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_address.h>
 19#include <linux/of_mdio.h>
 20#include <asm/io.h>
 21#include <asm/mpc52xx.h>
 22#include "fec_mpc52xx.h"
 23
 24struct mpc52xx_fec_mdio_priv {
 25	struct mpc52xx_fec __iomem *regs;
 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 registers */
 87	err = of_address_to_resource(np, 0, &res);
 88	if (err)
 89		goto out_free;
 90	priv->regs = ioremap(res.start, resource_size(&res));
 91	if (priv->regs == NULL) {
 92		err = -ENOMEM;
 93		goto out_free;
 94	}
 95
 96	snprintf(bus->id, MII_BUS_ID_SIZE, "%x", res.start);
 97	bus->priv = priv;
 98
 99	bus->parent = dev;
100	dev_set_drvdata(dev, bus);
101
102	/* set MII speed */
103	out_be32(&priv->regs->mii_speed, ((mpc5xxx_get_bus_frequency(dev) >> 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");