openocd/src/jtag/drivers/remote_bitbang.c

/***************************************************************************
 *   Copyright (C) 2011 by Richard Uhler                                   *
 *   ruhler@mit.edu                                                        *
 *                                                                         *
 *   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.,                                       *
 *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
 ***************************************************************************/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <sys/socket.h>
#include <sys/un.h>
#include <netdb.h>
#include <jtag/interface.h>
#include "bitbang.h"

// from unix man page and sys/un.h:
#define UNIX_PATH_MAX 108

// arbitrary limit on host name length:
#define REMOTE_BITBANG_HOST_MAX 255

#define REMOTE_BITBANG_RAISE_ERROR(expr ...) \
		LOG_ERROR(expr); LOG_ERROR("Terminating openocd."); exit(-1);

static char remote_bitbang_host[REMOTE_BITBANG_HOST_MAX] = "openocd";
static uint16_t remote_bitbang_port = 0;

FILE* remote_bitbang_in;
FILE* remote_bitbang_out;

static void remote_bitbang_putc(int c)
{
	if (EOF == fputc(c, remote_bitbang_out)) {
		REMOTE_BITBANG_RAISE_ERROR("remote_bitbang_putc: %s", strerror(errno));
	}
}

static int remote_bitbang_quit(void)
{
	if (EOF == fputc('Q', remote_bitbang_out)) {
		LOG_ERROR("fputs: %s", strerror(errno));
		return ERROR_FAIL;
	}

	if (EOF == fflush(remote_bitbang_out)) {
		LOG_ERROR("fflush: %s", strerror(errno));
		return ERROR_FAIL;
	}
		
	// We only need to close one of the FILE*s, because they both use the same
	// underlying file descriptor.
	if (EOF == fclose(remote_bitbang_out)) {
		LOG_ERROR("fclose: %s", strerror(errno));
		return ERROR_FAIL;
	}

	LOG_INFO("remote_bitbang interface quit");
	return ERROR_OK;
}

// Get the next read response.
static int remote_bitbang_rread(void)
{
	if (EOF == fflush(remote_bitbang_out)) {
		remote_bitbang_quit();
		REMOTE_BITBANG_RAISE_ERROR("fflush: %s", strerror(errno));
	}

	int c = fgetc(remote_bitbang_in);
	switch (c) {
		case '0': return 0;
		case '1': return 1;
		default:
			remote_bitbang_quit();
			REMOTE_BITBANG_RAISE_ERROR(
				"remote_bitbang: invalid read response: %c(%i)", c, c);
	}
}

static int remote_bitbang_read(void)
{
	remote_bitbang_putc('R');
	return remote_bitbang_rread();
}

static void remote_bitbang_write(int tck, int tms, int tdi)
{
	char c = '0' + ((tck ? 0x4 : 0x0) | (tms ? 0x2 : 0x0) | (tdi ? 0x1 : 0x0));
	remote_bitbang_putc(c);
}

static void remote_bitbang_reset(int trst, int srst)
{
	char c = 'r' + ((trst ? 0x2 : 0x0) | (srst ? 0x1 : 0x0));
	remote_bitbang_putc(c);
}

static void remote_bitbang_blink(int on)
{
	char c = on ? 'B' : 'b';
	remote_bitbang_putc(c);
}

static struct bitbang_interface remote_bitbang_bitbang = {
	.read = &remote_bitbang_read,
	.write = &remote_bitbang_write,
	.reset = &remote_bitbang_reset,
	.blink = &remote_bitbang_blink,
};

static int remote_bitbang_speed(int speed)
{
	return ERROR_OK;
}

static int remote_bitbang_init_tcp(void)
{
	LOG_INFO("Connecting to %s:%i", remote_bitbang_host, remote_bitbang_port);
	int fd = socket(PF_INET, SOCK_STREAM, 0);
	if (fd < 0) {
		LOG_ERROR("socket: %s", strerror(errno));
		return ERROR_FAIL;
	}

	struct hostent* hent = gethostbyname(remote_bitbang_host);
	if (hent == NULL) {
		char* errorstr = "???";
		switch (h_errno) {
			case HOST_NOT_FOUND: errorstr = "host not found"; break;
			case NO_ADDRESS: errorstr = "no address"; break;
			case NO_RECOVERY: errorstr = "no recovery"; break;
			case TRY_AGAIN: errorstr = "try again"; break;
		}
		LOG_ERROR("gethostbyname: %s", errorstr);
		return ERROR_FAIL;
	}

	struct sockaddr_in addr;
	addr.sin_family = AF_INET;
	addr.sin_port = htons(remote_bitbang_port);
	addr.sin_addr = *(struct in_addr*)hent->h_addr;
	if (connect(fd, (struct sockaddr*)&addr, sizeof(struct sockaddr_in)) < 0) {
		LOG_ERROR("connect: %s", strerror(errno));
		return ERROR_FAIL;
	}

	remote_bitbang_in = fdopen(fd, "r");
	if (remote_bitbang_in == NULL) {
		LOG_ERROR("fdopen: failed to open read stream");
		return ERROR_FAIL;
	}

	remote_bitbang_out = fdopen(fd, "w");
	if (remote_bitbang_out == NULL) {
		LOG_ERROR("fdopen: failed to open write stream");
		return ERROR_FAIL;
	}

	LOG_INFO("remote_bitbang driver initialized");
	return ERROR_OK;
}

static int remote_bitbang_init_unix(void)
{
	LOG_INFO("Connecting to unix socket %s", remote_bitbang_host);
	int fd = socket(PF_UNIX, SOCK_STREAM, 0);
	if (fd < 0) {
		LOG_ERROR("socket: %s", strerror(errno));
		return ERROR_FAIL;
	}

	struct sockaddr_un addr;
	addr.sun_family = AF_UNIX;
	strncpy(addr.sun_path, remote_bitbang_host, UNIX_PATH_MAX);
	addr.sun_path[UNIX_PATH_MAX-1] = '\0';

	if (connect(fd, (struct sockaddr*)&addr, sizeof(struct sockaddr_un)) < 0) {
		LOG_ERROR("connect: %s", strerror(errno));
		return ERROR_FAIL;
	}

	remote_bitbang_in = fdopen(fd, "r");
	if (remote_bitbang_in == NULL) {
		LOG_ERROR("fdopen: failed to open read stream");
		return ERROR_FAIL;
	}

	remote_bitbang_out = fdopen(fd, "w");
	if (remote_bitbang_out == NULL) {
		LOG_ERROR("fdopen: failed to open write stream");
		return ERROR_FAIL;
	}

	LOG_INFO("remote_bitbang driver initialized");
	return ERROR_OK;
}

static int remote_bitbang_init(void)
{
	bitbang_interface = &remote_bitbang_bitbang;

	LOG_INFO("Initializing remote_bitbang driver");
	if (remote_bitbang_port == 0) {
		return remote_bitbang_init_unix();
	}
	return remote_bitbang_init_tcp();
}

static int remote_bitbang_khz(int khz, int* jtag_speed)
{
	*jtag_speed = 0;
	return ERROR_OK;
}

static int remote_bitbang_speed_div(int speed, int* khz)
{
	// I don't think this really matters any.
	*khz = 1;
	return ERROR_OK;
}


COMMAND_HANDLER(remote_bitbang_handle_remote_bitbang_port_command)
{
	if (CMD_ARGC == 1) {
		COMMAND_PARSE_NUMBER(u16, CMD_ARGV[0], remote_bitbang_port);
		return ERROR_OK;
	}
	return ERROR_COMMAND_SYNTAX_ERROR;
}

COMMAND_HANDLER(remote_bitbang_handle_remote_bitbang_host_command)
{
	if (CMD_ARGC == 1) {
		strncpy(remote_bitbang_host, CMD_ARGV[0], REMOTE_BITBANG_HOST_MAX);
		remote_bitbang_host[REMOTE_BITBANG_HOST_MAX-1] = '\0';
		return ERROR_OK;
	}
	return ERROR_COMMAND_SYNTAX_ERROR;
}


static const struct command_registration remote_bitbang_command_handlers[] = {
	{
		.name = "remote_bitbang_port",
		.handler = remote_bitbang_handle_remote_bitbang_port_command,
		.mode = COMMAND_CONFIG,
		.help = "Set the port to use to connect to the remote jtag.\n"
			"  if 0, use unix sockets to connect to the remote jtag.",
		.usage = "port_number",
	},
	{
		.name = "remote_bitbang_host",
		.handler = remote_bitbang_handle_remote_bitbang_host_command,
		.mode = COMMAND_CONFIG,
		.help = "Set the host to use to connect to the remote jtag.\n"
			"  if port is 0, this is the name of the unix socket to use.",
		.usage = "host_name",
	},
	COMMAND_REGISTRATION_DONE,
};

struct jtag_interface remote_bitbang_interface = {
	.name = "remote_bitbang",
	.execute_queue = &bitbang_execute_queue,
	.speed = &remote_bitbang_speed,
	.commands = remote_bitbang_command_handlers,
	.init = &remote_bitbang_init,
	.quit = &remote_bitbang_quit,
	.khz = &remote_bitbang_khz,
	.speed_div = &remote_bitbang_speed_div,
};