[nrf fromtree] drivers: clock_control: nrf_clock_control: introduce startup time

Introduce get_startup_time API which allows users to request
clocks specs to be met in time for an event.

Signed-off-by: Bjarki Arge Andreasen <[email protected]>
(cherry picked from commit 6aeca71)

Author: bjarki-andreasen

include/zephyr/drivers/clock_control/nrf_clock_control.h

@@ -207,6 +207,9 @@ __subsystem struct nrf_clock_control_driver_api {
 	int (*resolve)(const struct device *dev,
 		       const struct nrf_clock_spec *req_spec,
 		       struct nrf_clock_spec *res_spec);
+	int (*get_startup_time)(const struct device *dev,
+				const struct nrf_clock_spec *spec,
+				uint32_t *startup_time_us);
 };
 
 /**
@@ -351,6 +354,29 @@ static inline int nrf_clock_control_resolve(const struct device *dev,
 	return api->resolve(dev, req_spec, res_spec);
 }
 
+/**
+ * @brief Get the startup timme of a clock.
+ *
+ * @param dev Device structure.
+ * @param startup_time_us Destination for startup time in microseconds.
+ *
+ * @retval Successful if successful.
+ * @retval -errno code if failure.
+ */
+static inline int nrf_clock_control_get_startup_time(const struct device *dev,
+						     const struct nrf_clock_spec *spec,
+						     uint32_t *startup_time_us)
+{
+	const struct nrf_clock_control_driver_api *api =
+		(const struct nrf_clock_control_driver_api *)dev->api;
+
+	if (api->get_startup_time == NULL) {
+		return -ENOSYS;
+	}
+
+	return api->get_startup_time(dev, spec, startup_time_us);
+}
+
 /** @brief Request the HFXO from Zero Latency Interrupt context.
  *
  * Function is optimized for use in Zero Latency Interrupt context.