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

[Changhuang Liang]

Hi, Conor

> 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.
> 

'm not sure about the hardware differences between 2.00a and 1.00a at the moment either.
I'll use the following method first:

compatible = "starfive,jhb100-spi", "snps,dwc-ssi-2.00a", "snps,dwc-ssi-1.01a"

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

Best Regards,
Changhuang