On Mon, Nov 15, 2021 at 4:23 PM Paul Cercueil <paul@xxxxxxxxxxxxxxx> wrote:
>
> Handle the IIO_BUFFER_DMABUF_CYCLIC flag to support cyclic buffers.
>
Reviewed-by: Alexandru Ardelean <ardeleanalex@xxxxxxxxx>
> Signed-off-by: Paul Cercueil <paul@xxxxxxxxxxxxxxx>
> ---
> drivers/iio/buffer/industrialio-buffer-dma.c | 1 +
> .../iio/buffer/industrialio-buffer-dmaengine.c | 15 ++++++++++++---
> include/linux/iio/buffer-dma.h | 3 +++
> 3 files changed, 16 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/iio/buffer/industrialio-buffer-dma.c b/drivers/iio/buffer/industrialio-buffer-dma.c
> index fb39054d8c15..6658f103ee17 100644
> --- a/drivers/iio/buffer/industrialio-buffer-dma.c
> +++ b/drivers/iio/buffer/industrialio-buffer-dma.c
> @@ -933,6 +933,7 @@ int iio_dma_buffer_enqueue_dmabuf(struct iio_buffer *buffer,
> }
>
> dma_block->bytes_used = iio_dmabuf->bytes_used ?: dma_block->size;
> + dma_block->cyclic = iio_dmabuf->flags & IIO_BUFFER_DMABUF_CYCLIC;
>
> switch (dma_block->state) {
> case IIO_BLOCK_STATE_QUEUED:
> diff --git a/drivers/iio/buffer/industrialio-buffer-dmaengine.c b/drivers/iio/buffer/industrialio-buffer-dmaengine.c
> index 57a8b2e4ba3c..952e2160a11e 100644
> --- a/drivers/iio/buffer/industrialio-buffer-dmaengine.c
> +++ b/drivers/iio/buffer/industrialio-buffer-dmaengine.c
> @@ -81,9 +81,18 @@ static int iio_dmaengine_buffer_submit_block(struct iio_dma_buffer_queue *queue,
> if (!block->bytes_used || block->bytes_used > max_size)
> return -EINVAL;
>
> - desc = dmaengine_prep_slave_single(dmaengine_buffer->chan,
> - block->phys_addr, block->bytes_used, dma_dir,
> - DMA_PREP_INTERRUPT);
> + if (block->cyclic) {
> + desc = dmaengine_prep_dma_cyclic(dmaengine_buffer->chan,
> + block->phys_addr,
> + block->size,
> + block->bytes_used,
> + dma_dir, 0);
> + } else {
> + desc = dmaengine_prep_slave_single(dmaengine_buffer->chan,
> + block->phys_addr,
> + block->bytes_used, dma_dir,
> + DMA_PREP_INTERRUPT);
> + }
> if (!desc)
> return -ENOMEM;
>
> diff --git a/include/linux/iio/buffer-dma.h b/include/linux/iio/buffer-dma.h
> index 85e55fe35282..27639fdf7b54 100644
> --- a/include/linux/iio/buffer-dma.h
> +++ b/include/linux/iio/buffer-dma.h
> @@ -42,6 +42,7 @@ enum iio_block_state {
> * @phys_addr: Physical address of the blocks memory
> * @queue: Parent DMA buffer queue
> * @state: Current state of the block
> + * @cyclic: True if this is a cyclic buffer
> * @fileio: True if this buffer is used for fileio mode
> * @dmabuf: Underlying DMABUF object
> */
> @@ -65,6 +66,8 @@ struct iio_dma_buffer_block {
> */
> enum iio_block_state state;
>
> + bool cyclic;
> +
> bool fileio;
> struct dma_buf *dmabuf;
> };
> --
> 2.33.0
>
