/*
 * 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 <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_net.h>
#include <linux/regulator/consumer.h>
#include <linux/if_vlan.h>

#include <asm/cacheflush.h>

#include "fec.h"

static void set_multicast_list(struct net_device *ndev);

#if defined(CONFIG_ARM)
#define FEC_ALIGNMENT   0xf
#else
#define FEC_ALIGNMENT   0x3
#endif

#define DRIVER_NAME     "fec"

/* 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

/* Controller is ENET-MAC */
#define FEC_QUIRK_ENET_MAC              (1 << 0)
/* Controller needs driver to swap frame */
#define FEC_QUIRK_SWAP_FRAME            (1 << 1)
/* Controller uses gasket */
#define FEC_QUIRK_USE_GASKET            (1 << 2)
/* Controller has GBIT support */
#define FEC_QUIRK_HAS_GBIT              (1 << 3)
/* Controller has extend desc buffer */
#define FEC_QUIRK_HAS_BUFDESC_EX        (1 << 4)
/* Controller has hardware checksum support */
#define FEC_QUIRK_HAS_CSUM              (1 << 5)
/* Controller has hardware vlan support */
#define FEC_QUIRK_HAS_VLAN              (1 << 6)
/* ENET IP errata ERR006358
 *
 * If the ready bit in the transmit buffer descriptor (TxBD[R]) is previously
 * detected as not set during a prior frame transmission, then the
 * ENET_TDAR[TDAR] bit is cleared at a later time, even if additional TxBDs
 * were added to the ring and the ENET_TDAR[TDAR] bit is set. This results in
 * frames not being transmitted until there is a 0-to-1 transition on
 * ENET_TDAR[TDAR].
 */
#define FEC_QUIRK_ERR006358            (1 << 7)

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,
        }, {
                .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,
        }, {
                /* 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,
};

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], },
        { /* 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 */

#if (((RX_RING_SIZE + TX_RING_SIZE) * 32) > PAGE_SIZE)
#error "FEC: descriptor ring size constants too large"
#endif

/* Interrupt events/masks. */
#define FEC_ENET_HBERR  ((uint)0x80000000)      /* Heartbeat error */
#define FEC_ENET_BABR   ((uint)0x40000000)      /* Babbling receiver */
#define FEC_ENET_BABT   ((uint)0x20000000)      /* Babbling transmitter */
#define FEC_ENET_GRA    ((uint)0x10000000)      /* Graceful stop complete */
#define FEC_ENET_TXF    ((uint)0x08000000)      /* Full frame transmitted */
#define FEC_ENET_TXB    ((uint)0x04000000)      /* A buffer was transmitted */
#define FEC_ENET_RXF    ((uint)0x02000000)      /* Full frame received */
#define FEC_ENET_RXB    ((uint)0x01000000)      /* A buffer was received */
#define FEC_ENET_MII    ((uint)0x00800000)      /* MII interrupt */
#define FEC_ENET_EBERR  ((uint)0x00400000)      /* SDMA bus error */

#define FEC_DEFAULT_IMASK (FEC_ENET_TXF | FEC_ENET_RXF | FEC_ENET_MII)
#define FEC_RX_DISABLED_IMASK (FEC_DEFAULT_IMASK & (~FEC_ENET_RXF))

/* 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)

#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

static int mii_cnt;

static inline
struct bufdesc *fec_enet_get_nextdesc(struct bufdesc *bdp, struct fec_enet_private *fep)
{
        struct bufdesc *new_bd = bdp + 1;
        struct bufdesc_ex *ex_new_bd = (struct bufdesc_ex *)bdp + 1;
        struct bufdesc_ex *ex_base;
        struct bufdesc *base;
        int ring_size;

        if (bdp >= fep->tx_bd_base) {
                base = fep->tx_bd_base;
                ring_size = fep->tx_ring_size;
                ex_base = (struct bufdesc_ex *)fep->tx_bd_base;
        } else {
                base = fep->rx_bd_base;
                ring_size = fep->rx_ring_size;
                ex_base = (struct bufdesc_ex *)fep->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)
{
        struct bufdesc *new_bd = bdp - 1;
        struct bufdesc_ex *ex_new_bd = (struct bufdesc_ex *)bdp - 1;
        struct bufdesc_ex *ex_base;
        struct bufdesc *base;
        int ring_size;

        if (bdp >= fep->tx_bd_base) {
                base = fep->tx_bd_base;
                ring_size = fep->tx_ring_size;
                ex_base = (struct bufdesc_ex *)fep->tx_bd_base;
        } else {
                base = fep->rx_bd_base;
                ring_size = fep->rx_ring_size;
                ex_base = (struct bufdesc_ex *)fep->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 void *swap_buffer(void *bufaddr, int len)
{
        int i;
        unsigned int *buf = bufaddr;

        for (i = 0; i < DIV_ROUND_UP(len, 4); i++, buf++)
                *buf = cpu_to_be32(*buf);

        return bufaddr;
}

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;

        *(__sum16 *)(skb->head + skb->csum_start + skb->csum_offset) = 0;

        return 0;
}

static netdev_tx_t
fec_enet_start_xmit(struct sk_buff *skb, struct net_device *ndev)
{
        struct fec_enet_private *fep = netdev_priv(ndev);
        const struct platform_device_id *id_entry =
                                platform_get_device_id(fep->pdev);
        struct bufdesc *bdp, *bdp_pre;
        void *bufaddr;
        unsigned short  status;
        unsigned int index;

        /* Fill in a Tx ring entry */
        bdp = fep->cur_tx;

        status = bdp->cbd_sc;

        if (status & BD_ENET_TX_READY) {
                /* Ooops.  All transmit buffers are full.  Bail out.
                 * This should not happen, since ndev->tbusy should be set.
                 */
                netdev_err(ndev, "tx queue full!\n");
                return NETDEV_TX_BUSY;
        }

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

        /* Clear all of the status flags */
        status &= ~BD_ENET_TX_STATS;

        /* Set buffer length and buffer pointer */
        bufaddr = skb->data;
        bdp->cbd_datlen = skb->len;

        /*
         * On some FEC implementations data must be aligned on
         * 4-byte boundaries. Use bounce buffers to copy data
         * and get it aligned. Ugh.
         */
        if (fep->bufdesc_ex)
                index = (struct bufdesc_ex *)bdp -
                        (struct bufdesc_ex *)fep->tx_bd_base;
        else
                index = bdp - fep->tx_bd_base;

        if (((unsigned long) bufaddr) & FEC_ALIGNMENT) {
                memcpy(fep->tx_bounce[index], skb->data, skb->len);
                bufaddr = fep->tx_bounce[index];
        }

        /*
         * Some design made an incorrect assumption on endian mode of
         * the system that it's running on. As the result, driver has to
         * swap every frame going to and coming from the controller.
         */
        if (id_entry->driver_data & FEC_QUIRK_SWAP_FRAME)
                swap_buffer(bufaddr, skb->len);

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

        /* Push the data cache so the CPM does not get stale memory
         * data.
         */
        bdp->cbd_bufaddr = dma_map_single(&fep->pdev->dev, bufaddr,
                        skb->len, DMA_TO_DEVICE);
        if (dma_mapping_error(&fep->pdev->dev, bdp->cbd_bufaddr)) {
                bdp->cbd_bufaddr = 0;
                fep->tx_skbuff[index] = NULL;
                dev_kfree_skb_any(skb);
                if (net_ratelimit())
                        netdev_err(ndev, "Tx DMA memory map failed\n");
                return NETDEV_TX_OK;
        }

        if (fep->bufdesc_ex) {

                struct bufdesc_ex *ebdp = (struct bufdesc_ex *)bdp;
                ebdp->cbd_bdu = 0;
                if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP &&
                        fep->hwts_tx_en)) {
                        ebdp->cbd_esc = (BD_ENET_TX_TS | BD_ENET_TX_INT);
                        skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;
                } else {
                        ebdp->cbd_esc = BD_ENET_TX_INT;

                        /* Enable protocol checksum flags
                         * We do not bother with the IP Checksum bits as they
                         * are done by the kernel
                         */
                        if (skb->ip_summed == CHECKSUM_PARTIAL)
                                ebdp->cbd_esc |= BD_ENET_TX_PINS;
                }
        }

        /* 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_INTR
                        | BD_ENET_TX_LAST | BD_ENET_TX_TC);
        bdp->cbd_sc = status;

        bdp_pre = fec_enet_get_prevdesc(bdp, fep);
        if ((id_entry->driver_data & FEC_QUIRK_ERR006358) &&
            !(bdp_pre->cbd_sc & BD_ENET_TX_READY)) {
                fep->delay_work.trig_tx = true;
                schedule_delayed_work(&(fep->delay_work.delay_work),
                                        msecs_to_jiffies(1));
        }

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

        skb_tx_timestamp(skb);

        fep->cur_tx = bdp;

        if (fep->cur_tx == fep->dirty_tx)
                netif_stop_queue(ndev);

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

        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 bufdesc *bdp;
        unsigned int i;

        /* Initialize the receive buffer descriptors. */
        bdp = fep->rx_bd_base;
        for (i = 0; i < fep->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);
        }

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

        fep->cur_rx = fep->rx_bd_base;

        /* ...and the same for transmit */
        bdp = fep->tx_bd_base;
        fep->cur_tx = bdp;
        for (i = 0; i < fep->tx_ring_size; i++) {

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

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

/* This function is called to start or restart the FEC during a link
 * change.  This only happens when switching between half and full
 * duplex.
 */
static void
fec_restart(struct net_device *ndev, int duplex)
{
        struct fec_enet_private *fep = netdev_priv(ndev);
        const struct platform_device_id *id_entry =
                                platform_get_device_id(fep->pdev);
        int i;
        u32 val;
        u32 temp_mac[2];
        u32 rcntl = OPT_FRAME_SIZE | 0x04;
        u32 ecntl = 0x2; /* ETHEREN */

        if (netif_running(ndev)) {
                netif_device_detach(ndev);
                napi_disable(&fep->napi);
                netif_stop_queue(ndev);
                netif_tx_lock_bh(ndev);
        }

        /* Whack a reset.  We should wait for this. */
        writel(1, fep->hwp + FEC_ECNTRL);
        udelay(10);

        /*
         * enet-mac reset will reset mac address registers too,
         * so need to reconfigure it.
         */
        if (id_entry->driver_data & 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(0xffc00000, fep->hwp + FEC_IEVENT);

        /* Set maximum receive buffer size. */
        writel(PKT_MAXBLR_SIZE, fep->hwp + FEC_R_BUFF_SIZE);

        fec_enet_bd_init(ndev);

        /* Set receive and transmit descriptor base. */
        writel(fep->bd_dma, fep->hwp + FEC_R_DES_START);
        if (fep->bufdesc_ex)
                writel((unsigned long)fep->bd_dma + sizeof(struct bufdesc_ex)
                        * fep->rx_ring_size, fep->hwp + FEC_X_DES_START);
        else
                writel((unsigned long)fep->bd_dma + sizeof(struct bufdesc)
                        * fep->rx_ring_size,    fep->hwp + FEC_X_DES_START);


        for (i = 0; i <= TX_RING_MOD_MASK; i++) {
                if (fep->tx_skbuff[i]) {
                        dev_kfree_skb_any(fep->tx_skbuff[i]);
                        fep->tx_skbuff[i] = NULL;
                }
        }

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

        fep->full_duplex = duplex;

        /* 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 (id_entry->driver_data & 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)
                        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 (id_entry->driver_data & 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 (id_entry->driver_data & 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);
        writel(0, fep->hwp + FEC_R_DES_ACTIVE);

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

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

        if (netif_running(ndev)) {
                netif_tx_unlock_bh(ndev);
                netif_wake_queue(ndev);
                napi_enable(&fep->napi);
                netif_device_attach(ndev);
        }
}

static void
fec_stop(struct net_device *ndev)
{
        struct fec_enet_private *fep = netdev_priv(ndev);
        const struct platform_device_id *id_entry =
                                platform_get_device_id(fep->pdev);
        u32 rmii_mode = readl(fep->hwp + FEC_R_CNTRL) & (1 << 8);

        /* 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. */
        writel(1, fep->hwp + FEC_ECNTRL);
        udelay(10);
        writel(fep->phy_speed, fep->hwp + FEC_MII_SPEED);
        writel(FEC_DEFAULT_IMASK, fep->hwp + FEC_IMASK);

        /* We have to keep ENET enabled to have MII interrupt stay working */
        if (id_entry->driver_data & FEC_QUIRK_ENET_MAC) {
                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);

        ndev->stats.tx_errors++;

        fep->delay_work.timeout = true;
        schedule_delayed_work(&(fep->delay_work.delay_work), 0);
}

static void fec_enet_work(struct work_struct *work)
{
        struct fec_enet_private *fep =
                container_of(work,
                             struct fec_enet_private,
                             delay_work.delay_work.work);

        if (fep->delay_work.timeout) {
                fep->delay_work.timeout = false;
                fec_restart(fep->netdev, fep->full_duplex);
                netif_wake_queue(fep->netdev);
        }

        if (fep->delay_work.trig_tx) {
                fep->delay_work.trig_tx = false;
                writel(0, fep->hwp + FEC_X_DES_ACTIVE);
        }
}

static void
fec_enet_tx(struct net_device *ndev)
{
        struct  fec_enet_private *fep;
        struct bufdesc *bdp;
        unsigned short status;
        struct  sk_buff *skb;
        int     index = 0;

        fep = netdev_priv(ndev);
        bdp = fep->dirty_tx;

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

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

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

                if (fep->bufdesc_ex)
                        index = (struct bufdesc_ex *)bdp -
                                (struct bufdesc_ex *)fep->tx_bd_base;
                else
                        index = bdp - fep->tx_bd_base;

                skb = fep->tx_skbuff[index];
                dma_unmap_single(&fep->pdev->dev, bdp->cbd_bufaddr, skb->len,
                                DMA_TO_DEVICE);
                bdp->cbd_bufaddr = 0;

                /* 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 += bdp->cbd_datlen;
                }

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

                        memset(&shhwtstamps, 0, sizeof(shhwtstamps));
                        spin_lock_irqsave(&fep->tmreg_lock, flags);
                        shhwtstamps.hwtstamp = ns_to_ktime(
                                timecounter_cyc2time(&fep->tc, ebdp->ts));
                        spin_unlock_irqrestore(&fep->tmreg_lock, flags);
                        skb_tstamp_tx(skb, &shhwtstamps);
                }

                if (status & BD_ENET_TX_READY)
                        netdev_err(ndev, "HEY! Enet xmit interrupt and TX_READY\n");

                /* 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);
                fep->tx_skbuff[index] = NULL;

                fep->dirty_tx = bdp;

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

                /* Since we have freed up a buffer, the ring is no longer full
                 */
                if (fep->dirty_tx != fep->cur_tx) {
                        if (netif_queue_stopped(ndev))
                                netif_wake_queue(ndev);
                }
        }
        return;
}


/* 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(struct net_device *ndev, int budget)
{
        struct fec_enet_private *fep = netdev_priv(ndev);
        const struct platform_device_id *id_entry =
                                platform_get_device_id(fep->pdev);
        struct bufdesc *bdp;
        unsigned short status;
        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;

#ifdef CONFIG_M532x
        flush_cache_all();
#endif

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

                if (!fep->opened)
                        goto rx_processing_done;

                /* 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;

                if (fep->bufdesc_ex)
                        index = (struct bufdesc_ex *)bdp -
                                (struct bufdesc_ex *)fep->rx_bd_base;
                else
                        index = bdp - fep->rx_bd_base;
                data = fep->rx_skbuff[index]->data;
                dma_sync_single_for_cpu(&fep->pdev->dev, bdp->cbd_bufaddr,
                                        FEC_ENET_RX_FRSIZE, DMA_FROM_DEVICE);

                if (id_entry->driver_data & FEC_QUIRK_SWAP_FRAME)
                        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);
                        pkt_len -= VLAN_HLEN;

                        vlan_packet_rcvd = true;
                }

                /* This does 16 byte alignment, exactly what we need.
                 * The packet length includes FCS, but we don't want to
                 * include that when passing upstream as it messes up
                 * bridging applications.
                 */
                skb = netdev_alloc_skb(ndev, pkt_len - 4 + NET_IP_ALIGN);

                if (unlikely(!skb)) {
                        ndev->stats.rx_dropped++;
                } else {
                        int payload_offset = (2 * ETH_ALEN);
                        skb_reserve(skb, NET_IP_ALIGN);
                        skb_put(skb, pkt_len - 4);      /* Make room */

                        /* Extract the frame data without the VLAN header. */
                        skb_copy_to_linear_data(skb, data, (2 * ETH_ALEN));
                        if (vlan_packet_rcvd)
                                payload_offset = (2 * ETH_ALEN) + VLAN_HLEN;
                        skb_copy_to_linear_data_offset(skb, (2 * ETH_ALEN),
                                                       data + payload_offset,
                                                       pkt_len - 4 - (2 * ETH_ALEN));

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

                        /* Get receive timestamp from the skb */
                        if (fep->hwts_rx_en && fep->bufdesc_ex) {
                                struct skb_shared_hwtstamps *shhwtstamps =
                                                            skb_hwtstamps(skb);
                                unsigned long flags;

                                memset(shhwtstamps, 0, sizeof(*shhwtstamps));

                                spin_lock_irqsave(&fep->tmreg_lock, flags);
                                shhwtstamps->hwtstamp = ns_to_ktime(
                                    timecounter_cyc2time(&fep->tc, ebdp->ts));
                                spin_unlock_irqrestore(&fep->tmreg_lock, flags);
                        }

                        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);
                }

                dma_sync_single_for_device(&fep->pdev->dev, bdp->cbd_bufaddr,
                                        FEC_ENET_RX_FRSIZE, DMA_FROM_DEVICE);
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);

                /* 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);
        }
        fep->cur_rx = bdp;

        return pkt_received;
}

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;

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

                if (int_events & (FEC_ENET_RXF | FEC_ENET_TXF)) {
                        ret = IRQ_HANDLED;

                        /* Disable the RX interrupt */
                        if (napi_schedule_prep(&fep->napi)) {
                                writel(FEC_RX_DISABLED_IMASK,
                                        fep->hwp + FEC_IMASK);
                                __napi_schedule(&fep->napi);
                        }
                }

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

        return ret;
}

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

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

                if (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)
                        fec_restart(ndev, phy_dev->duplex);
        } else {
                if (fep->link) {
                        fec_stop(ndev);
                        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_mii_probe(struct net_device *ndev)
{
        struct fec_enet_private *fep = netdev_priv(ndev);
        const struct platform_device_id *id_entry =
                                platform_get_device_id(fep->pdev);
        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;

        /* 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;
                strncpy(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");
                strncpy(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 (id_entry->driver_data & FEC_QUIRK_HAS_GBIT) {
                phy_dev->supported &= PHY_GBIT_FEATURES;
#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);
        const struct platform_device_id *id_entry =
                                platform_get_device_id(fep->pdev);
        int err = -ENXIO, i;

        /*
         * The dual fec interfaces are not equivalent with enet-mac.
         * 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 ((id_entry->driver_data & FEC_QUIRK_ENET_MAC) && 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.
         */
        fep->phy_speed = DIV_ROUND_UP(clk_get_rate(fep->clk_ahb), 5000000);
        if (id_entry->driver_data & FEC_QUIRK_ENET_MAC)
                fep->phy_speed--;
        fep->phy_speed <<= 1;
        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;

        if (mdiobus_register(fep->mii_bus))
                goto err_out_free_mdio_irq;

        mii_cnt++;

        /* save fec0 mii_bus */
        if (id_entry->driver_data & FEC_QUIRK_ENET_MAC)
                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 (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))
                fec_restart(ndev, 0);

        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);
}

static const struct ethtool_ops fec_enet_ethtool_ops = {
#if !defined(CONFIG_M5272)
        .get_pauseparam         = fec_enet_get_pauseparam,
        .set_pauseparam         = fec_enet_set_pauseparam,
#endif
        .get_settings           = fec_enet_get_settings,
        .set_settings           = fec_enet_set_settings,
        .get_drvinfo            = fec_enet_get_drvinfo,
        .get_link               = ethtool_op_get_link,
        .get_ts_info            = fec_enet_get_ts_info,
        .nway_reset             = fec_enet_nway_reset,
#ifndef CONFIG_M5272
        .get_ethtool_stats      = fec_enet_get_ethtool_stats,
        .get_strings            = fec_enet_get_strings,
        .get_sset_count         = fec_enet_get_sset_count,
#endif
};

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;

        bdp = fep->rx_bd_base;
        for (i = 0; i < fep->rx_ring_size; i++) {
                skb = fep->rx_skbuff[i];

                if (bdp->cbd_bufaddr)
                        dma_unmap_single(&fep->pdev->dev, bdp->cbd_bufaddr,
                                        FEC_ENET_RX_FRSIZE, DMA_FROM_DEVICE);
                if (skb)
                        dev_kfree_skb(skb);
                bdp = fec_enet_get_nextdesc(bdp, fep);
        }

        bdp = fep->tx_bd_base;
        for (i = 0; i < fep->tx_ring_size; i++)
                kfree(fep->tx_bounce[i]);
}

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

        bdp = fep->rx_bd_base;
        for (i = 0; i < fep->rx_ring_size; i++) {
                skb = netdev_alloc_skb(ndev, FEC_ENET_RX_FRSIZE);
                if (!skb) {
                        fec_enet_free_buffers(ndev);
                        return -ENOMEM;
                }
                fep->rx_skbuff[i] = skb;

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

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

        bdp = fep->tx_bd_base;
        for (i = 0; i < fep->tx_ring_size; i++) {
                fep->tx_bounce[i] = kmalloc(FEC_ENET_TX_FRSIZE, GFP_KERNEL);

                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);
        }

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

        return 0;
}

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

        /* Probe and connect to PHY when open the interface */
        ret = fec_enet_mii_probe(ndev);
        if (ret) {
                fec_enet_free_buffers(ndev);
                return ret;
        }

        napi_enable(&fep->napi);
        phy_start(fep->phy_dev);
        netif_start_queue(ndev);
        fep->opened = 1;
        return 0;
}

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

        /* Don't know what to do yet. */
        napi_disable(&fep->napi);
        fep->opened = 0;
        netif_stop_queue(ndev);
        fec_stop(ndev);

        if (fep->phy_dev) {
                phy_stop(fep->phy_dev);
                phy_disconnect(fep->phy_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

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;

        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;

                if (netif_running(netdev)) {
                        fec_stop(netdev);
                        fec_restart(netdev, fep->phy_dev->duplex);
                        netif_wake_queue(netdev);
                } else {
                        fec_restart(netdev, fep->phy_dev->duplex);
                }
        }

        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,
};

 /*
  * XXX:  We need to clean up on failure exits here.
  *
  */
static int fec_enet_init(struct net_device *ndev)
{
        struct fec_enet_private *fep = netdev_priv(ndev);
        const struct platform_device_id *id_entry =
                                platform_get_device_id(fep->pdev);
        struct bufdesc *cbd_base;

        /* Allocate memory for buffer descriptors. */
        cbd_base = dma_alloc_coherent(NULL, PAGE_SIZE, &fep->bd_dma,
                                      GFP_KERNEL);
        if (!cbd_base)
                return -ENOMEM;

        memset(cbd_base, 0, PAGE_SIZE);

        fep->netdev = ndev;

        /* Get the Ethernet address */
        fec_get_mac(ndev);
        /* make sure MAC we just acquired is programmed into the hw */
        fec_set_mac_address(ndev, NULL);

        /* init the tx & rx ring size */
        fep->tx_ring_size = TX_RING_SIZE;
        fep->rx_ring_size = RX_RING_SIZE;

        /* Set receive and transmit descriptor base. */
        fep->rx_bd_base = cbd_base;
        if (fep->bufdesc_ex)
                fep->tx_bd_base = (struct bufdesc *)
                        (((struct bufdesc_ex *)cbd_base) + fep->rx_ring_size);
        else
                fep->tx_bd_base = cbd_base + fep->rx_ring_size;

        /* The FEC Ethernet specific entries in the device structure */
        ndev->watchdog_timeo = TX_TIMEOUT;
        ndev->netdev_ops = &fec_netdev_ops;
        ndev->ethtool_ops = &fec_enet_ethtool_ops;

        writel(FEC_RX_DISABLED_IMASK, fep->hwp + FEC_IMASK);
        netif_napi_add(ndev, &fep->napi, fec_enet_rx_napi, NAPI_POLL_WEIGHT);

        if (id_entry->driver_data & FEC_QUIRK_HAS_VLAN) {
                /* enable hw VLAN support */
                ndev->features |= NETIF_F_HW_VLAN_CTAG_RX;
                ndev->hw_features |= NETIF_F_HW_VLAN_CTAG_RX;
        }

        if (id_entry->driver_data & FEC_QUIRK_HAS_CSUM) {
                /* enable hw accelerator */
                ndev->features |= (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM
                                | NETIF_F_RXCSUM);
                ndev->hw_features |= (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM
                                | NETIF_F_RXCSUM);
                fep->csum_flags |= FLAG_RX_CSUM_ENABLED;
        }

        fec_restart(ndev, 0);

        return 0;
}

#ifdef CONFIG_OF
static void fec_reset_phy(struct platform_device *pdev)
{
        int err, phy_reset;
        int msec = 1;
        struct device_node *np = pdev->dev.of_node;

        if (!np)
                return;

        of_property_read_u32(np, "phy-reset-duration", &msec);
        /* A sane reset duration should not be longer than 1s */
        if (msec > 1000)
                msec = 1;

        phy_reset = of_get_named_gpio(np, "phy-reset-gpios", 0);
        if (!gpio_is_valid(phy_reset))
                return;

        err = devm_gpio_request_one(&pdev->dev, phy_reset,
                                    GPIOF_OUT_INIT_LOW, "phy-reset");
        if (err) {
                dev_err(&pdev->dev, "failed to get phy-reset-gpios: %d\n", err);
                return;
        }
        msleep(msec);
        gpio_set_value(phy_reset, 1);
}
#else /* CONFIG_OF */
static void fec_reset_phy(struct platform_device *pdev)
{
        /*
         * In case of platform probe, the reset has been done
         * by machine code.
         */
}
#endif /* CONFIG_OF */

static int
fec_probe(struct platform_device *pdev)
{
        struct fec_enet_private *fep;
        struct fec_platform_data *pdata;
        struct net_device *ndev;
        int i, irq, ret = 0;
        struct resource *r;
        const struct of_device_id *of_id;
        static int dev_id;

        of_id = of_match_device(fec_dt_ids, &pdev->dev);
        if (of_id)
                pdev->id_entry = of_id->data;

        /* Init network device */
        ndev = alloc_etherdev(sizeof(struct fec_enet_private));
        if (!ndev)
                return -ENOMEM;

        SET_NETDEV_DEV(ndev, &pdev->dev);

        /* setup board info structure */
        fep = netdev_priv(ndev);

#if !defined(CONFIG_M5272)
        /* default enable pause frame auto negotiation */
        if (pdev->id_entry &&
            (pdev->id_entry->driver_data & FEC_QUIRK_HAS_GBIT))
                fep->pause_flag |= FEC_PAUSE_FLAG_AUTONEG;
#endif

        r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        fep->hwp = devm_ioremap_resource(&pdev->dev, r);
        if (IS_ERR(fep->hwp)) {
                ret = PTR_ERR(fep->hwp);
                goto failed_ioremap;
        }

        fep->pdev = pdev;
        fep->dev_id = dev_id++;

        fep->bufdesc_ex = 0;

        platform_set_drvdata(pdev, ndev);

        ret = of_get_phy_mode(pdev->dev.of_node);
        if (ret < 0) {
                pdata = dev_get_platdata(&pdev->dev);
                if (pdata)
                        fep->phy_interface = pdata->phy;
                else
                        fep->phy_interface = PHY_INTERFACE_MODE_MII;
        } else {
                fep->phy_interface = ret;
        }

        fep->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
        if (IS_ERR(fep->clk_ipg)) {
                ret = PTR_ERR(fep->clk_ipg);
                goto failed_clk;
        }

        fep->clk_ahb = devm_clk_get(&pdev->dev, "ahb");
        if (IS_ERR(fep->clk_ahb)) {
                ret = PTR_ERR(fep->clk_ahb);
                goto failed_clk;
        }

        /* enet_out is optional, depends on board */
        fep->clk_enet_out = devm_clk_get(&pdev->dev, "enet_out");
        if (IS_ERR(fep->clk_enet_out))
                fep->clk_enet_out = NULL;

        fep->clk_ptp = devm_clk_get(&pdev->dev, "ptp");
        fep->bufdesc_ex =
                pdev->id_entry->driver_data & FEC_QUIRK_HAS_BUFDESC_EX;
        if (IS_ERR(fep->clk_ptp)) {
                fep->clk_ptp = NULL;
                fep->bufdesc_ex = 0;
        }

        ret = clk_prepare_enable(fep->clk_ahb);
        if (ret)
                goto failed_clk;

        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) {
                ret = clk_prepare_enable(fep->clk_ptp);
                if (ret)
                        goto failed_clk_ptp;
        }

        fep->reg_phy = devm_regulator_get(&pdev->dev, "phy");
        if (!IS_ERR(fep->reg_phy)) {
                ret = regulator_enable(fep->reg_phy);
                if (ret) {
                        dev_err(&pdev->dev,
                                "Failed to enable phy regulator: %d\n", ret);
                        goto failed_regulator;
                }
        } else {
                fep->reg_phy = NULL;
        }

        fec_reset_phy(pdev);

        if (fep->bufdesc_ex)
                fec_ptp_init(pdev);

        ret = fec_enet_init(ndev);
        if (ret)
                goto failed_init;

        for (i = 0; i < FEC_IRQ_NUM; i++) {
                irq = platform_get_irq(pdev, i);
                if (irq < 0) {
                        if (i)
                                break;
                        ret = irq;
                        goto failed_irq;
                }
                ret = devm_request_irq(&pdev->dev, irq, fec_enet_interrupt,
                                       0, pdev->name, ndev);
                if (ret)
                        goto failed_irq;
        }

        ret = fec_enet_mii_init(pdev);
        if (ret)
                goto failed_mii_init;

        /* Carrier starts down, phylib will bring it up */
        netif_carrier_off(ndev);

        ret = register_netdev(ndev);
        if (ret)
                goto failed_register;

        if (fep->bufdesc_ex && fep->ptp_clock)
                netdev_info(ndev, "registered PHC device %d\n", fep->dev_id);

        INIT_DELAYED_WORK(&(fep->delay_work.delay_work), fec_enet_work);
        return 0;

failed_register:
        fec_enet_mii_remove(fep);
failed_mii_init:
failed_irq:
failed_init:
        if (fep->reg_phy)
                regulator_disable(fep->reg_phy);
failed_regulator:
        if (fep->clk_ptp)
                clk_disable_unprepare(fep->clk_ptp);
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);
failed_clk:
failed_ioremap:
        free_netdev(ndev);

        return ret;
}

static int
fec_drv_remove(struct platform_device *pdev)
{
        struct net_device *ndev = platform_get_drvdata(pdev);
        struct fec_enet_private *fep = netdev_priv(ndev);

        cancel_delayed_work_sync(&(fep->delay_work.delay_work));
        unregister_netdev(ndev);
        fec_enet_mii_remove(fep);
        del_timer_sync(&fep->time_keep);
        if (fep->reg_phy)
                regulator_disable(fep->reg_phy);
        if (fep->clk_ptp)
                clk_disable_unprepare(fep->clk_ptp);
        if (fep->ptp_clock)
                ptp_clock_unregister(fep->ptp_clock);
        if (fep->clk_enet_out)
                clk_disable_unprepare(fep->clk_enet_out);
        clk_disable_unprepare(fep->clk_ipg);
        clk_disable_unprepare(fep->clk_ahb);
        free_netdev(ndev);

        return 0;
}

#ifdef CONFIG_PM_SLEEP
static int
fec_suspend(struct device *dev)
{
        struct net_device *ndev = dev_get_drvdata(dev);
        struct fec_enet_private *fep = netdev_priv(ndev);

        if (netif_running(ndev)) {
                fec_stop(ndev);
                netif_device_detach(ndev);
        }
        if (fep->clk_ptp)
                clk_disable_unprepare(fep->clk_ptp);
        if (fep->clk_enet_out)
                clk_disable_unprepare(fep->clk_enet_out);
        clk_disable_unprepare(fep->clk_ipg);
        clk_disable_unprepare(fep->clk_ahb);

        if (fep->reg_phy)
                regulator_disable(fep->reg_phy);

        return 0;
}

static int
fec_resume(struct device *dev)
{
        struct net_device *ndev = dev_get_drvdata(dev);
        struct fec_enet_private *fep = netdev_priv(ndev);
        int ret;

        if (fep->reg_phy) {
                ret = regulator_enable(fep->reg_phy);
                if (ret)
                        return ret;
        }

        ret = clk_prepare_enable(fep->clk_ahb);
        if (ret)
                goto failed_clk_ahb;

        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) {
                ret = clk_prepare_enable(fep->clk_ptp);
                if (ret)
                        goto failed_clk_ptp;
        }

        if (netif_running(ndev)) {
                fec_restart(ndev, fep->full_duplex);
                netif_device_attach(ndev);
        }

        return 0;

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);
failed_clk_ahb:
        if (fep->reg_phy)
                regulator_disable(fep->reg_phy);
        return ret;
}
#endif /* CONFIG_PM_SLEEP */

static SIMPLE_DEV_PM_OPS(fec_pm_ops, fec_suspend, fec_resume);

static struct platform_driver fec_driver = {
        .driver = {
                .name   = DRIVER_NAME,
                .owner  = THIS_MODULE,
                .pm     = &fec_pm_ops,
                .of_match_table = fec_dt_ids,
        },
        .id_table = fec_devtype,
        .probe  = fec_probe,
        .remove = fec_drv_remove,
};

module_platform_driver(fec_driver);

MODULE_ALIAS("platform:"DRIVER_NAME);
MODULE_LICENSE("GPL");