| 1 | /* |
| 2 | * Generic uart / rs232/ serial port library |
| 3 | * |
| 4 | * Copyright (c) 2013, Roel Verdult |
| 5 | * All rights reserved. |
| 6 | * |
| 7 | * Redistribution and use in source and binary forms, with or without |
| 8 | * modification, are permitted provided that the following conditions are met: |
| 9 | * 1. Redistributions of source code must retain the above copyright |
| 10 | * notice, this list of conditions and the following disclaimer. |
| 11 | * 2. Redistributions in binary form must reproduce the above copyright |
| 12 | * notice, this list of conditions and the following disclaimer in the |
| 13 | * documentation and/or other materials provided with the distribution. |
| 14 | * 3. Neither the name of the copyright holders nor the |
| 15 | * names of its contributors may be used to endorse or promote products |
| 16 | * derived from this software without specific prior written permission. |
| 17 | * |
| 18 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ''AS IS'' AND ANY |
| 19 | * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED |
| 20 | * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
| 21 | * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY |
| 22 | * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES |
| 23 | * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| 24 | * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
| 25 | * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 26 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
| 27 | * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 28 | * |
| 29 | * @file uart.c |
| 30 | * @brief |
| 31 | * |
| 32 | */ |
| 33 | |
| 34 | #include "uart.h" |
| 35 | |
| 36 | // Test if we are dealing with unix operating systems |
| 37 | #ifndef _WIN32 |
| 38 | |
| 39 | #include <termios.h> |
| 40 | typedef struct termios term_info; |
| 41 | typedef struct { |
| 42 | int fd; // Serial port file descriptor |
| 43 | term_info tiOld; // Terminal info before using the port |
| 44 | term_info tiNew; // Terminal info during the transaction |
| 45 | } serial_port_unix; |
| 46 | |
| 47 | // Set time-out on 30 miliseconds |
| 48 | const struct timeval timeout = { |
| 49 | .tv_sec = 0, // 0 second |
| 50 | .tv_usec = 30000 // 30000 micro seconds |
| 51 | }; |
| 52 | |
| 53 | serial_port uart_open(const char* pcPortName) |
| 54 | { |
| 55 | serial_port_unix* sp = malloc(sizeof(serial_port_unix)); |
| 56 | if (sp == 0) return INVALID_SERIAL_PORT; |
| 57 | |
| 58 | sp->fd = open(pcPortName, O_RDWR | O_NOCTTY | O_NDELAY | O_NONBLOCK); |
| 59 | if(sp->fd == -1) { |
| 60 | uart_close(sp); |
| 61 | return INVALID_SERIAL_PORT; |
| 62 | } |
| 63 | |
| 64 | // Finally figured out a way to claim a serial port interface under unix |
| 65 | // We just try to set a (advisory) lock on the file descriptor |
| 66 | struct flock fl; |
| 67 | fl.l_type = F_WRLCK; |
| 68 | fl.l_whence = SEEK_SET; |
| 69 | fl.l_start = 0; |
| 70 | fl.l_len = 0; |
| 71 | fl.l_pid = getpid(); |
| 72 | |
| 73 | // Does the system allows us to place a lock on this file descriptor |
| 74 | if (fcntl(sp->fd, F_SETLK, &fl) == -1) { |
| 75 | // A conflicting lock is held by another process |
| 76 | free(sp); |
| 77 | return CLAIMED_SERIAL_PORT; |
| 78 | } |
| 79 | |
| 80 | // Try to retrieve the old (current) terminal info struct |
| 81 | if(tcgetattr(sp->fd,&sp->tiOld) == -1) { |
| 82 | uart_close(sp); |
| 83 | return INVALID_SERIAL_PORT; |
| 84 | } |
| 85 | |
| 86 | // Duplicate the (old) terminal info struct |
| 87 | sp->tiNew = sp->tiOld; |
| 88 | |
| 89 | // Configure the serial port |
| 90 | sp->tiNew.c_cflag = CS8 | CLOCAL | CREAD; |
| 91 | sp->tiNew.c_iflag = IGNPAR; |
| 92 | sp->tiNew.c_oflag = 0; |
| 93 | sp->tiNew.c_lflag = 0; |
| 94 | |
| 95 | // Block until n bytes are received |
| 96 | sp->tiNew.c_cc[VMIN] = 0; |
| 97 | // Block until a timer expires (n * 100 mSec.) |
| 98 | sp->tiNew.c_cc[VTIME] = 0; |
| 99 | |
| 100 | // Try to set the new terminal info struct |
| 101 | if(tcsetattr(sp->fd,TCSANOW,&sp->tiNew) == -1) { |
| 102 | uart_close(sp); |
| 103 | return INVALID_SERIAL_PORT; |
| 104 | } |
| 105 | |
| 106 | // Flush all lingering data that may exist |
| 107 | tcflush(sp->fd, TCIOFLUSH); |
| 108 | |
| 109 | return sp; |
| 110 | } |
| 111 | |
| 112 | void uart_close(const serial_port sp) { |
| 113 | serial_port_unix* spu = (serial_port_unix*)sp; |
| 114 | tcflush(spu->fd,TCIOFLUSH); |
| 115 | tcsetattr(spu->fd,TCSANOW,&(spu->tiOld)); |
| 116 | struct flock fl; |
| 117 | fl.l_type = F_UNLCK; |
| 118 | fl.l_whence = SEEK_SET; |
| 119 | fl.l_start = 0; |
| 120 | fl.l_len = 0; |
| 121 | fl.l_pid = getpid(); |
| 122 | fcntl(spu->fd, F_SETLK, &fl); |
| 123 | close(spu->fd); |
| 124 | free(sp); |
| 125 | } |
| 126 | |
| 127 | bool uart_set_speed(serial_port sp, const uint32_t uiPortSpeed) { |
| 128 | const serial_port_unix* spu = (serial_port_unix*)sp; |
| 129 | speed_t stPortSpeed; |
| 130 | switch (uiPortSpeed) { |
| 131 | case 0: stPortSpeed = B0; break; |
| 132 | case 50: stPortSpeed = B50; break; |
| 133 | case 75: stPortSpeed = B75; break; |
| 134 | case 110: stPortSpeed = B110; break; |
| 135 | case 134: stPortSpeed = B134; break; |
| 136 | case 150: stPortSpeed = B150; break; |
| 137 | case 300: stPortSpeed = B300; break; |
| 138 | case 600: stPortSpeed = B600; break; |
| 139 | case 1200: stPortSpeed = B1200; break; |
| 140 | case 1800: stPortSpeed = B1800; break; |
| 141 | case 2400: stPortSpeed = B2400; break; |
| 142 | case 4800: stPortSpeed = B4800; break; |
| 143 | case 9600: stPortSpeed = B9600; break; |
| 144 | case 19200: stPortSpeed = B19200; break; |
| 145 | case 38400: stPortSpeed = B38400; break; |
| 146 | # ifdef B57600 |
| 147 | case 57600: stPortSpeed = B57600; break; |
| 148 | # endif |
| 149 | # ifdef B115200 |
| 150 | case 115200: stPortSpeed = B115200; break; |
| 151 | # endif |
| 152 | # ifdef B230400 |
| 153 | case 230400: stPortSpeed = B230400; break; |
| 154 | # endif |
| 155 | # ifdef B460800 |
| 156 | case 460800: stPortSpeed = B460800; break; |
| 157 | # endif |
| 158 | # ifdef B921600 |
| 159 | case 921600: stPortSpeed = B921600; break; |
| 160 | # endif |
| 161 | default: return false; |
| 162 | }; |
| 163 | struct termios ti; |
| 164 | if (tcgetattr(spu->fd,&ti) == -1) return false; |
| 165 | // Set port speed (Input and Output) |
| 166 | cfsetispeed(&ti,stPortSpeed); |
| 167 | cfsetospeed(&ti,stPortSpeed); |
| 168 | return (tcsetattr(spu->fd,TCSANOW,&ti) != -1); |
| 169 | } |
| 170 | |
| 171 | uint32_t uart_get_speed(const serial_port sp) { |
| 172 | struct termios ti; |
| 173 | uint32_t uiPortSpeed; |
| 174 | const serial_port_unix* spu = (serial_port_unix*)sp; |
| 175 | if (tcgetattr(spu->fd,&ti) == -1) return 0; |
| 176 | // Set port speed (Input) |
| 177 | speed_t stPortSpeed = cfgetispeed(&ti); |
| 178 | switch (stPortSpeed) { |
| 179 | case B0: uiPortSpeed = 0; break; |
| 180 | case B50: uiPortSpeed = 50; break; |
| 181 | case B75: uiPortSpeed = 75; break; |
| 182 | case B110: uiPortSpeed = 110; break; |
| 183 | case B134: uiPortSpeed = 134; break; |
| 184 | case B150: uiPortSpeed = 150; break; |
| 185 | case B300: uiPortSpeed = 300; break; |
| 186 | case B600: uiPortSpeed = 600; break; |
| 187 | case B1200: uiPortSpeed = 1200; break; |
| 188 | case B1800: uiPortSpeed = 1800; break; |
| 189 | case B2400: uiPortSpeed = 2400; break; |
| 190 | case B4800: uiPortSpeed = 4800; break; |
| 191 | case B9600: uiPortSpeed = 9600; break; |
| 192 | case B19200: uiPortSpeed = 19200; break; |
| 193 | case B38400: uiPortSpeed = 38400; break; |
| 194 | # ifdef B57600 |
| 195 | case B57600: uiPortSpeed = 57600; break; |
| 196 | # endif |
| 197 | # ifdef B115200 |
| 198 | case B115200: uiPortSpeed = 115200; break; |
| 199 | # endif |
| 200 | # ifdef B230400 |
| 201 | case B230400: uiPortSpeed = 230400; break; |
| 202 | # endif |
| 203 | # ifdef B460800 |
| 204 | case B460800: uiPortSpeed = 460800; break; |
| 205 | # endif |
| 206 | # ifdef B921600 |
| 207 | case B921600: uiPortSpeed = 921600; break; |
| 208 | # endif |
| 209 | default: return 0; |
| 210 | }; |
| 211 | return uiPortSpeed; |
| 212 | } |
| 213 | |
| 214 | bool uart_set_parity(serial_port sp, serial_port_parity spp) { |
| 215 | struct termios ti; |
| 216 | const serial_port_unix* spu = (serial_port_unix*)sp; |
| 217 | if (tcgetattr(spu->fd,&ti) == -1) return false; |
| 218 | switch(spp) { |
| 219 | case SP_INVALID: return false; |
| 220 | case SP_NONE: ti.c_cflag &= ~(PARENB | PARODD); break; |
| 221 | case SP_EVEN: ti.c_cflag |= PARENB; ti.c_cflag &= ~(PARODD); break; |
| 222 | case SP_ODD: ti.c_cflag |= PARENB | PARODD; break; |
| 223 | } |
| 224 | return (tcsetattr(spu->fd,TCSANOW,&ti) != -1); |
| 225 | } |
| 226 | |
| 227 | serial_port_parity uart_get_parity(const serial_port sp) { |
| 228 | struct termios ti; |
| 229 | const serial_port_unix* spu = (serial_port_unix*)sp; |
| 230 | if (tcgetattr(spu->fd,&ti) == -1) return SP_INVALID; |
| 231 | |
| 232 | if (ti.c_cflag & PARENB) { |
| 233 | if (ti.c_cflag & PARODD) { |
| 234 | return SP_ODD; |
| 235 | } else { |
| 236 | return SP_EVEN; |
| 237 | } |
| 238 | } else { |
| 239 | return SP_NONE; |
| 240 | } |
| 241 | } |
| 242 | |
| 243 | bool uart_cts(const serial_port sp) { |
| 244 | char status; |
| 245 | if (ioctl(((serial_port_unix*)sp)->fd,TIOCMGET,&status) < 0) return false; |
| 246 | return (status & TIOCM_CTS); |
| 247 | } |
| 248 | |
| 249 | bool uart_receive(const serial_port sp, byte_t* pbtRx, size_t* pszRxLen) { |
| 250 | |
| 251 | int res; |
| 252 | int byteCount; |
| 253 | fd_set rfds; |
| 254 | struct timeval tv; |
| 255 | |
| 256 | // Reset the output count |
| 257 | *pszRxLen = 0; |
| 258 | |
| 259 | do { |
| 260 | // Reset file descriptor |
| 261 | FD_ZERO(&rfds); |
| 262 | FD_SET(((serial_port_unix*)sp)->fd,&rfds); |
| 263 | tv = timeout; |
| 264 | res = select(((serial_port_unix*)sp)->fd+1, &rfds, NULL, NULL, &tv); |
| 265 | |
| 266 | // Read error |
| 267 | if (res < 0) { |
| 268 | return false; |
| 269 | } |
| 270 | |
| 271 | // Read time-out |
| 272 | if (res == 0) { |
| 273 | if (*pszRxLen == 0) { |
| 274 | // Error, we received no data |
| 275 | return false; |
| 276 | } else { |
| 277 | // We received some data, but nothing more is available |
| 278 | return true; |
| 279 | } |
| 280 | } |
| 281 | |
| 282 | // Retrieve the count of the incoming bytes |
| 283 | res = ioctl(((serial_port_unix*)sp)->fd, FIONREAD, &byteCount); |
| 284 | if (res < 0) return false; |
| 285 | |
| 286 | // There is something available, read the data |
| 287 | res = read(((serial_port_unix*)sp)->fd,pbtRx+(*pszRxLen),byteCount); |
| 288 | |
| 289 | // Stop if the OS has some troubles reading the data |
| 290 | if (res <= 0) return false; |
| 291 | |
| 292 | *pszRxLen += res; |
| 293 | |
| 294 | if(res==byteCount) |
| 295 | return true; |
| 296 | |
| 297 | } while (byteCount); |
| 298 | |
| 299 | return true; |
| 300 | } |
| 301 | |
| 302 | bool uart_send(const serial_port sp, const byte_t* pbtTx, const size_t szTxLen) { |
| 303 | int32_t res; |
| 304 | size_t szPos = 0; |
| 305 | fd_set rfds; |
| 306 | struct timeval tv; |
| 307 | |
| 308 | while (szPos < szTxLen) { |
| 309 | // Reset file descriptor |
| 310 | FD_ZERO(&rfds); |
| 311 | FD_SET(((serial_port_unix*)sp)->fd,&rfds); |
| 312 | tv = timeout; |
| 313 | res = select(((serial_port_unix*)sp)->fd+1, NULL, &rfds, NULL, &tv); |
| 314 | |
| 315 | // Write error |
| 316 | if (res < 0) { |
| 317 | return false; |
| 318 | } |
| 319 | |
| 320 | // Write time-out |
| 321 | if (res == 0) { |
| 322 | return false; |
| 323 | } |
| 324 | |
| 325 | // Send away the bytes |
| 326 | res = write(((serial_port_unix*)sp)->fd,pbtTx+szPos,szTxLen-szPos); |
| 327 | |
| 328 | // Stop if the OS has some troubles sending the data |
| 329 | if (res <= 0) return false; |
| 330 | |
| 331 | szPos += res; |
| 332 | } |
| 333 | return true; |
| 334 | } |
| 335 | |
| 336 | #else |
| 337 | // The windows serial port implementation |
| 338 | |
| 339 | typedef struct { |
| 340 | HANDLE hPort; // Serial port handle |
| 341 | DCB dcb; // Device control settings |
| 342 | COMMTIMEOUTS ct; // Serial port time-out configuration |
| 343 | } serial_port_windows; |
| 344 | |
| 345 | void upcase(char *p) { |
| 346 | while(*p != '\0') { |
| 347 | if(*p >= 97 && *p <= 122) { |
| 348 | *p -= 32; |
| 349 | } |
| 350 | ++p; |
| 351 | } |
| 352 | } |
| 353 | |
| 354 | serial_port uart_open(const char* pcPortName) { |
| 355 | char acPortName[255]; |
| 356 | serial_port_windows* sp = malloc(sizeof(serial_port_windows)); |
| 357 | |
| 358 | // Copy the input "com?" to "\\.\COM?" format |
| 359 | sprintf(acPortName,"\\\\.\\%s",pcPortName); |
| 360 | upcase(acPortName); |
| 361 | |
| 362 | // Try to open the serial port |
| 363 | sp->hPort = CreateFileA(acPortName,GENERIC_READ|GENERIC_WRITE,0,NULL,OPEN_EXISTING,0,NULL); |
| 364 | if (sp->hPort == INVALID_HANDLE_VALUE) { |
| 365 | uart_close(sp); |
| 366 | return INVALID_SERIAL_PORT; |
| 367 | } |
| 368 | |
| 369 | // Prepare the device control |
| 370 | memset(&sp->dcb, 0, sizeof(DCB)); |
| 371 | sp->dcb.DCBlength = sizeof(DCB); |
| 372 | if(!BuildCommDCBA("baud=9600 data=8 parity=N stop=1",&sp->dcb)) { |
| 373 | uart_close(sp); |
| 374 | return INVALID_SERIAL_PORT; |
| 375 | } |
| 376 | |
| 377 | // Update the active serial port |
| 378 | if(!SetCommState(sp->hPort,&sp->dcb)) { |
| 379 | uart_close(sp); |
| 380 | return INVALID_SERIAL_PORT; |
| 381 | } |
| 382 | |
| 383 | sp->ct.ReadIntervalTimeout = 0; |
| 384 | sp->ct.ReadTotalTimeoutMultiplier = 0; |
| 385 | sp->ct.ReadTotalTimeoutConstant = 30; |
| 386 | sp->ct.WriteTotalTimeoutMultiplier = 0; |
| 387 | sp->ct.WriteTotalTimeoutConstant = 30; |
| 388 | |
| 389 | if(!SetCommTimeouts(sp->hPort,&sp->ct)) { |
| 390 | uart_close(sp); |
| 391 | return INVALID_SERIAL_PORT; |
| 392 | } |
| 393 | |
| 394 | PurgeComm(sp->hPort, PURGE_RXABORT | PURGE_RXCLEAR); |
| 395 | |
| 396 | return sp; |
| 397 | } |
| 398 | |
| 399 | void uart_close(const serial_port sp) { |
| 400 | CloseHandle(((serial_port_windows*)sp)->hPort); |
| 401 | free(sp); |
| 402 | } |
| 403 | |
| 404 | bool uart_set_speed(serial_port sp, const uint32_t uiPortSpeed) { |
| 405 | serial_port_windows* spw; |
| 406 | spw = (serial_port_windows*)sp; |
| 407 | spw->dcb.BaudRate = uiPortSpeed; |
| 408 | return SetCommState(spw->hPort, &spw->dcb); |
| 409 | } |
| 410 | |
| 411 | uint32_t uart_get_speed(const serial_port sp) { |
| 412 | const serial_port_windows* spw = (serial_port_windows*)sp; |
| 413 | if (!GetCommState(spw->hPort, (serial_port)&spw->dcb)) { |
| 414 | return spw->dcb.BaudRate; |
| 415 | } |
| 416 | return 0; |
| 417 | } |
| 418 | |
| 419 | bool uart_receive(const serial_port sp, byte_t* pbtRx, size_t* pszRxLen) { |
| 420 | ReadFile(((serial_port_windows*)sp)->hPort,pbtRx,*pszRxLen,(LPDWORD)pszRxLen,NULL); |
| 421 | return (*pszRxLen != 0); |
| 422 | } |
| 423 | |
| 424 | bool uart_send(const serial_port sp, const byte_t* pbtTx, const size_t szTxLen) { |
| 425 | DWORD dwTxLen = 0; |
| 426 | return WriteFile(((serial_port_windows*)sp)->hPort,pbtTx,szTxLen,&dwTxLen,NULL); |
| 427 | return (dwTxLen != 0); |
| 428 | } |
| 429 | |
| 430 | #endif |