// Raspberry Pi LPC1114 I/O Processor Expansion Board SPI Agent Firmware
// utility program to request ISP mode

// Copyright (C)2013-2018, Philip Munts, President, Munts AM Corp.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright notice,
//   this list of conditions and the following disclaimer.
//
// 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 <errno.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include <libsimpleio/libgpio.h>

#include <spi-agent.h>

extern void spiagent_open_ioctl(const char *servername, int32_t *error);

extern void spiagent_command_ioctl(SPIAGENT_COMMAND_MSG_t *cmd,
  SPIAGENT_RESPONSE_MSG_t *resp, int32_t *error);

// Enter LPC1114 ISP mode by twiddling ISP and reset pins

void ResetISP(int pin_isp, int pin_reset)
{
  int32_t fd_isp;
  int32_t fd_reset;
  int32_t error;

  GPIO_line_open(0, pin_reset, GPIOHANDLE_REQUEST_OUTPUT, 0, true, &fd_reset,
    &error);

  if (error)
  {
    fprintf(stderr, "ERROR: GPIO_line_open() failed, %s\n", strerror(error));
    exit(1);
  }

  GPIO_line_open(0, pin_isp, GPIOHANDLE_REQUEST_OUTPUT, 0, true, &fd_isp,
    &error);

  if (error)
  {
    fprintf(stderr, "ERROR: GPIO_line_open() failed, %s\n", strerror(error));
    exit(1);
  }

  usleep(1000);

  GPIO_line_write(fd_isp, false, &error);

  if (error)
  {
    fprintf(stderr, "ERROR: GPIO_line_write() failed, %s\n", strerror(error));
    exit(1);
  }

  usleep(1000);

  GPIO_line_write(fd_reset, false, &error);

  if (error)
  {
    fprintf(stderr, "ERROR: GPIO_line_write() failed, %s\n", strerror(error));
    exit(1);
  }

  usleep(1000);

  GPIO_line_write(fd_reset, true, &error);

  if (error)
  {
    fprintf(stderr, "ERROR: GPIO_line_write() failed, %s\n", strerror(error));
    exit(1);
  }

  usleep(1000);

  GPIO_line_write(fd_isp, true, &error);

  if (error)
  {
    fprintf(stderr, "ERROR: GPIO_line_write() failed, %s\n", strerror(error));
    exit(1);
  }

  GPIO_line_close(fd_isp, &error);

  if (error)
  {
    fprintf(stderr, "ERROR: GPIO_line_close() failed, %s\n", strerror(error));
    exit(1);
  }

  GPIO_line_close(fd_reset, &error);

  if (error)
  {
    fprintf(stderr, "ERROR: GPIO_line_close() failed, %s\n", strerror(error));
    exit(1);
  }
}

// Enter LPC1114 ISP mode by sending magic command

void CommandISP(void)
{
  SPIAGENT_COMMAND_MSG_t command;
  SPIAGENT_RESPONSE_MSG_t response;
  int32_t error;

  // Initialize the SPI Agent services library

  spiagent_open_ioctl(NULL, &error);

  if (error)
  {
    fprintf(stderr, "ERROR: spiagent_open_ioctl() failed, %s\n",
      strerror(error));
    exit(1);
  }

  // Command the LPC1114 to enter ISP mode

  command.command = 0x12345678;
  command.pin = 0x23456789;
  command.data = 0x3456789A;

  memset(&response, 0, sizeof(response));

  spiagent_command_ioctl(&command, &response, &error);

  if (error)
  {
    fprintf(stderr, "ERROR: spiagent_command_ioctl() failed, %s\n",
      strerror(error));
    exit(1);
  }

  if (response.error)
  {
    fprintf(stderr, "ERROR: ISP request operation failed, %s\n",
      strerror(response.error));
    exit(1);
  }
}

int main(void)
{
  char value[256];
  int32_t error;
  int pin_isp = -1;
  int pin_reset = -1;

  // Read pin assignments (if any) from the configuration file

  spiagent_config_open(&error);

  spiagent_config_get("LPC1114_ISP", value, sizeof(value), &error);
  if (error == 0) pin_isp = atoi(value);

  spiagent_config_get("LPC1114_RESET", value, sizeof(value), &error);
  if (error == 0) pin_reset = atoi(value);

  spiagent_config_close(&error);

  // Enter LPC1114 ISP mode

  if ((pin_isp > 0) && (pin_reset > 0))
    ResetISP(pin_isp, pin_reset);
  else
    CommandISP();

  exit(0);
}