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