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1// SPDX-License-Identifier: GPL-2.02/*3 * Allwinner EMAC MDIO interface driver4 *5 * Copyright 2012-2013 Stefan Roese <sr@denx.de>6 * Copyright 2013 Maxime Ripard <maxime.ripard@free-electrons.com>7 *8 * Based on the Linux driver provided by Allwinner:9 * Copyright (C) 1997 Sten Wang10 */11 12#include <linux/delay.h>13#include <linux/kernel.h>14#include <linux/module.h>15#include <linux/mutex.h>16#include <linux/of_address.h>17#include <linux/of_mdio.h>18#include <linux/phy.h>19#include <linux/platform_device.h>20#include <linux/regulator/consumer.h>21 22#define EMAC_MAC_MCMD_REG (0x00)23#define EMAC_MAC_MADR_REG (0x04)24#define EMAC_MAC_MWTD_REG (0x08)25#define EMAC_MAC_MRDD_REG (0x0c)26#define EMAC_MAC_MIND_REG (0x10)27#define EMAC_MAC_SSRR_REG (0x14)28 29#define MDIO_TIMEOUT (msecs_to_jiffies(100))30 31struct sun4i_mdio_data {32 void __iomem *membase;33 struct regulator *regulator;34};35 36static int sun4i_mdio_read(struct mii_bus *bus, int mii_id, int regnum)37{38 struct sun4i_mdio_data *data = bus->priv;39 unsigned long timeout_jiffies;40 int value;41 42 /* issue the phy address and reg */43 writel((mii_id << 8) | regnum, data->membase + EMAC_MAC_MADR_REG);44 /* pull up the phy io line */45 writel(0x1, data->membase + EMAC_MAC_MCMD_REG);46 47 /* Wait read complete */48 timeout_jiffies = jiffies + MDIO_TIMEOUT;49 while (readl(data->membase + EMAC_MAC_MIND_REG) & 0x1) {50 if (time_is_before_jiffies(timeout_jiffies))51 return -ETIMEDOUT;52 msleep(1);53 }54 55 /* push down the phy io line */56 writel(0x0, data->membase + EMAC_MAC_MCMD_REG);57 /* and read data */58 value = readl(data->membase + EMAC_MAC_MRDD_REG);59 60 return value;61}62 63static int sun4i_mdio_write(struct mii_bus *bus, int mii_id, int regnum,64 u16 value)65{66 struct sun4i_mdio_data *data = bus->priv;67 unsigned long timeout_jiffies;68 69 /* issue the phy address and reg */70 writel((mii_id << 8) | regnum, data->membase + EMAC_MAC_MADR_REG);71 /* pull up the phy io line */72 writel(0x1, data->membase + EMAC_MAC_MCMD_REG);73 74 /* Wait read complete */75 timeout_jiffies = jiffies + MDIO_TIMEOUT;76 while (readl(data->membase + EMAC_MAC_MIND_REG) & 0x1) {77 if (time_is_before_jiffies(timeout_jiffies))78 return -ETIMEDOUT;79 msleep(1);80 }81 82 /* push down the phy io line */83 writel(0x0, data->membase + EMAC_MAC_MCMD_REG);84 /* and write data */85 writel(value, data->membase + EMAC_MAC_MWTD_REG);86 87 return 0;88}89 90static int sun4i_mdio_probe(struct platform_device *pdev)91{92 struct device_node *np = pdev->dev.of_node;93 struct mii_bus *bus;94 struct sun4i_mdio_data *data;95 int ret;96 97 bus = mdiobus_alloc_size(sizeof(*data));98 if (!bus)99 return -ENOMEM;100 101 bus->name = "sun4i_mii_bus";102 bus->read = &sun4i_mdio_read;103 bus->write = &sun4i_mdio_write;104 snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mii", dev_name(&pdev->dev));105 bus->parent = &pdev->dev;106 107 data = bus->priv;108 data->membase = devm_platform_ioremap_resource(pdev, 0);109 if (IS_ERR(data->membase)) {110 ret = PTR_ERR(data->membase);111 goto err_out_free_mdiobus;112 }113 114 data->regulator = devm_regulator_get(&pdev->dev, "phy");115 if (IS_ERR(data->regulator)) {116 if (PTR_ERR(data->regulator) == -EPROBE_DEFER) {117 ret = -EPROBE_DEFER;118 goto err_out_free_mdiobus;119 }120 121 dev_info(&pdev->dev, "no regulator found\n");122 data->regulator = NULL;123 } else {124 ret = regulator_enable(data->regulator);125 if (ret)126 goto err_out_free_mdiobus;127 }128 129 ret = of_mdiobus_register(bus, np);130 if (ret < 0)131 goto err_out_disable_regulator;132 133 platform_set_drvdata(pdev, bus);134 135 return 0;136 137err_out_disable_regulator:138 if (data->regulator)139 regulator_disable(data->regulator);140err_out_free_mdiobus:141 mdiobus_free(bus);142 return ret;143}144 145static void sun4i_mdio_remove(struct platform_device *pdev)146{147 struct mii_bus *bus = platform_get_drvdata(pdev);148 struct sun4i_mdio_data *data = bus->priv;149 150 mdiobus_unregister(bus);151 if (data->regulator)152 regulator_disable(data->regulator);153 mdiobus_free(bus);154}155 156static const struct of_device_id sun4i_mdio_dt_ids[] = {157 { .compatible = "allwinner,sun4i-a10-mdio" },158 159 /* Deprecated */160 { .compatible = "allwinner,sun4i-mdio" },161 { }162};163MODULE_DEVICE_TABLE(of, sun4i_mdio_dt_ids);164 165static struct platform_driver sun4i_mdio_driver = {166 .probe = sun4i_mdio_probe,167 .remove_new = sun4i_mdio_remove,168 .driver = {169 .name = "sun4i-mdio",170 .of_match_table = sun4i_mdio_dt_ids,171 },172};173 174module_platform_driver(sun4i_mdio_driver);175 176MODULE_DESCRIPTION("Allwinner EMAC MDIO interface driver");177MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");178MODULE_LICENSE("GPL v2");179