On Wed, Nov 27, 2024 at 03:59:32PM +0100, Uwe Kleine-König wrote: > For the AD7124 chip and some of its cousins the logical irq line (̅R̅D̅Y) > is physically on the same pin as the spi MISO output (DOUT) and so > reading a register might trigger an interrupt. For correct operation > it's critical that the actual state of the pin can be read to judge if > an interrupt event is a real one or just a spurious one triggered by > toggling the line in its MISO mode. > > Allow specification of an "rdy-gpios" property that references a GPIO > that can be used for that purpose. While this is typically the same GPIO > also used (implicitly) as interrupt source, it is still supposed that > the interrupt is specified as before and usual. > > Signed-off-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxx> > --- > .../devicetree/bindings/iio/adc/adi,ad7124.yaml | 13 +++++++++++++ > .../devicetree/bindings/iio/adc/adi,ad7173.yaml | 12 ++++++++++++ > .../devicetree/bindings/iio/adc/adi,ad7192.yaml | 15 +++++++++++++++ > .../devicetree/bindings/iio/adc/adi,ad7780.yaml | 11 +++++++++++ > 4 files changed, 51 insertions(+) > > diff --git a/Documentation/devicetree/bindings/iio/adc/adi,ad7124.yaml b/Documentation/devicetree/bindings/iio/adc/adi,ad7124.yaml > index 35ed04350e28..9f34a055fdf1 100644 > --- a/Documentation/devicetree/bindings/iio/adc/adi,ad7124.yaml > +++ b/Documentation/devicetree/bindings/iio/adc/adi,ad7124.yaml > @@ -37,6 +37,17 @@ properties: > description: IRQ line for the ADC > maxItems: 1 > > + rdy-gpios: > + description: | > + GPIO reading the ̅̅R̅D̅Y line. Having such a GPIO is technically optional but > + highly recommended because DOUT/̅R̅D̅Y toggles during SPI transfers (in its > + DOUT aka MISO role) and so usually triggers a spurious interrupt. The > + distinction between such a spurious event and a real one can only be done > + by reading such a GPIO. (There is a register telling the same > + information, but accessing that one needs a SPI transfer which then > + triggers another interrupt event.) > + maxItems: 1 Rob commented to v2 which I missed to pickup: Don't need '|'. Otherwise, Reviewed-by: Rob Hering (Arm) <robh@xxxxxxxxxx> Dropped the | now in my tree in case we need a v5. Otherwise I'd ask Jonathan to drop the |s when applying. I probably would have dropped the R-b tag given the changes here (i.e. adding the property to several more bindings). Best regards and sorry, Uwe
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