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Date:   Fri, 29 Jul 2022 19:49:45 +0200
From:   Daniel =?iso-8859-1?Q?Gl=F6ckner?= <dg@emlix.com>
To:     Ivan Bornyakov <i.bornyakov@metrotek.ru>
Cc:     mdf@kernel.org, hao.wu@intel.com, yilun.xu@intel.com,
        trix@redhat.com, robh+dt@kernel.org,
        krzysztof.kozlowski+dt@linaro.org, linux-fpga@vger.kernel.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
        system@metrotek.ru,
        Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Subject: Re: [PATCH v5 2/2] dt-bindings: fpga: add binding doc for ecp5-spi
 fpga mgr
Message-ID: <20220729174945.GA7164@homes.emlix.com>
References: <20220719112335.9528-1-i.bornyakov@metrotek.ru>
 <20220719112335.9528-3-i.bornyakov@metrotek.ru>
 <20220729090123.GA28299@homes.emlix.com>
 <20220729163347.irqqqcvh2biliqg2@x260>
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On Fri, Jul 29, 2022 at 07:33:47PM +0300, Ivan Bornyakov wrote:
> On Fri, Jul 29, 2022 at 11:01:24AM +0200, Daniel Gl?ckner wrote:
> > On Tue, Jul 19, 2022 at 02:23:35PM +0300, Ivan Bornyakov wrote:
> > > +properties:
> > > +  compatible:
> > > +    enum:
> > > +      - lattice,ecp5-fpga-mgr
> > 
> > Since this driver uses the same interface as the existing
> > drivers/fpga/machxo2-spi.c driver, wouldn't it be advisable to use a
> > similar compatible id, i.e. lattice,ecp5-slave-spi?
> > 
> 
> To quote Krzysztof Kozlowski from v1 review:
>  > Do not encode interface name in compatible so no "spi"
> 
> See https://lore.kernel.org/linux-fpga/044a9736-a4ec-c250-7755-c80a5bcbe38b@linaro.org/

true... MachXO2 to MachXO5 and those Nexus chips speak that protocol both
over spi and i2c and the position in the device tree decides which one it
should be. Maybe the compatible string in the existing driver should be
changed to lattice,machxo2. After all there is no other MachXO2-specific
interface/protocol except maybe jtag.

Best regards,

  Daniel