linux/drivers/iio/buffer_cb.c
Jonathan Cameron 92d1079b28 staging:iio: add a callback buffer for in kernel push interface
This callback buffer is meant to be opaque to users, but basically
adds a very simple pass through buffer to which data may be
pushed when it is inserted into the buffer list.

Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2012-11-10 10:17:27 +00:00

114 lines
2.6 KiB
C

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/export.h>
#include <linux/iio/buffer.h>
#include <linux/iio/consumer.h>
struct iio_cb_buffer {
struct iio_buffer buffer;
int (*cb)(u8 *data, void *private);
void *private;
struct iio_channel *channels;
};
static int iio_buffer_cb_store_to(struct iio_buffer *buffer, u8 *data)
{
struct iio_cb_buffer *cb_buff = container_of(buffer,
struct iio_cb_buffer,
buffer);
return cb_buff->cb(data, cb_buff->private);
}
static struct iio_buffer_access_funcs iio_cb_access = {
.store_to = &iio_buffer_cb_store_to,
};
struct iio_cb_buffer *iio_channel_get_all_cb(const char *name,
int (*cb)(u8 *data,
void *private),
void *private)
{
int ret;
struct iio_cb_buffer *cb_buff;
struct iio_dev *indio_dev;
struct iio_channel *chan;
cb_buff = kzalloc(sizeof(*cb_buff), GFP_KERNEL);
if (cb_buff == NULL) {
ret = -ENOMEM;
goto error_ret;
}
cb_buff->private = private;
cb_buff->cb = cb;
cb_buff->buffer.access = &iio_cb_access;
INIT_LIST_HEAD(&cb_buff->buffer.demux_list);
cb_buff->channels = iio_channel_get_all(name);
if (IS_ERR(cb_buff->channels)) {
ret = PTR_ERR(cb_buff->channels);
goto error_free_cb_buff;
}
indio_dev = cb_buff->channels[0].indio_dev;
cb_buff->buffer.scan_mask
= kcalloc(BITS_TO_LONGS(indio_dev->masklength), sizeof(long),
GFP_KERNEL);
if (cb_buff->buffer.scan_mask == NULL) {
ret = -ENOMEM;
goto error_release_channels;
}
chan = &cb_buff->channels[0];
while (chan->indio_dev) {
if (chan->indio_dev != indio_dev) {
ret = -EINVAL;
goto error_release_channels;
}
set_bit(chan->channel->scan_index,
cb_buff->buffer.scan_mask);
chan++;
}
return cb_buff;
error_release_channels:
iio_channel_release_all(cb_buff->channels);
error_free_cb_buff:
kfree(cb_buff);
error_ret:
return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(iio_channel_get_all_cb);
int iio_channel_start_all_cb(struct iio_cb_buffer *cb_buff)
{
return iio_update_buffers(cb_buff->channels[0].indio_dev,
&cb_buff->buffer,
NULL);
}
EXPORT_SYMBOL_GPL(iio_channel_start_all_cb);
void iio_channel_stop_all_cb(struct iio_cb_buffer *cb_buff)
{
iio_update_buffers(cb_buff->channels[0].indio_dev,
NULL,
&cb_buff->buffer);
}
EXPORT_SYMBOL_GPL(iio_channel_stop_all_cb);
void iio_channel_release_all_cb(struct iio_cb_buffer *cb_buff)
{
iio_channel_release_all(cb_buff->channels);
kfree(cb_buff);
}
EXPORT_SYMBOL_GPL(iio_channel_release_all_cb);
struct iio_channel
*iio_channel_cb_get_channels(const struct iio_cb_buffer *cb_buffer)
{
return cb_buffer->channels;
}
EXPORT_SYMBOL_GPL(iio_channel_cb_get_channels);