--- /dev/null
+/*
+ * 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);