// lab5_starter.c
// Notes for Fur Elise, E155 Lab 5

// Pitch in Hz, duration in ms
const int notes[][2] = {
{659,	125},
{623,	125},
{659,	125},
{623,	125},
{659,	125},
{494,	125},
{587,	125},
{523,	125},
{440,	250},
{0,	125},
{262,	125},
{330,	125},
{440,	125},
{494,	250},
{0,	125},
{330,	125},
{416,	125},
{494,	125},
{523,	250},
{0,	125},
{330,	125},
{659,	125},
{623,	125},
{659,	125},
{623,	125},
{659,	125},
{494,	125},
{587,	125},
{523,	125},
{440,	250},
{0,	125},
{262,	125},
{330,	125},
{440,	125},
{494,	250},
{0,	125},
{330,	125},
{523,	125},
{494,	125},
{440,	250},
{0,	125},
{494,	125},
{523,	125},
{587,	125},
{659,	375},
{392,	125},
{699,	125},
{659,	125},
{587,	375},
{349,	125},
{659,	125},
{587,	125},
{523,	375},
{330,	125},
{587,	125},
{523,	125},
{494,	250},
{0,	125},
{330,	125},
{659,	125},
{0,	250},
{659,	125},
{1319,	125},
{0,	250},
{623,	125},
{659,	125},
{0,	250},
{623,	125},
{659,	125},
{623,	125},
{659,	125},
{623,	125},
{659,	125},
{494,	125},
{587,	125},
{523,	125},
{440,	250},
{0,	125},
{262,	125},
{330,	125},
{440,	125},
{494,	250},
{0,	125},
{330,	125},
{416,	125},
{494,	125},
{523,	250},
{0,	125},
{330,	125},
{659,	125},
{623,	125},
{659,	125},
{623,	125},
{659,	125},
{494,	125},
{587,	125},
{523,	125},
{440,	250},
{0,	125},
{262,	125},
{330,	125},
{440,	125},
{494,	250},
{0,	125},
{330,	125},
{523,	125},
{494,	125},
{440,	500},
{0,	0}};

#include <sys/mman.h>
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>

/////////////////////////////////////////////////////////////////////
// Constants
/////////////////////////////////////////////////////////////////////

// GPIO FSEL Types
#define INPUT  0
#define OUTPUT 1
#define ALT0   4
#define ALT1   5
#define ALT2   6
#define ALT3   7
#define ALT4   3
#define ALT5   2

#define GPFSEL   ((volatile unsigned int *) (gpio + 0))
#define GPSET    ((volatile unsigned int *) (gpio + 7))
#define GPCLR    ((volatile unsigned int *) (gpio + 10))
#define GPLEV    ((volatile unsigned int *) (gpio + 13))
#define INPUT  0
#define OUTPUT 1

// Physical addresses
#define BCM2836_PERI_BASE        0x3F000000
#define GPIO_BASE               (BCM2836_PERI_BASE + 0x200000)
#define BLOCK_SIZE (4*1024)

// Pointers that will be memory mapped when pioInit() is called
volatile unsigned int *gpio; //pointer to base of gpio

void pioInit() {
	int  mem_fd;
	void *reg_map;

	// /dev/mem is a psuedo-driver for accessing memory in the Linux filesystem
	if ((mem_fd = open("/dev/mem", O_RDWR|O_SYNC) ) < 0) {
	      printf("can't open /dev/mem \n");
	      exit(-1);
	}

	reg_map = mmap(
	  NULL,             //Address at which to start local mapping (null means don't-care)
      BLOCK_SIZE,       //Size of mapped memory block
      PROT_READ|PROT_WRITE,// Enable both reading and writing to the mapped memory
      MAP_SHARED,       // This program does not have exclusive access to this memory
      mem_fd,           // Map to /dev/mem
      GPIO_BASE);       // Offset to GPIO peripheral

	if (reg_map == MAP_FAILED) {
      printf("gpio mmap error %d\n", (int)reg_map);
      close(mem_fd);
      exit(-1);
    }

	gpio = (volatile unsigned *)reg_map;
}