[PATCH v3 1/3] dt-bindings: reset: Add Armada8K reset controller

[Wilson Ding]

> -----Original Message-----
> From: Krzysztof Kozlowski <krzk at kernel.org>
> Sent: Friday, March 7, 2025 12:57 AM
> To: Wilson Ding <dingwei at marvell.com>; Rob Herring (Arm)
> <robh at kernel.org>
> Cc: linux-arm-kernel at lists.infradead.org; Sanghoon Lee <salee at marvell.com>;
> conor+dt at kernel.org; linux-kernel at vger.kernel.org;
> gregory.clement at bootlin.com; p.zabel at pengutronix.de; Geethasowjanya
> Akula <gakula at marvell.com>; devicetree at vger.kernel.org; andrew at lunn.ch;
> krzk+dt at kernel.org; sebastian.hesselbarth at gmail.com
> Subject: [EXTERNAL] Re: [PATCH v3 1/3] dt-bindings: reset: Add Armada8K
> reset controller
> 
> On 07/03/2025 01:03, Wilson Ding wrote:
> >> reset.example.dts
> >>>   DTC [C]
> >>> Documentation/devicetree/bindings/reset/marvell,armada8k-
> reset.examp
> >>> le
> >>> .dtb
> >>>
> >>
> >> That's a bit odd but anyway warning is correct: you cannot have such
> >> compatibles alone.
> >
> > I understand I need to add one compatible here to resolve the warning.
> > However, as we agreed, we keep the sud-nodes while there will be no
> > new compatibles in parent node. So how shall I avoid this warning?
> >
> > If we do want to add a compatible in parent node, what should be used
> > for the compatible name? I think the most suitable name would be
> > something like "marvell,cp110-system-controller0".
> 
> I don't know. I don't work in Marvell, I know nothing about Marvell Armada
> and I was not involved in any Armada SoCs.
> 
> Read your datasheet and come up with some reasonable name based on
> datasheet. Why do you ask people who do not have datasheet?
> 
> > However, it was already taken for in Armada clock controller to be
> > compatible for legacy dt.
> >
> > https://urldefense.proofpoint.com/v2/url?u=https-3A__lore.kernel.org_a
> > ll_bb21ee9acc55efac884450ff710049b99b27f8bf.1496328934.git-
> 2Dseries.gr
> > egory.clement-40free-
> 2Delectrons.com_&d=DwICaQ&c=nKjWec2b6R0mOyPaz7xtf
> >
> Q&r=sXDQZu4GyqNVDlFUXakSGJl0Dh81ZIPlU26YS4KHGIA&m=nfrB1z6tgLEY
> 3BeUK8cH
> >
> 5CBEnUJhq1yHXS9xCDegRMGapzD2rOL7z092sJd1dzIo&s=LqUI_K0rnOXPmy
> dkE9n-hdK
> > KO2dmGhyN5H-raW6-6Dc&e=
> 
> I don't understand what it means.
> 
> >
> > This is something about 8 years ago. I wonder if we do need to have
> > the backward compatibility for the field devices at that time. Can we
> > drop it now?
> 
> Drop what? You need to keep ABI.

Do you mean once a compatible name was present in dt-binding, it
Should never be deleted in future (even these is no dts file using it)?

> 
> >
> >     syscon0: system-controller at 440000 {
> >         compatible = "marvell,cp110-system-controller0",
> >                                 "syscon", "simple-mfd";
> >         reg = <0x440000 0x2000>;
> >         #address-cells = <1>;
> >         #size-cells = <1>;
> >
> >         swrst: reset-controller at 268 {
> >             compatible = "marvell,armada8k-reset";
> >             reg = <0x268 0x4>;
> >             #reset-cells = <1>;
> >         };
> >     };
> >
> Best regards,
> Krzysztof