LXR linux/drivers/net/phy/mdio-sun4i.c

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Allwinner EMAC MDIO interface driver
   4 *
   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 Wang
  10 */
  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 int 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        return 0;
 156}
 157
 158static const struct of_device_id sun4i_mdio_dt_ids[] = {
 159        { .compatible = "allwinner,sun4i-a10-mdio" },
 160
 161        /* Deprecated */
 162        { .compatible = "allwinner,sun4i-mdio" },
 163        { }
 164};
 165MODULE_DEVICE_TABLE(of, sun4i_mdio_dt_ids);
 166
 167static struct platform_driver sun4i_mdio_driver = {
 168        .probe = sun4i_mdio_probe,
 169        .remove = sun4i_mdio_remove,
 170        .driver = {
 171                .name = "sun4i-mdio",
 172                .of_match_table = sun4i_mdio_dt_ids,
 173        },
 174};
 175
 176module_platform_driver(sun4i_mdio_driver);
 177
 178MODULE_DESCRIPTION("Allwinner EMAC MDIO interface driver");
 179MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
 180MODULE_LICENSE("GPL v2");
 181