[PATCH v3 07/12] dt-bindings: PCI: Add support for Tesla FSD SoC

[Shradha Todi]

> > +
> > +  phys:
> > +    maxItems: 1
> > +
> > +  samsung,syscon-pcie:
> > +    $ref: /schemas/types.yaml#/definitions/phandle-array
> > +    description: phandle for system control registers, used to
> > +                 control signals at system level
> 
> What is "system level"? and what are these "signals" being controlled?
> 

I will add a more detailed description for why the syscon is being used

> 
> > +title: Tesla FSD SoC series PCIe Host Controller
> > +
> > +maintainers:
> > +  - Shradha Todi <shradha.t at samsung.com>
> > +
> > +description:
> > +  Tesla FSD SoCs PCIe host controller inherits all the common
> > +  properties defined in samsung,exynos-pcie.yaml
> > +
> > +allOf:
> > +  - $ref: /schemas/pci/samsung,exynos-pcie.yaml#
> > +
> > +properties:
> > +  compatible:
> > +    const: tesla,fsd-pcie
> > +
> > +  clocks:
> > +    maxItems: 4
> > +
> > +  clock-names:
> > +    items:
> > +      - const: aux
> > +      - const: dbi
> > +      - const: mstr
> > +      - const: slv
> > +
> > +  num-lanes:
> > +    maximum: 4
> > +
> > +  samsung,syscon-pcie:
> > +    $ref: /schemas/types.yaml#/definitions/phandle-array
> > +    description: phandle for system control registers, used to
> > +                 control signals at system level
> > +
> > +required:
> > +  - samsung,syscon-pcie
> 
> clocks are required, compatible as well.
> 

Since this was inheriting the common exynos yaml file and that had these properties
under required, I did not mention again. Will take care in next version.

> Missing supplies, both as properties and required. PCI devices do not
> work without power.
> 

According to the HW design of FSD SoC, the control to manage PCIe power is given to
a separate CPU where custom firmware runs. Therefore, the Linux side does not control
the PCIe power supplies directly and are hence not included in the device tree.

> > +
> > +unevaluatedProperties: false
> > +
> > +examples:
> > +  - |
> > +    #include <dt-bindings/clock/fsd-clk.h>
> > +    #include <dt-bindings/interrupt-controller/arm-gic.h>
> > +
> > +    soc {
> > +        #address-cells = <2>;
> > +        #size-cells = <2>;
> > +
> > +        pcierc1: pcie at 16b00000 {
> > +            compatible = "tesla,fsd-pcie";
> > +            reg = <0x0 0x16b00000 0x0 0x2000>,
> > +                  <0x0 0x168c0000 0x0 0x1000>,
> > +                  <0x0 0x18000000 0x0 0x1000>;
> > +            reg-names = "dbi", "elbi", "config";
> > +            ranges =  <0x82000000 0x0 0x18001000 0x0 0x18001000 0x0 0xffefff>;
> 
> Misaligned. Follow closely DTS coding style.
> 

Will take care.