#include <stdlib.h>
#include <stdio.h>
#include <hw/inout.h>
#include <sys/mman.h>
#include <sys/neutrino.h>
#include <stdint.h>

#define AM335X_GPIO_SIZE                0x00001000
#define AM335X_GPIO1_BASE                0x4804C000
#define GPIO_DATAOUT                         0x13C
#define GPIO_OE                                        0x134

#define LED0                (1<<21)
#define LED1                (1<<22)
#define LED2                (1<<23)
#define LED3                (1<<24)
#define LEDS(n)                ((n&0xf)<<21)

int main(int argc, char *argv[])
{
        int i = 0;
        uintptr_t        gpio_base;
        uint32_t        val;
        ThreadCtl (_NTO_TCTL_IO,NULL);

    // Map device registers
    gpio_base = mmap_device_io(AM335X_GPIO_SIZE, AM335X_GPIO1_BASE);
    if(gpio_base == MAP_DEVICE_FAILED)
    {
        perror("Can't map device I/O");
        return 0;
    }

    // Read GPIO output enable register
    //  0 The corresponding GPIO port is configured as an output.
    //  1 The corresponding GPIO port is configured as an input.
    val  = in32(gpio_base + GPIO_OE);
    val &= ~(LED0|LED1|LED2|LED3);
    out32(gpio_base + GPIO_OE, val);

        while(i<16)
        {
                printf("i = %i\n", i);
                // Write GPIO data output register
                val  = in32(gpio_base + GPIO_DATAOUT);
                val &= ~(LED0|LED1|LED2|LED3);
                val |= (LEDS(i++));
                out32(gpio_base + GPIO_DATAOUT, val);
                sleep(5);
        }

    munmap_device_io(gpio_base, AM335X_GPIO_SIZE);

    return 1;
}