+++ /dev/null
-/***************************************************************************
- * Copyright (C) 2013 Paul Fertser <fercerpav@gmail.com> *
- * Copyright (C) 2012 by Creative Product Design, marc @ cpdesign.com.au *
- * *
- * This program is free software; you can redistribute it and/or modify *
- * it under the terms of the GNU General Public License as published by *
- * the Free Software Foundation; either version 2 of the License, or *
- * (at your option) any later version. *
- * *
- * This program is distributed in the hope that it will be useful, *
- * but WITHOUT ANY WARRANTY; without even the implied warranty of *
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
- * GNU General Public License for more details. *
- * *
- * You should have received a copy of the GNU General Public License *
- * along with this program; if not, write to the *
- * Free Software Foundation, Inc., *
- * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. *
- ***************************************************************************/
-
-/*
- This is a test application to be used as a remote bitbang server for
- the OpenOCD remote_bitbang interface driver.
-
- To compile run:
- gcc -Wall -ansi -pedantic -std=c99 -o remote_bitbang_sysfsgpio remote_bitbang_sysfsgpio.c
-
-
- Usage example:
-
- On Raspberry Pi run:
- socat TCP6-LISTEN:7777,fork EXEC:"sudo ./remote_bitbang_sysfsgpio tck 11 tms 25 tdo 9 tdi 10"
-
- On host run:
- openocd -c "interface remote_bitbang; remote_bitbang_host raspberrypi; remote_bitbang_port 7777" \
- -f target/stm32f1x.cfg
-
- Or if you want to test UNIX sockets, run both on Raspberry Pi:
- socat UNIX-LISTEN:/tmp/remotebitbang-socket,fork EXEC:"sudo ./remote_bitbang_sysfsgpio tck 11 tms 25 tdo 9 tdi 10"
- openocd -c "interface remote_bitbang; remote_bitbang_host /tmp/remotebitbang-socket" -f target/stm32f1x.cfg
-*/
-
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <fcntl.h>
-#include <unistd.h>
-#include <stdlib.h>
-#include <stdio.h>
-#include <string.h>
-#include <errno.h>
-
-#define LOG_ERROR(...) do { \
- fprintf(stderr, __VA_ARGS__); \
- fputc('\n', stderr); \
- } while (0)
-#define LOG_WARNING(...) LOG_ERROR(__VA_ARGS__)
-
-#define ERROR_OK (-1)
-#define ERROR_FAIL (-2)
-#define ERROR_JTAG_INIT_FAILED ERROR_FAIL
-
-/*
- * Helper func to determine if gpio number valid
- *
- * Assume here that there will be less than 1000 gpios on a system
- */
-static int is_gpio_valid(int gpio)
-{
- return gpio >= 0 && gpio < 1000;
-}
-
-/*
- * Helper func to open, write to and close a file
- * name and valstr must be null terminated.
- *
- * Returns negative on failure.
- */
-static int open_write_close(const char *name, const char *valstr)
-{
- int ret;
- int fd = open(name, O_WRONLY);
- if (fd < 0)
- return fd;
-
- ret = write(fd, valstr, strlen(valstr));
- close(fd);
-
- return ret;
-}
-
-/*
- * Helper func to unexport gpio from sysfs
- */
-static void unexport_sysfs_gpio(int gpio)
-{
- char gpiostr[4];
-
- if (!is_gpio_valid(gpio))
- return;
-
- snprintf(gpiostr, sizeof(gpiostr), "%d", gpio);
- if (open_write_close("/sys/class/gpio/unexport", gpiostr) < 0)
- LOG_ERROR("Couldn't unexport gpio %d", gpio);
-
- return;
-}
-
-/*
- * Exports and sets up direction for gpio.
- * If the gpio is an output, it is initialized according to init_high,
- * otherwise it is ignored.
- *
- * If the gpio is already exported we just show a warning and continue; if
- * openocd happened to crash (or was killed by user) then the gpios will not
- * have been cleaned up.
- */
-static int setup_sysfs_gpio(int gpio, int is_output, int init_high)
-{
- char buf[40];
- char gpiostr[4];
- int ret;
-
- if (!is_gpio_valid(gpio))
- return ERROR_OK;
-
- snprintf(gpiostr, sizeof(gpiostr), "%d", gpio);
- ret = open_write_close("/sys/class/gpio/export", gpiostr);
- if (ret < 0) {
- if (errno == EBUSY) {
- LOG_WARNING("gpio %d is already exported", gpio);
- } else {
- LOG_ERROR("Couldn't export gpio %d", gpio);
- perror("sysfsgpio: ");
- return ERROR_FAIL;
- }
- }
-
- snprintf(buf, sizeof(buf), "/sys/class/gpio/gpio%d/direction", gpio);
- ret = open_write_close(buf, is_output ? (init_high ? "high" : "low") : "in");
- if (ret < 0) {
- LOG_ERROR("Couldn't set direction for gpio %d", gpio);
- perror("sysfsgpio: ");
- unexport_sysfs_gpio(gpio);
- return ERROR_FAIL;
- }
-
- snprintf(buf, sizeof(buf), "/sys/class/gpio/gpio%d/value", gpio);
- if (is_output)
- ret = open(buf, O_WRONLY | O_NONBLOCK | O_SYNC);
- else
- ret = open(buf, O_RDONLY | O_NONBLOCK | O_SYNC);
-
- if (ret < 0)
- unexport_sysfs_gpio(gpio);
-
- return ret;
-}
-
-/*
- * file descriptors for /sys/class/gpio/gpioXX/value
- * Set up during init.
- */
-static int tck_fd = -1;
-static int tms_fd = -1;
-static int tdi_fd = -1;
-static int tdo_fd = -1;
-static int trst_fd = -1;
-static int srst_fd = -1;
-
-/*
- * Bitbang interface read of TDO
- *
- * The sysfs value will read back either '0' or '1'. The trick here is to call
- * lseek to bypass buffering in the sysfs kernel driver.
- */
-static int sysfsgpio_read(void)
-{
- char buf[1];
-
- /* important to seek to signal sysfs of new read */
- lseek(tdo_fd, 0, SEEK_SET);
- int ret = read(tdo_fd, &buf, sizeof(buf));
-
- if (ret < 0) {
- LOG_WARNING("reading tdo failed");
- return 0;
- }
-
- return buf[0];
-}
-
-/*
- * Bitbang interface write of TCK, TMS, TDI
- *
- * Seeing as this is the only function where the outputs are changed,
- * we can cache the old value to avoid needlessly writing it.
- */
-static void sysfsgpio_write(int tck, int tms, int tdi)
-{
- const char one[] = "1";
- const char zero[] = "0";
-
- static int last_tck;
- static int last_tms;
- static int last_tdi;
-
- static int first_time;
- size_t bytes_written;
-
- if (!first_time) {
- last_tck = !tck;
- last_tms = !tms;
- last_tdi = !tdi;
- first_time = 1;
- }
-
- if (tdi != last_tdi) {
- bytes_written = write(tdi_fd, tdi ? &one : &zero, 1);
- if (bytes_written != 1)
- LOG_WARNING("writing tdi failed");
- }
-
- if (tms != last_tms) {
- bytes_written = write(tms_fd, tms ? &one : &zero, 1);
- if (bytes_written != 1)
- LOG_WARNING("writing tms failed");
- }
-
- /* write clk last */
- if (tck != last_tck) {
- bytes_written = write(tck_fd, tck ? &one : &zero, 1);
- if (bytes_written != 1)
- LOG_WARNING("writing tck failed");
- }
-
- last_tdi = tdi;
- last_tms = tms;
- last_tck = tck;
-}
-
-/*
- * Bitbang interface to manipulate reset lines SRST and TRST
- *
- * (1) assert or (0) deassert reset lines
- */
-static void sysfsgpio_reset(int trst, int srst)
-{
- const char one[] = "1";
- const char zero[] = "0";
- size_t bytes_written;
-
- /* assume active low */
- if (srst_fd >= 0) {
- bytes_written = write(srst_fd, srst ? &zero : &one, 1);
- if (bytes_written != 1)
- LOG_WARNING("writing srst failed");
- }
-
- /* assume active low */
- if (trst_fd >= 0) {
- bytes_written = write(trst_fd, trst ? &zero : &one, 1);
- if (bytes_written != 1)
- LOG_WARNING("writing trst failed");
- }
-}
-
-/* gpio numbers for each gpio. Negative values are invalid */
-static int tck_gpio = -1;
-static int tms_gpio = -1;
-static int tdi_gpio = -1;
-static int tdo_gpio = -1;
-static int trst_gpio = -1;
-static int srst_gpio = -1;
-
-/* helper func to close and cleanup files only if they were valid/ used */
-static void cleanup_fd(int fd, int gpio)
-{
- if (gpio >= 0) {
- if (fd >= 0)
- close(fd);
-
- unexport_sysfs_gpio(gpio);
- }
-}
-
-static void cleanup_all_fds(void)
-{
- cleanup_fd(tck_fd, tck_gpio);
- cleanup_fd(tms_fd, tms_gpio);
- cleanup_fd(tdi_fd, tdi_gpio);
- cleanup_fd(tdo_fd, tdo_gpio);
- cleanup_fd(trst_fd, trst_gpio);
- cleanup_fd(srst_fd, srst_gpio);
-}
-
-static void process_remote_protocol(void)
-{
- int c;
- while (1) {
- c = getchar();
- if (c == EOF || c == 'Q') /* Quit */
- break;
- else if (c == 'b' || c == 'B') /* Blink */
- continue;
- else if (c >= 'r' && c <= 'r' + 2) { /* Reset */
- char d = c - 'r';
- sysfsgpio_reset(!!(d & 2),
- (d & 1));
- } else if (c >= '0' && c <= '0' + 7) {/* Write */
- char d = c - '0';
- sysfsgpio_write(!!(d & 4),
- !!(d & 2),
- (d & 1));
- } else if (c == 'R')
- putchar(sysfsgpio_read());
- else
- LOG_ERROR("Unknown command '%c' received", c);
- }
-}
-
-int main(int argc, char *argv[])
-{
- LOG_WARNING("SysfsGPIO remote_bitbang JTAG driver\n");
-
- for (int i = 1; i < argc; i++) {
- if (!strcmp(argv[i], "tck"))
- tck_gpio = atoi(argv[++i]);
- else if (!strcmp(argv[i], "tms"))
- tms_gpio = atoi(argv[++i]);
- else if (!strcmp(argv[i], "tdo"))
- tdo_gpio = atoi(argv[++i]);
- else if (!strcmp(argv[i], "tdi"))
- tdi_gpio = atoi(argv[++i]);
- else if (!strcmp(argv[i], "trst"))
- trst_gpio = atoi(argv[++i]);
- else if (!strcmp(argv[i], "srst"))
- srst_gpio = atoi(argv[++i]);
- else {
- LOG_ERROR("Usage:\n%s ((tck|tms|tdo|tdi|trst|srst) num)*", argv[0]);
- return -1;
- }
- }
-
- if (!(is_gpio_valid(tck_gpio)
- && is_gpio_valid(tms_gpio)
- && is_gpio_valid(tdi_gpio)
- && is_gpio_valid(tdo_gpio))) {
- if (!is_gpio_valid(tck_gpio))
- LOG_ERROR("gpio num for tck is invalid");
- if (!is_gpio_valid(tms_gpio))
- LOG_ERROR("gpio num for tms is invalid");
- if (!is_gpio_valid(tdo_gpio))
- LOG_ERROR("gpio num for tdo is invalid");
- if (!is_gpio_valid(tdi_gpio))
- LOG_ERROR("gpio num for tdi is invalid");
-
- LOG_ERROR("Require tck, tms, tdi and tdo gpios to all be specified");
- return ERROR_JTAG_INIT_FAILED;
- }
-
- /*
- * Configure TDO as an input, and TDI, TCK, TMS, TRST, SRST
- * as outputs. Drive TDI and TCK low, and TMS/TRST/SRST high.
- */
- tck_fd = setup_sysfs_gpio(tck_gpio, 1, 0);
- if (tck_fd < 0)
- goto out_error;
-
- tms_fd = setup_sysfs_gpio(tms_gpio, 1, 1);
- if (tms_fd < 0)
- goto out_error;
-
- tdi_fd = setup_sysfs_gpio(tdi_gpio, 1, 0);
- if (tdi_fd < 0)
- goto out_error;
-
- tdo_fd = setup_sysfs_gpio(tdo_gpio, 0, 0);
- if (tdo_fd < 0)
- goto out_error;
-
- /* assume active low */
- if (trst_gpio > 0) {
- trst_fd = setup_sysfs_gpio(trst_gpio, 1, 1);
- if (trst_fd < 0)
- goto out_error;
- }
-
- /* assume active low */
- if (srst_gpio > 0) {
- srst_fd = setup_sysfs_gpio(srst_gpio, 1, 1);
- if (srst_fd < 0)
- goto out_error;
- }
-
- LOG_WARNING("SysfsGPIO nums: tck = %d, tms = %d, tdi = %d, tdo = %d",
- tck_gpio, tms_gpio, tdi_gpio, tdo_gpio);
- LOG_WARNING("SysfsGPIO num: srst = %d", srst_gpio);
- LOG_WARNING("SysfsGPIO num: trst = %d", trst_gpio);
-
- setvbuf(stdout, NULL, _IONBF, 0);
- process_remote_protocol();
-
- cleanup_all_fds();
- return 0;
-out_error:
- cleanup_all_fds();
- return ERROR_JTAG_INIT_FAILED;
-}