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/*
    ChibiOS - Copyright (C) 2006..2016 Giovanni Di Sirio

    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.
    You may obtain a copy of the License at

        http://www.apache.org/licenses/LICENSE-2.0

    Unless required by applicable law or agreed to in writing, software
    distributed under the License is distributed on an "AS IS" BASIS,
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
    limitations under the License.
*/

/**
 * @file    hal_lld.c
 * @brief   PLATFORM HAL subsystem low level driver source.
 *
 * @addtogroup HAL
 * @{
 */

#include "hal.h"

/*===========================================================================*/
/* Driver local definitions.                                                 */
/*===========================================================================*/

#define SAMA_MOR_ONE                        (1 << 5)
#define SAMA_MOR_MOSCXTST                   CKGR_MOR_MOSCXTST(0xFF)

#define SAMA_PLLA_ONE                       (1 << 29)

/*===========================================================================*/
/* Driver exported variables.                                                */
/*===========================================================================*/

/*===========================================================================*/
/* Driver local variables and types.                                         */
/*===========================================================================*/

/*===========================================================================*/
/* Driver local functions.                                                   */
/*===========================================================================*/

/*===========================================================================*/
/* Driver interrupt handlers.                                                */
/*===========================================================================*/

/*===========================================================================*/
/* Driver exported functions.                                                */
/*===========================================================================*/

/**
 * @brief   Low level HAL driver initialization.
 *
 * @notapi
 */
void hal_lld_init(void) {
#if defined(SAMA5_DMA_REQUIRED)
  dmaInit();
#endif
}

/**
 * @brief   SAMA clocks and PLL initialization.
 * @note    All the involved constants come from the file @p board.h.
 * @note    This function should be invoked just after the system reset.
 *
 * @special
 */
void sama_clock_init(void) {
#if !SAMA_NO_INIT
/* Setting Slow clock source. */
SCKC->SCKC_CR = SAMA_OSC_SEL;

/* Disabling PMC write protection. */
PMC->PMC_WPMR = PMC_WPMR_WPKEY_PASSWD | PMC_WPMR_WPEN;
PMC->PMC_WPMR = PMC_WPMR_WPKEY_PASSWD;     

/*
 * Main oscillator configuration block.
 */
{
  /* Switching on RC. */
  uint32_t mor = SAMA_MOR_ONE | CKGR_MOR_KEY_PASSWD | CKGR_MOR_MOSCRCEN;
  PMC->CKGR_MOR |= mor;
  while (!(PMC->PMC_SR & PMC_SR_MOSCRCS))
    ;                                       /* Waits until MOSCRC is stable.*/

#if SAMA_MOSCXT_ENABLED
  uint32_t mor = SAMA_MOR_ONE | CKGR_MOR_KEY_PASSWD | CKGR_MOR_MOSCXTEN;
  PMC->CKGR_MOR |= mor;
  while (!(PMC->PMC_SR & PMC_SR_MOSCXTS))
    ;                                       /* Waits until MOSCXT is stable.*/
#endif

  /* Switching MOC source. */
  mor = SAMA_MOR_ONE | SAMA_MOR_MOSCXTST | CKGR_MOR_KEY_PASSWD |
        CKGR_MOR_MOSCRCEN;
  #if SAMA_MOSCXT_ENABLED
  mor |= CKGR_MOR_MOSCXTEN;
  #endif
  mor |= SAMA_MOSC_SEL;
  PMC->CKGR_MOR = mor;

  /* Disabling unused sources. */
#if !SAMA_MOSCXT_ENABLED
  PMC->CKGR_MOR &= ~ CKGR_MOR_MOSCXTEN;
#endif

#if !SAMA_MOSCRC_ENABLED
  PMC->CKGR_MOR &= ~ CKGR_MOR_MOSCRCEN;
#endif
}

/*
 * PLLA configuration block.
 */
{
  uint32_t pllar = SAMA_PLLA_ONE;
#if SAMA_ACTIVATE_PLLA
  pllar |= CKGR_PLLAR_DIVA_BYPASS | SAMA_PLLA_MUL; 
#endif
  PMC->CKGR_PLLAR = pllar;                  /* Writing PLLA register.       */

#if SAMA_ACTIVATE_PLLA
  while (!(PMC->PMC_SR & PMC_SR_LOCKA))
    ;                                       /* Waits until PLLA is locked.  */
#endif
}

/*
 * Master clock configuration block.
 */
{
  uint32_t mckr = SAMA_MCK_PRES | SAMA_MCK_MDIV | SAMA_MCK_SEL;
#if SAMA_PLLADIV2_EN
  mckr |= PMC_MCKR_PLLADIV2;
#endif
  PMC->PMC_MCKR = mckr;

  while (!(PMC->PMC_SR & PMC_SR_MCKRDY))
    ;                                       /* Waits until MCK is stable.   */
}

/* Enabling write protection.  */
PMC->PMC_WPMR = PMC_WPMR_WPKEY_PASSWD | PMC_WPMR_WPEN;             

#endif /* !SAMA_NO_INIT */
}
/** @} */