#include "fpga.h"
#include "fpga_bin.h"
#include "string.h"

uint8_t fsmc_dat;
uint16_t fsmc_add;

// A public method to flash iCE40 FPGA on Humpback
void flash_fpga()
{
    // Data buffer setup
    uint8_t dummy_bytes[13];
    memset(dummy_bytes, 0, 13);

    // Drive CRESET_B low
    HAL_GPIO_WritePin(FPGA_CRESET_GPIO_Port, FPGA_CRESET_Pin, GPIO_PIN_RESET);

    // Drive SPI_SS_B low
    HAL_GPIO_WritePin(SPI_FPGA_CS_GPIO_Port, SPI_FPGA_CS_Pin, GPIO_PIN_RESET);

    // Wait at least 200ns
    HAL_Delay(5);

    // Drive CRESET_B high
    HAL_GPIO_WritePin(FPGA_CRESET_GPIO_Port, FPGA_CRESET_Pin, GPIO_PIN_SET);

    // Wait at least another 1200us to clear internal config memory
    HAL_Delay(5);

    // Before data transmission starts, check if C_DONE is truly low
    // If C_DONE is high, the FPGA reset procedure is unsuccessful
    while (HAL_GPIO_ReadPin(FPGA_CDONE_GPIO_Port, FPGA_CDONE_Pin) == GPIO_PIN_SET);

    // Set SPI_SS_B high
    HAL_GPIO_WritePin(SPI_FPGA_CS_GPIO_Port, SPI_FPGA_CS_Pin, GPIO_PIN_SET);

    // Send 8 dummy clock, effectively 1 byte of 0x00
    HAL_SPI_Transmit(&hspi1, dummy_bytes, 1, 1000);

    // Drive SPI_SS_B low
    HAL_GPIO_WritePin(SPI_FPGA_CS_GPIO_Port, SPI_FPGA_CS_Pin, GPIO_PIN_RESET);

    // Send the whole image without interruption
    for (uint16_t i = 0; i < 1351U; i++)
    {
        HAL_SPI_Transmit(&hspi1, (uint8_t *)blinky_bin+100*i, 100, HAL_MAX_DELAY-1);
    }
    // HAL_SPI_Transmit(&hspi1, (uint8_t *)blinky_bin, 65535U, HAL_MAX_DELAY-1);
    // HAL_SPI_Transmit(&hspi1, (uint8_t *)&blinky_bin[65535U], 65535U, HAL_MAX_DELAY-1);
    // HAL_SPI_Transmit(&hspi1, (uint8_t *)&blinky_bin[131070UL], 4030U, HAL_MAX_DELAY-1);
    

    // Drive SPI_SS_B high
    HAL_GPIO_WritePin(SPI_FPGA_CS_GPIO_Port, SPI_FPGA_CS_Pin, GPIO_PIN_SET);

    // Send at another 100 dummy clocks (choosing 13 bytes)
    HAL_SPI_Transmit(&hspi1, dummy_bytes, 13, 1000);

    // Check the CDONE output from FPGA
    // CDONE needs to be high
    while (HAL_GPIO_ReadPin(FPGA_CDONE_GPIO_Port, FPGA_CDONE_Pin) == GPIO_PIN_RESET);

    // Send at least another 49 clock cycles to activate IO pins (choosing same 13 bytes)
    HAL_SPI_Transmit(&hspi1, dummy_bytes, 13, 1000);
}

void read_fsmc()
{
    HAL_SRAM_Read_8b(&hsram1, (uint32_t*)&fsmc_add, &fsmc_dat, 1);
}