/*
 * Blackfin On-Chip MAC Driver
 *
 * Copyright 2004-2010 Analog Devices Inc.
 *
 * Enter bugs at http://blackfin.uclinux.org/
 *
 * Licensed under the GPL-2 or later.
 */

#define DRV_VERSION     "1.1"
#define DRV_DESC        "Blackfin on-chip Ethernet MAC driver"

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/timer.h>
#include <linux/errno.h>
#include <linux/irq.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/crc32.h>
#include <linux/device.h>
#include <linux/spinlock.h>
#include <linux/mii.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/ethtool.h>
#include <linux/skbuff.h>
#include <linux/platform_device.h>

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

#include <asm/div64.h>
#include <asm/dpmc.h>
#include <asm/blackfin.h>
#include <asm/cacheflush.h>
#include <asm/portmux.h>
#include <mach/pll.h>

#include "bfin_mac.h"

MODULE_AUTHOR("Bryan Wu, Luke Yang");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION(DRV_DESC);
MODULE_ALIAS("platform:bfin_mac");

#if defined(CONFIG_BFIN_MAC_USE_L1)
# define bfin_mac_alloc(dma_handle, size, num)  l1_data_sram_zalloc(size*num)
# define bfin_mac_free(dma_handle, ptr, num)    l1_data_sram_free(ptr)
#else
# define bfin_mac_alloc(dma_handle, size, num) \
        dma_alloc_coherent(NULL, size*num, dma_handle, GFP_KERNEL)
# define bfin_mac_free(dma_handle, ptr, num) \
        dma_free_coherent(NULL, sizeof(*ptr)*num, ptr, dma_handle)
#endif

#define PKT_BUF_SZ 1580

#define MAX_TIMEOUT_CNT 500

/* pointers to maintain transmit list */
static struct net_dma_desc_tx *tx_list_head;
static struct net_dma_desc_tx *tx_list_tail;
static struct net_dma_desc_rx *rx_list_head;
static struct net_dma_desc_rx *rx_list_tail;
static struct net_dma_desc_rx *current_rx_ptr;
static struct net_dma_desc_tx *current_tx_ptr;
static struct net_dma_desc_tx *tx_desc;
static struct net_dma_desc_rx *rx_desc;

static void desc_list_free(void)
{
        struct net_dma_desc_rx *r;
        struct net_dma_desc_tx *t;
        int i;
#if !defined(CONFIG_BFIN_MAC_USE_L1)
        dma_addr_t dma_handle = 0;
#endif

        if (tx_desc) {
                t = tx_list_head;
                for (i = 0; i < CONFIG_BFIN_TX_DESC_NUM; i++) {
                        if (t) {
                                if (t->skb) {
                                        dev_kfree_skb(t->skb);
                                        t->skb = NULL;
                                }
                                t = t->next;
                        }
                }
                bfin_mac_free(dma_handle, tx_desc, CONFIG_BFIN_TX_DESC_NUM);
        }

        if (rx_desc) {
                r = rx_list_head;
                for (i = 0; i < CONFIG_BFIN_RX_DESC_NUM; i++) {
                        if (r) {
                                if (r->skb) {
                                        dev_kfree_skb(r->skb);
                                        r->skb = NULL;
                                }
                                r = r->next;
                        }
                }
                bfin_mac_free(dma_handle, rx_desc, CONFIG_BFIN_RX_DESC_NUM);
        }
}

static int desc_list_init(struct net_device *dev)
{
        int i;
        struct sk_buff *new_skb;
#if !defined(CONFIG_BFIN_MAC_USE_L1)
        /*
         * This dma_handle is useless in Blackfin dma_alloc_coherent().
         * The real dma handler is the return value of dma_alloc_coherent().
         */
        dma_addr_t dma_handle;
#endif

        tx_desc = bfin_mac_alloc(&dma_handle,
                                sizeof(struct net_dma_desc_tx),
                                CONFIG_BFIN_TX_DESC_NUM);
        if (tx_desc == NULL)
                goto init_error;

        rx_desc = bfin_mac_alloc(&dma_handle,
                                sizeof(struct net_dma_desc_rx),
                                CONFIG_BFIN_RX_DESC_NUM);
        if (rx_desc == NULL)
                goto init_error;

        /* init tx_list */
        tx_list_head = tx_list_tail = tx_desc;

        for (i = 0; i < CONFIG_BFIN_TX_DESC_NUM; i++) {
                struct net_dma_desc_tx *t = tx_desc + i;
                struct dma_descriptor *a = &(t->desc_a);
                struct dma_descriptor *b = &(t->desc_b);

                /*
                 * disable DMA
                 * read from memory WNR = 0
                 * wordsize is 32 bits
                 * 6 half words is desc size
                 * large desc flow
                 */
                a->config = WDSIZE_32 | NDSIZE_6 | DMAFLOW_LARGE;
                a->start_addr = (unsigned long)t->packet;
                a->x_count = 0;
                a->next_dma_desc = b;

                /*
                 * enabled DMA
                 * write to memory WNR = 1
                 * wordsize is 32 bits
                 * disable interrupt
                 * 6 half words is desc size
                 * large desc flow
                 */
                b->config = DMAEN | WNR | WDSIZE_32 | NDSIZE_6 | DMAFLOW_LARGE;
                b->start_addr = (unsigned long)(&(t->status));
                b->x_count = 0;

                t->skb = NULL;
                tx_list_tail->desc_b.next_dma_desc = a;
                tx_list_tail->next = t;
                tx_list_tail = t;
        }
        tx_list_tail->next = tx_list_head;      /* tx_list is a circle */
        tx_list_tail->desc_b.next_dma_desc = &(tx_list_head->desc_a);
        current_tx_ptr = tx_list_head;

        /* init rx_list */
        rx_list_head = rx_list_tail = rx_desc;

        for (i = 0; i < CONFIG_BFIN_RX_DESC_NUM; i++) {
                struct net_dma_desc_rx *r = rx_desc + i;
                struct dma_descriptor *a = &(r->desc_a);
                struct dma_descriptor *b = &(r->desc_b);

                /* allocate a new skb for next time receive */
                new_skb = netdev_alloc_skb(dev, PKT_BUF_SZ + NET_IP_ALIGN);
                if (!new_skb) {
                        pr_notice("init: low on mem - packet dropped\n");
                        goto init_error;
                }
                skb_reserve(new_skb, NET_IP_ALIGN);
                /* Invidate the data cache of skb->data range when it is write back
                 * cache. It will prevent overwritting the new data from DMA
                 */
                blackfin_dcache_invalidate_range((unsigned long)new_skb->head,
                                         (unsigned long)new_skb->end);
                r->skb = new_skb;

                /*
                 * enabled DMA
                 * write to memory WNR = 1
                 * wordsize is 32 bits
                 * disable interrupt
                 * 6 half words is desc size
                 * large desc flow
                 */
                a->config = DMAEN | WNR | WDSIZE_32 | NDSIZE_6 | DMAFLOW_LARGE;
                /* since RXDWA is enabled */
                a->start_addr = (unsigned long)new_skb->data - 2;
                a->x_count = 0;
                a->next_dma_desc = b;

                /*
                 * enabled DMA
                 * write to memory WNR = 1
                 * wordsize is 32 bits
                 * enable interrupt
                 * 6 half words is desc size
                 * large desc flow
                 */
                b->config = DMAEN | WNR | WDSIZE_32 | DI_EN |
                                NDSIZE_6 | DMAFLOW_LARGE;
                b->start_addr = (unsigned long)(&(r->status));
                b->x_count = 0;

                rx_list_tail->desc_b.next_dma_desc = a;
                rx_list_tail->next = r;
                rx_list_tail = r;
        }
        rx_list_tail->next = rx_list_head;      /* rx_list is a circle */
        rx_list_tail->desc_b.next_dma_desc = &(rx_list_head->desc_a);
        current_rx_ptr = rx_list_head;

        return 0;

init_error:
        desc_list_free();
        pr_err("kmalloc failed\n");
        return -ENOMEM;
}


/*---PHY CONTROL AND CONFIGURATION-----------------------------------------*/

/*
 * MII operations
 */
/* Wait until the previous MDC/MDIO transaction has completed */
static int bfin_mdio_poll(void)
{
        int timeout_cnt = MAX_TIMEOUT_CNT;

        /* poll the STABUSY bit */
        while ((bfin_read_EMAC_STAADD()) & STABUSY) {
                udelay(1);
                if (timeout_cnt-- < 0) {
                        pr_err("wait MDC/MDIO transaction to complete timeout\n");
                        return -ETIMEDOUT;
                }
        }

        return 0;
}

/* Read an off-chip register in a PHY through the MDC/MDIO port */
static int bfin_mdiobus_read(struct mii_bus *bus, int phy_addr, int regnum)
{
        int ret;

        ret = bfin_mdio_poll();
        if (ret)
                return ret;

        /* read mode */
        bfin_write_EMAC_STAADD(SET_PHYAD((u16) phy_addr) |
                                SET_REGAD((u16) regnum) |
                                STABUSY);

        ret = bfin_mdio_poll();
        if (ret)
                return ret;

        return (int) bfin_read_EMAC_STADAT();
}

/* Write an off-chip register in a PHY through the MDC/MDIO port */
static int bfin_mdiobus_write(struct mii_bus *bus, int phy_addr, int regnum,
                              u16 value)
{
        int ret;

        ret = bfin_mdio_poll();
        if (ret)
                return ret;

        bfin_write_EMAC_STADAT((u32) value);

        /* write mode */
        bfin_write_EMAC_STAADD(SET_PHYAD((u16) phy_addr) |
                                SET_REGAD((u16) regnum) |
                                STAOP |
                                STABUSY);

        return bfin_mdio_poll();
}

static int bfin_mdiobus_reset(struct mii_bus *bus)
{
        return 0;
}

static void bfin_mac_adjust_link(struct net_device *dev)
{
        struct bfin_mac_local *lp = netdev_priv(dev);
        struct phy_device *phydev = lp->phydev;
        unsigned long flags;
        int new_state = 0;

        spin_lock_irqsave(&lp->lock, flags);
        if (phydev->link) {
                /* Now we make sure that we can be in full duplex mode.
                 * If not, we operate in half-duplex mode. */
                if (phydev->duplex != lp->old_duplex) {
                        u32 opmode = bfin_read_EMAC_OPMODE();
                        new_state = 1;

                        if (phydev->duplex)
                                opmode |= FDMODE;
                        else
                                opmode &= ~(FDMODE);

                        bfin_write_EMAC_OPMODE(opmode);
                        lp->old_duplex = phydev->duplex;
                }

                if (phydev->speed != lp->old_speed) {
                        if (phydev->interface == PHY_INTERFACE_MODE_RMII) {
                                u32 opmode = bfin_read_EMAC_OPMODE();
                                switch (phydev->speed) {
                                case 10:
                                        opmode |= RMII_10;
                                        break;
                                case 100:
                                        opmode &= ~RMII_10;
                                        break;
                                default:
                                        netdev_warn(dev,
                                                "Ack! Speed (%d) is not 10/100!\n",
                                                phydev->speed);
                                        break;
                                }
                                bfin_write_EMAC_OPMODE(opmode);
                        }

                        new_state = 1;
                        lp->old_speed = phydev->speed;
                }

                if (!lp->old_link) {
                        new_state = 1;
                        lp->old_link = 1;
                }
        } else if (lp->old_link) {
                new_state = 1;
                lp->old_link = 0;
                lp->old_speed = 0;
                lp->old_duplex = -1;
        }

        if (new_state) {
                u32 opmode = bfin_read_EMAC_OPMODE();
                phy_print_status(phydev);
                pr_debug("EMAC_OPMODE = 0x%08x\n", opmode);
        }

        spin_unlock_irqrestore(&lp->lock, flags);
}

/* MDC  = 2.5 MHz */
#define MDC_CLK 2500000

static int mii_probe(struct net_device *dev, int phy_mode)
{
        struct bfin_mac_local *lp = netdev_priv(dev);
        struct phy_device *phydev = NULL;
        unsigned short sysctl;
        int i;
        u32 sclk, mdc_div;

        /* Enable PHY output early */
        if (!(bfin_read_VR_CTL() & CLKBUFOE))
                bfin_write_VR_CTL(bfin_read_VR_CTL() | CLKBUFOE);

        sclk = get_sclk();
        mdc_div = ((sclk / MDC_CLK) / 2) - 1;

        sysctl = bfin_read_EMAC_SYSCTL();
        sysctl = (sysctl & ~MDCDIV) | SET_MDCDIV(mdc_div);
        bfin_write_EMAC_SYSCTL(sysctl);

        /* search for connected PHY device */
        for (i = 0; i < PHY_MAX_ADDR; ++i) {
                struct phy_device *const tmp_phydev = lp->mii_bus->phy_map[i];

                if (!tmp_phydev)
                        continue; /* no PHY here... */

                phydev = tmp_phydev;
                break; /* found it */
        }

        /* now we are supposed to have a proper phydev, to attach to... */
        if (!phydev) {
                netdev_err(dev, "no phy device found\n");
                return -ENODEV;
        }

        if (phy_mode != PHY_INTERFACE_MODE_RMII &&
                phy_mode != PHY_INTERFACE_MODE_MII) {
                netdev_err(dev, "invalid phy interface mode\n");
                return -EINVAL;
        }

        phydev = phy_connect(dev, dev_name(&phydev->dev), &bfin_mac_adjust_link,
                        0, phy_mode);

        if (IS_ERR(phydev)) {
                netdev_err(dev, "could not attach PHY\n");
                return PTR_ERR(phydev);
        }

        /* mask with MAC supported features */
        phydev->supported &= (SUPPORTED_10baseT_Half
                              | SUPPORTED_10baseT_Full
                              | SUPPORTED_100baseT_Half
                              | SUPPORTED_100baseT_Full
                              | SUPPORTED_Autoneg
                              | SUPPORTED_Pause | SUPPORTED_Asym_Pause
                              | SUPPORTED_MII
                              | SUPPORTED_TP);

        phydev->advertising = phydev->supported;

        lp->old_link = 0;
        lp->old_speed = 0;
        lp->old_duplex = -1;
        lp->phydev = phydev;

        pr_info("attached PHY driver [%s] "
                "(mii_bus:phy_addr=%s, irq=%d, mdc_clk=%dHz(mdc_div=%d)@sclk=%dMHz)\n",
                phydev->drv->name, dev_name(&phydev->dev), phydev->irq,
                MDC_CLK, mdc_div, sclk/1000000);

        return 0;
}

/*
 * Ethtool support
 */

/*
 * interrupt routine for magic packet wakeup
 */
static irqreturn_t bfin_mac_wake_interrupt(int irq, void *dev_id)
{
        return IRQ_HANDLED;
}

static int
bfin_mac_ethtool_getsettings(struct net_device *dev, struct ethtool_cmd *cmd)
{
        struct bfin_mac_local *lp = netdev_priv(dev);

        if (lp->phydev)
                return phy_ethtool_gset(lp->phydev, cmd);

        return -EINVAL;
}

static int
bfin_mac_ethtool_setsettings(struct net_device *dev, struct ethtool_cmd *cmd)
{
        struct bfin_mac_local *lp = netdev_priv(dev);

        if (!capable(CAP_NET_ADMIN))
                return -EPERM;

        if (lp->phydev)
                return phy_ethtool_sset(lp->phydev, cmd);

        return -EINVAL;
}

static void bfin_mac_ethtool_getdrvinfo(struct net_device *dev,
                                        struct ethtool_drvinfo *info)
{
        strcpy(info->driver, KBUILD_MODNAME);
        strcpy(info->version, DRV_VERSION);
        strcpy(info->fw_version, "N/A");
        strcpy(info->bus_info, dev_name(&dev->dev));
}

static void bfin_mac_ethtool_getwol(struct net_device *dev,
        struct ethtool_wolinfo *wolinfo)
{
        struct bfin_mac_local *lp = netdev_priv(dev);

        wolinfo->supported = WAKE_MAGIC;
        wolinfo->wolopts = lp->wol;
}

static int bfin_mac_ethtool_setwol(struct net_device *dev,
        struct ethtool_wolinfo *wolinfo)
{
        struct bfin_mac_local *lp = netdev_priv(dev);
        int rc;

        if (wolinfo->wolopts & (WAKE_MAGICSECURE |
                                WAKE_UCAST |
                                WAKE_MCAST |
                                WAKE_BCAST |
                                WAKE_ARP))
                return -EOPNOTSUPP;

        lp->wol = wolinfo->wolopts;

        if (lp->wol && !lp->irq_wake_requested) {
                /* register wake irq handler */
                rc = request_irq(IRQ_MAC_WAKEDET, bfin_mac_wake_interrupt,
                                 IRQF_DISABLED, "EMAC_WAKE", dev);
                if (rc)
                        return rc;
                lp->irq_wake_requested = true;
        }

        if (!lp->wol && lp->irq_wake_requested) {
                free_irq(IRQ_MAC_WAKEDET, dev);
                lp->irq_wake_requested = false;
        }

        /* Make sure the PHY driver doesn't suspend */
        device_init_wakeup(&dev->dev, lp->wol);

        return 0;
}

static int bfin_mac_ethtool_get_ts_info(struct net_device *dev,
        struct ethtool_ts_info *info)
{
        info->so_timestamping =
                SOF_TIMESTAMPING_TX_HARDWARE |
                SOF_TIMESTAMPING_RX_HARDWARE |
                SOF_TIMESTAMPING_SYS_HARDWARE;
        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_PTP_V1_L4_EVENT) |
                (1 << HWTSTAMP_FILTER_PTP_V2_L2_EVENT) |
                (1 << HWTSTAMP_FILTER_PTP_V2_L4_EVENT);
        return 0;
}

static const struct ethtool_ops bfin_mac_ethtool_ops = {
        .get_settings = bfin_mac_ethtool_getsettings,
        .set_settings = bfin_mac_ethtool_setsettings,
        .get_link = ethtool_op_get_link,
        .get_drvinfo = bfin_mac_ethtool_getdrvinfo,
        .get_wol = bfin_mac_ethtool_getwol,
        .set_wol = bfin_mac_ethtool_setwol,
        .get_ts_info = bfin_mac_ethtool_get_ts_info,
};

/**************************************************************************/
static void setup_system_regs(struct net_device *dev)
{
        struct bfin_mac_local *lp = netdev_priv(dev);
        int i;
        unsigned short sysctl;

        /*
         * Odd word alignment for Receive Frame DMA word
         * Configure checksum support and rcve frame word alignment
         */
        sysctl = bfin_read_EMAC_SYSCTL();
        /*
         * check if interrupt is requested for any PHY,
         * enable PHY interrupt only if needed
         */
        for (i = 0; i < PHY_MAX_ADDR; ++i)
                if (lp->mii_bus->irq[i] != PHY_POLL)
                        break;
        if (i < PHY_MAX_ADDR)
                sysctl |= PHYIE;
        sysctl |= RXDWA;
#if defined(BFIN_MAC_CSUM_OFFLOAD)
        sysctl |= RXCKS;
#else
        sysctl &= ~RXCKS;
#endif
        bfin_write_EMAC_SYSCTL(sysctl);

        bfin_write_EMAC_MMC_CTL(RSTC | CROLL);

        /* Set vlan regs to let 1522 bytes long packets pass through */
        bfin_write_EMAC_VLAN1(lp->vlan1_mask);
        bfin_write_EMAC_VLAN2(lp->vlan2_mask);

        /* Initialize the TX DMA channel registers */
        bfin_write_DMA2_X_COUNT(0);
        bfin_write_DMA2_X_MODIFY(4);
        bfin_write_DMA2_Y_COUNT(0);
        bfin_write_DMA2_Y_MODIFY(0);

        /* Initialize the RX DMA channel registers */
        bfin_write_DMA1_X_COUNT(0);
        bfin_write_DMA1_X_MODIFY(4);
        bfin_write_DMA1_Y_COUNT(0);
        bfin_write_DMA1_Y_MODIFY(0);
}

static void setup_mac_addr(u8 *mac_addr)
{
        u32 addr_low = le32_to_cpu(*(__le32 *) & mac_addr[0]);
        u16 addr_hi = le16_to_cpu(*(__le16 *) & mac_addr[4]);

        /* this depends on a little-endian machine */
        bfin_write_EMAC_ADDRLO(addr_low);
        bfin_write_EMAC_ADDRHI(addr_hi);
}

static int bfin_mac_set_mac_address(struct net_device *dev, void *p)
{
        struct sockaddr *addr = p;
        if (netif_running(dev))
                return -EBUSY;
        memcpy(dev->dev_addr, addr->sa_data, dev->addr_len);
        dev->addr_assign_type &= ~NET_ADDR_RANDOM;
        setup_mac_addr(dev->dev_addr);
        return 0;
}

#ifdef CONFIG_BFIN_MAC_USE_HWSTAMP
#define bfin_mac_hwtstamp_is_none(cfg) ((cfg) == HWTSTAMP_FILTER_NONE)

static int bfin_mac_hwtstamp_ioctl(struct net_device *netdev,
                struct ifreq *ifr, int cmd)
{
        struct hwtstamp_config config;
        struct bfin_mac_local *lp = netdev_priv(netdev);
        u16 ptpctl;
        u32 ptpfv1, ptpfv2, ptpfv3, ptpfoff;

        if (copy_from_user(&config, ifr->ifr_data, sizeof(config)))
                return -EFAULT;

        pr_debug("%s config flag:0x%x, tx_type:0x%x, rx_filter:0x%x\n",
                        __func__, config.flags, config.tx_type, config.rx_filter);

        /* reserved for future extensions */
        if (config.flags)
                return -EINVAL;

        if ((config.tx_type != HWTSTAMP_TX_OFF) &&
                        (config.tx_type != HWTSTAMP_TX_ON))
                return -ERANGE;

        ptpctl = bfin_read_EMAC_PTP_CTL();

        switch (config.rx_filter) {
        case HWTSTAMP_FILTER_NONE:
                /*
                 * Dont allow any timestamping
                 */
                ptpfv3 = 0xFFFFFFFF;
                bfin_write_EMAC_PTP_FV3(ptpfv3);
                break;
        case HWTSTAMP_FILTER_PTP_V1_L4_EVENT:
        case HWTSTAMP_FILTER_PTP_V1_L4_SYNC:
        case HWTSTAMP_FILTER_PTP_V1_L4_DELAY_REQ:
                /*
                 * Clear the five comparison mask bits (bits[12:8]) in EMAC_PTP_CTL)
                 * to enable all the field matches.
                 */
                ptpctl &= ~0x1F00;
                bfin_write_EMAC_PTP_CTL(ptpctl);
                /*
                 * Keep the default values of the EMAC_PTP_FOFF register.
                 */
                ptpfoff = 0x4A24170C;
                bfin_write_EMAC_PTP_FOFF(ptpfoff);
                /*
                 * Keep the default values of the EMAC_PTP_FV1 and EMAC_PTP_FV2
                 * registers.
                 */
                ptpfv1 = 0x11040800;
                bfin_write_EMAC_PTP_FV1(ptpfv1);
                ptpfv2 = 0x0140013F;
                bfin_write_EMAC_PTP_FV2(ptpfv2);
                /*
                 * The default value (0xFFFC) allows the timestamping of both
                 * received Sync messages and Delay_Req messages.
                 */
                ptpfv3 = 0xFFFFFFFC;
                bfin_write_EMAC_PTP_FV3(ptpfv3);

                config.rx_filter = HWTSTAMP_FILTER_PTP_V1_L4_EVENT;
                break;
        case HWTSTAMP_FILTER_PTP_V2_L4_EVENT:
        case HWTSTAMP_FILTER_PTP_V2_L4_SYNC:
        case HWTSTAMP_FILTER_PTP_V2_DELAY_REQ:
                /* Clear all five comparison mask bits (bits[12:8]) in the
                 * EMAC_PTP_CTL register to enable all the field matches.
                 */
                ptpctl &= ~0x1F00;
                bfin_write_EMAC_PTP_CTL(ptpctl);
                /*
                 * Keep the default values of the EMAC_PTP_FOFF register, except set
                 * the PTPCOF field to 0x2A.
                 */
                ptpfoff = 0x2A24170C;
                bfin_write_EMAC_PTP_FOFF(ptpfoff);
                /*
                 * Keep the default values of the EMAC_PTP_FV1 and EMAC_PTP_FV2
                 * registers.
                 */
                ptpfv1 = 0x11040800;
                bfin_write_EMAC_PTP_FV1(ptpfv1);
                ptpfv2 = 0x0140013F;
                bfin_write_EMAC_PTP_FV2(ptpfv2);
                /*
                 * To allow the timestamping of Pdelay_Req and Pdelay_Resp, set
                 * the value to 0xFFF0.
                 */
                ptpfv3 = 0xFFFFFFF0;
                bfin_write_EMAC_PTP_FV3(ptpfv3);

                config.rx_filter = HWTSTAMP_FILTER_PTP_V2_L4_EVENT;
                break;
        case HWTSTAMP_FILTER_PTP_V2_L2_EVENT:
        case HWTSTAMP_FILTER_PTP_V2_L2_SYNC:
        case HWTSTAMP_FILTER_PTP_V2_L2_DELAY_REQ:
                /*
                 * Clear bits 8 and 12 of the EMAC_PTP_CTL register to enable only the
                 * EFTM and PTPCM field comparison.
                 */
                ptpctl &= ~0x1100;
                bfin_write_EMAC_PTP_CTL(ptpctl);
                /*
                 * Keep the default values of all the fields of the EMAC_PTP_FOFF
                 * register, except set the PTPCOF field to 0x0E.
                 */
                ptpfoff = 0x0E24170C;
                bfin_write_EMAC_PTP_FOFF(ptpfoff);
                /*
                 * Program bits [15:0] of the EMAC_PTP_FV1 register to 0x88F7, which
                 * corresponds to PTP messages on the MAC layer.
                 */
                ptpfv1 = 0x110488F7;
                bfin_write_EMAC_PTP_FV1(ptpfv1);
                ptpfv2 = 0x0140013F;
                bfin_write_EMAC_PTP_FV2(ptpfv2);
                /*
                 * To allow the timestamping of Pdelay_Req and Pdelay_Resp
                 * messages, set the value to 0xFFF0.
                 */
                ptpfv3 = 0xFFFFFFF0;
                bfin_write_EMAC_PTP_FV3(ptpfv3);

                config.rx_filter = HWTSTAMP_FILTER_PTP_V2_L2_EVENT;
                break;
        default:
                return -ERANGE;
        }

        if (config.tx_type == HWTSTAMP_TX_OFF &&
            bfin_mac_hwtstamp_is_none(config.rx_filter)) {
                ptpctl &= ~PTP_EN;
                bfin_write_EMAC_PTP_CTL(ptpctl);

                SSYNC();
        } else {
                ptpctl |= PTP_EN;
                bfin_write_EMAC_PTP_CTL(ptpctl);

                /*
                 * clear any existing timestamp
                 */
                bfin_read_EMAC_PTP_RXSNAPLO();
                bfin_read_EMAC_PTP_RXSNAPHI();

                bfin_read_EMAC_PTP_TXSNAPLO();
                bfin_read_EMAC_PTP_TXSNAPHI();

                /*
                 * Set registers so that rollover occurs soon to test this.
                 */
                bfin_write_EMAC_PTP_TIMELO(0x00000000);
                bfin_write_EMAC_PTP_TIMEHI(0xFF800000);

                SSYNC();

                lp->compare.last_update = 0;
                timecounter_init(&lp->clock,
                                &lp->cycles,
                                ktime_to_ns(ktime_get_real()));
                timecompare_update(&lp->compare, 0);
        }

        lp->stamp_cfg = config;
        return copy_to_user(ifr->ifr_data, &config, sizeof(config)) ?
                -EFAULT : 0;
}

static void bfin_dump_hwtamp(char *s, ktime_t *hw, ktime_t *ts, struct timecompare *cmp)
{
        ktime_t sys = ktime_get_real();

        pr_debug("%s %s hardware:%d,%d transform system:%d,%d system:%d,%d, cmp:%lld, %lld\n",
                        __func__, s, hw->tv.sec, hw->tv.nsec, ts->tv.sec, ts->tv.nsec, sys.tv.sec,
                        sys.tv.nsec, cmp->offset, cmp->skew);
}

static void bfin_tx_hwtstamp(struct net_device *netdev, struct sk_buff *skb)
{
        struct bfin_mac_local *lp = netdev_priv(netdev);

        if (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP) {
                int timeout_cnt = MAX_TIMEOUT_CNT;

                /* When doing time stamping, keep the connection to the socket
                 * a while longer
                 */
                skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;

                /*
                 * The timestamping is done at the EMAC module's MII/RMII interface
                 * when the module sees the Start of Frame of an event message packet. This
                 * interface is the closest possible place to the physical Ethernet transmission
                 * medium, providing the best timing accuracy.
                 */
                while ((!(bfin_read_EMAC_PTP_ISTAT() & TXTL)) && (--timeout_cnt))
                        udelay(1);
                if (timeout_cnt == 0)
                        netdev_err(netdev, "timestamp the TX packet failed\n");
                else {
                        struct skb_shared_hwtstamps shhwtstamps;
                        u64 ns;
                        u64 regval;

                        regval = bfin_read_EMAC_PTP_TXSNAPLO();
                        regval |= (u64)bfin_read_EMAC_PTP_TXSNAPHI() << 32;
                        memset(&shhwtstamps, 0, sizeof(shhwtstamps));
                        ns = timecounter_cyc2time(&lp->clock,
                                        regval);
                        timecompare_update(&lp->compare, ns);
                        shhwtstamps.hwtstamp = ns_to_ktime(ns);
                        shhwtstamps.syststamp =
                                timecompare_transform(&lp->compare, ns);
                        skb_tstamp_tx(skb, &shhwtstamps);

                        bfin_dump_hwtamp("TX", &shhwtstamps.hwtstamp, &shhwtstamps.syststamp, &lp->compare);
                }
        }
}

static void bfin_rx_hwtstamp(struct net_device *netdev, struct sk_buff *skb)
{
        struct bfin_mac_local *lp = netdev_priv(netdev);
        u32 valid;
        u64 regval, ns;
        struct skb_shared_hwtstamps *shhwtstamps;

        if (bfin_mac_hwtstamp_is_none(lp->stamp_cfg.rx_filter))
                return;

        valid = bfin_read_EMAC_PTP_ISTAT() & RXEL;
        if (!valid)
                return;

        shhwtstamps = skb_hwtstamps(skb);

        regval = bfin_read_EMAC_PTP_RXSNAPLO();
        regval |= (u64)bfin_read_EMAC_PTP_RXSNAPHI() << 32;
        ns = timecounter_cyc2time(&lp->clock, regval);
        timecompare_update(&lp->compare, ns);
        memset(shhwtstamps, 0, sizeof(*shhwtstamps));
        shhwtstamps->hwtstamp = ns_to_ktime(ns);
        shhwtstamps->syststamp = timecompare_transform(&lp->compare, ns);

        bfin_dump_hwtamp("RX", &shhwtstamps->hwtstamp, &shhwtstamps->syststamp, &lp->compare);
}

/*
 * bfin_read_clock - read raw cycle counter (to be used by time counter)
 */
static cycle_t bfin_read_clock(const struct cyclecounter *tc)
{
        u64 stamp;

        stamp =  bfin_read_EMAC_PTP_TIMELO();
        stamp |= (u64)bfin_read_EMAC_PTP_TIMEHI() << 32ULL;

        return stamp;
}

#define PTP_CLK 25000000

static void bfin_mac_hwtstamp_init(struct net_device *netdev)
{
        struct bfin_mac_local *lp = netdev_priv(netdev);
        u64 append;

        /* Initialize hardware timer */
        append = PTP_CLK * (1ULL << 32);
        do_div(append, get_sclk());
        bfin_write_EMAC_PTP_ADDEND((u32)append);

        memset(&lp->cycles, 0, sizeof(lp->cycles));
        lp->cycles.read = bfin_read_clock;
        lp->cycles.mask = CLOCKSOURCE_MASK(64);
        lp->cycles.mult = 1000000000 / PTP_CLK;
        lp->cycles.shift = 0;

        /* Synchronize our NIC clock against system wall clock */
        memset(&lp->compare, 0, sizeof(lp->compare));
        lp->compare.source = &lp->clock;
        lp->compare.target = ktime_get_real;
        lp->compare.num_samples = 10;

        /* Initialize hwstamp config */
        lp->stamp_cfg.rx_filter = HWTSTAMP_FILTER_NONE;
        lp->stamp_cfg.tx_type = HWTSTAMP_TX_OFF;
}

#else
# define bfin_mac_hwtstamp_is_none(cfg) 0
# define bfin_mac_hwtstamp_init(dev)
# define bfin_mac_hwtstamp_ioctl(dev, ifr, cmd) (-EOPNOTSUPP)
# define bfin_rx_hwtstamp(dev, skb)
# define bfin_tx_hwtstamp(dev, skb)
#endif

static inline void _tx_reclaim_skb(void)
{
        do {
                tx_list_head->desc_a.config &= ~DMAEN;
                tx_list_head->status.status_word = 0;
                if (tx_list_head->skb) {
                        dev_kfree_skb(tx_list_head->skb);
                        tx_list_head->skb = NULL;
                }
                tx_list_head = tx_list_head->next;

        } while (tx_list_head->status.status_word != 0);
}

static void tx_reclaim_skb(struct bfin_mac_local *lp)
{
        int timeout_cnt = MAX_TIMEOUT_CNT;

        if (tx_list_head->status.status_word != 0)
                _tx_reclaim_skb();

        if (current_tx_ptr->next == tx_list_head) {
                while (tx_list_head->status.status_word == 0) {
                        /* slow down polling to avoid too many queue stop. */
                        udelay(10);
                        /* reclaim skb if DMA is not running. */
                        if (!(bfin_read_DMA2_IRQ_STATUS() & DMA_RUN))
                                break;
                        if (timeout_cnt-- < 0)
                                break;
                }

                if (timeout_cnt >= 0)
                        _tx_reclaim_skb();
                else
                        netif_stop_queue(lp->ndev);
        }

        if (current_tx_ptr->next != tx_list_head &&
                netif_queue_stopped(lp->ndev))
                netif_wake_queue(lp->ndev);

        if (tx_list_head != current_tx_ptr) {
                /* shorten the timer interval if tx queue is stopped */
                if (netif_queue_stopped(lp->ndev))
                        lp->tx_reclaim_timer.expires =
                                jiffies + (TX_RECLAIM_JIFFIES >> 4);
                else
                        lp->tx_reclaim_timer.expires =
                                jiffies + TX_RECLAIM_JIFFIES;

                mod_timer(&lp->tx_reclaim_timer,
                        lp->tx_reclaim_timer.expires);
        }

        return;
}

static void tx_reclaim_skb_timeout(unsigned long lp)
{
        tx_reclaim_skb((struct bfin_mac_local *)lp);
}

static int bfin_mac_hard_start_xmit(struct sk_buff *skb,
                                struct net_device *dev)
{
        struct bfin_mac_local *lp = netdev_priv(dev);
        u16 *data;
        u32 data_align = (unsigned long)(skb->data) & 0x3;

        current_tx_ptr->skb = skb;

        if (data_align == 0x2) {
                /* move skb->data to current_tx_ptr payload */
                data = (u16 *)(skb->data) - 1;
                *data = (u16)(skb->len);
                /*
                 * When transmitting an Ethernet packet, the PTP_TSYNC module requires
                 * a DMA_Length_Word field associated with the packet. The lower 12 bits
                 * of this field are the length of the packet payload in bytes and the higher
                 * 4 bits are the timestamping enable field.
                 */
                if (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP)
                        *data |= 0x1000;

                current_tx_ptr->desc_a.start_addr = (u32)data;
                /* this is important! */
                blackfin_dcache_flush_range((u32)data,
                                (u32)((u8 *)data + skb->len + 4));
        } else {
                *((u16 *)(current_tx_ptr->packet)) = (u16)(skb->len);
                /* enable timestamping for the sent packet */
                if (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP)
                        *((u16 *)(current_tx_ptr->packet)) |= 0x1000;
                memcpy((u8 *)(current_tx_ptr->packet + 2), skb->data,
                        skb->len);
                current_tx_ptr->desc_a.start_addr =
                        (u32)current_tx_ptr->packet;
                blackfin_dcache_flush_range(
                        (u32)current_tx_ptr->packet,
                        (u32)(current_tx_ptr->packet + skb->len + 2));
        }

        /* make sure the internal data buffers in the core are drained
         * so that the DMA descriptors are completely written when the
         * DMA engine goes to fetch them below
         */
        SSYNC();

        /* always clear status buffer before start tx dma */
        current_tx_ptr->status.status_word = 0;

        /* enable this packet's dma */
        current_tx_ptr->desc_a.config |= DMAEN;

        /* tx dma is running, just return */
        if (bfin_read_DMA2_IRQ_STATUS() & DMA_RUN)
                goto out;

        /* tx dma is not running */
        bfin_write_DMA2_NEXT_DESC_PTR(&(current_tx_ptr->desc_a));
        /* dma enabled, read from memory, size is 6 */
        bfin_write_DMA2_CONFIG(current_tx_ptr->desc_a.config);
        /* Turn on the EMAC tx */
        bfin_write_EMAC_OPMODE(bfin_read_EMAC_OPMODE() | TE);

out:
        bfin_tx_hwtstamp(dev, skb);

        current_tx_ptr = current_tx_ptr->next;
        dev->stats.tx_packets++;
        dev->stats.tx_bytes += (skb->len);

        tx_reclaim_skb(lp);

        return NETDEV_TX_OK;
}

#define IP_HEADER_OFF  0
#define RX_ERROR_MASK (RX_LONG | RX_ALIGN | RX_CRC | RX_LEN | \
        RX_FRAG | RX_ADDR | RX_DMAO | RX_PHY | RX_LATE | RX_RANGE)

static void bfin_mac_rx(struct net_device *dev)
{
        struct sk_buff *skb, *new_skb;
        unsigned short len;
        struct bfin_mac_local *lp __maybe_unused = netdev_priv(dev);
#if defined(BFIN_MAC_CSUM_OFFLOAD)
        unsigned int i;
        unsigned char fcs[ETH_FCS_LEN + 1];
#endif

        /* check if frame status word reports an error condition
         * we which case we simply drop the packet
         */
        if (current_rx_ptr->status.status_word & RX_ERROR_MASK) {
                netdev_notice(dev, "rx: receive error - packet dropped\n");
                dev->stats.rx_dropped++;
                goto out;
        }

        /* allocate a new skb for next time receive */
        skb = current_rx_ptr->skb;

        new_skb = netdev_alloc_skb(dev, PKT_BUF_SZ + NET_IP_ALIGN);
        if (!new_skb) {
                netdev_notice(dev, "rx: low on mem - packet dropped\n");
                dev->stats.rx_dropped++;
                goto out;
        }
        /* reserve 2 bytes for RXDWA padding */
        skb_reserve(new_skb, NET_IP_ALIGN);
        /* Invidate the data cache of skb->data range when it is write back
         * cache. It will prevent overwritting the new data from DMA
         */
        blackfin_dcache_invalidate_range((unsigned long)new_skb->head,
                                         (unsigned long)new_skb->end);

        current_rx_ptr->skb = new_skb;
        current_rx_ptr->desc_a.start_addr = (unsigned long)new_skb->data - 2;

        len = (unsigned short)((current_rx_ptr->status.status_word) & RX_FRLEN);
        /* Deduce Ethernet FCS length from Ethernet payload length */
        len -= ETH_FCS_LEN;
        skb_put(skb, len);

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

        bfin_rx_hwtstamp(dev, skb);

#if defined(BFIN_MAC_CSUM_OFFLOAD)
        /* Checksum offloading only works for IPv4 packets with the standard IP header
         * length of 20 bytes, because the blackfin MAC checksum calculation is
         * based on that assumption. We must NOT use the calculated checksum if our
         * IP version or header break that assumption.
         */
        if (skb->data[IP_HEADER_OFF] == 0x45) {
                skb->csum = current_rx_ptr->status.ip_payload_csum;
                /*
                 * Deduce Ethernet FCS from hardware generated IP payload checksum.
                 * IP checksum is based on 16-bit one's complement algorithm.
                 * To deduce a value from checksum is equal to add its inversion.
                 * If the IP payload len is odd, the inversed FCS should also
                 * begin from odd address and leave first byte zero.
                 */
                if (skb->len % 2) {
                        fcs[0] = 0;
                        for (i = 0; i < ETH_FCS_LEN; i++)
                                fcs[i + 1] = ~skb->data[skb->len + i];
                        skb->csum = csum_partial(fcs, ETH_FCS_LEN + 1, skb->csum);
                } else {
                        for (i = 0; i < ETH_FCS_LEN; i++)
                                fcs[i] = ~skb->data[skb->len + i];
                        skb->csum = csum_partial(fcs, ETH_FCS_LEN, skb->csum);
                }
                skb->ip_summed = CHECKSUM_COMPLETE;
        }
#endif

        netif_rx(skb);
        dev->stats.rx_packets++;
        dev->stats.rx_bytes += len;
out:
        current_rx_ptr->status.status_word = 0x00000000;
        current_rx_ptr = current_rx_ptr->next;
}

/* interrupt routine to handle rx and error signal */
static irqreturn_t bfin_mac_interrupt(int irq, void *dev_id)
{
        struct net_device *dev = dev_id;
        int number = 0;

get_one_packet:
        if (current_rx_ptr->status.status_word == 0) {
                /* no more new packet received */
                if (number == 0) {
                        if (current_rx_ptr->next->status.status_word != 0) {
                                current_rx_ptr = current_rx_ptr->next;
                                goto real_rx;
                        }
                }
                bfin_write_DMA1_IRQ_STATUS(bfin_read_DMA1_IRQ_STATUS() |
                                           DMA_DONE | DMA_ERR);
                return IRQ_HANDLED;
        }

real_rx:
        bfin_mac_rx(dev);
        number++;
        goto get_one_packet;
}

#ifdef CONFIG_NET_POLL_CONTROLLER
static void bfin_mac_poll(struct net_device *dev)
{
        struct bfin_mac_local *lp = netdev_priv(dev);

        disable_irq(IRQ_MAC_RX);
        bfin_mac_interrupt(IRQ_MAC_RX, dev);
        tx_reclaim_skb(lp);
        enable_irq(IRQ_MAC_RX);
}
#endif                          /* CONFIG_NET_POLL_CONTROLLER */

static void bfin_mac_disable(void)
{
        unsigned int opmode;

        opmode = bfin_read_EMAC_OPMODE();
        opmode &= (~RE);
        opmode &= (~TE);
        /* Turn off the EMAC */
        bfin_write_EMAC_OPMODE(opmode);
}

/*
 * Enable Interrupts, Receive, and Transmit
 */
static int bfin_mac_enable(struct phy_device *phydev)
{
        int ret;
        u32 opmode;

        pr_debug("%s\n", __func__);

        /* Set RX DMA */
        bfin_write_DMA1_NEXT_DESC_PTR(&(rx_list_head->desc_a));
        bfin_write_DMA1_CONFIG(rx_list_head->desc_a.config);

        /* Wait MII done */
        ret = bfin_mdio_poll();
        if (ret)
                return ret;

        /* We enable only RX here */
        /* ASTP   : Enable Automatic Pad Stripping
           PR     : Promiscuous Mode for test
           PSF    : Receive frames with total length less than 64 bytes.
           FDMODE : Full Duplex Mode
           LB     : Internal Loopback for test
           RE     : Receiver Enable */
        opmode = bfin_read_EMAC_OPMODE();
        if (opmode & FDMODE)
                opmode |= PSF;
        else
                opmode |= DRO | DC | PSF;
        opmode |= RE;

        if (phydev->interface == PHY_INTERFACE_MODE_RMII) {
                opmode |= RMII; /* For Now only 100MBit are supported */
#if defined(CONFIG_BF537) || defined(CONFIG_BF536)
                if (__SILICON_REVISION__ < 3) {
                        /*
                         * This isn't publicly documented (fun times!), but in
                         * silicon <=0.2, the RX and TX pins are clocked together.
                         * So in order to recv, we must enable the transmit side
                         * as well.  This will cause a spurious TX interrupt too,
                         * but we can easily consume that.
                         */
                        opmode |= TE;
                }
#endif
        }

        /* Turn on the EMAC rx */
        bfin_write_EMAC_OPMODE(opmode);

        return 0;
}

/* Our watchdog timed out. Called by the networking layer */
static void bfin_mac_timeout(struct net_device *dev)
{
        struct bfin_mac_local *lp = netdev_priv(dev);

        pr_debug("%s: %s\n", dev->name, __func__);

        bfin_mac_disable();

        del_timer(&lp->tx_reclaim_timer);

        /* reset tx queue and free skb */
        while (tx_list_head != current_tx_ptr) {
                tx_list_head->desc_a.config &= ~DMAEN;
                tx_list_head->status.status_word = 0;
                if (tx_list_head->skb) {
                        dev_kfree_skb(tx_list_head->skb);
                        tx_list_head->skb = NULL;
                }
                tx_list_head = tx_list_head->next;
        }

        if (netif_queue_stopped(lp->ndev))
                netif_wake_queue(lp->ndev);

        bfin_mac_enable(lp->phydev);

        /* We can accept TX packets again */
        dev->trans_start = jiffies; /* prevent tx timeout */
        netif_wake_queue(dev);
}

static void bfin_mac_multicast_hash(struct net_device *dev)
{
        u32 emac_hashhi, emac_hashlo;
        struct netdev_hw_addr *ha;
        u32 crc;

        emac_hashhi = emac_hashlo = 0;

        netdev_for_each_mc_addr(ha, dev) {
                crc = ether_crc(ETH_ALEN, ha->addr);
                crc >>= 26;

                if (crc & 0x20)
                        emac_hashhi |= 1 << (crc & 0x1f);
                else
                        emac_hashlo |= 1 << (crc & 0x1f);
        }

        bfin_write_EMAC_HASHHI(emac_hashhi);
        bfin_write_EMAC_HASHLO(emac_hashlo);
}

/*
 * This routine will, depending on the values passed to it,
 * either make it accept multicast packets, go into
 * promiscuous mode (for TCPDUMP and cousins) or accept
 * a select set of multicast packets
 */
static void bfin_mac_set_multicast_list(struct net_device *dev)
{
        u32 sysctl;

        if (dev->flags & IFF_PROMISC) {
                netdev_info(dev, "set promisc mode\n");
                sysctl = bfin_read_EMAC_OPMODE();
                sysctl |= PR;
                bfin_write_EMAC_OPMODE(sysctl);
        } else if (dev->flags & IFF_ALLMULTI) {
                /* accept all multicast */
                sysctl = bfin_read_EMAC_OPMODE();
                sysctl |= PAM;
                bfin_write_EMAC_OPMODE(sysctl);
        } else if (!netdev_mc_empty(dev)) {
                /* set up multicast hash table */
                sysctl = bfin_read_EMAC_OPMODE();
                sysctl |= HM;
                bfin_write_EMAC_OPMODE(sysctl);
                bfin_mac_multicast_hash(dev);
        } else {
                /* clear promisc or multicast mode */
                sysctl = bfin_read_EMAC_OPMODE();
                sysctl &= ~(RAF | PAM);
                bfin_write_EMAC_OPMODE(sysctl);
        }
}

static int bfin_mac_ioctl(struct net_device *netdev, struct ifreq *ifr, int cmd)
{
        struct bfin_mac_local *lp = netdev_priv(netdev);

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

        switch (cmd) {
        case SIOCSHWTSTAMP:
                return bfin_mac_hwtstamp_ioctl(netdev, ifr, cmd);
        default:
                if (lp->phydev)
                        return phy_mii_ioctl(lp->phydev, ifr, cmd);
                else
                        return -EOPNOTSUPP;
        }
}

/*
 * this puts the device in an inactive state
 */
static void bfin_mac_shutdown(struct net_device *dev)
{
        /* Turn off the EMAC */
        bfin_write_EMAC_OPMODE(0x00000000);
        /* Turn off the EMAC RX DMA */
        bfin_write_DMA1_CONFIG(0x0000);
        bfin_write_DMA2_CONFIG(0x0000);
}

/*
 * Open and Initialize the interface
 *
 * Set up everything, reset the card, etc..
 */
static int bfin_mac_open(struct net_device *dev)
{
        struct bfin_mac_local *lp = netdev_priv(dev);
        int ret;
        pr_debug("%s: %s\n", dev->name, __func__);

        /*
         * Check that the address is valid.  If its not, refuse
         * to bring the device up.  The user must specify an
         * address using ifconfig eth0 hw ether xx:xx:xx:xx:xx:xx
         */
        if (!is_valid_ether_addr(dev->dev_addr)) {
                netdev_warn(dev, "no valid ethernet hw addr\n");
                return -EINVAL;
        }

        /* initial rx and tx list */
        ret = desc_list_init(dev);
        if (ret)
                return ret;

        phy_start(lp->phydev);
        phy_write(lp->phydev, MII_BMCR, BMCR_RESET);
        setup_system_regs(dev);
        setup_mac_addr(dev->dev_addr);

        bfin_mac_disable();
        ret = bfin_mac_enable(lp->phydev);
        if (ret)
                return ret;
        pr_debug("hardware init finished\n");

        netif_start_queue(dev);
        netif_carrier_on(dev);

        return 0;
}

/*
 * this makes the board clean up everything that it can
 * and not talk to the outside world.   Caused by
 * an 'ifconfig ethX down'
 */
static int bfin_mac_close(struct net_device *dev)
{
        struct bfin_mac_local *lp = netdev_priv(dev);
        pr_debug("%s: %s\n", dev->name, __func__);

        netif_stop_queue(dev);
        netif_carrier_off(dev);

        phy_stop(lp->phydev);
        phy_write(lp->phydev, MII_BMCR, BMCR_PDOWN);

        /* clear everything */
        bfin_mac_shutdown(dev);

        /* free the rx/tx buffers */
        desc_list_free();

        return 0;
}

static const struct net_device_ops bfin_mac_netdev_ops = {
        .ndo_open               = bfin_mac_open,
        .ndo_stop               = bfin_mac_close,
        .ndo_start_xmit         = bfin_mac_hard_start_xmit,
        .ndo_set_mac_address    = bfin_mac_set_mac_address,
        .ndo_tx_timeout         = bfin_mac_timeout,
        .ndo_set_rx_mode        = bfin_mac_set_multicast_list,
        .ndo_do_ioctl           = bfin_mac_ioctl,
        .ndo_validate_addr      = eth_validate_addr,
        .ndo_change_mtu         = eth_change_mtu,
#ifdef CONFIG_NET_POLL_CONTROLLER
        .ndo_poll_controller    = bfin_mac_poll,
#endif
};

static int __devinit bfin_mac_probe(struct platform_device *pdev)
{
        struct net_device *ndev;
        struct bfin_mac_local *lp;
        struct platform_device *pd;
        struct bfin_mii_bus_platform_data *mii_bus_data;
        int rc;

        ndev = alloc_etherdev(sizeof(struct bfin_mac_local));
        if (!ndev)
                return -ENOMEM;

        SET_NETDEV_DEV(ndev, &pdev->dev);
        platform_set_drvdata(pdev, ndev);
        lp = netdev_priv(ndev);
        lp->ndev = ndev;

        /* Grab the MAC address in the MAC */
        *(__le32 *) (&(ndev->dev_addr[0])) = cpu_to_le32(bfin_read_EMAC_ADDRLO());
        *(__le16 *) (&(ndev->dev_addr[4])) = cpu_to_le16((u16) bfin_read_EMAC_ADDRHI());

        /* probe mac */
        /*todo: how to proble? which is revision_register */
        bfin_write_EMAC_ADDRLO(0x12345678);
        if (bfin_read_EMAC_ADDRLO() != 0x12345678) {
                dev_err(&pdev->dev, "Cannot detect Blackfin on-chip ethernet MAC controller!\n");
                rc = -ENODEV;
                goto out_err_probe_mac;
        }


        /*
         * Is it valid? (Did bootloader initialize it?)
         * Grab the MAC from the board somehow
         * this is done in the arch/blackfin/mach-bfxxx/boards/eth_mac.c
         */
        if (!is_valid_ether_addr(ndev->dev_addr)) {
                if (bfin_get_ether_addr(ndev->dev_addr) ||
                     !is_valid_ether_addr(ndev->dev_addr)) {
                        /* Still not valid, get a random one */
                        netdev_warn(ndev, "Setting Ethernet MAC to a random one\n");
                        eth_hw_addr_random(ndev);
                }
        }

        setup_mac_addr(ndev->dev_addr);

        if (!pdev->dev.platform_data) {
                dev_err(&pdev->dev, "Cannot get platform device bfin_mii_bus!\n");
                rc = -ENODEV;
                goto out_err_probe_mac;
        }
        pd = pdev->dev.platform_data;
        lp->mii_bus = platform_get_drvdata(pd);
        if (!lp->mii_bus) {
                dev_err(&pdev->dev, "Cannot get mii_bus!\n");
                rc = -ENODEV;
                goto out_err_probe_mac;
        }
        lp->mii_bus->priv = ndev;
        mii_bus_data = pd->dev.platform_data;

        rc = mii_probe(ndev, mii_bus_data->phy_mode);
        if (rc) {
                dev_err(&pdev->dev, "MII Probe failed!\n");
                goto out_err_mii_probe;
        }

        lp->vlan1_mask = ETH_P_8021Q | mii_bus_data->vlan1_mask;
        lp->vlan2_mask = ETH_P_8021Q | mii_bus_data->vlan2_mask;

        /* Fill in the fields of the device structure with ethernet values. */
        ether_setup(ndev);

        ndev->netdev_ops = &bfin_mac_netdev_ops;
        ndev->ethtool_ops = &bfin_mac_ethtool_ops;

        init_timer(&lp->tx_reclaim_timer);
        lp->tx_reclaim_timer.data = (unsigned long)lp;
        lp->tx_reclaim_timer.function = tx_reclaim_skb_timeout;

        spin_lock_init(&lp->lock);

        /* now, enable interrupts */
        /* register irq handler */
        rc = request_irq(IRQ_MAC_RX, bfin_mac_interrupt,
                        IRQF_DISABLED, "EMAC_RX", ndev);
        if (rc) {
                dev_err(&pdev->dev, "Cannot request Blackfin MAC RX IRQ!\n");
                rc = -EBUSY;
                goto out_err_request_irq;
        }

        rc = register_netdev(ndev);
        if (rc) {
                dev_err(&pdev->dev, "Cannot register net device!\n");
                goto out_err_reg_ndev;
        }

        bfin_mac_hwtstamp_init(ndev);

        /* now, print out the card info, in a short format.. */
        netdev_info(ndev, "%s, Version %s\n", DRV_DESC, DRV_VERSION);

        return 0;

out_err_reg_ndev:
        free_irq(IRQ_MAC_RX, ndev);
out_err_request_irq:
out_err_mii_probe:
        mdiobus_unregister(lp->mii_bus);
        mdiobus_free(lp->mii_bus);
out_err_probe_mac:
        platform_set_drvdata(pdev, NULL);
        free_netdev(ndev);

        return rc;
}

static int __devexit bfin_mac_remove(struct platform_device *pdev)
{
        struct net_device *ndev = platform_get_drvdata(pdev);
        struct bfin_mac_local *lp = netdev_priv(ndev);

        platform_set_drvdata(pdev, NULL);

        lp->mii_bus->priv = NULL;

        unregister_netdev(ndev);

        free_irq(IRQ_MAC_RX, ndev);

        free_netdev(ndev);

        return 0;
}

#ifdef CONFIG_PM
static int bfin_mac_suspend(struct platform_device *pdev, pm_message_t mesg)
{
        struct net_device *net_dev = platform_get_drvdata(pdev);
        struct bfin_mac_local *lp = netdev_priv(net_dev);

        if (lp->wol) {
                bfin_write_EMAC_OPMODE((bfin_read_EMAC_OPMODE() & ~TE) | RE);
                bfin_write_EMAC_WKUP_CTL(MPKE);
                enable_irq_wake(IRQ_MAC_WAKEDET);
        } else {
                if (netif_running(net_dev))
                        bfin_mac_close(net_dev);
        }

        return 0;
}

static int bfin_mac_resume(struct platform_device *pdev)
{
        struct net_device *net_dev = platform_get_drvdata(pdev);
        struct bfin_mac_local *lp = netdev_priv(net_dev);

        if (lp->wol) {
                bfin_write_EMAC_OPMODE(bfin_read_EMAC_OPMODE() | TE);
                bfin_write_EMAC_WKUP_CTL(0);
                disable_irq_wake(IRQ_MAC_WAKEDET);
        } else {
                if (netif_running(net_dev))
                        bfin_mac_open(net_dev);
        }

        return 0;
}
#else
#define bfin_mac_suspend NULL
#define bfin_mac_resume NULL
#endif  /* CONFIG_PM */

static int __devinit bfin_mii_bus_probe(struct platform_device *pdev)
{
        struct mii_bus *miibus;
        struct bfin_mii_bus_platform_data *mii_bus_pd;
        const unsigned short *pin_req;
        int rc, i;

        mii_bus_pd = dev_get_platdata(&pdev->dev);
        if (!mii_bus_pd) {
                dev_err(&pdev->dev, "No peripherals in platform data!\n");
                return -EINVAL;
        }

        /*
         * We are setting up a network card,
         * so set the GPIO pins to Ethernet mode
         */
        pin_req = mii_bus_pd->mac_peripherals;
        rc = peripheral_request_list(pin_req, KBUILD_MODNAME);
        if (rc) {
                dev_err(&pdev->dev, "Requesting peripherals failed!\n");
                return rc;
        }

        rc = -ENOMEM;
        miibus = mdiobus_alloc();
        if (miibus == NULL)
                goto out_err_alloc;
        miibus->read = bfin_mdiobus_read;
        miibus->write = bfin_mdiobus_write;
        miibus->reset = bfin_mdiobus_reset;

        miibus->parent = &pdev->dev;
        miibus->name = "bfin_mii_bus";
        miibus->phy_mask = mii_bus_pd->phy_mask;

        snprintf(miibus->id, MII_BUS_ID_SIZE, "%s-%x",
                pdev->name, pdev->id);
        miibus->irq = kmalloc(sizeof(int)*PHY_MAX_ADDR, GFP_KERNEL);
        if (!miibus->irq)
                goto out_err_irq_alloc;

        for (i = rc; i < PHY_MAX_ADDR; ++i)
                miibus->irq[i] = PHY_POLL;

        rc = clamp(mii_bus_pd->phydev_number, 0, PHY_MAX_ADDR);
        if (rc != mii_bus_pd->phydev_number)
                dev_err(&pdev->dev, "Invalid number (%i) of phydevs\n",
                        mii_bus_pd->phydev_number);
        for (i = 0; i < rc; ++i) {
                unsigned short phyaddr = mii_bus_pd->phydev_data[i].addr;
                if (phyaddr < PHY_MAX_ADDR)
                        miibus->irq[phyaddr] = mii_bus_pd->phydev_data[i].irq;
                else
                        dev_err(&pdev->dev,
                                "Invalid PHY address %i for phydev %i\n",
                                phyaddr, i);
        }

        rc = mdiobus_register(miibus);
        if (rc) {
                dev_err(&pdev->dev, "Cannot register MDIO bus!\n");
                goto out_err_mdiobus_register;
        }

        platform_set_drvdata(pdev, miibus);
        return 0;

out_err_mdiobus_register:
        kfree(miibus->irq);
out_err_irq_alloc:
        mdiobus_free(miibus);
out_err_alloc:
        peripheral_free_list(pin_req);

        return rc;
}

static int __devexit bfin_mii_bus_remove(struct platform_device *pdev)
{
        struct mii_bus *miibus = platform_get_drvdata(pdev);
        struct bfin_mii_bus_platform_data *mii_bus_pd =
                dev_get_platdata(&pdev->dev);

        platform_set_drvdata(pdev, NULL);
        mdiobus_unregister(miibus);
        kfree(miibus->irq);
        mdiobus_free(miibus);
        peripheral_free_list(mii_bus_pd->mac_peripherals);

        return 0;
}

static struct platform_driver bfin_mii_bus_driver = {
        .probe = bfin_mii_bus_probe,
        .remove = __devexit_p(bfin_mii_bus_remove),
        .driver = {
                .name = "bfin_mii_bus",
                .owner  = THIS_MODULE,
        },
};

static struct platform_driver bfin_mac_driver = {
        .probe = bfin_mac_probe,
        .remove = __devexit_p(bfin_mac_remove),
        .resume = bfin_mac_resume,
        .suspend = bfin_mac_suspend,
        .driver = {
                .name = KBUILD_MODNAME,
                .owner  = THIS_MODULE,
        },
};

static int __init bfin_mac_init(void)
{
        int ret;
        ret = platform_driver_register(&bfin_mii_bus_driver);
        if (!ret)
                return platform_driver_register(&bfin_mac_driver);
        return -ENODEV;
}

module_init(bfin_mac_init);

static void __exit bfin_mac_cleanup(void)
{
        platform_driver_unregister(&bfin_mac_driver);
        platform_driver_unregister(&bfin_mii_bus_driver);
}

module_exit(bfin_mac_cleanup);