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 start_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         start_jiffies = jiffies;
  53         while (readl(data->membase + EMAC_MAC_MIND_REG) & 0x1) {
  54                 if (time_after(start_jiffies,
  55                                start_jiffies + MDIO_TIMEOUT))
  56                         return -ETIMEDOUT;
  57                 msleep(1);
  58         }
  59
  60         /* push down the phy io line */
  61         writel(0x0, data->membase + EMAC_MAC_MCMD_REG);
  62         /* and read data */
  63         value = readl(data->membase + EMAC_MAC_MRDD_REG);
  64
  65         return value;
  66 }
  67
  68 static int sun4i_mdio_write(struct mii_bus *bus, int mii_id, int regnum,
  69                             u16 value)
  70 {
  71         struct sun4i_mdio_data *data = bus->priv;
  72         unsigned long start_jiffies;
  73
  74         /* issue the phy address and reg */
  75         writel((mii_id << 8) | regnum, data->membase + EMAC_MAC_MADR_REG);
  76         /* pull up the phy io line */
  77         writel(0x1, data->membase + EMAC_MAC_MCMD_REG);
  78
  79         /* Wait read complete */
  80         start_jiffies = jiffies;
  81         while (readl(data->membase + EMAC_MAC_MIND_REG) & 0x1) {
  82                 if (time_after(start_jiffies,
  83                                start_jiffies + MDIO_TIMEOUT))
  84                         return -ETIMEDOUT;
  85                 msleep(1);
  86         }
  87
  88         /* push down the phy io line */
  89         writel(0x0, data->membase + EMAC_MAC_MCMD_REG);
  90         /* and write data */
  91         writel(value, data->membase + EMAC_MAC_MWTD_REG);
  92
  93         return 0;
  94 }
  95
  96 static int sun4i_mdio_reset(struct mii_bus *bus)
  97 {
  98         return 0;
  99 }
 100
 101 static int sun4i_mdio_probe(struct platform_device *pdev)
 102 {
 103         struct device_node *np = pdev->dev.of_node;
 104         struct mii_bus *bus;
 105         struct sun4i_mdio_data *data;
 106         int ret, i;
 107
 108         bus = mdiobus_alloc_size(sizeof(*data));
 109         if (!bus)
 110                 return -ENOMEM;
 111
 112         bus->name = "sun4i_mii_bus";
 113         bus->read = &sun4i_mdio_read;
 114         bus->write = &sun4i_mdio_write;
 115         bus->reset = &sun4i_mdio_reset;
 116         snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mii", dev_name(&pdev->dev));
 117         bus->parent = &pdev->dev;
 118
 119         bus->irq = kmalloc(sizeof(int) * PHY_MAX_ADDR, GFP_KERNEL);
 120         if (!bus->irq) {
 121                 ret = -ENOMEM;
 122                 goto err_out_free_mdiobus;
 123         }
 124
 125         for (i = 0; i < PHY_MAX_ADDR; i++)
 126                 bus->irq[i] = PHY_POLL;
 127
 128         data = bus->priv;
 129         data->membase = of_iomap(np, 0);
 130         if (!data->membase) {
 131                 ret = -ENOMEM;
 132                 goto err_out_free_mdio_irq;
 133         }
 134
 135         data->regulator = devm_regulator_get(&pdev->dev, "phy");
 136         if (IS_ERR(data->regulator)) {
 137                 if (PTR_ERR(data->regulator) == -EPROBE_DEFER)
 138                         return -EPROBE_DEFER;
 139
 140                 dev_info(&pdev->dev, "no regulator found\n");
 141         } else {
 142                 ret = regulator_enable(data->regulator);
 143                 if (ret)
 144                         goto err_out_free_mdio_irq;
 145         }
 146
 147         ret = of_mdiobus_register(bus, np);
 148         if (ret < 0)
 149                 goto err_out_disable_regulator;
 150
 151         platform_set_drvdata(pdev, bus);
 152
 153         return 0;
 154
 155 err_out_disable_regulator:
 156         regulator_disable(data->regulator);
 157 err_out_free_mdio_irq:
 158         kfree(bus->irq);
 159 err_out_free_mdiobus:
 160         mdiobus_free(bus);
 161         return ret;
 162 }
 163
 164 static int sun4i_mdio_remove(struct platform_device *pdev)
 165 {
 166         struct mii_bus *bus = platform_get_drvdata(pdev);
 167
 168         mdiobus_unregister(bus);
 169         kfree(bus->irq);
 170         mdiobus_free(bus);
 171
 172         return 0;
 173 }
 174
 175 static const struct of_device_id sun4i_mdio_dt_ids[] = {
 176         { .compatible = "allwinner,sun4i-mdio" },
 177         { }
 178 };
 179 MODULE_DEVICE_TABLE(of, sun4i_mdio_dt_ids);
 180
 181 static struct platform_driver sun4i_mdio_driver = {
 182         .probe = sun4i_mdio_probe,
 183         .remove = sun4i_mdio_remove,
 184         .driver = {
 185                 .name = "sun4i-mdio",
 186                 .of_match_table = sun4i_mdio_dt_ids,
 187         },
 188 };
 189
 190 module_platform_driver(sun4i_mdio_driver);
 191
 192 MODULE_DESCRIPTION("Allwinner EMAC MDIO interface driver");
 193 MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
 194 MODULE_LICENSE("GPL");