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		put_device(&priv->phy_dev->mdio.dev);
86		return -EPROBE_DEFER;
87	}
88
89	priv->mdio = mdiodev;
90	priv->phy_drv = priv->phy_dev->drv;
91	memcpy(&priv->conv_phy_drv, priv->phy_dev->drv,
92	       sizeof(struct phy_driver));
93	priv->conv_phy_drv.read_status = xgmiitorgmii_read_status;
94	mdiodev_set_drvdata(&priv->phy_dev->mdio, priv);
95	priv->phy_dev->drv = &priv->conv_phy_drv;
96
97	return 0;
98}
99
100static const struct of_device_id xgmiitorgmii_of_match[] = {
101	{ .compatible = "xlnx,gmii-to-rgmii-1.0" },
102	{},
103};
104MODULE_DEVICE_TABLE(of, xgmiitorgmii_of_match);
105
106static struct mdio_driver xgmiitorgmii_driver = {
107	.probe	= xgmiitorgmii_probe,
108	.mdiodrv.driver = {
109		.name = "xgmiitorgmii",
110		.of_match_table = xgmiitorgmii_of_match,
111	},
112};
113
114mdio_module_driver(xgmiitorgmii_driver);
115
116MODULE_DESCRIPTION("Xilinx GMII2RGMII converter driver");
117MODULE_LICENSE("GPL");
118