/*
 * 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.
 */

#include "fsl_common.h"
#include "fsl_smc.h"
#include "fsl_rtc.h"
#include "fsl_clock_config.h"

#define MCG_IRCLK_DISABLE                                 0U  /*!< MCGIRCLK disabled */
#define MCG_PLL_DISABLE                                   0U  /*!< MCGPLLCLK disabled */
#define OSC_CAP0P                                         0U  /*!< Oscillator 0pF capacitor load */
#define RTC_OSC_CAP_LOAD_0PF                            0x0U  /*!< RTC oscillator capacity load: 0pF */
#define RTC_RTC32KCLK_PERIPHERALS_ENABLED                 1U  /*!< RTC32KCLK to other peripherals: enabled */
#define SIM_CLKOUT_SEL_FLEXBUS_CLK                        0U  /*!< CLKOUT pin clock select: FlexBus clock */
#define SIM_OSC32KSEL_RTC32KCLK_CLK                       2U  /*!< OSC32KSEL select: RTC32KCLK clock (32.768kHz) */
#define SIM_PLLFLLSEL_MCGFLLCLK_CLK                       0U  /*!< PLLFLL select: MCGFLLCLK clock */

static void CLOCK_CONFIG_SetRtcClock(uint32_t capLoad, uint8_t enableOutPeriph)
{
  /* RTC clock gate enable */
  CLOCK_EnableClock(kCLOCK_Rtc0);
  if ((RTC->CR & RTC_CR_OSCE_MASK) == 0u) { /* Only if the Rtc oscillator is not already enabled */
    /* Set the specified capacitor configuration for the RTC oscillator */
    RTC_SetOscCapLoad(RTC, capLoad);
    /* Enable the RTC 32KHz oscillator */
    RTC->CR |= RTC_CR_OSCE_MASK;
  }
  /* Output to other peripherals */
  if (enableOutPeriph) {
    RTC->CR &= ~RTC_CR_CLKO_MASK;
  }
  else {
    RTC->CR |= RTC_CR_CLKO_MASK;
  }
  /* Set the XTAL32/RTC_CLKIN frequency based on board setting. */
  CLOCK_SetXtal32Freq(BOARD_XTAL32K_CLK_HZ);
  /* Set RTC_TSR if there is fault value in RTC */
  if (RTC->SR & RTC_SR_TIF_MASK) {
    RTC -> TSR = RTC -> TSR;
  }
  /* RTC clock gate disable */
  CLOCK_DisableClock(kCLOCK_Rtc0);
}

static void CLOCK_CONFIG_EnableIrc48MOsc()
{
  /* USB clock gate enable */
  CLOCK_EnableClock(kCLOCK_Usbfs0);
  /* IRC48M oscillator enable */
  USB0->CLK_RECOVER_IRC_EN = USB_CLK_RECOVER_IRC_EN_IRC_EN_MASK | USB_CLK_RECOVER_IRC_EN_REG_EN_MASK;
  /* USB clock gate disable */
  CLOCK_DisableClock(kCLOCK_Usbfs0);
}

static void CLOCK_CONFIG_SetFllExtRefDiv(uint8_t frdiv)
{
    MCG->C1 = ((MCG->C1 & ~MCG_C1_FRDIV_MASK) | MCG_C1_FRDIV(frdiv));
}

/*******************************************************************************
 * Definitions
 ******************************************************************************/
/*! @brief Clock configuration structure. */
typedef struct _clock_config
{
    mcg_config_t mcgConfig;       /*!< MCG configuration.      */
    sim_clock_config_t simConfig; /*!< SIM configuration.      */
    osc_config_t oscConfig;       /*!< OSC configuration.      */
    uint32_t coreClock;           /*!< core clock frequency.   */
} clock_config_t;

/*******************************************************************************
 * Variables
 ******************************************************************************/
/* System clock frequency. */
extern uint32_t SystemCoreClock;

/* Configuration for enter VLPR mode. Core clock = 4MHz. */
const clock_config_t g_defaultClockConfigVlpr = {
    .mcgConfig =
        {
            .mcgMode = kMCG_ModeBLPI,            /* Work in BLPI mode. */
            .irclkEnableMode = kMCG_IrclkEnable, /* MCGIRCLK enable. */
            .ircs = kMCG_IrcFast,                /* Select IRC4M. */
            .fcrdiv = 0U,                        /* FCRDIV is 0. */

            .frdiv = 0U,
            .drs = kMCG_DrsLow,         /* Low frequency range. */
            .dmx32 = kMCG_Dmx32Default, /* DCO has a default range of 25%. */
            .oscsel = kMCG_OscselOsc,   /* Select OSC. */

            .pll0Config =
                {
                    .enableMode = 0U, /* Don't eanble PLL. */
                    .prdiv = 0U,
                    .vdiv = 0U,
                },
        },
    .simConfig =
        {
            .pllFllSel = 3U,        /* PLLFLLSEL select IRC48MCLK. */
            .er32kSrc = 2U,         /* ERCLK32K selection, use RTC. */
            .clkdiv1 = 0x00040000U, /* SIM_CLKDIV1. */
        },
    .oscConfig = {.freq = BOARD_XTAL0_CLK_HZ,
                  .capLoad = 0,
                  .workMode = kOSC_ModeExt,
                  .oscerConfig =
                      {
                          .enableMode = kOSC_ErClkEnable,
#if (defined(FSL_FEATURE_OSC_HAS_EXT_REF_CLOCK_DIVIDER) && FSL_FEATURE_OSC_HAS_EXT_REF_CLOCK_DIVIDER)
                          .erclkDiv = 0U,
#endif
                      }},
    .coreClock = 4000000U, /* Core clock frequency */
};

/* Configuration for enter RUN mode. Core clock = 95.977472 MHz. */
const clock_config_t g_defaultClockConfigRun = {
    .mcgConfig =
        {
            .mcgMode = kMCG_ModePEE,                  /* PEE - PLL Engaged External */
            .irclkEnableMode = MCG_IRCLK_DISABLE,     /* MCGIRCLK disabled */
            .ircs = kMCG_IrcSlow,                     /* Slow internal reference clock selected */
            .fcrdiv = 0x0U,                           /* Fast IRC divider: divided by 1 */
            .frdiv = 0x2U,                            /* FLL reference clock divider: divided by 4 */
            .drs = kMCG_DrsLow,                       /* Low frequency range */
            .dmx32 = kMCG_Dmx32Default,               /* DCO has a default range of 25% */
            .oscsel = kMCG_OscselIrc,                 /* Selects 48 MHz IRC Oscillator */
            .pll0Config =
                {
                    .enableMode = MCG_PLL_DISABLE,    /* MCGPLLCLK disabled */
                    .prdiv = 0xbU,                    /* PLL Reference divider: divided by 12 */
                    .vdiv = 0x0U,                     /* VCO divider: multiplied by 24 */
                },
        },
    .simConfig = //OK
        {
            .pllFllSel = SIM_PLLFLLSEL_MCGFLLCLK_CLK, /* PLLFLL select: MCGFLLCLK clock */
            .er32kSrc = SIM_OSC32KSEL_RTC32KCLK_CLK,  /* OSC32KSEL select: RTC32KCLK clock (32.768kHz) */
            .clkdiv1 = 0x1240000U,                    /* SIM_CLKDIV1 - OUTDIV1: /1, OUTDIV2: /2, OUTDIV3: /3, OUTDIV4: /5 */
        },
    .oscConfig = 
        {
            .freq = 0U,                               /* Oscillator frequency: 0Hz */
            .capLoad = (OSC_CAP0P),                   /* Oscillator capacity load: 0pF */
            .workMode = kOSC_ModeExt,                 /* Use external clock */
            .oscerConfig =
                {
                    .enableMode = kOSC_ErClkEnable,   /* Enable external reference clock, disable external reference clock in STOP mode */

                }
        },
    .coreClock = 96000000U, /* Core clock frequency */
};

/*******************************************************************************
 * Code
 ******************************************************************************/
/*
 * How to setup clock using clock driver functions:
 *
 * 1. CLOCK_SetSimSafeDivs, to make sure core clock, bus clock, flexbus clock
 *    and flash clock are in allowed range during clock mode switch.
 *
 * 2. Call CLOCK_Osc0Init to setup OSC clock, if it is used in target mode.
 *
 * 3. Set MCG configuration, MCG includes three parts: FLL clock, PLL clock and
 *    internal reference clock(MCGIRCLK). Follow the steps to setup:
 *
 *    1). Call CLOCK_BootToXxxMode to set MCG to target mode.
 *
 *    2). If target mode is FBI/BLPI/PBI mode, the MCGIRCLK has been configured
 *        correctly. For other modes, need to call CLOCK_SetInternalRefClkConfig
 *        explicitly to setup MCGIRCLK.
 *
 *    3). Don't need to configure FLL explicitly, because if target mode is FLL
 *        mode, then FLL has been configured by the function CLOCK_BootToXxxMode,
 *        if the target mode is not FLL mode, the FLL is disabled.
 *
 *    4). If target mode is PEE/PBE/PEI/PBI mode, then the related PLL has been
 *        setup by CLOCK_BootToXxxMode. In FBE/FBI/FEE/FBE mode, the PLL could
 *        be enabled independently, call CLOCK_EnablePll0 explicitly in this case.
 *
 * 4. Call CLOCK_SetSimConfig to set the clock configuration in SIM.
 */
 
static void fllStableDelay(void)
{
    /*
       Should wait at least 1ms. Because in these modes, the core clock is 100MHz
       at most, so this function could obtain the 1ms delay.
     */
    volatile uint32_t i = 30000U;
    while (i--)
    {
        __NOP();
    }
}

void BOARD_BootClockVLPR(void)
{
    CLOCK_SetSimSafeDivs();

    CLOCK_BootToBlpiMode(g_defaultClockConfigVlpr.mcgConfig.fcrdiv, g_defaultClockConfigVlpr.mcgConfig.ircs,
                         g_defaultClockConfigVlpr.mcgConfig.irclkEnableMode);

    CLOCK_SetSimConfig(&g_defaultClockConfigVlpr.simConfig);

    SystemCoreClock = g_defaultClockConfigVlpr.coreClock;

    SMC_SetPowerModeProtection(SMC, kSMC_AllowPowerModeAll);
    SMC_SetPowerModeVlpr(SMC, false);
    while (SMC_GetPowerModeState(SMC) != kSMC_PowerStateVlpr)
    {
    }
}

void BOARD_BootClockRUN(void)
{
    /* Set the system clock dividers in SIM to safe value. */
    CLOCK_SetSimSafeDivs();
    /* Configure RTC clock including enabling RTC oscillator. */
    CLOCK_CONFIG_SetRtcClock(RTC_OSC_CAP_LOAD_0PF, RTC_RTC32KCLK_PERIPHERALS_ENABLED);
    /* Enable IRC48M oscillator for K24 as workaround because there is not enabled the oscillator automatically. */
    CLOCK_CONFIG_EnableIrc48MOsc();
    /* Configure FLL external reference divider (FRDIV). */
    CLOCK_CONFIG_SetFllExtRefDiv(g_defaultClockConfigRun.mcgConfig.frdiv);
    /* Set MCG to PEE mode. */
    CLOCK_BootToPeeMode(g_defaultClockConfigRun.mcgConfig.oscsel,
                        kMCG_PllClkSelPll0,
                        &g_defaultClockConfigRun.mcgConfig.pll0Config);
    /* Set the clock configuration in SIM module. */
    CLOCK_SetSimConfig(&g_defaultClockConfigRun.simConfig);
    /* Set SystemCoreClock variable. */
    SystemCoreClock = g_defaultClockConfigRun.coreClock;
    /* Set CLKOUT source. */
    CLOCK_SetClkOutClock(SIM_CLKOUT_SEL_FLEXBUS_CLK);
}

