dpll: extend pin notifier with notification source ID

Extend the DPLL pin notification API to include a source identifier
indicating where the notification originates. This allows notifier
consumers to distinguish between notifications coming from
an associated DPLL instance, a parent pin, or the pin itself.

A new field, src_clock_id, is added to struct dpll_pin_notifier_info
and is passed through all pin-related notification paths. Callers of
dpll_pin_notify() are updated to provide a meaningful source identifier
based on their context:
  - pin registration/unregistration uses the DPLL's clock_id,
  - pin-on-pin operations use the parent pin's clock_id,
  - pin changes use the pin's own clock_id.

As introduced in the commit ("dpll: allow registering FW-identified pin
with a different DPLL"), it is possible to share the same physical pin
via firmware description (fwnode) with DPLL objects from different
kernel modules. This means that a given pin can be registered multiple
times.

Driver such as ICE (E825 devices) rely on this mechanism when listening
for the event where a shared-fwnode pin appears, while avoiding reacting
to events triggered by their own registration logic.

This change only extends the notification metadata and does not alter
existing semantics for drivers that do not use the new field.

Reviewed-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com>
Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Grzegorz Nitka <grzegorz.nitka@intel.com>
Link: https://patch.msgid.link/20260607183045.1213735-9-grzegorz.nitka@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/linux/dpll.h b/include/linux/dpll.h
index 03a538167691..7a6f8796cda2 100644
--- a/include/linux/dpll.h
+++ b/include/linux/dpll.h
@@ -233,6 +233,7 @@ struct dpll_pin_notifier_info {
 	u64 clock_id;
 	const struct fwnode_handle *fwnode;
 	const struct dpll_pin_properties *prop;
+	u64 src_clock_id;
 };
 
 #if IS_ENABLED(CONFIG_DPLL)