dpll: Allow associating dpll pin with a firmware node

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>
Reviewed-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com>
Link: https://patch.msgid.link/20260203174002.705176-2-ivecera@redhat.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/drivers/dpll/dpll_core.c b/drivers/dpll/dpll_core.c
index 8879a72351561b63c9076559622ec5ea0ca8515c..f04ed7195cadd6c011805aa47f99a9ea58099419 100644 (file)
--- 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 8ce969bbeb64ef98eda0cfb31ed096868a1661f9..d3e17ff0ecef0492fd9128364babe1a29dc16d75 100644 (file)
--- 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 c6d0248fa5273b0f7cfa16392f5e83072212fb79..f2e8660e90cdfd6ecc569d402017f0d72ef2ffda 100644 (file)
--- 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);