Re: [PATCH v2 3/4] regulator: dt-bindings: Add Allwinner D1 LDOs

[Rob Herring <robh@kernel.org>]

On Tue, Aug 02, 2022 at 12:32:12AM -0500, Samuel Holland wrote:
> The Allwinner D1 SoC contains two pairs of in-package LDOs. One pair is
> for general purpose use. LDOA generally powers the board's 1.8 V rail.
> LDOB generally powers the in-package DRAM, where applicable.
> 
> The other pair of LDOs powers the analog power domains inside the SoC,
> including the audio codec, thermal sensor, and ADCs. These LDOs require
> a 0.9 V bandgap voltage reference. The calibration value for the voltage
> reference is stored in an eFuse, accessed via an NVMEM cell.
> 
> Neither LDO control register is in its own MMIO range; instead, each
> regulator device relies on a regmap/syscon exported by its parent.
> 
> Signed-off-by: Samuel Holland <samuel@sholland.org>
> ---
> 
> Changes in v2:
>  - Remove syscon property from bindings
>  - Update binding examples to fix warnings and provide context
> 
>  .../allwinner,sun20i-d1-analog-ldos.yaml      | 65 +++++++++++++++++++
>  .../allwinner,sun20i-d1-system-ldos.yaml      | 57 ++++++++++++++++
>  2 files changed, 122 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/regulator/allwinner,sun20i-d1-analog-ldos.yaml
>  create mode 100644 Documentation/devicetree/bindings/regulator/allwinner,sun20i-d1-system-ldos.yaml
> 
> diff --git a/Documentation/devicetree/bindings/regulator/allwinner,sun20i-d1-analog-ldos.yaml b/Documentation/devicetree/bindings/regulator/allwinner,sun20i-d1-analog-ldos.yaml
> new file mode 100644
> index 000000000000..19c984ef4e53
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/regulator/allwinner,sun20i-d1-analog-ldos.yaml
> @@ -0,0 +1,65 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/regulator/allwinner,sun20i-d1-analog-ldos.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Allwinner D1 Analog LDOs
> +
> +description:
> +  Allwinner D1 contains a set of LDOs which are designed to supply analog power
> +  inside and outside the SoC. They are controlled by a register within the audio
> +  codec MMIO space, but which is not part of the audio codec clock/reset domain.
> +
> +maintainers:
> +  - Samuel Holland <samuel@sholland.org>
> +
> +properties:
> +  compatible:
> +    enum:
> +      - allwinner,sun20i-d1-analog-ldos
> +
> +  nvmem-cells:
> +    items:
> +      - description: NVMEM cell for the calibrated bandgap reference trim value
> +
> +  nvmem-cell-names:
> +    items:
> +      - const: bg_trim
> +
> +patternProperties:
> +  "^(aldo|hpldo)$":

'^(a|hp)ldo$'

> +    type: object
> +    $ref: regulator.yaml#

       unevaluatedProperties: false

> +
> +required:
> +  - compatible
> +  - nvmem-cells
> +  - nvmem-cell-names
> +
> +unevaluatedProperties: false
> +
> +examples:
> +  - |
> +    audio-codec@2030000 {
> +        compatible = "simple-mfd", "syscon";

Needs a specific compatible. Obviously there's some other functionality 
here if this is an 'audio-codec'.

'simple-mfd' also means the child nodes have zero dependence on the 
parent node and its resources.

> +        reg = <0x2030000 0x1000>;
> +
> +        regulators {
> +            compatible = "allwinner,sun20i-d1-analog-ldos";

Is there a defined set of registers for these regulators? If so, put 
them into 'reg'.

> +            nvmem-cells = <&bg_trim>;
> +            nvmem-cell-names = "bg_trim";
> +
> +            reg_aldo: aldo {
> +                regulator-min-microvolt = <1800000>;
> +                regulator-max-microvolt = <1800000>;
> +            };
> +
> +            reg_hpldo: hpldo {
> +                regulator-min-microvolt = <1800000>;
> +                regulator-max-microvolt = <1800000>;
> +            };
> +        };
> +    };
> +
> +...
> diff --git a/Documentation/devicetree/bindings/regulator/allwinner,sun20i-d1-system-ldos.yaml b/Documentation/devicetree/bindings/regulator/allwinner,sun20i-d1-system-ldos.yaml
> new file mode 100644
> index 000000000000..c95030a827d6
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/regulator/allwinner,sun20i-d1-system-ldos.yaml
> @@ -0,0 +1,57 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/regulator/allwinner,sun20i-d1-system-ldos.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Allwinner D1 System LDOs
> +
> +description:
> +  Allwinner D1 contains a pair of general-purpose LDOs which are designed to
> +  supply power inside and outside the SoC. They are controlled by a register
> +  within the system control MMIO space.
> +
> +maintainers:
> +  - Samuel Holland <samuel@sholland.org>
> +
> +properties:
> +  compatible:
> +    enum:
> +      - allwinner,sun20i-d1-system-ldos
> +
> +patternProperties:
> +  "^(ldoa|ldob)$":

'^ldo[ab]$'

Any reason the naming is not consistent with 'ldo' as the prefix or 
suffix?

> +    type: object
> +    $ref: regulator.yaml#

       unevaluatedProperties: false

> +
> +required:
> +  - compatible
> +
> +unevaluatedProperties: false
> +
> +examples:
> +  - |
> +    syscon@3000000 {
> +        compatible = "allwinner,sun20i-d1-system-control";
> +        reg = <0x3000000 0x1000>;
> +        ranges;
> +        #address-cells = <1>;
> +        #size-cells = <1>;
> +
> +        regulators {
> +            compatible = "allwinner,sun20i-d1-system-ldos";
> +
> +            reg_ldoa: ldoa {
> +                regulator-min-microvolt = <1800000>;
> +                regulator-max-microvolt = <1800000>;
> +            };
> +
> +            reg_ldob: ldob {
> +                regulator-name = "vcc-dram";
> +                regulator-min-microvolt = <1500000>;
> +                regulator-max-microvolt = <1500000>;
> +            };
> +        };
> +    };
> +
> +...
> -- 
> 2.35.1
> 
>