Re: [PATCH v2 2/8] dt-bindings: arm: apple: Add apple,pmgr binding

[Rob Herring <robh@kernel.org>]

On Mon, Oct 25, 2021 at 11:47:12PM +0900, Hector Martin wrote:
> The PMGR block in Apple Silicon SoCs is responsible for SoC power
> management. There are two PMGRs in T8103, with different register
> layouts but compatible registers. In order to support this as well
> as future SoC generations with backwards-compatible registers, we
> declare these blocks as syscons and bind to individual registers
> in child nodes. Each register controls one SoC device.
> 
> The respective apple compatibles are defined in case device-specific
> quirks are necessary in the future, but currently these nodes are
> expected to be bound by the generic syscon driver.
> 
> Reviewed-by: Mark Kettenis <kettenis@openbsd.org>
> Signed-off-by: Hector Martin <marcan@marcan.st>
> ---
>  .../bindings/arm/apple/apple,pmgr.yaml        | 149 ++++++++++++++++++
>  1 file changed, 149 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/arm/apple/apple,pmgr.yaml
> 
> diff --git a/Documentation/devicetree/bindings/arm/apple/apple,pmgr.yaml b/Documentation/devicetree/bindings/arm/apple/apple,pmgr.yaml
> new file mode 100644
> index 000000000000..e8b7776163fc
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/arm/apple/apple,pmgr.yaml
> @@ -0,0 +1,149 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/arm/apple/apple,pmgr.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Apple SoC Power Manager (PMGR)
> +
> +maintainers:
> +  - Hector Martin <marcan@marcan.st>
> +
> +description: |
> +  Apple SoCs include a PMGR block responsible for power management,
> +  which can control various clocks, resets, power states, and
> +  performance features. This node represents the PMGR as a syscon,
> +  with sub-nodes representing individual features.
> +
> +  Apple SoCs may have a secondary "mini-PMGR"; it is represented
> +  separately in the device tree, but works the same way.
> +
> +select:
> +  properties:
> +    compatible:
> +      contains:
> +        enum:
> +          - apple,t8103-pmgr
> +          - apple,t8103-minipmgr
> +          - apple,pmgr

You shouldn't need this. The default select will filter out syscon and 
simple-mfd.

> +
> +  required:
> +    - compatible
> +
> +properties:
> +  $nodename:
> +    pattern: "^power-management@[0-9a-f]+$"
> +
> +  compatible:
> +    items:
> +      - enum:
> +          - apple,t8103-pmgr
> +          - apple,t8103-minipmgr
> +      - const: apple,pmgr
> +      - const: syscon
> +      - const: simple-mfd


'simple-mfd' means 'there's nothing in this node that any of the child 
nodes depend on'. You should be somewhat certain as dropping it later 
creates compatibility issues.

> +
> +  reg:
> +    maxItems: 1
> +
> +  "#address-cells":
> +    const: 1
> +
> +  "#size-cells":
> +    const: 1
> +
> +patternProperties:
> +  "power-controller@[0-9a-f]+$":
> +    description: |

Don't need '|' if no formatting to preserve.

> +      The individual power management domains within this controller
> +    type: object
> +    $ref: /power/apple,pmgr-pwrstate.yaml#
> +
> +required:
> +  - compatible
> +  - reg
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    soc {
> +        #address-cells = <2>;
> +        #size-cells = <2>;
> +
> +        power-management@23b700000 {
> +            compatible = "apple,t8103-pmgr", "apple,pmgr", "syscon", "simple-mfd";
> +            #address-cells = <1>;
> +            #size-cells = <1>;
> +            reg = <0x2 0x3b700000 0x0 0x14000>;
> +
> +            ps_sio: power-controller@1c0 {
> +                compatible = "apple,t8103-pmgr-pwrstate", "apple,pmgr-pwrstate";
> +                reg = <0x1c0 8>;
> +                #power-domain-cells = <0>;
> +                #reset-cells = <0>;
> +                label = "sio";
> +                apple,always-on;
> +            };
> +
> +            ps_uart_p: power-controller@220 {
> +                compatible = "apple,t8103-pmgr-pwrstate", "apple,pmgr-pwrstate";
> +                reg = <0x220 8>;
> +                #power-domain-cells = <0>;
> +                #reset-cells = <0>;
> +                label = "uart_p";
> +                power-domains = <&ps_sio>;
> +            };
> +
> +            ps_uart0: power-controller@270 {
> +                compatible = "apple,t8103-pmgr-pwrstate", "apple,pmgr-pwrstate";
> +                reg = <0x270 8>;
> +                #power-domain-cells = <0>;
> +                #reset-cells = <0>;
> +                label = "uart0";
> +                power-domains = <&ps_uart_p>;
> +            };
> +        };
> +
> +        power-management@23d280000 {
> +            compatible = "apple,t8103-minipmgr", "apple,pmgr", "syscon", "simple-mfd";
> +            #address-cells = <1>;
> +            #size-cells = <1>;
> +            reg = <0x2 0x3d280000 0x0 0xc000>;
> +
> +            ps_aop_filter: power-controller@4000 {
> +                compatible = "apple,t8103-pmgr-pwrstate", "apple,pmgr-pwrstate";
> +                reg = <0x4000 8>;
> +                #power-domain-cells = <0>;
> +                #reset-cells = <0>;
> +                label = "aop_filter";
> +            };
> +
> +            ps_aop_base: power-controller@4010 {
> +                compatible = "apple,t8103-pmgr-pwrstate", "apple,pmgr-pwrstate";
> +                reg = <0x4010 8>;
> +                #power-domain-cells = <0>;
> +                #reset-cells = <0>;
> +                label = "aop_base";
> +                power-domains = <&ps_aop_filter>;
> +            };
> +
> +            ps_aop_shim: power-controller@4038 {
> +                compatible = "apple,t8103-pmgr-pwrstate", "apple,pmgr-pwrstate";
> +                reg = <0x4038 8>;
> +                #power-domain-cells = <0>;
> +                #reset-cells = <0>;
> +                label = "aop_shim";
> +                power-domains = <&ps_aop_base>;
> +            };
> +
> +            ps_aop_uart0: power-controller@4048 {
> +                compatible = "apple,t8103-pmgr-pwrstate", "apple,pmgr-pwrstate";
> +                reg = <0x4048 8>;
> +                #power-domain-cells = <0>;
> +                #reset-cells = <0>;
> +                label = "aop_uart0";
> +                power-domains = <&ps_aop_shim>;
> +            };
> +        };
> +    };
> -- 
> 2.33.0
> 
>