[PATCH v4] ARM: dts: add DT for lan966 SoC and 2-port board pcb8291

[Kavyasree.Kotagiri at microchip.com]

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> Am 2022-02-18 13:28, schrieb Kavyasree.Kotagiri at microchip.com:
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> >> Am 2022-02-10 12:52, schrieb Kavyasree.Kotagiri at microchip.com:
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> >> >> Am 2022-02-10 10:40, schrieb Kavyasree.Kotagiri at microchip.com:
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> >> >>
> >> >> >> > +     clocks {
> >> >> >> [..]
> >> >> >> > +
> >> >> >> > +             nic_clk: nic_clk {
> >> >> >>
> >> >> >> What does nic_clk stand for? If I had to guess, it
> >> >> >> has something to do with network. But..
> >> >> >>
> >> >> > NIC clock is the clock used by AXI, AHB fabric and APB bridges which
> >> >> > connects all the peripherals.
> >> >> > It is named so because the AXI fabric is based on NIC400 IP from ARM
> >> >>
> >> >> Ok, thanks for clarification.
> >> >>
> >> >>
> >> >> >> > +             watchdog: watchdog at e0090000 {
> >> >> >> > +                     compatible = "snps,dw-wdt";
> >> >> >> > +                     reg = <0xe0090000 0x1000>;
> >> >> >> > +                     interrupts = <GIC_SPI 38 IRQ_TYPE_LEVEL_HIGH>;
> >> >> >> > +                     clocks = <&nic_clk>;
> >> >> >>
> >> >> >> Btw. can we disable all nodes by default and enable them
> >> >> >> in the board dts files?
> >> >> > I would like to have only board specific nodes enabled in dts files
> >> >> > and rest of them in dtsi file
> >> >>
> >> >> And how do you know which ones are board specific? E.g. I would like
> >> >> to add our board which is also based on the lan9668. Maybe I don't
> >> >> want a watchdog (or whatever node). Of course I could use
> >> >>
> >> >> &watchdog {
> >> >>    status = "disabled";
> >> >> };
> >> >>
> >> >> But IMHO opt-in is better. At least thats what we are doing for
> >> >> the layerscape over on arm64.
> >> >>
> >> > Basically, I am disabling only the nodes which have pinctrl settings
> >> > in dtsi file
> >> > and enable in dts to make sure there are no conflicts on pins on the
> >> > board.
> >>
> >> Thats not what I'm asking. I would like to see *optional* nodes
> >> disabled by default. Whether the watchdog is optional might be
> >> debatable, but what about the usb controller and the qspi
> >> controller? They don't have shared pins AFAIK, so according
> >> to your rule, they will be enabled by default and each board
> >> which doesn't have anything connected on these pins would have
> >> to disabled it.
> >>
> >> Please keep in mind that this .dtsi will also be used by boards
> >> not manufactured by microchip.
> >>
> > I agree with you - "disabling optional nodes in dtsi"
> > I have gone through all the nodes.
> > Confirmed and moved enabling optional node watchdog
> > to dts file.
> 
> Great, I just wanted to get to an agreement how the optional nodes
> should be handled. If it turns out, some are still optional or
> some aren't. It is easy to just mark them disabled and enable them
> in the board dts files in a later patch.
> 
Sorry, I didn't get you. Do you still see optional nodes in my dtsi?
I think GPIO controller, Interrupt controller, XDMA, timers, AES, SHA, TRNG are
not optional. So, I keep them enabled in dtsi. 
Please let me know your comments.

> -michael