Messages in this thread | | | Date | Wed, 15 Mar 2017 15:23:24 -0500 | From | Rob Herring <> | Subject | Re: [v2, 4/4] dt-bindings: mtd: Add Octal SPI support to Cadence QSPI. |
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On Fri, Mar 10, 2017 at 01:52:31PM +0100, Marek Vasut wrote: > On 03/10/2017 01:03 PM, Artur Jedrysek wrote: > > > >> From: Marek Vasut [mailto:marek.vasut@gmail.com] > >> Sent: 10 March 2017 04:39 > >> On 03/08/2017 09:05 AM, Artur Jedrysek wrote: > >>> This patch updates Cadence QSPI Device Tree documentation to include > >>> information about new compatible used to indicate, whether or not > >>> Octal SPI transfers are supported by the device. > >>> > >>> Signed-off-by: Artur Jedrysek <jartur@cadence.com> > >>> --- > >>> Changelog: > >>> v2: Use new compatible, instead of boolean property, to indicate > >>> Octal SPI support. > >>> --- > >>> Documentation/devicetree/bindings/mtd/cadence-quadspi.txt | 4 +++- > >>> 1 file changed, 3 insertions(+), 1 deletion(-) > >>> > >>> diff --git a/Documentation/devicetree/bindings/mtd/cadence-quadspi.txt > >> b/Documentation/devicetree/bindings/mtd/cadence-quadspi.txt > >>> index f248056..41d1e98 100644 > >>> --- a/Documentation/devicetree/bindings/mtd/cadence-quadspi.txt > >>> +++ b/Documentation/devicetree/bindings/mtd/cadence-quadspi.txt > >>> @@ -1,7 +1,9 @@ > >>> * Cadence Quad SPI controller > >>> > >>> Required properties: > >>> -- compatible : Should be "cdns,qspi-nor". > >>> +- compatible : Should be "cdns,{qspi|ospi}-nor". > >> > >> Please explicitly list all compatibles , ie. > >> Should be "cdns,qspi-nor" or "cdns,ospi-nor". > >> > > > > Two possible options are also explicitly listed right below. I did that > > in the way it was done in other driver for Cadence IP: > > /Documentation/devicetree/bindings/net/macb.txt > > Should I remove all of that and replace it with both options, separated > > by an "or" word? > > Wait for Rob to confirm.
As Marek suggested, but with one valid combination per line. I don't think checkpatch.pl will work with it as is.
> > >> But I think the ospi is backward compatible with qspi, right ? So the > >> binding for ospi should list both, ie. > >> compatible = "cdns,ospi-nor", "cdns,qspi-nor"; > >> > > > > Yes, the ospi is backwards compatible with qspi. However, the sole point > > of introducing new compatible was to differentiate between them (which > > was previously done using a boolean flag, but that was criticized). > > Listing both bindings for ospi would only help for kernels not > > containing driver update being subject of this patch series, as both > > ospi and qspi are handled by the same driver - just with a slight > > difference. I apologize if I got something wrong here. > > You got it right, I was just curious about the compatibility.
You are assuming every OS/user everywhere is updated. It doesn't hurt to have the backwards compatibility.
Rob
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