src/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 /** @cond PRIVATE */
  31 #define LOG_PREFIX "hwdriver"
  32 /** @endcond */
  33
  34 extern SR_PRIV struct sr_dev_driver *drivers_list[];
  35
  36 /**
  37  * @file
  38  *
  39  * Hardware driver handling in libsigrok.
  40  */
  41
  42 /**
  43  * @defgroup grp_driver Hardware drivers
  44  *
  45  * Hardware driver handling in libsigrok.
  46  *
  47  * @{
  48  */
  49
  50 static struct sr_config_info sr_config_info_data[] = {
  51         /* Device types */
  52         {SR_CONF_LOGIC_ANALYZER, SR_T_STRING, NULL, "Logic Analyzer", NULL},
  53         {SR_CONF_OSCILLOSCOPE, SR_T_STRING, NULL, "Oscilloscope", NULL},
  54         {SR_CONF_MULTIMETER, SR_T_STRING, NULL, "Multimeter", NULL},
  55         {SR_CONF_DEMO_DEV, SR_T_STRING, NULL, "Demo device", NULL},
  56         {SR_CONF_SOUNDLEVELMETER, SR_T_STRING, NULL, "Sound level meter", NULL},
  57         {SR_CONF_THERMOMETER, SR_T_STRING, NULL, "Thermometer", NULL},
  58         {SR_CONF_HYGROMETER, SR_T_STRING, NULL, "Hygrometer", NULL},
  59         {SR_CONF_ENERGYMETER, SR_T_STRING, NULL, "Energy meter", NULL},
  60         {SR_CONF_DEMODULATOR, SR_T_STRING, NULL, "Demodulator", NULL},
  61         {SR_CONF_POWER_SUPPLY, SR_T_STRING, NULL, "Power supply", NULL},
  62         {SR_CONF_LCRMETER, SR_T_STRING, NULL, "LCR meter", NULL},
  63
  64         /* Sample limiting */
  65         {SR_CONF_LIMIT_SAMPLES, SR_T_UINT64, "limit_samples",
  66                 "Sample limit", NULL},
  67         {SR_CONF_LIMIT_MSEC, SR_T_UINT64, "limit_time",
  68                 "Time limit", NULL},
  69         {SR_CONF_LIMIT_FRAMES, SR_T_UINT64, "limit_frames",
  70                 "Frame limit", NULL},
  71         {SR_CONF_CONTINUOUS, SR_T_UINT64, "continuous",
  72                 "Continuous sampling", NULL},
  73
  74         /* Scan options */
  75         {SR_CONF_CONN, SR_T_STRING, "conn",
  76                 "Connection", NULL},
  77         {SR_CONF_SERIALCOMM, SR_T_STRING, "serialcomm",
  78                 "Serial communication", NULL},
  79
  80         /* Device/channel group options */
  81         {SR_CONF_SAMPLERATE, SR_T_UINT64, "samplerate",
  82                 "Sample rate", NULL},
  83         {SR_CONF_CAPTURE_RATIO, SR_T_UINT64, "captureratio",
  84                 "Pre-trigger capture ratio", NULL},
  85         {SR_CONF_PATTERN_MODE, SR_T_STRING, "pattern",
  86                 "Pattern", NULL},
  87         {SR_CONF_TRIGGER_MATCH, SR_T_INT32, "triggermatch",
  88                 "Trigger matches", NULL},
  89         {SR_CONF_EXTERNAL_CLOCK, SR_T_BOOL, "external_clock",
  90                 "External clock mode", NULL},
  91         {SR_CONF_SWAP, SR_T_BOOL, "swap",
  92                 "Swap channel order", NULL},
  93         {SR_CONF_RLE, SR_T_BOOL, "rle",
  94                 "Run Length Encoding", NULL},
  95         {SR_CONF_TRIGGER_SLOPE, SR_T_STRING, "triggerslope",
  96                 "Trigger slope", NULL},
  97         {SR_CONF_TRIGGER_SOURCE, SR_T_STRING, "triggersource",
  98                 "Trigger source", NULL},
  99         {SR_CONF_HORIZ_TRIGGERPOS, SR_T_FLOAT, "horiz_triggerpos",
 100                 "Horizontal trigger position", NULL},
 101         {SR_CONF_BUFFERSIZE, SR_T_UINT64, "buffersize",
 102                 "Buffer size", NULL},
 103         {SR_CONF_TIMEBASE, SR_T_RATIONAL_PERIOD, "timebase",
 104                 "Time base", NULL},
 105         {SR_CONF_FILTER, SR_T_BOOL, "filter",
 106                 "Filter", NULL},
 107         {SR_CONF_VDIV, SR_T_RATIONAL_VOLT, "vdiv",
 108                 "Volts/div", NULL},
 109         {SR_CONF_COUPLING, SR_T_STRING, "coupling",
 110                 "Coupling", NULL},
 111         {SR_CONF_DATALOG, SR_T_BOOL, "datalog",
 112                 "Datalog", NULL},
 113         {SR_CONF_SPL_WEIGHT_FREQ, SR_T_STRING, "spl_weight_freq",
 114                 "Sound pressure level frequency weighting", NULL},
 115         {SR_CONF_SPL_WEIGHT_TIME, SR_T_STRING, "spl_weight_time",
 116                 "Sound pressure level time weighting", NULL},
 117         {SR_CONF_HOLD_MAX, SR_T_BOOL, "hold_max",
 118                 "Hold max", NULL},
 119         {SR_CONF_HOLD_MIN, SR_T_BOOL, "hold_min",
 120                 "Hold min", NULL},
 121         {SR_CONF_SPL_MEASUREMENT_RANGE, SR_T_UINT64_RANGE, "spl_meas_range",
 122                 "Sound pressure level measurement range", NULL},
 123         {SR_CONF_VOLTAGE_THRESHOLD, SR_T_DOUBLE_RANGE, "voltage_threshold",
 124                 "Voltage threshold", NULL },
 125         {SR_CONF_POWER_OFF, SR_T_BOOL, "power_off",
 126                 "Power off", NULL},
 127         {SR_CONF_DATA_SOURCE, SR_T_STRING, "data_source",
 128                 "Data source", NULL},
 129         {SR_CONF_NUM_LOGIC_CHANNELS, SR_T_INT32, "logic_channels",
 130                 "Number of logic channels", NULL},
 131         {SR_CONF_NUM_ANALOG_CHANNELS, SR_T_INT32, "analog_channels",
 132                 "Number of analog channels", NULL},
 133         {SR_CONF_OUTPUT_VOLTAGE, SR_T_FLOAT, "output_voltage",
 134                 "Current output voltage", NULL},
 135         {SR_CONF_OUTPUT_VOLTAGE_TARGET, SR_T_FLOAT, "output_voltage_target",
 136                 "Output voltage target", NULL},
 137         {SR_CONF_OUTPUT_CURRENT, SR_T_FLOAT, "output_current",
 138                 "Current output current", NULL},
 139         {SR_CONF_OUTPUT_CURRENT_LIMIT, SR_T_FLOAT, "output_current_limit",
 140                 "Output current limit", NULL},
 141         {SR_CONF_OUTPUT_ENABLED, SR_T_BOOL, "output_enabled",
 142                 "Output enabled", NULL},
 143         {SR_CONF_OUTPUT_CHANNEL_CONFIG, SR_T_STRING, "output_channel_config",
 144                 "Output channel modes", NULL},
 145         {SR_CONF_OVER_VOLTAGE_PROTECTION_ENABLED, SR_T_BOOL, "ovp_enabled",
 146                 "Over-voltage protection enabled", NULL},
 147         {SR_CONF_OVER_VOLTAGE_PROTECTION_ACTIVE, SR_T_BOOL, "ovp_active",
 148                 "Over-voltage protection active", NULL},
 149         {SR_CONF_OVER_VOLTAGE_PROTECTION_THRESHOLD, SR_T_FLOAT, "ovp_threshold",
 150                 "Over-voltage protection threshold", NULL},
 151         {SR_CONF_OVER_CURRENT_PROTECTION_ENABLED, SR_T_BOOL, "ocp_enabled",
 152                 "Over-current protection enabled", NULL},
 153         {SR_CONF_OVER_CURRENT_PROTECTION_ACTIVE, SR_T_BOOL, "ocp_active",
 154                 "Over-current protection active", NULL},
 155         {SR_CONF_OVER_CURRENT_PROTECTION_THRESHOLD, SR_T_FLOAT, "ocp_threshold",
 156                 "Over-current protection threshold", NULL},
 157         {SR_CONF_CLOCK_EDGE, SR_T_STRING, "clock_edge",
 158                 "Clock edge", NULL},
 159         {SR_CONF_AMPLITUDE, SR_T_FLOAT, "amplitude",
 160                 "Amplitude", NULL},
 161         {SR_CONF_OVER_TEMPERATURE_PROTECTION, SR_T_BOOL, "otp",
 162                 "Over-temperature protection", NULL},
 163         {SR_CONF_OUTPUT_REGULATION, SR_T_STRING, "output_regulation",
 164                 "Output channel regulation", NULL},
 165         {SR_CONF_OUTPUT_FREQUENCY, SR_T_UINT64, "output_frequency",
 166                 "Output frequency", NULL},
 167         {SR_CONF_MEASURED_QUANTITY, SR_T_STRING, "measured_quantity",
 168                 "Measured quantity", NULL},
 169         {SR_CONF_MEASURED_2ND_QUANTITY, SR_T_STRING, "measured_2nd_quantity",
 170                 "Measured secondary quantity", NULL},
 171         {SR_CONF_EQUIV_CIRCUIT_MODEL, SR_T_STRING, "equiv_circuit_model",
 172                 "Equivalent circuit model", NULL},
 173         {0, 0, NULL, NULL, NULL},
 174 };
 175
 176 SR_PRIV const GVariantType *sr_variant_type_get(int datatype)
 177 {
 178         switch (datatype) {
 179         case SR_T_INT32:
 180                 return G_VARIANT_TYPE_INT32;
 181         case SR_T_UINT64:
 182                 return G_VARIANT_TYPE_UINT64;
 183         case SR_T_STRING:
 184                 return G_VARIANT_TYPE_STRING;
 185         case SR_T_BOOL:
 186                 return G_VARIANT_TYPE_BOOLEAN;
 187         case SR_T_FLOAT:
 188                 return G_VARIANT_TYPE_DOUBLE;
 189         case SR_T_RATIONAL_PERIOD:
 190         case SR_T_RATIONAL_VOLT:
 191         case SR_T_UINT64_RANGE:
 192         case SR_T_DOUBLE_RANGE:
 193                 return G_VARIANT_TYPE_TUPLE;
 194         case SR_T_KEYVALUE:
 195                 return G_VARIANT_TYPE_DICTIONARY;
 196         default:
 197                 return NULL;
 198         }
 199 }
 200
 201 SR_PRIV int sr_variant_type_check(uint32_t key, GVariant *value)
 202 {
 203         const struct sr_config_info *info;
 204         const GVariantType *type, *expected;
 205         char *expected_string, *type_string;
 206
 207         info = sr_config_info_get(key);
 208         if (!info)
 209                 return SR_OK;
 210
 211         expected = sr_variant_type_get(info->datatype);
 212         type = g_variant_get_type(value);
 213         if (!g_variant_type_equal(type, expected)
 214                         && !g_variant_type_is_subtype_of(type, expected)) {
 215                 expected_string = g_variant_type_dup_string(expected);
 216                 type_string = g_variant_type_dup_string(type);
 217                 sr_err("Wrong variant type for key '%s': expected '%s', got '%s'",
 218                         info->name, expected_string, type_string);
 219                 g_free(expected_string);
 220                 g_free(type_string);
 221                 return SR_ERR_ARG;
 222         }
 223
 224         return SR_OK;
 225 }
 226
 227 /**
 228  * Return the list of supported hardware drivers.
 229  *
 230  * @return Pointer to the NULL-terminated list of hardware driver pointers.
 231  *
 232  * @since 0.1.0
 233  */
 234 SR_API struct sr_dev_driver **sr_driver_list(void)
 235 {
 236
 237         return drivers_list;
 238 }
 239
 240 /**
 241  * Initialize a hardware driver.
 242  *
 243  * This usually involves memory allocations and variable initializations
 244  * within the driver, but _not_ scanning for attached devices.
 245  * The API call sr_driver_scan() is used for that.
 246  *
 247  * @param ctx A libsigrok context object allocated by a previous call to
 248  *            sr_init(). Must not be NULL.
 249  * @param driver The driver to initialize. This must be a pointer to one of
 250  *               the entries returned by sr_driver_list(). Must not be NULL.
 251  *
 252  * @retval SR_OK Success
 253  * @retval SR_ERR_ARG Invalid parameter(s).
 254  * @retval SR_ERR_BUG Internal errors.
 255  * @retval other Another negative error code upon other errors.
 256  *
 257  * @since 0.2.0
 258  */
 259 SR_API int sr_driver_init(struct sr_context *ctx, struct sr_dev_driver *driver)
 260 {
 261         int ret;
 262
 263         if (!ctx) {
 264                 sr_err("Invalid libsigrok context, can't initialize.");
 265                 return SR_ERR_ARG;
 266         }
 267
 268         if (!driver) {
 269                 sr_err("Invalid driver, can't initialize.");
 270                 return SR_ERR_ARG;
 271         }
 272
 273         sr_spew("Initializing driver '%s'.", driver->name);
 274         if ((ret = driver->init(ctx)) < 0)
 275                 sr_err("Failed to initialize the driver: %d.", ret);
 276
 277         return ret;
 278 }
 279
 280 /**
 281  * Tell a hardware driver to scan for devices.
 282  *
 283  * In addition to the detection, the devices that are found are also
 284  * initialized automatically. On some devices, this involves a firmware upload,
 285  * or other such measures.
 286  *
 287  * The order in which the system is scanned for devices is not specified. The
 288  * caller should not assume or rely on any specific order.
 289  *
 290  * Before calling sr_driver_scan(), the user must have previously initialized
 291  * the driver by calling sr_driver_init().
 292  *
 293  * @param driver The driver that should scan. This must be a pointer to one of
 294  *               the entries returned by sr_driver_list(). Must not be NULL.
 295  * @param options A list of 'struct sr_hwopt' options to pass to the driver's
 296  *                scanner. Can be NULL/empty.
 297  *
 298  * @return A GSList * of 'struct sr_dev_inst', or NULL if no devices were
 299  *         found (or errors were encountered). This list must be freed by the
 300  *         caller using g_slist_free(), but without freeing the data pointed
 301  *         to in the list.
 302  *
 303  * @since 0.2.0
 304  */
 305 SR_API GSList *sr_driver_scan(struct sr_dev_driver *driver, GSList *options)
 306 {
 307         struct sr_config *src;
 308         const struct sr_config_info *srci;
 309         GSList *l;
 310         GVariant *gvar_opts;
 311         const uint32_t *opts;
 312         gsize num_opts, i;
 313         int ret;
 314
 315         if (!driver) {
 316                 sr_err("Invalid driver, can't scan for devices.");
 317                 return NULL;
 318         }
 319
 320         if (!driver->priv) {
 321                 sr_err("Driver not initialized, can't scan for devices.");
 322                 return NULL;
 323         }
 324
 325         ret = sr_config_list(driver, NULL, NULL, SR_CONF_SCAN_OPTIONS, &gvar_opts);
 326         if (ret != SR_OK && options) {
 327                 /* Driver publishes no scan options but some were given. */
 328                 sr_err("Driver does not support scan options.");
 329                 return NULL;
 330         }
 331         opts = g_variant_get_fixed_array(gvar_opts, &num_opts, sizeof(uint32_t));
 332         for (l = options; l; l = l->next) {
 333                 src = l->data;
 334                 for (i = 0; i < num_opts; i++) {
 335                         if (opts[i] == src->key)
 336                                 break;
 337                 }
 338                 if (i == num_opts) {
 339                         if (!(srci = sr_config_info_get(src->key)))
 340                                 sr_err("Driver does not support scan option %d.", src->key);
 341                         else
 342                                 sr_err("Driver does not support scan option '%s'.", srci->id);
 343                         g_variant_unref(gvar_opts);
 344                         return NULL;
 345                 }
 346                 if (sr_variant_type_check(src->key, src->data) != SR_OK) {
 347                         g_variant_unref(gvar_opts);
 348                         return NULL;
 349                 }
 350         }
 351         g_variant_unref(gvar_opts);
 352
 353         l = driver->scan(options);
 354
 355         sr_spew("Scan of '%s' found %d devices.", driver->name,
 356                 g_slist_length(l));
 357
 358         return l;
 359 }
 360
 361 /** Call driver cleanup function for all drivers.
 362  *  @private */
 363 SR_PRIV void sr_hw_cleanup_all(void)
 364 {
 365         int i;
 366         struct sr_dev_driver **drivers;
 367
 368         drivers = sr_driver_list();
 369         for (i = 0; drivers[i]; i++) {
 370                 if (drivers[i]->cleanup)
 371                         drivers[i]->cleanup();
 372         }
 373 }
 374
 375 /** Allocate struct sr_config.
 376  *  A floating reference can be passed in for data.
 377  *  @private
 378  */
 379 SR_PRIV struct sr_config *sr_config_new(uint32_t key, GVariant *data)
 380 {
 381         struct sr_config *src;
 382
 383         if (!(src = g_try_malloc(sizeof(struct sr_config))))
 384                 return NULL;
 385         src->key = key;
 386         src->data = g_variant_ref_sink(data);
 387
 388         return src;
 389 }
 390
 391 /** Free struct sr_config.
 392  *  @private
 393  */
 394 SR_PRIV void sr_config_free(struct sr_config *src)
 395 {
 396
 397         if (!src || !src->data) {
 398                 sr_err("%s: invalid data!", __func__);
 399                 return;
 400         }
 401
 402         g_variant_unref(src->data);
 403         g_free(src);
 404
 405 }
 406
 407 /**
 408  * Query value of a configuration key at the given driver or device instance.
 409  *
 410  * @param[in] driver The sr_dev_driver struct to query.
 411  * @param[in] sdi (optional) If the key is specific to a device, this must
 412  *            contain a pointer to the struct sr_dev_inst to be checked.
 413  *            Otherwise it must be NULL.
 414  * @param[in] cg The channel group on the device for which to list the
 415  *                    values, or NULL.
 416  * @param[in] key The configuration key (SR_CONF_*).
 417  * @param[in,out] data Pointer to a GVariant where the value will be stored.
 418  *             Must not be NULL. The caller is given ownership of the GVariant
 419  *             and must thus decrease the refcount after use. However if
 420  *             this function returns an error code, the field should be
 421  *             considered unused, and should not be unreferenced.
 422  *
 423  * @retval SR_OK Success.
 424  * @retval SR_ERR Error.
 425  * @retval SR_ERR_ARG The driver doesn't know that key, but this is not to be
 426  *          interpreted as an error by the caller; merely as an indication
 427  *          that it's not applicable.
 428  *
 429  * @since 0.3.0
 430  */
 431 SR_API int sr_config_get(const struct sr_dev_driver *driver,
 432                 const struct sr_dev_inst *sdi,
 433                 const struct sr_channel_group *cg,
 434                 uint32_t key, GVariant **data)
 435 {
 436         int ret;
 437
 438         if (!driver || !data)
 439                 return SR_ERR;
 440
 441         if (!driver->config_get)
 442                 return SR_ERR_ARG;
 443
 444         if ((ret = driver->config_get(key, data, sdi, cg)) == SR_OK) {
 445                 /* Got a floating reference from the driver. Sink it here,
 446                  * caller will need to unref when done with it. */
 447                 g_variant_ref_sink(*data);
 448         }
 449
 450         return ret;
 451 }
 452
 453 /**
 454  * Set value of a configuration key in a device instance.
 455  *
 456  * @param[in] sdi The device instance.
 457  * @param[in] cg The channel group on the device for which to list the
 458  *                    values, or NULL.
 459  * @param[in] key The configuration key (SR_CONF_*).
 460  * @param data The new value for the key, as a GVariant with GVariantType
 461  *        appropriate to that key. A floating reference can be passed
 462  *        in; its refcount will be sunk and unreferenced after use.
 463  *
 464  * @retval SR_OK Success.
 465  * @retval SR_ERR Error.
 466  * @retval SR_ERR_ARG The driver doesn't know that key, but this is not to be
 467  *          interpreted as an error by the caller; merely as an indication
 468  *          that it's not applicable.
 469  *
 470  * @since 0.3.0
 471  */
 472 SR_API int sr_config_set(const struct sr_dev_inst *sdi,
 473                 const struct sr_channel_group *cg,
 474                 uint32_t key, GVariant *data)
 475 {
 476         int ret;
 477
 478         g_variant_ref_sink(data);
 479
 480         if (!sdi || !sdi->driver || !data)
 481                 ret = SR_ERR;
 482         else if (!sdi->driver->config_set)
 483                 ret = SR_ERR_ARG;
 484         else if ((ret = sr_variant_type_check(key, data)) == SR_OK)
 485                 ret = sdi->driver->config_set(key, data, sdi, cg);
 486
 487         g_variant_unref(data);
 488
 489         return ret;
 490 }
 491
 492 /**
 493  * Apply configuration settings to the device hardware.
 494  *
 495  * @param sdi The device instance.
 496  *
 497  * @return SR_OK upon success or SR_ERR in case of error.
 498  *
 499  * @since 0.3.0
 500  */
 501 SR_API int sr_config_commit(const struct sr_dev_inst *sdi)
 502 {
 503         int ret;
 504
 505         if (!sdi || !sdi->driver)
 506                 ret = SR_ERR;
 507         else if (!sdi->driver->config_commit)
 508                 ret = SR_OK;
 509         else
 510                 ret = sdi->driver->config_commit(sdi);
 511
 512         return ret;
 513 }
 514
 515 /**
 516  * List all possible values for a configuration key.
 517  *
 518  * @param[in] driver The sr_dev_driver struct to query.
 519  * @param[in] sdi (optional) If the key is specific to a device, this must
 520  *            contain a pointer to the struct sr_dev_inst to be checked.
 521  * @param[in] cg The channel group on the device for which to list the
 522  *                    values, or NULL.
 523  * @param[in] key The configuration key (SR_CONF_*).
 524  * @param[in,out] data A pointer to a GVariant where the list will be stored.
 525  *             The 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  *
 530  * @retval SR_OK Success.
 531  * @retval SR_ERR Error.
 532  * @retval SR_ERR_ARG The driver doesn't know that key, but this is not to be
 533  *          interpreted as an error by the caller; merely as an indication
 534  *          that it's not applicable.
 535  *
 536  * @since 0.3.0
 537  */
 538 SR_API int sr_config_list(const struct sr_dev_driver *driver,
 539                 const struct sr_dev_inst *sdi,
 540                 const struct sr_channel_group *cg,
 541                 uint32_t key, GVariant **data)
 542 {
 543         int ret;
 544
 545         if (!driver || !data)
 546                 ret = SR_ERR;
 547         else if (!driver->config_list)
 548                 ret = SR_ERR_ARG;
 549         else if ((ret = driver->config_list(key, data, sdi, cg)) == SR_OK)
 550                 g_variant_ref_sink(*data);
 551
 552         return ret;
 553 }
 554
 555 /**
 556  * Get information about a configuration key, by key.
 557  *
 558  * @param[in] key The configuration key.
 559  *
 560  * @return A pointer to a struct sr_config_info, or NULL if the key
 561  *         was not found.
 562  *
 563  * @since 0.2.0
 564  */
 565 SR_API const struct sr_config_info *sr_config_info_get(uint32_t key)
 566 {
 567         int i;
 568
 569         for (i = 0; sr_config_info_data[i].key; i++) {
 570                 if (sr_config_info_data[i].key == key)
 571                         return &sr_config_info_data[i];
 572         }
 573
 574         return NULL;
 575 }
 576
 577 /**
 578  * Get information about a configuration key, by name.
 579  *
 580  * @param[in] optname The configuration key.
 581  *
 582  * @return A pointer to a struct sr_config_info, or NULL if the key
 583  *         was not found.
 584  *
 585  * @since 0.2.0
 586  */
 587 SR_API const struct sr_config_info *sr_config_info_name_get(const char *optname)
 588 {
 589         int i;
 590
 591         for (i = 0; sr_config_info_data[i].key; i++) {
 592                 if (!sr_config_info_data[i].id)
 593                         continue;
 594                 if (!strcmp(sr_config_info_data[i].id, optname))
 595                         return &sr_config_info_data[i];
 596         }
 597
 598         return NULL;
 599 }
 600
 601 /** @} */