Extend the DPLL core to support associating a DPLL pin with a firmware
node. This association is required to allow other subsystems (such as
network drivers) to locate and request specific DPLL pins defined in
the Device Tree or ACPI.

* Add a .fwnode field to the struct dpll_pin
* Introduce dpll_pin_fwnode_set() helper to allow the provider driver
  to associate a pin with a fwnode after the pin has been allocated
* Introduce fwnode_dpll_pin_find() helper to allow consumers to search
  for a registered DPLL pin using its associated fwnode handle
* Ensure the fwnode reference is properly released in dpll_pin_put()

Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Signed-off-by: Ivan Vecera <ivecera@redhat.com>
---
v4:
* fixed fwnode_dpll_pin_find() return value description
---
 drivers/dpll/dpll_core.c | 49 ++++++++++++++++++++++++++++++++++++++++
 drivers/dpll/dpll_core.h |  2 ++
 include/linux/dpll.h     | 11 +++++++++
 3 files changed, 62 insertions(+)

diff --git a/drivers/dpll/dpll_core.c b/drivers/dpll/dpll_core.c
index 8879a72351561..f04ed7195cadd 100644
--- a/drivers/dpll/dpll_core.c
+++ b/drivers/dpll/dpll_core.c
@@ -10,6 +10,7 @@
 
 #include <linux/device.h>
 #include <linux/err.h>
+#include <linux/property.h>
 #include <linux/slab.h>
 #include <linux/string.h>
 
@@ -595,12 +596,60 @@ void dpll_pin_put(struct dpll_pin *pin)
 		xa_destroy(&pin->parent_refs);
 		xa_destroy(&pin->ref_sync_pins);
 		dpll_pin_prop_free(&pin->prop);
+		fwnode_handle_put(pin->fwnode);
 		kfree_rcu(pin, rcu);
 	}
 	mutex_unlock(&dpll_lock);
 }
 EXPORT_SYMBOL_GPL(dpll_pin_put);
 
+/**
+ * dpll_pin_fwnode_set - set dpll pin firmware node reference
+ * @pin: pointer to a dpll pin
+ * @fwnode: firmware node handle
+ *
+ * Set firmware node handle for the given dpll pin.
+ */
+void dpll_pin_fwnode_set(struct dpll_pin *pin, struct fwnode_handle *fwnode)
+{
+	mutex_lock(&dpll_lock);
+	fwnode_handle_put(pin->fwnode); /* Drop fwnode previously set */
+	pin->fwnode = fwnode_handle_get(fwnode);
+	mutex_unlock(&dpll_lock);
+}
+EXPORT_SYMBOL_GPL(dpll_pin_fwnode_set);
+
+/**
+ * fwnode_dpll_pin_find - find dpll pin by firmware node reference
+ * @fwnode: reference to firmware node
+ *
+ * Get existing object of a pin that is associated with given firmware node
+ * reference.
+ *
+ * Context: Acquires a lock (dpll_lock)
+ * Return:
+ * * valid dpll_pin pointer on success
+ * * NULL when no such pin exists
+ */
+struct dpll_pin *fwnode_dpll_pin_find(struct fwnode_handle *fwnode)
+{
+	struct dpll_pin *pin, *ret = NULL;
+	unsigned long index;
+
+	mutex_lock(&dpll_lock);
+	xa_for_each(&dpll_pin_xa, index, pin) {
+		if (pin->fwnode == fwnode) {
+			ret = pin;
+			refcount_inc(&ret->refcount);
+			break;
+		}
+	}
+	mutex_unlock(&dpll_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(fwnode_dpll_pin_find);
+
 static int
 __dpll_pin_register(struct dpll_device *dpll, struct dpll_pin *pin,
 		    const struct dpll_pin_ops *ops, void *priv, void *cookie)
diff --git a/drivers/dpll/dpll_core.h b/drivers/dpll/dpll_core.h
index 8ce969bbeb64e..d3e17ff0ecef0 100644
--- a/drivers/dpll/dpll_core.h
+++ b/drivers/dpll/dpll_core.h
@@ -42,6 +42,7 @@ struct dpll_device {
  * @pin_idx:		index of a pin given by dev driver
  * @clock_id:		clock_id of creator
  * @module:		module of creator
+ * @fwnode:		optional reference to firmware node
  * @dpll_refs:		hold referencees to dplls pin was registered with
  * @parent_refs:	hold references to parent pins pin was registered with
  * @ref_sync_pins:	hold references to pins for Reference SYNC feature
@@ -54,6 +55,7 @@ struct dpll_pin {
 	u32 pin_idx;
 	u64 clock_id;
 	struct module *module;
+	struct fwnode_handle *fwnode;
 	struct xarray dpll_refs;
 	struct xarray parent_refs;
 	struct xarray ref_sync_pins;
diff --git a/include/linux/dpll.h b/include/linux/dpll.h
index c6d0248fa5273..f2e8660e90cdf 100644
--- a/include/linux/dpll.h
+++ b/include/linux/dpll.h
@@ -16,6 +16,7 @@
 struct dpll_device;
 struct dpll_pin;
 struct dpll_pin_esync;
+struct fwnode_handle;
 
 struct dpll_device_ops {
 	int (*mode_get)(const struct dpll_device *dpll, void *dpll_priv,
@@ -178,6 +179,8 @@ void dpll_netdev_pin_clear(struct net_device *dev);
 size_t dpll_netdev_pin_handle_size(const struct net_device *dev);
 int dpll_netdev_add_pin_handle(struct sk_buff *msg,
 			       const struct net_device *dev);
+
+struct dpll_pin *fwnode_dpll_pin_find(struct fwnode_handle *fwnode);
 #else
 static inline void
 dpll_netdev_pin_set(struct net_device *dev, struct dpll_pin *dpll_pin) { }
@@ -193,6 +196,12 @@ dpll_netdev_add_pin_handle(struct sk_buff *msg, const struct net_device *dev)
 {
 	return 0;
 }
+
+static inline struct dpll_pin *
+fwnode_dpll_pin_find(struct fwnode_handle *fwnode)
+{
+	return NULL;
+}
 #endif
 
 struct dpll_device *
@@ -218,6 +227,8 @@ void dpll_pin_unregister(struct dpll_device *dpll, struct dpll_pin *pin,
 
 void dpll_pin_put(struct dpll_pin *pin);
 
+void dpll_pin_fwnode_set(struct dpll_pin *pin, struct fwnode_handle *fwnode);
+
 int dpll_pin_on_pin_register(struct dpll_pin *parent, struct dpll_pin *pin,
 			     const struct dpll_pin_ops *ops, void *priv);
 
-- 
2.52.0

>From: Ivan Vecera <ivecera@redhat.com>
>Sent: Tuesday, February 3, 2026 6:40 PM
>
>Extend the DPLL core to support associating a DPLL pin with a firmware
>node. This association is required to allow other subsystems (such as
>network drivers) to locate and request specific DPLL pins defined in
>the Device Tree or ACPI.
>
>* Add a .fwnode field to the struct dpll_pin
>* Introduce dpll_pin_fwnode_set() helper to allow the provider driver
>  to associate a pin with a fwnode after the pin has been allocated
>* Introduce fwnode_dpll_pin_find() helper to allow consumers to search
>  for a registered DPLL pin using its associated fwnode handle
>* Ensure the fwnode reference is properly released in dpll_pin_put()
>
>Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
>Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>

LGTM,
Reviewed-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com>

>Signed-off-by: Ivan Vecera <ivecera@redhat.com>
>---
>v4:
>* fixed fwnode_dpll_pin_find() return value description
>---
> drivers/dpll/dpll_core.c | 49 ++++++++++++++++++++++++++++++++++++++++
> drivers/dpll/dpll_core.h |  2 ++
> include/linux/dpll.h     | 11 +++++++++
> 3 files changed, 62 insertions(+)
>
>diff --git a/drivers/dpll/dpll_core.c b/drivers/dpll/dpll_core.c
>index 8879a72351561..f04ed7195cadd 100644
>--- a/drivers/dpll/dpll_core.c
>+++ b/drivers/dpll/dpll_core.c
>@@ -10,6 +10,7 @@
>
> #include <linux/device.h>
> #include <linux/err.h>
>+#include <linux/property.h>
> #include <linux/slab.h>
> #include <linux/string.h>
>
>@@ -595,12 +596,60 @@ void dpll_pin_put(struct dpll_pin *pin)
> 		xa_destroy(&pin->parent_refs);
> 		xa_destroy(&pin->ref_sync_pins);
> 		dpll_pin_prop_free(&pin->prop);
>+		fwnode_handle_put(pin->fwnode);
> 		kfree_rcu(pin, rcu);
> 	}
> 	mutex_unlock(&dpll_lock);
> }
> EXPORT_SYMBOL_GPL(dpll_pin_put);
>
>+/**
>+ * dpll_pin_fwnode_set - set dpll pin firmware node reference
>+ * @pin: pointer to a dpll pin
>+ * @fwnode: firmware node handle
>+ *
>+ * Set firmware node handle for the given dpll pin.
>+ */
>+void dpll_pin_fwnode_set(struct dpll_pin *pin, struct fwnode_handle
>*fwnode)
>+{
>+	mutex_lock(&dpll_lock);
>+	fwnode_handle_put(pin->fwnode); /* Drop fwnode previously set */
>+	pin->fwnode = fwnode_handle_get(fwnode);
>+	mutex_unlock(&dpll_lock);
>+}
>+EXPORT_SYMBOL_GPL(dpll_pin_fwnode_set);
>+
>+/**
>+ * fwnode_dpll_pin_find - find dpll pin by firmware node reference
>+ * @fwnode: reference to firmware node
>+ *
>+ * Get existing object of a pin that is associated with given firmware
>node
>+ * reference.
>+ *
>+ * Context: Acquires a lock (dpll_lock)
>+ * Return:
>+ * * valid dpll_pin pointer on success
>+ * * NULL when no such pin exists
>+ */
>+struct dpll_pin *fwnode_dpll_pin_find(struct fwnode_handle *fwnode)
>+{
>+	struct dpll_pin *pin, *ret = NULL;
>+	unsigned long index;
>+
>+	mutex_lock(&dpll_lock);
>+	xa_for_each(&dpll_pin_xa, index, pin) {
>+		if (pin->fwnode == fwnode) {
>+			ret = pin;
>+			refcount_inc(&ret->refcount);
>+			break;
>+		}
>+	}
>+	mutex_unlock(&dpll_lock);
>+
>+	return ret;
>+}
>+EXPORT_SYMBOL_GPL(fwnode_dpll_pin_find);
>+
> static int
> __dpll_pin_register(struct dpll_device *dpll, struct dpll_pin *pin,
> 		    const struct dpll_pin_ops *ops, void *priv, void *cookie)
>diff --git a/drivers/dpll/dpll_core.h b/drivers/dpll/dpll_core.h
>index 8ce969bbeb64e..d3e17ff0ecef0 100644
>--- a/drivers/dpll/dpll_core.h
>+++ b/drivers/dpll/dpll_core.h
>@@ -42,6 +42,7 @@ struct dpll_device {
>  * @pin_idx:		index of a pin given by dev driver
>  * @clock_id:		clock_id of creator
>  * @module:		module of creator
>+ * @fwnode:		optional reference to firmware node
>  * @dpll_refs:		hold referencees to dplls pin was registered with
>  * @parent_refs:	hold references to parent pins pin was registered with
>  * @ref_sync_pins:	hold references to pins for Reference SYNC feature
>@@ -54,6 +55,7 @@ struct dpll_pin {
> 	u32 pin_idx;
> 	u64 clock_id;
> 	struct module *module;
>+	struct fwnode_handle *fwnode;
> 	struct xarray dpll_refs;
> 	struct xarray parent_refs;
> 	struct xarray ref_sync_pins;
>diff --git a/include/linux/dpll.h b/include/linux/dpll.h
>index c6d0248fa5273..f2e8660e90cdf 100644
>--- a/include/linux/dpll.h
>+++ b/include/linux/dpll.h
>@@ -16,6 +16,7 @@
> struct dpll_device;
> struct dpll_pin;
> struct dpll_pin_esync;
>+struct fwnode_handle;
>
> struct dpll_device_ops {
> 	int (*mode_get)(const struct dpll_device *dpll, void *dpll_priv,
>@@ -178,6 +179,8 @@ void dpll_netdev_pin_clear(struct net_device *dev);
> size_t dpll_netdev_pin_handle_size(const struct net_device *dev);
> int dpll_netdev_add_pin_handle(struct sk_buff *msg,
> 			       const struct net_device *dev);
>+
>+struct dpll_pin *fwnode_dpll_pin_find(struct fwnode_handle *fwnode);
> #else
> static inline void
> dpll_netdev_pin_set(struct net_device *dev, struct dpll_pin *dpll_pin) {
>}
>@@ -193,6 +196,12 @@ dpll_netdev_add_pin_handle(struct sk_buff *msg, const
>struct net_device *dev)
> {
> 	return 0;
> }
>+
>+static inline struct dpll_pin *
>+fwnode_dpll_pin_find(struct fwnode_handle *fwnode)
>+{
>+	return NULL;
>+}
> #endif
>
> struct dpll_device *
>@@ -218,6 +227,8 @@ void dpll_pin_unregister(struct dpll_device *dpll,
>struct dpll_pin *pin,
>
> void dpll_pin_put(struct dpll_pin *pin);
>
>+void dpll_pin_fwnode_set(struct dpll_pin *pin, struct fwnode_handle
>*fwnode);
>+
> int dpll_pin_on_pin_register(struct dpll_pin *parent, struct dpll_pin
>*pin,
> 			     const struct dpll_pin_ops *ops, void *priv);
>
>--
>2.52.0