Re: [PATCH 1/2] dt-bindings: iio: afe: add binding for adi,lt6106

[Rob Herring]

On Wed, Apr 11, 2018 at 04:15:54PM +0200, Peter Rosin wrote:
> This is a current sense amplifier from Analog Devices.
> 
> Signed-off-by: Peter Rosin <peda@xxxxxxxxxx>
> ---
>  .../devicetree/bindings/iio/afe/adi,lt6106.txt     | 50 ++++++++++++++++++++++
>  MAINTAINERS                                        |  1 +
>  2 files changed, 51 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/iio/afe/adi,lt6106.txt
> 
> diff --git a/Documentation/devicetree/bindings/iio/afe/adi,lt6106.txt b/Documentation/devicetree/bindings/iio/afe/adi,lt6106.txt
> new file mode 100644
> index 000000000000..98b6d93596f2
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/afe/adi,lt6106.txt
> @@ -0,0 +1,50 @@
> +LT6106 36V High Side Current Sence Amplifier
> +============================================
> +
> +This binding assumes the typical application of the current sense amplifier
> +as described in the LT6106 datasheet.
> +
> +http://www.analog.com/media/en/technical-documentation/data-sheets/6106fb.pdf
> +
> +                                             .------.
> +    Vin --------------------+--------------+-|Rsense|-+-----.
> +                            |              | '------' |     |
> +                            |              |          |   .---.
> +                 .--------------------.  .---.        |   | L |
> +                 |          V+        |  |Rin|        |   | O |
> +                 |                    |  '---'        |   | A |
> +                 |                    |    |          |   | D |
> +                 |                -IN |----'          |   '---'
> +    Vout ---+----| OUT   LT6106       |               |     |
> +            |    |                +IN |---------------'    GND
> +         .----.  |                    |
> +         |Rout|  |                    |
> +         '----'  |          V-        |
> +            |    '--------------------'
> +            |               |
> +           GND             GND
> +
> +The voltage Vsense over Rsense is measured by looking at Vout. They
> +are related as Vout = Vsense * Rout / Rin. The current Isense through
> +Rsense is (almost) the same as that through the LOAD. Hence, the
> +interesting LOAD current can be calculated as
> +
> +                 Vout * Rin / (Rout * Rsense)
> +
> +Required properties:
> +- compatible : "adi,lt6106"
> +- io-channels : Channel node of an io-channel measuring Vout.
> +- sense-resistor-micro-ohms : The Rsense resistance in microohms.

> +- input-resistor-ohms : The Rin resistance in ohms.
> +- output-resistor-ohms : The Rout resistance in ohms.

Are these generic or specific to this binding? For the latter, they 
shoudl have vendor prefix.

> +
> +Example:
> +
> +sysi {
> +	compatible = "adi,lt6106";
> +	io-channels = <&tiadc 0>;
> +
> +	sense-resistor-micro-ohms = <20000>;
> +	input-resistor-ohms = <200>;
> +	output-resistor-ohms = <10000>;
> +};