octeontx2-af: Initialize PTP_SEC_ROLLOVER register properly

Since the reset value of PTP_SEC_ROLLOVER is incorrect on
CNF10KB silicon, the ptp timestamps are inaccurate. This
patch initializes the PTP_SEC_ROLLOVER register properly
for the CNF10KB silicon.
Signed-off-by: Naveen Mamindlapalli <naveenm@marvell.com>
Signed-off-by: Sunil Kovvuri Goutham <sgoutham@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/marvell/octeontx2/af/ptp.c

@@ -52,12 +52,18 @@
 #define PTP_CLOCK_COMP				0xF18ULL
 #define PTP_TIMESTAMP				0xF20ULL
 #define PTP_CLOCK_SEC				0xFD0ULL
+#define PTP_SEC_ROLLOVER			0xFD8ULL
 
 #define CYCLE_MULT				1000
 
 static struct ptp *first_ptp_block;
 static const struct pci_device_id ptp_id_table[];
 
+static bool is_ptp_dev_cnf10kb(struct ptp *ptp)
+{
+	return (ptp->pdev->subsystem_device == PCI_SUBSYS_DEVID_CNF10K_B_PTP) ? true : false;
+}
+
 static bool is_ptp_dev_cn10k(struct ptp *ptp)
 {
 	return (ptp->pdev->device == PCI_DEVID_CN10K_PTP) ? true : false;
@@ -290,6 +296,10 @@ void ptp_start(struct ptp *ptp, u64 sclk, u32 ext_clk_freq, u32 extts)
 	/* sclk is in MHz */
 	ptp->clock_rate = sclk * 1000000;
 
+	/* Program the seconds rollover value to 1 second */
+	if (is_ptp_dev_cnf10kb(ptp))
+		writeq(0x3b9aca00, ptp->reg_base + PTP_SEC_ROLLOVER);
+
 	/* Enable PTP clock */
 	clock_cfg = readq(ptp->reg_base + PTP_CLOCK_CFG);