Memory mapped IO - RPI2

Question

I am trying to write a simple led blink program using mmap io. I know my circuit is working(i have already tried it with sysfs approach). Now I am trying to do it with mmap io and I am totally stacked and I can not find where am I doing wrong. If someone can help me, I would be appreciated.

Btw I am using Rpi 2 model B v1.1

Here is my code,

#include <stdio.h>      // perror
#include <sys/mman.h>   // mmap
#include <sys/types.h>  // fd open
#include <sys/stat.h>   // fd open
#include <fcntl.h>      // fd open
#include <unistd.h>     // fd close

#define BCM2708_PERI_BASE       0x20000000
#define GPIO_BASE               (BCM2708_PERI_BASE + 0x200000)   // GPIO controller

#define BLOCK_SIZE              (4 * 1024)

// GPIO setup macros. Always use INP_GPIO(x) before using OUT_GPIO(x)
#define INP_GPIO(g)         *(gpio.addr + ((g) / 10)) &= ~(7 << (((g) % 10) * 3))
#define OUT_GPIO(g)         *(gpio.addr + ((g) / 10)) |=  (1 << (((g) % 10) * 3))
#define SET_GPIO_ALT(g, a)  *(gpio.addr + (((g) / 10))) |= (((a) <= 3 ? (a) + 4 : (a) == 4 ? 3 : 2) << (((g) % 10) * 3))

#define GPIO_SET            *(gpio.addr + 7)  // sets   bits which are 1 ignores bits which are 0
#define GPIO_CLR            *(gpio.addr + 10) // clears bits which are 1 ignores bits which are 0

#define GPIO_READ(g)        *(gpio.addr + 13) &= (1 << (g))

struct bcm2835_peripheral {
    unsigned long addr_p;
    int mem_fd;
    void *map;
    volatile unsigned int *addr;
};

struct bcm2835_peripheral gpio = { GPIO_BASE };

// Exposes the physical address defined in the passed structure using mmap on /dev/mem
int map_peripheral(struct bcm2835_peripheral *p)
{
    // Open /dev/mem
    if ((p->mem_fd = open("/dev/mem", O_RDWR | O_SYNC) ) < 0) {
        fprintf(stderr, "Failed to open /dev/mem, try checking permissions.");
        return -1;
    }

    p->map = mmap(
                NULL,
                BLOCK_SIZE,
                PROT_READ | PROT_WRITE,
                MAP_SHARED,
                p->mem_fd,      // File descriptor to physical memory virtual file '/dev/mem'
                p->addr_p       // Address in physical map that we want this memory block to expose
                );

    if (p->map == MAP_FAILED) {
        perror("mmap");
        return -1;
    }

    p->addr = (volatile unsigned int *)p->map;

    return 0;
}

void unmap_peripheral(struct bcm2835_peripheral *p)
{

    munmap(p->map, BLOCK_SIZE);
    close(p->mem_fd);
}

int main()
{
    if(map_peripheral(&gpio) == -1) {
        fprintf(stderr, "Failed to map the physical GPIO registers into the virtual memory space.\n");
        return -1;
    }

    // Define pin 7 as output
    INP_GPIO(4);
    OUT_GPIO(4);

    while(1) {
        // Toggle pin 7 (blink a led!)
        GPIO_SET = 1 << 4;
        sleep(1);

        GPIO_CLR = 1 << 4;
        sleep(1);
    }

    return 0;
}

Answer 1

I answer my own question; well actually I was doing a silly mistake on the base address of peripherals. I was using rpi1's peri base addr.. peri base addr for rpi2 is 0x3F000000 and for GPIO 0x3F200000