Merge branch 'net-pcs-stmmac=add-C37-AN-SGMII-support'

Ong Boon Leong says:

====================
net: pcs, stmmac: add C37 AN SGMII support

This patch series adds MAC-side SGMII support to stmmac driver and it is
changed as follow:-

1/6: Refactor the current C73 implementation in pcs-xpcs to prepare for
     adding C37 AN later.
2/6: Add MAC-side SGMII C37 AN support to pcs-xpcs
3,4/6: make phylink_parse_mode() to work for non-DT platform so that
       we can use stmmac platform_data to set it.
5/6: Make stmmac_open() to only skip PHY init if C73 is used, otherwise
     C37 AN will need phydev to be connected to phylink.
6/6: Finally, add pcs-xpcs SGMII interface support to Intel mGbE
     controller.

The patch series have been tested on EHL CRB PCH TSN (eth2) controller
that has Marvell 88E1512 PHY attached over SGMII interface and the
iterative tests of speed change (AN) + ping test have been successful.

[63446.009295] intel-eth-pci 0000:00:1e.4 eth2: Link is Down
[63449.986365] intel-eth-pci 0000:00:1e.4 eth2: Link is Up - 1Gbps/Full - flow control off
[63449.987625] IPv6: ADDRCONF(NETDEV_CHANGE): eth2: link becomes ready
[63451.248064] intel-eth-pci 0000:00:1e.4 eth2: Link is Down
[63454.082366] intel-eth-pci 0000:00:1e.4 eth2: Link is Up - 100Mbps/Full - flow control off
[63454.083650] IPv6: ADDRCONF(NETDEV_CHANGE): eth2: link becomes ready
[63456.465179] intel-eth-pci 0000:00:1e.4 eth2: Link is Down
[63459.202367] intel-eth-pci 0000:00:1e.4 eth2: Link is Up - 10Mbps/Full - flow control off
[63459.203639] IPv6: ADDRCONF(NETDEV_CHANGE): eth2: link becomes ready
[63460.882832] intel-eth-pci 0000:00:1e.4 eth2: Link is Down
[63464.322366] intel-eth-pci 0000:00:1e.4 eth2: Link is Up - 1Gbps/Full - flow control off
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/stmicro/stmmac/dwmac-intel.c

@@ -9,6 +9,9 @@
 #include "dwmac4.h"
 #include "stmmac.h"
 
+#define INTEL_MGBE_ADHOC_ADDR	0x15
+#define INTEL_MGBE_XPCS_ADDR	0x16
+
 struct intel_priv_data {
 	int mdio_adhoc_addr;	/* mdio address for serdes & etc */
 };
@@ -333,6 +336,16 @@ static int intel_mgbe_common_data(struct pci_dev *pdev,
 	/* Use the last Rx queue */
 	plat->vlan_fail_q = plat->rx_queues_to_use - 1;
 
+	/* Intel mgbe SGMII interface uses pcs-xcps */
+	if (plat->phy_interface == PHY_INTERFACE_MODE_SGMII) {
+		plat->mdio_bus_data->has_xpcs = true;
+		plat->mdio_bus_data->xpcs_an_inband = true;
+	}
+
+	/* Ensure mdio bus scan skips intel serdes and pcs-xpcs */
+	plat->mdio_bus_data->phy_mask = 1 << INTEL_MGBE_ADHOC_ADDR;
+	plat->mdio_bus_data->phy_mask |= 1 << INTEL_MGBE_XPCS_ADDR;
+
 	return 0;
 }
 
@@ -664,7 +677,7 @@ static int intel_eth_pci_probe(struct pci_dev *pdev,
 	pci_set_master(pdev);
 
 	plat->bsp_priv = intel_priv;
-	intel_priv->mdio_adhoc_addr = 0x15;
+	intel_priv->mdio_adhoc_addr = INTEL_MGBE_ADHOC_ADDR;
 
 	ret = info->setup(pdev, plat);
 	if (ret)

drivers/net/ethernet/stmicro/stmmac/stmmac_main.c

@@ -1117,6 +1117,8 @@ static int stmmac_phy_setup(struct stmmac_priv *priv)
 	priv->phylink_config.dev = &priv->dev->dev;
 	priv->phylink_config.type = PHYLINK_NETDEV;
 	priv->phylink_config.pcs_poll = true;
+	priv->phylink_config.ovr_an_inband =
+		priv->plat->mdio_bus_data->xpcs_an_inband;
 
 	if (!fwnode)
 		fwnode = dev_fwnode(priv->device);
@@ -2896,7 +2898,7 @@ static int stmmac_open(struct net_device *dev)
 
 	if (priv->hw->pcs != STMMAC_PCS_TBI &&
 	    priv->hw->pcs != STMMAC_PCS_RTBI &&
-	    priv->hw->xpcs == NULL) {
+	    priv->hw->xpcs_args.an_mode != DW_AN_C73) {
 		ret = stmmac_init_phy(dev);
 		if (ret) {
 			netdev_err(priv->dev,

drivers/net/phy/phylink.c

@@ -271,8 +271,9 @@ static int phylink_parse_mode(struct phylink *pl, struct fwnode_handle *fwnode)
 		pl->cfg_link_an_mode = MLO_AN_FIXED;
 	fwnode_handle_put(dn);
 
-	if (fwnode_property_read_string(fwnode, "managed", &managed) == 0 &&
-	    strcmp(managed, "in-band-status") == 0) {
+	if ((fwnode_property_read_string(fwnode, "managed", &managed) == 0 &&
+	     strcmp(managed, "in-band-status") == 0) ||
+	    pl->config->ovr_an_inband) {
 		if (pl->cfg_link_an_mode == MLO_AN_FIXED) {
 			phylink_err(pl,
 				    "can't use both fixed-link and in-band-status\n");

include/linux/pcs/pcs-xpcs.h

@@ -10,10 +10,15 @@
 #include <linux/phy.h>
 #include <linux/phylink.h>
 
+/* AN mode */
+#define DW_AN_C73			1
+#define DW_AN_C37_SGMII			2
+
 struct mdio_xpcs_args {
 	__ETHTOOL_DECLARE_LINK_MODE_MASK(supported);
 	struct mii_bus *bus;
 	int addr;
+	int an_mode;
 };
 
 struct mdio_xpcs_ops {

include/linux/phylink.h

@@ -64,6 +64,7 @@ enum phylink_op_type {
  * @pcs_poll: MAC PCS cannot provide link change interrupt
  * @poll_fixed_state: if true, starts link_poll,
  *		      if MAC link is at %MLO_AN_FIXED mode.
+ * @ovr_an_inband: if true, override PCS to MLO_AN_INBAND
  * @get_fixed_state: callback to execute to determine the fixed link state,
  *		     if MAC link is at %MLO_AN_FIXED mode.
  */
@@ -72,6 +73,7 @@ struct phylink_config {
 	enum phylink_op_type type;
 	bool pcs_poll;
 	bool poll_fixed_state;
+	bool ovr_an_inband;
 	void (*get_fixed_state)(struct phylink_config *config,
 				struct phylink_link_state *state);
 };

include/linux/stmmac.h

@@ -81,6 +81,7 @@
 struct stmmac_mdio_bus_data {
 	unsigned int phy_mask;
 	unsigned int has_xpcs;
+	unsigned int xpcs_an_inband;
 	int *irqs;
 	int probed_phy_irq;
 	bool needs_reset;