drivers/net/phy/xilinx_gmii2rgmii.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /* Xilinx GMII2RGMII Converter driver
   3  *
   4  * Copyright (C) 2016 Xilinx, Inc.
   5  * Copyright (C) 2016 Andrew Lunn <andrew@lunn.ch>
   6  *
   7  * Author: Andrew Lunn <andrew@lunn.ch>
   8  * Author: Kedareswara rao Appana <appanad@xilinx.com>
   9  *
  10  * Description:
  11  * This driver is developed for Xilinx GMII2RGMII Converter
  12  */
  13 #include <linux/module.h>
  14 #include <linux/kernel.h>
  15 #include <linux/mii.h>
  16 #include <linux/mdio.h>
  17 #include <linux/phy.h>
  18 #include <linux/clk.h>
  19 #include <linux/of_mdio.h>
  20
  21 #define XILINX_GMII2RGMII_REG           0x10
  22 #define XILINX_GMII2RGMII_SPEED_MASK    (BMCR_SPEED1000 | BMCR_SPEED100)
  23
  24 struct gmii2rgmii {
  25         struct phy_device *phy_dev;
  26         const struct phy_driver *phy_drv;
  27         struct phy_driver conv_phy_drv;
  28         struct mdio_device *mdio;
  29 };
  30
  31 static void xgmiitorgmii_configure(struct gmii2rgmii *priv, int speed)
  32 {
  33         struct mii_bus *bus = priv->mdio->bus;
  34         int addr = priv->mdio->addr;
  35         u16 val;
  36
  37         val = mdiobus_read(bus, addr, XILINX_GMII2RGMII_REG);
  38         val &= ~XILINX_GMII2RGMII_SPEED_MASK;
  39
  40         if (speed == SPEED_1000)
  41                 val |= BMCR_SPEED1000;
  42         else if (speed == SPEED_100)
  43                 val |= BMCR_SPEED100;
  44         else
  45                 val |= BMCR_SPEED10;
  46
  47         mdiobus_write(bus, addr, XILINX_GMII2RGMII_REG, val);
  48 }
  49
  50 static int xgmiitorgmii_read_status(struct phy_device *phydev)
  51 {
  52         struct gmii2rgmii *priv = mdiodev_get_drvdata(&phydev->mdio);
  53         int err;
  54
  55         if (priv->phy_drv->read_status)
  56                 err = priv->phy_drv->read_status(phydev);
  57         else
  58                 err = genphy_read_status(phydev);
  59         if (err < 0)
  60                 return err;
  61
  62         xgmiitorgmii_configure(priv, phydev->speed);
  63
  64         return 0;
  65 }
  66
  67 static int xgmiitorgmii_set_loopback(struct phy_device *phydev, bool enable)
  68 {
  69         struct gmii2rgmii *priv = mdiodev_get_drvdata(&phydev->mdio);
  70         int err;
  71
  72         if (priv->phy_drv->set_loopback)
  73                 err = priv->phy_drv->set_loopback(phydev, enable);
  74         else
  75                 err = genphy_loopback(phydev, enable);
  76         if (err < 0)
  77                 return err;
  78
  79         xgmiitorgmii_configure(priv, phydev->speed);
  80
  81         return 0;
  82 }
  83
  84 static int xgmiitorgmii_probe(struct mdio_device *mdiodev)
  85 {
  86         struct device *dev = &mdiodev->dev;
  87         struct device_node *np = dev->of_node, *phy_node;
  88         struct gmii2rgmii *priv;
  89         struct clk *clkin;
  90
  91         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
  92         if (!priv)
  93                 return -ENOMEM;
  94
  95         clkin = devm_clk_get_optional_enabled(dev, NULL);
  96         if (IS_ERR(clkin))
  97                 return dev_err_probe(dev, PTR_ERR(clkin),
  98                                         "Failed to get and enable clock from Device Tree\n");
  99
 100         phy_node = of_parse_phandle(np, "phy-handle", 0);
 101         if (!phy_node) {
 102                 dev_err(dev, "Couldn't parse phy-handle\n");
 103                 return -ENODEV;
 104         }
 105
 106         priv->phy_dev = of_phy_find_device(phy_node);
 107         of_node_put(phy_node);
 108         if (!priv->phy_dev) {
 109                 dev_info(dev, "Couldn't find phydev\n");
 110                 return -EPROBE_DEFER;
 111         }
 112
 113         if (!priv->phy_dev->drv) {
 114                 dev_info(dev, "Attached phy not ready\n");
 115                 put_device(&priv->phy_dev->mdio.dev);
 116                 return -EPROBE_DEFER;
 117         }
 118
 119         priv->mdio = mdiodev;
 120         priv->phy_drv = priv->phy_dev->drv;
 121         memcpy(&priv->conv_phy_drv, priv->phy_dev->drv,
 122                sizeof(struct phy_driver));
 123         priv->conv_phy_drv.read_status = xgmiitorgmii_read_status;
 124         priv->conv_phy_drv.set_loopback = xgmiitorgmii_set_loopback;
 125         mdiodev_set_drvdata(&priv->phy_dev->mdio, priv);
 126         priv->phy_dev->drv = &priv->conv_phy_drv;
 127
 128         return 0;
 129 }
 130
 131 static const struct of_device_id xgmiitorgmii_of_match[] = {
 132         { .compatible = "xlnx,gmii-to-rgmii-1.0" },
 133         {},
 134 };
 135 MODULE_DEVICE_TABLE(of, xgmiitorgmii_of_match);
 136
 137 static struct mdio_driver xgmiitorgmii_driver = {
 138         .probe  = xgmiitorgmii_probe,
 139         .mdiodrv.driver = {
 140                 .name = "xgmiitorgmii",
 141                 .of_match_table = xgmiitorgmii_of_match,
 142         },
 143 };
 144
 145 mdio_module_driver(xgmiitorgmii_driver);
 146
 147 MODULE_DESCRIPTION("Xilinx GMII2RGMII converter driver");
 148 MODULE_LICENSE("GPL");