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serial.c
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1 /*
2  * This file is part of the sigrok project.
3  *
4  * Copyright (C) 2010-2012 Bert Vermeulen <bert@biot.com>
5  *
6  * This program is free software: you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation, either version 3 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program. If not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #include <string.h>
21 #include <sys/types.h>
22 #include <sys/stat.h>
23 #include <fcntl.h>
24 #include <unistd.h>
25 #ifdef _WIN32
26 #include <windows.h>
27 #else
28 #include <glob.h>
29 #include <termios.h>
30 #endif
31 #include <stdlib.h>
32 #include <glib.h>
33 #include "sigrok.h"
34 #include "sigrok-internal.h"
35 
36 // FIXME: Must be moved, or rather passed as function argument.
37 #ifdef _WIN32
38 static HANDLE hdl;
39 #endif
40 
41 static const char *serial_port_glob[] = {
42  /* Linux */
43  "/dev/ttyS*",
44  "/dev/ttyUSB*",
45  "/dev/ttyACM*",
46  /* MacOS X */
47  "/dev/ttys*",
48  "/dev/tty.USB-*",
49  "/dev/tty.Modem-*",
50  NULL,
51 };
52 
54 {
55  GSList *ports;
56 
57 #ifdef _WIN32
58  /* TODO */
59  ports = NULL;
60  ports = g_slist_append(ports, g_strdup("COM1"));
61 #else
62  glob_t g;
63  unsigned int i, j;
64 
65  ports = NULL;
66  for (i = 0; serial_port_glob[i]; i++) {
67  if (glob(serial_port_glob[i], 0, NULL, &g))
68  continue;
69  for (j = 0; j < g.gl_pathc; j++)
70  ports = g_slist_append(ports, g_strdup(g.gl_pathv[j]));
71  globfree(&g);
72  }
73 #endif
74 
75  return ports;
76 }
77 
78 SR_PRIV int serial_open(const char *pathname, int flags)
79 {
80 #ifdef _WIN32
81  /* FIXME: Don't hardcode COM1. */
82  hdl = CreateFile("COM1", GENERIC_READ | GENERIC_WRITE, 0, 0,
83  OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0);
84  if (hdl == INVALID_HANDLE_VALUE) {
85  /* TODO: Error handling. */
86  }
87  return 0;
88 #else
89  return open(pathname, flags);
90 #endif
91 }
92 
93 /*
94  * Close the serial port.
95  * Returns 0 upon success, -1 upon failure.
96  */
97 SR_PRIV int serial_close(int fd)
98 {
99 #ifdef _WIN32
100  /* Returns non-zero upon success, 0 upon failure. */
101  return (CloseHandle(hdl) == 0) ? -1 : 0;
102 #else
103  /* Returns 0 upon success, -1 upon failure. */
104  return close(fd);
105 #endif
106 }
107 
108 /*
109  * Flush serial port buffers (if any).
110  * Returns 0 upon success, -1 upon failure.
111  */
113 {
114 #ifdef _WIN32
115  /* Returns non-zero upon success, 0 upon failure. */
116  return (PurgeComm(hdl, PURGE_RXCLEAR | PURGE_TXCLEAR) == 0) ? -1 : 0;
117 #else
118  /* Returns 0 upon success, -1 upon failure. */
119  return tcflush(fd, TCIOFLUSH);
120 #endif
121 }
122 
123 /*
124  * Write a number of bytes to the specified serial port.
125  * Returns the number of bytes written, or -1 upon failure.
126  */
127 SR_PRIV int serial_write(int fd, const void *buf, size_t count)
128 {
129 #ifdef _WIN32
130  DWORD tmp = 0;
131 
132  /* FIXME */
133  /* Returns non-zero upon success, 0 upon failure. */
134  WriteFile(hdl, buf, count, &tmp, NULL);
135 #else
136  /* Returns the number of bytes written, or -1 upon failure. */
137  return write(fd, buf, count);
138 #endif
139 }
140 
141 /*
142  * Read a number of bytes from the specified serial port.
143  * Returns the number of bytes read, or -1 upon failure.
144  */
145 SR_PRIV int serial_read(int fd, void *buf, size_t count)
146 {
147 #ifdef _WIN32
148  DWORD tmp = 0;
149 
150  /* FIXME */
151  /* Returns non-zero upon success, 0 upon failure. */
152  return ReadFile(hdl, buf, count, &tmp, NULL);
153 #else
154  /* Returns the number of bytes read, or -1 upon failure. */
155  return read(fd, buf, count);
156 #endif
157 }
158 
160 {
161 #ifdef _WIN32
162  /* TODO */
163 #else
164  struct termios *term;
165 
166  /* TODO: 'term' is never g_free()'d? */
167  if (!(term = g_try_malloc(sizeof(struct termios)))) {
168  sr_err("serial: %s: term malloc failed", __func__);
169  return NULL;
170  }
171 
172  tcgetattr(fd, term);
173 
174  return term;
175 #endif
176 }
177 
178 SR_PRIV void serial_restore_params(int fd, void *backup)
179 {
180 #ifdef _WIN32
181  /* TODO */
182 #else
183  tcsetattr(fd, TCSADRAIN, (struct termios *)backup);
184 #endif
185 }
186 
187 /*
188  * Set serial parameters.
189  *
190  * flowcontrol: 1 = rts/cts, 2 = xon/xoff
191  * parity: 0 = none, 1 = even, 2 = odd
192  */
193 SR_PRIV int serial_set_params(int fd, int baudrate, int bits, int parity,
194  int stopbits, int flowcontrol)
195 {
196 #ifdef _WIN32
197  DCB dcb;
198 
199  if (!GetCommState(hdl, &dcb)) {
200  /* TODO: Error handling. */
201  return SR_ERR;
202  }
203 
204  switch (baudrate) {
205  /* TODO: Support for higher baud rates. */
206  case 115200:
207  dcb.BaudRate = CBR_115200;
208  break;
209  case 57600:
210  dcb.BaudRate = CBR_57600;
211  break;
212  case 38400:
213  dcb.BaudRate = CBR_38400;
214  break;
215  case 19200:
216  dcb.BaudRate = CBR_19200;
217  break;
218  case 9600:
219  dcb.BaudRate = CBR_9600;
220  break;
221  default:
222  /* TODO: Error handling. */
223  break;
224  }
225  dcb.ByteSize = bits;
226  dcb.Parity = NOPARITY; /* TODO: Don't hardcode. */
227  dcb.StopBits = ONESTOPBIT; /* TODO: Don't hardcode. */
228 
229  if (!SetCommState(hdl, &dcb)) {
230  /* TODO: Error handling. */
231  return SR_ERR;
232  }
233 #else
234  struct termios term;
235  speed_t baud;
236 
237  switch (baudrate) {
238  case 9600:
239  baud = B9600;
240  break;
241  case 38400:
242  baud = B38400;
243  break;
244  case 57600:
245  baud = B57600;
246  break;
247  case 115200:
248  baud = B115200;
249  break;
250 #ifndef __APPLE__
251  case 460800:
252  baud = B460800;
253  break;
254 #endif
255  default:
256  return SR_ERR;
257  }
258 
259  if (tcgetattr(fd, &term) < 0)
260  return SR_ERR;
261  if (cfsetispeed(&term, baud) < 0)
262  return SR_ERR;
263 
264  term.c_cflag &= ~CSIZE;
265  switch (bits) {
266  case 8:
267  term.c_cflag |= CS8;
268  break;
269  case 7:
270  term.c_cflag |= CS7;
271  break;
272  default:
273  return SR_ERR;
274  }
275 
276  term.c_cflag &= ~CSTOPB;
277  switch (stopbits) {
278  case 1:
279  break;
280  case 2:
281  term.c_cflag |= CSTOPB;
282  default:
283  return SR_ERR;
284  }
285 
286  term.c_cflag &= ~(IXON | IXOFF | CRTSCTS);
287  switch (flowcontrol) {
288  case 2:
289  term.c_cflag |= IXON | IXOFF;
290  break;
291  case 1:
292  term.c_cflag |= CRTSCTS;
293  default:
294  return SR_ERR;
295  }
296 
297  term.c_iflag &= ~IGNPAR;
298  term.c_cflag &= ~(PARODD | PARENB);
299  switch (parity) {
300  case 0:
301  term.c_iflag |= IGNPAR;
302  break;
303  case 1:
304  term.c_cflag |= PARENB;
305  break;
306  case 2:
307  term.c_cflag |= PARENB | PARODD;
308  break;
309  default:
310  return SR_ERR;
311  }
312 
313  if (tcsetattr(fd, TCSADRAIN, &term) < 0)
314  return SR_ERR;
315 #endif
316 
317  return SR_OK;
318 }