net: phy: add 802.3 clause 45 support to phylib

Add generic helpers for 802.3 clause 45 PHYs for >= 10Gbps support.
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/phy/Makefile

 # Makefile for Linux PHY drivers and MDIO bus drivers
 
-libphy-y			:= phy.o phy-core.o phy_device.o
+libphy-y			:= phy.o phy-c45.o phy-core.o phy_device.o
 mdio-bus-y			+= mdio_bus.o mdio_device.o
 
 ifdef CONFIG_MDIO_DEVICE

drivers/net/phy/phy-c45.c

+/*
+ * Clause 45 PHY support
+ */
+#include <linux/ethtool.h>
+#include <linux/export.h>
+#include <linux/mdio.h>
+#include <linux/mii.h>
+#include <linux/phy.h>
+
+/**
+ * genphy_c45_setup_forced - configures a forced speed
+ * @phydev: target phy_device struct
+ */
+int genphy_c45_pma_setup_forced(struct phy_device *phydev)
+{
+	int ctrl1, ctrl2, ret;
+
+	/* Half duplex is not supported */
+	if (phydev->duplex != DUPLEX_FULL)
+		return -EINVAL;
+
+	ctrl1 = phy_read_mmd(phydev, MDIO_MMD_PMAPMD, MDIO_CTRL1);
+	if (ctrl1 < 0)
+		return ctrl1;
+
+	ctrl2 = phy_read_mmd(phydev, MDIO_MMD_PMAPMD, MDIO_CTRL2);
+	if (ctrl2 < 0)
+		return ctrl2;
+
+	ctrl1 &= ~MDIO_CTRL1_SPEEDSEL;
+	/*
+	 * PMA/PMD type selection is 1.7.5:0 not 1.7.3:0.  See 45.2.1.6.1
+	 * in 802.3-2012 and 802.3-2015.
+	 */
+	ctrl2 &= ~(MDIO_PMA_CTRL2_TYPE | 0x30);
+
+	switch (phydev->speed) {
+	case SPEED_10:
+		ctrl2 |= MDIO_PMA_CTRL2_10BT;
+		break;
+	case SPEED_100:
+		ctrl1 |= MDIO_PMA_CTRL1_SPEED100;
+		ctrl2 |= MDIO_PMA_CTRL2_100BTX;
+		break;
+	case SPEED_1000:
+		ctrl1 |= MDIO_PMA_CTRL1_SPEED1000;
+		/* Assume 1000base-T */
+		ctrl2 |= MDIO_PMA_CTRL2_1000BT;
+		break;
+	case SPEED_10000:
+		ctrl1 |= MDIO_CTRL1_SPEED10G;
+		/* Assume 10Gbase-T */
+		ctrl2 |= MDIO_PMA_CTRL2_10GBT;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	ret = phy_write_mmd(phydev, MDIO_MMD_PMAPMD, MDIO_CTRL1, ctrl1);
+	if (ret < 0)
+		return ret;
+
+	return phy_write_mmd(phydev, MDIO_MMD_PMAPMD, MDIO_CTRL2, ctrl2);
+}
+EXPORT_SYMBOL_GPL(genphy_c45_pma_setup_forced);
+
+/**
+ * genphy_c45_an_disable_aneg - disable auto-negotiation
+ * @phydev: target phy_device struct
+ *
+ * Disable auto-negotiation in the Clause 45 PHY. The link parameters
+ * parameters are controlled through the PMA/PMD MMD registers.
+ *
+ * Returns zero on success, negative errno code on failure.
+ */
+int genphy_c45_an_disable_aneg(struct phy_device *phydev)
+{
+	int val;
+
+	val = phy_read_mmd(phydev, MDIO_MMD_AN, MDIO_CTRL1);
+	if (val < 0)
+		return val;
+
+	val &= ~(MDIO_AN_CTRL1_ENABLE | MDIO_AN_CTRL1_RESTART);
+
+	return phy_write_mmd(phydev, MDIO_MMD_AN, MDIO_CTRL1, val);
+}
+EXPORT_SYMBOL_GPL(genphy_c45_an_disable_aneg);
+
+/**
+ * genphy_c45_restart_aneg - Enable and restart auto-negotiation
+ * @phydev: target phy_device struct
+ *
+ * This assumes that the auto-negotiation MMD is present.
+ *
+ * Enable and restart auto-negotiation.
+ */
+int genphy_c45_restart_aneg(struct phy_device *phydev)
+{
+	int val;
+
+	val = phy_read_mmd(phydev, MDIO_MMD_AN, MDIO_CTRL1);
+	if (val < 0)
+		return val;
+
+	val |= MDIO_AN_CTRL1_ENABLE | MDIO_AN_CTRL1_RESTART;
+
+	return phy_write_mmd(phydev, MDIO_MMD_AN, MDIO_CTRL1, val);
+}
+EXPORT_SYMBOL_GPL(genphy_c45_restart_aneg);
+
+/**
+ * genphy_c45_aneg_done - return auto-negotiation complete status
+ * @phydev: target phy_device struct
+ *
+ * This assumes that the auto-negotiation MMD is present.
+ *
+ * Reads the status register from the auto-negotiation MMD, returning:
+ * - positive if auto-negotiation is complete
+ * - negative errno code on error
+ * - zero otherwise
+ */
+int genphy_c45_aneg_done(struct phy_device *phydev)
+{
+	int val = phy_read_mmd(phydev, MDIO_MMD_AN, MDIO_STAT1);
+
+	return val < 0 ? val : val & MDIO_AN_STAT1_COMPLETE ? 1 : 0;
+}
+EXPORT_SYMBOL_GPL(genphy_c45_aneg_done);
+
+/**
+ * genphy_c45_read_link - read the overall link status from the MMDs
+ * @phydev: target phy_device struct
+ * @mmd_mask: MMDs to read status from
+ *
+ * Read the link status from the specified MMDs, and if they all indicate
+ * that the link is up, return positive.  If an error is encountered,
+ * a negative errno will be returned, otherwise zero.
+ */
+int genphy_c45_read_link(struct phy_device *phydev, u32 mmd_mask)
+{
+	int val, devad;
+	bool link = true;
+
+	while (mmd_mask) {
+		devad = __ffs(mmd_mask);
+		mmd_mask &= ~BIT(devad);
+
+		/* The link state is latched low so that momentary link
+		 * drops can be detected.  Do not double-read the status
+		 * register if the link is down.
+		 */
+		val = phy_read_mmd(phydev, devad, MDIO_STAT1);
+		if (val < 0)
+			return val;
+
+		if (!(val & MDIO_STAT1_LSTATUS))
+			link = false;
+	}
+
+	return link;
+}
+EXPORT_SYMBOL_GPL(genphy_c45_read_link);
+
+/**
+ * genphy_c45_read_lpa - read the link partner advertisment and pause
+ * @phydev: target phy_device struct
+ *
+ * Read the Clause 45 defined base (7.19) and 10G (7.33) status registers,
+ * filling in the link partner advertisment, pause and asym_pause members
+ * in @phydev.  This assumes that the auto-negotiation MMD is present, and
+ * the backplane bit (7.48.0) is clear.  Clause 45 PHY drivers are expected
+ * to fill in the remainder of the link partner advert from vendor registers.
+ */
+int genphy_c45_read_lpa(struct phy_device *phydev)
+{
+	int val;
+
+	/* Read the link partner's base page advertisment */
+	val = phy_read_mmd(phydev, MDIO_MMD_AN, MDIO_AN_LPA);
+	if (val < 0)
+		return val;
+
+	phydev->lp_advertising = mii_lpa_to_ethtool_lpa_t(val);
+	phydev->pause = val & LPA_PAUSE_CAP ? 1 : 0;
+	phydev->asym_pause = val & LPA_PAUSE_ASYM ? 1 : 0;
+
+	/* Read the link partner's 10G advertisment */
+	val = phy_read_mmd(phydev, MDIO_MMD_AN, MDIO_AN_10GBT_STAT);
+	if (val < 0)
+		return val;
+
+	if (val & MDIO_AN_10GBT_STAT_LP10G)
+		phydev->lp_advertising |= ADVERTISED_10000baseT_Full;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(genphy_c45_read_lpa);
+
+/**
+ * genphy_c45_read_pma - read link speed etc from PMA
+ * @phydev: target phy_device struct
+ */
+int genphy_c45_read_pma(struct phy_device *phydev)
+{
+	int val;
+
+	val = phy_read_mmd(phydev, MDIO_MMD_PMAPMD, MDIO_CTRL1);
+	if (val < 0)
+		return val;
+
+	switch (val & MDIO_CTRL1_SPEEDSEL) {
+	case 0:
+		phydev->speed = SPEED_10;
+		break;
+	case MDIO_PMA_CTRL1_SPEED100:
+		phydev->speed = SPEED_100;
+		break;
+	case MDIO_PMA_CTRL1_SPEED1000:
+		phydev->speed = SPEED_1000;
+		break;
+	case MDIO_CTRL1_SPEED10G:
+		phydev->speed = SPEED_10000;
+		break;
+	default:
+		phydev->speed = SPEED_UNKNOWN;
+		break;
+	}
+
+	phydev->duplex = DUPLEX_FULL;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(genphy_c45_read_pma);

drivers/net/phy/phy_device.c

@@ -1508,27 +1508,19 @@ EXPORT_SYMBOL(genphy_read_status);
 
 static int gen10g_read_status(struct phy_device *phydev)
 {
-	int devad, reg;
 	u32 mmd_mask = phydev->c45_ids.devices_in_package;
-
-	phydev->link = 1;
+	int ret;
 
 	/* For now just lie and say it's 10G all the time */
 	phydev->speed = SPEED_10000;
 	phydev->duplex = DUPLEX_FULL;
 
-	for (devad = 0; mmd_mask; devad++, mmd_mask = mmd_mask >> 1) {
-		if (!(mmd_mask & 1))
-			continue;
+	/* Avoid reading the vendor MMDs */
+	mmd_mask &= ~(BIT(MDIO_MMD_VEND1) | BIT(MDIO_MMD_VEND2));
 
-		/* Read twice because link state is latched and a
-		 * read moves the current state into the register
-		 */
-		phy_read_mmd(phydev, devad, MDIO_STAT1);
-		reg = phy_read_mmd(phydev, devad, MDIO_STAT1);
-		if (reg < 0 || !(reg & MDIO_STAT1_LSTATUS))
-			phydev->link = 0;
-	}
+	ret = genphy_c45_read_link(phydev, mmd_mask);
+
+	phydev->link = ret > 0 ? 1 : 0;
 
 	return 0;
 }

include/linux/phy.h

@@ -827,6 +827,8 @@ static inline const char *phydev_name(const struct phy_device *phydev)
 void phy_attached_print(struct phy_device *phydev, const char *fmt, ...)
 	__printf(2, 3);
 void phy_attached_info(struct phy_device *phydev);
+
+/* Clause 22 PHY */
 int genphy_config_init(struct phy_device *phydev);
 int genphy_setup_forced(struct phy_device *phydev);
 int genphy_restart_aneg(struct phy_device *phydev);
@@ -841,6 +843,16 @@ static inline int genphy_no_soft_reset(struct phy_device *phydev)
 {
 	return 0;
 }
+
+/* Clause 45 PHY */
+int genphy_c45_restart_aneg(struct phy_device *phydev);
+int genphy_c45_aneg_done(struct phy_device *phydev);
+int genphy_c45_read_link(struct phy_device *phydev, u32 mmd_mask);
+int genphy_c45_read_lpa(struct phy_device *phydev);
+int genphy_c45_read_pma(struct phy_device *phydev);
+int genphy_c45_pma_setup_forced(struct phy_device *phydev);
+int genphy_c45_an_disable_aneg(struct phy_device *phydev);
+
 void phy_driver_unregister(struct phy_driver *drv);
 void phy_drivers_unregister(struct phy_driver *drv, int n);
 int phy_driver_register(struct phy_driver *new_driver, struct module *owner);