Re: [PATCH] dma: sun4i: expose block size and wait cycle configuration to DMA users

From: Vinod Koul
Date: Mon Mar 07 2016 - 09:51:00 EST


On Mon, Mar 07, 2016 at 10:59:31AM +0100, Boris Brezillon wrote:
> +/* Dedicated DMA parameter register layout */
> +#define SUN4I_DDMA_PARA_DST_DATA_BLK_SIZE(n) (((n) - 1) << 24)
> +#define SUN4I_DDMA_PARA_DST_WAIT_CYCLES(n) (((n) - 1) << 16)
> +#define SUN4I_DDMA_PARA_SRC_DATA_BLK_SIZE(n) (((n) - 1) << 8)
> +#define SUN4I_DDMA_PARA_SRC_WAIT_CYCLES(n) (((n) - 1) << 0)
> +
> +/**
> + * struct sun4i_dma_chan_config - DMA channel config
> + *
> + * @para: contains information about block size and time before checking
> + * DRQ line. This is device specific and only applicable to dedicated
> + * DMA channels

What information, can you elobrate.. And why can't you use existing
dma_slave_config for this?

> + */
> +struct sun4i_dma_chan_config {
> + u32 para;
> +};
> +
> +int sun4i_dma_set_chan_config(struct dma_chan *dchan,
> + const struct sun4i_dma_chan_config *cfg);
> +
> +#endif /* _SUN4I_DMA_H */

--
~Vinod