Re: [PATCH 3/4] arm64: dts: rockchip: Add base DT for rk3528 SoC

From: Dragan Simic <dsimic@manjaro.org>
To: Yao Zi <ziyao@disroot.org>
Cc: "Heiko Stübner" <heiko@sntech.de>,
	"Krzysztof Kozlowski" <krzk@kernel.org>,
	"Rob Herring" <robh@kernel.org>,
	"Krzysztof Kozlowski" <krzk+dt@kernel.org>,
	"Conor Dooley" <conor+dt@kernel.org>,
	"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
	"Jiri Slaby" <jirislaby@kernel.org>,
	"Chris Morgan" <macromorgan@hotmail.com>,
	"Jonas Karlman" <jonas@kwiboo.se>,
	"Tim Lunn" <tim@feathertop.org>, "Andy Yan" <andyshrk@163.com>,
	"Muhammed Efe Cetin" <efectn@protonmail.com>,
	"Jagan Teki" <jagan@edgeble.ai>, "Ondrej Jirman" <megi@xff.cz>,
	devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-rockchip@lists.infradead.org, linux-kernel@vger.kernel.org,
	linux-serial@vger.kernel.org
Subject: Re: [PATCH 3/4] arm64: dts: rockchip: Add base DT for rk3528 SoC
Date: Mon, 05 Aug 2024 21:13:53 +0200	[thread overview]
Message-ID: <303a27ab5681e13467f01de9bfe94b45@manjaro.org> (raw)
In-Reply-To: <ZrD8N7_tYAiKCg-C@ziyaolaptop.my.domain>

Hello Yao,

On 2024-08-05 18:22, Yao Zi wrote:
> On Mon, Aug 05, 2024 at 01:47:45PM +0200, Heiko Stübner wrote:
>> Am Montag, 5. August 2024, 13:37:11 CEST schrieb Dragan Simic:
>> > On 2024-08-05 12:59, Yao Zi wrote:
>> > > On Sun, Aug 04, 2024 at 04:05:24PM +0200, Krzysztof Kozlowski wrote:
>> > >> On 04/08/2024 15:20, Yao Zi wrote:
>> > >> >>
>> > >> >>> +		compatible = "fixed-clock";
>> > >> >>> +		#clock-cells = <0>;
>> > >> >>> +		clock-frequency = <24000000>;
>> > >> >>> +		clock-output-names = "xin24m";
>> > >> >>> +	};
>> > >> >>> +
>> > >> >>> +	gic: interrupt-controller@fed01000 {
>> > >> >>
>> > >> >> Why this all is outside of SoC?
>> > >> >
>> > >> > Just as Heiko says, device tree for all other Rockchip SoCs don't have
>> > >> > a "soc" node. I didn't know why before but just follow the style.
>> > >> >
>> > >> > If you prefer add a soc node, I am willing to.
>> > >>
>> > >> Surprising as usually we expect MMIO nodes being part of SoC to be
>> > >> under
>> > >> soc@, but if that's Rockchip preference then fine.
>> > >>
>> > >
>> > > Okay, then I would leave it as is.
>> > >
>> > > For the fixed-clock node, I think "xin24m: clock-24m { }" is okay and
>> > > follows the new rule?
>> >
>> > I find "xin24m: clock-xin24m { }" better, because keeping the "xin24m"
>> > part in /sys listing(s), for example, can only be helpful.
>> 
>> I would second that :-) . Like on a number of boards we have for 
>> example
>> 125MHz gmac clock generators ... with 2 gmacs, there are 2 of them.
>> 
>> I'm not sure the preferred name accounts for that?
>> 
>> Similarly we also keep the naming in the regulator node,
>> it's regulator-vcc3v3-somename {} instead of just regulator-3v3 {}.
> 
> "clock-xin24m" wouldn't be more descriptive than "clock-24m" and there
> are usually only a few fixed clocks in dt, thus finding corresponding
> definition isn't a problem I think.

Well, using "clock-xin24m" comes with another benefit, which is using
the same "xin24m" as in the actual clock name.  That way, the same clock
name gets used in various /sys listings and in the debug clock summary
in /sys.  Having that kind of consistency can only be beneficial.

> For the gmac case, Krzysztof, do you think something like
> "clock-125m-gmac1" is acceptable, just like what has been done for
> regulators?

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