fomu-flash/fpga.c

#include <stdint.h>
#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <string.h>
#include <stdlib.h>

#include "rpi.h"
#include "fpga.h"

struct ff_fpga {
	struct {
		int reset;
		int done;
		int cs;
	} pins;
};

int fpgaDone(struct ff_fpga *fpga) {
        return gpioRead(fpga->pins.done);
}

int fpgaResetSlave(struct ff_fpga *fpga) {
        // Put the FPGA into reset
        gpioSetMode(fpga->pins.reset, PI_OUTPUT);
        gpioWrite(fpga->pins.reset, 0);

        // Set the CS pin to a GPIO, which will let us control it
        gpioSetMode(fpga->pins.cs, PI_OUTPUT);

        // Set CS to 0, which will put the FPGA into slave mode
        gpioWrite(fpga->pins.cs, 0);

        usleep(10000); // XXX figure out correct sleep length here

        // Bring the FPGA out of reset
        gpioWrite(fpga->pins.reset, 1);

        usleep(1200); // 13.2.SPI Slave Configuration Process

	// Release the CS pin
        gpioWrite(fpga->pins.cs, 1);

	return 0;
}

int fpgaResetMaster(struct ff_fpga *fpga) {

        // Put the FPGA into reset
        gpioSetMode(fpga->pins.reset, PI_OUTPUT);
        gpioWrite(fpga->pins.reset, 0);

        // Set the CS pin to a GPIO, which will let us control it
        gpioSetMode(fpga->pins.cs, PI_OUTPUT);

        // Set CS to 1, which will put the FPGA into "self boot" mode
        gpioWrite(fpga->pins.cs, 1);

        usleep(10000); // XXX figure out correct sleep length here

        // Bring the FPGA out of reset
        gpioWrite(fpga->pins.reset, 1);

        usleep(1200); // 13.2.SPI Slave Configuration Process

	return 0;
}

int fpgaReset(struct ff_fpga *fpga) {
        // Put the FPGA into reset
        gpioSetMode(fpga->pins.reset, PI_OUTPUT);
        gpioWrite(fpga->pins.reset, 0);
	return 0;
}

int fpgaInit(struct ff_fpga *fpga) {
        // Put the FPGA into reset
        gpioSetMode(fpga->pins.reset, PI_OUTPUT);
        gpioWrite(fpga->pins.reset, 0);

        // Also monitor the C_DONE pin
        gpioSetMode(fpga->pins.done, PI_INPUT);

	return 0;
}

struct ff_fpga *fpgaAlloc(void) {
	struct ff_fpga *fpga = (struct ff_fpga *)malloc(sizeof(struct ff_fpga));
	memset(fpga, 0, sizeof(*fpga));
	return fpga;
}

void fpgaSetPin(struct ff_fpga *fpga, enum fpga_pin pin, int val) {
	switch (pin) {
	case FP_RESET: fpga->pins.reset = val; break;
        case FP_DONE: fpga->pins.done = val; break;
        case FP_CS: fpga->pins.cs = val; break;
	default: fprintf(stderr, "unrecognized pin: %d\n", pin); break;
	}
}

void fpgaFree(struct ff_fpga **fpga) {
	if (!fpga)
		return;
	if (!*fpga)
		return;

	free(*fpga);
	*fpga = NULL;
}