#include "drivers/spi/spi.h"
#include "stm32l1xx_hal.h"
#include "stm32l1xx_hal_spi.h"
#include "core/gpio.h"
#include "core/config_pins.h"

static SPI_HandleTypeDef handle_spi = {
  #if CONFIG_PERIF_EXTMEMSPI == CONFIG_PERIF_SPI1
  .Instance = SPI1
  #elif CONFIG_PERIF_EXTMEMSPI == CONFIG_PERIF_SPI2
  .Instance = SPI2
  #else
  #error Invalid SPI specified in 'config_pins.h': see 'CONFIG_PERIF_EXTMEMSPI' 
  #endif
};

static void SPI_SetNSS();
static void SPI_ClrNSS();
static void SPI_Init();
static void SPI_DeInit();
static void SPI_TransmitReceive( uint8_t * pTxBuf, uint8_t * pRxBuf, size_t size );
static void SPI_Receive( uint8_t * pRxBuf, size_t size );
static void SPI_Transmit( uint8_t * pTxBuf, size_t size );

const SPI_Handle_t SPIHandle = {
  .Init = SPI_Init,
  .DeInit = SPI_DeInit,
  .SetNSS = SPI_SetNSS,
  .ClrNSS = SPI_ClrNSS,
  .Transmit = SPI_Transmit,
  .Receive = SPI_Receive,
  .TransmitReceive = SPI_TransmitReceive
};
     
static void SPI_Init()
{ 
  // Initialize SPI handle
  #if CONFIG_PERIF_EXTMEMSPI == CONFIG_PERIF_SPI1
  handle_spi.Instance = SPI1;
  #elif CONFIG_PERIF_EXTMEMSPI == CONFIG_PERIF_SPI2
  handle_spi.Instance = SPI2;
  #else
  #error Invalid SPI specified in 'config_pins.h': see 'CONFIG_PERIF_EXTMEMSPI' 
  #endif
  handle_spi.Init.Mode = SPI_MODE_MASTER;
  handle_spi.Init.Direction = SPI_DIRECTION_2LINES;
  handle_spi.Init.DataSize = SPI_DATASIZE_8BIT;
  handle_spi.Init.CLKPolarity = SPI_POLARITY_LOW;
  handle_spi.Init.CLKPhase = SPI_PHASE_1EDGE;
  handle_spi.Init.NSS = SPI_NSS_SOFT;
  handle_spi.Init.BaudRatePrescaler = SPI_BAUDRATEPRESCALER_16;
  handle_spi.Init.FirstBit = SPI_FIRSTBIT_MSB;
  handle_spi.Init.TIMode = SPI_TIMODE_DISABLED;
  handle_spi.Init.CRCCalculation = SPI_CRCCALCULATION_DISABLED;
  handle_spi.Init.CRCPolynomial = 7;

  {
  GPIO_InitTypeDef GPIO_InitStruct = {0};
  // Configure GPIO pins for SPI
  GPIO_InitStruct.Pin = CONFIG_PIN__EXTMEMSPI__CK|CONFIG_PIN__EXTMEMSPI__SO|CONFIG_PIN__EXTMEMSPI__SI;  
  GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  #if CONFIG_PERIF_EXTMEMSPI == CONFIG_PERIF_SPI1
  GPIO_InitStruct.Alternate = GPIO_AF5_SPI1;
  #elif CONFIG_PERIF_EXTMEMSPI == CONFIG_PERIF_SPI2  
  GPIO_InitStruct.Alternate = GPIO_AF5_SPI2;
  #else
  #error Invalid SPI specified in 'config_pins.h': see 'CONFIG_PERIF_EXTMEMSPI' 
  #endif
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
  HAL_GPIO_Init(CONFIG_PORT__EXTMEMSPI__SO_SI_CK, &GPIO_InitStruct);
  }
  {
  GPIO_InitTypeDef GPIO_InitStruct = {0};
  // Configure GPIO pins for SPI : PB11 = Software NSS
  GPIO_InitStruct.Pin = CONFIG_PIN__EXTMEMSPI__CS;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_OD;
  GPIO_InitStruct.Pull = GPIO_PULLUP;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_MEDIUM;
  HAL_GPIO_Init(CONFIG_PORT__EXTMEMSPI__CS, &GPIO_InitStruct);
  HAL_GPIO_WritePin( CONFIG_PORT__EXTMEMSPI__CS, CONFIG_PIN__EXTMEMSPI__CS, GPIO_PIN_SET );
  }

  #if CONFIG_PERIF_EXTMEMSPI == CONFIG_PERIF_SPI1
  // Enable SPI1 Clocking
  __HAL_RCC_SPI1_CLK_ENABLE();
  #elif CONFIG_PERIF_EXTMEMSPI == CONFIG_PERIF_SPI2
  // Enable SPI2 Clocking
  __HAL_RCC_SPI2_CLK_ENABLE();
  #else
  #error Invalid SPI specified in 'config_pins.h': see 'CONFIG_PERIF_EXTMEMSPI' 
  #endif
  
  // Initialize SPI HAL
  HAL_SPI_Init( &handle_spi );

  // Set NSS to HIGH by default
  SPI_SetNSS();
}

static void SPI_DeInit()
{
   #if CONFIG_PERIF_EXTMEMSPI == CONFIG_PERIF_SPI1
   // Disable SPI1 Clocking
   handle_spi.Instance = SPI1;
   __HAL_RCC_SPI1_CLK_DISABLE();
   #elif CONFIG_PERIF_EXTMEMSPI == CONFIG_PERIF_SPI2
   // Disable SPI2 Clocking
   handle_spi.Instance = SPI2;
   __HAL_RCC_SPI2_CLK_DISABLE();
   #else
   #error Invalid SPI specified in 'config_pins.h': see 'CONFIG_PERIF_EXTMEMSPI' 
   #endif

   // Deinitialize ports
   // It is required to pull NSS (CS) to VCC to prevent
   // the slave activating!!!!

    // Configure GPIO pins for SPI 
   {
   GPIO_InitTypeDef GPIO_InitStruct = {0};
   GPIO_InitStruct.Pin = CONFIG_PIN__EXTMEMSPI__CK|CONFIG_PIN__EXTMEMSPI__SO|CONFIG_PIN__EXTMEMSPI__SI;
   GPIO_InitStruct.Mode = GPIO_MODE_ANALOG;
   GPIO_InitStruct.Pull = GPIO_NOPULL;   
   GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
   HAL_GPIO_Init(CONFIG_PORT__EXTMEMSPI__SO_SI_CK, &GPIO_InitStruct);
   }

   {
   GPIO_InitTypeDef GPIO_InitStruct = {0};
   GPIO_InitStruct.Pin = CONFIG_PIN__EXTMEMSPI__CS;
   #if SPI_KEEP_NSS_PULLEDUP 
   GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_OD;
   GPIO_InitStruct.Pull = GPIO_PULLUP; 
   #else
   GPIO_InitStruct.Mode = GPIO_MODE_ANALOG;
   GPIO_InitStruct.Pull = GPIO_NOPULL;   
   #endif
   GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
   HAL_GPIO_Init(CONFIG_PORT__EXTMEMSPI__CS, &GPIO_InitStruct);
   }

   // DeInitialize SPI HAL
   HAL_SPI_DeInit( &handle_spi );
}

static void SPI_SetNSS()
{
  HAL_GPIO_WritePin( CONFIG_PORT__EXTMEMSPI__CS, CONFIG_PIN__EXTMEMSPI__CS, GPIO_PIN_SET );
}

static void SPI_ClrNSS()
{
  HAL_GPIO_WritePin( CONFIG_PORT__EXTMEMSPI__CS, CONFIG_PIN__EXTMEMSPI__CS, GPIO_PIN_RESET );
}

static void SPI_Transmit( uint8_t * pTxBuf, size_t size )
{
  HAL_SPI_Transmit( &handle_spi, pTxBuf, size, HAL_MAX_DELAY );
}

static void SPI_Receive( uint8_t * pRxBuf, size_t size )
{
  HAL_SPI_Receive( &handle_spi, pRxBuf, size, HAL_MAX_DELAY );
}

static void SPI_TransmitReceive( uint8_t * pTxBuf, uint8_t * pRxBuf, size_t size )
{
  HAL_SPI_TransmitReceive( &handle_spi, pTxBuf, pRxBuf, size, HAL_MAX_DELAY );
}