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

#include "hps_0.h"


// The start address and length of the Lightweight bridge
#define HPS_TO_FPGA_LW_BASE 0xFF200000
#define HPS_TO_FPGA_LW_SPAN 0x0020000



int main(int argc, char **argv)
{

	void * lw_bridge_map = 0;
	int devmem_fd = 0;
	int result = 0;

	// Open up the /dev/mem device (aka, RAM)
	devmem_fd = open("/dev/mem", O_RDWR | O_SYNC);
	if(devmem_fd < 0) {
		perror("devmem open");
		exit(EXIT_FAILURE);
	}

	// mmap() the entire address space of the Lightweight bridge so we can access our custom module 
	lw_bridge_map = (uint32_t*)mmap(NULL, HPS_TO_FPGA_LW_SPAN, PROT_READ|PROT_WRITE, MAP_SHARED, devmem_fd, HPS_TO_FPGA_LW_BASE); 
	if(lw_bridge_map == MAP_FAILED) {
		perror("devmem mmap");
		close(devmem_fd);
		exit(EXIT_FAILURE);
	}

	volatile uint32_t* memory_avalon = (volatile uint32_t*) (lw_bridge_map + MEMORY_AVALON_0_BASE); // MEMORY_AVALON_0_BASE resolves to 0x0

	if(argc >= 3){ 
		// first get the address from the cmd line
		uint32_t addr = atoi(argv[2]);

		// then check if the user wants to read or write to <addr>
		if(strcmp(argv[1], "read") == 0){

			// determine absolute address of selected register
			volatile uint32_t* r = (volatile uint32_t*)  (memory_avalon + addr);

			// read content of selected register
			uint32_t data = *r;

			printf("reg[%x]=0x%08x(%d)\n", addr, data, data);

		}else if(strcmp(argv[1], "write") == 0){
			if(argc >= 4){
				// get data from the cmd line
				uint32_t data = atoi(argv[3]);

				// write data into selected register
				*(memory_avalon + addr) = data; 

				printf("Wrote (%u) @ (%x)\n", data, addr);
			}
		}

	}

	// dump the whole memory (which is 16 x 32 bit)
	// MEMORY_AVALON_0_SPAN resolves to 64
	for(uint32_t i = 0; i < MEMORY_AVALON_0_SPAN >> 2; i++){
		volatile uint32_t* r = (volatile uint32_t*)  (memory_avalon + i);
		uint32_t data = *r;
		printf("memory_avalon[%x]=0x%08x(%d)\n", i, data, data);
	}


	// Unmap everything and close the /dev/mem file descriptor
	result = munmap(lw_bridge_map, HPS_TO_FPGA_LW_SPAN); 
	if(result < 0) {
		perror("devmem munmap");
		close(devmem_fd);
		exit(EXIT_FAILURE);
	}

	close(devmem_fd);
	exit(EXIT_SUCCESS);
}