hwdriver.c

   1 /*
   2  * This file is part of the libsigrok project.
   3  *
   4  * Copyright (C) 2013 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 <stdlib.h>
  21 #include <stdio.h>
  22 #include <sys/types.h>
  23 #include <dirent.h>
  24 #include <string.h>
  25 #include <glib.h>
  26 #include "config.h" /* Needed for HAVE_LIBUSB_1_0 and others. */
  27 #include "libsigrok.h"
  28 #include "libsigrok-internal.h"
  29
  30 /* Message logging helpers with subsystem-specific prefix string. */
  31 #define LOG_PREFIX "hwdriver: "
  32 #define sr_log(l, s, args...) sr_log(l, LOG_PREFIX s, ## args)
  33 #define sr_spew(s, args...) sr_spew(LOG_PREFIX s, ## args)
  34 #define sr_dbg(s, args...) sr_dbg(LOG_PREFIX s, ## args)
  35 #define sr_info(s, args...) sr_info(LOG_PREFIX s, ## args)
  36 #define sr_warn(s, args...) sr_warn(LOG_PREFIX s, ## args)
  37 #define sr_err(s, args...) sr_err(LOG_PREFIX s, ## args)
  38
  39 /**
  40  * @file
  41  *
  42  * Hardware driver handling in libsigrok.
  43  */
  44
  45 /**
  46  * @defgroup grp_driver Hardware drivers
  47  *
  48  * Hardware driver handling in libsigrok.
  49  *
  50  * @{
  51  */
  52
  53 static struct sr_config_info sr_config_info_data[] = {
  54         {SR_CONF_CONN, SR_T_CHAR, "conn",
  55                 "Connection", NULL},
  56         {SR_CONF_SERIALCOMM, SR_T_CHAR, "serialcomm",
  57                 "Serial communication", NULL},
  58         {SR_CONF_SAMPLERATE, SR_T_UINT64, "samplerate",
  59                 "Sample rate", NULL},
  60         {SR_CONF_CAPTURE_RATIO, SR_T_UINT64, "captureratio",
  61                 "Pre-trigger capture ratio", NULL},
  62         {SR_CONF_PATTERN_MODE, SR_T_CHAR, "pattern",
  63                 "Pattern generator mode", NULL},
  64         {SR_CONF_TRIGGER_TYPE, SR_T_CHAR, "triggertype",
  65                 "Trigger types", NULL},
  66         {SR_CONF_RLE, SR_T_BOOL, "rle",
  67                 "Run Length Encoding", NULL},
  68         {SR_CONF_TRIGGER_SLOPE, SR_T_UINT64, "triggerslope",
  69                 "Trigger slope", NULL},
  70         {SR_CONF_TRIGGER_SOURCE, SR_T_CHAR, "triggersource",
  71                 "Trigger source", NULL},
  72         {SR_CONF_HORIZ_TRIGGERPOS, SR_T_FLOAT, "horiz_triggerpos",
  73                 "Horizontal trigger position", NULL},
  74         {SR_CONF_BUFFERSIZE, SR_T_UINT64, "buffersize",
  75                 "Buffer size", NULL},
  76         {SR_CONF_TIMEBASE, SR_T_RATIONAL_PERIOD, "timebase",
  77                 "Time base", NULL},
  78         {SR_CONF_FILTER, SR_T_CHAR, "filter",
  79                 "Filter targets", NULL},
  80         {SR_CONF_VDIV, SR_T_RATIONAL_VOLT, "vdiv",
  81                 "Volts/div", NULL},
  82         {SR_CONF_COUPLING, SR_T_CHAR, "coupling",
  83                 "Coupling", NULL},
  84         {SR_CONF_DATALOG, SR_T_BOOL, "datalog",
  85                 "Datalog", NULL},
  86         {SR_CONF_SPL_WEIGHT_FREQ, SR_T_CHAR, "spl_weight_freq",
  87                 "Sound pressure level frequency weighting", NULL},
  88         {SR_CONF_SPL_WEIGHT_TIME, SR_T_CHAR, "spl_weight_time",
  89                 "Sound pressure level time weighting", NULL},
  90         {SR_CONF_HOLD_MAX, SR_T_BOOL, "hold_max",
  91                 "Hold max", NULL},
  92         {SR_CONF_HOLD_MIN, SR_T_BOOL, "hold_min",
  93                 "Hold min", NULL},
  94         {SR_CONF_SPL_MEASUREMENT_RANGE, SR_T_UINT64_RANGE, "spl_meas_range",
  95                 "Sound pressure level measurement range", NULL},
  96         {SR_CONF_POWER_OFF, SR_T_BOOL, "power_off",
  97                 "Power off", NULL},
  98         {SR_CONF_DATA_SOURCE, SR_T_CHAR, "data_source",
  99                 "Data source", NULL},
 100         {0, 0, NULL, NULL, NULL},
 101 };
 102
 103 /** @cond PRIVATE */
 104 #ifdef HAVE_HW_BRYMEN_DMM
 105 extern SR_PRIV struct sr_dev_driver brymen_bm857_driver_info;
 106 #endif
 107 #ifdef HAVE_HW_CEM_DT_885X
 108 extern SR_PRIV struct sr_dev_driver cem_dt_885x_driver_info;
 109 #endif
 110 #ifdef HAVE_HW_CENTER_3XX
 111 extern SR_PRIV struct sr_dev_driver center_3xx_driver_info;
 112 #endif
 113 #ifdef HAVE_HW_COLEAD_SLM
 114 extern SR_PRIV struct sr_dev_driver colead_slm_driver_info;
 115 #endif
 116 #ifdef HAVE_HW_DEMO
 117 extern SR_PRIV struct sr_dev_driver demo_driver_info;
 118 #endif
 119 #ifdef HAVE_HW_IKALOGIC_SCANALOGIC2
 120 extern SR_PRIV struct sr_dev_driver ikalogic_scanalogic2_driver_info;
 121 #endif
 122 #ifdef HAVE_HW_IKALOGIC_SCANAPLUS
 123 extern SR_PRIV struct sr_dev_driver ikalogic_scanaplus_driver_info;
 124 #endif
 125 #ifdef HAVE_HW_KECHENG_KC_330B
 126 extern SR_PRIV struct sr_dev_driver kecheng_kc_330b_driver_info;
 127 #endif
 128 #ifdef HAVE_HW_LASCAR_EL_USB
 129 extern SR_PRIV struct sr_dev_driver lascar_el_usb_driver_info;
 130 #endif
 131 #ifdef HAVE_HW_MIC_985XX
 132 extern SR_PRIV struct sr_dev_driver mic_98581_driver_info;
 133 extern SR_PRIV struct sr_dev_driver mic_98583_driver_info;
 134 #endif
 135 #ifdef HAVE_HW_OLS
 136 extern SR_PRIV struct sr_dev_driver ols_driver_info;
 137 #endif
 138 #ifdef HAVE_HW_RIGOL_DS1XX2
 139 extern SR_PRIV struct sr_dev_driver rigol_ds1xx2_driver_info;
 140 #endif
 141 #ifdef HAVE_HW_TONDAJ_SL_814
 142 extern SR_PRIV struct sr_dev_driver tondaj_sl_814_driver_info;
 143 #endif
 144 #ifdef HAVE_HW_VICTOR_DMM
 145 extern SR_PRIV struct sr_dev_driver victor_dmm_driver_info;
 146 #endif
 147 #ifdef HAVE_HW_ZEROPLUS_LOGIC_CUBE
 148 extern SR_PRIV struct sr_dev_driver zeroplus_logic_cube_driver_info;
 149 #endif
 150 #ifdef HAVE_HW_ASIX_SIGMA
 151 extern SR_PRIV struct sr_dev_driver asix_sigma_driver_info;
 152 #endif
 153 #ifdef HAVE_HW_CHRONOVU_LA8
 154 extern SR_PRIV struct sr_dev_driver chronovu_la8_driver_info;
 155 #endif
 156 #ifdef HAVE_HW_LINK_MSO19
 157 extern SR_PRIV struct sr_dev_driver link_mso19_driver_info;
 158 #endif
 159 #ifdef HAVE_HW_ALSA
 160 extern SR_PRIV struct sr_dev_driver alsa_driver_info;
 161 #endif
 162 #ifdef HAVE_HW_FX2LAFW
 163 extern SR_PRIV struct sr_dev_driver fx2lafw_driver_info;
 164 #endif
 165 #ifdef HAVE_HW_HANTEK_DSO
 166 extern SR_PRIV struct sr_dev_driver hantek_dso_driver_info;
 167 #endif
 168 #ifdef HAVE_HW_AGILENT_DMM
 169 extern SR_PRIV struct sr_dev_driver agdmm_driver_info;
 170 #endif
 171 #ifdef HAVE_HW_FLUKE_DMM
 172 extern SR_PRIV struct sr_dev_driver flukedmm_driver_info;
 173 #endif
 174 #ifdef HAVE_HW_SERIAL_DMM
 175 extern SR_PRIV struct sr_dev_driver digitek_dt4000zc_driver_info;
 176 extern SR_PRIV struct sr_dev_driver tekpower_tp4000zc_driver_info;
 177 extern SR_PRIV struct sr_dev_driver metex_me31_driver_info;
 178 extern SR_PRIV struct sr_dev_driver peaktech_3410_driver_info;
 179 extern SR_PRIV struct sr_dev_driver mastech_mas345_driver_info;
 180 extern SR_PRIV struct sr_dev_driver va_va18b_driver_info;
 181 extern SR_PRIV struct sr_dev_driver metex_m3640d_driver_info;
 182 extern SR_PRIV struct sr_dev_driver peaktech_4370_driver_info;
 183 extern SR_PRIV struct sr_dev_driver pce_pce_dm32_driver_info;
 184 extern SR_PRIV struct sr_dev_driver radioshack_22_168_driver_info;
 185 extern SR_PRIV struct sr_dev_driver radioshack_22_805_driver_info;
 186 extern SR_PRIV struct sr_dev_driver radioshack_22_812_driver_info;
 187 extern SR_PRIV struct sr_dev_driver tecpel_dmm_8061_ser_driver_info;
 188 extern SR_PRIV struct sr_dev_driver voltcraft_m3650d_driver_info;
 189 extern SR_PRIV struct sr_dev_driver voltcraft_vc820_ser_driver_info;
 190 extern SR_PRIV struct sr_dev_driver voltcraft_vc830_ser_driver_info;
 191 extern SR_PRIV struct sr_dev_driver voltcraft_vc840_ser_driver_info;
 192 extern SR_PRIV struct sr_dev_driver uni_t_ut60a_ser_driver_info;
 193 extern SR_PRIV struct sr_dev_driver uni_t_ut60e_ser_driver_info;
 194 extern SR_PRIV struct sr_dev_driver uni_t_ut61d_ser_driver_info;
 195 extern SR_PRIV struct sr_dev_driver uni_t_ut61e_ser_driver_info;
 196 #endif
 197 #ifdef HAVE_HW_UNI_T_DMM
 198 extern SR_PRIV struct sr_dev_driver tecpel_dmm_8061_driver_info;
 199 extern SR_PRIV struct sr_dev_driver uni_t_ut60a_driver_info;
 200 extern SR_PRIV struct sr_dev_driver uni_t_ut60e_driver_info;
 201 extern SR_PRIV struct sr_dev_driver uni_t_ut61d_driver_info;
 202 extern SR_PRIV struct sr_dev_driver uni_t_ut61e_driver_info;
 203 extern SR_PRIV struct sr_dev_driver voltcraft_vc820_driver_info;
 204 extern SR_PRIV struct sr_dev_driver voltcraft_vc830_driver_info;
 205 extern SR_PRIV struct sr_dev_driver voltcraft_vc840_driver_info;
 206 #endif
 207 /** @endcond */
 208
 209 static struct sr_dev_driver *drivers_list[] = {
 210 #ifdef HAVE_HW_BRYMEN_DMM
 211         &brymen_bm857_driver_info,
 212 #endif
 213 #ifdef HAVE_HW_CEM_DT_885X
 214         &cem_dt_885x_driver_info,
 215 #endif
 216 #ifdef HAVE_HW_CENTER_3XX
 217         &center_3xx_driver_info,
 218 #endif
 219 #ifdef HAVE_HW_COLEAD_SLM
 220         &colead_slm_driver_info,
 221 #endif
 222 #ifdef HAVE_HW_DEMO
 223         &demo_driver_info,
 224 #endif
 225 #ifdef HAVE_HW_IKALOGIC_SCANALOGIC2
 226         &ikalogic_scanalogic2_driver_info,
 227 #endif
 228 #ifdef HAVE_HW_IKALOGIC_SCANAPLUS
 229         &ikalogic_scanaplus_driver_info,
 230 #endif
 231 #ifdef HAVE_HW_KECHENG_KC_330B
 232         &kecheng_kc_330b_driver_info,
 233 #endif
 234 #ifdef HAVE_HW_LASCAR_EL_USB
 235         &lascar_el_usb_driver_info,
 236 #endif
 237 #ifdef HAVE_HW_MIC_985XX
 238         &mic_98581_driver_info,
 239         &mic_98583_driver_info,
 240 #endif
 241 #ifdef HAVE_HW_OLS
 242         &ols_driver_info,
 243 #endif
 244 #ifdef HAVE_HW_RIGOL_DS1XX2
 245         &rigol_ds1xx2_driver_info,
 246 #endif
 247 #ifdef HAVE_HW_TONDAJ_SL_814
 248         &tondaj_sl_814_driver_info,
 249 #endif
 250 #ifdef HAVE_HW_VICTOR_DMM
 251         &victor_dmm_driver_info,
 252 #endif
 253 #ifdef HAVE_HW_ZEROPLUS_LOGIC_CUBE
 254         &zeroplus_logic_cube_driver_info,
 255 #endif
 256 #ifdef HAVE_HW_ASIX_SIGMA
 257         &asix_sigma_driver_info,
 258 #endif
 259 #ifdef HAVE_HW_CHRONOVU_LA8
 260         &chronovu_la8_driver_info,
 261 #endif
 262 #ifdef HAVE_HW_LINK_MSO19
 263         &link_mso19_driver_info,
 264 #endif
 265 #ifdef HAVE_HW_ALSA
 266         &alsa_driver_info,
 267 #endif
 268 #ifdef HAVE_HW_FX2LAFW
 269         &fx2lafw_driver_info,
 270 #endif
 271 #ifdef HAVE_HW_HANTEK_DSO
 272         &hantek_dso_driver_info,
 273 #endif
 274 #ifdef HAVE_HW_AGILENT_DMM
 275         &agdmm_driver_info,
 276 #endif
 277 #ifdef HAVE_HW_FLUKE_DMM
 278         &flukedmm_driver_info,
 279 #endif
 280 #ifdef HAVE_HW_SERIAL_DMM
 281         &digitek_dt4000zc_driver_info,
 282         &tekpower_tp4000zc_driver_info,
 283         &metex_me31_driver_info,
 284         &peaktech_3410_driver_info,
 285         &mastech_mas345_driver_info,
 286         &va_va18b_driver_info,
 287         &metex_m3640d_driver_info,
 288         &peaktech_4370_driver_info,
 289         &pce_pce_dm32_driver_info,
 290         &radioshack_22_168_driver_info,
 291         &radioshack_22_805_driver_info,
 292         &radioshack_22_812_driver_info,
 293         &tecpel_dmm_8061_ser_driver_info,
 294         &voltcraft_m3650d_driver_info,
 295         &voltcraft_vc820_ser_driver_info,
 296         &voltcraft_vc830_ser_driver_info,
 297         &voltcraft_vc840_ser_driver_info,
 298         &uni_t_ut60a_ser_driver_info,
 299         &uni_t_ut60e_ser_driver_info,
 300         &uni_t_ut61d_ser_driver_info,
 301         &uni_t_ut61e_ser_driver_info,
 302 #endif
 303 #ifdef HAVE_HW_UNI_T_DMM
 304         &tecpel_dmm_8061_driver_info,
 305         &uni_t_ut60a_driver_info,
 306         &uni_t_ut60e_driver_info,
 307         &uni_t_ut61d_driver_info,
 308         &uni_t_ut61e_driver_info,
 309         &voltcraft_vc820_driver_info,
 310         &voltcraft_vc830_driver_info,
 311         &voltcraft_vc840_driver_info,
 312 #endif
 313         NULL,
 314 };
 315
 316 /**
 317  * Return the list of supported hardware drivers.
 318  *
 319  * @return Pointer to the NULL-terminated list of hardware driver pointers.
 320  */
 321 SR_API struct sr_dev_driver **sr_driver_list(void)
 322 {
 323
 324         return drivers_list;
 325 }
 326
 327 /**
 328  * Initialize a hardware driver.
 329  *
 330  * This usually involves memory allocations and variable initializations
 331  * within the driver, but _not_ scanning for attached devices.
 332  * The API call sr_driver_scan() is used for that.
 333  *
 334  * @param ctx A libsigrok context object allocated by a previous call to
 335  *            sr_init(). Must not be NULL.
 336  * @param driver The driver to initialize. This must be a pointer to one of
 337  *               the entries returned by sr_driver_list(). Must not be NULL.
 338  *
 339  * @return SR_OK upon success, SR_ERR_ARG upon invalid parameters,
 340  *         SR_ERR_BUG upon internal errors, or another negative error code
 341  *         upon other errors.
 342  */
 343 SR_API int sr_driver_init(struct sr_context *ctx, struct sr_dev_driver *driver)
 344 {
 345         int ret;
 346
 347         if (!ctx) {
 348                 sr_err("Invalid libsigrok context, can't initialize.");
 349                 return SR_ERR_ARG;
 350         }
 351
 352         if (!driver) {
 353                 sr_err("Invalid driver, can't initialize.");
 354                 return SR_ERR_ARG;
 355         }
 356
 357         sr_spew("Initializing driver '%s'.", driver->name);
 358         if ((ret = driver->init(ctx)) < 0)
 359                 sr_err("Failed to initialize the driver: %d.", ret);
 360
 361         return ret;
 362 }
 363
 364 /**
 365  * Tell a hardware driver to scan for devices.
 366  *
 367  * In addition to the detection, the devices that are found are also
 368  * initialized automatically. On some devices, this involves a firmware upload,
 369  * or other such measures.
 370  *
 371  * The order in which the system is scanned for devices is not specified. The
 372  * caller should not assume or rely on any specific order.
 373  *
 374  * Before calling sr_driver_scan(), the user must have previously initialized
 375  * the driver by calling sr_driver_init().
 376  *
 377  * @param driver The driver that should scan. This must be a pointer to one of
 378  *               the entries returned by sr_driver_list(). Must not be NULL.
 379  * @param options A list of 'struct sr_hwopt' options to pass to the driver's
 380  *                scanner. Can be NULL/empty.
 381  *
 382  * @return A GSList * of 'struct sr_dev_inst', or NULL if no devices were
 383  *         found (or errors were encountered). This list must be freed by the
 384  *         caller using g_slist_free(), but without freeing the data pointed
 385  *         to in the list.
 386  */
 387 SR_API GSList *sr_driver_scan(struct sr_dev_driver *driver, GSList *options)
 388 {
 389         GSList *l;
 390
 391         if (!driver) {
 392                 sr_err("Invalid driver, can't scan for devices.");
 393                 return NULL;
 394         }
 395
 396         if (!driver->priv) {
 397                 sr_err("Driver not initialized, can't scan for devices.");
 398                 return NULL;
 399         }
 400
 401         l = driver->scan(options);
 402
 403         sr_spew("Scan of '%s' found %d devices.", driver->name,
 404                 g_slist_length(l));
 405
 406         return l;
 407 }
 408
 409 /** @private */
 410 SR_PRIV void sr_hw_cleanup_all(void)
 411 {
 412         int i;
 413         struct sr_dev_driver **drivers;
 414
 415         drivers = sr_driver_list();
 416         for (i = 0; drivers[i]; i++) {
 417                 if (drivers[i]->cleanup)
 418                         drivers[i]->cleanup();
 419         }
 420 }
 421
 422 /** A floating reference can be passed in for data. */
 423 SR_PRIV struct sr_config *sr_config_new(int key, GVariant *data)
 424 {
 425         struct sr_config *src;
 426
 427         if (!(src = g_try_malloc(sizeof(struct sr_config))))
 428                 return NULL;
 429         src->key = key;
 430         src->data = g_variant_ref_sink(data);
 431
 432         return src;
 433 }
 434
 435 SR_PRIV void sr_config_free(struct sr_config *src)
 436 {
 437
 438         if (!src || !src->data) {
 439                 sr_err("%s: invalid data!", __func__);
 440                 return;
 441         }
 442
 443         g_variant_unref(src->data);
 444         g_free(src);
 445
 446 }
 447
 448 /**
 449  * Returns information about the given driver or device instance.
 450  *
 451  * @param driver The sr_dev_driver struct to query.
 452  * @param key The configuration key (SR_CONF_*).
 453  * @param data Pointer to a GVariant where the value will be stored. Must
 454  *             not be NULL. The caller is given ownership of the GVariant
 455  *             and must thus decrease the refcount after use. However if
 456  *             this function returns an error code, the field should be
 457  *             considered unused, and should not be unreferenced.
 458  * @param sdi (optional) If the key is specific to a device, this must
 459  *            contain a pointer to the struct sr_dev_inst to be checked.
 460  *            Otherwise it must be NULL.
 461  *
 462  * @return SR_OK upon success or SR_ERR in case of error. Note SR_ERR_ARG
 463  *         may be returned by the driver indicating it doesn't know that key,
 464  *         but this is not to be flagged as an error by the caller; merely
 465  *         as an indication that it's not applicable.
 466  */
 467 SR_API int sr_config_get(const struct sr_dev_driver *driver, int key,
 468                 GVariant **data, const struct sr_dev_inst *sdi)
 469 {
 470         int ret;
 471
 472         if (!driver || !data)
 473                 return SR_ERR;
 474
 475         if (!driver->config_get)
 476                 return SR_ERR_ARG;
 477
 478         if ((ret = driver->config_get(key, data, sdi)) == SR_OK) {
 479                 /* Got a floating reference from the driver. Sink it here,
 480                  * caller will need to unref when done with it. */
 481                 g_variant_ref_sink(*data);
 482         }
 483
 484         return ret;
 485 }
 486
 487 /**
 488  * Set a configuration key in a device instance.
 489  *
 490  * @param sdi The device instance.
 491  * @param key The configuration key (SR_CONF_*).
 492  * @param data The new value for the key, as a GVariant with GVariantType
 493  *        appropriate to that key. A floating reference can be passed
 494  *        in; its refcount will be sunk and unreferenced after use.
 495  *
 496  * @return SR_OK upon success or SR_ERR in case of error. Note SR_ERR_ARG
 497  *         may be returned by the driver indicating it doesn't know that key,
 498  *         but this is not to be flagged as an error by the caller; merely
 499  *         as an indication that it's not applicable.
 500  */
 501 SR_API int sr_config_set(const struct sr_dev_inst *sdi, int key, GVariant *data)
 502 {
 503         int ret;
 504
 505         g_variant_ref_sink(data);
 506
 507         if (!sdi || !sdi->driver || !data)
 508                 ret = SR_ERR;
 509         else if (!sdi->driver->config_set)
 510                 ret = SR_ERR_ARG;
 511         else
 512                 ret = sdi->driver->config_set(key, data, sdi);
 513
 514         g_variant_unref(data);
 515
 516         return ret;
 517 }
 518
 519 /**
 520  * List all possible values for a configuration key.
 521  *
 522  * @param driver The sr_dev_driver struct to query.
 523  * @param key The configuration key (SR_CONF_*).
 524  * @param data A pointer to a GVariant where the list will be stored. The
 525  *             caller is given ownership of the GVariant and must thus
 526  *             unref the GVariant after use. However if this function
 527  *             returns an error code, the field should be considered
 528  *             unused, and should not be unreferenced.
 529  * @param sdi (optional) If the key is specific to a device, this must
 530  *            contain a pointer to the struct sr_dev_inst to be checked.
 531  *
 532  * @return SR_OK upon success or SR_ERR in case of error. Note SR_ERR_ARG
 533  *         may be returned by the driver indicating it doesn't know that key,
 534  *         but this is not to be flagged as an error by the caller; merely
 535  *         as an indication that it's not applicable.
 536  */
 537 SR_API int sr_config_list(const struct sr_dev_driver *driver, int key,
 538                 GVariant **data, const struct sr_dev_inst *sdi)
 539 {
 540         int ret;
 541
 542         if (!driver || !data)
 543                 ret = SR_ERR;
 544         else if (!driver->config_list)
 545                 ret = SR_ERR_ARG;
 546         else if ((ret = driver->config_list(key, data, sdi)) == SR_OK)
 547                 g_variant_ref_sink(*data);
 548
 549         return ret;
 550 }
 551
 552 /**
 553  * Get information about a configuration key.
 554  *
 555  * @param key The configuration key.
 556  *
 557  * @return A pointer to a struct sr_config_info, or NULL if the key
 558  *         was not found.
 559  */
 560 SR_API const struct sr_config_info *sr_config_info_get(int key)
 561 {
 562         int i;
 563
 564         for (i = 0; sr_config_info_data[i].key; i++) {
 565                 if (sr_config_info_data[i].key == key)
 566                         return &sr_config_info_data[i];
 567         }
 568
 569         return NULL;
 570 }
 571
 572 /**
 573  * Get information about an configuration key, by name.
 574  *
 575  * @param optname The configuration key.
 576  *
 577  * @return A pointer to a struct sr_config_info, or NULL if the key
 578  *         was not found.
 579  */
 580 SR_API const struct sr_config_info *sr_config_info_name_get(const char *optname)
 581 {
 582         int i;
 583
 584         for (i = 0; sr_config_info_data[i].key; i++) {
 585                 if (!strcmp(sr_config_info_data[i].id, optname))
 586                         return &sr_config_info_data[i];
 587         }
 588
 589         return NULL;
 590 }
 591
 592 /* Unnecessary level of indirection follows. */
 593
 594 /** @private */
 595 SR_PRIV int sr_source_remove(int fd)
 596 {
 597         return sr_session_source_remove(fd);
 598 }
 599
 600 /** @private */
 601 SR_PRIV int sr_source_add(int fd, int events, int timeout,
 602                           sr_receive_data_callback_t cb, void *cb_data)
 603 {
 604         return sr_session_source_add(fd, events, timeout, cb, cb_data);
 605 }
 606
 607 /** @} */