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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 | // Work-around to claim uart interface using the c_iflag (software input processing) from the termios struct | |
54 | #define CCLAIMED 0x00008000 | |
55 | ||
56 | char pcPort[255]; | |
57 | ||
58 | serial_port uart_open(const char* pcPortName) | |
59 | { | |
60 | serial_port_unix* sp = malloc(sizeof(serial_port_unix)); | |
61 | strcpy(pcPort,pcPortName); | |
62 | ||
63 | if (sp == 0) return INVALID_SERIAL_PORT; | |
64 | ||
65 | sp->fd = open(pcPortName, O_RDWR | O_NOCTTY | O_NDELAY | O_NONBLOCK); | |
66 | if(sp->fd == -1) | |
67 | { | |
68 | uart_close(sp); | |
69 | return INVALID_SERIAL_PORT; | |
70 | } | |
71 | ||
72 | if(tcgetattr(sp->fd,&sp->tiOld) == -1) | |
73 | { | |
74 | uart_close(sp); | |
75 | return INVALID_SERIAL_PORT; | |
76 | } | |
77 | ||
78 | // Make sure the port is not claimed already | |
79 | if (sp->tiOld.c_iflag & CCLAIMED) | |
80 | { | |
81 | uart_close(sp); | |
82 | return CLAIMED_SERIAL_PORT; | |
83 | } | |
84 | ||
85 | // Copy the old terminal info struct | |
86 | sp->tiNew = sp->tiOld; | |
87 | ||
88 | sp->tiNew.c_cflag = CS8 | CLOCAL | CREAD; | |
89 | sp->tiNew.c_iflag = CCLAIMED | IGNPAR; | |
90 | sp->tiNew.c_oflag = 0; | |
91 | sp->tiNew.c_lflag = 0; | |
92 | ||
93 | // Set serial port equivalent to raw mode | |
94 | // sp->tiNew.c_iflag &= ~(CCLAIMED | IGNBRK | BRKINT | IGNPAR | ISTRIP | INLCR | IGNCR | ICRNL | IXON); | |
95 | // sp->tiNew.c_oflag &= ~OPOST; | |
96 | // sp->tiNew.c_lflag &= ~(ECHO | ECHONL | ICANON | ISIG | IEXTEN); | |
97 | // sp->tiNew.c_cflag &= ~(CSIZE | PARENB | CS8 | CLOCAL | CREAD); | |
98 | ||
99 | sp->tiNew.c_cc[VMIN] = 0; // block until n bytes are received | |
100 | sp->tiNew.c_cc[VTIME] = 0; // block until a timer expires (n * 100 mSec.) | |
101 | ||
102 | if(tcsetattr(sp->fd,TCSANOW,&sp->tiNew) == -1) | |
103 | { | |
104 | uart_close(sp); | |
105 | return INVALID_SERIAL_PORT; | |
106 | } | |
107 | ||
108 | tcflush(sp->fd, TCIOFLUSH); | |
109 | return sp; | |
110 | } | |
111 | ||
112 | bool uart_set_speed(serial_port sp, const uint32_t uiPortSpeed) { | |
113 | // Set port speed (Input and Output) | |
114 | const serial_port_unix* spu = (serial_port_unix*)sp; | |
115 | cfsetispeed((struct termios*)&spu->tiNew, uiPortSpeed); | |
116 | cfsetospeed((struct termios*)&spu->tiNew, uiPortSpeed); | |
117 | return (tcsetattr(spu->fd, TCSADRAIN, &spu->tiNew) != -1); | |
118 | } | |
119 | ||
120 | uint32_t uart_get_speed(const serial_port sp) { | |
121 | uint32_t uiPortSpeed = 0; | |
122 | const serial_port_unix* spu = (serial_port_unix*)sp; | |
123 | uiPortSpeed = cfgetispeed(&spu->tiNew); | |
124 | return uiPortSpeed; | |
125 | } | |
126 | ||
127 | void uart_close(const serial_port sp) { | |
128 | tcflush(((serial_port_unix*)sp)->fd,TCIOFLUSH); | |
129 | tcsetattr(((serial_port_unix*)sp)->fd,TCSANOW,&((serial_port_unix*)sp)->tiOld); | |
130 | close(((serial_port_unix*)sp)->fd); | |
131 | free(sp); | |
132 | } | |
133 | ||
134 | bool uart_cts(const serial_port sp) { | |
135 | char status; | |
136 | if (ioctl(((serial_port_unix*)sp)->fd,TIOCMGET,&status) < 0) return false; | |
137 | return (status & TIOCM_CTS); | |
138 | } | |
139 | ||
140 | bool uart_receive(const serial_port sp, byte_t* pbtRx, size_t* pszRxLen) { | |
141 | int res; | |
142 | int byteCount; | |
143 | fd_set rfds; | |
144 | struct timeval tv; | |
145 | ||
146 | // Reset the output count | |
147 | *pszRxLen = 0; | |
148 | ||
149 | do { | |
150 | // Reset file descriptor | |
151 | FD_ZERO(&rfds); | |
152 | FD_SET(((serial_port_unix*)sp)->fd,&rfds); | |
153 | tv = timeout; | |
154 | res = select(((serial_port_unix*)sp)->fd+1, &rfds, NULL, NULL, &tv); | |
155 | ||
156 | // Read error | |
157 | if (res < 0) { | |
158 | return false; | |
159 | } | |
160 | ||
161 | // Read time-out | |
162 | if (res == 0) { | |
163 | if (*pszRxLen == 0) { | |
164 | // Error, we received no data | |
165 | return false; | |
166 | } else { | |
167 | // We received some data, but nothing more is available | |
168 | return true; | |
169 | } | |
170 | } | |
171 | ||
172 | // Retrieve the count of the incoming bytes | |
173 | res = ioctl(((serial_port_unix*)sp)->fd, FIONREAD, &byteCount); | |
174 | if (res < 0) return false; | |
175 | ||
176 | // There is something available, read the data | |
177 | res = read(((serial_port_unix*)sp)->fd,pbtRx+(*pszRxLen),byteCount); | |
178 | ||
179 | // Stop if the OS has some troubles reading the data | |
180 | if (res <= 0) return false; | |
181 | ||
182 | *pszRxLen += res; | |
183 | ||
184 | } while (byteCount); | |
185 | ||
186 | return true; | |
187 | } | |
188 | ||
189 | bool uart_send(const serial_port sp, const byte_t* pbtTx, const size_t szTxLen) { | |
190 | int32_t res; | |
191 | size_t szPos = 0; | |
192 | fd_set rfds; | |
193 | struct timeval tv; | |
194 | ||
195 | while (szPos < szTxLen) | |
196 | { | |
197 | // Reset file descriptor | |
198 | FD_ZERO(&rfds); | |
199 | FD_SET(((serial_port_unix*)sp)->fd,&rfds); | |
200 | tv = timeout; | |
201 | res = select(((serial_port_unix*)sp)->fd+1, NULL, &rfds, NULL, &tv); | |
202 | ||
203 | // Write error | |
204 | if (res < 0) { | |
205 | return false; | |
206 | } | |
207 | ||
208 | // Write time-out | |
209 | if (res == 0) { | |
210 | return false; | |
211 | } | |
212 | ||
213 | // Send away the bytes | |
214 | res = write(((serial_port_unix*)sp)->fd,pbtTx+szPos,szTxLen-szPos); | |
215 | ||
216 | // Stop if the OS has some troubles sending the data | |
217 | if (res <= 0) return false; | |
218 | ||
219 | szPos += res; | |
220 | } | |
221 | return true; | |
222 | } | |
223 | ||
224 | #else | |
225 | // The windows serial port implementation | |
226 | ||
227 | typedef struct { | |
228 | HANDLE hPort; // Serial port handle | |
229 | DCB dcb; // Device control settings | |
230 | COMMTIMEOUTS ct; // Serial port time-out configuration | |
231 | } serial_port_windows; | |
232 | ||
233 | void upcase(char *p) { | |
234 | while(*p != '\0') { | |
235 | if(*p >= 97 && *p <= 122) { | |
236 | *p -= 32; | |
237 | } | |
238 | ++p; | |
239 | } | |
240 | } | |
241 | ||
242 | serial_port uart_open(const char* pcPortName) { | |
243 | char acPortName[255]; | |
244 | serial_port_windows* sp = malloc(sizeof(serial_port_windows)); | |
245 | ||
246 | // Copy the input "com?" to "\\.\COM?" format | |
247 | sprintf(acPortName,"\\\\.\\%s",pcPortName); | |
248 | upcase(acPortName); | |
249 | ||
250 | // Try to open the serial port | |
251 | sp->hPort = CreateFileA(acPortName,GENERIC_READ|GENERIC_WRITE,0,NULL,OPEN_EXISTING,0,NULL); | |
252 | if (sp->hPort == INVALID_HANDLE_VALUE) | |
253 | { | |
254 | uart_close(sp); | |
255 | return INVALID_SERIAL_PORT; | |
256 | } | |
257 | ||
258 | // Prepare the device control | |
259 | memset(&sp->dcb, 0, sizeof(DCB)); | |
260 | sp->dcb.DCBlength = sizeof(DCB); | |
261 | if(!BuildCommDCBA("baud=9600 data=8 parity=N stop=1",&sp->dcb)) | |
262 | { | |
263 | uart_close(sp); | |
264 | return INVALID_SERIAL_PORT; | |
265 | } | |
266 | ||
267 | // Update the active serial port | |
268 | if(!SetCommState(sp->hPort,&sp->dcb)) | |
269 | { | |
270 | uart_close(sp); | |
271 | return INVALID_SERIAL_PORT; | |
272 | } | |
273 | ||
274 | sp->ct.ReadIntervalTimeout = 0; | |
275 | sp->ct.ReadTotalTimeoutMultiplier = 0; | |
276 | sp->ct.ReadTotalTimeoutConstant = 30; | |
277 | sp->ct.WriteTotalTimeoutMultiplier = 0; | |
278 | sp->ct.WriteTotalTimeoutConstant = 30; | |
279 | ||
280 | if(!SetCommTimeouts(sp->hPort,&sp->ct)) | |
281 | { | |
282 | uart_close(sp); | |
283 | return INVALID_SERIAL_PORT; | |
284 | } | |
285 | ||
286 | PurgeComm(sp->hPort, PURGE_RXABORT | PURGE_RXCLEAR); | |
287 | ||
288 | return sp; | |
289 | } | |
290 | ||
291 | void uart_close(const serial_port sp) { | |
292 | CloseHandle(((serial_port_windows*)sp)->hPort); | |
293 | free(sp); | |
294 | } | |
295 | ||
296 | bool uart_set_speed(serial_port sp, const uint32_t uiPortSpeed) { | |
297 | serial_port_windows* spw; | |
298 | spw = (serial_port_windows*)sp; | |
299 | spw->dcb.BaudRate = uiPortSpeed; | |
300 | return SetCommState(spw->hPort, &spw->dcb); | |
301 | } | |
302 | ||
303 | uint32_t uart_get_speed(const serial_port sp) { | |
304 | const serial_port_windows* spw = (serial_port_windows*)sp; | |
305 | if (!GetCommState(spw->hPort, (serial_port)&spw->dcb)) { | |
306 | return spw->dcb.BaudRate; | |
307 | } | |
308 | return 0; | |
309 | } | |
310 | ||
311 | bool uart_receive(const serial_port sp, byte_t* pbtRx, size_t* pszRxLen) { | |
312 | ReadFile(((serial_port_windows*)sp)->hPort,pbtRx,*pszRxLen,(LPDWORD)pszRxLen,NULL); | |
313 | return (*pszRxLen != 0); | |
314 | } | |
315 | ||
316 | bool uart_send(const serial_port sp, const byte_t* pbtTx, const size_t szTxLen) { | |
317 | DWORD dwTxLen = 0; | |
318 | return WriteFile(((serial_port_windows*)sp)->hPort,pbtTx,szTxLen,&dwTxLen,NULL); | |
319 | return (dwTxLen != 0); | |
320 | } | |
321 | ||
322 | #endif |