mdio: Expose 10GBASE-T MDI-X status via ethtool

This is available in a standard MDIO register in 10GBASE-T PHYs.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/mdio.c

@@ -296,6 +296,23 @@ void mdio45_ethtool_gset_npage(const struct mdio_if_info *mdio,
 		ecmd->duplex = (reg & MDIO_CTRL1_FULLDPLX ||
 				ecmd->speed == SPEED_10000);
 	}
+
+	/* 10GBASE-T MDI/MDI-X */
+	if (ecmd->port == PORT_TP && ecmd->speed == SPEED_10000) {
+		switch (mdio->mdio_read(mdio->dev, mdio->prtad, MDIO_MMD_PMAPMD,
+					MDIO_PMA_10GBT_SWAPPOL)) {
+		case MDIO_PMA_10GBT_SWAPPOL_ABNX | MDIO_PMA_10GBT_SWAPPOL_CDNX:
+			ecmd->eth_tp_mdix = ETH_TP_MDI;
+			break;
+		case 0:
+			ecmd->eth_tp_mdix = ETH_TP_MDI_X;
+			break;
+		default:
+			/* It's complicated... */
+			ecmd->eth_tp_mdix = ETH_TP_MDI_INVALID;
+			break;
+		}
+	}
 }
 EXPORT_SYMBOL(mdio45_ethtool_gset_npage);
 

include/linux/mdio.h

@@ -45,6 +45,7 @@
 #define MDIO_PHYXS_LNSTAT	24	/* PHY XGXS lane state */
 
 /* Media-dependent registers. */
+#define MDIO_PMA_10GBT_SWAPPOL	130	/* 10GBASE-T pair swap & polarity */
 #define MDIO_PMA_10GBT_TXPWR	131	/* 10GBASE-T TX power control */
 #define MDIO_PMA_10GBT_SNR	133	/* 10GBASE-T SNR margin, lane A.
 					 * Lanes B-D are numbered 134-136. */
@@ -195,6 +196,14 @@
 #define MDIO_PHYXS_LNSTAT_SYNC3		0x0008
 #define MDIO_PHYXS_LNSTAT_ALIGN		0x1000
 
+/* PMA 10GBASE-T pair swap & polarity */
+#define MDIO_PMA_10GBT_SWAPPOL_ABNX	0x0001	/* Pair A/B uncrossed */
+#define MDIO_PMA_10GBT_SWAPPOL_CDNX	0x0002	/* Pair C/D uncrossed */
+#define MDIO_PMA_10GBT_SWAPPOL_AREV	0x0100	/* Pair A polarity reversed */
+#define MDIO_PMA_10GBT_SWAPPOL_BREV	0x0200	/* Pair B polarity reversed */
+#define MDIO_PMA_10GBT_SWAPPOL_CREV	0x0400	/* Pair C polarity reversed */
+#define MDIO_PMA_10GBT_SWAPPOL_DREV	0x0800	/* Pair D polarity reversed */
+
 /* PMA 10GBASE-T TX power register. */
 #define MDIO_PMA_10GBT_TXPWR_SHORT	0x0001	/* Short-reach mode */