linux/drivers/iio/industrialio-buffer.c

1110 lines
28 KiB
C
Raw Normal View History

/* 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/sched.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",
};
static bool iio_buffer_is_active(struct iio_buffer *buf)
{
return !list_empty(&buf->buffer_list);
}
static bool iio_buffer_data_available(struct iio_buffer *buf)
{
return buf->access->data_available(buf);
}
/**
* 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;
int ret;
if (!indio_dev->info)
return -ENODEV;
if (!rb || !rb->access->read_first_n)
return -EINVAL;
do {
if (!iio_buffer_data_available(rb)) {
if (filp->f_flags & O_NONBLOCK)
return -EAGAIN;
ret = wait_event_interruptible(rb->pollq,
iio_buffer_data_available(rb) ||
indio_dev->info == NULL);
if (ret)
return ret;
if (indio_dev->info == NULL)
return -ENODEV;
}
ret = rb->access->read_first_n(rb, n, buf);
if (ret == 0 && (filp->f_flags & O_NONBLOCK))
ret = -EAGAIN;
} while (ret == 0);
return ret;
}
/**
* 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;
if (!indio_dev->info)
return -ENODEV;
poll_wait(filp, &rb->pollq, wait);
if (iio_buffer_data_available(rb))
return POLLIN | POLLRDNORM;
/* need a way of knowing if there may be enough data... */
return 0;
}
/**
* iio_buffer_wakeup_poll - Wakes up the buffer waitqueue
* @indio_dev: The IIO device
*
* Wakes up the event waitqueue used for poll(). Should usually
* be called when the device is unregistered.
*/
void iio_buffer_wakeup_poll(struct iio_dev *indio_dev)
{
if (!indio_dev->buffer)
return;
wake_up(&indio_dev->buffer->pollq);
}
void iio_buffer_init(struct iio_buffer *buffer)
{
INIT_LIST_HEAD(&buffer->demux_list);
INIT_LIST_HEAD(&buffer->buffer_list);
init_waitqueue_head(&buffer->pollq);
kref_init(&buffer->ref);
}
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
}
if (this_attr->c->scan_type.repeat > 1)
return sprintf(buf, "%s:%c%d/%dX%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.repeat,
this_attr->c->scan_type.shift);
else
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);
/* Ensure ret is 0 or 1. */
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_is_active(indio_dev->buffer)) {
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_is_active(indio_dev->buffer)) {
ret = -EBUSY;
goto error_ret;
}
indio_dev->buffer->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,
IIO_SEPARATE,
&indio_dev->dev,
&buffer->scan_el_dev_attr_list);
if (ret)
return 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)
return 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);
if (ret)
return ret;
attrcount++;
ret = attrcount;
return ret;
}
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++) {
if (channels[i].scan_index < 0)
continue;
/* Establish necessary mask length */
if (channels[i].scan_index >
(int)indio_dev->masklength - 1)
indio_dev->masklength
= 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_free_chan_devattr_list(&buffer->scan_el_dev_attr_list);
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_free_chan_devattr_list(&indio_dev->buffer->scan_el_dev_attr_list);
}
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)
{
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
struct iio_buffer *buffer = indio_dev->buffer;
unsigned int val;
int ret;
ret = kstrtouint(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_is_active(indio_dev->buffer)) {
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_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_is_active(indio_dev->buffer));
}
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 unsigned 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);
if (ch->scan_type.repeat > 1)
length = ch->scan_type.storagebits / 8 *
ch->scan_type.repeat;
else
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);
if (ch->scan_type.repeat > 1)
length = ch->scan_type.storagebits / 8 *
ch->scan_type.repeat;
else
length = ch->scan_type.storagebits / 8;
bytes = ALIGN(bytes, length);
bytes += length;
}
return bytes;
}
static void iio_buffer_activate(struct iio_dev *indio_dev,
struct iio_buffer *buffer)
{
iio_buffer_get(buffer);
list_add(&buffer->buffer_list, &indio_dev->buffer_list);
}
static void iio_buffer_deactivate(struct iio_buffer *buffer)
{
list_del_init(&buffer->buffer_list);
iio_buffer_put(buffer);
}
void iio_disable_all_buffers(struct iio_dev *indio_dev)
{
struct iio_buffer *buffer, *_buffer;
if (list_empty(&indio_dev->buffer_list))
return;
if (indio_dev->setup_ops->predisable)
indio_dev->setup_ops->predisable(indio_dev);
list_for_each_entry_safe(buffer, _buffer,
&indio_dev->buffer_list, buffer_list)
iio_buffer_deactivate(buffer);
indio_dev->currentmode = INDIO_DIRECT_MODE;
if (indio_dev->setup_ops->postdisable)
indio_dev->setup_ops->postdisable(indio_dev);
if (indio_dev->available_scan_masks == NULL)
kfree(indio_dev->active_scan_mask);
}
static void iio_buffer_update_bytes_per_datum(struct iio_dev *indio_dev,
struct iio_buffer *buffer)
{
unsigned int bytes;
if (!buffer->access->set_bytes_per_datum)
return;
bytes = iio_compute_scan_bytes(indio_dev, buffer->scan_mask,
buffer->scan_timestamp);
buffer->access->set_bytes_per_datum(buffer, bytes);
}
static int __iio_update_buffers(struct iio_dev *indio_dev,
struct iio_buffer *insert_buffer,
struct iio_buffer *remove_buffer)
{
int ret;
int success = 0;
struct iio_buffer *buffer;
unsigned long *compound_mask;
const unsigned long *old_mask;
/* Wind down existing buffers - iff there are any */
if (!list_empty(&indio_dev->buffer_list)) {
if (indio_dev->setup_ops->predisable) {
ret = indio_dev->setup_ops->predisable(indio_dev);
if (ret)
return ret;
}
indio_dev->currentmode = INDIO_DIRECT_MODE;
if (indio_dev->setup_ops->postdisable) {
ret = indio_dev->setup_ops->postdisable(indio_dev);
if (ret)
return ret;
}
}
/* Keep a copy of current setup to allow roll back */
old_mask = indio_dev->active_scan_mask;
if (!indio_dev->available_scan_masks)
indio_dev->active_scan_mask = NULL;
if (remove_buffer)
iio_buffer_deactivate(remove_buffer);
if (insert_buffer)
iio_buffer_activate(indio_dev, insert_buffer);
/* If no buffers in list, we are done */
if (list_empty(&indio_dev->buffer_list)) {
indio_dev->currentmode = INDIO_DIRECT_MODE;
if (indio_dev->available_scan_masks == NULL)
kfree(old_mask);
return 0;
}
/* What scan mask do we actually have? */
compound_mask = kcalloc(BITS_TO_LONGS(indio_dev->masklength),
sizeof(long), GFP_KERNEL);
if (compound_mask == NULL) {
if (indio_dev->available_scan_masks == NULL)
kfree(old_mask);
return -ENOMEM;
}
indio_dev->scan_timestamp = 0;
list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) {
bitmap_or(compound_mask, compound_mask, buffer->scan_mask,
indio_dev->masklength);
indio_dev->scan_timestamp |= buffer->scan_timestamp;
}
if (indio_dev->available_scan_masks) {
indio_dev->active_scan_mask =
iio_scan_mask_match(indio_dev->available_scan_masks,
indio_dev->masklength,
compound_mask);
if (indio_dev->active_scan_mask == NULL) {
/*
* Roll back.
* Note can only occur when adding a buffer.
*/
iio_buffer_deactivate(insert_buffer);
if (old_mask) {
indio_dev->active_scan_mask = old_mask;
success = -EINVAL;
}
else {
kfree(compound_mask);
ret = -EINVAL;
return ret;
}
}
} else {
indio_dev->active_scan_mask = compound_mask;
}
iio_update_demux(indio_dev);
/* Wind up again */
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 (%d)\n", ret);
goto error_remove_inserted;
}
}
indio_dev->scan_bytes =
iio_compute_scan_bytes(indio_dev,
indio_dev->active_scan_mask,
indio_dev->scan_timestamp);
list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) {
iio_buffer_update_bytes_per_datum(indio_dev, buffer);
if (buffer->access->request_update) {
ret = buffer->access->request_update(buffer);
if (ret) {
printk(KERN_INFO
"Buffer not started: buffer parameter update failed (%d)\n", ret);
goto error_run_postdisable;
}
}
}
if (indio_dev->info->update_scan_mode) {
ret = indio_dev->info
->update_scan_mode(indio_dev,
indio_dev->active_scan_mask);
if (ret < 0) {
printk(KERN_INFO "Buffer not started: update scan mode failed (%d)\n", ret);
goto error_run_postdisable;
}
}
/* 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;
/* Can only occur on first buffer */
goto error_run_postdisable;
}
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_run_postdisable;
}
if (indio_dev->setup_ops->postenable) {
ret = indio_dev->setup_ops->postenable(indio_dev);
if (ret) {
printk(KERN_INFO
"Buffer not started: postenable failed (%d)\n", ret);
indio_dev->currentmode = INDIO_DIRECT_MODE;
if (indio_dev->setup_ops->postdisable)
indio_dev->setup_ops->postdisable(indio_dev);
goto error_disable_all_buffers;
}
}
if (indio_dev->available_scan_masks)
kfree(compound_mask);
else
kfree(old_mask);
return success;
error_disable_all_buffers:
indio_dev->currentmode = INDIO_DIRECT_MODE;
error_run_postdisable:
if (indio_dev->setup_ops->postdisable)
indio_dev->setup_ops->postdisable(indio_dev);
error_remove_inserted:
if (insert_buffer)
iio_buffer_deactivate(insert_buffer);
indio_dev->active_scan_mask = old_mask;
kfree(compound_mask);
return ret;
}
int iio_update_buffers(struct iio_dev *indio_dev,
struct iio_buffer *insert_buffer,
struct iio_buffer *remove_buffer)
{
int ret;
if (insert_buffer == remove_buffer)
return 0;
mutex_lock(&indio_dev->info_exist_lock);
mutex_lock(&indio_dev->mlock);
if (insert_buffer && iio_buffer_is_active(insert_buffer))
insert_buffer = NULL;
if (remove_buffer && !iio_buffer_is_active(remove_buffer))
remove_buffer = NULL;
if (!insert_buffer && !remove_buffer) {
ret = 0;
goto out_unlock;
}
if (indio_dev->info == NULL) {
ret = -ENODEV;
goto out_unlock;
}
ret = __iio_update_buffers(indio_dev, insert_buffer, remove_buffer);
out_unlock:
mutex_unlock(&indio_dev->mlock);
mutex_unlock(&indio_dev->info_exist_lock);
return ret;
}
EXPORT_SYMBOL_GPL(iio_update_buffers);
ssize_t iio_buffer_store_enable(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t len)
{
int ret;
bool requested_state;
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
bool inlist;
ret = strtobool(buf, &requested_state);
if (ret < 0)
return ret;
mutex_lock(&indio_dev->mlock);
/* Find out if it is in the list */
inlist = iio_buffer_is_active(indio_dev->buffer);
/* Already in desired state */
if (inlist == requested_state)
goto done;
if (requested_state)
ret = __iio_update_buffers(indio_dev,
indio_dev->buffer, NULL);
else
ret = __iio_update_buffers(indio_dev,
NULL, indio_dev->buffer);
if (ret < 0)
goto done;
done:
mutex_unlock(&indio_dev->mlock);
return (ret < 0) ? ret : len;
}
EXPORT_SYMBOL(iio_buffer_store_enable);
/**
* iio_validate_scan_mask_onehot() - Validates that exactly one channel is selected
* @indio_dev: the iio device
* @mask: scan mask to be checked
*
* Return true if exactly one bit is set in the scan mask, false otherwise. It
* can be used for devices where only one channel can be active for sampling at
* a time.
*/
bool iio_validate_scan_mask_onehot(struct iio_dev *indio_dev,
const unsigned long *mask)
{
return bitmap_weight(mask, indio_dev->masklength) == 1;
}
EXPORT_SYMBOL_GPL(iio_validate_scan_mask_onehot);
static bool iio_validate_scan_mask(struct iio_dev *indio_dev,
const unsigned long *mask)
{
if (!indio_dev->setup_ops->validate_scan_mask)
return true;
return indio_dev->setup_ops->validate_scan_mask(indio_dev, mask);
}
/**
* iio_scan_mask_set() - set particular bit in the scan mask
* @indio_dev: the iio device
* @buffer: the buffer whose scan mask we are interested in
* @bit: the bit to be set.
*
* Note that at this point we have no way of knowing what other
* buffers might request, hence this code only verifies that the
* individual buffers request is plausible.
*/
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");
goto err_invalid_mask;
}
bitmap_copy(trialmask, buffer->scan_mask, indio_dev->masklength);
set_bit(bit, trialmask);
if (!iio_validate_scan_mask(indio_dev, trialmask))
goto err_invalid_mask;
if (indio_dev->available_scan_masks) {
mask = iio_scan_mask_match(indio_dev->available_scan_masks,
indio_dev->masklength,
trialmask);
if (!mask)
goto err_invalid_mask;
}
bitmap_copy(buffer->scan_mask, trialmask, indio_dev->masklength);
kfree(trialmask);
return 0;
err_invalid_mask:
kfree(trialmask);
return -EINVAL;
}
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;
/* Ensure return value is 0 or 1. */
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 const void *iio_demux(struct iio_buffer *buffer,
const void *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;
}
static int iio_push_to_buffer(struct iio_buffer *buffer, const void *data)
{
const void *dataout = iio_demux(buffer, data);
return buffer->access->store_to(buffer, dataout);
}
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_push_to_buffers(struct iio_dev *indio_dev, const void *data)
{
int ret;
struct iio_buffer *buf;
list_for_each_entry(buf, &indio_dev->buffer_list, buffer_list) {
ret = iio_push_to_buffer(buf, data);
if (ret < 0)
return ret;
}
return 0;
}
EXPORT_SYMBOL_GPL(iio_push_to_buffers);
static int iio_buffer_add_demux(struct iio_buffer *buffer,
struct iio_demux_table **p, unsigned int in_loc, unsigned int out_loc,
unsigned int length)
{
if (*p && (*p)->from + (*p)->length == in_loc &&
(*p)->to + (*p)->length == out_loc) {
(*p)->length += length;
} else {
*p = kmalloc(sizeof(*p), GFP_KERNEL);
if (*p == NULL)
return -ENOMEM;
(*p)->from = in_loc;
(*p)->to = out_loc;
(*p)->length = length;
list_add_tail(&(*p)->l, &buffer->demux_list);
}
return 0;
}
static int iio_buffer_update_demux(struct iio_dev *indio_dev,
struct iio_buffer *buffer)
{
const struct iio_chan_spec *ch;
int ret, in_ind = -1, out_ind, length;
unsigned in_loc = 0, out_loc = 0;
struct iio_demux_table *p = NULL;
/* 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);
if (ch->scan_type.repeat > 1)
length = ch->scan_type.storagebits / 8 *
ch->scan_type.repeat;
else
length = ch->scan_type.storagebits / 8;
/* Make sure we are aligned */
in_loc = roundup(in_loc, length) + length;
}
ch = iio_find_channel_from_si(indio_dev, in_ind);
if (ch->scan_type.repeat > 1)
length = ch->scan_type.storagebits / 8 *
ch->scan_type.repeat;
else
length = ch->scan_type.storagebits / 8;
out_loc = roundup(out_loc, length);
in_loc = roundup(in_loc, length);
ret = iio_buffer_add_demux(buffer, &p, in_loc, out_loc, length);
if (ret)
goto error_clear_mux_table;
out_loc += length;
in_loc += length;
}
/* Relies on scan_timestamp being last */
if (buffer->scan_timestamp) {
ch = iio_find_channel_from_si(indio_dev,
indio_dev->scan_index_timestamp);
if (ch->scan_type.repeat > 1)
length = ch->scan_type.storagebits / 8 *
ch->scan_type.repeat;
else
length = ch->scan_type.storagebits / 8;
out_loc = roundup(out_loc, length);
in_loc = roundup(in_loc, length);
ret = iio_buffer_add_demux(buffer, &p, in_loc, out_loc, length);
if (ret)
goto error_clear_mux_table;
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;
}
int iio_update_demux(struct iio_dev *indio_dev)
{
struct iio_buffer *buffer;
int ret;
list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) {
ret = iio_buffer_update_demux(indio_dev, buffer);
if (ret < 0)
goto error_clear_mux_table;
}
return 0;
error_clear_mux_table:
list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list)
iio_buffer_demux_free(buffer);
return ret;
}
EXPORT_SYMBOL_GPL(iio_update_demux);
/**
* iio_buffer_release() - Free a buffer's resources
* @ref: Pointer to the kref embedded in the iio_buffer struct
*
* This function is called when the last reference to the buffer has been
* dropped. It will typically free all resources allocated by the buffer. Do not
* call this function manually, always use iio_buffer_put() when done using a
* buffer.
*/
static void iio_buffer_release(struct kref *ref)
{
struct iio_buffer *buffer = container_of(ref, struct iio_buffer, ref);
buffer->access->release(buffer);
}
/**
* iio_buffer_get() - Grab a reference to the buffer
* @buffer: The buffer to grab a reference for, may be NULL
*
* Returns the pointer to the buffer that was passed into the function.
*/
struct iio_buffer *iio_buffer_get(struct iio_buffer *buffer)
{
if (buffer)
kref_get(&buffer->ref);
return buffer;
}
EXPORT_SYMBOL_GPL(iio_buffer_get);
/**
* iio_buffer_put() - Release the reference to the buffer
* @buffer: The buffer to release the reference for, may be NULL
*/
void iio_buffer_put(struct iio_buffer *buffer)
{
if (buffer)
kref_put(&buffer->ref, iio_buffer_release);
}
EXPORT_SYMBOL_GPL(iio_buffer_put);