src/jtag/drivers/remote_bitbang.c

   1 /***************************************************************************
   2  *   Copyright (C) 2011 by Richard Uhler                                   *
   3  *   ruhler@mit.edu                                                        *
   4  *                                                                         *
   5  *   This program is free software; you can redistribute it and/or modify  *
   6  *   it under the terms of the GNU General Public License as published by  *
   7  *   the Free Software Foundation; either version 2 of the License, or     *
   8  *   (at your option) any later version.                                   *
   9  *                                                                         *
  10  *   This program is distributed in the hope that it will be useful,       *
  11  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  13  *   GNU General Public License for more details.                          *
  14  *                                                                         *
  15  *   You should have received a copy of the GNU General Public License     *
  16  *   along with this program.  If not, see <http://www.gnu.org/licenses/>. *
  17  ***************************************************************************/
  18
  19 #ifdef HAVE_CONFIG_H
  20 #include "config.h"
  21 #endif
  22
  23 #ifndef _WIN32
  24 #include <sys/un.h>
  25 #include <netdb.h>
  26 #endif
  27 #include <jtag/interface.h>
  28 #include "bitbang.h"
  29
  30 /* arbitrary limit on host name length: */
  31 #define REMOTE_BITBANG_HOST_MAX 255
  32
  33 static char *remote_bitbang_host;
  34 static char *remote_bitbang_port;
  35
  36 static int remote_bitbang_fd;
  37
  38 /* Circular buffer. When start == end, the buffer is empty. */
  39 static char remote_bitbang_buf[64];
  40 static unsigned remote_bitbang_start;
  41 static unsigned remote_bitbang_end;
  42
  43 static int remote_bitbang_buf_full(void)
  44 {
  45         return remote_bitbang_end ==
  46                 ((remote_bitbang_start + sizeof(remote_bitbang_buf) - 1) %
  47                  sizeof(remote_bitbang_buf));
  48 }
  49
  50 /* Read any incoming data, placing it into the buffer. */
  51 static int remote_bitbang_fill_buf(void)
  52 {
  53         socket_nonblock(remote_bitbang_fd);
  54         while (!remote_bitbang_buf_full()) {
  55                 unsigned contiguous_available_space;
  56                 if (remote_bitbang_end >= remote_bitbang_start) {
  57                         contiguous_available_space = sizeof(remote_bitbang_buf) -
  58                                 remote_bitbang_end;
  59                         if (remote_bitbang_start == 0)
  60                                 contiguous_available_space -= 1;
  61                 } else {
  62                         contiguous_available_space = remote_bitbang_start -
  63                                 remote_bitbang_end - 1;
  64                 }
  65                 ssize_t count = read_socket(remote_bitbang_fd,
  66                                 remote_bitbang_buf + remote_bitbang_end,
  67                                 contiguous_available_space);
  68                 if (count > 0) {
  69                         remote_bitbang_end += count;
  70                         if (remote_bitbang_end == sizeof(remote_bitbang_buf))
  71                                 remote_bitbang_end = 0;
  72                 } else if (count == 0) {
  73                         return ERROR_OK;
  74                 } else if (count < 0) {
  75 #ifdef _WIN32
  76                         if (WSAGetLastError() == WSAEWOULDBLOCK) {
  77 #else
  78                         if (errno == EAGAIN) {
  79 #endif
  80                                 return ERROR_OK;
  81                         } else {
  82                                 log_socket_error("remote_bitbang_fill_buf");
  83                                 return ERROR_FAIL;
  84                         }
  85                 }
  86         }
  87
  88         return ERROR_OK;
  89 }
  90
  91 static int remote_bitbang_putc(int c)
  92 {
  93         char buf = c;
  94         ssize_t count = write_socket(remote_bitbang_fd, &buf, sizeof(buf));
  95         if (count < 0) {
  96                 log_socket_error("remote_bitbang_putc");
  97                 return ERROR_FAIL;
  98         }
  99         return ERROR_OK;
 100 }
 101
 102 static int remote_bitbang_quit(void)
 103 {
 104         if (remote_bitbang_putc('Q') == ERROR_FAIL)
 105                 return ERROR_FAIL;
 106
 107         if (close_socket(remote_bitbang_fd) != 0) {
 108                 log_socket_error("close_socket");
 109                 return ERROR_FAIL;
 110         }
 111
 112         free(remote_bitbang_host);
 113         free(remote_bitbang_port);
 114
 115         LOG_INFO("remote_bitbang interface quit");
 116         return ERROR_OK;
 117 }
 118
 119 static bb_value_t char_to_int(int c)
 120 {
 121         switch (c) {
 122                 case '0':
 123                         return BB_LOW;
 124                 case '1':
 125                         return BB_HIGH;
 126                 default:
 127                         remote_bitbang_quit();
 128                         LOG_ERROR("remote_bitbang: invalid read response: %c(%i)", c, c);
 129                         return BB_ERROR;
 130         }
 131 }
 132
 133 /* Get the next read response. */
 134 static bb_value_t remote_bitbang_rread(void)
 135 {
 136         /* Enable blocking access. */
 137         socket_block(remote_bitbang_fd);
 138         char c;
 139         ssize_t count = read_socket(remote_bitbang_fd, &c, 1);
 140         if (count == 1) {
 141                 return char_to_int(c);
 142         } else {
 143                 remote_bitbang_quit();
 144                 LOG_ERROR("read_socket: count=%d", (int) count);
 145                 log_socket_error("read_socket");
 146                 return BB_ERROR;
 147         }
 148 }
 149
 150 static int remote_bitbang_sample(void)
 151 {
 152         if (remote_bitbang_fill_buf() != ERROR_OK)
 153                 return ERROR_FAIL;
 154         assert(!remote_bitbang_buf_full());
 155         return remote_bitbang_putc('R');
 156 }
 157
 158 static bb_value_t remote_bitbang_read_sample(void)
 159 {
 160         if (remote_bitbang_start != remote_bitbang_end) {
 161                 int c = remote_bitbang_buf[remote_bitbang_start];
 162                 remote_bitbang_start =
 163                         (remote_bitbang_start + 1) % sizeof(remote_bitbang_buf);
 164                 return char_to_int(c);
 165         }
 166         return remote_bitbang_rread();
 167 }
 168
 169 static int remote_bitbang_write(int tck, int tms, int tdi)
 170 {
 171         char c = '0' + ((tck ? 0x4 : 0x0) | (tms ? 0x2 : 0x0) | (tdi ? 0x1 : 0x0));
 172         return remote_bitbang_putc(c);
 173 }
 174
 175 static int remote_bitbang_reset(int trst, int srst)
 176 {
 177         char c = 'r' + ((trst ? 0x2 : 0x0) | (srst ? 0x1 : 0x0));
 178         return remote_bitbang_putc(c);
 179 }
 180
 181 static int remote_bitbang_blink(int on)
 182 {
 183         char c = on ? 'B' : 'b';
 184         return remote_bitbang_putc(c);
 185 }
 186
 187 static struct bitbang_interface remote_bitbang_bitbang = {
 188         .buf_size = sizeof(remote_bitbang_buf) - 1,
 189         .sample = &remote_bitbang_sample,
 190         .read_sample = &remote_bitbang_read_sample,
 191         .write = &remote_bitbang_write,
 192         .blink = &remote_bitbang_blink,
 193 };
 194
 195 static int remote_bitbang_init_tcp(void)
 196 {
 197         struct addrinfo hints = { .ai_family = AF_UNSPEC, .ai_socktype = SOCK_STREAM };
 198         struct addrinfo *result, *rp;
 199         int fd = 0;
 200
 201         LOG_INFO("Connecting to %s:%s",
 202                         remote_bitbang_host ? remote_bitbang_host : "localhost",
 203                         remote_bitbang_port);
 204
 205         /* Obtain address(es) matching host/port */
 206         int s = getaddrinfo(remote_bitbang_host, remote_bitbang_port, &hints, &result);
 207         if (s != 0) {
 208                 LOG_ERROR("getaddrinfo: %s\n", gai_strerror(s));
 209                 return ERROR_FAIL;
 210         }
 211
 212         /* getaddrinfo() returns a list of address structures.
 213          Try each address until we successfully connect(2).
 214          If socket(2) (or connect(2)) fails, we (close the socket
 215          and) try the next address. */
 216
 217         for (rp = result; rp != NULL ; rp = rp->ai_next) {
 218                 fd = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
 219                 if (fd == -1)
 220                         continue;
 221
 222                 if (connect(fd, rp->ai_addr, rp->ai_addrlen) != -1)
 223                         break; /* Success */
 224
 225                 close(fd);
 226         }
 227
 228         freeaddrinfo(result); /* No longer needed */
 229
 230         if (rp == NULL) { /* No address succeeded */
 231                 log_socket_error("Failed to connect");
 232                 return ERROR_FAIL;
 233         }
 234
 235         return fd;
 236 }
 237
 238 static int remote_bitbang_init_unix(void)
 239 {
 240         if (remote_bitbang_host == NULL) {
 241                 LOG_ERROR("host/socket not specified");
 242                 return ERROR_FAIL;
 243         }
 244
 245         LOG_INFO("Connecting to unix socket %s", remote_bitbang_host);
 246         int fd = socket(PF_UNIX, SOCK_STREAM, 0);
 247         if (fd < 0) {
 248                 log_socket_error("socket");
 249                 return ERROR_FAIL;
 250         }
 251
 252         struct sockaddr_un addr;
 253         addr.sun_family = AF_UNIX;
 254         strncpy(addr.sun_path, remote_bitbang_host, sizeof(addr.sun_path));
 255         addr.sun_path[sizeof(addr.sun_path)-1] = '\0';
 256
 257         if (connect(fd, (struct sockaddr *)&addr, sizeof(struct sockaddr_un)) < 0) {
 258                 log_socket_error("connect");
 259                 return ERROR_FAIL;
 260         }
 261
 262         return fd;
 263 }
 264
 265 static int remote_bitbang_init(void)
 266 {
 267         bitbang_interface = &remote_bitbang_bitbang;
 268
 269         remote_bitbang_start = 0;
 270         remote_bitbang_end = 0;
 271
 272         LOG_INFO("Initializing remote_bitbang driver");
 273         if (remote_bitbang_port == NULL)
 274                 remote_bitbang_fd = remote_bitbang_init_unix();
 275         else
 276                 remote_bitbang_fd = remote_bitbang_init_tcp();
 277
 278         if (remote_bitbang_fd < 0)
 279                 return remote_bitbang_fd;
 280
 281         LOG_INFO("remote_bitbang driver initialized");
 282         return ERROR_OK;
 283 }
 284
 285 COMMAND_HANDLER(remote_bitbang_handle_remote_bitbang_port_command)
 286 {
 287         if (CMD_ARGC == 1) {
 288                 uint16_t port;
 289                 COMMAND_PARSE_NUMBER(u16, CMD_ARGV[0], port);
 290                 free(remote_bitbang_port);
 291                 remote_bitbang_port = port == 0 ? NULL : strdup(CMD_ARGV[0]);
 292                 return ERROR_OK;
 293         }
 294         return ERROR_COMMAND_SYNTAX_ERROR;
 295 }
 296
 297 COMMAND_HANDLER(remote_bitbang_handle_remote_bitbang_host_command)
 298 {
 299         if (CMD_ARGC == 1) {
 300                 free(remote_bitbang_host);
 301                 remote_bitbang_host = strdup(CMD_ARGV[0]);
 302                 return ERROR_OK;
 303         }
 304         return ERROR_COMMAND_SYNTAX_ERROR;
 305 }
 306
 307 static const struct command_registration remote_bitbang_command_handlers[] = {
 308         {
 309                 .name = "remote_bitbang_port",
 310                 .handler = remote_bitbang_handle_remote_bitbang_port_command,
 311                 .mode = COMMAND_CONFIG,
 312                 .help = "Set the port to use to connect to the remote jtag.\n"
 313                         "  if 0 or unset, use unix sockets to connect to the remote jtag.",
 314                 .usage = "port_number",
 315         },
 316         {
 317                 .name = "remote_bitbang_host",
 318                 .handler = remote_bitbang_handle_remote_bitbang_host_command,
 319                 .mode = COMMAND_CONFIG,
 320                 .help = "Set the host to use to connect to the remote jtag.\n"
 321                         "  if port is 0 or unset, this is the name of the unix socket to use.",
 322                 .usage = "host_name",
 323         },
 324         COMMAND_REGISTRATION_DONE,
 325 };
 326
 327 static struct jtag_interface remote_bitbang_interface = {
 328         .execute_queue = &bitbang_execute_queue,
 329 };
 330
 331 struct adapter_driver remote_bitbang_adapter_driver = {
 332         .name = "remote_bitbang",
 333         .transports = jtag_only,
 334         .commands = remote_bitbang_command_handlers,
 335
 336         .init = &remote_bitbang_init,
 337         .quit = &remote_bitbang_quit,
 338         .reset = &remote_bitbang_reset,
 339
 340         .jtag_ops = &remote_bitbang_interface,
 341 };