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");