Message-ID: <a4605e32-3af3-5636-6682-475bef8448d1@gmail.com>
Date:   Fri, 19 Nov 2021 11:31:15 +0100
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To:     Sam Shih <sam.shih@mediatek.com>, Rob Herring <robh+dt@kernel.org>,
        Hsin-Yi Wang <hsinyi@chromium.org>,
        Enric Balletbo i Serra <enric.balletbo@collabora.com>,
        Fabien Parent <fparent@baylibre.com>,
        Seiya Wang <seiya.wang@mediatek.com>,
        Sean Wang <sean.wang@mediatek.com>, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-mediatek@lists.infradead.org
Cc:     John Crispin <john@phrozen.org>, Ryder Lee <Ryder.Lee@mediatek.com>
References: <20211018114009.13350-1-sam.shih@mediatek.com>
 <20211018114009.13350-3-sam.shih@mediatek.com>
 <d411aec5-efa8-c71d-8179-54ff52c17039@gmail.com>
 <d299493d8fec0f34f527942f2cdedf15f2136c9a.camel@mediatek.com>
 <c5c0849d-a95a-25a0-11f8-9156770afc10@gmail.com>
 <59963509ec833009f5c10f0a1aee91670224c6c7.camel@mediatek.com>
From:   Matthias Brugger <matthias.bgg@gmail.com>
Subject: Re: [PATCH v7 2/3] arm64: dts: mediatek: add basic mt7986a support
In-Reply-To: <59963509ec833009f5c10f0a1aee91670224c6c7.camel@mediatek.com>
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On 18/11/2021 04:48, Sam Shih wrote:
> Hi
> 
> On Tue, 2021-11-16 at 12:18 +0100, Matthias Brugger wrote:
>>
>> On 16/11/2021 02:39, Sam Shih wrote:
>>> Hi,
>>>
>>> On Mon, 2021-11-15 at 17:27 +0100, Matthias Brugger wrote:
>>>> Hi,
>>>>
>>>> On 18/10/2021 13:40, Sam Shih wrote:
>>>>> Add basic chip support for Mediatek mt7986a, include
>>>>> basic uart nodes, rng node and watchdog node.
>>>>>
>>>>> Add cpu node, timer node, gic node, psci and reserved-memory
>>>>> node
>>>>> for ARM Trusted Firmware.
>>>>>
>>>>
>>>> What is the exact difference between mt7986a and mt7986b? Right
>>>> now,
>>>> it's only
>>>> the compatible, for that it makes no sense to split them.
>>>>
>>>
>>> The difference between mt7986a and mt7986b is pinout which
>>> described
>>> in our pinctrl patch series
>>>
> https://urldefense.com/v3/__https://lore.kernel.org/all/20211022124036.5291-3-sam.shih@mediatek.com/__;!!CTRNKA9wMg0ARbw!0kseU8x1KnHHXDErh6Yj6MKqecufPEfGyeumtTBism47e99UFO2Gs-HfWjL1_jUv$
>>>   
>>>
>>> You are right, in this "basic SoC support" patch series, only show
>>> compatible differences
>>>
>>>> It would be good to see what the exact differences are, so that
>>>> we
>>>> can see if it
>>>> makes sense to have one of the alternatives:
>>>> 1) use a common mt7986.dtsi which get included by
>>>> mt7986[a,b].dtsi
>>>> 2) Use on mt7986.dtsi and only add one mt7986a.dtsi or
>>>> mt7986b.dtsi
>>>> which has
>>>> add-ons.
>>>>
>>>
>>> In this case, can we use solution (1) to create a generic
>>> mt7986.dtsi
>>> in this patch series, and add mt7986[a,b].dtsi to the dts part of
>>> the
>>> pinctrl patch series to separate the difference nodes?
>>>
>>
>> If the only difference is the GPIO controller then why not go with
>> solution 2.
>> Create a mt7986.dtsi which holds e.g. the node for pincontroller
>> mt7986a and
>> then create a mt7986b.dtsi that just changes compatible and gpio-
>> ranges:
>>
>> &pio {
>>      compatible = "mediatek,mt7986b-pinctrl";
>>      gpio-ranges = <&pio 0 0 41>, <&pio 66 66 35>;
>> }
>>
>> What do you think?
> 
> Ok,
> 
> For this basic patch series DTS, I will send the next version:
> - Use "mt7986.dtsi" instead of "mt7986[a,b].dtsi",
>    And make"mt7986.dtsi" get included by "mt7986[a,b]-rfb.dts"
>    (No dedicated uart1/uart2 pinout for mt7986b-rfb, status of dts node
> shoud be set to "disabled")
> 
> 
> For the pinctrl patch series DTS, I will send th next version:
> - Add "mt7986b.dtsi" according to your suggestion,
>    the new include
> chain will be:
>    mt7986a-rfb.dts <-- mt7986.dtsi (mt7986a pinctrl)
>   
> mt7986b-rfb.dts <-- mt7986b.dtsi (mt7986b pinctrl) <-- mt7986.dtsi
> (mt7986a pinctrl)
> 
> Do you agree above proposal?
> 

I mean something like this:
mt7986a.dtsi:
pio: pinctrl@1001f000 {
	compatible = "mediatek,mt7986a-pinctrl";
	reg = <0 0x1001f000 0 0x1000>,
	      <0 0x11c30000 0 0x1000>,
	      <0 0x11c40000 0 0x1000>,
	      <0 0x11e20000 0 0x1000>,
	      <0 0x11e30000 0 0x1000>,
	      <0 0x11f00000 0 0x1000>,
	      <0 0x11f10000 0 0x1000>,
	      <0 0x1000b000 0 0x1000>;
	reg-names = "gpio", "iocfg_rt", "iocfg_rb", "iocfg_lt",
		    "iocfg_lb", "iocfg_tr", "iocfg_tl", "eint";
	gpio-controller;
	#gpio-cells = <2>;
	gpio-ranges = <&pio 0 0 100>;
	interrupt-controller;
	interrupts = <GIC_SPI 225 IRQ_TYPE_LEVEL_HIGH>;
	interrupt-parent = <&gic>;
	#interrupt-cells = <2>;
};

mt7986b.dtsi:
#include "mt7986a.dtsi"

&pio {
      compatible = "mediatek,mt7986b-pinctrl";
      gpio-ranges = <&pio 0 0 41>, <&pio 66 66 35>;
}

mt7986b-rfb.dts:
#include "mt7986b.dtsi"

&pio {
	uart1_pins: uart1-pins {
		mux { [...]


mt7986a-rfb.dts:
#include "mt7986a.dtsi"

&pio {
	uart1_pins: uart1-pins {
		mux { [...]


Makes sense?

Regards,
Matthias