inkern.c 20.8 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12
/* The industrial I/O core in kernel channel mapping
 *
 * Copyright (c) 2011 Jonathan Cameron
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 */
#include <linux/err.h>
#include <linux/export.h>
#include <linux/slab.h>
#include <linux/mutex.h>
Guenter Roeck's avatar
Guenter Roeck committed
13
#include <linux/of.h>
14

15
#include <linux/iio/iio.h>
16
#include "iio_core.h"
17 18 19
#include <linux/iio/machine.h>
#include <linux/iio/driver.h>
#include <linux/iio/consumer.h>
20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46

struct iio_map_internal {
	struct iio_dev *indio_dev;
	struct iio_map *map;
	struct list_head l;
};

static LIST_HEAD(iio_map_list);
static DEFINE_MUTEX(iio_map_list_lock);

int iio_map_array_register(struct iio_dev *indio_dev, struct iio_map *maps)
{
	int i = 0, ret = 0;
	struct iio_map_internal *mapi;

	if (maps == NULL)
		return 0;

	mutex_lock(&iio_map_list_lock);
	while (maps[i].consumer_dev_name != NULL) {
		mapi = kzalloc(sizeof(*mapi), GFP_KERNEL);
		if (mapi == NULL) {
			ret = -ENOMEM;
			goto error_ret;
		}
		mapi->map = &maps[i];
		mapi->indio_dev = indio_dev;
47
		list_add_tail(&mapi->l, &iio_map_list);
48 49 50 51 52 53 54 55 56 57
		i++;
	}
error_ret:
	mutex_unlock(&iio_map_list_lock);

	return ret;
}
EXPORT_SYMBOL_GPL(iio_map_array_register);


58 59
/*
 * Remove all map entries associated with the given iio device
60
 */
61
int iio_map_array_unregister(struct iio_dev *indio_dev)
62
{
63
	int ret = -ENODEV;
64
	struct iio_map_internal *mapi, *next;
65 66

	mutex_lock(&iio_map_list_lock);
67
	list_for_each_entry_safe(mapi, next, &iio_map_list, l) {
68 69 70 71
		if (indio_dev == mapi->indio_dev) {
			list_del(&mapi->l);
			kfree(mapi);
			ret = 0;
72 73 74 75 76 77 78 79
		}
	}
	mutex_unlock(&iio_map_list_lock);
	return ret;
}
EXPORT_SYMBOL_GPL(iio_map_array_unregister);

static const struct iio_chan_spec
80
*iio_chan_spec_from_name(const struct iio_dev *indio_dev, const char *name)
81 82 83 84 85 86 87 88 89 90 91 92 93
{
	int i;
	const struct iio_chan_spec *chan = NULL;

	for (i = 0; i < indio_dev->num_channels; i++)
		if (indio_dev->channels[i].datasheet_name &&
		    strcmp(name, indio_dev->channels[i].datasheet_name) == 0) {
			chan = &indio_dev->channels[i];
			break;
		}
	return chan;
}

Guenter Roeck's avatar
Guenter Roeck committed
94 95 96 97 98 99 100
#ifdef CONFIG_OF

static int iio_dev_node_match(struct device *dev, void *data)
{
	return dev->of_node == data && dev->type == &iio_device_type;
}

101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116
/**
 * __of_iio_simple_xlate - translate iiospec to the IIO channel index
 * @indio_dev:	pointer to the iio_dev structure
 * @iiospec:	IIO specifier as found in the device tree
 *
 * This is simple translation function, suitable for the most 1:1 mapped
 * channels in IIO chips. This function performs only one sanity check:
 * whether IIO index is less than num_channels (that is specified in the
 * iio_dev).
 */
static int __of_iio_simple_xlate(struct iio_dev *indio_dev,
				const struct of_phandle_args *iiospec)
{
	if (!iiospec->args_count)
		return 0;

117 118 119
	if (iiospec->args[0] >= indio_dev->num_channels) {
		dev_err(&indio_dev->dev, "invalid channel index %u\n",
			iiospec->args[0]);
120
		return -EINVAL;
121
	}
122 123 124 125

	return iiospec->args[0];
}

Guenter Roeck's avatar
Guenter Roeck committed
126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147
static int __of_iio_channel_get(struct iio_channel *channel,
				struct device_node *np, int index)
{
	struct device *idev;
	struct iio_dev *indio_dev;
	int err;
	struct of_phandle_args iiospec;

	err = of_parse_phandle_with_args(np, "io-channels",
					 "#io-channel-cells",
					 index, &iiospec);
	if (err)
		return err;

	idev = bus_find_device(&iio_bus_type, NULL, iiospec.np,
			       iio_dev_node_match);
	of_node_put(iiospec.np);
	if (idev == NULL)
		return -EPROBE_DEFER;

	indio_dev = dev_to_iio_dev(idev);
	channel->indio_dev = indio_dev;
148 149 150 151 152
	if (indio_dev->info->of_xlate)
		index = indio_dev->info->of_xlate(indio_dev, &iiospec);
	else
		index = __of_iio_simple_xlate(indio_dev, &iiospec);
	if (index < 0)
Guenter Roeck's avatar
Guenter Roeck committed
153 154 155 156 157 158 159
		goto err_put;
	channel->channel = &indio_dev->channels[index];

	return 0;

err_put:
	iio_device_put(indio_dev);
160
	return index;
Guenter Roeck's avatar
Guenter Roeck committed
161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204
}

static struct iio_channel *of_iio_channel_get(struct device_node *np, int index)
{
	struct iio_channel *channel;
	int err;

	if (index < 0)
		return ERR_PTR(-EINVAL);

	channel = kzalloc(sizeof(*channel), GFP_KERNEL);
	if (channel == NULL)
		return ERR_PTR(-ENOMEM);

	err = __of_iio_channel_get(channel, np, index);
	if (err)
		goto err_free_channel;

	return channel;

err_free_channel:
	kfree(channel);
	return ERR_PTR(err);
}

static struct iio_channel *of_iio_channel_get_by_name(struct device_node *np,
						      const char *name)
{
	struct iio_channel *chan = NULL;

	/* Walk up the tree of devices looking for a matching iio channel */
	while (np) {
		int index = 0;

		/*
		 * For named iio channels, first look up the name in the
		 * "io-channel-names" property.  If it cannot be found, the
		 * index will be an error code, and of_iio_channel_get()
		 * will fail.
		 */
		if (name)
			index = of_property_match_string(np, "io-channel-names",
							 name);
		chan = of_iio_channel_get(np, index);
205
		if (!IS_ERR(chan) || PTR_ERR(chan) == -EPROBE_DEFER)
Guenter Roeck's avatar
Guenter Roeck committed
206 207
			break;
		else if (name && index >= 0) {
208 209
			pr_err("ERROR: could not get IIO channel %pOF:%s(%i)\n",
				np, name ? name : "", index);
210
			return NULL;
Guenter Roeck's avatar
Guenter Roeck committed
211 212 213 214 215 216 217 218 219
		}

		/*
		 * No matching IIO channel found on this node.
		 * If the parent node has a "io-channel-ranges" property,
		 * then we can try one of its channels.
		 */
		np = np->parent;
		if (np && !of_get_property(np, "io-channel-ranges", NULL))
220
			return NULL;
Guenter Roeck's avatar
Guenter Roeck committed
221
	}
222

Guenter Roeck's avatar
Guenter Roeck committed
223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278
	return chan;
}

static struct iio_channel *of_iio_channel_get_all(struct device *dev)
{
	struct iio_channel *chans;
	int i, mapind, nummaps = 0;
	int ret;

	do {
		ret = of_parse_phandle_with_args(dev->of_node,
						 "io-channels",
						 "#io-channel-cells",
						 nummaps, NULL);
		if (ret < 0)
			break;
	} while (++nummaps);

	if (nummaps == 0)	/* no error, return NULL to search map table */
		return NULL;

	/* NULL terminated array to save passing size */
	chans = kcalloc(nummaps + 1, sizeof(*chans), GFP_KERNEL);
	if (chans == NULL)
		return ERR_PTR(-ENOMEM);

	/* Search for OF matches */
	for (mapind = 0; mapind < nummaps; mapind++) {
		ret = __of_iio_channel_get(&chans[mapind], dev->of_node,
					   mapind);
		if (ret)
			goto error_free_chans;
	}
	return chans;

error_free_chans:
	for (i = 0; i < mapind; i++)
		iio_device_put(chans[i].indio_dev);
	kfree(chans);
	return ERR_PTR(ret);
}

#else /* CONFIG_OF */

static inline struct iio_channel *
of_iio_channel_get_by_name(struct device_node *np, const char *name)
{
	return NULL;
}

static inline struct iio_channel *of_iio_channel_get_all(struct device *dev)
{
	return NULL;
}

#endif /* CONFIG_OF */
279

280 281
static struct iio_channel *iio_channel_get_sys(const char *name,
					       const char *channel_name)
282 283 284
{
	struct iio_map_internal *c_i = NULL, *c = NULL;
	struct iio_channel *channel;
285
	int err;
286 287 288 289 290 291 292 293 294 295 296 297

	if (name == NULL && channel_name == NULL)
		return ERR_PTR(-ENODEV);

	/* first find matching entry the channel map */
	mutex_lock(&iio_map_list_lock);
	list_for_each_entry(c_i, &iio_map_list, l) {
		if ((name && strcmp(name, c_i->map->consumer_dev_name) != 0) ||
		    (channel_name &&
		     strcmp(channel_name, c_i->map->consumer_channel) != 0))
			continue;
		c = c_i;
298
		iio_device_get(c->indio_dev);
299 300 301 302 303 304
		break;
	}
	mutex_unlock(&iio_map_list_lock);
	if (c == NULL)
		return ERR_PTR(-ENODEV);

305
	channel = kzalloc(sizeof(*channel), GFP_KERNEL);
306 307
	if (channel == NULL) {
		err = -ENOMEM;
308
		goto error_no_mem;
309
	}
310 311 312

	channel->indio_dev = c->indio_dev;

313
	if (c->map->adc_channel_label) {
314 315 316 317
		channel->channel =
			iio_chan_spec_from_name(channel->indio_dev,
						c->map->adc_channel_label);

318 319
		if (channel->channel == NULL) {
			err = -EINVAL;
320
			goto error_no_chan;
321
		}
322 323
	}

324
	return channel;
325 326 327

error_no_chan:
	kfree(channel);
328 329
error_no_mem:
	iio_device_put(c->indio_dev);
330
	return ERR_PTR(err);
331
}
332 333 334 335 336

struct iio_channel *iio_channel_get(struct device *dev,
				    const char *channel_name)
{
	const char *name = dev ? dev_name(dev) : NULL;
Guenter Roeck's avatar
Guenter Roeck committed
337
	struct iio_channel *channel;
338

Guenter Roeck's avatar
Guenter Roeck committed
339 340 341 342 343 344
	if (dev) {
		channel = of_iio_channel_get_by_name(dev->of_node,
						     channel_name);
		if (channel != NULL)
			return channel;
	}
345

346 347
	return iio_channel_get_sys(name, channel_name);
}
348
EXPORT_SYMBOL_GPL(iio_channel_get);
349

350
void iio_channel_release(struct iio_channel *channel)
351
{
352 353
	if (!channel)
		return;
354
	iio_device_put(channel->indio_dev);
355 356
	kfree(channel);
}
357
EXPORT_SYMBOL_GPL(iio_channel_release);
358

359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406
static void devm_iio_channel_free(struct device *dev, void *res)
{
	struct iio_channel *channel = *(struct iio_channel **)res;

	iio_channel_release(channel);
}

static int devm_iio_channel_match(struct device *dev, void *res, void *data)
{
	struct iio_channel **r = res;

	if (!r || !*r) {
		WARN_ON(!r || !*r);
		return 0;
	}

	return *r == data;
}

struct iio_channel *devm_iio_channel_get(struct device *dev,
					 const char *channel_name)
{
	struct iio_channel **ptr, *channel;

	ptr = devres_alloc(devm_iio_channel_free, sizeof(*ptr), GFP_KERNEL);
	if (!ptr)
		return ERR_PTR(-ENOMEM);

	channel = iio_channel_get(dev, channel_name);
	if (IS_ERR(channel)) {
		devres_free(ptr);
		return channel;
	}

	*ptr = channel;
	devres_add(dev, ptr);

	return channel;
}
EXPORT_SYMBOL_GPL(devm_iio_channel_get);

void devm_iio_channel_release(struct device *dev, struct iio_channel *channel)
{
	WARN_ON(devres_release(dev, devm_iio_channel_free,
			       devm_iio_channel_match, channel));
}
EXPORT_SYMBOL_GPL(devm_iio_channel_release);

407
struct iio_channel *iio_channel_get_all(struct device *dev)
408
{
409
	const char *name;
410 411 412 413 414 415
	struct iio_channel *chans;
	struct iio_map_internal *c = NULL;
	int nummaps = 0;
	int mapind = 0;
	int i, ret;

416
	if (dev == NULL)
417
		return ERR_PTR(-EINVAL);
Guenter Roeck's avatar
Guenter Roeck committed
418 419 420 421 422

	chans = of_iio_channel_get_all(dev);
	if (chans)
		return chans;

423
	name = dev_name(dev);
424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449

	mutex_lock(&iio_map_list_lock);
	/* first count the matching maps */
	list_for_each_entry(c, &iio_map_list, l)
		if (name && strcmp(name, c->map->consumer_dev_name) != 0)
			continue;
		else
			nummaps++;

	if (nummaps == 0) {
		ret = -ENODEV;
		goto error_ret;
	}

	/* NULL terminated array to save passing size */
	chans = kzalloc(sizeof(*chans)*(nummaps + 1), GFP_KERNEL);
	if (chans == NULL) {
		ret = -ENOMEM;
		goto error_ret;
	}

	/* for each map fill in the chans element */
	list_for_each_entry(c, &iio_map_list, l) {
		if (name && strcmp(name, c->map->consumer_dev_name) != 0)
			continue;
		chans[mapind].indio_dev = c->indio_dev;
450
		chans[mapind].data = c->map->consumer_data;
451 452 453 454 455 456 457
		chans[mapind].channel =
			iio_chan_spec_from_name(chans[mapind].indio_dev,
						c->map->adc_channel_label);
		if (chans[mapind].channel == NULL) {
			ret = -EINVAL;
			goto error_free_chans;
		}
458
		iio_device_get(chans[mapind].indio_dev);
459 460 461 462 463 464
		mapind++;
	}
	if (mapind == 0) {
		ret = -ENODEV;
		goto error_free_chans;
	}
465 466
	mutex_unlock(&iio_map_list_lock);

467 468 469 470
	return chans;

error_free_chans:
	for (i = 0; i < nummaps; i++)
471
		iio_device_put(chans[i].indio_dev);
472 473 474 475 476 477
	kfree(chans);
error_ret:
	mutex_unlock(&iio_map_list_lock);

	return ERR_PTR(ret);
}
478
EXPORT_SYMBOL_GPL(iio_channel_get_all);
479

480
void iio_channel_release_all(struct iio_channel *channels)
481 482 483 484
{
	struct iio_channel *chan = &channels[0];

	while (chan->indio_dev) {
485
		iio_device_put(chan->indio_dev);
486 487 488 489
		chan++;
	}
	kfree(channels);
}
490
EXPORT_SYMBOL_GPL(iio_channel_release_all);
491

492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527
static void devm_iio_channel_free_all(struct device *dev, void *res)
{
	struct iio_channel *channels = *(struct iio_channel **)res;

	iio_channel_release_all(channels);
}

struct iio_channel *devm_iio_channel_get_all(struct device *dev)
{
	struct iio_channel **ptr, *channels;

	ptr = devres_alloc(devm_iio_channel_free_all, sizeof(*ptr), GFP_KERNEL);
	if (!ptr)
		return ERR_PTR(-ENOMEM);

	channels = iio_channel_get_all(dev);
	if (IS_ERR(channels)) {
		devres_free(ptr);
		return channels;
	}

	*ptr = channels;
	devres_add(dev, ptr);

	return channels;
}
EXPORT_SYMBOL_GPL(devm_iio_channel_get_all);

void devm_iio_channel_release_all(struct device *dev,
				  struct iio_channel *channels)
{
	WARN_ON(devres_release(dev, devm_iio_channel_free_all,
			       devm_iio_channel_match, channels));
}
EXPORT_SYMBOL_GPL(devm_iio_channel_release_all);

528 529 530 531
static int iio_channel_read(struct iio_channel *chan, int *val, int *val2,
	enum iio_chan_info_enum info)
{
	int unused;
532 533 534
	int vals[INDIO_MAX_RAW_ELEMENTS];
	int ret;
	int val_len = 2;
535 536 537 538

	if (val2 == NULL)
		val2 = &unused;

539
	if (!iio_channel_has_info(chan->channel, info))
540 541
		return -EINVAL;

542 543 544 545 546 547 548 549 550 551 552
	if (chan->indio_dev->info->read_raw_multi) {
		ret = chan->indio_dev->info->read_raw_multi(chan->indio_dev,
					chan->channel, INDIO_MAX_RAW_ELEMENTS,
					vals, &val_len, info);
		*val = vals[0];
		*val2 = vals[1];
	} else
		ret = chan->indio_dev->info->read_raw(chan->indio_dev,
					chan->channel, val, val2, info);

	return ret;
553 554
}

555
int iio_read_channel_raw(struct iio_channel *chan, int *val)
556
{
557
	int ret;
558 559 560 561 562 563 564

	mutex_lock(&chan->indio_dev->info_exist_lock);
	if (chan->indio_dev->info == NULL) {
		ret = -ENODEV;
		goto err_unlock;
	}

565
	ret = iio_channel_read(chan, val, NULL, IIO_CHAN_INFO_RAW);
566 567 568 569 570
err_unlock:
	mutex_unlock(&chan->indio_dev->info_exist_lock);

	return ret;
}
571
EXPORT_SYMBOL_GPL(iio_read_channel_raw);
572

573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590
int iio_read_channel_average_raw(struct iio_channel *chan, int *val)
{
	int ret;

	mutex_lock(&chan->indio_dev->info_exist_lock);
	if (chan->indio_dev->info == NULL) {
		ret = -ENODEV;
		goto err_unlock;
	}

	ret = iio_channel_read(chan, val, NULL, IIO_CHAN_INFO_AVERAGE_RAW);
err_unlock:
	mutex_unlock(&chan->indio_dev->info_exist_lock);

	return ret;
}
EXPORT_SYMBOL_GPL(iio_read_channel_average_raw);

591 592 593 594 595 596 597
static int iio_convert_raw_to_processed_unlocked(struct iio_channel *chan,
	int raw, int *processed, unsigned int scale)
{
	int scale_type, scale_val, scale_val2, offset;
	s64 raw64 = raw;
	int ret;

598
	ret = iio_channel_read(chan, &offset, NULL, IIO_CHAN_INFO_OFFSET);
599
	if (ret >= 0)
600 601 602 603
		raw64 += offset;

	scale_type = iio_channel_read(chan, &scale_val, &scale_val2,
					IIO_CHAN_INFO_SCALE);
604 605 606 607 608 609 610 611
	if (scale_type < 0) {
		/*
		 * Just pass raw values as processed if no scaling is
		 * available.
		 */
		*processed = raw;
		return 0;
	}
612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636

	switch (scale_type) {
	case IIO_VAL_INT:
		*processed = raw64 * scale_val;
		break;
	case IIO_VAL_INT_PLUS_MICRO:
		if (scale_val2 < 0)
			*processed = -raw64 * scale_val;
		else
			*processed = raw64 * scale_val;
		*processed += div_s64(raw64 * (s64)scale_val2 * scale,
				      1000000LL);
		break;
	case IIO_VAL_INT_PLUS_NANO:
		if (scale_val2 < 0)
			*processed = -raw64 * scale_val;
		else
			*processed = raw64 * scale_val;
		*processed += div_s64(raw64 * (s64)scale_val2 * scale,
				      1000000000LL);
		break;
	case IIO_VAL_FRACTIONAL:
		*processed = div_s64(raw64 * (s64)scale_val * scale,
				     scale_val2);
		break;
637 638 639
	case IIO_VAL_FRACTIONAL_LOG2:
		*processed = (raw64 * (s64)scale_val * scale) >> scale_val2;
		break;
640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666
	default:
		return -EINVAL;
	}

	return 0;
}

int iio_convert_raw_to_processed(struct iio_channel *chan, int raw,
	int *processed, unsigned int scale)
{
	int ret;

	mutex_lock(&chan->indio_dev->info_exist_lock);
	if (chan->indio_dev->info == NULL) {
		ret = -ENODEV;
		goto err_unlock;
	}

	ret = iio_convert_raw_to_processed_unlocked(chan, raw, processed,
							scale);
err_unlock:
	mutex_unlock(&chan->indio_dev->info_exist_lock);

	return ret;
}
EXPORT_SYMBOL_GPL(iio_convert_raw_to_processed);

667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691
static int iio_read_channel_attribute(struct iio_channel *chan,
				      int *val, int *val2,
				      enum iio_chan_info_enum attribute)
{
	int ret;

	mutex_lock(&chan->indio_dev->info_exist_lock);
	if (chan->indio_dev->info == NULL) {
		ret = -ENODEV;
		goto err_unlock;
	}

	ret = iio_channel_read(chan, val, val2, attribute);
err_unlock:
	mutex_unlock(&chan->indio_dev->info_exist_lock);

	return ret;
}

int iio_read_channel_offset(struct iio_channel *chan, int *val, int *val2)
{
	return iio_read_channel_attribute(chan, val, val2, IIO_CHAN_INFO_OFFSET);
}
EXPORT_SYMBOL_GPL(iio_read_channel_offset);

692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718
int iio_read_channel_processed(struct iio_channel *chan, int *val)
{
	int ret;

	mutex_lock(&chan->indio_dev->info_exist_lock);
	if (chan->indio_dev->info == NULL) {
		ret = -ENODEV;
		goto err_unlock;
	}

	if (iio_channel_has_info(chan->channel, IIO_CHAN_INFO_PROCESSED)) {
		ret = iio_channel_read(chan, val, NULL,
				       IIO_CHAN_INFO_PROCESSED);
	} else {
		ret = iio_channel_read(chan, val, NULL, IIO_CHAN_INFO_RAW);
		if (ret < 0)
			goto err_unlock;
		ret = iio_convert_raw_to_processed_unlocked(chan, *val, val, 1);
	}

err_unlock:
	mutex_unlock(&chan->indio_dev->info_exist_lock);

	return ret;
}
EXPORT_SYMBOL_GPL(iio_read_channel_processed);

719
int iio_read_channel_scale(struct iio_channel *chan, int *val, int *val2)
720
{
721
	return iio_read_channel_attribute(chan, val, val2, IIO_CHAN_INFO_SCALE);
722
}
723
EXPORT_SYMBOL_GPL(iio_read_channel_scale);
724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752

static int iio_channel_read_avail(struct iio_channel *chan,
				  const int **vals, int *type, int *length,
				  enum iio_chan_info_enum info)
{
	if (!iio_channel_has_available(chan->channel, info))
		return -EINVAL;

	return chan->indio_dev->info->read_avail(chan->indio_dev, chan->channel,
						 vals, type, length, info);
}

int iio_read_avail_channel_raw(struct iio_channel *chan,
			       const int **vals, int *length)
{
	int ret;
	int type;

	mutex_lock(&chan->indio_dev->info_exist_lock);
	if (!chan->indio_dev->info) {
		ret = -ENODEV;
		goto err_unlock;
	}

	ret = iio_channel_read_avail(chan,
				     vals, &type, length, IIO_CHAN_INFO_RAW);
err_unlock:
	mutex_unlock(&chan->indio_dev->info_exist_lock);

753
	if (ret >= 0 && type != IIO_VAL_INT)
754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825
		/* raw values are assumed to be IIO_VAL_INT */
		ret = -EINVAL;

	return ret;
}
EXPORT_SYMBOL_GPL(iio_read_avail_channel_raw);

static int iio_channel_read_max(struct iio_channel *chan,
				int *val, int *val2, int *type,
				enum iio_chan_info_enum info)
{
	int unused;
	const int *vals;
	int length;
	int ret;

	if (!val2)
		val2 = &unused;

	ret = iio_channel_read_avail(chan, &vals, type, &length, info);
	switch (ret) {
	case IIO_AVAIL_RANGE:
		switch (*type) {
		case IIO_VAL_INT:
			*val = vals[2];
			break;
		default:
			*val = vals[4];
			*val2 = vals[5];
		}
		return 0;

	case IIO_AVAIL_LIST:
		if (length <= 0)
			return -EINVAL;
		switch (*type) {
		case IIO_VAL_INT:
			*val = vals[--length];
			while (length) {
				if (vals[--length] > *val)
					*val = vals[length];
			}
			break;
		default:
			/* FIXME: learn about max for other iio values */
			return -EINVAL;
		}
		return 0;

	default:
		return ret;
	}
}

int iio_read_max_channel_raw(struct iio_channel *chan, int *val)
{
	int ret;
	int type;

	mutex_lock(&chan->indio_dev->info_exist_lock);
	if (!chan->indio_dev->info) {
		ret = -ENODEV;
		goto err_unlock;
	}

	ret = iio_channel_read_max(chan, val, NULL, &type, IIO_CHAN_INFO_RAW);
err_unlock:
	mutex_unlock(&chan->indio_dev->info_exist_lock);

	return ret;
}
EXPORT_SYMBOL_GPL(iio_read_max_channel_raw);
826

827
int iio_get_channel_type(struct iio_channel *chan, enum iio_chan_type *type)
828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843
{
	int ret = 0;
	/* Need to verify underlying driver has not gone away */

	mutex_lock(&chan->indio_dev->info_exist_lock);
	if (chan->indio_dev->info == NULL) {
		ret = -ENODEV;
		goto err_unlock;
	}

	*type = chan->channel->type;
err_unlock:
	mutex_unlock(&chan->indio_dev->info_exist_lock);

	return ret;
}
844
EXPORT_SYMBOL_GPL(iio_get_channel_type);
845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869

static int iio_channel_write(struct iio_channel *chan, int val, int val2,
			     enum iio_chan_info_enum info)
{
	return chan->indio_dev->info->write_raw(chan->indio_dev,
						chan->channel, val, val2, info);
}

int iio_write_channel_raw(struct iio_channel *chan, int val)
{
	int ret;

	mutex_lock(&chan->indio_dev->info_exist_lock);
	if (chan->indio_dev->info == NULL) {
		ret = -ENODEV;
		goto err_unlock;
	}

	ret = iio_channel_write(chan, val, 0, IIO_CHAN_INFO_RAW);
err_unlock:
	mutex_unlock(&chan->indio_dev->info_exist_lock);

	return ret;
}
EXPORT_SYMBOL_GPL(iio_write_channel_raw);
870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929

unsigned int iio_get_channel_ext_info_count(struct iio_channel *chan)
{
	const struct iio_chan_spec_ext_info *ext_info;
	unsigned int i = 0;

	if (!chan->channel->ext_info)
		return i;

	for (ext_info = chan->channel->ext_info; ext_info->name; ext_info++)
		++i;

	return i;
}
EXPORT_SYMBOL_GPL(iio_get_channel_ext_info_count);

static const struct iio_chan_spec_ext_info *iio_lookup_ext_info(
						const struct iio_channel *chan,
						const char *attr)
{
	const struct iio_chan_spec_ext_info *ext_info;

	if (!chan->channel->ext_info)
		return NULL;

	for (ext_info = chan->channel->ext_info; ext_info->name; ++ext_info) {
		if (!strcmp(attr, ext_info->name))
			return ext_info;
	}

	return NULL;
}

ssize_t iio_read_channel_ext_info(struct iio_channel *chan,
				  const char *attr, char *buf)
{
	const struct iio_chan_spec_ext_info *ext_info;

	ext_info = iio_lookup_ext_info(chan, attr);
	if (!ext_info)
		return -EINVAL;

	return ext_info->read(chan->indio_dev, ext_info->private,
			      chan->channel, buf);
}
EXPORT_SYMBOL_GPL(iio_read_channel_ext_info);

ssize_t iio_write_channel_ext_info(struct iio_channel *chan, const char *attr,
				   const char *buf, size_t len)
{
	const struct iio_chan_spec_ext_info *ext_info;

	ext_info = iio_lookup_ext_info(chan, attr);
	if (!ext_info)
		return -EINVAL;

	return ext_info->write(chan->indio_dev, ext_info->private,
			       chan->channel, buf, len);
}
EXPORT_SYMBOL_GPL(iio_write_channel_ext_info);