Re: [PATCH v5 02/14] dt-bindings: iio: adc: ad7768-1: add trigger-sources property

Jonathan Santos
2025-04-17T00:23:04Z

On 04/11, David Lechner wrote:
> On 4/11/25 10:56 AM, Jonathan Santos wrote:
> > In addition to GPIO synchronization, The AD7768-1 also supports
> > synchronization over SPI, which use is recommended when the GPIO
> > cannot provide a pulse synchronous with the base MCLK signal. It
> > consists of looping back the SYNC_OUT to the SYNC_IN pin and send
> > a command via SPI to trigger the synchronization.
> >
> > Introduce the 'trigger-sources' property to support SPI-based
> > synchronization, along with additional optional entries for the SPI
> > offload trigger and the START signal via GPIO3.
> >
> > While at it, add description to the interrupts property.
> >
> > Signed-off-by: Jonathan Santos <Jonathan.Santos@analog.com>
> > ---
>
> ...
>
> > @@ -57,6 +80,15 @@ properties:
> > "#io-channel-cells":
> > const: 1
> >
> > + "#trigger-source-cells":
> > + description: |
> > + Indicates the trigger source type for each entry:
> > + 0 = Synchronization GPIO-based trigger
> > + 1 = Synchronization device trigger (e.g., another ad7768-1)
> > + 2 = GPIO3 pin acting as START signal
> > + 3 = DRDY pin acting as SPI offload trigger
> > + const: 1
> > +
>
> 0 and 1 don't sound like trigger outputs that this ADC is providing, so don't
> seem appropriate here. But the SYNC_OUT pin is missing from this list.
>
> Also, outputs could be used to trigger anything, not just SPI offload, so don't
> need to mention that.

You mean like this:

...
"#trigger-source-cells":
description: |
Cell indicates the trigger output signal: 0 = SYNC_OUT, 1 = GPIO3,
2 = DRDY.

const: 1
...

It would be like interfacing those output pins for a generic trigger
usage?

>