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
  16 #include <asm/system.h>
  17 #include <asm/auxio.h>
  18 #include <asm/prom.h>
  19 #include <asm/of_device.h>
  20 #include <asm/io.h>
  21 #include <asm/power.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 DECLARE_WAIT_QUEUE_HEAD(powerd_wait);
  35 static int button_pressed;
  36
  37 void wake_up_powerd(void)
  38 {
  39         if (button_pressed == 0) {
  40                 button_pressed = 1;
  41                 wake_up(&powerd_wait);
  42         }
  43 }
  44
  45 static irqreturn_t power_handler(int irq, void *dev_id)
  46 {
  47         wake_up_powerd();
  48
  49         /* FIXME: Check registers for status... */
  50         return IRQ_HANDLED;
  51 }
  52
  53 extern void machine_halt(void);
  54 extern void machine_alt_power_off(void);
  55 static void (*poweroff_method)(void) = machine_alt_power_off;
  56
  57 void machine_power_off(void)
  58 {
  59         sstate_poweroff();
  60         if (!serial_console || scons_pwroff) {
  61                 if (power_reg) {
  62                         /* Both register bits seem to have the
  63                          * same effect, so until I figure out
  64                          * what the difference is...
  65                          */
  66                         writel(AUXIO_PCIO_CPWR_OFF | AUXIO_PCIO_SPWR_OFF, power_reg);
  67                 } else {
  68                         if (poweroff_method != NULL) {
  69                                 poweroff_method();
  70                                 /* not reached */
  71                         }
  72                 }
  73         }
  74         machine_halt();
  75 }
  76
  77 void (*pm_power_off)(void) = machine_power_off;
  78 EXPORT_SYMBOL(pm_power_off);
  79
  80 static int powerd(void *__unused)
  81 {
  82         static char *envp[] = { "HOME=/", "TERM=linux", "PATH=/sbin:/usr/sbin:/bin:/usr/bin", NULL };
  83         char *argv[] = { "/sbin/shutdown", "-h", "now", NULL };
  84         DECLARE_WAITQUEUE(wait, current);
  85
  86         daemonize("powerd");
  87
  88         add_wait_queue(&powerd_wait, &wait);
  89
  90         for (;;) {
  91                 set_task_state(current, TASK_INTERRUPTIBLE);
  92                 if (button_pressed)
  93                         break;
  94                 flush_signals(current);
  95                 schedule();
  96         }
  97         __set_current_state(TASK_RUNNING);
  98         remove_wait_queue(&powerd_wait, &wait);
  99
 100         /* Ok, down we go... */
 101         button_pressed = 0;
 102         if (kernel_execve("/sbin/shutdown", argv, envp) < 0) {
 103                 printk(KERN_ERR "powerd: shutdown execution failed\n");
 104                 machine_power_off();
 105         }
 106         return 0;
 107 }
 108
 109 int start_powerd(void)
 110 {
 111         int err;
 112
 113         err = kernel_thread(powerd, NULL, CLONE_FS);
 114         if (err < 0)
 115                 printk(KERN_ERR "power: Failed to start power daemon.\n");
 116         else
 117                 printk(KERN_INFO "power: powerd running.\n");
 118
 119         return err;
 120 }
 121
 122 static int __init has_button_interrupt(unsigned int irq, struct device_node *dp)
 123 {
 124         if (irq == 0xffffffff)
 125                 return 0;
 126         if (!of_find_property(dp, "button", NULL))
 127                 return 0;
 128
 129         return 1;
 130 }
 131
 132 static int __devinit power_probe(struct of_device *op, const struct of_device_id *match)
 133 {
 134         struct resource *res = &op->resource[0];
 135         unsigned int irq= op->irqs[0];
 136
 137         power_reg = of_ioremap(res, 0, 0x4, "power");
 138
 139         printk("%s: Control reg at %lx ... ",
 140                op->node->name, res->start);
 141
 142         poweroff_method = machine_halt;  /* able to use the standard halt */
 143
 144         if (has_button_interrupt(irq, op->node)) {
 145                 if (start_powerd() < 0)
 146                         return 0;
 147
 148                 if (request_irq(irq,
 149                                 power_handler, 0, "power", NULL) < 0)
 150                         printk(KERN_ERR "power: Cannot setup IRQ handler.\n");
 151         } else {
 152                 printk(KERN_INFO "power: Not using powerd.\n");
 153         }
 154
 155         return 0;
 156 }
 157
 158 static struct of_device_id power_match[] = {
 159         {
 160                 .name = "power",
 161         },
 162         {},
 163 };
 164
 165 static struct of_platform_driver power_driver = {
 166         .name           = "power",
 167         .match_table    = power_match,
 168         .probe          = power_probe,
 169 };
 170
 171 void __init power_init(void)
 172 {
 173         of_register_driver(&power_driver, &of_bus_type);
 174         return;
 175 }