1 /* The industrial I/O core in kernel channel mapping
3 * Copyright (c) 2011 Jonathan Cameron
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.
10 #include <linux/export.h>
11 #include <linux/slab.h>
12 #include <linux/mutex.h>
15 #include <linux/iio/iio.h>
17 #include <linux/iio/machine.h>
18 #include <linux/iio/driver.h>
19 #include <linux/iio/consumer.h>
21 struct iio_map_internal {
22 struct iio_dev *indio_dev;
27 static LIST_HEAD(iio_map_list);
28 static DEFINE_MUTEX(iio_map_list_lock);
30 int iio_map_array_register(struct iio_dev *indio_dev, struct iio_map *maps)
33 struct iio_map_internal *mapi;
38 mutex_lock(&iio_map_list_lock);
39 while (maps[i].consumer_dev_name != NULL) {
40 mapi = kzalloc(sizeof(*mapi), GFP_KERNEL);
46 mapi->indio_dev = indio_dev;
47 list_add(&mapi->l, &iio_map_list);
51 mutex_unlock(&iio_map_list_lock);
55 EXPORT_SYMBOL_GPL(iio_map_array_register);
59 * Remove all map entries associated with the given iio device
61 int iio_map_array_unregister(struct iio_dev *indio_dev)
64 struct iio_map_internal *mapi;
65 struct list_head *pos, *tmp;
67 mutex_lock(&iio_map_list_lock);
68 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) {
76 mutex_unlock(&iio_map_list_lock);
79 EXPORT_SYMBOL_GPL(iio_map_array_unregister);
81 static const struct iio_chan_spec
82 *iio_chan_spec_from_name(const struct iio_dev *indio_dev, const char *name)
85 const struct iio_chan_spec *chan = NULL;
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];
98 static int iio_dev_node_match(struct device *dev, void *data)
100 return dev->of_node == data && dev->type == &iio_device_type;
104 * __of_iio_simple_xlate - translate iiospec to the IIO channel index
105 * @indio_dev: pointer to the iio_dev structure
106 * @iiospec: IIO specifier as found in the device tree
108 * This is simple translation function, suitable for the most 1:1 mapped
109 * channels in IIO chips. This function performs only one sanity check:
110 * whether IIO index is less than num_channels (that is specified in the
113 static int __of_iio_simple_xlate(struct iio_dev *indio_dev,
114 const struct of_phandle_args *iiospec)
116 if (!iiospec->args_count)
119 if (iiospec->args[0] >= indio_dev->num_channels)
122 return iiospec->args[0];
125 static int __of_iio_channel_get(struct iio_channel *channel,
126 struct device_node *np, int index)
129 struct iio_dev *indio_dev;
131 struct of_phandle_args iiospec;
133 err = of_parse_phandle_with_args(np, "io-channels",
139 idev = bus_find_device(&iio_bus_type, NULL, iiospec.np,
141 of_node_put(iiospec.np);
143 return -EPROBE_DEFER;
145 indio_dev = dev_to_iio_dev(idev);
146 channel->indio_dev = indio_dev;
147 if (indio_dev->info->of_xlate)
148 index = indio_dev->info->of_xlate(indio_dev, &iiospec);
150 index = __of_iio_simple_xlate(indio_dev, &iiospec);
153 channel->channel = &indio_dev->channels[index];
158 iio_device_put(indio_dev);
162 static struct iio_channel *of_iio_channel_get(struct device_node *np, int index)
164 struct iio_channel *channel;
168 return ERR_PTR(-EINVAL);
170 channel = kzalloc(sizeof(*channel), GFP_KERNEL);
172 return ERR_PTR(-ENOMEM);
174 err = __of_iio_channel_get(channel, np, index);
176 goto err_free_channel;
185 static struct iio_channel *of_iio_channel_get_by_name(struct device_node *np,
188 struct iio_channel *chan = NULL;
190 /* Walk up the tree of devices looking for a matching iio channel */
195 * For named iio channels, first look up the name in the
196 * "io-channel-names" property. If it cannot be found, the
197 * index will be an error code, and of_iio_channel_get()
201 index = of_property_match_string(np, "io-channel-names",
203 chan = of_iio_channel_get(np, index);
204 if (!IS_ERR(chan) || PTR_ERR(chan) == -EPROBE_DEFER)
206 else if (name && index >= 0) {
207 pr_err("ERROR: could not get IIO channel %s:%s(%i)\n",
208 np->full_name, name ? name : "", index);
213 * No matching IIO channel found on this node.
214 * If the parent node has a "io-channel-ranges" property,
215 * then we can try one of its channels.
218 if (np && !of_get_property(np, "io-channel-ranges", NULL))
225 static struct iio_channel *of_iio_channel_get_all(struct device *dev)
227 struct iio_channel *chans;
228 int i, mapind, nummaps = 0;
232 ret = of_parse_phandle_with_args(dev->of_node,
240 if (nummaps == 0) /* no error, return NULL to search map table */
243 /* NULL terminated array to save passing size */
244 chans = kcalloc(nummaps + 1, sizeof(*chans), GFP_KERNEL);
246 return ERR_PTR(-ENOMEM);
248 /* Search for OF matches */
249 for (mapind = 0; mapind < nummaps; mapind++) {
250 ret = __of_iio_channel_get(&chans[mapind], dev->of_node,
253 goto error_free_chans;
258 for (i = 0; i < mapind; i++)
259 iio_device_put(chans[i].indio_dev);
264 #else /* CONFIG_OF */
266 static inline struct iio_channel *
267 of_iio_channel_get_by_name(struct device_node *np, const char *name)
272 static inline struct iio_channel *of_iio_channel_get_all(struct device *dev)
277 #endif /* CONFIG_OF */
279 static struct iio_channel *iio_channel_get_sys(const char *name,
280 const char *channel_name)
282 struct iio_map_internal *c_i = NULL, *c = NULL;
283 struct iio_channel *channel;
286 if (name == NULL && channel_name == NULL)
287 return ERR_PTR(-ENODEV);
289 /* first find matching entry the channel map */
290 mutex_lock(&iio_map_list_lock);
291 list_for_each_entry(c_i, &iio_map_list, l) {
292 if ((name && strcmp(name, c_i->map->consumer_dev_name) != 0) ||
294 strcmp(channel_name, c_i->map->consumer_channel) != 0))
297 iio_device_get(c->indio_dev);
300 mutex_unlock(&iio_map_list_lock);
302 return ERR_PTR(-ENODEV);
304 channel = kzalloc(sizeof(*channel), GFP_KERNEL);
305 if (channel == NULL) {
310 channel->indio_dev = c->indio_dev;
312 if (c->map->adc_channel_label) {
314 iio_chan_spec_from_name(channel->indio_dev,
315 c->map->adc_channel_label);
317 if (channel->channel == NULL) {
328 iio_device_put(c->indio_dev);
332 struct iio_channel *iio_channel_get(struct device *dev,
333 const char *channel_name)
335 const char *name = dev ? dev_name(dev) : NULL;
336 struct iio_channel *channel;
339 channel = of_iio_channel_get_by_name(dev->of_node,
345 return iio_channel_get_sys(name, channel_name);
347 EXPORT_SYMBOL_GPL(iio_channel_get);
349 void iio_channel_release(struct iio_channel *channel)
351 iio_device_put(channel->indio_dev);
354 EXPORT_SYMBOL_GPL(iio_channel_release);
356 struct iio_channel *iio_channel_get_all(struct device *dev)
359 struct iio_channel *chans;
360 struct iio_map_internal *c = NULL;
366 return ERR_PTR(-EINVAL);
368 chans = of_iio_channel_get_all(dev);
372 name = dev_name(dev);
374 mutex_lock(&iio_map_list_lock);
375 /* first count the matching maps */
376 list_for_each_entry(c, &iio_map_list, l)
377 if (name && strcmp(name, c->map->consumer_dev_name) != 0)
387 /* NULL terminated array to save passing size */
388 chans = kzalloc(sizeof(*chans)*(nummaps + 1), GFP_KERNEL);
394 /* for each map fill in the chans element */
395 list_for_each_entry(c, &iio_map_list, l) {
396 if (name && strcmp(name, c->map->consumer_dev_name) != 0)
398 chans[mapind].indio_dev = c->indio_dev;
399 chans[mapind].data = c->map->consumer_data;
400 chans[mapind].channel =
401 iio_chan_spec_from_name(chans[mapind].indio_dev,
402 c->map->adc_channel_label);
403 if (chans[mapind].channel == NULL) {
405 goto error_free_chans;
407 iio_device_get(chans[mapind].indio_dev);
412 goto error_free_chans;
414 mutex_unlock(&iio_map_list_lock);
419 for (i = 0; i < nummaps; i++)
420 iio_device_put(chans[i].indio_dev);
423 mutex_unlock(&iio_map_list_lock);
427 EXPORT_SYMBOL_GPL(iio_channel_get_all);
429 void iio_channel_release_all(struct iio_channel *channels)
431 struct iio_channel *chan = &channels[0];
433 while (chan->indio_dev) {
434 iio_device_put(chan->indio_dev);
439 EXPORT_SYMBOL_GPL(iio_channel_release_all);
441 static int iio_channel_read(struct iio_channel *chan, int *val, int *val2,
442 enum iio_chan_info_enum info)
445 int vals[INDIO_MAX_RAW_ELEMENTS];
452 if(!iio_channel_has_info(chan->channel, info))
455 if (chan->indio_dev->info->read_raw_multi) {
456 ret = chan->indio_dev->info->read_raw_multi(chan->indio_dev,
457 chan->channel, INDIO_MAX_RAW_ELEMENTS,
458 vals, &val_len, info);
462 ret = chan->indio_dev->info->read_raw(chan->indio_dev,
463 chan->channel, val, val2, info);
468 int iio_read_channel_raw(struct iio_channel *chan, int *val)
472 mutex_lock(&chan->indio_dev->info_exist_lock);
473 if (chan->indio_dev->info == NULL) {
478 ret = iio_channel_read(chan, val, NULL, IIO_CHAN_INFO_RAW);
480 mutex_unlock(&chan->indio_dev->info_exist_lock);
484 EXPORT_SYMBOL_GPL(iio_read_channel_raw);
486 int iio_read_channel_average_raw(struct iio_channel *chan, int *val)
490 mutex_lock(&chan->indio_dev->info_exist_lock);
491 if (chan->indio_dev->info == NULL) {
496 ret = iio_channel_read(chan, val, NULL, IIO_CHAN_INFO_AVERAGE_RAW);
498 mutex_unlock(&chan->indio_dev->info_exist_lock);
502 EXPORT_SYMBOL_GPL(iio_read_channel_average_raw);
504 static int iio_convert_raw_to_processed_unlocked(struct iio_channel *chan,
505 int raw, int *processed, unsigned int scale)
507 int scale_type, scale_val, scale_val2, offset;
511 ret = iio_channel_read(chan, &offset, NULL, IIO_CHAN_INFO_OFFSET);
515 scale_type = iio_channel_read(chan, &scale_val, &scale_val2,
516 IIO_CHAN_INFO_SCALE);
520 switch (scale_type) {
522 *processed = raw64 * scale_val;
524 case IIO_VAL_INT_PLUS_MICRO:
526 *processed = -raw64 * scale_val;
528 *processed = raw64 * scale_val;
529 *processed += div_s64(raw64 * (s64)scale_val2 * scale,
532 case IIO_VAL_INT_PLUS_NANO:
534 *processed = -raw64 * scale_val;
536 *processed = raw64 * scale_val;
537 *processed += div_s64(raw64 * (s64)scale_val2 * scale,
540 case IIO_VAL_FRACTIONAL:
541 *processed = div_s64(raw64 * (s64)scale_val * scale,
544 case IIO_VAL_FRACTIONAL_LOG2:
545 *processed = (raw64 * (s64)scale_val * scale) >> scale_val2;
554 int iio_convert_raw_to_processed(struct iio_channel *chan, int raw,
555 int *processed, unsigned int scale)
559 mutex_lock(&chan->indio_dev->info_exist_lock);
560 if (chan->indio_dev->info == NULL) {
565 ret = iio_convert_raw_to_processed_unlocked(chan, raw, processed,
568 mutex_unlock(&chan->indio_dev->info_exist_lock);
572 EXPORT_SYMBOL_GPL(iio_convert_raw_to_processed);
574 int iio_read_channel_processed(struct iio_channel *chan, int *val)
578 mutex_lock(&chan->indio_dev->info_exist_lock);
579 if (chan->indio_dev->info == NULL) {
584 if (iio_channel_has_info(chan->channel, IIO_CHAN_INFO_PROCESSED)) {
585 ret = iio_channel_read(chan, val, NULL,
586 IIO_CHAN_INFO_PROCESSED);
588 ret = iio_channel_read(chan, val, NULL, IIO_CHAN_INFO_RAW);
591 ret = iio_convert_raw_to_processed_unlocked(chan, *val, val, 1);
595 mutex_unlock(&chan->indio_dev->info_exist_lock);
599 EXPORT_SYMBOL_GPL(iio_read_channel_processed);
601 int iio_read_channel_scale(struct iio_channel *chan, int *val, int *val2)
605 mutex_lock(&chan->indio_dev->info_exist_lock);
606 if (chan->indio_dev->info == NULL) {
611 ret = iio_channel_read(chan, val, val2, IIO_CHAN_INFO_SCALE);
613 mutex_unlock(&chan->indio_dev->info_exist_lock);
617 EXPORT_SYMBOL_GPL(iio_read_channel_scale);
619 int iio_get_channel_type(struct iio_channel *chan, enum iio_chan_type *type)
622 /* Need to verify underlying driver has not gone away */
624 mutex_lock(&chan->indio_dev->info_exist_lock);
625 if (chan->indio_dev->info == NULL) {
630 *type = chan->channel->type;
632 mutex_unlock(&chan->indio_dev->info_exist_lock);
636 EXPORT_SYMBOL_GPL(iio_get_channel_type);