linux/drivers/iio/industrialio-buffer.c

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/* The industrial I/O core
*
* Copyright (c) 2008 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.
*
* Handling of buffer allocation / resizing.
*
*
* Things to look at here.
* - Better memory allocation techniques?
* - Alternative access techniques?
*/
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/device.h>
#include <linux/fs.h>
#include <linux/cdev.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 08:04:11 +00:00
#include <linux/slab.h>
#include <linux/poll.h>
#include <linux/iio/iio.h>
#include "iio_core.h"
#include <linux/iio/sysfs.h>
#include <linux/iio/buffer.h>
static const char * const iio_endian_prefix[] = {
[IIO_BE] = "be",
[IIO_LE] = "le",
};
/**
* iio_buffer_read_first_n_outer() - chrdev read for buffer access
*
* This function relies on all buffer implementations having an
* iio_buffer as their first element.
**/
ssize_t iio_buffer_read_first_n_outer(struct file *filp, char __user *buf,
size_t n, loff_t *f_ps)
{
struct iio_dev *indio_dev = filp->private_data;
struct iio_buffer *rb = indio_dev->buffer;
if (!rb || !rb->access->read_first_n)
return -EINVAL;
return rb->access->read_first_n(rb, n, buf);
}
/**
* iio_buffer_poll() - poll the buffer to find out if it has data
*/
unsigned int iio_buffer_poll(struct file *filp,
struct poll_table_struct *wait)
{
struct iio_dev *indio_dev = filp->private_data;
struct iio_buffer *rb = indio_dev->buffer;
poll_wait(filp, &rb->pollq, wait);
if (rb->stufftoread)
return POLLIN | POLLRDNORM;
/* need a way of knowing if there may be enough data... */
return 0;
}
void iio_buffer_init(struct iio_buffer *buffer)
{
INIT_LIST_HEAD(&buffer->demux_list);
init_waitqueue_head(&buffer->pollq);
}
EXPORT_SYMBOL(iio_buffer_init);
static ssize_t iio_show_scan_index(struct device *dev,
struct device_attribute *attr,
char *buf)
{
return sprintf(buf, "%u\n", to_iio_dev_attr(attr)->c->scan_index);
}
static ssize_t iio_show_fixed_type(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
u8 type = this_attr->c->scan_type.endianness;
if (type == IIO_CPU) {
#ifdef __LITTLE_ENDIAN
type = IIO_LE;
#else
type = IIO_BE;
#endif
}
return sprintf(buf, "%s:%c%d/%d>>%u\n",
iio_endian_prefix[type],
this_attr->c->scan_type.sign,
this_attr->c->scan_type.realbits,
this_attr->c->scan_type.storagebits,
this_attr->c->scan_type.shift);
}
static ssize_t iio_scan_el_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
int ret;
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
ret = test_bit(to_iio_dev_attr(attr)->address,
indio_dev->buffer->scan_mask);
return sprintf(buf, "%d\n", ret);
}
static int iio_scan_mask_clear(struct iio_buffer *buffer, int bit)
{
clear_bit(bit, buffer->scan_mask);
return 0;
}
static ssize_t iio_scan_el_store(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t len)
{
int ret;
bool state;
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
struct iio_buffer *buffer = indio_dev->buffer;
struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
ret = strtobool(buf, &state);
if (ret < 0)
return ret;
mutex_lock(&indio_dev->mlock);
if (iio_buffer_enabled(indio_dev)) {
ret = -EBUSY;
goto error_ret;
}
ret = iio_scan_mask_query(indio_dev, buffer, this_attr->address);
if (ret < 0)
goto error_ret;
if (!state && ret) {
ret = iio_scan_mask_clear(buffer, this_attr->address);
if (ret)
goto error_ret;
} else if (state && !ret) {
ret = iio_scan_mask_set(indio_dev, buffer, this_attr->address);
if (ret)
goto error_ret;
}
error_ret:
mutex_unlock(&indio_dev->mlock);
return ret < 0 ? ret : len;
}
static ssize_t iio_scan_el_ts_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
return sprintf(buf, "%d\n", indio_dev->buffer->scan_timestamp);
}
static ssize_t iio_scan_el_ts_store(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t len)
{
int ret;
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
bool state;
ret = strtobool(buf, &state);
if (ret < 0)
return ret;
mutex_lock(&indio_dev->mlock);
if (iio_buffer_enabled(indio_dev)) {
ret = -EBUSY;
goto error_ret;
}
indio_dev->buffer->scan_timestamp = state;
indio_dev->scan_timestamp = state;
error_ret:
mutex_unlock(&indio_dev->mlock);
return ret ? ret : len;
}
static int iio_buffer_add_channel_sysfs(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan)
{
int ret, attrcount = 0;
struct iio_buffer *buffer = indio_dev->buffer;
ret = __iio_add_chan_devattr("index",
chan,
&iio_show_scan_index,
NULL,
0,
0,
&indio_dev->dev,
&buffer->scan_el_dev_attr_list);
if (ret)
goto error_ret;
attrcount++;
ret = __iio_add_chan_devattr("type",
chan,
&iio_show_fixed_type,
NULL,
0,
0,
&indio_dev->dev,
&buffer->scan_el_dev_attr_list);
if (ret)
goto error_ret;
attrcount++;
if (chan->type != IIO_TIMESTAMP)
ret = __iio_add_chan_devattr("en",
chan,
&iio_scan_el_show,
&iio_scan_el_store,
chan->scan_index,
0,
&indio_dev->dev,
&buffer->scan_el_dev_attr_list);
else
ret = __iio_add_chan_devattr("en",
chan,
&iio_scan_el_ts_show,
&iio_scan_el_ts_store,
chan->scan_index,
0,
&indio_dev->dev,
&buffer->scan_el_dev_attr_list);
attrcount++;
ret = attrcount;
error_ret:
return ret;
}
static void iio_buffer_remove_and_free_scan_dev_attr(struct iio_dev *indio_dev,
struct iio_dev_attr *p)
{
kfree(p->dev_attr.attr.name);
kfree(p);
}
static void __iio_buffer_attr_cleanup(struct iio_dev *indio_dev)
{
struct iio_dev_attr *p, *n;
struct iio_buffer *buffer = indio_dev->buffer;
list_for_each_entry_safe(p, n,
&buffer->scan_el_dev_attr_list, l)
iio_buffer_remove_and_free_scan_dev_attr(indio_dev, p);
}
static const char * const iio_scan_elements_group_name = "scan_elements";
int iio_buffer_register(struct iio_dev *indio_dev,
const struct iio_chan_spec *channels,
int num_channels)
{
struct iio_dev_attr *p;
struct attribute **attr;
struct iio_buffer *buffer = indio_dev->buffer;
int ret, i, attrn, attrcount, attrcount_orig = 0;
if (buffer->attrs)
indio_dev->groups[indio_dev->groupcounter++] = buffer->attrs;
if (buffer->scan_el_attrs != NULL) {
attr = buffer->scan_el_attrs->attrs;
while (*attr++ != NULL)
attrcount_orig++;
}
attrcount = attrcount_orig;
INIT_LIST_HEAD(&buffer->scan_el_dev_attr_list);
if (channels) {
/* new magic */
for (i = 0; i < num_channels; i++) {
/* Establish necessary mask length */
if (channels[i].scan_index >
(int)indio_dev->masklength - 1)
indio_dev->masklength
= indio_dev->channels[i].scan_index + 1;
ret = iio_buffer_add_channel_sysfs(indio_dev,
&channels[i]);
if (ret < 0)
goto error_cleanup_dynamic;
attrcount += ret;
if (channels[i].type == IIO_TIMESTAMP)
indio_dev->scan_index_timestamp =
channels[i].scan_index;
}
if (indio_dev->masklength && buffer->scan_mask == NULL) {
buffer->scan_mask = kcalloc(BITS_TO_LONGS(indio_dev->masklength),
sizeof(*buffer->scan_mask),
GFP_KERNEL);
if (buffer->scan_mask == NULL) {
ret = -ENOMEM;
goto error_cleanup_dynamic;
}
}
}
buffer->scan_el_group.name = iio_scan_elements_group_name;
buffer->scan_el_group.attrs = kcalloc(attrcount + 1,
sizeof(buffer->scan_el_group.attrs[0]),
GFP_KERNEL);
if (buffer->scan_el_group.attrs == NULL) {
ret = -ENOMEM;
goto error_free_scan_mask;
}
if (buffer->scan_el_attrs)
memcpy(buffer->scan_el_group.attrs, buffer->scan_el_attrs,
sizeof(buffer->scan_el_group.attrs[0])*attrcount_orig);
attrn = attrcount_orig;
list_for_each_entry(p, &buffer->scan_el_dev_attr_list, l)
buffer->scan_el_group.attrs[attrn++] = &p->dev_attr.attr;
indio_dev->groups[indio_dev->groupcounter++] = &buffer->scan_el_group;
return 0;
error_free_scan_mask:
kfree(buffer->scan_mask);
error_cleanup_dynamic:
__iio_buffer_attr_cleanup(indio_dev);
return ret;
}
EXPORT_SYMBOL(iio_buffer_register);
void iio_buffer_unregister(struct iio_dev *indio_dev)
{
kfree(indio_dev->buffer->scan_mask);
kfree(indio_dev->buffer->scan_el_group.attrs);
__iio_buffer_attr_cleanup(indio_dev);
}
EXPORT_SYMBOL(iio_buffer_unregister);
ssize_t iio_buffer_read_length(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
struct iio_buffer *buffer = indio_dev->buffer;
if (buffer->access->get_length)
return sprintf(buf, "%d\n",
buffer->access->get_length(buffer));
return 0;
}
EXPORT_SYMBOL(iio_buffer_read_length);
ssize_t iio_buffer_write_length(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t len)
{
int ret;
ulong val;
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
struct iio_buffer *buffer = indio_dev->buffer;
ret = strict_strtoul(buf, 10, &val);
if (ret)
return ret;
if (buffer->access->get_length)
if (val == buffer->access->get_length(buffer))
return len;
mutex_lock(&indio_dev->mlock);
if (iio_buffer_enabled(indio_dev)) {
ret = -EBUSY;
} else {
if (buffer->access->set_length)
buffer->access->set_length(buffer, val);
ret = 0;
}
mutex_unlock(&indio_dev->mlock);
return ret ? ret : len;
}
EXPORT_SYMBOL(iio_buffer_write_length);
ssize_t iio_buffer_store_enable(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t len)
{
int ret;
bool requested_state, current_state;
int previous_mode;
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
struct iio_buffer *buffer = indio_dev->buffer;
mutex_lock(&indio_dev->mlock);
previous_mode = indio_dev->currentmode;
requested_state = !(buf[0] == '0');
current_state = iio_buffer_enabled(indio_dev);
if (current_state == requested_state) {
printk(KERN_INFO "iio-buffer, current state requested again\n");
goto done;
}
if (requested_state) {
if (indio_dev->setup_ops->preenable) {
ret = indio_dev->setup_ops->preenable(indio_dev);
if (ret) {
printk(KERN_ERR
"Buffer not started:"
"buffer preenable failed\n");
goto error_ret;
}
}
if (buffer->access->request_update) {
ret = buffer->access->request_update(buffer);
if (ret) {
printk(KERN_INFO
"Buffer not started:"
"buffer parameter update failed\n");
goto error_ret;
}
}
/* Definitely possible for devices to support both of these.*/
if (indio_dev->modes & INDIO_BUFFER_TRIGGERED) {
if (!indio_dev->trig) {
printk(KERN_INFO
"Buffer not started: no trigger\n");
ret = -EINVAL;
goto error_ret;
}
indio_dev->currentmode = INDIO_BUFFER_TRIGGERED;
} else if (indio_dev->modes & INDIO_BUFFER_HARDWARE)
indio_dev->currentmode = INDIO_BUFFER_HARDWARE;
else { /* should never be reached */
ret = -EINVAL;
goto error_ret;
}
if (indio_dev->setup_ops->postenable) {
ret = indio_dev->setup_ops->postenable(indio_dev);
if (ret) {
printk(KERN_INFO
"Buffer not started:"
"postenable failed\n");
indio_dev->currentmode = previous_mode;
if (indio_dev->setup_ops->postdisable)
indio_dev->setup_ops->
postdisable(indio_dev);
goto error_ret;
}
}
} else {
if (indio_dev->setup_ops->predisable) {
ret = indio_dev->setup_ops->predisable(indio_dev);
if (ret)
goto error_ret;
}
indio_dev->currentmode = INDIO_DIRECT_MODE;
if (indio_dev->setup_ops->postdisable) {
ret = indio_dev->setup_ops->postdisable(indio_dev);
if (ret)
goto error_ret;
}
}
done:
mutex_unlock(&indio_dev->mlock);
return len;
error_ret:
mutex_unlock(&indio_dev->mlock);
return ret;
}
EXPORT_SYMBOL(iio_buffer_store_enable);
ssize_t iio_buffer_show_enable(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
return sprintf(buf, "%d\n", iio_buffer_enabled(indio_dev));
}
EXPORT_SYMBOL(iio_buffer_show_enable);
/* note NULL used as error indicator as it doesn't make sense. */
static const unsigned long *iio_scan_mask_match(const unsigned long *av_masks,
unsigned int masklength,
const unsigned long *mask)
{
if (bitmap_empty(mask, masklength))
return NULL;
while (*av_masks) {
if (bitmap_subset(mask, av_masks, masklength))
return av_masks;
av_masks += BITS_TO_LONGS(masklength);
}
return NULL;
}
static int iio_compute_scan_bytes(struct iio_dev *indio_dev, const long *mask,
bool timestamp)
{
const struct iio_chan_spec *ch;
unsigned bytes = 0;
int length, i;
/* How much space will the demuxed element take? */
for_each_set_bit(i, mask,
indio_dev->masklength) {
ch = iio_find_channel_from_si(indio_dev, i);
length = ch->scan_type.storagebits / 8;
bytes = ALIGN(bytes, length);
bytes += length;
}
if (timestamp) {
ch = iio_find_channel_from_si(indio_dev,
indio_dev->scan_index_timestamp);
length = ch->scan_type.storagebits / 8;
bytes = ALIGN(bytes, length);
bytes += length;
}
return bytes;
}
int iio_sw_buffer_preenable(struct iio_dev *indio_dev)
{
struct iio_buffer *buffer = indio_dev->buffer;
dev_dbg(&indio_dev->dev, "%s\n", __func__);
/* How much space will the demuxed element take? */
indio_dev->scan_bytes =
iio_compute_scan_bytes(indio_dev, buffer->scan_mask,
buffer->scan_timestamp);
buffer->access->set_bytes_per_datum(buffer, indio_dev->scan_bytes);
/* What scan mask do we actually have ?*/
if (indio_dev->available_scan_masks)
indio_dev->active_scan_mask =
iio_scan_mask_match(indio_dev->available_scan_masks,
indio_dev->masklength,
buffer->scan_mask);
else
indio_dev->active_scan_mask = buffer->scan_mask;
iio_update_demux(indio_dev);
if (indio_dev->info->update_scan_mode)
return indio_dev->info
->update_scan_mode(indio_dev,
indio_dev->active_scan_mask);
return 0;
}
EXPORT_SYMBOL(iio_sw_buffer_preenable);
/**
* iio_scan_mask_set() - set particular bit in the scan mask
* @buffer: the buffer whose scan mask we are interested in
* @bit: the bit to be set.
**/
int iio_scan_mask_set(struct iio_dev *indio_dev,
struct iio_buffer *buffer, int bit)
{
const unsigned long *mask;
unsigned long *trialmask;
trialmask = kmalloc(sizeof(*trialmask)*
BITS_TO_LONGS(indio_dev->masklength),
GFP_KERNEL);
if (trialmask == NULL)
return -ENOMEM;
if (!indio_dev->masklength) {
WARN_ON("trying to set scanmask prior to registering buffer\n");
kfree(trialmask);
return -EINVAL;
}
bitmap_copy(trialmask, buffer->scan_mask, indio_dev->masklength);
set_bit(bit, trialmask);
if (indio_dev->available_scan_masks) {
mask = iio_scan_mask_match(indio_dev->available_scan_masks,
indio_dev->masklength,
trialmask);
if (!mask) {
kfree(trialmask);
return -EINVAL;
}
}
bitmap_copy(buffer->scan_mask, trialmask, indio_dev->masklength);
kfree(trialmask);
return 0;
};
EXPORT_SYMBOL_GPL(iio_scan_mask_set);
int iio_scan_mask_query(struct iio_dev *indio_dev,
struct iio_buffer *buffer, int bit)
{
if (bit > indio_dev->masklength)
return -EINVAL;
if (!buffer->scan_mask)
return 0;
return test_bit(bit, buffer->scan_mask);
};
EXPORT_SYMBOL_GPL(iio_scan_mask_query);
/**
* struct iio_demux_table() - table describing demux memcpy ops
* @from: index to copy from
* @to: index to copy to
* @length: how many bytes to copy
* @l: list head used for management
*/
struct iio_demux_table {
unsigned from;
unsigned to;
unsigned length;
struct list_head l;
};
static unsigned char *iio_demux(struct iio_buffer *buffer,
unsigned char *datain)
{
struct iio_demux_table *t;
if (list_empty(&buffer->demux_list))
return datain;
list_for_each_entry(t, &buffer->demux_list, l)
memcpy(buffer->demux_bounce + t->to,
datain + t->from, t->length);
return buffer->demux_bounce;
}
int iio_push_to_buffer(struct iio_buffer *buffer, unsigned char *data,
s64 timestamp)
{
unsigned char *dataout = iio_demux(buffer, data);
return buffer->access->store_to(buffer, dataout, timestamp);
}
EXPORT_SYMBOL_GPL(iio_push_to_buffer);
static void iio_buffer_demux_free(struct iio_buffer *buffer)
{
struct iio_demux_table *p, *q;
list_for_each_entry_safe(p, q, &buffer->demux_list, l) {
list_del(&p->l);
kfree(p);
}
}
int iio_update_demux(struct iio_dev *indio_dev)
{
const struct iio_chan_spec *ch;
struct iio_buffer *buffer = indio_dev->buffer;
int ret, in_ind = -1, out_ind, length;
unsigned in_loc = 0, out_loc = 0;
struct iio_demux_table *p;
/* Clear out any old demux */
iio_buffer_demux_free(buffer);
kfree(buffer->demux_bounce);
buffer->demux_bounce = NULL;
/* First work out which scan mode we will actually have */
if (bitmap_equal(indio_dev->active_scan_mask,
buffer->scan_mask,
indio_dev->masklength))
return 0;
/* Now we have the two masks, work from least sig and build up sizes */
for_each_set_bit(out_ind,
indio_dev->active_scan_mask,
indio_dev->masklength) {
in_ind = find_next_bit(indio_dev->active_scan_mask,
indio_dev->masklength,
in_ind + 1);
while (in_ind != out_ind) {
in_ind = find_next_bit(indio_dev->active_scan_mask,
indio_dev->masklength,
in_ind + 1);
ch = iio_find_channel_from_si(indio_dev, in_ind);
length = ch->scan_type.storagebits/8;
/* Make sure we are aligned */
in_loc += length;
if (in_loc % length)
in_loc += length - in_loc % length;
}
p = kmalloc(sizeof(*p), GFP_KERNEL);
if (p == NULL) {
ret = -ENOMEM;
goto error_clear_mux_table;
}
ch = iio_find_channel_from_si(indio_dev, in_ind);
length = ch->scan_type.storagebits/8;
if (out_loc % length)
out_loc += length - out_loc % length;
if (in_loc % length)
in_loc += length - in_loc % length;
p->from = in_loc;
p->to = out_loc;
p->length = length;
list_add_tail(&p->l, &buffer->demux_list);
out_loc += length;
in_loc += length;
}
/* Relies on scan_timestamp being last */
if (buffer->scan_timestamp) {
p = kmalloc(sizeof(*p), GFP_KERNEL);
if (p == NULL) {
ret = -ENOMEM;
goto error_clear_mux_table;
}
ch = iio_find_channel_from_si(indio_dev,
indio_dev->scan_index_timestamp);
length = ch->scan_type.storagebits/8;
if (out_loc % length)
out_loc += length - out_loc % length;
if (in_loc % length)
in_loc += length - in_loc % length;
p->from = in_loc;
p->to = out_loc;
p->length = length;
list_add_tail(&p->l, &buffer->demux_list);
out_loc += length;
in_loc += length;
}
buffer->demux_bounce = kzalloc(out_loc, GFP_KERNEL);
if (buffer->demux_bounce == NULL) {
ret = -ENOMEM;
goto error_clear_mux_table;
}
return 0;
error_clear_mux_table:
iio_buffer_demux_free(buffer);
return ret;
}
EXPORT_SYMBOL_GPL(iio_update_demux);