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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 | return CLAIMED_SERIAL_PORT; | |
77 | } | |
78 | ||
79 | // Try to retrieve the old (current) terminal info struct | |
80 | if(tcgetattr(sp->fd,&sp->tiOld) == -1) { | |
81 | uart_close(sp); | |
82 | return INVALID_SERIAL_PORT; | |
83 | } | |
84 | ||
85 | // Duplicate the (old) terminal info struct | |
86 | sp->tiNew = sp->tiOld; | |
87 | ||
88 | // Configure the serial port | |
89 | sp->tiNew.c_cflag = CS8 | CLOCAL | CREAD; | |
90 | sp->tiNew.c_iflag = IGNPAR; | |
91 | sp->tiNew.c_oflag = 0; | |
92 | sp->tiNew.c_lflag = 0; | |
93 | ||
94 | // Block until n bytes are received | |
95 | sp->tiNew.c_cc[VMIN] = 0; | |
96 | // Block until a timer expires (n * 100 mSec.) | |
97 | sp->tiNew.c_cc[VTIME] = 0; | |
98 | ||
99 | // Try to set the new terminal info struct | |
100 | if(tcsetattr(sp->fd,TCSANOW,&sp->tiNew) == -1) { | |
101 | uart_close(sp); | |
102 | return INVALID_SERIAL_PORT; | |
103 | } | |
104 | ||
105 | // Flush all lingering data that may exist | |
106 | tcflush(sp->fd, TCIOFLUSH); | |
107 | ||
108 | return sp; | |
109 | } | |
110 | ||
111 | void uart_close(const serial_port sp) { | |
112 | serial_port_unix* spu = (serial_port_unix*)sp; | |
113 | tcflush(spu->fd,TCIOFLUSH); | |
114 | tcsetattr(spu->fd,TCSANOW,&(spu->tiOld)); | |
115 | struct flock fl; | |
116 | fl.l_type = F_UNLCK; | |
117 | fl.l_whence = SEEK_SET; | |
118 | fl.l_start = 0; | |
119 | fl.l_len = 0; | |
120 | fl.l_pid = getpid(); | |
121 | fcntl(spu->fd, F_SETLK, &fl); | |
122 | close(spu->fd); | |
123 | free(sp); | |
124 | } | |
125 | ||
126 | bool uart_set_speed(serial_port sp, const uint32_t uiPortSpeed) { | |
127 | const serial_port_unix* spu = (serial_port_unix*)sp; | |
128 | speed_t stPortSpeed; | |
129 | switch (uiPortSpeed) { | |
130 | case 0: stPortSpeed = B0; break; | |
131 | case 50: stPortSpeed = B50; break; | |
132 | case 75: stPortSpeed = B75; break; | |
133 | case 110: stPortSpeed = B110; break; | |
134 | case 134: stPortSpeed = B134; break; | |
135 | case 150: stPortSpeed = B150; break; | |
136 | case 300: stPortSpeed = B300; break; | |
137 | case 600: stPortSpeed = B600; break; | |
138 | case 1200: stPortSpeed = B1200; break; | |
139 | case 1800: stPortSpeed = B1800; break; | |
140 | case 2400: stPortSpeed = B2400; break; | |
141 | case 4800: stPortSpeed = B4800; break; | |
142 | case 9600: stPortSpeed = B9600; break; | |
143 | case 19200: stPortSpeed = B19200; break; | |
144 | case 38400: stPortSpeed = B38400; break; | |
145 | # ifdef B57600 | |
146 | case 57600: stPortSpeed = B57600; break; | |
147 | # endif | |
148 | # ifdef B115200 | |
149 | case 115200: stPortSpeed = B115200; break; | |
150 | # endif | |
151 | # ifdef B230400 | |
152 | case 230400: stPortSpeed = B230400; break; | |
153 | # endif | |
154 | # ifdef B460800 | |
155 | case 460800: stPortSpeed = B460800; break; | |
156 | # endif | |
157 | # ifdef B921600 | |
158 | case 921600: stPortSpeed = B921600; break; | |
159 | # endif | |
160 | default: return false; | |
161 | }; | |
162 | struct termios ti; | |
163 | if (tcgetattr(spu->fd,&ti) == -1) return false; | |
164 | // Set port speed (Input and Output) | |
165 | cfsetispeed(&ti,stPortSpeed); | |
166 | cfsetospeed(&ti,stPortSpeed); | |
167 | return (tcsetattr(spu->fd,TCSANOW,&ti) != -1); | |
168 | } | |
169 | ||
170 | uint32_t uart_get_speed(const serial_port sp) { | |
171 | struct termios ti; | |
172 | uint32_t uiPortSpeed; | |
173 | const serial_port_unix* spu = (serial_port_unix*)sp; | |
174 | if (tcgetattr(spu->fd,&ti) == -1) return 0; | |
175 | // Set port speed (Input) | |
176 | speed_t stPortSpeed = cfgetispeed(&ti); | |
177 | switch (stPortSpeed) { | |
178 | case B0: uiPortSpeed = 0; break; | |
179 | case B50: uiPortSpeed = 50; break; | |
180 | case B75: uiPortSpeed = 75; break; | |
181 | case B110: uiPortSpeed = 110; break; | |
182 | case B134: uiPortSpeed = 134; break; | |
183 | case B150: uiPortSpeed = 150; break; | |
184 | case B300: uiPortSpeed = 300; break; | |
185 | case B600: uiPortSpeed = 600; break; | |
186 | case B1200: uiPortSpeed = 1200; break; | |
187 | case B1800: uiPortSpeed = 1800; break; | |
188 | case B2400: uiPortSpeed = 2400; break; | |
189 | case B4800: uiPortSpeed = 4800; break; | |
190 | case B9600: uiPortSpeed = 9600; break; | |
191 | case B19200: uiPortSpeed = 19200; break; | |
192 | case B38400: uiPortSpeed = 38400; break; | |
193 | # ifdef B57600 | |
194 | case B57600: uiPortSpeed = 57600; break; | |
195 | # endif | |
196 | # ifdef B115200 | |
197 | case B115200: uiPortSpeed = 115200; break; | |
198 | # endif | |
199 | # ifdef B230400 | |
200 | case B230400: uiPortSpeed = 230400; break; | |
201 | # endif | |
202 | # ifdef B460800 | |
203 | case B460800: uiPortSpeed = 460800; break; | |
204 | # endif | |
205 | # ifdef B921600 | |
206 | case B921600: uiPortSpeed = 921600; break; | |
207 | # endif | |
208 | default: return 0; | |
209 | }; | |
210 | return uiPortSpeed; | |
211 | } | |
212 | ||
213 | bool uart_set_parity(serial_port sp, serial_port_parity spp) { | |
214 | struct termios ti; | |
215 | const serial_port_unix* spu = (serial_port_unix*)sp; | |
216 | if (tcgetattr(spu->fd,&ti) == -1) return false; | |
217 | switch(spp) { | |
218 | case SP_INVALID: return false; | |
219 | case SP_NONE: ti.c_cflag &= ~(PARENB | PARODD); break; | |
220 | case SP_EVEN: ti.c_cflag |= PARENB; ti.c_cflag &= ~(PARODD); break; | |
221 | case SP_ODD: ti.c_cflag |= PARENB | PARODD; break; | |
222 | } | |
223 | return (tcsetattr(spu->fd,TCSANOW,&ti) != -1); | |
224 | } | |
225 | ||
226 | serial_port_parity uart_get_parity(const serial_port sp) { | |
227 | struct termios ti; | |
228 | const serial_port_unix* spu = (serial_port_unix*)sp; | |
229 | if (tcgetattr(spu->fd,&ti) == -1) return SP_INVALID; | |
230 | ||
231 | if (ti.c_cflag & PARENB) { | |
232 | if (ti.c_cflag & PARODD) { | |
233 | return SP_ODD; | |
234 | } else { | |
235 | return SP_EVEN; | |
236 | } | |
237 | } else { | |
238 | return SP_NONE; | |
239 | } | |
240 | } | |
241 | ||
242 | bool uart_cts(const serial_port sp) { | |
243 | char status; | |
244 | if (ioctl(((serial_port_unix*)sp)->fd,TIOCMGET,&status) < 0) return false; | |
245 | return (status & TIOCM_CTS); | |
246 | } | |
247 | ||
248 | bool uart_receive(const serial_port sp, byte_t* pbtRx, size_t* pszRxLen) { | |
249 | ||
250 | int res; | |
251 | int byteCount; | |
252 | fd_set rfds; | |
253 | struct timeval tv; | |
254 | ||
255 | // Reset the output count | |
256 | *pszRxLen = 0; | |
257 | ||
258 | do { | |
259 | // Reset file descriptor | |
260 | FD_ZERO(&rfds); | |
261 | FD_SET(((serial_port_unix*)sp)->fd,&rfds); | |
262 | tv = timeout; | |
263 | res = select(((serial_port_unix*)sp)->fd+1, &rfds, NULL, NULL, &tv); | |
264 | ||
265 | // Read error | |
266 | if (res < 0) { | |
267 | return false; | |
268 | } | |
269 | ||
270 | // Read time-out | |
271 | if (res == 0) { | |
272 | if (*pszRxLen == 0) { | |
273 | // Error, we received no data | |
274 | return false; | |
275 | } else { | |
276 | // We received some data, but nothing more is available | |
277 | return true; | |
278 | } | |
279 | } | |
280 | ||
281 | // Retrieve the count of the incoming bytes | |
282 | res = ioctl(((serial_port_unix*)sp)->fd, FIONREAD, &byteCount); | |
283 | if (res < 0) return false; | |
284 | ||
285 | // There is something available, read the data | |
286 | res = read(((serial_port_unix*)sp)->fd,pbtRx+(*pszRxLen),byteCount); | |
287 | ||
288 | // Stop if the OS has some troubles reading the data | |
289 | if (res <= 0) return false; | |
290 | ||
291 | *pszRxLen += res; | |
292 | ||
293 | } while (byteCount); | |
294 | ||
295 | return true; | |
296 | } | |
297 | ||
298 | bool uart_send(const serial_port sp, const byte_t* pbtTx, const size_t szTxLen) { | |
299 | int32_t res; | |
300 | size_t szPos = 0; | |
301 | fd_set rfds; | |
302 | struct timeval tv; | |
303 | ||
304 | while (szPos < szTxLen) { | |
305 | // Reset file descriptor | |
306 | FD_ZERO(&rfds); | |
307 | FD_SET(((serial_port_unix*)sp)->fd,&rfds); | |
308 | tv = timeout; | |
309 | res = select(((serial_port_unix*)sp)->fd+1, NULL, &rfds, NULL, &tv); | |
310 | ||
311 | // Write error | |
312 | if (res < 0) { | |
313 | return false; | |
314 | } | |
315 | ||
316 | // Write time-out | |
317 | if (res == 0) { | |
318 | return false; | |
319 | } | |
320 | ||
321 | // Send away the bytes | |
322 | res = write(((serial_port_unix*)sp)->fd,pbtTx+szPos,szTxLen-szPos); | |
323 | ||
324 | // Stop if the OS has some troubles sending the data | |
325 | if (res <= 0) return false; | |
326 | ||
327 | szPos += res; | |
328 | } | |
329 | return true; | |
330 | } | |
331 | ||
332 | #else | |
333 | // The windows serial port implementation | |
334 | ||
335 | typedef struct { | |
336 | HANDLE hPort; // Serial port handle | |
337 | DCB dcb; // Device control settings | |
338 | COMMTIMEOUTS ct; // Serial port time-out configuration | |
339 | } serial_port_windows; | |
340 | ||
341 | void upcase(char *p) { | |
342 | while(*p != '\0') { | |
343 | if(*p >= 97 && *p <= 122) { | |
344 | *p -= 32; | |
345 | } | |
346 | ++p; | |
347 | } | |
348 | } | |
349 | ||
350 | serial_port uart_open(const char* pcPortName) { | |
351 | char acPortName[255]; | |
352 | serial_port_windows* sp = malloc(sizeof(serial_port_windows)); | |
353 | ||
354 | // Copy the input "com?" to "\\.\COM?" format | |
355 | sprintf(acPortName,"\\\\.\\%s",pcPortName); | |
356 | upcase(acPortName); | |
357 | ||
358 | // Try to open the serial port | |
359 | sp->hPort = CreateFileA(acPortName,GENERIC_READ|GENERIC_WRITE,0,NULL,OPEN_EXISTING,0,NULL); | |
360 | if (sp->hPort == INVALID_HANDLE_VALUE) { | |
361 | uart_close(sp); | |
362 | return INVALID_SERIAL_PORT; | |
363 | } | |
364 | ||
365 | // Prepare the device control | |
366 | memset(&sp->dcb, 0, sizeof(DCB)); | |
367 | sp->dcb.DCBlength = sizeof(DCB); | |
368 | if(!BuildCommDCBA("baud=9600 data=8 parity=N stop=1",&sp->dcb)) { | |
369 | uart_close(sp); | |
370 | return INVALID_SERIAL_PORT; | |
371 | } | |
372 | ||
373 | // Update the active serial port | |
374 | if(!SetCommState(sp->hPort,&sp->dcb)) { | |
375 | uart_close(sp); | |
376 | return INVALID_SERIAL_PORT; | |
377 | } | |
378 | ||
379 | sp->ct.ReadIntervalTimeout = 0; | |
380 | sp->ct.ReadTotalTimeoutMultiplier = 0; | |
381 | sp->ct.ReadTotalTimeoutConstant = 30; | |
382 | sp->ct.WriteTotalTimeoutMultiplier = 0; | |
383 | sp->ct.WriteTotalTimeoutConstant = 30; | |
384 | ||
385 | if(!SetCommTimeouts(sp->hPort,&sp->ct)) { | |
386 | uart_close(sp); | |
387 | return INVALID_SERIAL_PORT; | |
388 | } | |
389 | ||
390 | PurgeComm(sp->hPort, PURGE_RXABORT | PURGE_RXCLEAR); | |
391 | ||
392 | return sp; | |
393 | } | |
394 | ||
395 | void uart_close(const serial_port sp) { | |
396 | CloseHandle(((serial_port_windows*)sp)->hPort); | |
397 | free(sp); | |
398 | } | |
399 | ||
400 | bool uart_set_speed(serial_port sp, const uint32_t uiPortSpeed) { | |
401 | serial_port_windows* spw; | |
402 | spw = (serial_port_windows*)sp; | |
403 | spw->dcb.BaudRate = uiPortSpeed; | |
404 | return SetCommState(spw->hPort, &spw->dcb); | |
405 | } | |
406 | ||
407 | uint32_t uart_get_speed(const serial_port sp) { | |
408 | const serial_port_windows* spw = (serial_port_windows*)sp; | |
409 | if (!GetCommState(spw->hPort, (serial_port)&spw->dcb)) { | |
410 | return spw->dcb.BaudRate; | |
411 | } | |
412 | return 0; | |
413 | } | |
414 | ||
415 | bool uart_receive(const serial_port sp, byte_t* pbtRx, size_t* pszRxLen) { | |
416 | ReadFile(((serial_port_windows*)sp)->hPort,pbtRx,*pszRxLen,(LPDWORD)pszRxLen,NULL); | |
417 | return (*pszRxLen != 0); | |
418 | } | |
419 | ||
420 | bool uart_send(const serial_port sp, const byte_t* pbtTx, const size_t szTxLen) { | |
421 | DWORD dwTxLen = 0; | |
422 | return WriteFile(((serial_port_windows*)sp)->hPort,pbtTx,szTxLen,&dwTxLen,NULL); | |
423 | return (dwTxLen != 0); | |
424 | } | |
425 | ||
426 | #endif |