diff --git a/drivers/ptp/ptp_clock.c b/drivers/ptp/ptp_clock.c
index e189fa1be21e..e60eab7f8a61 100644
--- a/drivers/ptp/ptp_clock.c
+++ b/drivers/ptp/ptp_clock.c
@@ -63,7 +63,7 @@ static void enqueue_external_timestamp(struct timestamp_event_queue *queue,
 	spin_unlock_irqrestore(&queue->lock, flags);
 }
 
-static s32 scaled_ppm_to_ppb(long ppm)
+s32 scaled_ppm_to_ppb(long ppm)
 {
 	/*
 	 * The 'freq' field in the 'struct timex' is in parts per
@@ -82,6 +82,7 @@ static s32 scaled_ppm_to_ppb(long ppm)
 	ppb >>= 13;
 	return (s32) ppb;
 }
+EXPORT_SYMBOL(scaled_ppm_to_ppb);
 
 /* posix clock implementation */
 
diff --git a/include/linux/ptp_clock_kernel.h b/include/linux/ptp_clock_kernel.h
index 28eb9c792522..93cc4f1d444a 100644
--- a/include/linux/ptp_clock_kernel.h
+++ b/include/linux/ptp_clock_kernel.h
@@ -212,6 +212,14 @@ extern void ptp_clock_event(struct ptp_clock *ptp,
 
 extern int ptp_clock_index(struct ptp_clock *ptp);
 
+/**
+ * scaled_ppm_to_ppb() - convert scaled ppm to ppb
+ *
+ * @ppm:    Parts per million, but with a 16 bit binary fractional field
+ */
+
+extern s32 scaled_ppm_to_ppb(long ppm);
+
 /**
  * ptp_find_pin() - obtain the pin index of a given auxiliary function
  *