net: stmmac: use correct PPS capture input index

The stmmac supports up to 4 auxiliary snapshots that can be enabled by
setting the appropriate bits in the PTP_ACR bitfield.

Previously as of commit f4da5652 ("net: stmmac: Add support for
external trigger timestamping") instead of setting the bits, a fixed
value was written to this bitfield instead of passing the appropriate
bitmask.

Now the correct bit is set according to the ptp_clock_request.extts_index
passed as a parameter to stmmac_enable().
Signed-off-by: Johannes Zink <j.zink@pengutronix.de>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c

@@ -201,12 +201,11 @@ static int stmmac_enable(struct ptp_clock_info *ptp,
 		acr_value &= ~PTP_ACR_MASK;
 		if (on) {
 			/* Enable External snapshot trigger */
-			acr_value |= priv->plat->ext_snapshot_num;
+			acr_value |= PTP_ACR_ATSEN(rq->extts.index);
 			acr_value |= PTP_ACR_ATSFC;
 		}
 		netdev_dbg(priv->dev, "Auxiliary Snapshot %d %s.\n",
-			   priv->plat->ext_snapshot_num >> PTP_ACR_ATSEN_SHIFT,
-			   on ? "enabled" : "disabled");
+			   rq->extts.index, on ? "enabled" : "disabled");
 		writel(acr_value, ptpaddr + PTP_ACR);
 		mutex_unlock(&priv->aux_ts_lock);
 		/* wait for auxts fifo clear to finish */

drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.h

@@ -79,7 +79,7 @@
 #define	PTP_ACR_ATSEN1		BIT(5)	/* Auxiliary Snapshot 1 Enable */
 #define	PTP_ACR_ATSEN2		BIT(6)	/* Auxiliary Snapshot 2 Enable */
 #define	PTP_ACR_ATSEN3		BIT(7)	/* Auxiliary Snapshot 3 Enable */
-#define	PTP_ACR_ATSEN_SHIFT	5	/* Auxiliary Snapshot shift */
+#define	PTP_ACR_ATSEN(index)	(PTP_ACR_ATSEN0 << (index))
 #define	PTP_ACR_MASK		GENMASK(7, 4)	/* Aux Snapshot Mask */
 #define	PMC_ART_VALUE0		0x01	/* PMC_ART[15:0] timer value */
 #define	PMC_ART_VALUE1		0x02	/* PMC_ART[31:16] timer value */