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 #include <netinet/tcp.h>
  27 #endif
  28 #include "helper/system.h"
  29 #include "helper/replacements.h"
  30 #include <jtag/interface.h>
  31 #include "bitbang.h"
  32
  33 /* arbitrary limit on host name length: */
  34 #define REMOTE_BITBANG_HOST_MAX 255
  35
  36 static char *remote_bitbang_host;
  37 static char *remote_bitbang_port;
  38
  39 static int remote_bitbang_fd;
  40 static uint8_t remote_bitbang_send_buf[512];
  41 static unsigned int remote_bitbang_send_buf_used;
  42
  43 /* Circular buffer. When start == end, the buffer is empty. */
  44 static char remote_bitbang_recv_buf[256];
  45 static unsigned int remote_bitbang_recv_buf_start;
  46 static unsigned int remote_bitbang_recv_buf_end;
  47
  48 static bool remote_bitbang_recv_buf_full(void)
  49 {
  50         return remote_bitbang_recv_buf_end ==
  51                 ((remote_bitbang_recv_buf_start + sizeof(remote_bitbang_recv_buf) - 1) %
  52                  sizeof(remote_bitbang_recv_buf));
  53 }
  54
  55 static bool remote_bitbang_recv_buf_empty(void)
  56 {
  57         return remote_bitbang_recv_buf_start == remote_bitbang_recv_buf_end;
  58 }
  59
  60 static unsigned int remote_bitbang_recv_buf_contiguous_available_space(void)
  61 {
  62         if (remote_bitbang_recv_buf_end >= remote_bitbang_recv_buf_start) {
  63                 unsigned int space = sizeof(remote_bitbang_recv_buf) -
  64                                      remote_bitbang_recv_buf_end;
  65                 if (remote_bitbang_recv_buf_start == 0)
  66                         space -= 1;
  67                 return space;
  68         } else {
  69                 return remote_bitbang_recv_buf_start -
  70                        remote_bitbang_recv_buf_end - 1;
  71         }
  72 }
  73
  74 static int remote_bitbang_flush(void)
  75 {
  76         if (remote_bitbang_send_buf_used <= 0)
  77                 return ERROR_OK;
  78
  79         unsigned int offset = 0;
  80         while (offset < remote_bitbang_send_buf_used) {
  81                 ssize_t written = write_socket(remote_bitbang_fd, remote_bitbang_send_buf + offset,
  82                                                                            remote_bitbang_send_buf_used - offset);
  83                 if (written < 0) {
  84                         log_socket_error("remote_bitbang_putc");
  85                         remote_bitbang_send_buf_used = 0;
  86                         return ERROR_FAIL;
  87                 }
  88                 offset += written;
  89         }
  90         remote_bitbang_send_buf_used = 0;
  91         return ERROR_OK;
  92 }
  93
  94 enum block_bool {
  95         NO_BLOCK,
  96         BLOCK
  97 };
  98
  99 /* Read any incoming data, placing it into the buffer. */
 100 static int remote_bitbang_fill_buf(enum block_bool block)
 101 {
 102         if (remote_bitbang_recv_buf_empty()) {
 103                 /* If the buffer is empty, reset it to 0 so we get more
 104                  * contiguous space. */
 105                 remote_bitbang_recv_buf_start = 0;
 106                 remote_bitbang_recv_buf_end = 0;
 107         }
 108
 109         if (block == BLOCK) {
 110                 if (remote_bitbang_flush() != ERROR_OK)
 111                         return ERROR_FAIL;
 112                 socket_block(remote_bitbang_fd);
 113         }
 114
 115         bool first = true;
 116         while (!remote_bitbang_recv_buf_full()) {
 117                 unsigned int contiguous_available_space =
 118                                 remote_bitbang_recv_buf_contiguous_available_space();
 119                 ssize_t count = read_socket(remote_bitbang_fd,
 120                                 remote_bitbang_recv_buf + remote_bitbang_recv_buf_end,
 121                                 contiguous_available_space);
 122                 if (first && block == BLOCK)
 123                         socket_nonblock(remote_bitbang_fd);
 124                 first = false;
 125                 if (count > 0) {
 126                         remote_bitbang_recv_buf_end += count;
 127                         if (remote_bitbang_recv_buf_end == sizeof(remote_bitbang_recv_buf))
 128                                 remote_bitbang_recv_buf_end = 0;
 129                 } else if (count == 0) {
 130                         return ERROR_OK;
 131                 } else if (count < 0) {
 132 #ifdef _WIN32
 133                         if (WSAGetLastError() == WSAEWOULDBLOCK) {
 134 #else
 135                         if (errno == EAGAIN) {
 136 #endif
 137                                 return ERROR_OK;
 138                         } else {
 139                                 log_socket_error("remote_bitbang_fill_buf");
 140                                 return ERROR_FAIL;
 141                         }
 142                 }
 143         }
 144
 145         return ERROR_OK;
 146 }
 147
 148 typedef enum {
 149         NO_FLUSH,
 150         FLUSH_SEND_BUF
 151 } flush_bool_t;
 152
 153 static int remote_bitbang_queue(int c, flush_bool_t flush)
 154 {
 155         remote_bitbang_send_buf[remote_bitbang_send_buf_used++] = c;
 156         if (flush == FLUSH_SEND_BUF ||
 157                         remote_bitbang_send_buf_used >= ARRAY_SIZE(remote_bitbang_send_buf))
 158                 return remote_bitbang_flush();
 159         return ERROR_OK;
 160 }
 161
 162 static int remote_bitbang_quit(void)
 163 {
 164         if (remote_bitbang_queue('Q', FLUSH_SEND_BUF) == ERROR_FAIL)
 165                 return ERROR_FAIL;
 166
 167         if (close_socket(remote_bitbang_fd) != 0) {
 168                 log_socket_error("close_socket");
 169                 return ERROR_FAIL;
 170         }
 171
 172         free(remote_bitbang_host);
 173         free(remote_bitbang_port);
 174
 175         LOG_INFO("remote_bitbang interface quit");
 176         return ERROR_OK;
 177 }
 178
 179 static bb_value_t char_to_int(int c)
 180 {
 181         switch (c) {
 182                 case '0':
 183                         return BB_LOW;
 184                 case '1':
 185                         return BB_HIGH;
 186                 default:
 187                         remote_bitbang_quit();
 188                         LOG_ERROR("remote_bitbang: invalid read response: %c(%i)", c, c);
 189                         return BB_ERROR;
 190         }
 191 }
 192
 193 static int remote_bitbang_sample(void)
 194 {
 195         if (remote_bitbang_fill_buf(NO_BLOCK) != ERROR_OK)
 196                 return ERROR_FAIL;
 197         assert(!remote_bitbang_recv_buf_full());
 198         return remote_bitbang_queue('R', NO_FLUSH);
 199 }
 200
 201 static bb_value_t remote_bitbang_read_sample(void)
 202 {
 203         if (remote_bitbang_recv_buf_empty()) {
 204                 if (remote_bitbang_fill_buf(BLOCK) != ERROR_OK)
 205                         return BB_ERROR;
 206         }
 207         assert(!remote_bitbang_recv_buf_empty());
 208         int c = remote_bitbang_recv_buf[remote_bitbang_recv_buf_start];
 209         remote_bitbang_recv_buf_start =
 210                 (remote_bitbang_recv_buf_start + 1) % sizeof(remote_bitbang_recv_buf);
 211         return char_to_int(c);
 212 }
 213
 214 static int remote_bitbang_write(int tck, int tms, int tdi)
 215 {
 216         char c = '0' + ((tck ? 0x4 : 0x0) | (tms ? 0x2 : 0x0) | (tdi ? 0x1 : 0x0));
 217         return remote_bitbang_queue(c, NO_FLUSH);
 218 }
 219
 220 static int remote_bitbang_reset(int trst, int srst)
 221 {
 222         char c = 'r' + ((trst ? 0x2 : 0x0) | (srst ? 0x1 : 0x0));
 223         /* Always flush the send buffer on reset, because the reset call need not be
 224          * followed by jtag_execute_queue(). */
 225         return remote_bitbang_queue(c, FLUSH_SEND_BUF);
 226 }
 227
 228 static int remote_bitbang_blink(int on)
 229 {
 230         char c = on ? 'B' : 'b';
 231         return remote_bitbang_queue(c, FLUSH_SEND_BUF);
 232 }
 233
 234 static struct bitbang_interface remote_bitbang_bitbang = {
 235         .buf_size = sizeof(remote_bitbang_recv_buf) - 1,
 236         .sample = &remote_bitbang_sample,
 237         .read_sample = &remote_bitbang_read_sample,
 238         .write = &remote_bitbang_write,
 239         .blink = &remote_bitbang_blink,
 240 };
 241
 242 static int remote_bitbang_init_tcp(void)
 243 {
 244         struct addrinfo hints = { .ai_family = AF_UNSPEC, .ai_socktype = SOCK_STREAM };
 245         struct addrinfo *result, *rp;
 246         int fd = 0;
 247
 248         LOG_INFO("Connecting to %s:%s",
 249                         remote_bitbang_host ? remote_bitbang_host : "localhost",
 250                         remote_bitbang_port);
 251
 252         /* Obtain address(es) matching host/port */
 253         int s = getaddrinfo(remote_bitbang_host, remote_bitbang_port, &hints, &result);
 254         if (s != 0) {
 255                 LOG_ERROR("getaddrinfo: %s\n", gai_strerror(s));
 256                 return ERROR_FAIL;
 257         }
 258
 259         /* getaddrinfo() returns a list of address structures.
 260          Try each address until we successfully connect(2).
 261          If socket(2) (or connect(2)) fails, we (close the socket
 262          and) try the next address. */
 263
 264         for (rp = result; rp ; rp = rp->ai_next) {
 265                 fd = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
 266                 if (fd == -1)
 267                         continue;
 268
 269                 if (connect(fd, rp->ai_addr, rp->ai_addrlen) != -1)
 270                         break; /* Success */
 271
 272                 close(fd);
 273         }
 274
 275         /* We work hard to collapse the writes into the minimum number, so when
 276          * we write something we want to get it to the other end of the
 277          * connection as fast as possible. */
 278         int one = 1;
 279         /* On Windows optval has to be a const char *. */
 280         setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, (const char *)&one, sizeof(one));
 281
 282         freeaddrinfo(result); /* No longer needed */
 283
 284         if (!rp) { /* No address succeeded */
 285                 log_socket_error("Failed to connect");
 286                 return ERROR_FAIL;
 287         }
 288
 289         return fd;
 290 }
 291
 292 static int remote_bitbang_init_unix(void)
 293 {
 294         if (!remote_bitbang_host) {
 295                 LOG_ERROR("host/socket not specified");
 296                 return ERROR_FAIL;
 297         }
 298
 299         LOG_INFO("Connecting to unix socket %s", remote_bitbang_host);
 300         int fd = socket(PF_UNIX, SOCK_STREAM, 0);
 301         if (fd < 0) {
 302                 log_socket_error("socket");
 303                 return ERROR_FAIL;
 304         }
 305
 306         struct sockaddr_un addr;
 307         addr.sun_family = AF_UNIX;
 308         strncpy(addr.sun_path, remote_bitbang_host, sizeof(addr.sun_path));
 309         addr.sun_path[sizeof(addr.sun_path)-1] = '\0';
 310
 311         if (connect(fd, (struct sockaddr *)&addr, sizeof(struct sockaddr_un)) < 0) {
 312                 log_socket_error("connect");
 313                 return ERROR_FAIL;
 314         }
 315
 316         return fd;
 317 }
 318
 319 static int remote_bitbang_init(void)
 320 {
 321         bitbang_interface = &remote_bitbang_bitbang;
 322
 323         remote_bitbang_recv_buf_start = 0;
 324         remote_bitbang_recv_buf_end = 0;
 325
 326         LOG_INFO("Initializing remote_bitbang driver");
 327         if (!remote_bitbang_port)
 328                 remote_bitbang_fd = remote_bitbang_init_unix();
 329         else
 330                 remote_bitbang_fd = remote_bitbang_init_tcp();
 331
 332         if (remote_bitbang_fd < 0)
 333                 return remote_bitbang_fd;
 334
 335         socket_nonblock(remote_bitbang_fd);
 336
 337         LOG_INFO("remote_bitbang driver initialized");
 338         return ERROR_OK;
 339 }
 340
 341 COMMAND_HANDLER(remote_bitbang_handle_remote_bitbang_port_command)
 342 {
 343         if (CMD_ARGC == 1) {
 344                 uint16_t port;
 345                 COMMAND_PARSE_NUMBER(u16, CMD_ARGV[0], port);
 346                 free(remote_bitbang_port);
 347                 remote_bitbang_port = port == 0 ? NULL : strdup(CMD_ARGV[0]);
 348                 return ERROR_OK;
 349         }
 350         return ERROR_COMMAND_SYNTAX_ERROR;
 351 }
 352
 353 COMMAND_HANDLER(remote_bitbang_handle_remote_bitbang_host_command)
 354 {
 355         if (CMD_ARGC == 1) {
 356                 free(remote_bitbang_host);
 357                 remote_bitbang_host = strdup(CMD_ARGV[0]);
 358                 return ERROR_OK;
 359         }
 360         return ERROR_COMMAND_SYNTAX_ERROR;
 361 }
 362
 363 static const struct command_registration remote_bitbang_subcommand_handlers[] = {
 364         {
 365                 .name = "port",
 366                 .handler = remote_bitbang_handle_remote_bitbang_port_command,
 367                 .mode = COMMAND_CONFIG,
 368                 .help = "Set the port to use to connect to the remote jtag.\n"
 369                         "  if 0 or unset, use unix sockets to connect to the remote jtag.",
 370                 .usage = "port_number",
 371         },
 372         {
 373                 .name = "host",
 374                 .handler = remote_bitbang_handle_remote_bitbang_host_command,
 375                 .mode = COMMAND_CONFIG,
 376                 .help = "Set the host to use to connect to the remote jtag.\n"
 377                         "  if port is 0 or unset, this is the name of the unix socket to use.",
 378                 .usage = "host_name",
 379         },
 380         COMMAND_REGISTRATION_DONE,
 381 };
 382
 383 static const struct command_registration remote_bitbang_command_handlers[] = {
 384         {
 385                 .name = "remote_bitbang",
 386                 .mode = COMMAND_ANY,
 387                 .help = "perform remote_bitbang management",
 388                 .chain = remote_bitbang_subcommand_handlers,
 389                 .usage = "",
 390         },
 391         COMMAND_REGISTRATION_DONE
 392 };
 393
 394 static int remote_bitbang_execute_queue(void)
 395 {
 396         /* safety: the send buffer must be empty, no leftover characters from
 397          * previous transactions */
 398         assert(remote_bitbang_send_buf_used == 0);
 399
 400         /* process the JTAG command queue */
 401         int ret = bitbang_execute_queue();
 402         if (ret != ERROR_OK)
 403                 return ret;
 404
 405         /* flush not-yet-sent characters, if any */
 406         return remote_bitbang_flush();
 407 }
 408
 409 static struct jtag_interface remote_bitbang_interface = {
 410         .execute_queue = &remote_bitbang_execute_queue,
 411 };
 412
 413 struct adapter_driver remote_bitbang_adapter_driver = {
 414         .name = "remote_bitbang",
 415         .transports = jtag_only,
 416         .commands = remote_bitbang_command_handlers,
 417
 418         .init = &remote_bitbang_init,
 419         .quit = &remote_bitbang_quit,
 420         .reset = &remote_bitbang_reset,
 421
 422         .jtag_ops = &remote_bitbang_interface,
 423 };