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

Johan Hovold
2018-05-31T08:52:53Z

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