/*
 * Blackfin On-Chip MAC Driver
 *
 * Copyright 2004-2007 Analog Devices Inc.
 *
 * Enter bugs at http://blackfin.uclinux.org/
 *
 * Licensed under the GPL-2 or later.
 */

#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/phy.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/blackfin.h>
#include <asm/cacheflush.h>
#include <asm/portmux.h>

#include "bfin_mac.h"

#define DRV_NAME        "bfin_mac"
#define DRV_VERSION     "1.1"
#define DRV_AUTHOR      "Bryan Wu, Luke Yang"
#define DRV_DESC        "Blackfin on-chip Ethernet MAC driver"

MODULE_AUTHOR(DRV_AUTHOR);
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)  l1_data_sram_zalloc(size)
# define bfin_mac_free(dma_handle, ptr)    l1_data_sram_free(ptr)
#else
# define bfin_mac_alloc(dma_handle, size) \
        dma_alloc_coherent(NULL, size, dma_handle, GFP_KERNEL)
# define bfin_mac_free(dma_handle, ptr) \
        dma_free_coherent(NULL, sizeof(*ptr), 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;

#if defined(CONFIG_BFIN_MAC_RMII)
static u16 pin_req[] = P_RMII0;
#else
static u16 pin_req[] = P_MII0;
#endif

static void bfin_mac_disable(void);
static void bfin_mac_enable(void);

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);
        }

        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);
        }
}

static int desc_list_init(void)
{
        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 = dev_alloc_skb(PKT_BUF_SZ + NET_IP_ALIGN);
                if (!new_skb) {
                        printk(KERN_NOTICE DRV_NAME
                               ": init: low on mem - packet dropped\n");
                        goto init_error;
                }
                skb_reserve(new_skb, NET_IP_ALIGN);
                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();
        printk(KERN_ERR DRV_NAME ": kmalloc failed\n");
        return -ENOMEM;
}


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

/*
 * MII operations
 */
/* Wait until the previous MDC/MDIO transaction has completed */
static void 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) {
                        printk(KERN_ERR DRV_NAME
                        ": wait MDC/MDIO transaction to complete timeout\n");
                        break;
                }
        }
}

/* 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)
{
        bfin_mdio_poll();

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

        bfin_mdio_poll();

        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)
{
        bfin_mdio_poll();

        bfin_write_EMAC_STADAT((u32) value);

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

        bfin_mdio_poll();

        return 0;
}

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 defined(CONFIG_BFIN_MAC_RMII)
                        u32 opmode = bfin_read_EMAC_OPMODE();
                        switch (phydev->speed) {
                        case 10:
                                opmode |= RMII_10;
                                break;
                        case 100:
                                opmode &= ~(RMII_10);
                                break;
                        default:
                                printk(KERN_WARNING
                                        "%s: Ack!  Speed (%d) is not 10/100!\n",
                                        DRV_NAME, phydev->speed);
                                break;
                        }
                        bfin_write_EMAC_OPMODE(opmode);
#endif

                        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)
{
        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() & PHYCLKOE))
                bfin_write_VR_CTL(bfin_read_VR_CTL() | PHYCLKOE);

        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 connect 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) {
                printk(KERN_INFO "%s: Don't found any phy device at all\n",
                        dev->name);
                return -ENODEV;
        }

#if defined(CONFIG_BFIN_MAC_RMII)
        phydev = phy_connect(dev, dev_name(&phydev->dev), &bfin_mac_adjust_link,
                        0, PHY_INTERFACE_MODE_RMII);
#else
        phydev = phy_connect(dev, dev_name(&phydev->dev), &bfin_mac_adjust_link,
                        0, PHY_INTERFACE_MODE_MII);
#endif

        if (IS_ERR(phydev)) {
                printk(KERN_ERR "%s: Could not attach to PHY\n", dev->name);
                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;

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

        return 0;
}

/*
 * Ethtool support
 */

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, DRV_NAME);
        strcpy(info->version, DRV_VERSION);
        strcpy(info->fw_version, "N/A");
        strcpy(info->bus_info, dev_name(&dev->dev));
}

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,
};

/**************************************************************************/
void setup_system_regs(struct net_device *dev)
{
        unsigned short sysctl;

        /*
         * Odd word alignment for Receive Frame DMA word
         * Configure checksum support and rcve frame word alignment
         */
        sysctl = bfin_read_EMAC_SYSCTL();
#if defined(BFIN_MAC_CSUM_OFFLOAD)
        sysctl |= RXDWA | RXCKS;
#else
        sysctl |= RXDWA;
#endif
        bfin_write_EMAC_SYSCTL(sysctl);

        bfin_write_EMAC_MMC_CTL(RSTC | CROLL);

        /* 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);
        setup_mac_addr(dev->dev_addr);
        return 0;
}

static void adjust_tx_list(void)
{
        int timeout_cnt = MAX_TIMEOUT_CNT;

        if (tx_list_head->status.status_word != 0
            && current_tx_ptr != tx_list_head) {
                goto adjust_head;       /* released something, just return; */
        }

        /*
         * if nothing released, check wait condition
         * current's next can not be the head,
         * otherwise the dma will not stop as we want
         */
        if (current_tx_ptr->next->next == tx_list_head) {
                while (tx_list_head->status.status_word == 0) {
                        udelay(10);
                        if (tx_list_head->status.status_word != 0
                            || !(bfin_read_DMA2_IRQ_STATUS() & DMA_RUN)) {
                                goto adjust_head;
                        }
                        if (timeout_cnt-- < 0) {
                                printk(KERN_ERR DRV_NAME
                                ": wait for adjust tx list head timeout\n");
                                break;
                        }
                }
                if (tx_list_head->status.status_word != 0) {
                        goto adjust_head;
                }
        }

        return;

adjust_head:
        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;
                } else {
                        printk(KERN_ERR DRV_NAME
                               ": no sk_buff in a transmitted frame!\n");
                }
                tx_list_head = tx_list_head->next;
        } while (tx_list_head->status.status_word != 0
                 && current_tx_ptr != tx_list_head);
        return;

}

static int bfin_mac_hard_start_xmit(struct sk_buff *skb,
                                struct net_device *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);
                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);
                memcpy((u8 *)(current_tx_ptr->packet + 2), skb->data,
                        skb->len);
                current_tx_ptr->desc_a.start_addr =
                        (u32)current_tx_ptr->packet;
                if (current_tx_ptr->status.status_word != 0)
                        current_tx_ptr->status.status_word = 0;
                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();

        /* 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:
        adjust_tx_list();
        current_tx_ptr = current_tx_ptr->next;
        dev->trans_start = jiffies;
        dev->stats.tx_packets++;
        dev->stats.tx_bytes += (skb->len);
        return NETDEV_TX_OK;
}

static void bfin_mac_rx(struct net_device *dev)
{
        struct sk_buff *skb, *new_skb;
        unsigned short len;

        /* allocate a new skb for next time receive */
        skb = current_rx_ptr->skb;
        new_skb = dev_alloc_skb(PKT_BUF_SZ + NET_IP_ALIGN);
        if (!new_skb) {
                printk(KERN_NOTICE DRV_NAME
                       ": 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);
        current_rx_ptr->skb = new_skb;
        current_rx_ptr->desc_a.start_addr = (unsigned long)new_skb->data - 2;

        /* 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);

        len = (unsigned short)((current_rx_ptr->status.status_word) & RX_FRLEN);
        skb_put(skb, len);
        blackfin_dcache_invalidate_range((unsigned long)skb->head,
                                         (unsigned long)skb->tail);

        skb->protocol = eth_type_trans(skb, dev);
#if defined(BFIN_MAC_CSUM_OFFLOAD)
        skb->csum = current_rx_ptr->status.ip_payload_csum;
        skb->ip_summed = CHECKSUM_COMPLETE;
#endif

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

out:
        return;
}

/* 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)
{
        disable_irq(IRQ_MAC_RX);
        bfin_mac_interrupt(IRQ_MAC_RX, dev);
        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 void bfin_mac_enable(void)
{
        u32 opmode;

        pr_debug("%s: %s\n", DRV_NAME, __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 */
        bfin_mdio_poll();

        /* 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 defined(CONFIG_BFIN_MAC_RMII)
        opmode |= RMII; /* For Now only 100MBit are supported */
#if (defined(CONFIG_BF537) || defined(CONFIG_BF536)) && CONFIG_BF_REV_0_2
        opmode |= TE;
#endif
#endif
        /* Turn on the EMAC rx */
        bfin_write_EMAC_OPMODE(opmode);
}

/* Our watchdog timed out. Called by the networking layer */
static void bfin_mac_timeout(struct net_device *dev)
{
        pr_debug("%s: %s\n", dev->name, __func__);

        bfin_mac_disable();

        /* reset tx queue */
        tx_list_tail = tx_list_head->next;

        bfin_mac_enable();

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

static void bfin_mac_multicast_hash(struct net_device *dev)
{
        u32 emac_hashhi, emac_hashlo;
        struct dev_mc_list *dmi = dev->mc_list;
        char *addrs;
        int i;
        u32 crc;

        emac_hashhi = emac_hashlo = 0;

        for (i = 0; i < dev->mc_count; i++) {
                addrs = dmi->dmi_addr;
                dmi = dmi->next;

                /* skip non-multicast addresses */
                if (!(*addrs & 1))
                        continue;

                crc = ether_crc(ETH_ALEN, addrs);
                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);

        return;
}

/*
 * 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) {
                printk(KERN_INFO "%s: set to promisc mode\n", dev->name);
                sysctl = bfin_read_EMAC_OPMODE();
                sysctl |= RAF;
                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 (dev->mc_count) {
                /* 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);
        }
}

/*
 * 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 retval;
        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)) {
                printk(KERN_WARNING DRV_NAME ": no valid ethernet hw addr\n");
                return -EINVAL;
        }

        /* initial rx and tx list */
        retval = desc_list_init();

        if (retval)
                return retval;

        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();
        bfin_mac_enable();
        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_multicast_list = bfin_mac_set_multicast_list,
        .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;
        int rc;

        ndev = alloc_etherdev(sizeof(struct bfin_mac_local));
        if (!ndev) {
                dev_err(&pdev->dev, "Cannot allocate net device!\n");
                return -ENOMEM;
        }

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

        /* If still not valid, get a random one */
        if (!is_valid_ether_addr(ndev->dev_addr))
                random_ether_addr(ndev->dev_addr);

        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);
        lp->mii_bus->priv = ndev;

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

        /* 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;

        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;
        }

        /* now, print out the card info, in a short format.. */
        dev_info(&pdev->dev, "%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);
        peripheral_free_list(pin_req);
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);

        peripheral_free_list(pin_req);

        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);

        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);

        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;
        int rc, i;

        /*
         * We are setting up a network card,
         * so set the GPIO pins to Ethernet mode
         */
        rc = peripheral_request_list(pin_req, DRV_NAME);
        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";
        snprintf(miibus->id, MII_BUS_ID_SIZE, "0");
        miibus->irq = kmalloc(sizeof(int)*PHY_MAX_ADDR, GFP_KERNEL);
        if (miibus->irq == NULL)
                goto out_err_alloc;
        for (i = 0; i < PHY_MAX_ADDR; ++i)
                miibus->irq[i] = PHY_POLL;

        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:
        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);
        platform_set_drvdata(pdev, NULL);
        mdiobus_unregister(miibus);
        mdiobus_free(miibus);
        peripheral_free_list(pin_req);
        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 = DRV_NAME,
                .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);