2 * Generic uart / rs232/ serial port library
4 * Copyright (c) 2013, Roel Verdult
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.
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.
36 // Test if we are dealing with unix operating systems
40 typedef struct termios term_info
;
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
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
53 serial_port
uart_open(const char* pcPortName
)
55 serial_port_unix
* sp
= malloc(sizeof(serial_port_unix
));
56 if (sp
== 0) return INVALID_SERIAL_PORT
;
58 sp
->fd
= open(pcPortName
, O_RDWR
| O_NOCTTY
| O_NDELAY
| O_NONBLOCK
);
61 return INVALID_SERIAL_PORT
;
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
68 fl
.l_whence
= SEEK_SET
;
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
;
79 // Try to retrieve the old (current) terminal info struct
80 if(tcgetattr(sp
->fd
,&sp
->tiOld
) == -1) {
82 return INVALID_SERIAL_PORT
;
85 // Duplicate the (old) terminal info struct
86 sp
->tiNew
= sp
->tiOld
;
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;
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;
99 // Try to set the new terminal info struct
100 if(tcsetattr(sp
->fd
,TCSANOW
,&sp
->tiNew
) == -1) {
102 return INVALID_SERIAL_PORT
;
105 // Flush all lingering data that may exist
106 tcflush(sp
->fd
, TCIOFLUSH
);
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
));
117 fl
.l_whence
= SEEK_SET
;
121 fcntl(spu
->fd
, F_SETLK
, &fl
);
126 bool uart_set_speed(serial_port sp
, const uint32_t uiPortSpeed
) {
127 const serial_port_unix
* spu
= (serial_port_unix
*)sp
;
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;
146 case 57600: stPortSpeed
= B57600
; break;
149 case 115200: stPortSpeed
= B115200
; break;
152 case 230400: stPortSpeed
= B230400
; break;
155 case 460800: stPortSpeed
= B460800
; break;
158 case 921600: stPortSpeed
= B921600
; break;
160 default: return false;
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);
170 uint32_t uart_get_speed(const serial_port sp
) {
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;
194 case B57600
: uiPortSpeed
= 57600; break;
197 case B115200
: uiPortSpeed
= 115200; break;
200 case B230400
: uiPortSpeed
= 230400; break;
203 case B460800
: uiPortSpeed
= 460800; break;
206 case B921600
: uiPortSpeed
= 921600; break;
213 bool uart_set_parity(serial_port sp
, serial_port_parity spp
) {
215 const serial_port_unix
* spu
= (serial_port_unix
*)sp
;
216 if (tcgetattr(spu
->fd
,&ti
) == -1) return false;
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;
223 return (tcsetattr(spu
->fd
,TCSANOW
,&ti
) != -1);
226 serial_port_parity
uart_get_parity(const serial_port sp
) {
228 const serial_port_unix
* spu
= (serial_port_unix
*)sp
;
229 if (tcgetattr(spu
->fd
,&ti
) == -1) return SP_INVALID
;
231 if (ti
.c_cflag
& PARENB
) {
232 if (ti
.c_cflag
& PARODD
) {
242 bool uart_cts(const serial_port sp
) {
244 if (ioctl(((serial_port_unix
*)sp
)->fd
,TIOCMGET
,&status
) < 0) return false;
245 return (status
& TIOCM_CTS
);
248 bool uart_receive(const serial_port sp
, byte_t
* pbtRx
, size_t* pszRxLen
) {
255 // Reset the output count
259 // Reset file descriptor
261 FD_SET(((serial_port_unix
*)sp
)->fd
,&rfds
);
263 res
= select(((serial_port_unix
*)sp
)->fd
+1, &rfds
, NULL
, NULL
, &tv
);
272 if (*pszRxLen
== 0) {
273 // Error, we received no data
276 // We received some data, but nothing more is available
281 // Retrieve the count of the incoming bytes
282 res
= ioctl(((serial_port_unix
*)sp
)->fd
, FIONREAD
, &byteCount
);
283 if (res
< 0) return false;
285 // There is something available, read the data
286 res
= read(((serial_port_unix
*)sp
)->fd
,pbtRx
+(*pszRxLen
),byteCount
);
288 // Stop if the OS has some troubles reading the data
289 if (res
<= 0) return false;
298 bool uart_send(const serial_port sp
, const byte_t
* pbtTx
, const size_t szTxLen
) {
304 while (szPos
< szTxLen
) {
305 // Reset file descriptor
307 FD_SET(((serial_port_unix
*)sp
)->fd
,&rfds
);
309 res
= select(((serial_port_unix
*)sp
)->fd
+1, NULL
, &rfds
, NULL
, &tv
);
321 // Send away the bytes
322 res
= write(((serial_port_unix
*)sp
)->fd
,pbtTx
+szPos
,szTxLen
-szPos
);
324 // Stop if the OS has some troubles sending the data
325 if (res
<= 0) return false;
333 // The windows serial port implementation
336 HANDLE hPort
; // Serial port handle
337 DCB dcb
; // Device control settings
338 COMMTIMEOUTS ct
; // Serial port time-out configuration
339 } serial_port_windows
;
341 void upcase(char *p
) {
343 if(*p
>= 97 && *p
<= 122) {
350 serial_port
uart_open(const char* pcPortName
) {
351 char acPortName
[255];
352 serial_port_windows
* sp
= malloc(sizeof(serial_port_windows
));
354 // Copy the input "com?" to "\\.\COM?" format
355 sprintf(acPortName
,"\\\\.\\%s",pcPortName
);
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
) {
362 return INVALID_SERIAL_PORT
;
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
)) {
370 return INVALID_SERIAL_PORT
;
373 // Update the active serial port
374 if(!SetCommState(sp
->hPort
,&sp
->dcb
)) {
376 return INVALID_SERIAL_PORT
;
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;
385 if(!SetCommTimeouts(sp
->hPort
,&sp
->ct
)) {
387 return INVALID_SERIAL_PORT
;
390 PurgeComm(sp
->hPort
, PURGE_RXABORT
| PURGE_RXCLEAR
);
395 void uart_close(const serial_port sp
) {
396 CloseHandle(((serial_port_windows
*)sp
)->hPort
);
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
);
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
;
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);
420 bool uart_send(const serial_port sp
, const byte_t
* pbtTx
, const size_t szTxLen
) {
422 return WriteFile(((serial_port_windows
*)sp
)->hPort
,pbtTx
,szTxLen
,&dwTxLen
,NULL
);
423 return (dwTxLen
!= 0);