/*
 * Driver for the MPC5200 Fast Ethernet Controller
 *
 * Originally written by Dale Farnsworth <dfarnsworth@mvista.com> and
 * now maintained by Sylvain Munaut <tnt@246tNt.com>
 *
 * Copyright (C) 2007  Domen Puncer, Telargo, Inc.
 * Copyright (C) 2007  Sylvain Munaut <tnt@246tNt.com>
 * Copyright (C) 2003-2004  MontaVista, Software, Inc.
 *
 * 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.
 *
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/dma-mapping.h>
#include <linux/module.h>

#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/crc32.h>
#include <linux/hardirq.h>
#include <linux/delay.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/of_mdio.h>
#include <linux/of_net.h>
#include <linux/platform_device.h>

#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/ethtool.h>
#include <linux/skbuff.h>

#include <asm/io.h>
#include <asm/delay.h>
#include <asm/mpc52xx.h>

#include <linux/fsl/bestcomm/bestcomm.h>
#include <linux/fsl/bestcomm/fec.h>

#include "fec_mpc52xx.h"

#define DRIVER_NAME "mpc52xx-fec"

/* Private driver data structure */
struct mpc52xx_fec_priv {
        struct net_device *ndev;
        int duplex;
        int speed;
        int r_irq;
        int t_irq;
        struct mpc52xx_fec __iomem *fec;
        struct bcom_task *rx_dmatsk;
        struct bcom_task *tx_dmatsk;
        spinlock_t lock;
        int msg_enable;

        /* MDIO link details */
        unsigned int mdio_speed;
        struct device_node *phy_node;
        enum phy_state link;
        int seven_wire_mode;
};


static irqreturn_t mpc52xx_fec_interrupt(int, void *);
static irqreturn_t mpc52xx_fec_rx_interrupt(int, void *);
static irqreturn_t mpc52xx_fec_tx_interrupt(int, void *);
static void mpc52xx_fec_stop(struct net_device *dev, bool may_sleep);
static void mpc52xx_fec_start(struct net_device *dev);
static void mpc52xx_fec_reset(struct net_device *dev);

#define MPC52xx_MESSAGES_DEFAULT ( NETIF_MSG_DRV | NETIF_MSG_PROBE | \
                NETIF_MSG_LINK | NETIF_MSG_IFDOWN | NETIF_MSG_IFUP)
static int debug = -1;  /* the above default */
module_param(debug, int, 0);
MODULE_PARM_DESC(debug, "debugging messages level");

static void mpc52xx_fec_tx_timeout(struct net_device *dev, unsigned int txqueue)
{
        struct mpc52xx_fec_priv *priv = netdev_priv(dev);
        unsigned long flags;

        dev_warn(&dev->dev, "transmit timed out\n");

        spin_lock_irqsave(&priv->lock, flags);
        mpc52xx_fec_reset(dev);
        dev->stats.tx_errors++;
        spin_unlock_irqrestore(&priv->lock, flags);

        netif_wake_queue(dev);
}

static void mpc52xx_fec_set_paddr(struct net_device *dev, const u8 *mac)
{
        struct mpc52xx_fec_priv *priv = netdev_priv(dev);
        struct mpc52xx_fec __iomem *fec = priv->fec;

        out_be32(&fec->paddr1, *(const u32 *)(&mac[0]));
        out_be32(&fec->paddr2, (*(const u16 *)(&mac[4]) << 16) | FEC_PADDR2_TYPE);
}

static int mpc52xx_fec_set_mac_address(struct net_device *dev, void *addr)
{
        struct sockaddr *sock = addr;

        eth_hw_addr_set(dev, sock->sa_data);

        mpc52xx_fec_set_paddr(dev, sock->sa_data);
        return 0;
}

static void mpc52xx_fec_free_rx_buffers(struct net_device *dev, struct bcom_task *s)
{
        while (!bcom_queue_empty(s)) {
                struct bcom_fec_bd *bd;
                struct sk_buff *skb;

                skb = bcom_retrieve_buffer(s, NULL, (struct bcom_bd **)&bd);
                dma_unmap_single(dev->dev.parent, bd->skb_pa, skb->len,
                                 DMA_FROM_DEVICE);
                kfree_skb(skb);
        }
}

static void
mpc52xx_fec_rx_submit(struct net_device *dev, struct sk_buff *rskb)
{
        struct mpc52xx_fec_priv *priv = netdev_priv(dev);
        struct bcom_fec_bd *bd;

        bd = (struct bcom_fec_bd *) bcom_prepare_next_buffer(priv->rx_dmatsk);
        bd->status = FEC_RX_BUFFER_SIZE;
        bd->skb_pa = dma_map_single(dev->dev.parent, rskb->data,
                                    FEC_RX_BUFFER_SIZE, DMA_FROM_DEVICE);
        bcom_submit_next_buffer(priv->rx_dmatsk, rskb);
}

static int mpc52xx_fec_alloc_rx_buffers(struct net_device *dev, struct bcom_task *rxtsk)
{
        struct sk_buff *skb;

        while (!bcom_queue_full(rxtsk)) {
                skb = netdev_alloc_skb(dev, FEC_RX_BUFFER_SIZE);
                if (!skb)
                        return -EAGAIN;

                /* zero out the initial receive buffers to aid debugging */
                memset(skb->data, 0, FEC_RX_BUFFER_SIZE);
                mpc52xx_fec_rx_submit(dev, skb);
        }
        return 0;
}

/* based on generic_adjust_link from fs_enet-main.c */
static void mpc52xx_fec_adjust_link(struct net_device *dev)
{
        struct mpc52xx_fec_priv *priv = netdev_priv(dev);
        struct phy_device *phydev = dev->phydev;
        int new_state = 0;

        if (phydev->link != PHY_DOWN) {
                if (phydev->duplex != priv->duplex) {
                        struct mpc52xx_fec __iomem *fec = priv->fec;
                        u32 rcntrl;
                        u32 tcntrl;

                        new_state = 1;
                        priv->duplex = phydev->duplex;

                        rcntrl = in_be32(&fec->r_cntrl);
                        tcntrl = in_be32(&fec->x_cntrl);

                        rcntrl &= ~FEC_RCNTRL_DRT;
                        tcntrl &= ~FEC_TCNTRL_FDEN;
                        if (phydev->duplex == DUPLEX_FULL)
                                tcntrl |= FEC_TCNTRL_FDEN;      /* FD enable */
                        else
                                rcntrl |= FEC_RCNTRL_DRT;       /* disable Rx on Tx (HD) */

                        out_be32(&fec->r_cntrl, rcntrl);
                        out_be32(&fec->x_cntrl, tcntrl);
                }

                if (phydev->speed != priv->speed) {
                        new_state = 1;
                        priv->speed = phydev->speed;
                }

                if (priv->link == PHY_DOWN) {
                        new_state = 1;
                        priv->link = phydev->link;
                }

        } else if (priv->link) {
                new_state = 1;
                priv->link = PHY_DOWN;
                priv->speed = 0;
                priv->duplex = -1;
        }

        if (new_state && netif_msg_link(priv))
                phy_print_status(phydev);
}

static int mpc52xx_fec_open(struct net_device *dev)
{
        struct mpc52xx_fec_priv *priv = netdev_priv(dev);
        struct phy_device *phydev = NULL;
        int err = -EBUSY;

        if (priv->phy_node) {
                phydev = of_phy_connect(priv->ndev, priv->phy_node,
                                        mpc52xx_fec_adjust_link, 0, 0);
                if (!phydev) {
                        dev_err(&dev->dev, "of_phy_connect failed\n");
                        return -ENODEV;
                }
                phy_start(phydev);
        }

        if (request_irq(dev->irq, mpc52xx_fec_interrupt, IRQF_SHARED,
                        DRIVER_NAME "_ctrl", dev)) {
                dev_err(&dev->dev, "ctrl interrupt request failed\n");
                goto free_phy;
        }
        if (request_irq(priv->r_irq, mpc52xx_fec_rx_interrupt, 0,
                        DRIVER_NAME "_rx", dev)) {
                dev_err(&dev->dev, "rx interrupt request failed\n");
                goto free_ctrl_irq;
        }
        if (request_irq(priv->t_irq, mpc52xx_fec_tx_interrupt, 0,
                        DRIVER_NAME "_tx", dev)) {
                dev_err(&dev->dev, "tx interrupt request failed\n");
                goto free_2irqs;
        }

        bcom_fec_rx_reset(priv->rx_dmatsk);
        bcom_fec_tx_reset(priv->tx_dmatsk);

        err = mpc52xx_fec_alloc_rx_buffers(dev, priv->rx_dmatsk);
        if (err) {
                dev_err(&dev->dev, "mpc52xx_fec_alloc_rx_buffers failed\n");
                goto free_irqs;
        }

        bcom_enable(priv->rx_dmatsk);
        bcom_enable(priv->tx_dmatsk);

        mpc52xx_fec_start(dev);

        netif_start_queue(dev);

        return 0;

 free_irqs:
        free_irq(priv->t_irq, dev);
 free_2irqs:
        free_irq(priv->r_irq, dev);
 free_ctrl_irq:
        free_irq(dev->irq, dev);
 free_phy:
        if (phydev) {
                phy_stop(phydev);
                phy_disconnect(phydev);
        }

        return err;
}

static int mpc52xx_fec_close(struct net_device *dev)
{
        struct mpc52xx_fec_priv *priv = netdev_priv(dev);
        struct phy_device *phydev = dev->phydev;

        netif_stop_queue(dev);

        mpc52xx_fec_stop(dev, true);

        mpc52xx_fec_free_rx_buffers(dev, priv->rx_dmatsk);

        free_irq(dev->irq, dev);
        free_irq(priv->r_irq, dev);
        free_irq(priv->t_irq, dev);

        if (phydev) {
                /* power down phy */
                phy_stop(phydev);
                phy_disconnect(phydev);
        }

        return 0;
}

/* This will only be invoked if your driver is _not_ in XOFF state.
 * What this means is that you need not check it, and that this
 * invariant will hold if you make sure that the netif_*_queue()
 * calls are done at the proper times.
 */
static netdev_tx_t
mpc52xx_fec_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
        struct mpc52xx_fec_priv *priv = netdev_priv(dev);
        struct bcom_fec_bd *bd;
        unsigned long flags;

        if (bcom_queue_full(priv->tx_dmatsk)) {
                if (net_ratelimit())
                        dev_err(&dev->dev, "transmit queue overrun\n");
                return NETDEV_TX_BUSY;
        }

        spin_lock_irqsave(&priv->lock, flags);

        bd = (struct bcom_fec_bd *)
                bcom_prepare_next_buffer(priv->tx_dmatsk);

        bd->status = skb->len | BCOM_FEC_TX_BD_TFD | BCOM_FEC_TX_BD_TC;
        bd->skb_pa = dma_map_single(dev->dev.parent, skb->data, skb->len,
                                    DMA_TO_DEVICE);

        skb_tx_timestamp(skb);
        bcom_submit_next_buffer(priv->tx_dmatsk, skb);
        spin_unlock_irqrestore(&priv->lock, flags);

        if (bcom_queue_full(priv->tx_dmatsk)) {
                netif_stop_queue(dev);
        }

        return NETDEV_TX_OK;
}

#ifdef CONFIG_NET_POLL_CONTROLLER
static void mpc52xx_fec_poll_controller(struct net_device *dev)
{
        struct mpc52xx_fec_priv *priv = netdev_priv(dev);

        disable_irq(priv->t_irq);
        mpc52xx_fec_tx_interrupt(priv->t_irq, dev);
        enable_irq(priv->t_irq);
        disable_irq(priv->r_irq);
        mpc52xx_fec_rx_interrupt(priv->r_irq, dev);
        enable_irq(priv->r_irq);
}
#endif


/* This handles BestComm transmit task interrupts
 */
static irqreturn_t mpc52xx_fec_tx_interrupt(int irq, void *dev_id)
{
        struct net_device *dev = dev_id;
        struct mpc52xx_fec_priv *priv = netdev_priv(dev);

        spin_lock(&priv->lock);
        while (bcom_buffer_done(priv->tx_dmatsk)) {
                struct sk_buff *skb;
                struct bcom_fec_bd *bd;
                skb = bcom_retrieve_buffer(priv->tx_dmatsk, NULL,
                                (struct bcom_bd **)&bd);
                dma_unmap_single(dev->dev.parent, bd->skb_pa, skb->len,
                                 DMA_TO_DEVICE);

                dev_consume_skb_irq(skb);
        }
        spin_unlock(&priv->lock);

        netif_wake_queue(dev);

        return IRQ_HANDLED;
}

static irqreturn_t mpc52xx_fec_rx_interrupt(int irq, void *dev_id)
{
        struct net_device *dev = dev_id;
        struct mpc52xx_fec_priv *priv = netdev_priv(dev);
        struct sk_buff *rskb; /* received sk_buff */
        struct sk_buff *skb;  /* new sk_buff to enqueue in its place */
        struct bcom_fec_bd *bd;
        u32 status, physaddr;
        int length;

        spin_lock(&priv->lock);

        while (bcom_buffer_done(priv->rx_dmatsk)) {

                rskb = bcom_retrieve_buffer(priv->rx_dmatsk, &status,
                                            (struct bcom_bd **)&bd);
                physaddr = bd->skb_pa;

                /* Test for errors in received frame */
                if (status & BCOM_FEC_RX_BD_ERRORS) {
                        /* Drop packet and reuse the buffer */
                        mpc52xx_fec_rx_submit(dev, rskb);
                        dev->stats.rx_dropped++;
                        continue;
                }

                /* skbs are allocated on open, so now we allocate a new one,
                 * and remove the old (with the packet) */
                skb = netdev_alloc_skb(dev, FEC_RX_BUFFER_SIZE);
                if (!skb) {
                        /* Can't get a new one : reuse the same & drop pkt */
                        dev_notice(&dev->dev, "Low memory - dropped packet.\n");
                        mpc52xx_fec_rx_submit(dev, rskb);
                        dev->stats.rx_dropped++;
                        continue;
                }

                /* Enqueue the new sk_buff back on the hardware */
                mpc52xx_fec_rx_submit(dev, skb);

                /* Process the received skb - Drop the spin lock while
                 * calling into the network stack */
                spin_unlock(&priv->lock);

                dma_unmap_single(dev->dev.parent, physaddr, rskb->len,
                                 DMA_FROM_DEVICE);
                length = status & BCOM_FEC_RX_BD_LEN_MASK;
                skb_put(rskb, length - 4);      /* length without CRC32 */
                rskb->protocol = eth_type_trans(rskb, dev);
                if (!skb_defer_rx_timestamp(rskb))
                        netif_rx(rskb);

                spin_lock(&priv->lock);
        }

        spin_unlock(&priv->lock);

        return IRQ_HANDLED;
}

static irqreturn_t mpc52xx_fec_interrupt(int irq, void *dev_id)
{
        struct net_device *dev = dev_id;
        struct mpc52xx_fec_priv *priv = netdev_priv(dev);
        struct mpc52xx_fec __iomem *fec = priv->fec;
        u32 ievent;

        ievent = in_be32(&fec->ievent);

        ievent &= ~FEC_IEVENT_MII;      /* mii is handled separately */
        if (!ievent)
                return IRQ_NONE;

        out_be32(&fec->ievent, ievent);         /* clear pending events */

        /* on fifo error, soft-reset fec */
        if (ievent & (FEC_IEVENT_RFIFO_ERROR | FEC_IEVENT_XFIFO_ERROR)) {

                if (net_ratelimit() && (ievent & FEC_IEVENT_RFIFO_ERROR))
                        dev_warn(&dev->dev, "FEC_IEVENT_RFIFO_ERROR\n");
                if (net_ratelimit() && (ievent & FEC_IEVENT_XFIFO_ERROR))
                        dev_warn(&dev->dev, "FEC_IEVENT_XFIFO_ERROR\n");

                spin_lock(&priv->lock);
                mpc52xx_fec_reset(dev);
                spin_unlock(&priv->lock);

                return IRQ_HANDLED;
        }

        if (ievent & ~FEC_IEVENT_TFINT)
                dev_dbg(&dev->dev, "ievent: %08x\n", ievent);

        return IRQ_HANDLED;
}

/*
 * Get the current statistics.
 * This may be called with the card open or closed.
 */
static struct net_device_stats *mpc52xx_fec_get_stats(struct net_device *dev)
{
        struct mpc52xx_fec_priv *priv = netdev_priv(dev);
        struct net_device_stats *stats = &dev->stats;
        struct mpc52xx_fec __iomem *fec = priv->fec;

        stats->rx_bytes = in_be32(&fec->rmon_r_octets);
        stats->rx_packets = in_be32(&fec->rmon_r_packets);
        stats->rx_errors = in_be32(&fec->rmon_r_crc_align) +
                in_be32(&fec->rmon_r_undersize) +
                in_be32(&fec->rmon_r_oversize) +
                in_be32(&fec->rmon_r_frag) +
                in_be32(&fec->rmon_r_jab);

        stats->tx_bytes = in_be32(&fec->rmon_t_octets);
        stats->tx_packets = in_be32(&fec->rmon_t_packets);
        stats->tx_errors = in_be32(&fec->rmon_t_crc_align) +
                in_be32(&fec->rmon_t_undersize) +
                in_be32(&fec->rmon_t_oversize) +
                in_be32(&fec->rmon_t_frag) +
                in_be32(&fec->rmon_t_jab);

        stats->multicast = in_be32(&fec->rmon_r_mc_pkt);
        stats->collisions = in_be32(&fec->rmon_t_col);

        /* detailed rx_errors: */
        stats->rx_length_errors = in_be32(&fec->rmon_r_undersize)
                                        + in_be32(&fec->rmon_r_oversize)
                                        + in_be32(&fec->rmon_r_frag)
                                        + in_be32(&fec->rmon_r_jab);
        stats->rx_over_errors = in_be32(&fec->r_macerr);
        stats->rx_crc_errors = in_be32(&fec->ieee_r_crc);
        stats->rx_frame_errors = in_be32(&fec->ieee_r_align);
        stats->rx_fifo_errors = in_be32(&fec->rmon_r_drop);
        stats->rx_missed_errors = in_be32(&fec->rmon_r_drop);

        /* detailed tx_errors: */
        stats->tx_aborted_errors = 0;
        stats->tx_carrier_errors = in_be32(&fec->ieee_t_cserr);
        stats->tx_fifo_errors = in_be32(&fec->rmon_t_drop);
        stats->tx_heartbeat_errors = in_be32(&fec->ieee_t_sqe);
        stats->tx_window_errors = in_be32(&fec->ieee_t_lcol);

        return stats;
}

/*
 * Read MIB counters in order to reset them,
 * then zero all the stats fields in memory
 */
static void mpc52xx_fec_reset_stats(struct net_device *dev)
{
        struct mpc52xx_fec_priv *priv = netdev_priv(dev);
        struct mpc52xx_fec __iomem *fec = priv->fec;

        out_be32(&fec->mib_control, FEC_MIB_DISABLE);
        memset_io(&fec->rmon_t_drop, 0,
                   offsetof(struct mpc52xx_fec, reserved10) -
                   offsetof(struct mpc52xx_fec, rmon_t_drop));
        out_be32(&fec->mib_control, 0);

        memset(&dev->stats, 0, sizeof(dev->stats));
}

/*
 * Set or clear the multicast filter for this adaptor.
 */
static void mpc52xx_fec_set_multicast_list(struct net_device *dev)
{
        struct mpc52xx_fec_priv *priv = netdev_priv(dev);
        struct mpc52xx_fec __iomem *fec = priv->fec;
        u32 rx_control;

        rx_control = in_be32(&fec->r_cntrl);

        if (dev->flags & IFF_PROMISC) {
                rx_control |= FEC_RCNTRL_PROM;
                out_be32(&fec->r_cntrl, rx_control);
        } else {
                rx_control &= ~FEC_RCNTRL_PROM;
                out_be32(&fec->r_cntrl, rx_control);

                if (dev->flags & IFF_ALLMULTI) {
                        out_be32(&fec->gaddr1, 0xffffffff);
                        out_be32(&fec->gaddr2, 0xffffffff);
                } else {
                        u32 crc;
                        struct netdev_hw_addr *ha;
                        u32 gaddr1 = 0x00000000;
                        u32 gaddr2 = 0x00000000;

                        netdev_for_each_mc_addr(ha, dev) {
                                crc = ether_crc_le(6, ha->addr) >> 26;
                                if (crc >= 32)
                                        gaddr1 |= 1 << (crc-32);
                                else
                                        gaddr2 |= 1 << crc;
                        }
                        out_be32(&fec->gaddr1, gaddr1);
                        out_be32(&fec->gaddr2, gaddr2);
                }
        }
}

/**
 * mpc52xx_fec_hw_init
 * @dev: network device
 *
 * Setup various hardware setting, only needed once on start
 */
static void mpc52xx_fec_hw_init(struct net_device *dev)
{
        struct mpc52xx_fec_priv *priv = netdev_priv(dev);
        struct mpc52xx_fec __iomem *fec = priv->fec;
        int i;

        /* Whack a reset.  We should wait for this. */
        out_be32(&fec->ecntrl, FEC_ECNTRL_RESET);
        for (i = 0; i < FEC_RESET_DELAY; ++i) {
                if ((in_be32(&fec->ecntrl) & FEC_ECNTRL_RESET) == 0)
                        break;
                udelay(1);
        }
        if (i == FEC_RESET_DELAY)
                dev_err(&dev->dev, "FEC Reset timeout!\n");

        /* set pause to 0x20 frames */
        out_be32(&fec->op_pause, FEC_OP_PAUSE_OPCODE | 0x20);

        /* high service request will be deasserted when there's < 7 bytes in fifo
         * low service request will be deasserted when there's < 4*7 bytes in fifo
         */
        out_be32(&fec->rfifo_cntrl, FEC_FIFO_CNTRL_FRAME | FEC_FIFO_CNTRL_LTG_7);
        out_be32(&fec->tfifo_cntrl, FEC_FIFO_CNTRL_FRAME | FEC_FIFO_CNTRL_LTG_7);

        /* alarm when <= x bytes in FIFO */
        out_be32(&fec->rfifo_alarm, 0x0000030c);
        out_be32(&fec->tfifo_alarm, 0x00000100);

        /* begin transmission when 256 bytes are in FIFO (or EOF or FIFO full) */
        out_be32(&fec->x_wmrk, FEC_FIFO_WMRK_256B);

        /* enable crc generation */
        out_be32(&fec->xmit_fsm, FEC_XMIT_FSM_APPEND_CRC | FEC_XMIT_FSM_ENABLE_CRC);
        out_be32(&fec->iaddr1, 0x00000000);     /* No individual filter */
        out_be32(&fec->iaddr2, 0x00000000);     /* No individual filter */

        /* set phy speed.
         * this can't be done in phy driver, since it needs to be called
         * before fec stuff (even on resume) */
        out_be32(&fec->mii_speed, priv->mdio_speed);
}

/**
 * mpc52xx_fec_start
 * @dev: network device
 *
 * This function is called to start or restart the FEC during a link
 * change.  This happens on fifo errors or when switching between half
 * and full duplex.
 */
static void mpc52xx_fec_start(struct net_device *dev)
{
        struct mpc52xx_fec_priv *priv = netdev_priv(dev);
        struct mpc52xx_fec __iomem *fec = priv->fec;
        u32 rcntrl;
        u32 tcntrl;
        u32 tmp;

        /* clear sticky error bits */
        tmp = FEC_FIFO_STATUS_ERR | FEC_FIFO_STATUS_UF | FEC_FIFO_STATUS_OF;
        out_be32(&fec->rfifo_status, in_be32(&fec->rfifo_status) & tmp);
        out_be32(&fec->tfifo_status, in_be32(&fec->tfifo_status) & tmp);

        /* FIFOs will reset on mpc52xx_fec_enable */
        out_be32(&fec->reset_cntrl, FEC_RESET_CNTRL_ENABLE_IS_RESET);

        /* Set station address. */
        mpc52xx_fec_set_paddr(dev, dev->dev_addr);

        mpc52xx_fec_set_multicast_list(dev);

        /* set max frame len, enable flow control, select mii mode */
        rcntrl = FEC_RX_BUFFER_SIZE << 16;      /* max frame length */
        rcntrl |= FEC_RCNTRL_FCE;

        if (!priv->seven_wire_mode)
                rcntrl |= FEC_RCNTRL_MII_MODE;

        if (priv->duplex == DUPLEX_FULL)
                tcntrl = FEC_TCNTRL_FDEN;       /* FD enable */
        else {
                rcntrl |= FEC_RCNTRL_DRT;       /* disable Rx on Tx (HD) */
                tcntrl = 0;
        }
        out_be32(&fec->r_cntrl, rcntrl);
        out_be32(&fec->x_cntrl, tcntrl);

        /* Clear any outstanding interrupt. */
        out_be32(&fec->ievent, 0xffffffff);

        /* Enable interrupts we wish to service. */
        out_be32(&fec->imask, FEC_IMASK_ENABLE);

        /* And last, enable the transmit and receive processing. */
        out_be32(&fec->ecntrl, FEC_ECNTRL_ETHER_EN);
        out_be32(&fec->r_des_active, 0x01000000);
}

/**
 * mpc52xx_fec_stop
 * @dev: network device
 *
 * stop all activity on fec and empty dma buffers
 */
static void mpc52xx_fec_stop(struct net_device *dev, bool may_sleep)
{
        struct mpc52xx_fec_priv *priv = netdev_priv(dev);
        struct mpc52xx_fec __iomem *fec = priv->fec;
        unsigned long timeout;

        /* disable all interrupts */
        out_be32(&fec->imask, 0);

        /* Disable the rx task. */
        bcom_disable(priv->rx_dmatsk);

        /* Wait for tx queue to drain, but only if we're in process context */
        if (may_sleep) {
                timeout = jiffies + msecs_to_jiffies(2000);
                while (time_before(jiffies, timeout) &&
                                !bcom_queue_empty(priv->tx_dmatsk))
                        msleep(100);

                if (time_after_eq(jiffies, timeout))
                        dev_err(&dev->dev, "queues didn't drain\n");
#if 1
                if (time_after_eq(jiffies, timeout)) {
                        dev_err(&dev->dev, "  tx: index: %i, outdex: %i\n",
                                        priv->tx_dmatsk->index,
                                        priv->tx_dmatsk->outdex);
                        dev_err(&dev->dev, "  rx: index: %i, outdex: %i\n",
                                        priv->rx_dmatsk->index,
                                        priv->rx_dmatsk->outdex);
                }
#endif
        }

        bcom_disable(priv->tx_dmatsk);

        /* Stop FEC */
        out_be32(&fec->ecntrl, in_be32(&fec->ecntrl) & ~FEC_ECNTRL_ETHER_EN);
}

/* reset fec and bestcomm tasks */
static void mpc52xx_fec_reset(struct net_device *dev)
{
        struct mpc52xx_fec_priv *priv = netdev_priv(dev);
        struct mpc52xx_fec __iomem *fec = priv->fec;

        mpc52xx_fec_stop(dev, false);

        out_be32(&fec->rfifo_status, in_be32(&fec->rfifo_status));
        out_be32(&fec->reset_cntrl, FEC_RESET_CNTRL_RESET_FIFO);

        mpc52xx_fec_free_rx_buffers(dev, priv->rx_dmatsk);

        mpc52xx_fec_hw_init(dev);

        bcom_fec_rx_reset(priv->rx_dmatsk);
        bcom_fec_tx_reset(priv->tx_dmatsk);

        mpc52xx_fec_alloc_rx_buffers(dev, priv->rx_dmatsk);

        bcom_enable(priv->rx_dmatsk);
        bcom_enable(priv->tx_dmatsk);

        mpc52xx_fec_start(dev);

        netif_wake_queue(dev);
}


/* ethtool interface */

static u32 mpc52xx_fec_get_msglevel(struct net_device *dev)
{
        struct mpc52xx_fec_priv *priv = netdev_priv(dev);
        return priv->msg_enable;
}

static void mpc52xx_fec_set_msglevel(struct net_device *dev, u32 level)
{
        struct mpc52xx_fec_priv *priv = netdev_priv(dev);
        priv->msg_enable = level;
}

static const struct ethtool_ops mpc52xx_fec_ethtool_ops = {
        .get_link = ethtool_op_get_link,
        .get_msglevel = mpc52xx_fec_get_msglevel,
        .set_msglevel = mpc52xx_fec_set_msglevel,
        .get_ts_info = ethtool_op_get_ts_info,
        .get_link_ksettings = phy_ethtool_get_link_ksettings,
        .set_link_ksettings = phy_ethtool_set_link_ksettings,
};


static const struct net_device_ops mpc52xx_fec_netdev_ops = {
        .ndo_open = mpc52xx_fec_open,
        .ndo_stop = mpc52xx_fec_close,
        .ndo_start_xmit = mpc52xx_fec_start_xmit,
        .ndo_set_rx_mode = mpc52xx_fec_set_multicast_list,
        .ndo_set_mac_address = mpc52xx_fec_set_mac_address,
        .ndo_validate_addr = eth_validate_addr,
        .ndo_eth_ioctl = phy_do_ioctl,
        .ndo_tx_timeout = mpc52xx_fec_tx_timeout,
        .ndo_get_stats = mpc52xx_fec_get_stats,
#ifdef CONFIG_NET_POLL_CONTROLLER
        .ndo_poll_controller = mpc52xx_fec_poll_controller,
#endif
};

/* ======================================================================== */
/* OF Driver                                                                */
/* ======================================================================== */

static int mpc52xx_fec_probe(struct platform_device *op)
{
        int rv;
        struct net_device *ndev;
        struct mpc52xx_fec_priv *priv = NULL;
        struct resource mem;
        const u32 *prop;
        int prop_size;
        struct device_node *np = op->dev.of_node;

        phys_addr_t rx_fifo;
        phys_addr_t tx_fifo;

        /* Get the ether ndev & it's private zone */
        ndev = alloc_etherdev(sizeof(struct mpc52xx_fec_priv));
        if (!ndev)
                return -ENOMEM;

        priv = netdev_priv(ndev);
        priv->ndev = ndev;

        /* Reserve FEC control zone */
        rv = of_address_to_resource(np, 0, &mem);
        if (rv) {
                pr_err("Error while parsing device node resource\n");
                goto err_netdev;
        }
        if (resource_size(&mem) < sizeof(struct mpc52xx_fec)) {
                pr_err("invalid resource size (%lx < %x), check mpc52xx_devices.c\n",
                       (unsigned long)resource_size(&mem),
                       sizeof(struct mpc52xx_fec));
                rv = -EINVAL;
                goto err_netdev;
        }

        if (!request_mem_region(mem.start, sizeof(struct mpc52xx_fec),
                                DRIVER_NAME)) {
                rv = -EBUSY;
                goto err_netdev;
        }

        /* Init ether ndev with what we have */
        ndev->netdev_ops        = &mpc52xx_fec_netdev_ops;
        ndev->ethtool_ops       = &mpc52xx_fec_ethtool_ops;
        ndev->watchdog_timeo    = FEC_WATCHDOG_TIMEOUT;
        ndev->base_addr         = mem.start;
        SET_NETDEV_DEV(ndev, &op->dev);

        spin_lock_init(&priv->lock);

        /* ioremap the zones */
        priv->fec = ioremap(mem.start, sizeof(struct mpc52xx_fec));

        if (!priv->fec) {
                rv = -ENOMEM;
                goto err_mem_region;
        }

        /* Bestcomm init */
        rx_fifo = ndev->base_addr + offsetof(struct mpc52xx_fec, rfifo_data);
        tx_fifo = ndev->base_addr + offsetof(struct mpc52xx_fec, tfifo_data);

        priv->rx_dmatsk = bcom_fec_rx_init(FEC_RX_NUM_BD, rx_fifo, FEC_RX_BUFFER_SIZE);
        priv->tx_dmatsk = bcom_fec_tx_init(FEC_TX_NUM_BD, tx_fifo);

        if (!priv->rx_dmatsk || !priv->tx_dmatsk) {
                pr_err("Can not init SDMA tasks\n");
                rv = -ENOMEM;
                goto err_rx_tx_dmatsk;
        }

        /* Get the IRQ we need one by one */
                /* Control */
        ndev->irq = irq_of_parse_and_map(np, 0);

                /* RX */
        priv->r_irq = bcom_get_task_irq(priv->rx_dmatsk);

                /* TX */
        priv->t_irq = bcom_get_task_irq(priv->tx_dmatsk);

        /*
         * MAC address init:
         *
         * First try to read MAC address from DT
         */
        rv = of_get_ethdev_address(np, ndev);
        if (rv) {
                struct mpc52xx_fec __iomem *fec = priv->fec;
                u8 addr[ETH_ALEN] __aligned(4);

                /*
                 * If the MAC addresse is not provided via DT then read
                 * it back from the controller regs
                 */
                *(u32 *)(&addr[0]) = in_be32(&fec->paddr1);
                *(u16 *)(&addr[4]) = in_be32(&fec->paddr2) >> 16;
                eth_hw_addr_set(ndev, addr);
        }

        /*
         * Check if the MAC address is valid, if not get a random one
         */
        if (!is_valid_ether_addr(ndev->dev_addr)) {
                eth_hw_addr_random(ndev);
                dev_warn(&ndev->dev, "using random MAC address %pM\n",
                         ndev->dev_addr);
        }

        priv->msg_enable = netif_msg_init(debug, MPC52xx_MESSAGES_DEFAULT);

        /*
         * Link mode configuration
         */

        /* Start with safe defaults for link connection */
        priv->speed = 100;
        priv->duplex = DUPLEX_HALF;
        priv->mdio_speed = ((mpc5xxx_get_bus_frequency(&op->dev) >> 20) / 5) << 1;

        /* The current speed preconfigures the speed of the MII link */
        prop = of_get_property(np, "current-speed", &prop_size);
        if (prop && (prop_size >= sizeof(u32) * 2)) {
                priv->speed = prop[0];
                priv->duplex = prop[1] ? DUPLEX_FULL : DUPLEX_HALF;
        }

        /* If there is a phy handle, then get the PHY node */
        priv->phy_node = of_parse_phandle(np, "phy-handle", 0);

        /* the 7-wire property means don't use MII mode */
        if (of_property_read_bool(np, "fsl,7-wire-mode")) {
                priv->seven_wire_mode = 1;
                dev_info(&ndev->dev, "using 7-wire PHY mode\n");
        }

        /* Hardware init */
        mpc52xx_fec_hw_init(ndev);
        mpc52xx_fec_reset_stats(ndev);

        rv = register_netdev(ndev);
        if (rv < 0)
                goto err_node;

        /* We're done ! */
        platform_set_drvdata(op, ndev);
        netdev_info(ndev, "%pOF MAC %pM\n",
                    op->dev.of_node, ndev->dev_addr);

        return 0;

err_node:
        of_node_put(priv->phy_node);
        irq_dispose_mapping(ndev->irq);
err_rx_tx_dmatsk:
        if (priv->rx_dmatsk)
                bcom_fec_rx_release(priv->rx_dmatsk);
        if (priv->tx_dmatsk)
                bcom_fec_tx_release(priv->tx_dmatsk);
        iounmap(priv->fec);
err_mem_region:
        release_mem_region(mem.start, sizeof(struct mpc52xx_fec));
err_netdev:
        free_netdev(ndev);

        return rv;
}

static void
mpc52xx_fec_remove(struct platform_device *op)
{
        struct net_device *ndev;
        struct mpc52xx_fec_priv *priv;

        ndev = platform_get_drvdata(op);
        priv = netdev_priv(ndev);

        unregister_netdev(ndev);

        of_node_put(priv->phy_node);
        priv->phy_node = NULL;

        irq_dispose_mapping(ndev->irq);

        bcom_fec_rx_release(priv->rx_dmatsk);
        bcom_fec_tx_release(priv->tx_dmatsk);

        iounmap(priv->fec);

        release_mem_region(ndev->base_addr, sizeof(struct mpc52xx_fec));

        free_netdev(ndev);
}

#ifdef CONFIG_PM
static int mpc52xx_fec_of_suspend(struct platform_device *op, pm_message_t state)
{
        struct net_device *dev = platform_get_drvdata(op);

        if (netif_running(dev))
                mpc52xx_fec_close(dev);

        return 0;
}

static int mpc52xx_fec_of_resume(struct platform_device *op)
{
        struct net_device *dev = platform_get_drvdata(op);

        mpc52xx_fec_hw_init(dev);
        mpc52xx_fec_reset_stats(dev);

        if (netif_running(dev))
                mpc52xx_fec_open(dev);

        return 0;
}
#endif

static const struct of_device_id mpc52xx_fec_match[] = {
        { .compatible = "fsl,mpc5200b-fec", },
        { .compatible = "fsl,mpc5200-fec", },
        { .compatible = "mpc5200-fec", },
        { }
};

MODULE_DEVICE_TABLE(of, mpc52xx_fec_match);

static struct platform_driver mpc52xx_fec_driver = {
        .driver = {
                .name = DRIVER_NAME,
                .of_match_table = mpc52xx_fec_match,
        },
        .probe          = mpc52xx_fec_probe,
        .remove         = mpc52xx_fec_remove,
#ifdef CONFIG_PM
        .suspend        = mpc52xx_fec_of_suspend,
        .resume         = mpc52xx_fec_of_resume,
#endif
};


/* ======================================================================== */
/* Module                                                                   */
/* ======================================================================== */

static struct platform_driver * const drivers[] = {
#ifdef CONFIG_FEC_MPC52xx_MDIO
        &mpc52xx_fec_mdio_driver,
#endif
        &mpc52xx_fec_driver,
};

static int __init
mpc52xx_fec_init(void)
{
        return platform_register_drivers(drivers, ARRAY_SIZE(drivers));
}

static void __exit
mpc52xx_fec_exit(void)
{
        platform_unregister_drivers(drivers, ARRAY_SIZE(drivers));
}


module_init(mpc52xx_fec_init);
module_exit(mpc52xx_fec_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Dale Farnsworth");
MODULE_DESCRIPTION("Ethernet driver for the Freescale MPC52xx FEC");