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
 24struct 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
 31static 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
 50static 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
 67static 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
 84static 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
131static const struct of_device_id xgmiitorgmii_of_match[] = {
132	{ .compatible = "xlnx,gmii-to-rgmii-1.0" },
133	{},
134};
135MODULE_DEVICE_TABLE(of, xgmiitorgmii_of_match);
136
137static 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
145mdio_module_driver(xgmiitorgmii_driver);
146
147MODULE_DESCRIPTION("Xilinx GMII2RGMII converter driver");
148MODULE_LICENSE("GPL");