Re: [PATCH v1 1/2] dt-bindings: spi: snps,dw-apb-ssi: Add support for snps,dwc-ssi-2.00a

[Conor Dooley]

On Mon, Jun 15, 2026 at 10:49:07AM +0000, Changhuang Liang wrote:
> Hi, Conor
> 
> > On Sat, Jun 13, 2026 at 03:38:46AM +0000, Changhuang Liang wrote:
> > > Hi, Conor
> > >
> > > Thanks for the review.
> > >
> > > > On Fri, Jun 12, 2026 at 05:58:55AM -0700, Changhuang Liang wrote:
> > > > > Add a new compatible string "snps,dwc-ssi-2.00a" for the Synopsys
> > > > > DesignWare SSI controller version 2.00a.
> > > >
> > > > Two things. Firstly, driver patch suggests a fallback to 1.01a is
> > > > possible. Why haven't you added one?
> > >
> > > Will support fallback.
> > >
> > > > Secondly, I am going to expect that when your starfive user for this
> > > > appears in my inbox that it has a device-specific compatible, so you
> > > > may as well add that now.
> > >
> > > Our standard SPI control is completely based on the Synopsys DesignWare
> > SSI controller version 2.00a.
> > > However, for the controller that accesses the flash, a set of
> > > modifications has been made based on the Synopsys DesignWare SSI
> > controller version 2.00a, and the driver part also requires specific adaptation.
> > >
> > > Therefore, on the JHB100 SoC, the initial device tree source I have planned
> > looks like this:
> > >
> > > spi0: spi@17f20000 {
> > >       compatible = "snps,dwc-ssi-2.00a";
> > >       reg = <0x0 0x17f20000 0x0 0x10000>; };
> > >
> > > sfc0: spi@18000000 {
> > >       compatible = "starfive,jhb100-spi";
> > >       reg = <0x0 0x18000000 0x0 0x10000>; };
> > >
> > > Thus, I plan to add a new "starfive,jhb100-spi" compatible string for the
> > controller that accesses the flash.
> > > For now, I intend to keep these as two separate series.
> > 
> > No, if you have two integrations of the designware IP with different
> > programming models on the jhb100 I expect to see two different soc-specific
> > compatibles used. I don't want to see bare synopsys compatibles on the
> > platforms I am looking after.
> 
> Okay, I will change it to the following:
> 
> spi0: spi@17f20000 {
>       compatible = " starfive,jhb100-spi";

This one is compatible with "snps,dwc-ssi-2.00a" and "snps,dwc-ssi-1.00a",
so it should probably have those as fallbacks. The latter for sure, the
former if you know there's some non-discoverable differences between 2.00a
and 1.00a hardware.

Cheers,
Conor.

>       reg = <0x0 0x17f20000 0x0 0x10000>; 
> };
> 
> sfc0: spi@18000000 {
>       compatible = "starfive,jhb100-sfc";
>       reg = <0x0 0x18000000 0x0 0x10000>; 
> };
> 
> Best Regards,
> Changhuang
>

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