diff --git a/drivers/net/ethernet/intel/igb/igb_ptp.c b/drivers/net/ethernet/intel/igb/igb_ptp.c
index 6f471b91f562016914dcf6f230f04e31d06b8809..405886ee526151a81c11b237e6bf991fa5b7a3fc 100644
--- a/drivers/net/ethernet/intel/igb/igb_ptp.c
+++ b/drivers/net/ethernet/intel/igb/igb_ptp.c
@@ -67,6 +67,7 @@
 #define INCVALUE_82576_MASK		GENMASK(E1000_TIMINCA_16NS_SHIFT - 1, 0)
 #define INCVALUE_82576			(16u << IGB_82576_TSYNC_SHIFT)
 #define IGB_NBITS_82580			40
+#define IGB_82580_BASE_PERIOD		0x800000000
 
 static void igb_ptp_tx_hwtstamp(struct igb_adapter *adapter);
 static void igb_ptp_sdp_init(struct igb_adapter *adapter);
@@ -209,17 +210,11 @@ static int igb_ptp_adjfine_82580(struct ptp_clock_info *ptp, long scaled_ppm)
 	struct igb_adapter *igb = container_of(ptp, struct igb_adapter,
 					       ptp_caps);
 	struct e1000_hw *hw = &igb->hw;
-	int neg_adj = 0;
+	bool neg_adj;
 	u64 rate;
 	u32 inca;
 
-	if (scaled_ppm < 0) {
-		neg_adj = 1;
-		scaled_ppm = -scaled_ppm;
-	}
-	rate = scaled_ppm;
-	rate <<= 13;
-	rate = div_u64(rate, 15625);
+	neg_adj = diff_by_scaled_ppm(IGB_82580_BASE_PERIOD, scaled_ppm, &rate);
 
 	inca = rate & INCVALUE_MASK;
 	if (neg_adj)