13 files changed, 440 insertions, 404 deletions

diff --git a/MAINTAINERS b/MAINTAINERS
index b0e909937499..a1c15b6714a0 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -10293,6 +10293,13 @@ S:	Maintained
 W:	http://linux-test-project.github.io/
 T:	git git://github.com/linux-test-project/ltp.git
 
+LYNX PCS MODULE
+M:	Ioana Ciornei <ioana.ciornei@nxp.com>
+L:	netdev@vger.kernel.org
+S:	Supported
+F:	drivers/net/phy/pcs-lynx.c
+F:	include/linux/pcs-lynx.h
+
 M68K ARCHITECTURE
 M:	Geert Uytterhoeven <geert@linux-m68k.org>
 L:	linux-m68k@lists.linux-m68k.org
diff --git a/drivers/net/dsa/ocelot/Kconfig b/drivers/net/dsa/ocelot/Kconfig
index 2d23ccef7d0e..e19718d4a7d4 100644
--- a/drivers/net/dsa/ocelot/Kconfig
+++ b/drivers/net/dsa/ocelot/Kconfig
@@ -8,6 +8,7 @@ config NET_DSA_MSCC_FELIX
 	select MSCC_OCELOT_SWITCH_LIB
 	select NET_DSA_TAG_OCELOT
 	select FSL_ENETC_MDIO
+	select PCS_LYNX
 	help
 	  This driver supports network switches from the Vitesse /
 	  Microsemi / Microchip Ocelot family of switching cores that are
diff --git a/drivers/net/dsa/ocelot/felix.c b/drivers/net/dsa/ocelot/felix.c
index c69d9592a2b7..ccc0427faf02 100644
--- a/drivers/net/dsa/ocelot/felix.c
+++ b/drivers/net/dsa/ocelot/felix.c
@@ -19,6 +19,7 @@
 #include <linux/of_net.h>
 #include <linux/pci.h>
 #include <linux/of.h>
+#include <linux/pcs-lynx.h>
 #include <net/pkt_sched.h>
 #include <net/dsa.h>
 #include "felix.h"
@@ -196,27 +197,16 @@ static void felix_phylink_validate(struct dsa_switch *ds, int port,
 		felix->info->phylink_validate(ocelot, port, supported, state);
 }
 
-static int felix_phylink_mac_pcs_get_state(struct dsa_switch *ds, int port,
-					   struct phylink_link_state *state)
-{
-	struct ocelot *ocelot = ds->priv;
-	struct felix *felix = ocelot_to_felix(ocelot);
-
-	if (felix->info->pcs_link_state)
-		felix->info->pcs_link_state(ocelot, port, state);
-
-	return 0;
-}
-
 static void felix_phylink_mac_config(struct dsa_switch *ds, int port,
 				     unsigned int link_an_mode,
 				     const struct phylink_link_state *state)
 {
 	struct ocelot *ocelot = ds->priv;
 	struct felix *felix = ocelot_to_felix(ocelot);
+	struct dsa_port *dp = dsa_to_port(ds, port);
 
-	if (felix->info->pcs_config)
-		felix->info->pcs_config(ocelot, port, link_an_mode, state);
+	if (felix->pcs[port])
+		phylink_set_pcs(dp->pl, &felix->pcs[port]->pcs);
 }
 
 static void felix_phylink_mac_link_down(struct dsa_switch *ds, int port,
@@ -306,10 +296,6 @@ static void felix_phylink_mac_link_up(struct dsa_switch *ds, int port,
 	ocelot_fields_write(ocelot, port,
 			    QSYS_SWITCH_PORT_MODE_PORT_ENA, 1);
 
-	if (felix->info->pcs_link_up)
-		felix->info->pcs_link_up(ocelot, port, link_an_mode, interface,
-					 speed, duplex);
-
 	if (felix->info->port_sched_speed_set)
 		felix->info->port_sched_speed_set(ocelot, port, speed);
 }
@@ -626,11 +612,6 @@ static int felix_setup(struct dsa_switch *ds)
 
 	ds->mtu_enforcement_ingress = true;
 	ds->configure_vlan_while_not_filtering = true;
-	/* It looks like the MAC/PCS interrupt register - PM0_IEVENT (0x8040)
-	 * isn't instantiated for the Felix PF.
-	 * In-band AN may take a few ms to complete, so we need to poll.
-	 */
-	ds->pcs_poll = true;
 
 	return 0;
 }
@@ -786,7 +767,6 @@ const struct dsa_switch_ops felix_switch_ops = {
 	.get_sset_count		= felix_get_sset_count,
 	.get_ts_info		= felix_get_ts_info,
 	.phylink_validate	= felix_phylink_validate,
-	.phylink_mac_link_state	= felix_phylink_mac_pcs_get_state,
 	.phylink_mac_config	= felix_phylink_mac_config,
 	.phylink_mac_link_down	= felix_phylink_mac_link_down,
 	.phylink_mac_link_up	= felix_phylink_mac_link_up,
diff --git a/drivers/net/dsa/ocelot/felix.h b/drivers/net/dsa/ocelot/felix.h
index 98f14621ac23..9bceb994b7db 100644
--- a/drivers/net/dsa/ocelot/felix.h
+++ b/drivers/net/dsa/ocelot/felix.h
@@ -28,15 +28,6 @@ struct felix_info {
 	int				imdio_pci_bar;
 	int	(*mdio_bus_alloc)(struct ocelot *ocelot);
 	void	(*mdio_bus_free)(struct ocelot *ocelot);
-	void	(*pcs_config)(struct ocelot *ocelot, int port,
-			      unsigned int link_an_mode,
-			      const struct phylink_link_state *state);
-	void	(*pcs_link_up)(struct ocelot *ocelot, int port,
-			       unsigned int link_an_mode,
-			       phy_interface_t interface,
-			       int speed, int duplex);
-	void	(*pcs_link_state)(struct ocelot *ocelot, int port,
-				  struct phylink_link_state *state);
 	void	(*phylink_validate)(struct ocelot *ocelot, int port,
 				    unsigned long *supported,
 				    struct phylink_link_state *state);
@@ -59,20 +50,11 @@ struct felix {
 	const struct felix_info		*info;
 	struct ocelot			ocelot;
 	struct mii_bus			*imdio;
-	struct phy_device		**pcs;
+	struct lynx_pcs			**pcs;
 	resource_size_t			switch_base;
 	resource_size_t			imdio_base;
 };
 
-void vsc9959_pcs_link_state(struct ocelot *ocelot, int port,
-			    struct phylink_link_state *state);
-void vsc9959_pcs_config(struct ocelot *ocelot, int port,
-			unsigned int link_an_mode,
-			const struct phylink_link_state *state);
-void vsc9959_pcs_link_up(struct ocelot *ocelot, int port,
-			 unsigned int link_an_mode,
-			 phy_interface_t interface,
-			 int speed, int duplex);
 void vsc9959_mdio_bus_free(struct ocelot *ocelot);
 
 #endif
diff --git a/drivers/net/dsa/ocelot/felix_vsc9959.c b/drivers/net/dsa/ocelot/felix_vsc9959.c
index 9b720c8ddfc3..126a53a811f7 100644
--- a/drivers/net/dsa/ocelot/felix_vsc9959.c
+++ b/drivers/net/dsa/ocelot/felix_vsc9959.c
@@ -9,6 +9,7 @@
 #include <soc/mscc/ocelot_sys.h>
 #include <soc/mscc/ocelot.h>
 #include <linux/packing.h>
+#include <linux/pcs-lynx.h>
 #include <net/pkt_sched.h>
 #include <linux/iopoll.h>
 #include <linux/mdio.h>
@@ -766,347 +767,6 @@ static int vsc9959_reset(struct ocelot *ocelot)
 	return 0;
 }
 
-/* We enable SGMII AN only when the PHY has managed = "in-band-status" in the
- * device tree. If we are in MLO_AN_PHY mode, we program directly state->speed
- * into the PCS, which is retrieved out-of-band over MDIO. This also has the
- * benefit of working with SGMII fixed-links, like downstream switches, where
- * both link partners attempt to operate as AN slaves and therefore AN never
- * completes.  But it also has the disadvantage that some PHY chips don't pass
- * traffic if SGMII AN is enabled but not completed (acknowledged by us), so
- * setting MLO_AN_INBAND is actually required for those.
- */
-static void vsc9959_pcs_config_sgmii(struct phy_device *pcs,
-				     unsigned int link_an_mode,
-				     const struct phylink_link_state *state)
-{
-	int bmsr, bmcr;
-
-	/* Some PHYs like VSC8234 don't like it when AN restarts on
-	 * their system  side and they restart line side AN too, going
-	 * into an endless link up/down loop.  Don't restart PCS AN if
-	 * link is up already.
-	 * We do check that AN is enabled just in case this is the 1st
-	 * call, PCS detects a carrier but AN is disabled from power on
-	 * or by boot loader.
-	 */
-	bmcr = phy_read(pcs, MII_BMCR);
-	if (bmcr < 0)
-		return;
-
-	bmsr = phy_read(pcs, MII_BMSR);
-	if (bmsr < 0)
-		return;
-
-	if ((bmcr & BMCR_ANENABLE) && (bmsr & BMSR_LSTATUS))
-		return;
-
-	/* SGMII spec requires tx_config_Reg[15:0] to be exactly 0x4001
-	 * for the MAC PCS in order to acknowledge the AN.
-	 */
-	phy_write(pcs, MII_ADVERTISE, ADVERTISE_SGMII |
-				      ADVERTISE_LPACK);
-
-	phy_write(pcs, ENETC_PCS_IF_MODE,
-		  ENETC_PCS_IF_MODE_SGMII_EN |
-		  ENETC_PCS_IF_MODE_USE_SGMII_AN);
-
-	/* Adjust link timer for SGMII */
-	phy_write(pcs, ENETC_PCS_LINK_TIMER1,
-		  ENETC_PCS_LINK_TIMER1_VAL);
-	phy_write(pcs, ENETC_PCS_LINK_TIMER2,
-		  ENETC_PCS_LINK_TIMER2_VAL);
-
-	phy_set_bits(pcs, MII_BMCR, BMCR_ANENABLE);
-}
-
-static void vsc9959_pcs_config_usxgmii(struct phy_device *pcs,
-				       unsigned int link_an_mode,
-				       const struct phylink_link_state *state)
-{
-	/* Configure device ability for the USXGMII Replicator */
-	phy_write_mmd(pcs, MDIO_MMD_VEND2, MII_ADVERTISE,
-		      MDIO_USXGMII_2500FULL |
-		      MDIO_USXGMII_LINK |
-		      ADVERTISE_SGMII |
-		      ADVERTISE_LPACK);
-}
-
-void vsc9959_pcs_config(struct ocelot *ocelot, int port,
-			unsigned int link_an_mode,
-			const struct phylink_link_state *state)
-{
-	struct felix *felix = ocelot_to_felix(ocelot);
-	struct phy_device *pcs = felix->pcs[port];
-
-	if (!pcs)
-		return;
-
-	/* The PCS does not implement the BMSR register fully, so capability
-	 * detection via genphy_read_abilities does not work. Since we can get
-	 * the PHY config word from the LPA register though, there is still
-	 * value in using the generic phy_resolve_aneg_linkmode function. So
-	 * populate the supported and advertising link modes manually here.
-	 */
-	linkmode_set_bit_array(phy_basic_ports_array,
-			       ARRAY_SIZE(phy_basic_ports_array),
-			       pcs->supported);
-	linkmode_set_bit(ETHTOOL_LINK_MODE_10baseT_Half_BIT, pcs->supported);
-	linkmode_set_bit(ETHTOOL_LINK_MODE_10baseT_Full_BIT, pcs->supported);
-	linkmode_set_bit(ETHTOOL_LINK_MODE_100baseT_Half_BIT, pcs->supported);
-	linkmode_set_bit(ETHTOOL_LINK_MODE_100baseT_Full_BIT, pcs->supported);
-	linkmode_set_bit(ETHTOOL_LINK_MODE_1000baseT_Half_BIT, pcs->supported);
-	linkmode_set_bit(ETHTOOL_LINK_MODE_1000baseT_Full_BIT, pcs->supported);
-	if (pcs->interface == PHY_INTERFACE_MODE_2500BASEX ||
-	    pcs->interface == PHY_INTERFACE_MODE_USXGMII)
-		linkmode_set_bit(ETHTOOL_LINK_MODE_2500baseX_Full_BIT,
-				 pcs->supported);
-	if (pcs->interface != PHY_INTERFACE_MODE_2500BASEX)
-		linkmode_set_bit(ETHTOOL_LINK_MODE_Autoneg_BIT,
-				 pcs->supported);
-	phy_advertise_supported(pcs);
-
-	if (!phylink_autoneg_inband(link_an_mode))
-		return;
-
-	switch (pcs->interface) {
-	case PHY_INTERFACE_MODE_SGMII:
-	case PHY_INTERFACE_MODE_QSGMII:
-		vsc9959_pcs_config_sgmii(pcs, link_an_mode, state);
-		break;
-	case PHY_INTERFACE_MODE_2500BASEX:
-		phydev_err(pcs, "AN not supported on 3.125GHz SerDes lane\n");
-		break;
-	case PHY_INTERFACE_MODE_USXGMII:
-		vsc9959_pcs_config_usxgmii(pcs, link_an_mode, state);
-		break;
-	default:
-		dev_err(ocelot->dev, "Unsupported link mode %s\n",
-			phy_modes(pcs->interface));
-	}
-}
-
-static void vsc9959_pcs_link_up_sgmii(struct phy_device *pcs,
-				      unsigned int link_an_mode,
-				      int speed, int duplex)
-{
-	u16 if_mode = ENETC_PCS_IF_MODE_SGMII_EN;
-
-	switch (speed) {
-	case SPEED_1000:
-		if_mode |= ENETC_PCS_IF_MODE_SGMII_SPEED(ENETC_PCS_SPEED_1000);
-		break;
-	case SPEED_100:
-		if_mode |= ENETC_PCS_IF_MODE_SGMII_SPEED(ENETC_PCS_SPEED_100);
-		break;
-	case SPEED_10:
-		if_mode |= ENETC_PCS_IF_MODE_SGMII_SPEED(ENETC_PCS_SPEED_10);
-		break;
-	default:
-		phydev_err(pcs, "Invalid PCS speed %d\n", speed);
-		return;
-	}
-
-	if (duplex == DUPLEX_HALF)
-		if_mode |= ENETC_PCS_IF_MODE_DUPLEX_HALF;
-
-	phy_write(pcs, ENETC_PCS_IF_MODE, if_mode);
-	phy_clear_bits(pcs, MII_BMCR, BMCR_ANENABLE);
-}
-
-/* 2500Base-X is SerDes protocol 7 on Felix and 6 on ENETC. It is a SerDes lane
- * clocked at 3.125 GHz which encodes symbols with 8b/10b and does not have
- * auto-negotiation of any link parameters. Electrically it is compatible with
- * a single lane of XAUI.
- * The hardware reference manual wants to call this mode SGMII, but it isn't
- * really, since the fundamental features of SGMII:
- * - Downgrading the link speed by duplicating symbols
- * - Auto-negotiation
- * are not there.
- * The speed is configured at 1000 in the IF_MODE and BMCR MDIO registers
- * because the clock frequency is actually given by a PLL configured in the
- * Reset Configuration Word (RCW).
- * Since there is no difference between fixed speed SGMII w/o AN and 802.3z w/o
- * AN, we call this PHY interface type 2500Base-X. In case a PHY negotiates a
- * lower link speed on line side, the system-side interface remains fixed at
- * 2500 Mbps and we do rate adaptation through pause frames.
- */
-static void vsc9959_pcs_link_up_2500basex(struct phy_device *pcs,
-					  unsigned int link_an_mode,
-					  int speed, int duplex)
-{
-	u16 if_mode = ENETC_PCS_IF_MODE_SGMII_SPEED(ENETC_PCS_SPEED_2500) |
-		      ENETC_PCS_IF_MODE_SGMII_EN;
-
-	if (duplex == DUPLEX_HALF)
-		if_mode |= ENETC_PCS_IF_MODE_DUPLEX_HALF;
-
-	phy_write(pcs, ENETC_PCS_IF_MODE, if_mode);
-	phy_clear_bits(pcs, MII_BMCR, BMCR_ANENABLE);
-}
-
-void vsc9959_pcs_link_up(struct ocelot *ocelot, int port,
-			 unsigned int link_an_mode,
-			 phy_interface_t interface,
-			 int speed, int duplex)
-{
-	struct felix *felix = ocelot_to_felix(ocelot);
-	struct phy_device *pcs = felix->pcs[port];
-
-	if (!pcs)
-		return;
-
-	if (phylink_autoneg_inband(link_an_mode))
-		return;
-
-	switch (interface) {
-	case PHY_INTERFACE_MODE_SGMII:
-	case PHY_INTERFACE_MODE_QSGMII:
-		vsc9959_pcs_link_up_sgmii(pcs, link_an_mode, speed, duplex);
-		break;
-	case PHY_INTERFACE_MODE_2500BASEX:
-		vsc9959_pcs_link_up_2500basex(pcs, link_an_mode, speed,
-					      duplex);
-		break;
-	case PHY_INTERFACE_MODE_USXGMII:
-		phydev_err(pcs, "USXGMII only supports in-band AN for now\n");
-		break;
-	default:
-		dev_err(ocelot->dev, "Unsupported link mode %s\n",
-			phy_modes(pcs->interface));
-	}
-}
-
-static void vsc9959_pcs_link_state_resolve(struct phy_device *pcs,
-					   struct phylink_link_state *state)
-{
-	state->an_complete = pcs->autoneg_complete;
-	state->an_enabled = pcs->autoneg;
-	state->link = pcs->link;
-	state->duplex = pcs->duplex;
-	state->speed = pcs->speed;
-	/* SGMII AN does not negotiate flow control, but that's ok,
-	 * since phylink already knows that, and does:
-	 *	link_state.pause |= pl->phy_state.pause;
-	 */
-	state->pause = MLO_PAUSE_NONE;
-
-	phydev_dbg(pcs,
-		   "mode=%s/%s/%s adv=%*pb lpa=%*pb link=%u an_enabled=%u an_complete=%u\n",
-		   phy_modes(pcs->interface),
-		   phy_speed_to_str(pcs->speed),
-		   phy_duplex_to_str(pcs->duplex),
-		   __ETHTOOL_LINK_MODE_MASK_NBITS, pcs->advertising,
-		   __ETHTOOL_LINK_MODE_MASK_NBITS, pcs->lp_advertising,
-		   pcs->link, pcs->autoneg, pcs->autoneg_complete);
-}
-
-static void vsc9959_pcs_link_state_sgmii(struct phy_device *pcs,
-					 struct phylink_link_state *state)
-{
-	int err;
-
-	err = genphy_update_link(pcs);
-	if (err < 0)
-		return;
-
-	if (pcs->autoneg_complete) {
-		u16 lpa = phy_read(pcs, MII_LPA);
-
-		mii_lpa_to_linkmode_lpa_sgmii(pcs->lp_advertising, lpa);
-
-		phy_resolve_aneg_linkmode(pcs);
-	}
-}
-
-static void vsc9959_pcs_link_state_2500basex(struct phy_device *pcs,
-					     struct phylink_link_state *state)
-{
-	int err;
-
-	err = genphy_update_link(pcs);
-	if (err < 0)
-		return;
-
-	pcs->speed = SPEED_2500;
-	pcs->asym_pause = true;
-	pcs->pause = true;
-}
-
-static void vsc9959_pcs_link_state_usxgmii(struct phy_device *pcs,
-					   struct phylink_link_state *state)
-{
-	int status, lpa;
-
-	status = phy_read_mmd(pcs, MDIO_MMD_VEND2, MII_BMSR);
-	if (status < 0)
-		return;
-
-	pcs->autoneg = true;
-	pcs->autoneg_complete = !!(status & BMSR_ANEGCOMPLETE);
-	pcs->link = !!(status & BMSR_LSTATUS);
-
-	if (!pcs->link || !pcs->autoneg_complete)
-		return;
-
-	lpa = phy_read_mmd(pcs, MDIO_MMD_VEND2, MII_LPA);
-	if (lpa < 0)
-		return;
-
-	switch (lpa & MDIO_USXGMII_SPD_MASK) {
-	case MDIO_USXGMII_10:
-		pcs->speed = SPEED_10;
-		break;
-	case MDIO_USXGMII_100:
-		pcs->speed = SPEED_100;
-		break;
-	case MDIO_USXGMII_1000:
-		pcs->speed = SPEED_1000;
-		break;
-	case MDIO_USXGMII_2500:
-		pcs->speed = SPEED_2500;
-		break;
-	default:
-		break;
-	}
-
-	if (lpa & MDIO_USXGMII_FULL_DUPLEX)
-		pcs->duplex = DUPLEX_FULL;
-	else
-		pcs->duplex = DUPLEX_HALF;
-}
-
-void vsc9959_pcs_link_state(struct ocelot *ocelot, int port,
-			    struct phylink_link_state *state)
-{
-	struct felix *felix = ocelot_to_felix(ocelot);
-	struct phy_device *pcs = felix->pcs[port];
-
-	if (!pcs)
-		return;
-
-	pcs->speed = SPEED_UNKNOWN;
-	pcs->duplex = DUPLEX_UNKNOWN;
-	pcs->pause = 0;
-	pcs->asym_pause = 0;
-
-	switch (pcs->interface) {
-	case PHY_INTERFACE_MODE_SGMII:
-	case PHY_INTERFACE_MODE_QSGMII:
-		vsc9959_pcs_link_state_sgmii(pcs, state);
-		break;
-	case PHY_INTERFACE_MODE_2500BASEX:
-		vsc9959_pcs_link_state_2500basex(pcs, state);
-		break;
-	case PHY_INTERFACE_MODE_USXGMII:
-		vsc9959_pcs_link_state_usxgmii(pcs, state);
-		break;
-	default:
-		return;
-	}
-
-	vsc9959_pcs_link_state_resolve(pcs, state);
-}
-
 static void vsc9959_phylink_validate(struct ocelot *ocelot, int port,
 				     unsigned long *supported,
 				     struct phylink_link_state *state)
@@ -1195,7 +855,7 @@ static int vsc9959_mdio_bus_alloc(struct ocelot *ocelot)
 	int rc;
 
 	felix->pcs = devm_kcalloc(dev, felix->info->num_ports,
-				  sizeof(struct phy_device *),
+				  sizeof(struct lynx_pcs *),
 				  GFP_KERNEL);
 	if (!felix->pcs) {
 		dev_err(dev, "failed to allocate array for PCS PHYs\n");
@@ -1246,18 +906,26 @@ static int vsc9959_mdio_bus_alloc(struct ocelot *ocelot)
 
 	for (port = 0; port < felix->info->num_ports; port++) {
 		struct ocelot_port *ocelot_port = ocelot->ports[port];
-		struct phy_device *pcs;
-		bool is_c45 = false;
+		struct mdio_device *pcs;
+		struct lynx_pcs *lynx;
+
+		if (dsa_is_unused_port(felix->ds, port))
+			continue;
 
-		if (ocelot_port->phy_mode == PHY_INTERFACE_MODE_USXGMII)
-			is_c45 = true;
+		if (ocelot_port->phy_mode == PHY_INTERFACE_MODE_INTERNAL)
+			continue;
 
-		pcs = get_phy_device(felix->imdio, port, is_c45);
+		pcs = mdio_device_create(felix->imdio, port);
 		if (IS_ERR(pcs))
 			continue;
 
-		pcs->interface = ocelot_port->phy_mode;
-		felix->pcs[port] = pcs;
+		lynx = lynx_pcs_create(pcs);
+		if (!lynx) {
+			mdio_device_free(pcs);
+			continue;
+		}
+
+		felix->pcs[port] = lynx;
 
 		dev_info(dev, "Found PCS at internal MDIO address %d\n", port);
 	}
@@ -1271,12 +939,13 @@ void vsc9959_mdio_bus_free(struct ocelot *ocelot)
 	int port;
 
 	for (port = 0; port < ocelot->num_phys_ports; port++) {
-		struct phy_device *pcs = felix->pcs[port];
+		struct lynx_pcs *pcs = felix->pcs[port];
 
 		if (!pcs)
 			continue;
 
-		put_device(&pcs->mdio.dev);
+		mdio_device_free(pcs->mdio);
+		lynx_pcs_destroy(pcs);
 	}
 	mdiobus_unregister(felix->imdio);
 }
@@ -1499,9 +1168,6 @@ static const struct felix_info felix_info_vsc9959 = {
 	.imdio_pci_bar		= 0,
 	.mdio_bus_alloc		= vsc9959_mdio_bus_alloc,
 	.mdio_bus_free		= vsc9959_mdio_bus_free,
-	.pcs_config		= vsc9959_pcs_config,
-	.pcs_link_up		= vsc9959_pcs_link_up,
-	.pcs_link_state		= vsc9959_pcs_link_state,
 	.phylink_validate	= vsc9959_phylink_validate,
 	.prevalidate_phy_mode	= vsc9959_prevalidate_phy_mode,
 	.port_setup_tc          = vsc9959_port_setup_tc,
diff --git a/drivers/net/dsa/ocelot/seville_vsc9953.c b/drivers/net/dsa/ocelot/seville_vsc9953.c
index 625b1891d955..2d6a5f5758f8 100644
--- a/drivers/net/dsa/ocelot/seville_vsc9953.c
+++ b/drivers/net/dsa/ocelot/seville_vsc9953.c
@@ -7,6 +7,7 @@
 #include <soc/mscc/ocelot_sys.h>
 #include <soc/mscc/ocelot.h>
 #include <linux/of_platform.h>
+#include <linux/pcs-lynx.h>
 #include <linux/packing.h>
 #include <linux/iopoll.h>
 #include "felix.h"
@@ -960,18 +961,27 @@ static int vsc9953_mdio_bus_alloc(struct ocelot *ocelot)
 
 	for (port = 0; port < felix->info->num_ports; port++) {
 		struct ocelot_port *ocelot_port = ocelot->ports[port];
-		struct phy_device *pcs;
 		int addr = port + 4;
+		struct mdio_device *pcs;
+		struct lynx_pcs *lynx;
+
+		if (dsa_is_unused_port(felix->ds, port))
+			continue;
 
 		if (ocelot_port->phy_mode == PHY_INTERFACE_MODE_INTERNAL)
 			continue;
 
-		pcs = get_phy_device(felix->imdio, addr, false);
+		pcs = mdio_device_create(felix->imdio, addr);
 		if (IS_ERR(pcs))
 			continue;
 
-		pcs->interface = ocelot_port->phy_mode;
-		felix->pcs[port] = pcs;
+		lynx = lynx_pcs_create(pcs);
+		if (!lynx) {
+			mdio_device_free(pcs);
+			continue;
+		}
+
+		felix->pcs[port] = lynx;
 
 		dev_info(dev, "Found PCS at internal MDIO address %d\n", addr);
 	}
@@ -1013,9 +1023,6 @@ static const struct felix_info seville_info_vsc9953 = {
 	.num_ports		= 10,
 	.mdio_bus_alloc		= vsc9953_mdio_bus_alloc,
 	.mdio_bus_free		= vsc9959_mdio_bus_free,
-	.pcs_config		= vsc9959_pcs_config,
-	.pcs_link_up		= vsc9959_pcs_link_up,
-	.pcs_link_state		= vsc9959_pcs_link_state,
 	.phylink_validate	= vsc9953_phylink_validate,
 	.prevalidate_phy_mode	= vsc9953_prevalidate_phy_mode,
 	.xmit_template_populate	= vsc9953_xmit_template_populate,
diff --git a/drivers/net/pcs/Kconfig b/drivers/net/pcs/Kconfig
index 9d6e2be32060..074fb3f5db18 100644
--- a/drivers/net/pcs/Kconfig
+++ b/drivers/net/pcs/Kconfig
@@ -13,4 +13,10 @@ config PCS_XPCS
 	  This module provides helper functions for Synopsys DesignWare XPCS
 	  controllers.
 
+config PCS_LYNX
+	tristate
+	help
+	  This module provides helpers to phylink for managing the Lynx PCS
+	  which is part of the Layerscape and QorIQ Ethernet SERDES.
+
 endmenu
diff --git a/drivers/net/pcs/Makefile b/drivers/net/pcs/Makefile
index f0480afc7157..c23146755972 100644
--- a/drivers/net/pcs/Makefile
+++ b/drivers/net/pcs/Makefile
@@ -2,3 +2,4 @@
 # Makefile for Linux PCS drivers
 
 obj-$(CONFIG_PCS_XPCS)		+= pcs-xpcs.o
+obj-$(CONFIG_PCS_LYNX)		+= pcs-lynx.o
diff --git a/drivers/net/pcs/pcs-lynx.c b/drivers/net/pcs/pcs-lynx.c
new file mode 100644
index 000000000000..c43d97682083
--- /dev/null
+++ b/drivers/net/pcs/pcs-lynx.c
@@ -0,0 +1,312 @@
+// SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)
+/* Copyright 2020 NXP
+ * Lynx PCS MDIO helpers
+ */
+
+#include <linux/mdio.h>
+#include <linux/phylink.h>
+#include <linux/pcs-lynx.h>
+
+#define SGMII_CLOCK_PERIOD_NS		8 /* PCS is clocked at 125 MHz */
+#define LINK_TIMER_VAL(ns)		((u32)((ns) / SGMII_CLOCK_PERIOD_NS))
+
+#define SGMII_AN_LINK_TIMER_NS		1600000 /* defined by SGMII spec */
+
+#define LINK_TIMER_LO			0x12
+#define LINK_TIMER_HI			0x13
+#define IF_MODE				0x14
+#define IF_MODE_SGMII_EN		BIT(0)
+#define IF_MODE_USE_SGMII_AN		BIT(1)
+#define IF_MODE_SPEED(x)		(((x) << 2) & GENMASK(3, 2))
+#define IF_MODE_SPEED_MSK		GENMASK(3, 2)
+#define IF_MODE_HALF_DUPLEX		BIT(4)
+
+enum sgmii_speed {
+	SGMII_SPEED_10		= 0,
+	SGMII_SPEED_100		= 1,
+	SGMII_SPEED_1000	= 2,
+	SGMII_SPEED_2500	= 2,
+};
+
+#define phylink_pcs_to_lynx(pl_pcs) container_of((pl_pcs), struct lynx_pcs, pcs)
+
+static void lynx_pcs_get_state_usxgmii(struct mdio_device *pcs,
+				       struct phylink_link_state *state)
+{
+	struct mii_bus *bus = pcs->bus;
+	int addr = pcs->addr;
+	int status, lpa;
+
+	status = mdiobus_c45_read(bus, addr, MDIO_MMD_VEND2, MII_BMSR);
+	if (status < 0)
+		return;
+
+	state->link = !!(status & MDIO_STAT1_LSTATUS);
+	state->an_complete = !!(status & MDIO_AN_STAT1_COMPLETE);
+	if (!state->link || !state->an_complete)
+		return;
+
+	lpa = mdiobus_c45_read(bus, addr, MDIO_MMD_VEND2, MII_LPA);
+	if (lpa < 0)
+		return;
+
+	phylink_decode_usxgmii_word(state, lpa);
+}
+
+static void lynx_pcs_get_state_2500basex(struct mdio_device *pcs,
+					 struct phylink_link_state *state)
+{
+	struct mii_bus *bus = pcs->bus;
+	int addr = pcs->addr;
+	int bmsr, lpa;
+
+	bmsr = mdiobus_read(bus, addr, MII_BMSR);
+	lpa = mdiobus_read(bus, addr, MII_LPA);
+	if (bmsr < 0 || lpa < 0) {
+		state->link = false;
+		return;
+	}
+
+	state->link = !!(bmsr & BMSR_LSTATUS);
+	state->an_complete = !!(bmsr & BMSR_ANEGCOMPLETE);
+	if (!state->link)
+		return;
+
+	state->speed = SPEED_2500;
+	state->pause |= MLO_PAUSE_TX | MLO_PAUSE_RX;
+	state->duplex = DUPLEX_FULL;
+}
+
+static void lynx_pcs_get_state(struct phylink_pcs *pcs,
+			       struct phylink_link_state *state)
+{
+	struct lynx_pcs *lynx = phylink_pcs_to_lynx(pcs);
+
+	switch (state->interface) {
+	case PHY_INTERFACE_MODE_SGMII:
+	case PHY_INTERFACE_MODE_QSGMII:
+		phylink_mii_c22_pcs_get_state(lynx->mdio, state);
+		break;
+	case PHY_INTERFACE_MODE_2500BASEX:
+		lynx_pcs_get_state_2500basex(lynx->mdio, state);
+		break;
+	case PHY_INTERFACE_MODE_USXGMII:
+		lynx_pcs_get_state_usxgmii(lynx->mdio, state);
+		break;
+	default:
+		break;
+	}
+
+	dev_dbg(&lynx->mdio->dev,
+		"mode=%s/%s/%s link=%u an_enabled=%u an_complete=%u\n",
+		phy_modes(state->interface),
+		phy_speed_to_str(state->speed),
+		phy_duplex_to_str(state->duplex),
+		state->link, state->an_enabled, state->an_complete);
+}
+
+static int lynx_pcs_config_sgmii(struct mdio_device *pcs, unsigned int mode,
+				 const unsigned long *advertising)
+{
+	struct mii_bus *bus = pcs->bus;
+	int addr = pcs->addr;
+	u16 if_mode;
+	int err;
+
+	if_mode = IF_MODE_SGMII_EN;
+	if (mode == MLO_AN_INBAND) {
+		u32 link_timer;
+
+		if_mode |= IF_MODE_USE_SGMII_AN;
+
+		/* Adjust link timer for SGMII */
+		link_timer = LINK_TIMER_VAL(SGMII_AN_LINK_TIMER_NS);
+		mdiobus_write(bus, addr, LINK_TIMER_LO, link_timer & 0xffff);
+		mdiobus_write(bus, addr, LINK_TIMER_HI, link_timer >> 16);
+	}
+	err = mdiobus_modify(bus, addr, IF_MODE,
+			     IF_MODE_SGMII_EN | IF_MODE_USE_SGMII_AN,
+			     if_mode);
+	if (err)
+		return err;
+
+	return phylink_mii_c22_pcs_config(pcs, mode, PHY_INTERFACE_MODE_SGMII,
+					 advertising);
+}
+
+static int lynx_pcs_config_usxgmii(struct mdio_device *pcs, unsigned int mode,
+				   const unsigned long *advertising)
+{
+	struct mii_bus *bus = pcs->bus;
+	int addr = pcs->addr;
+
+	if (!phylink_autoneg_inband(mode)) {
+		dev_err(&pcs->dev, "USXGMII only supports in-band AN for now\n");
+		return -EOPNOTSUPP;
+	}
+
+	/* Configure device ability for the USXGMII Replicator */
+	return mdiobus_c45_write(bus, addr, MDIO_MMD_VEND2, MII_ADVERTISE,
+				 MDIO_USXGMII_10G | MDIO_USXGMII_LINK |
+				 MDIO_USXGMII_FULL_DUPLEX |
+				 ADVERTISE_SGMII | ADVERTISE_LPACK);
+}
+
+static int lynx_pcs_config(struct phylink_pcs *pcs, unsigned int mode,
+			   phy_interface_t ifmode,
+			   const unsigned long *advertising,
+			   bool permit)
+{
+	struct lynx_pcs *lynx = phylink_pcs_to_lynx(pcs);
+
+	switch (ifmode) {
+	case PHY_INTERFACE_MODE_SGMII:
+	case PHY_INTERFACE_MODE_QSGMII:
+		return lynx_pcs_config_sgmii(lynx->mdio, mode, advertising);
+	case PHY_INTERFACE_MODE_2500BASEX:
+		if (phylink_autoneg_inband(mode)) {
+			dev_err(&lynx->mdio->dev,
+				"AN not supported on 3.125GHz SerDes lane\n");
+			return -EOPNOTSUPP;
+		}
+		break;
+	case PHY_INTERFACE_MODE_USXGMII:
+		return lynx_pcs_config_usxgmii(lynx->mdio, mode, advertising);
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
+}
+
+static void lynx_pcs_link_up_sgmii(struct mdio_device *pcs, unsigned int mode,
+				   int speed, int duplex)
+{
+	struct mii_bus *bus = pcs->bus;
+	u16 if_mode = 0, sgmii_speed;
+	int addr = pcs->addr;
+
+	/* The PCS needs to be configured manually only
+	 * when not operating on in-band mode
+	 */
+	if (mode == MLO_AN_INBAND)
+		return;
+
+	if (duplex == DUPLEX_HALF)
+		if_mode |= IF_MODE_HALF_DUPLEX;
+
+	switch (speed) {
+	case SPEED_1000:
+		sgmii_speed = SGMII_SPEED_1000;
+		break;
+	case SPEED_100:
+		sgmii_speed = SGMII_SPEED_100;
+		break;
+	case SPEED_10:
+		sgmii_speed = SGMII_SPEED_10;
+		break;
+	case SPEED_UNKNOWN:
+		/* Silently don't do anything */
+		return;
+	default:
+		dev_err(&pcs->dev, "Invalid PCS speed %d\n", speed);
+		return;
+	}
+	if_mode |= IF_MODE_SPEED(sgmii_speed);
+
+	mdiobus_modify(bus, addr, IF_MODE,
+		       IF_MODE_HALF_DUPLEX | IF_MODE_SPEED_MSK,
+		       if_mode);
+}
+
+/* 2500Base-X is SerDes protocol 7 on Felix and 6 on ENETC. It is a SerDes lane
+ * clocked at 3.125 GHz which encodes symbols with 8b/10b and does not have
+ * auto-negotiation of any link parameters. Electrically it is compatible with
+ * a single lane of XAUI.
+ * The hardware reference manual wants to call this mode SGMII, but it isn't
+ * really, since the fundamental features of SGMII:
+ * - Downgrading the link speed by duplicating symbols
+ * - Auto-negotiation
+ * are not there.
+ * The speed is configured at 1000 in the IF_MODE because the clock frequency
+ * is actually given by a PLL configured in the Reset Configuration Word (RCW).
+ * Since there is no difference between fixed speed SGMII w/o AN and 802.3z w/o
+ * AN, we call this PHY interface type 2500Base-X. In case a PHY negotiates a
+ * lower link speed on line side, the system-side interface remains fixed at
+ * 2500 Mbps and we do rate adaptation through pause frames.
+ */
+static void lynx_pcs_link_up_2500basex(struct mdio_device *pcs,
+				       unsigned int mode,
+				       int speed, int duplex)
+{
+	struct mii_bus *bus = pcs->bus;
+	int addr = pcs->addr;
+	u16 if_mode = 0;
+
+	if (mode == MLO_AN_INBAND) {
+		dev_err(&pcs->dev, "AN not supported for 2500BaseX\n");
+		return;
+	}
+
+	if (duplex == DUPLEX_HALF)
+		if_mode |= IF_MODE_HALF_DUPLEX;
+	if_mode |= IF_MODE_SPEED(SGMII_SPEED_2500);
+
+	mdiobus_modify(bus, addr, IF_MODE,
+		       IF_MODE_HALF_DUPLEX | IF_MODE_SPEED_MSK,
+		       if_mode);
+}
+
+static void lynx_pcs_link_up(struct phylink_pcs *pcs, unsigned int mode,
+			     phy_interface_t interface,
+			     int speed, int duplex)
+{
+	struct lynx_pcs *lynx = phylink_pcs_to_lynx(pcs);
+
+	switch (interface) {
+	case PHY_INTERFACE_MODE_SGMII:
+	case PHY_INTERFACE_MODE_QSGMII:
+		lynx_pcs_link_up_sgmii(lynx->mdio, mode, speed, duplex);
+		break;
+	case PHY_INTERFACE_MODE_2500BASEX:
+		lynx_pcs_link_up_2500basex(lynx->mdio, mode, speed, duplex);
+		break;
+	case PHY_INTERFACE_MODE_USXGMII:
+		/* At the moment, only in-band AN is supported for USXGMII
+		 * so nothing to do in link_up
+		 */
+		break;
+	default:
+		break;
+	}
+}
+
+static const struct phylink_pcs_ops lynx_pcs_phylink_ops = {
+	.pcs_get_state = lynx_pcs_get_state,
+	.pcs_config = lynx_pcs_config,
+	.pcs_link_up = lynx_pcs_link_up,
+};
+
+struct lynx_pcs *lynx_pcs_create(struct mdio_device *mdio)
+{
+	struct lynx_pcs *lynx_pcs;
+
+	lynx_pcs = kzalloc(sizeof(*lynx_pcs), GFP_KERNEL);
+	if (!lynx_pcs)
+		return NULL;
+
+	lynx_pcs->mdio = mdio;
+	lynx_pcs->pcs.ops = &lynx_pcs_phylink_ops;
+	lynx_pcs->pcs.poll = true;
+
+	return lynx_pcs;
+}
+EXPORT_SYMBOL(lynx_pcs_create);
+
+void lynx_pcs_destroy(struct lynx_pcs *pcs)
+{
+	kfree(pcs);
+}
+EXPORT_SYMBOL(lynx_pcs_destroy);
+
+MODULE_LICENSE("Dual BSD/GPL");
diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
index 5e4cb12972eb..d0738302a958 100644
--- a/drivers/net/phy/phylink.c
+++ b/drivers/net/phy/phylink.c
@@ -2321,6 +2321,49 @@ static void phylink_decode_sgmii_word(struct phylink_link_state *state,
 }
 
 /**
+ * phylink_decode_usxgmii_word() - decode the USXGMII word from a MAC PCS
+ * @state: a pointer to a struct phylink_link_state.
+ * @lpa: a 16 bit value which stores the USXGMII auto-negotiation word
+ *
+ * Helper for MAC PCS supporting the USXGMII protocol and the auto-negotiation
+ * code word.  Decode the USXGMII code word and populate the corresponding fields
+ * (speed, duplex) into the phylink_link_state structure.
+ */
+void phylink_decode_usxgmii_word(struct phylink_link_state *state,
+				 uint16_t lpa)
+{
+	switch (lpa & MDIO_USXGMII_SPD_MASK) {
+	case MDIO_USXGMII_10:
+		state->speed = SPEED_10;
+		break;
+	case MDIO_USXGMII_100:
+		state->speed = SPEED_100;
+		break;
+	case MDIO_USXGMII_1000:
+		state->speed = SPEED_1000;
+		break;
+	case MDIO_USXGMII_2500:
+		state->speed = SPEED_2500;
+		break;
+	case MDIO_USXGMII_5000:
+		state->speed = SPEED_5000;
+		break;
+	case MDIO_USXGMII_10G:
+		state->speed = SPEED_10000;
+		break;
+	default:
+		state->link = false;
+		return;
+	}
+
+	if (lpa & MDIO_USXGMII_FULL_DUPLEX)
+		state->duplex = DUPLEX_FULL;
+	else
+		state->duplex = DUPLEX_HALF;
+}
+EXPORT_SYMBOL_GPL(phylink_decode_usxgmii_word);
+
+/**
  * phylink_mii_c22_pcs_get_state() - read the MAC PCS state
  * @pcs: a pointer to a &struct mdio_device.
  * @state: a pointer to a &struct phylink_link_state.
@@ -2363,6 +2406,7 @@ void phylink_mii_c22_pcs_get_state(struct mdio_device *pcs,
 		break;
 
 	case PHY_INTERFACE_MODE_SGMII:
+	case PHY_INTERFACE_MODE_QSGMII:
 		phylink_decode_sgmii_word(state, lpa);
 		break;
 
diff --git a/include/linux/mdio.h b/include/linux/mdio.h
index 898cbf00332a..3a88b699b758 100644
--- a/include/linux/mdio.h
+++ b/include/linux/mdio.h
@@ -358,6 +358,12 @@ static inline int mdiobus_c45_read(struct mii_bus *bus, int prtad, int devad,
 	return mdiobus_read(bus, prtad, mdiobus_c45_addr(devad, regnum));
 }
 
+static inline int mdiobus_c45_write(struct mii_bus *bus, int prtad, int devad,
+				    u16 regnum, u16 val)
+{
+	return mdiobus_write(bus, prtad, mdiobus_c45_addr(devad, regnum), val);
+}
+
 int mdiobus_register_device(struct mdio_device *mdiodev);
 int mdiobus_unregister_device(struct mdio_device *mdiodev);
 bool mdiobus_is_registered_device(struct mii_bus *bus, int addr);
diff --git a/include/linux/pcs-lynx.h b/include/linux/pcs-lynx.h
new file mode 100644
index 000000000000..a6440d6ebe95
--- /dev/null
+++ b/include/linux/pcs-lynx.h
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause) */
+/* Copyright 2020 NXP
+ * Lynx PCS helpers
+ */
+
+#ifndef __LINUX_PCS_LYNX_H
+#define __LINUX_PCS_LYNX_H
+
+#include <linux/mdio.h>
+#include <linux/phylink.h>
+
+struct lynx_pcs {
+	struct phylink_pcs pcs;
+	struct mdio_device *mdio;
+};
+
+struct lynx_pcs *lynx_pcs_create(struct mdio_device *mdio);
+
+void lynx_pcs_destroy(struct lynx_pcs *pcs);
+
+#endif /* __LINUX_PCS_LYNX_H */
diff --git a/include/linux/phylink.h b/include/linux/phylink.h
index c36fb41a7d90..d81a714cfbbd 100644
--- a/include/linux/phylink.h
+++ b/include/linux/phylink.h
@@ -490,4 +490,7 @@ void phylink_mii_c22_pcs_an_restart(struct mdio_device *pcs);
 
 void phylink_mii_c45_pcs_get_state(struct mdio_device *pcs,
 				   struct phylink_link_state *state);
+
+void phylink_decode_usxgmii_word(struct phylink_link_state *state,
+				 uint16_t lpa);
 #endif