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iio: kfifo-buffer: Add output buffer support

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Add output buffer support to the kfifo buffer implementation.

The implementation is straight forward and mostly just wraps the kfifo
API to provide the required operations.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Mihail Chindris <mihail.chindris@analog.com>
Link: https://lore.kernel.org/r/20211007080035.2531-3-mihail.chindris@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This commit is contained in:
Lars-Peter Clausen 2021-10-07 08:00:31 +00:00 committed by Jonathan Cameron
parent 9eeee3b0bf
commit 1546d6718d
1 changed files with 50 additions and 0 deletions
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50
drivers/iio/buffer/kfifo_buf.c
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@ -138,10 +138,60 @@ static void iio_kfifo_buffer_release(struct iio_buffer *buffer)
kfree(kf);
}
static size_t iio_kfifo_buf_space_available(struct iio_buffer *r)
{
struct iio_kfifo *kf = iio_to_kfifo(r);
size_t avail;
mutex_lock(&kf->user_lock);
avail = kfifo_avail(&kf->kf);
mutex_unlock(&kf->user_lock);
return avail;
}
static int iio_kfifo_remove_from(struct iio_buffer *r, void *data)
{
int ret;
struct iio_kfifo *kf = iio_to_kfifo(r);
if (kfifo_size(&kf->kf) < 1)
return -EBUSY;
ret = kfifo_out(&kf->kf, data, 1);
if (ret != 1)
return -EBUSY;
wake_up_interruptible_poll(&r->pollq, EPOLLOUT | EPOLLWRNORM);
return 0;
}
static int iio_kfifo_write(struct iio_buffer *r, size_t n,
const char __user *buf)
{
struct iio_kfifo *kf = iio_to_kfifo(r);
int ret, copied;
mutex_lock(&kf->user_lock);
if (!kfifo_initialized(&kf->kf) || n < kfifo_esize(&kf->kf))
ret = -EINVAL;
else
ret = kfifo_from_user(&kf->kf, buf, n, &copied);
mutex_unlock(&kf->user_lock);
if (ret)
return ret;
return copied;
}
static const struct iio_buffer_access_funcs kfifo_access_funcs = {
.store_to = &iio_store_to_kfifo,
.read = &iio_read_kfifo,
.data_available = iio_kfifo_buf_data_available,
.remove_from = &iio_kfifo_remove_from,
.write = &iio_kfifo_write,
.space_available = &iio_kfifo_buf_space_available,
.request_update = &iio_request_update_kfifo,
.set_bytes_per_datum = &iio_set_bytes_per_datum_kfifo,
.set_length = &iio_set_length_kfifo,