RE: [PATCH net-next] misc: Add Renesas Synchronization Management Unit (SMU) support

From: Min Li
Date: Tue Feb 16 2021 - 12:11:11 EST


> >
> > If I come up with a new file and move all the abstraction code there,
> > does that work?
>
> I think so, but it's more important to figure out a good user space interface
> first. The ioctl interfaces should be written on a higher-level abstraction, to
> ensure they can work with any hardware implementation and are not
> specific to Renesas devices.
>
> Can you describe on an abstract level how a user would use the character
> device, and what they achieve by that?
>
> Arnd

Hi Arnd

This driver is meant to be used by Renesas PTP Clock Manager for
Linux (pcm4l) software for Renesas device only.

About how pcm4l uses the char device, pcm4l will open the device
and do the supported ioctl cmds on the device, simple like that.

At the same time, pcm4l will also open ptp hardware clock device,
which is /dev/ptp[x], to do clock adjustments.

Min