ip22-reset.c

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/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 1997, 1998, 2001, 03, 05, 06 by Ralf Baechle
 */
#include <linux/linkage.h>
#include <linux/init.h>
#include <linux/ds1286.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/notifier.h>
#include <linux/pm.h>
#include <linux/timer.h>

#include <asm/io.h>
#include <asm/irq.h>
#include <asm/reboot.h>
#include <asm/sgialib.h>
#include <asm/sgi/ioc.h>
#include <asm/sgi/hpc3.h>
#include <asm/sgi/mc.h>
#include <asm/sgi/ip22.h>

/*
 * Just powerdown if init hasn't done after POWERDOWN_TIMEOUT seconds.
 * I'm not sure if this feature is a good idea, for now it's here just to
 * make the power button make behave just like under IRIX.
 */
#define POWERDOWN_TIMEOUT   120

/*
 * Blink frequency during reboot grace period and when panicked.
 */
#define POWERDOWN_FREQ      (HZ / 4)
#define PANIC_FREQ      (HZ / 8)

static struct timer_list power_timer, blink_timer, debounce_timer;

#define MACHINE_PANICED     1
#define MACHINE_SHUTTING_DOWN   2

static int machine_state;

static void __noreturn sgi_machine_power_off(void)
{
    unsigned int tmp;

    local_irq_disable();

    /* Disable watchdog */
    tmp = hpc3c0->rtcregs[RTC_CMD] & 0xff;
    hpc3c0->rtcregs[RTC_CMD] = tmp | RTC_WAM;
    hpc3c0->rtcregs[RTC_WSEC] = 0;
    hpc3c0->rtcregs[RTC_WHSEC] = 0;

    while (1) {
        sgioc->panel = ~SGIOC_PANEL_POWERON;
        /* Good bye cruel world ...  */

        /* If we're still running, we probably got sent an alarm
           interrupt.  Read the flag to clear it.  */
        tmp = hpc3c0->rtcregs[RTC_HOURS_ALARM];
    }
}

static void __noreturn sgi_machine_restart(char *command)
{
    if (machine_state & MACHINE_SHUTTING_DOWN)
        sgi_machine_power_off();
    sgimc->cpuctrl0 |= SGIMC_CCTRL0_SYSINIT;
    while (1);
}

static void __noreturn sgi_machine_halt(void)
{
    if (machine_state & MACHINE_SHUTTING_DOWN)
        sgi_machine_power_off();
    ArcEnterInteractiveMode();
}

static void power_timeout(unsigned long data)
{
    sgi_machine_power_off();
}

static void blink_timeout(unsigned long data)
{
    /* XXX fix this for fullhouse  */
    sgi_ioc_reset ^= (SGIOC_RESET_LC0OFF|SGIOC_RESET_LC1OFF);
    sgioc->reset = sgi_ioc_reset;

    mod_timer(&blink_timer, jiffies + data);
}

static void debounce(unsigned long data)
{
    del_timer(&debounce_timer);
    if (sgint->istat1 & SGINT_ISTAT1_PWR) {
        /* Interrupt still being sent. */
        debounce_timer.expires = jiffies + (HZ / 20); /* 0.05s  */
        add_timer(&debounce_timer);

        sgioc->panel = SGIOC_PANEL_POWERON | SGIOC_PANEL_POWERINTR |
                   SGIOC_PANEL_VOLDNINTR | SGIOC_PANEL_VOLDNHOLD |
                   SGIOC_PANEL_VOLUPINTR | SGIOC_PANEL_VOLUPHOLD;

        return;
    }

    if (machine_state & MACHINE_PANICED)
        sgimc->cpuctrl0 |= SGIMC_CCTRL0_SYSINIT;

    enable_irq(SGI_PANEL_IRQ);
}

static inline void power_button(void)
{
    if (machine_state & MACHINE_PANICED)
        return;

    if ((machine_state & MACHINE_SHUTTING_DOWN) ||
            kill_cad_pid(SIGINT, 1)) {
        /* No init process or button pressed twice.  */
        sgi_machine_power_off();
    }

    machine_state |= MACHINE_SHUTTING_DOWN;
    blink_timer.data = POWERDOWN_FREQ;
    blink_timeout(POWERDOWN_FREQ);

    init_timer(&power_timer);
    power_timer.function = power_timeout;
    power_timer.expires = jiffies + POWERDOWN_TIMEOUT * HZ;
    add_timer(&power_timer);
}

static irqreturn_t panel_int(int irq, void *dev_id)
{
    unsigned int buttons;

    buttons = sgioc->panel;
    sgioc->panel = SGIOC_PANEL_POWERON | SGIOC_PANEL_POWERINTR;

    if (sgint->istat1 & SGINT_ISTAT1_PWR) {
        /* Wait until interrupt goes away */
        disable_irq_nosync(SGI_PANEL_IRQ);
        init_timer(&debounce_timer);
        debounce_timer.function = debounce;
        debounce_timer.expires = jiffies + 5;
        add_timer(&debounce_timer);
    }

    /* Power button was pressed
     * ioc.ps page 22: "The Panel Register is called Power Control by Full
     * House. Only lowest 2 bits are used. Guiness uses upper four bits
     * for volume control". This is not true, all bits are pulled high
     * on fullhouse */
    if (!(buttons & SGIOC_PANEL_POWERINTR))
        power_button();

    return IRQ_HANDLED;
}

static int panic_event(struct notifier_block *this, unsigned long event,
                      void *ptr)
{
    if (machine_state & MACHINE_PANICED)
        return NOTIFY_DONE;
    machine_state |= MACHINE_PANICED;

    blink_timer.data = PANIC_FREQ;
    blink_timeout(PANIC_FREQ);

    return NOTIFY_DONE;
}

static struct notifier_block panic_block = {
    .notifier_call  = panic_event,
};

static int __init reboot_setup(void)
{
    int res;

    _machine_restart = sgi_machine_restart;
    _machine_halt = sgi_machine_halt;
    pm_power_off = sgi_machine_power_off;

    res = request_irq(SGI_PANEL_IRQ, panel_int, 0, "Front Panel", NULL);
    if (res) {
        printk(KERN_ERR "Allocation of front panel IRQ failed\n");
        return res;
    }

    init_timer(&blink_timer);
    blink_timer.function = blink_timeout;
    atomic_notifier_chain_register(&panic_notifier_list, &panic_block);

    return 0;
}

subsys_initcall(reboot_setup);