- 根目录:
- 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;
}
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;
index = iiospec.args_count ? iiospec.args[0] : 0;
if (index >= indio_dev->num_channels) {
err = -EINVAL;
goto err_put;
}
channel->channel = &indio_dev->channels[index];
return 0;
err_put:
iio_device_put(indio_dev);
return err;
}
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))
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 chan;
}
/*
* 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))
break;
}
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;
if (val2 == NULL)
val2 = &unused;
return chan->indio_dev->info->read_raw(chan->indio_dev, chan->channel,
val, val2, info);
}
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);
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);