Re: [PATCH v7 2/3] arm64: dts: mediatek: add basic mt7986a support

[Matthias Brugger]

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@xxxxxxxxxxxx/__;!!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