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1// SPDX-License-Identifier: GPL-2.02/* MOXA ART Ethernet (RTL8201CP) MDIO interface driver3 *4 * Copyright (C) 2013 Jonas Jensen <jonas.jensen@gmail.com>5 */6 7#include <linux/delay.h>8#include <linux/kernel.h>9#include <linux/module.h>10#include <linux/mutex.h>11#include <linux/of_address.h>12#include <linux/of_mdio.h>13#include <linux/phy.h>14#include <linux/platform_device.h>15 16#define REG_PHY_CTRL 017#define REG_PHY_WRITE_DATA 418 19/* REG_PHY_CTRL */20#define MIIWR BIT(27) /* init write sequence (auto cleared)*/21#define MIIRD BIT(26)22#define REGAD_MASK 0x3e0000023#define PHYAD_MASK 0x1f000024#define MIIRDATA_MASK 0xffff25 26/* REG_PHY_WRITE_DATA */27#define MIIWDATA_MASK 0xffff28 29struct moxart_mdio_data {30 void __iomem *base;31};32 33static int moxart_mdio_read(struct mii_bus *bus, int mii_id, int regnum)34{35 struct moxart_mdio_data *data = bus->priv;36 u32 ctrl = 0;37 unsigned int count = 5;38 39 dev_dbg(&bus->dev, "%s\n", __func__);40 41 ctrl |= MIIRD | ((mii_id << 16) & PHYAD_MASK) |42 ((regnum << 21) & REGAD_MASK);43 44 writel(ctrl, data->base + REG_PHY_CTRL);45 46 do {47 ctrl = readl(data->base + REG_PHY_CTRL);48 49 if (!(ctrl & MIIRD))50 return ctrl & MIIRDATA_MASK;51 52 mdelay(10);53 count--;54 } while (count > 0);55 56 dev_dbg(&bus->dev, "%s timed out\n", __func__);57 58 return -ETIMEDOUT;59}60 61static int moxart_mdio_write(struct mii_bus *bus, int mii_id,62 int regnum, u16 value)63{64 struct moxart_mdio_data *data = bus->priv;65 u32 ctrl = 0;66 unsigned int count = 5;67 68 dev_dbg(&bus->dev, "%s\n", __func__);69 70 ctrl |= MIIWR | ((mii_id << 16) & PHYAD_MASK) |71 ((regnum << 21) & REGAD_MASK);72 73 value &= MIIWDATA_MASK;74 75 writel(value, data->base + REG_PHY_WRITE_DATA);76 writel(ctrl, data->base + REG_PHY_CTRL);77 78 do {79 ctrl = readl(data->base + REG_PHY_CTRL);80 81 if (!(ctrl & MIIWR))82 return 0;83 84 mdelay(10);85 count--;86 } while (count > 0);87 88 dev_dbg(&bus->dev, "%s timed out\n", __func__);89 90 return -ETIMEDOUT;91}92 93static int moxart_mdio_reset(struct mii_bus *bus)94{95 int data, i;96 97 for (i = 0; i < PHY_MAX_ADDR; i++) {98 data = moxart_mdio_read(bus, i, MII_BMCR);99 if (data < 0)100 continue;101 102 data |= BMCR_RESET;103 if (moxart_mdio_write(bus, i, MII_BMCR, data) < 0)104 continue;105 }106 107 return 0;108}109 110static int moxart_mdio_probe(struct platform_device *pdev)111{112 struct device_node *np = pdev->dev.of_node;113 struct mii_bus *bus;114 struct moxart_mdio_data *data;115 int ret, i;116 117 bus = mdiobus_alloc_size(sizeof(*data));118 if (!bus)119 return -ENOMEM;120 121 bus->name = "MOXA ART Ethernet MII";122 bus->read = &moxart_mdio_read;123 bus->write = &moxart_mdio_write;124 bus->reset = &moxart_mdio_reset;125 snprintf(bus->id, MII_BUS_ID_SIZE, "%s-%d-mii", pdev->name, pdev->id);126 bus->parent = &pdev->dev;127 128 /* Setting PHY_MAC_INTERRUPT here even if it has no effect,129 * of_mdiobus_register() sets these PHY_POLL.130 * Ideally, the interrupt from MAC controller could be used to131 * detect link state changes, not polling, i.e. if there was132 * a way phy_driver could set PHY_HAS_INTERRUPT but have that133 * interrupt handled in ethernet drivercode.134 */135 for (i = 0; i < PHY_MAX_ADDR; i++)136 bus->irq[i] = PHY_MAC_INTERRUPT;137 138 data = bus->priv;139 data->base = devm_platform_ioremap_resource(pdev, 0);140 if (IS_ERR(data->base)) {141 ret = PTR_ERR(data->base);142 goto err_out_free_mdiobus;143 }144 145 ret = of_mdiobus_register(bus, np);146 if (ret < 0)147 goto err_out_free_mdiobus;148 149 platform_set_drvdata(pdev, bus);150 151 return 0;152 153err_out_free_mdiobus:154 mdiobus_free(bus);155 return ret;156}157 158static void moxart_mdio_remove(struct platform_device *pdev)159{160 struct mii_bus *bus = platform_get_drvdata(pdev);161 162 mdiobus_unregister(bus);163 mdiobus_free(bus);164}165 166static const struct of_device_id moxart_mdio_dt_ids[] = {167 { .compatible = "moxa,moxart-mdio" },168 { }169};170MODULE_DEVICE_TABLE(of, moxart_mdio_dt_ids);171 172static struct platform_driver moxart_mdio_driver = {173 .probe = moxart_mdio_probe,174 .remove_new = moxart_mdio_remove,175 .driver = {176 .name = "moxart-mdio",177 .of_match_table = moxart_mdio_dt_ids,178 },179};180 181module_platform_driver(moxart_mdio_driver);182 183MODULE_DESCRIPTION("MOXA ART MDIO interface driver");184MODULE_AUTHOR("Jonas Jensen <jonas.jensen@gmail.com>");185MODULE_LICENSE("GPL v2");186