Re: [PATCH 02/10] dt-bindings: power: Add r8a774a3 SYSC power domain definitions

[Krzysztof Kozlowski <krzk@kernel.org>]

On 01/09/2026 16:11, Ayman Chaudhry wrote:
> Hi Krzysztof,
> 
> Thanks for the review.
> 
>> From: Krzysztof Kozlowski <krzk@kernel.org>
>> Sent: Saturday, August 22, 2026 8:30 AM
>> To: Ayman Chaudhry <ayman.chaudhry.kc@renesas.com>; Geert
>> Uytterhoeven <geert+renesas@glider.be>; magnus.damm
>> <magnus.damm@gmail.com>; Rob Herring <robh@kernel.org>; Krzysztof
>> Kozlowski <krzk+dt@kernel.org>; Conor Dooley <conor+dt@kernel.org>;
>> Stephen Boyd <sboyd@kernel.org>; Brian Masney
>> <bmasney+clk@redhat.com>; Jerome Brunet <jbrunet+clk@baylibre.com>;
>> Ulf Hansson <ulfh@kernel.org>
>> Cc: linux-renesas-soc@vger.kernel.org; devicetree@vger.kernel.org; linux-
>> kernel@vger.kernel.org; linux-clk@vger.kernel.org; linux-pm@vger.kernel.org;
>> Chris Paterson <Chris.Paterson2@renesas.com>; Biju Das
>> <biju.das.jz@bp.renesas.com>; Fabrizio Castro
>> <fabrizio.castro.jz@renesas.com>; Prabhakar Mahadev Lad
>> <prabhakar.mahadev-lad.rj@bp.renesas.com>
>> Subject: Re: [PATCH 02/10] dt-bindings: power: Add r8a774a3 SYSC power
>> domain definitions
>>
>> On 21/08/2026 17:03, Ayman Chaudhry wrote:
>>> This patch adds power domain indices for the Renesas RZ/G2M v3.0
>>
>>
>> Please do not use "This commit/patch/change", but imperative mood. See
>> longer explanation here:
>> https://elixir.bootlin.com/linux/v6.16/source/Documentation/process/submi
>> tting-patches.rst#L94
>>
> 
> Agreed, I will update the commit message.
> 
>>> (a.k.a. R8A774A3) SoC.
>>>
>>> Signed-off-by: Ayman Chaudhry <ayman.chaudhry.kc@renesas.com>
>>> ---
>>>  include/dt-bindings/power/r8a774a3-sysc.h | 30
>>> +++++++++++++++++++++++
>>
>> Filename must match compatible.
>>
> 
> Agreed, I will rename the file.
> 
> The bindings specify the filename, should I add an exception for this platform?
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=981a340540381532652731a500ba9df768bcef7d
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=61cada8da2f4c67026e41915f91673f045d4b18c
> 
>>
>>>  1 file changed, 30 insertions(+)
>>>  create mode 100644 include/dt-bindings/power/r8a774a3-sysc.h
>>>
>>> diff --git a/include/dt-bindings/power/r8a774a3-sysc.h
>>> b/include/dt-bindings/power/r8a774a3-sysc.h
>>> new file mode 100644
>>> index 000000000000..5694a422b771
>>> --- /dev/null
>>> +++ b/include/dt-bindings/power/r8a774a3-sysc.h
>>> @@ -0,0 +1,30 @@
>>> +/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */
>>> +/*
>>> + * Copyright (C) 2026 Renesas Electronics Corp.
>>> + */
>>> +#ifndef __DT_BINDINGS_POWER_R8A774A3_SYSC_H__
>>> +#define __DT_BINDINGS_POWER_R8A774A3_SYSC_H__
>>> +
>>> +/*
>>> + * These power domain indices match the numbers of the interrupt bits
>>
>> No, that's not a binding then.
>>
>> Also, why is this sent separately from the binding?
> 
> The binding is already present in the kernel:
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=3eb434de00b39c843249e89cf151757410e8a6ad

And where is it explained? Bindings are supposed to be complete so why
they were not posted complete?

> 
>>
>>> + * representing the power areas in the various Interrupt Registers
>>> + * (e.g. SYSCISR, Interrupt Status Register) */
>>> +
>>> +#define R8A774A3_PD_CA57_CPU0		 0
>>> +#define R8A774A3_PD_CA57_CPU1		 1
>>> +#define R8A774A3_PD_CA53_CPU0		 5
>>
>> No, value is 2. Or not a binding.
> 
> The values are pulled directly from the R8A774A3 hardware manual and
> as a result are not sequential.

So not really a binding.

> 
> This is compliant with header files for similar devices, so if we were to change
> the approach now it would probably make things more confusing for the

No, it is not compliant. Maybe it is done the same way as old devices,
but feedback was provided already for a few years, so plenty of time to
accept it.


> user and it would also require some special handling. Given that this is
> compliant with the style for similar devices adopting the same bindings,

It is not compliant.

> it's easy to understand as the numbers come straight from the HW manual,
> I would actually prefer if we could stick with this numbering scheme if
> possible.

Nope, as explained many times already for obvious reasons. Otherwise
provide me clear pieces of code which you bind here (as in DT bindings
header purpose).

Best regards,
Krzysztof