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Jonathan Camerone27d75d2012-02-15 19:48:01 +00001/* The industrial I/O core in kernel channel mapping
2 *
3 * Copyright (c) 2011 Jonathan Cameron
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 as published by
7 * the Free Software Foundation.
8 */
9#include <linux/err.h>
10#include <linux/export.h>
11#include <linux/slab.h>
12#include <linux/mutex.h>
Guenter Roeck17d82b42013-02-07 17:09:00 +000013#include <linux/of.h>
Jonathan Camerone27d75d2012-02-15 19:48:01 +000014
Jonathan Cameron06458e22012-04-25 15:54:58 +010015#include <linux/iio/iio.h>
Jonathan Camerone27d75d2012-02-15 19:48:01 +000016#include "iio_core.h"
Jonathan Cameron06458e22012-04-25 15:54:58 +010017#include <linux/iio/machine.h>
18#include <linux/iio/driver.h>
19#include <linux/iio/consumer.h>
Jonathan Camerone27d75d2012-02-15 19:48:01 +000020
21struct iio_map_internal {
22 struct iio_dev *indio_dev;
23 struct iio_map *map;
24 struct list_head l;
25};
26
27static LIST_HEAD(iio_map_list);
28static DEFINE_MUTEX(iio_map_list_lock);
29
30int iio_map_array_register(struct iio_dev *indio_dev, struct iio_map *maps)
31{
32 int i = 0, ret = 0;
33 struct iio_map_internal *mapi;
34
35 if (maps == NULL)
36 return 0;
37
38 mutex_lock(&iio_map_list_lock);
39 while (maps[i].consumer_dev_name != NULL) {
40 mapi = kzalloc(sizeof(*mapi), GFP_KERNEL);
41 if (mapi == NULL) {
42 ret = -ENOMEM;
43 goto error_ret;
44 }
45 mapi->map = &maps[i];
46 mapi->indio_dev = indio_dev;
47 list_add(&mapi->l, &iio_map_list);
48 i++;
49 }
50error_ret:
51 mutex_unlock(&iio_map_list_lock);
52
53 return ret;
54}
55EXPORT_SYMBOL_GPL(iio_map_array_register);
56
57
Guenter Roeck6cb2afd2013-01-31 21:43:00 +000058/*
59 * Remove all map entries associated with the given iio device
Jonathan Camerone27d75d2012-02-15 19:48:01 +000060 */
Guenter Roeck6cb2afd2013-01-31 21:43:00 +000061int iio_map_array_unregister(struct iio_dev *indio_dev)
Jonathan Camerone27d75d2012-02-15 19:48:01 +000062{
Guenter Roeck6cb2afd2013-01-31 21:43:00 +000063 int ret = -ENODEV;
Jonathan Camerone27d75d2012-02-15 19:48:01 +000064 struct iio_map_internal *mapi;
Guenter Roeck6cb2afd2013-01-31 21:43:00 +000065 struct list_head *pos, *tmp;
Jonathan Camerone27d75d2012-02-15 19:48:01 +000066
67 mutex_lock(&iio_map_list_lock);
Guenter Roeck6cb2afd2013-01-31 21:43:00 +000068 list_for_each_safe(pos, tmp, &iio_map_list) {
69 mapi = list_entry(pos, struct iio_map_internal, l);
70 if (indio_dev == mapi->indio_dev) {
71 list_del(&mapi->l);
72 kfree(mapi);
73 ret = 0;
Jonathan Camerone27d75d2012-02-15 19:48:01 +000074 }
Jonathan Camerone27d75d2012-02-15 19:48:01 +000075 }
Jonathan Camerone27d75d2012-02-15 19:48:01 +000076 mutex_unlock(&iio_map_list_lock);
Jonathan Camerone27d75d2012-02-15 19:48:01 +000077 return ret;
78}
79EXPORT_SYMBOL_GPL(iio_map_array_unregister);
80
81static const struct iio_chan_spec
Jonathan Cameron314be142012-05-01 21:04:24 +010082*iio_chan_spec_from_name(const struct iio_dev *indio_dev, const char *name)
Jonathan Camerone27d75d2012-02-15 19:48:01 +000083{
84 int i;
85 const struct iio_chan_spec *chan = NULL;
86
87 for (i = 0; i < indio_dev->num_channels; i++)
88 if (indio_dev->channels[i].datasheet_name &&
89 strcmp(name, indio_dev->channels[i].datasheet_name) == 0) {
90 chan = &indio_dev->channels[i];
91 break;
92 }
93 return chan;
94}
95
Guenter Roeck17d82b42013-02-07 17:09:00 +000096#ifdef CONFIG_OF
97
98static int iio_dev_node_match(struct device *dev, void *data)
99{
100 return dev->of_node == data && dev->type == &iio_device_type;
101}
102
103static int __of_iio_channel_get(struct iio_channel *channel,
104 struct device_node *np, int index)
105{
106 struct device *idev;
107 struct iio_dev *indio_dev;
108 int err;
109 struct of_phandle_args iiospec;
110
111 err = of_parse_phandle_with_args(np, "io-channels",
112 "#io-channel-cells",
113 index, &iiospec);
114 if (err)
115 return err;
116
117 idev = bus_find_device(&iio_bus_type, NULL, iiospec.np,
118 iio_dev_node_match);
119 of_node_put(iiospec.np);
120 if (idev == NULL)
121 return -EPROBE_DEFER;
122
123 indio_dev = dev_to_iio_dev(idev);
124 channel->indio_dev = indio_dev;
125 index = iiospec.args_count ? iiospec.args[0] : 0;
126 if (index >= indio_dev->num_channels) {
Joe Perchese916b802013-06-04 15:44:00 +0100127 err = -EINVAL;
Guenter Roeck17d82b42013-02-07 17:09:00 +0000128 goto err_put;
129 }
130 channel->channel = &indio_dev->channels[index];
131
132 return 0;
133
134err_put:
135 iio_device_put(indio_dev);
136 return err;
137}
138
139static struct iio_channel *of_iio_channel_get(struct device_node *np, int index)
140{
141 struct iio_channel *channel;
142 int err;
143
144 if (index < 0)
145 return ERR_PTR(-EINVAL);
146
147 channel = kzalloc(sizeof(*channel), GFP_KERNEL);
148 if (channel == NULL)
149 return ERR_PTR(-ENOMEM);
150
151 err = __of_iio_channel_get(channel, np, index);
152 if (err)
153 goto err_free_channel;
154
155 return channel;
156
157err_free_channel:
158 kfree(channel);
159 return ERR_PTR(err);
160}
161
162static struct iio_channel *of_iio_channel_get_by_name(struct device_node *np,
163 const char *name)
164{
165 struct iio_channel *chan = NULL;
166
167 /* Walk up the tree of devices looking for a matching iio channel */
168 while (np) {
169 int index = 0;
170
171 /*
172 * For named iio channels, first look up the name in the
173 * "io-channel-names" property. If it cannot be found, the
174 * index will be an error code, and of_iio_channel_get()
175 * will fail.
176 */
177 if (name)
178 index = of_property_match_string(np, "io-channel-names",
179 name);
180 chan = of_iio_channel_get(np, index);
181 if (!IS_ERR(chan))
182 break;
183 else if (name && index >= 0) {
184 pr_err("ERROR: could not get IIO channel %s:%s(%i)\n",
185 np->full_name, name ? name : "", index);
186 return chan;
187 }
188
189 /*
190 * No matching IIO channel found on this node.
191 * If the parent node has a "io-channel-ranges" property,
192 * then we can try one of its channels.
193 */
194 np = np->parent;
195 if (np && !of_get_property(np, "io-channel-ranges", NULL))
196 break;
197 }
198 return chan;
199}
200
201static struct iio_channel *of_iio_channel_get_all(struct device *dev)
202{
203 struct iio_channel *chans;
204 int i, mapind, nummaps = 0;
205 int ret;
206
207 do {
208 ret = of_parse_phandle_with_args(dev->of_node,
209 "io-channels",
210 "#io-channel-cells",
211 nummaps, NULL);
212 if (ret < 0)
213 break;
214 } while (++nummaps);
215
216 if (nummaps == 0) /* no error, return NULL to search map table */
217 return NULL;
218
219 /* NULL terminated array to save passing size */
220 chans = kcalloc(nummaps + 1, sizeof(*chans), GFP_KERNEL);
221 if (chans == NULL)
222 return ERR_PTR(-ENOMEM);
223
224 /* Search for OF matches */
225 for (mapind = 0; mapind < nummaps; mapind++) {
226 ret = __of_iio_channel_get(&chans[mapind], dev->of_node,
227 mapind);
228 if (ret)
229 goto error_free_chans;
230 }
231 return chans;
232
233error_free_chans:
234 for (i = 0; i < mapind; i++)
235 iio_device_put(chans[i].indio_dev);
236 kfree(chans);
237 return ERR_PTR(ret);
238}
239
240#else /* CONFIG_OF */
241
242static inline struct iio_channel *
243of_iio_channel_get_by_name(struct device_node *np, const char *name)
244{
245 return NULL;
246}
247
248static inline struct iio_channel *of_iio_channel_get_all(struct device *dev)
249{
250 return NULL;
251}
252
253#endif /* CONFIG_OF */
Jonathan Camerone27d75d2012-02-15 19:48:01 +0000254
Guenter Roeck5aa57f02013-02-04 20:26:00 +0000255static struct iio_channel *iio_channel_get_sys(const char *name,
256 const char *channel_name)
Jonathan Camerone27d75d2012-02-15 19:48:01 +0000257{
258 struct iio_map_internal *c_i = NULL, *c = NULL;
259 struct iio_channel *channel;
Kim, Milo3183bac2012-09-18 05:56:00 +0100260 int err;
Jonathan Camerone27d75d2012-02-15 19:48:01 +0000261
262 if (name == NULL && channel_name == NULL)
263 return ERR_PTR(-ENODEV);
264
265 /* first find matching entry the channel map */
266 mutex_lock(&iio_map_list_lock);
267 list_for_each_entry(c_i, &iio_map_list, l) {
268 if ((name && strcmp(name, c_i->map->consumer_dev_name) != 0) ||
269 (channel_name &&
270 strcmp(channel_name, c_i->map->consumer_channel) != 0))
271 continue;
272 c = c_i;
Lars-Peter Clausen1875ffd2012-06-04 10:50:03 +0200273 iio_device_get(c->indio_dev);
Jonathan Camerone27d75d2012-02-15 19:48:01 +0000274 break;
275 }
276 mutex_unlock(&iio_map_list_lock);
277 if (c == NULL)
278 return ERR_PTR(-ENODEV);
279
Kim, Milo2cc412b2012-09-14 02:24:00 +0100280 channel = kzalloc(sizeof(*channel), GFP_KERNEL);
Kim, Milo3183bac2012-09-18 05:56:00 +0100281 if (channel == NULL) {
282 err = -ENOMEM;
Kim, Milo801c4b52012-09-18 05:55:00 +0100283 goto error_no_mem;
Kim, Milo3183bac2012-09-18 05:56:00 +0100284 }
Jonathan Camerone27d75d2012-02-15 19:48:01 +0000285
286 channel->indio_dev = c->indio_dev;
287
Kim, Milob2b79ff2012-09-17 09:44:00 +0100288 if (c->map->adc_channel_label) {
Jonathan Camerone27d75d2012-02-15 19:48:01 +0000289 channel->channel =
290 iio_chan_spec_from_name(channel->indio_dev,
291 c->map->adc_channel_label);
292
Kim, Milo3183bac2012-09-18 05:56:00 +0100293 if (channel->channel == NULL) {
294 err = -EINVAL;
Kim, Milob2b79ff2012-09-17 09:44:00 +0100295 goto error_no_chan;
Kim, Milo3183bac2012-09-18 05:56:00 +0100296 }
Kim, Milob2b79ff2012-09-17 09:44:00 +0100297 }
298
Jonathan Camerone27d75d2012-02-15 19:48:01 +0000299 return channel;
Kim, Milob2b79ff2012-09-17 09:44:00 +0100300
301error_no_chan:
Kim, Milob2b79ff2012-09-17 09:44:00 +0100302 kfree(channel);
Kim, Milo801c4b52012-09-18 05:55:00 +0100303error_no_mem:
304 iio_device_put(c->indio_dev);
Kim, Milo3183bac2012-09-18 05:56:00 +0100305 return ERR_PTR(err);
Jonathan Camerone27d75d2012-02-15 19:48:01 +0000306}
Guenter Roeck5aa57f02013-02-04 20:26:00 +0000307
308struct iio_channel *iio_channel_get(struct device *dev,
309 const char *channel_name)
310{
311 const char *name = dev ? dev_name(dev) : NULL;
Guenter Roeck17d82b42013-02-07 17:09:00 +0000312 struct iio_channel *channel;
Guenter Roeck5aa57f02013-02-04 20:26:00 +0000313
Guenter Roeck17d82b42013-02-07 17:09:00 +0000314 if (dev) {
315 channel = of_iio_channel_get_by_name(dev->of_node,
316 channel_name);
317 if (channel != NULL)
318 return channel;
319 }
Guenter Roeck5aa57f02013-02-04 20:26:00 +0000320 return iio_channel_get_sys(name, channel_name);
321}
Jonathan Cameron314be142012-05-01 21:04:24 +0100322EXPORT_SYMBOL_GPL(iio_channel_get);
Jonathan Camerone27d75d2012-02-15 19:48:01 +0000323
Jonathan Cameron314be142012-05-01 21:04:24 +0100324void iio_channel_release(struct iio_channel *channel)
Jonathan Camerone27d75d2012-02-15 19:48:01 +0000325{
Lars-Peter Clausen1875ffd2012-06-04 10:50:03 +0200326 iio_device_put(channel->indio_dev);
Jonathan Camerone27d75d2012-02-15 19:48:01 +0000327 kfree(channel);
328}
Jonathan Cameron314be142012-05-01 21:04:24 +0100329EXPORT_SYMBOL_GPL(iio_channel_release);
Jonathan Camerone27d75d2012-02-15 19:48:01 +0000330
Guenter Roeckca7d98d2013-01-31 21:43:00 +0000331struct iio_channel *iio_channel_get_all(struct device *dev)
Jonathan Camerone27d75d2012-02-15 19:48:01 +0000332{
Guenter Roeckca7d98d2013-01-31 21:43:00 +0000333 const char *name;
Jonathan Camerone27d75d2012-02-15 19:48:01 +0000334 struct iio_channel *chans;
335 struct iio_map_internal *c = NULL;
336 int nummaps = 0;
337 int mapind = 0;
338 int i, ret;
339
Guenter Roeckca7d98d2013-01-31 21:43:00 +0000340 if (dev == NULL)
Jonathan Camerone27d75d2012-02-15 19:48:01 +0000341 return ERR_PTR(-EINVAL);
Guenter Roeck17d82b42013-02-07 17:09:00 +0000342
343 chans = of_iio_channel_get_all(dev);
344 if (chans)
345 return chans;
346
Guenter Roeckca7d98d2013-01-31 21:43:00 +0000347 name = dev_name(dev);
Jonathan Camerone27d75d2012-02-15 19:48:01 +0000348
349 mutex_lock(&iio_map_list_lock);
350 /* first count the matching maps */
351 list_for_each_entry(c, &iio_map_list, l)
352 if (name && strcmp(name, c->map->consumer_dev_name) != 0)
353 continue;
354 else
355 nummaps++;
356
357 if (nummaps == 0) {
358 ret = -ENODEV;
359 goto error_ret;
360 }
361
362 /* NULL terminated array to save passing size */
363 chans = kzalloc(sizeof(*chans)*(nummaps + 1), GFP_KERNEL);
364 if (chans == NULL) {
365 ret = -ENOMEM;
366 goto error_ret;
367 }
368
369 /* for each map fill in the chans element */
370 list_for_each_entry(c, &iio_map_list, l) {
371 if (name && strcmp(name, c->map->consumer_dev_name) != 0)
372 continue;
373 chans[mapind].indio_dev = c->indio_dev;
Jonathan Cameron04644152012-06-30 20:06:00 +0100374 chans[mapind].data = c->map->consumer_data;
Jonathan Camerone27d75d2012-02-15 19:48:01 +0000375 chans[mapind].channel =
376 iio_chan_spec_from_name(chans[mapind].indio_dev,
377 c->map->adc_channel_label);
378 if (chans[mapind].channel == NULL) {
379 ret = -EINVAL;
Jonathan Camerone27d75d2012-02-15 19:48:01 +0000380 goto error_free_chans;
381 }
Lars-Peter Clausen1875ffd2012-06-04 10:50:03 +0200382 iio_device_get(chans[mapind].indio_dev);
Jonathan Camerone27d75d2012-02-15 19:48:01 +0000383 mapind++;
384 }
Jonathan Camerone27d75d2012-02-15 19:48:01 +0000385 if (mapind == 0) {
386 ret = -ENODEV;
387 goto error_free_chans;
388 }
Dan Carpentere59b9af2012-07-11 07:34:00 +0100389 mutex_unlock(&iio_map_list_lock);
390
Jonathan Camerone27d75d2012-02-15 19:48:01 +0000391 return chans;
392
393error_free_chans:
394 for (i = 0; i < nummaps; i++)
Lars-Peter Clausen1875ffd2012-06-04 10:50:03 +0200395 iio_device_put(chans[i].indio_dev);
Jonathan Camerone27d75d2012-02-15 19:48:01 +0000396 kfree(chans);
397error_ret:
398 mutex_unlock(&iio_map_list_lock);
399
400 return ERR_PTR(ret);
401}
Jonathan Cameron314be142012-05-01 21:04:24 +0100402EXPORT_SYMBOL_GPL(iio_channel_get_all);
Jonathan Camerone27d75d2012-02-15 19:48:01 +0000403
Jonathan Cameron314be142012-05-01 21:04:24 +0100404void iio_channel_release_all(struct iio_channel *channels)
Jonathan Camerone27d75d2012-02-15 19:48:01 +0000405{
406 struct iio_channel *chan = &channels[0];
407
408 while (chan->indio_dev) {
Lars-Peter Clausen1875ffd2012-06-04 10:50:03 +0200409 iio_device_put(chan->indio_dev);
Jonathan Camerone27d75d2012-02-15 19:48:01 +0000410 chan++;
411 }
412 kfree(channels);
413}
Jonathan Cameron314be142012-05-01 21:04:24 +0100414EXPORT_SYMBOL_GPL(iio_channel_release_all);
Jonathan Camerone27d75d2012-02-15 19:48:01 +0000415
Lars-Peter Clausen48e44ce2012-09-17 13:17:00 +0100416static int iio_channel_read(struct iio_channel *chan, int *val, int *val2,
417 enum iio_chan_info_enum info)
418{
419 int unused;
420
421 if (val2 == NULL)
422 val2 = &unused;
423
424 return chan->indio_dev->info->read_raw(chan->indio_dev, chan->channel,
425 val, val2, info);
426}
427
Jonathan Cameron314be142012-05-01 21:04:24 +0100428int iio_read_channel_raw(struct iio_channel *chan, int *val)
Jonathan Camerone27d75d2012-02-15 19:48:01 +0000429{
Lars-Peter Clausen48e44ce2012-09-17 13:17:00 +0100430 int ret;
Jonathan Camerone27d75d2012-02-15 19:48:01 +0000431
432 mutex_lock(&chan->indio_dev->info_exist_lock);
433 if (chan->indio_dev->info == NULL) {
434 ret = -ENODEV;
435 goto err_unlock;
436 }
437
Lars-Peter Clausen48e44ce2012-09-17 13:17:00 +0100438 ret = iio_channel_read(chan, val, NULL, IIO_CHAN_INFO_RAW);
Jonathan Camerone27d75d2012-02-15 19:48:01 +0000439err_unlock:
440 mutex_unlock(&chan->indio_dev->info_exist_lock);
441
442 return ret;
443}
Jonathan Cameron314be142012-05-01 21:04:24 +0100444EXPORT_SYMBOL_GPL(iio_read_channel_raw);
Jonathan Camerone27d75d2012-02-15 19:48:01 +0000445
Lars-Peter Clausen48e44ce2012-09-17 13:17:00 +0100446static int iio_convert_raw_to_processed_unlocked(struct iio_channel *chan,
447 int raw, int *processed, unsigned int scale)
448{
449 int scale_type, scale_val, scale_val2, offset;
450 s64 raw64 = raw;
451 int ret;
452
Michael Hennerich6c5d4c92013-06-03 09:04:00 +0100453 ret = iio_channel_read(chan, &offset, NULL, IIO_CHAN_INFO_OFFSET);
Alexandre Bellonif91d1b62013-07-01 17:40:00 +0100454 if (ret >= 0)
Lars-Peter Clausen48e44ce2012-09-17 13:17:00 +0100455 raw64 += offset;
456
457 scale_type = iio_channel_read(chan, &scale_val, &scale_val2,
458 IIO_CHAN_INFO_SCALE);
459 if (scale_type < 0)
460 return scale_type;
461
462 switch (scale_type) {
463 case IIO_VAL_INT:
464 *processed = raw64 * scale_val;
465 break;
466 case IIO_VAL_INT_PLUS_MICRO:
467 if (scale_val2 < 0)
468 *processed = -raw64 * scale_val;
469 else
470 *processed = raw64 * scale_val;
471 *processed += div_s64(raw64 * (s64)scale_val2 * scale,
472 1000000LL);
473 break;
474 case IIO_VAL_INT_PLUS_NANO:
475 if (scale_val2 < 0)
476 *processed = -raw64 * scale_val;
477 else
478 *processed = raw64 * scale_val;
479 *processed += div_s64(raw64 * (s64)scale_val2 * scale,
480 1000000000LL);
481 break;
482 case IIO_VAL_FRACTIONAL:
483 *processed = div_s64(raw64 * (s64)scale_val * scale,
484 scale_val2);
485 break;
Lars-Peter Clausen103d9fb2012-10-16 17:29:00 +0100486 case IIO_VAL_FRACTIONAL_LOG2:
487 *processed = (raw64 * (s64)scale_val * scale) >> scale_val2;
488 break;
Lars-Peter Clausen48e44ce2012-09-17 13:17:00 +0100489 default:
490 return -EINVAL;
491 }
492
493 return 0;
494}
495
496int iio_convert_raw_to_processed(struct iio_channel *chan, int raw,
497 int *processed, unsigned int scale)
498{
499 int ret;
500
501 mutex_lock(&chan->indio_dev->info_exist_lock);
502 if (chan->indio_dev->info == NULL) {
503 ret = -ENODEV;
504 goto err_unlock;
505 }
506
507 ret = iio_convert_raw_to_processed_unlocked(chan, raw, processed,
508 scale);
509err_unlock:
510 mutex_unlock(&chan->indio_dev->info_exist_lock);
511
512 return ret;
513}
514EXPORT_SYMBOL_GPL(iio_convert_raw_to_processed);
515
516int iio_read_channel_processed(struct iio_channel *chan, int *val)
517{
518 int ret;
519
520 mutex_lock(&chan->indio_dev->info_exist_lock);
521 if (chan->indio_dev->info == NULL) {
522 ret = -ENODEV;
523 goto err_unlock;
524 }
525
526 if (iio_channel_has_info(chan->channel, IIO_CHAN_INFO_PROCESSED)) {
527 ret = iio_channel_read(chan, val, NULL,
528 IIO_CHAN_INFO_PROCESSED);
529 } else {
530 ret = iio_channel_read(chan, val, NULL, IIO_CHAN_INFO_RAW);
531 if (ret < 0)
532 goto err_unlock;
533 ret = iio_convert_raw_to_processed_unlocked(chan, *val, val, 1);
534 }
535
536err_unlock:
537 mutex_unlock(&chan->indio_dev->info_exist_lock);
538
539 return ret;
540}
541EXPORT_SYMBOL_GPL(iio_read_channel_processed);
542
Jonathan Cameron314be142012-05-01 21:04:24 +0100543int iio_read_channel_scale(struct iio_channel *chan, int *val, int *val2)
Jonathan Camerone27d75d2012-02-15 19:48:01 +0000544{
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
Lars-Peter Clausen48e44ce2012-09-17 13:17:00 +0100553 ret = iio_channel_read(chan, val, val2, IIO_CHAN_INFO_SCALE);
Jonathan Camerone27d75d2012-02-15 19:48:01 +0000554err_unlock:
555 mutex_unlock(&chan->indio_dev->info_exist_lock);
556
557 return ret;
558}
Jonathan Cameron314be142012-05-01 21:04:24 +0100559EXPORT_SYMBOL_GPL(iio_read_channel_scale);
Jonathan Camerone27d75d2012-02-15 19:48:01 +0000560
Jonathan Cameron314be142012-05-01 21:04:24 +0100561int iio_get_channel_type(struct iio_channel *chan, enum iio_chan_type *type)
Jonathan Camerone27d75d2012-02-15 19:48:01 +0000562{
563 int ret = 0;
564 /* Need to verify underlying driver has not gone away */
565
566 mutex_lock(&chan->indio_dev->info_exist_lock);
567 if (chan->indio_dev->info == NULL) {
568 ret = -ENODEV;
569 goto err_unlock;
570 }
571
572 *type = chan->channel->type;
573err_unlock:
574 mutex_unlock(&chan->indio_dev->info_exist_lock);
575
576 return ret;
577}
Jonathan Cameron314be142012-05-01 21:04:24 +0100578EXPORT_SYMBOL_GPL(iio_get_channel_type);