drivers: clock_control: z_nrf_clock: add get_startup_time API

Implement vendor specific
z_nrf_clock_bt_ctlr_hf_get_startup_time_us() which gets the startup
time of the high frequency clock used for Bluetooth.

Signed-off-by: Bjarki Arge Andreasen <bjarki.andreasen@nordicsemi.no>

Author: bjarki-andreasen

drivers/clock_control/clock_control_nrf.c

@@ -436,6 +436,13 @@ void z_nrf_clock_bt_ctlr_hf_release(void)
 	irq_unlock(key);
 }
 
+#if DT_NODE_EXISTS(DT_NODELABEL(hfxo))
+uint32_t z_nrf_clock_bt_ctlr_hf_get_startup_time_us(void)
+{
+	return DT_PROP(DT_NODELABEL(hfxo), startup_time_us);
+}
+#endif
+
 static int stop(const struct device *dev, clock_control_subsys_t subsys,
 		uint32_t ctx)
 {

include/zephyr/drivers/clock_control/nrf_clock_control.h

@@ -162,6 +162,13 @@ void z_nrf_clock_bt_ctlr_hf_request(void);
  */
 void z_nrf_clock_bt_ctlr_hf_release(void);
 
+/**
+ * @brief Get clock startup time
+ *
+ * @retval HFCLK startup time in microseconds
+ */
+uint32_t z_nrf_clock_bt_ctlr_hf_get_startup_time_us(void);
+
 #endif /* defined(CONFIG_CLOCK_CONTROL_NRF) */