1 // SPDX-License-Identifier: GPL-2.0+ 2 /* Driver for Asix PHYs 3 * 4 * Author: Michael Schmitz <schmitzmic@gmail.com> 5 */ 6 #include <linux/kernel.h> 7 #include <linux/errno.h> 8 #include <linux/init.h> 9 #include <linux/module.h> 10 #include <linux/mii.h> 11 #include <linux/phy.h> 12 13 #define PHY_ID_ASIX_AX88772A 0x003b1861 14 #define PHY_ID_ASIX_AX88772C 0x003b1881 15 #define PHY_ID_ASIX_AX88796B 0x003b1841 16 17 MODULE_DESCRIPTION("Asix PHY driver"); 18 MODULE_AUTHOR("Michael Schmitz <schmitzmic@gmail.com>"); 19 MODULE_LICENSE("GPL"); 20 21 /** 22 * asix_soft_reset - software reset the PHY via BMCR_RESET bit 23 * @phydev: target phy_device struct 24 * 25 * Description: Perform a software PHY reset using the standard 26 * BMCR_RESET bit and poll for the reset bit to be cleared. 27 * Toggle BMCR_RESET bit off to accommodate broken AX8796B PHY implementation 28 * such as used on the Individual Computers' X-Surf 100 Zorro card. 29 * 30 * Returns: 0 on success, < 0 on failure 31 */ 32 static int asix_soft_reset(struct phy_device *phydev) 33 { 34 int ret; 35 36 /* Asix PHY won't reset unless reset bit toggles */ 37 ret = phy_write(phydev, MII_BMCR, 0); 38 if (ret < 0) 39 return ret; 40 41 return genphy_soft_reset(phydev); 42 } 43 44 /* AX88772A is not working properly with some old switches (NETGEAR EN 108TP): 45 * after autoneg is done and the link status is reported as active, the MII_LPA 46 * register is 0. This issue is not reproducible on AX88772C. 47 */ 48 static int asix_ax88772a_read_status(struct phy_device *phydev) 49 { 50 int ret, val; 51 52 ret = genphy_update_link(phydev); 53 if (ret) 54 return ret; 55 56 if (!phydev->link) 57 return 0; 58 59 /* If MII_LPA is 0, phy_resolve_aneg_linkmode() will fail to resolve 60 * linkmode so use MII_BMCR as default values. 61 */ 62 val = phy_read(phydev, MII_BMCR); 63 if (val < 0) 64 return val; 65 66 if (val & BMCR_SPEED100) 67 phydev->speed = SPEED_100; 68 else 69 phydev->speed = SPEED_10; 70 71 if (val & BMCR_FULLDPLX) 72 phydev->duplex = DUPLEX_FULL; 73 else 74 phydev->duplex = DUPLEX_HALF; 75 76 ret = genphy_read_lpa(phydev); 77 if (ret < 0) 78 return ret; 79 80 if (phydev->autoneg == AUTONEG_ENABLE && phydev->autoneg_complete) 81 phy_resolve_aneg_linkmode(phydev); 82 83 return 0; 84 } 85 86 static void asix_ax88772a_link_change_notify(struct phy_device *phydev) 87 { 88 /* Reset PHY, otherwise MII_LPA will provide outdated information. 89 * This issue is reproducible only with some link partner PHYs 90 */ 91 if (phydev->state == PHY_NOLINK && phydev->drv->soft_reset) 92 phydev->drv->soft_reset(phydev); 93 } 94 95 static struct phy_driver asix_driver[] = { 96 { 97 PHY_ID_MATCH_EXACT(PHY_ID_ASIX_AX88772A), 98 .name = "Asix Electronics AX88772A", 99 .flags = PHY_IS_INTERNAL, 100 .read_status = asix_ax88772a_read_status, 101 .suspend = genphy_suspend, 102 .resume = genphy_resume, 103 .soft_reset = asix_soft_reset, 104 .link_change_notify = asix_ax88772a_link_change_notify, 105 }, { 106 PHY_ID_MATCH_EXACT(PHY_ID_ASIX_AX88772C), 107 .name = "Asix Electronics AX88772C", 108 .flags = PHY_IS_INTERNAL, 109 .suspend = genphy_suspend, 110 .resume = genphy_resume, 111 .soft_reset = asix_soft_reset, 112 }, { 113 .phy_id = PHY_ID_ASIX_AX88796B, 114 .name = "Asix Electronics AX88796B", 115 .phy_id_mask = 0xfffffff0, 116 /* PHY_BASIC_FEATURES */ 117 .soft_reset = asix_soft_reset, 118 } }; 119 120 module_phy_driver(asix_driver); 121 122 static struct mdio_device_id __maybe_unused asix_tbl[] = { 123 { PHY_ID_MATCH_EXACT(PHY_ID_ASIX_AX88772A) }, 124 { PHY_ID_MATCH_EXACT(PHY_ID_ASIX_AX88772C) }, 125 { PHY_ID_ASIX_AX88796B, 0xfffffff0 }, 126 { } 127 }; 128 129 MODULE_DEVICE_TABLE(mdio, asix_tbl); 130