linux/drivers/net/phy/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        struct resource *res;
  78        int ret;
  79
  80        bus = mdiobus_alloc_size(sizeof(*data));
  81        if (!bus)
  82                return -ENOMEM;
  83
  84        bus->name = "hisi_femac_mii_bus";
  85        bus->read = &hisi_femac_mdio_read;
  86        bus->write = &hisi_femac_mdio_write;
  87        snprintf(bus->id, MII_BUS_ID_SIZE, "%s", pdev->name);
  88        bus->parent = &pdev->dev;
  89
  90        data = bus->priv;
  91        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  92        data->membase = devm_ioremap_resource(&pdev->dev, res);
  93        if (IS_ERR(data->membase)) {
  94                ret = PTR_ERR(data->membase);
  95                goto err_out_free_mdiobus;
  96        }
  97
  98        data->clk = devm_clk_get(&pdev->dev, NULL);
  99        if (IS_ERR(data->clk)) {
 100                ret = PTR_ERR(data->clk);
 101                goto err_out_free_mdiobus;
 102        }
 103
 104        ret = clk_prepare_enable(data->clk);
 105        if (ret)
 106                goto err_out_free_mdiobus;
 107
 108        ret = of_mdiobus_register(bus, np);
 109        if (ret)
 110                goto err_out_disable_clk;
 111
 112        platform_set_drvdata(pdev, bus);
 113
 114        return 0;
 115
 116err_out_disable_clk:
 117        clk_disable_unprepare(data->clk);
 118err_out_free_mdiobus:
 119        mdiobus_free(bus);
 120        return ret;
 121}
 122
 123static int hisi_femac_mdio_remove(struct platform_device *pdev)
 124{
 125        struct mii_bus *bus = platform_get_drvdata(pdev);
 126        struct hisi_femac_mdio_data *data = bus->priv;
 127
 128        mdiobus_unregister(bus);
 129        clk_disable_unprepare(data->clk);
 130        mdiobus_free(bus);
 131
 132        return 0;
 133}
 134
 135static const struct of_device_id hisi_femac_mdio_dt_ids[] = {
 136        { .compatible = "hisilicon,hisi-femac-mdio" },
 137        { }
 138};
 139MODULE_DEVICE_TABLE(of, hisi_femac_mdio_dt_ids);
 140
 141static struct platform_driver hisi_femac_mdio_driver = {
 142        .probe = hisi_femac_mdio_probe,
 143        .remove = hisi_femac_mdio_remove,
 144        .driver = {
 145                .name = "hisi-femac-mdio",
 146                .of_match_table = hisi_femac_mdio_dt_ids,
 147        },
 148};
 149
 150module_platform_driver(hisi_femac_mdio_driver);
 151
 152MODULE_DESCRIPTION("Hisilicon Fast Ethernet MAC MDIO interface driver");
 153MODULE_AUTHOR("Dongpo Li <lidongpo@hisilicon.com>");
 154MODULE_LICENSE("GPL");
 155