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/mm.h>
  11#include <linux/mutex.h>
  12#include <linux/property.h>
  13#include <linux/slab.h>
  14#include <linux/units.h>
  15
  16#include <linux/iio/iio.h>
  17#include <linux/iio/iio-opaque.h>
  18#include "iio_core.h"
  19#include <linux/iio/machine.h>
  20#include <linux/iio/driver.h>
  21#include <linux/iio/consumer.h>
  22
  23struct iio_map_internal {
  24	struct iio_dev *indio_dev;
  25	const struct iio_map *map;
  26	struct list_head l;
  27};
  28
  29static LIST_HEAD(iio_map_list);
  30static DEFINE_MUTEX(iio_map_list_lock);
  31
  32static int iio_map_array_unregister_locked(struct iio_dev *indio_dev)
  33{
  34	int ret = -ENODEV;
  35	struct iio_map_internal *mapi, *next;
  36
  37	list_for_each_entry_safe(mapi, next, &iio_map_list, l) {
  38		if (indio_dev == mapi->indio_dev) {
  39			list_del(&mapi->l);
  40			kfree(mapi);
  41			ret = 0;
  42		}
  43	}
  44	return ret;
  45}
  46
  47int iio_map_array_register(struct iio_dev *indio_dev, const struct iio_map *maps)
  48{
  49	struct iio_map_internal *mapi;
  50	int i = 0;
  51	int ret;
  52
  53	if (!maps)
  54		return 0;
  55
  56	guard(mutex)(&iio_map_list_lock);
  57	while (maps[i].consumer_dev_name) {
  58		mapi = kzalloc(sizeof(*mapi), GFP_KERNEL);
  59		if (!mapi) {
  60			ret = -ENOMEM;
  61			goto error_ret;
  62		}
  63		mapi->map = &maps[i];
  64		mapi->indio_dev = indio_dev;
  65		list_add_tail(&mapi->l, &iio_map_list);
  66		i++;
  67	}
  68
  69	return 0;
  70error_ret:
  71	iio_map_array_unregister_locked(indio_dev);
  72	return ret;
  73}
  74EXPORT_SYMBOL_GPL(iio_map_array_register);
  75
  76/*
  77 * Remove all map entries associated with the given iio device
  78 */
  79int iio_map_array_unregister(struct iio_dev *indio_dev)
  80{
  81	guard(mutex)(&iio_map_list_lock);
  82	return iio_map_array_unregister_locked(indio_dev);
  83}
  84EXPORT_SYMBOL_GPL(iio_map_array_unregister);
  85
  86static void iio_map_array_unregister_cb(void *indio_dev)
  87{
  88	iio_map_array_unregister(indio_dev);
  89}
  90
  91int devm_iio_map_array_register(struct device *dev, struct iio_dev *indio_dev,
  92				const struct iio_map *maps)
  93{
  94	int ret;
  95
  96	ret = iio_map_array_register(indio_dev, maps);
  97	if (ret)
  98		return ret;
  99
 100	return devm_add_action_or_reset(dev, iio_map_array_unregister_cb, indio_dev);
 101}
 102EXPORT_SYMBOL_GPL(devm_iio_map_array_register);
 103
 104static const struct iio_chan_spec
 105*iio_chan_spec_from_name(const struct iio_dev *indio_dev, const char *name)
 106{
 107	int i;
 108	const struct iio_chan_spec *chan = NULL;
 109
 110	for (i = 0; i < indio_dev->num_channels; i++)
 111		if (indio_dev->channels[i].datasheet_name &&
 112		    strcmp(name, indio_dev->channels[i].datasheet_name) == 0) {
 113			chan = &indio_dev->channels[i];
 114			break;
 115		}
 116	return chan;
 117}
 118
 119/**
 120 * __fwnode_iio_simple_xlate - translate iiospec to the IIO channel index
 121 * @indio_dev:	pointer to the iio_dev structure
 122 * @iiospec:	IIO specifier as found in the device tree
 123 *
 124 * This is simple translation function, suitable for the most 1:1 mapped
 125 * channels in IIO chips. This function performs only one sanity check:
 126 * whether IIO index is less than num_channels (that is specified in the
 127 * iio_dev).
 128 */
 129static int __fwnode_iio_simple_xlate(struct iio_dev *indio_dev,
 130				     const struct fwnode_reference_args *iiospec)
 131{
 132	if (!iiospec->nargs)
 133		return 0;
 134
 135	if (iiospec->args[0] >= indio_dev->num_channels) {
 136		dev_err(&indio_dev->dev, "invalid channel index %llu\n",
 137			iiospec->args[0]);
 138		return -EINVAL;
 139	}
 140
 141	return iiospec->args[0];
 142}
 143
 144static int __fwnode_iio_channel_get(struct iio_channel *channel,
 145				    struct fwnode_handle *fwnode, int index)
 146{
 147	struct fwnode_reference_args iiospec;
 148	struct device *idev;
 149	struct iio_dev *indio_dev;
 150	int err;
 151
 152	err = fwnode_property_get_reference_args(fwnode, "io-channels",
 153						 "#io-channel-cells", 0,
 154						 index, &iiospec);
 155	if (err)
 156		return err;
 157
 158	idev = bus_find_device_by_fwnode(&iio_bus_type, iiospec.fwnode);
 159	if (!idev) {
 160		fwnode_handle_put(iiospec.fwnode);
 161		return -EPROBE_DEFER;
 162	}
 163
 164	indio_dev = dev_to_iio_dev(idev);
 165	channel->indio_dev = indio_dev;
 166	if (indio_dev->info->fwnode_xlate)
 167		index = indio_dev->info->fwnode_xlate(indio_dev, &iiospec);
 168	else
 169		index = __fwnode_iio_simple_xlate(indio_dev, &iiospec);
 170	fwnode_handle_put(iiospec.fwnode);
 171	if (index < 0)
 172		goto err_put;
 173	channel->channel = &indio_dev->channels[index];
 174
 175	return 0;
 176
 177err_put:
 178	iio_device_put(indio_dev);
 179	return index;
 180}
 181
 182static struct iio_channel *fwnode_iio_channel_get(struct fwnode_handle *fwnode,
 183						  int index)
 184{
 185	int err;
 186
 187	if (index < 0)
 188		return ERR_PTR(-EINVAL);
 189
 190	struct iio_channel *channel __free(kfree) =
 191		kzalloc(sizeof(*channel), GFP_KERNEL);
 192	if (!channel)
 193		return ERR_PTR(-ENOMEM);
 194
 195	err = __fwnode_iio_channel_get(channel, fwnode, index);
 196	if (err)
 197		return ERR_PTR(err);
 198
 199	return_ptr(channel);
 200}
 201
 202static struct iio_channel *
 203__fwnode_iio_channel_get_by_name(struct fwnode_handle *fwnode, const char *name)
 204{
 205	struct iio_channel *chan;
 206	int index = 0;
 207
 208	/*
 209	 * For named iio channels, first look up the name in the
 210	 * "io-channel-names" property.  If it cannot be found, the
 211	 * index will be an error code, and fwnode_iio_channel_get()
 212	 * will fail.
 213	 */
 214	if (name)
 215		index = fwnode_property_match_string(fwnode, "io-channel-names",
 216						     name);
 217
 218	chan = fwnode_iio_channel_get(fwnode, index);
 219	if (!IS_ERR(chan) || PTR_ERR(chan) == -EPROBE_DEFER)
 220		return chan;
 221	if (name) {
 222		if (index >= 0) {
 223			pr_err("ERROR: could not get IIO channel %pfw:%s(%i)\n",
 224			       fwnode, name, index);
 225			/*
 226			 * In this case, we found 'name' in 'io-channel-names'
 227			 * but somehow we still fail so that we should not proceed
 228			 * with any other lookup. Hence, explicitly return -EINVAL
 229			 * (maybe not the better error code) so that the caller
 230			 * won't do a system lookup.
 231			 */
 232			return ERR_PTR(-EINVAL);
 233		}
 234		/*
 235		 * If index < 0, then fwnode_property_get_reference_args() fails
 236		 * with -EINVAL or -ENOENT (ACPI case) which is expected. We
 237		 * should not proceed if we get any other error.
 238		 */
 239		if (PTR_ERR(chan) != -EINVAL && PTR_ERR(chan) != -ENOENT)
 240			return chan;
 241	} else if (PTR_ERR(chan) != -ENOENT) {
 242		/*
 243		 * if !name, then we should only proceed the lookup if
 244		 * fwnode_property_get_reference_args() returns -ENOENT.
 245		 */
 246		return chan;
 247	}
 248
 249	/* so we continue the lookup */
 250	return ERR_PTR(-ENODEV);
 251}
 252
 253struct iio_channel *fwnode_iio_channel_get_by_name(struct fwnode_handle *fwnode,
 254						   const char *name)
 255{
 256	struct fwnode_handle *parent;
 257	struct iio_channel *chan;
 258
 259	/* Walk up the tree of devices looking for a matching iio channel */
 260	chan = __fwnode_iio_channel_get_by_name(fwnode, name);
 261	if (!IS_ERR(chan) || PTR_ERR(chan) != -ENODEV)
 262		return chan;
 263
 264	/*
 265	 * No matching IIO channel found on this node.
 266	 * If the parent node has a "io-channel-ranges" property,
 267	 * then we can try one of its channels.
 268	 */
 269	fwnode_for_each_parent_node(fwnode, parent) {
 270		if (!fwnode_property_present(parent, "io-channel-ranges")) {
 271			fwnode_handle_put(parent);
 272			return ERR_PTR(-ENODEV);
 273		}
 274
 275		chan = __fwnode_iio_channel_get_by_name(parent, name);
 276		if (!IS_ERR(chan) || PTR_ERR(chan) != -ENODEV) {
 277			fwnode_handle_put(parent);
 278 			return chan;
 279		}
 280	}
 281
 282	return ERR_PTR(-ENODEV);
 283}
 284EXPORT_SYMBOL_GPL(fwnode_iio_channel_get_by_name);
 285
 286static struct iio_channel *fwnode_iio_channel_get_all(struct device *dev)
 287{
 288	struct fwnode_handle *fwnode = dev_fwnode(dev);
 289	int i, mapind, nummaps = 0;
 290	int ret;
 291
 292	do {
 293		ret = fwnode_property_get_reference_args(fwnode, "io-channels",
 294							 "#io-channel-cells", 0,
 295							 nummaps, NULL);
 296		if (ret < 0)
 297			break;
 298	} while (++nummaps);
 299
 300	if (nummaps == 0)
 301		return ERR_PTR(-ENODEV);
 302
 303	/* NULL terminated array to save passing size */
 304	struct iio_channel *chans __free(kfree) =
 305		kcalloc(nummaps + 1, sizeof(*chans), GFP_KERNEL);
 306	if (!chans)
 307		return ERR_PTR(-ENOMEM);
 308
 309	/* Search for FW matches */
 310	for (mapind = 0; mapind < nummaps; mapind++) {
 311		ret = __fwnode_iio_channel_get(&chans[mapind], fwnode, mapind);
 312		if (ret)
 313			goto error_free_chans;
 314	}
 315	return_ptr(chans);
 316
 317error_free_chans:
 318	for (i = 0; i < mapind; i++)
 319		iio_device_put(chans[i].indio_dev);
 320	return ERR_PTR(ret);
 321}
 322
 323static struct iio_channel *iio_channel_get_sys(const char *name,
 324					       const char *channel_name)
 325{
 326	struct iio_map_internal *c_i = NULL, *c = NULL;
 327	int err;
 328
 329	if (!(name || channel_name))
 330		return ERR_PTR(-ENODEV);
 331
 332	/* first find matching entry the channel map */
 333	scoped_guard(mutex, &iio_map_list_lock) {
 334		list_for_each_entry(c_i, &iio_map_list, l) {
 335			if ((name && strcmp(name, c_i->map->consumer_dev_name) != 0) ||
 336			    (channel_name &&
 337			     strcmp(channel_name, c_i->map->consumer_channel) != 0))
 338				continue;
 339			c = c_i;
 340			iio_device_get(c->indio_dev);
 341			break;
 342		}
 343	}
 344	if (!c)
 345		return ERR_PTR(-ENODEV);
 346
 347	struct iio_channel *channel __free(kfree) =
 348		kzalloc(sizeof(*channel), GFP_KERNEL);
 349	if (!channel) {
 350		err = -ENOMEM;
 351		goto error_no_mem;
 352	}
 353
 354	channel->indio_dev = c->indio_dev;
 355
 356	if (c->map->adc_channel_label) {
 357		channel->channel =
 358			iio_chan_spec_from_name(channel->indio_dev,
 359						c->map->adc_channel_label);
 360
 361		if (!channel->channel) {
 362			err = -EINVAL;
 363			goto error_no_mem;
 364		}
 365	}
 366
 367	return_ptr(channel);
 368
 369error_no_mem:
 370	iio_device_put(c->indio_dev);
 371	return ERR_PTR(err);
 372}
 373
 374struct iio_channel *iio_channel_get(struct device *dev,
 375				    const char *channel_name)
 376{
 377	const char *name = dev ? dev_name(dev) : NULL;
 378	struct iio_channel *channel;
 379
 380	if (dev) {
 381		channel = fwnode_iio_channel_get_by_name(dev_fwnode(dev),
 382							 channel_name);
 383		if (!IS_ERR(channel) || PTR_ERR(channel) != -ENODEV)
 384			return channel;
 385	}
 386
 387	return iio_channel_get_sys(name, channel_name);
 388}
 389EXPORT_SYMBOL_GPL(iio_channel_get);
 390
 391void iio_channel_release(struct iio_channel *channel)
 392{
 393	if (!channel)
 394		return;
 395	iio_device_put(channel->indio_dev);
 396	kfree(channel);
 397}
 398EXPORT_SYMBOL_GPL(iio_channel_release);
 399
 400static void devm_iio_channel_free(void *iio_channel)
 401{
 402	iio_channel_release(iio_channel);
 403}
 404
 405struct iio_channel *devm_iio_channel_get(struct device *dev,
 406					 const char *channel_name)
 407{
 408	struct iio_channel *channel;
 409	int ret;
 410
 411	channel = iio_channel_get(dev, channel_name);
 412	if (IS_ERR(channel))
 413		return channel;
 414
 415	ret = devm_add_action_or_reset(dev, devm_iio_channel_free, channel);
 416	if (ret)
 417		return ERR_PTR(ret);
 418
 419	return channel;
 420}
 421EXPORT_SYMBOL_GPL(devm_iio_channel_get);
 422
 423struct iio_channel *devm_fwnode_iio_channel_get_by_name(struct device *dev,
 424							struct fwnode_handle *fwnode,
 425							const char *channel_name)
 426{
 427	struct iio_channel *channel;
 428	int ret;
 429
 430	channel = fwnode_iio_channel_get_by_name(fwnode, channel_name);
 431	if (IS_ERR(channel))
 432		return channel;
 433
 434	ret = devm_add_action_or_reset(dev, devm_iio_channel_free, channel);
 435	if (ret)
 436		return ERR_PTR(ret);
 437
 438	return channel;
 439}
 440EXPORT_SYMBOL_GPL(devm_fwnode_iio_channel_get_by_name);
 441
 442struct iio_channel *iio_channel_get_all(struct device *dev)
 443{
 444	const char *name;
 445	struct iio_map_internal *c = NULL;
 446	struct iio_channel *fw_chans;
 447	int nummaps = 0;
 448	int mapind = 0;
 449	int i, ret;
 450
 451	if (!dev)
 452		return ERR_PTR(-EINVAL);
 453
 454	fw_chans = fwnode_iio_channel_get_all(dev);
 455	/*
 456	 * We only want to carry on if the error is -ENODEV.  Anything else
 457	 * should be reported up the stack.
 458	 */
 459	if (!IS_ERR(fw_chans) || PTR_ERR(fw_chans) != -ENODEV)
 460		return fw_chans;
 461
 462	name = dev_name(dev);
 463
 464	guard(mutex)(&iio_map_list_lock);
 465	/* first count the matching maps */
 466	list_for_each_entry(c, &iio_map_list, l)
 467		if (name && strcmp(name, c->map->consumer_dev_name) != 0)
 468			continue;
 469		else
 470			nummaps++;
 471
 472	if (nummaps == 0)
 473		return ERR_PTR(-ENODEV);
 474
 475	/* NULL terminated array to save passing size */
 476	struct iio_channel *chans __free(kfree) =
 477		kcalloc(nummaps + 1, sizeof(*chans), GFP_KERNEL);
 478	if (!chans)
 479		return ERR_PTR(-ENOMEM);
 480
 481	/* for each map fill in the chans element */
 482	list_for_each_entry(c, &iio_map_list, l) {
 483		if (name && strcmp(name, c->map->consumer_dev_name) != 0)
 484			continue;
 485		chans[mapind].indio_dev = c->indio_dev;
 486		chans[mapind].data = c->map->consumer_data;
 487		chans[mapind].channel =
 488			iio_chan_spec_from_name(chans[mapind].indio_dev,
 489						c->map->adc_channel_label);
 490		if (!chans[mapind].channel) {
 491			ret = -EINVAL;
 492			goto error_free_chans;
 493		}
 494		iio_device_get(chans[mapind].indio_dev);
 495		mapind++;
 496	}
 497	if (mapind == 0) {
 498		ret = -ENODEV;
 499		goto error_free_chans;
 500	}
 501
 502	return_ptr(chans);
 503
 504error_free_chans:
 505	for (i = 0; i < mapind; i++)
 506		iio_device_put(chans[i].indio_dev);
 507	return ERR_PTR(ret);
 508}
 509EXPORT_SYMBOL_GPL(iio_channel_get_all);
 510
 511void iio_channel_release_all(struct iio_channel *channels)
 512{
 513	struct iio_channel *chan = &channels[0];
 514
 515	while (chan->indio_dev) {
 516		iio_device_put(chan->indio_dev);
 517		chan++;
 518	}
 519	kfree(channels);
 520}
 521EXPORT_SYMBOL_GPL(iio_channel_release_all);
 522
 523static void devm_iio_channel_free_all(void *iio_channels)
 524{
 525	iio_channel_release_all(iio_channels);
 526}
 527
 528struct iio_channel *devm_iio_channel_get_all(struct device *dev)
 529{
 530	struct iio_channel *channels;
 531	int ret;
 532
 533	channels = iio_channel_get_all(dev);
 534	if (IS_ERR(channels))
 535		return channels;
 536
 537	ret = devm_add_action_or_reset(dev, devm_iio_channel_free_all,
 538				       channels);
 539	if (ret)
 540		return ERR_PTR(ret);
 541
 542	return channels;
 543}
 544EXPORT_SYMBOL_GPL(devm_iio_channel_get_all);
 545
 546static int iio_channel_read(struct iio_channel *chan, int *val, int *val2,
 547			    enum iio_chan_info_enum info)
 548{
 549	const struct iio_info *iio_info = chan->indio_dev->info;
 550	int unused;
 551	int vals[INDIO_MAX_RAW_ELEMENTS];
 552	int ret;
 553	int val_len = 2;
 554
 555	if (!val2)
 556		val2 = &unused;
 557
 558	if (!iio_channel_has_info(chan->channel, info))
 559		return -EINVAL;
 560
 561	if (iio_info->read_raw_multi) {
 562		ret = iio_info->read_raw_multi(chan->indio_dev,
 563					       chan->channel,
 564					       INDIO_MAX_RAW_ELEMENTS,
 565					       vals, &val_len, info);
 566		*val = vals[0];
 567		*val2 = vals[1];
 568	} else if (iio_info->read_raw) {
 569		ret = iio_info->read_raw(chan->indio_dev,
 570					 chan->channel, val, val2, info);
 571	} else {
 572		return -EINVAL;
 573	}
 574
 575	return ret;
 576}
 577
 578int iio_read_channel_raw(struct iio_channel *chan, int *val)
 579{
 580	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(chan->indio_dev);
 581
 582	guard(mutex)(&iio_dev_opaque->info_exist_lock);
 583	if (!chan->indio_dev->info)
 584		return -ENODEV;
 585
 586	return iio_channel_read(chan, val, NULL, IIO_CHAN_INFO_RAW);
 587}
 588EXPORT_SYMBOL_GPL(iio_read_channel_raw);
 589
 590int iio_read_channel_average_raw(struct iio_channel *chan, int *val)
 591{
 592	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(chan->indio_dev);
 593
 594	guard(mutex)(&iio_dev_opaque->info_exist_lock);
 595	if (!chan->indio_dev->info)
 596		return -ENODEV;
 597
 598	return iio_channel_read(chan, val, NULL, IIO_CHAN_INFO_AVERAGE_RAW);
 599}
 600EXPORT_SYMBOL_GPL(iio_read_channel_average_raw);
 601
 602int iio_multiply_value(int *result, s64 multiplier,
 603		       unsigned int type, int val, int val2)
 604{
 605	s64 denominator;
 606
 607	switch (type) {
 608	case IIO_VAL_INT:
 609		*result = multiplier * val;
 610		return IIO_VAL_INT;
 611	case IIO_VAL_INT_PLUS_MICRO:
 612	case IIO_VAL_INT_PLUS_NANO:
 613		switch (type) {
 614		case IIO_VAL_INT_PLUS_MICRO:
 615			denominator = MICRO;
 616			break;
 617		case IIO_VAL_INT_PLUS_NANO:
 618			denominator = NANO;
 619			break;
 620		}
 621		*result = multiplier * abs(val);
 622		*result += div_s64(multiplier * abs(val2), denominator);
 623		if (val < 0 || val2 < 0)
 624			*result *= -1;
 625		return IIO_VAL_INT;
 626	case IIO_VAL_FRACTIONAL:
 627		*result = div_s64(multiplier * val, val2);
 628		return IIO_VAL_INT;
 629	case IIO_VAL_FRACTIONAL_LOG2:
 630		*result = (multiplier * val) >> val2;
 631		return IIO_VAL_INT;
 632	default:
 633		return -EINVAL;
 634	}
 635}
 636EXPORT_SYMBOL_NS_GPL(iio_multiply_value, "IIO_UNIT_TEST");
 637
 638static int iio_convert_raw_to_processed_unlocked(struct iio_channel *chan,
 639						 int raw, int *processed,
 640						 unsigned int scale)
 641{
 642	int scale_type, scale_val, scale_val2;
 643	int offset_type, offset_val, offset_val2;
 644	s64 raw64 = raw;
 645	int ret;
 646
 647	offset_type = iio_channel_read(chan, &offset_val, &offset_val2,
 648				       IIO_CHAN_INFO_OFFSET);
 649	if (offset_type >= 0) {
 650		switch (offset_type) {
 651		case IIO_VAL_INT:
 652			break;
 653		case IIO_VAL_INT_PLUS_MICRO:
 654		case IIO_VAL_INT_PLUS_NANO:
 655			/*
 656			 * Both IIO_VAL_INT_PLUS_MICRO and IIO_VAL_INT_PLUS_NANO
 657			 * implicitely truncate the offset to it's integer form.
 658			 */
 659			break;
 660		case IIO_VAL_FRACTIONAL:
 661			offset_val /= offset_val2;
 662			break;
 663		case IIO_VAL_FRACTIONAL_LOG2:
 664			offset_val >>= offset_val2;
 665			break;
 666		default:
 667			return -EINVAL;
 668		}
 669
 670		raw64 += offset_val;
 671	}
 672
 673	scale_type = iio_channel_read(chan, &scale_val, &scale_val2,
 674				      IIO_CHAN_INFO_SCALE);
 675	if (scale_type < 0) {
 676		/*
 677		 * If no channel scaling is available apply consumer scale to
 678		 * raw value and return.
 679		 */
 680		*processed = raw64 * scale;
 681		return 0;
 682	}
 683
 684	ret = iio_multiply_value(processed, raw64 * scale,
 685				 scale_type, scale_val, scale_val2);
 686	if (ret < 0)
 687		return ret;
 688
 689	return 0;
 690}
 691
 692int iio_convert_raw_to_processed(struct iio_channel *chan, int raw,
 693				 int *processed, unsigned int scale)
 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_convert_raw_to_processed_unlocked(chan, raw, processed,
 702						     scale);
 703}
 704EXPORT_SYMBOL_GPL(iio_convert_raw_to_processed);
 705
 706int iio_read_channel_attribute(struct iio_channel *chan, int *val, int *val2,
 707			       enum iio_chan_info_enum attribute)
 708{
 709	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(chan->indio_dev);
 710
 711	guard(mutex)(&iio_dev_opaque->info_exist_lock);
 712	if (!chan->indio_dev->info)
 713		return -ENODEV;
 714
 715	return iio_channel_read(chan, val, val2, attribute);
 716}
 717EXPORT_SYMBOL_GPL(iio_read_channel_attribute);
 718
 719int iio_read_channel_offset(struct iio_channel *chan, int *val, int *val2)
 720{
 721	return iio_read_channel_attribute(chan, val, val2, IIO_CHAN_INFO_OFFSET);
 722}
 723EXPORT_SYMBOL_GPL(iio_read_channel_offset);
 724
 725int iio_read_channel_processed_scale(struct iio_channel *chan, int *val,
 726				     unsigned int scale)
 727{
 728	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(chan->indio_dev);
 729	int ret, pval, pval2;
 730
 731	guard(mutex)(&iio_dev_opaque->info_exist_lock);
 732	if (!chan->indio_dev->info)
 733		return -ENODEV;
 734
 735	if (iio_channel_has_info(chan->channel, IIO_CHAN_INFO_PROCESSED)) {
 736		ret = iio_channel_read(chan, &pval, &pval2,
 737				       IIO_CHAN_INFO_PROCESSED);
 738		if (ret < 0)
 739			return ret;
 740
 741		return iio_multiply_value(val, scale, ret, pval, pval2);
 742	} else {
 743		ret = iio_channel_read(chan, val, NULL, IIO_CHAN_INFO_RAW);
 744		if (ret < 0)
 745			return ret;
 746
 747		return iio_convert_raw_to_processed_unlocked(chan, *val, val,
 748							     scale);
 749	}
 750}
 751EXPORT_SYMBOL_GPL(iio_read_channel_processed_scale);
 752
 753int iio_read_channel_processed(struct iio_channel *chan, int *val)
 754{
 755	/* This is just a special case with scale factor 1 */
 756	return iio_read_channel_processed_scale(chan, val, 1);
 757}
 758EXPORT_SYMBOL_GPL(iio_read_channel_processed);
 759
 760int iio_read_channel_scale(struct iio_channel *chan, int *val, int *val2)
 761{
 762	return iio_read_channel_attribute(chan, val, val2, IIO_CHAN_INFO_SCALE);
 763}
 764EXPORT_SYMBOL_GPL(iio_read_channel_scale);
 765
 766static int iio_channel_read_avail(struct iio_channel *chan,
 767				  const int **vals, int *type, int *length,
 768				  enum iio_chan_info_enum info)
 769{
 770	const struct iio_info *iio_info = chan->indio_dev->info;
 771
 772	if (!iio_channel_has_available(chan->channel, info))
 773		return -EINVAL;
 774
 775	if (iio_info->read_avail)
 776		return iio_info->read_avail(chan->indio_dev, chan->channel,
 777					    vals, type, length, info);
 778	return -EINVAL;
 779}
 780
 781int iio_read_avail_channel_attribute(struct iio_channel *chan,
 782				     const int **vals, int *type, int *length,
 783				     enum iio_chan_info_enum attribute)
 784{
 785	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(chan->indio_dev);
 786
 787	guard(mutex)(&iio_dev_opaque->info_exist_lock);
 788	if (!chan->indio_dev->info)
 789		return -ENODEV;
 790
 791	return iio_channel_read_avail(chan, vals, type, length, attribute);
 792}
 793EXPORT_SYMBOL_GPL(iio_read_avail_channel_attribute);
 794
 795int iio_read_avail_channel_raw(struct iio_channel *chan,
 796			       const int **vals, int *length)
 797{
 798	int ret;
 799	int type;
 800
 801	ret = iio_read_avail_channel_attribute(chan, vals, &type, length,
 802					       IIO_CHAN_INFO_RAW);
 803
 804	if (ret >= 0 && type != IIO_VAL_INT)
 805		/* raw values are assumed to be IIO_VAL_INT */
 806		ret = -EINVAL;
 807
 808	return ret;
 809}
 810EXPORT_SYMBOL_GPL(iio_read_avail_channel_raw);
 811
 812static int iio_channel_read_max(struct iio_channel *chan,
 813				int *val, int *val2, int *type,
 814				enum iio_chan_info_enum info)
 815{
 816	const int *vals;
 817	int length;
 818	int ret;
 819
 820	ret = iio_channel_read_avail(chan, &vals, type, &length, info);
 821	if (ret < 0)
 822		return ret;
 823
 824	switch (ret) {
 825	case IIO_AVAIL_RANGE:
 826		switch (*type) {
 827		case IIO_VAL_INT:
 828			*val = vals[2];
 829			break;
 830		default:
 831			*val = vals[4];
 832			if (val2)
 833				*val2 = vals[5];
 834		}
 835		return 0;
 836
 837	case IIO_AVAIL_LIST:
 838		if (length <= 0)
 839			return -EINVAL;
 840		switch (*type) {
 841		case IIO_VAL_INT:
 842			*val = max_array(vals, length);
 843			break;
 844		default:
 845			/* TODO: learn about max for other iio values */
 846			return -EINVAL;
 847		}
 848		return 0;
 849
 850	default:
 851		return -EINVAL;
 852	}
 853}
 854
 855int iio_read_max_channel_raw(struct iio_channel *chan, int *val)
 856{
 857	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(chan->indio_dev);
 858	int type;
 859
 860	guard(mutex)(&iio_dev_opaque->info_exist_lock);
 861	if (!chan->indio_dev->info)
 862		return -ENODEV;
 863
 864	return iio_channel_read_max(chan, val, NULL, &type, IIO_CHAN_INFO_RAW);
 865}
 866EXPORT_SYMBOL_GPL(iio_read_max_channel_raw);
 867
 868static int iio_channel_read_min(struct iio_channel *chan,
 869				int *val, int *val2, int *type,
 870				enum iio_chan_info_enum info)
 871{
 872	const int *vals;
 873	int length;
 874	int ret;
 875
 876	ret = iio_channel_read_avail(chan, &vals, type, &length, info);
 877	if (ret < 0)
 878		return ret;
 879
 880	switch (ret) {
 881	case IIO_AVAIL_RANGE:
 882		switch (*type) {
 883		case IIO_VAL_INT:
 884			*val = vals[0];
 885			break;
 886		default:
 887			*val = vals[0];
 888			if (val2)
 889				*val2 = vals[1];
 890		}
 891		return 0;
 892
 893	case IIO_AVAIL_LIST:
 894		if (length <= 0)
 895			return -EINVAL;
 896		switch (*type) {
 897		case IIO_VAL_INT:
 898			*val = min_array(vals, length);
 899			break;
 900		default:
 901			/* TODO: learn about min for other iio values */
 902			return -EINVAL;
 903		}
 904		return 0;
 905
 906	default:
 907		return -EINVAL;
 908	}
 909}
 910
 911int iio_read_min_channel_raw(struct iio_channel *chan, int *val)
 912{
 913	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(chan->indio_dev);
 914	int type;
 915
 916	guard(mutex)(&iio_dev_opaque->info_exist_lock);
 917	if (!chan->indio_dev->info)
 918		return -ENODEV;
 919
 920	return iio_channel_read_min(chan, val, NULL, &type, IIO_CHAN_INFO_RAW);
 921}
 922EXPORT_SYMBOL_GPL(iio_read_min_channel_raw);
 923
 924int iio_get_channel_type(struct iio_channel *chan, enum iio_chan_type *type)
 925{
 926	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(chan->indio_dev);
 927
 928	guard(mutex)(&iio_dev_opaque->info_exist_lock);
 929	if (!chan->indio_dev->info)
 930		return -ENODEV;
 931
 932	*type = chan->channel->type;
 933
 934	return 0;
 935}
 936EXPORT_SYMBOL_GPL(iio_get_channel_type);
 937
 938static int iio_channel_write(struct iio_channel *chan, int val, int val2,
 939			     enum iio_chan_info_enum info)
 940{
 941	const struct iio_info *iio_info = chan->indio_dev->info;
 942
 943	if (iio_info->write_raw)
 944		return iio_info->write_raw(chan->indio_dev,
 945					   chan->channel, val, val2, info);
 946	return -EINVAL;
 947}
 948
 949int iio_write_channel_attribute(struct iio_channel *chan, int val, int val2,
 950				enum iio_chan_info_enum attribute)
 951{
 952	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(chan->indio_dev);
 953
 954	guard(mutex)(&iio_dev_opaque->info_exist_lock);
 955	if (!chan->indio_dev->info)
 956		return -ENODEV;
 957
 958	return iio_channel_write(chan, val, val2, attribute);
 959}
 960EXPORT_SYMBOL_GPL(iio_write_channel_attribute);
 961
 962int iio_write_channel_raw(struct iio_channel *chan, int val)
 963{
 964	return iio_write_channel_attribute(chan, val, 0, IIO_CHAN_INFO_RAW);
 965}
 966EXPORT_SYMBOL_GPL(iio_write_channel_raw);
 967
 968unsigned int iio_get_channel_ext_info_count(struct iio_channel *chan)
 969{
 970	const struct iio_chan_spec_ext_info *ext_info;
 971	unsigned int i = 0;
 972
 973	if (!chan->channel->ext_info)
 974		return i;
 975
 976	for (ext_info = chan->channel->ext_info; ext_info->name; ext_info++)
 977		++i;
 978
 979	return i;
 980}
 981EXPORT_SYMBOL_GPL(iio_get_channel_ext_info_count);
 982
 983static const struct iio_chan_spec_ext_info *
 984iio_lookup_ext_info(const struct iio_channel *chan, const char *attr)
 985{
 986	const struct iio_chan_spec_ext_info *ext_info;
 987
 988	if (!chan->channel->ext_info)
 989		return NULL;
 990
 991	for (ext_info = chan->channel->ext_info; ext_info->name; ++ext_info) {
 992		if (!strcmp(attr, ext_info->name))
 993			return ext_info;
 994	}
 995
 996	return NULL;
 997}
 998
 999ssize_t iio_read_channel_ext_info(struct iio_channel *chan,
1000				  const char *attr, char *buf)
1001{
1002	const struct iio_chan_spec_ext_info *ext_info;
1003
1004	if (!buf || offset_in_page(buf)) {
1005		pr_err("iio: invalid ext_info read buffer\n");
1006		return -EINVAL;
1007	}
1008
1009	ext_info = iio_lookup_ext_info(chan, attr);
1010	if (!ext_info)
1011		return -EINVAL;
1012
1013	return ext_info->read(chan->indio_dev, ext_info->private,
1014			      chan->channel, buf);
1015}
1016EXPORT_SYMBOL_GPL(iio_read_channel_ext_info);
1017
1018ssize_t iio_write_channel_ext_info(struct iio_channel *chan, const char *attr,
1019				   const char *buf, size_t len)
1020{
1021	const struct iio_chan_spec_ext_info *ext_info;
1022
1023	ext_info = iio_lookup_ext_info(chan, attr);
1024	if (!ext_info)
1025		return -EINVAL;
1026
1027	return ext_info->write(chan->indio_dev, ext_info->private,
1028			       chan->channel, buf, len);
1029}
1030EXPORT_SYMBOL_GPL(iio_write_channel_ext_info);
1031
1032ssize_t iio_read_channel_label(struct iio_channel *chan, char *buf)
1033{
1034	if (!buf || offset_in_page(buf)) {
1035		pr_err("iio: invalid label read buffer\n");
1036		return -EINVAL;
1037	}
1038
1039	return do_iio_read_channel_label(chan->indio_dev, chan->channel, buf);
1040}
1041EXPORT_SYMBOL_GPL(iio_read_channel_label);