Re: [PATCH v2 2/3] dt-bindings: iio: frequency: Add docs for ADF4360 PLL

[Rob Herring <robh@kernel.org>]

On Wed, Jan 22, 2020 at 03:20:03PM +0200, Alexandru Ardelean wrote:
> From: Edward Kigwana <ekigwana@gmail.com>
> 
> This change adds the device-tree bindings documentation for the ADF4360
> family of PLLs.
> 
> Signed-off-by: Edward Kigwana <ekigwana@gmail.com>
> Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
> ---
>  .../bindings/iio/frequency/adf4371.yaml       |  24 +--
>  .../bindings/iio/frequency/adi,adf4360.yaml   | 158 ++++++++++++++++++
>  2 files changed, 170 insertions(+), 12 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/iio/frequency/adi,adf4360.yaml
> 
> diff --git a/Documentation/devicetree/bindings/iio/frequency/adf4371.yaml b/Documentation/devicetree/bindings/iio/frequency/adf4371.yaml
> index 7ec3ec94356b..6edb68e8febf 100644
> --- a/Documentation/devicetree/bindings/iio/frequency/adf4371.yaml
> +++ b/Documentation/devicetree/bindings/iio/frequency/adf4371.yaml
> @@ -48,16 +48,16 @@ required:
>  
>  examples:
>    - |
> -    spi0 {
> -        #address-cells = <1>;
> -        #size-cells = <0>;
> -
> -        frequency@0 {
> -                compatible = "adi,adf4371";
> -                reg = <0>;
> -                spi-max-frequency = <1000000>;
> -                clocks = <&adf4371_clkin>;
> -                clock-names = "clkin";
> -        };
> -    };
> +      spi0 {
> +          #address-cells = <1>;
> +          #size-cells = <0>;
> +
> +          frequency@0 {
> +                  compatible = "adi,adf4371";
> +                  reg = <0>;
> +                  spi-max-frequency = <1000000>;
> +                  clocks = <&adf4371_clkin>;
> +                  clock-names = "clkin";
> +          };
> +      };

What's this change for?

>  ...
> diff --git a/Documentation/devicetree/bindings/iio/frequency/adi,adf4360.yaml b/Documentation/devicetree/bindings/iio/frequency/adi,adf4360.yaml
> new file mode 100644
> index 000000000000..1a7f166d2a3f
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/frequency/adi,adf4360.yaml
> @@ -0,0 +1,158 @@
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright 2019-2020 Edward Kigwana
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/iio/frequency/adi,adf4360.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Analog Devices ADF4360 PLL device driver
> +
> +maintainers:
> +  - Lars-Peter Clausen <lars@metafoo.de>
> +  - Edward Kigwana <ekigwana@gmail.com>
> +
> +description: |
> +  Bindings for the Analog Devices ADF4360 family of clock generator phase-locked
> +  loop (PLL) devices with an integrated voltage-controlled oscillator (VCO).
> +  Each of the parts in the family supports a specific frequency range.
> +  Datasheets can be found here:
> +  https://www.analog.com/media/en/technical-documentation/data-sheets/ADF4360-0.pdf
> +  https://www.analog.com/media/en/technical-documentation/data-sheets/ADF4360-1.pdf
> +  https://www.analog.com/media/en/technical-documentation/data-sheets/ADF4360-2.pdf
> +  https://www.analog.com/media/en/technical-documentation/data-sheets/ADF4360-3.pdf
> +  https://www.analog.com/media/en/technical-documentation/data-sheets/ADF4360-4.pdf
> +  https://www.analog.com/media/en/technical-documentation/data-sheets/ADF4360-5.pdf
> +  https://www.analog.com/media/en/technical-documentation/data-sheets/ADF4360-6.pdf
> +  https://www.analog.com/media/en/technical-documentation/data-sheets/ADF4360-7.pdf
> +  https://www.analog.com/media/en/technical-documentation/data-sheets/ADF4360-8.pdf
> +  https://www.analog.com/media/en/technical-documentation/data-sheets/ADF4360-9.pdf
> +
> +properties:
> +  compatible:
> +    enum:
> +      - adi,adf4360-0
> +      - adi,adf4360-1
> +      - adi,adf4360-2
> +      - adi,adf4360-3
> +      - adi,adf4360-4
> +      - adi,adf4360-5
> +      - adi,adf4360-6
> +      - adi,adf4360-7
> +      - adi,adf4360-8
> +      - adi,adf4360-9

The enum can be just:

pattern: '^adi,adf4360-[0-9]$'


> +
> +  reg:
> +    maxItems: 1
> +
> +  clocks:
> +    description: phandle to external reference clock.

Not all that specific to this define, so drop.

> +    maxItems: 1
> +
> +  clock-names:
> +    items:
> +      - const: clkin
> +
> +  '#clock-cells':
> +    const: 0
> +
> +  adi,loop-filter-pfd-frequency-hz:
> +    description: |
> +      The phase-frequency-detector frequency that the external loop filter was
> +      designed for.
> +    allOf:
> +      - $ref: /schemas/types.yaml#/definitions/uint32

Standard type suffixes have a type already, so you can drop this.

> +    maxItems: 1

Any constraints in the value?

> +
> +  adi,loop-filter-charger-pump-current-microamp:
> +    description: |
> +      The charge pump current that the external loop filter was designed for.
> +      The provided value is clamped to the closest enumerated value.
> +    allOf:
> +      - $ref: /schemas/types.yaml#/definitions/uint32

Can be dropped. Same goes for the rest.

> +      - enum: [310, 620, 930, 1250, 1560, 1870, 2180, 2500]
> +    maxItems: 1
> +
> +  adi,vco-minimum-frequency-hz:
> +    description: |
> +      Required for ADF4360-7, ADF4360-8 and ADF4360-9. Minimum VCO frequency
> +      that can be supported by the tuning range set by the external inductor.
> +    allOf:
> +      - $ref: /schemas/types.yaml#/definitions/uint32
> +    maxItems: 1
> +
> +  adi,vco-maximum-frequency-hz:
> +    description: |
> +      Required for ADF4360-7, ADF4360-8 and ADF4360-9. Maximum VCO frequency
> +      that can be supported by the tuning range set by the external inductor.
> +    allOf:
> +      - $ref: /schemas/types.yaml#/definitions/uint32
> +    maxItems: 1
> +
> +  adi,loop-filter-inverting:
> +    description: Indicates that the external loop filter is an inverting filter.
> +    type: boolean
> +
> +  adi,power-up-frequency-hz:
> +    description: |
> +      PLL tunes to the set frequency on probe or defaults to either the minimum
> +      for the part or value set using adi,vco-minimum-frequency-hz.
> +    allOf:
> +      - $ref: /schemas/types.yaml#/definitions/uint32
> +    maxItems: 1
> +
> +  adi,vdd-supply:
> +    description: |
> +      vdd supply is used to enable or disable chip when regulator power down
> +      mode is set. Other power down modes are used to mitigate the case of a
> +      shared regulator.
> +    maxItems: 1

-supply is always 1 item, so drop.

> +
> +  adi,enable-gpios:

enable-gpios is a standard name, so drop the vendor prefix.

> +    description: |
> +      Chip enable gpio is used to enable or disable chip when chip enable power
> +      down mode is set.
> +    maxItems: 1
> +
> +  adi,muxout-gpios:
> +    description: |
> +      MUX out gpio is used to detect chip and test pll lock state on read when
> +      muxout control is set to lock detect.
> +    maxItems: 1
> +
> +  adi,power-out-level-microamp:
> +    description: |
> +      Chip support setting of output power level. This property is optional.
> +      If it is not provided by default 11000 uA will be set.
> +    allOf:
> +      - enum: [3500, 5000, 7500, 11000]

Don't need the 'allOf'.

> +
> +required:
> +  - compatible
> +  - reg
> +  - clocks
> +  - clock-names
> +  - adi,loop-filter-charge-pump-current
> +  - adi,loop-filter-pfd-frequency-hz
> +
> +examples:
> +  - |
> +      spi0 {
> +          #address-cells = <1>;
> +          #size-cells = <0>;
> +
> +          pll@0 {
> +                  compatible = "adi,adf4360-7";
> +                  reg = <0>;
> +                  spi-max-frequency = <2000000>;
> +                  clocks = <&ref_clock>;
> +                  #clock-cells = <0>;
> +                  clock-names = "clkin";
> +                  clock-output-names = "adf4360-7";
> +
> +                  adi,loop-filter-charge-pump-current = <5>;
> +                  adi,loop-filter-pfd-frequency-hz = <2500000>;
> +                  adi,vco-minimum-frequency-hz = <700000000>;
> +                  adi,vco-maximum-frequency-hz = <840000000>;
> +          };
> +      };
> +...
> -- 
> 2.20.1
>