amd-xgbe: Add support for a KR redriver

This patch provides support for the presence of a KR redriver chip in
between the device PCS and an external PHY.  When a redriver chip is
present the device must perform clause 73 auto-negotiation in order to
set the redriver chip for the downstream connection.
Signed-off-by: NTom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/amd/xgbe/xgbe-common.h

@@ -1062,6 +1062,16 @@
 #define XP_PROP_4_MUX_ADDR_LO_WIDTH		3
 #define XP_PROP_4_MUX_CHAN_INDEX		4
 #define XP_PROP_4_MUX_CHAN_WIDTH		3
+#define XP_PROP_4_REDRV_ADDR_INDEX		16
+#define XP_PROP_4_REDRV_ADDR_WIDTH		7
+#define XP_PROP_4_REDRV_IF_INDEX		23
+#define XP_PROP_4_REDRV_IF_WIDTH		1
+#define XP_PROP_4_REDRV_LANE_INDEX		24
+#define XP_PROP_4_REDRV_LANE_WIDTH		3
+#define XP_PROP_4_REDRV_MODEL_INDEX		28
+#define XP_PROP_4_REDRV_MODEL_WIDTH		3
+#define XP_PROP_4_REDRV_PRESENT_INDEX		31
+#define XP_PROP_4_REDRV_PRESENT_WIDTH		1
 
 /* I2C Control register offsets */
 #define IC_CON					0x0000

drivers/net/ethernet/amd/xgbe/xgbe-mdio.c

@@ -179,6 +179,7 @@ static void xgbe_an_enable_interrupts(struct xgbe_prv_data *pdata)
 {
 	switch (pdata->an_mode) {
 	case XGBE_AN_MODE_CL73:
+	case XGBE_AN_MODE_CL73_REDRV:
 		xgbe_an73_enable_interrupts(pdata);
 		break;
 	case XGBE_AN_MODE_CL37:
@@ -254,6 +255,10 @@ static void xgbe_kx_1000_mode(struct xgbe_prv_data *pdata)
 
 static void xgbe_sfi_mode(struct xgbe_prv_data *pdata)
 {
+	/* If a KR re-driver is present, change to KR mode instead */
+	if (pdata->kr_redrv)
+		return xgbe_kr_mode(pdata);
+
 	/* Disable KR training */
 	xgbe_an73_disable_kr_training(pdata);
 
@@ -433,6 +438,7 @@ static void xgbe_an_restart(struct xgbe_prv_data *pdata)
 {
 	switch (pdata->an_mode) {
 	case XGBE_AN_MODE_CL73:
+	case XGBE_AN_MODE_CL73_REDRV:
 		xgbe_an73_restart(pdata);
 		break;
 	case XGBE_AN_MODE_CL37:
@@ -448,6 +454,7 @@ static void xgbe_an_disable(struct xgbe_prv_data *pdata)
 {
 	switch (pdata->an_mode) {
 	case XGBE_AN_MODE_CL73:
+	case XGBE_AN_MODE_CL73_REDRV:
 		xgbe_an73_disable(pdata);
 		break;
 	case XGBE_AN_MODE_CL37:
@@ -687,6 +694,7 @@ static irqreturn_t xgbe_an_isr(int irq, void *data)
 
 	switch (pdata->an_mode) {
 	case XGBE_AN_MODE_CL73:
+	case XGBE_AN_MODE_CL73_REDRV:
 		xgbe_an73_isr(pdata);
 		break;
 	case XGBE_AN_MODE_CL37:
@@ -895,6 +903,7 @@ static void xgbe_an_state_machine(struct work_struct *work)
 
 	switch (pdata->an_mode) {
 	case XGBE_AN_MODE_CL73:
+	case XGBE_AN_MODE_CL73_REDRV:
 		xgbe_an73_state_machine(pdata);
 		break;
 	case XGBE_AN_MODE_CL37:
@@ -910,16 +919,18 @@ static void xgbe_an_state_machine(struct work_struct *work)
 
 static void xgbe_an37_init(struct xgbe_prv_data *pdata)
 {
-	unsigned int reg;
+	unsigned int advertising, reg;
+
+	advertising = pdata->phy_if.phy_impl.an_advertising(pdata);
 
 	/* Set up Advertisement register */
 	reg = XMDIO_READ(pdata, MDIO_MMD_VEND2, MDIO_VEND2_AN_ADVERTISE);
-	if (pdata->phy.advertising & ADVERTISED_Pause)
+	if (advertising & ADVERTISED_Pause)
 		reg |= 0x100;
 	else
 		reg &= ~0x100;
 
-	if (pdata->phy.advertising & ADVERTISED_Asym_Pause)
+	if (advertising & ADVERTISED_Asym_Pause)
 		reg |= 0x80;
 	else
 		reg &= ~0x80;
@@ -954,11 +965,13 @@ static void xgbe_an37_init(struct xgbe_prv_data *pdata)
 
 static void xgbe_an73_init(struct xgbe_prv_data *pdata)
 {
-	unsigned int reg;
+	unsigned int advertising, reg;
+
+	advertising = pdata->phy_if.phy_impl.an_advertising(pdata);
 
 	/* Set up Advertisement register 3 first */
 	reg = XMDIO_READ(pdata, MDIO_MMD_AN, MDIO_AN_ADVERTISE + 2);
-	if (pdata->phy.advertising & ADVERTISED_10000baseR_FEC)
+	if (advertising & ADVERTISED_10000baseR_FEC)
 		reg |= 0xc000;
 	else
 		reg &= ~0xc000;
@@ -967,13 +980,13 @@ static void xgbe_an73_init(struct xgbe_prv_data *pdata)
 
 	/* Set up Advertisement register 2 next */
 	reg = XMDIO_READ(pdata, MDIO_MMD_AN, MDIO_AN_ADVERTISE + 1);
-	if (pdata->phy.advertising & ADVERTISED_10000baseKR_Full)
+	if (advertising & ADVERTISED_10000baseKR_Full)
 		reg |= 0x80;
 	else
 		reg &= ~0x80;
 
-	if ((pdata->phy.advertising & ADVERTISED_1000baseKX_Full) ||
-	    (pdata->phy.advertising & ADVERTISED_2500baseX_Full))
+	if ((advertising & ADVERTISED_1000baseKX_Full) ||
+	    (advertising & ADVERTISED_2500baseX_Full))
 		reg |= 0x20;
 	else
 		reg &= ~0x20;
@@ -982,12 +995,12 @@ static void xgbe_an73_init(struct xgbe_prv_data *pdata)
 
 	/* Set up Advertisement register 1 last */
 	reg = XMDIO_READ(pdata, MDIO_MMD_AN, MDIO_AN_ADVERTISE);
-	if (pdata->phy.advertising & ADVERTISED_Pause)
+	if (advertising & ADVERTISED_Pause)
 		reg |= 0x400;
 	else
 		reg &= ~0x400;
 
-	if (pdata->phy.advertising & ADVERTISED_Asym_Pause)
+	if (advertising & ADVERTISED_Asym_Pause)
 		reg |= 0x800;
 	else
 		reg &= ~0x800;
@@ -1006,6 +1019,7 @@ static void xgbe_an_init(struct xgbe_prv_data *pdata)
 	pdata->an_mode = pdata->phy_if.phy_impl.an_mode(pdata);
 	switch (pdata->an_mode) {
 	case XGBE_AN_MODE_CL73:
+	case XGBE_AN_MODE_CL73_REDRV:
 		xgbe_an73_init(pdata);
 		break;
 	case XGBE_AN_MODE_CL37:
@@ -1149,10 +1163,15 @@ static int __xgbe_phy_config_aneg(struct xgbe_prv_data *pdata)
 	if (ret)
 		return ret;
 
-	if (pdata->phy.autoneg != AUTONEG_ENABLE)
-		return xgbe_phy_config_fixed(pdata);
+	if (pdata->phy.autoneg != AUTONEG_ENABLE) {
+		ret = xgbe_phy_config_fixed(pdata);
+		if (ret || !pdata->kr_redrv)
+			return ret;
 
-	netif_dbg(pdata, link, pdata->netdev, "AN PHY configuration\n");
+		netif_dbg(pdata, link, pdata->netdev, "AN redriver support\n");
+	} else {
+		netif_dbg(pdata, link, pdata->netdev, "AN PHY configuration\n");
+	}
 
 	/* Disable auto-negotiation interrupt */
 	disable_irq(pdata->an_irq);

drivers/net/ethernet/amd/xgbe/xgbe-phy-v1.c

@@ -295,6 +295,11 @@ static enum xgbe_mode xgbe_phy_an_outcome(struct xgbe_prv_data *pdata)
 	return mode;
 }
 
+static unsigned int xgbe_phy_an_advertising(struct xgbe_prv_data *pdata)
+{
+	return pdata->phy.advertising;
+}
+
 static int xgbe_phy_an_config(struct xgbe_prv_data *pdata)
 {
 	/* Nothing uniquely required for an configuration */
@@ -831,6 +836,8 @@ void xgbe_init_function_ptrs_phy_v1(struct xgbe_phy_if *phy_if)
 
 	phy_impl->an_config		= xgbe_phy_an_config;
 
+	phy_impl->an_advertising	= xgbe_phy_an_advertising;
+
 	phy_impl->an_outcome		= xgbe_phy_an_outcome;
 
 	phy_impl->kr_training_pre	= xgbe_phy_kr_training_pre;

drivers/net/ethernet/amd/xgbe/xgbe-phy-v2.c

@@ -277,6 +277,26 @@ enum xgbe_mdio_reset {
 	XGBE_MDIO_RESET_MAX,
 };
 
+/* Re-driver related definitions */
+enum xgbe_phy_redrv_if {
+	XGBE_PHY_REDRV_IF_MDIO = 0,
+	XGBE_PHY_REDRV_IF_I2C,
+	XGBE_PHY_REDRV_IF_MAX,
+};
+
+enum xgbe_phy_redrv_model {
+	XGBE_PHY_REDRV_MODEL_4223 = 0,
+	XGBE_PHY_REDRV_MODEL_4227,
+	XGBE_PHY_REDRV_MODEL_MAX,
+};
+
+enum xgbe_phy_redrv_mode {
+	XGBE_PHY_REDRV_MODE_CX = 5,
+	XGBE_PHY_REDRV_MODE_SR = 9,
+};
+
+#define XGBE_PHY_REDRV_MODE_REG	0x12b0
+
 /* PHY related configuration information */
 struct xgbe_phy_data {
 	enum xgbe_port_mode port_mode;
@@ -327,6 +347,13 @@ struct xgbe_phy_data {
 	enum xgbe_mdio_reset mdio_reset;
 	unsigned int mdio_reset_addr;
 	unsigned int mdio_reset_gpio;
+
+	/* Re-driver support */
+	unsigned int redrv;
+	unsigned int redrv_if;
+	unsigned int redrv_addr;
+	unsigned int redrv_lane;
+	unsigned int redrv_model;
 };
 
 /* I2C, MDIO and GPIO lines are muxed, so only one device at a time */
@@ -346,6 +373,68 @@ static int xgbe_phy_i2c_xfer(struct xgbe_prv_data *pdata,
 	return pdata->i2c_if.i2c_xfer(pdata, i2c_op);
 }
 
+static int xgbe_phy_redrv_write(struct xgbe_prv_data *pdata, unsigned int reg,
+				unsigned int val)
+{
+	struct xgbe_phy_data *phy_data = pdata->phy_data;
+	struct xgbe_i2c_op i2c_op;
+	__be16 *redrv_val;
+	u8 redrv_data[5], csum;
+	unsigned int i, retry;
+	int ret;
+
+	/* High byte of register contains read/write indicator */
+	redrv_data[0] = ((reg >> 8) & 0xff) << 1;
+	redrv_data[1] = reg & 0xff;
+	redrv_val = (__be16 *)&redrv_data[2];
+	*redrv_val = cpu_to_be16(val);
+
+	/* Calculate 1 byte checksum */
+	csum = 0;
+	for (i = 0; i < 4; i++) {
+		csum += redrv_data[i];
+		if (redrv_data[i] > csum)
+			csum++;
+	}
+	redrv_data[4] = ~csum;
+
+	retry = 1;
+again1:
+	i2c_op.cmd = XGBE_I2C_CMD_WRITE;
+	i2c_op.target = phy_data->redrv_addr;
+	i2c_op.len = sizeof(redrv_data);
+	i2c_op.buf = redrv_data;
+	ret = xgbe_phy_i2c_xfer(pdata, &i2c_op);
+	if (ret) {
+		if ((ret == -EAGAIN) && retry--)
+			goto again1;
+
+		return ret;
+	}
+
+	retry = 1;
+again2:
+	i2c_op.cmd = XGBE_I2C_CMD_READ;
+	i2c_op.target = phy_data->redrv_addr;
+	i2c_op.len = 1;
+	i2c_op.buf = redrv_data;
+	ret = xgbe_phy_i2c_xfer(pdata, &i2c_op);
+	if (ret) {
+		if ((ret == -EAGAIN) && retry--)
+			goto again2;
+
+		return ret;
+	}
+
+	if (redrv_data[0] != 0xff) {
+		netif_dbg(pdata, drv, pdata->netdev,
+			  "Redriver write checksum error\n");
+		ret = -EIO;
+	}
+
+	return ret;
+}
+
 static int xgbe_phy_i2c_write(struct xgbe_prv_data *pdata, unsigned int target,
 			      void *val, unsigned int val_len)
 {
@@ -1144,38 +1233,49 @@ static void xgbe_phy_sfp_detect(struct xgbe_prv_data *pdata)
 	xgbe_phy_put_comm_ownership(pdata);
 }
 
-static enum xgbe_mode xgbe_phy_an37_sgmii_outcome(struct xgbe_prv_data *pdata)
+static void xgbe_phy_phydev_flowctrl(struct xgbe_prv_data *pdata)
 {
 	struct xgbe_phy_data *phy_data = pdata->phy_data;
-	enum xgbe_mode mode;
+	u16 lcl_adv = 0, rmt_adv = 0;
+	u8 fc;
 
-	pdata->phy.lp_advertising |= ADVERTISED_Autoneg;
-	pdata->phy.lp_advertising |= ADVERTISED_TP;
+	pdata->phy.tx_pause = 0;
+	pdata->phy.rx_pause = 0;
 
-	if (pdata->phy.pause_autoneg && phy_data->phydev) {
-		/* Flow control is obtained from the attached PHY */
-		u16 lcl_adv = 0, rmt_adv = 0;
-		u8 fc;
+	if (!phy_data->phydev)
+		return;
 
-		pdata->phy.tx_pause = 0;
-		pdata->phy.rx_pause = 0;
+	if (phy_data->phydev->advertising & ADVERTISED_Pause)
+		lcl_adv |= ADVERTISE_PAUSE_CAP;
+	if (phy_data->phydev->advertising & ADVERTISED_Asym_Pause)
+		lcl_adv |= ADVERTISE_PAUSE_ASYM;
 
-		if (phy_data->phydev->advertising & ADVERTISED_Pause)
-			lcl_adv |= ADVERTISE_PAUSE_CAP;
-		if (phy_data->phydev->advertising & ADVERTISED_Asym_Pause)
-			lcl_adv |= ADVERTISE_PAUSE_ASYM;
+	if (phy_data->phydev->pause) {
+		pdata->phy.lp_advertising |= ADVERTISED_Pause;
+		rmt_adv |= LPA_PAUSE_CAP;
+	}
+	if (phy_data->phydev->asym_pause) {
+		pdata->phy.lp_advertising |= ADVERTISED_Asym_Pause;
+		rmt_adv |= LPA_PAUSE_ASYM;
+	}
 
-		if (phy_data->phydev->pause)
-			rmt_adv |= LPA_PAUSE_CAP;
-		if (phy_data->phydev->asym_pause)
-			rmt_adv |= LPA_PAUSE_ASYM;
+	fc = mii_resolve_flowctrl_fdx(lcl_adv, rmt_adv);
+	if (fc & FLOW_CTRL_TX)
+		pdata->phy.tx_pause = 1;
+	if (fc & FLOW_CTRL_RX)
+		pdata->phy.rx_pause = 1;
+}
 
-		fc = mii_resolve_flowctrl_fdx(lcl_adv, rmt_adv);
-		if (fc & FLOW_CTRL_TX)
-			pdata->phy.tx_pause = 1;
-		if (fc & FLOW_CTRL_RX)
-			pdata->phy.rx_pause = 1;
-	}
+static enum xgbe_mode xgbe_phy_an37_sgmii_outcome(struct xgbe_prv_data *pdata)
+{
+	enum xgbe_mode mode;
+
+	pdata->phy.lp_advertising |= ADVERTISED_Autoneg;
+	pdata->phy.lp_advertising |= ADVERTISED_TP;
+
+	/* Use external PHY to determine flow control */
+	if (pdata->phy.pause_autoneg)
+		xgbe_phy_phydev_flowctrl(pdata);
 
 	switch (pdata->an_status & XGBE_SGMII_AN_LINK_SPEED) {
 	case XGBE_SGMII_AN_LINK_SPEED_100:
@@ -1249,6 +1349,83 @@ static enum xgbe_mode xgbe_phy_an37_outcome(struct xgbe_prv_data *pdata)
 	return mode;
 }
 
+static enum xgbe_mode xgbe_phy_an73_redrv_outcome(struct xgbe_prv_data *pdata)
+{
+	struct xgbe_phy_data *phy_data = pdata->phy_data;
+	enum xgbe_mode mode;
+	unsigned int ad_reg, lp_reg;
+
+	pdata->phy.lp_advertising |= ADVERTISED_Autoneg;
+	pdata->phy.lp_advertising |= ADVERTISED_Backplane;
+
+	/* Use external PHY to determine flow control */
+	if (pdata->phy.pause_autoneg)
+		xgbe_phy_phydev_flowctrl(pdata);
+
+	/* Compare Advertisement and Link Partner register 2 */
+	ad_reg = XMDIO_READ(pdata, MDIO_MMD_AN, MDIO_AN_ADVERTISE + 1);
+	lp_reg = XMDIO_READ(pdata, MDIO_MMD_AN, MDIO_AN_LPA + 1);
+	if (lp_reg & 0x80)
+		pdata->phy.lp_advertising |= ADVERTISED_10000baseKR_Full;
+	if (lp_reg & 0x20)
+		pdata->phy.lp_advertising |= ADVERTISED_1000baseKX_Full;
+
+	ad_reg &= lp_reg;
+	if (ad_reg & 0x80) {
+		switch (phy_data->port_mode) {
+		case XGBE_PORT_MODE_BACKPLANE:
+			mode = XGBE_MODE_KR;
+			break;
+		default:
+			mode = XGBE_MODE_SFI;
+			break;
+		}
+	} else if (ad_reg & 0x20) {
+		switch (phy_data->port_mode) {
+		case XGBE_PORT_MODE_BACKPLANE:
+			mode = XGBE_MODE_KX_1000;
+			break;
+		case XGBE_PORT_MODE_1000BASE_X:
+			mode = XGBE_MODE_X;
+			break;
+		case XGBE_PORT_MODE_SFP:
+			switch (phy_data->sfp_base) {
+			case XGBE_SFP_BASE_1000_T:
+				if (phy_data->phydev &&
+				    (phy_data->phydev->speed == SPEED_100))
+					mode = XGBE_MODE_SGMII_100;
+				else
+					mode = XGBE_MODE_SGMII_1000;
+				break;
+			case XGBE_SFP_BASE_1000_SX:
+			case XGBE_SFP_BASE_1000_LX:
+			case XGBE_SFP_BASE_1000_CX:
+			default:
+				mode = XGBE_MODE_X;
+				break;
+			}
+			break;
+		default:
+			if (phy_data->phydev &&
+			    (phy_data->phydev->speed == SPEED_100))
+				mode = XGBE_MODE_SGMII_100;
+			else
+				mode = XGBE_MODE_SGMII_1000;
+			break;
+		}
+	} else {
+		mode = XGBE_MODE_UNKNOWN;
+	}
+
+	/* Compare Advertisement and Link Partner register 3 */
+	ad_reg = XMDIO_READ(pdata, MDIO_MMD_AN, MDIO_AN_ADVERTISE + 2);
+	lp_reg = XMDIO_READ(pdata, MDIO_MMD_AN, MDIO_AN_LPA + 2);
+	if (lp_reg & 0xc000)
+		pdata->phy.lp_advertising |= ADVERTISED_10000baseR_FEC;
+
+	return mode;
+}
+
 static enum xgbe_mode xgbe_phy_an73_outcome(struct xgbe_prv_data *pdata)
 {
 	enum xgbe_mode mode;
@@ -1311,6 +1488,8 @@ static enum xgbe_mode xgbe_phy_an_outcome(struct xgbe_prv_data *pdata)
 	switch (pdata->an_mode) {
 	case XGBE_AN_MODE_CL73:
 		return xgbe_phy_an73_outcome(pdata);
+	case XGBE_AN_MODE_CL73_REDRV:
+		return xgbe_phy_an73_redrv_outcome(pdata);
 	case XGBE_AN_MODE_CL37:
 		return xgbe_phy_an37_outcome(pdata);
 	case XGBE_AN_MODE_CL37_SGMII:
@@ -1320,6 +1499,63 @@ static enum xgbe_mode xgbe_phy_an_outcome(struct xgbe_prv_data *pdata)
 	}
 }
 
+static unsigned int xgbe_phy_an_advertising(struct xgbe_prv_data *pdata)
+{
+	struct xgbe_phy_data *phy_data = pdata->phy_data;
+	unsigned int advertising;
+
+	/* Without a re-driver, just return current advertising */
+	if (!phy_data->redrv)
+		return pdata->phy.advertising;
+
+	/* With the KR re-driver we need to advertise a single speed */
+	advertising = pdata->phy.advertising;
+	advertising &= ~ADVERTISED_1000baseKX_Full;
+	advertising &= ~ADVERTISED_10000baseKR_Full;
+
+	switch (phy_data->port_mode) {
+	case XGBE_PORT_MODE_BACKPLANE:
+		advertising |= ADVERTISED_10000baseKR_Full;
+		break;
+	case XGBE_PORT_MODE_BACKPLANE_2500:
+		advertising |= ADVERTISED_1000baseKX_Full;
+		break;
+	case XGBE_PORT_MODE_1000BASE_T:
+	case XGBE_PORT_MODE_1000BASE_X:
+	case XGBE_PORT_MODE_NBASE_T:
+		advertising |= ADVERTISED_1000baseKX_Full;
+		break;
+	case XGBE_PORT_MODE_10GBASE_T:
+		if (phy_data->phydev &&
+		    (phy_data->phydev->speed == SPEED_10000))
+			advertising |= ADVERTISED_10000baseKR_Full;
+		else
+			advertising |= ADVERTISED_1000baseKX_Full;
+		break;
+	case XGBE_PORT_MODE_10GBASE_R:
+		advertising |= ADVERTISED_10000baseKR_Full;
+		break;
+	case XGBE_PORT_MODE_SFP:
+		switch (phy_data->sfp_base) {
+		case XGBE_SFP_BASE_1000_T:
+		case XGBE_SFP_BASE_1000_SX:
+		case XGBE_SFP_BASE_1000_LX:
+		case XGBE_SFP_BASE_1000_CX:
+			advertising |= ADVERTISED_1000baseKX_Full;
+			break;
+		default:
+			advertising |= ADVERTISED_10000baseKR_Full;
+			break;
+		}
+		break;
+	default:
+		advertising |= ADVERTISED_10000baseKR_Full;
+		break;
+	}
+
+	return advertising;
+}
+
 static int xgbe_phy_an_config(struct xgbe_prv_data *pdata)
 {
 	struct xgbe_phy_data *phy_data = pdata->phy_data;
@@ -1364,6 +1600,10 @@ static enum xgbe_an_mode xgbe_phy_an_mode(struct xgbe_prv_data *pdata)
 {
 	struct xgbe_phy_data *phy_data = pdata->phy_data;
 
+	/* A KR re-driver will always require CL73 AN */
+	if (phy_data->redrv)
+		return XGBE_AN_MODE_CL73_REDRV;
+
 	switch (phy_data->port_mode) {
 	case XGBE_PORT_MODE_BACKPLANE:
 		return XGBE_AN_MODE_CL73;
@@ -1386,6 +1626,61 @@ static enum xgbe_an_mode xgbe_phy_an_mode(struct xgbe_prv_data *pdata)
 	}
 }
 
+static int xgbe_phy_set_redrv_mode_mdio(struct xgbe_prv_data *pdata,
+					enum xgbe_phy_redrv_mode mode)
+{
+	struct xgbe_phy_data *phy_data = pdata->phy_data;
+	u16 redrv_reg, redrv_val;
+
+	redrv_reg = XGBE_PHY_REDRV_MODE_REG + (phy_data->redrv_lane * 0x1000);
+	redrv_val = (u16)mode;
+
+	return pdata->hw_if.write_ext_mii_regs(pdata, phy_data->redrv_addr,
+					       redrv_reg, redrv_val);
+}
+
+static int xgbe_phy_set_redrv_mode_i2c(struct xgbe_prv_data *pdata,
+				       enum xgbe_phy_redrv_mode mode)
+{
+	struct xgbe_phy_data *phy_data = pdata->phy_data;
+	unsigned int redrv_reg;
+	int ret;
+
+	/* Calculate the register to write */
+	redrv_reg = XGBE_PHY_REDRV_MODE_REG + (phy_data->redrv_lane * 0x1000);
+
+	ret = xgbe_phy_redrv_write(pdata, redrv_reg, mode);
+
+	return ret;
+}
+
+static void xgbe_phy_set_redrv_mode(struct xgbe_prv_data *pdata)
+{
+	struct xgbe_phy_data *phy_data = pdata->phy_data;
+	enum xgbe_phy_redrv_mode mode;
+	int ret;
+
+	if (!phy_data->redrv)
+		return;
+
+	mode = XGBE_PHY_REDRV_MODE_CX;
+	if ((phy_data->port_mode == XGBE_PORT_MODE_SFP) &&
+	    (phy_data->sfp_base != XGBE_SFP_BASE_1000_CX) &&
+	    (phy_data->sfp_base != XGBE_SFP_BASE_10000_CR))
+		mode = XGBE_PHY_REDRV_MODE_SR;
+
+	ret = xgbe_phy_get_comm_ownership(pdata);
+	if (ret)
+		return;
+
+	if (phy_data->redrv_if)
+		xgbe_phy_set_redrv_mode_i2c(pdata, mode);
+	else
+		xgbe_phy_set_redrv_mode_mdio(pdata, mode);
+
+	xgbe_phy_put_comm_ownership(pdata);
+}
+
 static void xgbe_phy_start_ratechange(struct xgbe_prv_data *pdata)
 {
 	if (!XP_IOREAD_BITS(pdata, XP_DRIVER_INT_RO, STATUS))
@@ -1457,6 +1752,8 @@ static void xgbe_phy_sfi_mode(struct xgbe_prv_data *pdata)
 	struct xgbe_phy_data *phy_data = pdata->phy_data;
 	unsigned int s0;
 
+	xgbe_phy_set_redrv_mode(pdata);
+
 	xgbe_phy_start_ratechange(pdata);
 
 	/* 10G/SFI */
@@ -1492,6 +1789,8 @@ static void xgbe_phy_x_mode(struct xgbe_prv_data *pdata)
 	struct xgbe_phy_data *phy_data = pdata->phy_data;
 	unsigned int s0;
 
+	xgbe_phy_set_redrv_mode(pdata);
+
 	xgbe_phy_start_ratechange(pdata);
 
 	/* 1G/X */
@@ -1516,6 +1815,8 @@ static void xgbe_phy_sgmii_1000_mode(struct xgbe_prv_data *pdata)
 	struct xgbe_phy_data *phy_data = pdata->phy_data;
 	unsigned int s0;
 
+	xgbe_phy_set_redrv_mode(pdata);
+
 	xgbe_phy_start_ratechange(pdata);
 
 	/* 1G/SGMII */
@@ -1540,6 +1841,8 @@ static void xgbe_phy_sgmii_100_mode(struct xgbe_prv_data *pdata)
 	struct xgbe_phy_data *phy_data = pdata->phy_data;
 	unsigned int s0;
 
+	xgbe_phy_set_redrv_mode(pdata);
+
 	xgbe_phy_start_ratechange(pdata);
 
 	/* 1G/SGMII */
@@ -1564,6 +1867,8 @@ static void xgbe_phy_kr_mode(struct xgbe_prv_data *pdata)
 	struct xgbe_phy_data *phy_data = pdata->phy_data;
 	unsigned int s0;
 
+	xgbe_phy_set_redrv_mode(pdata);
+
 	xgbe_phy_start_ratechange(pdata);
 
 	/* 10G/KR */
@@ -1588,6 +1893,8 @@ static void xgbe_phy_kx_2500_mode(struct xgbe_prv_data *pdata)
 	struct xgbe_phy_data *phy_data = pdata->phy_data;
 	unsigned int s0;
 
+	xgbe_phy_set_redrv_mode(pdata);
+
 	xgbe_phy_start_ratechange(pdata);
 
 	/* 2.5G/KX */
@@ -1612,6 +1919,8 @@ static void xgbe_phy_kx_1000_mode(struct xgbe_prv_data *pdata)
 	struct xgbe_phy_data *phy_data = pdata->phy_data;
 	unsigned int s0;
 
+	xgbe_phy_set_redrv_mode(pdata);
+
 	xgbe_phy_start_ratechange(pdata);
 
 	/* 1G/KX */
@@ -2232,6 +2541,30 @@ static int xgbe_phy_mdio_reset(struct xgbe_prv_data *pdata)
 	return ret;
 }
 
+static bool xgbe_phy_redrv_error(struct xgbe_phy_data *phy_data)
+{
+	if (!phy_data->redrv)
+		return false;
+
+	if (phy_data->redrv_if >= XGBE_PHY_REDRV_IF_MAX)
+		return true;
+
+	switch (phy_data->redrv_model) {
+	case XGBE_PHY_REDRV_MODEL_4223:
+		if (phy_data->redrv_lane > 3)
+			return true;
+		break;
+	case XGBE_PHY_REDRV_MODEL_4227:
+		if (phy_data->redrv_lane > 1)
+			return true;
+		break;
+	default:
+		return true;
+	}
+
+	return false;
+}
+
 static int xgbe_phy_mdio_reset_setup(struct xgbe_prv_data *pdata)
 {
 	struct xgbe_phy_data *phy_data = pdata->phy_data;
@@ -2481,6 +2814,20 @@ static int xgbe_phy_init(struct xgbe_prv_data *pdata)
 		dev_dbg(pdata->dev, "mdio addr=%u\n", phy_data->mdio_addr);
 	}
 
+	reg = XP_IOREAD(pdata, XP_PROP_4);
+	phy_data->redrv = XP_GET_BITS(reg, XP_PROP_4, REDRV_PRESENT);
+	phy_data->redrv_if = XP_GET_BITS(reg, XP_PROP_4, REDRV_IF);
+	phy_data->redrv_addr = XP_GET_BITS(reg, XP_PROP_4, REDRV_ADDR);
+	phy_data->redrv_lane = XP_GET_BITS(reg, XP_PROP_4, REDRV_LANE);
+	phy_data->redrv_model = XP_GET_BITS(reg, XP_PROP_4, REDRV_MODEL);
+	if (phy_data->redrv && netif_msg_probe(pdata)) {
+		dev_dbg(pdata->dev, "redrv present\n");
+		dev_dbg(pdata->dev, "redrv i/f=%u\n", phy_data->redrv_if);
+		dev_dbg(pdata->dev, "redrv addr=%#x\n", phy_data->redrv_addr);
+		dev_dbg(pdata->dev, "redrv lane=%u\n", phy_data->redrv_lane);
+		dev_dbg(pdata->dev, "redrv model=%u\n", phy_data->redrv_model);
+	}
+
 	/* Validate the connection requested */
 	if (xgbe_phy_conn_type_mismatch(pdata)) {
 		dev_err(pdata->dev, "phy mode/connection mismatch (%#x/%#x)\n",
@@ -2499,6 +2846,13 @@ static int xgbe_phy_init(struct xgbe_prv_data *pdata)
 	if (ret)
 		return ret;
 
+	/* Validate the re-driver information */
+	if (xgbe_phy_redrv_error(phy_data)) {
+		dev_err(pdata->dev, "phy re-driver settings error\n");
+		return -EINVAL;
+	}
+	pdata->kr_redrv = phy_data->redrv;
+
 	/* Indicate current mode is unknown */
 	phy_data->cur_mode = XGBE_MODE_UNKNOWN;
 
@@ -2651,6 +3005,29 @@ static int xgbe_phy_init(struct xgbe_prv_data *pdata)
 		dev_dbg(pdata->dev, "phy supported=%#x\n",
 			pdata->phy.supported);
 
+	if ((phy_data->conn_type & XGBE_CONN_TYPE_MDIO) &&
+	    (phy_data->phydev_mode != XGBE_MDIO_MODE_NONE)) {
+		ret = pdata->hw_if.set_ext_mii_mode(pdata, phy_data->mdio_addr,
+						    phy_data->phydev_mode);
+		if (ret) {
+			dev_err(pdata->dev,
+				"mdio port/clause not compatible (%d/%u)\n",
+				phy_data->mdio_addr, phy_data->phydev_mode);
+			return -EINVAL;
+		}
+	}
+
+	if (phy_data->redrv && !phy_data->redrv_if) {
+		ret = pdata->hw_if.set_ext_mii_mode(pdata, phy_data->redrv_addr,
+						    XGBE_MDIO_MODE_CL22);
+		if (ret) {
+			dev_err(pdata->dev,
+				"redriver mdio port not compatible (%u)\n",
+				phy_data->redrv_addr);
+			return -EINVAL;
+		}
+	}
+
 	/* Register for driving external PHYs */
 	mii = devm_mdiobus_alloc(pdata->dev);
 	if (!mii) {
@@ -2700,5 +3077,7 @@ void xgbe_init_function_ptrs_phy_v2(struct xgbe_phy_if *phy_if)
 
 	phy_impl->an_config		= xgbe_phy_an_config;
 
+	phy_impl->an_advertising	= xgbe_phy_an_advertising;
+
 	phy_impl->an_outcome		= xgbe_phy_an_outcome;
 }

drivers/net/ethernet/amd/xgbe/xgbe.h

@@ -508,6 +508,7 @@ enum xgbe_xpcs_access {
 
 enum xgbe_an_mode {
 	XGBE_AN_MODE_CL73 = 0,
+	XGBE_AN_MODE_CL73_REDRV,
 	XGBE_AN_MODE_CL37,
 	XGBE_AN_MODE_CL37_SGMII,
 	XGBE_AN_MODE_NONE,
@@ -807,6 +808,9 @@ struct xgbe_phy_impl_if {
 	/* Configure auto-negotiation settings */
 	int (*an_config)(struct xgbe_prv_data *);
 
+	/* Set/override auto-negotiation advertisement settings */
+	unsigned int (*an_advertising)(struct xgbe_prv_data *);
+
 	/* Process results of auto-negotiation */
 	enum xgbe_mode (*an_outcome)(struct xgbe_prv_data *);
 
@@ -1124,6 +1128,8 @@ struct xgbe_prv_data {
 	unsigned long link_check;
 	struct completion mdio_complete;
 
+	unsigned int kr_redrv;
+
 	char an_name[IFNAMSIZ + 32];
 	struct workqueue_struct *an_workqueue;