root/drivers/net/ethernet/sun/sunbmac.c
// SPDX-License-Identifier: GPL-2.0
/* sunbmac.c: Driver for Sparc BigMAC 100baseT ethernet adapters.
 *
 * Copyright (C) 1997, 1998, 1999, 2003, 2008 David S. Miller (davem@davemloft.net)
 */

#include <linux/module.h>
#include <linux/pgtable.h>

#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/in.h>
#include <linux/string.h>
#include <linux/delay.h>
#include <linux/crc32.h>
#include <linux/errno.h>
#include <linux/ethtool.h>
#include <linux/mii.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/bitops.h>
#include <linux/dma-mapping.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/gfp.h>

#include <asm/auxio.h>
#include <asm/byteorder.h>
#include <asm/dma.h>
#include <asm/idprom.h>
#include <asm/io.h>
#include <asm/openprom.h>
#include <asm/oplib.h>

#include "sunbmac.h"

#define DRV_NAME        "sunbmac"
#define DRV_VERSION     "2.1"
#define DRV_RELDATE     "August 26, 2008"
#define DRV_AUTHOR      "David S. Miller (davem@davemloft.net)"

static char version[] =
        DRV_NAME ".c:v" DRV_VERSION " " DRV_RELDATE " " DRV_AUTHOR "\n";

MODULE_VERSION(DRV_VERSION);
MODULE_AUTHOR(DRV_AUTHOR);
MODULE_DESCRIPTION("Sun BigMAC 100baseT ethernet driver");
MODULE_LICENSE("GPL");

#undef DEBUG_PROBE
#undef DEBUG_TX
#undef DEBUG_IRQ

#ifdef DEBUG_PROBE
#define DP(x)  printk x
#else
#define DP(x)
#endif

#ifdef DEBUG_TX
#define DTX(x)  printk x
#else
#define DTX(x)
#endif

#ifdef DEBUG_IRQ
#define DIRQ(x)  printk x
#else
#define DIRQ(x)
#endif

#define DEFAULT_JAMSIZE    4 /* Toe jam */

#define QEC_RESET_TRIES 200

static int qec_global_reset(void __iomem *gregs)
{
        int tries = QEC_RESET_TRIES;

        sbus_writel(GLOB_CTRL_RESET, gregs + GLOB_CTRL);
        while (--tries) {
                if (sbus_readl(gregs + GLOB_CTRL) & GLOB_CTRL_RESET) {
                        udelay(20);
                        continue;
                }
                break;
        }
        if (tries)
                return 0;
        printk(KERN_ERR "BigMAC: Cannot reset the QEC.\n");
        return -1;
}

static void qec_init(struct bigmac *bp)
{
        struct platform_device *qec_op = bp->qec_op;
        void __iomem *gregs = bp->gregs;
        u8 bsizes = bp->bigmac_bursts;
        u32 regval;

        /* 64byte bursts do not work at the moment, do
         * not even try to enable them.  -DaveM
         */
        if (bsizes & DMA_BURST32)
                regval = GLOB_CTRL_B32;
        else
                regval = GLOB_CTRL_B16;
        sbus_writel(regval | GLOB_CTRL_BMODE, gregs + GLOB_CTRL);
        sbus_writel(GLOB_PSIZE_2048, gregs + GLOB_PSIZE);

        /* All of memsize is given to bigmac. */
        sbus_writel(resource_size(&qec_op->resource[1]),
                    gregs + GLOB_MSIZE);

        /* Half to the transmitter, half to the receiver. */
        sbus_writel(resource_size(&qec_op->resource[1]) >> 1,
                    gregs + GLOB_TSIZE);
        sbus_writel(resource_size(&qec_op->resource[1]) >> 1,
                    gregs + GLOB_RSIZE);
}

#define TX_RESET_TRIES     32
#define RX_RESET_TRIES     32

static void bigmac_tx_reset(void __iomem *bregs)
{
        int tries = TX_RESET_TRIES;

        sbus_writel(0, bregs + BMAC_TXCFG);

        /* The fifo threshold bit is read-only and does
         * not clear.  -DaveM
         */
        while ((sbus_readl(bregs + BMAC_TXCFG) & ~(BIGMAC_TXCFG_FIFO)) != 0 &&
               --tries != 0)
                udelay(20);

        if (!tries) {
                printk(KERN_ERR "BIGMAC: Transmitter will not reset.\n");
                printk(KERN_ERR "BIGMAC: tx_cfg is %08x\n",
                       sbus_readl(bregs + BMAC_TXCFG));
        }
}

static void bigmac_rx_reset(void __iomem *bregs)
{
        int tries = RX_RESET_TRIES;

        sbus_writel(0, bregs + BMAC_RXCFG);
        while (sbus_readl(bregs + BMAC_RXCFG) && --tries)
                udelay(20);

        if (!tries) {
                printk(KERN_ERR "BIGMAC: Receiver will not reset.\n");
                printk(KERN_ERR "BIGMAC: rx_cfg is %08x\n",
                       sbus_readl(bregs + BMAC_RXCFG));
        }
}

/* Reset the transmitter and receiver. */
static void bigmac_stop(struct bigmac *bp)
{
        bigmac_tx_reset(bp->bregs);
        bigmac_rx_reset(bp->bregs);
}

static void bigmac_get_counters(struct bigmac *bp, void __iomem *bregs)
{
        struct net_device_stats *stats = &bp->dev->stats;

        stats->rx_crc_errors += sbus_readl(bregs + BMAC_RCRCECTR);
        sbus_writel(0, bregs + BMAC_RCRCECTR);

        stats->rx_frame_errors += sbus_readl(bregs + BMAC_UNALECTR);
        sbus_writel(0, bregs + BMAC_UNALECTR);

        stats->rx_length_errors += sbus_readl(bregs + BMAC_GLECTR);
        sbus_writel(0, bregs + BMAC_GLECTR);

        stats->tx_aborted_errors += sbus_readl(bregs + BMAC_EXCTR);

        stats->collisions +=
                (sbus_readl(bregs + BMAC_EXCTR) +
                 sbus_readl(bregs + BMAC_LTCTR));
        sbus_writel(0, bregs + BMAC_EXCTR);
        sbus_writel(0, bregs + BMAC_LTCTR);
}

static void bigmac_clean_rings(struct bigmac *bp)
{
        int i;

        for (i = 0; i < RX_RING_SIZE; i++) {
                if (bp->rx_skbs[i] != NULL) {
                        dev_kfree_skb_any(bp->rx_skbs[i]);
                        bp->rx_skbs[i] = NULL;
                }
        }

        for (i = 0; i < TX_RING_SIZE; i++) {
                if (bp->tx_skbs[i] != NULL) {
                        dev_kfree_skb_any(bp->tx_skbs[i]);
                        bp->tx_skbs[i] = NULL;
                }
        }
}

static void bigmac_init_rings(struct bigmac *bp, bool non_blocking)
{
        struct bmac_init_block *bb = bp->bmac_block;
        int i;
        gfp_t gfp_flags = GFP_KERNEL;

        if (non_blocking)
                gfp_flags = GFP_ATOMIC;

        bp->rx_new = bp->rx_old = bp->tx_new = bp->tx_old = 0;

        /* Free any skippy bufs left around in the rings. */
        bigmac_clean_rings(bp);

        /* Now get new skbufs for the receive ring. */
        for (i = 0; i < RX_RING_SIZE; i++) {
                struct sk_buff *skb;

                skb = big_mac_alloc_skb(RX_BUF_ALLOC_SIZE, gfp_flags);
                if (!skb)
                        continue;

                bp->rx_skbs[i] = skb;

                /* Because we reserve afterwards. */
                skb_put(skb, ETH_FRAME_LEN);
                skb_reserve(skb, 34);

                bb->be_rxd[i].rx_addr =
                        dma_map_single(&bp->bigmac_op->dev,
                                       skb->data,
                                       RX_BUF_ALLOC_SIZE - 34,
                                       DMA_FROM_DEVICE);
                bb->be_rxd[i].rx_flags =
                        (RXD_OWN | ((RX_BUF_ALLOC_SIZE - 34) & RXD_LENGTH));
        }

        for (i = 0; i < TX_RING_SIZE; i++)
                bb->be_txd[i].tx_flags = bb->be_txd[i].tx_addr = 0;
}

#define MGMT_CLKON  (MGMT_PAL_INT_MDIO|MGMT_PAL_EXT_MDIO|MGMT_PAL_OENAB|MGMT_PAL_DCLOCK)
#define MGMT_CLKOFF (MGMT_PAL_INT_MDIO|MGMT_PAL_EXT_MDIO|MGMT_PAL_OENAB)

static void idle_transceiver(void __iomem *tregs)
{
        int i = 20;

        while (i--) {
                sbus_writel(MGMT_CLKOFF, tregs + TCVR_MPAL);
                sbus_readl(tregs + TCVR_MPAL);
                sbus_writel(MGMT_CLKON, tregs + TCVR_MPAL);
                sbus_readl(tregs + TCVR_MPAL);
        }
}

static void write_tcvr_bit(struct bigmac *bp, void __iomem *tregs, int bit)
{
        if (bp->tcvr_type == internal) {
                bit = (bit & 1) << 3;
                sbus_writel(bit | (MGMT_PAL_OENAB | MGMT_PAL_EXT_MDIO),
                            tregs + TCVR_MPAL);
                sbus_readl(tregs + TCVR_MPAL);
                sbus_writel(bit | MGMT_PAL_OENAB | MGMT_PAL_EXT_MDIO | MGMT_PAL_DCLOCK,
                            tregs + TCVR_MPAL);
                sbus_readl(tregs + TCVR_MPAL);
        } else if (bp->tcvr_type == external) {
                bit = (bit & 1) << 2;
                sbus_writel(bit | MGMT_PAL_INT_MDIO | MGMT_PAL_OENAB,
                            tregs + TCVR_MPAL);
                sbus_readl(tregs + TCVR_MPAL);
                sbus_writel(bit | MGMT_PAL_INT_MDIO | MGMT_PAL_OENAB | MGMT_PAL_DCLOCK,
                            tregs + TCVR_MPAL);
                sbus_readl(tregs + TCVR_MPAL);
        } else {
                printk(KERN_ERR "write_tcvr_bit: No transceiver type known!\n");
        }
}

static int read_tcvr_bit(struct bigmac *bp, void __iomem *tregs)
{
        int retval = 0;

        if (bp->tcvr_type == internal) {
                sbus_writel(MGMT_PAL_EXT_MDIO, tregs + TCVR_MPAL);
                sbus_readl(tregs + TCVR_MPAL);
                sbus_writel(MGMT_PAL_EXT_MDIO | MGMT_PAL_DCLOCK,
                            tregs + TCVR_MPAL);
                sbus_readl(tregs + TCVR_MPAL);
                retval = (sbus_readl(tregs + TCVR_MPAL) & MGMT_PAL_INT_MDIO) >> 3;
        } else if (bp->tcvr_type == external) {
                sbus_writel(MGMT_PAL_INT_MDIO, tregs + TCVR_MPAL);
                sbus_readl(tregs + TCVR_MPAL);
                sbus_writel(MGMT_PAL_INT_MDIO | MGMT_PAL_DCLOCK, tregs + TCVR_MPAL);
                sbus_readl(tregs + TCVR_MPAL);
                retval = (sbus_readl(tregs + TCVR_MPAL) & MGMT_PAL_EXT_MDIO) >> 2;
        } else {
                printk(KERN_ERR "read_tcvr_bit: No transceiver type known!\n");
        }
        return retval;
}

static int read_tcvr_bit2(struct bigmac *bp, void __iomem *tregs)
{
        int retval = 0;

        if (bp->tcvr_type == internal) {
                sbus_writel(MGMT_PAL_EXT_MDIO, tregs + TCVR_MPAL);
                sbus_readl(tregs + TCVR_MPAL);
                retval = (sbus_readl(tregs + TCVR_MPAL) & MGMT_PAL_INT_MDIO) >> 3;
                sbus_writel(MGMT_PAL_EXT_MDIO | MGMT_PAL_DCLOCK, tregs + TCVR_MPAL);
                sbus_readl(tregs + TCVR_MPAL);
        } else if (bp->tcvr_type == external) {
                sbus_writel(MGMT_PAL_INT_MDIO, tregs + TCVR_MPAL);
                sbus_readl(tregs + TCVR_MPAL);
                retval = (sbus_readl(tregs + TCVR_MPAL) & MGMT_PAL_EXT_MDIO) >> 2;
                sbus_writel(MGMT_PAL_INT_MDIO | MGMT_PAL_DCLOCK, tregs + TCVR_MPAL);
                sbus_readl(tregs + TCVR_MPAL);
        } else {
                printk(KERN_ERR "read_tcvr_bit2: No transceiver type known!\n");
        }
        return retval;
}

static void put_tcvr_byte(struct bigmac *bp,
                          void __iomem *tregs,
                          unsigned int byte)
{
        int shift = 4;

        do {
                write_tcvr_bit(bp, tregs, ((byte >> shift) & 1));
                shift -= 1;
        } while (shift >= 0);
}

static void bigmac_tcvr_write(struct bigmac *bp, void __iomem *tregs,
                              int reg, unsigned short val)
{
        int shift;

        reg &= 0xff;
        val &= 0xffff;
        switch(bp->tcvr_type) {
        case internal:
        case external:
                break;

        default:
                printk(KERN_ERR "bigmac_tcvr_read: Whoops, no known transceiver type.\n");
                return;
        }

        idle_transceiver(tregs);
        write_tcvr_bit(bp, tregs, 0);
        write_tcvr_bit(bp, tregs, 1);
        write_tcvr_bit(bp, tregs, 0);
        write_tcvr_bit(bp, tregs, 1);

        put_tcvr_byte(bp, tregs,
                      ((bp->tcvr_type == internal) ?
                       BIGMAC_PHY_INTERNAL : BIGMAC_PHY_EXTERNAL));

        put_tcvr_byte(bp, tregs, reg);

        write_tcvr_bit(bp, tregs, 1);
        write_tcvr_bit(bp, tregs, 0);

        shift = 15;
        do {
                write_tcvr_bit(bp, tregs, (val >> shift) & 1);
                shift -= 1;
        } while (shift >= 0);
}

static unsigned short bigmac_tcvr_read(struct bigmac *bp,
                                       void __iomem *tregs,
                                       int reg)
{
        unsigned short retval = 0;

        reg &= 0xff;
        switch(bp->tcvr_type) {
        case internal:
        case external:
                break;

        default:
                printk(KERN_ERR "bigmac_tcvr_read: Whoops, no known transceiver type.\n");
                return 0xffff;
        }

        idle_transceiver(tregs);
        write_tcvr_bit(bp, tregs, 0);
        write_tcvr_bit(bp, tregs, 1);
        write_tcvr_bit(bp, tregs, 1);
        write_tcvr_bit(bp, tregs, 0);

        put_tcvr_byte(bp, tregs,
                      ((bp->tcvr_type == internal) ?
                       BIGMAC_PHY_INTERNAL : BIGMAC_PHY_EXTERNAL));

        put_tcvr_byte(bp, tregs, reg);

        if (bp->tcvr_type == external) {
                int shift = 15;

                (void) read_tcvr_bit2(bp, tregs);
                (void) read_tcvr_bit2(bp, tregs);

                do {
                        int tmp;

                        tmp = read_tcvr_bit2(bp, tregs);
                        retval |= ((tmp & 1) << shift);
                        shift -= 1;
                } while (shift >= 0);

                (void) read_tcvr_bit2(bp, tregs);
                (void) read_tcvr_bit2(bp, tregs);
                (void) read_tcvr_bit2(bp, tregs);
        } else {
                int shift = 15;

                (void) read_tcvr_bit(bp, tregs);
                (void) read_tcvr_bit(bp, tregs);

                do {
                        int tmp;

                        tmp = read_tcvr_bit(bp, tregs);
                        retval |= ((tmp & 1) << shift);
                        shift -= 1;
                } while (shift >= 0);

                (void) read_tcvr_bit(bp, tregs);
                (void) read_tcvr_bit(bp, tregs);
                (void) read_tcvr_bit(bp, tregs);
        }
        return retval;
}

static void bigmac_tcvr_init(struct bigmac *bp)
{
        void __iomem *tregs = bp->tregs;
        u32 mpal;

        idle_transceiver(tregs);
        sbus_writel(MGMT_PAL_INT_MDIO | MGMT_PAL_EXT_MDIO | MGMT_PAL_DCLOCK,
                    tregs + TCVR_MPAL);
        sbus_readl(tregs + TCVR_MPAL);

        /* Only the bit for the present transceiver (internal or
         * external) will stick, set them both and see what stays.
         */
        sbus_writel(MGMT_PAL_INT_MDIO | MGMT_PAL_EXT_MDIO, tregs + TCVR_MPAL);
        sbus_readl(tregs + TCVR_MPAL);
        udelay(20);

        mpal = sbus_readl(tregs + TCVR_MPAL);
        if (mpal & MGMT_PAL_EXT_MDIO) {
                bp->tcvr_type = external;
                sbus_writel(~(TCVR_PAL_EXTLBACK | TCVR_PAL_MSENSE | TCVR_PAL_LTENABLE),
                            tregs + TCVR_TPAL);
                sbus_readl(tregs + TCVR_TPAL);
        } else if (mpal & MGMT_PAL_INT_MDIO) {
                bp->tcvr_type = internal;
                sbus_writel(~(TCVR_PAL_SERIAL | TCVR_PAL_EXTLBACK |
                              TCVR_PAL_MSENSE | TCVR_PAL_LTENABLE),
                            tregs + TCVR_TPAL);
                sbus_readl(tregs + TCVR_TPAL);
        } else {
                printk(KERN_ERR "BIGMAC: AIEEE, neither internal nor "
                       "external MDIO available!\n");
                printk(KERN_ERR "BIGMAC: mgmt_pal[%08x] tcvr_pal[%08x]\n",
                       sbus_readl(tregs + TCVR_MPAL),
                       sbus_readl(tregs + TCVR_TPAL));
        }
}

static int bigmac_init_hw(struct bigmac *, bool);

static int try_next_permutation(struct bigmac *bp, void __iomem *tregs)
{
        if (bp->sw_bmcr & BMCR_SPEED100) {
                int timeout;

                /* Reset the PHY. */
                bp->sw_bmcr     = (BMCR_ISOLATE | BMCR_PDOWN | BMCR_LOOPBACK);
                bigmac_tcvr_write(bp, tregs, MII_BMCR, bp->sw_bmcr);
                bp->sw_bmcr     = (BMCR_RESET);
                bigmac_tcvr_write(bp, tregs, MII_BMCR, bp->sw_bmcr);

                timeout = 64;
                while (--timeout) {
                        bp->sw_bmcr = bigmac_tcvr_read(bp, tregs, MII_BMCR);
                        if ((bp->sw_bmcr & BMCR_RESET) == 0)
                                break;
                        udelay(20);
                }
                if (timeout == 0)
                        printk(KERN_ERR "%s: PHY reset failed.\n", bp->dev->name);

                bp->sw_bmcr = bigmac_tcvr_read(bp, tregs, MII_BMCR);

                /* Now we try 10baseT. */
                bp->sw_bmcr &= ~(BMCR_SPEED100);
                bigmac_tcvr_write(bp, tregs, MII_BMCR, bp->sw_bmcr);
                return 0;
        }

        /* We've tried them all. */
        return -1;
}

static void bigmac_timer(struct timer_list *t)
{
        struct bigmac *bp = timer_container_of(bp, t, bigmac_timer);
        void __iomem *tregs = bp->tregs;
        int restart_timer = 0;

        bp->timer_ticks++;
        if (bp->timer_state == ltrywait) {
                bp->sw_bmsr = bigmac_tcvr_read(bp, tregs, MII_BMSR);
                bp->sw_bmcr = bigmac_tcvr_read(bp, tregs, MII_BMCR);
                if (bp->sw_bmsr & BMSR_LSTATUS) {
                        printk(KERN_INFO "%s: Link is now up at %s.\n",
                               bp->dev->name,
                               (bp->sw_bmcr & BMCR_SPEED100) ?
                               "100baseT" : "10baseT");
                        bp->timer_state = asleep;
                        restart_timer = 0;
                } else {
                        if (bp->timer_ticks >= 4) {
                                int ret;

                                ret = try_next_permutation(bp, tregs);
                                if (ret == -1) {
                                        printk(KERN_ERR "%s: Link down, cable problem?\n",
                                               bp->dev->name);
                                        ret = bigmac_init_hw(bp, true);
                                        if (ret) {
                                                printk(KERN_ERR "%s: Error, cannot re-init the "
                                                       "BigMAC.\n", bp->dev->name);
                                        }
                                        return;
                                }
                                bp->timer_ticks = 0;
                                restart_timer = 1;
                        } else {
                                restart_timer = 1;
                        }
                }
        } else {
                /* Can't happens.... */
                printk(KERN_ERR "%s: Aieee, link timer is asleep but we got one anyways!\n",
                       bp->dev->name);
                restart_timer = 0;
                bp->timer_ticks = 0;
                bp->timer_state = asleep; /* foo on you */
        }

        if (restart_timer != 0) {
                bp->bigmac_timer.expires = jiffies + ((12 * HZ)/10); /* 1.2 sec. */
                add_timer(&bp->bigmac_timer);
        }
}

/* Well, really we just force the chip into 100baseT then
 * 10baseT, each time checking for a link status.
 */
static void bigmac_begin_auto_negotiation(struct bigmac *bp)
{
        void __iomem *tregs = bp->tregs;
        int timeout;

        /* Grab new software copies of PHY registers. */
        bp->sw_bmsr     = bigmac_tcvr_read(bp, tregs, MII_BMSR);
        bp->sw_bmcr     = bigmac_tcvr_read(bp, tregs, MII_BMCR);

        /* Reset the PHY. */
        bp->sw_bmcr     = (BMCR_ISOLATE | BMCR_PDOWN | BMCR_LOOPBACK);
        bigmac_tcvr_write(bp, tregs, MII_BMCR, bp->sw_bmcr);
        bp->sw_bmcr     = (BMCR_RESET);
        bigmac_tcvr_write(bp, tregs, MII_BMCR, bp->sw_bmcr);

        timeout = 64;
        while (--timeout) {
                bp->sw_bmcr = bigmac_tcvr_read(bp, tregs, MII_BMCR);
                if ((bp->sw_bmcr & BMCR_RESET) == 0)
                        break;
                udelay(20);
        }
        if (timeout == 0)
                printk(KERN_ERR "%s: PHY reset failed.\n", bp->dev->name);

        bp->sw_bmcr = bigmac_tcvr_read(bp, tregs, MII_BMCR);

        /* First we try 100baseT. */
        bp->sw_bmcr |= BMCR_SPEED100;
        bigmac_tcvr_write(bp, tregs, MII_BMCR, bp->sw_bmcr);

        bp->timer_state = ltrywait;
        bp->timer_ticks = 0;
        bp->bigmac_timer.expires = jiffies + (12 * HZ) / 10;
        add_timer(&bp->bigmac_timer);
}

static int bigmac_init_hw(struct bigmac *bp, bool non_blocking)
{
        void __iomem *gregs        = bp->gregs;
        void __iomem *cregs        = bp->creg;
        void __iomem *bregs        = bp->bregs;
        __u32 bblk_dvma = (__u32)bp->bblock_dvma;
        const unsigned char *e = &bp->dev->dev_addr[0];

        /* Latch current counters into statistics. */
        bigmac_get_counters(bp, bregs);

        /* Reset QEC. */
        qec_global_reset(gregs);

        /* Init QEC. */
        qec_init(bp);

        /* Alloc and reset the tx/rx descriptor chains. */
        bigmac_init_rings(bp, non_blocking);

        /* Initialize the PHY. */
        bigmac_tcvr_init(bp);

        /* Stop transmitter and receiver. */
        bigmac_stop(bp);

        /* Set hardware ethernet address. */
        sbus_writel(((e[4] << 8) | e[5]), bregs + BMAC_MACADDR2);
        sbus_writel(((e[2] << 8) | e[3]), bregs + BMAC_MACADDR1);
        sbus_writel(((e[0] << 8) | e[1]), bregs + BMAC_MACADDR0);

        /* Clear the hash table until mc upload occurs. */
        sbus_writel(0, bregs + BMAC_HTABLE3);
        sbus_writel(0, bregs + BMAC_HTABLE2);
        sbus_writel(0, bregs + BMAC_HTABLE1);
        sbus_writel(0, bregs + BMAC_HTABLE0);

        /* Enable Big Mac hash table filter. */
        sbus_writel(BIGMAC_RXCFG_HENABLE | BIGMAC_RXCFG_FIFO,
                    bregs + BMAC_RXCFG);
        udelay(20);

        /* Ok, configure the Big Mac transmitter. */
        sbus_writel(BIGMAC_TXCFG_FIFO, bregs + BMAC_TXCFG);

        /* The HME docs recommend to use the 10LSB of our MAC here. */
        sbus_writel(((e[5] | e[4] << 8) & 0x3ff),
                    bregs + BMAC_RSEED);

        /* Enable the output drivers no matter what. */
        sbus_writel(BIGMAC_XCFG_ODENABLE | BIGMAC_XCFG_RESV,
                    bregs + BMAC_XIFCFG);

        /* Tell the QEC where the ring descriptors are. */
        sbus_writel(bblk_dvma + bib_offset(be_rxd, 0),
                    cregs + CREG_RXDS);
        sbus_writel(bblk_dvma + bib_offset(be_txd, 0),
                    cregs + CREG_TXDS);

        /* Setup the FIFO pointers into QEC local memory. */
        sbus_writel(0, cregs + CREG_RXRBUFPTR);
        sbus_writel(0, cregs + CREG_RXWBUFPTR);
        sbus_writel(sbus_readl(gregs + GLOB_RSIZE),
                    cregs + CREG_TXRBUFPTR);
        sbus_writel(sbus_readl(gregs + GLOB_RSIZE),
                    cregs + CREG_TXWBUFPTR);

        /* Tell bigmac what interrupts we don't want to hear about. */
        sbus_writel(BIGMAC_IMASK_GOTFRAME | BIGMAC_IMASK_SENTFRAME,
                    bregs + BMAC_IMASK);

        /* Enable the various other irq's. */
        sbus_writel(0, cregs + CREG_RIMASK);
        sbus_writel(0, cregs + CREG_TIMASK);
        sbus_writel(0, cregs + CREG_QMASK);
        sbus_writel(0, cregs + CREG_BMASK);

        /* Set jam size to a reasonable default. */
        sbus_writel(DEFAULT_JAMSIZE, bregs + BMAC_JSIZE);

        /* Clear collision counter. */
        sbus_writel(0, cregs + CREG_CCNT);

        /* Enable transmitter and receiver. */
        sbus_writel(sbus_readl(bregs + BMAC_TXCFG) | BIGMAC_TXCFG_ENABLE,
                    bregs + BMAC_TXCFG);
        sbus_writel(sbus_readl(bregs + BMAC_RXCFG) | BIGMAC_RXCFG_ENABLE,
                    bregs + BMAC_RXCFG);

        /* Ok, start detecting link speed/duplex. */
        bigmac_begin_auto_negotiation(bp);

        /* Success. */
        return 0;
}

/* Error interrupts get sent here. */
static void bigmac_is_medium_rare(struct bigmac *bp, u32 qec_status, u32 bmac_status)
{
        printk(KERN_ERR "bigmac_is_medium_rare: ");
        if (qec_status & (GLOB_STAT_ER | GLOB_STAT_BM)) {
                if (qec_status & GLOB_STAT_ER)
                        printk("QEC_ERROR, ");
                if (qec_status & GLOB_STAT_BM)
                        printk("QEC_BMAC_ERROR, ");
        }
        if (bmac_status & CREG_STAT_ERRORS) {
                if (bmac_status & CREG_STAT_BERROR)
                        printk("BMAC_ERROR, ");
                if (bmac_status & CREG_STAT_TXDERROR)
                        printk("TXD_ERROR, ");
                if (bmac_status & CREG_STAT_TXLERR)
                        printk("TX_LATE_ERROR, ");
                if (bmac_status & CREG_STAT_TXPERR)
                        printk("TX_PARITY_ERROR, ");
                if (bmac_status & CREG_STAT_TXSERR)
                        printk("TX_SBUS_ERROR, ");

                if (bmac_status & CREG_STAT_RXDROP)
                        printk("RX_DROP_ERROR, ");

                if (bmac_status & CREG_STAT_RXSMALL)
                        printk("RX_SMALL_ERROR, ");
                if (bmac_status & CREG_STAT_RXLERR)
                        printk("RX_LATE_ERROR, ");
                if (bmac_status & CREG_STAT_RXPERR)
                        printk("RX_PARITY_ERROR, ");
                if (bmac_status & CREG_STAT_RXSERR)
                        printk("RX_SBUS_ERROR, ");
        }

        printk(" RESET\n");
        bigmac_init_hw(bp, true);
}

/* BigMAC transmit complete service routines. */
static void bigmac_tx(struct bigmac *bp)
{
        struct be_txd *txbase = &bp->bmac_block->be_txd[0];
        struct net_device *dev = bp->dev;
        int elem;

        spin_lock(&bp->lock);

        elem = bp->tx_old;
        DTX(("bigmac_tx: tx_old[%d] ", elem));
        while (elem != bp->tx_new) {
                struct sk_buff *skb;
                struct be_txd *this = &txbase[elem];

                DTX(("this(%p) [flags(%08x)addr(%08x)]",
                     this, this->tx_flags, this->tx_addr));

                if (this->tx_flags & TXD_OWN)
                        break;
                skb = bp->tx_skbs[elem];
                dev->stats.tx_packets++;
                dev->stats.tx_bytes += skb->len;
                dma_unmap_single(&bp->bigmac_op->dev,
                                 this->tx_addr, skb->len,
                                 DMA_TO_DEVICE);

                DTX(("skb(%p) ", skb));
                bp->tx_skbs[elem] = NULL;
                dev_consume_skb_irq(skb);

                elem = NEXT_TX(elem);
        }
        DTX((" DONE, tx_old=%d\n", elem));
        bp->tx_old = elem;

        if (netif_queue_stopped(dev) &&
            TX_BUFFS_AVAIL(bp) > 0)
                netif_wake_queue(bp->dev);

        spin_unlock(&bp->lock);
}

/* BigMAC receive complete service routines. */
static void bigmac_rx(struct bigmac *bp)
{
        struct be_rxd *rxbase = &bp->bmac_block->be_rxd[0];
        struct be_rxd *this;
        int elem = bp->rx_new, drops = 0;
        u32 flags;

        this = &rxbase[elem];
        while (!((flags = this->rx_flags) & RXD_OWN)) {
                struct sk_buff *skb;
                int len = (flags & RXD_LENGTH); /* FCS not included */

                /* Check for errors. */
                if (len < ETH_ZLEN) {
                        bp->dev->stats.rx_errors++;
                        bp->dev->stats.rx_length_errors++;

        drop_it:
                        /* Return it to the BigMAC. */
                        bp->dev->stats.rx_dropped++;
                        this->rx_flags =
                                (RXD_OWN | ((RX_BUF_ALLOC_SIZE - 34) & RXD_LENGTH));
                        goto next;
                }
                skb = bp->rx_skbs[elem];
                if (len > RX_COPY_THRESHOLD) {
                        struct sk_buff *new_skb;

                        /* Now refill the entry, if we can. */
                        new_skb = big_mac_alloc_skb(RX_BUF_ALLOC_SIZE, GFP_ATOMIC);
                        if (new_skb == NULL) {
                                drops++;
                                goto drop_it;
                        }
                        dma_unmap_single(&bp->bigmac_op->dev,
                                         this->rx_addr,
                                         RX_BUF_ALLOC_SIZE - 34,
                                         DMA_FROM_DEVICE);
                        bp->rx_skbs[elem] = new_skb;
                        skb_put(new_skb, ETH_FRAME_LEN);
                        skb_reserve(new_skb, 34);
                        this->rx_addr =
                                dma_map_single(&bp->bigmac_op->dev,
                                               new_skb->data,
                                               RX_BUF_ALLOC_SIZE - 34,
                                               DMA_FROM_DEVICE);
                        this->rx_flags =
                                (RXD_OWN | ((RX_BUF_ALLOC_SIZE - 34) & RXD_LENGTH));

                        /* Trim the original skb for the netif. */
                        skb_trim(skb, len);
                } else {
                        struct sk_buff *copy_skb = netdev_alloc_skb(bp->dev, len + 2);

                        if (copy_skb == NULL) {
                                drops++;
                                goto drop_it;
                        }
                        skb_reserve(copy_skb, 2);
                        skb_put(copy_skb, len);
                        dma_sync_single_for_cpu(&bp->bigmac_op->dev,
                                                this->rx_addr, len,
                                                DMA_FROM_DEVICE);
                        skb_copy_to_linear_data(copy_skb, (unsigned char *)skb->data, len);
                        dma_sync_single_for_device(&bp->bigmac_op->dev,
                                                   this->rx_addr, len,
                                                   DMA_FROM_DEVICE);

                        /* Reuse original ring buffer. */
                        this->rx_flags =
                                (RXD_OWN | ((RX_BUF_ALLOC_SIZE - 34) & RXD_LENGTH));

                        skb = copy_skb;
                }

                /* No checksums done by the BigMAC ;-( */
                skb->protocol = eth_type_trans(skb, bp->dev);
                netif_rx(skb);
                bp->dev->stats.rx_packets++;
                bp->dev->stats.rx_bytes += len;
        next:
                elem = NEXT_RX(elem);
                this = &rxbase[elem];
        }
        bp->rx_new = elem;
        if (drops)
                printk(KERN_NOTICE "%s: Memory squeeze, deferring packet.\n", bp->dev->name);
}

static irqreturn_t bigmac_interrupt(int irq, void *dev_id)
{
        struct bigmac *bp = (struct bigmac *) dev_id;
        u32 qec_status, bmac_status;

        DIRQ(("bigmac_interrupt: "));

        /* Latch status registers now. */
        bmac_status = sbus_readl(bp->creg + CREG_STAT);
        qec_status = sbus_readl(bp->gregs + GLOB_STAT);

        DIRQ(("qec_status=%08x bmac_status=%08x\n", qec_status, bmac_status));
        if ((qec_status & (GLOB_STAT_ER | GLOB_STAT_BM)) ||
           (bmac_status & CREG_STAT_ERRORS))
                bigmac_is_medium_rare(bp, qec_status, bmac_status);

        if (bmac_status & CREG_STAT_TXIRQ)
                bigmac_tx(bp);

        if (bmac_status & CREG_STAT_RXIRQ)
                bigmac_rx(bp);

        return IRQ_HANDLED;
}

static int bigmac_open(struct net_device *dev)
{
        struct bigmac *bp = netdev_priv(dev);
        int ret;

        ret = request_irq(dev->irq, bigmac_interrupt, IRQF_SHARED, dev->name, bp);
        if (ret) {
                printk(KERN_ERR "BIGMAC: Can't order irq %d to go.\n", dev->irq);
                return ret;
        }
        timer_setup(&bp->bigmac_timer, bigmac_timer, 0);
        ret = bigmac_init_hw(bp, false);
        if (ret)
                free_irq(dev->irq, bp);
        return ret;
}

static int bigmac_close(struct net_device *dev)
{
        struct bigmac *bp = netdev_priv(dev);

        timer_delete(&bp->bigmac_timer);
        bp->timer_state = asleep;
        bp->timer_ticks = 0;

        bigmac_stop(bp);
        bigmac_clean_rings(bp);
        free_irq(dev->irq, bp);
        return 0;
}

static void bigmac_tx_timeout(struct net_device *dev, unsigned int txqueue)
{
        struct bigmac *bp = netdev_priv(dev);

        bigmac_init_hw(bp, true);
        netif_wake_queue(dev);
}

/* Put a packet on the wire. */
static netdev_tx_t
bigmac_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
        struct bigmac *bp = netdev_priv(dev);
        int len, entry;
        u32 mapping;

        len = skb->len;
        mapping = dma_map_single(&bp->bigmac_op->dev, skb->data,
                                 len, DMA_TO_DEVICE);

        /* Avoid a race... */
        spin_lock_irq(&bp->lock);
        entry = bp->tx_new;
        DTX(("bigmac_start_xmit: len(%d) entry(%d)\n", len, entry));
        bp->bmac_block->be_txd[entry].tx_flags = TXD_UPDATE;
        bp->tx_skbs[entry] = skb;
        bp->bmac_block->be_txd[entry].tx_addr = mapping;
        bp->bmac_block->be_txd[entry].tx_flags =
                (TXD_OWN | TXD_SOP | TXD_EOP | (len & TXD_LENGTH));
        bp->tx_new = NEXT_TX(entry);
        if (TX_BUFFS_AVAIL(bp) <= 0)
                netif_stop_queue(dev);
        spin_unlock_irq(&bp->lock);

        /* Get it going. */
        sbus_writel(CREG_CTRL_TWAKEUP, bp->creg + CREG_CTRL);


        return NETDEV_TX_OK;
}

static struct net_device_stats *bigmac_get_stats(struct net_device *dev)
{
        struct bigmac *bp = netdev_priv(dev);

        bigmac_get_counters(bp, bp->bregs);
        return &dev->stats;
}

static void bigmac_set_multicast(struct net_device *dev)
{
        struct bigmac *bp = netdev_priv(dev);
        void __iomem *bregs = bp->bregs;
        struct netdev_hw_addr *ha;
        u32 tmp, crc;

        /* Disable the receiver.  The bit self-clears when
         * the operation is complete.
         */
        tmp = sbus_readl(bregs + BMAC_RXCFG);
        tmp &= ~(BIGMAC_RXCFG_ENABLE);
        sbus_writel(tmp, bregs + BMAC_RXCFG);
        while ((sbus_readl(bregs + BMAC_RXCFG) & BIGMAC_RXCFG_ENABLE) != 0)
                udelay(20);

        if ((dev->flags & IFF_ALLMULTI) || (netdev_mc_count(dev) > 64)) {
                sbus_writel(0xffff, bregs + BMAC_HTABLE0);
                sbus_writel(0xffff, bregs + BMAC_HTABLE1);
                sbus_writel(0xffff, bregs + BMAC_HTABLE2);
                sbus_writel(0xffff, bregs + BMAC_HTABLE3);
        } else if (dev->flags & IFF_PROMISC) {
                tmp = sbus_readl(bregs + BMAC_RXCFG);
                tmp |= BIGMAC_RXCFG_PMISC;
                sbus_writel(tmp, bregs + BMAC_RXCFG);
        } else {
                u16 hash_table[4] = { 0 };

                netdev_for_each_mc_addr(ha, dev) {
                        crc = ether_crc_le(6, ha->addr);
                        crc >>= 26;
                        hash_table[crc >> 4] |= 1 << (crc & 0xf);
                }
                sbus_writel(hash_table[0], bregs + BMAC_HTABLE0);
                sbus_writel(hash_table[1], bregs + BMAC_HTABLE1);
                sbus_writel(hash_table[2], bregs + BMAC_HTABLE2);
                sbus_writel(hash_table[3], bregs + BMAC_HTABLE3);
        }

        /* Re-enable the receiver. */
        tmp = sbus_readl(bregs + BMAC_RXCFG);
        tmp |= BIGMAC_RXCFG_ENABLE;
        sbus_writel(tmp, bregs + BMAC_RXCFG);
}

/* Ethtool support... */
static void bigmac_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
{
        strscpy(info->driver, "sunbmac", sizeof(info->driver));
        strscpy(info->version, "2.0", sizeof(info->version));
}

static u32 bigmac_get_link(struct net_device *dev)
{
        struct bigmac *bp = netdev_priv(dev);

        spin_lock_irq(&bp->lock);
        bp->sw_bmsr = bigmac_tcvr_read(bp, bp->tregs, MII_BMSR);
        spin_unlock_irq(&bp->lock);

        return (bp->sw_bmsr & BMSR_LSTATUS);
}

static const struct ethtool_ops bigmac_ethtool_ops = {
        .get_drvinfo            = bigmac_get_drvinfo,
        .get_link               = bigmac_get_link,
};

static const struct net_device_ops bigmac_ops = {
        .ndo_open               = bigmac_open,
        .ndo_stop               = bigmac_close,
        .ndo_start_xmit         = bigmac_start_xmit,
        .ndo_get_stats          = bigmac_get_stats,
        .ndo_set_rx_mode        = bigmac_set_multicast,
        .ndo_tx_timeout         = bigmac_tx_timeout,
        .ndo_set_mac_address    = eth_mac_addr,
        .ndo_validate_addr      = eth_validate_addr,
};

static int bigmac_ether_init(struct platform_device *op,
                             struct platform_device *qec_op)
{
        static int version_printed;
        struct net_device *dev;
        u8 bsizes, bsizes_more;
        struct bigmac *bp;

        /* Get a new device struct for this interface. */
        dev = alloc_etherdev(sizeof(struct bigmac));
        if (!dev)
                return -ENOMEM;

        if (version_printed++ == 0)
                printk(KERN_INFO "%s", version);

        eth_hw_addr_set(dev, idprom->id_ethaddr);

        /* Setup softc, with backpointers to QEC and BigMAC SBUS device structs. */
        bp = netdev_priv(dev);
        bp->qec_op = qec_op;
        bp->bigmac_op = op;

        SET_NETDEV_DEV(dev, &op->dev);

        spin_lock_init(&bp->lock);

        /* Map in QEC global control registers. */
        bp->gregs = of_ioremap(&qec_op->resource[0], 0,
                               GLOB_REG_SIZE, "BigMAC QEC GLobal Regs");
        if (!bp->gregs) {
                printk(KERN_ERR "BIGMAC: Cannot map QEC global registers.\n");
                goto fail_and_cleanup;
        }

        /* Make sure QEC is in BigMAC mode. */
        if ((sbus_readl(bp->gregs + GLOB_CTRL) & 0xf0000000) != GLOB_CTRL_BMODE) {
                printk(KERN_ERR "BigMAC: AIEEE, QEC is not in BigMAC mode!\n");
                goto fail_and_cleanup;
        }

        /* Reset the QEC. */
        if (qec_global_reset(bp->gregs))
                goto fail_and_cleanup;

        /* Get supported SBUS burst sizes. */
        bsizes = of_getintprop_default(qec_op->dev.of_node, "burst-sizes", 0xff);
        bsizes_more = of_getintprop_default(qec_op->dev.of_node, "burst-sizes", 0xff);

        bsizes &= 0xff;
        if (bsizes_more != 0xff)
                bsizes &= bsizes_more;
        if (bsizes == 0xff || (bsizes & DMA_BURST16) == 0 ||
            (bsizes & DMA_BURST32) == 0)
                bsizes = (DMA_BURST32 - 1);
        bp->bigmac_bursts = bsizes;

        /* Perform QEC initialization. */
        qec_init(bp);

        /* Map in the BigMAC channel registers. */
        bp->creg = of_ioremap(&op->resource[0], 0,
                              CREG_REG_SIZE, "BigMAC QEC Channel Regs");
        if (!bp->creg) {
                printk(KERN_ERR "BIGMAC: Cannot map QEC channel registers.\n");
                goto fail_and_cleanup;
        }

        /* Map in the BigMAC control registers. */
        bp->bregs = of_ioremap(&op->resource[1], 0,
                               BMAC_REG_SIZE, "BigMAC Primary Regs");
        if (!bp->bregs) {
                printk(KERN_ERR "BIGMAC: Cannot map BigMAC primary registers.\n");
                goto fail_and_cleanup;
        }

        /* Map in the BigMAC transceiver registers, this is how you poke at
         * the BigMAC's PHY.
         */
        bp->tregs = of_ioremap(&op->resource[2], 0,
                               TCVR_REG_SIZE, "BigMAC Transceiver Regs");
        if (!bp->tregs) {
                printk(KERN_ERR "BIGMAC: Cannot map BigMAC transceiver registers.\n");
                goto fail_and_cleanup;
        }

        /* Stop the BigMAC. */
        bigmac_stop(bp);

        /* Allocate transmit/receive descriptor DVMA block. */
        bp->bmac_block = dma_alloc_coherent(&bp->bigmac_op->dev,
                                            PAGE_SIZE,
                                            &bp->bblock_dvma, GFP_ATOMIC);
        if (bp->bmac_block == NULL || bp->bblock_dvma == 0)
                goto fail_and_cleanup;

        /* Get the board revision of this BigMAC. */
        bp->board_rev = of_getintprop_default(bp->bigmac_op->dev.of_node,
                                              "board-version", 1);

        /* Init auto-negotiation timer state. */
        timer_setup(&bp->bigmac_timer, bigmac_timer, 0);
        bp->timer_state = asleep;
        bp->timer_ticks = 0;

        /* Backlink to generic net device struct. */
        bp->dev = dev;

        /* Set links to our BigMAC open and close routines. */
        dev->ethtool_ops = &bigmac_ethtool_ops;
        dev->netdev_ops = &bigmac_ops;
        dev->watchdog_timeo = 5*HZ;

        /* Finish net device registration. */
        dev->irq = bp->bigmac_op->archdata.irqs[0];
        dev->dma = 0;

        if (register_netdev(dev)) {
                printk(KERN_ERR "BIGMAC: Cannot register device.\n");
                goto fail_and_cleanup;
        }

        dev_set_drvdata(&bp->bigmac_op->dev, bp);

        printk(KERN_INFO "%s: BigMAC 100baseT Ethernet %pM\n",
               dev->name, dev->dev_addr);

        return 0;

fail_and_cleanup:
        /* Something went wrong, undo whatever we did so far. */
        /* Free register mappings if any. */
        if (bp->gregs)
                of_iounmap(&qec_op->resource[0], bp->gregs, GLOB_REG_SIZE);
        if (bp->creg)
                of_iounmap(&op->resource[0], bp->creg, CREG_REG_SIZE);
        if (bp->bregs)
                of_iounmap(&op->resource[1], bp->bregs, BMAC_REG_SIZE);
        if (bp->tregs)
                of_iounmap(&op->resource[2], bp->tregs, TCVR_REG_SIZE);

        if (bp->bmac_block)
                dma_free_coherent(&bp->bigmac_op->dev,
                                  PAGE_SIZE,
                                  bp->bmac_block,
                                  bp->bblock_dvma);

        /* This also frees the co-located private data */
        free_netdev(dev);
        return -ENODEV;
}

/* QEC can be the parent of either QuadEthernet or a BigMAC.  We want
 * the latter.
 */
static int bigmac_sbus_probe(struct platform_device *op)
{
        struct device *parent = op->dev.parent;
        struct platform_device *qec_op;

        qec_op = to_platform_device(parent);

        return bigmac_ether_init(op, qec_op);
}

static void bigmac_sbus_remove(struct platform_device *op)
{
        struct bigmac *bp = platform_get_drvdata(op);
        struct device *parent = op->dev.parent;
        struct net_device *net_dev = bp->dev;
        struct platform_device *qec_op;

        qec_op = to_platform_device(parent);

        unregister_netdev(net_dev);

        of_iounmap(&qec_op->resource[0], bp->gregs, GLOB_REG_SIZE);
        of_iounmap(&op->resource[0], bp->creg, CREG_REG_SIZE);
        of_iounmap(&op->resource[1], bp->bregs, BMAC_REG_SIZE);
        of_iounmap(&op->resource[2], bp->tregs, TCVR_REG_SIZE);
        dma_free_coherent(&op->dev,
                          PAGE_SIZE,
                          bp->bmac_block,
                          bp->bblock_dvma);

        free_netdev(net_dev);
}

static const struct of_device_id bigmac_sbus_match[] = {
        {
                .name = "be",
        },
        {},
};

MODULE_DEVICE_TABLE(of, bigmac_sbus_match);

static struct platform_driver bigmac_sbus_driver = {
        .driver = {
                .name = "sunbmac",
                .of_match_table = bigmac_sbus_match,
        },
        .probe          = bigmac_sbus_probe,
        .remove         = bigmac_sbus_remove,
};

module_platform_driver(bigmac_sbus_driver);