NOTE: This series is intentionally submitted on net-next (not
intel-wired-lan) as early feedback of DPLL subsystem changes is
welcomed. In the past possible approaches were discussed in [1].
This series adds TX reference clock support for E825 devices and exposes
TX clock selection and synchronization status via the Linux DPLL
subsystem.
Here is the high-level connection diagram for E825 device:
+------------------------------------------------------------------+
| |
| +-----------------------------+ |
| | | |
| | MAC | |
| |+------------+-----+ | |
| ||RX/1588 |PHC|tspll<----\ | |
+---+----+ ||MUX +---+-^---| | | |
| E | RX >---------------------> | >--\ | | |
| T | | /----------------> | >-\| | | |
| H |----+ | |+---------+----^---+ || | | |
| 1 | TX <----|----------------+TX MUX < OCXO | || | | |
| |PLL | | || |--------| || | | |
+---+----+ | /----+ <-ext_ref<-||-|----|------ext_ref
| E | RX >----/ | || |--------+ || | | |
| T | | | || < SyncE | || | | |
| H |----+ | |+-----------^------+ || | | |
| 2 | TX <----------------/ | | /------||-/ | |
| |PLL | +------------|-|------||------+ |
+---+----+ /--/ | || |
| . | RX >--- | | || |
| . | | +----------|----|------||--+ |
| . |----+ | +-^-+--^+ || | |
| | TX <--- | |EEC|PPS| || | |
| |PLL | | +-------+ || | |
+---+----+ | | <-CLK0/| | |
| E | RX >--- | | DPLL | | | |
| T | | | | <-CLK1-/ | |
| H |----+ | | | | |
| X | TX <--- | | <---SMA---< |
| |PLL | | | | | |
+---+----+ | | <---GPS---< |
| | | | | |
| | | <---...---< |
| | | | | |
| | +-------+ | |
| | External timing module | |
| +--------------------------+ |
+------------------------------------------------------------------+
E825 hardware contains a dedicated TX clock domain with per-port source
selection behavior that is distinct from PPS handling and from board-level
EEC distribution. TX reference clock selection is device-wide, shared
across ports, and mediated by firmware as part of link bring-up. As a
result, TX clock selection intent may differ from effective hardware
configuration, and software must verify outcome after link-up.
To support this, the series extends the DPLL core and the ice driver
incrementally. The series also introduces DPLL_TYPE_GENERIC as a broad
UAPI class for DPLL instances outside PPS/EEC categories. The intent is
to keep type naming reusable and scalable across different ASIC
topologies while preserving functional discoverability via
driver/device context and pin topology.
This follows netdev discussion guidance that UAPI type naming should avoid
location-specific or vendor-specific taxonomy, because such labels do not
scale across different ASIC designs. The function of a given DPLL instance
is already discoverable from driver/device context and pin topology, and
does not require an additional narrow type identifier in UAPI.
At the same time, a separate DPLL object is still needed for E825 TX clock
control/reporting semantics. Using DPLL_TYPE_GENERIC provides a reusable
class for devices outside PPS/EEC without overfitting UAPI naming to one
topology.
The relevant discussion is in [2].
Series content
- add a new generic DPLL type for devices outside PPS/EEC classes;
- relax DPLL pin registration rules for firmware-described shared pins
and extend pin notifications with a source identifier;
- allow dynamic state control of SyncE reference pins where hardware
supports it;
- add CPI infrastructure for PHY-side TX clock control on E825C;
- introduce a TX-clock DPLL device and TX reference clock pins
(EXT_EREF0 and SYNCE) in the ice driver;
- extend the Restart Auto-Negotiation command to carry a TX reference
clock index;
- implement hardware-backed TX reference clock switching, post-link
verification, and TX synchronization reporting.
TXCLK pins report TX reference topology only. Actual synchronization
success is reported via DPLL lock status, updated after hardware
verification: external TX references report LOCKED, while the internal
ENET/TXCO source reports UNLOCKED.
This provides reliable TX reference selection and observability on E825
devices using standard DPLL interfaces, without conflating user intent
with effective hardware behavior.
[1] https://lore.kernel.org/netdev/20250905160333.715c34ac@kernel.org/
[2] https://lore.kernel.org/netdev/20260402230626.3826719-1-grzegorz.nitka@intel.com/
Changes in v10:
- rebased
Addressed AI review (Sashiko) concerns (all in patch 8/8):
- moved INIT_WORK(txclk_work) and added init_rwsem(txclk_notify_rwsem)
next to mutex_init(&d->lock) in ice_dpll_init_e825() so both are
initialized before any path that can fail and trigger ice_dpll_deinit()
- added struct rw_semaphore txclk_notify_rwsem to struct ice_dplls and
used it (down_read across the whole critical region of
ice_txclk_update_and_notify(), including the out-of-lock dpll_*_change_ntf()
calls; down_write/up_write barrier in ice_dpll_deinit() to drain
in-flight notifiers before pins and the TXC DPLL device are freed) -
closes a use-after-free window on rmmod
- ice_dpll_txclk_state_on_dpll_set(): reject pin states other than
CONNECTED/DISCONNECTED with -EINVAL and NL_SET_ERR_MSG() instead of
silently treating them as a connect request
- ice_dpll_txclk_work(): on a failed switch, capture old/new pin pointers
under the lock and emit dpll_pin_change_ntf() after dropping it, so
userspace sees the requested pin flip back to DISCONNECTED and the
effective pin to CONNECTED
- ice_dpll_txclk_work(): only clear txclk_switch_requested / roll back
tx_clk_req when no newer request arrived while the lock was dropped,
so a re-queued worker run picks up the updated value
- ice_txclk_update_and_notify(): replaced the
pf->dplls.txc.dpll = ERR_PTR(-ENODEV) "suppress notification" hack
with an explicit local bool notify_dpll; the dpll_state update and
the notification decision are made under the lock, the notification
itself is emitted after unlock
- ice_ptp_setup_pf(): seed the per-PHY Tx reference clock usage map
only on E825 and explained the "no locking needed" invariant in a
comment (runs before pf->dplls.lock exists and before any link event
or DPLL callback can observe the map)
- moved port_num/phy and tx_ref_clk locals into the E825-only branches
where they are actually used
- ice_txclk_enable_peer(): use ice_pf_to_dev(pf) for dev_err() to match
the rest of the file (was ice_hw_to_dev(&pf->hw))
- extended ctrl_pf->dplls.lock coverage in ice_txclk_set_clk() and
ice_txclk_enable_peer() across both the usage check and the
ice_cpi_ena_dis_clk_ref() AQ command so two PFs racing to switch to
the same (phy, clk) cannot both observe clk_in_use == false and issue
duplicate enables
Other:
- replaced ternary-for-statement-effect (`(clk == i) ? set_bit() :
clear_bit();`) with plain if/else in the two tx_refclks bitmap loops
- dropped 15 unused CFG_*/CFG_RESERVED* SERDES field defines in
ice_ptp_hw.h; kept only CFG_ICTL_PCS_REF_SEL_RX_NT,
CFG_ICTL_PCS_REF_SEL_TX_NT and REF_SEL_NT_ENET/EREF0/SYNCE which are
actually consumed
- updated kernel-doc for struct ice_dpll
Patch 7/8:
- cosmetic: removed a stray double space in the
ice_aq_set_link_restart_an() prototype
Patches 1-6: unchanged
Changes in v9:
- rebased
- fixed kernel-doc: member 'module_name' not described in 'dpll_pin' (patch 2/8)
Addressed AI review concerns:
- reworded commit message to use 'src_clock_id' instead 'src_id' (patch 3/8)
- use rclk.num_parents when setting is_rclk_parent (patch 5/8)
- fixed retry mechanism in ice_cpi_wait_ack (patch 6/8)
- fixed txclk_switch_requested, tx_clk, tx_clk_req settings on HW
failure (patch 8/8)
- use cancel_work_sync instead flush_work (patch 8/8)
- protect clearing ICE_FLAG_DPLL flag with mitex on DPLL
deinit (patch 8/8)
- dpll_state update and the notify_dpll decision are made inside
the lock (patch 8/8)
Changes in v8:
- rebased
Addressed AI review concerns:
- caching the module name in the pin object at allocation time and using
the cached string in netlink paths (patch 2/8)
- dropped references to netlink in the commit message for (patch 3/8, it's
internal notification only)
- replaced the commit 4/8 with the new one (relax the capability check in
dpll_pin_state_set)
- resolved potential teradown race between ice_dpll_deinit_txclk_pins and
ice_dpll_pin_notify_work() that is about to register the SYNCE pin
(patch 5/8)
- resolved potential path deadlock during driver probe and error path
(patch 5/8)
- relaxed kernel-doc regarding cpi mutex usage (patch 6/8)
- fixed ice_cpi.c header (patch 6/8)
- fix retry mechanism in ice_cpi_wait_req0_ack0 (patch 6/8)
- fix potrntial leaving LM.REQ stuck asserted on the hardware (patch 6/8)
- fix kernel-doc for ice_cpi_ena_dis_clk_ref
- removed unused CPI definitions (patch 6/8)
- fix header inclusion (patch 6/8)
- addressed Sashiko issues for patch (8/8)
Changes in v7:
- rebased
- replace TXC-specific DPLL type with DPLL_TYPE_GENERIC (patch 1/8)
- update TXC framework to use DPLL_TYPE_GENERIC instead of DPLL_TYPE_GENERIC
(patch 5/8)
- AI-review: added short trailing comment to the local mutex declaration
to satisfy checkpatch report (patch 6/8)
Changes in v6:
- rebased
- AI-review: fix unprotected concurrent access to shared clock
bitmap (patch 8/8)
- AI-review: fix potential issue in tx-clk pin state request handling
('already set' early-exit based now on tx_clk_req comparison, patch 8/8)
- AI-review: CPI transaction serialization (patch 6/8)
Changes in v5:
- rebased
- reworded cover letter
- replace 'ntfy_src' new argument name with 'src_clk_id' and use it
consistently in DPLL notification calls (patch 3/8)
- reworded commit message (patch 5/8)
- use FIELD_PREP/GENMSK macros instead of struct bitfields (patch 6/8)
- reworded commit message (patch 5/8, patch 8/8)
- refactor the code to avoid sleeping while DPLL mutex is held (using
work_queue, patch 8/8)
- added TXCLK pins and TXC DPLL notifications (patch 8/8)
- removed 'unused clock disable' mechanism from the scope of this series
Changes in v4:
- rebased
- edited, shortened the commit message in 3/8 patch
- moved ice_get_ctrl_pf to the header file (patch 8/8) and
removed duplicated static definitions from ice_ptp and ice_txlck
modules
- add NULL/invalid pointer checker for returned pointer from
ice_get_ctrl_pf (patch 8/8)
- edited error message in case AN restart failure (patch 8/8)
Changes in v3:
- improved commit message (patch 1/8, AI review comment)
- improved deinitialization path in ice_dpll_deinit_txclk_pins to
avoid potential NULL dereference. NULL checking moved to
ice_dpll_unregister_pins (patch 5/8, found by AI review)
- removed redundant semicolon (patch 6/8)
Changes in v2:
- rebased
- added autogenerated DPLL files (patch 1/8)
- fixed checkpatch 'parenthesis alignment' warning (patch 2/8)
- fixed error path in ice_dpll_init_txclk_pins (AI warning, patch 5/8)
- fixed kdoc warnings (patch 6/8, patch 8/8)
Grzegorz Nitka (8):
dpll: add generic DPLL type
dpll: allow registering FW-identified pin with a different DPLL
dpll: extend pin notifier with notification source ID
dpll: allow fwnode pins to attempt state change without capability bit
ice: introduce TXC DPLL device and TX ref clock pin framework for E825
ice: implement CPI support for E825C
ice: add Tx reference clock index handling to AN restart command
ice: implement E825 TX ref clock control and TXC hardware sync status
Documentation/netlink/specs/dpll.yaml | 3 +
drivers/dpll/dpll_core.c | 34 +-
drivers/dpll/dpll_core.h | 5 +-
drivers/dpll/dpll_netlink.c | 26 +-
drivers/dpll/dpll_netlink.h | 4 +-
drivers/dpll/dpll_nl.c | 2 +-
drivers/net/ethernet/intel/ice/Makefile | 2 +-
drivers/net/ethernet/intel/ice/ice.h | 12 +
drivers/net/ethernet/intel/ice/ice_adapter.c | 4 +
drivers/net/ethernet/intel/ice/ice_adapter.h | 7 +
.../net/ethernet/intel/ice/ice_adminq_cmd.h | 2 +
drivers/net/ethernet/intel/ice/ice_common.c | 5 +-
drivers/net/ethernet/intel/ice/ice_common.h | 2 +-
drivers/net/ethernet/intel/ice/ice_cpi.c | 362 ++++++++++++++
drivers/net/ethernet/intel/ice/ice_cpi.h | 58 +++
drivers/net/ethernet/intel/ice/ice_dpll.c | 468 +++++++++++++++++-
drivers/net/ethernet/intel/ice/ice_dpll.h | 36 +-
drivers/net/ethernet/intel/ice/ice_lib.c | 3 +-
drivers/net/ethernet/intel/ice/ice_ptp.c | 37 +-
drivers/net/ethernet/intel/ice/ice_ptp.h | 7 +
drivers/net/ethernet/intel/ice/ice_ptp_hw.c | 37 ++
drivers/net/ethernet/intel/ice/ice_ptp_hw.h | 17 +
drivers/net/ethernet/intel/ice/ice_sbq_cmd.h | 5 +-
drivers/net/ethernet/intel/ice/ice_txclk.c | 320 ++++++++++++
drivers/net/ethernet/intel/ice/ice_txclk.h | 40 ++
drivers/net/ethernet/intel/ice/ice_type.h | 2 +
include/linux/dpll.h | 1 +
include/uapi/linux/dpll.h | 2 +
28 files changed, 1442 insertions(+), 61 deletions(-)
create mode 100644 drivers/net/ethernet/intel/ice/ice_cpi.c
create mode 100644 drivers/net/ethernet/intel/ice/ice_cpi.h
create mode 100644 drivers/net/ethernet/intel/ice/ice_txclk.c
create mode 100644 drivers/net/ethernet/intel/ice/ice_txclk.h
base-commit: 794cd1c77f53309f5eb8c05b4b833ad3723eccff
--
2.39.3