Re: [PATCH v2 11/13] dt-bindings: iio: add binding for BME680 driver

[Jonathan Cameron <Jonathan.Cameron@Huawei.com>]

On Tue, 22 Oct 2024 08:41:02 -0500
Rob Herring <robh@kernel.org> wrote:

> On Mon, Oct 21, 2024 at 09:53:14PM +0200, Vasileios Amoiridis wrote:
> > Add dt-binding for BME680 gas sensor device. The device incorporates as
> > well temperature, pressure and relative humidity sensors.  
> 
> You aren't adding a binding for bme680, but extending it.
> 
> Drop the 2nd 'bindings' from subject. 
> 
> Something like this:
> 
> dt-bindings: iio/chemical: bosch,bme680: Add supply properties
> 
> > 
> > Signed-off-by: Vasileios Amoiridis <vassilisamir@gmail.com>
> > ---
> >  .../bindings/iio/chemical/bosch,bme680.yaml   | 64 +++++++++++++++++++
> >  .../devicetree/bindings/trivial-devices.yaml  |  2 -
> >  2 files changed, 64 insertions(+), 2 deletions(-)
> >  create mode 100644 Documentation/devicetree/bindings/iio/chemical/bosch,bme680.yaml
> > 
> > diff --git a/Documentation/devicetree/bindings/iio/chemical/bosch,bme680.yaml b/Documentation/devicetree/bindings/iio/chemical/bosch,bme680.yaml
> > new file mode 100644
> > index 000000000000..e54df3afa7b2
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/iio/chemical/bosch,bme680.yaml
> > @@ -0,0 +1,64 @@
> > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/iio/chemical/bosch,bme680.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Bosch BME680 Gas sensor
> > +
> > +maintainers:
> > +  - Vasileios Amoiridis <vassilisamir@gmail.com>
> > +
> > +description:  
> 
> You need '>' to maintain paragraphs.
> 
> > +  BME680 is a gas sensor which combines relative humidity, barometric pressure,
> > +  ambient temperature and gas (VOC - Volatile Organic Compounds) measurements.
> > +
> > +  https://www.bosch-sensortec.com/media/boschsensortec/downloads/datasheets/bst-bme680-ds001.pdf
> > +
> > +properties:
> > +  compatible:
> > +    const: bosch,bme680
> > +
> > +  reg:
> > +    maxItems: 1
> > +
> > +  vdd-supply: true
> > +  vddio-supply: true
> > +
> > +required:
> > +  - compatible
> > +  - reg
> > +  - vdd-supply
> > +  - vddio-supply  
> 
> These supplies can't be required. That's an ABI change from what was 
> already supported.
Hi Rob,

I thought for supplies the convention was that if the power is needed
for functioning device then to put them as required.

In case were they were missing in an original binding
allow stub regulators to deal with a DT that predates that.
Non linux cases are obviously trickier to predict but these
supplies must be on or the binding wouldn't have worked before this
point.

I remember I was very much on the side that they were optional and
convinced by others that this was the way to go.

We've added supplies for old bindings as required in the past
so probably broken someone if I have this wrong :(

Jonathan