[mirror_ubuntu-artful-kernel.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/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);


/* Assumes the exact same array (e.g. memory locations)
 * used at unregistration as used at registration rather than
 * more complex checking of contents.
 */
int iio_map_array_unregister(struct iio_dev *indio_dev,
			     struct iio_map *maps)
{
	int i = 0, ret = 0;
	bool found_it;
	struct iio_map_internal *mapi;

	if (maps == NULL)
		return 0;

	mutex_lock(&iio_map_list_lock);
	while (maps[i].consumer_dev_name != NULL) {
		found_it = false;
		list_for_each_entry(mapi, &iio_map_list, l)
			if (&maps[i] == mapi->map) {
				list_del(&mapi->l);
				kfree(mapi);
				found_it = true;
				break;
			}
		if (found_it == false) {
			ret = -ENODEV;
			goto error_ret;
		}
		i++;
	}
error_ret:
	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;
}


struct iio_channel *iio_channel_get(const char *name, const char *channel_name)
{
	struct iio_map_internal *c_i = NULL, *c = NULL;
	struct iio_channel *channel;

	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)
		return ERR_PTR(-ENOMEM);

	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)
			goto error_no_chan;
	}

	return channel;

error_no_chan:
	iio_device_put(c->indio_dev);
	kfree(channel);
	return ERR_PTR(-EINVAL);
}
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(const char *name)
{
	struct iio_channel *chans;
	struct iio_map_internal *c = NULL;
	int nummaps = 0;
	int mapind = 0;
	int i, ret;

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

	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].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);

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

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

	ret = chan->indio_dev->info->read_raw(chan->indio_dev,
					      chan->channel,
					      val, &val2,
					      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_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 = chan->indio_dev->info->read_raw(chan->indio_dev,
					      chan->channel,
					      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);
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>
	13
06458e27	14	#include <linux/iio/iio.h>
e27d75d7	15	#include "iio_core.h"
06458e27 JC	16	#include <linux/iio/machine.h>
	17	#include <linux/iio/driver.h>
	18	#include <linux/iio/consumer.h>
e27d75d7 JC	19
	20	struct iio_map_internal {
	21	struct iio_dev *indio_dev;
	22	struct iio_map *map;
	23	struct list_head l;
	24	};
	25
	26	static LIST_HEAD(iio_map_list);
	27	static DEFINE_MUTEX(iio_map_list_lock);
	28
	29	int iio_map_array_register(struct iio_dev indio_dev, struct iio_map maps)
	30	{
	31	int i = 0, ret = 0;
	32	struct iio_map_internal *mapi;
	33
	34	if (maps == NULL)
	35	return 0;
	36
	37	mutex_lock(&iio_map_list_lock);
	38	while (maps[i].consumer_dev_name != NULL) {
	39	mapi = kzalloc(sizeof(*mapi), GFP_KERNEL);
	40	if (mapi == NULL) {
	41	ret = -ENOMEM;
	42	goto error_ret;
	43	}
	44	mapi->map = &maps[i];
	45	mapi->indio_dev = indio_dev;
	46	list_add(&mapi->l, &iio_map_list);
	47	i++;
	48	}
	49	error_ret:
	50	mutex_unlock(&iio_map_list_lock);
	51
	52	return ret;
	53	}
	54	EXPORT_SYMBOL_GPL(iio_map_array_register);
	55
	56
	57	/* Assumes the exact same array (e.g. memory locations)
	58	* used at unregistration as used at registration rather than
	59	* more complex checking of contents.
	60	*/
	61	int iio_map_array_unregister(struct iio_dev *indio_dev,
	62	struct iio_map *maps)
	63	{
	64	int i = 0, ret = 0;
	65	bool found_it;
	66	struct iio_map_internal *mapi;
	67
	68	if (maps == NULL)
	69	return 0;
	70
	71	mutex_lock(&iio_map_list_lock);
	72	while (maps[i].consumer_dev_name != NULL) {
	73	found_it = false;
	74	list_for_each_entry(mapi, &iio_map_list, l)
	75	if (&maps[i] == mapi->map) {
	76	list_del(&mapi->l);
	77	kfree(mapi);
	78	found_it = true;
	79	break;
	80	}
	81	if (found_it == false) {
	82	ret = -ENODEV;
83	goto error_ret;
84	}
218f4d43	85	i++;
e27d75d7 JC	86	}
	87	error_ret:
	88	mutex_unlock(&iio_map_list_lock);
	89
	90	return ret;
	91	}
	92	EXPORT_SYMBOL_GPL(iio_map_array_unregister);
	93
	94	static const struct iio_chan_spec
314be14b	95	iio_chan_spec_from_name(const struct iio_dev indio_dev, const char *name)
e27d75d7 JC	96	{
	97	int i;
	98	const struct iio_chan_spec *chan = NULL;
	99
	100	for (i = 0; i < indio_dev->num_channels; i++)
	101	if (indio_dev->channels[i].datasheet_name &&
	102	strcmp(name, indio_dev->channels[i].datasheet_name) == 0) {
	103	chan = &indio_dev->channels[i];
	104	break;
	105	}
	106	return chan;
	107	}
	108
	109
314be14b	110	struct iio_channel iio_channel_get(const char name, const char *channel_name)
e27d75d7 JC	111	{
	112	struct iio_map_internal c_i = NULL, c = NULL;
	113	struct iio_channel *channel;
	114
	115	if (name == NULL && channel_name == NULL)
	116	return ERR_PTR(-ENODEV);
	117
	118	/* first find matching entry the channel map */
	119	mutex_lock(&iio_map_list_lock);
	120	list_for_each_entry(c_i, &iio_map_list, l) {
	121	if ((name && strcmp(name, c_i->map->consumer_dev_name) != 0) \|\|
	122	(channel_name &&
	123	strcmp(channel_name, c_i->map->consumer_channel) != 0))
	124	continue;
	125	c = c_i;
1875ffd2	126	iio_device_get(c->indio_dev);
e27d75d7 JC	127	break;
	128	}
	129	mutex_unlock(&iio_map_list_lock);
	130	if (c == NULL)
	131	return ERR_PTR(-ENODEV);
	132
2cc412b5	133	channel = kzalloc(sizeof(*channel), GFP_KERNEL);
e27d75d7 JC	134	if (channel == NULL)
	135	return ERR_PTR(-ENOMEM);
	136
	137	channel->indio_dev = c->indio_dev;
	138
b2b79ffa	139	if (c->map->adc_channel_label) {
e27d75d7 JC	140	channel->channel =
	141	iio_chan_spec_from_name(channel->indio_dev,
	142	c->map->adc_channel_label);
	143
b2b79ffa KM	144	if (channel->channel == NULL)
	145	goto error_no_chan;
	146	}
	147
e27d75d7	148	return channel;
b2b79ffa KM	149
	150	error_no_chan:
	151	iio_device_put(c->indio_dev);
	152	kfree(channel);
	153	return ERR_PTR(-EINVAL);
e27d75d7	154	}
314be14b	155	EXPORT_SYMBOL_GPL(iio_channel_get);
e27d75d7	156
314be14b	157	void iio_channel_release(struct iio_channel *channel)
e27d75d7	158	{
1875ffd2	159	iio_device_put(channel->indio_dev);
e27d75d7 JC	160	kfree(channel);
e27d75d7 JC	161	}
314be14b	162	EXPORT_SYMBOL_GPL(iio_channel_release);
e27d75d7	163
314be14b	164	struct iio_channel iio_channel_get_all(const char name)
e27d75d7 JC	165	{
	166	struct iio_channel *chans;
	167	struct iio_map_internal *c = NULL;
	168	int nummaps = 0;
	169	int mapind = 0;
	170	int i, ret;
	171
	172	if (name == NULL)
	173	return ERR_PTR(-EINVAL);
	174
	175	mutex_lock(&iio_map_list_lock);
	176	/* first count the matching maps */
	177	list_for_each_entry(c, &iio_map_list, l)
	178	if (name && strcmp(name, c->map->consumer_dev_name) != 0)
	179	continue;
	180	else
	181	nummaps++;
	182
	183	if (nummaps == 0) {
	184	ret = -ENODEV;
	185	goto error_ret;
	186	}
	187
	188	/* NULL terminated array to save passing size */
	189	chans = kzalloc(sizeof(chans)(nummaps + 1), GFP_KERNEL);
	190	if (chans == NULL) {
	191	ret = -ENOMEM;
	192	goto error_ret;
	193	}
	194
	195	/* for each map fill in the chans element */
	196	list_for_each_entry(c, &iio_map_list, l) {
	197	if (name && strcmp(name, c->map->consumer_dev_name) != 0)
	198	continue;
	199	chans[mapind].indio_dev = c->indio_dev;
	200	chans[mapind].channel =
	201	iio_chan_spec_from_name(chans[mapind].indio_dev,
	202	c->map->adc_channel_label);
	203	if (chans[mapind].channel == NULL) {
	204	ret = -EINVAL;
e27d75d7 JC	205	goto error_free_chans;
e27d75d7 JC	206	}
1875ffd2	207	iio_device_get(chans[mapind].indio_dev);
e27d75d7 JC	208	mapind++;
e27d75d7 JC	209	}
e27d75d7 JC	210	if (mapind == 0) {
	211	ret = -ENODEV;
	212	goto error_free_chans;
	213	}
e59b9afe DC	214	mutex_unlock(&iio_map_list_lock);
e59b9afe DC	215
e27d75d7 JC	216	return chans;
	217
	218	error_free_chans:
	219	for (i = 0; i < nummaps; i++)
1875ffd2	220	iio_device_put(chans[i].indio_dev);
e27d75d7 JC	221	kfree(chans);
	222	error_ret:
	223	mutex_unlock(&iio_map_list_lock);
	224
	225	return ERR_PTR(ret);
	226	}
314be14b	227	EXPORT_SYMBOL_GPL(iio_channel_get_all);
e27d75d7	228
314be14b	229	void iio_channel_release_all(struct iio_channel *channels)
e27d75d7 JC	230	{
	231	struct iio_channel *chan = &channels[0];
	232
	233	while (chan->indio_dev) {
1875ffd2	234	iio_device_put(chan->indio_dev);
e27d75d7 JC	235	chan++;
	236	}
	237	kfree(channels);
	238	}
314be14b	239	EXPORT_SYMBOL_GPL(iio_channel_release_all);
e27d75d7	240
314be14b	241	int iio_read_channel_raw(struct iio_channel chan, int val)
e27d75d7 JC	242	{
	243	int val2, ret;
	244
	245	mutex_lock(&chan->indio_dev->info_exist_lock);
	246	if (chan->indio_dev->info == NULL) {
	247	ret = -ENODEV;
	248	goto err_unlock;
	249	}
	250
d965a8bc KM	251	ret = chan->indio_dev->info->read_raw(chan->indio_dev,
	252	chan->channel,
	253	val, &val2,
	254	IIO_CHAN_INFO_RAW);
e27d75d7 JC	255	err_unlock:
	256	mutex_unlock(&chan->indio_dev->info_exist_lock);
	257
	258	return ret;
	259	}
314be14b	260	EXPORT_SYMBOL_GPL(iio_read_channel_raw);
e27d75d7	261
314be14b	262	int iio_read_channel_scale(struct iio_channel chan, int val, int *val2)
e27d75d7 JC	263	{
	264	int ret;
	265
	266	mutex_lock(&chan->indio_dev->info_exist_lock);
	267	if (chan->indio_dev->info == NULL) {
	268	ret = -ENODEV;
	269	goto err_unlock;
	270	}
	271
	272	ret = chan->indio_dev->info->read_raw(chan->indio_dev,
	273	chan->channel,
	274	val, val2,
	275	IIO_CHAN_INFO_SCALE);
	276	err_unlock:
	277	mutex_unlock(&chan->indio_dev->info_exist_lock);
	278
	279	return ret;
	280	}
314be14b	281	EXPORT_SYMBOL_GPL(iio_read_channel_scale);
e27d75d7	282
314be14b	283	int iio_get_channel_type(struct iio_channel chan, enum iio_chan_type type)
e27d75d7 JC	284	{
	285	int ret = 0;
	286	/* Need to verify underlying driver has not gone away */
	287
	288	mutex_lock(&chan->indio_dev->info_exist_lock);
	289	if (chan->indio_dev->info == NULL) {
	290	ret = -ENODEV;
	291	goto err_unlock;
	292	}
	293
	294	*type = chan->channel->type;
	295	err_unlock:
	296	mutex_unlock(&chan->indio_dev->info_exist_lock);
	297
	298	return ret;
	299	}
314be14b	300	EXPORT_SYMBOL_GPL(iio_get_channel_type);