Merge branch 'net-phy-QUSGMII'

Maxime Chevallier says:

====================
net: Introduce QUSGMII phy mode

Re-sending, since the previous v4 was sent while net-next was closed.

This is a resend of the V4 of a previous series [1] initially aimed at
introducing inband extensions, with modes like QUSGMII. This mode allows
passing info in the ethernet preamble between the MAC and the PHY, such as
timestamps.

This series has now become a preliminary series, that simply introduces
the new interface mode, without support for inband extensions, that will
come later.

The reasonning is that work will need to be done in the networking
subsystem, but also in the generic phy driver subsystem to allow serdes
configuration for qusgmii.

This series add the mode, the relevant binding changes, adds support for
it in the lan966x driver, and also introduces a small helper to get the
number of links a given phy mode can carry (think 1 for SGMII and 4 for
QSGMII). This allows for better readability and will prove useful
when (if) we support PSGMII (5 links on 1 interface) and OUSGMII (8
links on one interface).

V4 contains no change but the collected Reviewed-by from Andrew.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/devicetree/bindings/net/ethernet-controller.yaml

@@ -67,6 +67,7 @@ properties:
       - gmii
       - sgmii
       - qsgmii
+      - qusgmii
       - tbi
       - rev-mii
       - rmii

Documentation/networking/phy.rst

@@ -308,6 +308,15 @@ Some of the interface modes are described below:
     rate of 125Mpbs using a 4B/5B encoding scheme, resulting in an underlying
     data rate of 100Mpbs.
 
+``PHY_INTERFACE_MODE_QUSGMII``
+    This defines the Cisco the Quad USGMII mode, which is the Quad variant of
+    the USGMII (Universal SGMII) link. It's very similar to QSGMII, but uses
+    a Packet Control Header (PCH) instead of the 7 bytes preamble to carry not
+    only the port id, but also so-called "extensions". The only documented
+    extension so-far in the specification is the inclusion of timestamps, for
+    PTP-enabled PHYs. This mode isn't compatible with QSGMII, but offers the
+    same capabilities in terms of link speed and negociation.
+
 Pause frames / flow control
 ===========================
 

drivers/net/ethernet/microchip/lan966x/lan966x_main.c

@@ -778,6 +778,8 @@ static int lan966x_probe_port(struct lan966x *lan966x, u32 p,
 		  port->phylink_config.supported_interfaces);
 	__set_bit(PHY_INTERFACE_MODE_QSGMII,
 		  port->phylink_config.supported_interfaces);
+	__set_bit(PHY_INTERFACE_MODE_QUSGMII,
+		  port->phylink_config.supported_interfaces);
 	__set_bit(PHY_INTERFACE_MODE_1000BASEX,
 		  port->phylink_config.supported_interfaces);
 	__set_bit(PHY_INTERFACE_MODE_2500BASEX,

drivers/net/ethernet/microchip/lan966x/lan966x_phylink.c

@@ -28,11 +28,12 @@ static int lan966x_phylink_mac_prepare(struct phylink_config *config,
 				       phy_interface_t iface)
 {
 	struct lan966x_port *port = netdev_priv(to_net_dev(config->dev));
+	phy_interface_t serdes_mode = iface;
 	int err;
 
 	if (port->serdes) {
 		err = phy_set_mode_ext(port->serdes, PHY_MODE_ETHERNET,
-				       iface);
+				       serdes_mode);
 		if (err) {
 			netdev_err(to_net_dev(config->dev),
 				   "Could not set mode of SerDes\n");

drivers/net/ethernet/microchip/lan966x/lan966x_port.c

@@ -168,7 +168,7 @@ static void lan966x_port_link_up(struct lan966x_port *port)
 	/* Also the GIGA_MODE_ENA(1) needs to be set regardless of the
 	 * port speed for QSGMII ports.
 	 */
-	if (config->portmode == PHY_INTERFACE_MODE_QSGMII)
+	if (phy_interface_num_ports(config->portmode) == 4)
 		mode = DEV_MAC_MODE_CFG_GIGA_MODE_ENA_SET(1);
 
 	lan_wr(config->duplex | mode,
@@ -331,10 +331,14 @@ int lan966x_port_pcs_set(struct lan966x_port *port,
 	struct lan966x *lan966x = port->lan966x;
 	bool inband_aneg = false;
 	bool outband;
+	bool full_preamble = false;
+
+	if (config->portmode == PHY_INTERFACE_MODE_QUSGMII)
+		full_preamble = true;
 
 	if (config->inband) {
 		if (config->portmode == PHY_INTERFACE_MODE_SGMII ||
-		    config->portmode == PHY_INTERFACE_MODE_QSGMII)
+		    phy_interface_num_ports(config->portmode) == 4)
 			inband_aneg = true; /* Cisco-SGMII in-band-aneg */
 		else if (config->portmode == PHY_INTERFACE_MODE_1000BASEX &&
 			 config->autoneg)
@@ -345,9 +349,15 @@ int lan966x_port_pcs_set(struct lan966x_port *port,
 		outband = true;
 	}
 
-	/* Disable or enable inband */
-	lan_rmw(DEV_PCS1G_MODE_CFG_SGMII_MODE_ENA_SET(outband),
-		DEV_PCS1G_MODE_CFG_SGMII_MODE_ENA,
+	/* Disable or enable inband.
+	 * For QUSGMII, we rely on the preamble to transmit data such as
+	 * timestamps, therefore force full preamble transmission, and prevent
+	 * premable shortening
+	 */
+	lan_rmw(DEV_PCS1G_MODE_CFG_SGMII_MODE_ENA_SET(outband) |
+		DEV_PCS1G_MODE_CFG_SAVE_PREAMBLE_ENA_SET(full_preamble),
+		DEV_PCS1G_MODE_CFG_SGMII_MODE_ENA |
+		DEV_PCS1G_MODE_CFG_SAVE_PREAMBLE_ENA,
 		lan966x, DEV_PCS1G_MODE_CFG(port->chip_port));
 
 	/* Enable PCS */
@@ -396,7 +406,7 @@ void lan966x_port_init(struct lan966x_port *port)
 	if (lan966x->fdma)
 		lan966x_fdma_netdev_init(lan966x, port->dev);
 
-	if (config->portmode != PHY_INTERFACE_MODE_QSGMII)
+	if (phy_interface_num_ports(config->portmode) != 4)
 		return;
 
 	lan_rmw(DEV_CLOCK_CFG_PCS_RX_RST_SET(0) |

drivers/net/ethernet/microchip/lan966x/lan966x_regs.h

@@ -504,6 +504,12 @@ enum lan966x_target {
 #define DEV_PCS1G_MODE_CFG_SGMII_MODE_ENA_GET(x)\
 	FIELD_GET(DEV_PCS1G_MODE_CFG_SGMII_MODE_ENA, x)
 
+#define DEV_PCS1G_MODE_CFG_SAVE_PREAMBLE_ENA        BIT(1)
+#define DEV_PCS1G_MODE_CFG_SAVE_PREAMBLE_ENA_SET(x)\
+	FIELD_PREP(DEV_PCS1G_MODE_CFG_SAVE_PREAMBLE_ENA, x)
+#define DEV_PCS1G_MODE_CFG_SAVE_PREAMBLE_ENA_GET(x)\
+	FIELD_GET(DEV_PCS1G_MODE_CFG_SAVE_PREAMBLE_ENA, x)
+
 /*      DEV:PCS1G_CFG_STATUS:PCS1G_SD_CFG */
 #define DEV_PCS1G_SD_CFG(t)       __REG(TARGET_DEV, t, 8, 72, 0, 1, 68, 8, 0, 1, 4)
 

drivers/net/phy/phy-core.c

@@ -74,6 +74,58 @@ const char *phy_duplex_to_str(unsigned int duplex)
 }
 EXPORT_SYMBOL_GPL(phy_duplex_to_str);
 
+/**
+ * phy_interface_num_ports - Return the number of links that can be carried by
+ *			     a given MAC-PHY physical link. Returns 0 if this is
+ *			     unknown, the number of links else.
+ *
+ * @interface: The interface mode we want to get the number of ports
+ */
+int phy_interface_num_ports(phy_interface_t interface)
+{
+	switch (interface) {
+	case PHY_INTERFACE_MODE_NA:
+		return 0;
+	case PHY_INTERFACE_MODE_INTERNAL:
+	case PHY_INTERFACE_MODE_MII:
+	case PHY_INTERFACE_MODE_GMII:
+	case PHY_INTERFACE_MODE_TBI:
+	case PHY_INTERFACE_MODE_REVMII:
+	case PHY_INTERFACE_MODE_RMII:
+	case PHY_INTERFACE_MODE_REVRMII:
+	case PHY_INTERFACE_MODE_RGMII:
+	case PHY_INTERFACE_MODE_RGMII_ID:
+	case PHY_INTERFACE_MODE_RGMII_RXID:
+	case PHY_INTERFACE_MODE_RGMII_TXID:
+	case PHY_INTERFACE_MODE_RTBI:
+	case PHY_INTERFACE_MODE_XGMII:
+	case PHY_INTERFACE_MODE_XLGMII:
+	case PHY_INTERFACE_MODE_MOCA:
+	case PHY_INTERFACE_MODE_TRGMII:
+	case PHY_INTERFACE_MODE_USXGMII:
+	case PHY_INTERFACE_MODE_SGMII:
+	case PHY_INTERFACE_MODE_SMII:
+	case PHY_INTERFACE_MODE_1000BASEX:
+	case PHY_INTERFACE_MODE_2500BASEX:
+	case PHY_INTERFACE_MODE_5GBASER:
+	case PHY_INTERFACE_MODE_10GBASER:
+	case PHY_INTERFACE_MODE_25GBASER:
+	case PHY_INTERFACE_MODE_10GKR:
+	case PHY_INTERFACE_MODE_100BASEX:
+	case PHY_INTERFACE_MODE_RXAUI:
+	case PHY_INTERFACE_MODE_XAUI:
+		return 1;
+	case PHY_INTERFACE_MODE_QSGMII:
+	case PHY_INTERFACE_MODE_QUSGMII:
+		return 4;
+	case PHY_INTERFACE_MODE_MAX:
+		WARN_ONCE(1, "PHY_INTERFACE_MODE_MAX isn't a valid interface mode");
+		return 0;
+	}
+	return 0;
+}
+EXPORT_SYMBOL_GPL(phy_interface_num_ports);
+
 /* A mapping of all SUPPORTED settings to speed/duplex.  This table
  * must be grouped by speed and sorted in descending match priority
  * - iow, descending speed.

drivers/net/phy/phylink.c

@@ -321,6 +321,7 @@ void phylink_get_linkmodes(unsigned long *linkmodes, phy_interface_t interface,
 	case PHY_INTERFACE_MODE_RGMII_ID:
 	case PHY_INTERFACE_MODE_RGMII:
 	case PHY_INTERFACE_MODE_QSGMII:
+	case PHY_INTERFACE_MODE_QUSGMII:
 	case PHY_INTERFACE_MODE_SGMII:
 	case PHY_INTERFACE_MODE_GMII:
 		caps |= MAC_1000HD | MAC_1000FD;
@@ -632,6 +633,7 @@ static int phylink_parse_mode(struct phylink *pl, struct fwnode_handle *fwnode)
 		switch (pl->link_config.interface) {
 		case PHY_INTERFACE_MODE_SGMII:
 		case PHY_INTERFACE_MODE_QSGMII:
+		case PHY_INTERFACE_MODE_QUSGMII:
 			phylink_set(pl->supported, 10baseT_Half);
 			phylink_set(pl->supported, 10baseT_Full);
 			phylink_set(pl->supported, 100baseT_Half);
@@ -2929,6 +2931,7 @@ void phylink_mii_c22_pcs_decode_state(struct phylink_link_state *state,
 
 	case PHY_INTERFACE_MODE_SGMII:
 	case PHY_INTERFACE_MODE_QSGMII:
+	case PHY_INTERFACE_MODE_QUSGMII:
 		phylink_decode_sgmii_word(state, lpa);
 		break;
 

include/linux/phy.h

@@ -115,6 +115,7 @@ extern const int phy_10gbit_features_array[1];
  * @PHY_INTERFACE_MODE_25GBASER: 25G BaseR
  * @PHY_INTERFACE_MODE_USXGMII:  Universal Serial 10GE MII
  * @PHY_INTERFACE_MODE_10GKR: 10GBASE-KR - with Clause 73 AN
+ * @PHY_INTERFACE_MODE_QUSGMII: Quad Universal SGMII
  * @PHY_INTERFACE_MODE_MAX: Book keeping
  *
  * Describes the interface between the MAC and PHY.
@@ -152,6 +153,7 @@ typedef enum {
 	PHY_INTERFACE_MODE_USXGMII,
 	/* 10GBASE-KR - with Clause 73 AN */
 	PHY_INTERFACE_MODE_10GKR,
+	PHY_INTERFACE_MODE_QUSGMII,
 	PHY_INTERFACE_MODE_MAX,
 } phy_interface_t;
 
@@ -267,6 +269,8 @@ static inline const char *phy_modes(phy_interface_t interface)
 		return "10gbase-kr";
 	case PHY_INTERFACE_MODE_100BASEX:
 		return "100base-x";
+	case PHY_INTERFACE_MODE_QUSGMII:
+		return "qusgmii";
 	default:
 		return "unknown";
 	}
@@ -964,6 +968,8 @@ struct phy_fixup {
 const char *phy_speed_to_str(int speed);
 const char *phy_duplex_to_str(unsigned int duplex);
 
+int phy_interface_num_ports(phy_interface_t interface);
+
 /* A structure for mapping a particular speed and duplex
  * combination to a particular SUPPORTED and ADVERTISED value
  */