Re: [PATCH v2 0/8] gnss: add new GNSS subsystem

[Johan Hovold]

On Wed, May 30, 2018 at 07:38:22AM -0700, Richard Cochran wrote:
> On Wed, May 30, 2018 at 12:32:34PM +0200, Johan Hovold wrote:
> > Another possible extension is to add generic 1PPS support.
> 
> There are two possibilities to consider.
> 
> 1. If the PPS causes an interrupt, then it should hook into the PPS
>    subsystem.

Registering a PPS child device is what I had in mind for this.

> 2. If the PPS is a HW signal routed for example to the input pin of a
>    MAC based PTP Hardware Clock (PHC), then it would make sense to
>    model the GNSS device as a PHC as well.  This PHC would be readable
>    but not writable, and more importantly it would offer an output
>    signal.  Then user space could use the existing interfaces to
>    dial the PPS signal from one device the another.

Ok.

> (Come to think of it, modeling the GNSS as PHC would also give you the
> interface for #1 as well.)

Thanks
Johan