1/*
2 * Driver for the MPC5200 Fast Ethernet Controller - MDIO bus driver
3 *
4 * Copyright (C) 2007  Domen Puncer, Telargo, Inc.
5 * Copyright (C) 2008  Wolfram Sang, Pengutronix
6 *
7 * This file is licensed under the terms of the GNU General Public License
8 * version 2. This program is licensed "as is" without any warranty of any
9 * kind, whether express or implied.
10 */
11
12#include <linux/kernel.h>
13#include <linux/module.h>
14#include <linux/netdevice.h>
15#include <linux/phy.h>
16#include <linux/of_platform.h>
17#include <linux/slab.h>
18#include <linux/of_mdio.h>
19#include <asm/io.h>
20#include <asm/mpc52xx.h>
21#include "fec_mpc52xx.h"
22
23struct mpc52xx_fec_mdio_priv {
24	struct mpc52xx_fec __iomem *regs;
25	int mdio_irqs[PHY_MAX_ADDR];
26};
27
28static int mpc52xx_fec_mdio_transfer(struct mii_bus *bus, int phy_id,
29		int reg, u32 value)
30{
31	struct mpc52xx_fec_mdio_priv *priv = bus->priv;
32	struct mpc52xx_fec __iomem *fec = priv->regs;
33	int tries = 3;
34
35	value |= (phy_id << FEC_MII_DATA_PA_SHIFT) & FEC_MII_DATA_PA_MSK;
36	value |= (reg << FEC_MII_DATA_RA_SHIFT) & FEC_MII_DATA_RA_MSK;
37
38	out_be32(&fec->ievent, FEC_IEVENT_MII);
39	out_be32(&fec->mii_data, value);
40
41	/* wait for it to finish, this takes about 23 us on lite5200b */
42	while (!(in_be32(&fec->ievent) & FEC_IEVENT_MII) && --tries)
43		msleep(1);
44
45	if (!tries)
46		return -ETIMEDOUT;
47
48	return value & FEC_MII_DATA_OP_RD ?
49		in_be32(&fec->mii_data) & FEC_MII_DATA_DATAMSK : 0;
50}
51
52static int mpc52xx_fec_mdio_read(struct mii_bus *bus, int phy_id, int reg)
53{
54	return mpc52xx_fec_mdio_transfer(bus, phy_id, reg, FEC_MII_READ_FRAME);
55}
56
57static int mpc52xx_fec_mdio_write(struct mii_bus *bus, int phy_id, int reg,
58		u16 data)
59{
60	return mpc52xx_fec_mdio_transfer(bus, phy_id, reg,
61		data | FEC_MII_WRITE_FRAME);
62}
63
64static int mpc52xx_fec_mdio_probe(struct platform_device *of)
65{
66	struct device *dev = &of->dev;
67	struct device_node *np = of->dev.of_node;
68	struct mii_bus *bus;
69	struct mpc52xx_fec_mdio_priv *priv;
70	struct resource res;
71	int err;
72
73	bus = mdiobus_alloc();
74	if (bus == NULL)
75		return -ENOMEM;
76	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
77	if (priv == NULL) {
78		err = -ENOMEM;
79		goto out_free;
80	}
81
82	bus->name = "mpc52xx MII bus";
83	bus->read = mpc52xx_fec_mdio_read;
84	bus->write = mpc52xx_fec_mdio_write;
85
86	/* setup irqs */
87	bus->irq = priv->mdio_irqs;
88
89	/* setup registers */
90	err = of_address_to_resource(np, 0, &res);
91	if (err)
92		goto out_free;
93	priv->regs = ioremap(res.start, resource_size(&res));
94	if (priv->regs == NULL) {
95		err = -ENOMEM;
96		goto out_free;
97	}
98
99	snprintf(bus->id, MII_BUS_ID_SIZE, "%x", res.start);
100	bus->priv = priv;
101
102	bus->parent = dev;
103	dev_set_drvdata(dev, bus);
104
105	/* set MII speed */
106	out_be32(&priv->regs->mii_speed,
107		((mpc5xxx_get_bus_frequency(of->dev.of_node) >> 20) / 5) << 1);
108
109	err = of_mdiobus_register(bus, np);
110	if (err)
111		goto out_unmap;
112
113	return 0;
114
115 out_unmap:
116	iounmap(priv->regs);
117 out_free:
118	kfree(priv);
119	mdiobus_free(bus);
120
121	return err;
122}
123
124static int mpc52xx_fec_mdio_remove(struct platform_device *of)
125{
126	struct device *dev = &of->dev;
127	struct mii_bus *bus = dev_get_drvdata(dev);
128	struct mpc52xx_fec_mdio_priv *priv = bus->priv;
129
130	mdiobus_unregister(bus);
131	dev_set_drvdata(dev, NULL);
132	iounmap(priv->regs);
133	kfree(priv);
134	mdiobus_free(bus);
135
136	return 0;
137}
138
139static struct of_device_id mpc52xx_fec_mdio_match[] = {
140	{ .compatible = "fsl,mpc5200b-mdio", },
141	{ .compatible = "fsl,mpc5200-mdio", },
142	{ .compatible = "mpc5200b-fec-phy", },
143	{}
144};
145MODULE_DEVICE_TABLE(of, mpc52xx_fec_mdio_match);
146
147struct platform_driver mpc52xx_fec_mdio_driver = {
148	.driver = {
149		.name = "mpc5200b-fec-phy",
150		.owner = THIS_MODULE,
151		.of_match_table = mpc52xx_fec_mdio_match,
152	},
153	.probe = mpc52xx_fec_mdio_probe,
154	.remove = mpc52xx_fec_mdio_remove,
155};
156
157/* let fec driver call it, since this has to be registered before it */
158EXPORT_SYMBOL_GPL(mpc52xx_fec_mdio_driver);
159
160MODULE_LICENSE("Dual BSD/GPL");
161