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 void xgmiitorgmii_configure(struct gmii2rgmii *priv, int speed)
 31{
 32	struct mii_bus *bus = priv->mdio->bus;
 33	int addr = priv->mdio->addr;
 34	u16 val;
 35
 36	val = mdiobus_read(bus, addr, XILINX_GMII2RGMII_REG);
 37	val &= ~XILINX_GMII2RGMII_SPEED_MASK;
 38
 39	if (speed == SPEED_1000)
 40		val |= BMCR_SPEED1000;
 41	else if (speed == SPEED_100)
 42		val |= BMCR_SPEED100;
 43	else
 44		val |= BMCR_SPEED10;
 45
 46	mdiobus_write(bus, addr, XILINX_GMII2RGMII_REG, val);
 47}
 48
 49static int xgmiitorgmii_read_status(struct phy_device *phydev)
 50{
 51	struct gmii2rgmii *priv = mdiodev_get_drvdata(&phydev->mdio);
 52	int err;
 53
 54	if (priv->phy_drv->read_status)
 55		err = priv->phy_drv->read_status(phydev);
 56	else
 57		err = genphy_read_status(phydev);
 58	if (err < 0)
 59		return err;
 60
 61	xgmiitorgmii_configure(priv, phydev->speed);
 62
 63	return 0;
 64}
 65
 66static int xgmiitorgmii_set_loopback(struct phy_device *phydev, bool enable)
 67{
 68	struct gmii2rgmii *priv = mdiodev_get_drvdata(&phydev->mdio);
 69	int err;
 70
 71	if (priv->phy_drv->set_loopback)
 72		err = priv->phy_drv->set_loopback(phydev, enable);
 73	else
 74		err = genphy_loopback(phydev, enable);
 75	if (err < 0)
 76		return err;
 77
 78	xgmiitorgmii_configure(priv, phydev->speed);
 79
 80	return 0;
 81}
 82
 83static int xgmiitorgmii_probe(struct mdio_device *mdiodev)
 84{
 85	struct device *dev = &mdiodev->dev;
 86	struct device_node *np = dev->of_node, *phy_node;
 87	struct gmii2rgmii *priv;
 88
 89	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 90	if (!priv)
 91		return -ENOMEM;
 92
 93	phy_node = of_parse_phandle(np, "phy-handle", 0);
 94	if (!phy_node) {
 95		dev_err(dev, "Couldn't parse phy-handle\n");
 96		return -ENODEV;
 97	}
 98
 99	priv->phy_dev = of_phy_find_device(phy_node);
100	of_node_put(phy_node);
101	if (!priv->phy_dev) {
102		dev_info(dev, "Couldn't find phydev\n");
103		return -EPROBE_DEFER;
104	}
105
106	if (!priv->phy_dev->drv) {
107		dev_info(dev, "Attached phy not ready\n");
108		put_device(&priv->phy_dev->mdio.dev);
109		return -EPROBE_DEFER;
110	}
111
112	priv->mdio = mdiodev;
113	priv->phy_drv = priv->phy_dev->drv;
114	memcpy(&priv->conv_phy_drv, priv->phy_dev->drv,
115	       sizeof(struct phy_driver));
116	priv->conv_phy_drv.read_status = xgmiitorgmii_read_status;
117	priv->conv_phy_drv.set_loopback = xgmiitorgmii_set_loopback;
118	mdiodev_set_drvdata(&priv->phy_dev->mdio, priv);
119	priv->phy_dev->drv = &priv->conv_phy_drv;
120
121	return 0;
122}
123
124static const struct of_device_id xgmiitorgmii_of_match[] = {
125	{ .compatible = "xlnx,gmii-to-rgmii-1.0" },
126	{},
127};
128MODULE_DEVICE_TABLE(of, xgmiitorgmii_of_match);
129
130static struct mdio_driver xgmiitorgmii_driver = {
131	.probe	= xgmiitorgmii_probe,
132	.mdiodrv.driver = {
133		.name = "xgmiitorgmii",
134		.of_match_table = xgmiitorgmii_of_match,
135	},
136};
137
138mdio_module_driver(xgmiitorgmii_driver);
139
140MODULE_DESCRIPTION("Xilinx GMII2RGMII converter driver");
141MODULE_LICENSE("GPL");