Commit 1546d671 authored by Lars-Peter Clausen's avatar Lars-Peter Clausen Committed by Jonathan Cameron
Browse files

iio: kfifo-buffer: Add output buffer support 



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: default avatarLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: default avatarAlexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: default avatarMihail Chindris <mihail.chindris@analog.com>
Link: https://lore.kernel.org/r/20211007080035.2531-3-mihail.chindris@analog.com


Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent 9eeee3b0

drivers/iio/buffer/kfifo_buf.c

+50 −0
Original line number Diff line number Diff line
@@ -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,