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                         return -EPROBE_DEFER;
 123
 124                 dev_info(&pdev->dev, "no regulator found\n");
 125                 data->regulator = NULL;
 126         } else {
 127                 ret = regulator_enable(data->regulator);
 128                 if (ret)
 129                         goto err_out_free_mdiobus;
 130         }
 131
 132         ret = of_mdiobus_register(bus, np);
 133         if (ret < 0)
 134                 goto err_out_disable_regulator;
 135
 136         platform_set_drvdata(pdev, bus);
 137
 138         return 0;
 139
 140 err_out_disable_regulator:
 141         if (data->regulator)
 142                 regulator_disable(data->regulator);
 143 err_out_free_mdiobus:
 144         mdiobus_free(bus);
 145         return ret;
 146 }
 147
 148 static int sun4i_mdio_remove(struct platform_device *pdev)
 149 {
 150         struct mii_bus *bus = platform_get_drvdata(pdev);
 151
 152         mdiobus_unregister(bus);
 153         mdiobus_free(bus);
 154
 155         return 0;
 156 }
 157
 158 static const struct of_device_id sun4i_mdio_dt_ids[] = {
 159         { .compatible = "allwinner,sun4i-a10-mdio" },
 160
 161         /* Deprecated */
 162         { .compatible = "allwinner,sun4i-mdio" },
 163         { }
 164 };
 165 MODULE_DEVICE_TABLE(of, sun4i_mdio_dt_ids);
 166
 167 static struct platform_driver sun4i_mdio_driver = {
 168         .probe = sun4i_mdio_probe,
 169         .remove = sun4i_mdio_remove,
 170         .driver = {
 171                 .name = "sun4i-mdio",
 172                 .of_match_table = sun4i_mdio_dt_ids,
 173         },
 174 };
 175
 176 module_platform_driver(sun4i_mdio_driver);
 177
 178 MODULE_DESCRIPTION("Allwinner EMAC MDIO interface driver");
 179 MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
 180 MODULE_LICENSE("GPL");