Re: [PATCH v6 4/7] dt-bindings: iio: accel: adxl345: make interrupts not a required property

Krzysztof Kozlowski
2024-12-13T08:49:15Z

On Fri, Dec 13, 2024 at 09:06:39AM +0100, Lothar Rubusch wrote:
> On Thu, Dec 12, 2024 at 9:11 AM Krzysztof Kozlowski <krzk@kernel.org> wrote:
> >
> > On Wed, Dec 11, 2024 at 11:06:45PM +0000, Lothar Rubusch wrote:
> > > Remove interrupts from the list of required properties. The ADXL345
> > > provides two interrupt lines. Anyway, the interrupts are an option, to
> > > be used for additional event features. The driver can measure without
> > > interrupts. Hence, interrupts should never have been required for the
> > > ADXL345. Thus having interrupts required can be considered to be a
> > > mistake.
> >
> > Partially this explains my question on previous patch, so consider
> > reordering them.
> >
>
> I understand.
>
> > And with combined knowledge, your driver now depends on interrupt names
> > to setup interrupts. "interrupts" property alone is not sufficient, so
> > you should encode it in the binding and explain in rationale why this is
> > required (it is a change in ABI).
> >
> > https://elixir.bootlin.com/linux/v6.8-rc3/source/Documentation/devicetree/bindings/example-schema.yaml#L193
> >
>
> The accelerometer does not need interrupts connected/configured for
> basic functionality. Interrupt declaration allows for additional
> features. Then there are two possible interrupt lines, only one is
> connected. Thus, either only one INT out of two, or none needs to be
> configured in the DT depending on the hardware setup. This also needs
> to be configured then in the sensor, which INT line to use for
> signalling. Thus we need the information if INT1 or INT2 was setup, if
> any.

I meant, explain in the commit msg.

>
> Hence, configuring an "interrupts" property only makes sense, if also
> a "interrupt-names" is configured, and vice versa. None of them are
> required for basic accelerometer functionality.

I know, I already stated this. But almost every question should have its
answer in the commit msg.

Best regards,
Krzysztof