1 /* Xilinx GMII2RGMII Converter driver
2  *
3  * Copyright (C) 2016 Xilinx, Inc.
4  * Copyright (C) 2016 Andrew Lunn <andrew@lunn.ch>
5  *
6  * Author: Andrew Lunn <andrew@lunn.ch>
7  * Author: Kedareswara rao Appana <appanad@xilinx.com>
8  *
9  * Description:
10  * This driver is developed for Xilinx GMII2RGMII Converter
11  *
12  * This program is free software: you can redistribute it and/or modify
13  * it under the terms of the GNU General Public License as published by
14  * the Free Software Foundation, either version 2 of the License, or
15  * (at your option) any later version.
16  *
17  * This program is distributed in the hope that it will be useful,
18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  * GNU General Public License for more details.
21  */
22 #include <linux/module.h>
23 #include <linux/kernel.h>
24 #include <linux/mii.h>
25 #include <linux/mdio.h>
26 #include <linux/phy.h>
27 #include <linux/of_mdio.h>
28 
29 #define XILINX_GMII2RGMII_REG		0x10
30 #define XILINX_GMII2RGMII_SPEED_MASK	(BMCR_SPEED1000 | BMCR_SPEED100)
31 
32 struct gmii2rgmii {
33 	struct phy_device *phy_dev;
34 	struct phy_driver *phy_drv;
35 	struct phy_driver conv_phy_drv;
36 	struct mdio_device *mdio;
37 };
38 
39 static int xgmiitorgmii_read_status(struct phy_device *phydev)
40 {
41 	struct gmii2rgmii *priv = phydev->priv;
42 	struct mii_bus *bus = priv->mdio->bus;
43 	int addr = priv->mdio->addr;
44 	u16 val = 0;
45 	int err;
46 
47 	if (priv->phy_drv->read_status)
48 		err = priv->phy_drv->read_status(phydev);
49 	else
50 		err = genphy_read_status(phydev);
51 	if (err < 0)
52 		return err;
53 
54 	val = mdiobus_read(bus, addr, XILINX_GMII2RGMII_REG);
55 	val &= ~XILINX_GMII2RGMII_SPEED_MASK;
56 
57 	if (phydev->speed == SPEED_1000)
58 		val |= BMCR_SPEED1000;
59 	else if (phydev->speed == SPEED_100)
60 		val |= BMCR_SPEED100;
61 	else
62 		val |= BMCR_SPEED10;
63 
64 	mdiobus_write(bus, addr, XILINX_GMII2RGMII_REG, val);
65 
66 	return 0;
67 }
68 
69 static int xgmiitorgmii_probe(struct mdio_device *mdiodev)
70 {
71 	struct device *dev = &mdiodev->dev;
72 	struct device_node *np = dev->of_node, *phy_node;
73 	struct gmii2rgmii *priv;
74 
75 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
76 	if (!priv)
77 		return -ENOMEM;
78 
79 	phy_node = of_parse_phandle(np, "phy-handle", 0);
80 	if (!phy_node) {
81 		dev_err(dev, "Couldn't parse phy-handle\n");
82 		return -ENODEV;
83 	}
84 
85 	priv->phy_dev = of_phy_find_device(phy_node);
86 	of_node_put(phy_node);
87 	if (!priv->phy_dev) {
88 		dev_info(dev, "Couldn't find phydev\n");
89 		return -EPROBE_DEFER;
90 	}
91 
92 	if (!priv->phy_dev->drv) {
93 		dev_info(dev, "Attached phy not ready\n");
94 		return -EPROBE_DEFER;
95 	}
96 
97 	priv->mdio = mdiodev;
98 	priv->phy_drv = priv->phy_dev->drv;
99 	memcpy(&priv->conv_phy_drv, priv->phy_dev->drv,
100 	       sizeof(struct phy_driver));
101 	priv->conv_phy_drv.read_status = xgmiitorgmii_read_status;
102 	priv->phy_dev->priv = priv;
103 	priv->phy_dev->drv = &priv->conv_phy_drv;
104 
105 	return 0;
106 }
107 
108 static const struct of_device_id xgmiitorgmii_of_match[] = {
109 	{ .compatible = "xlnx,gmii-to-rgmii-1.0" },
110 	{},
111 };
112 MODULE_DEVICE_TABLE(of, xgmiitorgmii_of_match);
113 
114 static struct mdio_driver xgmiitorgmii_driver = {
115 	.probe	= xgmiitorgmii_probe,
116 	.mdiodrv.driver = {
117 		.name = "xgmiitorgmii",
118 		.of_match_table = xgmiitorgmii_of_match,
119 	},
120 };
121 
122 mdio_module_driver(xgmiitorgmii_driver);
123 
124 MODULE_DESCRIPTION("Xilinx GMII2RGMII converter driver");
125 MODULE_LICENSE("GPL");
126