Re: [PATCH v4 02/10] arm64: dts: qcom: qcs6490-rb3gen2: Add TC956x PCIe switch node

Dmitry Baryshkov
2025-03-17T11:27:39Z

On Mon, Mar 17, 2025 at 03:05:17PM +0530, Krishna Chaitanya Chundru wrote:
>
>
> On 2/25/2025 5:19 PM, Dmitry Baryshkov wrote:
> > On Tue, Feb 25, 2025 at 03:03:59PM +0530, Krishna Chaitanya Chundru wrote:
> > > Add a node for the TC956x PCIe switch, which has three downstream ports.
> > > Two embedded Ethernet devices are present on one of the downstream ports.
> > >
> > > Power to the TC956x is supplied through two LDO regulators, controlled by
> > > two GPIOs, which are added as fixed regulators. Configure the TC956x
> > > through I2C.
> > >
> > > Signed-off-by: Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>
> > > Reviewed-by: Bjorn Andersson <andersson@kernel.org>
> > > Acked-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> > > ---
> > > arch/arm64/boot/dts/qcom/qcs6490-rb3gen2.dts | 116 +++++++++++++++++++++++++++
> > > arch/arm64/boot/dts/qcom/sc7280.dtsi | 2 +-
> > > 2 files changed, 117 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/arch/arm64/boot/dts/qcom/qcs6490-rb3gen2.dts b/arch/arm64/boot/dts/qcom/qcs6490-rb3gen2.dts
> > > index 7a36c90ad4ec..13dbb24a3179 100644
> > > --- a/arch/arm64/boot/dts/qcom/qcs6490-rb3gen2.dts
> > > +++ b/arch/arm64/boot/dts/qcom/qcs6490-rb3gen2.dts
> > > @@ -218,6 +218,31 @@ vph_pwr: vph-pwr-regulator {
> > > regulator-min-microvolt = <3700000>;
> > > regulator-max-microvolt = <3700000>;
> > > };
> > > +
> > > + vdd_ntn_0p9: regulator-vdd-ntn-0p9 {
> > > + compatible = "regulator-fixed";
> > > + regulator-name = "VDD_NTN_0P9";
> > > + gpio = <&pm8350c_gpios 2 GPIO_ACTIVE_HIGH>;
> > > + regulator-min-microvolt = <899400>;
> > > + regulator-max-microvolt = <899400>;
> > > + enable-active-high;
> > > + pinctrl-0 = <&ntn_0p9_en>;
> > > + pinctrl-names = "default";
> > > + regulator-enable-ramp-delay = <4300>;
> > > + };
> > > +
> > > + vdd_ntn_1p8: regulator-vdd-ntn-1p8 {
> > > + compatible = "regulator-fixed";
> > > + regulator-name = "VDD_NTN_1P8";
> > > + gpio = <&pm8350c_gpios 3 GPIO_ACTIVE_HIGH>;
> > > + regulator-min-microvolt = <1800000>;
> > > + regulator-max-microvolt = <1800000>;
> > > + enable-active-high;
> > > + pinctrl-0 = <&ntn_1p8_en>;
> > > + pinctrl-names = "default";
> > > + regulator-enable-ramp-delay = <10000>;
> > > + };
> > > +
> > > };
> > > &apps_rsc {
> > > @@ -735,6 +760,75 @@ &pcie1_phy {
> > > status = "okay";
> > > };
> > > +&pcie1_port {
> > > + pcie@0,0 {
> > > + compatible = "pci1179,0623", "pciclass,0604";
> > > + reg = <0x10000 0x0 0x0 0x0 0x0>;
> > > + #address-cells = <3>;
> > > + #size-cells = <2>;
> > > +
> > > + device_type = "pci";
> > > + ranges;
> > > + bus-range = <0x2 0xff>;
> > > +
> > > + vddc-supply = <&vdd_ntn_0p9>;
> > > + vdd18-supply = <&vdd_ntn_1p8>;
> > > + vdd09-supply = <&vdd_ntn_0p9>;
> > > + vddio1-supply = <&vdd_ntn_1p8>;
> > > + vddio2-supply = <&vdd_ntn_1p8>;
> > > + vddio18-supply = <&vdd_ntn_1p8>;
> > > +
> > > + i2c-parent = <&i2c0 0x77>;
> > > +
> > > + reset-gpios = <&pm8350c_gpios 1 GPIO_ACTIVE_LOW>;
> > > +
> > > + pcie@1,0 {
> >
> > PCIe bus can be autodetected. Is there a reason for describing all the
> > ports and a full topology? If so, it should be stated in the commit
> > message.
> >
> As these ports are fixed we are defining them here, I will mention this
> in the commit message. It is similar to how we added pcieport for all
> the platforms, I tried to add full topology here. And if we want to
> configure any ports like l0s entry delay, l1 entry delay etc in future
> we need these full topology to be present.

Ack

>
> - Krishna Chaitanya.
> > > + reg = <0x20800 0x0 0x0 0x0 0x0>;
> > > + #address-cells = <3>;
> > > + #size-cells = <2>;
> > > +
> > > + device_type = "pci";
> > > + ranges;
> > > + bus-range = <0x3 0xff>;
> > > + };
> > > +
> > > + pcie@2,0 {
> > > + reg = <0x21000 0x0 0x0 0x0 0x0>;
> > > + #address-cells = <3>;
> > > + #size-cells = <2>;
> > > +
> > > + device_type = "pci";
> > > + ranges;
> > > + bus-range = <0x4 0xff>;
> > > + };
> > > +
> > > + pcie@3,0 {
> >

--
With best wishes
Dmitry