>From: Ivan Vecera <[email protected]>
>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 <[email protected]>
>Reviewed-by: Vadim Fedorenko <[email protected]>

LGTM,
Reviewed-by: Arkadiusz Kubalewski <[email protected]>

>Signed-off-by: Ivan Vecera <[email protected]>
>---
>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

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