drivers/iio/inkern.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /* The industrial I/O core in kernel channel mapping
   3  *
   4  * Copyright (c) 2011 Jonathan Cameron
   5  */
   6 #include <linux/cleanup.h>
   7 #include <linux/err.h>
   8 #include <linux/export.h>
   9 #include <linux/minmax.h>
  10 #include <linux/mutex.h>
  11 #include <linux/property.h>
  12 #include <linux/slab.h>
  13
  14 #include <linux/iio/iio.h>
  15 #include <linux/iio/iio-opaque.h>
  16 #include "iio_core.h"
  17 #include <linux/iio/machine.h>
  18 #include <linux/iio/driver.h>
  19 #include <linux/iio/consumer.h>
  20
  21 struct iio_map_internal {
  22         struct iio_dev *indio_dev;
  23         struct iio_map *map;
  24         struct list_head l;
  25 };
  26
  27 static LIST_HEAD(iio_map_list);
  28 static DEFINE_MUTEX(iio_map_list_lock);
  29
  30 static int iio_map_array_unregister_locked(struct iio_dev *indio_dev)
  31 {
  32         int ret = -ENODEV;
  33         struct iio_map_internal *mapi, *next;
  34
  35         list_for_each_entry_safe(mapi, next, &iio_map_list, l) {
  36                 if (indio_dev == mapi->indio_dev) {
  37                         list_del(&mapi->l);
  38                         kfree(mapi);
  39                         ret = 0;
  40                 }
  41         }
  42         return ret;
  43 }
  44
  45 int iio_map_array_register(struct iio_dev *indio_dev, struct iio_map *maps)
  46 {
  47         struct iio_map_internal *mapi;
  48         int i = 0;
  49         int ret;
  50
  51         if (!maps)
  52                 return 0;
  53
  54         guard(mutex)(&iio_map_list_lock);
  55         while (maps[i].consumer_dev_name) {
  56                 mapi = kzalloc(sizeof(*mapi), GFP_KERNEL);
  57                 if (!mapi) {
  58                         ret = -ENOMEM;
  59                         goto error_ret;
  60                 }
  61                 mapi->map = &maps[i];
  62                 mapi->indio_dev = indio_dev;
  63                 list_add_tail(&mapi->l, &iio_map_list);
  64                 i++;
  65         }
  66
  67         return 0;
  68 error_ret:
  69         iio_map_array_unregister_locked(indio_dev);
  70         return ret;
  71 }
  72 EXPORT_SYMBOL_GPL(iio_map_array_register);
  73
  74 /*
  75  * Remove all map entries associated with the given iio device
  76  */
  77 int iio_map_array_unregister(struct iio_dev *indio_dev)
  78 {
  79         guard(mutex)(&iio_map_list_lock);
  80         return iio_map_array_unregister_locked(indio_dev);
  81 }
  82 EXPORT_SYMBOL_GPL(iio_map_array_unregister);
  83
  84 static void iio_map_array_unregister_cb(void *indio_dev)
  85 {
  86         iio_map_array_unregister(indio_dev);
  87 }
  88
  89 int devm_iio_map_array_register(struct device *dev, struct iio_dev *indio_dev, struct iio_map *maps)
  90 {
  91         int ret;
  92
  93         ret = iio_map_array_register(indio_dev, maps);
  94         if (ret)
  95                 return ret;
  96
  97         return devm_add_action_or_reset(dev, iio_map_array_unregister_cb, indio_dev);
  98 }
  99 EXPORT_SYMBOL_GPL(devm_iio_map_array_register);
 100
 101 static const struct iio_chan_spec
 102 *iio_chan_spec_from_name(const struct iio_dev *indio_dev, const char *name)
 103 {
 104         int i;
 105         const struct iio_chan_spec *chan = NULL;
 106
 107         for (i = 0; i < indio_dev->num_channels; i++)
 108                 if (indio_dev->channels[i].datasheet_name &&
 109                     strcmp(name, indio_dev->channels[i].datasheet_name) == 0) {
 110                         chan = &indio_dev->channels[i];
 111                         break;
 112                 }
 113         return chan;
 114 }
 115
 116 /**
 117  * __fwnode_iio_simple_xlate - translate iiospec to the IIO channel index
 118  * @indio_dev:  pointer to the iio_dev structure
 119  * @iiospec:    IIO specifier as found in the device tree
 120  *
 121  * This is simple translation function, suitable for the most 1:1 mapped
 122  * channels in IIO chips. This function performs only one sanity check:
 123  * whether IIO index is less than num_channels (that is specified in the
 124  * iio_dev).
 125  */
 126 static int __fwnode_iio_simple_xlate(struct iio_dev *indio_dev,
 127                                      const struct fwnode_reference_args *iiospec)
 128 {
 129         if (!iiospec->nargs)
 130                 return 0;
 131
 132         if (iiospec->args[0] >= indio_dev->num_channels) {
 133                 dev_err(&indio_dev->dev, "invalid channel index %llu\n",
 134                         iiospec->args[0]);
 135                 return -EINVAL;
 136         }
 137
 138         return iiospec->args[0];
 139 }
 140
 141 static int __fwnode_iio_channel_get(struct iio_channel *channel,
 142                                     struct fwnode_handle *fwnode, int index)
 143 {
 144         struct fwnode_reference_args iiospec;
 145         struct device *idev;
 146         struct iio_dev *indio_dev;
 147         int err;
 148
 149         err = fwnode_property_get_reference_args(fwnode, "io-channels",
 150                                                  "#io-channel-cells", 0,
 151                                                  index, &iiospec);
 152         if (err)
 153                 return err;
 154
 155         idev = bus_find_device_by_fwnode(&iio_bus_type, iiospec.fwnode);
 156         if (!idev) {
 157                 fwnode_handle_put(iiospec.fwnode);
 158                 return -EPROBE_DEFER;
 159         }
 160
 161         indio_dev = dev_to_iio_dev(idev);
 162         channel->indio_dev = indio_dev;
 163         if (indio_dev->info->fwnode_xlate)
 164                 index = indio_dev->info->fwnode_xlate(indio_dev, &iiospec);
 165         else
 166                 index = __fwnode_iio_simple_xlate(indio_dev, &iiospec);
 167         fwnode_handle_put(iiospec.fwnode);
 168         if (index < 0)
 169                 goto err_put;
 170         channel->channel = &indio_dev->channels[index];
 171
 172         return 0;
 173
 174 err_put:
 175         iio_device_put(indio_dev);
 176         return index;
 177 }
 178
 179 static struct iio_channel *fwnode_iio_channel_get(struct fwnode_handle *fwnode,
 180                                                   int index)
 181 {
 182         int err;
 183
 184         if (index < 0)
 185                 return ERR_PTR(-EINVAL);
 186
 187         struct iio_channel *channel __free(kfree) =
 188                 kzalloc(sizeof(*channel), GFP_KERNEL);
 189         if (!channel)
 190                 return ERR_PTR(-ENOMEM);
 191
 192         err = __fwnode_iio_channel_get(channel, fwnode, index);
 193         if (err)
 194                 return ERR_PTR(err);
 195
 196         return_ptr(channel);
 197 }
 198
 199 static struct iio_channel *
 200 __fwnode_iio_channel_get_by_name(struct fwnode_handle *fwnode, const char *name)
 201 {
 202         struct iio_channel *chan;
 203         int index = 0;
 204
 205         /*
 206          * For named iio channels, first look up the name in the
 207          * "io-channel-names" property.  If it cannot be found, the
 208          * index will be an error code, and fwnode_iio_channel_get()
 209          * will fail.
 210          */
 211         if (name)
 212                 index = fwnode_property_match_string(fwnode, "io-channel-names",
 213                                                      name);
 214
 215         chan = fwnode_iio_channel_get(fwnode, index);
 216         if (!IS_ERR(chan) || PTR_ERR(chan) == -EPROBE_DEFER)
 217                 return chan;
 218         if (name) {
 219                 if (index >= 0) {
 220                         pr_err("ERROR: could not get IIO channel %pfw:%s(%i)\n",
 221                                fwnode, name, index);
 222                         /*
 223                          * In this case, we found 'name' in 'io-channel-names'
 224                          * but somehow we still fail so that we should not proceed
 225                          * with any other lookup. Hence, explicitly return -EINVAL
 226                          * (maybe not the better error code) so that the caller
 227                          * won't do a system lookup.
 228                          */
 229                         return ERR_PTR(-EINVAL);
 230                 }
 231                 /*
 232                  * If index < 0, then fwnode_property_get_reference_args() fails
 233                  * with -EINVAL or -ENOENT (ACPI case) which is expected. We
 234                  * should not proceed if we get any other error.
 235                  */
 236                 if (PTR_ERR(chan) != -EINVAL && PTR_ERR(chan) != -ENOENT)
 237                         return chan;
 238         } else if (PTR_ERR(chan) != -ENOENT) {
 239                 /*
 240                  * if !name, then we should only proceed the lookup if
 241                  * fwnode_property_get_reference_args() returns -ENOENT.
 242                  */
 243                 return chan;
 244         }
 245
 246         /* so we continue the lookup */
 247         return ERR_PTR(-ENODEV);
 248 }
 249
 250 struct iio_channel *fwnode_iio_channel_get_by_name(struct fwnode_handle *fwnode,
 251                                                    const char *name)
 252 {
 253         struct fwnode_handle *parent;
 254         struct iio_channel *chan;
 255
 256         /* Walk up the tree of devices looking for a matching iio channel */
 257         chan = __fwnode_iio_channel_get_by_name(fwnode, name);
 258         if (!IS_ERR(chan) || PTR_ERR(chan) != -ENODEV)
 259                 return chan;
 260
 261         /*
 262          * No matching IIO channel found on this node.
 263          * If the parent node has a "io-channel-ranges" property,
 264          * then we can try one of its channels.
 265          */
 266         fwnode_for_each_parent_node(fwnode, parent) {
 267                 if (!fwnode_property_present(parent, "io-channel-ranges")) {
 268                         fwnode_handle_put(parent);
 269                         return ERR_PTR(-ENODEV);
 270                 }
 271
 272                 chan = __fwnode_iio_channel_get_by_name(fwnode, name);
 273                 if (!IS_ERR(chan) || PTR_ERR(chan) != -ENODEV) {
 274                         fwnode_handle_put(parent);
 275                         return chan;
 276                 }
 277         }
 278
 279         return ERR_PTR(-ENODEV);
 280 }
 281 EXPORT_SYMBOL_GPL(fwnode_iio_channel_get_by_name);
 282
 283 static struct iio_channel *fwnode_iio_channel_get_all(struct device *dev)
 284 {
 285         struct fwnode_handle *fwnode = dev_fwnode(dev);
 286         int i, mapind, nummaps = 0;
 287         int ret;
 288
 289         do {
 290                 ret = fwnode_property_get_reference_args(fwnode, "io-channels",
 291                                                          "#io-channel-cells", 0,
 292                                                          nummaps, NULL);
 293                 if (ret < 0)
 294                         break;
 295         } while (++nummaps);
 296
 297         if (nummaps == 0)
 298                 return ERR_PTR(-ENODEV);
 299
 300         /* NULL terminated array to save passing size */
 301         struct iio_channel *chans __free(kfree) =
 302                 kcalloc(nummaps + 1, sizeof(*chans), GFP_KERNEL);
 303         if (!chans)
 304                 return ERR_PTR(-ENOMEM);
 305
 306         /* Search for FW matches */
 307         for (mapind = 0; mapind < nummaps; mapind++) {
 308                 ret = __fwnode_iio_channel_get(&chans[mapind], fwnode, mapind);
 309                 if (ret)
 310                         goto error_free_chans;
 311         }
 312         return_ptr(chans);
 313
 314 error_free_chans:
 315         for (i = 0; i < mapind; i++)
 316                 iio_device_put(chans[i].indio_dev);
 317         return ERR_PTR(ret);
 318 }
 319
 320 static struct iio_channel *iio_channel_get_sys(const char *name,
 321                                                const char *channel_name)
 322 {
 323         struct iio_map_internal *c_i = NULL, *c = NULL;
 324         int err;
 325
 326         if (!(name || channel_name))
 327                 return ERR_PTR(-ENODEV);
 328
 329         /* first find matching entry the channel map */
 330         scoped_guard(mutex, &iio_map_list_lock) {
 331                 list_for_each_entry(c_i, &iio_map_list, l) {
 332                         if ((name && strcmp(name, c_i->map->consumer_dev_name) != 0) ||
 333                             (channel_name &&
 334                              strcmp(channel_name, c_i->map->consumer_channel) != 0))
 335                                 continue;
 336                         c = c_i;
 337                         iio_device_get(c->indio_dev);
 338                         break;
 339                 }
 340         }
 341         if (!c)
 342                 return ERR_PTR(-ENODEV);
 343
 344         struct iio_channel *channel __free(kfree) =
 345                 kzalloc(sizeof(*channel), GFP_KERNEL);
 346         if (!channel) {
 347                 err = -ENOMEM;
 348                 goto error_no_mem;
 349         }
 350
 351         channel->indio_dev = c->indio_dev;
 352
 353         if (c->map->adc_channel_label) {
 354                 channel->channel =
 355                         iio_chan_spec_from_name(channel->indio_dev,
 356                                                 c->map->adc_channel_label);
 357
 358                 if (!channel->channel) {
 359                         err = -EINVAL;
 360                         goto error_no_mem;
 361                 }
 362         }
 363
 364         return_ptr(channel);
 365
 366 error_no_mem:
 367         iio_device_put(c->indio_dev);
 368         return ERR_PTR(err);
 369 }
 370
 371 struct iio_channel *iio_channel_get(struct device *dev,
 372                                     const char *channel_name)
 373 {
 374         const char *name = dev ? dev_name(dev) : NULL;
 375         struct iio_channel *channel;
 376
 377         if (dev) {
 378                 channel = fwnode_iio_channel_get_by_name(dev_fwnode(dev),
 379                                                          channel_name);
 380                 if (!IS_ERR(channel) || PTR_ERR(channel) != -ENODEV)
 381                         return channel;
 382         }
 383
 384         return iio_channel_get_sys(name, channel_name);
 385 }
 386 EXPORT_SYMBOL_GPL(iio_channel_get);
 387
 388 void iio_channel_release(struct iio_channel *channel)
 389 {
 390         if (!channel)
 391                 return;
 392         iio_device_put(channel->indio_dev);
 393         kfree(channel);
 394 }
 395 EXPORT_SYMBOL_GPL(iio_channel_release);
 396
 397 static void devm_iio_channel_free(void *iio_channel)
 398 {
 399         iio_channel_release(iio_channel);
 400 }
 401
 402 struct iio_channel *devm_iio_channel_get(struct device *dev,
 403                                          const char *channel_name)
 404 {
 405         struct iio_channel *channel;
 406         int ret;
 407
 408         channel = iio_channel_get(dev, channel_name);
 409         if (IS_ERR(channel))
 410                 return channel;
 411
 412         ret = devm_add_action_or_reset(dev, devm_iio_channel_free, channel);
 413         if (ret)
 414                 return ERR_PTR(ret);
 415
 416         return channel;
 417 }
 418 EXPORT_SYMBOL_GPL(devm_iio_channel_get);
 419
 420 struct iio_channel *devm_fwnode_iio_channel_get_by_name(struct device *dev,
 421                                                         struct fwnode_handle *fwnode,
 422                                                         const char *channel_name)
 423 {
 424         struct iio_channel *channel;
 425         int ret;
 426
 427         channel = fwnode_iio_channel_get_by_name(fwnode, channel_name);
 428         if (IS_ERR(channel))
 429                 return channel;
 430
 431         ret = devm_add_action_or_reset(dev, devm_iio_channel_free, channel);
 432         if (ret)
 433                 return ERR_PTR(ret);
 434
 435         return channel;
 436 }
 437 EXPORT_SYMBOL_GPL(devm_fwnode_iio_channel_get_by_name);
 438
 439 struct iio_channel *iio_channel_get_all(struct device *dev)
 440 {
 441         const char *name;
 442         struct iio_map_internal *c = NULL;
 443         struct iio_channel *fw_chans;
 444         int nummaps = 0;
 445         int mapind = 0;
 446         int i, ret;
 447
 448         if (!dev)
 449                 return ERR_PTR(-EINVAL);
 450
 451         fw_chans = fwnode_iio_channel_get_all(dev);
 452         /*
 453          * We only want to carry on if the error is -ENODEV.  Anything else
 454          * should be reported up the stack.
 455          */
 456         if (!IS_ERR(fw_chans) || PTR_ERR(fw_chans) != -ENODEV)
 457                 return fw_chans;
 458
 459         name = dev_name(dev);
 460
 461         guard(mutex)(&iio_map_list_lock);
 462         /* first count the matching maps */
 463         list_for_each_entry(c, &iio_map_list, l)
 464                 if (name && strcmp(name, c->map->consumer_dev_name) != 0)
 465                         continue;
 466                 else
 467                         nummaps++;
 468
 469         if (nummaps == 0)
 470                 return ERR_PTR(-ENODEV);
 471
 472         /* NULL terminated array to save passing size */
 473         struct iio_channel *chans __free(kfree) =
 474                 kcalloc(nummaps + 1, sizeof(*chans), GFP_KERNEL);
 475         if (!chans)
 476                 return ERR_PTR(-ENOMEM);
 477
 478         /* for each map fill in the chans element */
 479         list_for_each_entry(c, &iio_map_list, l) {
 480                 if (name && strcmp(name, c->map->consumer_dev_name) != 0)
 481                         continue;
 482                 chans[mapind].indio_dev = c->indio_dev;
 483                 chans[mapind].data = c->map->consumer_data;
 484                 chans[mapind].channel =
 485                         iio_chan_spec_from_name(chans[mapind].indio_dev,
 486                                                 c->map->adc_channel_label);
 487                 if (!chans[mapind].channel) {
 488                         ret = -EINVAL;
 489                         goto error_free_chans;
 490                 }
 491                 iio_device_get(chans[mapind].indio_dev);
 492                 mapind++;
 493         }
 494         if (mapind == 0) {
 495                 ret = -ENODEV;
 496                 goto error_free_chans;
 497         }
 498
 499         return_ptr(chans);
 500
 501 error_free_chans:
 502         for (i = 0; i < nummaps; i++)
 503                 iio_device_put(chans[i].indio_dev);
 504         return ERR_PTR(ret);
 505 }
 506 EXPORT_SYMBOL_GPL(iio_channel_get_all);
 507
 508 void iio_channel_release_all(struct iio_channel *channels)
 509 {
 510         struct iio_channel *chan = &channels[0];
 511
 512         while (chan->indio_dev) {
 513                 iio_device_put(chan->indio_dev);
 514                 chan++;
 515         }
 516         kfree(channels);
 517 }
 518 EXPORT_SYMBOL_GPL(iio_channel_release_all);
 519
 520 static void devm_iio_channel_free_all(void *iio_channels)
 521 {
 522         iio_channel_release_all(iio_channels);
 523 }
 524
 525 struct iio_channel *devm_iio_channel_get_all(struct device *dev)
 526 {
 527         struct iio_channel *channels;
 528         int ret;
 529
 530         channels = iio_channel_get_all(dev);
 531         if (IS_ERR(channels))
 532                 return channels;
 533
 534         ret = devm_add_action_or_reset(dev, devm_iio_channel_free_all,
 535                                        channels);
 536         if (ret)
 537                 return ERR_PTR(ret);
 538
 539         return channels;
 540 }
 541 EXPORT_SYMBOL_GPL(devm_iio_channel_get_all);
 542
 543 static int iio_channel_read(struct iio_channel *chan, int *val, int *val2,
 544                             enum iio_chan_info_enum info)
 545 {
 546         const struct iio_info *iio_info = chan->indio_dev->info;
 547         int unused;
 548         int vals[INDIO_MAX_RAW_ELEMENTS];
 549         int ret;
 550         int val_len = 2;
 551
 552         if (!val2)
 553                 val2 = &unused;
 554
 555         if (!iio_channel_has_info(chan->channel, info))
 556                 return -EINVAL;
 557
 558         if (iio_info->read_raw_multi) {
 559                 ret = iio_info->read_raw_multi(chan->indio_dev,
 560                                                chan->channel,
 561                                                INDIO_MAX_RAW_ELEMENTS,
 562                                                vals, &val_len, info);
 563                 *val = vals[0];
 564                 *val2 = vals[1];
 565         } else if (iio_info->read_raw) {
 566                 ret = iio_info->read_raw(chan->indio_dev,
 567                                          chan->channel, val, val2, info);
 568         } else {
 569                 return -EINVAL;
 570         }
 571
 572         return ret;
 573 }
 574
 575 int iio_read_channel_raw(struct iio_channel *chan, int *val)
 576 {
 577         struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(chan->indio_dev);
 578
 579         guard(mutex)(&iio_dev_opaque->info_exist_lock);
 580         if (!chan->indio_dev->info)
 581                 return -ENODEV;
 582
 583         return iio_channel_read(chan, val, NULL, IIO_CHAN_INFO_RAW);
 584 }
 585 EXPORT_SYMBOL_GPL(iio_read_channel_raw);
 586
 587 int iio_read_channel_average_raw(struct iio_channel *chan, int *val)
 588 {
 589         struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(chan->indio_dev);
 590
 591         guard(mutex)(&iio_dev_opaque->info_exist_lock);
 592         if (!chan->indio_dev->info)
 593                 return -ENODEV;
 594
 595         return iio_channel_read(chan, val, NULL, IIO_CHAN_INFO_AVERAGE_RAW);
 596 }
 597 EXPORT_SYMBOL_GPL(iio_read_channel_average_raw);
 598
 599 static int iio_convert_raw_to_processed_unlocked(struct iio_channel *chan,
 600                                                  int raw, int *processed,
 601                                                  unsigned int scale)
 602 {
 603         int scale_type, scale_val, scale_val2;
 604         int offset_type, offset_val, offset_val2;
 605         s64 raw64 = raw;
 606
 607         offset_type = iio_channel_read(chan, &offset_val, &offset_val2,
 608                                        IIO_CHAN_INFO_OFFSET);
 609         if (offset_type >= 0) {
 610                 switch (offset_type) {
 611                 case IIO_VAL_INT:
 612                         break;
 613                 case IIO_VAL_INT_PLUS_MICRO:
 614                 case IIO_VAL_INT_PLUS_NANO:
 615                         /*
 616                          * Both IIO_VAL_INT_PLUS_MICRO and IIO_VAL_INT_PLUS_NANO
 617                          * implicitely truncate the offset to it's integer form.
 618                          */
 619                         break;
 620                 case IIO_VAL_FRACTIONAL:
 621                         offset_val /= offset_val2;
 622                         break;
 623                 case IIO_VAL_FRACTIONAL_LOG2:
 624                         offset_val >>= offset_val2;
 625                         break;
 626                 default:
 627                         return -EINVAL;
 628                 }
 629
 630                 raw64 += offset_val;
 631         }
 632
 633         scale_type = iio_channel_read(chan, &scale_val, &scale_val2,
 634                                       IIO_CHAN_INFO_SCALE);
 635         if (scale_type < 0) {
 636                 /*
 637                  * If no channel scaling is available apply consumer scale to
 638                  * raw value and return.
 639                  */
 640                 *processed = raw * scale;
 641                 return 0;
 642         }
 643
 644         switch (scale_type) {
 645         case IIO_VAL_INT:
 646                 *processed = raw64 * scale_val * scale;
 647                 break;
 648         case IIO_VAL_INT_PLUS_MICRO:
 649                 if (scale_val2 < 0)
 650                         *processed = -raw64 * scale_val;
 651                 else
 652                         *processed = raw64 * scale_val;
 653                 *processed += div_s64(raw64 * (s64)scale_val2 * scale,
 654                                       1000000LL);
 655                 break;
 656         case IIO_VAL_INT_PLUS_NANO:
 657                 if (scale_val2 < 0)
 658                         *processed = -raw64 * scale_val;
 659                 else
 660                         *processed = raw64 * scale_val;
 661                 *processed += div_s64(raw64 * (s64)scale_val2 * scale,
 662                                       1000000000LL);
 663                 break;
 664         case IIO_VAL_FRACTIONAL:
 665                 *processed = div_s64(raw64 * (s64)scale_val * scale,
 666                                      scale_val2);
 667                 break;
 668         case IIO_VAL_FRACTIONAL_LOG2:
 669                 *processed = (raw64 * (s64)scale_val * scale) >> scale_val2;
 670                 break;
 671         default:
 672                 return -EINVAL;
 673         }
 674
 675         return 0;
 676 }
 677
 678 int iio_convert_raw_to_processed(struct iio_channel *chan, int raw,
 679                                  int *processed, unsigned int scale)
 680 {
 681         struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(chan->indio_dev);
 682
 683         guard(mutex)(&iio_dev_opaque->info_exist_lock);
 684         if (!chan->indio_dev->info)
 685                 return -ENODEV;
 686
 687         return iio_convert_raw_to_processed_unlocked(chan, raw, processed,
 688                                                      scale);
 689 }
 690 EXPORT_SYMBOL_GPL(iio_convert_raw_to_processed);
 691
 692 int iio_read_channel_attribute(struct iio_channel *chan, int *val, int *val2,
 693                                enum iio_chan_info_enum attribute)
 694 {
 695         struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(chan->indio_dev);
 696
 697         guard(mutex)(&iio_dev_opaque->info_exist_lock);
 698         if (!chan->indio_dev->info)
 699                 return -ENODEV;
 700
 701         return iio_channel_read(chan, val, val2, attribute);
 702 }
 703 EXPORT_SYMBOL_GPL(iio_read_channel_attribute);
 704
 705 int iio_read_channel_offset(struct iio_channel *chan, int *val, int *val2)
 706 {
 707         return iio_read_channel_attribute(chan, val, val2, IIO_CHAN_INFO_OFFSET);
 708 }
 709 EXPORT_SYMBOL_GPL(iio_read_channel_offset);
 710
 711 int iio_read_channel_processed_scale(struct iio_channel *chan, int *val,
 712                                      unsigned int scale)
 713 {
 714         struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(chan->indio_dev);
 715         int ret;
 716
 717         guard(mutex)(&iio_dev_opaque->info_exist_lock);
 718         if (!chan->indio_dev->info)
 719                 return -ENODEV;
 720
 721         if (iio_channel_has_info(chan->channel, IIO_CHAN_INFO_PROCESSED)) {
 722                 ret = iio_channel_read(chan, val, NULL,
 723                                        IIO_CHAN_INFO_PROCESSED);
 724                 if (ret < 0)
 725                         return ret;
 726                 *val *= scale;
 727
 728                 return ret;
 729         } else {
 730                 ret = iio_channel_read(chan, val, NULL, IIO_CHAN_INFO_RAW);
 731                 if (ret < 0)
 732                         return ret;
 733
 734                 return iio_convert_raw_to_processed_unlocked(chan, *val, val,
 735                                                              scale);
 736         }
 737 }
 738 EXPORT_SYMBOL_GPL(iio_read_channel_processed_scale);
 739
 740 int iio_read_channel_processed(struct iio_channel *chan, int *val)
 741 {
 742         /* This is just a special case with scale factor 1 */
 743         return iio_read_channel_processed_scale(chan, val, 1);
 744 }
 745 EXPORT_SYMBOL_GPL(iio_read_channel_processed);
 746
 747 int iio_read_channel_scale(struct iio_channel *chan, int *val, int *val2)
 748 {
 749         return iio_read_channel_attribute(chan, val, val2, IIO_CHAN_INFO_SCALE);
 750 }
 751 EXPORT_SYMBOL_GPL(iio_read_channel_scale);
 752
 753 static int iio_channel_read_avail(struct iio_channel *chan,
 754                                   const int **vals, int *type, int *length,
 755                                   enum iio_chan_info_enum info)
 756 {
 757         const struct iio_info *iio_info = chan->indio_dev->info;
 758
 759         if (!iio_channel_has_available(chan->channel, info))
 760                 return -EINVAL;
 761
 762         if (iio_info->read_avail)
 763                 return iio_info->read_avail(chan->indio_dev, chan->channel,
 764                                             vals, type, length, info);
 765         return -EINVAL;
 766 }
 767
 768 int iio_read_avail_channel_attribute(struct iio_channel *chan,
 769                                      const int **vals, int *type, int *length,
 770                                      enum iio_chan_info_enum attribute)
 771 {
 772         struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(chan->indio_dev);
 773
 774         guard(mutex)(&iio_dev_opaque->info_exist_lock);
 775         if (!chan->indio_dev->info)
 776                 return -ENODEV;
 777
 778         return iio_channel_read_avail(chan, vals, type, length, attribute);
 779 }
 780 EXPORT_SYMBOL_GPL(iio_read_avail_channel_attribute);
 781
 782 int iio_read_avail_channel_raw(struct iio_channel *chan,
 783                                const int **vals, int *length)
 784 {
 785         int ret;
 786         int type;
 787
 788         ret = iio_read_avail_channel_attribute(chan, vals, &type, length,
 789                                                IIO_CHAN_INFO_RAW);
 790
 791         if (ret >= 0 && type != IIO_VAL_INT)
 792                 /* raw values are assumed to be IIO_VAL_INT */
 793                 ret = -EINVAL;
 794
 795         return ret;
 796 }
 797 EXPORT_SYMBOL_GPL(iio_read_avail_channel_raw);
 798
 799 static int iio_channel_read_max(struct iio_channel *chan,
 800                                 int *val, int *val2, int *type,
 801                                 enum iio_chan_info_enum info)
 802 {
 803         const int *vals;
 804         int length;
 805         int ret;
 806
 807         ret = iio_channel_read_avail(chan, &vals, type, &length, info);
 808         if (ret < 0)
 809                 return ret;
 810
 811         switch (ret) {
 812         case IIO_AVAIL_RANGE:
 813                 switch (*type) {
 814                 case IIO_VAL_INT:
 815                         *val = vals[2];
 816                         break;
 817                 default:
 818                         *val = vals[4];
 819                         if (val2)
 820                                 *val2 = vals[5];
 821                 }
 822                 return 0;
 823
 824         case IIO_AVAIL_LIST:
 825                 if (length <= 0)
 826                         return -EINVAL;
 827                 switch (*type) {
 828                 case IIO_VAL_INT:
 829                         *val = max_array(vals, length);
 830                         break;
 831                 default:
 832                         /* TODO: learn about max for other iio values */
 833                         return -EINVAL;
 834                 }
 835                 return 0;
 836
 837         default:
 838                 return -EINVAL;
 839         }
 840 }
 841
 842 int iio_read_max_channel_raw(struct iio_channel *chan, int *val)
 843 {
 844         struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(chan->indio_dev);
 845         int type;
 846
 847         guard(mutex)(&iio_dev_opaque->info_exist_lock);
 848         if (!chan->indio_dev->info)
 849                 return -ENODEV;
 850
 851         return iio_channel_read_max(chan, val, NULL, &type, IIO_CHAN_INFO_RAW);
 852 }
 853 EXPORT_SYMBOL_GPL(iio_read_max_channel_raw);
 854
 855 static int iio_channel_read_min(struct iio_channel *chan,
 856                                 int *val, int *val2, int *type,
 857                                 enum iio_chan_info_enum info)
 858 {
 859         const int *vals;
 860         int length;
 861         int ret;
 862
 863         ret = iio_channel_read_avail(chan, &vals, type, &length, info);
 864         if (ret < 0)
 865                 return ret;
 866
 867         switch (ret) {
 868         case IIO_AVAIL_RANGE:
 869                 switch (*type) {
 870                 case IIO_VAL_INT:
 871                         *val = vals[0];
 872                         break;
 873                 default:
 874                         *val = vals[0];
 875                         if (val2)
 876                                 *val2 = vals[1];
 877                 }
 878                 return 0;
 879
 880         case IIO_AVAIL_LIST:
 881                 if (length <= 0)
 882                         return -EINVAL;
 883                 switch (*type) {
 884                 case IIO_VAL_INT:
 885                         *val = min_array(vals, length);
 886                         break;
 887                 default:
 888                         /* TODO: learn about min for other iio values */
 889                         return -EINVAL;
 890                 }
 891                 return 0;
 892
 893         default:
 894                 return -EINVAL;
 895         }
 896 }
 897
 898 int iio_read_min_channel_raw(struct iio_channel *chan, int *val)
 899 {
 900         struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(chan->indio_dev);
 901         int type;
 902
 903         guard(mutex)(&iio_dev_opaque->info_exist_lock);
 904         if (!chan->indio_dev->info)
 905                 return -ENODEV;
 906
 907         return iio_channel_read_min(chan, val, NULL, &type, IIO_CHAN_INFO_RAW);
 908 }
 909 EXPORT_SYMBOL_GPL(iio_read_min_channel_raw);
 910
 911 int iio_get_channel_type(struct iio_channel *chan, enum iio_chan_type *type)
 912 {
 913         struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(chan->indio_dev);
 914
 915         guard(mutex)(&iio_dev_opaque->info_exist_lock);
 916         if (!chan->indio_dev->info)
 917                 return -ENODEV;
 918
 919         *type = chan->channel->type;
 920
 921         return 0;
 922 }
 923 EXPORT_SYMBOL_GPL(iio_get_channel_type);
 924
 925 static int iio_channel_write(struct iio_channel *chan, int val, int val2,
 926                              enum iio_chan_info_enum info)
 927 {
 928         const struct iio_info *iio_info = chan->indio_dev->info;
 929
 930         if (iio_info->write_raw)
 931                 return iio_info->write_raw(chan->indio_dev,
 932                                            chan->channel, val, val2, info);
 933         return -EINVAL;
 934 }
 935
 936 int iio_write_channel_attribute(struct iio_channel *chan, int val, int val2,
 937                                 enum iio_chan_info_enum attribute)
 938 {
 939         struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(chan->indio_dev);
 940
 941         guard(mutex)(&iio_dev_opaque->info_exist_lock);
 942         if (!chan->indio_dev->info)
 943                 return -ENODEV;
 944
 945         return iio_channel_write(chan, val, val2, attribute);
 946 }
 947 EXPORT_SYMBOL_GPL(iio_write_channel_attribute);
 948
 949 int iio_write_channel_raw(struct iio_channel *chan, int val)
 950 {
 951         return iio_write_channel_attribute(chan, val, 0, IIO_CHAN_INFO_RAW);
 952 }
 953 EXPORT_SYMBOL_GPL(iio_write_channel_raw);
 954
 955 unsigned int iio_get_channel_ext_info_count(struct iio_channel *chan)
 956 {
 957         const struct iio_chan_spec_ext_info *ext_info;
 958         unsigned int i = 0;
 959
 960         if (!chan->channel->ext_info)
 961                 return i;
 962
 963         for (ext_info = chan->channel->ext_info; ext_info->name; ext_info++)
 964                 ++i;
 965
 966         return i;
 967 }
 968 EXPORT_SYMBOL_GPL(iio_get_channel_ext_info_count);
 969
 970 static const struct iio_chan_spec_ext_info *
 971 iio_lookup_ext_info(const struct iio_channel *chan, const char *attr)
 972 {
 973         const struct iio_chan_spec_ext_info *ext_info;
 974
 975         if (!chan->channel->ext_info)
 976                 return NULL;
 977
 978         for (ext_info = chan->channel->ext_info; ext_info->name; ++ext_info) {
 979                 if (!strcmp(attr, ext_info->name))
 980                         return ext_info;
 981         }
 982
 983         return NULL;
 984 }
 985
 986 ssize_t iio_read_channel_ext_info(struct iio_channel *chan,
 987                                   const char *attr, char *buf)
 988 {
 989         const struct iio_chan_spec_ext_info *ext_info;
 990
 991         ext_info = iio_lookup_ext_info(chan, attr);
 992         if (!ext_info)
 993                 return -EINVAL;
 994
 995         return ext_info->read(chan->indio_dev, ext_info->private,
 996                               chan->channel, buf);
 997 }
 998 EXPORT_SYMBOL_GPL(iio_read_channel_ext_info);
 999
1000 ssize_t iio_write_channel_ext_info(struct iio_channel *chan, const char *attr,
1001                                    const char *buf, size_t len)
1002 {
1003         const struct iio_chan_spec_ext_info *ext_info;
1004
1005         ext_info = iio_lookup_ext_info(chan, attr);
1006         if (!ext_info)
1007                 return -EINVAL;
1008
1009         return ext_info->write(chan->indio_dev, ext_info->private,
1010                                chan->channel, buf, len);
1011 }
1012 EXPORT_SYMBOL_GPL(iio_write_channel_ext_info);
1013
1014 ssize_t iio_read_channel_label(struct iio_channel *chan, char *buf)
1015 {
1016         return do_iio_read_channel_label(chan->indio_dev, chan->channel, buf);
1017 }
1018 EXPORT_SYMBOL_GPL(iio_read_channel_label);