/*
 * Fast Ethernet Controller (FEC) driver for Motorola MPC8xx.
 * Copyright (c) 1997 Dan Malek (dmalek@jlc.net)
 *
 * Right now, I am very wasteful with the buffers.  I allocate memory
 * pages and then divide them into 2K frame buffers.  This way I know I
 * have buffers large enough to hold one frame within one buffer descriptor.
 * Once I get this working, I will use 64 or 128 byte CPM buffers, which
 * will be much more memory efficient and will easily handle lots of
 * small packets.
 *
 * Much better multiple PHY support by Magnus Damm.
 * Copyright (c) 2000 Ericsson Radio Systems AB.
 *
 * Support for FEC controller of ColdFire processors.
 * Copyright (c) 2001-2005 Greg Ungerer (gerg@snapgear.com)
 *
 * Bug fixes and cleanup by Philippe De Muyter (phdm@macqel.be)
 * Copyright (c) 2004-2006 Macq Electronique SA.
 *
 * Copyright (C) 2010-2011 Freescale Semiconductor, Inc.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/ptrace.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/in.h>
#include <linux/ip.h>
#include <net/ip.h>
#include <net/tso.h>
#include <linux/tcp.h>
#include <linux/udp.h>
#include <linux/icmp.h>
#include <linux/spinlock.h>
#include <linux/workqueue.h>
#include <linux/bitops.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/clk.h>
#include <linux/platform_device.h>
#include <linux/phy.h>
#include <linux/fec.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_gpio.h>
#include <linux/of_mdio.h>
#include <linux/of_net.h>
#include <linux/regulator/consumer.h>
#include <linux/if_vlan.h>
#include <linux/pinctrl/consumer.h>
#include <linux/prefetch.h>

#include <asm/cacheflush.h>

#include "fec.h"

static void set_multicast_list(struct net_device *ndev);
static void fec_enet_itr_coal_init(struct net_device *ndev);

#define DRIVER_NAME     "fec"

#define FEC_ENET_GET_QUQUE(_x) ((_x == 0) ? 1 : ((_x == 1) ? 2 : 0))

/* Pause frame feild and FIFO threshold */
#define FEC_ENET_FCE    (1 << 5)
#define FEC_ENET_RSEM_V 0x84
#define FEC_ENET_RSFL_V 16
#define FEC_ENET_RAEM_V 0x8
#define FEC_ENET_RAFL_V 0x8
#define FEC_ENET_OPD_V  0xFFF0

static struct platform_device_id fec_devtype[] = {
        {
                /* keep it for coldfire */
                .name = DRIVER_NAME,
                .driver_data = 0,
        }, {
                .name = "imx25-fec",
                .driver_data = FEC_QUIRK_USE_GASKET,
        }, {
                .name = "imx27-fec",
                .driver_data = 0,
        }, {
                .name = "imx28-fec",
                .driver_data = FEC_QUIRK_ENET_MAC | FEC_QUIRK_SWAP_FRAME |
                                FEC_QUIRK_SINGLE_MDIO,
        }, {
                .name = "imx6q-fec",
                .driver_data = FEC_QUIRK_ENET_MAC | FEC_QUIRK_HAS_GBIT |
                                FEC_QUIRK_HAS_BUFDESC_EX | FEC_QUIRK_HAS_CSUM |
                                FEC_QUIRK_HAS_VLAN | FEC_QUIRK_ERR006358,
        }, {
                .name = "mvf600-fec",
                .driver_data = FEC_QUIRK_ENET_MAC,
        }, {
                .name = "imx6sx-fec",
                .driver_data = FEC_QUIRK_ENET_MAC | FEC_QUIRK_HAS_GBIT |
                                FEC_QUIRK_HAS_BUFDESC_EX | FEC_QUIRK_HAS_CSUM |
                                FEC_QUIRK_HAS_VLAN | FEC_QUIRK_HAS_AVB |
                                FEC_QUIRK_ERR007885 | FEC_QUIRK_BUG_CAPTURE,
        }, {
                /* sentinel */
        }
};
MODULE_DEVICE_TABLE(platform, fec_devtype);

enum imx_fec_type {
        IMX25_FEC = 1,  /* runs on i.mx25/50/53 */
        IMX27_FEC,      /* runs on i.mx27/35/51 */
        IMX28_FEC,
        IMX6Q_FEC,
        MVF600_FEC,
        IMX6SX_FEC,
};

static const struct of_device_id fec_dt_ids[] = {
        { .compatible = "fsl,imx25-fec", .data = &fec_devtype[IMX25_FEC], },
        { .compatible = "fsl,imx27-fec", .data = &fec_devtype[IMX27_FEC], },
        { .compatible = "fsl,imx28-fec", .data = &fec_devtype[IMX28_FEC], },
        { .compatible = "fsl,imx6q-fec", .data = &fec_devtype[IMX6Q_FEC], },
        { .compatible = "fsl,mvf600-fec", .data = &fec_devtype[MVF600_FEC], },
        { .compatible = "fsl,imx6sx-fec", .data = &fec_devtype[IMX6SX_FEC], },
        { /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, fec_dt_ids);

static unsigned char macaddr[ETH_ALEN];
module_param_array(macaddr, byte, NULL, 0);
MODULE_PARM_DESC(macaddr, "FEC Ethernet MAC address");

#if defined(CONFIG_M5272)
/*
 * Some hardware gets it MAC address out of local flash memory.
 * if this is non-zero then assume it is the address to get MAC from.
 */
#if defined(CONFIG_NETtel)
#define FEC_FLASHMAC    0xf0006006
#elif defined(CONFIG_GILBARCONAP) || defined(CONFIG_SCALES)
#define FEC_FLASHMAC    0xf0006000
#elif defined(CONFIG_CANCam)
#define FEC_FLASHMAC    0xf0020000
#elif defined (CONFIG_M5272C3)
#define FEC_FLASHMAC    (0xffe04000 + 4)
#elif defined(CONFIG_MOD5272)
#define FEC_FLASHMAC    0xffc0406b
#else
#define FEC_FLASHMAC    0
#endif
#endif /* CONFIG_M5272 */

/* The FEC stores dest/src/type/vlan, data, and checksum for receive packets.
 */
#define PKT_MAXBUF_SIZE         1522
#define PKT_MINBUF_SIZE         64
#define PKT_MAXBLR_SIZE         1536

/* FEC receive acceleration */
#define FEC_RACC_IPDIS          (1 << 1)
#define FEC_RACC_PRODIS         (1 << 2)
#define FEC_RACC_OPTIONS        (FEC_RACC_IPDIS | FEC_RACC_PRODIS)

/*
 * The 5270/5271/5280/5282/532x RX control register also contains maximum frame
 * size bits. Other FEC hardware does not, so we need to take that into
 * account when setting it.
 */
#if defined(CONFIG_M523x) || defined(CONFIG_M527x) || defined(CONFIG_M528x) || \
    defined(CONFIG_M520x) || defined(CONFIG_M532x) || defined(CONFIG_ARM)
#define OPT_FRAME_SIZE  (PKT_MAXBUF_SIZE << 16)
#else
#define OPT_FRAME_SIZE  0
#endif

/* FEC MII MMFR bits definition */
#define FEC_MMFR_ST             (1 << 30)
#define FEC_MMFR_OP_READ        (2 << 28)
#define FEC_MMFR_OP_WRITE       (1 << 28)
#define FEC_MMFR_PA(v)          ((v & 0x1f) << 23)
#define FEC_MMFR_RA(v)          ((v & 0x1f) << 18)
#define FEC_MMFR_TA             (2 << 16)
#define FEC_MMFR_DATA(v)        (v & 0xffff)
/* FEC ECR bits definition */
#define FEC_ECR_MAGICEN         (1 << 2)
#define FEC_ECR_SLEEP           (1 << 3)

#define FEC_MII_TIMEOUT         30000 /* us */

/* Transmitter timeout */
#define TX_TIMEOUT (2 * HZ)

#define FEC_PAUSE_FLAG_AUTONEG  0x1
#define FEC_PAUSE_FLAG_ENABLE   0x2
#define FEC_WOL_HAS_MAGIC_PACKET        (0x1 << 0)
#define FEC_WOL_FLAG_ENABLE             (0x1 << 1)
#define FEC_WOL_FLAG_SLEEP_ON           (0x1 << 2)

#define COPYBREAK_DEFAULT       256

#define TSO_HEADER_SIZE         128
/* Max number of allowed TCP segments for software TSO */
#define FEC_MAX_TSO_SEGS        100
#define FEC_MAX_SKB_DESCS       (FEC_MAX_TSO_SEGS * 2 + MAX_SKB_FRAGS)

#define IS_TSO_HEADER(txq, addr) \
        ((addr >= txq->tso_hdrs_dma) && \
        (addr < txq->tso_hdrs_dma + txq->tx_ring_size * TSO_HEADER_SIZE))

static int mii_cnt;

static inline
struct bufdesc *fec_enet_get_nextdesc(struct bufdesc *bdp,
                                      struct fec_enet_private *fep,
                                      int queue_id)
{
        struct bufdesc *new_bd = bdp + 1;
        struct bufdesc_ex *ex_new_bd = (struct bufdesc_ex *)bdp + 1;
        struct fec_enet_priv_tx_q *txq = fep->tx_queue[queue_id];
        struct fec_enet_priv_rx_q *rxq = fep->rx_queue[queue_id];
        struct bufdesc_ex *ex_base;
        struct bufdesc *base;
        int ring_size;

        if (bdp >= txq->tx_bd_base) {
                base = txq->tx_bd_base;
                ring_size = txq->tx_ring_size;
                ex_base = (struct bufdesc_ex *)txq->tx_bd_base;
        } else {
                base = rxq->rx_bd_base;
                ring_size = rxq->rx_ring_size;
                ex_base = (struct bufdesc_ex *)rxq->rx_bd_base;
        }

        if (fep->bufdesc_ex)
                return (struct bufdesc *)((ex_new_bd >= (ex_base + ring_size)) ?
                        ex_base : ex_new_bd);
        else
                return (new_bd >= (base + ring_size)) ?
                        base : new_bd;
}

static inline
struct bufdesc *fec_enet_get_prevdesc(struct bufdesc *bdp,
                                      struct fec_enet_private *fep,
                                      int queue_id)
{
        struct bufdesc *new_bd = bdp - 1;
        struct bufdesc_ex *ex_new_bd = (struct bufdesc_ex *)bdp - 1;
        struct fec_enet_priv_tx_q *txq = fep->tx_queue[queue_id];
        struct fec_enet_priv_rx_q *rxq = fep->rx_queue[queue_id];
        struct bufdesc_ex *ex_base;
        struct bufdesc *base;
        int ring_size;

        if (bdp >= txq->tx_bd_base) {
                base = txq->tx_bd_base;
                ring_size = txq->tx_ring_size;
                ex_base = (struct bufdesc_ex *)txq->tx_bd_base;
        } else {
                base = rxq->rx_bd_base;
                ring_size = rxq->rx_ring_size;
                ex_base = (struct bufdesc_ex *)rxq->rx_bd_base;
        }

        if (fep->bufdesc_ex)
                return (struct bufdesc *)((ex_new_bd < ex_base) ?
                        (ex_new_bd + ring_size) : ex_new_bd);
        else
                return (new_bd < base) ? (new_bd + ring_size) : new_bd;
}

static int fec_enet_get_bd_index(struct bufdesc *base, struct bufdesc *bdp,
                                struct fec_enet_private *fep)
{
        return ((const char *)bdp - (const char *)base) / fep->bufdesc_size;
}

static int fec_enet_get_free_txdesc_num(struct fec_enet_private *fep,
                                        struct fec_enet_priv_tx_q *txq)
{
        int entries;

        entries = ((const char *)txq->dirty_tx -
                        (const char *)txq->cur_tx) / fep->bufdesc_size - 1;

        return entries > 0 ? entries : entries + txq->tx_ring_size;
}

static void swap_buffer(void *bufaddr, int len)
{
        int i;
        unsigned int *buf = bufaddr;

        for (i = 0; i < len; i += 4, buf++)
                swab32s(buf);
}

static void swap_buffer2(void *dst_buf, void *src_buf, int len)
{
        int i;
        unsigned int *src = src_buf;
        unsigned int *dst = dst_buf;

        for (i = 0; i < len; i += 4, src++, dst++)
                *dst = swab32p(src);
}

static void fec_dump(struct net_device *ndev)
{
        struct fec_enet_private *fep = netdev_priv(ndev);
        struct bufdesc *bdp;
        struct fec_enet_priv_tx_q *txq;
        int index = 0;

        netdev_info(ndev, "TX ring dump\n");
        pr_info("Nr     SC     addr       len  SKB\n");

        txq = fep->tx_queue[0];
        bdp = txq->tx_bd_base;

        do {
                pr_info("%3u %c%c 0x%04x 0x%08lx %4u %p\n",
                        index,
                        bdp == txq->cur_tx ? 'S' : ' ',
                        bdp == txq->dirty_tx ? 'H' : ' ',
                        bdp->cbd_sc, bdp->cbd_bufaddr, bdp->cbd_datlen,
                        txq->tx_skbuff[index]);
                bdp = fec_enet_get_nextdesc(bdp, fep, 0);
                index++;
        } while (bdp != txq->tx_bd_base);
}

static inline bool is_ipv4_pkt(struct sk_buff *skb)
{
        return skb->protocol == htons(ETH_P_IP) && ip_hdr(skb)->version == 4;
}

static int
fec_enet_clear_csum(struct sk_buff *skb, struct net_device *ndev)
{
        /* Only run for packets requiring a checksum. */
        if (skb->ip_summed != CHECKSUM_PARTIAL)
                return 0;

        if (unlikely(skb_cow_head(skb, 0)))
                return -1;

        if (is_ipv4_pkt(skb))
                ip_hdr(skb)->check = 0;
        *(__sum16 *)(skb->head + skb->csum_start + skb->csum_offset) = 0;

        return 0;
}

static int
fec_enet_txq_submit_frag_skb(struct fec_enet_priv_tx_q *txq,
                             struct sk_buff *skb,
                             struct net_device *ndev)
{
        struct fec_enet_private *fep = netdev_priv(ndev);
        struct bufdesc *bdp = txq->cur_tx;
        struct bufdesc_ex *ebdp;
        int nr_frags = skb_shinfo(skb)->nr_frags;
        unsigned short queue = skb_get_queue_mapping(skb);
        int frag, frag_len;
        unsigned short status;
        unsigned int estatus = 0;
        skb_frag_t *this_frag;
        unsigned int index;
        void *bufaddr;
        dma_addr_t addr;
        int i;

        for (frag = 0; frag < nr_frags; frag++) {
                this_frag = &skb_shinfo(skb)->frags[frag];
                bdp = fec_enet_get_nextdesc(bdp, fep, queue);
                ebdp = (struct bufdesc_ex *)bdp;

                status = bdp->cbd_sc;
                status &= ~BD_ENET_TX_STATS;
                status |= (BD_ENET_TX_TC | BD_ENET_TX_READY);
                frag_len = skb_shinfo(skb)->frags[frag].size;

                /* Handle the last BD specially */
                if (frag == nr_frags - 1) {
                        status |= (BD_ENET_TX_INTR | BD_ENET_TX_LAST);
                        if (fep->bufdesc_ex) {
                                estatus |= BD_ENET_TX_INT;
                                if (unlikely(skb_shinfo(skb)->tx_flags &
                                        SKBTX_HW_TSTAMP && fep->hwts_tx_en))
                                        estatus |= BD_ENET_TX_TS;
                        }
                }

                if (fep->bufdesc_ex) {
                        if (fep->quirks & FEC_QUIRK_HAS_AVB)
                                estatus |= FEC_TX_BD_FTYPE(queue);
                        if (skb->ip_summed == CHECKSUM_PARTIAL)
                                estatus |= BD_ENET_TX_PINS | BD_ENET_TX_IINS;
                        ebdp->cbd_bdu = 0;
                        ebdp->cbd_esc = estatus;
                }

                bufaddr = page_address(this_frag->page.p) + this_frag->page_offset;

                index = fec_enet_get_bd_index(txq->tx_bd_base, bdp, fep);
                if (((unsigned long) bufaddr) & fep->tx_align ||
                        fep->quirks & FEC_QUIRK_SWAP_FRAME) {
                        memcpy(txq->tx_bounce[index], bufaddr, frag_len);
                        bufaddr = txq->tx_bounce[index];

                        if (fep->quirks & FEC_QUIRK_SWAP_FRAME)
                                swap_buffer(bufaddr, frag_len);
                }

                addr = dma_map_single(&fep->pdev->dev, bufaddr, frag_len,
                                      DMA_TO_DEVICE);
                if (dma_mapping_error(&fep->pdev->dev, addr)) {
                        dev_kfree_skb_any(skb);
                        if (net_ratelimit())
                                netdev_err(ndev, "Tx DMA memory map failed\n");
                        goto dma_mapping_error;
                }

                bdp->cbd_bufaddr = addr;
                bdp->cbd_datlen = frag_len;
                bdp->cbd_sc = status;
        }

        txq->cur_tx = bdp;

        return 0;

dma_mapping_error:
        bdp = txq->cur_tx;
        for (i = 0; i < frag; i++) {
                bdp = fec_enet_get_nextdesc(bdp, fep, queue);
                dma_unmap_single(&fep->pdev->dev, bdp->cbd_bufaddr,
                                bdp->cbd_datlen, DMA_TO_DEVICE);
        }
        return NETDEV_TX_OK;
}

static int fec_enet_txq_submit_skb(struct fec_enet_priv_tx_q *txq,
                                   struct sk_buff *skb, struct net_device *ndev)
{
        struct fec_enet_private *fep = netdev_priv(ndev);
        int nr_frags = skb_shinfo(skb)->nr_frags;
        struct bufdesc *bdp, *last_bdp;
        void *bufaddr;
        dma_addr_t addr;
        unsigned short status;
        unsigned short buflen;
        unsigned short queue;
        unsigned int estatus = 0;
        unsigned int index;
        int entries_free;
        int ret;

        entries_free = fec_enet_get_free_txdesc_num(fep, txq);
        if (entries_free < MAX_SKB_FRAGS + 1) {
                dev_kfree_skb_any(skb);
                if (net_ratelimit())
                        netdev_err(ndev, "NOT enough BD for SG!\n");
                return NETDEV_TX_OK;
        }

        /* Protocol checksum off-load for TCP and UDP. */
        if (fec_enet_clear_csum(skb, ndev)) {
                dev_kfree_skb_any(skb);
                return NETDEV_TX_OK;
        }

        /* Fill in a Tx ring entry */
        bdp = txq->cur_tx;
        status = bdp->cbd_sc;
        status &= ~BD_ENET_TX_STATS;

        /* Set buffer length and buffer pointer */
        bufaddr = skb->data;
        buflen = skb_headlen(skb);

        queue = skb_get_queue_mapping(skb);
        index = fec_enet_get_bd_index(txq->tx_bd_base, bdp, fep);
        if (((unsigned long) bufaddr) & fep->tx_align ||
                fep->quirks & FEC_QUIRK_SWAP_FRAME) {
                memcpy(txq->tx_bounce[index], skb->data, buflen);
                bufaddr = txq->tx_bounce[index];

                if (fep->quirks & FEC_QUIRK_SWAP_FRAME)
                        swap_buffer(bufaddr, buflen);
        }

        /* Push the data cache so the CPM does not get stale memory data. */
        addr = dma_map_single(&fep->pdev->dev, bufaddr, buflen, DMA_TO_DEVICE);
        if (dma_mapping_error(&fep->pdev->dev, addr)) {
                dev_kfree_skb_any(skb);
                if (net_ratelimit())
                        netdev_err(ndev, "Tx DMA memory map failed\n");
                return NETDEV_TX_OK;
        }

        if (nr_frags) {
                ret = fec_enet_txq_submit_frag_skb(txq, skb, ndev);
                if (ret)
                        return ret;
        } else {
                status |= (BD_ENET_TX_INTR | BD_ENET_TX_LAST);
                if (fep->bufdesc_ex) {
                        estatus = BD_ENET_TX_INT;
                        if (unlikely(skb_shinfo(skb)->tx_flags &
                                SKBTX_HW_TSTAMP && fep->hwts_tx_en))
                                estatus |= BD_ENET_TX_TS;
                }
        }

        if (fep->bufdesc_ex) {

                struct bufdesc_ex *ebdp = (struct bufdesc_ex *)bdp;

                if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP &&
                        fep->hwts_tx_en))
                        skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;

                if (fep->quirks & FEC_QUIRK_HAS_AVB)
                        estatus |= FEC_TX_BD_FTYPE(queue);

                if (skb->ip_summed == CHECKSUM_PARTIAL)
                        estatus |= BD_ENET_TX_PINS | BD_ENET_TX_IINS;

                ebdp->cbd_bdu = 0;
                ebdp->cbd_esc = estatus;
        }

        last_bdp = txq->cur_tx;
        index = fec_enet_get_bd_index(txq->tx_bd_base, last_bdp, fep);
        /* Save skb pointer */
        txq->tx_skbuff[index] = skb;

        bdp->cbd_datlen = buflen;
        bdp->cbd_bufaddr = addr;

        /* Send it on its way.  Tell FEC it's ready, interrupt when done,
         * it's the last BD of the frame, and to put the CRC on the end.
         */
        status |= (BD_ENET_TX_READY | BD_ENET_TX_TC);
        bdp->cbd_sc = status;

        /* If this was the last BD in the ring, start at the beginning again. */
        bdp = fec_enet_get_nextdesc(last_bdp, fep, queue);

        skb_tx_timestamp(skb);

        txq->cur_tx = bdp;

        /* Trigger transmission start */
        writel(0, fep->hwp + FEC_X_DES_ACTIVE(queue));

        return 0;
}

static int
fec_enet_txq_put_data_tso(struct fec_enet_priv_tx_q *txq, struct sk_buff *skb,
                          struct net_device *ndev,
                          struct bufdesc *bdp, int index, char *data,
                          int size, bool last_tcp, bool is_last)
{
        struct fec_enet_private *fep = netdev_priv(ndev);
        struct bufdesc_ex *ebdp = container_of(bdp, struct bufdesc_ex, desc);
        unsigned short queue = skb_get_queue_mapping(skb);
        unsigned short status;
        unsigned int estatus = 0;
        dma_addr_t addr;

        status = bdp->cbd_sc;
        status &= ~BD_ENET_TX_STATS;

        status |= (BD_ENET_TX_TC | BD_ENET_TX_READY);

        if (((unsigned long) data) & fep->tx_align ||
                fep->quirks & FEC_QUIRK_SWAP_FRAME) {
                memcpy(txq->tx_bounce[index], data, size);
                data = txq->tx_bounce[index];

                if (fep->quirks & FEC_QUIRK_SWAP_FRAME)
                        swap_buffer(data, size);
        }

        addr = dma_map_single(&fep->pdev->dev, data, size, DMA_TO_DEVICE);
        if (dma_mapping_error(&fep->pdev->dev, addr)) {
                dev_kfree_skb_any(skb);
                if (net_ratelimit())
                        netdev_err(ndev, "Tx DMA memory map failed\n");
                return NETDEV_TX_BUSY;
        }

        bdp->cbd_datlen = size;
        bdp->cbd_bufaddr = addr;

        if (fep->bufdesc_ex) {
                if (fep->quirks & FEC_QUIRK_HAS_AVB)
                        estatus |= FEC_TX_BD_FTYPE(queue);
                if (skb->ip_summed == CHECKSUM_PARTIAL)
                        estatus |= BD_ENET_TX_PINS | BD_ENET_TX_IINS;
                ebdp->cbd_bdu = 0;
                ebdp->cbd_esc = estatus;
        }

        /* Handle the last BD specially */
        if (last_tcp)
                status |= (BD_ENET_TX_LAST | BD_ENET_TX_TC);
        if (is_last) {
                status |= BD_ENET_TX_INTR;
                if (fep->bufdesc_ex)
                        ebdp->cbd_esc |= BD_ENET_TX_INT;
        }

        bdp->cbd_sc = status;

        return 0;
}

static int
fec_enet_txq_put_hdr_tso(struct fec_enet_priv_tx_q *txq,
                         struct sk_buff *skb, struct net_device *ndev,
                         struct bufdesc *bdp, int index)
{
        struct fec_enet_private *fep = netdev_priv(ndev);
        int hdr_len = skb_transport_offset(skb) + tcp_hdrlen(skb);
        struct bufdesc_ex *ebdp = container_of(bdp, struct bufdesc_ex, desc);
        unsigned short queue = skb_get_queue_mapping(skb);
        void *bufaddr;
        unsigned long dmabuf;
        unsigned short status;
        unsigned int estatus = 0;

        status = bdp->cbd_sc;
        status &= ~BD_ENET_TX_STATS;
        status |= (BD_ENET_TX_TC | BD_ENET_TX_READY);

        bufaddr = txq->tso_hdrs + index * TSO_HEADER_SIZE;
        dmabuf = txq->tso_hdrs_dma + index * TSO_HEADER_SIZE;
        if (((unsigned long)bufaddr) & fep->tx_align ||
                fep->quirks & FEC_QUIRK_SWAP_FRAME) {
                memcpy(txq->tx_bounce[index], skb->data, hdr_len);
                bufaddr = txq->tx_bounce[index];

                if (fep->quirks & FEC_QUIRK_SWAP_FRAME)
                        swap_buffer(bufaddr, hdr_len);

                dmabuf = dma_map_single(&fep->pdev->dev, bufaddr,
                                        hdr_len, DMA_TO_DEVICE);
                if (dma_mapping_error(&fep->pdev->dev, dmabuf)) {
                        dev_kfree_skb_any(skb);
                        if (net_ratelimit())
                                netdev_err(ndev, "Tx DMA memory map failed\n");
                        return NETDEV_TX_BUSY;
                }
        }

        bdp->cbd_bufaddr = dmabuf;
        bdp->cbd_datlen = hdr_len;

        if (fep->bufdesc_ex) {
                if (fep->quirks & FEC_QUIRK_HAS_AVB)
                        estatus |= FEC_TX_BD_FTYPE(queue);
                if (skb->ip_summed == CHECKSUM_PARTIAL)
                        estatus |= BD_ENET_TX_PINS | BD_ENET_TX_IINS;
                ebdp->cbd_bdu = 0;
                ebdp->cbd_esc = estatus;
        }

        bdp->cbd_sc = status;

        return 0;
}

static int fec_enet_txq_submit_tso(struct fec_enet_priv_tx_q *txq,
                                   struct sk_buff *skb,
                                   struct net_device *ndev)
{
        struct fec_enet_private *fep = netdev_priv(ndev);
        int hdr_len = skb_transport_offset(skb) + tcp_hdrlen(skb);
        int total_len, data_left;
        struct bufdesc *bdp = txq->cur_tx;
        unsigned short queue = skb_get_queue_mapping(skb);
        struct tso_t tso;
        unsigned int index = 0;
        int ret;

        if (tso_count_descs(skb) >= fec_enet_get_free_txdesc_num(fep, txq)) {
                dev_kfree_skb_any(skb);
                if (net_ratelimit())
                        netdev_err(ndev, "NOT enough BD for TSO!\n");
                return NETDEV_TX_OK;
        }

        /* Protocol checksum off-load for TCP and UDP. */
        if (fec_enet_clear_csum(skb, ndev)) {
                dev_kfree_skb_any(skb);
                return NETDEV_TX_OK;
        }

        /* Initialize the TSO handler, and prepare the first payload */
        tso_start(skb, &tso);

        total_len = skb->len - hdr_len;
        while (total_len > 0) {
                char *hdr;

                index = fec_enet_get_bd_index(txq->tx_bd_base, bdp, fep);
                data_left = min_t(int, skb_shinfo(skb)->gso_size, total_len);
                total_len -= data_left;

                /* prepare packet headers: MAC + IP + TCP */
                hdr = txq->tso_hdrs + index * TSO_HEADER_SIZE;
                tso_build_hdr(skb, hdr, &tso, data_left, total_len == 0);
                ret = fec_enet_txq_put_hdr_tso(txq, skb, ndev, bdp, index);
                if (ret)
                        goto err_release;

                while (data_left > 0) {
                        int size;

                        size = min_t(int, tso.size, data_left);
                        bdp = fec_enet_get_nextdesc(bdp, fep, queue);
                        index = fec_enet_get_bd_index(txq->tx_bd_base,
                                                      bdp, fep);
                        ret = fec_enet_txq_put_data_tso(txq, skb, ndev,
                                                        bdp, index,
                                                        tso.data, size,
                                                        size == data_left,
                                                        total_len == 0);
                        if (ret)
                                goto err_release;

                        data_left -= size;
                        tso_build_data(skb, &tso, size);
                }

                bdp = fec_enet_get_nextdesc(bdp, fep, queue);
        }

        /* Save skb pointer */
        txq->tx_skbuff[index] = skb;

        skb_tx_timestamp(skb);
        txq->cur_tx = bdp;

        /* Trigger transmission start */
        if (!(fep->quirks & FEC_QUIRK_ERR007885) ||
            !readl(fep->hwp + FEC_X_DES_ACTIVE(queue)) ||
            !readl(fep->hwp + FEC_X_DES_ACTIVE(queue)) ||
            !readl(fep->hwp + FEC_X_DES_ACTIVE(queue)) ||
            !readl(fep->hwp + FEC_X_DES_ACTIVE(queue)))
                writel(0, fep->hwp + FEC_X_DES_ACTIVE(queue));

        return 0;

err_release:
        /* TODO: Release all used data descriptors for TSO */
        return ret;
}

static netdev_tx_t
fec_enet_start_xmit(struct sk_buff *skb, struct net_device *ndev)
{
        struct fec_enet_private *fep = netdev_priv(ndev);
        int entries_free;
        unsigned short queue;
        struct fec_enet_priv_tx_q *txq;
        struct netdev_queue *nq;
        int ret;

        queue = skb_get_queue_mapping(skb);
        txq = fep->tx_queue[queue];
        nq = netdev_get_tx_queue(ndev, queue);

        if (skb_is_gso(skb))
                ret = fec_enet_txq_submit_tso(txq, skb, ndev);
        else
                ret = fec_enet_txq_submit_skb(txq, skb, ndev);
        if (ret)
                return ret;

        entries_free = fec_enet_get_free_txdesc_num(fep, txq);
        if (entries_free <= txq->tx_stop_threshold)
                netif_tx_stop_queue(nq);

        return NETDEV_TX_OK;
}

/* Init RX & TX buffer descriptors
 */
static void fec_enet_bd_init(struct net_device *dev)
{
        struct fec_enet_private *fep = netdev_priv(dev);
        struct fec_enet_priv_tx_q *txq;
        struct fec_enet_priv_rx_q *rxq;
        struct bufdesc *bdp;
        unsigned int i;
        unsigned int q;

        for (q = 0; q < fep->num_rx_queues; q++) {
                /* Initialize the receive buffer descriptors. */
                rxq = fep->rx_queue[q];
                bdp = rxq->rx_bd_base;

                for (i = 0; i < rxq->rx_ring_size; i++) {

                        /* Initialize the BD for every fragment in the page. */
                        if (bdp->cbd_bufaddr)
                                bdp->cbd_sc = BD_ENET_RX_EMPTY;
                        else
                                bdp->cbd_sc = 0;
                        bdp = fec_enet_get_nextdesc(bdp, fep, q);
                }

                /* Set the last buffer to wrap */
                bdp = fec_enet_get_prevdesc(bdp, fep, q);
                bdp->cbd_sc |= BD_SC_WRAP;

                rxq->cur_rx = rxq->rx_bd_base;
        }

        for (q = 0; q < fep->num_tx_queues; q++) {
                /* ...and the same for transmit */
                txq = fep->tx_queue[q];
                bdp = txq->tx_bd_base;
                txq->cur_tx = bdp;

                for (i = 0; i < txq->tx_ring_size; i++) {
                        /* Initialize the BD for every fragment in the page. */
                        bdp->cbd_sc = 0;
                        if (txq->tx_skbuff[i]) {
                                dev_kfree_skb_any(txq->tx_skbuff[i]);
                                txq->tx_skbuff[i] = NULL;
                        }
                        bdp->cbd_bufaddr = 0;
                        bdp = fec_enet_get_nextdesc(bdp, fep, q);
                }

                /* Set the last buffer to wrap */
                bdp = fec_enet_get_prevdesc(bdp, fep, q);
                bdp->cbd_sc |= BD_SC_WRAP;
                txq->dirty_tx = bdp;
        }
}

static void fec_enet_active_rxring(struct net_device *ndev)
{
        struct fec_enet_private *fep = netdev_priv(ndev);
        int i;

        for (i = 0; i < fep->num_rx_queues; i++)
                writel(0, fep->hwp + FEC_R_DES_ACTIVE(i));
}

static void fec_enet_enable_ring(struct net_device *ndev)
{
        struct fec_enet_private *fep = netdev_priv(ndev);
        struct fec_enet_priv_tx_q *txq;
        struct fec_enet_priv_rx_q *rxq;
        int i;

        for (i = 0; i < fep->num_rx_queues; i++) {
                rxq = fep->rx_queue[i];
                writel(rxq->bd_dma, fep->hwp + FEC_R_DES_START(i));
                writel(PKT_MAXBLR_SIZE, fep->hwp + FEC_R_BUFF_SIZE(i));

                /* enable DMA1/2 */
                if (i)
                        writel(RCMR_MATCHEN | RCMR_CMP(i),
                               fep->hwp + FEC_RCMR(i));
        }

        for (i = 0; i < fep->num_tx_queues; i++) {
                txq = fep->tx_queue[i];
                writel(txq->bd_dma, fep->hwp + FEC_X_DES_START(i));

                /* enable DMA1/2 */
                if (i)
                        writel(DMA_CLASS_EN | IDLE_SLOPE(i),
                               fep->hwp + FEC_DMA_CFG(i));
        }
}

static void fec_enet_reset_skb(struct net_device *ndev)
{
        struct fec_enet_private *fep = netdev_priv(ndev);
        struct fec_enet_priv_tx_q *txq;
        int i, j;

        for (i = 0; i < fep->num_tx_queues; i++) {
                txq = fep->tx_queue[i];

                for (j = 0; j < txq->tx_ring_size; j++) {
                        if (txq->tx_skbuff[j]) {
                                dev_kfree_skb_any(txq->tx_skbuff[j]);
                                txq->tx_skbuff[j] = NULL;
                        }
                }
        }
}

/*
 * This function is called to start or restart the FEC during a link
 * change, transmit timeout, or to reconfigure the FEC.  The network
 * packet processing for this device must be stopped before this call.
 */
static void
fec_restart(struct net_device *ndev)
{
        struct fec_enet_private *fep = netdev_priv(ndev);
        u32 val;
        u32 temp_mac[2];
        u32 rcntl = OPT_FRAME_SIZE | 0x04;
        u32 ecntl = 0x2; /* ETHEREN */

        /* Whack a reset.  We should wait for this.
         * For i.MX6SX SOC, enet use AXI bus, we use disable MAC
         * instead of reset MAC itself.
         */
        if (fep->quirks & FEC_QUIRK_HAS_AVB) {
                writel(0, fep->hwp + FEC_ECNTRL);
        } else {
                writel(1, fep->hwp + FEC_ECNTRL);
                udelay(10);
        }

        /*
         * enet-mac reset will reset mac address registers too,
         * so need to reconfigure it.
         */
        if (fep->quirks & FEC_QUIRK_ENET_MAC) {
                memcpy(&temp_mac, ndev->dev_addr, ETH_ALEN);
                writel(cpu_to_be32(temp_mac[0]), fep->hwp + FEC_ADDR_LOW);
                writel(cpu_to_be32(temp_mac[1]), fep->hwp + FEC_ADDR_HIGH);
        }

        /* Clear any outstanding interrupt. */
        writel(0xffffffff, fep->hwp + FEC_IEVENT);

        fec_enet_bd_init(ndev);

        fec_enet_enable_ring(ndev);

        /* Reset tx SKB buffers. */
        fec_enet_reset_skb(ndev);

        /* Enable MII mode */
        if (fep->full_duplex == DUPLEX_FULL) {
                /* FD enable */
                writel(0x04, fep->hwp + FEC_X_CNTRL);
        } else {
                /* No Rcv on Xmit */
                rcntl |= 0x02;
                writel(0x0, fep->hwp + FEC_X_CNTRL);
        }

        /* Set MII speed */
        writel(fep->phy_speed, fep->hwp + FEC_MII_SPEED);

#if !defined(CONFIG_M5272)
        /* set RX checksum */
        val = readl(fep->hwp + FEC_RACC);
        if (fep->csum_flags & FLAG_RX_CSUM_ENABLED)
                val |= FEC_RACC_OPTIONS;
        else
                val &= ~FEC_RACC_OPTIONS;
        writel(val, fep->hwp + FEC_RACC);
#endif

        /*
         * The phy interface and speed need to get configured
         * differently on enet-mac.
         */
        if (fep->quirks & FEC_QUIRK_ENET_MAC) {
                /* Enable flow control and length check */
                rcntl |= 0x40000000 | 0x00000020;

                /* RGMII, RMII or MII */
                if (fep->phy_interface == PHY_INTERFACE_MODE_RGMII ||
                    fep->phy_interface == PHY_INTERFACE_MODE_RGMII_ID ||
                    fep->phy_interface == PHY_INTERFACE_MODE_RGMII_RXID ||
                    fep->phy_interface == PHY_INTERFACE_MODE_RGMII_TXID)
                        rcntl |= (1 << 6);
                else if (fep->phy_interface == PHY_INTERFACE_MODE_RMII)
                        rcntl |= (1 << 8);
                else
                        rcntl &= ~(1 << 8);

                /* 1G, 100M or 10M */
                if (fep->phy_dev) {
                        if (fep->phy_dev->speed == SPEED_1000)
                                ecntl |= (1 << 5);
                        else if (fep->phy_dev->speed == SPEED_100)
                                rcntl &= ~(1 << 9);
                        else
                                rcntl |= (1 << 9);
                }
        } else {
#ifdef FEC_MIIGSK_ENR
                if (fep->quirks & FEC_QUIRK_USE_GASKET) {
                        u32 cfgr;
                        /* disable the gasket and wait */
                        writel(0, fep->hwp + FEC_MIIGSK_ENR);
                        while (readl(fep->hwp + FEC_MIIGSK_ENR) & 4)
                                udelay(1);

                        /*
                         * configure the gasket:
                         *   RMII, 50 MHz, no loopback, no echo
                         *   MII, 25 MHz, no loopback, no echo
                         */
                        cfgr = (fep->phy_interface == PHY_INTERFACE_MODE_RMII)
                                ? BM_MIIGSK_CFGR_RMII : BM_MIIGSK_CFGR_MII;
                        if (fep->phy_dev && fep->phy_dev->speed == SPEED_10)
                                cfgr |= BM_MIIGSK_CFGR_FRCONT_10M;
                        writel(cfgr, fep->hwp + FEC_MIIGSK_CFGR);

                        /* re-enable the gasket */
                        writel(2, fep->hwp + FEC_MIIGSK_ENR);
                }
#endif
        }

#if !defined(CONFIG_M5272)
        /* enable pause frame*/
        if ((fep->pause_flag & FEC_PAUSE_FLAG_ENABLE) ||
            ((fep->pause_flag & FEC_PAUSE_FLAG_AUTONEG) &&
             fep->phy_dev && fep->phy_dev->pause)) {
                rcntl |= FEC_ENET_FCE;

                /* set FIFO threshold parameter to reduce overrun */
                writel(FEC_ENET_RSEM_V, fep->hwp + FEC_R_FIFO_RSEM);
                writel(FEC_ENET_RSFL_V, fep->hwp + FEC_R_FIFO_RSFL);
                writel(FEC_ENET_RAEM_V, fep->hwp + FEC_R_FIFO_RAEM);
                writel(FEC_ENET_RAFL_V, fep->hwp + FEC_R_FIFO_RAFL);

                /* OPD */
                writel(FEC_ENET_OPD_V, fep->hwp + FEC_OPD);
        } else {
                rcntl &= ~FEC_ENET_FCE;
        }
#endif /* !defined(CONFIG_M5272) */

        writel(rcntl, fep->hwp + FEC_R_CNTRL);

        /* Setup multicast filter. */
        set_multicast_list(ndev);
#ifndef CONFIG_M5272
        writel(0, fep->hwp + FEC_HASH_TABLE_HIGH);
        writel(0, fep->hwp + FEC_HASH_TABLE_LOW);
#endif

        if (fep->quirks & FEC_QUIRK_ENET_MAC) {
                /* enable ENET endian swap */
                ecntl |= (1 << 8);
                /* enable ENET store and forward mode */
                writel(1 << 8, fep->hwp + FEC_X_WMRK);
        }

        if (fep->bufdesc_ex)
                ecntl |= (1 << 4);

#ifndef CONFIG_M5272
        /* Enable the MIB statistic event counters */
        writel(0 << 31, fep->hwp + FEC_MIB_CTRLSTAT);
#endif

        /* And last, enable the transmit and receive processing */
        writel(ecntl, fep->hwp + FEC_ECNTRL);
        fec_enet_active_rxring(ndev);

        if (fep->bufdesc_ex)
                fec_ptp_start_cyclecounter(ndev);

        /* Enable interrupts we wish to service */
        if (fep->link)
                writel(FEC_DEFAULT_IMASK, fep->hwp + FEC_IMASK);
        else
                writel(FEC_ENET_MII, fep->hwp + FEC_IMASK);

        /* Init the interrupt coalescing */
        fec_enet_itr_coal_init(ndev);

}

static void
fec_stop(struct net_device *ndev)
{
        struct fec_enet_private *fep = netdev_priv(ndev);
        struct fec_platform_data *pdata = fep->pdev->dev.platform_data;
        u32 rmii_mode = readl(fep->hwp + FEC_R_CNTRL) & (1 << 8);
        u32 val;

        /* We cannot expect a graceful transmit stop without link !!! */
        if (fep->link) {
                writel(1, fep->hwp + FEC_X_CNTRL); /* Graceful transmit stop */
                udelay(10);
                if (!(readl(fep->hwp + FEC_IEVENT) & FEC_ENET_GRA))
                        netdev_err(ndev, "Graceful transmit stop did not complete!\n");
        }

        /* Whack a reset.  We should wait for this.
         * For i.MX6SX SOC, enet use AXI bus, we use disable MAC
         * instead of reset MAC itself.
         */
        if (!(fep->wol_flag & FEC_WOL_FLAG_SLEEP_ON)) {
                if (fep->quirks & FEC_QUIRK_HAS_AVB) {
                        writel(0, fep->hwp + FEC_ECNTRL);
                } else {
                        writel(1, fep->hwp + FEC_ECNTRL);
                        udelay(10);
                }
                writel(FEC_DEFAULT_IMASK, fep->hwp + FEC_IMASK);
        } else {
                writel(FEC_DEFAULT_IMASK | FEC_ENET_WAKEUP, fep->hwp + FEC_IMASK);
                val = readl(fep->hwp + FEC_ECNTRL);
                val |= (FEC_ECR_MAGICEN | FEC_ECR_SLEEP);
                writel(val, fep->hwp + FEC_ECNTRL);

                if (pdata && pdata->sleep_mode_enable)
                        pdata->sleep_mode_enable(true);
        }
        writel(fep->phy_speed, fep->hwp + FEC_MII_SPEED);

        /* We have to keep ENET enabled to have MII interrupt stay working */
        if (fep->quirks & FEC_QUIRK_ENET_MAC &&
                !(fep->wol_flag & FEC_WOL_FLAG_SLEEP_ON)) {
                writel(2, fep->hwp + FEC_ECNTRL);
                writel(rmii_mode, fep->hwp + FEC_R_CNTRL);
        }
}


static void
fec_timeout(struct net_device *ndev)
{
        struct fec_enet_private *fep = netdev_priv(ndev);

        fec_dump(ndev);

        ndev->stats.tx_errors++;

        schedule_work(&fep->tx_timeout_work);
}

static void fec_enet_timeout_work(struct work_struct *work)
{
        struct fec_enet_private *fep =
                container_of(work, struct fec_enet_private, tx_timeout_work);
        struct net_device *ndev = fep->netdev;

        rtnl_lock();
        if (netif_device_present(ndev) || netif_running(ndev)) {
                napi_disable(&fep->napi);
                netif_tx_lock_bh(ndev);
                fec_restart(ndev);
                netif_wake_queue(ndev);
                netif_tx_unlock_bh(ndev);
                napi_enable(&fep->napi);
        }
        rtnl_unlock();
}

static void
fec_enet_hwtstamp(struct fec_enet_private *fep, unsigned ts,
        struct skb_shared_hwtstamps *hwtstamps)
{
        unsigned long flags;
        u64 ns;

        spin_lock_irqsave(&fep->tmreg_lock, flags);
        ns = timecounter_cyc2time(&fep->tc, ts);
        spin_unlock_irqrestore(&fep->tmreg_lock, flags);

        memset(hwtstamps, 0, sizeof(*hwtstamps));
        hwtstamps->hwtstamp = ns_to_ktime(ns);
}

static void
fec_enet_tx_queue(struct net_device *ndev, u16 queue_id)
{
        struct  fec_enet_private *fep;
        struct bufdesc *bdp;
        unsigned short status;
        struct  sk_buff *skb;
        struct fec_enet_priv_tx_q *txq;
        struct netdev_queue *nq;
        int     index = 0;
        int     entries_free;

        fep = netdev_priv(ndev);

        queue_id = FEC_ENET_GET_QUQUE(queue_id);

        txq = fep->tx_queue[queue_id];
        /* get next bdp of dirty_tx */
        nq = netdev_get_tx_queue(ndev, queue_id);
        bdp = txq->dirty_tx;

        /* get next bdp of dirty_tx */
        bdp = fec_enet_get_nextdesc(bdp, fep, queue_id);

        while (((status = bdp->cbd_sc) & BD_ENET_TX_READY) == 0) {

                /* current queue is empty */
                if (bdp == txq->cur_tx)
                        break;

                index = fec_enet_get_bd_index(txq->tx_bd_base, bdp, fep);

                skb = txq->tx_skbuff[index];
                txq->tx_skbuff[index] = NULL;
                if (!IS_TSO_HEADER(txq, bdp->cbd_bufaddr))
                        dma_unmap_single(&fep->pdev->dev, bdp->cbd_bufaddr,
                                        bdp->cbd_datlen, DMA_TO_DEVICE);
                bdp->cbd_bufaddr = 0;
                if (!skb) {
                        bdp = fec_enet_get_nextdesc(bdp, fep, queue_id);
                        continue;
                }

                /* Check for errors. */
                if (status & (BD_ENET_TX_HB | BD_ENET_TX_LC |
                                   BD_ENET_TX_RL | BD_ENET_TX_UN |
                                   BD_ENET_TX_CSL)) {
                        ndev->stats.tx_errors++;
                        if (status & BD_ENET_TX_HB)  /* No heartbeat */
                                ndev->stats.tx_heartbeat_errors++;
                        if (status & BD_ENET_TX_LC)  /* Late collision */
                                ndev->stats.tx_window_errors++;
                        if (status & BD_ENET_TX_RL)  /* Retrans limit */
                                ndev->stats.tx_aborted_errors++;
                        if (status & BD_ENET_TX_UN)  /* Underrun */
                                ndev->stats.tx_fifo_errors++;
                        if (status & BD_ENET_TX_CSL) /* Carrier lost */
                                ndev->stats.tx_carrier_errors++;
                } else {
                        ndev->stats.tx_packets++;
                        ndev->stats.tx_bytes += skb->len;
                }

                if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS) &&
                        fep->bufdesc_ex) {
                        struct skb_shared_hwtstamps shhwtstamps;
                        struct bufdesc_ex *ebdp = (struct bufdesc_ex *)bdp;

                        fec_enet_hwtstamp(fep, ebdp->ts, &shhwtstamps);
                        skb_tstamp_tx(skb, &shhwtstamps);
                }

                /* Deferred means some collisions occurred during transmit,
                 * but we eventually sent the packet OK.
                 */
                if (status & BD_ENET_TX_DEF)
                        ndev->stats.collisions++;

                /* Free the sk buffer associated with this last transmit */
                dev_kfree_skb_any(skb);

                txq->dirty_tx = bdp;

                /* Update pointer to next buffer descriptor to be transmitted */
                bdp = fec_enet_get_nextdesc(bdp, fep, queue_id);

                /* Since we have freed up a buffer, the ring is no longer full
                 */
                if (netif_queue_stopped(ndev)) {
                        entries_free = fec_enet_get_free_txdesc_num(fep, txq);
                        if (entries_free >= txq->tx_wake_threshold)
                                netif_tx_wake_queue(nq);
                }
        }

        /* ERR006538: Keep the transmitter going */
        if (bdp != txq->cur_tx &&
            readl(fep->hwp + FEC_X_DES_ACTIVE(queue_id)) == 0)
                writel(0, fep->hwp + FEC_X_DES_ACTIVE(queue_id));
}

static void
fec_enet_tx(struct net_device *ndev)
{
        struct fec_enet_private *fep = netdev_priv(ndev);
        u16 queue_id;
        /* First process class A queue, then Class B and Best Effort queue */
        for_each_set_bit(queue_id, &fep->work_tx, FEC_ENET_MAX_TX_QS) {
                clear_bit(queue_id, &fep->work_tx);
                fec_enet_tx_queue(ndev, queue_id);
        }
        return;
}

static int
fec_enet_new_rxbdp(struct net_device *ndev, struct bufdesc *bdp, struct sk_buff *skb)
{
        struct  fec_enet_private *fep = netdev_priv(ndev);
        int off;

        off = ((unsigned long)skb->data) & fep->rx_align;
        if (off)
                skb_reserve(skb, fep->rx_align + 1 - off);

        bdp->cbd_bufaddr = dma_map_single(&fep->pdev->dev, skb->data,
                                          FEC_ENET_RX_FRSIZE - fep->rx_align,
                                          DMA_FROM_DEVICE);
        if (dma_mapping_error(&fep->pdev->dev, bdp->cbd_bufaddr)) {
                if (net_ratelimit())
                        netdev_err(ndev, "Rx DMA memory map failed\n");
                return -ENOMEM;
        }

        return 0;
}

static bool fec_enet_copybreak(struct net_device *ndev, struct sk_buff **skb,
                               struct bufdesc *bdp, u32 length, bool swap)
{
        struct  fec_enet_private *fep = netdev_priv(ndev);
        struct sk_buff *new_skb;

        if (length > fep->rx_copybreak)
                return false;

        new_skb = netdev_alloc_skb(ndev, length);
        if (!new_skb)
                return false;

        dma_sync_single_for_cpu(&fep->pdev->dev, bdp->cbd_bufaddr,
                                FEC_ENET_RX_FRSIZE - fep->rx_align,
                                DMA_FROM_DEVICE);
        if (!swap)
                memcpy(new_skb->data, (*skb)->data, length);
        else
                swap_buffer2(new_skb->data, (*skb)->data, length);
        *skb = new_skb;

        return true;
}

/* During a receive, the cur_rx points to the current incoming buffer.
 * When we update through the ring, if the next incoming buffer has
 * not been given to the system, we just set the empty indicator,
 * effectively tossing the packet.
 */
static int
fec_enet_rx_queue(struct net_device *ndev, int budget, u16 queue_id)
{
        struct fec_enet_private *fep = netdev_priv(ndev);
        struct fec_enet_priv_rx_q *rxq;
        struct bufdesc *bdp;
        unsigned short status;
        struct  sk_buff *skb_new = NULL;
        struct  sk_buff *skb;
        ushort  pkt_len;
        __u8 *data;
        int     pkt_received = 0;
        struct  bufdesc_ex *ebdp = NULL;
        bool    vlan_packet_rcvd = false;
        u16     vlan_tag;
        int     index = 0;
        bool    is_copybreak;
        bool    need_swap = fep->quirks & FEC_QUIRK_SWAP_FRAME;

#ifdef CONFIG_M532x
        flush_cache_all();
#endif
        queue_id = FEC_ENET_GET_QUQUE(queue_id);
        rxq = fep->rx_queue[queue_id];

        /* First, grab all of the stats for the incoming packet.
         * These get messed up if we get called due to a busy condition.
         */
        bdp = rxq->cur_rx;

        while (!((status = bdp->cbd_sc) & BD_ENET_RX_EMPTY)) {

                if (pkt_received >= budget)
                        break;
                pkt_received++;

                /* Since we have allocated space to hold a complete frame,
                 * the last indicator should be set.
                 */
                if ((status & BD_ENET_RX_LAST) == 0)
                        netdev_err(ndev, "rcv is not +last\n");


                /* Check for errors. */
                if (status & (BD_ENET_RX_LG | BD_ENET_RX_SH | BD_ENET_RX_NO |
                           BD_ENET_RX_CR | BD_ENET_RX_OV)) {
                        ndev->stats.rx_errors++;
                        if (status & (BD_ENET_RX_LG | BD_ENET_RX_SH)) {
                                /* Frame too long or too short. */
                                ndev->stats.rx_length_errors++;
                        }
                        if (status & BD_ENET_RX_NO)     /* Frame alignment */
                                ndev->stats.rx_frame_errors++;
                        if (status & BD_ENET_RX_CR)     /* CRC Error */
                                ndev->stats.rx_crc_errors++;
                        if (status & BD_ENET_RX_OV)     /* FIFO overrun */
                                ndev->stats.rx_fifo_errors++;
                }

                /* Report late collisions as a frame error.
                 * On this error, the BD is closed, but we don't know what we
                 * have in the buffer.  So, just drop this frame on the floor.
                 */
                if (status & BD_ENET_RX_CL) {
                        ndev->stats.rx_errors++;
                        ndev->stats.rx_frame_errors++;
                        goto rx_processing_done;
                }

                /* Process the incoming frame. */
                ndev->stats.rx_packets++;
                pkt_len = bdp->cbd_datlen;
                ndev->stats.rx_bytes += pkt_len;

                index = fec_enet_get_bd_index(rxq->rx_bd_base, bdp, fep);
                skb = rxq->rx_skbuff[index];

                /* The packet length includes FCS, but we don't want to
                 * include that when passing upstream as it messes up
                 * bridging applications.
                 */
                is_copybreak = fec_enet_copybreak(ndev, &skb, bdp, pkt_len - 4,
                                                  need_swap);
                if (!is_copybreak) {
                        skb_new = netdev_alloc_skb(ndev, FEC_ENET_RX_FRSIZE);
                        if (unlikely(!skb_new)) {
                                ndev->stats.rx_dropped++;
                                goto rx_processing_done;
                        }
                        dma_unmap_single(&fep->pdev->dev, bdp->cbd_bufaddr,
                                         FEC_ENET_RX_FRSIZE - fep->rx_align,
                                         DMA_FROM_DEVICE);
                }

                prefetch(skb->data - NET_IP_ALIGN);
                skb_put(skb, pkt_len - 4);
                data = skb->data;
                if (!is_copybreak && need_swap)
                        swap_buffer(data, pkt_len);

                /* Extract the enhanced buffer descriptor */
                ebdp = NULL;
                if (fep->bufdesc_ex)
                        ebdp = (struct bufdesc_ex *)bdp;

                /* If this is a VLAN packet remove the VLAN Tag */
                vlan_packet_rcvd = false;
                if ((ndev->features & NETIF_F_HW_VLAN_CTAG_RX) &&
                        fep->bufdesc_ex && (ebdp->cbd_esc & BD_ENET_RX_VLAN)) {
                        /* Push and remove the vlan tag */
                        struct vlan_hdr *vlan_header =
                                        (struct vlan_hdr *) (data + ETH_HLEN);
                        vlan_tag = ntohs(vlan_header->h_vlan_TCI);

                        vlan_packet_rcvd = true;

                        memmove(skb->data + VLAN_HLEN, data, ETH_ALEN * 2);
                        skb_pull(skb, VLAN_HLEN);
                }

                skb->protocol = eth_type_trans(skb, ndev);

                /* Get receive timestamp from the skb */
                if (fep->hwts_rx_en && fep->bufdesc_ex)
                        fec_enet_hwtstamp(fep, ebdp->ts,
                                          skb_hwtstamps(skb));

                if (fep->bufdesc_ex &&
                    (fep->csum_flags & FLAG_RX_CSUM_ENABLED)) {
                        if (!(ebdp->cbd_esc & FLAG_RX_CSUM_ERROR)) {
                                /* don't check it */
                                skb->ip_summed = CHECKSUM_UNNECESSARY;
                        } else {
                                skb_checksum_none_assert(skb);
                        }
                }

                /* Handle received VLAN packets */
                if (vlan_packet_rcvd)
                        __vlan_hwaccel_put_tag(skb,
                                               htons(ETH_P_8021Q),
                                               vlan_tag);

                napi_gro_receive(&fep->napi, skb);

                if (is_copybreak) {
                        dma_sync_single_for_device(&fep->pdev->dev, bdp->cbd_bufaddr,
                                                   FEC_ENET_RX_FRSIZE - fep->rx_align,
                                                   DMA_FROM_DEVICE);
                } else {
                        rxq->rx_skbuff[index] = skb_new;
                        fec_enet_new_rxbdp(ndev, bdp, skb_new);
                }

rx_processing_done:
                /* Clear the status flags for this buffer */
                status &= ~BD_ENET_RX_STATS;

                /* Mark the buffer empty */
                status |= BD_ENET_RX_EMPTY;
                bdp->cbd_sc = status;

                if (fep->bufdesc_ex) {
                        struct bufdesc_ex *ebdp = (struct bufdesc_ex *)bdp;

                        ebdp->cbd_esc = BD_ENET_RX_INT;
                        ebdp->cbd_prot = 0;
                        ebdp->cbd_bdu = 0;
                }

                /* Update BD pointer to next entry */
                bdp = fec_enet_get_nextdesc(bdp, fep, queue_id);

                /* Doing this here will keep the FEC running while we process
                 * incoming frames.  On a heavily loaded network, we should be
                 * able to keep up at the expense of system resources.
                 */
                writel(0, fep->hwp + FEC_R_DES_ACTIVE(queue_id));
        }
        rxq->cur_rx = bdp;
        return pkt_received;
}

static int
fec_enet_rx(struct net_device *ndev, int budget)
{
        int     pkt_received = 0;
        u16     queue_id;
        struct fec_enet_private *fep = netdev_priv(ndev);

        for_each_set_bit(queue_id, &fep->work_rx, FEC_ENET_MAX_RX_QS) {
                clear_bit(queue_id, &fep->work_rx);
                pkt_received += fec_enet_rx_queue(ndev,
                                        budget - pkt_received, queue_id);
        }
        return pkt_received;
}

static bool
fec_enet_collect_events(struct fec_enet_private *fep, uint int_events)
{
        if (int_events == 0)
                return false;

        if (int_events & FEC_ENET_RXF)
                fep->work_rx |= (1 << 2);
        if (int_events & FEC_ENET_RXF_1)
                fep->work_rx |= (1 << 0);
        if (int_events & FEC_ENET_RXF_2)
                fep->work_rx |= (1 << 1);

        if (int_events & FEC_ENET_TXF)
                fep->work_tx |= (1 << 2);
        if (int_events & FEC_ENET_TXF_1)
                fep->work_tx |= (1 << 0);
        if (int_events & FEC_ENET_TXF_2)
                fep->work_tx |= (1 << 1);

        return true;
}

static irqreturn_t
fec_enet_interrupt(int irq, void *dev_id)
{
        struct net_device *ndev = dev_id;
        struct fec_enet_private *fep = netdev_priv(ndev);
        uint int_events;
        irqreturn_t ret = IRQ_NONE;

        int_events = readl(fep->hwp + FEC_IEVENT);
        writel(int_events, fep->hwp + FEC_IEVENT);
        fec_enet_collect_events(fep, int_events);

        if ((fep->work_tx || fep->work_rx) && fep->link) {
                ret = IRQ_HANDLED;

                if (napi_schedule_prep(&fep->napi)) {
                        /* Disable the NAPI interrupts */
                        writel(FEC_ENET_MII, fep->hwp + FEC_IMASK);
                        __napi_schedule(&fep->napi);
                }
        }

        if (int_events & FEC_ENET_MII) {
                ret = IRQ_HANDLED;
                complete(&fep->mdio_done);
        }

        if (fep->ptp_clock)
                fec_ptp_check_pps_event(fep);

        return ret;
}

static int fec_enet_rx_napi(struct napi_struct *napi, int budget)
{
        struct net_device *ndev = napi->dev;
        struct fec_enet_private *fep = netdev_priv(ndev);
        int pkts;

        pkts = fec_enet_rx(ndev, budget);

        fec_enet_tx(ndev);

        if (pkts < budget) {
                napi_complete(napi);
                writel(FEC_DEFAULT_IMASK, fep->hwp + FEC_IMASK);
        }
        return pkts;
}

/* ------------------------------------------------------------------------- */
static void fec_get_mac(struct net_device *ndev)
{
        struct fec_enet_private *fep = netdev_priv(ndev);
        struct fec_platform_data *pdata = dev_get_platdata(&fep->pdev->dev);
        unsigned char *iap, tmpaddr[ETH_ALEN];

        /*
         * try to get mac address in following order:
         *
         * 1) module parameter via kernel command line in form
         *    fec.macaddr=0x00,0x04,0x9f,0x01,0x30,0xe0
         */
        iap = macaddr;

        /*
         * 2) from device tree data
         */
        if (!is_valid_ether_addr(iap)) {
                struct device_node *np = fep->pdev->dev.of_node;
                if (np) {
                        const char *mac = of_get_mac_address(np);
                        if (mac)
                                iap = (unsigned char *) mac;
                }
        }

        /*
         * 3) from flash or fuse (via platform data)
         */
        if (!is_valid_ether_addr(iap)) {
#ifdef CONFIG_M5272
                if (FEC_FLASHMAC)
                        iap = (unsigned char *)FEC_FLASHMAC;
#else
                if (pdata)
                        iap = (unsigned char *)&pdata->mac;
#endif
        }

        /*
         * 4) FEC mac registers set by bootloader
         */
        if (!is_valid_ether_addr(iap)) {
                *((__be32 *) &tmpaddr[0]) =
                        cpu_to_be32(readl(fep->hwp + FEC_ADDR_LOW));
                *((__be16 *) &tmpaddr[4]) =
                        cpu_to_be16(readl(fep->hwp + FEC_ADDR_HIGH) >> 16);
                iap = &tmpaddr[0];
        }

        /*
         * 5) random mac address
         */
        if (!is_valid_ether_addr(iap)) {
                /* Report it and use a random ethernet address instead */
                netdev_err(ndev, "Invalid MAC address: %pM\n", iap);
                eth_hw_addr_random(ndev);
                netdev_info(ndev, "Using random MAC address: %pM\n",
                            ndev->dev_addr);
                return;
        }

        memcpy(ndev->dev_addr, iap, ETH_ALEN);

        /* Adjust MAC if using macaddr */
        if (iap == macaddr)
                 ndev->dev_addr[ETH_ALEN-1] = macaddr[ETH_ALEN-1] + fep->dev_id;
}

/* ------------------------------------------------------------------------- */

/*
 * Phy section
 */
static void fec_enet_adjust_link(struct net_device *ndev)
{
        struct fec_enet_private *fep = netdev_priv(ndev);
        struct phy_device *phy_dev = fep->phy_dev;
        int status_change = 0;

        /* Prevent a state halted on mii error */
        if (fep->mii_timeout && phy_dev->state == PHY_HALTED) {
                phy_dev->state = PHY_RESUMING;
                return;
        }

        /*
         * If the netdev is down, or is going down, we're not interested
         * in link state events, so just mark our idea of the link as down
         * and ignore the event.
         */
        if (!netif_running(ndev) || !netif_device_present(ndev)) {
                fep->link = 0;
        } else if (phy_dev->link) {
                if (!fep->link) {
                        fep->link = phy_dev->link;
                        status_change = 1;
                }

                if (fep->full_duplex != phy_dev->duplex) {
                        fep->full_duplex = phy_dev->duplex;
                        status_change = 1;
                }

                if (phy_dev->speed != fep->speed) {
                        fep->speed = phy_dev->speed;
                        status_change = 1;
                }

                /* if any of the above changed restart the FEC */
                if (status_change) {
                        napi_disable(&fep->napi);
                        netif_tx_lock_bh(ndev);
                        fec_restart(ndev);
                        netif_wake_queue(ndev);
                        netif_tx_unlock_bh(ndev);
                        napi_enable(&fep->napi);
                }
        } else {
                if (fep->link) {
                        napi_disable(&fep->napi);
                        netif_tx_lock_bh(ndev);
                        fec_stop(ndev);
                        netif_tx_unlock_bh(ndev);
                        napi_enable(&fep->napi);
                        fep->link = phy_dev->link;
                        status_change = 1;
                }
        }

        if (status_change)
                phy_print_status(phy_dev);
}

static int fec_enet_mdio_read(struct mii_bus *bus, int mii_id, int regnum)
{
        struct fec_enet_private *fep = bus->priv;
        unsigned long time_left;

        fep->mii_timeout = 0;
        init_completion(&fep->mdio_done);

        /* start a read op */
        writel(FEC_MMFR_ST | FEC_MMFR_OP_READ |
                FEC_MMFR_PA(mii_id) | FEC_MMFR_RA(regnum) |
                FEC_MMFR_TA, fep->hwp + FEC_MII_DATA);

        /* wait for end of transfer */
        time_left = wait_for_completion_timeout(&fep->mdio_done,
                        usecs_to_jiffies(FEC_MII_TIMEOUT));
        if (time_left == 0) {
                fep->mii_timeout = 1;
                netdev_err(fep->netdev, "MDIO read timeout\n");
                return -ETIMEDOUT;
        }

        /* return value */
        return FEC_MMFR_DATA(readl(fep->hwp + FEC_MII_DATA));
}

static int fec_enet_mdio_write(struct mii_bus *bus, int mii_id, int regnum,
                           u16 value)
{
        struct fec_enet_private *fep = bus->priv;
        unsigned long time_left;

        fep->mii_timeout = 0;
        init_completion(&fep->mdio_done);

        /* start a write op */
        writel(FEC_MMFR_ST | FEC_MMFR_OP_WRITE |
                FEC_MMFR_PA(mii_id) | FEC_MMFR_RA(regnum) |
                FEC_MMFR_TA | FEC_MMFR_DATA(value),
                fep->hwp + FEC_MII_DATA);

        /* wait for end of transfer */
        time_left = wait_for_completion_timeout(&fep->mdio_done,
                        usecs_to_jiffies(FEC_MII_TIMEOUT));
        if (time_left == 0) {
                fep->mii_timeout = 1;
                netdev_err(fep->netdev, "MDIO write timeout\n");
                return -ETIMEDOUT;
        }

        return 0;
}

static int fec_enet_clk_enable(struct net_device *ndev, bool enable)
{
        struct fec_enet_private *fep = netdev_priv(ndev);
        int ret;

        if (enable) {
                ret = clk_prepare_enable(fep->clk_ahb);
                if (ret)
                        return ret;
                ret = clk_prepare_enable(fep->clk_ipg);
                if (ret)
                        goto failed_clk_ipg;
                if (fep->clk_enet_out) {
                        ret = clk_prepare_enable(fep->clk_enet_out);
                        if (ret)
                                goto failed_clk_enet_out;
                }
                if (fep->clk_ptp) {
                        mutex_lock(&fep->ptp_clk_mutex);
                        ret = clk_prepare_enable(fep->clk_ptp);
                        if (ret) {
                                mutex_unlock(&fep->ptp_clk_mutex);
                                goto failed_clk_ptp;
                        } else {
                                fep->ptp_clk_on = true;
                        }
                        mutex_unlock(&fep->ptp_clk_mutex);
                }
                if (fep->clk_ref) {
                        ret = clk_prepare_enable(fep->clk_ref);
                        if (ret)
                                goto failed_clk_ref;
                }
        } else {
                clk_disable_unprepare(fep->clk_ahb);
                clk_disable_unprepare(fep->clk_ipg);
                if (fep->clk_enet_out)
                        clk_disable_unprepare(fep->clk_enet_out);
                if (fep->clk_ptp) {
                        mutex_lock(&fep->ptp_clk_mutex);
                        clk_disable_unprepare(fep->clk_ptp);
                        fep->ptp_clk_on = false;
                        mutex_unlock(&fep->ptp_clk_mutex);
                }
                if (fep->clk_ref)
                        clk_disable_unprepare(fep->clk_ref);
        }

        return 0;

failed_clk_ref:
        if (fep->clk_ref)
                clk_disable_unprepare(fep->clk_ref);
failed_clk_ptp:
        if (fep->clk_enet_out)
                clk_disable_unprepare(fep->clk_enet_out);
failed_clk_enet_out:
                clk_disable_unprepare(fep->clk_ipg);
failed_clk_ipg:
                clk_disable_unprepare(fep->clk_ahb);

        return ret;
}

static int fec_enet_mii_probe(struct net_device *ndev)
{
        struct fec_enet_private *fep = netdev_priv(ndev);
        struct phy_device *phy_dev = NULL;
        char mdio_bus_id[MII_BUS_ID_SIZE];
        char phy_name[MII_BUS_ID_SIZE + 3];
        int phy_id;
        int dev_id = fep->dev_id;

        fep->phy_dev = NULL;

        if (fep->phy_node) {
                phy_dev = of_phy_connect(ndev, fep->phy_node,
                                         &fec_enet_adjust_link, 0,
                                         fep->phy_interface);
                if (!phy_dev)
                        return -ENODEV;
        } else {
                /* check for attached phy */
                for (phy_id = 0; (phy_id < PHY_MAX_ADDR); phy_id++) {
                        if ((fep->mii_bus->phy_mask & (1 << phy_id)))
                                continue;
                        if (fep->mii_bus->phy_map[phy_id] == NULL)
                                continue;
                        if (fep->mii_bus->phy_map[phy_id]->phy_id == 0)
                                continue;
                        if (dev_id--)
                                continue;
                        strlcpy(mdio_bus_id, fep->mii_bus->id, MII_BUS_ID_SIZE);
                        break;
                }

                if (phy_id >= PHY_MAX_ADDR) {
                        netdev_info(ndev, "no PHY, assuming direct connection to switch\n");
                        strlcpy(mdio_bus_id, "fixed-0", MII_BUS_ID_SIZE);
                        phy_id = 0;
                }

                snprintf(phy_name, sizeof(phy_name),
                         PHY_ID_FMT, mdio_bus_id, phy_id);
                phy_dev = phy_connect(ndev, phy_name, &fec_enet_adjust_link,
                                      fep->phy_interface);
        }

        if (IS_ERR(phy_dev)) {
                netdev_err(ndev, "could not attach to PHY\n");
                return PTR_ERR(phy_dev);
        }

        /* mask with MAC supported features */
        if (fep->quirks & FEC_QUIRK_HAS_GBIT) {
                phy_dev->supported &= PHY_GBIT_FEATURES;
                phy_dev->supported &= ~SUPPORTED_1000baseT_Half;
#if !defined(CONFIG_M5272)
                phy_dev->supported |= SUPPORTED_Pause;
#endif
        }
        else
                phy_dev->supported &= PHY_BASIC_FEATURES;

        phy_dev->advertising = phy_dev->supported;

        fep->phy_dev = phy_dev;
        fep->link = 0;
        fep->full_duplex = 0;

        netdev_info(ndev, "Freescale FEC PHY driver [%s] (mii_bus:phy_addr=%s, irq=%d)\n",
                    fep->phy_dev->drv->name, dev_name(&fep->phy_dev->dev),
                    fep->phy_dev->irq);

        return 0;
}

static int fec_enet_mii_init(struct platform_device *pdev)
{
        static struct mii_bus *fec0_mii_bus;
        struct net_device *ndev = platform_get_drvdata(pdev);
        struct fec_enet_private *fep = netdev_priv(ndev);
        struct device_node *node;
        int err = -ENXIO, i;
        u32 mii_speed, holdtime;

        /*
         * The i.MX28 dual fec interfaces are not equal.
         * Here are the differences:
         *
         *  - fec0 supports MII & RMII modes while fec1 only supports RMII
         *  - fec0 acts as the 1588 time master while fec1 is slave
         *  - external phys can only be configured by fec0
         *
         * That is to say fec1 can not work independently. It only works
         * when fec0 is working. The reason behind this design is that the
         * second interface is added primarily for Switch mode.
         *
         * Because of the last point above, both phys are attached on fec0
         * mdio interface in board design, and need to be configured by
         * fec0 mii_bus.
         */
        if ((fep->quirks & FEC_QUIRK_SINGLE_MDIO) && fep->dev_id > 0) {
                /* fec1 uses fec0 mii_bus */
                if (mii_cnt && fec0_mii_bus) {
                        fep->mii_bus = fec0_mii_bus;
                        mii_cnt++;
                        return 0;
                }
                return -ENOENT;
        }

        fep->mii_timeout = 0;

        /*
         * Set MII speed to 2.5 MHz (= clk_get_rate() / 2 * phy_speed)
         *
         * The formula for FEC MDC is 'ref_freq / (MII_SPEED x 2)' while
         * for ENET-MAC is 'ref_freq / ((MII_SPEED + 1) x 2)'.  The i.MX28
         * Reference Manual has an error on this, and gets fixed on i.MX6Q
         * document.
         */
        mii_speed = DIV_ROUND_UP(clk_get_rate(fep->clk_ipg), 5000000);
        if (fep->quirks & FEC_QUIRK_ENET_MAC)
                mii_speed--;

        if (mii_speed > 63) {
                dev_err(&pdev->dev,
                        "fec clock (%lu) to fast to get right mii speed\n",
                        clk_get_rate(fep->clk_ipg));
                err = -EINVAL;
                goto err_out;
        }

        /*
         * The i.MX28 and i.MX6 types have another filed in the MSCR (aka
         * MII_SPEED) register that defines the MDIO output hold time. Earlier
         * versions are RAZ there, so just ignore the difference and write the
         * register always.
         * The minimal hold time according to IEE802.3 (clause 22) is 10 ns.
         * HOLDTIME + 1 is the number of clk cycles the fec is holding the
         * output.
         * The HOLDTIME bitfield takes values between 0 and 7 (inclusive).
         * Given that ceil(clkrate / 5000000) <= 64, the calculation for
         * holdtime cannot result in a value greater than 3.
         */
        holdtime = DIV_ROUND_UP(clk_get_rate(fep->clk_ipg), 100000000) - 1;

        fep->phy_speed = mii_speed << 1 | holdtime << 8;

        writel(fep->phy_speed, fep->hwp + FEC_MII_SPEED);

        fep->mii_bus = mdiobus_alloc();
        if (fep->mii_bus == NULL) {
                err = -ENOMEM;
                goto err_out;
        }

        fep->mii_bus->name = "fec_enet_mii_bus";
        fep->mii_bus->read = fec_enet_mdio_read;
        fep->mii_bus->write = fec_enet_mdio_write;
        snprintf(fep->mii_bus->id, MII_BUS_ID_SIZE, "%s-%x",
                pdev->name, fep->dev_id + 1);
        fep->mii_bus->priv = fep;
        fep->mii_bus->parent = &pdev->dev;

        fep->mii_bus->irq = kmalloc(sizeof(int) * PHY_MAX_ADDR, GFP_KERNEL);
        if (!fep->mii_bus->irq) {
                err = -ENOMEM;
                goto err_out_free_mdiobus;
        }

        for (i = 0; i < PHY_MAX_ADDR; i++)
                fep->mii_bus->irq[i] = PHY_POLL;

        node = of_get_child_by_name(pdev->dev.of_node, "mdio");
        if (node) {
                err = of_mdiobus_register(fep->mii_bus, node);
                of_node_put(node);
        } else {
                err = mdiobus_register(fep->mii_bus);
        }

        if (err)
                goto err_out_free_mdio_irq;

        mii_cnt++;

        /* save fec0 mii_bus */
        if (fep->quirks & FEC_QUIRK_SINGLE_MDIO)
                fec0_mii_bus = fep->mii_bus;

        return 0;

err_out_free_mdio_irq:
        kfree(fep->mii_bus->irq);
err_out_free_mdiobus:
        mdiobus_free(fep->mii_bus);
err_out:
        return err;
}

static void fec_enet_mii_remove(struct fec_enet_private *fep)
{
        if (--mii_cnt == 0) {
                mdiobus_unregister(fep->mii_bus);
                kfree(fep->mii_bus->irq);
                mdiobus_free(fep->mii_bus);
        }
}

static int fec_enet_get_settings(struct net_device *ndev,
                                  struct ethtool_cmd *cmd)
{
        struct fec_enet_private *fep = netdev_priv(ndev);
        struct phy_device *phydev = fep->phy_dev;

        if (!phydev)
                return -ENODEV;

        return phy_ethtool_gset(phydev, cmd);
}

static int fec_enet_set_settings(struct net_device *ndev,
                                 struct ethtool_cmd *cmd)
{
        struct fec_enet_private *fep = netdev_priv(ndev);
        struct phy_device *phydev = fep->phy_dev;

        if (!phydev)
                return -ENODEV;

        return phy_ethtool_sset(phydev, cmd);
}

static void fec_enet_get_drvinfo(struct net_device *ndev,
                                 struct ethtool_drvinfo *info)
{
        struct fec_enet_private *fep = netdev_priv(ndev);

        strlcpy(info->driver, fep->pdev->dev.driver->name,
                sizeof(info->driver));
        strlcpy(info->version, "Revision: 1.0", sizeof(info->version));
        strlcpy(info->bus_info, dev_name(&ndev->dev), sizeof(info->bus_info));
}

static int fec_enet_get_ts_info(struct net_device *ndev,
                                struct ethtool_ts_info *info)
{
        struct fec_enet_private *fep = netdev_priv(ndev);

        if (fep->bufdesc_ex) {

                info->so_timestamping = SOF_TIMESTAMPING_TX_SOFTWARE |
                                        SOF_TIMESTAMPING_RX_SOFTWARE |
                                        SOF_TIMESTAMPING_SOFTWARE |
                                        SOF_TIMESTAMPING_TX_HARDWARE |
                                        SOF_TIMESTAMPING_RX_HARDWARE |
                                        SOF_TIMESTAMPING_RAW_HARDWARE;
                if (fep->ptp_clock)
                        info->phc_index = ptp_clock_index(fep->ptp_clock);
                else
                        info->phc_index = -1;

                info->tx_types = (1 << HWTSTAMP_TX_OFF) |
                                 (1 << HWTSTAMP_TX_ON);

                info->rx_filters = (1 << HWTSTAMP_FILTER_NONE) |
                                   (1 << HWTSTAMP_FILTER_ALL);
                return 0;
        } else {
                return ethtool_op_get_ts_info(ndev, info);
        }
}

#if !defined(CONFIG_M5272)

static void fec_enet_get_pauseparam(struct net_device *ndev,
                                    struct ethtool_pauseparam *pause)
{
        struct fec_enet_private *fep = netdev_priv(ndev);

        pause->autoneg = (fep->pause_flag & FEC_PAUSE_FLAG_AUTONEG) != 0;
        pause->tx_pause = (fep->pause_flag & FEC_PAUSE_FLAG_ENABLE) != 0;
        pause->rx_pause = pause->tx_pause;
}

static int fec_enet_set_pauseparam(struct net_device *ndev,
                                   struct ethtool_pauseparam *pause)
{
        struct fec_enet_private *fep = netdev_priv(ndev);

        if (!fep->phy_dev)
                return -ENODEV;

        if (pause->tx_pause != pause->rx_pause) {
                netdev_info(ndev,
                        "hardware only support enable/disable both tx and rx");
                return -EINVAL;
        }

        fep->pause_flag = 0;

        /* tx pause must be same as rx pause */
        fep->pause_flag |= pause->rx_pause ? FEC_PAUSE_FLAG_ENABLE : 0;
        fep->pause_flag |= pause->autoneg ? FEC_PAUSE_FLAG_AUTONEG : 0;

        if (pause->rx_pause || pause->autoneg) {
                fep->phy_dev->supported |= ADVERTISED_Pause;
                fep->phy_dev->advertising |= ADVERTISED_Pause;
        } else {
                fep->phy_dev->supported &= ~ADVERTISED_Pause;
                fep->phy_dev->advertising &= ~ADVERTISED_Pause;
        }

        if (pause->autoneg) {
                if (netif_running(ndev))
                        fec_stop(ndev);
                phy_start_aneg(fep->phy_dev);
        }
        if (netif_running(ndev)) {
                napi_disable(&fep->napi);
                netif_tx_lock_bh(ndev);
                fec_restart(ndev);
                netif_wake_queue(ndev);
                netif_tx_unlock_bh(ndev);
                napi_enable(&fep->napi);
        }

        return 0;
}

static const struct fec_stat {
        char name[ETH_GSTRING_LEN];
        u16 offset;
} fec_stats[] = {
        /* RMON TX */
        { "tx_dropped", RMON_T_DROP },
        { "tx_packets", RMON_T_PACKETS },
        { "tx_broadcast", RMON_T_BC_PKT },
        { "tx_multicast", RMON_T_MC_PKT },
        { "tx_crc_errors", RMON_T_CRC_ALIGN },
        { "tx_undersize", RMON_T_UNDERSIZE },
        { "tx_oversize", RMON_T_OVERSIZE },
        { "tx_fragment", RMON_T_FRAG },
        { "tx_jabber", RMON_T_JAB },
        { "tx_collision", RMON_T_COL },
        { "tx_64byte", RMON_T_P64 },
        { "tx_65to127byte", RMON_T_P65TO127 },
        { "tx_128to255byte", RMON_T_P128TO255 },
        { "tx_256to511byte", RMON_T_P256TO511 },
        { "tx_512to1023byte", RMON_T_P512TO1023 },
        { "tx_1024to2047byte", RMON_T_P1024TO2047 },
        { "tx_GTE2048byte", RMON_T_P_GTE2048 },
        { "tx_octets", RMON_T_OCTETS },

        /* IEEE TX */
        { "IEEE_tx_drop", IEEE_T_DROP },
        { "IEEE_tx_frame_ok", IEEE_T_FRAME_OK },
        { "IEEE_tx_1col", IEEE_T_1COL },
        { "IEEE_tx_mcol", IEEE_T_MCOL },
        { "IEEE_tx_def", IEEE_T_DEF },
        { "IEEE_tx_lcol", IEEE_T_LCOL },
        { "IEEE_tx_excol", IEEE_T_EXCOL },
        { "IEEE_tx_macerr", IEEE_T_MACERR },
        { "IEEE_tx_cserr", IEEE_T_CSERR },
        { "IEEE_tx_sqe", IEEE_T_SQE },
        { "IEEE_tx_fdxfc", IEEE_T_FDXFC },
        { "IEEE_tx_octets_ok", IEEE_T_OCTETS_OK },

        /* RMON RX */
        { "rx_packets", RMON_R_PACKETS },
        { "rx_broadcast", RMON_R_BC_PKT },
        { "rx_multicast", RMON_R_MC_PKT },
        { "rx_crc_errors", RMON_R_CRC_ALIGN },
        { "rx_undersize", RMON_R_UNDERSIZE },
        { "rx_oversize", RMON_R_OVERSIZE },
        { "rx_fragment", RMON_R_FRAG },
        { "rx_jabber", RMON_R_JAB },
        { "rx_64byte", RMON_R_P64 },
        { "rx_65to127byte", RMON_R_P65TO127 },
        { "rx_128to255byte", RMON_R_P128TO255 },
        { "rx_256to511byte", RMON_R_P256TO511 },
        { "rx_512to1023byte", RMON_R_P512TO1023 },
        { "rx_1024to2047byte", RMON_R_P1024TO2047 },
        { "rx_GTE2048byte", RMON_R_P_GTE2048 },
        { "rx_octets", RMON_R_OCTETS },

        /* IEEE RX */
        { "IEEE_rx_drop", IEEE_R_DROP },
        { "IEEE_rx_frame_ok", IEEE_R_FRAME_OK },
        { "IEEE_rx_crc", IEEE_R_CRC },
        { "IEEE_rx_align", IEEE_R_ALIGN },
        { "IEEE_rx_macerr", IEEE_R_MACERR },
        { "IEEE_rx_fdxfc", IEEE_R_FDXFC },
        { "IEEE_rx_octets_ok", IEEE_R_OCTETS_OK },
};

static void fec_enet_get_ethtool_stats(struct net_device *dev,
        struct ethtool_stats *stats, u64 *data)
{
        struct fec_enet_private *fep = netdev_priv(dev);
        int i;

        for (i = 0; i < ARRAY_SIZE(fec_stats); i++)
                data[i] = readl(fep->hwp + fec_stats[i].offset);
}

static void fec_enet_get_strings(struct net_device *netdev,
        u32 stringset, u8 *data)
{
        int i;
        switch (stringset) {
        case ETH_SS_STATS:
                for (i = 0; i < ARRAY_SIZE(fec_stats); i++)
                        memcpy(data + i * ETH_GSTRING_LEN,
                                fec_stats[i].name, ETH_GSTRING_LEN);
                break;
        }
}

static int fec_enet_get_sset_count(struct net_device *dev, int sset)
{
        switch (sset) {
        case ETH_SS_STATS:
                return ARRAY_SIZE(fec_stats);
        default:
                return -EOPNOTSUPP;
        }
}
#endif /* !defined(CONFIG_M5272) */

static int fec_enet_nway_reset(struct net_device *dev)
{
        struct fec_enet_private *fep = netdev_priv(dev);
        struct phy_device *phydev = fep->phy_dev;

        if (!phydev)
                return -ENODEV;

        return genphy_restart_aneg(phydev);
}

/* ITR clock source is enet system clock (clk_ahb).
 * TCTT unit is cycle_ns * 64 cycle
 * So, the ICTT value = X us / (cycle_ns * 64)
 */
static int fec_enet_us_to_itr_clock(struct net_device *ndev, int us)
{
        struct fec_enet_private *fep = netdev_priv(ndev);

        return us * (fep->itr_clk_rate / 64000) / 1000;
}

/* Set threshold for interrupt coalescing */
static void fec_enet_itr_coal_set(struct net_device *ndev)
{
        struct fec_enet_private *fep = netdev_priv(ndev);
        int rx_itr, tx_itr;

        if (!(fep->quirks & FEC_QUIRK_HAS_AVB))
                return;

        /* Must be greater than zero to avoid unpredictable behavior */
        if (!fep->rx_time_itr || !fep->rx_pkts_itr ||
            !fep->tx_time_itr || !fep->tx_pkts_itr)
                return;

        /* Select enet system clock as Interrupt Coalescing
         * timer Clock Source
         */
        rx_itr = FEC_ITR_CLK_SEL;
        tx_itr = FEC_ITR_CLK_SEL;

        /* set ICFT and ICTT */
        rx_itr |= FEC_ITR_ICFT(fep->rx_pkts_itr);
        rx_itr |= FEC_ITR_ICTT(fec_enet_us_to_itr_clock(ndev, fep->rx_time_itr));
        tx_itr |= FEC_ITR_ICFT(fep->tx_pkts_itr);
        tx_itr |= FEC_ITR_ICTT(fec_enet_us_to_itr_clock(ndev, fep->tx_time_itr));

        rx_itr |= FEC_ITR_EN;
        tx_itr |= FEC_ITR_EN;

        writel(tx_itr, fep->hwp + FEC_TXIC0);
        writel(rx_itr, fep->hwp + FEC_RXIC0);
        writel(tx_itr, fep->hwp + FEC_TXIC1);
        writel(rx_itr, fep->hwp + FEC_RXIC1);
        writel(tx_itr, fep->hwp + FEC_TXIC2);
        writel(rx_itr, fep->hwp + FEC_RXIC2);
}

static int
fec_enet_get_coalesce(struct net_device *ndev, struct ethtool_coalesce *ec)
{
        struct fec_enet_private *fep = netdev_priv(ndev);

        if (!(fep->quirks & FEC_QUIRK_HAS_AVB))
                return -EOPNOTSUPP;

        ec->rx_coalesce_usecs = fep->rx_time_itr;
        ec->rx_max_coalesced_frames = fep->rx_pkts_itr;

        ec->tx_coalesce_usecs = fep->tx_time_itr;
        ec->tx_max_coalesced_frames = fep->tx_pkts_itr;

        return 0;
}

static int
fec_enet_set_coalesce(struct net_device *ndev, struct ethtool_coalesce *ec)
{
        struct fec_enet_private *fep = netdev_priv(ndev);
        unsigned int cycle;

        if (!(fep->quirks & FEC_QUIRK_HAS_AVB))
                return -EOPNOTSUPP;

        if (ec->rx_max_coalesced_frames > 255) {
                pr_err("Rx coalesced frames exceed hardware limiation");
                return -EINVAL;
        }

        if (ec->tx_max_coalesced_frames > 255) {
                pr_err("Tx coalesced frame exceed hardware limiation");
                return -EINVAL;
        }

        cycle = fec_enet_us_to_itr_clock(ndev, fep->rx_time_itr);
        if (cycle > 0xFFFF) {
                pr_err("Rx coalesed usec exceeed hardware limiation");
                return -EINVAL;
        }

        cycle = fec_enet_us_to_itr_clock(ndev, fep->tx_time_itr);
        if (cycle > 0xFFFF) {
                pr_err("Rx coalesed usec exceeed hardware limiation");
                return -EINVAL;
        }

        fep->rx_time_itr = ec->rx_coalesce_usecs;
        fep->rx_pkts_itr = ec->rx_max_coalesced_frames;

        fep->tx_time_itr = ec->tx_coalesce_usecs;
        fep->tx_pkts_itr = ec->tx_max_coalesced_frames;

        fec_enet_itr_coal_set(ndev);

        return 0;
}

static void fec_enet_itr_coal_init(struct net_device *ndev)
{
        struct ethtool_coalesce ec;

        ec.rx_coalesce_usecs = FEC_ITR_ICTT_DEFAULT;
        ec.rx_max_coalesced_frames = FEC_ITR_ICFT_DEFAULT;

        ec.tx_coalesce_usecs = FEC_ITR_ICTT_DEFAULT;
        ec.tx_max_coalesced_frames = FEC_ITR_ICFT_DEFAULT;

        fec_enet_set_coalesce(ndev, &ec);
}

static int fec_enet_get_tunable(struct net_device *netdev,
                                const struct ethtool_tunable *tuna,
                                void *data)
{
        struct fec_enet_private *fep = netdev_priv(netdev);
        int ret = 0;

        switch (tuna->id) {
        case ETHTOOL_RX_COPYBREAK:
                *(u32 *)data = fep->rx_copybreak;
                break;
        default:
                ret = -EINVAL;
                break;
        }

        return ret;
}

static int fec_enet_set_tunable(struct net_device *netdev,
                                const struct ethtool_tunable *tuna,
                                const void *data)
{
        struct fec_enet_private *fep = netdev_priv(netdev);
        int ret = 0;

        switch (tuna->id) {
        case ETHTOOL_RX_COPYBREAK:
                fep->rx_copybreak = *(u32 *)data;
                break;
        default:
                ret = -EINVAL;
                break;
        }

        return ret;
}

static void
fec_enet_get_wol(struct net_device *ndev, struct ethtool_wolinfo *wol)
{
        struct fec_enet_private *fep = netdev_priv(ndev);

        if (fep->wol_flag & FEC_WOL_HAS_MAGIC_PACKET) {
                wol->supported = WAKE_MAGIC;
                wol->wolopts = fep->wol_flag & FEC_WOL_FLAG_ENABLE ? WAKE_MAGIC : 0;
        } else {
                wol->supported = wol->wolopts = 0;
        }
}

static int
fec_enet_set_wol(struct net_device *ndev, struct ethtool_wolinfo *wol)
{
        struct fec_enet_private *fep = netdev_priv(ndev);

        if (!(fep->wol_flag & FEC_WOL_HAS_MAGIC_PACKET))
                return -EINVAL;

        if (wol->wolopts & ~WAKE_MAGIC)
                return -EINVAL;

        device_set_wakeup_enable(&ndev->dev, wol->wolopts & WAKE_MAGIC);
        if (device_may_wakeup(&ndev->dev)) {
                fep->wol_flag |= FEC_WOL_FLAG_ENABLE;
                if (fep->irq[0] > 0)
                        enable_irq_wake(fep->irq[0]);
        } else {
                fep->wol_flag &= (~FEC_WOL_FLAG_ENABLE);
                if (fep->irq[0] > 0)
                        disable_irq_wake(fep->irq[0]);
        }

        return 0;
}

static const struct ethtool_ops fec_enet_ethtool_ops = {
        .get_settings           = fec_enet_get_settings,
        .set_settings           = fec_enet_set_settings,
        .get_drvinfo            = fec_enet_get_drvinfo,
        .nway_reset             = fec_enet_nway_reset,
        .get_link               = ethtool_op_get_link,
        .get_coalesce           = fec_enet_get_coalesce,
        .set_coalesce           = fec_enet_set_coalesce,
#ifndef CONFIG_M5272
        .get_pauseparam         = fec_enet_get_pauseparam,
        .set_pauseparam         = fec_enet_set_pauseparam,
        .get_strings            = fec_enet_get_strings,
        .get_ethtool_stats      = fec_enet_get_ethtool_stats,
        .get_sset_count         = fec_enet_get_sset_count,
#endif
        .get_ts_info            = fec_enet_get_ts_info,
        .get_tunable            = fec_enet_get_tunable,
        .set_tunable            = fec_enet_set_tunable,
        .get_wol                = fec_enet_get_wol,
        .set_wol                = fec_enet_set_wol,
};

static int fec_enet_ioctl(struct net_device *ndev, struct ifreq *rq, int cmd)
{
        struct fec_enet_private *fep = netdev_priv(ndev);
        struct phy_device *phydev = fep->phy_dev;

        if (!netif_running(ndev))
                return -EINVAL;

        if (!phydev)
                return -ENODEV;

        if (fep->bufdesc_ex) {
                if (cmd == SIOCSHWTSTAMP)
                        return fec_ptp_set(ndev, rq);
                if (cmd == SIOCGHWTSTAMP)
                        return fec_ptp_get(ndev, rq);
        }

        return phy_mii_ioctl(phydev, rq, cmd);
}

static void fec_enet_free_buffers(struct net_device *ndev)
{
        struct fec_enet_private *fep = netdev_priv(ndev);
        unsigned int i;
        struct sk_buff *skb;
        struct bufdesc  *bdp;
        struct fec_enet_priv_tx_q *txq;
        struct fec_enet_priv_rx_q *rxq;
        unsigned int q;

        for (q = 0; q < fep->num_rx_queues; q++) {
                rxq = fep->rx_queue[q];
                bdp = rxq->rx_bd_base;
                for (i = 0; i < rxq->rx_ring_size; i++) {
                        skb = rxq->rx_skbuff[i];
                        rxq->rx_skbuff[i] = NULL;
                        if (skb) {
                                dma_unmap_single(&fep->pdev->dev,
                                                 bdp->cbd_bufaddr,
                                                 FEC_ENET_RX_FRSIZE - fep->rx_align,
                                                 DMA_FROM_DEVICE);
                                dev_kfree_skb(skb);
                        }
                        bdp = fec_enet_get_nextdesc(bdp, fep, q);
                }
        }

        for (q = 0; q < fep->num_tx_queues; q++) {
                txq = fep->tx_queue[q];
                bdp = txq->tx_bd_base;
                for (i = 0; i < txq->tx_ring_size; i++) {
                        kfree(txq->tx_bounce[i]);
                        txq->tx_bounce[i] = NULL;
                        skb = txq->tx_skbuff[i];
                        txq->tx_skbuff[i] = NULL;
                        dev_kfree_skb(skb);
                }
        }
}

static void fec_enet_free_queue(struct net_device *ndev)
{
        struct fec_enet_private *fep = netdev_priv(ndev);
        int i;
        struct fec_enet_priv_tx_q *txq;

        for (i = 0; i < fep->num_tx_queues; i++)
                if (fep->tx_queue[i] && fep->tx_queue[i]->tso_hdrs) {
                        txq = fep->tx_queue[i];
                        dma_free_coherent(NULL,
                                          txq->tx_ring_size * TSO_HEADER_SIZE,
                                          txq->tso_hdrs,
                                          txq->tso_hdrs_dma);
                }

        for (i = 0; i < fep->num_rx_queues; i++)
                kfree(fep->rx_queue[i]);
        for (i = 0; i < fep->num_tx_queues; i++)
                kfree(fep->tx_queue[i]);
}

static int fec_enet_alloc_queue(struct net_device *ndev)
{
        struct fec_enet_private *fep = netdev_priv(ndev);
        int i;
        int ret = 0;
        struct fec_enet_priv_tx_q *txq;

        for (i = 0; i < fep->num_tx_queues; i++) {
                txq = kzalloc(sizeof(*txq), GFP_KERNEL);
                if (!txq) {
                        ret = -ENOMEM;
                        goto alloc_failed;
                }

                fep->tx_queue[i] = txq;
                txq->tx_ring_size = TX_RING_SIZE;
                fep->total_tx_ring_size += fep->tx_queue[i]->tx_ring_size;

                txq->tx_stop_threshold = FEC_MAX_SKB_DESCS;
                txq->tx_wake_threshold =
                                (txq->tx_ring_size - txq->tx_stop_threshold) / 2;

                txq->tso_hdrs = dma_alloc_coherent(NULL,
                                        txq->tx_ring_size * TSO_HEADER_SIZE,
                                        &txq->tso_hdrs_dma,
                                        GFP_KERNEL);
                if (!txq->tso_hdrs) {
                        ret = -ENOMEM;
                        goto alloc_failed;
                }
        }

        for (i = 0; i < fep->num_rx_queues; i++) {
                fep->rx_queue[i] = kzalloc(sizeof(*fep->rx_queue[i]),
                                           GFP_KERNEL);
                if (!fep->rx_queue[i]) {
                        ret = -ENOMEM;
                        goto alloc_failed;
                }

                fep->rx_queue[i]->rx_ring_size = RX_RING_SIZE;
                fep->total_rx_ring_size += fep->rx_queue[i]->rx_ring_size;
        }
        return ret;

alloc_failed:
        fec_enet_free_queue(ndev);
        return ret;
}

static int
fec_enet_alloc_rxq_buffers(struct net_device *ndev, unsigned int queue)
{
        struct fec_enet_private *fep = netdev_priv(ndev);
        unsigned int i;
        struct sk_buff *skb;
        struct bufdesc  *bdp;
        struct fec_enet_priv_rx_q *rxq;

        rxq = fep->rx_queue[queue];
        bdp = rxq->rx_bd_base;
        for (i = 0; i < rxq->rx_ring_size; i++) {
                skb = netdev_alloc_skb(ndev, FEC_ENET_RX_FRSIZE);
                if (!skb)
                        goto err_alloc;

                if (fec_enet_new_rxbdp(ndev, bdp, skb)) {
                        dev_kfree_skb(skb);
                        goto err_alloc;
                }

                rxq->rx_skbuff[i] = skb;
                bdp->cbd_sc = BD_ENET_RX_EMPTY;

                if (fep->bufdesc_ex) {
                        struct bufdesc_ex *ebdp = (struct bufdesc_ex *)bdp;
                        ebdp->cbd_esc = BD_ENET_RX_INT;
                }

                bdp = fec_enet_get_nextdesc(bdp, fep, queue);
        }

        /* Set the last buffer to wrap. */
        bdp = fec_enet_get_prevdesc(bdp, fep, queue);
        bdp->cbd_sc |= BD_SC_WRAP;
        return 0;

 err_alloc:
        fec_enet_free_buffers(ndev);
        return -ENOMEM;
}

static int
fec_enet_alloc_txq_buffers(struct net_device *ndev, unsigned int queue)
{
        struct fec_enet_private *fep = netdev_priv(ndev);
        unsigned int i;
        struct bufdesc  *bdp;
        struct fec_enet_priv_tx_q *txq;

        txq = fep->tx_queue[queue];
        bdp = txq->tx_bd_base;
        for (i = 0; i < txq->tx_ring_size; i++) {
                txq->tx_bounce[i] = kmalloc(FEC_ENET_TX_FRSIZE, GFP_KERNEL);
                if (!txq->tx_bounce[i])
                        goto err_alloc;

                bdp->cbd_sc = 0;
                bdp->cbd_bufaddr = 0;

                if (fep->bufdesc_ex) {
                        struct bufdesc_ex *ebdp = (struct bufdesc_ex *)bdp;
                        ebdp->cbd_esc = BD_ENET_TX_INT;
                }

                bdp = fec_enet_get_nextdesc(bdp, fep, queue);
        }

        /* Set the last buffer to wrap. */
        bdp = fec_enet_get_prevdesc(bdp, fep, queue);
        bdp->cbd_sc |= BD_SC_WRAP;

        return 0;

 err_alloc:
        fec_enet_free_buffers(ndev);
        return -ENOMEM;
}

static int fec_enet_alloc_buffers(struct net_device *ndev)
{
        struct fec_enet_private *fep = netdev_priv(ndev);
        unsigned int i;

        for (i = 0; i < fep->num_rx_queues; i++)
                if (fec_enet_alloc_rxq_buffers(ndev, i))
                        return -ENOMEM;

        for (i = 0; i < fep->num_tx_queues; i++)
                if (fec_enet_alloc_txq_buffers(ndev, i))
                        return -ENOMEM;
        return 0;
}

static int
fec_enet_open(struct net_device *ndev)
{
        struct fec_enet_private *fep = netdev_priv(ndev);
        int ret;

        pinctrl_pm_select_default_state(&fep->pdev->dev);
        ret = fec_enet_clk_enable(ndev, true);
        if (ret)
                return ret;

        /* I should reset the ring buffers here, but I don't yet know
         * a simple way to do that.
         */

        ret = fec_enet_alloc_buffers(ndev);
        if (ret)
                goto err_enet_alloc;

        /* Probe and connect to PHY when open the interface */
        ret = fec_enet_mii_probe(ndev);
        if (ret)
                goto err_enet_mii_probe;

        fec_restart(ndev);
        napi_enable(&fep->napi);
        phy_start(fep->phy_dev);
        netif_tx_start_all_queues(ndev);

        device_set_wakeup_enable(&ndev->dev, fep->wol_flag &
                                 FEC_WOL_FLAG_ENABLE);

        return 0;

err_enet_mii_probe:
        fec_enet_free_buffers(ndev);
err_enet_alloc:
        fec_enet_clk_enable(ndev, false);
        pinctrl_pm_select_sleep_state(&fep->pdev->dev);
        return ret;
}

static int
fec_enet_close(struct net_device *ndev)
{
        struct fec_enet_private *fep = netdev_priv(ndev);

        phy_stop(fep->phy_dev);

        if (netif_device_present(ndev)) {
                napi_disable(&fep->napi);
                netif_tx_disable(ndev);
                fec_stop(ndev);
        }

        phy_disconnect(fep->phy_dev);
        fep->phy_dev = NULL;

        fec_enet_clk_enable(ndev, false);
        pinctrl_pm_select_sleep_state(&fep->pdev->dev);
        fec_enet_free_buffers(ndev);

        return 0;
}

/* Set or clear the multicast filter for this adaptor.
 * Skeleton taken from sunlance driver.
 * The CPM Ethernet implementation allows Multicast as well as individual
 * MAC address filtering.  Some of the drivers check to make sure it is
 * a group multicast address, and discard those that are not.  I guess I
 * will do the same for now, but just remove the test if you want
 * individual filtering as well (do the upper net layers want or support
 * this kind of feature?).
 */

#define HASH_BITS       6               /* #bits in hash */
#define CRC32_POLY      0xEDB88320

static void set_multicast_list(struct net_device *ndev)
{
        struct fec_enet_private *fep = netdev_priv(ndev);
        struct netdev_hw_addr *ha;
        unsigned int i, bit, data, crc, tmp;
        unsigned char hash;

        if (ndev->flags & IFF_PROMISC) {
                tmp = readl(fep->hwp + FEC_R_CNTRL);
                tmp |= 0x8;
                writel(tmp, fep->hwp + FEC_R_CNTRL);
                return;
        }

        tmp = readl(fep->hwp + FEC_R_CNTRL);
        tmp &= ~0x8;
        writel(tmp, fep->hwp + FEC_R_CNTRL);

        if (ndev->flags & IFF_ALLMULTI) {
                /* Catch all multicast addresses, so set the
                 * filter to all 1's
                 */
                writel(0xffffffff, fep->hwp + FEC_GRP_HASH_TABLE_HIGH);
                writel(0xffffffff, fep->hwp + FEC_GRP_HASH_TABLE_LOW);

                return;
        }

        /* Clear filter and add the addresses in hash register
         */
        writel(0, fep->hwp + FEC_GRP_HASH_TABLE_HIGH);
        writel(0, fep->hwp + FEC_GRP_HASH_TABLE_LOW);

        netdev_for_each_mc_addr(ha, ndev) {
                /* calculate crc32 value of mac address */
                crc = 0xffffffff;

                for (i = 0; i < ndev->addr_len; i++) {
                        data = ha->addr[i];
                        for (bit = 0; bit < 8; bit++, data >>= 1) {
                                crc = (crc >> 1) ^
                                (((crc ^ data) & 1) ? CRC32_POLY : 0);
                        }
                }

                /* only upper 6 bits (HASH_BITS) are used
                 * which point to specific bit in he hash registers
                 */
                hash = (crc >> (32 - HASH_BITS)) & 0x3f;

                if (hash > 31) {
                        tmp = readl(fep->hwp + FEC_GRP_HASH_TABLE_HIGH);
                        tmp |= 1 << (hash - 32);
                        writel(tmp, fep->hwp + FEC_GRP_HASH_TABLE_HIGH);
                } else {
                        tmp = readl(fep->hwp + FEC_GRP_HASH_TABLE_LOW);
                        tmp |= 1 << hash;
                        writel(tmp, fep->hwp + FEC_GRP_HASH_TABLE_LOW);
                }
        }
}

/* Set a MAC change in hardware. */
static int
fec_set_mac_address(struct net_device *ndev, void *p)
{
        struct fec_enet_private *fep = netdev_priv(ndev);
        struct sockaddr *addr = p;

        if (addr) {
                if (!is_valid_ether_addr(addr->sa_data))
                        return -EADDRNOTAVAIL;
                memcpy(ndev->dev_addr, addr->sa_data, ndev->addr_len);
        }

        writel(ndev->dev_addr[3] | (ndev->dev_addr[2] << 8) |
                (ndev->dev_addr[1] << 16) | (ndev->dev_addr[0] << 24),
                fep->hwp + FEC_ADDR_LOW);
        writel((ndev->dev_addr[5] << 16) | (ndev->dev_addr[4] << 24),
                fep->hwp + FEC_ADDR_HIGH);
        return 0;
}

#ifdef CONFIG_NET_POLL_CONTROLLER
/**
 * fec_poll_controller - FEC Poll controller function
 * @dev: The FEC network adapter
 *
 * Polled functionality used by netconsole and others in non interrupt mode
 *
 */
static void fec_poll_controller(struct net_device *dev)
{
        int i;
        struct fec_enet_private *fep = netdev_priv(dev);

        for (i = 0; i < FEC_IRQ_NUM; i++) {
                if (fep->irq[i] > 0) {
                        disable_irq(fep->irq[i]);
                        fec_enet_interrupt(fep->irq[i], dev);
                        enable_irq(fep->irq[i]);
                }
        }
}
#endif

#define FEATURES_NEED_QUIESCE NETIF_F_RXCSUM
static inline void fec_enet_set_netdev_features(struct net_device *netdev,
        netdev_features_t features)
{
        struct fec_enet_private *fep = netdev_priv(netdev);
        netdev_features_t changed = features ^ netdev->features;

        netdev->features = features;

        /* Receive checksum has been changed */
        if (changed & NETIF_F_RXCSUM) {
                if (features & NETIF_F_RXCSUM)
                        fep->csum_flags |= FLAG_RX_CSUM_ENABLED;
                else
                        fep->csum_flags &= ~FLAG_RX_CSUM_ENABLED;
        }
}

static int fec_set_features(struct net_device *netdev,
        netdev_features_t features)
{
        struct fec_enet_private *fep = netdev_priv(netdev);
        netdev_features_t changed = features ^ netdev->features;

        if (netif_running(netdev) && changed & FEATURES_NEED_QUIESCE) {
                napi_disable(&fep->napi);
                netif_tx_lock_bh(netdev);
                fec_stop(netdev);
                fec_enet_set_netdev_features(netdev, features);
                fec_restart(netdev);
                netif_tx_wake_all_queues(netdev);
                netif_tx_unlock_bh(netdev);
                napi_enable(&fep->napi);
        } else {
                fec_enet_set_netdev_features(netdev, features);
        }

        return 0;
}

static const struct net_device_ops fec_netdev_ops = {
        .ndo_open               = fec_enet_open,
        .ndo_stop               = fec_enet_close,
        .ndo_start_xmit         = fec_enet_start_xmit,
        .ndo_set_rx_mode        = set_multicast_list,
        .ndo_change_mtu         = eth_change_mtu,
        .ndo_validate_addr      = eth_validate_addr,
        .ndo_tx_timeout         = fec_timeout,
        .ndo_set_mac_address    = fec_set_mac_address,
        .ndo_do_ioctl           = fec_enet_ioctl,
#ifdef CONFIG_NET_POLL_CONTROLLER
        .ndo_poll_controller    = fec_poll_controller,
#endif
        .ndo_set_features       = fec_set_features,
};