Re: [PATCH v2 1/8] dt-bindings: PCI: Add binding for qps615
From: Krishna Chaitanya Chundru
Date: Mon Aug 05 2024 - 00:12:06 EST
On 8/4/2024 2:23 PM, Krzysztof Kozlowski wrote:
On 03/08/2024 05:22, 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 | 191 +++++++++++++++++++++
1 file changed, 191 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..ea0c953ee56f
--- /dev/null
+++ b/Documentation/devicetree/bindings/pci/qcom,qps615.yaml
@@ -0,0 +1,191 @@
+# 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
+
+ qcom,qps615-controller:
+ $ref: /schemas/types.yaml#/definitions/phandle
+ description:
+ Reference to the I2C client used to do configure qps615
Why?
+
+ 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.
+
+ qps615,axi-clk-freq-hz:
+ description:
+ AXI clock which internal bus of the switch.
No need, use CCF.
ack
+
+ qcom,l0s-entry-delay-ns:
+ description: Aspm l0s entry delay in nanoseconds.
+
+ qcom,l1-entry-delay-ns:
+ description: Aspm l1 entry delay in nanoseconds.
+
+ qcom,tx-amplitude-millivolt:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: Change Tx Margin setting for low power consumption.
+
+ qcom,no-dfe:
+ type: boolean
+ description: Disables DFE (Decision Feedback Equalizer).
You described the desired Linux feature or behavior, not the actual
hardware. The bindings are about the latter, so instead you need to
rephrase the property and its description to match actual hardware
capabilities/features/configuration etc.
ack
+
+ qcom,nfts:
+ $ref: /schemas/types.yaml#/definitions/uint8
+ description:
+ Fast Training Sequence (FTS) is the mechanism that
+ is used for bit and Symbol lock.
What are the values? Why this is uint8?
These represents number of fast training sequence and doesn't have
any units and the maximum value for this is 0xFF only so we used
uint8.
You described the desired Linux feature or behavior, not the actual
hardware. The bindings are about the latter, so instead you need to
rephrase the property and its description to match actual hardware
capabilities/features/configuration etc.
ack.
+
+allOf:
+ - $ref: /schemas/pci/pci-bus-common.yaml#
+ - if:
+ properties:
+ compatible:
+ contains:
+ const: pci1179,0623
+ required:
+ - compatible
Why do you have entire if? You do not have multiple variants, drop.
The child nodes also referencing the qcom,qps615.yaml# node, I tried
to use this way to say "the below properties are for the required for
parent and optional for child".
+ then:
+ required:
+ - vdd18-supply
+ - vdd09-supply
+ - vddc-supply
+ - vddio1-supply
+ - vddio2-supply
+ - vddio18-supply
+ - qcom,qps615-controller
+ - reset-gpios
+
+patternProperties:
+ "@1?[0-9a-f](,[0-7])?$":
+ type: object
+ $ref: qcom,qps615.yaml#
+ additionalProperties: true
Nope, drop pattern Properties or explain what is this.
the child nodes represent the downstream ports of the PCIe
switch which wants to use same properties that is why
I tried to use this pattern properties.
+
+additionalProperties: true
This cannot be true,
Let me check on this correct in next versions.
+
+examples:
+ - |
+
+ #include <dt-bindings/gpio/gpio.h>
+
+ pcie {
+ #address-cells = <3>;
+ #size-cells = <2>;
+
+ pcie@0 {
+ device_type = "pci";
+ reg = <0x0 0x0 0x0 0x0 0x0>;
+
+ #address-cells = <3>;
+ #size-cells = <2>;
+ ranges;
+
+ pcie@0,0 {
+ compatible = "pci1179,0623";
+ reg = <0x10000 0x0 0x0 0x0 0x0>;
+ device_type = "pci";
+ #address-cells = <3>;
+ #size-cells = <2>;
+ ranges;
+
+ qcom,qps615-controller = <&qps615_controller>;
+
+ vdd18-supply = <&vdd>;
+ vdd09-supply = <&vdd>;
+ vddc-supply = <&vdd>;
+ vddio1-supply = <&vdd>;
+ vddio2-supply = <&vdd>;
+ vddio18-supply = <&vdd>;
+
+ reset-gpios = <&gpio 1 GPIO_ACTIVE_LOW>;
+
+ pcie@1,0 {
+ reg = <0x20800 0x0 0x0 0x0 0x0>;
Where is the compatible? You claim this is the same device as child?
These all the PCIe downstream nodes and compatible is optional for the
PCIe nodes.
+ #address-cells = <3>;
+ #size-cells = <2>;
+ device_type = "pci";
+ ranges;
+
+ qcom,no-dfe;
+ };
+
+ pcie@2,0 {
+ reg = <0x21000 0x0 0x0 0x0 0x0>;
+ #address-cells = <3>;
+ #size-cells = <2>;
+ device_type = "pci";
+ ranges;
+
+ qcom,nfts = /bits/ 8 <10>;
+ };
+
+ pcie@3,0 {
+ reg = <0x21800 0x0 0x0 0x0 0x0>;
+ #address-cells = <3>;
+ #size-cells = <2>;
+ device_type = "pci";
+ ranges;
+
+ qcom,tx-amplitude-millivolt = <10>;
+
+ pcie@0,0 {
Total mess in indentation.
Let me correct in next version.
- Krishna Chaitanya.
Best regards,
Krzysztof