Merge branch 'ravb-add-gptp-support-for-gen4'

Niklas Söderlund says:

====================
ravb: Add gPTP support for Gen4

This series is the second part cleaning up how PTP timer support is
implemented on R-Car Gen4. Currently there is partial support for it
in some of the Ethernet devices that can use it, but not all.

On Gen2 and Gen3 each RAVB instance have it's own private PTP clock as
part of the RAVB register space. For this reason the PTP functionally
was implemented directly in the RAVB driver. For Gen4 however there is
a system-wide PTP clock shared by all RAVB instances, and on some Gen4
platforms with other Ethernet devices.

The RAVB Gen4 driver currently advertise PTP support to user-space, but
the support is in fact completely broken. It tries to use RAVB private
PTP clock, which do not exist on Gen4.

Further more the PTP clock behaved slightly different on Gen2 and Gen3.
These differences have been handled by adding platform specific flags
inside the driver.

The usage of these flags have grown organically and been extended all
over the driver as it gained new features. Adding a new third set of
flags for Gen4 would be messy and add to the confusion.

Therefore patches 1/10 thru 8/10 refactors the usage of the PTP flags
into optional callbacks and untangles the usage. This allows adding Gen4
support easy as it can just implement it's own set of Gen4 specific
callbacks without altering the driver logic.

Patch 9/10 is a small DT binding addition adding an optional phandle to
link a RAVB device to the external PTP clock. Ideally this property
should be mandatory, but for backward comp ability is is made optional.
If the phandle is not set, or the PTP clock not enabled, the RAVB driver
will continue to faction as before, but no longer advertise PTP support
to user space.

Finally patch 10/10 adds the Gen4 specific PTP callbacks which allows
the driver to use the external PTP clock.

For part one of this work see [1]. The two series are independent of
each other but both are needed before a third series liking the RAVB to
the PTP clock in the platforms device tree. I will hold posting the
third series until all dependencies are merged. For this reason there
is no user of the new renesas,gptp device tree property added in this
series.

The work is tested on both Gen3 and Gen4 R-Car devices (with [1] and
appropriate DTS). I do however not have access to any Gen2 device where
the RAVB IP is wired to a MAC, so the small rework of the flags for Gen2
to callbacks have only been compiled tested. If anybody have a RZ device
where RAVB is wired and uses the Gen2 method of starting/stopping the
PTP timer together with the DMAC please test this.

[1] https://lore.kernel.org/20260803095232.3527111-1-niklas.soderlund+renesas@ragnatech.se/
====================

Link: https://patch.msgid.link/20260921175037.4084310-1-niklas.soderlund+renesas@ragnatech.se
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

0 files changed, 0 insertions, 0 deletions