5 files changed, 337 insertions, 144 deletions

diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c
index e3c5d64ba340..e4c328f61188 100644
--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c
@@ -526,6 +526,7 @@ struct mvneta_port {
 	unsigned int tx_csum_limit;
 	struct phylink *phylink;
 	struct phylink_config phylink_config;
+	struct phylink_pcs phylink_pcs;
 	struct phy *comphy;
 
 	struct mvneta_bm *bm_priv;
@@ -3846,9 +3847,14 @@ static int mvneta_set_mac_addr(struct net_device *dev, void *addr)
 	return 0;
 }
 
-static void mvneta_validate(struct phylink_config *config,
-			    unsigned long *supported,
-			    struct phylink_link_state *state)
+static struct mvneta_port *mvneta_pcs_to_port(struct phylink_pcs *pcs)
+{
+	return container_of(pcs, struct mvneta_port, phylink_pcs);
+}
+
+static int mvneta_pcs_validate(struct phylink_pcs *pcs,
+			       unsigned long *supported,
+			       const struct phylink_link_state *state)
 {
 	/* We only support QSGMII, SGMII, 802.3z and RGMII modes.
 	 * When in 802.3z mode, we must have AN enabled:
@@ -3856,19 +3862,16 @@ static void mvneta_validate(struct phylink_config *config,
 	 * When <PortType> = 1 (1000BASE-X) this field must be set to 1."
 	 */
 	if (phy_interface_mode_is_8023z(state->interface) &&
-	    !phylink_test(state->advertising, Autoneg)) {
-		linkmode_zero(supported);
-		return;
-	}
+	    !phylink_test(state->advertising, Autoneg))
+		return -EINVAL;
 
-	phylink_generic_validate(config, supported, state);
+	return 0;
 }
 
-static void mvneta_mac_pcs_get_state(struct phylink_config *config,
-				     struct phylink_link_state *state)
+static void mvneta_pcs_get_state(struct phylink_pcs *pcs,
+				 struct phylink_link_state *state)
 {
-	struct net_device *ndev = to_net_dev(config->dev);
-	struct mvneta_port *pp = netdev_priv(ndev);
+	struct mvneta_port *pp = mvneta_pcs_to_port(pcs);
 	u32 gmac_stat;
 
 	gmac_stat = mvreg_read(pp, MVNETA_GMAC_STATUS);
@@ -3886,17 +3889,71 @@ static void mvneta_mac_pcs_get_state(struct phylink_config *config,
 	state->link = !!(gmac_stat & MVNETA_GMAC_LINK_UP);
 	state->duplex = !!(gmac_stat & MVNETA_GMAC_FULL_DUPLEX);
 
-	state->pause = 0;
 	if (gmac_stat & MVNETA_GMAC_RX_FLOW_CTRL_ENABLE)
 		state->pause |= MLO_PAUSE_RX;
 	if (gmac_stat & MVNETA_GMAC_TX_FLOW_CTRL_ENABLE)
 		state->pause |= MLO_PAUSE_TX;
 }
 
-static void mvneta_mac_an_restart(struct phylink_config *config)
+static int mvneta_pcs_config(struct phylink_pcs *pcs,
+			     unsigned int mode, phy_interface_t interface,
+			     const unsigned long *advertising,
+			     bool permit_pause_to_mac)
 {
-	struct net_device *ndev = to_net_dev(config->dev);
-	struct mvneta_port *pp = netdev_priv(ndev);
+	struct mvneta_port *pp = mvneta_pcs_to_port(pcs);
+	u32 mask, val, an, old_an, changed;
+
+	mask = MVNETA_GMAC_INBAND_AN_ENABLE |
+	       MVNETA_GMAC_INBAND_RESTART_AN |
+	       MVNETA_GMAC_AN_SPEED_EN |
+	       MVNETA_GMAC_AN_FLOW_CTRL_EN |
+	       MVNETA_GMAC_AN_DUPLEX_EN;
+
+	if (phylink_autoneg_inband(mode)) {
+		mask |= MVNETA_GMAC_CONFIG_MII_SPEED |
+			MVNETA_GMAC_CONFIG_GMII_SPEED |
+			MVNETA_GMAC_CONFIG_FULL_DUPLEX;
+		val = MVNETA_GMAC_INBAND_AN_ENABLE;
+
+		if (interface == PHY_INTERFACE_MODE_SGMII) {
+			/* SGMII mode receives the speed and duplex from PHY */
+			val |= MVNETA_GMAC_AN_SPEED_EN |
+			       MVNETA_GMAC_AN_DUPLEX_EN;
+		} else {
+			/* 802.3z mode has fixed speed and duplex */
+			val |= MVNETA_GMAC_CONFIG_GMII_SPEED |
+			       MVNETA_GMAC_CONFIG_FULL_DUPLEX;
+
+			/* The FLOW_CTRL_EN bit selects either the hardware
+			 * automatically or the CONFIG_FLOW_CTRL manually
+			 * controls the GMAC pause mode.
+			 */
+			if (permit_pause_to_mac)
+				val |= MVNETA_GMAC_AN_FLOW_CTRL_EN;
+
+			/* Update the advertisement bits */
+			mask |= MVNETA_GMAC_ADVERT_SYM_FLOW_CTRL;
+			if (phylink_test(advertising, Pause))
+				val |= MVNETA_GMAC_ADVERT_SYM_FLOW_CTRL;
+		}
+	} else {
+		/* Phy or fixed speed - disable in-band AN modes */
+		val = 0;
+	}
+
+	old_an = an = mvreg_read(pp, MVNETA_GMAC_AUTONEG_CONFIG);
+	an = (an & ~mask) | val;
+	changed = old_an ^ an;
+	if (changed)
+		mvreg_write(pp, MVNETA_GMAC_AUTONEG_CONFIG, an);
+
+	/* We are only interested in the advertisement bits changing */
+	return !!(changed & MVNETA_GMAC_ADVERT_SYM_FLOW_CTRL);
+}
+
+static void mvneta_pcs_an_restart(struct phylink_pcs *pcs)
+{
+	struct mvneta_port *pp = mvneta_pcs_to_port(pcs);
 	u32 gmac_an = mvreg_read(pp, MVNETA_GMAC_AUTONEG_CONFIG);
 
 	mvreg_write(pp, MVNETA_GMAC_AUTONEG_CONFIG,
@@ -3905,6 +3962,47 @@ static void mvneta_mac_an_restart(struct phylink_config *config)
 		    gmac_an & ~MVNETA_GMAC_INBAND_RESTART_AN);
 }
 
+static const struct phylink_pcs_ops mvneta_phylink_pcs_ops = {
+	.pcs_validate = mvneta_pcs_validate,
+	.pcs_get_state = mvneta_pcs_get_state,
+	.pcs_config = mvneta_pcs_config,
+	.pcs_an_restart = mvneta_pcs_an_restart,
+};
+
+static int mvneta_mac_prepare(struct phylink_config *config, unsigned int mode,
+			      phy_interface_t interface)
+{
+	struct net_device *ndev = to_net_dev(config->dev);
+	struct mvneta_port *pp = netdev_priv(ndev);
+	u32 val;
+
+	if (pp->phy_interface != interface ||
+	    phylink_autoneg_inband(mode)) {
+		/* Force the link down when changing the interface or if in
+		 * in-band mode. According to Armada 370 documentation, we
+		 * can only change the port mode and in-band enable when the
+		 * link is down.
+		 */
+		val = mvreg_read(pp, MVNETA_GMAC_AUTONEG_CONFIG);
+		val &= ~MVNETA_GMAC_FORCE_LINK_PASS;
+		val |= MVNETA_GMAC_FORCE_LINK_DOWN;
+		mvreg_write(pp, MVNETA_GMAC_AUTONEG_CONFIG, val);
+	}
+
+	if (pp->phy_interface != interface)
+		WARN_ON(phy_power_off(pp->comphy));
+
+	/* Enable the 1ms clock */
+	if (phylink_autoneg_inband(mode)) {
+		unsigned long rate = clk_get_rate(pp->clk);
+
+		mvreg_write(pp, MVNETA_GMAC_CLOCK_DIVIDER,
+			    MVNETA_GMAC_1MS_CLOCK_ENABLE | (rate / 1000));
+	}
+
+	return 0;
+}
+
 static void mvneta_mac_config(struct phylink_config *config, unsigned int mode,
 			      const struct phylink_link_state *state)
 {
@@ -3913,20 +4011,11 @@ static void mvneta_mac_config(struct phylink_config *config, unsigned int mode,
 	u32 new_ctrl0, gmac_ctrl0 = mvreg_read(pp, MVNETA_GMAC_CTRL_0);
 	u32 new_ctrl2, gmac_ctrl2 = mvreg_read(pp, MVNETA_GMAC_CTRL_2);
 	u32 new_ctrl4, gmac_ctrl4 = mvreg_read(pp, MVNETA_GMAC_CTRL_4);
-	u32 new_clk, gmac_clk = mvreg_read(pp, MVNETA_GMAC_CLOCK_DIVIDER);
-	u32 new_an, gmac_an = mvreg_read(pp, MVNETA_GMAC_AUTONEG_CONFIG);
 
 	new_ctrl0 = gmac_ctrl0 & ~MVNETA_GMAC0_PORT_1000BASE_X;
 	new_ctrl2 = gmac_ctrl2 & ~(MVNETA_GMAC2_INBAND_AN_ENABLE |
 				   MVNETA_GMAC2_PORT_RESET);
 	new_ctrl4 = gmac_ctrl4 & ~(MVNETA_GMAC4_SHORT_PREAMBLE_ENABLE);
-	new_clk = gmac_clk & ~MVNETA_GMAC_1MS_CLOCK_ENABLE;
-	new_an = gmac_an & ~(MVNETA_GMAC_INBAND_AN_ENABLE |
-			     MVNETA_GMAC_INBAND_RESTART_AN |
-			     MVNETA_GMAC_AN_SPEED_EN |
-			     MVNETA_GMAC_ADVERT_SYM_FLOW_CTRL |
-			     MVNETA_GMAC_AN_FLOW_CTRL_EN |
-			     MVNETA_GMAC_AN_DUPLEX_EN);
 
 	/* Even though it might look weird, when we're configured in
 	 * SGMII or QSGMII mode, the RGMII bit needs to be set.
@@ -3938,9 +4027,6 @@ static void mvneta_mac_config(struct phylink_config *config, unsigned int mode,
 	    phy_interface_mode_is_8023z(state->interface))
 		new_ctrl2 |= MVNETA_GMAC2_PCS_ENABLE;
 
-	if (phylink_test(state->advertising, Pause))
-		new_an |= MVNETA_GMAC_ADVERT_SYM_FLOW_CTRL;
-
 	if (!phylink_autoneg_inband(mode)) {
 		/* Phy or fixed speed - nothing to do, leave the
 		 * configured speed, duplex and flow control as-is.
@@ -3948,70 +4034,23 @@ static void mvneta_mac_config(struct phylink_config *config, unsigned int mode,
 	} else if (state->interface == PHY_INTERFACE_MODE_SGMII) {
 		/* SGMII mode receives the state from the PHY */
 		new_ctrl2 |= MVNETA_GMAC2_INBAND_AN_ENABLE;
-		new_clk = MVNETA_GMAC_1MS_CLOCK_ENABLE;
-		new_an = (new_an & ~(MVNETA_GMAC_FORCE_LINK_DOWN |
-				     MVNETA_GMAC_FORCE_LINK_PASS |
-				     MVNETA_GMAC_CONFIG_MII_SPEED |
-				     MVNETA_GMAC_CONFIG_GMII_SPEED |
-				     MVNETA_GMAC_CONFIG_FULL_DUPLEX)) |
-			 MVNETA_GMAC_INBAND_AN_ENABLE |
-			 MVNETA_GMAC_AN_SPEED_EN |
-			 MVNETA_GMAC_AN_DUPLEX_EN;
 	} else {
 		/* 802.3z negotiation - only 1000base-X */
 		new_ctrl0 |= MVNETA_GMAC0_PORT_1000BASE_X;
-		new_clk = MVNETA_GMAC_1MS_CLOCK_ENABLE;
-		new_an = (new_an & ~(MVNETA_GMAC_FORCE_LINK_DOWN |
-				     MVNETA_GMAC_FORCE_LINK_PASS |
-				     MVNETA_GMAC_CONFIG_MII_SPEED)) |
-			 MVNETA_GMAC_INBAND_AN_ENABLE |
-			 MVNETA_GMAC_CONFIG_GMII_SPEED |
-			 /* The MAC only supports FD mode */
-			 MVNETA_GMAC_CONFIG_FULL_DUPLEX;
-
-		if (state->pause & MLO_PAUSE_AN && state->an_enabled)
-			new_an |= MVNETA_GMAC_AN_FLOW_CTRL_EN;
 	}
 
-	/* Set the 1ms clock divisor */
-	if (new_clk == MVNETA_GMAC_1MS_CLOCK_ENABLE)
-		new_clk |= clk_get_rate(pp->clk) / 1000;
-
-	/* Armada 370 documentation says we can only change the port mode
-	 * and in-band enable when the link is down, so force it down
-	 * while making these changes. We also do this for GMAC_CTRL2
-	 */
-	if ((new_ctrl0 ^ gmac_ctrl0) & MVNETA_GMAC0_PORT_1000BASE_X ||
-	    (new_ctrl2 ^ gmac_ctrl2) & MVNETA_GMAC2_INBAND_AN_ENABLE ||
-	    (new_an  ^ gmac_an) & MVNETA_GMAC_INBAND_AN_ENABLE) {
-		mvreg_write(pp, MVNETA_GMAC_AUTONEG_CONFIG,
-			    (gmac_an & ~MVNETA_GMAC_FORCE_LINK_PASS) |
-			    MVNETA_GMAC_FORCE_LINK_DOWN);
-	}
-
-
 	/* When at 2.5G, the link partner can send frames with shortened
 	 * preambles.
 	 */
 	if (state->interface == PHY_INTERFACE_MODE_2500BASEX)
 		new_ctrl4 |= MVNETA_GMAC4_SHORT_PREAMBLE_ENABLE;
 
-	if (pp->phy_interface != state->interface) {
-		if (pp->comphy)
-			WARN_ON(phy_power_off(pp->comphy));
-		WARN_ON(mvneta_config_interface(pp, state->interface));
-	}
-
 	if (new_ctrl0 != gmac_ctrl0)
 		mvreg_write(pp, MVNETA_GMAC_CTRL_0, new_ctrl0);
 	if (new_ctrl2 != gmac_ctrl2)
 		mvreg_write(pp, MVNETA_GMAC_CTRL_2, new_ctrl2);
 	if (new_ctrl4 != gmac_ctrl4)
 		mvreg_write(pp, MVNETA_GMAC_CTRL_4, new_ctrl4);
-	if (new_clk != gmac_clk)
-		mvreg_write(pp, MVNETA_GMAC_CLOCK_DIVIDER, new_clk);
-	if (new_an != gmac_an)
-		mvreg_write(pp, MVNETA_GMAC_AUTONEG_CONFIG, new_an);
 
 	if (gmac_ctrl2 & MVNETA_GMAC2_PORT_RESET) {
 		while ((mvreg_read(pp, MVNETA_GMAC_CTRL_2) &
@@ -4020,6 +4059,36 @@ static void mvneta_mac_config(struct phylink_config *config, unsigned int mode,
 	}
 }
 
+static int mvneta_mac_finish(struct phylink_config *config, unsigned int mode,
+			     phy_interface_t interface)
+{
+	struct net_device *ndev = to_net_dev(config->dev);
+	struct mvneta_port *pp = netdev_priv(ndev);
+	u32 val, clk;
+
+	/* Disable 1ms clock if not in in-band mode */
+	if (!phylink_autoneg_inband(mode)) {
+		clk = mvreg_read(pp, MVNETA_GMAC_CLOCK_DIVIDER);
+		clk &= ~MVNETA_GMAC_1MS_CLOCK_ENABLE;
+		mvreg_write(pp, MVNETA_GMAC_CLOCK_DIVIDER, clk);
+	}
+
+	if (pp->phy_interface != interface)
+		/* Enable the Serdes PHY */
+		WARN_ON(mvneta_config_interface(pp, interface));
+
+	/* Allow the link to come up if in in-band mode, otherwise the
+	 * link is forced via mac_link_down()/mac_link_up()
+	 */
+	if (phylink_autoneg_inband(mode)) {
+		val = mvreg_read(pp, MVNETA_GMAC_AUTONEG_CONFIG);
+		val &= ~MVNETA_GMAC_FORCE_LINK_DOWN;
+		mvreg_write(pp, MVNETA_GMAC_AUTONEG_CONFIG, val);
+	}
+
+	return 0;
+}
+
 static void mvneta_set_eee(struct mvneta_port *pp, bool enable)
 {
 	u32 lpi_ctl1;
@@ -4106,10 +4175,10 @@ static void mvneta_mac_link_up(struct phylink_config *config,
 }
 
 static const struct phylink_mac_ops mvneta_phylink_ops = {
-	.validate = mvneta_validate,
-	.mac_pcs_get_state = mvneta_mac_pcs_get_state,
-	.mac_an_restart = mvneta_mac_an_restart,
+	.validate = phylink_generic_validate,
+	.mac_prepare = mvneta_mac_prepare,
 	.mac_config = mvneta_mac_config,
+	.mac_finish = mvneta_mac_finish,
 	.mac_link_down = mvneta_mac_link_down,
 	.mac_link_up = mvneta_mac_link_up,
 };
@@ -5275,7 +5344,6 @@ static int mvneta_probe(struct platform_device *pdev)
 
 	pp->phylink_config.dev = &dev->dev;
 	pp->phylink_config.type = PHYLINK_NETDEV;
-	pp->phylink_config.legacy_pre_march2020 = true;
 	pp->phylink_config.mac_capabilities = MAC_SYM_PAUSE | MAC_10 |
 		MAC_100 | MAC_1000FD | MAC_2500FD;
 
@@ -5350,6 +5418,9 @@ static int mvneta_probe(struct platform_device *pdev)
 		goto err_clk;
 	}
 
+	pp->phylink_pcs.ops = &mvneta_phylink_pcs_ops;
+	phylink_set_pcs(phylink, &pp->phylink_pcs);
+
 	/* Alloc per-cpu port structure */
 	pp->ports = alloc_percpu(struct mvneta_pcpu_port);
 	if (!pp->ports) {
diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2.h b/drivers/net/ethernet/marvell/mvpp2/mvpp2.h
index cf8acabb90ac..ad73a488fc5f 100644
--- a/drivers/net/ethernet/marvell/mvpp2/mvpp2.h
+++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2.h
@@ -1239,7 +1239,8 @@ struct mvpp2_port {
 	phy_interface_t phy_interface;
 	struct phylink *phylink;
 	struct phylink_config phylink_config;
-	struct phylink_pcs phylink_pcs;
+	struct phylink_pcs pcs_gmac;
+	struct phylink_pcs pcs_xlg;
 	struct phy *comphy;
 
 	struct mvpp2_bm_pool *pool_long;
diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
index b1cce4425296..339ae274021e 100644
--- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
+++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
@@ -6115,15 +6115,20 @@ static struct mvpp2_port *mvpp2_phylink_to_port(struct phylink_config *config)
 	return container_of(config, struct mvpp2_port, phylink_config);
 }
 
-static struct mvpp2_port *mvpp2_pcs_to_port(struct phylink_pcs *pcs)
+static struct mvpp2_port *mvpp2_pcs_xlg_to_port(struct phylink_pcs *pcs)
 {
-	return container_of(pcs, struct mvpp2_port, phylink_pcs);
+	return container_of(pcs, struct mvpp2_port, pcs_xlg);
+}
+
+static struct mvpp2_port *mvpp2_pcs_gmac_to_port(struct phylink_pcs *pcs)
+{
+	return container_of(pcs, struct mvpp2_port, pcs_gmac);
 }
 
 static void mvpp2_xlg_pcs_get_state(struct phylink_pcs *pcs,
 				    struct phylink_link_state *state)
 {
-	struct mvpp2_port *port = mvpp2_pcs_to_port(pcs);
+	struct mvpp2_port *port = mvpp2_pcs_xlg_to_port(pcs);
 	u32 val;
 
 	if (port->phy_interface == PHY_INTERFACE_MODE_5GBASER)
@@ -6158,10 +6163,25 @@ static const struct phylink_pcs_ops mvpp2_phylink_xlg_pcs_ops = {
 	.pcs_config = mvpp2_xlg_pcs_config,
 };
 
+static int mvpp2_gmac_pcs_validate(struct phylink_pcs *pcs,
+				   unsigned long *supported,
+				   const struct phylink_link_state *state)
+{
+	/* When in 802.3z mode, we must have AN enabled:
+	 * Bit 2 Field InBandAnEn In-band Auto-Negotiation enable. ...
+	 * When <PortType> = 1 (1000BASE-X) this field must be set to 1.
+	 */
+	if (phy_interface_mode_is_8023z(state->interface) &&
+	    !phylink_test(state->advertising, Autoneg))
+		return -EINVAL;
+
+	return 0;
+}
+
 static void mvpp2_gmac_pcs_get_state(struct phylink_pcs *pcs,
 				     struct phylink_link_state *state)
 {
-	struct mvpp2_port *port = mvpp2_pcs_to_port(pcs);
+	struct mvpp2_port *port = mvpp2_pcs_gmac_to_port(pcs);
 	u32 val;
 
 	val = readl(port->base + MVPP2_GMAC_STATUS0);
@@ -6198,7 +6218,7 @@ static int mvpp2_gmac_pcs_config(struct phylink_pcs *pcs, unsigned int mode,
 				 const unsigned long *advertising,
 				 bool permit_pause_to_mac)
 {
-	struct mvpp2_port *port = mvpp2_pcs_to_port(pcs);
+	struct mvpp2_port *port = mvpp2_pcs_gmac_to_port(pcs);
 	u32 mask, val, an, old_an, changed;
 
 	mask = MVPP2_GMAC_IN_BAND_AUTONEG_BYPASS |
@@ -6252,7 +6272,7 @@ static int mvpp2_gmac_pcs_config(struct phylink_pcs *pcs, unsigned int mode,
 
 static void mvpp2_gmac_pcs_an_restart(struct phylink_pcs *pcs)
 {
-	struct mvpp2_port *port = mvpp2_pcs_to_port(pcs);
+	struct mvpp2_port *port = mvpp2_pcs_gmac_to_port(pcs);
 	u32 val = readl(port->base + MVPP2_GMAC_AUTONEG_CONFIG);
 
 	writel(val | MVPP2_GMAC_IN_BAND_RESTART_AN,
@@ -6262,30 +6282,12 @@ static void mvpp2_gmac_pcs_an_restart(struct phylink_pcs *pcs)
 }
 
 static const struct phylink_pcs_ops mvpp2_phylink_gmac_pcs_ops = {
+	.pcs_validate = mvpp2_gmac_pcs_validate,
 	.pcs_get_state = mvpp2_gmac_pcs_get_state,
 	.pcs_config = mvpp2_gmac_pcs_config,
 	.pcs_an_restart = mvpp2_gmac_pcs_an_restart,
 };
 
-static void mvpp2_phylink_validate(struct phylink_config *config,
-				   unsigned long *supported,
-				   struct phylink_link_state *state)
-{
-	/* When in 802.3z mode, we must have AN enabled:
-	 * Bit 2 Field InBandAnEn In-band Auto-Negotiation enable. ...
-	 * When <PortType> = 1 (1000BASE-X) this field must be set to 1.
-	 */
-	if (phy_interface_mode_is_8023z(state->interface) &&
-	    !phylink_test(state->advertising, Autoneg))
-		goto empty_set;
-
-	phylink_generic_validate(config, supported, state);
-	return;
-
-empty_set:
-	linkmode_zero(supported);
-}
-
 static void mvpp2_xlg_config(struct mvpp2_port *port, unsigned int mode,
 			     const struct phylink_link_state *state)
 {
@@ -6365,8 +6367,23 @@ static void mvpp2_gmac_config(struct mvpp2_port *port, unsigned int mode,
 		writel(ctrl4, port->base + MVPP22_GMAC_CTRL_4_REG);
 }
 
-static int mvpp2__mac_prepare(struct phylink_config *config, unsigned int mode,
-			      phy_interface_t interface)
+static struct phylink_pcs *mvpp2_select_pcs(struct phylink_config *config,
+					    phy_interface_t interface)
+{
+	struct mvpp2_port *port = mvpp2_phylink_to_port(config);
+
+	/* Select the appropriate PCS operations depending on the
+	 * configured interface mode. We will only switch to a mode
+	 * that the validate() checks have already passed.
+	 */
+	if (mvpp2_is_xlg(interface))
+		return &port->pcs_xlg;
+	else
+		return &port->pcs_gmac;
+}
+
+static int mvpp2_mac_prepare(struct phylink_config *config, unsigned int mode,
+			     phy_interface_t interface)
 {
 	struct mvpp2_port *port = mvpp2_phylink_to_port(config);
 
@@ -6415,31 +6432,9 @@ static int mvpp2__mac_prepare(struct phylink_config *config, unsigned int mode,
 		}
 	}
 
-	/* Select the appropriate PCS operations depending on the
-	 * configured interface mode. We will only switch to a mode
-	 * that the validate() checks have already passed.
-	 */
-	if (mvpp2_is_xlg(interface))
-		port->phylink_pcs.ops = &mvpp2_phylink_xlg_pcs_ops;
-	else
-		port->phylink_pcs.ops = &mvpp2_phylink_gmac_pcs_ops;
-
 	return 0;
 }
 
-static int mvpp2_mac_prepare(struct phylink_config *config, unsigned int mode,
-			     phy_interface_t interface)
-{
-	struct mvpp2_port *port = mvpp2_phylink_to_port(config);
-	int ret;
-
-	ret = mvpp2__mac_prepare(config, mode, interface);
-	if (ret == 0)
-		phylink_set_pcs(port->phylink, &port->phylink_pcs);
-
-	return ret;
-}
-
 static void mvpp2_mac_config(struct phylink_config *config, unsigned int mode,
 			     const struct phylink_link_state *state)
 {
@@ -6610,7 +6605,8 @@ static void mvpp2_mac_link_down(struct phylink_config *config,
 }
 
 static const struct phylink_mac_ops mvpp2_phylink_ops = {
-	.validate = mvpp2_phylink_validate,
+	.validate = phylink_generic_validate,
+	.mac_select_pcs = mvpp2_select_pcs,
 	.mac_prepare = mvpp2_mac_prepare,
 	.mac_config = mvpp2_mac_config,
 	.mac_finish = mvpp2_mac_finish,
@@ -6628,12 +6624,15 @@ static void mvpp2_acpi_start(struct mvpp2_port *port)
 	struct phylink_link_state state = {
 		.interface = port->phy_interface,
 	};
-	mvpp2__mac_prepare(&port->phylink_config, MLO_AN_INBAND,
-			   port->phy_interface);
+	struct phylink_pcs *pcs;
+
+	pcs = mvpp2_select_pcs(&port->phylink_config, port->phy_interface);
+
+	mvpp2_mac_prepare(&port->phylink_config, MLO_AN_INBAND,
+			  port->phy_interface);
 	mvpp2_mac_config(&port->phylink_config, MLO_AN_INBAND, &state);
-	port->phylink_pcs.ops->pcs_config(&port->phylink_pcs, MLO_AN_INBAND,
-					  port->phy_interface,
-					  state.advertising, false);
+	pcs->ops->pcs_config(pcs, MLO_AN_INBAND, port->phy_interface,
+			     state.advertising, false);
 	mvpp2_mac_finish(&port->phylink_config, MLO_AN_INBAND,
 			 port->phy_interface);
 	mvpp2_mac_link_up(&port->phylink_config, NULL,
@@ -6941,6 +6940,9 @@ static int mvpp2_port_probe(struct platform_device *pdev,
 				  port->phylink_config.supported_interfaces);
 		}
 
+		port->pcs_gmac.ops = &mvpp2_phylink_gmac_pcs_ops;
+		port->pcs_xlg.ops = &mvpp2_phylink_xlg_pcs_ops;
+
 		phylink = phylink_create(&port->phylink_config, port_fwnode,
 					 phy_mode, &mvpp2_phylink_ops);
 		if (IS_ERR(phylink)) {
diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
index 20df8af3e201..420201858564 100644
--- a/drivers/net/phy/phylink.c
+++ b/drivers/net/phy/phylink.c
@@ -419,6 +419,54 @@ void phylink_generic_validate(struct phylink_config *config,
 }
 EXPORT_SYMBOL_GPL(phylink_generic_validate);
 
+static int phylink_validate_mac_and_pcs(struct phylink *pl,
+					unsigned long *supported,
+					struct phylink_link_state *state)
+{
+	struct phylink_pcs *pcs;
+	int ret;
+
+	/* Get the PCS for this interface mode */
+	if (pl->mac_ops->mac_select_pcs) {
+		pcs = pl->mac_ops->mac_select_pcs(pl->config, state->interface);
+		if (IS_ERR(pcs))
+			return PTR_ERR(pcs);
+	} else {
+		pcs = pl->pcs;
+	}
+
+	if (pcs) {
+		/* The PCS, if present, must be setup before phylink_create()
+		 * has been called. If the ops is not initialised, print an
+		 * error and backtrace rather than oopsing the kernel.
+		 */
+		if (!pcs->ops) {
+			phylink_err(pl, "interface %s: uninitialised PCS\n",
+				    phy_modes(state->interface));
+			dump_stack();
+			return -EINVAL;
+		}
+
+		/* Validate the link parameters with the PCS */
+		if (pcs->ops->pcs_validate) {
+			ret = pcs->ops->pcs_validate(pcs, supported, state);
+			if (ret < 0 || phylink_is_empty_linkmode(supported))
+				return -EINVAL;
+
+			/* Ensure the advertising mask is a subset of the
+			 * supported mask.
+			 */
+			linkmode_and(state->advertising, state->advertising,
+				     supported);
+		}
+	}
+
+	/* Then validate the link parameters with the MAC */
+	pl->mac_ops->validate(pl->config, supported, state);
+
+	return phylink_is_empty_linkmode(supported) ? -EINVAL : 0;
+}
+
 static int phylink_validate_any(struct phylink *pl, unsigned long *supported,
 				struct phylink_link_state *state)
 {
@@ -434,9 +482,10 @@ static int phylink_validate_any(struct phylink *pl, unsigned long *supported,
 
 			t = *state;
 			t.interface = intf;
-			pl->mac_ops->validate(pl->config, s, &t);
-			linkmode_or(all_s, all_s, s);
-			linkmode_or(all_adv, all_adv, t.advertising);
+			if (!phylink_validate_mac_and_pcs(pl, s, &t)) {
+				linkmode_or(all_s, all_s, s);
+				linkmode_or(all_adv, all_adv, t.advertising);
+			}
 		}
 	}
 
@@ -458,9 +507,7 @@ static int phylink_validate(struct phylink *pl, unsigned long *supported,
 			return -EINVAL;
 	}
 
-	pl->mac_ops->validate(pl->config, supported, state);
-
-	return phylink_is_empty_linkmode(supported) ? -EINVAL : 0;
+	return phylink_validate_mac_and_pcs(pl, supported, state);
 }
 
 static int phylink_parse_fixedlink(struct phylink *pl,
@@ -750,10 +797,21 @@ static void phylink_mac_pcs_an_restart(struct phylink *pl)
 static void phylink_major_config(struct phylink *pl, bool restart,
 				  const struct phylink_link_state *state)
 {
+	struct phylink_pcs *pcs = NULL;
 	int err;
 
 	phylink_dbg(pl, "major config %s\n", phy_modes(state->interface));
 
+	if (pl->mac_ops->mac_select_pcs) {
+		pcs = pl->mac_ops->mac_select_pcs(pl->config, state->interface);
+		if (IS_ERR(pcs)) {
+			phylink_err(pl,
+				    "mac_select_pcs unexpectedly failed: %pe\n",
+				    pcs);
+			return;
+		}
+	}
+
 	if (pl->mac_ops->mac_prepare) {
 		err = pl->mac_ops->mac_prepare(pl->config, pl->cur_link_an_mode,
 					       state->interface);
@@ -764,6 +822,12 @@ static void phylink_major_config(struct phylink *pl, bool restart,
 		}
 	}
 
+	/* If we have a new PCS, switch to the new PCS after preparing the MAC
+	 * for the change.
+	 */
+	if (pcs)
+		phylink_set_pcs(pl, pcs);
+
 	phylink_mac_config(pl, state);
 
 	if (pl->pcs_ops) {
@@ -1155,6 +1219,14 @@ struct phylink *phylink_create(struct phylink_config *config,
 	struct phylink *pl;
 	int ret;
 
+	/* Validate the supplied configuration */
+	if (mac_ops->mac_select_pcs &&
+	    phy_interface_empty(config->supported_interfaces)) {
+		dev_err(config->dev,
+			"phylink: error: empty supported_interfaces but mac_select_pcs() method present\n");
+		return ERR_PTR(-EINVAL);
+	}
+
 	pl = kzalloc(sizeof(*pl), GFP_KERNEL);
 	if (!pl)
 		return ERR_PTR(-ENOMEM);
@@ -1222,9 +1294,10 @@ EXPORT_SYMBOL_GPL(phylink_create);
  * @pl: a pointer to a &struct phylink returned from phylink_create()
  * @pcs: a pointer to the &struct phylink_pcs
  *
- * Bind the MAC PCS to phylink.  This may be called after phylink_create(),
- * in mac_prepare() or mac_config() methods if it is desired to dynamically
- * change the PCS.
+ * Bind the MAC PCS to phylink.  This may be called after phylink_create().
+ * If it is desired to dynamically change the PCS, then the preferred method
+ * is to use mac_select_pcs(), but it may also be called in mac_prepare()
+ * or mac_config().
  *
  * Please note that there are behavioural changes with the mac_config()
  * callback if a PCS is present (denoting a newer setup) so removing a PCS
@@ -1235,6 +1308,14 @@ void phylink_set_pcs(struct phylink *pl, struct phylink_pcs *pcs)
 {
 	pl->pcs = pcs;
 	pl->pcs_ops = pcs->ops;
+
+	if (!pl->phylink_disable_state &&
+	    pl->cfg_link_an_mode == MLO_AN_INBAND) {
+		if (pl->config->pcs_poll || pcs->poll)
+			mod_timer(&pl->link_poll, jiffies + HZ);
+		else
+			del_timer(&pl->link_poll);
+	}
 }
 EXPORT_SYMBOL_GPL(phylink_set_pcs);
 
diff --git a/include/linux/phylink.h b/include/linux/phylink.h
index a2f266cc3442..713a0c928b7c 100644
--- a/include/linux/phylink.h
+++ b/include/linux/phylink.h
@@ -112,6 +112,7 @@ struct phylink_config {
 /**
  * struct phylink_mac_ops - MAC operations structure.
  * @validate: Validate and update the link configuration.
+ * @mac_select_pcs: Select a PCS for the interface mode.
  * @mac_pcs_get_state: Read the current link state from the hardware.
  * @mac_prepare: prepare for a major reconfiguration of the interface.
  * @mac_config: configure the MAC for the selected mode and state.
@@ -126,6 +127,8 @@ struct phylink_mac_ops {
 	void (*validate)(struct phylink_config *config,
 			 unsigned long *supported,
 			 struct phylink_link_state *state);
+	struct phylink_pcs *(*mac_select_pcs)(struct phylink_config *config,
+					      phy_interface_t interface);
 	void (*mac_pcs_get_state)(struct phylink_config *config,
 				  struct phylink_link_state *state);
 	int (*mac_prepare)(struct phylink_config *config, unsigned int mode,
@@ -178,6 +181,21 @@ struct phylink_mac_ops {
  */
 void validate(struct phylink_config *config, unsigned long *supported,
 	      struct phylink_link_state *state);
+/**
+ * mac_select_pcs: Select a PCS for the interface mode.
+ * @config: a pointer to a &struct phylink_config.
+ * @interface: PHY interface mode for PCS
+ *
+ * Return the &struct phylink_pcs for the specified interface mode, or
+ * NULL if none is required, or an error pointer on error.
+ *
+ * This must not modify any state. It is used to query which PCS should
+ * be used. Phylink will use this during validation to ensure that the
+ * configuration is valid, and when setting a configuration to internally
+ * set the PCS that will be used.
+ */
+struct phylink_pcs *mac_select_pcs(struct phylink_config *config,
+				   phy_interface_t interface);
 
 /**
  * mac_pcs_get_state() - Read the current inband link state from the hardware
@@ -398,6 +416,7 @@ struct phylink_pcs {
 
 /**
  * struct phylink_pcs_ops - MAC PCS operations structure.
+ * @pcs_validate: validate the link configuration.
  * @pcs_get_state: read the current MAC PCS link state from the hardware.
  * @pcs_config: configure the MAC PCS for the selected mode and state.
  * @pcs_an_restart: restart 802.3z BaseX autonegotiation.
@@ -405,6 +424,8 @@ struct phylink_pcs {
  *               (where necessary).
  */
 struct phylink_pcs_ops {
+	int (*pcs_validate)(struct phylink_pcs *pcs, unsigned long *supported,
+			    const struct phylink_link_state *state);
 	void (*pcs_get_state)(struct phylink_pcs *pcs,
 			      struct phylink_link_state *state);
 	int (*pcs_config)(struct phylink_pcs *pcs, unsigned int mode,
@@ -418,6 +439,23 @@ struct phylink_pcs_ops {
 
 #if 0 /* For kernel-doc purposes only. */
 /**
+ * pcs_validate() - validate the link configuration.
+ * @pcs: a pointer to a &struct phylink_pcs.
+ * @supported: ethtool bitmask for supported link modes.
+ * @state: a const pointer to a &struct phylink_link_state.
+ *
+ * Validate the interface mode, and advertising's autoneg bit, removing any
+ * media ethtool link modes that would not be supportable from the supported
+ * mask. Phylink will propagate the changes to the advertising mask. See the
+ * &struct phylink_mac_ops validate() method.
+ *
+ * Returns -EINVAL if the interface mode/autoneg mode is not supported.
+ * Returns non-zero positive if the link state can be supported.
+ */
+int pcs_validate(struct phylink_pcs *pcs, unsigned long *supported,
+		 const struct phylink_link_state *state);
+
+/**
  * pcs_get_state() - Read the current inband link state from the hardware
  * @pcs: a pointer to a &struct phylink_pcs.
  * @state: a pointer to a &struct phylink_link_state.