libsigrok  0.2.0
sigrok hardware access and backend library
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backend.c
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1 /*
2  * This file is part of the libsigrok project.
3  *
4  * Copyright (C) 2010-2012 Bert Vermeulen <bert@biot.com>
5  * Copyright (C) 2012 Peter Stuge <peter@stuge.se>
6  *
7  * This program is free software: you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation, either version 3 of the License, or
10  * (at your option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program. If not, see <http://www.gnu.org/licenses/>.
19  */
20 
21 #include <glib.h>
22 #include "config.h" /* Needed for HAVE_LIBUSB_1_0 and others. */
23 #include "libsigrok.h"
24 #include "libsigrok-internal.h"
25 
26 /**
27  * @mainpage libsigrok API
28  *
29  * @section sec_intro Introduction
30  *
31  * The <a href="http://sigrok.org">sigrok</a> project aims at creating a
32  * portable, cross-platform, Free/Libre/Open-Source signal analysis software
33  * suite that supports various device types (such as logic analyzers,
34  * oscilloscopes, multimeters, and more).
35  *
36  * <a href="http://sigrok.org/wiki/Libsigrok">libsigrok</a> is a shared
37  * library written in C which provides the basic API for talking to
38  * <a href="http://sigrok.org/wiki/Supported_hardware">supported hardware</a>
39  * and reading/writing the acquired data into various
40  * <a href="http://sigrok.org/wiki/Input_output_formats">input/output
41  * file formats</a>.
42  *
43  * @section sec_api API reference
44  *
45  * See the "Modules" page for an introduction to various libsigrok
46  * related topics and the detailed API documentation of the respective
47  * functions.
48  *
49  * You can also browse the API documentation by file, or review all
50  * data structures.
51  *
52  * @section sec_mailinglists Mailing lists
53  *
54  * There are two mailing lists for sigrok/libsigrok: <a href="https://lists.sourceforge.net/lists/listinfo/sigrok-devel">sigrok-devel</a> and <a href="https://lists.sourceforge.net/lists/listinfo/sigrok-commits">sigrok-commits</a>.
55  *
56  * @section sec_irc IRC
57  *
58  * You can find the sigrok developers in the
59  * <a href="irc://chat.freenode.net/sigrok">\#sigrok</a>
60  * IRC channel on Freenode.
61  *
62  * @section sec_website Website
63  *
64  * <a href="http://sigrok.org/wiki/Libsigrok">sigrok.org/wiki/Libsigrok</a>
65  */
66 
67 /**
68  * @file
69  *
70  * Initializing and shutting down libsigrok.
71  */
72 
73 /**
74  * @defgroup grp_init Initialization
75  *
76  * Initializing and shutting down libsigrok.
77  *
78  * Before using any of the libsigrok functionality, sr_init() must
79  * be called to initialize the library, which will return a struct sr_context
80  * when the initialization was successful.
81  *
82  * When libsigrok functionality is no longer needed, sr_exit() should be
83  * called, which will (among other things) free the struct sr_context.
84  *
85  * Example for a minimal program using libsigrok:
86  *
87  * @code{.c}
88  * #include <stdio.h>
89  * #include <libsigrok/libsigrok.h>
90  *
91  * int main(int argc, char **argv)
92  * {
93  * int ret;
94  * struct sr_context *sr_ctx;
95  *
96  * if ((ret = sr_init(&sr_ctx)) != SR_OK) {
97  * printf("Error initializing libsigrok (%s): %s.",
98  * sr_strerror_name(ret), sr_strerror(ret));
99  * return 1;
100  * }
101  *
102  * // Use libsigrok functions here...
103  *
104  * if ((ret = sr_exit(sr_ctx)) != SR_OK) {
105  * printf("Error shutting down libsigrok (%s): %s.",
106  * sr_strerror_name(ret), sr_strerror(ret));
107  * return 1;
108  * }
109  *
110  * return 0;
111  * }
112  * @endcode
113  *
114  * @{
115  */
116 
117 /**
118  * Sanity-check all libsigrok drivers.
119  *
120  * @return SR_OK if all drivers are OK, SR_ERR if one or more have issues.
121  */
122 static int sanity_check_all_drivers(void)
123 {
124  int i, errors, ret = SR_OK;
125  struct sr_dev_driver **drivers;
126  const char *d;
127 
128  sr_spew("Sanity-checking all drivers.");
129 
130  drivers = sr_driver_list();
131  for (i = 0; drivers[i]; i++) {
132  errors = 0;
133 
134  d = (drivers[i]->name) ? drivers[i]->name : "NULL";
135 
136  if (!drivers[i]->name) {
137  sr_err("No name in driver %d ('%s').", i, d);
138  errors++;
139  }
140  if (!drivers[i]->longname) {
141  sr_err("No longname in driver %d ('%s').", i, d);
142  errors++;
143  }
144  if (drivers[i]->api_version < 1) {
145  sr_err("API version in driver %d ('%s') < 1.", i, d);
146  errors++;
147  }
148  if (!drivers[i]->init) {
149  sr_err("No init in driver %d ('%s').", i, d);
150  errors++;
151  }
152  if (!drivers[i]->cleanup) {
153  sr_err("No cleanup in driver %d ('%s').", i, d);
154  errors++;
155  }
156  if (!drivers[i]->scan) {
157  sr_err("No scan in driver %d ('%s').", i, d);
158  errors++;
159  }
160  if (!drivers[i]->dev_list) {
161  sr_err("No dev_list in driver %d ('%s').", i, d);
162  errors++;
163  }
164  if (!drivers[i]->dev_clear) {
165  sr_err("No dev_clear in driver %d ('%s').", i, d);
166  errors++;
167  }
168  /* Note: config_get() is optional. */
169  if (!drivers[i]->config_set) {
170  sr_err("No config_set in driver %d ('%s').", i, d);
171  errors++;
172  }
173  if (!drivers[i]->config_list) {
174  sr_err("No config_list in driver %d ('%s').", i, d);
175  errors++;
176  }
177  if (!drivers[i]->dev_open) {
178  sr_err("No dev_open in driver %d ('%s').", i, d);
179  errors++;
180  }
181  if (!drivers[i]->dev_close) {
182  sr_err("No dev_close in driver %d ('%s').", i, d);
183  errors++;
184  }
185  if (!drivers[i]->dev_acquisition_start) {
186  sr_err("No dev_acquisition_start in driver %d ('%s').",
187  i, d);
188  errors++;
189  }
190  if (!drivers[i]->dev_acquisition_stop) {
191  sr_err("No dev_acquisition_stop in driver %d ('%s').",
192  i, d);
193  errors++;
194  }
195 
196  /* Note: 'priv' is allowed to be NULL. */
197 
198  if (errors == 0)
199  continue;
200 
201  ret = SR_ERR;
202  }
203 
204  return ret;
205 }
206 
207 /**
208  * Sanity-check all libsigrok input modules.
209  *
210  * @return SR_OK if all modules are OK, SR_ERR if one or more have issues.
211  */
212 static int sanity_check_all_input_modules(void)
213 {
214  int i, errors, ret = SR_OK;
215  struct sr_input_format **inputs;
216  const char *d;
217 
218  sr_spew("Sanity-checking all input modules.");
219 
220  inputs = sr_input_list();
221  for (i = 0; inputs[i]; i++) {
222  errors = 0;
223 
224  d = (inputs[i]->id) ? inputs[i]->id : "NULL";
225 
226  if (!inputs[i]->id) {
227  sr_err("No ID in module %d ('%s').", i, d);
228  errors++;
229  }
230  if (!inputs[i]->description) {
231  sr_err("No description in module %d ('%s').", i, d);
232  errors++;
233  }
234  if (!inputs[i]->format_match) {
235  sr_err("No format_match in module %d ('%s').", i, d);
236  errors++;
237  }
238  if (!inputs[i]->init) {
239  sr_err("No init in module %d ('%s').", i, d);
240  errors++;
241  }
242  if (!inputs[i]->loadfile) {
243  sr_err("No loadfile in module %d ('%s').", i, d);
244  errors++;
245  }
246 
247  if (errors == 0)
248  continue;
249 
250  ret = SR_ERR;
251  }
252 
253  return ret;
254 }
255 
256 /**
257  * Sanity-check all libsigrok output modules.
258  *
259  * @return SR_OK if all modules are OK, SR_ERR if one or more have issues.
260  */
261 static int sanity_check_all_output_modules(void)
262 {
263  int i, errors, ret = SR_OK;
264  struct sr_output_format **outputs;
265  const char *d;
266 
267  sr_spew("Sanity-checking all output modules.");
268 
269  outputs = sr_output_list();
270  for (i = 0; outputs[i]; i++) {
271  errors = 0;
272 
273  d = (outputs[i]->id) ? outputs[i]->id : "NULL";
274 
275  if (!outputs[i]->id) {
276  sr_err("No ID in module %d ('%s').", i, d);
277  errors++;
278  }
279  if (!outputs[i]->description) {
280  sr_err("No description in module %d ('%s').", i, d);
281  errors++;
282  }
283  if (outputs[i]->df_type < 10000 || outputs[i]->df_type > 10007) {
284  sr_err("Invalid df_type %d in module %d ('%s').",
285  outputs[i]->df_type, i, d);
286  errors++;
287  }
288 
289  /* All modules must provide a data or recv API callback. */
290  if (!outputs[i]->data && !outputs[i]->receive) {
291  sr_err("No data/receive in module %d ('%s').", i, d);
292  errors++;
293  }
294 
295  /*
296  * Currently most API calls are optional (their function
297  * pointers can thus be NULL) in theory: init, event, cleanup.
298  */
299 
300  if (errors == 0)
301  continue;
302 
303  ret = SR_ERR;
304  }
305 
306  return ret;
307 }
308 
309 /**
310  * Initialize libsigrok.
311  *
312  * This function must be called before any other libsigrok function.
313  *
314  * @param ctx Pointer to a libsigrok context struct pointer. Must not be NULL.
315  * This will be a pointer to a newly allocated libsigrok context
316  * object upon success, and is undefined upon errors.
317  *
318  * @return SR_OK upon success, a (negative) error code otherwise. Upon errors
319  * the 'ctx' pointer is undefined and should not be used. Upon success,
320  * the context will be free'd by sr_exit() as part of the libsigrok
321  * shutdown.
322  *
323  * @since 0.1.0 (but the API changed in 0.2.0)
324  */
325 SR_API int sr_init(struct sr_context **ctx)
326 {
327  int ret = SR_ERR;
328  struct sr_context *context;
329 
330  if (!ctx) {
331  sr_err("%s(): libsigrok context was NULL.", __func__);
332  return SR_ERR;
333  }
334 
335  if (sanity_check_all_drivers() < 0) {
336  sr_err("Internal driver error(s), aborting.");
337  return ret;
338  }
339 
340  if (sanity_check_all_input_modules() < 0) {
341  sr_err("Internal input module error(s), aborting.");
342  return ret;
343  }
344 
345  if (sanity_check_all_output_modules() < 0) {
346  sr_err("Internal output module error(s), aborting.");
347  return ret;
348  }
349 
350  /* + 1 to handle when struct sr_context has no members. */
351  context = g_try_malloc0(sizeof(struct sr_context) + 1);
352 
353  if (!context) {
354  ret = SR_ERR_MALLOC;
355  goto done;
356  }
357 
358 #ifdef HAVE_LIBUSB_1_0
359  ret = libusb_init(&context->libusb_ctx);
360  if (LIBUSB_SUCCESS != ret) {
361  sr_err("libusb_init() returned %s.\n", libusb_error_name(ret));
362  ret = SR_ERR;
363  goto done;
364  }
365 #endif
366 
367  *ctx = context;
368  context = NULL;
369  ret = SR_OK;
370 
371 done:
372  if (context)
373  g_free(context);
374  return ret;
375 }
376 
377 /**
378  * Shutdown libsigrok.
379  *
380  * @param ctx Pointer to a libsigrok context struct. Must not be NULL.
381  *
382  * @return SR_OK upon success, a (negative) error code otherwise.
383  *
384  * @since 0.1.0 (but the API changed in 0.2.0)
385  */
386 SR_API int sr_exit(struct sr_context *ctx)
387 {
388  if (!ctx) {
389  sr_err("%s(): libsigrok context was NULL.", __func__);
390  return SR_ERR;
391  }
392 
393  sr_hw_cleanup_all();
394 
395 #ifdef HAVE_LIBUSB_1_0
396  libusb_exit(ctx->libusb_ctx);
397 #endif
398 
399  g_free(ctx);
400 
401  return SR_OK;
402 }
403 
404 /** @} */