Re: [PATCH 1/2] dt-bindings: iio: adc: Add binding for current-from-voltage

[Rob Herring <robh@kernel.org>]

On Fri, May 15, 2020 at 07:26:18PM -0700, Jonathan Bakker wrote:
> Some devices may require a current adc, but only have a voltage
> ADC onboard.  In order to read the current, they have a resistor
> connected to the ADC.  Add bindings for this possibility.
> 
> Signed-off-by: Jonathan Bakker <xc-racer2@live.ca>
> ---
>  .../iio/adc/linux,current-from-voltage.yaml   | 47 +++++++++++++++++++
>  1 file changed, 47 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/iio/adc/linux,current-from-voltage.yaml
> 
> diff --git a/Documentation/devicetree/bindings/iio/adc/linux,current-from-voltage.yaml b/Documentation/devicetree/bindings/iio/adc/linux,current-from-voltage.yaml
> new file mode 100644
> index 000000000000..385d317607c3
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/adc/linux,current-from-voltage.yaml
> @@ -0,0 +1,47 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/iio/adc/linux,current-from-voltage.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Current ADC from voltage ADC and resistor
> +
> +maintainers:
> +  - Jonathan Bakker <xc-racer2@live.ca>
> +
> +properties:
> +  compatible:
> +    const: linux,current-from-voltage

How is an ADC with a resistor attached a Linux thing? So you don't need 
'linux', but then 'current-from-voltage' isn't the best naming. I don't 
have a suggestion ATM.

> +
> +  io-channel-names:
> +    const: adc
> +
> +  io-channels:
> +    maxItems: 1
> +    description: Voltage ADC channel
> +
> +  linux,resistor-ohms:
> +    description: Strength of resistor connected to voltage ADC

Wouldn't you need this to be micro-ohms? Otherwise, there'd be too much 
voltage drop?

Rob