//ttyS1init.cpp
// set pCduino pins 0,1 to serial port functionality. M.H. 1/14/14
// current pcDuino linux image doesn't set these pins to serial mode
// replaces setuart2 hack by bGood. 

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <termios.h>
#include <unistd.h>
#include <fcntl.h>
#include "serial_test.h"

// Life is easier if we make a constant for our port name.
static const char* portName = "/dev/ttyS1";

int main(void)
{

  // The very first thing we need to do is make sure that the pins are set
  //   to SERIAL mode, rather than, say, GPIO mode.
  char path[256];

  for (int i = 0; i<=1; i++)
  {
    // Clear the path variable...
    memset(path,0,sizeof(path));
    // ...then assemble the path variable for the current pin mode file...
    sprintf(path, "%s%s%d", GPIO_MODE_PATH, GPIO_FILENAME, i);
    // ...and create a file descriptor...
    int pinMode = open(path, O_RDWR);
    // ...which we then use to set the pin mode to SERIAL...
    setPinMode(pinMode, SERIAL);
    // ...and then, close the pinMode file.
    printf("pcDuino pin %d set to Serial Port Mode\n", i);
    close(pinMode);
  }

} // end main()

void setPinMode(int pinID, int mode)
{
  writeFile(pinID, mode);
}

// While it seems okay to only *read* the first value from the file, you
//   seemingly must write four bytes to the file to get the I/O setting to
//   work properly. This function does that.
void writeFile(int fileID, int value)
{
  char buffer[4];  // A place to build our four-byte string.
  memset((void *)buffer, 0, sizeof(buffer)); // clear the buffer out.
  sprintf(buffer, "%d", value);
  lseek(fileID, 0, SEEK_SET);   // Make sure we're at the top of the file!
  int res = write(fileID, buffer, sizeof(buffer));
}