octeontx2-af: return correct ptp timestamp for CN10K silicon

The MIO_PTP_TIMESTAMP format has been changed in CN10K silicon
family. The upper 32-bits represents seconds and lower 32-bits
represents nanoseconds. This patch returns nanosecond timestamp
to NIX PF driver.
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

@@ -56,6 +56,11 @@
 static struct ptp *first_ptp_block;
 static const struct pci_device_id ptp_id_table[];
 
+static bool is_ptp_dev_cn10k(struct ptp *ptp)
+{
+	return (ptp->pdev->device == PCI_DEVID_CN10K_PTP) ? true : false;
+}
+
 static bool cn10k_ptp_errata(struct ptp *ptp)
 {
 	if (ptp->pdev->subsystem_device == PCI_SUBSYS_DEVID_CN10K_A_PTP ||
@@ -282,7 +287,14 @@ void ptp_start(struct ptp *ptp, u64 sclk, u32 ext_clk_freq, u32 extts)
 
 static int ptp_get_tstmp(struct ptp *ptp, u64 *clk)
 {
-	*clk = readq(ptp->reg_base + PTP_TIMESTAMP);
+	u64 timestamp;
+
+	if (is_ptp_dev_cn10k(ptp)) {
+		timestamp = readq(ptp->reg_base + PTP_TIMESTAMP);
+		*clk = (timestamp >> 32) * NSEC_PER_SEC + (timestamp & 0xFFFFFFFF);
+	} else {
+		*clk = readq(ptp->reg_base + PTP_TIMESTAMP);
+	}
 
 	return 0;
 }