/*
** ###################################################################
**     Processors:          MKL25Z128FM4
**                          MKL25Z128FT4
**                          MKL25Z128LH4
**                          MKL25Z128VLK4
**
**     Compilers:           Keil ARM C/C++ Compiler
**                          Freescale C/C++ for Embedded ARM
**                          GNU C Compiler
**                          GNU C Compiler - CodeSourcery Sourcery G++
**                          IAR ANSI C/C++ Compiler for ARM
**
**     Reference manual:    KL25P80M48SF0RM, Rev.3, Sep 2012
**     Version:             rev. 2.5, 2015-02-19
**     Build:               b150220
**
**     Abstract:
**         Provides a system configuration function and a global variable that
**         contains the system frequency. It configures the device and initializes
**         the oscillator (PLL) that is part of the microcontroller device.
**
**     Copyright (c) 2015 Freescale Semiconductor, Inc.
**     All rights reserved.
**
**     Redistribution and use in source and binary forms, with or without modification,
**     are permitted provided that the following conditions are met:
**
**     o Redistributions of source code must retain the above copyright notice, this list
**       of conditions and the following disclaimer.
**
**     o Redistributions in binary form must reproduce the above copyright notice, this
**       list of conditions and the following disclaimer in the documentation and/or
**       other materials provided with the distribution.
**
**     o Neither the name of Freescale Semiconductor, Inc. nor the names of its
**       contributors may be used to endorse or promote products derived from this
**       software without specific prior written permission.
**
**     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
**     ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
**     WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
**     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS 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.
**
**     http:                 www.freescale.com
**     mail:                 support@freescale.com
**
**     Revisions:
**     - rev. 1.0 (2012-06-13)
**         Initial version.
**     - rev. 1.1 (2012-06-21)
**         Update according to reference manual rev. 1.
**     - rev. 1.2 (2012-08-01)
**         Device type UARTLP changed to UART0.
**     - rev. 1.3 (2012-10-04)
**         Update according to reference manual rev. 3.
**     - rev. 1.4 (2012-11-22)
**         MCG module - bit LOLS in MCG_S register renamed to LOLS0.
**         NV registers - bit EZPORT_DIS in NV_FOPT register removed.
**     - rev. 1.5 (2013-04-05)
**         Changed start of doxygen comment.
**     - rev. 2.0 (2013-10-29)
**         Register accessor macros added to the memory map.
**         Symbols for Processor Expert memory map compatibility added to the memory map.
**         Startup file for gcc has been updated according to CMSIS 3.2.
**         System initialization updated.
**     - rev. 2.1 (2014-07-16)
**         Module access macro module_BASES replaced by module_BASE_PTRS.
**         System initialization and startup updated.
**     - rev. 2.2 (2014-08-22)
**         System initialization updated - default clock config changed.
**     - rev. 2.3 (2014-08-28)
**         Update of startup files - possibility to override DefaultISR added.
**     - rev. 2.4 (2014-10-14)
**         Interrupt INT_LPTimer renamed to INT_LPTMR0.
**     - rev. 2.5 (2015-02-19)
**         Renamed interrupt vector LLW to LLWU.
**
** ###################################################################
*/

/*!
 * @file MKL25Z4
 * @version 2.5
 * @date 2015-02-19
 * @brief Device specific configuration file for MKL25Z4 (implementation file)
 *
 * Provides a system configuration function and a global variable that contains
 * the system frequency. It configures the device and initializes the oscillator
 * (PLL) that is part of the microcontroller device.
 */

#include <stdint.h>
#include "MKL25Z4.h"

//内核时钟频率
uint32_t SystemCoreClock = DEFAULT_SYSTEM_CLOCK;

//======================================================================
//函数名称：SystemInit
//函数返回：无
//参数说明：无
//功能概要：初始化系统的时钟
//======================================================================
void SystemInit (void) {

#if (DISABLE_WDOG)  //关闭看门狗
    SIM->COPC = (uint32_t)0x00u;    //SIM_COPC: COPT=0,COPCLKS=0,COPW=0
#endif

#ifdef CLOCK_SETUP
  if((RCM->SRS0 & RCM_SRS0_WAKEUP_MASK) != 0x00U)
  {
    if((PMC->REGSC & PMC_REGSC_ACKISO_MASK) != 0x00U)
    {
       PMC->REGSC |= PMC_REGSC_ACKISO_MASK; /* 释放ACKISO */
    }
  }

  /* 电源模式保护初始化 */
#ifdef SYSTEM_SMC_PMPROT_VALUE
  SMC->PMPROT = SYSTEM_SMC_PMPROT_VALUE;
#endif

  /* 系统时钟初始化 */
  /* 内部参考时钟修正初始化 */
#if defined(SLOW_TRIM_ADDRESS)
  if ( *((uint8_t*)SLOW_TRIM_ADDRESS) != 0xFFU) {
    MCG->C3 = *((uint8_t*)SLOW_TRIM_ADDRESS);
  #endif /* defined(SLOW_TRIM_ADDRESS) */
  #if defined(SLOW_FINE_TRIM_ADDRESS)
    MCG->C4 = (MCG->C4 & ~(MCG_C4_SCFTRIM_MASK)) | ((*((uint8_t*) SLOW_FINE_TRIM_ADDRESS)) & MCG_C4_SCFTRIM_MASK);
  #endif
  #if defined(FAST_TRIM_ADDRESS)
    MCG->C4 = (MCG->C4 & ~(MCG_C4_FCTRIM_MASK)) |((*((uint8_t*) FAST_TRIM_ADDRESS)) & MCG_C4_FCTRIM_MASK);
  #endif
#if defined(SLOW_TRIM_ADDRESS)
  }
  #endif

  /* 设置系统预分频和时钟的值 */
  SIM->CLKDIV1 = SYSTEM_SIM_CLKDIV1_VALUE; /* Set system prescalers */
  SIM->SOPT1 = ((SIM->SOPT1) & (uint32_t)(~(SIM_SOPT1_OSC32KSEL_MASK))) | ((SYSTEM_SIM_SOPT1_VALUE) & (SIM_SOPT1_OSC32KSEL_MASK)); /* Set 32 kHz clock source (ERCLK32K) */
  SIM->SOPT2 = ((SIM->SOPT2) & (uint32_t)(~(SIM_SOPT2_PLLFLLSEL_MASK))) | ((SYSTEM_SIM_SOPT2_VALUE) & (SIM_SOPT2_PLLFLLSEL_MASK)); /* Selects the high frequency clock for various peripheral clocking options. */
  SIM->SOPT2 = ((SIM->SOPT2) & (uint32_t)(~(SIM_SOPT2_TPMSRC_MASK))) | ((SYSTEM_SIM_SOPT2_VALUE) & (SIM_SOPT2_TPMSRC_MASK)); /* Selects the clock source for the TPM counter clock. */
#if ((MCG_MODE == MCG_MODE_FEI) || (MCG_MODE == MCG_MODE_FBI) || (MCG_MODE == MCG_MODE_BLPI))
  /* Set MCG and OSC */
#if  ((((SYSTEM_OSC0_CR_VALUE) & OSC_CR_ERCLKEN_MASK) != 0x00U) || (((SYSTEM_MCG_C5_VALUE) & MCG_C5_PLLCLKEN0_MASK) != 0x00U))
  /* SIM_SCGC5: PORTA=1 */
  SIM_SCGC5 |= SIM_SCGC5_PORTA_MASK;
  /* PORTA_PCR18: ISF=0,MUX=0 */
  PORTA_PCR18 &= (uint32_t)~(uint32_t)((PORT_PCR_ISF_MASK | PORT_PCR_MUX(0x07)));
  if (((SYSTEM_MCG_C2_VALUE) & MCG_C2_EREFS0_MASK) != 0x00U) {
  /* PORTA_PCR19: ISF=0,MUX=0 */
  PORTA_PCR19 &= (uint32_t)~(uint32_t)((PORT_PCR_ISF_MASK | PORT_PCR_MUX(0x07)));
  }
#endif
  MCG->SC = SYSTEM_MCG_SC_VALUE;       /* Set SC (fast clock internal reference divider) */
  MCG->C1 = SYSTEM_MCG_C1_VALUE;       /* Set C1 (clock source selection, FLL ext. reference divider, int. reference enable etc.) */
  /* Check that the source of the FLL reference clock is the requested one. */
  if (((SYSTEM_MCG_C1_VALUE) & MCG_C1_IREFS_MASK) != 0x00U) {
    while((MCG->S & MCG_S_IREFST_MASK) == 0x00U) {
    }
  } else {
    while((MCG->S & MCG_S_IREFST_MASK) != 0x00U) {
    }
  }
  MCG->C2 = (SYSTEM_MCG_C2_VALUE) & (uint8_t)(~(MCG_C2_LP_MASK)); /* Set C2 (freq. range, ext. and int. reference selection etc.; low power bit is set later) */
  MCG->C4 = ((SYSTEM_MCG_C4_VALUE) & (uint8_t)(~(MCG_C4_FCTRIM_MASK | MCG_C4_SCFTRIM_MASK))) | (MCG->C4 & (MCG_C4_FCTRIM_MASK | MCG_C4_SCFTRIM_MASK)); /* Set C4 (FLL output; trim values not changed) */
  OSC0->CR = SYSTEM_OSC0_CR_VALUE;     /* Set OSC_CR (OSCERCLK enable, oscillator capacitor load) */
  #if (MCG_MODE == MCG_MODE_BLPI)
  /* BLPI specific */
  MCG->C2 |= (MCG_C2_LP_MASK);         /* Disable FLL and PLL in bypass mode */
  #endif

#else /* MCG_MODE */
  /* Set MCG and OSC */
  /* SIM_SCGC5: PORTA=1 */
  SIM_SCGC5 |= SIM_SCGC5_PORTA_MASK;
  /* PORTA_PCR18: ISF=0,MUX=0 */
  PORTA_PCR18 &= (uint32_t)~(uint32_t)((PORT_PCR_ISF_MASK | PORT_PCR_MUX(0x07)));
  if (((SYSTEM_MCG_C2_VALUE) & MCG_C2_EREFS0_MASK) != 0x00U) {
  /* PORTA_PCR19: ISF=0,MUX=0 */
  PORTA_PCR19 &= (uint32_t)~(uint32_t)((PORT_PCR_ISF_MASK | PORT_PCR_MUX(0x07)));
  }
  MCG->SC = SYSTEM_MCG_SC_VALUE;       /* Set SC (fast clock internal reference divider) */
  MCG->C2 = (SYSTEM_MCG_C2_VALUE) & (uint8_t)(~(MCG_C2_LP_MASK)); /* Set C2 (freq. range, ext. and int. reference selection etc.; low power bit is set later) */
  OSC0->CR = SYSTEM_OSC0_CR_VALUE;     /* Set OSC_CR (OSCERCLK enable, oscillator capacitor load) */
  #if (MCG_MODE == MCG_MODE_PEE)
  MCG->C1 = (SYSTEM_MCG_C1_VALUE) | MCG_C1_CLKS(0x02); /* Set C1 (clock source selection, FLL ext. reference divider, int. reference enable etc.) - PBE mode*/
  #else
  MCG->C1 = SYSTEM_MCG_C1_VALUE;       /* Set C1 (clock source selection, FLL ext. reference divider, int. reference enable etc.) */
  #endif
  if (((SYSTEM_MCG_C2_VALUE) & MCG_C2_EREFS0_MASK) != 0x00U) {
    while((MCG->S & MCG_S_OSCINIT0_MASK) == 0x00U) { /* Check that the oscillator is running */
    }
  }
  /* Check that the source of the FLL reference clock is the requested one. */
  if (((SYSTEM_MCG_C1_VALUE) & MCG_C1_IREFS_MASK) != 0x00U) {
    while((MCG->S & MCG_S_IREFST_MASK) == 0x00U) {
    }
  } else {
    while((MCG->S & MCG_S_IREFST_MASK) != 0x00U) {
    }
  }
  MCG->C4 = ((SYSTEM_MCG_C4_VALUE)  & (uint8_t)(~(MCG_C4_FCTRIM_MASK | MCG_C4_SCFTRIM_MASK))) | (MCG->C4 & (MCG_C4_FCTRIM_MASK | MCG_C4_SCFTRIM_MASK)); /* Set C4 (FLL output; trim values not changed) */
#endif /* MCG_MODE */

  /* Common for all MCG modes */

  /* PLL clock can be used to generate clock for some devices regardless of clock generator (MCGOUTCLK) mode. */
  MCG->C5 = (SYSTEM_MCG_C5_VALUE) & (uint8_t)(~(MCG_C5_PLLCLKEN0_MASK)); /* Set C5 (PLL settings, PLL reference divider etc.) */
  MCG->C6 = (SYSTEM_MCG_C6_VALUE) & (uint8_t)~(MCG_C6_PLLS_MASK); /* Set C6 (PLL select, VCO divider etc.) */
  if ((SYSTEM_MCG_C5_VALUE) & MCG_C5_PLLCLKEN0_MASK) {
    MCG->C5 |= MCG_C5_PLLCLKEN0_MASK;  /* PLL clock enable in mode other than PEE or PBE */
  }
  /* BLPE, PEE and PBE MCG mode specific */

#if (MCG_MODE == MCG_MODE_BLPE)
  MCG->C2 |= (MCG_C2_LP_MASK);         /* Disable FLL and PLL in bypass mode */
#elif ((MCG_MODE == MCG_MODE_PBE) || (MCG_MODE == MCG_MODE_PEE))
  MCG->C6 |= (MCG_C6_PLLS_MASK);       /* Set C6 (PLL select, VCO divider etc.) */
  while((MCG->S & MCG_S_LOCK0_MASK) == 0x00U) { /* Wait until PLL is locked*/
  }
  #if (MCG_MODE == MCG_MODE_PEE)
  MCG->C1 &= (uint8_t)~(MCG_C1_CLKS_MASK);
  #endif
#endif
#if ((MCG_MODE == MCG_MODE_FEI) || (MCG_MODE == MCG_MODE_FEE))
  while((MCG->S & MCG_S_CLKST_MASK) != 0x00U) { /* Wait until output of the FLL is selected */
  }
  /* Use LPTMR to wait for 1ms for FLL clock stabilization */
  SIM_SCGC5 |= SIM_SCGC5_LPTMR_MASK;   /* Alow software control of LPMTR */
  LPTMR0->CMR = LPTMR_CMR_COMPARE(0);  /* Default 1 LPO tick */
  LPTMR0->CSR = (LPTMR_CSR_TCF_MASK | LPTMR_CSR_TPS(0x00));
  LPTMR0->PSR = (LPTMR_PSR_PCS(0x01) | LPTMR_PSR_PBYP_MASK); /* Clock source: LPO, Prescaler bypass enable */
  LPTMR0->CSR = LPTMR_CSR_TEN_MASK;    /* LPMTR enable */
  while((LPTMR0_CSR & LPTMR_CSR_TCF_MASK) == 0u) {
  }
  LPTMR0_CSR = 0x00;                   /* Disable LPTMR */
  SIM_SCGC5 &= (uint32_t)~(uint32_t)SIM_SCGC5_LPTMR_MASK;
#elif ((MCG_MODE == MCG_MODE_FBI) || (MCG_MODE == MCG_MODE_BLPI))
  while((MCG->S & MCG_S_CLKST_MASK) != 0x04U) { /* Wait until internal reference clock is selected as MCG output */
  }
#elif ((MCG_MODE == MCG_MODE_FBE) || (MCG_MODE == MCG_MODE_PBE) || (MCG_MODE == MCG_MODE_BLPE))
  while((MCG->S & MCG_S_CLKST_MASK) != 0x08U) { /* Wait until external reference clock is selected as MCG output */
  }
#elif (MCG_MODE == MCG_MODE_PEE)
  while((MCG->S & MCG_S_CLKST_MASK) != 0x0CU) { /* Wait until output of the PLL is selected */
  }
#endif
#if (((SYSTEM_SMC_PMCTRL_VALUE) & SMC_PMCTRL_RUNM_MASK) == (0x02U << SMC_PMCTRL_RUNM_SHIFT))
  SMC->PMCTRL = (uint8_t)((SYSTEM_SMC_PMCTRL_VALUE) & (SMC_PMCTRL_RUNM_MASK)); /* Enable VLPR mode */
  while(SMC->PMSTAT != 0x04U) {        /* Wait until the system is in VLPR mode */
  }
#endif

  /* PLL loss of lock interrupt request initialization */
  if (((SYSTEM_MCG_C6_VALUE) & MCG_C6_LOLIE0_MASK) != 0U) {
    NVIC_EnableIRQ(MCG_IRQn);          /* Enable PLL loss of lock interrupt request */
  }
#endif

    //初始化后，开始PORT模块时钟
    SIM_SCGC5 |= SIM_SCGC5_PORTA_MASK
                | SIM_SCGC5_PORTB_MASK
                | SIM_SCGC5_PORTC_MASK
                | SIM_SCGC5_PORTD_MASK
                | SIM_SCGC5_PORTE_MASK;
}
