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