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/slab.h>
17#include <linux/of.h>
18#include <linux/of_address.h>
19#include <linux/of_mdio.h>
20#include <linux/platform_device.h>
21#include <asm/io.h>
22#include <asm/mpc52xx.h>
23#include "fec_mpc52xx.h"
24
25struct mpc52xx_fec_mdio_priv {
26	struct mpc52xx_fec __iomem *regs;
27};
28
29static int mpc52xx_fec_mdio_transfer(struct mii_bus *bus, int phy_id,
30		int reg, u32 value)
31{
32	struct mpc52xx_fec_mdio_priv *priv = bus->priv;
33	struct mpc52xx_fec __iomem *fec = priv->regs;
34	int tries = 3;
35
36	value |= (phy_id << FEC_MII_DATA_PA_SHIFT) & FEC_MII_DATA_PA_MSK;
37	value |= (reg << FEC_MII_DATA_RA_SHIFT) & FEC_MII_DATA_RA_MSK;
38
39	out_be32(&fec->ievent, FEC_IEVENT_MII);
40	out_be32(&fec->mii_data, value);
41
42	/* wait for it to finish, this takes about 23 us on lite5200b */
43	while (!(in_be32(&fec->ievent) & FEC_IEVENT_MII) && --tries)
44		msleep(1);
45
46	if (!tries)
47		return -ETIMEDOUT;
48
49	return value & FEC_MII_DATA_OP_RD ?
50		in_be32(&fec->mii_data) & FEC_MII_DATA_DATAMSK : 0;
51}
52
53static int mpc52xx_fec_mdio_read(struct mii_bus *bus, int phy_id, int reg)
54{
55	return mpc52xx_fec_mdio_transfer(bus, phy_id, reg, FEC_MII_READ_FRAME);
56}
57
58static int mpc52xx_fec_mdio_write(struct mii_bus *bus, int phy_id, int reg,
59		u16 data)
60{
61	return mpc52xx_fec_mdio_transfer(bus, phy_id, reg,
62		data | FEC_MII_WRITE_FRAME);
63}
64
65static int mpc52xx_fec_mdio_probe(struct platform_device *of)
66{
67	struct device *dev = &of->dev;
68	struct device_node *np = of->dev.of_node;
69	struct mii_bus *bus;
70	struct mpc52xx_fec_mdio_priv *priv;
71	struct resource res;
72	int err;
73
74	bus = mdiobus_alloc();
75	if (bus == NULL)
76		return -ENOMEM;
77	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
78	if (priv == NULL) {
79		err = -ENOMEM;
80		goto out_free;
81	}
82
83	bus->name = "mpc52xx MII bus";
84	bus->read = mpc52xx_fec_mdio_read;
85	bus->write = mpc52xx_fec_mdio_write;
86
87	/* setup registers */
88	err = of_address_to_resource(np, 0, &res);
89	if (err)
90		goto out_free;
91	priv->regs = ioremap(res.start, resource_size(&res));
92	if (priv->regs == NULL) {
93		err = -ENOMEM;
94		goto out_free;
95	}
96
97	snprintf(bus->id, MII_BUS_ID_SIZE, "%x", res.start);
98	bus->priv = priv;
99
100	bus->parent = dev;
101	dev_set_drvdata(dev, bus);
102
103	/* set MII speed */
104	out_be32(&priv->regs->mii_speed, ((mpc5xxx_get_bus_frequency(dev) >> 20) / 5) << 1);
105
106	err = of_mdiobus_register(bus, np);
107	if (err)
108		goto out_unmap;
109
110	return 0;
111
112 out_unmap:
113	iounmap(priv->regs);
114 out_free:
115	kfree(priv);
116	mdiobus_free(bus);
117
118	return err;
119}
120
121static void mpc52xx_fec_mdio_remove(struct platform_device *of)
122{
123	struct mii_bus *bus = platform_get_drvdata(of);
124	struct mpc52xx_fec_mdio_priv *priv = bus->priv;
125
126	mdiobus_unregister(bus);
127	iounmap(priv->regs);
128	kfree(priv);
129	mdiobus_free(bus);
130}
131
132static const struct of_device_id mpc52xx_fec_mdio_match[] = {
133	{ .compatible = "fsl,mpc5200b-mdio", },
134	{ .compatible = "fsl,mpc5200-mdio", },
135	{ .compatible = "mpc5200b-fec-phy", },
136	{}
137};
138MODULE_DEVICE_TABLE(of, mpc52xx_fec_mdio_match);
139
140struct platform_driver mpc52xx_fec_mdio_driver = {
141	.driver = {
142		.name = "mpc5200b-fec-phy",
143		.owner = THIS_MODULE,
144		.of_match_table = mpc52xx_fec_mdio_match,
145	},
146	.probe = mpc52xx_fec_mdio_probe,
147	.remove_new = mpc52xx_fec_mdio_remove,
148};
149
150/* let fec driver call it, since this has to be registered before it */
151EXPORT_SYMBOL_GPL(mpc52xx_fec_mdio_driver);
152
153MODULE_LICENSE("Dual BSD/GPL");
154