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/* ----------------------------------------------------------------------------
* 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"
//------------------------------------------------------------------------------
// Internal definitions
//------------------------------------------------------------------------------
#define NORMAL_POWER_MODE 0
#define LOW_POWER_MODE 1
//------------------------------------------------------------------------------
// Internal variables
//------------------------------------------------------------------------------
static volatile unsigned char powerMode = NORMAL_POWER_MODE;
static unsigned int oldFmr0;
static unsigned int oldFmr1;
static unsigned int oldPll;
static unsigned int oldMck;
//------------------------------------------------------------------------------
// Internal functions
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
/// Save and restore working clock.
/// Here working clock must be running from PLL
/// and external crystal oscillator is used.
//------------------------------------------------------------------------------
static void SaveWorkingClock(unsigned int *pOldPll, unsigned int *pOldMck)
{
// Save previous values for PLL A and Master Clock configuration
*pOldPll = AT91C_BASE_CKGR->CKGR_PLLAR;
*pOldMck = AT91C_BASE_PMC->PMC_MCKR;
}
static void RestoreWorkingClock(unsigned int oldPll, unsigned int oldMck)
{
// Switch to slow clock first
AT91C_BASE_PMC->PMC_MCKR = (AT91C_BASE_PMC->PMC_MCKR & ~AT91C_PMC_CSS)
| AT91C_PMC_CSS_SLOW_CLK;
while (!(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_MCKRDY));
AT91C_BASE_PMC->PMC_MCKR = (AT91C_BASE_PMC->PMC_MCKR & ~AT91C_PMC_PRES)
| AT91C_PMC_PRES_CLK;
while (!(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_MCKRDY));
// Restart Main Oscillator
AT91C_BASE_PMC->PMC_MOR = (0x37 << 16)
| (0x3F<<8)
| AT91C_CKGR_MOSCRCEN
| AT91C_CKGR_MOSCXTEN;
while (!(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_MOSCXTS));
// Switch to moscsel
AT91C_BASE_PMC->PMC_MOR = (0x37 << 16)
| (0x3F<<8)
| AT91C_CKGR_MOSCRCEN
| AT91C_CKGR_MOSCXTEN
| AT91C_CKGR_MOSCSEL;
while (!(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_MOSCSELS));
// Switch to main oscillator
AT91C_BASE_PMC->PMC_MCKR = (AT91C_BASE_PMC->PMC_MCKR & ~AT91C_PMC_CSS)
| AT91C_PMC_CSS_MAIN_CLK;
while (!(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_MCKRDY));
AT91C_BASE_PMC->PMC_MCKR = (AT91C_BASE_PMC->PMC_MCKR & ~AT91C_PMC_PRES)
| AT91C_PMC_PRES_CLK;
while (!(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_MCKRDY));
// Restart PLL A
AT91C_BASE_CKGR->CKGR_PLLAR = oldPll;
while(!(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_LOCKA));
// Switch to fast clock
AT91C_BASE_PMC->PMC_MCKR = (oldMck & ~AT91C_PMC_CSS)
| AT91C_PMC_CSS_MAIN_CLK;
while (!(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_MCKRDY));
AT91C_BASE_PMC->PMC_MCKR = oldMck;
while (!(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_MCKRDY));
// Setup Flash waitstates
AT91C_BASE_EFC0->EFC_FMR = oldFmr0;
AT91C_BASE_EFC1->EFC_FMR = oldFmr1;
}
//------------------------------------------------------------------------------
// 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;
SaveWorkingClock(&oldPll, &oldMck);
oldFmr0 = AT91C_BASE_EFC0->EFC_FMR;
AT91C_BASE_EFC0->EFC_FMR = AT91C_EFC_FWS_3WS;
oldFmr1 = AT91C_BASE_EFC1->EFC_FMR;
AT91C_BASE_EFC1->EFC_FMR = AT91C_EFC_FWS_3WS;
AT91C_BASE_PMC->PMC_MCKR = (AT91C_BASE_PMC->PMC_MCKR & ~AT91C_PMC_CSS)
| AT91C_PMC_CSS_SLOW_CLK;
while (!(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_MCKRDY));
AT91C_BASE_PMC->PMC_MCKR = (AT91C_BASE_PMC->PMC_MCKR & ~AT91C_PMC_PRES)
| AT91C_PMC_PRES_CLK;
while (!(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_MCKRDY));
// Stop PLL A
// MULA: PLL A Multiplier 0 = The PLL A is deactivated.
// STMODE must be set at 2 when the PLLA is Off
AT91C_BASE_PMC->PMC_PLLAR = 0x2 << 14;
// Stop Main Oscillator
AT91C_BASE_PMC->PMC_MOR = (0x37 << 16) | (0x3F << 8);
}
//------------------------------------------------------------------------------
/// 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;
RestoreWorkingClock(oldPll, oldMck);
powerMode = NORMAL_POWER_MODE;
}
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