Re: [PATCH v3 3/5] spi: dw: Add support for master mode selection for DWC SSI controller

[Mark Brown]

On Thu, Nov 11, 2021 at 02:51:59PM +0800, nandhini.srikandan@xxxxxxxxx wrote:

> Add support to select the controller mode as master mode by setting
> Bit 31 of CTRLR0 register. This feature is supported for controller
> versions above v1.02.

Clearly older versions of the controller can also run in this mode...

> -		if (dws->caps & DW_SPI_CAP_KEEMBAY_MST)
> -			cr0 |= DWC_SSI_CTRLR0_KEEMBAY_MST;
> +		/* CTRLR0[31] MST */
> +		cr0 |= DWC_SSI_CTRLR0_MST;

This makes the configuration unconditional, it's not gated by controller
version checks or any kind of quirk any more meaning that if anything
interprets that bit differently things might break.  If this is really
required to put the controller in master mode it seems that either the
1.02 version is not widespread or this is generally the hardware
default.

Attachment: signature.asc
Description: PGP signature