/**
  ******************************************************************************
  * @file    system_stm32l4xx.c
  * @author  MCD Application Team
  * @version V1.3.1
  * @date    21-April-2017
  * @brief   CMSIS Cortex-M4 Device Peripheral Access Layer System Source File
  *
  *   This file provides two functions and one global variable to be called from
  *   user application:
  *      - SystemInit(): This function is called at startup just after reset and
  *                      before branch to main program. This call is made inside
  *                      the "startup_stm32l4xx.s" file.
  *
  *      - SystemCoreClock variable: Contains the core clock (HCLK), it can be used
  *                                  by the user application to setup the SysTick
  *                                  timer or configure other parameters.
  *
  *      - SystemCoreClockUpdate(): Updates the variable SystemCoreClock and must
  *                                 be called whenever the core clock is changed
  *                                 during program execution.
  *
  *   After each device reset the MSI (4 MHz) is used as system clock source.
  *   Then SystemInit() function is called, in "startup_stm32l4xx.s" file, to
  *   configure the system clock before to branch to main program.
  *
  *   This file configures the system clock as follows:
  *=============================================================================
  * System clock source                | 1- PLL_HSE_EXTC        | 3- PLL_HSI
  *                                    | (external 8 MHz clock) | (internal 16 MHz)
  *                                    | 2- PLL_HSE_XTAL        | or PLL_MSI
  *                                    | (external 8 MHz xtal)  | (internal 4 MHz)
  *-----------------------------------------------------------------------------
  * SYSCLK(MHz)                        | 48                     | 80
  *-----------------------------------------------------------------------------
  * AHBCLK (MHz)                       | 48                     | 80
  *-----------------------------------------------------------------------------
  * APB1CLK (MHz)                      | 48                     | 80
  *-----------------------------------------------------------------------------
  * APB2CLK (MHz)                      | 48                     | 80
  *-----------------------------------------------------------------------------
  * USB capable (48 MHz precise clock) | YES                    | NO
  *-----------------------------------------------------------------------------
**/

#include "stm32l4xx.h"
#include "nvic_addr.h"
#include "mbed_assert.h"

/*!< Uncomment the following line if you need to relocate your vector Table in
     Internal SRAM. */
/* #define VECT_TAB_SRAM */
#define VECT_TAB_OFFSET  0x00 /*!< Vector Table base offset field.
                                   This value must be a multiple of 0x200. */


// clock source is selected with CLOCK_SOURCE in json config
#define USE_PLL_HSE_EXTC 0x8 // Use external clock (ST Link MCO - not enabled by default)
#define USE_PLL_HSE_XTAL 0x4 // Use external xtal (X3 on board - not provided by default)
#define USE_PLL_HSI      0x2 // Use HSI internal clock
#define USE_PLL_MSI      0x1 // Use MSI internal clock

#define DEBUG_MCO        (0) // Output the MCO on PA8 for debugging (0=OFF, 1=SYSCLK, 2=HSE, 3=HSI, 4=MSI)

#if ( ((CLOCK_SOURCE) & USE_PLL_HSE_XTAL) || ((CLOCK_SOURCE) & USE_PLL_HSE_EXTC) )
uint8_t SetSysClock_PLL_HSE(uint8_t bypass);
#endif /* ((CLOCK_SOURCE) & USE_PLL_HSE_XTAL) || ((CLOCK_SOURCE) & USE_PLL_HSE_EXTC) */

#if ((CLOCK_SOURCE) & USE_PLL_HSI)
uint8_t SetSysClock_PLL_HSI(void);
#endif /* ((CLOCK_SOURCE) & USE_PLL_HSI) */

#if ((CLOCK_SOURCE) & USE_PLL_MSI)
uint8_t SetSysClock_PLL_MSI(void);
#endif /* ((CLOCK_SOURCE) & USE_PLL_MSI) */


/**
  * @brief  Setup the microcontroller system.
  * @param  None
  * @retval None
  */

void SystemInit(void)
{
    /* FPU settings ------------------------------------------------------------*/
#if (__FPU_PRESENT == 1) && (__FPU_USED == 1)
    SCB->CPACR |= ((3UL << 10*2)|(3UL << 11*2));  /* set CP10 and CP11 Full Access */
#endif
    /* Reset the RCC clock configuration to the default reset state ------------*/
    /* Set MSION bit */
    RCC->CR |= RCC_CR_MSION;

    /* Reset CFGR register */
    RCC->CFGR = 0x00000000;

    /* Reset HSEON, CSSON , HSION, and PLLON bits */
    RCC->CR &= (uint32_t)0xEAF6FFFF;

    /* Reset PLLCFGR register */
    RCC->PLLCFGR = 0x00001000;

    /* Reset HSEBYP bit */
    RCC->CR &= (uint32_t)0xFFFBFFFF;

    /* Disable all interrupts */
    RCC->CIER = 0x00000000;

    /* Configure the Vector Table location add offset address ------------------*/
#ifdef VECT_TAB_SRAM
    SCB->VTOR = SRAM_BASE | VECT_TAB_OFFSET; /* Vector Table Relocation in Internal SRAM */
#else
    SCB->VTOR = FLASH_BASE | VECT_TAB_OFFSET; /* Vector Table Relocation in Internal FLASH */
#endif

}


/**
  * @brief  Configures the System clock source, PLL Multiplier and Divider factors,
  *               AHB/APBx prescalers and Flash settings
  * @note   This function should be called only once the RCC clock configuration
  *         is reset to the default reset state (done in SystemInit() function).
  * @param  None
  * @retval None
  */

void SetSysClock(void)
{
#if ((CLOCK_SOURCE) & USE_PLL_HSE_EXTC)
    /* 1- Try to start with HSE and external clock */
    if (SetSysClock_PLL_HSE(1) == 0)
#endif
    {
#if ((CLOCK_SOURCE) & USE_PLL_HSE_XTAL)
        /* 2- If fail try to start with HSE and external xtal */
        if (SetSysClock_PLL_HSE(0) == 0)
#endif
        {
#if ((CLOCK_SOURCE) & USE_PLL_HSI)
            /* 3- If fail start with HSI clock */
            if (SetSysClock_PLL_HSI()==0)
#endif
            {
#if ((CLOCK_SOURCE) & USE_PLL_MSI)
                /* 4- If fail start with MSI clock */
                if (SetSysClock_PLL_MSI() == 0)
#endif
                {
                    while(1) {
                        MBED_ASSERT(1);
                    }
                }
            }
        }
    }

    // Output clock on MCO1 pin(PA8) for debugging purpose
#if DEBUG_MCO == 1
    HAL_RCC_MCOConfig(RCC_MCO1, RCC_MCO1SOURCE_SYSCLK, RCC_MCODIV_1);
#endif
}

#if ( ((CLOCK_SOURCE) & USE_PLL_HSE_XTAL) || ((CLOCK_SOURCE) & USE_PLL_HSE_EXTC) )
/******************************************************************************/
/*            PLL (clocked by HSE) used as System clock source                */
/******************************************************************************/
uint8_t SetSysClock_PLL_HSE(uint8_t bypass)
{
    RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
    RCC_OscInitTypeDef RCC_OscInitStruct = {0};
    RCC_PeriphCLKInitTypeDef RCC_PeriphClkInit = {0};

    // Used to gain time after DeepSleep in case HSI is used
    if (__HAL_RCC_GET_FLAG(RCC_FLAG_HSIRDY) != RESET) {
        return 0;
    }

    // Select MSI as system clock source to allow modification of the PLL configuration
    RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_SYSCLK;
    RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_MSI;
    HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_0);

    // Enable HSE oscillator and activate PLL with HSE as source
    RCC_OscInitStruct.OscillatorType        = RCC_OSCILLATORTYPE_HSE | RCC_OSCILLATORTYPE_HSI;
    if (bypass == 0) {
        RCC_OscInitStruct.HSEState            = RCC_HSE_ON; // External 8 MHz xtal on OSC_IN/OSC_OUT
    } else {
        RCC_OscInitStruct.HSEState            = RCC_HSE_BYPASS; // External 8 MHz clock on OSC_IN
    }
    RCC_OscInitStruct.HSIState              = RCC_HSI_OFF;
    RCC_OscInitStruct.PLL.PLLSource         = RCC_PLLSOURCE_HSE; // 8 MHz
    RCC_OscInitStruct.PLL.PLLState          = RCC_PLL_ON;
    RCC_OscInitStruct.PLL.PLLM              = 1; // VCO input clock = 8 MHz (8 MHz / 1)
    RCC_OscInitStruct.PLL.PLLN              = 20; // VCO output clock = 160 MHz (8 MHz * 20)
    RCC_OscInitStruct.PLL.PLLP              = 7; // PLLSAI3 clock = 22 MHz (160 MHz / 7)
    RCC_OscInitStruct.PLL.PLLQ              = 2;
    RCC_OscInitStruct.PLL.PLLR              = 2; // PLL clock = 80 MHz (160 MHz / 2)

    if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK) {
        return 0; // FAIL
    }

    // Select PLL clock as system clock source and configure the HCLK, PCLK1 and PCLK2 clocks dividers
    RCC_ClkInitStruct.ClockType      = (RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2);
    RCC_ClkInitStruct.SYSCLKSource   = RCC_SYSCLKSOURCE_PLLCLK; // 80 MHz or 48 MHz
    RCC_ClkInitStruct.AHBCLKDivider  = RCC_SYSCLK_DIV1;         // 80 MHz or 48 MHz
    RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;           // 80 MHz or 48 MHz
    RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;           // 80 MHz or 48 MHz
    if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_4) != HAL_OK) {
        return 0; // FAIL
    }

    RCC_PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_USB;
    RCC_PeriphClkInit.UsbClockSelection = RCC_USBCLKSOURCE_PLLSAI1;
    RCC_PeriphClkInit.PLLSAI1.PLLSAI1Source = RCC_PLLSOURCE_HSE;
    RCC_PeriphClkInit.PLLSAI1.PLLSAI1M = 1;
    RCC_PeriphClkInit.PLLSAI1.PLLSAI1N = 12;
    RCC_PeriphClkInit.PLLSAI1.PLLSAI1P = RCC_PLLP_DIV7;
    RCC_PeriphClkInit.PLLSAI1.PLLSAI1Q = RCC_PLLQ_DIV2;
    RCC_PeriphClkInit.PLLSAI1.PLLSAI1R = RCC_PLLR_DIV2;
    RCC_PeriphClkInit.PLLSAI1.PLLSAI1ClockOut = RCC_PLLSAI1_48M2CLK;
    if (HAL_RCCEx_PeriphCLKConfig(&RCC_PeriphClkInit) != HAL_OK) {
        return 0; // FAIL
    }

    // Disable MSI Oscillator
    RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_MSI;
    RCC_OscInitStruct.MSIState       = RCC_MSI_OFF;
    RCC_OscInitStruct.PLL.PLLState   = RCC_PLL_NONE; // No PLL update
    HAL_RCC_OscConfig(&RCC_OscInitStruct);

    // Output clock on MCO1 pin(PA8) for debugging purpose
#if DEBUG_MCO == 2
    if (bypass == 0)
        HAL_RCC_MCOConfig(RCC_MCO1, RCC_MCO1SOURCE_HSE, RCC_MCODIV_2); // 4 MHz
    else
        HAL_RCC_MCOConfig(RCC_MCO1, RCC_MCO1SOURCE_HSE, RCC_MCODIV_1); // 8 MHz
#endif

    return 1; // OK
}
#endif /* ((CLOCK_SOURCE) & USE_PLL_HSE_XTAL) || ((CLOCK_SOURCE) & USE_PLL_HSE_EXTC) */

#if ((CLOCK_SOURCE) & USE_PLL_HSI)
/******************************************************************************/
/*            PLL (clocked by HSI) used as System clock source                */
/******************************************************************************/
uint8_t SetSysClock_PLL_HSI(void)
{
    RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
    RCC_OscInitTypeDef RCC_OscInitStruct = {0};
    RCC_PeriphCLKInitTypeDef RCC_PeriphClkInit = {0};

    // Select MSI as system clock source to allow modification of the PLL configuration
    RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_SYSCLK;
    RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_MSI;
    HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_0);

    // Enable HSI oscillator and activate PLL with HSI as source
    RCC_OscInitStruct.OscillatorType       = RCC_OSCILLATORTYPE_HSI | RCC_OSCILLATORTYPE_HSE;
    RCC_OscInitStruct.HSEState             = RCC_HSE_OFF;
    RCC_OscInitStruct.HSIState             = RCC_HSI_ON;
    RCC_OscInitStruct.HSICalibrationValue  = RCC_HSICALIBRATION_DEFAULT;
    RCC_OscInitStruct.PLL.PLLState         = RCC_PLL_ON;
    RCC_OscInitStruct.PLL.PLLSource        = RCC_PLLSOURCE_HSI; // 16 MHz
    RCC_OscInitStruct.PLL.PLLM             = 2; // VCO input clock = 8 MHz (16 MHz / 2)
    RCC_OscInitStruct.PLL.PLLN             = 20; // VCO output clock = 160 MHz (8 MHz * 20)
    RCC_OscInitStruct.PLL.PLLP             = 7; // PLLSAI3 clock = 22 MHz (160 MHz / 7)
    RCC_OscInitStruct.PLL.PLLQ             = 2;
    RCC_OscInitStruct.PLL.PLLR             = 2; // PLL clock = 80 MHz (160 MHz / 2)
    if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK) {
        return 0; // FAIL
    }

    // Select PLL as system clock source and configure the HCLK, PCLK1 and PCLK2 clocks dividers
    RCC_ClkInitStruct.ClockType      = (RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2);
    RCC_ClkInitStruct.SYSCLKSource   = RCC_SYSCLKSOURCE_PLLCLK; // 80 MHz
    RCC_ClkInitStruct.AHBCLKDivider  = RCC_SYSCLK_DIV1;         // 80 MHz
    RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;           // 80 MHz
    RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;           // 80 MHz
    if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_4) != HAL_OK) {
        return 0; // FAIL
    }

    RCC_PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_USB;
    RCC_PeriphClkInit.UsbClockSelection = RCC_USBCLKSOURCE_PLLSAI1;
    RCC_PeriphClkInit.PLLSAI1.PLLSAI1Source = RCC_PLLSOURCE_HSI;
    RCC_PeriphClkInit.PLLSAI1.PLLSAI1M = 2;
    RCC_PeriphClkInit.PLLSAI1.PLLSAI1N = 12;
    RCC_PeriphClkInit.PLLSAI1.PLLSAI1P = RCC_PLLP_DIV7;
    RCC_PeriphClkInit.PLLSAI1.PLLSAI1Q = RCC_PLLQ_DIV2;
    RCC_PeriphClkInit.PLLSAI1.PLLSAI1R = RCC_PLLR_DIV2;
    RCC_PeriphClkInit.PLLSAI1.PLLSAI1ClockOut = RCC_PLLSAI1_48M2CLK;
    if (HAL_RCCEx_PeriphCLKConfig(&RCC_PeriphClkInit) != HAL_OK) {
        return 0; // FAIL
    }

    // Disable MSI Oscillator
    RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_MSI;
    RCC_OscInitStruct.MSIState       = RCC_MSI_OFF;
    RCC_OscInitStruct.PLL.PLLState   = RCC_PLL_NONE; // No PLL update
    HAL_RCC_OscConfig(&RCC_OscInitStruct);

    // Output clock on MCO1 pin(PA8) for debugging purpose
#if DEBUG_MCO == 3
    HAL_RCC_MCOConfig(RCC_MCO1, RCC_MCO1SOURCE_HSI, RCC_MCODIV_1); // 16 MHz
#endif

    return 1; // OK
}
#endif /* ((CLOCK_SOURCE) & USE_PLL_HSI) */

#if ((CLOCK_SOURCE) & USE_PLL_MSI)
/******************************************************************************/
/*            PLL (clocked by MSI) used as System clock source                */
/******************************************************************************/
uint8_t SetSysClock_PLL_MSI(void)
{
    RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
    RCC_OscInitTypeDef RCC_OscInitStruct = {0};
    RCC_PeriphCLKInitTypeDef PeriphClkInitStruct = {0};

    // Enable LSE Oscillator to automatically calibrate the MSI clock
    RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_LSE;
    RCC_OscInitStruct.PLL.PLLState   = RCC_PLL_NONE; // No PLL update
    RCC_OscInitStruct.LSEState       = RCC_LSE_ON; // External 32.768 kHz clock on OSC_IN/OSC_OUT
    if (HAL_RCC_OscConfig(&RCC_OscInitStruct) == HAL_OK) {
        RCC->CR |= RCC_CR_MSIPLLEN; // Enable MSI PLL-mode
    }

    HAL_RCCEx_DisableLSECSS();
    /* Enable MSI Oscillator and activate PLL with MSI as source */
    RCC_OscInitStruct.OscillatorType      = RCC_OSCILLATORTYPE_MSI | RCC_OSCILLATORTYPE_HSI | RCC_OSCILLATORTYPE_HSE;
    RCC_OscInitStruct.MSIState             = RCC_MSI_ON;
    RCC_OscInitStruct.HSEState             = RCC_HSE_OFF;
    RCC_OscInitStruct.HSIState             = RCC_HSI_OFF;

    RCC_OscInitStruct.MSICalibrationValue = RCC_MSICALIBRATION_DEFAULT;
    RCC_OscInitStruct.MSIClockRange       = RCC_MSIRANGE_11; /* 48 MHz */
    RCC_OscInitStruct.PLL.PLLState        = RCC_PLL_ON;
    RCC_OscInitStruct.PLL.PLLSource       = RCC_PLLSOURCE_MSI;
    RCC_OscInitStruct.PLL.PLLM            = 6;    /* 8 MHz */
    RCC_OscInitStruct.PLL.PLLN            = 40;   /* 320 MHz */
    RCC_OscInitStruct.PLL.PLLP            = 7;    /* 45 MHz */
    RCC_OscInitStruct.PLL.PLLQ            = 4;    /* 80 MHz */
    RCC_OscInitStruct.PLL.PLLR            = 4;    /* 80 MHz */
    if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK) {
        return 0; // FAIL
    }
    /* Enable MSI Auto-calibration through LSE */
    HAL_RCCEx_EnableMSIPLLMode();
    /* Select MSI output as USB clock source */
    PeriphClkInitStruct.PeriphClockSelection = RCC_PERIPHCLK_USB;
    PeriphClkInitStruct.UsbClockSelection = RCC_USBCLKSOURCE_MSI; /* 48 MHz */
    HAL_RCCEx_PeriphCLKConfig(&PeriphClkInitStruct);
    // Select PLL as system clock source and configure the HCLK, PCLK1 and PCLK2 clocks dividers
    RCC_ClkInitStruct.ClockType      = (RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2);
    RCC_ClkInitStruct.SYSCLKSource   = RCC_SYSCLKSOURCE_PLLCLK; /* 80 MHz */
    RCC_ClkInitStruct.AHBCLKDivider  = RCC_SYSCLK_DIV1;         /* 80 MHz */
    RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;           /* 80 MHz */
    RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;           /* 80 MHz */
    if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_4) != HAL_OK) {
        return 0; // FAIL
    }

    // Output clock on MCO1 pin(PA8) for debugging purpose
#if DEBUG_MCO == 4
    HAL_RCC_MCOConfig(RCC_MCO1, RCC_MCO1SOURCE_MSI, RCC_MCODIV_2); // 2 MHz
#endif

    return 1; // OK
}
#endif /* ((CLOCK_SOURCE) & USE_PLL_MSI) */
