linux/drivers/iio/industrialio-buffer.c
Nuno Sá 3da1814184 iio: buffer: make sure O_NONBLOCK is respected
For output buffers, there's no guarantee that the buffer won't be full
in the first iteration of the loop in which case we would block
independently of userspace passing O_NONBLOCK or not. Fix it by always
checking the flag before going to sleep.

While at it (and as it's a bit related), refactored the loop so that the
stop condition is 'written != n', i.e, run the loop until all data has
been copied into the IIO buffers. This makes the code a bit simpler.

Fixes: 9eeee3b0bf ("iio: Add output buffer support")
Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Link: https://lore.kernel.org/r/20230216101452.591805-3-nuno.sa@analog.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2023-02-18 14:07:58 +00:00

2008 lines
51 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/* The industrial I/O core
*
* Copyright (c) 2008 Jonathan Cameron
*
* Handling of buffer allocation / resizing.
*
* Things to look at here.
* - Better memory allocation techniques?
* - Alternative access techniques?
*/
#include <linux/anon_inodes.h>
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/device.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/cdev.h>
#include <linux/slab.h>
#include <linux/poll.h>
#include <linux/sched/signal.h>
#include <linux/iio/iio.h>
#include <linux/iio/iio-opaque.h>
#include "iio_core.h"
#include "iio_core_trigger.h"
#include <linux/iio/sysfs.h>
#include <linux/iio/buffer.h>
#include <linux/iio/buffer_impl.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 size_t iio_buffer_data_available(struct iio_buffer *buf)
{
return buf->access->data_available(buf);
}
static int iio_buffer_flush_hwfifo(struct iio_dev *indio_dev,
struct iio_buffer *buf, size_t required)
{
if (!indio_dev->info->hwfifo_flush_to_buffer)
return -ENODEV;
return indio_dev->info->hwfifo_flush_to_buffer(indio_dev, required);
}
static bool iio_buffer_ready(struct iio_dev *indio_dev, struct iio_buffer *buf,
size_t to_wait, int to_flush)
{
size_t avail;
int flushed = 0;
/* wakeup if the device was unregistered */
if (!indio_dev->info)
return true;
/* drain the buffer if it was disabled */
if (!iio_buffer_is_active(buf)) {
to_wait = min_t(size_t, to_wait, 1);
to_flush = 0;
}
avail = iio_buffer_data_available(buf);
if (avail >= to_wait) {
/* force a flush for non-blocking reads */
if (!to_wait && avail < to_flush)
iio_buffer_flush_hwfifo(indio_dev, buf,
to_flush - avail);
return true;
}
if (to_flush)
flushed = iio_buffer_flush_hwfifo(indio_dev, buf,
to_wait - avail);
if (flushed <= 0)
return false;
if (avail + flushed >= to_wait)
return true;
return false;
}
/**
* iio_buffer_read() - chrdev read for buffer access
* @filp: File structure pointer for the char device
* @buf: Destination buffer for iio buffer read
* @n: First n bytes to read
* @f_ps: Long offset provided by the user as a seek position
*
* This function relies on all buffer implementations having an
* iio_buffer as their first element.
*
* Return: negative values corresponding to error codes or ret != 0
* for ending the reading activity
**/
static ssize_t iio_buffer_read(struct file *filp, char __user *buf,
size_t n, loff_t *f_ps)
{
struct iio_dev_buffer_pair *ib = filp->private_data;
struct iio_buffer *rb = ib->buffer;
struct iio_dev *indio_dev = ib->indio_dev;
DEFINE_WAIT_FUNC(wait, woken_wake_function);
size_t datum_size;
size_t to_wait;
int ret = 0;
if (!indio_dev->info)
return -ENODEV;
if (!rb || !rb->access->read)
return -EINVAL;
if (rb->direction != IIO_BUFFER_DIRECTION_IN)
return -EPERM;
datum_size = rb->bytes_per_datum;
/*
* If datum_size is 0 there will never be anything to read from the
* buffer, so signal end of file now.
*/
if (!datum_size)
return 0;
if (filp->f_flags & O_NONBLOCK)
to_wait = 0;
else
to_wait = min_t(size_t, n / datum_size, rb->watermark);
add_wait_queue(&rb->pollq, &wait);
do {
if (!indio_dev->info) {
ret = -ENODEV;
break;
}
if (!iio_buffer_ready(indio_dev, rb, to_wait, n / datum_size)) {
if (signal_pending(current)) {
ret = -ERESTARTSYS;
break;
}
wait_woken(&wait, TASK_INTERRUPTIBLE,
MAX_SCHEDULE_TIMEOUT);
continue;
}
ret = rb->access->read(rb, n, buf);
if (ret == 0 && (filp->f_flags & O_NONBLOCK))
ret = -EAGAIN;
} while (ret == 0);
remove_wait_queue(&rb->pollq, &wait);
return ret;
}
static size_t iio_buffer_space_available(struct iio_buffer *buf)
{
if (buf->access->space_available)
return buf->access->space_available(buf);
return SIZE_MAX;
}
static ssize_t iio_buffer_write(struct file *filp, const char __user *buf,
size_t n, loff_t *f_ps)
{
struct iio_dev_buffer_pair *ib = filp->private_data;
struct iio_buffer *rb = ib->buffer;
struct iio_dev *indio_dev = ib->indio_dev;
DEFINE_WAIT_FUNC(wait, woken_wake_function);
int ret = 0;
size_t written;
if (!indio_dev->info)
return -ENODEV;
if (!rb || !rb->access->write)
return -EINVAL;
if (rb->direction != IIO_BUFFER_DIRECTION_OUT)
return -EPERM;
written = 0;
add_wait_queue(&rb->pollq, &wait);
do {
if (indio_dev->info == NULL)
return -ENODEV;
if (!iio_buffer_space_available(rb)) {
if (signal_pending(current)) {
ret = -ERESTARTSYS;
break;
}
if (filp->f_flags & O_NONBLOCK) {
if (!written)
ret = -EAGAIN;
break;
}
wait_woken(&wait, TASK_INTERRUPTIBLE,
MAX_SCHEDULE_TIMEOUT);
continue;
}
ret = rb->access->write(rb, n - written, buf + written);
if (ret < 0)
break;
written += ret;
} while (written != n);
remove_wait_queue(&rb->pollq, &wait);
return ret < 0 ? ret : written;
}
/**
* iio_buffer_poll() - poll the buffer to find out if it has data
* @filp: File structure pointer for device access
* @wait: Poll table structure pointer for which the driver adds
* a wait queue
*
* Return: (EPOLLIN | EPOLLRDNORM) if data is available for reading
* or 0 for other cases
*/
static __poll_t iio_buffer_poll(struct file *filp,
struct poll_table_struct *wait)
{
struct iio_dev_buffer_pair *ib = filp->private_data;
struct iio_buffer *rb = ib->buffer;
struct iio_dev *indio_dev = ib->indio_dev;
if (!indio_dev->info || rb == NULL)
return 0;
poll_wait(filp, &rb->pollq, wait);
switch (rb->direction) {
case IIO_BUFFER_DIRECTION_IN:
if (iio_buffer_ready(indio_dev, rb, rb->watermark, 0))
return EPOLLIN | EPOLLRDNORM;
break;
case IIO_BUFFER_DIRECTION_OUT:
if (iio_buffer_space_available(rb))
return EPOLLOUT | EPOLLWRNORM;
break;
}
return 0;
}
ssize_t iio_buffer_read_wrapper(struct file *filp, char __user *buf,
size_t n, loff_t *f_ps)
{
struct iio_dev_buffer_pair *ib = filp->private_data;
struct iio_buffer *rb = ib->buffer;
/* check if buffer was opened through new API */
if (test_bit(IIO_BUSY_BIT_POS, &rb->flags))
return -EBUSY;
return iio_buffer_read(filp, buf, n, f_ps);
}
ssize_t iio_buffer_write_wrapper(struct file *filp, const char __user *buf,
size_t n, loff_t *f_ps)
{
struct iio_dev_buffer_pair *ib = filp->private_data;
struct iio_buffer *rb = ib->buffer;
/* check if buffer was opened through new API */
if (test_bit(IIO_BUSY_BIT_POS, &rb->flags))
return -EBUSY;
return iio_buffer_write(filp, buf, n, f_ps);
}
__poll_t iio_buffer_poll_wrapper(struct file *filp,
struct poll_table_struct *wait)
{
struct iio_dev_buffer_pair *ib = filp->private_data;
struct iio_buffer *rb = ib->buffer;
/* check if buffer was opened through new API */
if (test_bit(IIO_BUSY_BIT_POS, &rb->flags))
return 0;
return iio_buffer_poll(filp, wait);
}
/**
* 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)
{
struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
struct iio_buffer *buffer;
unsigned int i;
for (i = 0; i < iio_dev_opaque->attached_buffers_cnt; i++) {
buffer = iio_dev_opaque->attached_buffers[i];
wake_up(&buffer->pollq);
}
}
int iio_pop_from_buffer(struct iio_buffer *buffer, void *data)
{
if (!buffer || !buffer->access || !buffer->access->remove_from)
return -EINVAL;
return buffer->access->remove_from(buffer, data);
}
EXPORT_SYMBOL_GPL(iio_pop_from_buffer);
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);
if (!buffer->watermark)
buffer->watermark = 1;
}
EXPORT_SYMBOL(iio_buffer_init);
void iio_device_detach_buffers(struct iio_dev *indio_dev)
{
struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
struct iio_buffer *buffer;
unsigned int i;
for (i = 0; i < iio_dev_opaque->attached_buffers_cnt; i++) {
buffer = iio_dev_opaque->attached_buffers[i];
iio_buffer_put(buffer);
}
kfree(iio_dev_opaque->attached_buffers);
}
static ssize_t iio_show_scan_index(struct device *dev,
struct device_attribute *attr,
char *buf)
{
return sysfs_emit(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 sysfs_emit(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 sysfs_emit(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_buffer *buffer = to_iio_dev_attr(attr)->buffer;
/* Ensure ret is 0 or 1. */
ret = !!test_bit(to_iio_dev_attr(attr)->address,
buffer->scan_mask);
return sysfs_emit(buf, "%d\n", ret);
}
/* 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,
bool strict)
{
if (bitmap_empty(mask, masklength))
return NULL;
while (*av_masks) {
if (strict) {
if (bitmap_equal(mask, av_masks, masklength))
return av_masks;
} else {
if (bitmap_subset(mask, av_masks, masklength))
return av_masks;
}
av_masks += BITS_TO_LONGS(masklength);
}
return NULL;
}
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.
*/
static int iio_scan_mask_set(struct iio_dev *indio_dev,
struct iio_buffer *buffer, int bit)
{
const unsigned long *mask;
unsigned long *trialmask;
if (!indio_dev->masklength) {
WARN(1, "Trying to set scanmask prior to registering buffer\n");
return -EINVAL;
}
trialmask = bitmap_alloc(indio_dev->masklength, GFP_KERNEL);
if (!trialmask)
return -ENOMEM;
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, false);
if (!mask)
goto err_invalid_mask;
}
bitmap_copy(buffer->scan_mask, trialmask, indio_dev->masklength);
bitmap_free(trialmask);
return 0;
err_invalid_mask:
bitmap_free(trialmask);
return -EINVAL;
}
static int iio_scan_mask_clear(struct iio_buffer *buffer, int bit)
{
clear_bit(bit, buffer->scan_mask);
return 0;
}
static 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);
};
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_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
struct iio_buffer *buffer = this_attr->buffer;
ret = kstrtobool(buf, &state);
if (ret < 0)
return ret;
mutex_lock(&iio_dev_opaque->mlock);
if (iio_buffer_is_active(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(&iio_dev_opaque->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_buffer *buffer = to_iio_dev_attr(attr)->buffer;
return sysfs_emit(buf, "%d\n", 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);
struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer;
bool state;
ret = kstrtobool(buf, &state);
if (ret < 0)
return ret;
mutex_lock(&iio_dev_opaque->mlock);
if (iio_buffer_is_active(buffer)) {
ret = -EBUSY;
goto error_ret;
}
buffer->scan_timestamp = state;
error_ret:
mutex_unlock(&iio_dev_opaque->mlock);
return ret ? ret : len;
}
static int iio_buffer_add_channel_sysfs(struct iio_dev *indio_dev,
struct iio_buffer *buffer,
const struct iio_chan_spec *chan)
{
int ret, attrcount = 0;
ret = __iio_add_chan_devattr("index",
chan,
&iio_show_scan_index,
NULL,
0,
IIO_SEPARATE,
&indio_dev->dev,
buffer,
&buffer->buffer_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,
&buffer->buffer_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,
&buffer->buffer_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,
&buffer->buffer_attr_list);
if (ret)
return ret;
attrcount++;
ret = attrcount;
return ret;
}
static ssize_t length_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer;
return sysfs_emit(buf, "%d\n", buffer->length);
}
static ssize_t length_store(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_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer;
unsigned int val;
int ret;
ret = kstrtouint(buf, 10, &val);
if (ret)
return ret;
if (val == buffer->length)
return len;
mutex_lock(&iio_dev_opaque->mlock);
if (iio_buffer_is_active(buffer)) {
ret = -EBUSY;
} else {
buffer->access->set_length(buffer, val);
ret = 0;
}
if (ret)
goto out;
if (buffer->length && buffer->length < buffer->watermark)
buffer->watermark = buffer->length;
out:
mutex_unlock(&iio_dev_opaque->mlock);
return ret ? ret : len;
}
static ssize_t enable_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer;
return sysfs_emit(buf, "%d\n", iio_buffer_is_active(buffer));
}
static unsigned int iio_storage_bytes_for_si(struct iio_dev *indio_dev,
unsigned int scan_index)
{
const struct iio_chan_spec *ch;
unsigned int bytes;
ch = iio_find_channel_from_si(indio_dev, scan_index);
bytes = ch->scan_type.storagebits / 8;
if (ch->scan_type.repeat > 1)
bytes *= ch->scan_type.repeat;
return bytes;
}
static unsigned int iio_storage_bytes_for_timestamp(struct iio_dev *indio_dev)
{
struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
return iio_storage_bytes_for_si(indio_dev,
iio_dev_opaque->scan_index_timestamp);
}
static int iio_compute_scan_bytes(struct iio_dev *indio_dev,
const unsigned long *mask, bool timestamp)
{
unsigned int bytes = 0;
int length, i, largest = 0;
/* How much space will the demuxed element take? */
for_each_set_bit(i, mask,
indio_dev->masklength) {
length = iio_storage_bytes_for_si(indio_dev, i);
bytes = ALIGN(bytes, length);
bytes += length;
largest = max(largest, length);
}
if (timestamp) {
length = iio_storage_bytes_for_timestamp(indio_dev);
bytes = ALIGN(bytes, length);
bytes += length;
largest = max(largest, length);
}
bytes = ALIGN(bytes, largest);
return bytes;
}
static void iio_buffer_activate(struct iio_dev *indio_dev,
struct iio_buffer *buffer)
{
struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
iio_buffer_get(buffer);
list_add(&buffer->buffer_list, &iio_dev_opaque->buffer_list);
}
static void iio_buffer_deactivate(struct iio_buffer *buffer)
{
list_del_init(&buffer->buffer_list);
wake_up_interruptible(&buffer->pollq);
iio_buffer_put(buffer);
}
static void iio_buffer_deactivate_all(struct iio_dev *indio_dev)
{
struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
struct iio_buffer *buffer, *_buffer;
list_for_each_entry_safe(buffer, _buffer,
&iio_dev_opaque->buffer_list, buffer_list)
iio_buffer_deactivate(buffer);
}
static int iio_buffer_enable(struct iio_buffer *buffer,
struct iio_dev *indio_dev)
{
if (!buffer->access->enable)
return 0;
return buffer->access->enable(buffer, indio_dev);
}
static int iio_buffer_disable(struct iio_buffer *buffer,
struct iio_dev *indio_dev)
{
if (!buffer->access->disable)
return 0;
return buffer->access->disable(buffer, indio_dev);
}
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_buffer_request_update(struct iio_dev *indio_dev,
struct iio_buffer *buffer)
{
int ret;
iio_buffer_update_bytes_per_datum(indio_dev, buffer);
if (buffer->access->request_update) {
ret = buffer->access->request_update(buffer);
if (ret) {
dev_dbg(&indio_dev->dev,
"Buffer not started: buffer parameter update failed (%d)\n",
ret);
return ret;
}
}
return 0;
}
static void iio_free_scan_mask(struct iio_dev *indio_dev,
const unsigned long *mask)
{
/* If the mask is dynamically allocated free it, otherwise do nothing */
if (!indio_dev->available_scan_masks)
bitmap_free(mask);
}
struct iio_device_config {
unsigned int mode;
unsigned int watermark;
const unsigned long *scan_mask;
unsigned int scan_bytes;
bool scan_timestamp;
};
static int iio_verify_update(struct iio_dev *indio_dev,
struct iio_buffer *insert_buffer, struct iio_buffer *remove_buffer,
struct iio_device_config *config)
{
struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
unsigned long *compound_mask;
const unsigned long *scan_mask;
bool strict_scanmask = false;
struct iio_buffer *buffer;
bool scan_timestamp;
unsigned int modes;
if (insert_buffer &&
bitmap_empty(insert_buffer->scan_mask, indio_dev->masklength)) {
dev_dbg(&indio_dev->dev,
"At least one scan element must be enabled first\n");
return -EINVAL;
}
memset(config, 0, sizeof(*config));
config->watermark = ~0;
/*
* If there is just one buffer and we are removing it there is nothing
* to verify.
*/
if (remove_buffer && !insert_buffer &&
list_is_singular(&iio_dev_opaque->buffer_list))
return 0;
modes = indio_dev->modes;
list_for_each_entry(buffer, &iio_dev_opaque->buffer_list, buffer_list) {
if (buffer == remove_buffer)
continue;
modes &= buffer->access->modes;
config->watermark = min(config->watermark, buffer->watermark);
}
if (insert_buffer) {
modes &= insert_buffer->access->modes;
config->watermark = min(config->watermark,
insert_buffer->watermark);
}
/* Definitely possible for devices to support both of these. */
if ((modes & INDIO_BUFFER_TRIGGERED) && indio_dev->trig) {
config->mode = INDIO_BUFFER_TRIGGERED;
} else if (modes & INDIO_BUFFER_HARDWARE) {
/*
* Keep things simple for now and only allow a single buffer to
* be connected in hardware mode.
*/
if (insert_buffer && !list_empty(&iio_dev_opaque->buffer_list))
return -EINVAL;
config->mode = INDIO_BUFFER_HARDWARE;
strict_scanmask = true;
} else if (modes & INDIO_BUFFER_SOFTWARE) {
config->mode = INDIO_BUFFER_SOFTWARE;
} else {
/* Can only occur on first buffer */
if (indio_dev->modes & INDIO_BUFFER_TRIGGERED)
dev_dbg(&indio_dev->dev, "Buffer not started: no trigger\n");
return -EINVAL;
}
/* What scan mask do we actually have? */
compound_mask = bitmap_zalloc(indio_dev->masklength, GFP_KERNEL);
if (compound_mask == NULL)
return -ENOMEM;
scan_timestamp = false;
list_for_each_entry(buffer, &iio_dev_opaque->buffer_list, buffer_list) {
if (buffer == remove_buffer)
continue;
bitmap_or(compound_mask, compound_mask, buffer->scan_mask,
indio_dev->masklength);
scan_timestamp |= buffer->scan_timestamp;
}
if (insert_buffer) {
bitmap_or(compound_mask, compound_mask,
insert_buffer->scan_mask, indio_dev->masklength);
scan_timestamp |= insert_buffer->scan_timestamp;
}
if (indio_dev->available_scan_masks) {
scan_mask = iio_scan_mask_match(indio_dev->available_scan_masks,
indio_dev->masklength,
compound_mask,
strict_scanmask);
bitmap_free(compound_mask);
if (scan_mask == NULL)
return -EINVAL;
} else {
scan_mask = compound_mask;
}
config->scan_bytes = iio_compute_scan_bytes(indio_dev,
scan_mask, scan_timestamp);
config->scan_mask = scan_mask;
config->scan_timestamp = scan_timestamp;
return 0;
}
/**
* 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 int from;
unsigned int to;
unsigned int length;
struct list_head l;
};
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);
}
}
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)
{
int ret, in_ind = -1, out_ind, length;
unsigned int 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,
buffer->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) {
length = iio_storage_bytes_for_si(indio_dev, in_ind);
/* Make sure we are aligned */
in_loc = roundup(in_loc, length) + length;
in_ind = find_next_bit(indio_dev->active_scan_mask,
indio_dev->masklength,
in_ind + 1);
}
length = iio_storage_bytes_for_si(indio_dev, in_ind);
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) {
length = iio_storage_bytes_for_timestamp(indio_dev);
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;
}
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;
}
static int iio_update_demux(struct iio_dev *indio_dev)
{
struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
struct iio_buffer *buffer;
int ret;
list_for_each_entry(buffer, &iio_dev_opaque->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, &iio_dev_opaque->buffer_list, buffer_list)
iio_buffer_demux_free(buffer);
return ret;
}
static int iio_enable_buffers(struct iio_dev *indio_dev,
struct iio_device_config *config)
{
struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
struct iio_buffer *buffer, *tmp = NULL;
int ret;
indio_dev->active_scan_mask = config->scan_mask;
indio_dev->scan_timestamp = config->scan_timestamp;
indio_dev->scan_bytes = config->scan_bytes;
iio_dev_opaque->currentmode = config->mode;
iio_update_demux(indio_dev);
/* Wind up again */
if (indio_dev->setup_ops->preenable) {
ret = indio_dev->setup_ops->preenable(indio_dev);
if (ret) {
dev_dbg(&indio_dev->dev,
"Buffer not started: buffer preenable failed (%d)\n", ret);
goto err_undo_config;
}
}
if (indio_dev->info->update_scan_mode) {
ret = indio_dev->info
->update_scan_mode(indio_dev,
indio_dev->active_scan_mask);
if (ret < 0) {
dev_dbg(&indio_dev->dev,
"Buffer not started: update scan mode failed (%d)\n",
ret);
goto err_run_postdisable;
}
}
if (indio_dev->info->hwfifo_set_watermark)
indio_dev->info->hwfifo_set_watermark(indio_dev,
config->watermark);
list_for_each_entry(buffer, &iio_dev_opaque->buffer_list, buffer_list) {
ret = iio_buffer_enable(buffer, indio_dev);
if (ret) {
tmp = buffer;
goto err_disable_buffers;
}
}
if (iio_dev_opaque->currentmode == INDIO_BUFFER_TRIGGERED) {
ret = iio_trigger_attach_poll_func(indio_dev->trig,
indio_dev->pollfunc);
if (ret)
goto err_disable_buffers;
}
if (indio_dev->setup_ops->postenable) {
ret = indio_dev->setup_ops->postenable(indio_dev);
if (ret) {
dev_dbg(&indio_dev->dev,
"Buffer not started: postenable failed (%d)\n", ret);
goto err_detach_pollfunc;
}
}
return 0;
err_detach_pollfunc:
if (iio_dev_opaque->currentmode == INDIO_BUFFER_TRIGGERED) {
iio_trigger_detach_poll_func(indio_dev->trig,
indio_dev->pollfunc);
}
err_disable_buffers:
buffer = list_prepare_entry(tmp, &iio_dev_opaque->buffer_list, buffer_list);
list_for_each_entry_continue_reverse(buffer, &iio_dev_opaque->buffer_list,
buffer_list)
iio_buffer_disable(buffer, indio_dev);
err_run_postdisable:
if (indio_dev->setup_ops->postdisable)
indio_dev->setup_ops->postdisable(indio_dev);
err_undo_config:
iio_dev_opaque->currentmode = INDIO_DIRECT_MODE;
indio_dev->active_scan_mask = NULL;
return ret;
}
static int iio_disable_buffers(struct iio_dev *indio_dev)
{
struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
struct iio_buffer *buffer;
int ret = 0;
int ret2;
/* Wind down existing buffers - iff there are any */
if (list_empty(&iio_dev_opaque->buffer_list))
return 0;
/*
* If things go wrong at some step in disable we still need to continue
* to perform the other steps, otherwise we leave the device in a
* inconsistent state. We return the error code for the first error we
* encountered.
*/
if (indio_dev->setup_ops->predisable) {
ret2 = indio_dev->setup_ops->predisable(indio_dev);
if (ret2 && !ret)
ret = ret2;
}
if (iio_dev_opaque->currentmode == INDIO_BUFFER_TRIGGERED) {
iio_trigger_detach_poll_func(indio_dev->trig,
indio_dev->pollfunc);
}
list_for_each_entry(buffer, &iio_dev_opaque->buffer_list, buffer_list) {
ret2 = iio_buffer_disable(buffer, indio_dev);
if (ret2 && !ret)
ret = ret2;
}
if (indio_dev->setup_ops->postdisable) {
ret2 = indio_dev->setup_ops->postdisable(indio_dev);
if (ret2 && !ret)
ret = ret2;
}
iio_free_scan_mask(indio_dev, indio_dev->active_scan_mask);
indio_dev->active_scan_mask = NULL;
iio_dev_opaque->currentmode = INDIO_DIRECT_MODE;
return ret;
}
static int __iio_update_buffers(struct iio_dev *indio_dev,
struct iio_buffer *insert_buffer,
struct iio_buffer *remove_buffer)
{
struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
struct iio_device_config new_config;
int ret;
ret = iio_verify_update(indio_dev, insert_buffer, remove_buffer,
&new_config);
if (ret)
return ret;
if (insert_buffer) {
ret = iio_buffer_request_update(indio_dev, insert_buffer);
if (ret)
goto err_free_config;
}
ret = iio_disable_buffers(indio_dev);
if (ret)
goto err_deactivate_all;
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(&iio_dev_opaque->buffer_list))
return 0;
ret = iio_enable_buffers(indio_dev, &new_config);
if (ret)
goto err_deactivate_all;
return 0;
err_deactivate_all:
/*
* We've already verified that the config is valid earlier. If things go
* wrong in either enable or disable the most likely reason is an IO
* error from the device. In this case there is no good recovery
* strategy. Just make sure to disable everything and leave the device
* in a sane state. With a bit of luck the device might come back to
* life again later and userspace can try again.
*/
iio_buffer_deactivate_all(indio_dev);
err_free_config:
iio_free_scan_mask(indio_dev, new_config.scan_mask);
return ret;
}
int iio_update_buffers(struct iio_dev *indio_dev,
struct iio_buffer *insert_buffer,
struct iio_buffer *remove_buffer)
{
struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
int ret;
if (insert_buffer == remove_buffer)
return 0;
if (insert_buffer &&
(insert_buffer->direction == IIO_BUFFER_DIRECTION_OUT))
return -EINVAL;
mutex_lock(&iio_dev_opaque->info_exist_lock);
mutex_lock(&iio_dev_opaque->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(&iio_dev_opaque->mlock);
mutex_unlock(&iio_dev_opaque->info_exist_lock);
return ret;
}
EXPORT_SYMBOL_GPL(iio_update_buffers);
void iio_disable_all_buffers(struct iio_dev *indio_dev)
{
iio_disable_buffers(indio_dev);
iio_buffer_deactivate_all(indio_dev);
}
static ssize_t enable_store(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);
struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer;
bool inlist;
ret = kstrtobool(buf, &requested_state);
if (ret < 0)
return ret;
mutex_lock(&iio_dev_opaque->mlock);
/* Find out if it is in the list */
inlist = iio_buffer_is_active(buffer);
/* Already in desired state */
if (inlist == requested_state)
goto done;
if (requested_state)
ret = __iio_update_buffers(indio_dev, buffer, NULL);
else
ret = __iio_update_buffers(indio_dev, NULL, buffer);
done:
mutex_unlock(&iio_dev_opaque->mlock);
return (ret < 0) ? ret : len;
}
static ssize_t watermark_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer;
return sysfs_emit(buf, "%u\n", buffer->watermark);
}
static ssize_t watermark_store(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_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer;
unsigned int val;
int ret;
ret = kstrtouint(buf, 10, &val);
if (ret)
return ret;
if (!val)
return -EINVAL;
mutex_lock(&iio_dev_opaque->mlock);
if (val > buffer->length) {
ret = -EINVAL;
goto out;
}
if (iio_buffer_is_active(buffer)) {
ret = -EBUSY;
goto out;
}
buffer->watermark = val;
out:
mutex_unlock(&iio_dev_opaque->mlock);
return ret ? ret : len;
}
static ssize_t data_available_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer;
return sysfs_emit(buf, "%zu\n", iio_buffer_data_available(buffer));
}
static ssize_t direction_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer;
switch (buffer->direction) {
case IIO_BUFFER_DIRECTION_IN:
return sysfs_emit(buf, "in\n");
case IIO_BUFFER_DIRECTION_OUT:
return sysfs_emit(buf, "out\n");
default:
return -EINVAL;
}
}
static DEVICE_ATTR_RW(length);
static struct device_attribute dev_attr_length_ro = __ATTR_RO(length);
static DEVICE_ATTR_RW(enable);
static DEVICE_ATTR_RW(watermark);
static struct device_attribute dev_attr_watermark_ro = __ATTR_RO(watermark);
static DEVICE_ATTR_RO(data_available);
static DEVICE_ATTR_RO(direction);
/*
* When adding new attributes here, put the at the end, at least until
* the code that handles the length/length_ro & watermark/watermark_ro
* assignments gets cleaned up. Otherwise these can create some weird
* duplicate attributes errors under some setups.
*/
static struct attribute *iio_buffer_attrs[] = {
&dev_attr_length.attr,
&dev_attr_enable.attr,
&dev_attr_watermark.attr,
&dev_attr_data_available.attr,
&dev_attr_direction.attr,
};
#define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)
static struct attribute *iio_buffer_wrap_attr(struct iio_buffer *buffer,
struct attribute *attr)
{
struct device_attribute *dattr = to_dev_attr(attr);
struct iio_dev_attr *iio_attr;
iio_attr = kzalloc(sizeof(*iio_attr), GFP_KERNEL);
if (!iio_attr)
return NULL;
iio_attr->buffer = buffer;
memcpy(&iio_attr->dev_attr, dattr, sizeof(iio_attr->dev_attr));
iio_attr->dev_attr.attr.name = kstrdup_const(attr->name, GFP_KERNEL);
if (!iio_attr->dev_attr.attr.name) {
kfree(iio_attr);
return NULL;
}
sysfs_attr_init(&iio_attr->dev_attr.attr);
list_add(&iio_attr->l, &buffer->buffer_attr_list);
return &iio_attr->dev_attr.attr;
}
static int iio_buffer_register_legacy_sysfs_groups(struct iio_dev *indio_dev,
struct attribute **buffer_attrs,
int buffer_attrcount,
int scan_el_attrcount)
{
struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
struct attribute_group *group;
struct attribute **attrs;
int ret;
attrs = kcalloc(buffer_attrcount + 1, sizeof(*attrs), GFP_KERNEL);
if (!attrs)
return -ENOMEM;
memcpy(attrs, buffer_attrs, buffer_attrcount * sizeof(*attrs));
group = &iio_dev_opaque->legacy_buffer_group;
group->attrs = attrs;
group->name = "buffer";
ret = iio_device_register_sysfs_group(indio_dev, group);
if (ret)
goto error_free_buffer_attrs;
attrs = kcalloc(scan_el_attrcount + 1, sizeof(*attrs), GFP_KERNEL);
if (!attrs) {
ret = -ENOMEM;
goto error_free_buffer_attrs;
}
memcpy(attrs, &buffer_attrs[buffer_attrcount],
scan_el_attrcount * sizeof(*attrs));
group = &iio_dev_opaque->legacy_scan_el_group;
group->attrs = attrs;
group->name = "scan_elements";
ret = iio_device_register_sysfs_group(indio_dev, group);
if (ret)
goto error_free_scan_el_attrs;
return 0;
error_free_scan_el_attrs:
kfree(iio_dev_opaque->legacy_scan_el_group.attrs);
error_free_buffer_attrs:
kfree(iio_dev_opaque->legacy_buffer_group.attrs);
return ret;
}
static void iio_buffer_unregister_legacy_sysfs_groups(struct iio_dev *indio_dev)
{
struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
kfree(iio_dev_opaque->legacy_buffer_group.attrs);
kfree(iio_dev_opaque->legacy_scan_el_group.attrs);
}
static int iio_buffer_chrdev_release(struct inode *inode, struct file *filep)
{
struct iio_dev_buffer_pair *ib = filep->private_data;
struct iio_dev *indio_dev = ib->indio_dev;
struct iio_buffer *buffer = ib->buffer;
wake_up(&buffer->pollq);
kfree(ib);
clear_bit(IIO_BUSY_BIT_POS, &buffer->flags);
iio_device_put(indio_dev);
return 0;
}
static const struct file_operations iio_buffer_chrdev_fileops = {
.owner = THIS_MODULE,
.llseek = noop_llseek,
.read = iio_buffer_read,
.write = iio_buffer_write,
.poll = iio_buffer_poll,
.release = iio_buffer_chrdev_release,
};
static long iio_device_buffer_getfd(struct iio_dev *indio_dev, unsigned long arg)
{
struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
int __user *ival = (int __user *)arg;
struct iio_dev_buffer_pair *ib;
struct iio_buffer *buffer;
int fd, idx, ret;
if (copy_from_user(&idx, ival, sizeof(idx)))
return -EFAULT;
if (idx >= iio_dev_opaque->attached_buffers_cnt)
return -ENODEV;
iio_device_get(indio_dev);
buffer = iio_dev_opaque->attached_buffers[idx];
if (test_and_set_bit(IIO_BUSY_BIT_POS, &buffer->flags)) {
ret = -EBUSY;
goto error_iio_dev_put;
}
ib = kzalloc(sizeof(*ib), GFP_KERNEL);
if (!ib) {
ret = -ENOMEM;
goto error_clear_busy_bit;
}
ib->indio_dev = indio_dev;
ib->buffer = buffer;
fd = anon_inode_getfd("iio:buffer", &iio_buffer_chrdev_fileops,
ib, O_RDWR | O_CLOEXEC);
if (fd < 0) {
ret = fd;
goto error_free_ib;
}
if (copy_to_user(ival, &fd, sizeof(fd))) {
/*
* "Leak" the fd, as there's not much we can do about this
* anyway. 'fd' might have been closed already, as
* anon_inode_getfd() called fd_install() on it, which made
* it reachable by userland.
*
* Instead of allowing a malicious user to play tricks with
* us, rely on the process exit path to do any necessary
* cleanup, as in releasing the file, if still needed.
*/
return -EFAULT;
}
return 0;
error_free_ib:
kfree(ib);
error_clear_busy_bit:
clear_bit(IIO_BUSY_BIT_POS, &buffer->flags);
error_iio_dev_put:
iio_device_put(indio_dev);
return ret;
}
static long iio_device_buffer_ioctl(struct iio_dev *indio_dev, struct file *filp,
unsigned int cmd, unsigned long arg)
{
switch (cmd) {
case IIO_BUFFER_GET_FD_IOCTL:
return iio_device_buffer_getfd(indio_dev, arg);
default:
return IIO_IOCTL_UNHANDLED;
}
}
static int __iio_buffer_alloc_sysfs_and_mask(struct iio_buffer *buffer,
struct iio_dev *indio_dev,
int index)
{
struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
struct iio_dev_attr *p;
const struct iio_dev_attr *id_attr;
struct attribute **attr;
int ret, i, attrn, scan_el_attrcount, buffer_attrcount;
const struct iio_chan_spec *channels;
buffer_attrcount = 0;
if (buffer->attrs) {
while (buffer->attrs[buffer_attrcount] != NULL)
buffer_attrcount++;
}
buffer_attrcount += ARRAY_SIZE(iio_buffer_attrs);
scan_el_attrcount = 0;
INIT_LIST_HEAD(&buffer->buffer_attr_list);
channels = indio_dev->channels;
if (channels) {
/* new magic */
for (i = 0; i < indio_dev->num_channels; i++) {
if (channels[i].scan_index < 0)
continue;
/* Verify that sample bits fit into storage */
if (channels[i].scan_type.storagebits <
channels[i].scan_type.realbits +
channels[i].scan_type.shift) {
dev_err(&indio_dev->dev,
"Channel %d storagebits (%d) < shifted realbits (%d + %d)\n",
i, channels[i].scan_type.storagebits,
channels[i].scan_type.realbits,
channels[i].scan_type.shift);
ret = -EINVAL;
goto error_cleanup_dynamic;
}
ret = iio_buffer_add_channel_sysfs(indio_dev, buffer,
&channels[i]);
if (ret < 0)
goto error_cleanup_dynamic;
scan_el_attrcount += ret;
if (channels[i].type == IIO_TIMESTAMP)
iio_dev_opaque->scan_index_timestamp =
channels[i].scan_index;
}
if (indio_dev->masklength && buffer->scan_mask == NULL) {
buffer->scan_mask = bitmap_zalloc(indio_dev->masklength,
GFP_KERNEL);
if (buffer->scan_mask == NULL) {
ret = -ENOMEM;
goto error_cleanup_dynamic;
}
}
}
attrn = buffer_attrcount + scan_el_attrcount;
attr = kcalloc(attrn + 1, sizeof(*attr), GFP_KERNEL);
if (!attr) {
ret = -ENOMEM;
goto error_free_scan_mask;
}
memcpy(attr, iio_buffer_attrs, sizeof(iio_buffer_attrs));
if (!buffer->access->set_length)
attr[0] = &dev_attr_length_ro.attr;
if (buffer->access->flags & INDIO_BUFFER_FLAG_FIXED_WATERMARK)
attr[2] = &dev_attr_watermark_ro.attr;
if (buffer->attrs)
for (i = 0, id_attr = buffer->attrs[i];
(id_attr = buffer->attrs[i]); i++)
attr[ARRAY_SIZE(iio_buffer_attrs) + i] =
(struct attribute *)&id_attr->dev_attr.attr;
buffer->buffer_group.attrs = attr;
for (i = 0; i < buffer_attrcount; i++) {
struct attribute *wrapped;
wrapped = iio_buffer_wrap_attr(buffer, attr[i]);
if (!wrapped) {
ret = -ENOMEM;
goto error_free_buffer_attrs;
}
attr[i] = wrapped;
}
attrn = 0;
list_for_each_entry(p, &buffer->buffer_attr_list, l)
attr[attrn++] = &p->dev_attr.attr;
buffer->buffer_group.name = kasprintf(GFP_KERNEL, "buffer%d", index);
if (!buffer->buffer_group.name) {
ret = -ENOMEM;
goto error_free_buffer_attrs;
}
ret = iio_device_register_sysfs_group(indio_dev, &buffer->buffer_group);
if (ret)
goto error_free_buffer_attr_group_name;
/* we only need to register the legacy groups for the first buffer */
if (index > 0)
return 0;
ret = iio_buffer_register_legacy_sysfs_groups(indio_dev, attr,
buffer_attrcount,
scan_el_attrcount);
if (ret)
goto error_free_buffer_attr_group_name;
return 0;
error_free_buffer_attr_group_name:
kfree(buffer->buffer_group.name);
error_free_buffer_attrs:
kfree(buffer->buffer_group.attrs);
error_free_scan_mask:
bitmap_free(buffer->scan_mask);
error_cleanup_dynamic:
iio_free_chan_devattr_list(&buffer->buffer_attr_list);
return ret;
}
static void __iio_buffer_free_sysfs_and_mask(struct iio_buffer *buffer,
struct iio_dev *indio_dev,
int index)
{
if (index == 0)
iio_buffer_unregister_legacy_sysfs_groups(indio_dev);
bitmap_free(buffer->scan_mask);
kfree(buffer->buffer_group.name);
kfree(buffer->buffer_group.attrs);
iio_free_chan_devattr_list(&buffer->buffer_attr_list);
}
int iio_buffers_alloc_sysfs_and_mask(struct iio_dev *indio_dev)
{
struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
const struct iio_chan_spec *channels;
struct iio_buffer *buffer;
int ret, i, idx;
size_t sz;
channels = indio_dev->channels;
if (channels) {
int ml = indio_dev->masklength;
for (i = 0; i < indio_dev->num_channels; i++)
ml = max(ml, channels[i].scan_index + 1);
indio_dev->masklength = ml;
}
if (!iio_dev_opaque->attached_buffers_cnt)
return 0;
for (idx = 0; idx < iio_dev_opaque->attached_buffers_cnt; idx++) {
buffer = iio_dev_opaque->attached_buffers[idx];
ret = __iio_buffer_alloc_sysfs_and_mask(buffer, indio_dev, idx);
if (ret)
goto error_unwind_sysfs_and_mask;
}
sz = sizeof(*(iio_dev_opaque->buffer_ioctl_handler));
iio_dev_opaque->buffer_ioctl_handler = kzalloc(sz, GFP_KERNEL);
if (!iio_dev_opaque->buffer_ioctl_handler) {
ret = -ENOMEM;
goto error_unwind_sysfs_and_mask;
}
iio_dev_opaque->buffer_ioctl_handler->ioctl = iio_device_buffer_ioctl;
iio_device_ioctl_handler_register(indio_dev,
iio_dev_opaque->buffer_ioctl_handler);
return 0;
error_unwind_sysfs_and_mask:
while (idx--) {
buffer = iio_dev_opaque->attached_buffers[idx];
__iio_buffer_free_sysfs_and_mask(buffer, indio_dev, idx);
}
return ret;
}
void iio_buffers_free_sysfs_and_mask(struct iio_dev *indio_dev)
{
struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
struct iio_buffer *buffer;
int i;
if (!iio_dev_opaque->attached_buffers_cnt)
return;
iio_device_ioctl_handler_unregister(iio_dev_opaque->buffer_ioctl_handler);
kfree(iio_dev_opaque->buffer_ioctl_handler);
for (i = iio_dev_opaque->attached_buffers_cnt - 1; i >= 0; i--) {
buffer = iio_dev_opaque->attached_buffers[i];
__iio_buffer_free_sysfs_and_mask(buffer, indio_dev, i);
}
}
/**
* 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 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);
int ret;
ret = buffer->access->store_to(buffer, dataout);
if (ret)
return ret;
/*
* We can't just test for watermark to decide if we wake the poll queue
* because read may request less samples than the watermark.
*/
wake_up_interruptible_poll(&buffer->pollq, EPOLLIN | EPOLLRDNORM);
return 0;
}
/**
* iio_push_to_buffers() - push to a registered buffer.
* @indio_dev: iio_dev structure for device.
* @data: Full scan.
*/
int iio_push_to_buffers(struct iio_dev *indio_dev, const void *data)
{
struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
int ret;
struct iio_buffer *buf;
list_for_each_entry(buf, &iio_dev_opaque->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);
/**
* iio_push_to_buffers_with_ts_unaligned() - push to registered buffer,
* no alignment or space requirements.
* @indio_dev: iio_dev structure for device.
* @data: channel data excluding the timestamp.
* @data_sz: size of data.
* @timestamp: timestamp for the sample data.
*
* This special variant of iio_push_to_buffers_with_timestamp() does
* not require space for the timestamp, or 8 byte alignment of data.
* It does however require an allocation on first call and additional
* copies on all calls, so should be avoided if possible.
*/
int iio_push_to_buffers_with_ts_unaligned(struct iio_dev *indio_dev,
const void *data,
size_t data_sz,
int64_t timestamp)
{
struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
/*
* Conservative estimate - we can always safely copy the minimum
* of either the data provided or the length of the destination buffer.
* This relaxed limit allows the calling drivers to be lax about
* tracking the size of the data they are pushing, at the cost of
* unnecessary copying of padding.
*/
data_sz = min_t(size_t, indio_dev->scan_bytes, data_sz);
if (iio_dev_opaque->bounce_buffer_size != indio_dev->scan_bytes) {
void *bb;
bb = devm_krealloc(&indio_dev->dev,
iio_dev_opaque->bounce_buffer,
indio_dev->scan_bytes, GFP_KERNEL);
if (!bb)
return -ENOMEM;
iio_dev_opaque->bounce_buffer = bb;
iio_dev_opaque->bounce_buffer_size = indio_dev->scan_bytes;
}
memcpy(iio_dev_opaque->bounce_buffer, data, data_sz);
return iio_push_to_buffers_with_timestamp(indio_dev,
iio_dev_opaque->bounce_buffer,
timestamp);
}
EXPORT_SYMBOL_GPL(iio_push_to_buffers_with_ts_unaligned);
/**
* 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);
/**
* iio_device_attach_buffer - Attach a buffer to a IIO device
* @indio_dev: The device the buffer should be attached to
* @buffer: The buffer to attach to the device
*
* Return 0 if successful, negative if error.
*
* This function attaches a buffer to a IIO device. The buffer stays attached to
* the device until the device is freed. For legacy reasons, the first attached
* buffer will also be assigned to 'indio_dev->buffer'.
* The array allocated here, will be free'd via the iio_device_detach_buffers()
* call which is handled by the iio_device_free().
*/
int iio_device_attach_buffer(struct iio_dev *indio_dev,
struct iio_buffer *buffer)
{
struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
struct iio_buffer **new, **old = iio_dev_opaque->attached_buffers;
unsigned int cnt = iio_dev_opaque->attached_buffers_cnt;
cnt++;
new = krealloc(old, sizeof(*new) * cnt, GFP_KERNEL);
if (!new)
return -ENOMEM;
iio_dev_opaque->attached_buffers = new;
buffer = iio_buffer_get(buffer);
/* first buffer is legacy; attach it to the IIO device directly */
if (!indio_dev->buffer)
indio_dev->buffer = buffer;
iio_dev_opaque->attached_buffers[cnt - 1] = buffer;
iio_dev_opaque->attached_buffers_cnt = cnt;
return 0;
}
EXPORT_SYMBOL_GPL(iio_device_attach_buffer);