linux/drivers/net/mdio/mdio-hisi-femac.c
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   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * Hisilicon Fast Ethernet MDIO Bus Driver
   4 *
   5 * Copyright (c) 2016 HiSilicon Technologies Co., Ltd.
   6 */
   7
   8#include <linux/clk.h>
   9#include <linux/iopoll.h>
  10#include <linux/kernel.h>
  11#include <linux/module.h>
  12#include <linux/of_address.h>
  13#include <linux/of_mdio.h>
  14#include <linux/platform_device.h>
  15
  16#define MDIO_RWCTRL             0x00
  17#define MDIO_RO_DATA            0x04
  18#define MDIO_WRITE              BIT(13)
  19#define MDIO_RW_FINISH          BIT(15)
  20#define BIT_PHY_ADDR_OFFSET     8
  21#define BIT_WR_DATA_OFFSET      16
  22
  23struct hisi_femac_mdio_data {
  24        struct clk *clk;
  25        void __iomem *membase;
  26};
  27
  28static int hisi_femac_mdio_wait_ready(struct hisi_femac_mdio_data *data)
  29{
  30        u32 val;
  31
  32        return readl_poll_timeout(data->membase + MDIO_RWCTRL,
  33                                  val, val & MDIO_RW_FINISH, 20, 10000);
  34}
  35
  36static int hisi_femac_mdio_read(struct mii_bus *bus, int mii_id, int regnum)
  37{
  38        struct hisi_femac_mdio_data *data = bus->priv;
  39        int ret;
  40
  41        ret = hisi_femac_mdio_wait_ready(data);
  42        if (ret)
  43                return ret;
  44
  45        writel((mii_id << BIT_PHY_ADDR_OFFSET) | regnum,
  46               data->membase + MDIO_RWCTRL);
  47
  48        ret = hisi_femac_mdio_wait_ready(data);
  49        if (ret)
  50                return ret;
  51
  52        return readl(data->membase + MDIO_RO_DATA) & 0xFFFF;
  53}
  54
  55static int hisi_femac_mdio_write(struct mii_bus *bus, int mii_id, int regnum,
  56                                 u16 value)
  57{
  58        struct hisi_femac_mdio_data *data = bus->priv;
  59        int ret;
  60
  61        ret = hisi_femac_mdio_wait_ready(data);
  62        if (ret)
  63                return ret;
  64
  65        writel(MDIO_WRITE | (value << BIT_WR_DATA_OFFSET) |
  66               (mii_id << BIT_PHY_ADDR_OFFSET) | regnum,
  67               data->membase + MDIO_RWCTRL);
  68
  69        return hisi_femac_mdio_wait_ready(data);
  70}
  71
  72static int hisi_femac_mdio_probe(struct platform_device *pdev)
  73{
  74        struct device_node *np = pdev->dev.of_node;
  75        struct mii_bus *bus;
  76        struct hisi_femac_mdio_data *data;
  77        int ret;
  78
  79        bus = mdiobus_alloc_size(sizeof(*data));
  80        if (!bus)
  81                return -ENOMEM;
  82
  83        bus->name = "hisi_femac_mii_bus";
  84        bus->read = &hisi_femac_mdio_read;
  85        bus->write = &hisi_femac_mdio_write;
  86        snprintf(bus->id, MII_BUS_ID_SIZE, "%s", pdev->name);
  87        bus->parent = &pdev->dev;
  88
  89        data = bus->priv;
  90        data->membase = devm_platform_ioremap_resource(pdev, 0);
  91        if (IS_ERR(data->membase)) {
  92                ret = PTR_ERR(data->membase);
  93                goto err_out_free_mdiobus;
  94        }
  95
  96        data->clk = devm_clk_get(&pdev->dev, NULL);
  97        if (IS_ERR(data->clk)) {
  98                ret = PTR_ERR(data->clk);
  99                goto err_out_free_mdiobus;
 100        }
 101
 102        ret = clk_prepare_enable(data->clk);
 103        if (ret)
 104                goto err_out_free_mdiobus;
 105
 106        ret = of_mdiobus_register(bus, np);
 107        if (ret)
 108                goto err_out_disable_clk;
 109
 110        platform_set_drvdata(pdev, bus);
 111
 112        return 0;
 113
 114err_out_disable_clk:
 115        clk_disable_unprepare(data->clk);
 116err_out_free_mdiobus:
 117        mdiobus_free(bus);
 118        return ret;
 119}
 120
 121static int hisi_femac_mdio_remove(struct platform_device *pdev)
 122{
 123        struct mii_bus *bus = platform_get_drvdata(pdev);
 124        struct hisi_femac_mdio_data *data = bus->priv;
 125
 126        mdiobus_unregister(bus);
 127        clk_disable_unprepare(data->clk);
 128        mdiobus_free(bus);
 129
 130        return 0;
 131}
 132
 133static const struct of_device_id hisi_femac_mdio_dt_ids[] = {
 134        { .compatible = "hisilicon,hisi-femac-mdio" },
 135        { }
 136};
 137MODULE_DEVICE_TABLE(of, hisi_femac_mdio_dt_ids);
 138
 139static struct platform_driver hisi_femac_mdio_driver = {
 140        .probe = hisi_femac_mdio_probe,
 141        .remove = hisi_femac_mdio_remove,
 142        .driver = {
 143                .name = "hisi-femac-mdio",
 144                .of_match_table = hisi_femac_mdio_dt_ids,
 145        },
 146};
 147
 148module_platform_driver(hisi_femac_mdio_driver);
 149
 150MODULE_DESCRIPTION("Hisilicon Fast Ethernet MAC MDIO interface driver");
 151MODULE_AUTHOR("Dongpo Li <lidongpo@hisilicon.com>");
 152MODULE_LICENSE("GPL");
 153