drivers/net/phy/mdio-sun4i.c

   1 /*
   2  * Allwinner EMAC MDIO interface driver
   3  *
   4  * Copyright 2012-2013 Stefan Roese <sr@denx.de>
   5  * Copyright 2013 Maxime Ripard <maxime.ripard@free-electrons.com>
   6  *
   7  * Based on the Linux driver provided by Allwinner:
   8  * Copyright (C) 1997  Sten Wang
   9  *
  10  * This file is licensed under the terms of the GNU General Public
  11  * License version 2. This program is licensed "as is" without any
  12  * warranty of any kind, whether express or implied.
  13  */
  14
  15 #include <linux/delay.h>
  16 #include <linux/init.h>
  17 #include <linux/kernel.h>
  18 #include <linux/module.h>
  19 #include <linux/mutex.h>
  20 #include <linux/of_address.h>
  21 #include <linux/of_mdio.h>
  22 #include <linux/phy.h>
  23 #include <linux/platform_device.h>
  24 #include <linux/regulator/consumer.h>
  25
  26 #define EMAC_MAC_MCMD_REG       (0x00)
  27 #define EMAC_MAC_MADR_REG       (0x04)
  28 #define EMAC_MAC_MWTD_REG       (0x08)
  29 #define EMAC_MAC_MRDD_REG       (0x0c)
  30 #define EMAC_MAC_MIND_REG       (0x10)
  31 #define EMAC_MAC_SSRR_REG       (0x14)
  32
  33 #define MDIO_TIMEOUT            (msecs_to_jiffies(100))
  34
  35 struct sun4i_mdio_data {
  36         void __iomem            *membase;
  37         struct regulator        *regulator;
  38 };
  39
  40 static int sun4i_mdio_read(struct mii_bus *bus, int mii_id, int regnum)
  41 {
  42         struct sun4i_mdio_data *data = bus->priv;
  43         unsigned long timeout_jiffies;
  44         int value;
  45
  46         /* issue the phy address and reg */
  47         writel((mii_id << 8) | regnum, data->membase + EMAC_MAC_MADR_REG);
  48         /* pull up the phy io line */
  49         writel(0x1, data->membase + EMAC_MAC_MCMD_REG);
  50
  51         /* Wait read complete */
  52         timeout_jiffies = jiffies + MDIO_TIMEOUT;
  53         while (readl(data->membase + EMAC_MAC_MIND_REG) & 0x1) {
  54                 if (time_is_before_jiffies(timeout_jiffies))
  55                         return -ETIMEDOUT;
  56                 msleep(1);
  57         }
  58
  59         /* push down the phy io line */
  60         writel(0x0, data->membase + EMAC_MAC_MCMD_REG);
  61         /* and read data */
  62         value = readl(data->membase + EMAC_MAC_MRDD_REG);
  63
  64         return value;
  65 }
  66
  67 static int sun4i_mdio_write(struct mii_bus *bus, int mii_id, int regnum,
  68                             u16 value)
  69 {
  70         struct sun4i_mdio_data *data = bus->priv;
  71         unsigned long timeout_jiffies;
  72
  73         /* issue the phy address and reg */
  74         writel((mii_id << 8) | regnum, data->membase + EMAC_MAC_MADR_REG);
  75         /* pull up the phy io line */
  76         writel(0x1, data->membase + EMAC_MAC_MCMD_REG);
  77
  78         /* Wait read complete */
  79         timeout_jiffies = jiffies + MDIO_TIMEOUT;
  80         while (readl(data->membase + EMAC_MAC_MIND_REG) & 0x1) {
  81                 if (time_is_before_jiffies(timeout_jiffies))
  82                         return -ETIMEDOUT;
  83                 msleep(1);
  84         }
  85
  86         /* push down the phy io line */
  87         writel(0x0, data->membase + EMAC_MAC_MCMD_REG);
  88         /* and write data */
  89         writel(value, data->membase + EMAC_MAC_MWTD_REG);
  90
  91         return 0;
  92 }
  93
  94 static int sun4i_mdio_reset(struct mii_bus *bus)
  95 {
  96         return 0;
  97 }
  98
  99 static int sun4i_mdio_probe(struct platform_device *pdev)
 100 {
 101         struct device_node *np = pdev->dev.of_node;
 102         struct mii_bus *bus;
 103         struct sun4i_mdio_data *data;
 104         int ret, i;
 105
 106         bus = mdiobus_alloc_size(sizeof(*data));
 107         if (!bus)
 108                 return -ENOMEM;
 109
 110         bus->name = "sun4i_mii_bus";
 111         bus->read = &sun4i_mdio_read;
 112         bus->write = &sun4i_mdio_write;
 113         bus->reset = &sun4i_mdio_reset;
 114         snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mii", dev_name(&pdev->dev));
 115         bus->parent = &pdev->dev;
 116
 117         bus->irq = kmalloc(sizeof(int) * PHY_MAX_ADDR, GFP_KERNEL);
 118         if (!bus->irq) {
 119                 ret = -ENOMEM;
 120                 goto err_out_free_mdiobus;
 121         }
 122
 123         for (i = 0; i < PHY_MAX_ADDR; i++)
 124                 bus->irq[i] = PHY_POLL;
 125
 126         data = bus->priv;
 127         data->membase = of_iomap(np, 0);
 128         if (!data->membase) {
 129                 ret = -ENOMEM;
 130                 goto err_out_free_mdio_irq;
 131         }
 132
 133         data->regulator = devm_regulator_get(&pdev->dev, "phy");
 134         if (IS_ERR(data->regulator)) {
 135                 if (PTR_ERR(data->regulator) == -EPROBE_DEFER)
 136                         return -EPROBE_DEFER;
 137
 138                 dev_info(&pdev->dev, "no regulator found\n");
 139         } else {
 140                 ret = regulator_enable(data->regulator);
 141                 if (ret)
 142                         goto err_out_free_mdio_irq;
 143         }
 144
 145         ret = of_mdiobus_register(bus, np);
 146         if (ret < 0)
 147                 goto err_out_disable_regulator;
 148
 149         platform_set_drvdata(pdev, bus);
 150
 151         return 0;
 152
 153 err_out_disable_regulator:
 154         regulator_disable(data->regulator);
 155 err_out_free_mdio_irq:
 156         kfree(bus->irq);
 157 err_out_free_mdiobus:
 158         mdiobus_free(bus);
 159         return ret;
 160 }
 161
 162 static int sun4i_mdio_remove(struct platform_device *pdev)
 163 {
 164         struct mii_bus *bus = platform_get_drvdata(pdev);
 165
 166         mdiobus_unregister(bus);
 167         kfree(bus->irq);
 168         mdiobus_free(bus);
 169
 170         return 0;
 171 }
 172
 173 static const struct of_device_id sun4i_mdio_dt_ids[] = {
 174         { .compatible = "allwinner,sun4i-mdio" },
 175         { }
 176 };
 177 MODULE_DEVICE_TABLE(of, sun4i_mdio_dt_ids);
 178
 179 static struct platform_driver sun4i_mdio_driver = {
 180         .probe = sun4i_mdio_probe,
 181         .remove = sun4i_mdio_remove,
 182         .driver = {
 183                 .name = "sun4i-mdio",
 184                 .of_match_table = sun4i_mdio_dt_ids,
 185         },
 186 };
 187
 188 module_platform_driver(sun4i_mdio_driver);
 189
 190 MODULE_DESCRIPTION("Allwinner EMAC MDIO interface driver");
 191 MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
 192 MODULE_LICENSE("GPL");