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

Stephen Boyd
2019-09-09T16:17:06Z

Quoting Jorge Ramirez-Ortiz, Linaro (2019-09-09 07:17:40)
> On 09/09/19 03:21:16, Stephen Boyd wrote:
> > Quoting Jorge Ramirez-Ortiz (2019-08-26 09:45:07)
> > > @@ -76,10 +88,11 @@ static int qcom_apcs_msm8916_clk_probe(struct platform_device *pdev)
> > > a53cc->src_shift = 8;
> > > a53cc->parent_map = gpll0_a53cc_map;
> > >
> > > - a53cc->pclk = devm_clk_get(parent, NULL);
> > > + a53cc->pclk = of_clk_get(parent->of_node, pll_index);
> >
> > Presumably the PLL was always index 0, so why are we changing it to
> > index 1 sometimes? Seems unnecessary.
> >
>
> it came as a personal preference. hope it is acceptable (I would
> rather not change it)
>
> apcs-msm8916.c declares the following
>
> [..]
> static const u32 gpll0_a53cc_map[] = { 4, 5 };
> static const char *gpll0_a53cc[] = {
> "gpll0_vote",
> "a53pll",
> };
> [..]
>
>
> now will be doing this
>
> --- 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>;
> };
>
>
> so I chose to keep the consistency between the clocks definition and
> just change the index before calling of_clk_get.
>

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.