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_309_driver_info;
 112 extern SR_PRIV struct sr_dev_driver voltcraft_k204_driver_info;
 113 #endif
 114 #ifdef HAVE_HW_COLEAD_SLM
 115 extern SR_PRIV struct sr_dev_driver colead_slm_driver_info;
 116 #endif
 117 #ifdef HAVE_HW_DEMO
 118 extern SR_PRIV struct sr_dev_driver demo_driver_info;
 119 #endif
 120 #ifdef HAVE_HW_IKALOGIC_SCANALOGIC2
 121 extern SR_PRIV struct sr_dev_driver ikalogic_scanalogic2_driver_info;
 122 #endif
 123 #ifdef HAVE_HW_IKALOGIC_SCANAPLUS
 124 extern SR_PRIV struct sr_dev_driver ikalogic_scanaplus_driver_info;
 125 #endif
 126 #ifdef HAVE_HW_KECHENG_KC_330B
 127 extern SR_PRIV struct sr_dev_driver kecheng_kc_330b_driver_info;
 128 #endif
 129 #ifdef HAVE_HW_LASCAR_EL_USB
 130 extern SR_PRIV struct sr_dev_driver lascar_el_usb_driver_info;
 131 #endif
 132 #ifdef HAVE_HW_MIC_985XX
 133 extern SR_PRIV struct sr_dev_driver mic_98581_driver_info;
 134 extern SR_PRIV struct sr_dev_driver mic_98583_driver_info;
 135 #endif
 136 #ifdef HAVE_HW_OLS
 137 extern SR_PRIV struct sr_dev_driver ols_driver_info;
 138 #endif
 139 #ifdef HAVE_HW_RIGOL_DS1XX2
 140 extern SR_PRIV struct sr_dev_driver rigol_ds1xx2_driver_info;
 141 #endif
 142 #ifdef HAVE_HW_SALEAE_LOGIC16
 143 extern SR_PRIV struct sr_dev_driver saleae_logic16_driver_info;
 144 #endif
 145 #ifdef HAVE_HW_TONDAJ_SL_814
 146 extern SR_PRIV struct sr_dev_driver tondaj_sl_814_driver_info;
 147 #endif
 148 #ifdef HAVE_HW_UNI_T_UT32X
 149 extern SR_PRIV struct sr_dev_driver uni_t_ut32x_driver_info;
 150 #endif
 151 #ifdef HAVE_HW_VICTOR_DMM
 152 extern SR_PRIV struct sr_dev_driver victor_dmm_driver_info;
 153 #endif
 154 #ifdef HAVE_HW_ZEROPLUS_LOGIC_CUBE
 155 extern SR_PRIV struct sr_dev_driver zeroplus_logic_cube_driver_info;
 156 #endif
 157 #ifdef HAVE_HW_ASIX_SIGMA
 158 extern SR_PRIV struct sr_dev_driver asix_sigma_driver_info;
 159 #endif
 160 #ifdef HAVE_HW_CHRONOVU_LA8
 161 extern SR_PRIV struct sr_dev_driver chronovu_la8_driver_info;
 162 #endif
 163 #ifdef HAVE_HW_LINK_MSO19
 164 extern SR_PRIV struct sr_dev_driver link_mso19_driver_info;
 165 #endif
 166 #ifdef HAVE_HW_ALSA
 167 extern SR_PRIV struct sr_dev_driver alsa_driver_info;
 168 #endif
 169 #ifdef HAVE_HW_FX2LAFW
 170 extern SR_PRIV struct sr_dev_driver fx2lafw_driver_info;
 171 #endif
 172 #ifdef HAVE_HW_HANTEK_DSO
 173 extern SR_PRIV struct sr_dev_driver hantek_dso_driver_info;
 174 #endif
 175 #ifdef HAVE_HW_AGILENT_DMM
 176 extern SR_PRIV struct sr_dev_driver agdmm_driver_info;
 177 #endif
 178 #ifdef HAVE_HW_FLUKE_DMM
 179 extern SR_PRIV struct sr_dev_driver flukedmm_driver_info;
 180 #endif
 181 #ifdef HAVE_HW_SERIAL_DMM
 182 extern SR_PRIV struct sr_dev_driver digitek_dt4000zc_driver_info;
 183 extern SR_PRIV struct sr_dev_driver tekpower_tp4000zc_driver_info;
 184 extern SR_PRIV struct sr_dev_driver metex_me31_driver_info;
 185 extern SR_PRIV struct sr_dev_driver peaktech_3410_driver_info;
 186 extern SR_PRIV struct sr_dev_driver mastech_mas345_driver_info;
 187 extern SR_PRIV struct sr_dev_driver va_va18b_driver_info;
 188 extern SR_PRIV struct sr_dev_driver metex_m3640d_driver_info;
 189 extern SR_PRIV struct sr_dev_driver peaktech_4370_driver_info;
 190 extern SR_PRIV struct sr_dev_driver pce_pce_dm32_driver_info;
 191 extern SR_PRIV struct sr_dev_driver radioshack_22_168_driver_info;
 192 extern SR_PRIV struct sr_dev_driver radioshack_22_805_driver_info;
 193 extern SR_PRIV struct sr_dev_driver radioshack_22_812_driver_info;
 194 extern SR_PRIV struct sr_dev_driver tecpel_dmm_8061_ser_driver_info;
 195 extern SR_PRIV struct sr_dev_driver voltcraft_m3650d_driver_info;
 196 extern SR_PRIV struct sr_dev_driver voltcraft_vc820_ser_driver_info;
 197 extern SR_PRIV struct sr_dev_driver voltcraft_vc830_ser_driver_info;
 198 extern SR_PRIV struct sr_dev_driver voltcraft_vc840_ser_driver_info;
 199 extern SR_PRIV struct sr_dev_driver uni_t_ut60a_ser_driver_info;
 200 extern SR_PRIV struct sr_dev_driver uni_t_ut60e_ser_driver_info;
 201 extern SR_PRIV struct sr_dev_driver uni_t_ut61d_ser_driver_info;
 202 extern SR_PRIV struct sr_dev_driver uni_t_ut61e_ser_driver_info;
 203 #endif
 204 #ifdef HAVE_HW_UNI_T_DMM
 205 extern SR_PRIV struct sr_dev_driver tecpel_dmm_8061_driver_info;
 206 extern SR_PRIV struct sr_dev_driver uni_t_ut60a_driver_info;
 207 extern SR_PRIV struct sr_dev_driver uni_t_ut60e_driver_info;
 208 extern SR_PRIV struct sr_dev_driver uni_t_ut61d_driver_info;
 209 extern SR_PRIV struct sr_dev_driver uni_t_ut61e_driver_info;
 210 extern SR_PRIV struct sr_dev_driver voltcraft_vc820_driver_info;
 211 extern SR_PRIV struct sr_dev_driver voltcraft_vc830_driver_info;
 212 extern SR_PRIV struct sr_dev_driver voltcraft_vc840_driver_info;
 213 #endif
 214 /** @endcond */
 215
 216 static struct sr_dev_driver *drivers_list[] = {
 217 #ifdef HAVE_HW_BRYMEN_DMM
 218         &brymen_bm857_driver_info,
 219 #endif
 220 #ifdef HAVE_HW_CEM_DT_885X
 221         &cem_dt_885x_driver_info,
 222 #endif
 223 #ifdef HAVE_HW_CENTER_3XX
 224         &center_309_driver_info,
 225         &voltcraft_k204_driver_info,
 226 #endif
 227 #ifdef HAVE_HW_COLEAD_SLM
 228         &colead_slm_driver_info,
 229 #endif
 230 #ifdef HAVE_HW_DEMO
 231         &demo_driver_info,
 232 #endif
 233 #ifdef HAVE_HW_IKALOGIC_SCANALOGIC2
 234         &ikalogic_scanalogic2_driver_info,
 235 #endif
 236 #ifdef HAVE_HW_IKALOGIC_SCANAPLUS
 237         &ikalogic_scanaplus_driver_info,
 238 #endif
 239 #ifdef HAVE_HW_KECHENG_KC_330B
 240         &kecheng_kc_330b_driver_info,
 241 #endif
 242 #ifdef HAVE_HW_LASCAR_EL_USB
 243         &lascar_el_usb_driver_info,
 244 #endif
 245 #ifdef HAVE_HW_MIC_985XX
 246         &mic_98581_driver_info,
 247         &mic_98583_driver_info,
 248 #endif
 249 #ifdef HAVE_HW_OLS
 250         &ols_driver_info,
 251 #endif
 252 #ifdef HAVE_HW_RIGOL_DS1XX2
 253         &rigol_ds1xx2_driver_info,
 254 #endif
 255 #ifdef HAVE_HW_SALEAE_LOGIC16
 256         &saleae_logic16_driver_info,
 257 #endif
 258 #ifdef HAVE_HW_TONDAJ_SL_814
 259         &tondaj_sl_814_driver_info,
 260 #endif
 261 #ifdef HAVE_HW_UNI_T_UT32X
 262         &uni_t_ut32x_driver_info,
 263 #endif
 264 #ifdef HAVE_HW_VICTOR_DMM
 265         &victor_dmm_driver_info,
 266 #endif
 267 #ifdef HAVE_HW_ZEROPLUS_LOGIC_CUBE
 268         &zeroplus_logic_cube_driver_info,
 269 #endif
 270 #ifdef HAVE_HW_ASIX_SIGMA
 271         &asix_sigma_driver_info,
 272 #endif
 273 #ifdef HAVE_HW_CHRONOVU_LA8
 274         &chronovu_la8_driver_info,
 275 #endif
 276 #ifdef HAVE_HW_LINK_MSO19
 277         &link_mso19_driver_info,
 278 #endif
 279 #ifdef HAVE_HW_ALSA
 280         &alsa_driver_info,
 281 #endif
 282 #ifdef HAVE_HW_FX2LAFW
 283         &fx2lafw_driver_info,
 284 #endif
 285 #ifdef HAVE_HW_HANTEK_DSO
 286         &hantek_dso_driver_info,
 287 #endif
 288 #ifdef HAVE_HW_AGILENT_DMM
 289         &agdmm_driver_info,
 290 #endif
 291 #ifdef HAVE_HW_FLUKE_DMM
 292         &flukedmm_driver_info,
 293 #endif
 294 #ifdef HAVE_HW_SERIAL_DMM
 295         &digitek_dt4000zc_driver_info,
 296         &tekpower_tp4000zc_driver_info,
 297         &metex_me31_driver_info,
 298         &peaktech_3410_driver_info,
 299         &mastech_mas345_driver_info,
 300         &va_va18b_driver_info,
 301         &metex_m3640d_driver_info,
 302         &peaktech_4370_driver_info,
 303         &pce_pce_dm32_driver_info,
 304         &radioshack_22_168_driver_info,
 305         &radioshack_22_805_driver_info,
 306         &radioshack_22_812_driver_info,
 307         &tecpel_dmm_8061_ser_driver_info,
 308         &voltcraft_m3650d_driver_info,
 309         &voltcraft_vc820_ser_driver_info,
 310         &voltcraft_vc830_ser_driver_info,
 311         &voltcraft_vc840_ser_driver_info,
 312         &uni_t_ut60a_ser_driver_info,
 313         &uni_t_ut60e_ser_driver_info,
 314         &uni_t_ut61d_ser_driver_info,
 315         &uni_t_ut61e_ser_driver_info,
 316 #endif
 317 #ifdef HAVE_HW_UNI_T_DMM
 318         &tecpel_dmm_8061_driver_info,
 319         &uni_t_ut60a_driver_info,
 320         &uni_t_ut60e_driver_info,
 321         &uni_t_ut61d_driver_info,
 322         &uni_t_ut61e_driver_info,
 323         &voltcraft_vc820_driver_info,
 324         &voltcraft_vc830_driver_info,
 325         &voltcraft_vc840_driver_info,
 326 #endif
 327         NULL,
 328 };
 329
 330 /**
 331  * Return the list of supported hardware drivers.
 332  *
 333  * @return Pointer to the NULL-terminated list of hardware driver pointers.
 334  */
 335 SR_API struct sr_dev_driver **sr_driver_list(void)
 336 {
 337
 338         return drivers_list;
 339 }
 340
 341 /**
 342  * Initialize a hardware driver.
 343  *
 344  * This usually involves memory allocations and variable initializations
 345  * within the driver, but _not_ scanning for attached devices.
 346  * The API call sr_driver_scan() is used for that.
 347  *
 348  * @param ctx A libsigrok context object allocated by a previous call to
 349  *            sr_init(). Must not be NULL.
 350  * @param driver The driver to initialize. This must be a pointer to one of
 351  *               the entries returned by sr_driver_list(). Must not be NULL.
 352  *
 353  * @return SR_OK upon success, SR_ERR_ARG upon invalid parameters,
 354  *         SR_ERR_BUG upon internal errors, or another negative error code
 355  *         upon other errors.
 356  */
 357 SR_API int sr_driver_init(struct sr_context *ctx, struct sr_dev_driver *driver)
 358 {
 359         int ret;
 360
 361         if (!ctx) {
 362                 sr_err("Invalid libsigrok context, can't initialize.");
 363                 return SR_ERR_ARG;
 364         }
 365
 366         if (!driver) {
 367                 sr_err("Invalid driver, can't initialize.");
 368                 return SR_ERR_ARG;
 369         }
 370
 371         sr_spew("Initializing driver '%s'.", driver->name);
 372         if ((ret = driver->init(ctx)) < 0)
 373                 sr_err("Failed to initialize the driver: %d.", ret);
 374
 375         return ret;
 376 }
 377
 378 /**
 379  * Tell a hardware driver to scan for devices.
 380  *
 381  * In addition to the detection, the devices that are found are also
 382  * initialized automatically. On some devices, this involves a firmware upload,
 383  * or other such measures.
 384  *
 385  * The order in which the system is scanned for devices is not specified. The
 386  * caller should not assume or rely on any specific order.
 387  *
 388  * Before calling sr_driver_scan(), the user must have previously initialized
 389  * the driver by calling sr_driver_init().
 390  *
 391  * @param driver The driver that should scan. This must be a pointer to one of
 392  *               the entries returned by sr_driver_list(). Must not be NULL.
 393  * @param options A list of 'struct sr_hwopt' options to pass to the driver's
 394  *                scanner. Can be NULL/empty.
 395  *
 396  * @return A GSList * of 'struct sr_dev_inst', or NULL if no devices were
 397  *         found (or errors were encountered). This list must be freed by the
 398  *         caller using g_slist_free(), but without freeing the data pointed
 399  *         to in the list.
 400  */
 401 SR_API GSList *sr_driver_scan(struct sr_dev_driver *driver, GSList *options)
 402 {
 403         GSList *l;
 404
 405         if (!driver) {
 406                 sr_err("Invalid driver, can't scan for devices.");
 407                 return NULL;
 408         }
 409
 410         if (!driver->priv) {
 411                 sr_err("Driver not initialized, can't scan for devices.");
 412                 return NULL;
 413         }
 414
 415         l = driver->scan(options);
 416
 417         sr_spew("Scan of '%s' found %d devices.", driver->name,
 418                 g_slist_length(l));
 419
 420         return l;
 421 }
 422
 423 /** @private */
 424 SR_PRIV void sr_hw_cleanup_all(void)
 425 {
 426         int i;
 427         struct sr_dev_driver **drivers;
 428
 429         drivers = sr_driver_list();
 430         for (i = 0; drivers[i]; i++) {
 431                 if (drivers[i]->cleanup)
 432                         drivers[i]->cleanup();
 433         }
 434 }
 435
 436 /** A floating reference can be passed in for data. */
 437 SR_PRIV struct sr_config *sr_config_new(int key, GVariant *data)
 438 {
 439         struct sr_config *src;
 440
 441         if (!(src = g_try_malloc(sizeof(struct sr_config))))
 442                 return NULL;
 443         src->key = key;
 444         src->data = g_variant_ref_sink(data);
 445
 446         return src;
 447 }
 448
 449 SR_PRIV void sr_config_free(struct sr_config *src)
 450 {
 451
 452         if (!src || !src->data) {
 453                 sr_err("%s: invalid data!", __func__);
 454                 return;
 455         }
 456
 457         g_variant_unref(src->data);
 458         g_free(src);
 459
 460 }
 461
 462 /**
 463  * Returns information about the given driver or device instance.
 464  *
 465  * @param driver The sr_dev_driver struct to query.
 466  * @param key The configuration key (SR_CONF_*).
 467  * @param data Pointer to a GVariant where the value will be stored. Must
 468  *             not be NULL. The caller is given ownership of the GVariant
 469  *             and must thus decrease the refcount after use. However if
 470  *             this function returns an error code, the field should be
 471  *             considered unused, and should not be unreferenced.
 472  * @param sdi (optional) If the key is specific to a device, this must
 473  *            contain a pointer to the struct sr_dev_inst to be checked.
 474  *            Otherwise it must be NULL.
 475  *
 476  * @return SR_OK upon success or SR_ERR in case of error. Note SR_ERR_ARG
 477  *         may be returned by the driver indicating it doesn't know that key,
 478  *         but this is not to be flagged as an error by the caller; merely
 479  *         as an indication that it's not applicable.
 480  */
 481 SR_API int sr_config_get(const struct sr_dev_driver *driver, int key,
 482                 GVariant **data, const struct sr_dev_inst *sdi)
 483 {
 484         int ret;
 485
 486         if (!driver || !data)
 487                 return SR_ERR;
 488
 489         if (!driver->config_get)
 490                 return SR_ERR_ARG;
 491
 492         if ((ret = driver->config_get(key, data, sdi)) == SR_OK) {
 493                 /* Got a floating reference from the driver. Sink it here,
 494                  * caller will need to unref when done with it. */
 495                 g_variant_ref_sink(*data);
 496         }
 497
 498         return ret;
 499 }
 500
 501 /**
 502  * Set a configuration key in a device instance.
 503  *
 504  * @param sdi The device instance.
 505  * @param key The configuration key (SR_CONF_*).
 506  * @param data The new value for the key, as a GVariant with GVariantType
 507  *        appropriate to that key. A floating reference can be passed
 508  *        in; its refcount will be sunk and unreferenced after use.
 509  *
 510  * @return SR_OK upon success or SR_ERR in case of error. Note SR_ERR_ARG
 511  *         may be returned by the driver indicating it doesn't know that key,
 512  *         but this is not to be flagged as an error by the caller; merely
 513  *         as an indication that it's not applicable.
 514  */
 515 SR_API int sr_config_set(const struct sr_dev_inst *sdi, int key, GVariant *data)
 516 {
 517         int ret;
 518
 519         g_variant_ref_sink(data);
 520
 521         if (!sdi || !sdi->driver || !data)
 522                 ret = SR_ERR;
 523         else if (!sdi->driver->config_set)
 524                 ret = SR_ERR_ARG;
 525         else
 526                 ret = sdi->driver->config_set(key, data, sdi);
 527
 528         g_variant_unref(data);
 529
 530         return ret;
 531 }
 532
 533 /**
 534  * List all possible values for a configuration key.
 535  *
 536  * @param driver The sr_dev_driver struct to query.
 537  * @param key The configuration key (SR_CONF_*).
 538  * @param data A pointer to a GVariant where the list will be stored. The
 539  *             caller is given ownership of the GVariant and must thus
 540  *             unref the GVariant after use. However if this function
 541  *             returns an error code, the field should be considered
 542  *             unused, and should not be unreferenced.
 543  * @param sdi (optional) If the key is specific to a device, this must
 544  *            contain a pointer to the struct sr_dev_inst to be checked.
 545  *
 546  * @return SR_OK upon success or SR_ERR in case of error. Note SR_ERR_ARG
 547  *         may be returned by the driver indicating it doesn't know that key,
 548  *         but this is not to be flagged as an error by the caller; merely
 549  *         as an indication that it's not applicable.
 550  */
 551 SR_API int sr_config_list(const struct sr_dev_driver *driver, int key,
 552                 GVariant **data, const struct sr_dev_inst *sdi)
 553 {
 554         int ret;
 555
 556         if (!driver || !data)
 557                 ret = SR_ERR;
 558         else if (!driver->config_list)
 559                 ret = SR_ERR_ARG;
 560         else if ((ret = driver->config_list(key, data, sdi)) == SR_OK)
 561                 g_variant_ref_sink(*data);
 562
 563         return ret;
 564 }
 565
 566 /**
 567  * Get information about a configuration key.
 568  *
 569  * @param key The configuration key.
 570  *
 571  * @return A pointer to a struct sr_config_info, or NULL if the key
 572  *         was not found.
 573  */
 574 SR_API const struct sr_config_info *sr_config_info_get(int key)
 575 {
 576         int i;
 577
 578         for (i = 0; sr_config_info_data[i].key; i++) {
 579                 if (sr_config_info_data[i].key == key)
 580                         return &sr_config_info_data[i];
 581         }
 582
 583         return NULL;
 584 }
 585
 586 /**
 587  * Get information about an configuration key, by name.
 588  *
 589  * @param optname The configuration key.
 590  *
 591  * @return A pointer to a struct sr_config_info, or NULL if the key
 592  *         was not found.
 593  */
 594 SR_API const struct sr_config_info *sr_config_info_name_get(const char *optname)
 595 {
 596         int i;
 597
 598         for (i = 0; sr_config_info_data[i].key; i++) {
 599                 if (!strcmp(sr_config_info_data[i].id, optname))
 600                         return &sr_config_info_data[i];
 601         }
 602
 603         return NULL;
 604 }
 605
 606 /* Unnecessary level of indirection follows. */
 607
 608 /** @private */
 609 SR_PRIV int sr_source_remove(int fd)
 610 {
 611         return sr_session_source_remove(fd);
 612 }
 613
 614 /** @private */
 615 SR_PRIV int sr_source_add(int fd, int events, int timeout,
 616                           sr_receive_data_callback_t cb, void *cb_data)
 617 {
 618         return sr_session_source_add(fd, events, timeout, cb, cb_data);
 619 }
 620
 621 /** @} */