Re: [PATCH v4 4/9] dt-bindings: mmc: Add Black Sesame Technologies DWCMSHC SDHCI

Albert Yang
2025-09-26T03:21:36Z

On Tue, Sep 23, 2025 at 08:56:20AM -0500, Rob Herring wrote:
> On Tue, Sep 23, 2025 at 02:10:10PM +0800, Albert Yang wrote:
> > Add device tree binding documentation for the Black Sesame Technologies
> > (BST) DWCMSHC SDHCI controller.

Hi Rob,

Thanks for the review.

> Thanks for the changelog here, but the subject should have 'PATCH v4' so
> various tools work.

Understood. Will ensure v5 has the proper subject format with 'PATCH v5'.

> Filename should match compatible.

Fixed. Renamed from bst,dwcmshc-sdhci.yaml to bst,c1200-dwcmshc.yaml
to match the compatible string "bst,c1200-dwcmshc", and updated the
$id field accordingly.

> Not really any point in having -names when there is only 1 entry.

Agreed. I've dropped clock-names from the schema, DTS, and removed it
from required properties.

> Having this is odd. Please add a description saying what it is for.

Added description for memory-region: "Reserved memory region for bounce
buffer. Required due to controller's 32-bit DMA limitation while system
RAM is above 32-bit addressable range."

Updated example:

mmc@22200000 {
compatible = "bst,c1200-dwcmshc";
reg = <0x0 0x22200000 0x0 0x1000>,
<0x0 0x23006000 0x0 0x1000>;
interrupts = <GIC_SPI 144 IRQ_TYPE_LEVEL_HIGH>;
clocks = <&clk_mmc>;
memory-region = <&mmc0_reserved>;
max-frequency = <200000000>;
bus-width = <8>;
non-removable;
dma-coherent;
};

Please let me know if you have any other concerns or suggestions for
this binding. I'll send v5 with these fixes.

Thanks,
Albert Yang