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
  31 struct sun4i_mdio_data {
  32         void __iomem            *membase;
  33         struct regulator        *regulator;
  34 };
  35
  36 static 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
  63 static 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
  90 static 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         struct resource *res;
  96         int ret;
  97
  98         bus = mdiobus_alloc_size(sizeof(*data));
  99         if (!bus)
 100                 return -ENOMEM;
 101
 102         bus->name = "sun4i_mii_bus";
 103         bus->read = &sun4i_mdio_read;
 104         bus->write = &sun4i_mdio_write;
 105         snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mii", dev_name(&pdev->dev));
 106         bus->parent = &pdev->dev;
 107
 108         data = bus->priv;
 109         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 110         data->membase = devm_ioremap_resource(&pdev->dev, res);
 111         if (IS_ERR(data->membase)) {
 112                 ret = PTR_ERR(data->membase);
 113                 goto err_out_free_mdiobus;
 114         }
 115
 116         data->regulator = devm_regulator_get(&pdev->dev, "phy");
 117         if (IS_ERR(data->regulator)) {
 118                 if (PTR_ERR(data->regulator) == -EPROBE_DEFER) {
 119                         ret = -EPROBE_DEFER;
 120                         goto err_out_free_mdiobus;
 121                 }
 122
 123                 dev_info(&pdev->dev, "no regulator found\n");
 124                 data->regulator = NULL;
 125         } else {
 126                 ret = regulator_enable(data->regulator);
 127                 if (ret)
 128                         goto err_out_free_mdiobus;
 129         }
 130
 131         ret = of_mdiobus_register(bus, np);
 132         if (ret < 0)
 133                 goto err_out_disable_regulator;
 134
 135         platform_set_drvdata(pdev, bus);
 136
 137         return 0;
 138
 139 err_out_disable_regulator:
 140         if (data->regulator)
 141                 regulator_disable(data->regulator);
 142 err_out_free_mdiobus:
 143         mdiobus_free(bus);
 144         return ret;
 145 }
 146
 147 static int sun4i_mdio_remove(struct platform_device *pdev)
 148 {
 149         struct mii_bus *bus = platform_get_drvdata(pdev);
 150
 151         mdiobus_unregister(bus);
 152         mdiobus_free(bus);
 153
 154         return 0;
 155 }
 156
 157 static const struct of_device_id sun4i_mdio_dt_ids[] = {
 158         { .compatible = "allwinner,sun4i-a10-mdio" },
 159
 160         /* Deprecated */
 161         { .compatible = "allwinner,sun4i-mdio" },
 162         { }
 163 };
 164 MODULE_DEVICE_TABLE(of, sun4i_mdio_dt_ids);
 165
 166 static struct platform_driver sun4i_mdio_driver = {
 167         .probe = sun4i_mdio_probe,
 168         .remove = sun4i_mdio_remove,
 169         .driver = {
 170                 .name = "sun4i-mdio",
 171                 .of_match_table = sun4i_mdio_dt_ids,
 172         },
 173 };
 174
 175 module_platform_driver(sun4i_mdio_driver);
 176
 177 MODULE_DESCRIPTION("Allwinner EMAC MDIO interface driver");
 178 MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
 179 MODULE_LICENSE("GPL v2");