[PATCH net-next 0/2] dpll: rework fractional frequency offset reporting

[Ivan Vecera <ivecera@redhat.com>]

Rework how the fractional frequency offset (FFO) is reported in
the DPLL subsystem.

The fractional-frequency-offset-ppt attribute is moved from the
top-level pin attributes into the pin-parent-device nested attribute
set. This makes it consistent with phase-offset (which is already
per-parent) and clarifies that FFO PPT represents the frequency
difference between a pin and its parent DPLL device.

The two FFO contexts are distinguished in the ffo_get callback:
dpll=NULL for the top-level RX vs TX symbol rate offset and a valid
dpll pointer for the nested pin vs DPLL offset.

Patch 1 restructures the DPLL subsystem netlink handling, updates
the YAML spec and driver-api documentation, and adds NULL guards
to mlx5 and zl3073x drivers.

Patch 2 implements the nested FFO for zl3073x using the
dpll_df_offset_x register with ref_ofst=1, providing 2^-48
resolution. The old per-reference frequency measurement is removed
as it was redundant with measured-frequency.

Ivan Vecera (2):
  dpll: move fractional-frequency-offset-ppt under pin-parent-device
  dpll: zl3073x: report FFO as DPLL vs input reference offset

 Documentation/driver-api/dpll.rst             | 16 +++++++
 Documentation/netlink/specs/dpll.yaml         | 11 +++--
 drivers/dpll/dpll_netlink.c                   | 34 ++++++++++----
 drivers/dpll/dpll_nl.c                        |  1 +
 drivers/dpll/zl3073x/chan.c                   | 31 ++++++++++++-
 drivers/dpll/zl3073x/chan.h                   | 14 ++++++
 drivers/dpll/zl3073x/core.c                   | 45 -------------------
 drivers/dpll/zl3073x/dpll.c                   | 34 +++++++-------
 drivers/dpll/zl3073x/ref.h                    | 14 ------
 drivers/dpll/zl3073x/regs.h                   | 15 +++++++
 .../net/ethernet/mellanox/mlx5/core/dpll.c    |  4 ++
 11 files changed, 126 insertions(+), 93 deletions(-)


-- 
2.53.0