Re: [PATCH RFC 1/7] dt: bindings: add qcom,qps615.yaml

[Rob Herring <robh@kernel.org>]

On Wed, Jun 26, 2024 at 06:07:49PM +0530, Krishna chaitanya chundru wrote:
> qps615 is a driver for Qualcomm PCIe switch driver which controls
> power & configuration of the hardware.
> Add a bindings document for the driver.
> 
> Signed-off-by: Krishna chaitanya chundru <quic_krichai@quicinc.com>
> ---
>  .../devicetree/bindings/pci/qcom,qps615.yaml       | 73 ++++++++++++++++++++++
>  1 file changed, 73 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..f090683f9e2f
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/pci/qcom,qps615.yaml
> @@ -0,0 +1,73 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/pci/qcom,pcie-qps615.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Qualcomm QPS615 PCIe switch
> +
> +maintainers:
> +  - Krishna chaitanya chundru <quic_krichai@quicinc.com>
> +
> +description: |
> +  Qualcomm QPS615 PCIe switch has one upstream and three downstream
> +  ports. One of the downstream ports is used as endpoint device of
> +  Ethernet MAC. Other two downstream ports are supposed to connect
> +  to external device.
> +
> +  The power controlled by the GPIO's, if we enable the GPIO's the
> +  power to the switch will be on.
> +
> +  The QPS615 PCIe switch is configured through I2C interface before
> +  PCIe link is established.
> +

As a PCI device and implementing a PCI bus, you need to reference 
pci-pci-bridge.yaml. And you'll need to fix your example when you add 
that.

> +properties:
> +  compatible:
> +    enum:
> +      - pci1179,0623
> +
> +  reg:
> +    maxItems: 1
> +
> +  vdd-supply:
> +    description: |
> +      Phandle to the vdd input voltage which are fixed regulators which
> +      in are mapped to the GPIO's.
> +
> +  switch-i2c-cntrl:
> +    description: |
> +      phandle to i2c controller which is used to configure the PCIe
> +      switch.

There's a somewhat standard property for this purpose: i2c-bus

> +
> +required:
> +  - compatible
> +  - reg
> +  - vdd-supply
> +  - switch-i2c-cntrl
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    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;
> +
> +            bus-range = <0x01 0xff>;

Unless there's a h/w limitation, you don't need this.

> +
> +            qps615@0 {
> +                compatible = "pci1179,0623";
> +                reg = <0x10000 0x0 0x0 0x0 0x0>;
> +
> +                vdd-supply = <&vdd>;
> +		switch-i2c-cntrl = <&foo>;
> +            };
> +        };
> +    };
> 
> -- 
> 2.42.0
>