Re: [PATCH RFC 2/5] arm64: dts: qcom: sc7280: move pipe mux handling to phy

[Dmitry Baryshkov <dmitry.baryshkov@linaro.org>]

On Fri, 22 Apr 2022 at 13:07, Johan Hovold <johan@kernel.org> wrote:
>
> On Thu, Apr 21, 2022 at 01:59:04PM +0300, Dmitry Baryshkov wrote:
> > On 21/04/2022 13:20, Johan Hovold wrote:
> > > The QMP PHY pipe clock remuxing is part of the PHY, which is both the
> > > producer and the consumer of the pipe clock.
> > >
> > > Update the PCIe controller and PHY node to reflect the new binding.
> > >
> > > Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> > > ---
> > >   arch/arm64/boot/dts/qcom/sc7280.dtsi | 18 ++++++------------
> > >   1 file changed, 6 insertions(+), 12 deletions(-)
> > >
> > > diff --git a/arch/arm64/boot/dts/qcom/sc7280.dtsi b/arch/arm64/boot/dts/qcom/sc7280.dtsi
> > > index c07765df9303..b3a9630262dc 100644
> > > --- a/arch/arm64/boot/dts/qcom/sc7280.dtsi
> > > +++ b/arch/arm64/boot/dts/qcom/sc7280.dtsi
> > > @@ -1837,11 +1837,7 @@ pcie1: pci@1c08000 {
> > >                                     <0 0 0 3 &intc 0 0 0 438 IRQ_TYPE_LEVEL_HIGH>,
> > >                                     <0 0 0 4 &intc 0 0 0 439 IRQ_TYPE_LEVEL_HIGH>;
> > >
> > > -                   clocks = <&gcc GCC_PCIE_1_PIPE_CLK>,
> > > -                            <&gcc GCC_PCIE_1_PIPE_CLK_SRC>,
> > > -                            <&pcie1_lane 0>,
> > > -                            <&rpmhcc RPMH_CXO_CLK>,
> > > -                            <&gcc GCC_PCIE_1_AUX_CLK>,
> > > +                   clocks = <&gcc GCC_PCIE_1_AUX_CLK>,
> > >                              <&gcc GCC_PCIE_1_CFG_AHB_CLK>,
> > >                              <&gcc GCC_PCIE_1_MSTR_AXI_CLK>,
> > >                              <&gcc GCC_PCIE_1_SLV_AXI_CLK>,
> > > @@ -1849,11 +1845,7 @@ pcie1: pci@1c08000 {
> > >                              <&gcc GCC_AGGRE_NOC_PCIE_TBU_CLK>,
> > >                              <&gcc GCC_DDRSS_PCIE_SF_CLK>;
> > >
> > > -                   clock-names = "pipe",
> > > -                                 "pipe_mux",
> > > -                                 "phy_pipe",
> > > -                                 "ref",
> > > -                                 "aux",
> > > +                   clock-names = "aux",
> > >                                   "cfg",
> > >                                   "bus_master",
> > >                                   "bus_slave",
> > > @@ -1910,8 +1902,10 @@ pcie1_lane: lanes@1c0e200 {
> > >                                   <0 0x01c0e600 0 0x170>,
> > >                                   <0 0x01c0e800 0 0x200>,
> > >                                   <0 0x01c0ee00 0 0xf4>;
> > > -                           clocks = <&gcc GCC_PCIE_1_PIPE_CLK>;
> > > -                           clock-names = "pipe0";
> > > +                           clocks = <&gcc GCC_PCIE_1_PIPE_CLK>,
> > > +                                    <&gcc GCC_PCIE_1_PIPE_CLK_SRC>,
> > > +                                    <&rpmhcc RPMH_CXO_CLK>;
> > > +                           clock-names = "pipe0", "mux", "ref";
> >
> > This will not be compatible with earlier DTB files, which was a problem
> > up to now.
>
> That depends. The above wasn't added until 5.16 so we may still be able
> to fix it.

That would depend on Rob/Krzyshtof. But the whole process should be described.
The driver can nod depend on the clocks being there.

>
> The NAK you got from Rob earlier was when you removed clocks that have
> been in the devicetree for several years:
>
>         https://lore.kernel.org/all/YgQ+tGhLqwUCsTUo@robh.at.kernel.org/
>
> and would still be needed by older kernels.
>
> Worst case, we need to keep both sets for sc7280 (i.e. like we need to
> do with the pipe clocks that have been around for years).
>
> Johan



-- 
With best wishes
Dmitry