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