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device.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 <stdio.h>
21 #include <glib.h>
22 #include "sigrok.h"
23 #include "sigrok-internal.h"
24 
25 static GSList *devs = NULL;
26 
27 /**
28  * Scan the system for attached logic analyzers / devices.
29  *
30  * This will try to autodetect all supported logic analyzer devices:
31  *
32  * - Those attached via USB (can be reliably detected via USB VID/PID).
33  *
34  * - Those using a (real or virtual) serial port (detected by sending
35  * device-specific commands to all OS-specific serial port devices such
36  * as /dev/ttyS*, /dev/ttyUSB*, /dev/ttyACM*, and others).
37  * The autodetection for this kind of devices can potentially be unreliable.
38  *
39  * Also, sending various bytes/commands to (all!) devices which happen to
40  * be attached to the system via a (real or virtual) serial port can be
41  * problematic. There is no way for libsigrok to know how unknown devices
42  * react to the bytes libsigrok sends. Potentially they could lead to the
43  * device getting into invalid/error states, losing/overwriting data, or...
44  *
45  * In addition to the detection, the devices that are found are also
46  * initialized automatically. On some devices, this involves a firmware upload,
47  * or other such measures.
48  *
49  * The order in which the system is scanned for devices is not specified. The
50  * caller should not assume or rely on any specific order.
51  *
52  * After the system has been scanned for devices, the list of detected (and
53  * supported) devices can be acquired via sr_dev_list().
54  *
55  * TODO: Error checks?
56  * TODO: Option to only scan for specific devices or device classes.
57  *
58  * @return SR_OK upon success, SR_ERR_BUG upon internal errors.
59  */
61 {
62  int i;
63  struct sr_dev_driver **drivers;
64 
65  drivers = sr_driver_list();
66  if (!drivers[0]) {
67  sr_err("dev: %s: no supported hardware drivers", __func__);
68  return SR_ERR_BUG;
69  }
70 
71  /*
72  * Initialize all drivers first. Since the init() call may involve
73  * a firmware upload and associated delay, we may as well get all
74  * of these out of the way first.
75  */
76  for (i = 0; drivers[i]; i++)
77  sr_driver_init(drivers[i]);
78 
79  return SR_OK;
80 }
81 
82 /**
83  * Return the list of logic analyzer devices libsigrok has detected.
84  *
85  * If the libsigrok-internal device list is empty, a scan for attached
86  * devices -- via a call to sr_dev_scan() -- is performed first.
87  *
88  * TODO: Error handling?
89  *
90  * @return The list (GSList) of detected devices, or NULL if none were found.
91  */
92 SR_API GSList *sr_dev_list(void)
93 {
94  if (!devs)
95  sr_dev_scan();
96 
97  return devs;
98 }
99 
100 /**
101  * Create a new device.
102  *
103  * The device is added to the (libsigrok-internal) list of devices, but
104  * additionally a pointer to the newly created device is also returned.
105  *
106  * The device has no probes attached to it yet after this call. You can
107  * use sr_dev_probe_add() to add one or more probes.
108  *
109  * TODO: Should return int, so that we can return SR_OK, SR_ERR_* etc.
110  *
111  * It is the caller's responsibility to g_free() the allocated memory when
112  * no longer needed. TODO: Using which API function?
113  *
114  * @param driver TODO.
115  * If 'driver' is NULL, the created device is a "virtual" one.
116  * @param driver_index TODO
117  *
118  * @return Pointer to the newly allocated device, or NULL upon errors.
119  */
121  int driver_index)
122 {
123  struct sr_dev *dev;
124 
125  /* TODO: Check if driver_index valid? */
126 
127  if (!(dev = g_try_malloc0(sizeof(struct sr_dev)))) {
128  sr_err("dev: %s: dev malloc failed", __func__);
129  return NULL;
130  }
131 
132  dev->driver = (struct sr_dev_driver *)driver;
133  dev->driver_index = driver_index;
134  devs = g_slist_append(devs, dev);
135 
136  return dev;
137 }
138 
139 /**
140  * Add a probe with the specified name to the specified device.
141  *
142  * The added probe is automatically enabled (the 'enabled' field is TRUE).
143  *
144  * The 'trigger' field of the added probe is set to NULL. A trigger can be
145  * added via sr_dev_trigger_set().
146  *
147  * TODO: Are duplicate names allowed?
148  * TODO: Do we enforce a maximum probe number for a device?
149  * TODO: Error if the max. probe number for the specific LA is reached, e.g.
150  * if the caller tries to add more probes than the device actually has.
151  *
152  * @param dev The device to which to add a probe with the specified name.
153  * Must not be NULL.
154  * @param name The name of the probe to add to this device. Must not be NULL.
155  * TODO: Maximum length, allowed characters, etc.
156  *
157  * @return SR_OK upon success, SR_ERR_MALLOC upon memory allocation errors,
158  * or SR_ERR_ARG upon invalid arguments.
159  * If something other than SR_OK is returned, 'dev' is unchanged.
160  */
161 SR_API int sr_dev_probe_add(struct sr_dev *dev, const char *name)
162 {
163  struct sr_probe *p;
164  int probenum;
165 
166  if (!dev) {
167  sr_err("dev: %s: dev was NULL", __func__);
168  return SR_ERR_ARG;
169  }
170 
171  if (!name) {
172  sr_err("dev: %s: name was NULL", __func__);
173  return SR_ERR_ARG;
174  }
175 
176  /* TODO: Further checks to ensure name is valid. */
177 
178  probenum = g_slist_length(dev->probes) + 1;
179 
180  if (!(p = g_try_malloc0(sizeof(struct sr_probe)))) {
181  sr_err("dev: %s: p malloc failed", __func__);
182  return SR_ERR_MALLOC;
183  }
184 
185  p->index = probenum;
186  p->enabled = TRUE;
187  p->name = g_strdup(name);
188  p->trigger = NULL;
189  dev->probes = g_slist_append(dev->probes, p);
190 
191  return SR_OK;
192 }
193 
194 /**
195  * Find the probe with the specified number in the specified device.
196  *
197  * TODO
198  *
199  * @param dev TODO. Must not be NULL.
200  * @param probenum The number of the probe whose 'struct sr_probe' we want.
201  * Note that the probe numbers start at 1 (not 0!).
202  *
203  * TODO: Should return int.
204  * TODO: probenum should be unsigned.
205  *
206  * @return A pointer to the requested probe's 'struct sr_probe', or NULL
207  * if the probe could not be found.
208  */
209 SR_API struct sr_probe *sr_dev_probe_find(const struct sr_dev *dev,
210  int probenum)
211 {
212  GSList *l;
213  struct sr_probe *p, *found_probe;
214 
215  if (!dev) {
216  sr_err("dev: %s: dev was NULL", __func__);
217  return NULL; /* TODO: SR_ERR_ARG */
218  }
219 
220  /* TODO: Sanity check on probenum. */
221 
222  found_probe = NULL;
223  for (l = dev->probes; l; l = l->next) {
224  p = l->data;
225  /* TODO: Check for p != NULL. */
226  if (p->index == probenum) {
227  found_probe = p;
228  break;
229  }
230  }
231 
232  return found_probe;
233 }
234 
235 /**
236  * Set the name of the specified probe in the specified device.
237  *
238  * If the probe already has a different name assigned to it, it will be
239  * removed, and the new name will be saved instead.
240  *
241  * @param dev TODO
242  * @param probenum The number of the probe whose name to set.
243  * Note that the probe numbers start at 1 (not 0!).
244  * @param name The new name that the specified probe should get.
245  *
246  * @return SR_OK upon success, SR_ERR_ARG upon invalid arguments, or SR_ERR
247  * upon other errors.
248  * If something other than SR_OK is returned, 'dev' is unchanged.
249  */
250 SR_API int sr_dev_probe_name_set(struct sr_dev *dev, int probenum,
251  const char *name)
252 {
253  struct sr_probe *p;
254 
255  if (!dev) {
256  sr_err("dev: %s: dev was NULL", __func__);
257  return SR_ERR_ARG;
258  }
259 
260  p = sr_dev_probe_find(dev, probenum);
261  if (!p) {
262  sr_err("dev: %s: probe %d not found", __func__, probenum);
263  return SR_ERR; /* TODO: More specific error? */
264  }
265 
266  /* TODO: Sanity check on 'name'. */
267 
268  /* If the probe already has a name, kill it first. */
269  g_free(p->name);
270 
271  p->name = g_strdup(name);
272 
273  return SR_OK;
274 }
275 
276 /**
277  * Remove all triggers set up for the specified device.
278  *
279  * TODO: Better description.
280  *
281  * @param dev TODO
282  *
283  * @return SR_OK upon success, SR_ERR_ARG upon invalid arguments.
284  * If something other than SR_OK is returned, 'dev' is unchanged.
285  */
287 {
288  struct sr_probe *p;
289  unsigned int pnum; /* TODO: uint16_t? */
290 
291  if (!dev) {
292  sr_err("dev: %s: dev was NULL", __func__);
293  return SR_ERR_ARG;
294  }
295 
296  if (!dev->probes) {
297  sr_err("dev: %s: dev->probes was NULL", __func__);
298  return SR_ERR_ARG;
299  }
300 
301  for (pnum = 1; pnum <= g_slist_length(dev->probes); pnum++) {
302  p = sr_dev_probe_find(dev, pnum);
303  /* TODO: Silently ignore probes which cannot be found? */
304  if (p) {
305  g_free(p->trigger);
306  p->trigger = NULL;
307  }
308  }
309 
310  return SR_OK;
311 }
312 
313 /**
314  * Add a trigger to the specified device (and the specified probe).
315  *
316  * If the specified probe of this device already has a trigger, it will
317  * be silently replaced.
318  *
319  * TODO: Better description.
320  * TODO: Describe valid format of the 'trigger' string.
321  *
322  * @param dev TODO. Must not be NULL.
323  * @param probenum The number of the probe. TODO.
324  * Note that the probe numbers start at 1 (not 0!).
325  * @param trigger TODO.
326  * TODO: Is NULL allowed?
327  *
328  * @return SR_OK upon success, SR_ERR_ARG upon invalid arguments, or SR_ERR
329  * upon other errors.
330  * If something other than SR_OK is returned, 'dev' is unchanged.
331  */
332 SR_API int sr_dev_trigger_set(struct sr_dev *dev, int probenum,
333  const char *trigger)
334 {
335  struct sr_probe *p;
336 
337  if (!dev) {
338  sr_err("dev: %s: dev was NULL", __func__);
339  return SR_ERR_ARG;
340  }
341 
342  /* TODO: Sanity check on 'probenum'. */
343 
344  /* TODO: Sanity check on 'trigger'. */
345 
346  p = sr_dev_probe_find(dev, probenum);
347  if (!p) {
348  sr_err("dev: %s: probe %d not found", __func__, probenum);
349  return SR_ERR; /* TODO: More specific error? */
350  }
351 
352  /* If the probe already has a trigger, kill it first. */
353  g_free(p->trigger);
354 
355  p->trigger = g_strdup(trigger);
356  sr_dbg("dev: %s: Setting '%s' trigger for probe %d.", __func__,
357  p->trigger, probenum);
358 
359  return SR_OK;
360 }
361 
362 /**
363  * Determine whether the specified device has the specified capability.
364  *
365  * @param dev Pointer to the device to be checked. Must not be NULL.
366  * If the device's 'driver' field is NULL (virtual device), this
367  * function will always return FALSE (virtual devices don't have
368  * a hardware capabilities list).
369  * @param hwcap The capability that should be checked (whether it's supported
370  * by the specified device).
371  *
372  * @return TRUE, if the device has the specified capability, FALSE otherwise.
373  * FALSE is also returned upon invalid input parameters or other
374  * error conditions.
375  */
376 SR_API gboolean sr_dev_has_hwcap(const struct sr_dev *dev, int hwcap)
377 {
378  int *hwcaps, i;
379 
380  sr_spew("dev: %s: requesting hwcap %d", __func__, hwcap);
381 
382  if (!dev) {
383  sr_err("dev: %s: dev was NULL", __func__);
384  return FALSE;
385  }
386 
387  /*
388  * Virtual devices (which have dev->driver set to NULL) always say that
389  * they don't have the capability (they can't call hwcap_get_all()).
390  */
391  if (!dev->driver) {
392  sr_dbg("dev: %s: dev->driver was NULL, this seems to be "
393  "a virtual device without capabilities", __func__);
394  return FALSE;
395  }
396 
397  /* TODO: Sanity check on 'hwcap'. */
398 
399  if (!(hwcaps = dev->driver->hwcap_get_all())) {
400  sr_err("dev: %s: dev has no capabilities", __func__);
401  return FALSE;
402  }
403 
404  for (i = 0; hwcaps[i]; i++) {
405  if (hwcaps[i] != hwcap)
406  continue;
407  sr_spew("dev: %s: found hwcap %d", __func__, hwcap);
408  return TRUE;
409  }
410 
411  sr_spew("dev: %s: hwcap %d not found", __func__, hwcap);
412 
413  return FALSE;
414 }
415 
416 /**
417  * Returns information about the given device.
418  *
419  * @param dev Pointer to the device to be checked. Must not be NULL.
420  * The device's 'driver' field must not be NULL either.
421  * @param id The type of information.
422  * @param data The return value. Must not be NULL.
423  *
424  * @return SR_OK upon success, SR_ERR_ARG upon invalid arguments, or SR_ERR
425  * upon other errors.
426  */
427 SR_API int sr_dev_info_get(const struct sr_dev *dev, int id, const void **data)
428 {
429  if ((dev == NULL) || (dev->driver == NULL))
430  return SR_ERR_ARG;
431 
432  if (data == NULL)
433  return SR_ERR_ARG;
434 
435  *data = dev->driver->dev_info_get(dev->driver_index, id);
436 
437  if (*data == NULL)
438  return SR_ERR;
439 
440  return SR_OK;
441 }