/*
 * Driver for the MPC5200 Fast Ethernet Controller - MDIO bus driver
 *
 * Copyright (C) 2007  Domen Puncer, Telargo, Inc.
 * Copyright (C) 2008  Wolfram Sang, Pengutronix
 *
 * This file is licensed under the terms of the GNU General Public License
 * version 2. This program is licensed "as is" without any warranty of any
 * kind, whether express or implied.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/phy.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_mdio.h>
#include <linux/platform_device.h>
#include <asm/io.h>
#include <asm/mpc52xx.h>
#include "fec_mpc52xx.h"

struct mpc52xx_fec_mdio_priv {
        struct mpc52xx_fec __iomem *regs;
};

static int mpc52xx_fec_mdio_transfer(struct mii_bus *bus, int phy_id,
                int reg, u32 value)
{
        struct mpc52xx_fec_mdio_priv *priv = bus->priv;
        struct mpc52xx_fec __iomem *fec = priv->regs;
        int tries = 3;

        value |= (phy_id << FEC_MII_DATA_PA_SHIFT) & FEC_MII_DATA_PA_MSK;
        value |= (reg << FEC_MII_DATA_RA_SHIFT) & FEC_MII_DATA_RA_MSK;

        out_be32(&fec->ievent, FEC_IEVENT_MII);
        out_be32(&fec->mii_data, value);

        /* wait for it to finish, this takes about 23 us on lite5200b */
        while (!(in_be32(&fec->ievent) & FEC_IEVENT_MII) && --tries)
                msleep(1);

        if (!tries)
                return -ETIMEDOUT;

        return value & FEC_MII_DATA_OP_RD ?
                in_be32(&fec->mii_data) & FEC_MII_DATA_DATAMSK : 0;
}

static int mpc52xx_fec_mdio_read(struct mii_bus *bus, int phy_id, int reg)
{
        return mpc52xx_fec_mdio_transfer(bus, phy_id, reg, FEC_MII_READ_FRAME);
}

static int mpc52xx_fec_mdio_write(struct mii_bus *bus, int phy_id, int reg,
                u16 data)
{
        return mpc52xx_fec_mdio_transfer(bus, phy_id, reg,
                data | FEC_MII_WRITE_FRAME);
}

static int mpc52xx_fec_mdio_probe(struct platform_device *of)
{
        struct device *dev = &of->dev;
        struct device_node *np = of->dev.of_node;
        struct mii_bus *bus;
        struct mpc52xx_fec_mdio_priv *priv;
        struct resource res;
        int err;

        bus = mdiobus_alloc();
        if (bus == NULL)
                return -ENOMEM;
        priv = kzalloc_obj(*priv);
        if (priv == NULL) {
                err = -ENOMEM;
                goto out_free;
        }

        bus->name = "mpc52xx MII bus";
        bus->read = mpc52xx_fec_mdio_read;
        bus->write = mpc52xx_fec_mdio_write;

        /* setup registers */
        err = of_address_to_resource(np, 0, &res);
        if (err)
                goto out_free;
        priv->regs = ioremap(res.start, resource_size(&res));
        if (priv->regs == NULL) {
                err = -ENOMEM;
                goto out_free;
        }

        snprintf(bus->id, MII_BUS_ID_SIZE, "%pa", &res.start);
        bus->priv = priv;

        bus->parent = dev;
        dev_set_drvdata(dev, bus);

        /* set MII speed */
        out_be32(&priv->regs->mii_speed, ((mpc5xxx_get_bus_frequency(dev) >> 20) / 5) << 1);

        err = of_mdiobus_register(bus, np);
        if (err)
                goto out_unmap;

        return 0;

 out_unmap:
        iounmap(priv->regs);
 out_free:
        kfree(priv);
        mdiobus_free(bus);

        return err;
}

static void mpc52xx_fec_mdio_remove(struct platform_device *of)
{
        struct mii_bus *bus = platform_get_drvdata(of);
        struct mpc52xx_fec_mdio_priv *priv = bus->priv;

        mdiobus_unregister(bus);
        iounmap(priv->regs);
        kfree(priv);
        mdiobus_free(bus);
}

static const struct of_device_id mpc52xx_fec_mdio_match[] = {
        { .compatible = "fsl,mpc5200b-mdio", },
        { .compatible = "fsl,mpc5200-mdio", },
        { .compatible = "mpc5200b-fec-phy", },
        {}
};
MODULE_DEVICE_TABLE(of, mpc52xx_fec_mdio_match);

struct platform_driver mpc52xx_fec_mdio_driver = {
        .driver = {
                .name = "mpc5200b-fec-phy",
                .owner = THIS_MODULE,
                .of_match_table = mpc52xx_fec_mdio_match,
        },
        .probe = mpc52xx_fec_mdio_probe,
        .remove = mpc52xx_fec_mdio_remove,
};

/* let fec driver call it, since this has to be registered before it */
EXPORT_SYMBOL_GPL(mpc52xx_fec_mdio_driver);

MODULE_LICENSE("Dual BSD/GPL");