On Thu, Sep 26, 2024 at 10:46:54AM +0200, Rodolfo Giometti wrote: > On 25/09/24 23:55, Hall, Christopher S wrote: > > Hi Rodolfo, > > Hello. > > > > From: Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> > > > Sent: Tuesday, September 03, 2024 3:25 AM > > > To: Rodolfo Giometti <giometti@xxxxxxxxxxxx> > > > > > Subject: Re: [PATCH v12 2/3] Documentation: driver-api: pps: Add Intel Timed > > > I/O PPS generator > > > > > > > > > If you are willing to stop the inclusion due this fact maybe its time to add > > > > such PPS generators interface... on the other hand, if you agree for > > > > inclusion we can do this job as soon as the code has been included, in order > > > > to fix this anomalous status. > > > > > > Please make a generic pps subsystem for this, it would make it simpler > > > for everyone. > > > > What is required to move this? We can certainly test the code and do some > > of this work, but I would look to you to define the interface. > > The problem is that a pps-generator has no related device, then no sysfs entries. > > I think the right-thing(TM) to do is adding a new class named > "pps-generator", so we will get the directory /sys/class/pps-generator with > several devices as pps-generator0, pps-generator1, etc. For each device we > should add at least these sysfs entries: > > - system : This file return "1" if the generator takes the timing from > the system clock, while it returns "0" if not (i.e. from a > peripheral device clock). > > - time : This file contains the current time stored into the generator > clock as two integers representing the current time seconds and > nanoseconds. > > - enable : This write-only file enables or disables generation of the > PPS signal. > > - period : This file defines the period for the generator signal. When > read, by default, it returns "1 0" which represent the period > second and nanoseconds (i.e. a PPS signal). When written, it > sets the period accordingly or ENOTSUPP if not supported. > > - start_time : This file defines the starting time for the the generator > signal. When read, by default, it returns "0 0" which means > "now". When written, it sets the starting time accordingly or > ENOTSUPP if not supported. This seems sane to me, thanks for writing it up! greg k-h
