ptp: ptp_clock: Publish scaled_ppm_to_ppb

Publish scaled_ppm_to_ppb to allow drivers to use it.
Signed-off-by: Shalom Toledo <shalomt@mellanox.com>
Reviewed-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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 */
 

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
  *