[nrf fromtree] drivers: clock_control: nrf_clock_control: introduce resolve API

Introduce API which allows users to determine what the actual
minimum spec will be resulting from a requested minimum spec. This
is useful for optimizing code as the requested minimum may be
way worse than what will actually be applied.

Signed-off-by: Bjarki Arge Andreasen <[email protected]>
(cherry picked from commit b1a5588)

Author: bjarki-andreasen

include/zephyr/drivers/clock_control/nrf_clock_control.h

@@ -204,6 +204,9 @@ __subsystem struct nrf_clock_control_driver_api {
 	int (*cancel_or_release)(const struct device *dev,
 				 const struct nrf_clock_spec *spec,
 				 struct onoff_client *cli);
+	int (*resolve)(const struct device *dev,
+		       const struct nrf_clock_spec *req_spec,
+		       struct nrf_clock_spec *res_spec);
 };
 
 /**
@@ -324,6 +327,30 @@ int nrf_clock_control_cancel_or_release(const struct device *dev,
 	return api->cancel_or_release(dev, spec, cli);
 }
 
+/**
+ * @brief Resolve a requested clock spec to resulting spec.
+ *
+ * @param dev Device structure.
+ * @param req_spec The requested clock specification.
+ * @param res_spec Destination for the resulting clock specification.
+ *
+ * @retval Successful if successful.
+ * @retval -errno code if failure
+ */
+static inline int nrf_clock_control_resolve(const struct device *dev,
+					    const struct nrf_clock_spec *req_spec,
+					    struct nrf_clock_spec *res_spec)
+{
+	const struct nrf_clock_control_driver_api *api =
+		(const struct nrf_clock_control_driver_api *)dev->api;
+
+	if (api->resolve == NULL) {
+		return -ENOSYS;
+	}
+
+	return api->resolve(dev, req_spec, res_spec);
+}
+
 /** @brief Request the HFXO from Zero Latency Interrupt context.
  *
  * Function is optimized for use in Zero Latency Interrupt context.