Parallel port access via IOPERM

#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include <time.h>
#include <unistd.h>
#include <stdint.h>
#include <sys/io.h>

#define DEBUG_LOG 0
#define TRACE_LOG 1

void debug_log(char *s, int t)
{
    printf("\n%s",s);
}

#define PARALLEL_PORT_ADDR 0x378
#define SENSOR_PORT_ADDR (PARALLEL_PORT_ADDR + 2)
#define LOWPAPER_SENSOR_PORT (PARALLEL_PORT_ADDR + 1)
#define MOTOR_PORT_ADDR (PARALLEL_PORT_ADDR + 2)

#define BIT(x) (1 << x)
#define SENSOR_CTRL_BIT BIT(2)
#define SENSOR_VALUE(x) (((x) & SENSOR_CTRL_BIT) >> 2)
#define LOWPAPER_SENSOR_BIT BIT(3)
#define LOWPAPER_SENSOR_VALUE(x) (((x) & LOWPAPER_SENSOR_BIT) >> 3)
#define MOTOR_CTRL_BIT BIT(0)

#define SENSOR_CLEAR 1
#define SENSOR_BLOCK 0

#define MOTOR_START 1
#define MOTOR_STOP 0

int16_t readSensorVal(void)
{
    static int16_t portValPrev = 0;
    int16_t portVal = 0;
    char charBuf[128] = {'\0'};

    outb(inb(SENSOR_PORT_ADDR) | SENSOR_CTRL_BIT, MOTOR_PORT_ADDR);
    usleep(5000);// Delay to make sure the value is reflected in any up-coming read
    portVal = inb(SENSOR_PORT_ADDR);
    if(portVal != portValPrev)
    {
        memset(charBuf, 0, sizeof(charBuf));
        sprintf(charBuf, "PERIPHERAL:JOURNALPRINTER: portVal=%#x, Sensor=%d, Motor=%d\n", portVal, (portVal & 0x04) >> 2, portVal & 0x01);
        debug_log(charBuf, DEBUG_LOG);
        portValPrev = portVal;
    }
    portVal = SENSOR_VALUE(portVal);

    return portVal;
}

void rewindMotorCtrl(uint8_t option)
{
    uint8_t portVal = 0;

    portVal = inb(MOTOR_PORT_ADDR);
    if(option == MOTOR_START)
        portVal |= MOTOR_CTRL_BIT;
    else if(option == MOTOR_STOP)
        portVal &= ~MOTOR_CTRL_BIT;
    outb(portVal, MOTOR_PORT_ADDR);

}


int main(int argc,char *argv[])
{
    int type = atoi(argv[1]);
    unsigned int SensorValue = 0;
    char debugBuf[1024] = {'\0'};

    if (ioperm(PARALLEL_PORT_ADDR, 3, 1))
    {
        perror("ioperm");
        exit(1);
    }

    printf("Type: %d", type);

    rewindMotorCtrl(type);

    SensorValue = readSensorVal();
    if(SensorValue == SENSOR_CLEAR)
    {
        memset(debugBuf,0,sizeof(debugBuf));
        sprintf(debugBuf,"SYSTEM:  Sensor Clear: %d", SensorValue);
        debug_log(debugBuf,TRACE_LOG);
    }
    else
    {
        memset(debugBuf,0,sizeof(debugBuf));
        sprintf(debugBuf,"SYSTEM:  Sensor Block: %d", SensorValue);
        debug_log(debugBuf,TRACE_LOG);
    }

    printf("\n");
    return 0;
}