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