */
  24 int scons_pwroff = 1;
  25
  26 static void __iomem *power_reg;
  27
  28 static irqreturn_t power_handler(int irq, void *dev_id)
  29 {
  30         orderly_poweroff(true);
  31
  32         /* FIXME: Check registers for status... */
  33         return IRQ_HANDLED;
  34 }
  35
  36 static void (*poweroff_method)(void) = machine_alt_power_off;
  37
  38 void machine_power_off(void)
  39 {
  40         sstate_poweroff();
  41         if (strcmp(of_console_device->type, "serial") || scons_pwroff) {
  42                 if (power_reg) {
  43                         /* Both register bits seem to have the
  44                          * same effect, so until I figure out
  45                          * what the difference is...
  46                          */
  47                         writel(AUXIO_PCIO_CPWR_OFF | AUXIO_PCIO_SPWR_OFF, power_reg);
  48                 } else {
  49                         if (poweroff_method != NULL) {
  50                                 poweroff_method();
  51                                 /* not reached */
  52                         }
  53                 }
  54         }
  55         machine_halt();
  56 }
  57
  58 void (*pm_power_off)(void) = machine_power_off;
  59 EXPORT_SYMBOL(pm_power_off);
  60
  61 static int __init has_button_interrupt(unsigned int irq, struct device_node *dp)
  62 {
  63         if (irq == 0xffffffff)
  64                 return 0;
  65         if (!of_find_property(dp, "button", NULL))
  66                 return 0;
  67
  68         return 1;
  69 }
  70
  71 static int __devinit power_probe(struct of_device *op, const struct of_device_id *match)
  72 {
  73         struct resource *res = &op->resource[0];
  74         unsigned int irq= op->irqs[0];
  75
  76         power_reg = of_ioremap(res, 0, 0x4, "power");
  77
  78         printk(KERN_INFO "%s: Control reg at %lx\n",
  79                op->node->name, res->start);
  80
  81         poweroff_method = machine_halt;  /* able to use the standard halt */
  82
  83         if (has_button_interrupt(irq, op->node)) {
  84                 if (request_irq(irq,
  85                                 power_handler, 0, "power", NULL) < 0)
  86                         printk(KERN_ERR "power: Cannot setup IRQ handler.\n");
  87         }
  88
  89         return 0;
  90 }
  91
  92 static struct of_device_id __initdata power_match[] = {
  93         {
  94                 .name = "power",
  95         },
  96         {},
  97 };
  98
  99 static struct of_platform_driver power_driver = {
 100         .match_table    = power_match,
 101         .probe          = power_probe,
 102         .driver         = {
 103                 .name   = "power",
 104         },
 105 };
 106
 107 static int __init power_init(void)
 108 {
 109         return of_register_driver(&power_driver, &of_platform_bus_type);
 110 }
 111
 112 device_initcall(power_init);