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};
26
27static int mpc52xx_fec_mdio_transfer(struct mii_bus *bus, int phy_id,
28		int reg, u32 value)
29{
30	struct mpc52xx_fec_mdio_priv *priv = bus->priv;
31	struct mpc52xx_fec __iomem *fec = priv->regs;
32	int tries = 3;
33
34	value |= (phy_id << FEC_MII_DATA_PA_SHIFT) & FEC_MII_DATA_PA_MSK;
35	value |= (reg << FEC_MII_DATA_RA_SHIFT) & FEC_MII_DATA_RA_MSK;
36
37	out_be32(&fec->ievent, FEC_IEVENT_MII);
38	out_be32(&fec->mii_data, value);
39
40	/* wait for it to finish, this takes about 23 us on lite5200b */
41	while (!(in_be32(&fec->ievent) & FEC_IEVENT_MII) && --tries)
42		msleep(1);
43
44	if (!tries)
45		return -ETIMEDOUT;
46
47	return value & FEC_MII_DATA_OP_RD ?
48		in_be32(&fec->mii_data) & FEC_MII_DATA_DATAMSK : 0;
49}
50
51static int mpc52xx_fec_mdio_read(struct mii_bus *bus, int phy_id, int reg)
52{
53	return mpc52xx_fec_mdio_transfer(bus, phy_id, reg, FEC_MII_READ_FRAME);
54}
55
56static int mpc52xx_fec_mdio_write(struct mii_bus *bus, int phy_id, int reg,
57		u16 data)
58{
59	return mpc52xx_fec_mdio_transfer(bus, phy_id, reg,
60		data | FEC_MII_WRITE_FRAME);
61}
62
63static int mpc52xx_fec_mdio_probe(struct platform_device *of)
64{
65	struct device *dev = &of->dev;
66	struct device_node *np = of->dev.of_node;
67	struct mii_bus *bus;
68	struct mpc52xx_fec_mdio_priv *priv;
69	struct resource res;
70	int err;
71
72	bus = mdiobus_alloc();
73	if (bus == NULL)
74		return -ENOMEM;
75	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
76	if (priv == NULL) {
77		err = -ENOMEM;
78		goto out_free;
79	}
80
81	bus->name = "mpc52xx MII bus";
82	bus->read = mpc52xx_fec_mdio_read;
83	bus->write = mpc52xx_fec_mdio_write;
84
85	/* setup registers */
86	err = of_address_to_resource(np, 0, &res);
87	if (err)
88		goto out_free;
89	priv->regs = ioremap(res.start, resource_size(&res));
90	if (priv->regs == NULL) {
91		err = -ENOMEM;
92		goto out_free;
93	}
94
95	snprintf(bus->id, MII_BUS_ID_SIZE, "%x", res.start);
96	bus->priv = priv;
97
98	bus->parent = dev;
99	dev_set_drvdata(dev, bus);
100
101	/* set MII speed */
102	out_be32(&priv->regs->mii_speed,
103		((mpc5xxx_get_bus_frequency(of->dev.of_node) >> 20) / 5) << 1);
104
105	err = of_mdiobus_register(bus, np);
106	if (err)
107		goto out_unmap;
108
109	return 0;
110
111 out_unmap:
112	iounmap(priv->regs);
113 out_free:
114	kfree(priv);
115	mdiobus_free(bus);
116
117	return err;
118}
119
120static int mpc52xx_fec_mdio_remove(struct platform_device *of)
121{
122	struct mii_bus *bus = platform_get_drvdata(of);
123	struct mpc52xx_fec_mdio_priv *priv = bus->priv;
124
125	mdiobus_unregister(bus);
126	iounmap(priv->regs);
127	kfree(priv);
128	mdiobus_free(bus);
129
130	return 0;
131}
132
133static const struct of_device_id mpc52xx_fec_mdio_match[] = {
134	{ .compatible = "fsl,mpc5200b-mdio", },
135	{ .compatible = "fsl,mpc5200-mdio", },
136	{ .compatible = "mpc5200b-fec-phy", },
137	{}
138};
139MODULE_DEVICE_TABLE(of, mpc52xx_fec_mdio_match);
140
141struct platform_driver mpc52xx_fec_mdio_driver = {
142	.driver = {
143		.name = "mpc5200b-fec-phy",
144		.owner = THIS_MODULE,
145		.of_match_table = mpc52xx_fec_mdio_match,
146	},
147	.probe = mpc52xx_fec_mdio_probe,
148	.remove = mpc52xx_fec_mdio_remove,
149};
150
151/* let fec driver call it, since this has to be registered before it */
152EXPORT_SYMBOL_GPL(mpc52xx_fec_mdio_driver);
153
154MODULE_LICENSE("Dual BSD/GPL");
155