1 // SPDX-License-Identifier: GPL-2.0-only
2 /* The industrial I/O core in kernel channel mapping
4 * Copyright (c) 2011 Jonathan Cameron
7 #include <linux/export.h>
8 #include <linux/slab.h>
9 #include <linux/mutex.h>
12 #include <linux/iio/iio.h>
14 #include <linux/iio/machine.h>
15 #include <linux/iio/driver.h>
16 #include <linux/iio/consumer.h>
18 struct iio_map_internal {
19 struct iio_dev *indio_dev;
24 static LIST_HEAD(iio_map_list);
25 static DEFINE_MUTEX(iio_map_list_lock);
27 int iio_map_array_register(struct iio_dev *indio_dev, struct iio_map *maps)
30 struct iio_map_internal *mapi;
35 mutex_lock(&iio_map_list_lock);
36 while (maps[i].consumer_dev_name != NULL) {
37 mapi = kzalloc(sizeof(*mapi), GFP_KERNEL);
43 mapi->indio_dev = indio_dev;
44 list_add_tail(&mapi->l, &iio_map_list);
48 mutex_unlock(&iio_map_list_lock);
52 EXPORT_SYMBOL_GPL(iio_map_array_register);
56 * Remove all map entries associated with the given iio device
58 int iio_map_array_unregister(struct iio_dev *indio_dev)
61 struct iio_map_internal *mapi, *next;
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) {
71 mutex_unlock(&iio_map_list_lock);
74 EXPORT_SYMBOL_GPL(iio_map_array_unregister);
76 static const struct iio_chan_spec
77 *iio_chan_spec_from_name(const struct iio_dev *indio_dev, const char *name)
80 const struct iio_chan_spec *chan = NULL;
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];
93 static int iio_dev_node_match(struct device *dev, const void *data)
95 return dev->of_node == data && dev->type == &iio_device_type;
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
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
108 static int __of_iio_simple_xlate(struct iio_dev *indio_dev,
109 const struct of_phandle_args *iiospec)
111 if (!iiospec->args_count)
114 if (iiospec->args[0] >= indio_dev->num_channels) {
115 dev_err(&indio_dev->dev, "invalid channel index %u\n",
120 return iiospec->args[0];
123 static int __of_iio_channel_get(struct iio_channel *channel,
124 struct device_node *np, int index)
127 struct iio_dev *indio_dev;
129 struct of_phandle_args iiospec;
131 err = of_parse_phandle_with_args(np, "io-channels",
137 idev = bus_find_device(&iio_bus_type, NULL, iiospec.np,
139 of_node_put(iiospec.np);
141 return -EPROBE_DEFER;
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);
148 index = __of_iio_simple_xlate(indio_dev, &iiospec);
151 channel->channel = &indio_dev->channels[index];
156 iio_device_put(indio_dev);
160 static struct iio_channel *of_iio_channel_get(struct device_node *np, int index)
162 struct iio_channel *channel;
166 return ERR_PTR(-EINVAL);
168 channel = kzalloc(sizeof(*channel), GFP_KERNEL);
170 return ERR_PTR(-ENOMEM);
172 err = __of_iio_channel_get(channel, np, index);
174 goto err_free_channel;
183 static struct iio_channel *of_iio_channel_get_by_name(struct device_node *np,
186 struct iio_channel *chan = NULL;
188 /* Walk up the tree of devices looking for a matching iio channel */
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()
199 index = of_property_match_string(np, "io-channel-names",
201 chan = of_iio_channel_get(np, index);
202 if (!IS_ERR(chan) || PTR_ERR(chan) == -EPROBE_DEFER)
204 else if (name && index >= 0) {
205 pr_err("ERROR: could not get IIO channel %pOF:%s(%i)\n",
206 np, name ? name : "", index);
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.
216 if (np && !of_get_property(np, "io-channel-ranges", NULL))
223 static struct iio_channel *of_iio_channel_get_all(struct device *dev)
225 struct iio_channel *chans;
226 int i, mapind, nummaps = 0;
230 ret = of_parse_phandle_with_args(dev->of_node,
238 if (nummaps == 0) /* no error, return NULL to search map table */
241 /* NULL terminated array to save passing size */
242 chans = kcalloc(nummaps + 1, sizeof(*chans), GFP_KERNEL);
244 return ERR_PTR(-ENOMEM);
246 /* Search for OF matches */
247 for (mapind = 0; mapind < nummaps; mapind++) {
248 ret = __of_iio_channel_get(&chans[mapind], dev->of_node,
251 goto error_free_chans;
256 for (i = 0; i < mapind; i++)
257 iio_device_put(chans[i].indio_dev);
262 #else /* CONFIG_OF */
264 static inline struct iio_channel *
265 of_iio_channel_get_by_name(struct device_node *np, const char *name)
270 static inline struct iio_channel *of_iio_channel_get_all(struct device *dev)
275 #endif /* CONFIG_OF */
277 static struct iio_channel *iio_channel_get_sys(const char *name,
278 const char *channel_name)
280 struct iio_map_internal *c_i = NULL, *c = NULL;
281 struct iio_channel *channel;
284 if (name == NULL && channel_name == NULL)
285 return ERR_PTR(-ENODEV);
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) ||
292 strcmp(channel_name, c_i->map->consumer_channel) != 0))
295 iio_device_get(c->indio_dev);
298 mutex_unlock(&iio_map_list_lock);
300 return ERR_PTR(-ENODEV);
302 channel = kzalloc(sizeof(*channel), GFP_KERNEL);
303 if (channel == NULL) {
308 channel->indio_dev = c->indio_dev;
310 if (c->map->adc_channel_label) {
312 iio_chan_spec_from_name(channel->indio_dev,
313 c->map->adc_channel_label);
315 if (channel->channel == NULL) {
326 iio_device_put(c->indio_dev);
330 struct iio_channel *iio_channel_get(struct device *dev,
331 const char *channel_name)
333 const char *name = dev ? dev_name(dev) : NULL;
334 struct iio_channel *channel;
337 channel = of_iio_channel_get_by_name(dev->of_node,
343 return iio_channel_get_sys(name, channel_name);
345 EXPORT_SYMBOL_GPL(iio_channel_get);
347 void iio_channel_release(struct iio_channel *channel)
351 iio_device_put(channel->indio_dev);
354 EXPORT_SYMBOL_GPL(iio_channel_release);
356 static void devm_iio_channel_free(struct device *dev, void *res)
358 struct iio_channel *channel = *(struct iio_channel **)res;
360 iio_channel_release(channel);
363 static int devm_iio_channel_match(struct device *dev, void *res, void *data)
365 struct iio_channel **r = res;
375 struct iio_channel *devm_iio_channel_get(struct device *dev,
376 const char *channel_name)
378 struct iio_channel **ptr, *channel;
380 ptr = devres_alloc(devm_iio_channel_free, sizeof(*ptr), GFP_KERNEL);
382 return ERR_PTR(-ENOMEM);
384 channel = iio_channel_get(dev, channel_name);
385 if (IS_ERR(channel)) {
391 devres_add(dev, ptr);
395 EXPORT_SYMBOL_GPL(devm_iio_channel_get);
397 void devm_iio_channel_release(struct device *dev, struct iio_channel *channel)
399 WARN_ON(devres_release(dev, devm_iio_channel_free,
400 devm_iio_channel_match, channel));
402 EXPORT_SYMBOL_GPL(devm_iio_channel_release);
404 struct iio_channel *iio_channel_get_all(struct device *dev)
407 struct iio_channel *chans;
408 struct iio_map_internal *c = NULL;
414 return ERR_PTR(-EINVAL);
416 chans = of_iio_channel_get_all(dev);
420 name = dev_name(dev);
422 mutex_lock(&iio_map_list_lock);
423 /* first count the matching maps */
424 list_for_each_entry(c, &iio_map_list, l)
425 if (name && strcmp(name, c->map->consumer_dev_name) != 0)
435 /* NULL terminated array to save passing size */
436 chans = kcalloc(nummaps + 1, sizeof(*chans), GFP_KERNEL);
442 /* for each map fill in the chans element */
443 list_for_each_entry(c, &iio_map_list, l) {
444 if (name && strcmp(name, c->map->consumer_dev_name) != 0)
446 chans[mapind].indio_dev = c->indio_dev;
447 chans[mapind].data = c->map->consumer_data;
448 chans[mapind].channel =
449 iio_chan_spec_from_name(chans[mapind].indio_dev,
450 c->map->adc_channel_label);
451 if (chans[mapind].channel == NULL) {
453 goto error_free_chans;
455 iio_device_get(chans[mapind].indio_dev);
460 goto error_free_chans;
462 mutex_unlock(&iio_map_list_lock);
467 for (i = 0; i < nummaps; i++)
468 iio_device_put(chans[i].indio_dev);
471 mutex_unlock(&iio_map_list_lock);
475 EXPORT_SYMBOL_GPL(iio_channel_get_all);
477 void iio_channel_release_all(struct iio_channel *channels)
479 struct iio_channel *chan = &channels[0];
481 while (chan->indio_dev) {
482 iio_device_put(chan->indio_dev);
487 EXPORT_SYMBOL_GPL(iio_channel_release_all);
489 static void devm_iio_channel_free_all(struct device *dev, void *res)
491 struct iio_channel *channels = *(struct iio_channel **)res;
493 iio_channel_release_all(channels);
496 struct iio_channel *devm_iio_channel_get_all(struct device *dev)
498 struct iio_channel **ptr, *channels;
500 ptr = devres_alloc(devm_iio_channel_free_all, sizeof(*ptr), GFP_KERNEL);
502 return ERR_PTR(-ENOMEM);
504 channels = iio_channel_get_all(dev);
505 if (IS_ERR(channels)) {
511 devres_add(dev, ptr);
515 EXPORT_SYMBOL_GPL(devm_iio_channel_get_all);
517 void devm_iio_channel_release_all(struct device *dev,
518 struct iio_channel *channels)
520 WARN_ON(devres_release(dev, devm_iio_channel_free_all,
521 devm_iio_channel_match, channels));
523 EXPORT_SYMBOL_GPL(devm_iio_channel_release_all);
525 static int iio_channel_read(struct iio_channel *chan, int *val, int *val2,
526 enum iio_chan_info_enum info)
529 int vals[INDIO_MAX_RAW_ELEMENTS];
536 if (!iio_channel_has_info(chan->channel, info))
539 if (chan->indio_dev->info->read_raw_multi) {
540 ret = chan->indio_dev->info->read_raw_multi(chan->indio_dev,
541 chan->channel, INDIO_MAX_RAW_ELEMENTS,
542 vals, &val_len, info);
546 ret = chan->indio_dev->info->read_raw(chan->indio_dev,
547 chan->channel, val, val2, info);
552 int iio_read_channel_raw(struct iio_channel *chan, int *val)
556 mutex_lock(&chan->indio_dev->info_exist_lock);
557 if (chan->indio_dev->info == NULL) {
562 ret = iio_channel_read(chan, val, NULL, IIO_CHAN_INFO_RAW);
564 mutex_unlock(&chan->indio_dev->info_exist_lock);
568 EXPORT_SYMBOL_GPL(iio_read_channel_raw);
570 int iio_read_channel_average_raw(struct iio_channel *chan, int *val)
574 mutex_lock(&chan->indio_dev->info_exist_lock);
575 if (chan->indio_dev->info == NULL) {
580 ret = iio_channel_read(chan, val, NULL, IIO_CHAN_INFO_AVERAGE_RAW);
582 mutex_unlock(&chan->indio_dev->info_exist_lock);
586 EXPORT_SYMBOL_GPL(iio_read_channel_average_raw);
588 static int iio_convert_raw_to_processed_unlocked(struct iio_channel *chan,
589 int raw, int *processed, unsigned int scale)
591 int scale_type, scale_val, scale_val2, offset;
595 ret = iio_channel_read(chan, &offset, NULL, IIO_CHAN_INFO_OFFSET);
599 scale_type = iio_channel_read(chan, &scale_val, &scale_val2,
600 IIO_CHAN_INFO_SCALE);
601 if (scale_type < 0) {
603 * Just pass raw values as processed if no scaling is
610 switch (scale_type) {
612 *processed = raw64 * scale_val;
614 case IIO_VAL_INT_PLUS_MICRO:
616 *processed = -raw64 * scale_val;
618 *processed = raw64 * scale_val;
619 *processed += div_s64(raw64 * (s64)scale_val2 * scale,
622 case IIO_VAL_INT_PLUS_NANO:
624 *processed = -raw64 * scale_val;
626 *processed = raw64 * scale_val;
627 *processed += div_s64(raw64 * (s64)scale_val2 * scale,
630 case IIO_VAL_FRACTIONAL:
631 *processed = div_s64(raw64 * (s64)scale_val * scale,
634 case IIO_VAL_FRACTIONAL_LOG2:
635 *processed = (raw64 * (s64)scale_val * scale) >> scale_val2;
644 int iio_convert_raw_to_processed(struct iio_channel *chan, int raw,
645 int *processed, unsigned int scale)
649 mutex_lock(&chan->indio_dev->info_exist_lock);
650 if (chan->indio_dev->info == NULL) {
655 ret = iio_convert_raw_to_processed_unlocked(chan, raw, processed,
658 mutex_unlock(&chan->indio_dev->info_exist_lock);
662 EXPORT_SYMBOL_GPL(iio_convert_raw_to_processed);
664 int iio_read_channel_attribute(struct iio_channel *chan, int *val, int *val2,
665 enum iio_chan_info_enum attribute)
669 mutex_lock(&chan->indio_dev->info_exist_lock);
670 if (chan->indio_dev->info == NULL) {
675 ret = iio_channel_read(chan, val, val2, attribute);
677 mutex_unlock(&chan->indio_dev->info_exist_lock);
681 EXPORT_SYMBOL_GPL(iio_read_channel_attribute);
683 int iio_read_channel_offset(struct iio_channel *chan, int *val, int *val2)
685 return iio_read_channel_attribute(chan, val, val2, IIO_CHAN_INFO_OFFSET);
687 EXPORT_SYMBOL_GPL(iio_read_channel_offset);
689 int iio_read_channel_processed(struct iio_channel *chan, int *val)
693 mutex_lock(&chan->indio_dev->info_exist_lock);
694 if (chan->indio_dev->info == NULL) {
699 if (iio_channel_has_info(chan->channel, IIO_CHAN_INFO_PROCESSED)) {
700 ret = iio_channel_read(chan, val, NULL,
701 IIO_CHAN_INFO_PROCESSED);
703 ret = iio_channel_read(chan, val, NULL, IIO_CHAN_INFO_RAW);
706 ret = iio_convert_raw_to_processed_unlocked(chan, *val, val, 1);
710 mutex_unlock(&chan->indio_dev->info_exist_lock);
714 EXPORT_SYMBOL_GPL(iio_read_channel_processed);
716 int iio_read_channel_scale(struct iio_channel *chan, int *val, int *val2)
718 return iio_read_channel_attribute(chan, val, val2, IIO_CHAN_INFO_SCALE);
720 EXPORT_SYMBOL_GPL(iio_read_channel_scale);
722 static int iio_channel_read_avail(struct iio_channel *chan,
723 const int **vals, int *type, int *length,
724 enum iio_chan_info_enum info)
726 if (!iio_channel_has_available(chan->channel, info))
729 return chan->indio_dev->info->read_avail(chan->indio_dev, chan->channel,
730 vals, type, length, info);
733 int iio_read_avail_channel_attribute(struct iio_channel *chan,
734 const int **vals, int *type, int *length,
735 enum iio_chan_info_enum attribute)
739 mutex_lock(&chan->indio_dev->info_exist_lock);
740 if (!chan->indio_dev->info) {
745 ret = iio_channel_read_avail(chan, vals, type, length, attribute);
747 mutex_unlock(&chan->indio_dev->info_exist_lock);
751 EXPORT_SYMBOL_GPL(iio_read_avail_channel_attribute);
753 int iio_read_avail_channel_raw(struct iio_channel *chan,
754 const int **vals, int *length)
759 ret = iio_read_avail_channel_attribute(chan, vals, &type, length,
762 if (ret >= 0 && type != IIO_VAL_INT)
763 /* raw values are assumed to be IIO_VAL_INT */
768 EXPORT_SYMBOL_GPL(iio_read_avail_channel_raw);
770 static int iio_channel_read_max(struct iio_channel *chan,
771 int *val, int *val2, int *type,
772 enum iio_chan_info_enum info)
782 ret = iio_channel_read_avail(chan, &vals, type, &length, info);
784 case IIO_AVAIL_RANGE:
800 *val = vals[--length];
802 if (vals[--length] > *val)
807 /* FIXME: learn about max for other iio values */
817 int iio_read_max_channel_raw(struct iio_channel *chan, int *val)
822 mutex_lock(&chan->indio_dev->info_exist_lock);
823 if (!chan->indio_dev->info) {
828 ret = iio_channel_read_max(chan, val, NULL, &type, IIO_CHAN_INFO_RAW);
830 mutex_unlock(&chan->indio_dev->info_exist_lock);
834 EXPORT_SYMBOL_GPL(iio_read_max_channel_raw);
836 int iio_get_channel_type(struct iio_channel *chan, enum iio_chan_type *type)
839 /* Need to verify underlying driver has not gone away */
841 mutex_lock(&chan->indio_dev->info_exist_lock);
842 if (chan->indio_dev->info == NULL) {
847 *type = chan->channel->type;
849 mutex_unlock(&chan->indio_dev->info_exist_lock);
853 EXPORT_SYMBOL_GPL(iio_get_channel_type);
855 static int iio_channel_write(struct iio_channel *chan, int val, int val2,
856 enum iio_chan_info_enum info)
858 return chan->indio_dev->info->write_raw(chan->indio_dev,
859 chan->channel, val, val2, info);
862 int iio_write_channel_attribute(struct iio_channel *chan, int val, int val2,
863 enum iio_chan_info_enum attribute)
867 mutex_lock(&chan->indio_dev->info_exist_lock);
868 if (chan->indio_dev->info == NULL) {
873 ret = iio_channel_write(chan, val, val2, attribute);
875 mutex_unlock(&chan->indio_dev->info_exist_lock);
879 EXPORT_SYMBOL_GPL(iio_write_channel_attribute);
881 int iio_write_channel_raw(struct iio_channel *chan, int val)
883 return iio_write_channel_attribute(chan, val, 0, IIO_CHAN_INFO_RAW);
885 EXPORT_SYMBOL_GPL(iio_write_channel_raw);
887 unsigned int iio_get_channel_ext_info_count(struct iio_channel *chan)
889 const struct iio_chan_spec_ext_info *ext_info;
892 if (!chan->channel->ext_info)
895 for (ext_info = chan->channel->ext_info; ext_info->name; ext_info++)
900 EXPORT_SYMBOL_GPL(iio_get_channel_ext_info_count);
902 static const struct iio_chan_spec_ext_info *iio_lookup_ext_info(
903 const struct iio_channel *chan,
906 const struct iio_chan_spec_ext_info *ext_info;
908 if (!chan->channel->ext_info)
911 for (ext_info = chan->channel->ext_info; ext_info->name; ++ext_info) {
912 if (!strcmp(attr, ext_info->name))
919 ssize_t iio_read_channel_ext_info(struct iio_channel *chan,
920 const char *attr, char *buf)
922 const struct iio_chan_spec_ext_info *ext_info;
924 ext_info = iio_lookup_ext_info(chan, attr);
928 return ext_info->read(chan->indio_dev, ext_info->private,
931 EXPORT_SYMBOL_GPL(iio_read_channel_ext_info);
933 ssize_t iio_write_channel_ext_info(struct iio_channel *chan, const char *attr,
934 const char *buf, size_t len)
936 const struct iio_chan_spec_ext_info *ext_info;
938 ext_info = iio_lookup_ext_info(chan, attr);
942 return ext_info->write(chan->indio_dev, ext_info->private,
943 chan->channel, buf, len);
945 EXPORT_SYMBOL_GPL(iio_write_channel_ext_info);