Re: [PATCH v2 15/17] dt-bindings:iio:adc:ad7280a: Add binding

[Jonathan Cameron <jic23@kernel.org>]

On Sat, 18 Dec 2021 18:18:12 -0300
Marcelo Schmitt <marcelo.schmitt1@gmail.com> wrote:

> Think it would be more intuitive to use the number of active channels as enum
> elements for adi,temp-alert-last-chan and adi,voltage-alert-last-chan.

Just to check I understand correctly, you mean active number of channels
across all devices, or just in the last device?

If all devices it would get tricky to handle because if set to a value
before the last device I'm not sure how we'd handle it.

Or do you mean just index in that device form 1, so when we disable
VIN5 we still have VIN0,1,2,3,4 so 5 devices?

The AUX version as per earlier patch is a real pain to describe. If
we do support it we'll probably just have to fall back to strings
or similar which isn't nice.

Jonathan

> This, though, is just my personal opinion so 
> Reviewed-by: Marcelo Schmitt <marcelo.schmitt1@gmail.com>
> 
> On 12/05, Jonathan Cameron wrote:
> > From: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> > 
> > Add a binding for this Lithium Ion Battery monitoring chip/chain of chips
> > as it is now clean and ready to move out of staging.
> > 
> > Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> > Reviewed-by: Rob Herring <robh@kernel.org>
> > ---
> >  .../bindings/iio/adc/adi,ad7280a.yaml         | 87 +++++++++++++++++++
> >  1 file changed, 87 insertions(+)
> > 
> > diff --git a/Documentation/devicetree/bindings/iio/adc/adi,ad7280a.yaml b/Documentation/devicetree/bindings/iio/adc/adi,ad7280a.yaml
> > new file mode 100644
> > index 000000000000..77b8f67fe446
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/iio/adc/adi,ad7280a.yaml
> > @@ -0,0 +1,87 @@
> > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/iio/adc/adi,ad7280a.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Analog Devices AD7280a Lithium Ion Battery Monitoring System
> > +
> > +maintainers:
> > +  - Michael Hennerich <michael.hennerich@analog.com>
> > +  - Jonathan Cameron <jic23@kernel.org>
> > +
> > +description: |
> > +  Bindings for the Analog Devices AD7280a Battery Monitoring System.
> > +  Used in devices such as hybrid electric cars, battery backup and power tools.
> > +  Multiple chips can be daisy chained and accessed via a single SPI interface.
> > +  Data sheet found here:
> > +    https://www.analog.com/media/en/technical-documentation/data-sheets/AD7280A.pdf
> > +
> > +properties:
> > +  compatible:
> > +    const: adi,ad7280a
> > +
> > +  reg:
> > +    maxItems: 1
> > +
> > +  interrupts:
> > +    description: IRQ line for the ADC
> > +    maxItems: 1
> > +
> > +  spi-max-frequency: true
> > +
> > +  adi,temp-alert-last-chan:
> > +    $ref: /schemas/types.yaml#/definitions/uint32
> > +    description:
> > +      Allows limiting of scope of which channels are considered for temperature
> > +      alerts, typically because not all are wired to anything. Only applies to
> > +      last device in the daisy chain.
> > +    default: 5
> > +    enum: [3, 4, 5]
> > +
> > +  adi,voltage-alert-last-chan:
> > +    $ref: /schemas/types.yaml#/definitions/uint32
> > +    description:
> > +      Allows limiting of scope of which channels are considered for voltage
> > +      alerts, typically because not all are wired to anything. Only applies to
> > +      last device in the daisy chain.
> > +    default: 5
> > +    enum: [3, 4, 5]
> > +
> > +  adi,acquisition-time-ns:
> > +    description:
> > +      Additional time may be needed to charge the sampling capacitors depending
> > +      on external writing.
> > +    default: 400
> > +    enum: [400, 800, 1200, 1600]
> > +
> > +  adi,thermistor-termination:
> > +    type: boolean
> > +    description:
> > +      Enable the thermistor termination function.
> > +
> > +required:
> > +  - compatible
> > +  - reg
> > +
> > +additionalProperties: false
> > +
> > +examples:
> > +  - |
> > +    spi {
> > +      #address-cells = <1>;
> > +      #size-cells = <0>;
> > +
> > +      adc@0 {
> > +        compatible = "adi,ad7280a";
> > +        reg = <0>;
> > +        spi-max-frequency = <700000>;
> > +        interrupt-parent = <&gpio>;
> > +        interrupts = <25 2>;
> > +        adi,thermistor-termination;
> > +        adi,acquisition-time-ns = <800>;
> > +        adi,voltage-alert-last-chan = <5>;
> > +        adi,temp-alert-last-chan = <5>;
> > +      };
> > +    };
> > +...
> > -- 
> > 2.34.1
> >