diff --git a/drivers/net/ethernet/stmicro/stmmac/common.h b/drivers/net/ethernet/stmicro/stmmac/common.h
index f4518bc2cd28..1e19c8fd8b82 100644
--- a/drivers/net/ethernet/stmicro/stmmac/common.h
+++ b/drivers/net/ethernet/stmicro/stmmac/common.h
@@ -439,7 +439,7 @@ struct stmmac_ops {
 /* PTP and HW Timer helpers */
 struct stmmac_hwtimestamp {
 	void (*config_hw_tstamping) (void __iomem *ioaddr, u32 data);
-	void (*config_sub_second_increment) (void __iomem *ioaddr);
+	u32 (*config_sub_second_increment) (void __iomem *ioaddr, u32 clk_rate);
 	int (*init_systime) (void __iomem *ioaddr, u32 sec, u32 nsec);
 	int (*config_addend) (void __iomem *ioaddr, u32 addend);
 	int (*adjust_systime) (void __iomem *ioaddr, u32 sec, u32 nsec,
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c
index 76ad214b4036..a77f68918010 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c
@@ -33,22 +33,25 @@ static void stmmac_config_hw_tstamping(void __iomem *ioaddr, u32 data)
 	writel(data, ioaddr + PTP_TCR);
 }
 
-static void stmmac_config_sub_second_increment(void __iomem *ioaddr)
+static u32 stmmac_config_sub_second_increment(void __iomem *ioaddr,
+					      u32 ptp_clock)
 {
 	u32 value = readl(ioaddr + PTP_TCR);
 	unsigned long data;
 
 	/* Convert the ptp_clock to nano second
-	 * formula = (1/ptp_clock) * 1000000000
+	 * formula = (2/ptp_clock) * 1000000000
 	 * where, ptp_clock = 50MHz.
 	 */
-	data = (1000000000ULL / 50000000);
+	data = (2000000000ULL / ptp_clock);
 
 	/* 0.465ns accuracy */
 	if (!(value & PTP_TCR_TSCTRLSSR))
 		data = (data * 1000) / 465;
 
 	writel(data, ioaddr + PTP_SSIR);
+
+	return data;
 }
 
 static int stmmac_init_systime(void __iomem *ioaddr, u32 sec, u32 nsec)
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 0b0fea73a7a7..6d4c33a7f0b4 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -53,6 +53,7 @@
 #include "stmmac.h"
 #include <linux/reset.h>
 #include <linux/of_mdio.h>
+#include "dwmac1000.h"
 
 #define STMMAC_ALIGN(x)	L1_CACHE_ALIGN(x)
 
@@ -185,7 +186,7 @@ static void stmmac_clk_csr_set(struct stmmac_priv *priv)
 			priv->clk_csr = STMMAC_CSR_100_150M;
 		else if ((clk_rate >= CSR_F_150M) && (clk_rate < CSR_F_250M))
 			priv->clk_csr = STMMAC_CSR_150_250M;
-		else if ((clk_rate >= CSR_F_250M) && (clk_rate <= CSR_F_300M))
+		else if ((clk_rate >= CSR_F_250M) && (clk_rate < CSR_F_300M))
 			priv->clk_csr = STMMAC_CSR_250_300M;
 	}
 }
@@ -435,6 +436,7 @@ static int stmmac_hwtstamp_ioctl(struct net_device *dev, struct ifreq *ifr)
 	u32 ts_master_en = 0;
 	u32 ts_event_en = 0;
 	u32 value = 0;
+	u32 sec_inc;
 
 	if (!(priv->dma_cap.time_stamp || priv->adv_ts)) {
 		netdev_alert(priv->dev, "No support for HW time stamping\n");
@@ -598,24 +600,19 @@ static int stmmac_hwtstamp_ioctl(struct net_device *dev, struct ifreq *ifr)
 			 tstamp_all | ptp_v2 | ptp_over_ethernet |
 			 ptp_over_ipv6_udp | ptp_over_ipv4_udp | ts_event_en |
 			 ts_master_en | snap_type_sel);
-
 		priv->hw->ptp->config_hw_tstamping(priv->ioaddr, value);
 
 		/* program Sub Second Increment reg */
-		priv->hw->ptp->config_sub_second_increment(priv->ioaddr);
+		sec_inc = priv->hw->ptp->config_sub_second_increment(
+			priv->ioaddr, priv->clk_ptp_rate);
+		temp = div_u64(1000000000ULL, sec_inc);
 
 		/* calculate default added value:
 		 * formula is :
 		 * addend = (2^32)/freq_div_ratio;
-		 * where, freq_div_ratio = clk_ptp_ref_i/50MHz
-		 * hence, addend = ((2^32) * 50MHz)/clk_ptp_ref_i;
-		 * NOTE: clk_ptp_ref_i should be >= 50MHz to
-		 *       achieve 20ns accuracy.
-		 *
-		 * 2^x * y == (y << x), hence
-		 * 2^32 * 50000000 ==> (50000000 << 32)
+		 * where, freq_div_ratio = 1e9ns/sec_inc
 		 */
-		temp = (u64) (50000000ULL << 32);
+		temp = (u64)(temp << 32);
 		priv->default_addend = div_u64(temp, priv->clk_ptp_rate);
 		priv->hw->ptp->config_addend(priv->ioaddr,
 					     priv->default_addend);