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/module.h> 17 #include <linux/of.h> 18 #include <linux/of_net.h> 19 #include <linux/of_mdio.h> 20 #include <linux/phy.h> 21 #include <linux/iopoll.h> 22 #include <linux/acpi.h> 23 #include "emac.h" 24 #include "emac-mac.h" 25 26 /* EMAC base register offsets */ 27 #define EMAC_MDIO_CTRL 0x001414 28 #define EMAC_PHY_STS 0x001418 29 #define EMAC_MDIO_EX_CTRL 0x001440 30 31 /* EMAC_MDIO_CTRL */ 32 #define MDIO_MODE BIT(30) 33 #define MDIO_PR BIT(29) 34 #define MDIO_AP_EN BIT(28) 35 #define MDIO_BUSY BIT(27) 36 #define MDIO_CLK_SEL_BMSK 0x7000000 37 #define MDIO_CLK_SEL_SHFT 24 38 #define MDIO_START BIT(23) 39 #define SUP_PREAMBLE BIT(22) 40 #define MDIO_RD_NWR BIT(21) 41 #define MDIO_REG_ADDR_BMSK 0x1f0000 42 #define MDIO_REG_ADDR_SHFT 16 43 #define MDIO_DATA_BMSK 0xffff 44 #define MDIO_DATA_SHFT 0 45 46 /* EMAC_PHY_STS */ 47 #define PHY_ADDR_BMSK 0x1f0000 48 #define PHY_ADDR_SHFT 16 49 50 #define MDIO_CLK_25_4 0 51 #define MDIO_CLK_25_28 7 52 53 #define MDIO_WAIT_TIMES 1000 54 55 #define EMAC_LINK_SPEED_DEFAULT (\ 56 EMAC_LINK_SPEED_10_HALF |\ 57 EMAC_LINK_SPEED_10_FULL |\ 58 EMAC_LINK_SPEED_100_HALF |\ 59 EMAC_LINK_SPEED_100_FULL |\ 60 EMAC_LINK_SPEED_1GB_FULL) 61 62 /** 63 * emac_phy_mdio_autopoll_disable() - disable mdio autopoll 64 * @adpt: the emac adapter 65 * 66 * The autopoll feature takes over the MDIO bus. In order for 67 * the PHY driver to be able to talk to the PHY over the MDIO 68 * bus, we need to temporarily disable the autopoll feature. 69 */ 70 static int emac_phy_mdio_autopoll_disable(struct emac_adapter *adpt) 71 { 72 u32 val; 73 74 /* disable autopoll */ 75 emac_reg_update32(adpt->base + EMAC_MDIO_CTRL, MDIO_AP_EN, 0); 76 77 /* wait for any mdio polling to complete */ 78 if (!readl_poll_timeout(adpt->base + EMAC_MDIO_CTRL, val, 79 !(val & MDIO_BUSY), 100, MDIO_WAIT_TIMES * 100)) 80 return 0; 81 82 /* failed to disable; ensure it is enabled before returning */ 83 emac_reg_update32(adpt->base + EMAC_MDIO_CTRL, 0, MDIO_AP_EN); 84 85 return -EBUSY; 86 } 87 88 /** 89 * emac_phy_mdio_autopoll_disable() - disable mdio autopoll 90 * @adpt: the emac adapter 91 * 92 * The EMAC has the ability to poll the external PHY on the MDIO 93 * bus for link state changes. This eliminates the need for the 94 * driver to poll the phy. If if the link state does change, 95 * the EMAC issues an interrupt on behalf of the PHY. 96 */ 97 static void emac_phy_mdio_autopoll_enable(struct emac_adapter *adpt) 98 { 99 emac_reg_update32(adpt->base + EMAC_MDIO_CTRL, 0, MDIO_AP_EN); 100 } 101 102 static int emac_mdio_read(struct mii_bus *bus, int addr, int regnum) 103 { 104 struct emac_adapter *adpt = bus->priv; 105 u32 reg; 106 int ret; 107 108 ret = emac_phy_mdio_autopoll_disable(adpt); 109 if (ret) 110 return ret; 111 112 emac_reg_update32(adpt->base + EMAC_PHY_STS, PHY_ADDR_BMSK, 113 (addr << PHY_ADDR_SHFT)); 114 115 reg = SUP_PREAMBLE | 116 ((MDIO_CLK_25_4 << MDIO_CLK_SEL_SHFT) & MDIO_CLK_SEL_BMSK) | 117 ((regnum << MDIO_REG_ADDR_SHFT) & MDIO_REG_ADDR_BMSK) | 118 MDIO_START | MDIO_RD_NWR; 119 120 writel(reg, adpt->base + EMAC_MDIO_CTRL); 121 122 if (readl_poll_timeout(adpt->base + EMAC_MDIO_CTRL, reg, 123 !(reg & (MDIO_START | MDIO_BUSY)), 124 100, MDIO_WAIT_TIMES * 100)) 125 ret = -EIO; 126 else 127 ret = (reg >> MDIO_DATA_SHFT) & MDIO_DATA_BMSK; 128 129 emac_phy_mdio_autopoll_enable(adpt); 130 131 return ret; 132 } 133 134 static int emac_mdio_write(struct mii_bus *bus, int addr, int regnum, u16 val) 135 { 136 struct emac_adapter *adpt = bus->priv; 137 u32 reg; 138 int ret; 139 140 ret = emac_phy_mdio_autopoll_disable(adpt); 141 if (ret) 142 return ret; 143 144 emac_reg_update32(adpt->base + EMAC_PHY_STS, PHY_ADDR_BMSK, 145 (addr << PHY_ADDR_SHFT)); 146 147 reg = SUP_PREAMBLE | 148 ((MDIO_CLK_25_4 << MDIO_CLK_SEL_SHFT) & MDIO_CLK_SEL_BMSK) | 149 ((regnum << MDIO_REG_ADDR_SHFT) & MDIO_REG_ADDR_BMSK) | 150 ((val << MDIO_DATA_SHFT) & MDIO_DATA_BMSK) | 151 MDIO_START; 152 153 writel(reg, adpt->base + EMAC_MDIO_CTRL); 154 155 if (readl_poll_timeout(adpt->base + EMAC_MDIO_CTRL, reg, 156 !(reg & (MDIO_START | MDIO_BUSY)), 100, 157 MDIO_WAIT_TIMES * 100)) 158 ret = -EIO; 159 160 emac_phy_mdio_autopoll_enable(adpt); 161 162 return ret; 163 } 164 165 /* Configure the MDIO bus and connect the external PHY */ 166 int emac_phy_config(struct platform_device *pdev, struct emac_adapter *adpt) 167 { 168 struct device_node *np = pdev->dev.of_node; 169 struct mii_bus *mii_bus; 170 int ret; 171 172 /* Create the mii_bus object for talking to the MDIO bus */ 173 adpt->mii_bus = mii_bus = devm_mdiobus_alloc(&pdev->dev); 174 if (!mii_bus) 175 return -ENOMEM; 176 177 mii_bus->name = "emac-mdio"; 178 snprintf(mii_bus->id, MII_BUS_ID_SIZE, "%s", pdev->name); 179 mii_bus->read = emac_mdio_read; 180 mii_bus->write = emac_mdio_write; 181 mii_bus->parent = &pdev->dev; 182 mii_bus->priv = adpt; 183 184 if (has_acpi_companion(&pdev->dev)) { 185 u32 phy_addr; 186 187 ret = mdiobus_register(mii_bus); 188 if (ret) { 189 dev_err(&pdev->dev, "could not register mdio bus\n"); 190 return ret; 191 } 192 ret = device_property_read_u32(&pdev->dev, "phy-channel", 193 &phy_addr); 194 if (ret) 195 /* If we can't read a valid phy address, then assume 196 * that there is only one phy on this mdio bus. 197 */ 198 adpt->phydev = phy_find_first(mii_bus); 199 else 200 adpt->phydev = mdiobus_get_phy(mii_bus, phy_addr); 201 202 /* of_phy_find_device() claims a reference to the phydev, 203 * so we do that here manually as well. When the driver 204 * later unloads, it can unilaterally drop the reference 205 * without worrying about ACPI vs DT. 206 */ 207 if (adpt->phydev) 208 get_device(&adpt->phydev->mdio.dev); 209 } else { 210 struct device_node *phy_np; 211 212 ret = of_mdiobus_register(mii_bus, np); 213 if (ret) { 214 dev_err(&pdev->dev, "could not register mdio bus\n"); 215 return ret; 216 } 217 218 phy_np = of_parse_phandle(np, "phy-handle", 0); 219 adpt->phydev = of_phy_find_device(phy_np); 220 of_node_put(phy_np); 221 } 222 223 if (!adpt->phydev) { 224 dev_err(&pdev->dev, "could not find external phy\n"); 225 mdiobus_unregister(mii_bus); 226 return -ENODEV; 227 } 228 229 return 0; 230 } 231