diff mbox series

[v2,14/15] spi: dt-bindings: snps,dw-ahb-ssi: Add generic dw-ahb-ssi version

Message ID 20221212180732.79167-15-sudip.mukherjee@sifive.com (mailing list archive)
State New, archived
Headers show
Series Add support for enhanced SPI for Designware SPI controllers | expand

Commit Message

Sudip Mukherjee Dec. 12, 2022, 6:07 p.m. UTC
Add new snps,dw-ahb-ssi version to the bindings.

Signed-off-by: Sudip Mukherjee <sudip.mukherjee@sifive.com>
---
 Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml | 1 +
 1 file changed, 1 insertion(+)

Comments

Rob Herring Dec. 13, 2022, 4:32 p.m. UTC | #1
On Mon, Dec 12, 2022 at 06:07:31PM +0000, Sudip Mukherjee wrote:
> Add new snps,dw-ahb-ssi version to the bindings.

Yes, I can see that in the diff. Tell me something useful here. Why 
do we need a new compatible? What does this compatible imply in the 
h/w that the existing ones don't. How do I know which compatible to 
use?

Really, this should probably only be a fallback with an SoC specific 
compatible. Future quirk properties which are not board specific only 
will be rejected. You've been warned.

> 
> Signed-off-by: Sudip Mukherjee <sudip.mukherjee@sifive.com>
> ---
>  Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml b/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml
> index d33b72fabc5d8..af36df67a4c0e 100644
> --- a/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml
> +++ b/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml
> @@ -45,6 +45,7 @@ properties:
>          enum:
>            - snps,dw-apb-ssi
>            - snps,dwc-ssi-1.01a
> +          - snps,dw-ahb-ssi
>        - description: Microsemi Ocelot/Jaguar2 SoC SPI Controller
>          items:
>            - enum:
> -- 
> 2.30.2
> 
>
Mark Brown Dec. 13, 2022, 4:59 p.m. UTC | #2
On Tue, Dec 13, 2022 at 10:32:09AM -0600, Rob Herring wrote:
> On Mon, Dec 12, 2022 at 06:07:31PM +0000, Sudip Mukherjee wrote:

> > Add new snps,dw-ahb-ssi version to the bindings.

> Really, this should probably only be a fallback with an SoC specific 
> compatible. Future quirk properties which are not board specific only 
> will be rejected. You've been warned.

Given how widely used DesignWare stuff is and usage in FPGAs it does
seem reasonable to have compatibles for just the IP rather than SoC
specific ones - we do have quirked versions that have been modified but
these are things that people manage to deploy without needing that and
SoC specific compatibles for FPGA instantiations would get painful.
Sudip Mukherjee Dec. 13, 2022, 5:47 p.m. UTC | #3
On Tue, Dec 13, 2022 at 4:59 PM Mark Brown <broonie@kernel.org> wrote:
>
> On Tue, Dec 13, 2022 at 10:32:09AM -0600, Rob Herring wrote:
> > On Mon, Dec 12, 2022 at 06:07:31PM +0000, Sudip Mukherjee wrote:
>
> > > Add new snps,dw-ahb-ssi version to the bindings.
>
> > Really, this should probably only be a fallback with an SoC specific
> > compatible. Future quirk properties which are not board specific only
> > will be rejected. You've been warned.
>
> Given how widely used DesignWare stuff is and usage in FPGAs it does
> seem reasonable to have compatibles for just the IP rather than SoC
> specific ones - we do have quirked versions that have been modified but
> these are things that people manage to deploy without needing that and
> SoC specific compatibles for FPGA instantiations would get painful.

Also, this patchset adds the autodetect procedure as discussed in the review
of the previous series at
https://lore.kernel.org/lkml/20220826233116.uulisbo663cxiadt@mobilestation/

So, we should be able to replace "snps,dw-apb-ssi" and
"snps,dwc-ssi-1.01a" with "snps,dw-ahb-ssi" after this.
And, also this generic compatible has been tested with the new 1.03a
version we are working with, which was
mentioned in my v1 at
https://lore.kernel.org/lkml/20220826233305.5ugpukokzldum7y5@mobilestation/
Serge Semin Dec. 13, 2022, 6:29 p.m. UTC | #4
On Tue, Dec 13, 2022 at 05:47:53PM +0000, Sudip Mukherjee wrote:
> On Tue, Dec 13, 2022 at 4:59 PM Mark Brown <broonie@kernel.org> wrote:
> >
> > On Tue, Dec 13, 2022 at 10:32:09AM -0600, Rob Herring wrote:
> > > On Mon, Dec 12, 2022 at 06:07:31PM +0000, Sudip Mukherjee wrote:
> >
> > > > Add new snps,dw-ahb-ssi version to the bindings.
> >
> > > Really, this should probably only be a fallback with an SoC specific
> > > compatible. Future quirk properties which are not board specific only
> > > will be rejected. You've been warned.
> >
> > Given how widely used DesignWare stuff is and usage in FPGAs it does
> > seem reasonable to have compatibles for just the IP rather than SoC
> > specific ones - we do have quirked versions that have been modified but
> > these are things that people manage to deploy without needing that and
> > SoC specific compatibles for FPGA instantiations would get painful.
> 

> Also, this patchset adds the autodetect procedure as discussed in the review
> of the previous series at
> https://lore.kernel.org/lkml/20220826233116.uulisbo663cxiadt@mobilestation/
> 
> So, we should be able to replace "snps,dw-apb-ssi" and
> "snps,dwc-ssi-1.01a" with "snps,dw-ahb-ssi" after this.

Just "snps,dwc-ssi-1.01a". That is the IP-core
https://www.synopsys.com/dw/ipdir.php?c=dwc_ssi
which support was added in
https://lore.kernel.org/linux-spi/20200505130618.554-4-wan.ahmad.zainie.wan.mohamad@intel.com/
Since the IP-core version is auto-detectable there is no need in
having the version attached to the compatible string. That's why I
asked @Sudip to introduce a new generic device name free of the
version suffix. It should be used instead of "snps,dwc-ssi-1.01a"
from now.

The "snps,dw-apb-ssi" compatible string will stay since it corresponds
to another IP-core:
https://www.synopsys.com/dw/ipdir.php?c=DW_apb_ssi

Answering to the @Rob note regarding the quirk properties. All the
features added by Sudip here were supposed to be auto-detectable.
So the generic IP-core name will be still useful as before with no
need in adding any quirks.

@Rob AFAIR you used to be against the generic fallback compatible
names, but had nothing against just generic compatibles. Has something
changed?

-Serge(y)

> And, also this generic compatible has been tested with the new 1.03a
> version we are working with, which was
> mentioned in my v1 at
> https://lore.kernel.org/lkml/20220826233305.5ugpukokzldum7y5@mobilestation/
> 
> -- 
> Regards
> Sudip
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml b/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml
index d33b72fabc5d8..af36df67a4c0e 100644
--- a/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml
+++ b/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml
@@ -45,6 +45,7 @@  properties:
         enum:
           - snps,dw-apb-ssi
           - snps,dwc-ssi-1.01a
+          - snps,dw-ahb-ssi
       - description: Microsemi Ocelot/Jaguar2 SoC SPI Controller
         items:
           - enum: