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/of_mdio.h>
 19
 20#define XILINX_GMII2RGMII_REG		0x10
 21#define XILINX_GMII2RGMII_SPEED_MASK	(BMCR_SPEED1000 | BMCR_SPEED100)
 22
 23struct gmii2rgmii {
 24	struct phy_device *phy_dev;
 25	struct phy_driver *phy_drv;
 26	struct phy_driver conv_phy_drv;
 27	struct mdio_device *mdio;
 28};
 29
 30static int xgmiitorgmii_read_status(struct phy_device *phydev)
 31{
 32	struct gmii2rgmii *priv = mdiodev_get_drvdata(&phydev->mdio);
 33	struct mii_bus *bus = priv->mdio->bus;
 34	int addr = priv->mdio->addr;
 35	u16 val = 0;
 36	int err;
 37
 38	if (priv->phy_drv->read_status)
 39		err = priv->phy_drv->read_status(phydev);
 40	else
 41		err = genphy_read_status(phydev);
 42	if (err < 0)
 43		return err;
 44
 45	val = mdiobus_read(bus, addr, XILINX_GMII2RGMII_REG);
 46	val &= ~XILINX_GMII2RGMII_SPEED_MASK;
 47
 48	if (phydev->speed == SPEED_1000)
 49		val |= BMCR_SPEED1000;
 50	else if (phydev->speed == SPEED_100)
 51		val |= BMCR_SPEED100;
 52	else
 53		val |= BMCR_SPEED10;
 54
 55	mdiobus_write(bus, addr, XILINX_GMII2RGMII_REG, val);
 56
 57	return 0;
 58}
 59
 60static int xgmiitorgmii_probe(struct mdio_device *mdiodev)
 61{
 62	struct device *dev = &mdiodev->dev;
 63	struct device_node *np = dev->of_node, *phy_node;
 64	struct gmii2rgmii *priv;
 65
 66	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 67	if (!priv)
 68		return -ENOMEM;
 69
 70	phy_node = of_parse_phandle(np, "phy-handle", 0);
 71	if (!phy_node) {
 72		dev_err(dev, "Couldn't parse phy-handle\n");
 73		return -ENODEV;
 74	}
 75
 76	priv->phy_dev = of_phy_find_device(phy_node);
 77	of_node_put(phy_node);
 78	if (!priv->phy_dev) {
 79		dev_info(dev, "Couldn't find phydev\n");
 80		return -EPROBE_DEFER;
 81	}
 82
 83	if (!priv->phy_dev->drv) {
 84		dev_info(dev, "Attached phy not ready\n");
 85		return -EPROBE_DEFER;
 86	}
 87
 88	priv->mdio = mdiodev;
 89	priv->phy_drv = priv->phy_dev->drv;
 90	memcpy(&priv->conv_phy_drv, priv->phy_dev->drv,
 91	       sizeof(struct phy_driver));
 92	priv->conv_phy_drv.read_status = xgmiitorgmii_read_status;
 93	mdiodev_set_drvdata(&priv->phy_dev->mdio, priv);
 94	priv->phy_dev->drv = &priv->conv_phy_drv;
 95
 96	return 0;
 97}
 98
 99static const struct of_device_id xgmiitorgmii_of_match[] = {
100	{ .compatible = "xlnx,gmii-to-rgmii-1.0" },
101	{},
102};
103MODULE_DEVICE_TABLE(of, xgmiitorgmii_of_match);
104
105static struct mdio_driver xgmiitorgmii_driver = {
106	.probe	= xgmiitorgmii_probe,
107	.mdiodrv.driver = {
108		.name = "xgmiitorgmii",
109		.of_match_table = xgmiitorgmii_of_match,
110	},
111};
112
113mdio_module_driver(xgmiitorgmii_driver);
114
115MODULE_DESCRIPTION("Xilinx GMII2RGMII converter driver");
116MODULE_LICENSE("GPL");