/*
 * FR-V Power Management Routines
 *
 * Copyright (c) 2004 Red Hat, Inc.
 *
 * Based on SA1100 version:
 * Copyright (c) 2001 Cliff Brake <cbrake@accelent.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License.
 *
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/pm.h>
#include <linux/sched.h>
#include <linux/interrupt.h>
#include <linux/sysctl.h>
#include <linux/errno.h>
#include <linux/delay.h>
#include <asm/uaccess.h>

#include <asm/mb86943a.h>

#include "local.h"

/*
 * Debug macros
 */
#define DEBUG

int pm_do_suspend(void)
{
        local_irq_disable();

        __set_LEDS(0xb1);

        /* go zzz */
        frv_cpu_suspend(pdm_suspend_mode);

        __set_LEDS(0xb2);

        local_irq_enable();

        return 0;
}

static unsigned long __irq_mask;

/*
 * Setup interrupt masks, etc to enable wakeup by power switch
 */
static void __default_power_switch_setup(void)
{
        /* default is to mask all interrupt sources. */
        __irq_mask = *(unsigned long *)0xfeff9820;
        *(unsigned long *)0xfeff9820 = 0xfffe0000;
}

/*
 * Cleanup interrupt masks, etc after wakeup by power switch
 */
static void __default_power_switch_cleanup(void)
{
        *(unsigned long *)0xfeff9820 = __irq_mask;
}

/*
 * Return non-zero if wakeup irq was caused by power switch
 */
static int __default_power_switch_check(void)
{
        return 1;
}

void (*__power_switch_wake_setup)(void) = __default_power_switch_setup;
int  (*__power_switch_wake_check)(void) = __default_power_switch_check;
void (*__power_switch_wake_cleanup)(void) = __default_power_switch_cleanup;

int pm_do_bus_sleep(void)
{
        local_irq_disable();

        /*
         * Here is where we need some platform-dependent setup
         * of the interrupt state so that appropriate wakeup
         * sources are allowed and all others are masked.
         */
        __power_switch_wake_setup();

        __set_LEDS(0xa1);

        /* go zzz
         *
         * This is in a loop in case power switch shares an irq with other
         * devices. The wake_check() tells us if we need to finish waking
         * or go back to sleep.
         */
        do {
                frv_cpu_suspend(HSR0_PDM_BUS_SLEEP);
        } while (__power_switch_wake_check && !__power_switch_wake_check());

        __set_LEDS(0xa2);

        /*
         * Here is where we need some platform-dependent restore
         * of the interrupt state prior to being called.
         */
        __power_switch_wake_cleanup();

        local_irq_enable();

        return 0;
}

unsigned long sleep_phys_sp(void *sp)
{
        return virt_to_phys(sp);
}

#ifdef CONFIG_SYSCTL
/*
 * Use a temporary sysctl number. Horrid, but will be cleaned up in 2.6
 * when all the PM interfaces exist nicely.
 */
#define CTL_PM_SUSPEND 1
#define CTL_PM_CMODE 2
#define CTL_PM_P0 4
#define CTL_PM_CM 5

static int user_atoi(char __user *ubuf, size_t len)
{
        char buf[16];
        unsigned long ret;

        if (len > 15)
                return -EINVAL;

        if (copy_from_user(buf, ubuf, len))
                return -EFAULT;

        buf[len] = 0;
        ret = simple_strtoul(buf, NULL, 0);
        if (ret > INT_MAX)
                return -ERANGE;
        return ret;
}

/*
 * Send us to sleep.
 */
static int sysctl_pm_do_suspend(struct ctl_table *ctl, int write,
                                void __user *buffer, size_t *lenp, loff_t *fpos)
{
        int mode;

        if (*lenp <= 0)
                return -EIO;

        mode = user_atoi(buffer, *lenp);
        switch (mode) {
        case 1:
            return pm_do_suspend();

        case 5:
            return pm_do_bus_sleep();

        default:
            return -EINVAL;
        }
}

static int try_set_cmode(int new_cmode)
{
        if (new_cmode > 15)
                return -EINVAL;
        if (!(clock_cmodes_permitted & (1<<new_cmode)))
                return -EINVAL;

        /* now change cmode */
        local_irq_disable();
        frv_dma_pause_all();

        frv_change_cmode(new_cmode);

        determine_clocks(0);
        time_divisor_init();

#ifdef DEBUG
        determine_clocks(1);
#endif
        frv_dma_resume_all();
        local_irq_enable();

        return 0;
}


static int cmode_procctl(struct ctl_table *ctl, int write,
                         void __user *buffer, size_t *lenp, loff_t *fpos)
{
        int new_cmode;

        if (!write)
                return proc_dointvec(ctl, write, buffer, lenp, fpos);

        new_cmode = user_atoi(buffer, *lenp);

        return try_set_cmode(new_cmode)?:*lenp;
}

static int try_set_p0(int new_p0)
{
        unsigned long flags, clkc;

        if (new_p0 < 0 || new_p0 > 1)
                return -EINVAL;

        local_irq_save(flags);
        __set_PSR(flags & ~PSR_ET);

        frv_dma_pause_all();

        clkc = __get_CLKC();
        if (new_p0)
                clkc |= CLKC_P0;
        else
                clkc &= ~CLKC_P0;
        __set_CLKC(clkc);

        determine_clocks(0);
        time_divisor_init();

#ifdef DEBUG
        determine_clocks(1);
#endif
        frv_dma_resume_all();
        local_irq_restore(flags);
        return 0;
}

static int try_set_cm(int new_cm)
{
        unsigned long flags, clkc;

        if (new_cm < 0 || new_cm > 1)
                return -EINVAL;

        local_irq_save(flags);
        __set_PSR(flags & ~PSR_ET);

        frv_dma_pause_all();

        clkc = __get_CLKC();
        clkc &= ~CLKC_CM;
        clkc |= new_cm;
        __set_CLKC(clkc);

        determine_clocks(0);
        time_divisor_init();

#if 1 //def DEBUG
        determine_clocks(1);
#endif

        frv_dma_resume_all();
        local_irq_restore(flags);
        return 0;
}

static int p0_procctl(struct ctl_table *ctl, int write,
                      void __user *buffer, size_t *lenp, loff_t *fpos)
{
        int new_p0;

        if (!write)
                return proc_dointvec(ctl, write, buffer, lenp, fpos);

        new_p0 = user_atoi(buffer, *lenp);

        return try_set_p0(new_p0)?:*lenp;
}

static int cm_procctl(struct ctl_table *ctl, int write,
                      void __user *buffer, size_t *lenp, loff_t *fpos)
{
        int new_cm;

        if (!write)
                return proc_dointvec(ctl, write, buffer, lenp, fpos);

        new_cm = user_atoi(buffer, *lenp);

        return try_set_cm(new_cm)?:*lenp;
}

static struct ctl_table pm_table[] =
{
        {
                .procname       = "suspend",
                .data           = NULL,
                .maxlen         = 0,
                .mode           = 0200,
                .proc_handler   = sysctl_pm_do_suspend,
        },
        {
                .procname       = "cmode",
                .data           = &clock_cmode_current,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = cmode_procctl,
        },
        {
                .procname       = "p0",
                .data           = &clock_p0_current,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = p0_procctl,
        },
        {
                .procname       = "cm",
                .data           = &clock_cm_current,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = cm_procctl,
        },
        { }
};

static struct ctl_table pm_dir_table[] =
{
        {
                .procname       = "pm",
                .mode           = 0555,
                .child          = pm_table,
        },
        { }
};

/*
 * Initialize power interface
 */
static int __init pm_init(void)
{
        register_sysctl_table(pm_dir_table);
        return 0;
}

__initcall(pm_init);

#endif