linux/drivers/iio/inkern.c

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/* 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 = kmalloc(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);
return channel;
}
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, 0);
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);