Re: [PATCH v4 2/3] dmaengine: add peripheral configuration

Peter Ujfalusi
2020-10-09T09:04:11Z

On 08/10/2020 15.31, Vinod Koul wrote:
> Some complex dmaengine controllers have capability to program the
> peripheral device, so pass on the peripheral configuration as part of
> dma_slave_config
>
> Signed-off-by: Vinod Koul <vkoul@kernel.org>
> ---
> include/linux/dmaengine.h | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
> index 6fbd5c99e30c..a15dc2960f6d 100644
> --- a/include/linux/dmaengine.h
> +++ b/include/linux/dmaengine.h
> @@ -418,6 +418,9 @@ enum dma_slave_buswidth {
> * @slave_id: Slave requester id. Only valid for slave channels. The dma
> * slave peripheral will have unique id as dma requester which need to be
> * pass as slave config.
> + * @peripheral_config: peripheral configuration for programming peripheral
> + * for dmaengine transfer
> + * @peripheral_size: peripheral configuration buffer size
> *
> * This struct is passed in as configuration data to a DMA engine
> * in order to set up a certain channel for DMA transport at runtime.
> @@ -443,6 +446,8 @@ struct dma_slave_config {
> u32 dst_port_window_size;
> bool device_fc;
> unsigned int slave_id;
> + void *peripheral_config;
> + size_t peripheral_size;

Do you foresee a need of src/dst pair of these?
If we do DEV_TO_DEV with different type of peripherals it is going to
cause issues.

AASRC to McASP and McASP to AASRC for example.

> };
>
> /**
>

- Péter

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