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/kernel.h>
  17 #include <linux/module.h>
  18 #include <linux/mutex.h>
  19 #include <linux/of_address.h>
  20 #include <linux/of_mdio.h>
  21 #include <linux/phy.h>
  22 #include <linux/platform_device.h>
  23 #include <linux/regulator/consumer.h>
  24
  25 #define EMAC_MAC_MCMD_REG       (0x00)
  26 #define EMAC_MAC_MADR_REG       (0x04)
  27 #define EMAC_MAC_MWTD_REG       (0x08)
  28 #define EMAC_MAC_MRDD_REG       (0x0c)
  29 #define EMAC_MAC_MIND_REG       (0x10)
  30 #define EMAC_MAC_SSRR_REG       (0x14)
  31
  32 #define MDIO_TIMEOUT            (msecs_to_jiffies(100))
  33
  34 struct sun4i_mdio_data {
  35         void __iomem            *membase;
  36         struct regulator        *regulator;
  37 };
  38
  39 static int sun4i_mdio_read(struct mii_bus *bus, int mii_id, int regnum)
  40 {
  41         struct sun4i_mdio_data *data = bus->priv;
  42         unsigned long timeout_jiffies;
  43         int value;
  44
  45         /* issue the phy address and reg */
  46         writel((mii_id << 8) | regnum, data->membase + EMAC_MAC_MADR_REG);
  47         /* pull up the phy io line */
  48         writel(0x1, data->membase + EMAC_MAC_MCMD_REG);
  49
  50         /* Wait read complete */
  51         timeout_jiffies = jiffies + MDIO_TIMEOUT;
  52         while (readl(data->membase + EMAC_MAC_MIND_REG) & 0x1) {
  53                 if (time_is_before_jiffies(timeout_jiffies))
  54                         return -ETIMEDOUT;
  55                 msleep(1);
  56         }
  57
  58         /* push down the phy io line */
  59         writel(0x0, data->membase + EMAC_MAC_MCMD_REG);
  60         /* and read data */
  61         value = readl(data->membase + EMAC_MAC_MRDD_REG);
  62
  63         return value;
  64 }
  65
  66 static int sun4i_mdio_write(struct mii_bus *bus, int mii_id, int regnum,
  67                             u16 value)
  68 {
  69         struct sun4i_mdio_data *data = bus->priv;
  70         unsigned long timeout_jiffies;
  71
  72         /* issue the phy address and reg */
  73         writel((mii_id << 8) | regnum, data->membase + EMAC_MAC_MADR_REG);
  74         /* pull up the phy io line */
  75         writel(0x1, data->membase + EMAC_MAC_MCMD_REG);
  76
  77         /* Wait read complete */
  78         timeout_jiffies = jiffies + MDIO_TIMEOUT;
  79         while (readl(data->membase + EMAC_MAC_MIND_REG) & 0x1) {
  80                 if (time_is_before_jiffies(timeout_jiffies))
  81                         return -ETIMEDOUT;
  82                 msleep(1);
  83         }
  84
  85         /* push down the phy io line */
  86         writel(0x0, data->membase + EMAC_MAC_MCMD_REG);
  87         /* and write data */
  88         writel(value, data->membase + EMAC_MAC_MWTD_REG);
  89
  90         return 0;
  91 }
  92
  93 static int sun4i_mdio_probe(struct platform_device *pdev)
  94 {
  95         struct device_node *np = pdev->dev.of_node;
  96         struct mii_bus *bus;
  97         struct sun4i_mdio_data *data;
  98         struct resource *res;
  99         int ret;
 100
 101         bus = mdiobus_alloc_size(sizeof(*data));
 102         if (!bus)
 103                 return -ENOMEM;
 104
 105         bus->name = "sun4i_mii_bus";
 106         bus->read = &sun4i_mdio_read;
 107         bus->write = &sun4i_mdio_write;
 108         snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mii", dev_name(&pdev->dev));
 109         bus->parent = &pdev->dev;
 110
 111         data = bus->priv;
 112         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 113         data->membase = devm_ioremap_resource(&pdev->dev, res);
 114         if (IS_ERR(data->membase)) {
 115                 ret = PTR_ERR(data->membase);
 116                 goto err_out_free_mdiobus;
 117         }
 118
 119         data->regulator = devm_regulator_get(&pdev->dev, "phy");
 120         if (IS_ERR(data->regulator)) {
 121                 if (PTR_ERR(data->regulator) == -EPROBE_DEFER) {
 122                         ret = -EPROBE_DEFER;
 123                         goto err_out_free_mdiobus;
 124                 }
 125
 126                 dev_info(&pdev->dev, "no regulator found\n");
 127                 data->regulator = NULL;
 128         } else {
 129                 ret = regulator_enable(data->regulator);
 130                 if (ret)
 131                         goto err_out_free_mdiobus;
 132         }
 133
 134         ret = of_mdiobus_register(bus, np);
 135         if (ret < 0)
 136                 goto err_out_disable_regulator;
 137
 138         platform_set_drvdata(pdev, bus);
 139
 140         return 0;
 141
 142 err_out_disable_regulator:
 143         if (data->regulator)
 144                 regulator_disable(data->regulator);
 145 err_out_free_mdiobus:
 146         mdiobus_free(bus);
 147         return ret;
 148 }
 149
 150 static int sun4i_mdio_remove(struct platform_device *pdev)
 151 {
 152         struct mii_bus *bus = platform_get_drvdata(pdev);
 153
 154         mdiobus_unregister(bus);
 155         mdiobus_free(bus);
 156
 157         return 0;
 158 }
 159
 160 static const struct of_device_id sun4i_mdio_dt_ids[] = {
 161         { .compatible = "allwinner,sun4i-a10-mdio" },
 162
 163         /* Deprecated */
 164         { .compatible = "allwinner,sun4i-mdio" },
 165         { }
 166 };
 167 MODULE_DEVICE_TABLE(of, sun4i_mdio_dt_ids);
 168
 169 static struct platform_driver sun4i_mdio_driver = {
 170         .probe = sun4i_mdio_probe,
 171         .remove = sun4i_mdio_remove,
 172         .driver = {
 173                 .name = "sun4i-mdio",
 174                 .of_match_table = sun4i_mdio_dt_ids,
 175         },
 176 };
 177
 178 module_platform_driver(sun4i_mdio_driver);
 179
 180 MODULE_DESCRIPTION("Allwinner EMAC MDIO interface driver");
 181 MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
 182 MODULE_LICENSE("GPL");