[deliverable/linux.git] / drivers / iio / inkern.c

/* The industrial I/O core in kernel channel mapping
 *
 * Copyright (c) 2011 Jonathan Cameron
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 */
#include <linux/err.h>
#include <linux/export.h>
#include <linux/slab.h>
#include <linux/mutex.h>
#include <linux/of.h>

#include <linux/iio/iio.h>
#include "iio_core.h"
#include <linux/iio/machine.h>
#include <linux/iio/driver.h>
#include <linux/iio/consumer.h>

struct iio_map_internal {
	struct iio_dev *indio_dev;
	struct iio_map *map;
	struct list_head l;
};

static LIST_HEAD(iio_map_list);
static DEFINE_MUTEX(iio_map_list_lock);

int iio_map_array_register(struct iio_dev *indio_dev, struct iio_map *maps)
{
	int i = 0, ret = 0;
	struct iio_map_internal *mapi;

	if (maps == NULL)
		return 0;

	mutex_lock(&iio_map_list_lock);
	while (maps[i].consumer_dev_name != NULL) {
		mapi = kzalloc(sizeof(*mapi), GFP_KERNEL);
		if (mapi == NULL) {
			ret = -ENOMEM;
			goto error_ret;
		}
		mapi->map = &maps[i];
		mapi->indio_dev = indio_dev;
		list_add(&mapi->l, &iio_map_list);
		i++;
	}
error_ret:
	mutex_unlock(&iio_map_list_lock);

	return ret;
}
EXPORT_SYMBOL_GPL(iio_map_array_register);


/*
 * Remove all map entries associated with the given iio device
 */
int iio_map_array_unregister(struct iio_dev *indio_dev)
{
	int ret = -ENODEV;
	struct iio_map_internal *mapi;
	struct list_head *pos, *tmp;

	mutex_lock(&iio_map_list_lock);
	list_for_each_safe(pos, tmp, &iio_map_list) {
		mapi = list_entry(pos, struct iio_map_internal, l);
		if (indio_dev == mapi->indio_dev) {
			list_del(&mapi->l);
			kfree(mapi);
			ret = 0;
		}
	}
	mutex_unlock(&iio_map_list_lock);
	return ret;
}
EXPORT_SYMBOL_GPL(iio_map_array_unregister);

static const struct iio_chan_spec
*iio_chan_spec_from_name(const struct iio_dev *indio_dev, const char *name)
{
	int i;
	const struct iio_chan_spec *chan = NULL;

	for (i = 0; i < indio_dev->num_channels; i++)
		if (indio_dev->channels[i].datasheet_name &&
		    strcmp(name, indio_dev->channels[i].datasheet_name) == 0) {
			chan = &indio_dev->channels[i];
			break;
		}
	return chan;
}

#ifdef CONFIG_OF

static int iio_dev_node_match(struct device *dev, void *data)
{
	return dev->of_node == data && dev->type == &iio_device_type;
}

/**
 * __of_iio_simple_xlate - translate iiospec to the IIO channel index
 * @indio_dev:	pointer to the iio_dev structure
 * @iiospec:	IIO specifier as found in the device tree
 *
 * This is simple translation function, suitable for the most 1:1 mapped
 * channels in IIO chips. This function performs only one sanity check:
 * whether IIO index is less than num_channels (that is specified in the
 * iio_dev).
 */
static int __of_iio_simple_xlate(struct iio_dev *indio_dev,
				const struct of_phandle_args *iiospec)
{
	if (!iiospec->args_count)
		return 0;

	if (iiospec->args[0] >= indio_dev->num_channels) {
		dev_err(&indio_dev->dev, "invalid channel index %u\n",
			iiospec->args[0]);
		return -EINVAL;
	}

	return iiospec->args[0];
}

static int __of_iio_channel_get(struct iio_channel *channel,
				struct device_node *np, int index)
{
	struct device *idev;
	struct iio_dev *indio_dev;
	int err;
	struct of_phandle_args iiospec;

	err = of_parse_phandle_with_args(np, "io-channels",
					 "#io-channel-cells",
					 index, &iiospec);
	if (err)
		return err;

	idev = bus_find_device(&iio_bus_type, NULL, iiospec.np,
			       iio_dev_node_match);
	of_node_put(iiospec.np);
	if (idev == NULL)
		return -EPROBE_DEFER;

	indio_dev = dev_to_iio_dev(idev);
	channel->indio_dev = indio_dev;
	if (indio_dev->info->of_xlate)
		index = indio_dev->info->of_xlate(indio_dev, &iiospec);
	else
		index = __of_iio_simple_xlate(indio_dev, &iiospec);
	if (index < 0)
		goto err_put;
	channel->channel = &indio_dev->channels[index];

	return 0;

err_put:
	iio_device_put(indio_dev);
	return index;
}

static struct iio_channel *of_iio_channel_get(struct device_node *np, int index)
{
	struct iio_channel *channel;
	int err;

	if (index < 0)
		return ERR_PTR(-EINVAL);

	channel = kzalloc(sizeof(*channel), GFP_KERNEL);
	if (channel == NULL)
		return ERR_PTR(-ENOMEM);

	err = __of_iio_channel_get(channel, np, index);
	if (err)
		goto err_free_channel;

	return channel;

err_free_channel:
	kfree(channel);
	return ERR_PTR(err);
}

static struct iio_channel *of_iio_channel_get_by_name(struct device_node *np,
						      const char *name)
{
	struct iio_channel *chan = NULL;

	/* Walk up the tree of devices looking for a matching iio channel */
	while (np) {
		int index = 0;

		/*
		 * For named iio channels, first look up the name in the
		 * "io-channel-names" property.  If it cannot be found, the
		 * index will be an error code, and of_iio_channel_get()
		 * will fail.
		 */
		if (name)
			index = of_property_match_string(np, "io-channel-names",
							 name);
		chan = of_iio_channel_get(np, index);
		if (!IS_ERR(chan) || PTR_ERR(chan) == -EPROBE_DEFER)
			break;
		else if (name && index >= 0) {
			pr_err("ERROR: could not get IIO channel %s:%s(%i)\n",
				np->full_name, name ? name : "", index);
			return NULL;
		}

		/*
		 * No matching IIO channel found on this node.
		 * If the parent node has a "io-channel-ranges" property,
		 * then we can try one of its channels.
		 */
		np = np->parent;
		if (np && !of_get_property(np, "io-channel-ranges", NULL))
			return NULL;
	}

	return chan;
}

static struct iio_channel *of_iio_channel_get_all(struct device *dev)
{
	struct iio_channel *chans;
	int i, mapind, nummaps = 0;
	int ret;

	do {
		ret = of_parse_phandle_with_args(dev->of_node,
						 "io-channels",
						 "#io-channel-cells",
						 nummaps, NULL);
		if (ret < 0)
			break;
	} while (++nummaps);

	if (nummaps == 0)	/* no error, return NULL to search map table */
		return NULL;

	/* NULL terminated array to save passing size */
	chans = kcalloc(nummaps + 1, sizeof(*chans), GFP_KERNEL);
	if (chans == NULL)
		return ERR_PTR(-ENOMEM);

	/* Search for OF matches */
	for (mapind = 0; mapind < nummaps; mapind++) {
		ret = __of_iio_channel_get(&chans[mapind], dev->of_node,
					   mapind);
		if (ret)
			goto error_free_chans;
	}
	return chans;

error_free_chans:
	for (i = 0; i < mapind; i++)
		iio_device_put(chans[i].indio_dev);
	kfree(chans);
	return ERR_PTR(ret);
}

#else /* CONFIG_OF */

static inline struct iio_channel *
of_iio_channel_get_by_name(struct device_node *np, const char *name)
{
	return NULL;
}

static inline struct iio_channel *of_iio_channel_get_all(struct device *dev)
{
	return NULL;
}

#endif /* CONFIG_OF */

static struct iio_channel *iio_channel_get_sys(const char *name,
					       const char *channel_name)
{
	struct iio_map_internal *c_i = NULL, *c = NULL;
	struct iio_channel *channel;
	int err;

	if (name == NULL && channel_name == NULL)
		return ERR_PTR(-ENODEV);

	/* first find matching entry the channel map */
	mutex_lock(&iio_map_list_lock);
	list_for_each_entry(c_i, &iio_map_list, l) {
		if ((name && strcmp(name, c_i->map->consumer_dev_name) != 0) ||
		    (channel_name &&
		     strcmp(channel_name, c_i->map->consumer_channel) != 0))
			continue;
		c = c_i;
		iio_device_get(c->indio_dev);
		break;
	}
	mutex_unlock(&iio_map_list_lock);
	if (c == NULL)
		return ERR_PTR(-ENODEV);

	channel = kzalloc(sizeof(*channel), GFP_KERNEL);
	if (channel == NULL) {
		err = -ENOMEM;
		goto error_no_mem;
	}

	channel->indio_dev = c->indio_dev;

	if (c->map->adc_channel_label) {
		channel->channel =
			iio_chan_spec_from_name(channel->indio_dev,
						c->map->adc_channel_label);

		if (channel->channel == NULL) {
			err = -EINVAL;
			goto error_no_chan;
		}
	}

	return channel;

error_no_chan:
	kfree(channel);
error_no_mem:
	iio_device_put(c->indio_dev);
	return ERR_PTR(err);
}

struct iio_channel *iio_channel_get(struct device *dev,
				    const char *channel_name)
{
	const char *name = dev ? dev_name(dev) : NULL;
	struct iio_channel *channel;

	if (dev) {
		channel = of_iio_channel_get_by_name(dev->of_node,
						     channel_name);
		if (channel != NULL)
			return channel;
	}

	return iio_channel_get_sys(name, channel_name);
}
EXPORT_SYMBOL_GPL(iio_channel_get);

void iio_channel_release(struct iio_channel *channel)
{
	iio_device_put(channel->indio_dev);
	kfree(channel);
}
EXPORT_SYMBOL_GPL(iio_channel_release);

struct iio_channel *iio_channel_get_all(struct device *dev)
{
	const char *name;
	struct iio_channel *chans;
	struct iio_map_internal *c = NULL;
	int nummaps = 0;
	int mapind = 0;
	int i, ret;

	if (dev == NULL)
		return ERR_PTR(-EINVAL);

	chans = of_iio_channel_get_all(dev);
	if (chans)
		return chans;

	name = dev_name(dev);

	mutex_lock(&iio_map_list_lock);
	/* first count the matching maps */
	list_for_each_entry(c, &iio_map_list, l)
		if (name && strcmp(name, c->map->consumer_dev_name) != 0)
			continue;
		else
			nummaps++;

	if (nummaps == 0) {
		ret = -ENODEV;
		goto error_ret;
	}

	/* NULL terminated array to save passing size */
	chans = kzalloc(sizeof(*chans)*(nummaps + 1), GFP_KERNEL);
	if (chans == NULL) {
		ret = -ENOMEM;
		goto error_ret;
	}

	/* for each map fill in the chans element */
	list_for_each_entry(c, &iio_map_list, l) {
		if (name && strcmp(name, c->map->consumer_dev_name) != 0)
			continue;
		chans[mapind].indio_dev = c->indio_dev;
		chans[mapind].data = c->map->consumer_data;
		chans[mapind].channel =
			iio_chan_spec_from_name(chans[mapind].indio_dev,
						c->map->adc_channel_label);
		if (chans[mapind].channel == NULL) {
			ret = -EINVAL;
			goto error_free_chans;
		}
		iio_device_get(chans[mapind].indio_dev);
		mapind++;
	}
	if (mapind == 0) {
		ret = -ENODEV;
		goto error_free_chans;
	}
	mutex_unlock(&iio_map_list_lock);

	return chans;

error_free_chans:
	for (i = 0; i < nummaps; i++)
		iio_device_put(chans[i].indio_dev);
	kfree(chans);
error_ret:
	mutex_unlock(&iio_map_list_lock);

	return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(iio_channel_get_all);

void iio_channel_release_all(struct iio_channel *channels)
{
	struct iio_channel *chan = &channels[0];

	while (chan->indio_dev) {
		iio_device_put(chan->indio_dev);
		chan++;
	}
	kfree(channels);
}
EXPORT_SYMBOL_GPL(iio_channel_release_all);

static int iio_channel_read(struct iio_channel *chan, int *val, int *val2,
	enum iio_chan_info_enum info)
{
	int unused;
	int vals[INDIO_MAX_RAW_ELEMENTS];
	int ret;
	int val_len = 2;

	if (val2 == NULL)
		val2 = &unused;

	if(!iio_channel_has_info(chan->channel, info))
		return -EINVAL;

	if (chan->indio_dev->info->read_raw_multi) {
		ret = chan->indio_dev->info->read_raw_multi(chan->indio_dev,
					chan->channel, INDIO_MAX_RAW_ELEMENTS,
					vals, &val_len, info);
		*val = vals[0];
		*val2 = vals[1];
	} else
		ret = chan->indio_dev->info->read_raw(chan->indio_dev,
					chan->channel, val, val2, info);

	return ret;
}

int iio_read_channel_raw(struct iio_channel *chan, int *val)
{
	int ret;

	mutex_lock(&chan->indio_dev->info_exist_lock);
	if (chan->indio_dev->info == NULL) {
		ret = -ENODEV;
		goto err_unlock;
	}

	ret = iio_channel_read(chan, val, NULL, IIO_CHAN_INFO_RAW);
err_unlock:
	mutex_unlock(&chan->indio_dev->info_exist_lock);

	return ret;
}
EXPORT_SYMBOL_GPL(iio_read_channel_raw);

int iio_read_channel_average_raw(struct iio_channel *chan, int *val)
{
	int ret;

	mutex_lock(&chan->indio_dev->info_exist_lock);
	if (chan->indio_dev->info == NULL) {
		ret = -ENODEV;
		goto err_unlock;
	}

	ret = iio_channel_read(chan, val, NULL, IIO_CHAN_INFO_AVERAGE_RAW);
err_unlock:
	mutex_unlock(&chan->indio_dev->info_exist_lock);

	return ret;
}
EXPORT_SYMBOL_GPL(iio_read_channel_average_raw);

static int iio_convert_raw_to_processed_unlocked(struct iio_channel *chan,
	int raw, int *processed, unsigned int scale)
{
	int scale_type, scale_val, scale_val2, offset;
	s64 raw64 = raw;
	int ret;

	ret = iio_channel_read(chan, &offset, NULL, IIO_CHAN_INFO_OFFSET);
	if (ret >= 0)
		raw64 += offset;

	scale_type = iio_channel_read(chan, &scale_val, &scale_val2,
					IIO_CHAN_INFO_SCALE);
	if (scale_type < 0)
		return scale_type;

	switch (scale_type) {
	case IIO_VAL_INT:
		*processed = raw64 * scale_val;
		break;
	case IIO_VAL_INT_PLUS_MICRO:
		if (scale_val2 < 0)
			*processed = -raw64 * scale_val;
		else
			*processed = raw64 * scale_val;
		*processed += div_s64(raw64 * (s64)scale_val2 * scale,
				      1000000LL);
		break;
	case IIO_VAL_INT_PLUS_NANO:
		if (scale_val2 < 0)
			*processed = -raw64 * scale_val;
		else
			*processed = raw64 * scale_val;
		*processed += div_s64(raw64 * (s64)scale_val2 * scale,
				      1000000000LL);
		break;
	case IIO_VAL_FRACTIONAL:
		*processed = div_s64(raw64 * (s64)scale_val * scale,
				     scale_val2);
		break;
	case IIO_VAL_FRACTIONAL_LOG2:
		*processed = (raw64 * (s64)scale_val * scale) >> scale_val2;
		break;
	default:
		return -EINVAL;
	}

	return 0;
}

int iio_convert_raw_to_processed(struct iio_channel *chan, int raw,
	int *processed, unsigned int scale)
{
	int ret;

	mutex_lock(&chan->indio_dev->info_exist_lock);
	if (chan->indio_dev->info == NULL) {
		ret = -ENODEV;
		goto err_unlock;
	}

	ret = iio_convert_raw_to_processed_unlocked(chan, raw, processed,
							scale);
err_unlock:
	mutex_unlock(&chan->indio_dev->info_exist_lock);

	return ret;
}
EXPORT_SYMBOL_GPL(iio_convert_raw_to_processed);

int iio_read_channel_processed(struct iio_channel *chan, int *val)
{
	int ret;

	mutex_lock(&chan->indio_dev->info_exist_lock);
	if (chan->indio_dev->info == NULL) {
		ret = -ENODEV;
		goto err_unlock;
	}

	if (iio_channel_has_info(chan->channel, IIO_CHAN_INFO_PROCESSED)) {
		ret = iio_channel_read(chan, val, NULL,
				       IIO_CHAN_INFO_PROCESSED);
	} else {
		ret = iio_channel_read(chan, val, NULL, IIO_CHAN_INFO_RAW);
		if (ret < 0)
			goto err_unlock;
		ret = iio_convert_raw_to_processed_unlocked(chan, *val, val, 1);
	}

err_unlock:
	mutex_unlock(&chan->indio_dev->info_exist_lock);

	return ret;
}
EXPORT_SYMBOL_GPL(iio_read_channel_processed);

int iio_read_channel_scale(struct iio_channel *chan, int *val, int *val2)
{
	int ret;

	mutex_lock(&chan->indio_dev->info_exist_lock);
	if (chan->indio_dev->info == NULL) {
		ret = -ENODEV;
		goto err_unlock;
	}

	ret = iio_channel_read(chan, val, val2, IIO_CHAN_INFO_SCALE);
err_unlock:
	mutex_unlock(&chan->indio_dev->info_exist_lock);

	return ret;
}
EXPORT_SYMBOL_GPL(iio_read_channel_scale);

int iio_get_channel_type(struct iio_channel *chan, enum iio_chan_type *type)
{
	int ret = 0;
	/* Need to verify underlying driver has not gone away */

	mutex_lock(&chan->indio_dev->info_exist_lock);
	if (chan->indio_dev->info == NULL) {
		ret = -ENODEV;
		goto err_unlock;
	}

	*type = chan->channel->type;
err_unlock:
	mutex_unlock(&chan->indio_dev->info_exist_lock);

	return ret;
}
EXPORT_SYMBOL_GPL(iio_get_channel_type);

static int iio_channel_write(struct iio_channel *chan, int val, int val2,
			     enum iio_chan_info_enum info)
{
	return chan->indio_dev->info->write_raw(chan->indio_dev,
						chan->channel, val, val2, info);
}

int iio_write_channel_raw(struct iio_channel *chan, int val)
{
	int ret;

	mutex_lock(&chan->indio_dev->info_exist_lock);
	if (chan->indio_dev->info == NULL) {
		ret = -ENODEV;
		goto err_unlock;
	}

	ret = iio_channel_write(chan, val, 0, IIO_CHAN_INFO_RAW);
err_unlock:
	mutex_unlock(&chan->indio_dev->info_exist_lock);

	return ret;
}
EXPORT_SYMBOL_GPL(iio_write_channel_raw);
Commit	Line	Data
e27d75d7 JC	1	/* 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>
17d82b47	13	#include <linux/of.h>
e27d75d7	14
06458e27	15	#include <linux/iio/iio.h>
e27d75d7	16	#include "iio_core.h"
06458e27 JC	17	#include <linux/iio/machine.h>
	18	#include <linux/iio/driver.h>
	19	#include <linux/iio/consumer.h>
e27d75d7 JC	20
	21	struct iio_map_internal {
	22	struct iio_dev *indio_dev;
	23	struct iio_map *map;
	24	struct list_head l;
	25	};
	26
	27	static LIST_HEAD(iio_map_list);
	28	static DEFINE_MUTEX(iio_map_list_lock);
	29
	30	int 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	}
	50	error_ret:
	51	mutex_unlock(&iio_map_list_lock);
	52
	53	return ret;
	54	}
	55	EXPORT_SYMBOL_GPL(iio_map_array_register);
	56
	57
6cb2afd7 GR	58	/*
6cb2afd7 GR	59	* Remove all map entries associated with the given iio device
e27d75d7	60	*/
6cb2afd7	61	int iio_map_array_unregister(struct iio_dev *indio_dev)
e27d75d7	62	{
6cb2afd7	63	int ret = -ENODEV;
e27d75d7	64	struct iio_map_internal *mapi;
6cb2afd7	65	struct list_head pos, tmp;
e27d75d7 JC	66
e27d75d7 JC	67	mutex_lock(&iio_map_list_lock);
6cb2afd7 GR	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) {
	71	list_del(&mapi->l);
	72	kfree(mapi);
	73	ret = 0;
e27d75d7 JC	74	}
e27d75d7 JC	75	}
e27d75d7	76	mutex_unlock(&iio_map_list_lock);
e27d75d7 JC	77	return ret;
	78	}
	79	EXPORT_SYMBOL_GPL(iio_map_array_unregister);
	80
	81	static const struct iio_chan_spec
314be14b	82	iio_chan_spec_from_name(const struct iio_dev indio_dev, const char *name)
e27d75d7 JC	83	{
	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
17d82b47 GR	96	#ifdef CONFIG_OF
	97
	98	static int iio_dev_node_match(struct device dev, void data)
	99	{
	100	return dev->of_node == data && dev->type == &iio_device_type;
	101	}
	102
acd82567 II	103	/**
	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
	107	*
	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
	111	* iio_dev).
	112	*/
	113	static int __of_iio_simple_xlate(struct iio_dev *indio_dev,
	114	const struct of_phandle_args *iiospec)
	115	{
	116	if (!iiospec->args_count)
	117	return 0;
	118
1f202725 SW	119	if (iiospec->args[0] >= indio_dev->num_channels) {
	120	dev_err(&indio_dev->dev, "invalid channel index %u\n",
	121	iiospec->args[0]);
acd82567	122	return -EINVAL;
1f202725	123	}
acd82567 II	124
	125	return iiospec->args[0];
	126	}
	127
17d82b47 GR	128	static int __of_iio_channel_get(struct iio_channel *channel,
	129	struct device_node *np, int index)
	130	{
	131	struct device *idev;
	132	struct iio_dev *indio_dev;
	133	int err;
	134	struct of_phandle_args iiospec;
	135
	136	err = of_parse_phandle_with_args(np, "io-channels",
	137	"#io-channel-cells",
	138	index, &iiospec);
	139	if (err)
	140	return err;
	141
	142	idev = bus_find_device(&iio_bus_type, NULL, iiospec.np,
	143	iio_dev_node_match);
	144	of_node_put(iiospec.np);
	145	if (idev == NULL)
	146	return -EPROBE_DEFER;
	147
	148	indio_dev = dev_to_iio_dev(idev);
	149	channel->indio_dev = indio_dev;
acd82567 II	150	if (indio_dev->info->of_xlate)
	151	index = indio_dev->info->of_xlate(indio_dev, &iiospec);
	152	else
	153	index = __of_iio_simple_xlate(indio_dev, &iiospec);
	154	if (index < 0)
17d82b47	155	goto err_put;
17d82b47 GR	156	channel->channel = &indio_dev->channels[index];
	157
	158	return 0;
	159
	160	err_put:
	161	iio_device_put(indio_dev);
acd82567	162	return index;
17d82b47 GR	163	}
	164
	165	static struct iio_channel of_iio_channel_get(struct device_node np, int index)
	166	{
	167	struct iio_channel *channel;
	168	int err;
	169
	170	if (index < 0)
	171	return ERR_PTR(-EINVAL);
	172
	173	channel = kzalloc(sizeof(*channel), GFP_KERNEL);
	174	if (channel == NULL)
	175	return ERR_PTR(-ENOMEM);
	176
	177	err = __of_iio_channel_get(channel, np, index);
	178	if (err)
	179	goto err_free_channel;
	180
	181	return channel;
	182
	183	err_free_channel:
	184	kfree(channel);
	185	return ERR_PTR(err);
	186	}
	187
	188	static struct iio_channel of_iio_channel_get_by_name(struct device_node np,
	189	const char *name)
	190	{
	191	struct iio_channel *chan = NULL;
	192
	193	/* Walk up the tree of devices looking for a matching iio channel */
	194	while (np) {
	195	int index = 0;
	196
	197	/*
	198	* For named iio channels, first look up the name in the
	199	* "io-channel-names" property. If it cannot be found, the
	200	* index will be an error code, and of_iio_channel_get()
	201	* will fail.
	202	*/
	203	if (name)
	204	index = of_property_match_string(np, "io-channel-names",
	205	name);
	206	chan = of_iio_channel_get(np, index);
872687f6	207	if (!IS_ERR(chan) \|\| PTR_ERR(chan) == -EPROBE_DEFER)
17d82b47 GR	208	break;
	209	else if (name && index >= 0) {
	210	pr_err("ERROR: could not get IIO channel %s:%s(%i)\n",
	211	np->full_name, name ? name : "", index);
a2c12493	212	return NULL;
17d82b47 GR	213	}
	214
	215	/*
	216	* No matching IIO channel found on this node.
	217	* If the parent node has a "io-channel-ranges" property,
	218	* then we can try one of its channels.
	219	*/
	220	np = np->parent;
	221	if (np && !of_get_property(np, "io-channel-ranges", NULL))
a2c12493	222	return NULL;
17d82b47	223	}
a2c12493	224
17d82b47 GR	225	return chan;
	226	}
	227
	228	static struct iio_channel of_iio_channel_get_all(struct device dev)
	229	{
	230	struct iio_channel *chans;
	231	int i, mapind, nummaps = 0;
	232	int ret;
	233
	234	do {
	235	ret = of_parse_phandle_with_args(dev->of_node,
	236	"io-channels",
	237	"#io-channel-cells",
	238	nummaps, NULL);
	239	if (ret < 0)
	240	break;
	241	} while (++nummaps);
	242
	243	if (nummaps == 0) /* no error, return NULL to search map table */
	244	return NULL;
	245
	246	/* NULL terminated array to save passing size */
	247	chans = kcalloc(nummaps + 1, sizeof(*chans), GFP_KERNEL);
	248	if (chans == NULL)
	249	return ERR_PTR(-ENOMEM);
	250
	251	/* Search for OF matches */
	252	for (mapind = 0; mapind < nummaps; mapind++) {
	253	ret = __of_iio_channel_get(&chans[mapind], dev->of_node,
	254	mapind);
	255	if (ret)
	256	goto error_free_chans;
	257	}
	258	return chans;
	259
	260	error_free_chans:
	261	for (i = 0; i < mapind; i++)
	262	iio_device_put(chans[i].indio_dev);
	263	kfree(chans);
	264	return ERR_PTR(ret);
	265	}
	266
	267	#else /* CONFIG_OF */
	268
	269	static inline struct iio_channel *
	270	of_iio_channel_get_by_name(struct device_node np, const char name)
	271	{
	272	return NULL;
	273	}
	274
	275	static inline struct iio_channel of_iio_channel_get_all(struct device dev)
	276	{
	277	return NULL;
	278	}
	279
	280	#endif /* CONFIG_OF */
e27d75d7	281
5aa57f0a GR	282	static struct iio_channel iio_channel_get_sys(const char name,
5aa57f0a GR	283	const char *channel_name)
e27d75d7 JC	284	{
	285	struct iio_map_internal c_i = NULL, c = NULL;
	286	struct iio_channel *channel;
3183bac1	287	int err;
e27d75d7 JC	288
	289	if (name == NULL && channel_name == NULL)
	290	return ERR_PTR(-ENODEV);
	291
	292	/* first find matching entry the channel map */
	293	mutex_lock(&iio_map_list_lock);
	294	list_for_each_entry(c_i, &iio_map_list, l) {
	295	if ((name && strcmp(name, c_i->map->consumer_dev_name) != 0) \|\|
	296	(channel_name &&
	297	strcmp(channel_name, c_i->map->consumer_channel) != 0))
	298	continue;
	299	c = c_i;
1875ffd2	300	iio_device_get(c->indio_dev);
e27d75d7 JC	301	break;
	302	}
	303	mutex_unlock(&iio_map_list_lock);
	304	if (c == NULL)
	305	return ERR_PTR(-ENODEV);
	306
2cc412b5	307	channel = kzalloc(sizeof(*channel), GFP_KERNEL);
3183bac1 KM	308	if (channel == NULL) {
3183bac1 KM	309	err = -ENOMEM;
801c4b5c	310	goto error_no_mem;
3183bac1	311	}
e27d75d7 JC	312
	313	channel->indio_dev = c->indio_dev;
	314
b2b79ffa	315	if (c->map->adc_channel_label) {
e27d75d7 JC	316	channel->channel =
	317	iio_chan_spec_from_name(channel->indio_dev,
	318	c->map->adc_channel_label);
	319
3183bac1 KM	320	if (channel->channel == NULL) {
3183bac1 KM	321	err = -EINVAL;
b2b79ffa	322	goto error_no_chan;
3183bac1	323	}
b2b79ffa KM	324	}
b2b79ffa KM	325
e27d75d7	326	return channel;
b2b79ffa KM	327
b2b79ffa KM	328	error_no_chan:
b2b79ffa	329	kfree(channel);
801c4b5c KM	330	error_no_mem:
801c4b5c KM	331	iio_device_put(c->indio_dev);
3183bac1	332	return ERR_PTR(err);
e27d75d7	333	}
5aa57f0a GR	334
	335	struct iio_channel iio_channel_get(struct device dev,
	336	const char *channel_name)
	337	{
	338	const char *name = dev ? dev_name(dev) : NULL;
17d82b47	339	struct iio_channel *channel;
5aa57f0a	340
17d82b47 GR	341	if (dev) {
	342	channel = of_iio_channel_get_by_name(dev->of_node,
	343	channel_name);
	344	if (channel != NULL)
	345	return channel;
	346	}
a2c12493	347
5aa57f0a GR	348	return iio_channel_get_sys(name, channel_name);
5aa57f0a GR	349	}
314be14b	350	EXPORT_SYMBOL_GPL(iio_channel_get);
e27d75d7	351
314be14b	352	void iio_channel_release(struct iio_channel *channel)
e27d75d7	353	{
1875ffd2	354	iio_device_put(channel->indio_dev);
e27d75d7 JC	355	kfree(channel);
e27d75d7 JC	356	}
314be14b	357	EXPORT_SYMBOL_GPL(iio_channel_release);
e27d75d7	358
ca7d98db	359	struct iio_channel iio_channel_get_all(struct device dev)
e27d75d7	360	{
ca7d98db	361	const char *name;
e27d75d7 JC	362	struct iio_channel *chans;
	363	struct iio_map_internal *c = NULL;
	364	int nummaps = 0;
	365	int mapind = 0;
	366	int i, ret;
	367
ca7d98db	368	if (dev == NULL)
e27d75d7	369	return ERR_PTR(-EINVAL);
17d82b47 GR	370
	371	chans = of_iio_channel_get_all(dev);
	372	if (chans)
	373	return chans;
	374
ca7d98db	375	name = dev_name(dev);
e27d75d7 JC	376
	377	mutex_lock(&iio_map_list_lock);
	378	/* first count the matching maps */
	379	list_for_each_entry(c, &iio_map_list, l)
	380	if (name && strcmp(name, c->map->consumer_dev_name) != 0)
	381	continue;
	382	else
	383	nummaps++;
	384
	385	if (nummaps == 0) {
	386	ret = -ENODEV;
	387	goto error_ret;
	388	}
	389
	390	/* NULL terminated array to save passing size */
	391	chans = kzalloc(sizeof(chans)(nummaps + 1), GFP_KERNEL);
	392	if (chans == NULL) {
	393	ret = -ENOMEM;
	394	goto error_ret;
	395	}
	396
	397	/* for each map fill in the chans element */
	398	list_for_each_entry(c, &iio_map_list, l) {
	399	if (name && strcmp(name, c->map->consumer_dev_name) != 0)
	400	continue;
	401	chans[mapind].indio_dev = c->indio_dev;
0464415d	402	chans[mapind].data = c->map->consumer_data;
e27d75d7 JC	403	chans[mapind].channel =
	404	iio_chan_spec_from_name(chans[mapind].indio_dev,
	405	c->map->adc_channel_label);
	406	if (chans[mapind].channel == NULL) {
	407	ret = -EINVAL;
e27d75d7 JC	408	goto error_free_chans;
e27d75d7 JC	409	}
1875ffd2	410	iio_device_get(chans[mapind].indio_dev);
e27d75d7 JC	411	mapind++;
e27d75d7 JC	412	}
e27d75d7 JC	413	if (mapind == 0) {
	414	ret = -ENODEV;
	415	goto error_free_chans;
	416	}
e59b9afe DC	417	mutex_unlock(&iio_map_list_lock);
e59b9afe DC	418
e27d75d7 JC	419	return chans;
	420
	421	error_free_chans:
	422	for (i = 0; i < nummaps; i++)
1875ffd2	423	iio_device_put(chans[i].indio_dev);
e27d75d7 JC	424	kfree(chans);
	425	error_ret:
	426	mutex_unlock(&iio_map_list_lock);
	427
	428	return ERR_PTR(ret);
	429	}
314be14b	430	EXPORT_SYMBOL_GPL(iio_channel_get_all);
e27d75d7	431
314be14b	432	void iio_channel_release_all(struct iio_channel *channels)
e27d75d7 JC	433	{
	434	struct iio_channel *chan = &channels[0];
	435
	436	while (chan->indio_dev) {
1875ffd2	437	iio_device_put(chan->indio_dev);
e27d75d7 JC	438	chan++;
	439	}
	440	kfree(channels);
	441	}
314be14b	442	EXPORT_SYMBOL_GPL(iio_channel_release_all);
e27d75d7	443
48e44ce0 LPC	444	static int iio_channel_read(struct iio_channel chan, int val, int *val2,
	445	enum iio_chan_info_enum info)
	446	{
	447	int unused;
9fbfb4b3 SP	448	int vals[INDIO_MAX_RAW_ELEMENTS];
	449	int ret;
	450	int val_len = 2;
48e44ce0 LPC	451
	452	if (val2 == NULL)
	453	val2 = &unused;
	454
65de7654 FP	455	if(!iio_channel_has_info(chan->channel, info))
	456	return -EINVAL;
	457
9fbfb4b3 SP	458	if (chan->indio_dev->info->read_raw_multi) {
	459	ret = chan->indio_dev->info->read_raw_multi(chan->indio_dev,
	460	chan->channel, INDIO_MAX_RAW_ELEMENTS,
	461	vals, &val_len, info);
	462	*val = vals[0];
	463	*val2 = vals[1];
	464	} else
	465	ret = chan->indio_dev->info->read_raw(chan->indio_dev,
	466	chan->channel, val, val2, info);
	467
	468	return ret;
48e44ce0 LPC	469	}
48e44ce0 LPC	470
314be14b	471	int iio_read_channel_raw(struct iio_channel chan, int val)
e27d75d7	472	{
48e44ce0	473	int ret;
e27d75d7 JC	474
	475	mutex_lock(&chan->indio_dev->info_exist_lock);
	476	if (chan->indio_dev->info == NULL) {
	477	ret = -ENODEV;
	478	goto err_unlock;
	479	}
	480
48e44ce0	481	ret = iio_channel_read(chan, val, NULL, IIO_CHAN_INFO_RAW);
e27d75d7 JC	482	err_unlock:
	483	mutex_unlock(&chan->indio_dev->info_exist_lock);
	484
	485	return ret;
	486	}
314be14b	487	EXPORT_SYMBOL_GPL(iio_read_channel_raw);
e27d75d7	488
476d4af2 SR	489	int iio_read_channel_average_raw(struct iio_channel chan, int val)
	490	{
	491	int ret;
	492
	493	mutex_lock(&chan->indio_dev->info_exist_lock);
	494	if (chan->indio_dev->info == NULL) {
	495	ret = -ENODEV;
	496	goto err_unlock;
	497	}
	498
	499	ret = iio_channel_read(chan, val, NULL, IIO_CHAN_INFO_AVERAGE_RAW);
	500	err_unlock:
	501	mutex_unlock(&chan->indio_dev->info_exist_lock);
	502
	503	return ret;
	504	}
	505	EXPORT_SYMBOL_GPL(iio_read_channel_average_raw);
	506
48e44ce0 LPC	507	static int iio_convert_raw_to_processed_unlocked(struct iio_channel *chan,
	508	int raw, int *processed, unsigned int scale)
	509	{
	510	int scale_type, scale_val, scale_val2, offset;
	511	s64 raw64 = raw;
	512	int ret;
	513
6c5d4c96	514	ret = iio_channel_read(chan, &offset, NULL, IIO_CHAN_INFO_OFFSET);
f91d1b63	515	if (ret >= 0)
48e44ce0 LPC	516	raw64 += offset;
	517
	518	scale_type = iio_channel_read(chan, &scale_val, &scale_val2,
	519	IIO_CHAN_INFO_SCALE);
	520	if (scale_type < 0)
	521	return scale_type;
	522
	523	switch (scale_type) {
	524	case IIO_VAL_INT:
	525	processed = raw64 scale_val;
	526	break;
	527	case IIO_VAL_INT_PLUS_MICRO:
	528	if (scale_val2 < 0)
	529	processed = -raw64 scale_val;
	530	else
	531	processed = raw64 scale_val;
	532	processed += div_s64(raw64 (s64)scale_val2 * scale,
	533	1000000LL);
	534	break;
	535	case IIO_VAL_INT_PLUS_NANO:
	536	if (scale_val2 < 0)
	537	processed = -raw64 scale_val;
	538	else
	539	processed = raw64 scale_val;
	540	processed += div_s64(raw64 (s64)scale_val2 * scale,
	541	1000000000LL);
	542	break;
	543	case IIO_VAL_FRACTIONAL:
	544	processed = div_s64(raw64 (s64)scale_val * scale,
	545	scale_val2);
	546	break;
103d9fb9 LPC	547	case IIO_VAL_FRACTIONAL_LOG2:
	548	processed = (raw64 (s64)scale_val * scale) >> scale_val2;
	549	break;
48e44ce0 LPC	550	default:
	551	return -EINVAL;
	552	}
	553
	554	return 0;
	555	}
	556
	557	int iio_convert_raw_to_processed(struct iio_channel *chan, int raw,
	558	int *processed, unsigned int scale)
	559	{
	560	int ret;
	561
	562	mutex_lock(&chan->indio_dev->info_exist_lock);
	563	if (chan->indio_dev->info == NULL) {
	564	ret = -ENODEV;
	565	goto err_unlock;
	566	}
	567
	568	ret = iio_convert_raw_to_processed_unlocked(chan, raw, processed,
	569	scale);
	570	err_unlock:
	571	mutex_unlock(&chan->indio_dev->info_exist_lock);
	572
	573	return ret;
	574	}
	575	EXPORT_SYMBOL_GPL(iio_convert_raw_to_processed);
	576
	577	int iio_read_channel_processed(struct iio_channel chan, int val)
	578	{
	579	int ret;
	580
	581	mutex_lock(&chan->indio_dev->info_exist_lock);
	582	if (chan->indio_dev->info == NULL) {
	583	ret = -ENODEV;
	584	goto err_unlock;
	585	}
	586
	587	if (iio_channel_has_info(chan->channel, IIO_CHAN_INFO_PROCESSED)) {
	588	ret = iio_channel_read(chan, val, NULL,
	589	IIO_CHAN_INFO_PROCESSED);
	590	} else {
	591	ret = iio_channel_read(chan, val, NULL, IIO_CHAN_INFO_RAW);
	592	if (ret < 0)
	593	goto err_unlock;
	594	ret = iio_convert_raw_to_processed_unlocked(chan, *val, val, 1);
	595	}
	596
	597	err_unlock:
	598	mutex_unlock(&chan->indio_dev->info_exist_lock);
	599
	600	return ret;
	601	}
	602	EXPORT_SYMBOL_GPL(iio_read_channel_processed);
	603
314be14b	604	int iio_read_channel_scale(struct iio_channel chan, int val, int *val2)
e27d75d7 JC	605	{
	606	int ret;
	607
	608	mutex_lock(&chan->indio_dev->info_exist_lock);
	609	if (chan->indio_dev->info == NULL) {
	610	ret = -ENODEV;
	611	goto err_unlock;
	612	}
	613
48e44ce0	614	ret = iio_channel_read(chan, val, val2, IIO_CHAN_INFO_SCALE);
e27d75d7 JC	615	err_unlock:
	616	mutex_unlock(&chan->indio_dev->info_exist_lock);
	617
	618	return ret;
	619	}
314be14b	620	EXPORT_SYMBOL_GPL(iio_read_channel_scale);
e27d75d7	621
314be14b	622	int iio_get_channel_type(struct iio_channel chan, enum iio_chan_type type)
e27d75d7 JC	623	{
	624	int ret = 0;
	625	/* Need to verify underlying driver has not gone away */
	626
	627	mutex_lock(&chan->indio_dev->info_exist_lock);
	628	if (chan->indio_dev->info == NULL) {
	629	ret = -ENODEV;
	630	goto err_unlock;
	631	}
	632
	633	*type = chan->channel->type;
	634	err_unlock:
	635	mutex_unlock(&chan->indio_dev->info_exist_lock);
	636
	637	return ret;
	638	}
314be14b	639	EXPORT_SYMBOL_GPL(iio_get_channel_type);
f9380e71 DES	640
	641	static int iio_channel_write(struct iio_channel *chan, int val, int val2,
	642	enum iio_chan_info_enum info)
	643	{
	644	return chan->indio_dev->info->write_raw(chan->indio_dev,
	645	chan->channel, val, val2, info);
	646	}
	647
	648	int iio_write_channel_raw(struct iio_channel *chan, int val)
	649	{
	650	int ret;
	651
	652	mutex_lock(&chan->indio_dev->info_exist_lock);
	653	if (chan->indio_dev->info == NULL) {
	654	ret = -ENODEV;
	655	goto err_unlock;
	656	}
	657
	658	ret = iio_channel_write(chan, val, 0, IIO_CHAN_INFO_RAW);
	659	err_unlock:
	660	mutex_unlock(&chan->indio_dev->info_exist_lock);
	661
	662	return ret;
	663	}
	664	EXPORT_SYMBOL_GPL(iio_write_channel_raw);