On Fri, Dec 27, 2024 at 07:44:49AM +0530, Krishna Chaitanya Chundru wrote: > > > On 12/24/2024 12:27 AM, Dmitry Baryshkov wrote: > > On Sun, Nov 24, 2024 at 07:02:48AM +0530, Krishna Chaitanya Chundru wrote: > > > > > > > > > On 11/15/2024 9:48 PM, Rob Herring wrote: > > > > On Tue, Nov 12, 2024 at 08:31:33PM +0530, Krishna chaitanya chundru wrote: > > > > > Add binding describing the Qualcomm PCIe switch, QPS615, > > > > > which provides Ethernet MAC integrated to the 3rd downstream port > > > > > and two downstream PCIe ports. > > > > > > > > > > Signed-off-by: Krishna chaitanya chundru <quic_krichai@xxxxxxxxxxx> > > > > > --- > > > > > .../devicetree/bindings/pci/qcom,qps615.yaml | 205 +++++++++++++++++++++ > > > > > 1 file changed, 205 insertions(+) > > > > > > > > > > diff --git a/Documentation/devicetree/bindings/pci/qcom,qps615.yaml b/Documentation/devicetree/bindings/pci/qcom,qps615.yaml > > > > > new file mode 100644 > > > > > index 000000000000..e6a63a0bb0f3 > > > > > --- /dev/null > > > > > +++ b/Documentation/devicetree/bindings/pci/qcom,qps615.yaml > > > > > @@ -0,0 +1,205 @@ > > > > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > > > > > +%YAML 1.2 > > > > > +--- > > > > > +$id: http://devicetree.org/schemas/pci/qcom,qps615.yaml# > > > > > +$schema: http://devicetree.org/meta-schemas/core.yaml# > > > > > + > > > > > +title: Qualcomm QPS615 PCIe switch > > > > > + > > > > > +maintainers: > > > > > + - Krishna chaitanya chundru <quic_krichai@xxxxxxxxxxx> > > > > > + > > > > > +description: | > > > > > + Qualcomm QPS615 PCIe switch has one upstream and three downstream > > > > > + ports. The 3rd downstream port has integrated endpoint device of > > > > > + Ethernet MAC. Other two downstream ports are supposed to connect > > > > > + to external device. > > > > > + > > > > > + The QPS615 PCIe switch can be configured through I2C interface before > > > > > + PCIe link is established to change FTS, ASPM related entry delays, > > > > > + tx amplitude etc for better power efficiency and functionality. > > > > > + > > > > > +properties: > > > > > + compatible: > > > > > + enum: > > > > > + - pci1179,0623 > > > > > + > > > > > + reg: > > > > > + maxItems: 1 > > > > > + > > > > > + i2c-parent: > > > > > + $ref: /schemas/types.yaml#/definitions/phandle-array > > > > > + description: | > > > > > > > > Don't need '|' if no formatting to preserve. > > > > > > > ack > > > > > + A phandle to the parent I2C node and the slave address of the device > > > > > + used to do configure qps615 to change FTS, tx amplitude etc. > > > > > + items: > > > > > + - description: Phandle to the I2C controller node > > > > > + - description: I2C slave address > > > > > + > > > > > + vdd18-supply: true > > > > > + > > > > > + vdd09-supply: true > > > > > + > > > > > + vddc-supply: true > > > > > + > > > > > + vddio1-supply: true > > > > > + > > > > > + vddio2-supply: true > > > > > + > > > > > + vddio18-supply: true > > > > > + > > > > > + reset-gpios: > > > > > + maxItems: 1 > > > > > + description: > > > > > + GPIO controlling the RESX# pin. > > > > > > > > Is the PERST# or something else? > > > > > > > it is not PERST GPIO, it is similar to PERST in terms > > > of functionality which brings switch out from reset. > > > > Do you have an actual PERST# on upstream facing port? Is it a separate > > wire? Judging by the RB3 Gen2 this line is being used as PERST# > > > > > > > + > > > > > + qps615,axi-clk-freq-hz: > > > > > > > > qps615 is not a vendor prefix. > > > > > > > > > + description: > > > > > + AXI clock rate which is internal bus of the switch > > > > > + The switch only runs in two frequencies i.e 250MHz and 125MHz. > > > > > + enum: [125000000, 250000000] > > > > > + > > > > > +allOf: > > > > > + - $ref: "#/$defs/qps615-node" > > > > > + > > > > > +patternProperties: > > > > > + "@1?[0-9a-f](,[0-7])?$": > > > > > > > > You have 3 ports. So isn't this fixed and limited to 0-2? > > > > > > > sure I will change it to below as suggested > > > "@1?[0-3](,[0-1])?$" > > > > Why do you still need '1?' ? > > > > > > > + description: child nodes describing the internal downstream ports > > > > > + the qps615 switch. > > > > > > > > Please be consistent with starting after the ':' or on the next line. > > > > > > > > And start with capital C. > > > > > > > > > > > ack > > > > > > > > + type: object > > > > > + $ref: "#/$defs/qps615-node" > > > > > + unevaluatedProperties: false > > > > > + > > > > > +$defs: > > > > > + qps615-node: > > > > > + type: object > > > > > + > > > > > + properties: > > > > > + qcom,l0s-entry-delay-ns: > > > > > + description: Aspm l0s entry delay. > > > > > + > > > > > + qcom,l1-entry-delay-ns: > > > > > + description: Aspm l1 entry delay. > > > > > > > > These should probably be common being standard PCIe things. Though, why > > > > are they needed? I'm sure the timing is defined by the PCIe spec, so > > > > they are not compliant? > > > > > > > Usually the firmware in the endpoints/switches should do this these > > > configurations. But the qps615 PCIe switch doesn't have any firmware > > > running to configure these. So the hardware exposes i2c interface to > > > configure these before link training. > > > > If they are following the standard, why do you need to have them in the > > DT? Can you hardcode thos evalues in the driver? > > > > > > > + > > > > > + qcom,tx-amplitude-millivolt: > > > > > + $ref: /schemas/types.yaml#/definitions/uint32 > > > > > + description: Change Tx Margin setting for low power consumption. > > > > > + > > > > > + qcom,no-dfe-support: > > > > > + type: boolean > > > > > + description: Disable DFE (Decision Feedback Equalizer), which mitigates > > > > > + intersymbol interference and some reflections caused by impedance mismatches. > > > > > + > > > > > + qcom,nfts: > > > > > + $ref: /schemas/types.yaml#/definitions/uint32 > > > > > + description: > > > > > + Number of Fast Training Sequence (FTS) used during L0s to L0 exit > > > > > + for bit and Symbol lock. > > > > > > > > Also something common. > > > > > > > > The problem I have with all these properties is you are using them on > > > > both the upstream and downstream sides of the PCIe links. They belong in > > > > either the device's node (downstream) or the bus's node (upstream). > > > > > > > This switch allows us to configure both upstream, downstream ports and > > > also embedded Ethernet port which is internal to the switch. These > > > properties are applicable for all of those. > > > > > + > > > > > + allOf: > > > > > + - $ref: /schemas/pci/pci-bus.yaml# > > > > > > > > pci-pci-bridge.yaml is more specific and closer to what this device is. > > > > > > > I tried this now, I was getting warning saying the compatible > > > /local/mnt/workspace/skales/kobj/Documentation/devicetree/bindings/pci/qcom,qps615.example.dtb: > > > pcie@0,0: compatible: ['pci1179,0623'] does not contain items matching the > > > given schema > > > from schema $id: http://devicetree.org/schemas/pci/qcom,qps615.yaml# > > > /local/mnt/workspace/skales/kobj/Documentation/devicetree/bindings/pci/qcom,qps615.example.dtb: > > > pcie@0,0: Unevaluated properties are not allowed ('#address-cells', > > > '#size-cells', 'bus-range', 'device_type', 'ranges' were unexpected) > > > > > > I think pci-pci-bridge is expecting the compatible string in this format > > > only "pciclass,0604". > > > > I think the pci-pci-bridge schema requires to have "pciclass,0604" among > > other compatibles. So you should be able to do something like: > > > > compatible = "pci1179,0623", "pciclass,0604"; > > > > At least if follows PCI Bus Binding to Open Firmware document. > > > There is a slot driver which is using this pciclass,0604 can we use > still the suggested way. The suggested way is to describe devices properly. > > https://lore.kernel.org/linux-pci/20241210-pci-pwrctrl-slot-v1-4-eae45e488040@xxxxxxxxxx/ -- With best wishes Dmitry
