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1// SPDX-License-Identifier: GPL-2.0-only2/* Copyright (c) 2013-2016, The Linux Foundation. All rights reserved.3 */4 5/* Qualcomm Technologies, Inc. EMAC PHY Controller driver.6 */7 8#include <linux/of_mdio.h>9#include <linux/phy.h>10#include <linux/iopoll.h>11#include <linux/acpi.h>12#include "emac.h"13 14/* EMAC base register offsets */15#define EMAC_MDIO_CTRL 0x00141416#define EMAC_PHY_STS 0x00141817#define EMAC_MDIO_EX_CTRL 0x00144018 19/* EMAC_MDIO_CTRL */20#define MDIO_MODE BIT(30)21#define MDIO_PR BIT(29)22#define MDIO_AP_EN BIT(28)23#define MDIO_BUSY BIT(27)24#define MDIO_CLK_SEL_BMSK 0x700000025#define MDIO_CLK_SEL_SHFT 2426#define MDIO_START BIT(23)27#define SUP_PREAMBLE BIT(22)28#define MDIO_RD_NWR BIT(21)29#define MDIO_REG_ADDR_BMSK 0x1f000030#define MDIO_REG_ADDR_SHFT 1631#define MDIO_DATA_BMSK 0xffff32#define MDIO_DATA_SHFT 033 34/* EMAC_PHY_STS */35#define PHY_ADDR_BMSK 0x1f000036#define PHY_ADDR_SHFT 1637 38#define MDIO_CLK_25_4 039#define MDIO_CLK_25_28 740 41#define MDIO_WAIT_TIMES 100042#define MDIO_STATUS_DELAY_TIME 143 44static int emac_mdio_read(struct mii_bus *bus, int addr, int regnum)45{46 struct emac_adapter *adpt = bus->priv;47 u32 reg;48 49 emac_reg_update32(adpt->base + EMAC_PHY_STS, PHY_ADDR_BMSK,50 (addr << PHY_ADDR_SHFT));51 52 reg = SUP_PREAMBLE |53 ((MDIO_CLK_25_4 << MDIO_CLK_SEL_SHFT) & MDIO_CLK_SEL_BMSK) |54 ((regnum << MDIO_REG_ADDR_SHFT) & MDIO_REG_ADDR_BMSK) |55 MDIO_START | MDIO_RD_NWR;56 57 writel(reg, adpt->base + EMAC_MDIO_CTRL);58 59 if (readl_poll_timeout(adpt->base + EMAC_MDIO_CTRL, reg,60 !(reg & (MDIO_START | MDIO_BUSY)),61 MDIO_STATUS_DELAY_TIME, MDIO_WAIT_TIMES * 100))62 return -EIO;63 64 return (reg >> MDIO_DATA_SHFT) & MDIO_DATA_BMSK;65}66 67static int emac_mdio_write(struct mii_bus *bus, int addr, int regnum, u16 val)68{69 struct emac_adapter *adpt = bus->priv;70 u32 reg;71 72 emac_reg_update32(adpt->base + EMAC_PHY_STS, PHY_ADDR_BMSK,73 (addr << PHY_ADDR_SHFT));74 75 reg = SUP_PREAMBLE |76 ((MDIO_CLK_25_4 << MDIO_CLK_SEL_SHFT) & MDIO_CLK_SEL_BMSK) |77 ((regnum << MDIO_REG_ADDR_SHFT) & MDIO_REG_ADDR_BMSK) |78 ((val << MDIO_DATA_SHFT) & MDIO_DATA_BMSK) |79 MDIO_START;80 81 writel(reg, adpt->base + EMAC_MDIO_CTRL);82 83 if (readl_poll_timeout(adpt->base + EMAC_MDIO_CTRL, reg,84 !(reg & (MDIO_START | MDIO_BUSY)),85 MDIO_STATUS_DELAY_TIME, MDIO_WAIT_TIMES * 100))86 return -EIO;87 88 return 0;89}90 91/* Configure the MDIO bus and connect the external PHY */92int emac_phy_config(struct platform_device *pdev, struct emac_adapter *adpt)93{94 struct device_node *np = pdev->dev.of_node;95 struct mii_bus *mii_bus;96 int ret;97 98 /* Create the mii_bus object for talking to the MDIO bus */99 adpt->mii_bus = mii_bus = devm_mdiobus_alloc(&pdev->dev);100 if (!mii_bus)101 return -ENOMEM;102 103 mii_bus->name = "emac-mdio";104 snprintf(mii_bus->id, MII_BUS_ID_SIZE, "%s", pdev->name);105 mii_bus->read = emac_mdio_read;106 mii_bus->write = emac_mdio_write;107 mii_bus->parent = &pdev->dev;108 mii_bus->priv = adpt;109 110 if (has_acpi_companion(&pdev->dev)) {111 u32 phy_addr;112 113 ret = mdiobus_register(mii_bus);114 if (ret) {115 dev_err(&pdev->dev, "could not register mdio bus\n");116 return ret;117 }118 ret = device_property_read_u32(&pdev->dev, "phy-channel",119 &phy_addr);120 if (ret)121 /* If we can't read a valid phy address, then assume122 * that there is only one phy on this mdio bus.123 */124 adpt->phydev = phy_find_first(mii_bus);125 else126 adpt->phydev = mdiobus_get_phy(mii_bus, phy_addr);127 128 /* of_phy_find_device() claims a reference to the phydev,129 * so we do that here manually as well. When the driver130 * later unloads, it can unilaterally drop the reference131 * without worrying about ACPI vs DT.132 */133 if (adpt->phydev)134 get_device(&adpt->phydev->mdio.dev);135 } else {136 struct device_node *phy_np;137 138 ret = of_mdiobus_register(mii_bus, np);139 if (ret) {140 dev_err(&pdev->dev, "could not register mdio bus\n");141 return ret;142 }143 144 phy_np = of_parse_phandle(np, "phy-handle", 0);145 adpt->phydev = of_phy_find_device(phy_np);146 of_node_put(phy_np);147 }148 149 if (!adpt->phydev) {150 dev_err(&pdev->dev, "could not find external phy\n");151 mdiobus_unregister(mii_bus);152 return -ENODEV;153 }154 155 return 0;156}157