Re: [PATCH 1/4] dt-bindings: PCI: qcom,pcie-sc8180x: Drop unrelated clocks from PCIe hosts

From: Qiang Yu
Date: Thu Jun 19 2025 - 04:00:35 EST


On Fri, Jun 13, 2025 at 02:43:38PM +0530, Manivannan Sadhasivam wrote:
> + Krishna
>
> On Wed, May 21, 2025 at 03:38:10PM +0200, Konrad Dybcio wrote:
> > From: Konrad Dybcio <konrad.dybcio@xxxxxxxxxxxxxxxx>
> >
> > The TBU clock belongs to the Translation Buffer Unit, part of the SMMU.
> > The ref clock is already being driven upstream through some of the
> > branches.
> >
>
> Can you please cross check with the hardware programming guide (I don't have
> access to atm) that the 'ref' clock is no longer voted by the driver?
>

CLKREF is required for PHY. Since it has been voted in PCIe PHY driver,
omitting it here is reasonable.

- Qiang Yu

> - Mani
>
> > Signed-off-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxxxxxxxx>
> > ---
> > .../devicetree/bindings/pci/qcom,pcie-sc8180x.yaml | 14 ++++----------
> > 1 file changed, 4 insertions(+), 10 deletions(-)
> >
> > diff --git a/Documentation/devicetree/bindings/pci/qcom,pcie-sc8180x.yaml b/Documentation/devicetree/bindings/pci/qcom,pcie-sc8180x.yaml
> > index 331fc25d7a17d657d4db3863f0c538d0e44dc840..34a4d7b2c8459aeb615736f54c1971014adb205f 100644
> > --- a/Documentation/devicetree/bindings/pci/qcom,pcie-sc8180x.yaml
> > +++ b/Documentation/devicetree/bindings/pci/qcom,pcie-sc8180x.yaml
> > @@ -33,8 +33,8 @@ properties:
> > - const: mhi # MHI registers
> >
> > clocks:
> > - minItems: 8
> > - maxItems: 8
> > + minItems: 6
> > + maxItems: 6
> >
> > clock-names:
> > items:
> > @@ -44,8 +44,6 @@ properties:
> > - const: bus_master # Master AXI clock
> > - const: bus_slave # Slave AXI clock
> > - const: slave_q2a # Slave Q2A clock
> > - - const: ref # REFERENCE clock
> > - - const: tbu # PCIe TBU clock
> >
> > interrupts:
> > minItems: 8
> > @@ -117,17 +115,13 @@ examples:
> > <&gcc GCC_PCIE_0_CFG_AHB_CLK>,
> > <&gcc GCC_PCIE_0_MSTR_AXI_CLK>,
> > <&gcc GCC_PCIE_0_SLV_AXI_CLK>,
> > - <&gcc GCC_PCIE_0_SLV_Q2A_AXI_CLK>,
> > - <&gcc GCC_PCIE_0_CLKREF_CLK>,
> > - <&gcc GCC_AGGRE_NOC_PCIE_TBU_CLK>;
> > + <&gcc GCC_PCIE_0_SLV_Q2A_AXI_CLK>;
> > clock-names = "pipe",
> > "aux",
> > "cfg",
> > "bus_master",
> > "bus_slave",
> > - "slave_q2a",
> > - "ref",
> > - "tbu";
> > + "slave_q2a";
> >
> > dma-coherent;
> >
> >
> > --
> > 2.49.0
> >
>
> --
> மணிவண்ணன் சதாசிவம்
>