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path: root/cleopatre/linux-2.6.25.10-spc300/arch/arm/mach-spc300/spc300-device-wdt.c
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/*
 * arch/arm/mach-spc300/spc300_device_wdt.c
 *
 * (C) Copyright 2009 SPiDCOM Technologies
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */

#include <linux/init.h>
#include <linux/device.h>
#include <linux/interrupt.h>

#include <asm/hardware.h>
#include <asm/arch/wdt.h>

uint32_t spc300_wdt_user_mode = 0;
EXPORT_SYMBOL(spc300_wdt_user_mode);

/**
 * Refresh watchdog timer.
 *
 * \param  va  true if need to use virtual address to access register, false
 * for physical address.
 */
static void spc300_wdt_refresh_(bool va)
{
    uint32_t reg = WDT_BF(CR, WDT_CR_VAL);
    if (va)
        WDT_CRR_VA = reg;
    else
        WDT_CRR_PA = reg;
}

/**
 * Start watchdog timer countdown.
 *
 * \param  timeout_s  timeout of the watchdog (in second).
 * \param  va  true if need to use virtual address to access register, false
 * for physical address.
 * \return  0 if no error, error value otherwise (-EINVAL if timeout_s is too
 * big).
 */
static int spc300_wdt_start_(uint timeout_s, bool va)
{
    uint32_t cnt_value, top, reg;

    //Timeout period = (2^(16+ TOP_reg)) / PCLK

    // Configure timeout?
    if(timeout_s)
    {
        if(timeout_s > WDT_MAX_TIME)
            return -EINVAL;

        cnt_value = timeout_s * PCLK;

        for(top=15 ; top>0 ; top--)
        {
            if(cnt_value >= (1<<(top+16)))
            {
                if (va)
                    WDT_TORR_VA = WDT_BFINS(TOP, top, WDT_TORR_VA);
                else
                    WDT_TORR_PA = WDT_BFINS(TOP, top, WDT_TORR_PA);
                break;
            }
        }
    }
    //Enable WDT with reset pulse = 32pclk and without interrupt management
    reg = WDT_BF(RPL, 4) | WDT_BF(RMOD, 0) | WDT_BF(EN, 1);
    if (va)
        WDT_CR_VA = reg;
    else
        WDT_CR_PA = reg;
    spc300_wdt_refresh_(va);
    return 0;
}

int spc300_wdt_start(uint timeout_s)
{
    return spc300_wdt_start_(timeout_s, true);
}

int spc300_wdt_start_pa(uint timeout_s)
{
    return spc300_wdt_start_(timeout_s, false);
}

void spc300_wdt_switch(int use_umode)
{
    if(use_umode)
        spc300_wdt_user_mode = 1;
    else
        spc300_wdt_user_mode = 0;
}

void spc300_wdt_refresh(void)
{
    spc300_wdt_refresh_ (true);
}

void spc300_wdt_refresh_pa(void)
{
    spc300_wdt_refresh_ (false);
}

int spc300_wdt_gettimeout(void)
{
    uint32_t top;

     //Timeout period = (2^(16+ TOP_reg)) / PCLK

    top = WDT_BFEXT(TOP, WDT_TORR_VA);

    return ((1 << (top+16)) / PCLK);
}