/*
 *      Davicom DM9000 Fast Ethernet driver for Linux.
 *      Copyright (C) 1997  Sten Wang
 *
 *      This program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License
 *      as published by the Free Software Foundation; either version 2
 *      of the License, or (at your option) any later version.
 *
 *      This program is distributed in the hope that it will be useful,
 *      but WITHOUT ANY WARRANTY; without even the implied warranty of
 *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *      GNU General Public License for more details.
 *
 * (C) Copyright 1997-1998 DAVICOM Semiconductor,Inc. All Rights Reserved.
 *
 * Additional updates, Copyright:
 *      Ben Dooks <ben@simtec.co.uk>
 *      Sascha Hauer <s.hauer@pengutronix.de>
 */

#include <linux/module.h>
#include <linux/ioport.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/init.h>
#include <linux/skbuff.h>
#include <linux/spinlock.h>
#include <linux/crc32.h>
#include <linux/mii.h>
#include <linux/ethtool.h>
#include <linux/dm9000.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
#include <linux/irq.h>

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

#include "dm9000.h"

/* Board/System/Debug information/definition ---------------- */

#define DM9000_PHY              0x40    /* PHY address 0x01 */

#define CARDNAME        "dm9000"
#define DRV_VERSION     "1.31"

/*
 * Transmit timeout, default 5 seconds.
 */
static int watchdog = 5000;
module_param(watchdog, int, 0400);
MODULE_PARM_DESC(watchdog, "transmit timeout in milliseconds");

/* DM9000 register address locking.
 *
 * The DM9000 uses an address register to control where data written
 * to the data register goes. This means that the address register
 * must be preserved over interrupts or similar calls.
 *
 * During interrupt and other critical calls, a spinlock is used to
 * protect the system, but the calls themselves save the address
 * in the address register in case they are interrupting another
 * access to the device.
 *
 * For general accesses a lock is provided so that calls which are
 * allowed to sleep are serialised so that the address register does
 * not need to be saved. This lock also serves to serialise access
 * to the EEPROM and PHY access registers which are shared between
 * these two devices.
 */

/* The driver supports the original DM9000E, and now the two newer
 * devices, DM9000A and DM9000B.
 */

enum dm9000_type {
        TYPE_DM9000E,   /* original DM9000 */
        TYPE_DM9000A,
        TYPE_DM9000B
};

/* Structure/enum declaration ------------------------------- */
typedef struct board_info {

        void __iomem    *io_addr;       /* Register I/O base address */
        void __iomem    *io_data;       /* Data I/O address */
        u16              irq;           /* IRQ */

        u16             tx_pkt_cnt;
        u16             queue_pkt_len;
        u16             queue_start_addr;
        u16             queue_ip_summed;
        u16             dbug_cnt;
        u8              io_mode;                /* 0:word, 2:byte */
        u8              phy_addr;
        u8              imr_all;

        unsigned int    flags;
        unsigned int    in_suspend :1;
        int             debug_level;

        enum dm9000_type type;

        void (*inblk)(void __iomem *port, void *data, int length);
        void (*outblk)(void __iomem *port, void *data, int length);
        void (*dumpblk)(void __iomem *port, int length);

        struct device   *dev;        /* parent device */

        struct resource *addr_res;   /* resources found */
        struct resource *data_res;
        struct resource *addr_req;   /* resources requested */
        struct resource *data_req;
        struct resource *irq_res;

        struct mutex     addr_lock;     /* phy and eeprom access lock */

        struct delayed_work phy_poll;
        struct net_device  *ndev;

        spinlock_t      lock;

        struct mii_if_info mii;
        u32             msg_enable;

        int             rx_csum;
        int             can_csum;
        int             ip_summed;
} board_info_t;

/* debug code */

#define dm9000_dbg(db, lev, msg...) do {                \
        if ((lev) < CONFIG_DM9000_DEBUGLEVEL &&         \
            (lev) < db->debug_level) {                  \
                dev_dbg(db->dev, msg);                  \
        }                                               \
} while (0)

static inline board_info_t *to_dm9000_board(struct net_device *dev)
{
        return netdev_priv(dev);
}

/* DM9000 network board routine ---------------------------- */

static void
dm9000_reset(board_info_t * db)
{
        dev_dbg(db->dev, "resetting device\n");

        /* RESET device */
        writeb(DM9000_NCR, db->io_addr);
        udelay(200);
        writeb(NCR_RST, db->io_data);
        udelay(200);
}

/*
 *   Read a byte from I/O port
 */
static u8
ior(board_info_t * db, int reg)
{
        writeb(reg, db->io_addr);
        return readb(db->io_data);
}

/*
 *   Write a byte to I/O port
 */

static void
iow(board_info_t * db, int reg, int value)
{
        writeb(reg, db->io_addr);
        writeb(value, db->io_data);
}

/* routines for sending block to chip */

static void dm9000_outblk_8bit(void __iomem *reg, void *data, int count)
{
        writesb(reg, data, count);
}

static void dm9000_outblk_16bit(void __iomem *reg, void *data, int count)
{
        writesw(reg, data, (count+1) >> 1);
}

static void dm9000_outblk_32bit(void __iomem *reg, void *data, int count)
{
        writesl(reg, data, (count+3) >> 2);
}

/* input block from chip to memory */

static void dm9000_inblk_8bit(void __iomem *reg, void *data, int count)
{
        readsb(reg, data, count);
}


static void dm9000_inblk_16bit(void __iomem *reg, void *data, int count)
{
        readsw(reg, data, (count+1) >> 1);
}

static void dm9000_inblk_32bit(void __iomem *reg, void *data, int count)
{
        readsl(reg, data, (count+3) >> 2);
}

/* dump block from chip to null */

static void dm9000_dumpblk_8bit(void __iomem *reg, int count)
{
        int i;
        int tmp;

        for (i = 0; i < count; i++)
                tmp = readb(reg);
}

static void dm9000_dumpblk_16bit(void __iomem *reg, int count)
{
        int i;
        int tmp;

        count = (count + 1) >> 1;

        for (i = 0; i < count; i++)
                tmp = readw(reg);
}

static void dm9000_dumpblk_32bit(void __iomem *reg, int count)
{
        int i;
        int tmp;

        count = (count + 3) >> 2;

        for (i = 0; i < count; i++)
                tmp = readl(reg);
}

/* dm9000_set_io
 *
 * select the specified set of io routines to use with the
 * device
 */

static void dm9000_set_io(struct board_info *db, int byte_width)
{
        /* use the size of the data resource to work out what IO
         * routines we want to use
         */

        switch (byte_width) {
        case 1:
                db->dumpblk = dm9000_dumpblk_8bit;
                db->outblk  = dm9000_outblk_8bit;
                db->inblk   = dm9000_inblk_8bit;
                break;


        case 3:
                dev_dbg(db->dev, ": 3 byte IO, falling back to 16bit\n");
        case 2:
                db->dumpblk = dm9000_dumpblk_16bit;
                db->outblk  = dm9000_outblk_16bit;
                db->inblk   = dm9000_inblk_16bit;
                break;

        case 4:
        default:
                db->dumpblk = dm9000_dumpblk_32bit;
                db->outblk  = dm9000_outblk_32bit;
                db->inblk   = dm9000_inblk_32bit;
                break;
        }
}

static void dm9000_schedule_poll(board_info_t *db)
{
        if (db->type == TYPE_DM9000E)
                schedule_delayed_work(&db->phy_poll, HZ * 2);
}

static int dm9000_ioctl(struct net_device *dev, struct ifreq *req, int cmd)
{
        board_info_t *dm = to_dm9000_board(dev);

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

        return generic_mii_ioctl(&dm->mii, if_mii(req), cmd, NULL);
}

static unsigned int
dm9000_read_locked(board_info_t *db, int reg)
{
        unsigned long flags;
        unsigned int ret;

        spin_lock_irqsave(&db->lock, flags);
        ret = ior(db, reg);
        spin_unlock_irqrestore(&db->lock, flags);

        return ret;
}

static int dm9000_wait_eeprom(board_info_t *db)
{
        unsigned int status;
        int timeout = 8;        /* wait max 8msec */

        /* The DM9000 data sheets say we should be able to
         * poll the ERRE bit in EPCR to wait for the EEPROM
         * operation. From testing several chips, this bit
         * does not seem to work.
         *
         * We attempt to use the bit, but fall back to the
         * timeout (which is why we do not return an error
         * on expiry) to say that the EEPROM operation has
         * completed.
         */

        while (1) {
                status = dm9000_read_locked(db, DM9000_EPCR);

                if ((status & EPCR_ERRE) == 0)
                        break;

                msleep(1);

                if (timeout-- < 0) {
                        dev_dbg(db->dev, "timeout waiting EEPROM\n");
                        break;
                }
        }

        return 0;
}

/*
 *  Read a word data from EEPROM
 */
static void
dm9000_read_eeprom(board_info_t *db, int offset, u8 *to)
{
        unsigned long flags;

        if (db->flags & DM9000_PLATF_NO_EEPROM) {
                to[0] = 0xff;
                to[1] = 0xff;
                return;
        }

        mutex_lock(&db->addr_lock);

        spin_lock_irqsave(&db->lock, flags);

        iow(db, DM9000_EPAR, offset);
        iow(db, DM9000_EPCR, EPCR_ERPRR);

        spin_unlock_irqrestore(&db->lock, flags);

        dm9000_wait_eeprom(db);

        /* delay for at-least 150uS */
        msleep(1);

        spin_lock_irqsave(&db->lock, flags);

        iow(db, DM9000_EPCR, 0x0);

        to[0] = ior(db, DM9000_EPDRL);
        to[1] = ior(db, DM9000_EPDRH);

        spin_unlock_irqrestore(&db->lock, flags);

        mutex_unlock(&db->addr_lock);
}

/*
 * Write a word data to SROM
 */
static void
dm9000_write_eeprom(board_info_t *db, int offset, u8 *data)
{
        unsigned long flags;

        if (db->flags & DM9000_PLATF_NO_EEPROM)
                return;

        mutex_lock(&db->addr_lock);

        spin_lock_irqsave(&db->lock, flags);
        iow(db, DM9000_EPAR, offset);
        iow(db, DM9000_EPDRH, data[1]);
        iow(db, DM9000_EPDRL, data[0]);
        iow(db, DM9000_EPCR, EPCR_WEP | EPCR_ERPRW);
        spin_unlock_irqrestore(&db->lock, flags);

        dm9000_wait_eeprom(db);

        mdelay(1);      /* wait at least 150uS to clear */

        spin_lock_irqsave(&db->lock, flags);
        iow(db, DM9000_EPCR, 0);
        spin_unlock_irqrestore(&db->lock, flags);

        mutex_unlock(&db->addr_lock);
}

/* ethtool ops */

static void dm9000_get_drvinfo(struct net_device *dev,
                               struct ethtool_drvinfo *info)
{
        board_info_t *dm = to_dm9000_board(dev);

        strcpy(info->driver, CARDNAME);
        strcpy(info->version, DRV_VERSION);
        strcpy(info->bus_info, to_platform_device(dm->dev)->name);
}

static u32 dm9000_get_msglevel(struct net_device *dev)
{
        board_info_t *dm = to_dm9000_board(dev);

        return dm->msg_enable;
}

static void dm9000_set_msglevel(struct net_device *dev, u32 value)
{
        board_info_t *dm = to_dm9000_board(dev);

        dm->msg_enable = value;
}

static int dm9000_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
{
        board_info_t *dm = to_dm9000_board(dev);

        mii_ethtool_gset(&dm->mii, cmd);
        return 0;
}

static int dm9000_set_settings(struct net_device *dev, struct ethtool_cmd *cmd)
{
        board_info_t *dm = to_dm9000_board(dev);

        return mii_ethtool_sset(&dm->mii, cmd);
}

static int dm9000_nway_reset(struct net_device *dev)
{
        board_info_t *dm = to_dm9000_board(dev);
        return mii_nway_restart(&dm->mii);
}

static uint32_t dm9000_get_rx_csum(struct net_device *dev)
{
        board_info_t *dm = to_dm9000_board(dev);
        return dm->rx_csum;
}

static int dm9000_set_rx_csum(struct net_device *dev, uint32_t data)
{
        board_info_t *dm = to_dm9000_board(dev);
        unsigned long flags;

        if (dm->can_csum) {
                dm->rx_csum = data;

                spin_lock_irqsave(&dm->lock, flags);
                iow(dm, DM9000_RCSR, dm->rx_csum ? RCSR_CSUM : 0);
                spin_unlock_irqrestore(&dm->lock, flags);

                return 0;
        }

        return -EOPNOTSUPP;
}

static int dm9000_set_tx_csum(struct net_device *dev, uint32_t data)
{
        board_info_t *dm = to_dm9000_board(dev);
        int ret = -EOPNOTSUPP;

        if (dm->can_csum)
                ret = ethtool_op_set_tx_csum(dev, data);
        return ret;
}

static u32 dm9000_get_link(struct net_device *dev)
{
        board_info_t *dm = to_dm9000_board(dev);
        u32 ret;

        if (dm->flags & DM9000_PLATF_EXT_PHY)
                ret = mii_link_ok(&dm->mii);
        else
                ret = dm9000_read_locked(dm, DM9000_NSR) & NSR_LINKST ? 1 : 0;

        return ret;
}

#define DM_EEPROM_MAGIC         (0x444D394B)

static int dm9000_get_eeprom_len(struct net_device *dev)
{
        return 128;
}

static int dm9000_get_eeprom(struct net_device *dev,
                             struct ethtool_eeprom *ee, u8 *data)
{
        board_info_t *dm = to_dm9000_board(dev);
        int offset = ee->offset;
        int len = ee->len;
        int i;

        /* EEPROM access is aligned to two bytes */

        if ((len & 1) != 0 || (offset & 1) != 0)
                return -EINVAL;

        if (dm->flags & DM9000_PLATF_NO_EEPROM)
                return -ENOENT;

        ee->magic = DM_EEPROM_MAGIC;

        for (i = 0; i < len; i += 2)
                dm9000_read_eeprom(dm, (offset + i) / 2, data + i);

        return 0;
}

static int dm9000_set_eeprom(struct net_device *dev,
                             struct ethtool_eeprom *ee, u8 *data)
{
        board_info_t *dm = to_dm9000_board(dev);
        int offset = ee->offset;
        int len = ee->len;
        int i;

        /* EEPROM access is aligned to two bytes */

        if ((len & 1) != 0 || (offset & 1) != 0)
                return -EINVAL;

        if (dm->flags & DM9000_PLATF_NO_EEPROM)
                return -ENOENT;

        if (ee->magic != DM_EEPROM_MAGIC)
                return -EINVAL;

        for (i = 0; i < len; i += 2)
                dm9000_write_eeprom(dm, (offset + i) / 2, data + i);

        return 0;
}

static const struct ethtool_ops dm9000_ethtool_ops = {
        .get_drvinfo            = dm9000_get_drvinfo,
        .get_settings           = dm9000_get_settings,
        .set_settings           = dm9000_set_settings,
        .get_msglevel           = dm9000_get_msglevel,
        .set_msglevel           = dm9000_set_msglevel,
        .nway_reset             = dm9000_nway_reset,
        .get_link               = dm9000_get_link,
        .get_eeprom_len         = dm9000_get_eeprom_len,
        .get_eeprom             = dm9000_get_eeprom,
        .set_eeprom             = dm9000_set_eeprom,
        .get_rx_csum            = dm9000_get_rx_csum,
        .set_rx_csum            = dm9000_set_rx_csum,
        .get_tx_csum            = ethtool_op_get_tx_csum,
        .set_tx_csum            = dm9000_set_tx_csum,
};

static void dm9000_show_carrier(board_info_t *db,
                                unsigned carrier, unsigned nsr)
{
        struct net_device *ndev = db->ndev;
        unsigned ncr = dm9000_read_locked(db, DM9000_NCR);

        if (carrier)
                dev_info(db->dev, "%s: link up, %dMbps, %s-duplex, no LPA\n",
                         ndev->name, (nsr & NSR_SPEED) ? 10 : 100,
                         (ncr & NCR_FDX) ? "full" : "half");
        else
                dev_info(db->dev, "%s: link down\n", ndev->name);
}

static void
dm9000_poll_work(struct work_struct *w)
{
        struct delayed_work *dw = to_delayed_work(w);
        board_info_t *db = container_of(dw, board_info_t, phy_poll);
        struct net_device *ndev = db->ndev;

        if (db->flags & DM9000_PLATF_SIMPLE_PHY &&
            !(db->flags & DM9000_PLATF_EXT_PHY)) {
                unsigned nsr = dm9000_read_locked(db, DM9000_NSR);
                unsigned old_carrier = netif_carrier_ok(ndev) ? 1 : 0;
                unsigned new_carrier;

                new_carrier = (nsr & NSR_LINKST) ? 1 : 0;

                if (old_carrier != new_carrier) {
                        if (netif_msg_link(db))
                                dm9000_show_carrier(db, new_carrier, nsr);

                        if (!new_carrier)
                                netif_carrier_off(ndev);
                        else
                                netif_carrier_on(ndev);
                }
        } else
                mii_check_media(&db->mii, netif_msg_link(db), 0);
        
        if (netif_running(ndev))
                dm9000_schedule_poll(db);
}

/* dm9000_release_board
 *
 * release a board, and any mapped resources
 */

static void
dm9000_release_board(struct platform_device *pdev, struct board_info *db)
{
        /* unmap our resources */

        iounmap(db->io_addr);
        iounmap(db->io_data);

        /* release the resources */

        release_resource(db->data_req);
        kfree(db->data_req);

        release_resource(db->addr_req);
        kfree(db->addr_req);
}

static unsigned char dm9000_type_to_char(enum dm9000_type type)
{
        switch (type) {
        case TYPE_DM9000E: return 'e';
        case TYPE_DM9000A: return 'a';
        case TYPE_DM9000B: return 'b';
        }

        return '?';
}

/*
 *  Set DM9000 multicast address
 */
static void
dm9000_hash_table(struct net_device *dev)
{
        board_info_t *db = netdev_priv(dev);
        struct dev_mc_list *mcptr = dev->mc_list;
        int mc_cnt = dev->mc_count;
        int i, oft;
        u32 hash_val;
        u16 hash_table[4];
        u8 rcr = RCR_DIS_LONG | RCR_DIS_CRC | RCR_RXEN;
        unsigned long flags;

        dm9000_dbg(db, 1, "entering %s\n", __func__);

        spin_lock_irqsave(&db->lock, flags);

        for (i = 0, oft = DM9000_PAR; i < 6; i++, oft++)
                iow(db, oft, dev->dev_addr[i]);

        /* Clear Hash Table */
        for (i = 0; i < 4; i++)
                hash_table[i] = 0x0;

        /* broadcast address */
        hash_table[3] = 0x8000;

        if (dev->flags & IFF_PROMISC)
                rcr |= RCR_PRMSC;

        if (dev->flags & IFF_ALLMULTI)
                rcr |= RCR_ALL;

        /* the multicast address in Hash Table : 64 bits */
        for (i = 0; i < mc_cnt; i++, mcptr = mcptr->next) {
                hash_val = ether_crc_le(6, mcptr->dmi_addr) & 0x3f;
                hash_table[hash_val / 16] |= (u16) 1 << (hash_val % 16);
        }

        /* Write the hash table to MAC MD table */
        for (i = 0, oft = DM9000_MAR; i < 4; i++) {
                iow(db, oft++, hash_table[i]);
                iow(db, oft++, hash_table[i] >> 8);
        }

        iow(db, DM9000_RCR, rcr);
        spin_unlock_irqrestore(&db->lock, flags);
}

/*
 * Initilize dm9000 board
 */
static void
dm9000_init_dm9000(struct net_device *dev)
{
        board_info_t *db = netdev_priv(dev);
        unsigned int imr;

        dm9000_dbg(db, 1, "entering %s\n", __func__);

        /* I/O mode */
        db->io_mode = ior(db, DM9000_ISR) >> 6; /* ISR bit7:6 keeps I/O mode */

        /* Checksum mode */
        dm9000_set_rx_csum(dev, db->rx_csum);

        /* GPIO0 on pre-activate PHY */
        iow(db, DM9000_GPR, 0); /* REG_1F bit0 activate phyxcer */
        iow(db, DM9000_GPCR, GPCR_GEP_CNTL);    /* Let GPIO0 output */
        iow(db, DM9000_GPR, 0); /* Enable PHY */

        if (db->flags & DM9000_PLATF_EXT_PHY)
                iow(db, DM9000_NCR, NCR_EXT_PHY);

        /* Program operating register */
        iow(db, DM9000_TCR, 0);         /* TX Polling clear */
        iow(db, DM9000_BPTR, 0x3f);     /* Less 3Kb, 200us */
        iow(db, DM9000_FCR, 0xff);      /* Flow Control */
        iow(db, DM9000_SMCR, 0);        /* Special Mode */
        /* clear TX status */
        iow(db, DM9000_NSR, NSR_WAKEST | NSR_TX2END | NSR_TX1END);
        iow(db, DM9000_ISR, ISR_CLR_STATUS); /* Clear interrupt status */

        /* Set address filter table */
        dm9000_hash_table(dev);

        imr = IMR_PAR | IMR_PTM | IMR_PRM;
        if (db->type != TYPE_DM9000E)
                imr |= IMR_LNKCHNG;

        db->imr_all = imr;

        /* Enable TX/RX interrupt mask */
        iow(db, DM9000_IMR, imr);

        /* Init Driver variable */
        db->tx_pkt_cnt = 0;
        db->queue_pkt_len = 0;
        dev->trans_start = 0;
}

/* Our watchdog timed out. Called by the networking layer */
static void dm9000_timeout(struct net_device *dev)
{
        board_info_t *db = netdev_priv(dev);
        u8 reg_save;
        unsigned long flags;

        /* Save previous register address */
        reg_save = readb(db->io_addr);
        spin_lock_irqsave(&db->lock, flags);

        netif_stop_queue(dev);
        dm9000_reset(db);
        dm9000_init_dm9000(dev);
        /* We can accept TX packets again */
        dev->trans_start = jiffies;
        netif_wake_queue(dev);

        /* Restore previous register address */
        writeb(reg_save, db->io_addr);
        spin_unlock_irqrestore(&db->lock, flags);
}

static void dm9000_send_packet(struct net_device *dev,
                               int ip_summed,
                               u16 pkt_len)
{
        board_info_t *dm = to_dm9000_board(dev);

        /* The DM9000 is not smart enough to leave fragmented packets alone. */
        if (dm->ip_summed != ip_summed) {
                if (ip_summed == CHECKSUM_NONE)
                        iow(dm, DM9000_TCCR, 0);
                else
                        iow(dm, DM9000_TCCR, TCCR_IP | TCCR_UDP | TCCR_TCP);
                dm->ip_summed = ip_summed;
        }

        /* Set TX length to DM9000 */
        iow(dm, DM9000_TXPLL, pkt_len);
        iow(dm, DM9000_TXPLH, pkt_len >> 8);

        /* Issue TX polling command */
        iow(dm, DM9000_TCR, TCR_TXREQ); /* Cleared after TX complete */
}

/*
 *  Hardware start transmission.
 *  Send a packet to media from the upper layer.
 */
static int
dm9000_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
        unsigned long flags;
        board_info_t *db = netdev_priv(dev);

        dm9000_dbg(db, 3, "%s:\n", __func__);

        if (db->tx_pkt_cnt > 1)
                return NETDEV_TX_BUSY;

        spin_lock_irqsave(&db->lock, flags);

        /* Move data to DM9000 TX RAM */
        writeb(DM9000_MWCMD, db->io_addr);

        (db->outblk)(db->io_data, skb->data, skb->len);
        dev->stats.tx_bytes += skb->len;

        db->tx_pkt_cnt++;
        /* TX control: First packet immediately send, second packet queue */
        if (db->tx_pkt_cnt == 1) {
                dm9000_send_packet(dev, skb->ip_summed, skb->len);
        } else {
                /* Second packet */
                db->queue_pkt_len = skb->len;
                db->queue_ip_summed = skb->ip_summed;
                netif_stop_queue(dev);
        }

        spin_unlock_irqrestore(&db->lock, flags);

        /* free this SKB */
        dev_kfree_skb(skb);

        return NETDEV_TX_OK;
}

/*
 * DM9000 interrupt handler
 * receive the packet to upper layer, free the transmitted packet
 */

static void dm9000_tx_done(struct net_device *dev, board_info_t *db)
{
        int tx_status = ior(db, DM9000_NSR);    /* Got TX status */

        if (tx_status & (NSR_TX2END | NSR_TX1END)) {
                /* One packet sent complete */
                db->tx_pkt_cnt--;
                dev->stats.tx_packets++;

                if (netif_msg_tx_done(db))
                        dev_dbg(db->dev, "tx done, NSR %02x\n", tx_status);

                /* Queue packet check & send */
                if (db->tx_pkt_cnt > 0)
                        dm9000_send_packet(dev, db->queue_ip_summed,
                                           db->queue_pkt_len);
                netif_wake_queue(dev);
        }
}

struct dm9000_rxhdr {
        u8      RxPktReady;
        u8      RxStatus;
        __le16  RxLen;
} __attribute__((__packed__));

/*
 *  Received a packet and pass to upper layer
 */
static void
dm9000_rx(struct net_device *dev)
{
        board_info_t *db = netdev_priv(dev);
        struct dm9000_rxhdr rxhdr;
        struct sk_buff *skb;
        u8 rxbyte, *rdptr;
        bool GoodPacket;
        int RxLen;

        /* Check packet ready or not */
        do {
                ior(db, DM9000_MRCMDX); /* Dummy read */

                /* Get most updated data */
                rxbyte = readb(db->io_data);

                /* Status check: this byte must be 0 or 1 */
                if (rxbyte & DM9000_PKT_ERR) {
                        dev_warn(db->dev, "status check fail: %d\n", rxbyte);
                        iow(db, DM9000_RCR, 0x00);      /* Stop Device */
                        iow(db, DM9000_ISR, IMR_PAR);   /* Stop INT request */
                        return;
                }

                if (!(rxbyte & DM9000_PKT_RDY))
                        return;

                /* A packet ready now  & Get status/length */
                GoodPacket = true;
                writeb(DM9000_MRCMD, db->io_addr);

                (db->inblk)(db->io_data, &rxhdr, sizeof(rxhdr));

                RxLen = le16_to_cpu(rxhdr.RxLen);

                if (netif_msg_rx_status(db))
                        dev_dbg(db->dev, "RX: status %02x, length %04x\n",
                                rxhdr.RxStatus, RxLen);

                /* Packet Status check */
                if (RxLen < 0x40) {
                        GoodPacket = false;
                        if (netif_msg_rx_err(db))
                                dev_dbg(db->dev, "RX: Bad Packet (runt)\n");
                }

                if (RxLen > DM9000_PKT_MAX) {
                        dev_dbg(db->dev, "RST: RX Len:%x\n", RxLen);
                }

                /* rxhdr.RxStatus is identical to RSR register. */
                if (rxhdr.RxStatus & (RSR_FOE | RSR_CE | RSR_AE |
                                      RSR_PLE | RSR_RWTO |
                                      RSR_LCS | RSR_RF)) {
                        GoodPacket = false;
                        if (rxhdr.RxStatus & RSR_FOE) {
                                if (netif_msg_rx_err(db))
                                        dev_dbg(db->dev, "fifo error\n");
                                dev->stats.rx_fifo_errors++;
                        }
                        if (rxhdr.RxStatus & RSR_CE) {
                                if (netif_msg_rx_err(db))
                                        dev_dbg(db->dev, "crc error\n");
                                dev->stats.rx_crc_errors++;
                        }
                        if (rxhdr.RxStatus & RSR_RF) {
                                if (netif_msg_rx_err(db))
                                        dev_dbg(db->dev, "length error\n");
                                dev->stats.rx_length_errors++;
                        }
                }

                /* Move data from DM9000 */
                if (GoodPacket
                    && ((skb = dev_alloc_skb(RxLen + 4)) != NULL)) {
                        skb_reserve(skb, 2);
                        rdptr = (u8 *) skb_put(skb, RxLen - 4);

                        /* Read received packet from RX SRAM */

                        (db->inblk)(db->io_data, rdptr, RxLen);
                        dev->stats.rx_bytes += RxLen;

                        /* Pass to upper layer */
                        skb->protocol = eth_type_trans(skb, dev);
                        if (db->rx_csum) {
                                if ((((rxbyte & 0x1c) << 3) & rxbyte) == 0)
                                        skb->ip_summed = CHECKSUM_UNNECESSARY;
                                else
                                        skb->ip_summed = CHECKSUM_NONE;
                        }
                        netif_rx(skb);
                        dev->stats.rx_packets++;

                } else {
                        /* need to dump the packet's data */

                        (db->dumpblk)(db->io_data, RxLen);
                }
        } while (rxbyte & DM9000_PKT_RDY);
}

static irqreturn_t dm9000_interrupt(int irq, void *dev_id)
{
        struct net_device *dev = dev_id;
        board_info_t *db = netdev_priv(dev);
        int int_status;
        unsigned long flags;
        u8 reg_save;

        dm9000_dbg(db, 3, "entering %s\n", __func__);

        /* A real interrupt coming */

        /* holders of db->lock must always block IRQs */
        spin_lock_irqsave(&db->lock, flags);

        /* Save previous register address */
        reg_save = readb(db->io_addr);

        /* Disable all interrupts */
        iow(db, DM9000_IMR, IMR_PAR);

        /* Got DM9000 interrupt status */
        int_status = ior(db, DM9000_ISR);       /* Got ISR */
        iow(db, DM9000_ISR, int_status);        /* Clear ISR status */

        if (netif_msg_intr(db))
                dev_dbg(db->dev, "interrupt status %02x\n", int_status);

        /* Received the coming packet */
        if (int_status & ISR_PRS)
                dm9000_rx(dev);

        /* Trnasmit Interrupt check */
        if (int_status & ISR_PTS)
                dm9000_tx_done(dev, db);

        if (db->type != TYPE_DM9000E) {
                if (int_status & ISR_LNKCHNG) {
                        /* fire a link-change request */
                        schedule_delayed_work(&db->phy_poll, 1);
                }
        }

        /* Re-enable interrupt mask */
        iow(db, DM9000_IMR, db->imr_all);

        /* Restore previous register address */
        writeb(reg_save, db->io_addr);

        spin_unlock_irqrestore(&db->lock, flags);

        return IRQ_HANDLED;
}

#ifdef CONFIG_NET_POLL_CONTROLLER
/*
 *Used by netconsole
 */
static void dm9000_poll_controller(struct net_device *dev)
{
        disable_irq(dev->irq);
        dm9000_interrupt(dev->irq, dev);
        enable_irq(dev->irq);
}
#endif

/*
 *  Open the interface.
 *  The interface is opened whenever "ifconfig" actives it.
 */
static int
dm9000_open(struct net_device *dev)
{
        board_info_t *db = netdev_priv(dev);
        unsigned long irqflags = db->irq_res->flags & IRQF_TRIGGER_MASK;

        if (netif_msg_ifup(db))
                dev_dbg(db->dev, "enabling %s\n", dev->name);

        /* If there is no IRQ type specified, default to something that
         * may work, and tell the user that this is a problem */

        if (irqflags == IRQF_TRIGGER_NONE)
                dev_warn(db->dev, "WARNING: no IRQ resource flags set.\n");

        irqflags |= IRQF_SHARED;

        if (request_irq(dev->irq, &dm9000_interrupt, irqflags, dev->name, dev))
                return -EAGAIN;

        /* Initialize DM9000 board */
        dm9000_reset(db);
        dm9000_init_dm9000(dev);

        /* Init driver variable */
        db->dbug_cnt = 0;

        mii_check_media(&db->mii, netif_msg_link(db), 1);
        netif_start_queue(dev);
        
        dm9000_schedule_poll(db);

        return 0;
}

/*
 * Sleep, either by using msleep() or if we are suspending, then
 * use mdelay() to sleep.
 */
static void dm9000_msleep(board_info_t *db, unsigned int ms)
{
        if (db->in_suspend)
                mdelay(ms);
        else
                msleep(ms);
}

/*
 *   Read a word from phyxcer
 */
static int
dm9000_phy_read(struct net_device *dev, int phy_reg_unused, int reg)
{
        board_info_t *db = netdev_priv(dev);
        unsigned long flags;
        unsigned int reg_save;
        int ret;

        mutex_lock(&db->addr_lock);

        spin_lock_irqsave(&db->lock,flags);

        /* Save previous register address */
        reg_save = readb(db->io_addr);

        /* Fill the phyxcer register into REG_0C */
        iow(db, DM9000_EPAR, DM9000_PHY | reg);

        iow(db, DM9000_EPCR, EPCR_ERPRR | EPCR_EPOS);   /* Issue phyxcer read command */

        writeb(reg_save, db->io_addr);
        spin_unlock_irqrestore(&db->lock,flags);

        dm9000_msleep(db, 1);           /* Wait read complete */

        spin_lock_irqsave(&db->lock,flags);
        reg_save = readb(db->io_addr);

        iow(db, DM9000_EPCR, 0x0);      /* Clear phyxcer read command */

        /* The read data keeps on REG_0D & REG_0E */
        ret = (ior(db, DM9000_EPDRH) << 8) | ior(db, DM9000_EPDRL);

        /* restore the previous address */
        writeb(reg_save, db->io_addr);
        spin_unlock_irqrestore(&db->lock,flags);

        mutex_unlock(&db->addr_lock);

        dm9000_dbg(db, 5, "phy_read[%02x] -> %04x\n", reg, ret);
        return ret;
}

/*
 *   Write a word to phyxcer
 */
static void
dm9000_phy_write(struct net_device *dev,
                 int phyaddr_unused, int reg, int value)
{
        board_info_t *db = netdev_priv(dev);
        unsigned long flags;
        unsigned long reg_save;

        dm9000_dbg(db, 5, "phy_write[%02x] = %04x\n", reg, value);
        mutex_lock(&db->addr_lock);

        spin_lock_irqsave(&db->lock,flags);

        /* Save previous register address */
        reg_save = readb(db->io_addr);

        /* Fill the phyxcer register into REG_0C */
        iow(db, DM9000_EPAR, DM9000_PHY | reg);

        /* Fill the written data into REG_0D & REG_0E */
        iow(db, DM9000_EPDRL, value);
        iow(db, DM9000_EPDRH, value >> 8);

        iow(db, DM9000_EPCR, EPCR_EPOS | EPCR_ERPRW);   /* Issue phyxcer write command */

        writeb(reg_save, db->io_addr);
        spin_unlock_irqrestore(&db->lock, flags);

        dm9000_msleep(db, 1);           /* Wait write complete */

        spin_lock_irqsave(&db->lock,flags);
        reg_save = readb(db->io_addr);

        iow(db, DM9000_EPCR, 0x0);      /* Clear phyxcer write command */

        /* restore the previous address */
        writeb(reg_save, db->io_addr);

        spin_unlock_irqrestore(&db->lock, flags);
        mutex_unlock(&db->addr_lock);
}

static void
dm9000_shutdown(struct net_device *dev)
{
        board_info_t *db = netdev_priv(dev);

        /* RESET device */
        dm9000_phy_write(dev, 0, MII_BMCR, BMCR_RESET); /* PHY RESET */
        iow(db, DM9000_GPR, 0x01);      /* Power-Down PHY */
        iow(db, DM9000_IMR, IMR_PAR);   /* Disable all interrupt */
        iow(db, DM9000_RCR, 0x00);      /* Disable RX */
}

/*
 * Stop the interface.
 * The interface is stopped when it is brought.
 */
static int
dm9000_stop(struct net_device *ndev)
{
        board_info_t *db = netdev_priv(ndev);

        if (netif_msg_ifdown(db))
                dev_dbg(db->dev, "shutting down %s\n", ndev->name);

        cancel_delayed_work_sync(&db->phy_poll);

        netif_stop_queue(ndev);
        netif_carrier_off(ndev);

        /* free interrupt */
        free_irq(ndev->irq, ndev);

        dm9000_shutdown(ndev);

        return 0;
}

static const struct net_device_ops dm9000_netdev_ops = {
        .ndo_open               = dm9000_open,
        .ndo_stop               = dm9000_stop,
        .ndo_start_xmit         = dm9000_start_xmit,
        .ndo_tx_timeout         = dm9000_timeout,
        .ndo_set_multicast_list = dm9000_hash_table,
        .ndo_do_ioctl           = dm9000_ioctl,
        .ndo_change_mtu         = eth_change_mtu,
        .ndo_validate_addr      = eth_validate_addr,
        .ndo_set_mac_address    = eth_mac_addr,
#ifdef CONFIG_NET_POLL_CONTROLLER
        .ndo_poll_controller    = dm9000_poll_controller,
#endif
};

/*
 * Search DM9000 board, allocate space and register it
 */
static int __devinit
dm9000_probe(struct platform_device *pdev)
{
        struct dm9000_plat_data *pdata = pdev->dev.platform_data;
        struct board_info *db;  /* Point a board information structure */
        struct net_device *ndev;
        const unsigned char *mac_src;
        int ret = 0;
        int iosize;
        int i;
        u32 id_val;

        /* Init network device */
        ndev = alloc_etherdev(sizeof(struct board_info));
        if (!ndev) {
                dev_err(&pdev->dev, "could not allocate device.\n");
                return -ENOMEM;
        }

        SET_NETDEV_DEV(ndev, &pdev->dev);

        dev_dbg(&pdev->dev, "dm9000_probe()\n");

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

        db->dev = &pdev->dev;
        db->ndev = ndev;

        spin_lock_init(&db->lock);
        mutex_init(&db->addr_lock);

        INIT_DELAYED_WORK(&db->phy_poll, dm9000_poll_work);

        db->addr_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        db->data_res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
        db->irq_res  = platform_get_resource(pdev, IORESOURCE_IRQ, 0);

        if (db->addr_res == NULL || db->data_res == NULL ||
            db->irq_res == NULL) {
                dev_err(db->dev, "insufficient resources\n");
                ret = -ENOENT;
                goto out;
        }

        iosize = resource_size(db->addr_res);
        db->addr_req = request_mem_region(db->addr_res->start, iosize,
                                          pdev->name);

        if (db->addr_req == NULL) {
                dev_err(db->dev, "cannot claim address reg area\n");
                ret = -EIO;
                goto out;
        }

        db->io_addr = ioremap(db->addr_res->start, iosize);

        if (db->io_addr == NULL) {
                dev_err(db->dev, "failed to ioremap address reg\n");
                ret = -EINVAL;
                goto out;
        }

        iosize = resource_size(db->data_res);
        db->data_req = request_mem_region(db->data_res->start, iosize,
                                          pdev->name);

        if (db->data_req == NULL) {
                dev_err(db->dev, "cannot claim data reg area\n");
                ret = -EIO;
                goto out;
        }

        db->io_data = ioremap(db->data_res->start, iosize);

        if (db->io_data == NULL) {
                dev_err(db->dev, "failed to ioremap data reg\n");
                ret = -EINVAL;
                goto out;
        }

        /* fill in parameters for net-dev structure */
        ndev->base_addr = (unsigned long)db->io_addr;
        ndev->irq       = db->irq_res->start;

        /* ensure at least we have a default set of IO routines */
        dm9000_set_io(db, iosize);

        /* check to see if anything is being over-ridden */
        if (pdata != NULL) {
                /* check to see if the driver wants to over-ride the
                 * default IO width */

                if (pdata->flags & DM9000_PLATF_8BITONLY)
                        dm9000_set_io(db, 1);

                if (pdata->flags & DM9000_PLATF_16BITONLY)
                        dm9000_set_io(db, 2);

                if (pdata->flags & DM9000_PLATF_32BITONLY)
                        dm9000_set_io(db, 4);

                /* check to see if there are any IO routine
                 * over-rides */

                if (pdata->inblk != NULL)
                        db->inblk = pdata->inblk;

                if (pdata->outblk != NULL)
                        db->outblk = pdata->outblk;

                if (pdata->dumpblk != NULL)
                        db->dumpblk = pdata->dumpblk;

                db->flags = pdata->flags;
        }

#ifdef CONFIG_DM9000_FORCE_SIMPLE_PHY_POLL
        db->flags |= DM9000_PLATF_SIMPLE_PHY;
#endif

        dm9000_reset(db);

        /* try multiple times, DM9000 sometimes gets the read wrong */
        for (i = 0; i < 8; i++) {
                id_val  = ior(db, DM9000_VIDL);
                id_val |= (u32)ior(db, DM9000_VIDH) << 8;
                id_val |= (u32)ior(db, DM9000_PIDL) << 16;
                id_val |= (u32)ior(db, DM9000_PIDH) << 24;

                if (id_val == DM9000_ID)
                        break;
                dev_err(db->dev, "read wrong id 0x%08x\n", id_val);
        }

        if (id_val != DM9000_ID) {
                dev_err(db->dev, "wrong id: 0x%08x\n", id_val);
                ret = -ENODEV;
                goto out;
        }

        /* Identify what type of DM9000 we are working on */

        id_val = ior(db, DM9000_CHIPR);
        dev_dbg(db->dev, "dm9000 revision 0x%02x\n", id_val);

        switch (id_val) {
        case CHIPR_DM9000A:
                db->type = TYPE_DM9000A;
                break;
        case CHIPR_DM9000B:
                db->type = TYPE_DM9000B;
                break;
        default:
                dev_dbg(db->dev, "ID %02x => defaulting to DM9000E\n", id_val);
                db->type = TYPE_DM9000E;
        }

        /* dm9000a/b are capable of hardware checksum offload */
        if (db->type == TYPE_DM9000A || db->type == TYPE_DM9000B) {
                db->can_csum = 1;
                db->rx_csum = 1;
                ndev->features |= NETIF_F_IP_CSUM;
        }

        /* from this point we assume that we have found a DM9000 */

        /* driver system function */
        ether_setup(ndev);

        ndev->netdev_ops        = &dm9000_netdev_ops;
        ndev->watchdog_timeo    = msecs_to_jiffies(watchdog);
        ndev->ethtool_ops       = &dm9000_ethtool_ops;

        db->msg_enable       = NETIF_MSG_LINK;
        db->mii.phy_id_mask  = 0x1f;
        db->mii.reg_num_mask = 0x1f;
        db->mii.force_media  = 0;
        db->mii.full_duplex  = 0;
        db->mii.dev          = ndev;
        db->mii.mdio_read    = dm9000_phy_read;
        db->mii.mdio_write   = dm9000_phy_write;

        mac_src = "eeprom";

        /* try reading the node address from the attached EEPROM */
        for (i = 0; i < 6; i += 2)
                dm9000_read_eeprom(db, i / 2, ndev->dev_addr+i);

        if (!is_valid_ether_addr(ndev->dev_addr) && pdata != NULL) {
                mac_src = "platform data";
                memcpy(ndev->dev_addr, pdata->dev_addr, 6);
        }

        if (!is_valid_ether_addr(ndev->dev_addr)) {
                /* try reading from mac */
                
                mac_src = "chip";
                for (i = 0; i < 6; i++)
                        ndev->dev_addr[i] = ior(db, i+DM9000_PAR);
        }

        if (!is_valid_ether_addr(ndev->dev_addr))
                dev_warn(db->dev, "%s: Invalid ethernet MAC address. Please "
                         "set using ifconfig\n", ndev->name);

        platform_set_drvdata(pdev, ndev);
        ret = register_netdev(ndev);

        if (ret == 0)
                printk(KERN_INFO "%s: dm9000%c at %p,%p IRQ %d MAC: %pM (%s)\n",
                       ndev->name, dm9000_type_to_char(db->type),
                       db->io_addr, db->io_data, ndev->irq,
                       ndev->dev_addr, mac_src);
        return 0;

out:
        dev_err(db->dev, "not found (%d).\n", ret);

        dm9000_release_board(pdev, db);
        free_netdev(ndev);

        return ret;
}

static int
dm9000_drv_suspend(struct device *dev)
{
        struct platform_device *pdev = to_platform_device(dev);
        struct net_device *ndev = platform_get_drvdata(pdev);
        board_info_t *db;

        if (ndev) {
                db = netdev_priv(ndev);
                db->in_suspend = 1;

                if (netif_running(ndev)) {
                        netif_device_detach(ndev);
                        dm9000_shutdown(ndev);
                }
        }
        return 0;
}

static int
dm9000_drv_resume(struct device *dev)
{
        struct platform_device *pdev = to_platform_device(dev);
        struct net_device *ndev = platform_get_drvdata(pdev);
        board_info_t *db = netdev_priv(ndev);

        if (ndev) {

                if (netif_running(ndev)) {
                        dm9000_reset(db);
                        dm9000_init_dm9000(ndev);

                        netif_device_attach(ndev);
                }

                db->in_suspend = 0;
        }
        return 0;
}

static struct dev_pm_ops dm9000_drv_pm_ops = {
        .suspend        = dm9000_drv_suspend,
        .resume         = dm9000_drv_resume,
};

static int __devexit
dm9000_drv_remove(struct platform_device *pdev)
{
        struct net_device *ndev = platform_get_drvdata(pdev);

        platform_set_drvdata(pdev, NULL);

        unregister_netdev(ndev);
        dm9000_release_board(pdev, (board_info_t *) netdev_priv(ndev));
        free_netdev(ndev);              /* free device structure */

        dev_dbg(&pdev->dev, "released and freed device\n");
        return 0;
}

static struct platform_driver dm9000_driver = {
        .driver = {
                .name    = "dm9000",
                .owner   = THIS_MODULE,
                .pm      = &dm9000_drv_pm_ops,
        },
        .probe   = dm9000_probe,
        .remove  = __devexit_p(dm9000_drv_remove),
};

static int __init
dm9000_init(void)
{
        printk(KERN_INFO "%s Ethernet Driver, V%s\n", CARDNAME, DRV_VERSION);

        return platform_driver_register(&dm9000_driver);
}

static void __exit
dm9000_cleanup(void)
{
        platform_driver_unregister(&dm9000_driver);
}

module_init(dm9000_init);
module_exit(dm9000_cleanup);

MODULE_AUTHOR("Sascha Hauer, Ben Dooks");
MODULE_DESCRIPTION("Davicom DM9000 network driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:dm9000");