Re: [PATCH 2/5] clk: qcom: apcs-msm8916: get parent clock names from DT

[Stephen Boyd <sboyd@kernel.org>]

Quoting Jorge Ramirez-Ortiz, Linaro (2019-09-09 09:54:08)
> On 09/09/19 09:17:03, Stephen Boyd wrote:
> > But now the binding is different for the same compatible. I'd prefer we
> > keep using devm_clk_get() and use a device pointer here and reorder the
> > map and parent arrays instead. The clocks property shouldn't change in a
> > way that isn't "additive" so that we maintain backwards compatibility.
> > 
> 
> but the backwards compatibility is fully maintained - that is the main reason
> behind the change. the new stuff is that  instead of hardcoding the
> names in the source - like it is being done on the msm8916- we provide
> the clocks in the dts node (a cleaner approach with the obvious
> benefit of allowing new users to be added without having to modify the
> sources).
> 

This is not a backwards compatible change.

> > > --- a/arch/arm64/boot/dts/qcom/msm8916.dtsi
> > > +++ b/arch/arm64/boot/dts/qcom/msm8916.dtsi
> > > @@ -429,7 +429,8 @@
> > >      compatible = "qcom,msm8916-apcs-kpss-global", "syscon";
> > >      reg = <0xb011000 0x1000>;
> > >      #mbox-cells = <1>;
> > > -                   clocks = <&a53pll>;
> > > +                 clocks = <&gcc GPLL0_VOTE>, <&a53pll>;
> > > +                 clock-names = "aux", "pll";
> > >                       #clock-cells = <0>;
> > >                };
> > >                                                                                                                 

Because the "clocks" property changed from

	<&a53pll>

to

	<&gcc GPLL0_VOTE>, <&a53pll>

and that moves pll to cell 1 instead of cell 0.