#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>   /* File Control Definitions           */
#include <termios.h> /* POSIX Terminal Control Definitions */
#include <unistd.h>  /* UNIX Standard Definitions      */
#include <errno.h>   /* ERROR Number Definitions           */
#include <string.h>

// Number of strings in array argv
// int main( int argc,            char *argv[],
// void main(void)

static void print_msg(void)
{
    printf("=============================================================\n");
    printf("Usage :\n");
    printf("./fii_app.o dir <val> : val : 0 => output; 1 => input\n");
    printf("./fii_app.o wr  <val> : val : 0x43c0_0004 address value\n");
    printf("./fii_app.o rd        : \n");
    printf("=============================================================\n");

    return;
}

static void func_read(int fd,  int read_cnt)
{
    char rd_buf[32];        /* Buffer to store the data received              */
    int  bytes_read = 0;    /* Number of bytes read by the read() system call */
    unsigned int temp;

    printf("Press ctrl+C to exit \n");
    tcflush(fd, TCIFLUSH);   /* Discards old data in the rx buffer */
    lseek(fd, 0, SEEK_SET);

    bytes_read = read(fd, rd_buf, read_cnt);

    printf("\n\nBytes Rxed = %d \n", bytes_read); /* Print the number of bytes read */

    temp = rd_buf[0];
    temp = (temp << 8) | rd_buf[1];
    temp = (temp << 8) | rd_buf[2];
    temp = (temp << 8) | rd_buf[3];

    printf("read value = 0x%08x \n", temp);

    temp = rd_buf[4];
    temp = (temp << 8) | rd_buf[5];
    temp = (temp << 8) | rd_buf[6];
    temp = (temp << 8) | rd_buf[7];

    printf("read dir   = 0x%08x \n", temp);

    printf("\n +----------------------------------+\n\n\n");

//    usleep(1000000);

    return;
}

static void func_write(int fd,  char *p)
{
    char wr_buf[32];
    ssize_t bytes_written = 0;
    unsigned int value;
    memset (wr_buf, 0x0a, 32);
    value = atoi(p);

    printf("value = %x \n" , value);

    wr_buf[0] = 'w';
    wr_buf[1] = ' ';
    wr_buf[2] = value >> 24;
    wr_buf[3] = (value >> 16) & 0xff;
    wr_buf[4] = (value >> 8) & 0xff;
    wr_buf[5] = value & 0xff;

    bytes_written = write(fd, wr_buf, 7);

    return;
}

static void func_direction(int fd,  char *p)
{
    char wr_buf[32];
    ssize_t bytes_written = 0;
    unsigned int value;
    memset (wr_buf, 0x0a, 32);
    value = atoi(p);

    printf("value = %x \n" , value);

    wr_buf[0] = 'd';
    wr_buf[1] = ' ';
    wr_buf[2] = value >> 24;
    wr_buf[3] = (value >> 16) & 0xff;
    wr_buf[3] = (value >> 8) & 0xff;
    wr_buf[5] = value & 0xff;

    bytes_written = write(fd, wr_buf, 7);
}

int main( int argc, char *argv[])
{
    int fd;/*File Descriptor*/
    unsigned int value = 0;
    char * cmd_p;

    /* O_RDWR    - Read/Write access to serial port     */
    /* O_RDONLY  - Read access to serial port           */
    /* O_WRONLY  - Write access to serial port          */
    /* O_NOCTTY  - No terminal will control the process */

    /* Open in blocking mode,read will wait             */

    fd = open("/dev/fii-module",O_RDWR );

    printf("\n +----------------------------------+");
    printf("\n |     fii-driver function          |");
    printf("\n +----------------------------------+");

    if(fd == -1)                             /* Error Checking */
        printf("\n  Error! in Opening swled  \n");

    else
        printf("\n  fii-driver Opened Successfully \n");

    cmd_p = argv[1];

    if(argc == 2)
    {
        if( strcmp (cmd_p , "rd") == 0 )
        {
            func_read(fd,  8);
            return 0;
        }

        else
        {
            print_msg();
            close(fd); /* Close the serial port */
            return 1;
        }
    }

    else if (argc == 3)
    {
        if( strcmp (cmd_p , "wr") == 0 )
        {
            func_write(fd, argv[2]);
            close(fd); /* Close the serial port */
            return 0;
        }

        else if( strcmp (cmd_p , "dir") == 0 )
        {
            func_direction(fd, argv[2]);
            close(fd); /* Close the serial port */
            return 0;
        }
    }

    else
    {
        print_msg();
        close(fd); /* Close the serial port */
        return 1;
    }

    return 0;
}