// SPDX-License-Identifier: GPL-2.0+ /* Driver for Asix PHYs * * Author: Michael Schmitz <schmitzmic@gmail.com> */ #include <linux/kernel.h> #include <linux/errno.h> #include <linux/init.h> #include <linux/module.h> #include <linux/mii.h> #include <linux/phy.h> #define PHY_ID_ASIX_AX88772A 0x003b1861 #define PHY_ID_ASIX_AX88772C 0x003b1881 #define PHY_ID_ASIX_AX88796B 0x003b1841 MODULE_DESCRIPTION("Asix PHY driver"); MODULE_AUTHOR("Michael Schmitz <schmitzmic@gmail.com>"); MODULE_LICENSE("GPL"); /** * asix_soft_reset - software reset the PHY via BMCR_RESET bit * @phydev: target phy_device struct * * Description: Perform a software PHY reset using the standard * BMCR_RESET bit and poll for the reset bit to be cleared. * Toggle BMCR_RESET bit off to accommodate broken AX8796B PHY implementation * such as used on the Individual Computers' X-Surf 100 Zorro card. * * Returns: 0 on success, < 0 on failure */ static int asix_soft_reset(struct phy_device *phydev) { int ret; /* Asix PHY won't reset unless reset bit toggles */ ret = phy_write(phydev, MII_BMCR, 0); if (ret < 0) return ret; return genphy_soft_reset(phydev); } /* AX88772A is not working properly with some old switches (NETGEAR EN 108TP): * after autoneg is done and the link status is reported as active, the MII_LPA * register is 0. This issue is not reproducible on AX88772C. */ static int asix_ax88772a_read_status(struct phy_device *phydev) { int ret, val; ret = genphy_update_link(phydev); if (ret) return ret; if (!phydev->link) return 0; /* If MII_LPA is 0, phy_resolve_aneg_linkmode() will fail to resolve * linkmode so use MII_BMCR as default values. */ val = phy_read(phydev, MII_BMCR); if (val < 0) return val; if (val & BMCR_SPEED100) phydev->speed = SPEED_100; else phydev->speed = SPEED_10; if (val & BMCR_FULLDPLX) phydev->duplex = DUPLEX_FULL; else phydev->duplex = DUPLEX_HALF; ret = genphy_read_lpa(phydev); if (ret < 0) return ret; if (phydev->autoneg == AUTONEG_ENABLE && phydev->autoneg_complete) phy_resolve_aneg_linkmode(phydev); return 0; } static void asix_ax88772a_link_change_notify(struct phy_device *phydev) { /* Reset PHY, otherwise MII_LPA will provide outdated information. * This issue is reproducible only with some link partner PHYs */ if (phydev->state == PHY_NOLINK) { phy_init_hw(phydev); _phy_start_aneg(phydev); } } static struct phy_driver asix_driver[] = { { PHY_ID_MATCH_EXACT(PHY_ID_ASIX_AX88772A), .name = "Asix Electronics AX88772A", .flags = PHY_IS_INTERNAL, .read_status = asix_ax88772a_read_status, .suspend = genphy_suspend, .resume = genphy_resume, .soft_reset = asix_soft_reset, .link_change_notify = asix_ax88772a_link_change_notify, }, { PHY_ID_MATCH_EXACT(PHY_ID_ASIX_AX88772C), .name = "Asix Electronics AX88772C", .flags = PHY_IS_INTERNAL, .suspend = genphy_suspend, .resume = genphy_resume, .soft_reset = asix_soft_reset, }, { .phy_id = PHY_ID_ASIX_AX88796B, .name = "Asix Electronics AX88796B", .phy_id_mask = 0xfffffff0, /* PHY_BASIC_FEATURES */ .soft_reset = asix_soft_reset, } }; module_phy_driver(asix_driver); static struct mdio_device_id __maybe_unused asix_tbl[] = { { PHY_ID_MATCH_EXACT(PHY_ID_ASIX_AX88772A) }, { PHY_ID_MATCH_EXACT(PHY_ID_ASIX_AX88772C) }, { PHY_ID_ASIX_AX88796B, 0xfffffff0 }, { } }; MODULE_DEVICE_TABLE(mdio, asix_tbl);