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;
103 static int __of_iio_channel_get(struct iio_channel *channel,
104 struct device_node *np, int index)
107 struct iio_dev *indio_dev;
109 struct of_phandle_args iiospec;
111 err = of_parse_phandle_with_args(np, "io-channels",
117 idev = bus_find_device(&iio_bus_type, NULL, iiospec.np,
119 of_node_put(iiospec.np);
121 return -EPROBE_DEFER;
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) {
130 channel->channel = &indio_dev->channels[index];
135 iio_device_put(indio_dev);
139 static struct iio_channel *of_iio_channel_get(struct device_node *np, int index)
141 struct iio_channel *channel;
145 return ERR_PTR(-EINVAL);
147 channel = kzalloc(sizeof(*channel), GFP_KERNEL);
149 return ERR_PTR(-ENOMEM);
151 err = __of_iio_channel_get(channel, np, index);
153 goto err_free_channel;
162 static struct iio_channel *of_iio_channel_get_by_name(struct device_node *np,
165 struct iio_channel *chan = NULL;
167 /* Walk up the tree of devices looking for a matching iio channel */
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()
178 index = of_property_match_string(np, "io-channel-names",
180 chan = of_iio_channel_get(np, index);
181 if (!IS_ERR(chan) || PTR_ERR(chan) == -EPROBE_DEFER)
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);
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.
195 if (np && !of_get_property(np, "io-channel-ranges", NULL))
202 static struct iio_channel *of_iio_channel_get_all(struct device *dev)
204 struct iio_channel *chans;
205 int i, mapind, nummaps = 0;
209 ret = of_parse_phandle_with_args(dev->of_node,
217 if (nummaps == 0) /* no error, return NULL to search map table */
220 /* NULL terminated array to save passing size */
221 chans = kcalloc(nummaps + 1, sizeof(*chans), GFP_KERNEL);
223 return ERR_PTR(-ENOMEM);
225 /* Search for OF matches */
226 for (mapind = 0; mapind < nummaps; mapind++) {
227 ret = __of_iio_channel_get(&chans[mapind], dev->of_node,
230 goto error_free_chans;
235 for (i = 0; i < mapind; i++)
236 iio_device_put(chans[i].indio_dev);
241 #else /* CONFIG_OF */
243 static inline struct iio_channel *
244 of_iio_channel_get_by_name(struct device_node *np, const char *name)
249 static inline struct iio_channel *of_iio_channel_get_all(struct device *dev)
254 #endif /* CONFIG_OF */
256 static struct iio_channel *iio_channel_get_sys(const char *name,
257 const char *channel_name)
259 struct iio_map_internal *c_i = NULL, *c = NULL;
260 struct iio_channel *channel;
263 if (name == NULL && channel_name == NULL)
264 return ERR_PTR(-ENODEV);
266 /* first find matching entry the channel map */
267 mutex_lock(&iio_map_list_lock);
268 list_for_each_entry(c_i, &iio_map_list, l) {
269 if ((name && strcmp(name, c_i->map->consumer_dev_name) != 0) ||
271 strcmp(channel_name, c_i->map->consumer_channel) != 0))
274 iio_device_get(c->indio_dev);
277 mutex_unlock(&iio_map_list_lock);
279 return ERR_PTR(-ENODEV);
281 channel = kzalloc(sizeof(*channel), GFP_KERNEL);
282 if (channel == NULL) {
287 channel->indio_dev = c->indio_dev;
289 if (c->map->adc_channel_label) {
291 iio_chan_spec_from_name(channel->indio_dev,
292 c->map->adc_channel_label);
294 if (channel->channel == NULL) {
305 iio_device_put(c->indio_dev);
309 struct iio_channel *iio_channel_get(struct device *dev,
310 const char *channel_name)
312 const char *name = dev ? dev_name(dev) : NULL;
313 struct iio_channel *channel;
316 channel = of_iio_channel_get_by_name(dev->of_node,
322 return iio_channel_get_sys(name, channel_name);
324 EXPORT_SYMBOL_GPL(iio_channel_get);
326 void iio_channel_release(struct iio_channel *channel)
328 iio_device_put(channel->indio_dev);
331 EXPORT_SYMBOL_GPL(iio_channel_release);
333 struct iio_channel *iio_channel_get_all(struct device *dev)
336 struct iio_channel *chans;
337 struct iio_map_internal *c = NULL;
343 return ERR_PTR(-EINVAL);
345 chans = of_iio_channel_get_all(dev);
349 name = dev_name(dev);
351 mutex_lock(&iio_map_list_lock);
352 /* first count the matching maps */
353 list_for_each_entry(c, &iio_map_list, l)
354 if (name && strcmp(name, c->map->consumer_dev_name) != 0)
364 /* NULL terminated array to save passing size */
365 chans = kzalloc(sizeof(*chans)*(nummaps + 1), GFP_KERNEL);
371 /* for each map fill in the chans element */
372 list_for_each_entry(c, &iio_map_list, l) {
373 if (name && strcmp(name, c->map->consumer_dev_name) != 0)
375 chans[mapind].indio_dev = c->indio_dev;
376 chans[mapind].data = c->map->consumer_data;
377 chans[mapind].channel =
378 iio_chan_spec_from_name(chans[mapind].indio_dev,
379 c->map->adc_channel_label);
380 if (chans[mapind].channel == NULL) {
382 goto error_free_chans;
384 iio_device_get(chans[mapind].indio_dev);
389 goto error_free_chans;
391 mutex_unlock(&iio_map_list_lock);
396 for (i = 0; i < nummaps; i++)
397 iio_device_put(chans[i].indio_dev);
400 mutex_unlock(&iio_map_list_lock);
404 EXPORT_SYMBOL_GPL(iio_channel_get_all);
406 void iio_channel_release_all(struct iio_channel *channels)
408 struct iio_channel *chan = &channels[0];
410 while (chan->indio_dev) {
411 iio_device_put(chan->indio_dev);
416 EXPORT_SYMBOL_GPL(iio_channel_release_all);
418 static int iio_channel_read(struct iio_channel *chan, int *val, int *val2,
419 enum iio_chan_info_enum info)
426 return chan->indio_dev->info->read_raw(chan->indio_dev, chan->channel,
430 int iio_read_channel_raw(struct iio_channel *chan, int *val)
434 mutex_lock(&chan->indio_dev->info_exist_lock);
435 if (chan->indio_dev->info == NULL) {
440 ret = iio_channel_read(chan, val, NULL, IIO_CHAN_INFO_RAW);
442 mutex_unlock(&chan->indio_dev->info_exist_lock);
446 EXPORT_SYMBOL_GPL(iio_read_channel_raw);
448 static int iio_convert_raw_to_processed_unlocked(struct iio_channel *chan,
449 int raw, int *processed, unsigned int scale)
451 int scale_type, scale_val, scale_val2, offset;
455 ret = iio_channel_read(chan, &offset, NULL, IIO_CHAN_INFO_OFFSET);
459 scale_type = iio_channel_read(chan, &scale_val, &scale_val2,
460 IIO_CHAN_INFO_SCALE);
464 switch (scale_type) {
466 *processed = raw64 * scale_val;
468 case IIO_VAL_INT_PLUS_MICRO:
470 *processed = -raw64 * scale_val;
472 *processed = raw64 * scale_val;
473 *processed += div_s64(raw64 * (s64)scale_val2 * scale,
476 case IIO_VAL_INT_PLUS_NANO:
478 *processed = -raw64 * scale_val;
480 *processed = raw64 * scale_val;
481 *processed += div_s64(raw64 * (s64)scale_val2 * scale,
484 case IIO_VAL_FRACTIONAL:
485 *processed = div_s64(raw64 * (s64)scale_val * scale,
488 case IIO_VAL_FRACTIONAL_LOG2:
489 *processed = (raw64 * (s64)scale_val * scale) >> scale_val2;
498 int iio_convert_raw_to_processed(struct iio_channel *chan, int raw,
499 int *processed, unsigned int scale)
503 mutex_lock(&chan->indio_dev->info_exist_lock);
504 if (chan->indio_dev->info == NULL) {
509 ret = iio_convert_raw_to_processed_unlocked(chan, raw, processed,
512 mutex_unlock(&chan->indio_dev->info_exist_lock);
516 EXPORT_SYMBOL_GPL(iio_convert_raw_to_processed);
518 int iio_read_channel_processed(struct iio_channel *chan, int *val)
522 mutex_lock(&chan->indio_dev->info_exist_lock);
523 if (chan->indio_dev->info == NULL) {
528 if (iio_channel_has_info(chan->channel, IIO_CHAN_INFO_PROCESSED)) {
529 ret = iio_channel_read(chan, val, NULL,
530 IIO_CHAN_INFO_PROCESSED);
532 ret = iio_channel_read(chan, val, NULL, IIO_CHAN_INFO_RAW);
535 ret = iio_convert_raw_to_processed_unlocked(chan, *val, val, 1);
539 mutex_unlock(&chan->indio_dev->info_exist_lock);
543 EXPORT_SYMBOL_GPL(iio_read_channel_processed);
545 int iio_read_channel_scale(struct iio_channel *chan, int *val, int *val2)
549 mutex_lock(&chan->indio_dev->info_exist_lock);
550 if (chan->indio_dev->info == NULL) {
555 ret = iio_channel_read(chan, val, val2, IIO_CHAN_INFO_SCALE);
557 mutex_unlock(&chan->indio_dev->info_exist_lock);
561 EXPORT_SYMBOL_GPL(iio_read_channel_scale);
563 int iio_get_channel_type(struct iio_channel *chan, enum iio_chan_type *type)
566 /* Need to verify underlying driver has not gone away */
568 mutex_lock(&chan->indio_dev->info_exist_lock);
569 if (chan->indio_dev->info == NULL) {
574 *type = chan->channel->type;
576 mutex_unlock(&chan->indio_dev->info_exist_lock);
580 EXPORT_SYMBOL_GPL(iio_get_channel_type);