Re: [PATCH v2 4/4] arm64: dts: mt7622: group clock DT nodes into separate DT file

From: Sean Wang
Date: Mon May 29 2017 - 21:16:46 EST


On Mon, 2017-05-29 at 17:09 +0200, Matthias Brugger wrote:
>
> On 29/05/17 14:56, sean.wang@xxxxxxxxxxxx wrote:
> > From: Sean Wang <sean.wang@xxxxxxxxxxxx>
> >
> > For more readability and maintenance, all the clock related DT
> > nodes for mt7622 SoC are grouped into a separate DT file. And
> > currently mt7622-clock.dtsi only includes the fixed clock for
> > uart0 and the oscillator which would be extended after MT7622
> > clock driver is introduced.
> >
>
> We've not done this for any other Mediatek SoC at the moment.
> Do you expect the m7622 to have more clock nodes then for example mt7623?


clocks on mt7622 has fewer nodes than mt7623

> Apart from that this clock nodes are just dummy clocks which should
> disappear as soon as the clock driver got merged.
> Last point, you break bisectability if add a clock node in a patch
> *after* the consumer was added.
>
> So please add the clock nodes to the dtsi as we did up to now. If in the
> future we see that mt7622 has a whole bunch of clock nodes, we can still
> abstract them in an external dtsi file.
>

Okay, I will merge back them into the main dtsi files for those reasons
in the next version.


Appreciate all your reviewing and suggestions

Sean

> Thanks,
> Matthias
>
> > Signed-off-by: Sean Wang <sean.wang@xxxxxxxxxxxx>
> > ---
> > arch/arm64/boot/dts/mediatek/mt7622-clock.dtsi | 20 ++++++++++++++++++++
> > arch/arm64/boot/dts/mediatek/mt7622.dtsi | 1 +
> > 2 files changed, 21 insertions(+)
> > create mode 100644 arch/arm64/boot/dts/mediatek/mt7622-clock.dtsi
> >
> > diff --git a/arch/arm64/boot/dts/mediatek/mt7622-clock.dtsi b/arch/arm64/boot/dts/mediatek/mt7622-clock.dtsi
> > new file mode 100644
> > index 0000000..264421d
> > --- /dev/null
> > +++ b/arch/arm64/boot/dts/mediatek/mt7622-clock.dtsi
> > @@ -0,0 +1,20 @@
> > +/*
> > + * Copyright (c) 2017 MediaTek Inc.
> > + * Author: Sean Wang <sean.wang@xxxxxxxxxxxx>
> > + *
> > + * SPDX-License-Identifier: (GPL-2.0 OR MIT)
> > + */
> > +/ {
> > + clk25m: oscillator@0 {
> > + compatible = "fixed-clock";
> > + #clock-cells = <0>;
> > + clock-frequency = <25000000>;
> > + clock-output-names = "clkxtal";
> > + };
> > +
> > + uart_clk: dummy26m {
> > + compatible = "fixed-clock";
> > + #clock-cells = <0>;
> > + clock-frequency = <25000000>;
> > + };
> > +};
> > diff --git a/arch/arm64/boot/dts/mediatek/mt7622.dtsi b/arch/arm64/boot/dts/mediatek/mt7622.dtsi
> > index 3a729d9..3768c28 100644
> > --- a/arch/arm64/boot/dts/mediatek/mt7622.dtsi
> > +++ b/arch/arm64/boot/dts/mediatek/mt7622.dtsi
> > @@ -8,6 +8,7 @@
> >
> > #include <dt-bindings/interrupt-controller/irq.h>
> > #include <dt-bindings/interrupt-controller/arm-gic.h>
> > +#include "mt7622-clock.dtsi"
> >
> > / {
> > compatible = "mediatek,mt7622";
> >