arch/mips/sgi-ip32/ip32-reset.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 2001 Keith M Wesolowski
   7  * Copyright (C) 2001 Paul Mundt
   8  * Copyright (C) 2003 Guido Guenther <agx@sigxcpu.org>
   9  */
  10
  11 #include <linux/compiler.h>
  12 #include <linux/init.h>
  13 #include <linux/kernel.h>
  14 #include <linux/module.h>
  15 #include <linux/panic_notifier.h>
  16 #include <linux/sched.h>
  17 #include <linux/sched/signal.h>
  18 #include <linux/notifier.h>
  19 #include <linux/delay.h>
  20 #include <linux/rtc/ds1685.h>
  21 #include <linux/interrupt.h>
  22 #include <linux/pm.h>
  23
  24 #include <asm/addrspace.h>
  25 #include <asm/irq.h>
  26 #include <asm/reboot.h>
  27 #include <asm/wbflush.h>
  28 #include <asm/ip32/mace.h>
  29 #include <asm/ip32/crime.h>
  30 #include <asm/ip32/ip32_ints.h>
  31
  32 #include "ip32-common.h"
  33
  34 #define POWERDOWN_TIMEOUT       120
  35 /*
  36  * Blink frequency during reboot grace period and when panicked.
  37  */
  38 #define POWERDOWN_FREQ          (HZ / 4)
  39 #define PANIC_FREQ              (HZ / 8)
  40
  41 extern struct platform_device ip32_rtc_device;
  42
  43 static struct timer_list power_timer, blink_timer;
  44 static unsigned long blink_timer_timeout;
  45 static int has_panicked, shutting_down;
  46
  47 static __noreturn void ip32_poweroff(void *data)
  48 {
  49         void (*poweroff_func)(struct platform_device *) =
  50                 symbol_get(ds1685_rtc_poweroff);
  51
  52 #ifdef CONFIG_MODULES
  53         /* If the first __symbol_get failed, our module wasn't loaded. */
  54         if (!poweroff_func) {
  55                 request_module("rtc-ds1685");
  56                 poweroff_func = symbol_get(ds1685_rtc_poweroff);
  57         }
  58 #endif
  59
  60         if (!poweroff_func)
  61                 pr_emerg("RTC not available for power-off.  Spinning forever ...\n");
  62         else {
  63                 (*poweroff_func)((struct platform_device *)data);
  64                 symbol_put(ds1685_rtc_poweroff);
  65         }
  66
  67         unreachable();
  68 }
  69
  70 static void ip32_machine_restart(char *cmd) __noreturn;
  71 static void ip32_machine_restart(char *cmd)
  72 {
  73         msleep(20);
  74         crime->control = CRIME_CONTROL_HARD_RESET;
  75         unreachable();
  76 }
  77
  78 static void blink_timeout(struct timer_list *unused)
  79 {
  80         unsigned long led = mace->perif.ctrl.misc ^ MACEISA_LED_RED;
  81         mace->perif.ctrl.misc = led;
  82         mod_timer(&blink_timer, jiffies + blink_timer_timeout);
  83 }
  84
  85 static void ip32_machine_halt(void)
  86 {
  87         ip32_poweroff(&ip32_rtc_device);
  88 }
  89
  90 static void power_timeout(struct timer_list *unused)
  91 {
  92         ip32_poweroff(&ip32_rtc_device);
  93 }
  94
  95 void ip32_prepare_poweroff(void)
  96 {
  97         if (has_panicked)
  98                 return;
  99
 100         if (shutting_down || kill_cad_pid(SIGINT, 1)) {
 101                 /* No init process or button pressed twice.  */
 102                 ip32_poweroff(&ip32_rtc_device);
 103         }
 104
 105         shutting_down = 1;
 106         blink_timer_timeout = POWERDOWN_FREQ;
 107         blink_timeout(&blink_timer);
 108
 109         timer_setup(&power_timer, power_timeout, 0);
 110         power_timer.expires = jiffies + POWERDOWN_TIMEOUT * HZ;
 111         add_timer(&power_timer);
 112 }
 113
 114 static int panic_event(struct notifier_block *this, unsigned long event,
 115                        void *ptr)
 116 {
 117         unsigned long led;
 118
 119         if (has_panicked)
 120                 return NOTIFY_DONE;
 121         has_panicked = 1;
 122
 123         /* turn off the green LED */
 124         led = mace->perif.ctrl.misc | MACEISA_LED_GREEN;
 125         mace->perif.ctrl.misc = led;
 126
 127         blink_timer_timeout = PANIC_FREQ;
 128         blink_timeout(&blink_timer);
 129
 130         return NOTIFY_DONE;
 131 }
 132
 133 static struct notifier_block panic_block = {
 134         .notifier_call = panic_event,
 135 };
 136
 137 static __init int ip32_reboot_setup(void)
 138 {
 139         /* turn on the green led only */
 140         unsigned long led = mace->perif.ctrl.misc;
 141         led |= MACEISA_LED_RED;
 142         led &= ~MACEISA_LED_GREEN;
 143         mace->perif.ctrl.misc = led;
 144
 145         _machine_restart = ip32_machine_restart;
 146         _machine_halt = ip32_machine_halt;
 147         pm_power_off = ip32_machine_halt;
 148
 149         timer_setup(&blink_timer, blink_timeout, 0);
 150         atomic_notifier_chain_register(&panic_notifier_list, &panic_block);
 151
 152         return 0;
 153 }
 154
 155 subsys_initcall(ip32_reboot_setup);