1 /* Copyright (c) 2013-2016, The Linux Foundation. All rights reserved. 2 * 3 * This program is free software; you can redistribute it and/or modify 4 * it under the terms of the GNU General Public License version 2 and 5 * only version 2 as published by the Free Software Foundation. 6 * 7 * This program is distributed in the hope that it will be useful, 8 * but WITHOUT ANY WARRANTY; without even the implied warranty of 9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 10 * GNU General Public License for more details. 11 */ 12 13 /* Qualcomm Technologies, Inc. EMAC PHY Controller driver. 14 */ 15 16 #include <linux/of_mdio.h> 17 #include <linux/phy.h> 18 #include <linux/iopoll.h> 19 #include <linux/acpi.h> 20 #include "emac.h" 21 22 /* EMAC base register offsets */ 23 #define EMAC_MDIO_CTRL 0x001414 24 #define EMAC_PHY_STS 0x001418 25 #define EMAC_MDIO_EX_CTRL 0x001440 26 27 /* EMAC_MDIO_CTRL */ 28 #define MDIO_MODE BIT(30) 29 #define MDIO_PR BIT(29) 30 #define MDIO_AP_EN BIT(28) 31 #define MDIO_BUSY BIT(27) 32 #define MDIO_CLK_SEL_BMSK 0x7000000 33 #define MDIO_CLK_SEL_SHFT 24 34 #define MDIO_START BIT(23) 35 #define SUP_PREAMBLE BIT(22) 36 #define MDIO_RD_NWR BIT(21) 37 #define MDIO_REG_ADDR_BMSK 0x1f0000 38 #define MDIO_REG_ADDR_SHFT 16 39 #define MDIO_DATA_BMSK 0xffff 40 #define MDIO_DATA_SHFT 0 41 42 /* EMAC_PHY_STS */ 43 #define PHY_ADDR_BMSK 0x1f0000 44 #define PHY_ADDR_SHFT 16 45 46 #define MDIO_CLK_25_4 0 47 #define MDIO_CLK_25_28 7 48 49 #define MDIO_WAIT_TIMES 1000 50 #define MDIO_STATUS_DELAY_TIME 1 51 52 static int emac_mdio_read(struct mii_bus *bus, int addr, int regnum) 53 { 54 struct emac_adapter *adpt = bus->priv; 55 u32 reg; 56 57 emac_reg_update32(adpt->base + EMAC_PHY_STS, PHY_ADDR_BMSK, 58 (addr << PHY_ADDR_SHFT)); 59 60 reg = SUP_PREAMBLE | 61 ((MDIO_CLK_25_4 << MDIO_CLK_SEL_SHFT) & MDIO_CLK_SEL_BMSK) | 62 ((regnum << MDIO_REG_ADDR_SHFT) & MDIO_REG_ADDR_BMSK) | 63 MDIO_START | MDIO_RD_NWR; 64 65 writel(reg, adpt->base + EMAC_MDIO_CTRL); 66 67 if (readl_poll_timeout(adpt->base + EMAC_MDIO_CTRL, reg, 68 !(reg & (MDIO_START | MDIO_BUSY)), 69 MDIO_STATUS_DELAY_TIME, MDIO_WAIT_TIMES * 100)) 70 return -EIO; 71 72 return (reg >> MDIO_DATA_SHFT) & MDIO_DATA_BMSK; 73 } 74 75 static int emac_mdio_write(struct mii_bus *bus, int addr, int regnum, u16 val) 76 { 77 struct emac_adapter *adpt = bus->priv; 78 u32 reg; 79 80 emac_reg_update32(adpt->base + EMAC_PHY_STS, PHY_ADDR_BMSK, 81 (addr << PHY_ADDR_SHFT)); 82 83 reg = SUP_PREAMBLE | 84 ((MDIO_CLK_25_4 << MDIO_CLK_SEL_SHFT) & MDIO_CLK_SEL_BMSK) | 85 ((regnum << MDIO_REG_ADDR_SHFT) & MDIO_REG_ADDR_BMSK) | 86 ((val << MDIO_DATA_SHFT) & MDIO_DATA_BMSK) | 87 MDIO_START; 88 89 writel(reg, adpt->base + EMAC_MDIO_CTRL); 90 91 if (readl_poll_timeout(adpt->base + EMAC_MDIO_CTRL, reg, 92 !(reg & (MDIO_START | MDIO_BUSY)), 93 MDIO_STATUS_DELAY_TIME, MDIO_WAIT_TIMES * 100)) 94 return -EIO; 95 96 return 0; 97 } 98 99 /* Configure the MDIO bus and connect the external PHY */ 100 int emac_phy_config(struct platform_device *pdev, struct emac_adapter *adpt) 101 { 102 struct device_node *np = pdev->dev.of_node; 103 struct mii_bus *mii_bus; 104 int ret; 105 106 /* Create the mii_bus object for talking to the MDIO bus */ 107 adpt->mii_bus = mii_bus = devm_mdiobus_alloc(&pdev->dev); 108 if (!mii_bus) 109 return -ENOMEM; 110 111 mii_bus->name = "emac-mdio"; 112 snprintf(mii_bus->id, MII_BUS_ID_SIZE, "%s", pdev->name); 113 mii_bus->read = emac_mdio_read; 114 mii_bus->write = emac_mdio_write; 115 mii_bus->parent = &pdev->dev; 116 mii_bus->priv = adpt; 117 118 if (has_acpi_companion(&pdev->dev)) { 119 u32 phy_addr; 120 121 ret = mdiobus_register(mii_bus); 122 if (ret) { 123 dev_err(&pdev->dev, "could not register mdio bus\n"); 124 return ret; 125 } 126 ret = device_property_read_u32(&pdev->dev, "phy-channel", 127 &phy_addr); 128 if (ret) 129 /* If we can't read a valid phy address, then assume 130 * that there is only one phy on this mdio bus. 131 */ 132 adpt->phydev = phy_find_first(mii_bus); 133 else 134 adpt->phydev = mdiobus_get_phy(mii_bus, phy_addr); 135 136 /* of_phy_find_device() claims a reference to the phydev, 137 * so we do that here manually as well. When the driver 138 * later unloads, it can unilaterally drop the reference 139 * without worrying about ACPI vs DT. 140 */ 141 if (adpt->phydev) 142 get_device(&adpt->phydev->mdio.dev); 143 } else { 144 struct device_node *phy_np; 145 146 ret = of_mdiobus_register(mii_bus, np); 147 if (ret) { 148 dev_err(&pdev->dev, "could not register mdio bus\n"); 149 return ret; 150 } 151 152 phy_np = of_parse_phandle(np, "phy-handle", 0); 153 adpt->phydev = of_phy_find_device(phy_np); 154 of_node_put(phy_np); 155 } 156 157 if (!adpt->phydev) { 158 dev_err(&pdev->dev, "could not find external phy\n"); 159 mdiobus_unregister(mii_bus); 160 return -ENODEV; 161 } 162 163 return 0; 164 } 165