Re: [PATCH 1/4] arm64: dts: ti: k3-j721e-main: Fix external refclk input to SERDES

[Nishanth Menon]

On 14:00-20210517, Kishon Vijay Abraham I wrote:
> Hi Nishanth,
> 
> On 13/05/21 7:31 pm, Nishanth Menon wrote:
> > On 17:41-20210513, Kishon Vijay Abraham I wrote:
> >> Hi Nishanth,
> >>
> >> On 13/05/21 12:21 am, Nishanth Menon wrote:
> >>> On 20:42-20210512, Kishon Vijay Abraham I wrote:
> >>>> Rename the external refclk inputs to the SERDES from
> >>>> dummy_cmn_refclk/dummy_cmn_refclk1 to cmn_refclk/cmn_refclk1
> >>>> respectively. Also move the external refclk DT nodes outside the
> >>>> cbass_main DT node. Since in j721e common processor board, only the
> >>>> cmn_refclk1 is connected to 100MHz clock, fix the clock frequency.
> >>>>
> >>>> Fixes: afd094ebe69f ("arm64: dts: ti: k3-j721e-main: Add WIZ and SERDES PHY nodes")
> >>>
> >>> Assume we want this part of 5.13 fixes?
> >>
> >> This doesn't fix any functionality. Okay for me to go in 5.14 along with
> >> the rest of the series.
> > 
> > 
> >>>
> >>>> Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx>
> >>>> ---
> >>>>  .../dts/ti/k3-j721e-common-proc-board.dts     |  4 ++
> >>>>  arch/arm64/boot/dts/ti/k3-j721e-main.dtsi     | 58 ++++++++++---------
> >>>>  2 files changed, 34 insertions(+), 28 deletions(-)
> >>>>
> >>>> diff --git a/arch/arm64/boot/dts/ti/k3-j721e-common-proc-board.dts b/arch/arm64/boot/dts/ti/k3-j721e-common-proc-board.dts
> >>>> index 60764366e22b..86f7ab511ee8 100644
> >>>> --- a/arch/arm64/boot/dts/ti/k3-j721e-common-proc-board.dts
> >>>> +++ b/arch/arm64/boot/dts/ti/k3-j721e-common-proc-board.dts
> >>>> @@ -635,6 +635,10 @@
> >>>>  	status = "disabled";
> >>>>  };
> >>>>  
> >>>> +&cmn_refclk1 {
> >>>> +	clock-frequency = <100000000>;
> >>>> +};
> >>>> +
> >>>>  &serdes0 {
> >>>>  	serdes0_pcie_link: link@0 {
> >>>>  		reg = <0>;
> >>>> diff --git a/arch/arm64/boot/dts/ti/k3-j721e-main.dtsi b/arch/arm64/boot/dts/ti/k3-j721e-main.dtsi
> >>>> index c2aa45a3ac79..002a0c1520ee 100644
> >>>> --- a/arch/arm64/boot/dts/ti/k3-j721e-main.dtsi
> >>>> +++ b/arch/arm64/boot/dts/ti/k3-j721e-main.dtsi
> >>>> @@ -8,6 +8,20 @@
> >>>>  #include <dt-bindings/mux/mux.h>
> >>>>  #include <dt-bindings/mux/ti-serdes.h>
> >>>>  
> >>>> +/ {
> >>>> +	cmn_refclk: cmn-refclk {
> >>>> +		#clock-cells = <0>;
> >>>> +		compatible = "fixed-clock";
> >>>> +		clock-frequency = <0>;
> >>>> +	};
> >>>> +
> >>>> +	cmn_refclk1: cmn-refclk1 {
> >>>
> >>> Just curious: why cant we use the standard nodenames with clock?
> >>
> >> We can use standard names here. Is there any defined nodename for
> >> clocks? clk or clock? Don't see $nodename defined for clocks in
> >> dt-schema repository.
> > 
> > Looking at the fixed-clock example, lets go with clock
> 
> Since I have two clocks here adding clock@0 and clock@1 introduces the
> following error.
> /home/a0393678/repos/linux-wip/arch/arm64/boot/dts/ti/k3-j721e-common-proc-board.dt.yaml:
> /: clock@0: 'anyOf' conditional failed, one must be fixed:
>         'reg' is a required property
>         'ranges' is a required property
> 
> The current "fixed-clock" binding doesn't allow adding "reg" property.
> We'll stick to non standard names? or do you think the binding has to be
> fixed?

Look at other fixed-clock examples in other arm64 examples
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/arm64/boot/dts/freescale/imx8mm.dtsi#n147
is a good one.. Binding is fine, IMHO.

-- 
Regards,
Nishanth Menon
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