Re: [PATCH 20/29] dt-bindings:iio:dac:microchip,mcp4725 yaml conversion

[Tomas Novotny <tomas@novotny.cz>]

Hi Jonathan,

On Sun, 11 Oct 2020 18:07:40 +0100
Jonathan Cameron <jic23@kernel.org> wrote:

> From: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> 
> I'm not sure vdd-supply absolutely has to be provided if vref-supply
> is, but as the previous binding docs stated it was required it seems
> reasonable to leave it as such.

Good catch. Vdd is useless on MCP4726 if Vref is specified. The driver
requires Vdd...

How to proceed there?

Thanks,

Tomas

> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> Cc:  Tomas Novotny <tomas@novotny.cz>
> ---
>  .../devicetree/bindings/iio/dac/mcp4725.txt   | 35 ---------
>  .../bindings/iio/dac/microchip,mcp4725.yaml   | 71 +++++++++++++++++++
>  2 files changed, 71 insertions(+), 35 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/iio/dac/mcp4725.txt b/Documentation/devicetree/bindings/iio/dac/mcp4725.txt
> deleted file mode 100644
> index 1bc6c093fbfe..000000000000
> --- a/Documentation/devicetree/bindings/iio/dac/mcp4725.txt
> +++ /dev/null
> @@ -1,35 +0,0 @@
> -Microchip mcp4725 and mcp4726 DAC device driver
> -
> -Required properties:
> -	- compatible: Must be "microchip,mcp4725" or "microchip,mcp4726"
> -	- reg: Should contain the DAC I2C address
> -	- vdd-supply: Phandle to the Vdd power supply. This supply is used as a
> -	  voltage reference on mcp4725. It is used as a voltage reference on
> -	  mcp4726 if there is no vref-supply specified.
> -
> -Optional properties (valid only for mcp4726):
> -	- vref-supply: Optional phandle to the Vref power supply. Vref pin is
> -	  used as a voltage reference when this supply is specified.
> -	- microchip,vref-buffered: Boolean to enable buffering of the external
> -	  Vref pin. This boolean is not valid without the vref-supply. Quoting
> -	  the datasheet: This is offered in cases where the reference voltage
> -	  does not have the current capability not to drop its voltage when
> -	  connected to the internal resistor ladder circuit.
> -
> -Examples:
> -
> -	/* simple mcp4725 */
> -	mcp4725@60 {
> -		compatible = "microchip,mcp4725";
> -		reg = <0x60>;
> -		vdd-supply = <&vdac_vdd>;
> -	};
> -
> -	/* mcp4726 with the buffered external reference voltage */
> -	mcp4726@60 {
> -		compatible = "microchip,mcp4726";
> -		reg = <0x60>;
> -		vdd-supply = <&vdac_vdd>;
> -		vref-supply = <&vdac_vref>;
> -		microchip,vref-buffered;
> -	};
> diff --git a/Documentation/devicetree/bindings/iio/dac/microchip,mcp4725.yaml b/Documentation/devicetree/bindings/iio/dac/microchip,mcp4725.yaml
> new file mode 100644
> index 000000000000..271998610ceb
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/dac/microchip,mcp4725.yaml
> @@ -0,0 +1,71 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/iio/dac/microchip,mcp4725.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Microchip mcp4725 and mcp4726 DAC
> +
> +maintainers:
> +  - Tomas Novotny <tomas@novotny.cz>
> +
> +properties:
> +  compatible:
> +    enum:
> +      - microchip,mcp4725
> +      - microchip,mcp4726
> +
> +  reg:
> +    maxItems: 1
> +
> +  vdd-supply:
> +    description: |
> +      Provides both power and acts as the reference supply on the mcp4725.
> +      For the mcp4726 it will be used as the reference voltage if vref-supply
> +      is not provided.
> +
> +  vref-supply:
> +    description:
> +      Vref pin is used as a voltage reference when this supply is specified.
> +
> +  microchip,vref-buffered:
> +    type: boolean
> +    description: |
> +      Enable buffering of the external Vref pin. This boolean is not valid
> +      without the vref-supply. Quoting the datasheet: This is offered in
> +      cases where the reference voltage does not have the current
> +      capability not to drop its voltage when connected to the internal
> +      resistor ladder circuit.
> +
> +allOf:
> +  - if:
> +      not:
> +        properties:
> +          compatible:
> +            contains:
> +              const: microchip,mcp4726
> +    then:
> +      properties:
> +        vref-supply: false
> +        microchip,vref-buffered: false
> +
> +required:
> +  - compatible
> +  - reg
> +  - vdd-supply
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    i2c {
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        mcp4725@60 {
> +            compatible = "microchip,mcp4725";
> +            reg = <0x60>;
> +            vdd-supply = <&vdac_vdd>;
> +        };
> +    };
> +...