Re: [PATCH v6 8/9] dmaengine: dw-edma: Add DW_EDMA_CHIP_32BIT_DBI for chip specific flags

[Serge Semin <fancer.lancer@gmail.com>]

On Wed, Apr 06, 2022 at 10:23:46AM -0500, Frank Li wrote:
> DW_EDMA_CHIP_32BIT_DBI was used by the controller drivers like i.MX8 that
> allows only 32bit access to the DBI region.
> 
> Signed-off-by: Frank Li <Frank.Li@nxp.com>
> ---
> Change from v5 to v6
> - use enum instead of define
> New patch at v5
> - fix kernel test robot build error
> 
>  drivers/dma/dw-edma/dw-edma-v0-core.c | 13 ++++++++-----
>  include/linux/dma/edma.h              |  2 ++
>  2 files changed, 10 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/dma/dw-edma/dw-edma-v0-core.c b/drivers/dma/dw-edma/dw-edma-v0-core.c
> index 30f8bfe6e5712..b2b2cbe75fe4f 100644
> --- a/drivers/dma/dw-edma/dw-edma-v0-core.c
> +++ b/drivers/dma/dw-edma/dw-edma-v0-core.c
> @@ -417,15 +417,18 @@ void dw_edma_v0_core_start(struct dw_edma_chunk *chunk, bool first)
>  		SET_CH_32(dw, chan->dir, chan->id, ch_control1,
>  			  (DW_EDMA_V0_CCS | DW_EDMA_V0_LLE));
>  		/* Linked list */
> -		#ifdef CONFIG_64BIT
> -			SET_CH_64(dw, chan->dir, chan->id, llp.reg,
> -				  chunk->ll_region.paddr);
> -		#else /* CONFIG_64BIT */
> +		if ((chan->dw->chip->flags & DW_EDMA_CHIP_32BIT_DBI) ||
> +		    !IS_ENABLED(CONFIG_64BIT)) {
>  			SET_CH_32(dw, chan->dir, chan->id, llp.lsb,
>  				  lower_32_bits(chunk->ll_region.paddr));
>  			SET_CH_32(dw, chan->dir, chan->id, llp.msb,
>  				  upper_32_bits(chunk->ll_region.paddr));
> -		#endif /* CONFIG_64BIT */
> +		} else {
> +		#ifdef CONFIG_64BIT
> +			SET_CH_64(dw, chan->dir, chan->id, llp.reg,
> +				  chunk->ll_region.paddr);
> +		#endif
> +		}
>  	}
>  	/* Doorbell */
>  	SET_RW_32(dw, chan->dir, doorbell,
> diff --git a/include/linux/dma/edma.h b/include/linux/dma/edma.h
> index bec444e2939b2..dc353a33a4a25 100644
> --- a/include/linux/dma/edma.h
> +++ b/include/linux/dma/edma.h
> @@ -36,9 +36,11 @@ enum dw_edma_map_format {
>  /**
>   * enum dw_edma_chip_flags - Flags specific to an eDMA chip
>   * @DW_EDMA_CHIP_LOCAL:		eDMA is used locally by an endpoint

> + * @DW_EDMA_CHIP_32BIT_DBI	Only support 32bit DBI register access
>   */
>  enum dw_edma_chip_flags {
>  	DW_EDMA_CHIP_LOCAL	= BIT(0),
> +	DW_EDMA_CHIP_32BIT_DBI	= BIT(1),

Please see my comment to "[PATCH v6 7/9] dmaengine: dw-edma: Add
support for chip specific flags" regarding the anonymous enumeration
here.

-Sergey

>  };
>  
>  /**
> -- 
> 2.35.1
>