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fomu-flash/fpga.c

113 lines
2.6 KiB

#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;
}