/*
    ChibiOS - Copyright (C) 2014-2015 Fabio Utzig

    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    templates/hal_lld.c
 * @brief   HAL Driver subsystem low level driver source template.
 *
 * @addtogroup HAL
 * @{
 */

#include "hal.h"

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

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

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

#ifdef __CC_ARM
__attribute__ ((section(".ARM.__at_0x400")))
#else
__attribute__ ((used,section(".cfmconfig")))
#endif
const uint8_t _cfm[0x10] = {
  0xFF,  /* NV_BACKKEY3: KEY=0xFF */
  0xFF,  /* NV_BACKKEY2: KEY=0xFF */
  0xFF,  /* NV_BACKKEY1: KEY=0xFF */
  0xFF,  /* NV_BACKKEY0: KEY=0xFF */
  0xFF,  /* NV_BACKKEY7: KEY=0xFF */
  0xFF,  /* NV_BACKKEY6: KEY=0xFF */
  0xFF,  /* NV_BACKKEY5: KEY=0xFF */
  0xFF,  /* NV_BACKKEY4: KEY=0xFF */
  0xFF,  /* NV_FPROT3: PROT=0xFF */
  0xFF,  /* NV_FPROT2: PROT=0xFF */
  0xFF,  /* NV_FPROT1: PROT=0xFF */
  0xFF,  /* NV_FPROT0: PROT=0xFF */
  0x7E,  /* NV_FSEC: KEYEN=1,MEEN=3,FSLACC=3,SEC=2 */
  0xFF,  /* NV_FOPT: ??=1,??=1,FAST_INIT=1,LPBOOT1=1,RESET_PIN_CFG=1,
                      NMI_DIS=1,EZPORT_DIS=1,LPBOOT0=1 */
  0xFF,
  0xFF
};

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

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

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

/**
 * @brief   Low level HAL driver initialization.
 * @todo    Use a macro to define the system clock frequency.
 *
 * @notapi
 */
void hal_lld_init(void) {

}

/**
 * @brief   K20x clock initialization.
 * @note    All the involved constants come from the file @p board.h.
 * @note    This function is meant to be invoked early during the system
 *          initialization, it is usually invoked from the file
 *          @p board.c.
 * @todo    This function needs to be more generic.
 *
 * @special
 */
void k20x_clock_init(void) {
#if !KINETIS_NO_INIT

  /* Disable the watchdog */
  WDOG->UNLOCK = 0xC520;
  WDOG->UNLOCK = 0xD928;
  WDOG->STCTRLH &= ~WDOG_STCTRLH_WDOGEN;

  SIM->SCGC5 |= SIM_SCGC5_PORTA |
                SIM_SCGC5_PORTB |
                SIM_SCGC5_PORTC |
                SIM_SCGC5_PORTD |
                SIM_SCGC5_PORTE;

#if KINETIS_MCG_MODE == KINETIS_MCG_MODE_FEI
  /* This is the default mode at reset. */

  /* Configure FEI mode */
  MCG->C4 = MCG_C4_DRST_DRS(KINETIS_MCG_FLL_DRS) |
            (KINETIS_MCG_FLL_DMX32 ? MCG_C4_DMX32 : 0);

  /* Set clock dividers */
  SIM->CLKDIV1 = SIM_CLKDIV1_OUTDIV1(KINETIS_CLKDIV1_OUTDIV1-1) |
                 SIM_CLKDIV1_OUTDIV2(KINETIS_CLKDIV1_OUTDIV2-1) |
                 SIM_CLKDIV1_OUTDIV4(KINETIS_CLKDIV1_OUTDIV4-1);
  SIM->CLKDIV2 = SIM_CLKDIV2_USBDIV(0); /* not strictly necessary since usb_lld will set this */

#elif KINETIS_MCG_MODE == KINETIS_MCG_MODE_PEE

  uint32_t ratio, frdiv;
  uint32_t ratios[] = { 32, 64, 128, 256, 512, 1024, 1280, 1536 };
  uint8_t ratio_quantity = sizeof(ratios) / sizeof(ratios[0]);
  uint8_t i;

  /* EXTAL0 and XTAL0 */
  PORTA->PCR[18] = 0;
  PORTA->PCR[19] = 0;

  /*
   * Start in FEI mode
   */

  /* Internal capacitors for crystal */
#if defined(KINETIS_BOARD_OSCILLATOR_SETTING)
  OSC0->CR = KINETIS_BOARD_OSCILLATOR_SETTING;
#else /* KINETIS_BOARD_OSCILLATOR_SETTING */
  /* Disable the internal capacitors */
  OSC0->CR = 0;
#endif /* KINETIS_BOARD_OSCILLATOR_SETTING */

  /* TODO: need to add more flexible calculation, specially regarding
   *       divisors which may not be available depending on the XTAL
   *       frequency, which would required other registers to be modified.
   */
  /* Enable OSC, low power mode */
  MCG->C2 = MCG_C2_LOCRE0 | MCG_C2_EREFS0;
  if (KINETIS_XTAL_FREQUENCY > 8000000UL)
    MCG->C2 |= MCG_C2_RANGE0(2);
  else
    MCG->C2 |= MCG_C2_RANGE0(1);

  frdiv = 7;
  ratio = KINETIS_XTAL_FREQUENCY / 31250UL;
  for (i = 0; i < ratio_quantity; ++i) {
    if (ratio == ratios[i]) {
      frdiv = i;
      break;
    }
  }

  /* Switch to crystal as clock source, FLL input of 31.25 KHz */
  MCG->C1 = MCG_C1_CLKS(2) | MCG_C1_FRDIV(frdiv);

  /* Wait for crystal oscillator to begin */
  while (!(MCG->S & MCG_S_OSCINIT0));

  /* Wait for the FLL to use the oscillator */
  while (MCG->S & MCG_S_IREFST);

  /* Wait for the MCGOUTCLK to use the oscillator */
  while ((MCG->S & MCG_S_CLKST_MASK) != MCG_S_CLKST(2));

  /*
   * Now in FBE mode
   */
  #define KINETIS_PLLIN_FREQUENCY 2000000UL
  /*
   * Config PLL input for 2 MHz
   * TODO: Make sure KINETIS_XTAL_FREQUENCY >= 2Mhz && <= 50Mhz
   */
  MCG->C5 = MCG_C5_PRDIV0((KINETIS_XTAL_FREQUENCY/KINETIS_PLLIN_FREQUENCY) - 1);

  /*
   * Config PLL output to match KINETIS_SYSCLK_FREQUENCY
   * TODO: make sure KINETIS_SYSCLK_FREQUENCY is a match
   */
  for(i = 24; i < 56; i++)
  {
    if(i == (KINETIS_PLLCLK_FREQUENCY/KINETIS_PLLIN_FREQUENCY))
    {
      /* Config PLL to match KINETIS_PLLCLK_FREQUENCY */
      MCG->C6 = MCG_C6_PLLS | MCG_C6_VDIV0(i-24);
      break;
    }
  }

  if(i>=56)  /* Config PLL for 96 MHz output as default setting */
    MCG->C6 = MCG_C6_PLLS | MCG_C6_VDIV0(0);

  /* Wait for PLL to start using crystal as its input, and to lock */
  while ((MCG->S & (MCG_S_PLLST|MCG_S_LOCK0))!=(MCG_S_PLLST|MCG_S_LOCK0));

  /*
   * Now in PBE mode
   */
  /* Set the PLL dividers for the different clocks */
  SIM->CLKDIV1 = SIM_CLKDIV1_OUTDIV1(KINETIS_CLKDIV1_OUTDIV1-1) |
                 SIM_CLKDIV1_OUTDIV2(KINETIS_CLKDIV1_OUTDIV2-1) |
                 SIM_CLKDIV1_OUTDIV4(KINETIS_CLKDIV1_OUTDIV4-1);
  SIM->CLKDIV2 = SIM_CLKDIV2_USBDIV(0);
  SIM->SOPT2 = SIM_SOPT2_PLLFLLSEL;

  /* Switch to PLL as clock source */
  MCG->C1 = MCG_C1_CLKS(0);

  /* Wait for PLL clock to be used */
  while ((MCG->S & MCG_S_CLKST_MASK) != MCG_S_CLKST_PLL);

  /*
   * Now in PEE mode
   */
#else /* KINETIS_MCG_MODE == KINETIS_MCG_MODE_PEE */
#error Unimplemented KINETIS_MCG_MODE
#endif /* KINETIS_MCG_MODE == ... */

#endif /* !KINETIS_NO_INIT */
}

/** @} */
