1 files changed, 34 insertions, 9 deletions

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c
index a77f68918010..10d6059b2f26 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c
@@ -34,21 +34,29 @@ static void stmmac_config_hw_tstamping(void __iomem *ioaddr, u32 data)
 }
 
 static u32 stmmac_config_sub_second_increment(void __iomem *ioaddr,
-					      u32 ptp_clock)
+					      u32 ptp_clock, int gmac4)
 {
 	u32 value = readl(ioaddr + PTP_TCR);
 	unsigned long data;
 
-	/* Convert the ptp_clock to nano second
-	 * formula = (2/ptp_clock) * 1000000000
-	 * where, ptp_clock = 50MHz.
+	/* For GMAC3.x, 4.x versions, convert the ptp_clock to nano second
+	 *	formula = (1/ptp_clock) * 1000000000
+	 * where ptp_clock is 50MHz if fine method is used to update system
 	 */
-	data = (2000000000ULL / ptp_clock);
+	if (value & PTP_TCR_TSCFUPDT)
+		data = (1000000000ULL / 50000000);
+	else
+		data = (1000000000ULL / ptp_clock);
 
 	/* 0.465ns accuracy */
 	if (!(value & PTP_TCR_TSCTRLSSR))
 		data = (data * 1000) / 465;
 
+	data &= PTP_SSIR_SSINC_MASK;
+
+	if (gmac4)
+		data = data << GMAC4_PTP_SSIR_SSINC_SHIFT;
+
 	writel(data, ioaddr + PTP_SSIR);
 
 	return data;
@@ -104,14 +112,30 @@ static int stmmac_config_addend(void __iomem *ioaddr, u32 addend)
 }
 
 static int stmmac_adjust_systime(void __iomem *ioaddr, u32 sec, u32 nsec,
-				 int add_sub)
+				 int add_sub, int gmac4)
 {
 	u32 value;
 	int limit;
 
+	if (add_sub) {
+		/* If the new sec value needs to be subtracted with
+		 * the system time, then MAC_STSUR reg should be
+		 * programmed with (2^32 – <new_sec_value>)
+		 */
+		if (gmac4)
+			sec = (100000000ULL - sec);
+
+		value = readl(ioaddr + PTP_TCR);
+		if (value & PTP_TCR_TSCTRLSSR)
+			nsec = (PTP_DIGITAL_ROLLOVER_MODE - nsec);
+		else
+			nsec = (PTP_BINARY_ROLLOVER_MODE - nsec);
+	}
+
 	writel(sec, ioaddr + PTP_STSUR);
-	writel(((add_sub << PTP_STNSUR_ADDSUB_SHIFT) | nsec),
-		ioaddr + PTP_STNSUR);
+	value = (add_sub << PTP_STNSUR_ADDSUB_SHIFT) | nsec;
+	writel(value, ioaddr + PTP_STNSUR);
+
 	/* issue command to initialize the system time value */
 	value = readl(ioaddr + PTP_TCR);
 	value |= PTP_TCR_TSUPDT;
@@ -134,8 +158,9 @@ static u64 stmmac_get_systime(void __iomem *ioaddr)
 {
 	u64 ns;
 
+	/* Get the TSSS value */
 	ns = readl(ioaddr + PTP_STNSR);
-	/* convert sec time value to nanosecond */
+	/* Get the TSS and convert sec time value to nanosecond */
 	ns += readl(ioaddr + PTP_STSR) * 1000000000ULL;
 
 	return ns;