Re: [PATCH v5 1/2] dt-bindings: adc: provide max34408/9 device tree binding document

[Jonathan Cameron]

On Tue, 10 Oct 2023 23:22:48 +0300
Ivan Mikhaylov <fr0st61te@xxxxxxxxx> wrote:

> On Tue, 2023-10-10 at 15:40 +0100, Jonathan Cameron wrote:
> > On Sun,  8 Oct 2023 02:48:37 +0300
> > Ivan Mikhaylov <fr0st61te@xxxxxxxxx> wrote:
> >   
> > > The hardware binding for i2c current monitoring device with
> > > overcurrent
> > > control.
> > > 
> > > Signed-off-by: Ivan Mikhaylov <fr0st61te@xxxxxxxxx>
> > > ---
> > >  .../bindings/iio/adc/maxim,max34408.yaml      | 141
> > > ++++++++++++++++++
> > >  1 file changed, 141 insertions(+)
> > >  create mode 100644
> > > Documentation/devicetree/bindings/iio/adc/maxim,max34408.yaml
> > > 
> > > diff --git
> > > a/Documentation/devicetree/bindings/iio/adc/maxim,max34408.yaml
> > > b/Documentation/devicetree/bindings/iio/adc/maxim,max34408.yaml
> > > new file mode 100644
> > > index 000000000000..9749f1fd1802
> > > --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/iio/adc/maxim,max34408.yaml
> > > @@ -0,0 +1,141 @@
> > > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> > > +%YAML 1.2
> > > +---
> > > +$id: http://devicetree.org/schemas/iio/adc/maxim,max34408.yaml#
> > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > +
> > > +title: Two- and four-channel current monitors with overcurrent
> > > control
> > > +
> > > +maintainers:
> > > +  - Ivan Mikhaylov <fr0st61te@xxxxxxxxx>
> > > +
> > > +description: |
> > > +  The MAX34408/MAX34409 are two- and four-channel current monitors
> > > that are
> > > +  configured and monitored with a standard I2C/SMBus serial
> > > interface. Each
> > > +  unidirectional current sensor offers precision high-side
> > > operation with a
> > > +  low full-scale sense voltage. The devices automatically sequence
> > > through
> > > +  two or four channels and collect the current-sense samples and
> > > average them
> > > +  to reduce the effect of impulse noise. The raw ADC samples are
> > > compared to
> > > +  user-programmable digital thresholds to indicate overcurrent
> > > conditions.
> > > +  Overcurrent conditions trigger a hardware output to provide an
> > > immediate
> > > +  indication to shut down any necessary external circuitry.
> > > +
> > > +  Specifications about the devices can be found at:
> > > + 
> > > https://www.analog.com/media/en/technical-documentation/data-sheets/MAX34408-MAX34409.pdf
> > > +
> > > +properties:
> > > +  compatible:
> > > +    enum:
> > > +      - maxim,max34408
> > > +      - maxim,max34409
> > > +
> > > +  "#address-cells":
> > > +    const: 1
> > > +
> > > +  "#size-cells":
> > > +    const: 0
> > > +
> > > +  reg:
> > > +    maxItems: 1
> > > +
> > > +  interrupts:
> > > +    maxItems: 1
> > > +
> > > +  powerdown-gpios:
> > > +    description:
> > > +      Shutdown Output. Open-drain output. This output transitions
> > > to high impedance
> > > +      when any of the digital comparator thresholds are exceeded
> > > as long as the ENA
> > > +      pin is high.
> > > +    maxItems: 1
> > > +
> > > +  shtdn-enable-gpios:  
> > 
> > I guess the review crossed with you sending v5.  There is some
> > feedback on v4 you need
> > to address here.  
> 
> Jonathan, I thought I did, I've changed ena to powerdown-gpios from
> Krzysztof's comments but about this one pin I'm still not sure, it
> looks like *-enable-gpios (like in *-enable-gpios pins in
> iio/frequency/adi,adf4377.yaml) pin or is it not? Or maybe any other
> suggestions about naming of this one?
> 
> Thanks.

shutdown-gpios and make the sense (active high / low) such that setting
it results in teh device being shut down.
Or treat it as an enable and enable-gpios

Something that indicates both shutdown and enable is confusing ;)

Jonathan


> 
> >   
> > > +    description:
> > > +      SHTDN Enable Input. CMOS digital input. Connect to GND to
> > > clear the latch and
> > > +      unconditionally deassert (force low) the SHTDN output and
> > > reset the shutdown
> > > +      delay. Connect to VDD to enable normal latch operation of
> > > the SHTDN output.
> > > +    maxItems: 1
> > > +
> > > +  vdd-supply: true
> > > +
> > > +patternProperties:
> > > +  "^channel@[0-3]$":
> > > +    $ref: adc.yaml
> > > +    type: object
> > > +    description:
> > > +      Represents the internal channels of the ADC.
> > > +
> > > +    properties:
> > > +      reg:
> > > +        items:
> > > +          minimum: 0
> > > +          maximum: 3
> > > +
> > > +      maxim,rsense-val-micro-ohms:
> > > +        description:
> > > +          Adjust the Rsense value to monitor higher or lower
> > > current levels for
> > > +          input.
> > > +        enum: [250, 500, 1000, 5000, 10000, 50000, 100000, 200000,
> > > 500000]
> > > +        default: 1000
> > > +
> > > +    required:
> > > +      - reg
> > > +      - maxim,rsense-val-micro-ohms
> > > +
> > > +    unevaluatedProperties: false
> > > +
> > > +required:
> > > +  - compatible
> > > +  - reg
> > > +
> > > +allOf:
> > > +  - if:
> > > +      properties:
> > > +        compatible:
> > > +          contains:
> > > +            const: maxim,max34408
> > > +    then:
> > > +      patternProperties:
> > > +        "^channel@[2-3]$": false
> > > +        "^channel@[0-1]$":
> > > +          properties:
> > > +            reg:
> > > +              minimum: 0
> > > +              maximum: 1
> > > +    else:
> > > +      patternProperties:
> > > +        "^channel@[0-3]$":
> > > +          properties:
> > > +            reg:
> > > +              minimum: 0
> > > +              maximum: 3
> > > +
> > > +additionalProperties: false
> > > +
> > > +examples:
> > > +  - |
> > > +    #include <dt-bindings/gpio/gpio.h>
> > > +
> > > +    i2c {
> > > +        #address-cells = <1>;
> > > +        #size-cells = <0>;
> > > +
> > > +        adc@1e {
> > > +              compatible = "maxim,max34409";
> > > +              reg = <0x1e>;
> > > +              powerdown-gpios = <&gpio0 1 GPIO_ACTIVE_LOW>;
> > > +              shtdn-enable-gpios = <&gpio0 2 GPIO_ACTIVE_HIGH>;
> > > +
> > > +              #address-cells = <1>;
> > > +              #size-cells = <0>;
> > > +
> > > +              channel@0 {
> > > +                  reg = <0x0>;
> > > +                  maxim,rsense-val-micro-ohms = <5000>;
> > > +              };
> > > +
> > > +              channel@1 {
> > > +                  reg = <0x1>;
> > > +                  maxim,rsense-val-micro-ohms = <10000>;
> > > +             };
> > > +        };
> > > +    };  
> >   
>