Re: [PATCH 1/5] dmaengine: sprd: Define the DMA transfer step type

[Vinod Koul <vinod.koul@intel.com>]

On Tue, Apr 10, 2018 at 03:46:03PM +0800, Baolin Wang wrote:
> From: Eric Long <eric.long@spreadtrum.com>
> 
> Define the DMA transfer step type to make code more readable.
> 
> Signed-off-by: Eric Long <eric.long@spreadtrum.com>
> Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
> ---
>  drivers/dma/sprd-dma.c |   28 ++++++++++++++++++++++------
>  1 file changed, 22 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/dma/sprd-dma.c b/drivers/dma/sprd-dma.c
> index b106e8a..af9c156 100644
> --- a/drivers/dma/sprd-dma.c
> +++ b/drivers/dma/sprd-dma.c
> @@ -169,6 +169,22 @@ enum sprd_dma_int_type {
>  	SPRD_DMA_CFGERR_INT,
>  };
>  
> +/*
> + * enum sprd_dma_step: define the DMA transfer step type
> + * @SPRD_DMA_NONE_STEP: transfer do not need step
> + * @SPRD_DMA_BYTE_STEP: transfer step is one byte
> + * @SPRD_DMA_SHORT_STEP: transfer step is two bytes
> + * @SPRD_DMA_WORD_STEP: transfer step is one word
> + * @SPRD_DMA_DWORD_STEP: transfer step is double word
> + */
> +enum sprd_dma_step {

looking at bit defines, does it need to be enum? a #define would just be fine.

> +	SPRD_DMA_NONE_STEP,
> +	SPRD_DMA_BYTE_STEP = BIT(0),
> +	SPRD_DMA_SHORT_STEP = BIT(1),
> +	SPRD_DMA_WORD_STEP = BIT(2),
> +	SPRD_DMA_DWORD_STEP = BIT(3),
> +};
> +
>  /* dma channel hardware configuration */
>  struct sprd_dma_chn_hw {
>  	u32 pause;
> @@ -598,16 +614,16 @@ static int sprd_dma_config(struct dma_chan *chan, struct sprd_dma_desc *sdesc,
>  
>  	if (IS_ALIGNED(len, 4)) {
>  		datawidth = 2;
> -		src_step = 4;
> -		des_step = 4;
> +		src_step = SPRD_DMA_WORD_STEP;
> +		des_step = SPRD_DMA_WORD_STEP;
>  	} else if (IS_ALIGNED(len, 2)) {
>  		datawidth = 1;
> -		src_step = 2;
> -		des_step = 2;
> +		src_step = SPRD_DMA_SHORT_STEP;
> +		des_step = SPRD_DMA_SHORT_STEP;
>  	} else {
>  		datawidth = 0;
> -		src_step = 1;
> -		des_step = 1;
> +		src_step = SPRD_DMA_BYTE_STEP;
> +		des_step = SPRD_DMA_BYTE_STEP;
>  	}
>  
>  	fragment_len = SPRD_DMA_MEMCPY_MIN_SIZE;
> -- 
> 1.7.9.5
> 

-- 
~Vinod