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Date:   Fri, 8 Jul 2022 18:29:19 +0200
From:   Marek =?UTF-8?B?QmVow7pu?= <kabel@kernel.org>
To:     Pali =?UTF-8?B?Um9ow6Fy?= <pali@kernel.org>
Cc:     Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
        Pavel Machek <pavel@ucw.cz>, Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        linux-leds@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 1/2] [RFT] dt-bindings: leds: Add
 cznic,turris1x-leds.yaml binding
Message-ID: <20220708182919.2a1e4a52@thinkpad>
In-Reply-To: <20220708160528.ysy4lzxfpwobfiwr@pali>
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        <20220706111912.hz2mx4dc35lgq6l5@pali>
        <20220706172732.6228d180@thinkpad>
        <25b43586-eeb3-4b7b-7362-2d599aa89cf0@linaro.org>
        <20220708160528.ysy4lzxfpwobfiwr@pali>
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On Fri, 8 Jul 2022 18:05:28 +0200
Pali Roh=C3=A1r <pali@kernel.org> wrote:

> On Wednesday 06 July 2022 17:36:43 Krzysztof Kozlowski wrote:
> > On 06/07/2022 17:27, Marek Beh=C3=BAn wrote: =20
> > > On Wed, 6 Jul 2022 13:19:12 +0200
> > > Pali Roh=C3=A1r <pali@kernel.org> wrote:
> > >  =20
> > >> On Wednesday 06 July 2022 13:15:07 Marek Beh=C3=BAn wrote: =20
> > >>> On Tue,  5 Jul 2022 17:59:28 +0200
> > >>> Pali Roh=C3=A1r <pali@kernel.org> wrote:
> > >>>    =20
> > >>>> +examples:
> > >>>> +  - |
> > >>>> +    #include <dt-bindings/leds/common.h>
> > >>>> +
> > >>>> +    cpld@3,0 {   =20
> > >>>
> > >>> The generic node name should be just "bus". That it is a CPLD
> > >>> implementation should come from compatible string.   =20
> > >>
> > >> Sorry, I do not understand why "bus". Why other memory chips are nam=
ed
> > >> e.g. "nand" or "nor" and not "bus" too? =20
> > >=20
> > > As far as I understand this is because that is the preferred name for
> > > busses and this is a bus, since there is also the simple-bus compatib=
le.
> > >  =20
> > >> By this logic should not be _every_ node called just "bus"? Hm... an=
d=20
> > >> are names needed at all then? =20
> > >=20
> > > :-)
> > >=20
> > > The schema
> > >   https://github.com/devicetree-org/dt-schema/blob/main/dtschema/sche=
mas/simple-bus.yaml
> > > allows for different names (soc|axi|ahb|*-bus) to avoid warnings on
> > > existing old dts files.
> > >=20
> > > The preferred way is to not have the implementation in nodename,
> > > similar to how we use 'switch' instead of 'mv88e6xxx', or
> > > 'ethernet-phy' instead of 'mv88e151x', or 'led-controller', ... =20
> >=20
> > Thanks Marek for detailed explanation.
> > The cases above rather trigger my comments and this one here, after
> > Pali's explanation, do not fit them. pld is a generic class of a device,
> > so it is okay here. cpld probably as well (although one could argue that
> > it is a subset of pld, so the generic name is pld, but then one would
> > say fpga also should be called pld). For me it does not have to be bus,
> > just don't want mv88e6xxx or any other vendor/model names. Therefore
> > cpld is fine. =20
>=20
> Exactly. cpld, fpga, nor, nand, soc... all of them are not real buses.
>=20
> simple-bus here is just name invented by device tree and without which
> existing kernel drivers refuse to work.

OK, then cpld seems correct. I thought it was considered a bus in a way,
since "simple-bus" is used in compatible.

Marek