/* ----------------------------------------------------------------------------
 *         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.
 * ----------------------------------------------------------------------------
 */

//------------------------------------------------------------------------------
/// \unit
///
/// !Purpose
///
/// Provides the low-level initialization function that gets called on chip
/// startup.
///
/// !Usage
///
/// LowLevelInit() is called in #board_cstartup.S#.
//------------------------------------------------------------------------------

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

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

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

/* Settings at 400/133MHz */
#define BOARD_OSCOUNT           (AT91C_CKGR_OSCOUNT & (64 << 8))
#define BOARD_CKGR_PLLA         (AT91C_CKGR_SRCA | AT91C_CKGR_OUTA_0)
#define BOARD_PLLACOUNT         (0x3F << 8)
#define BOARD_MULA              (AT91C_CKGR_MULA & (199 << 16))
#define BOARD_DIVA              (AT91C_CKGR_DIVA & 3)

//#define BOARD_PRESCALER         (0x00001300) //400/133MHz
#define BOARD_PRESCALER         (0x00001200) //400/100MHz

//------------------------------------------------------------------------------
//         Internal functions
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
/// Default spurious interrupt handler. Infinite loop.
//------------------------------------------------------------------------------
void defaultSpuriousHandler( void )
{
    while (1);
}

//------------------------------------------------------------------------------
/// Default handler for fast interrupt requests. Infinite loop.
//------------------------------------------------------------------------------
void defaultFiqHandler( void )
{
    while (1);
}

//------------------------------------------------------------------------------
/// Default handler for standard interrupt requests. Infinite loop.
//------------------------------------------------------------------------------
void defaultIrqHandler( void )
{
    while (1);
}

//------------------------------------------------------------------------------
//         Exported functions
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
/// Performs the low-level initialization of the chip. Initialisation depends
/// on where the application is executed: 
/// - in sdram: it means that sdram has previously been initialized. No further
///             initialization is required.
/// - in sram:  PLL shall be initialized in LowLevelInit. Other initializations 
///             can be done later by the application.
/// - in norflash: LowLevelInit can't be executed in norflash because SMC 
///             settings can't be changed while executing in external flash.
///             LowLevelInit shall be executed in internal sram. It initializes
///             PLL and SMC. 
/// This function also reset the AIC and disable RTT and PIT interrupts
//------------------------------------------------------------------------------
void LowLevelInit(void)
{
    unsigned char i;

#if !defined(ddram)

for(i=0;i<3;i++) /* it seems that the PLL doesn't start up propely the 1st time it's programmed */
{
    /* Initialize main oscillator    
     ****************************/
    AT91C_BASE_PMC->PMC_MOR = BOARD_OSCOUNT | AT91C_CKGR_MOSCEN;
    while (!(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_MOSCS));

    /* Initialize PLLA */
    AT91C_BASE_PMC->PMC_PLLAR = BOARD_CKGR_PLLA
                                | BOARD_PLLACOUNT
                                | BOARD_MULA
                                | BOARD_DIVA;
    while (!(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_LOCKA));
    
    /* Wait for the master clock if it was already initialized */
    while (!(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_MCKRDY));

    /* Switch to fast clock
     **********************/
    /* Switch to main oscillator + prescaler */
    AT91C_BASE_PMC->PMC_MCKR = (AT91C_BASE_PMC->PMC_MCKR & 0x3) | BOARD_PRESCALER;
    while (!(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_MCKRDY));

    /* Switch to PLL + prescaler */
    AT91C_BASE_PMC->PMC_MCKR = (AT91C_BASE_PMC->PMC_MCKR & 0xfffffffc) | AT91C_PMC_CSS_PLLA_CLK;
    while (!(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_MCKRDY));
}
#endif

    /* Initialize AIC
     ****************/
    AT91C_BASE_AIC->AIC_IDCR = 0xFFFFFFFF;
    AT91C_BASE_AIC->AIC_SVR[0] = (unsigned int) defaultFiqHandler;
    for (i = 1; i < 31; i++) {

        AT91C_BASE_AIC->AIC_SVR[i] = (unsigned int) defaultIrqHandler;
    }
    AT91C_BASE_AIC->AIC_SPU = (unsigned int) defaultSpuriousHandler;

    // Unstack nested interrupts
    for (i = 0; i < 8 ; i++) {

        AT91C_BASE_AIC->AIC_EOICR = 0;
    }


    /* Watchdog initialization
     *************************/
  #ifndef WDT_APP // Watchdog init in application ?
    AT91C_BASE_WDTC->WDTC_WDMR = AT91C_WDTC_WDDIS;
  #endif

    /* Remap
     *******/
    BOARD_RemapRam();

    // Disable RTT and PIT interrupts (potential problem when program A
    // configures RTT, then program B wants to use PIT only, interrupts
    // from the RTT will still occur since they both use AT91C_ID_SYS)
    AT91C_BASE_RTTC->RTTC_RTMR &= ~(AT91C_RTTC_ALMIEN | AT91C_RTTC_RTTINCIEN);
    AT91C_BASE_PITC->PITC_PIMR &= ~AT91C_PITC_PITIEN;
    
#if defined(norflash)
    BOARD_ConfigureNorFlash(BOARD_NORFLASH_DFT_BUS_SIZE);
#endif    
}

