Re: [PATCH v3 3/4] dmaengine: dw-edma: Add support for native HDMA

[Bjorn Helgaas]

On Mon, Feb 13, 2023 at 09:24:08PM +0800, Cai Huoqing wrote:
> From: Cai huoqing <cai.huoqing@xxxxxxxxx>
> 
> Add support for HDMA NATIVE, as long the IP design has set
> the compatible register map parameter-HDMA_NATIVE,
> which allows compatibility for native HDMA register configuration.

Rewrap to fill 75 columns.  Also applies below.

> The HDMA Hyper-DMA IP is an enhancement of the eDMA embedded-DMA IP.
> And the native HDMA registers are different from eDMA,
> so this patch add support for HDMA NATIVE mode.
> 
> HDMA write and read channels operate independently to maximize
> the performance of the HDMA read and write data transfer over
> the link When you configure the HDMA with multiple read channels,
> then it uses a round robin (RR) arbitration scheme to select
> the next read channel to be serviced.
> The same applies when you have multiple write channels.

Wrap into a single paragraph or add a blank line if you want the last
sentence to be a new paragraph.

> The native HDMA driver also supports a maximum of 16 independent
> channels (8 write + 8 read), which can run simultaneously.
> Both SAR (Source Address Register) and DAR (Destination Address Register)
> are alignmented to byte.

s/alignmented/aligned/

> +	u32 watermark_en;			/* 0x0030 */
> +	u32	control1;			/* 0x0034 */
> +	u32	func_num;			/* 0x0038 */
> +	u32	qos;				/* 0x003c */
> +	u32	reserved;			/* 0x0040..0x007c */
> +	u32 ch_stat;				/* 0x0080 */

Weird indentation of control1, func_num, etc.  Is that meaningful or a
mistake?

> +	union {
> +		u64 reg;			/* 0x00a0..0x00a4 */
> +		struct {
> +			u32 lsb;		/* 0x00a0 */
> +			u32 msb;		/* 0x00a4 */
> +		};
> +	} msi_abort;
> +	u32	msi_msgdata;			/* 0x00a8 */

Again here.

Bjorn