Subject: Re: [PATCH v4 11/11] arm64: dts: mt2712: use non-empty ranges for usb-phy

From: Chunfeng Yun <[email-masked]>
Date: Wed, 13 Nov 2019 11:18:22 +0800

On Tue, 2019-11-12 at 14:12 +0100, Matthias Brugger wrote:
> 
> On 12/11/2019 09:36, Chunfeng Yun wrote:
> > Use non-empty ranges for usb-phy to make the layout of
> > its registers clearer;
> > Replace deprecated compatible by generic
> > 
> > Signed-off-by: Chunfeng Yun <[email-masked]>
> > ---
> > v3~v4: no changes
> > 
> > v2: use generic compatible
> > ---
> >  arch/arm64/boot/dts/mediatek/mt2712e.dtsi | 42 ++++++++++++-----------
> >  1 file changed, 22 insertions(+), 20 deletions(-)
> > 
> > diff --git a/arch/arm64/boot/dts/mediatek/mt2712e.dtsi b/arch/arm64/boot/dts/mediatek/mt2712e.dtsi
> > index 43307bad3f0d..e24f2f2f6004 100644
> > --- a/arch/arm64/boot/dts/mediatek/mt2712e.dtsi
> > +++ b/arch/arm64/boot/dts/mediatek/mt2712e.dtsi
> > @@ -697,30 +697,31 @@
> >  	};
> >  
> >  	u3phy0: usb-phy@11290000 {
> > -		compatible = "mediatek,mt2712-u3phy";
> > -		#address-cells = <2>;
> > -		#size-cells = <2>;
> > -		ranges;
> > +		compatible = "mediatek,mt2712-tphy",
> > +			     "mediatek,generic-tphy-v2";
> > +		#address-cells = <1>;
> > +		#size-cells = <1>;
> 
> At a first glance I don't understand why you change address and size cells.
> Commit message doesn't explain it and AFAIS it's not part of the binding changes.
When Ryder sent DTS patch for mt7629, Rob suggested to use 1 cell,
non-empty ranges and provide the offset for v2 tphy which hasn't shared
registers between sub-phys, it'll make layout more clear.

See: https://patchwork.kernel.org/patch/10850925/

> 
> Can you explain why we need that, and update the commit message accordingly?

Just want to take it as an example when support other platforms.

> 
> Regrads,
> Matthias
> 
> > +		ranges = <0 0 0x11290000 0x9000>;
> >  		status = "okay";
> >  
> > -		u2port0: usb-phy@11290000 {
> > -			reg = <0 0x11290000 0 0x700>;
> > +		u2port0: usb-phy@0 {
> > +			reg = <0x0 0x700>;
> >  			clocks = <&clk26m>;
> >  			clock-names = "ref";
> >  			#phy-cells = <1>;
> >  			status = "okay";
> >  		};
> >  
> > -		u2port1: usb-phy@11298000 {
> > -			reg = <0 0x11298000 0 0x700>;
> > +		u2port1: usb-phy@8000 {
> > +			reg = <0x8000 0x700>;
> >  			clocks = <&clk26m>;
> >  			clock-names = "ref";
> >  			#phy-cells = <1>;
> >  			status = "okay";
> >  		};
> >  
> > -		u3port0: usb-phy@11298700 {
> > -			reg = <0 0x11298700 0 0x900>;
> > +		u3port0: usb-phy@8700 {
> > +			reg = <0x8700 0x900>;
> >  			clocks = <&clk26m>;
> >  			clock-names = "ref";
> >  			#phy-cells = <1>;
> > @@ -760,30 +761,31 @@
> >  	};
> >  
> >  	u3phy1: usb-phy@112e0000 {
> > -		compatible = "mediatek,mt2712-u3phy";
> > -		#address-cells = <2>;
> > -		#size-cells = <2>;
> > -		ranges;
> > +		compatible = "mediatek,mt2712-tphy",
> > +			     "mediatek,generic-tphy-v2";
> > +		#address-cells = <1>;
> > +		#size-cells = <1>;
> > +		ranges = <0 0 0x112e0000 0x9000>;
> >  		status = "okay";
> >  
> > -		u2port2: usb-phy@112e0000 {
> > -			reg = <0 0x112e0000 0 0x700>;
> > +		u2port2: usb-phy@0 {
> > +			reg = <0x0 0x700>;
> >  			clocks = <&clk26m>;
> >  			clock-names = "ref";
> >  			#phy-cells = <1>;
> >  			status = "okay";
> >  		};
> >  
> > -		u2port3: usb-phy@112e8000 {
> > -			reg = <0 0x112e8000 0 0x700>;
> > +		u2port3: usb-phy@8000 {
> > +			reg = <0x8000 0x700>;
> >  			clocks = <&clk26m>;
> >  			clock-names = "ref";
> >  			#phy-cells = <1>;
> >  			status = "okay";
> >  		};
> >  
> > -		u3port1: usb-phy@112e8700 {
> > -			reg = <0 0x112e8700 0 0x900>;
> > +		u3port1: usb-phy@8700 {
> > +			reg = <0x8700 0x900>;
> >  			clocks = <&clk26m>;
> >  			clock-names = "ref";
> >  			#phy-cells = <1>;
> > 

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