net: stmmac: Integrate it with DesignWare XPCS

Adds all the necessary logic so that stmmac can be used with Synopsys
DesignWare XPCS.

Signed-off-by: Jose Abreu <Jose.Abreu@synopsys.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/stmicro/stmmac/Kconfig

@@ -3,6 +3,7 @@ config STMMAC_ETH
 	tristate "STMicroelectronics Multi-Gigabit Ethernet driver"
 	depends on HAS_IOMEM && HAS_DMA
 	select MII
+	select MDIO_XPCS
 	select PAGE_POOL
 	select PHYLINK
 	select CRC32

drivers/net/ethernet/stmicro/stmmac/common.h

@@ -15,6 +15,7 @@
 #include <linux/netdevice.h>
 #include <linux/stmmac.h>
 #include <linux/phy.h>
+#include <linux/mdio-xpcs.h>
 #include <linux/module.h>
 #if IS_ENABLED(CONFIG_VLAN_8021Q)
 #define STMMAC_VLAN_TAG_USED
@@ -446,6 +447,8 @@ struct mac_device_info {
 	const struct stmmac_hwtimestamp *ptp;
 	const struct stmmac_tc_ops *tc;
 	const struct stmmac_mmc_ops *mmc;
+	const struct mdio_xpcs_ops *xpcs;
+	struct mdio_xpcs_args xpcs_args;
 	struct mii_regs mii;	/* MII register Addresses */
 	struct mac_link link;
 	void __iomem *pcsr;     /* vpointer to device CSRs */

drivers/net/ethernet/stmicro/stmmac/hwif.h

@@ -577,6 +577,18 @@ struct stmmac_mmc_ops {
 #define stmmac_mmc_read(__priv, __args...) \
 	stmmac_do_void_callback(__priv, mmc, read, __args)
 
+/* XPCS callbacks */
+#define stmmac_xpcs_validate(__priv, __args...) \
+	stmmac_do_callback(__priv, xpcs, validate, __args)
+#define stmmac_xpcs_config(__priv, __args...) \
+	stmmac_do_callback(__priv, xpcs, config, __args)
+#define stmmac_xpcs_get_state(__priv, __args...) \
+	stmmac_do_callback(__priv, xpcs, get_state, __args)
+#define stmmac_xpcs_link_up(__priv, __args...) \
+	stmmac_do_callback(__priv, xpcs, link_up, __args)
+#define stmmac_xpcs_probe(__priv, __args...) \
+	stmmac_do_callback(__priv, xpcs, probe, __args)
+
 struct stmmac_regs_off {
 	u32 ptp_off;
 	u32 mmc_off;

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

@@ -863,18 +863,26 @@ static void stmmac_validate(struct phylink_config *config,
 
 	linkmode_and(state->advertising, state->advertising, mac_supported);
 	linkmode_andnot(state->advertising, state->advertising, mask);
+
+	/* If PCS is supported, check which modes it supports. */
+	stmmac_xpcs_validate(priv, &priv->hw->xpcs_args, supported, state);
 }
 
 static void stmmac_mac_pcs_get_state(struct phylink_config *config,
 				     struct phylink_link_state *state)
 {
+	struct stmmac_priv *priv = netdev_priv(to_net_dev(config->dev));
+
 	state->link = 0;
+	stmmac_xpcs_get_state(priv, &priv->hw->xpcs_args, state);
 }
 
 static void stmmac_mac_config(struct phylink_config *config, unsigned int mode,
 			      const struct phylink_link_state *state)
 {
-	/* Nothing for now. */
+	struct stmmac_priv *priv = netdev_priv(to_net_dev(config->dev));
+
+	stmmac_xpcs_config(priv, &priv->hw->xpcs_args, state);
 }
 
 static void stmmac_mac_an_restart(struct phylink_config *config)
@@ -902,6 +910,8 @@ static void stmmac_mac_link_up(struct phylink_config *config,
 	struct stmmac_priv *priv = netdev_priv(to_net_dev(config->dev));
 	u32 ctrl;
 
+	stmmac_xpcs_link_up(priv, &priv->hw->xpcs_args, speed, interface);
+
 	ctrl = readl(priv->ioaddr + MAC_CTRL_REG);
 	ctrl &= ~priv->hw->link.speed_mask;
 
@@ -1042,6 +1052,7 @@ 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;
 
 	if (!fwnode)
 		fwnode = dev_fwnode(priv->device);
@@ -2689,7 +2700,8 @@ static int stmmac_open(struct net_device *dev)
 	int ret;
 
 	if (priv->hw->pcs != STMMAC_PCS_TBI &&
-	    priv->hw->pcs != STMMAC_PCS_RTBI) {
+	    priv->hw->pcs != STMMAC_PCS_RTBI &&
+	    priv->hw->xpcs == NULL) {
 		ret = stmmac_init_phy(dev);
 		if (ret) {
 			netdev_err(priv->dev,

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

@@ -382,6 +382,14 @@ int stmmac_mdio_register(struct net_device *ndev)
 		max_addr = PHY_MAX_ADDR;
 	}
 
+	if (mdio_bus_data->has_xpcs) {
+		priv->hw->xpcs = mdio_xpcs_get_ops();
+		if (!priv->hw->xpcs) {
+			err = -ENODEV;
+			goto bus_register_fail;
+		}
+	}
+
 	if (mdio_bus_data->needs_reset)
 		new_bus->reset = &stmmac_mdio_reset;
 
@@ -433,6 +441,25 @@ int stmmac_mdio_register(struct net_device *ndev)
 		found = 1;
 	}
 
+	/* Try to probe the XPCS by scanning all addresses. */
+	if (priv->hw->xpcs) {
+		struct mdio_xpcs_args *xpcs = &priv->hw->xpcs_args;
+		int ret, mode = priv->plat->phy_interface;
+		max_addr = PHY_MAX_ADDR;
+
+		xpcs->bus = new_bus;
+
+		for (addr = 0; addr < max_addr; addr++) {
+			xpcs->addr = addr;
+
+			ret = stmmac_xpcs_probe(priv, xpcs, mode);
+			if (!ret) {
+				found = 1;
+				break;
+			}
+		}
+	}
+
 	if (!found && !mdio_node) {
 		dev_warn(dev, "No PHY found\n");
 		mdiobus_unregister(new_bus);

include/linux/stmmac.h

@@ -80,6 +80,7 @@
 
 struct stmmac_mdio_bus_data {
 	unsigned int phy_mask;
+	unsigned int has_xpcs;
 	int *irqs;
 	int probed_phy_irq;
 	bool needs_reset;