Get sunxi VE version

ve-version.c

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

#define IOCTL_GET_ENV_INFO	0x101
#define IOCTL_ENGINE_REQ	0x206
#define IOCTL_ENGINE_REL	0x207

#define REG_VE_VERSION		0x0f0

struct ve_info
{
	uint32_t reserved_mem;
	int reserved_mem_size;
	uint32_t registers;
};

static inline uint32_t readl(void *addr)
{
	return *((volatile uint32_t *) addr);
}

int main(void)
{
	int fd;
	struct ve_info info;
	void *regs;

	fd = open("/dev/cedar_dev", O_RDWR);
	if (fd == -1)
	{
		fprintf(stderr, "Could not open /dev/cedar_dev: %s\n", strerror(errno));
		return 1;
	}

	if (ioctl(fd, IOCTL_GET_ENV_INFO, (void *)(&info)) == -1)
	{
		fprintf(stderr, "Could not get env_info: %s\n", strerror(errno));
		close(fd);
		return 1;
	}

	regs = mmap(NULL, 0x800, PROT_READ | PROT_WRITE, MAP_SHARED, fd, info.registers);
	if (regs == MAP_FAILED)
	{
		fprintf(stderr, "Could not mmap register space: %s\n", strerror(errno));
		close(fd);
		return 1;
	}

	ioctl(fd, IOCTL_ENGINE_REQ, 0);

	printf("VE Version: 0x%08x\n", readl(regs + REG_VE_VERSION));

	ioctl(fd, IOCTL_ENGINE_REL, 0);

	munmap(regs, 0x800);
	close(fd);

	return 0;
}