[PATCH net-next v7 0/3] dpll: add SiTime SiT9531x DPLL clock driver

From: Ali Rouhi

Date: Sat Aug 15 2026 - 18:20:41 EST


This series adds a DPLL subsystem driver for the SiTime SiT95316 and
SiT95317 I2C clock generators. Each device integrates four PLLs with
automatic/manual reference selection and on-chip TDC phase-offset
measurement, and is used for synchronization in telecom, networking,
and data-center timing.

The series contains the device-tree binding, the driver under
drivers/dpll/sit9531x/, and the MAINTAINERS entry.

v1: https://lore.kernel.org/netdev/20260511211143.19792-1-arouhi@xxxxxxxxxx/
v2: https://lore.kernel.org/netdev/20260520191943.73938-1-arouhi@xxxxxxxxxx/
v3: https://lore.kernel.org/netdev/20260731180951.65725-1-arouhi@xxxxxxxxxx/
v4: https://lore.kernel.org/netdev/20260806232439.27551-1-arouhi@xxxxxxxxxx/
v5: https://lore.kernel.org/netdev/20260810230439.22866-1-arouhi@xxxxxxxxxx/
v6: https://lore.kernel.org/netdev/20260812175337.18155-1-arouhi@xxxxxxxxxx/

Changes since v6 (driver only; the bindings are unchanged):

- Remove a conflict marker that slipped into a comment block in
dpll.c. It sat inside /* */, so it built and checkpatch, which has
no check for markers, did not report it.
- Unwind DPLL registration when it fails partway. dev_start() returned
on the first failure without unregistering the DPLLs already done,
and the caller then freed them, leaving the subsystem with pointers
into freed memory.
- Report an input as selectable only for the DPLL that can select it.
The test used the physical receiver state, which every DPLL fed from
that lane shares. A lane in LOS no longer drops to disconnected
either: signal quality belongs in the pin's own attributes.
- Refuse DPLL_PIN_STATE_CONNECTED on an input instead of treating it
as selectable. The device selects by priority and has no mode that
pins one reference, so the request cannot be honoured.
- Keep the rest of the priority table when one input moves. prio_set
used to fill every lower-priority slot with the same source, which
discarded the fallbacks the caller had not asked about.
- Refuse to drive INTSYNC from a PLL that already selects it.
- Drop the SYSREF/SYNCB/pulser claim from the commit message: only the
esync default is reachable, the other modes are not exposed.

The AI review also reported a use-after-free of the pin properties. It
is a false positive: dpll_pin_alloc() calls dpll_pin_prop_dup(), which
copies freq_supported with kmemdup() and the labels with kstrdup(), so
the core owns its copies and the driver has to free its own.


Ali Rouhi (3):
dt-bindings: vendor-prefixes: add SiTime Corporation
dt-bindings: dpll: add SiTime SiT95316 clock generator
dpll: add SiTime SiT9531x DPLL clock driver

.../bindings/dpll/sitime,sit95316.yaml | 171 +
.../devicetree/bindings/vendor-prefixes.yaml | 2 +
MAINTAINERS | 7 +
drivers/dpll/Kconfig | 1 +
drivers/dpll/Makefile | 1 +
drivers/dpll/sit9531x/Kconfig | 17 +
drivers/dpll/sit9531x/Makefile | 4 +
drivers/dpll/sit9531x/core.c | 3111 +++++++++++++++++
drivers/dpll/sit9531x/core.h | 372 ++
drivers/dpll/sit9531x/dpll.c | 1232 +++++++
drivers/dpll/sit9531x/dpll.h | 69 +
drivers/dpll/sit9531x/prop.c | 397 +++
drivers/dpll/sit9531x/prop.h | 39 +
drivers/dpll/sit9531x/regs.h | 371 ++
14 files changed, 5794 insertions(+)
create mode 100644 Documentation/devicetree/bindings/dpll/sitime,sit95316.yaml
create mode 100644 drivers/dpll/sit9531x/Kconfig
create mode 100644 drivers/dpll/sit9531x/Makefile
create mode 100644 drivers/dpll/sit9531x/core.c
create mode 100644 drivers/dpll/sit9531x/core.h
create mode 100644 drivers/dpll/sit9531x/dpll.c
create mode 100644 drivers/dpll/sit9531x/dpll.h
create mode 100644 drivers/dpll/sit9531x/prop.c
create mode 100644 drivers/dpll/sit9531x/prop.h
create mode 100644 drivers/dpll/sit9531x/regs.h


base-commit: 001b5d347d8ba39b2dccaefcc57967b18caec8fe
--
2.34.1