/* ----------------------------------------------------------------------------
 *         ATMEL Microcontroller Software Support 
 * ----------------------------------------------------------------------------
 * Copyright (c) 2008, Atmel Corporation
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * - Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the disclaimer below.
 *
 * Atmel's name may not be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * DISCLAIMER: THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
 * DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
 * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 * ----------------------------------------------------------------------------
 */

//------------------------------------------------------------------------------
//         Headers
//------------------------------------------------------------------------------

#include "board.h"
#include <pmc/pmc.h>

//------------------------------------------------------------------------------
//         Internal definitions
//------------------------------------------------------------------------------

#define NORMAL_POWER_MODE   0
#define LOW_POWER_MODE      1

//------------------------------------------------------------------------------
//         Internal variables
//------------------------------------------------------------------------------

static volatile unsigned char powerMode = NORMAL_POWER_MODE;

//------------------------------------------------------------------------------
//         Internal functions
//------------------------------------------------------------------------------

//------------------------------------------------------------------------------
//         Exported functions
//------------------------------------------------------------------------------

//------------------------------------------------------------------------------
/// Put the CPU in 32kHz, disable PLL, main oscillator
/// Put voltage regulator in standby mode
/// USB clock is automatically disabled.
//------------------------------------------------------------------------------
void LowPowerMode(void)
{
    if (powerMode == LOW_POWER_MODE)
        return;

    powerMode = LOW_POWER_MODE;

    // MCK=48MHz to MCK=32kHz
    // MCK = SLCK/2 : change source first from 48 000 000 to 18. / 2 = 9M
    AT91C_BASE_PMC->PMC_MCKR = AT91C_PMC_PRES_CLK_2;
    while( !( AT91C_BASE_PMC->PMC_SR & AT91C_PMC_MCKRDY ) );
    // MCK=SLCK : then change prescaler
    AT91C_BASE_PMC->PMC_MCKR = AT91C_PMC_CSS_SLOW_CLK;
    while( !( AT91C_BASE_PMC->PMC_SR & AT91C_PMC_MCKRDY ) );
    // disable PLL
    AT91C_BASE_PMC->PMC_PLLR = 0;
    // Disable Main Oscillator
    AT91C_BASE_PMC->PMC_MOR = 0;

    // Voltage regulator in standby mode : Enable VREG Low Power Mode
    AT91C_BASE_VREG->VREG_MR |= AT91C_VREG_PSTDBY;

    PMC_DisableProcessorClock();
}

//------------------------------------------------------------------------------
/// Put voltage regulator in normal mode
/// Return the CPU to normal speed enable PLLs, main oscillator
/// USB clock is automatically enabled.
//------------------------------------------------------------------------------
void NormalPowerMode(void)
{
    if (powerMode == NORMAL_POWER_MODE)
        return;

    // Voltage regulator in normal mode : Disable VREG Low Power Mode
    AT91C_BASE_VREG->VREG_MR &= ~AT91C_VREG_PSTDBY;

    // MCK=32kHz to MCK=48MHz
    // enable Main Oscillator
    AT91C_BASE_PMC->PMC_MOR = (( (AT91C_CKGR_OSCOUNT & (0x06 <<8)) | AT91C_CKGR_MOSCEN ));
    while( !( AT91C_BASE_PMC->PMC_SR & AT91C_PMC_MOSCS ) );

    // enable PLL@96MHz
    AT91C_BASE_PMC->PMC_PLLR = ((AT91C_CKGR_DIV & 0x0E) |
         (AT91C_CKGR_PLLCOUNT & (28<<8)) |
         (AT91C_CKGR_MUL & (0x48<<16)));
    while( !( AT91C_BASE_PMC->PMC_SR & AT91C_PMC_LOCK ) );
    while( !( AT91C_BASE_PMC->PMC_SR & AT91C_PMC_MCKRDY ) );
    AT91C_BASE_CKGR->CKGR_PLLR |= AT91C_CKGR_USBDIV_1 ;
    // MCK=SLCK/2 : change prescaler first
    AT91C_BASE_PMC->PMC_MCKR = AT91C_PMC_PRES_CLK_2;
    while( !( AT91C_BASE_PMC->PMC_SR & AT91C_PMC_MCKRDY ) );
    // MCK=PLLCK/2 : then change source
    AT91C_BASE_PMC->PMC_MCKR |= AT91C_PMC_CSS_PLL_CLK  ;
    while( !( AT91C_BASE_PMC->PMC_SR & AT91C_PMC_MCKRDY ) );
    
    powerMode = NORMAL_POWER_MODE;
}