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 
23 struct 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 
30 static int xgmiitorgmii_read_status(struct phy_device *phydev)
31 {
32 	struct gmii2rgmii *priv = phydev->priv;
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 
60 static 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 	priv->phy_dev->priv = priv;
94 	priv->phy_dev->drv = &priv->conv_phy_drv;
95 
96 	return 0;
97 }
98 
99 static const struct of_device_id xgmiitorgmii_of_match[] = {
100 	{ .compatible = "xlnx,gmii-to-rgmii-1.0" },
101 	{},
102 };
103 MODULE_DEVICE_TABLE(of, xgmiitorgmii_of_match);
104 
105 static 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 
113 mdio_module_driver(xgmiitorgmii_driver);
114 
115 MODULE_DESCRIPTION("Xilinx GMII2RGMII converter driver");
116 MODULE_LICENSE("GPL");
117