linux/arch/mips/sgi-ip22/ip22-reset.c
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   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) 1997, 1998, 2001, 03, 05, 06 by Ralf Baechle
   7 */
   8#include <linux/linkage.h>
   9#include <linux/init.h>
  10#include <linux/ds1286.h>
  11#include <linux/module.h>
  12#include <linux/interrupt.h>
  13#include <linux/kernel.h>
  14#include <linux/sched.h>
  15#include <linux/notifier.h>
  16#include <linux/pm.h>
  17#include <linux/timer.h>
  18
  19#include <asm/io.h>
  20#include <asm/irq.h>
  21#include <asm/system.h>
  22#include <asm/reboot.h>
  23#include <asm/sgialib.h>
  24#include <asm/sgi/ioc.h>
  25#include <asm/sgi/hpc3.h>
  26#include <asm/sgi/mc.h>
  27#include <asm/sgi/ip22.h>
  28
  29/*
  30 * Just powerdown if init hasn't done after POWERDOWN_TIMEOUT seconds.
  31 * I'm not sure if this feature is a good idea, for now it's here just to
  32 * make the power button make behave just like under IRIX.
  33 */
  34#define POWERDOWN_TIMEOUT       120
  35
  36/*
  37 * Blink frequency during reboot grace period and when panicked.
  38 */
  39#define POWERDOWN_FREQ          (HZ / 4)
  40#define PANIC_FREQ              (HZ / 8)
  41
  42static struct timer_list power_timer, blink_timer, debounce_timer;
  43
  44#define MACHINE_PANICED         1
  45#define MACHINE_SHUTTING_DOWN   2
  46
  47static int machine_state;
  48
  49static void __noreturn sgi_machine_power_off(void)
  50{
  51        unsigned int tmp;
  52
  53        local_irq_disable();
  54
  55        /* Disable watchdog */
  56        tmp = hpc3c0->rtcregs[RTC_CMD] & 0xff;
  57        hpc3c0->rtcregs[RTC_CMD] = tmp | RTC_WAM;
  58        hpc3c0->rtcregs[RTC_WSEC] = 0;
  59        hpc3c0->rtcregs[RTC_WHSEC] = 0;
  60
  61        while (1) {
  62                sgioc->panel = ~SGIOC_PANEL_POWERON;
  63                /* Good bye cruel world ...  */
  64
  65                /* If we're still running, we probably got sent an alarm
  66                   interrupt.  Read the flag to clear it.  */
  67                tmp = hpc3c0->rtcregs[RTC_HOURS_ALARM];
  68        }
  69}
  70
  71static void __noreturn sgi_machine_restart(char *command)
  72{
  73        if (machine_state & MACHINE_SHUTTING_DOWN)
  74                sgi_machine_power_off();
  75        sgimc->cpuctrl0 |= SGIMC_CCTRL0_SYSINIT;
  76        while (1);
  77}
  78
  79static void __noreturn sgi_machine_halt(void)
  80{
  81        if (machine_state & MACHINE_SHUTTING_DOWN)
  82                sgi_machine_power_off();
  83        ArcEnterInteractiveMode();
  84}
  85
  86static void power_timeout(unsigned long data)
  87{
  88        sgi_machine_power_off();
  89}
  90
  91static void blink_timeout(unsigned long data)
  92{
  93        /* XXX fix this for fullhouse  */
  94        sgi_ioc_reset ^= (SGIOC_RESET_LC0OFF|SGIOC_RESET_LC1OFF);
  95        sgioc->reset = sgi_ioc_reset;
  96
  97        mod_timer(&blink_timer, jiffies + data);
  98}
  99
 100static void debounce(unsigned long data)
 101{
 102        del_timer(&debounce_timer);
 103        if (sgint->istat1 & SGINT_ISTAT1_PWR) {
 104                /* Interrupt still being sent. */
 105                debounce_timer.expires = jiffies + (HZ / 20); /* 0.05s  */
 106                add_timer(&debounce_timer);
 107
 108                sgioc->panel = SGIOC_PANEL_POWERON | SGIOC_PANEL_POWERINTR |
 109                               SGIOC_PANEL_VOLDNINTR | SGIOC_PANEL_VOLDNHOLD |
 110                               SGIOC_PANEL_VOLUPINTR | SGIOC_PANEL_VOLUPHOLD;
 111
 112                return;
 113        }
 114
 115        if (machine_state & MACHINE_PANICED)
 116                sgimc->cpuctrl0 |= SGIMC_CCTRL0_SYSINIT;
 117
 118        enable_irq(SGI_PANEL_IRQ);
 119}
 120
 121static inline void power_button(void)
 122{
 123        if (machine_state & MACHINE_PANICED)
 124                return;
 125
 126        if ((machine_state & MACHINE_SHUTTING_DOWN) ||
 127                        kill_cad_pid(SIGINT, 1)) {
 128                /* No init process or button pressed twice.  */
 129                sgi_machine_power_off();
 130        }
 131
 132        machine_state |= MACHINE_SHUTTING_DOWN;
 133        blink_timer.data = POWERDOWN_FREQ;
 134        blink_timeout(POWERDOWN_FREQ);
 135
 136        init_timer(&power_timer);
 137        power_timer.function = power_timeout;
 138        power_timer.expires = jiffies + POWERDOWN_TIMEOUT * HZ;
 139        add_timer(&power_timer);
 140}
 141
 142static irqreturn_t panel_int(int irq, void *dev_id)
 143{
 144        unsigned int buttons;
 145
 146        buttons = sgioc->panel;
 147        sgioc->panel = SGIOC_PANEL_POWERON | SGIOC_PANEL_POWERINTR;
 148
 149        if (sgint->istat1 & SGINT_ISTAT1_PWR) {
 150                /* Wait until interrupt goes away */
 151                disable_irq_nosync(SGI_PANEL_IRQ);
 152                init_timer(&debounce_timer);
 153                debounce_timer.function = debounce;
 154                debounce_timer.expires = jiffies + 5;
 155                add_timer(&debounce_timer);
 156        }
 157
 158        /* Power button was pressed
 159         * ioc.ps page 22: "The Panel Register is called Power Control by Full
 160         * House. Only lowest 2 bits are used. Guiness uses upper four bits
 161         * for volume control". This is not true, all bits are pulled high
 162         * on fullhouse */
 163        if (!(buttons & SGIOC_PANEL_POWERINTR))
 164                power_button();
 165
 166        return IRQ_HANDLED;
 167}
 168
 169static int panic_event(struct notifier_block *this, unsigned long event,
 170                      void *ptr)
 171{
 172        if (machine_state & MACHINE_PANICED)
 173                return NOTIFY_DONE;
 174        machine_state |= MACHINE_PANICED;
 175
 176        blink_timer.data = PANIC_FREQ;
 177        blink_timeout(PANIC_FREQ);
 178
 179        return NOTIFY_DONE;
 180}
 181
 182static struct notifier_block panic_block = {
 183        .notifier_call  = panic_event,
 184};
 185
 186static int __init reboot_setup(void)
 187{
 188        int res;
 189
 190        _machine_restart = sgi_machine_restart;
 191        _machine_halt = sgi_machine_halt;
 192        pm_power_off = sgi_machine_power_off;
 193
 194        res = request_irq(SGI_PANEL_IRQ, panel_int, 0, "Front Panel", NULL);
 195        if (res) {
 196                printk(KERN_ERR "Allocation of front panel IRQ failed\n");
 197                return res;
 198        }
 199
 200        init_timer(&blink_timer);
 201        blink_timer.function = blink_timeout;
 202        atomic_notifier_chain_register(&panic_notifier_list, &panic_block);
 203
 204        return 0;
 205}
 206
 207subsys_initcall(reboot_setup);
 208
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