linux/drivers/iio/inkern.c
Srinivas Pandruvada 9fbfb4b37e IIO: core: Introduce read_raw_multi
This callback is introduced to overcome some limitations of existing
read_raw callback. The functionality of both existing read_raw and
read_raw_multi is similar, both are used to request values from the
device. The current read_raw callback allows only two return values.
The new read_raw_multi allows returning multiple values. Instead of
passing just address of val and val2, it passes length and pointer
to values. Depending on the type and length of passed buffer, iio
client drivers can return multiple values.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2014-04-29 22:05:32 +01:00

609 lines
14 KiB
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;
int vals[INDIO_MAX_RAW_ELEMENTS];
int ret;
int val_len = 2;
if (val2 == NULL)
val2 = &unused;
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);