/*
 * Cadence MACB/GEM Ethernet Controller driver
 *
 * Copyright (C) 2004-2006 Atmel Corporation
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/clk.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/circ_buf.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/gpio.h>
#include <linux/interrupt.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/dma-mapping.h>
#include <linux/platform_data/macb.h>
#include <linux/platform_device.h>
#include <linux/phy.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_mdio.h>
#include <linux/of_net.h>
#include <linux/pinctrl/consumer.h>

#include "macb.h"

#define MACB_RX_BUFFER_SIZE     128
#define RX_BUFFER_MULTIPLE      64  /* bytes */
#define RX_RING_SIZE            512 /* must be power of 2 */
#define RX_RING_BYTES           (sizeof(struct macb_dma_desc) * RX_RING_SIZE)

#define TX_RING_SIZE            128 /* must be power of 2 */
#define TX_RING_BYTES           (sizeof(struct macb_dma_desc) * TX_RING_SIZE)

/* level of occupied TX descriptors under which we wake up TX process */
#define MACB_TX_WAKEUP_THRESH   (3 * TX_RING_SIZE / 4)

#define MACB_RX_INT_FLAGS       (MACB_BIT(RCOMP) | MACB_BIT(RXUBR)      \
                                 | MACB_BIT(ISR_ROVR))
#define MACB_TX_ERR_FLAGS       (MACB_BIT(ISR_TUND)                     \
                                        | MACB_BIT(ISR_RLE)             \
                                        | MACB_BIT(TXERR))
#define MACB_TX_INT_FLAGS       (MACB_TX_ERR_FLAGS | MACB_BIT(TCOMP))

/*
 * Graceful stop timeouts in us. We should allow up to
 * 1 frame time (10 Mbits/s, full-duplex, ignoring collisions)
 */
#define MACB_HALT_TIMEOUT       1230

/* Ring buffer accessors */
static unsigned int macb_tx_ring_wrap(unsigned int index)
{
        return index & (TX_RING_SIZE - 1);
}

static struct macb_dma_desc *macb_tx_desc(struct macb *bp, unsigned int index)
{
        return &bp->tx_ring[macb_tx_ring_wrap(index)];
}

static struct macb_tx_skb *macb_tx_skb(struct macb *bp, unsigned int index)
{
        return &bp->tx_skb[macb_tx_ring_wrap(index)];
}

static dma_addr_t macb_tx_dma(struct macb *bp, unsigned int index)
{
        dma_addr_t offset;

        offset = macb_tx_ring_wrap(index) * sizeof(struct macb_dma_desc);

        return bp->tx_ring_dma + offset;
}

static unsigned int macb_rx_ring_wrap(unsigned int index)
{
        return index & (RX_RING_SIZE - 1);
}

static struct macb_dma_desc *macb_rx_desc(struct macb *bp, unsigned int index)
{
        return &bp->rx_ring[macb_rx_ring_wrap(index)];
}

static void *macb_rx_buffer(struct macb *bp, unsigned int index)
{
        return bp->rx_buffers + bp->rx_buffer_size * macb_rx_ring_wrap(index);
}

void macb_set_hwaddr(struct macb *bp)
{
        u32 bottom;
        u16 top;

        bottom = cpu_to_le32(*((u32 *)bp->dev->dev_addr));
        macb_or_gem_writel(bp, SA1B, bottom);
        top = cpu_to_le16(*((u16 *)(bp->dev->dev_addr + 4)));
        macb_or_gem_writel(bp, SA1T, top);

        /* Clear unused address register sets */
        macb_or_gem_writel(bp, SA2B, 0);
        macb_or_gem_writel(bp, SA2T, 0);
        macb_or_gem_writel(bp, SA3B, 0);
        macb_or_gem_writel(bp, SA3T, 0);
        macb_or_gem_writel(bp, SA4B, 0);
        macb_or_gem_writel(bp, SA4T, 0);
}
EXPORT_SYMBOL_GPL(macb_set_hwaddr);

void macb_get_hwaddr(struct macb *bp)
{
        struct macb_platform_data *pdata;
        u32 bottom;
        u16 top;
        u8 addr[6];
        int i;

        pdata = dev_get_platdata(&bp->pdev->dev);

        /* Check all 4 address register for vaild address */
        for (i = 0; i < 4; i++) {
                bottom = macb_or_gem_readl(bp, SA1B + i * 8);
                top = macb_or_gem_readl(bp, SA1T + i * 8);

                if (pdata && pdata->rev_eth_addr) {
                        addr[5] = bottom & 0xff;
                        addr[4] = (bottom >> 8) & 0xff;
                        addr[3] = (bottom >> 16) & 0xff;
                        addr[2] = (bottom >> 24) & 0xff;
                        addr[1] = top & 0xff;
                        addr[0] = (top & 0xff00) >> 8;
                } else {
                        addr[0] = bottom & 0xff;
                        addr[1] = (bottom >> 8) & 0xff;
                        addr[2] = (bottom >> 16) & 0xff;
                        addr[3] = (bottom >> 24) & 0xff;
                        addr[4] = top & 0xff;
                        addr[5] = (top >> 8) & 0xff;
                }

                if (is_valid_ether_addr(addr)) {
                        memcpy(bp->dev->dev_addr, addr, sizeof(addr));
                        return;
                }
        }

        netdev_info(bp->dev, "invalid hw address, using random\n");
        eth_hw_addr_random(bp->dev);
}
EXPORT_SYMBOL_GPL(macb_get_hwaddr);

static int macb_mdio_read(struct mii_bus *bus, int mii_id, int regnum)
{
        struct macb *bp = bus->priv;
        int value;

        macb_writel(bp, MAN, (MACB_BF(SOF, MACB_MAN_SOF)
                              | MACB_BF(RW, MACB_MAN_READ)
                              | MACB_BF(PHYA, mii_id)
                              | MACB_BF(REGA, regnum)
                              | MACB_BF(CODE, MACB_MAN_CODE)));

        /* wait for end of transfer */
        while (!MACB_BFEXT(IDLE, macb_readl(bp, NSR)))
                cpu_relax();

        value = MACB_BFEXT(DATA, macb_readl(bp, MAN));

        return value;
}

static int macb_mdio_write(struct mii_bus *bus, int mii_id, int regnum,
                           u16 value)
{
        struct macb *bp = bus->priv;

        macb_writel(bp, MAN, (MACB_BF(SOF, MACB_MAN_SOF)
                              | MACB_BF(RW, MACB_MAN_WRITE)
                              | MACB_BF(PHYA, mii_id)
                              | MACB_BF(REGA, regnum)
                              | MACB_BF(CODE, MACB_MAN_CODE)
                              | MACB_BF(DATA, value)));

        /* wait for end of transfer */
        while (!MACB_BFEXT(IDLE, macb_readl(bp, NSR)))
                cpu_relax();

        return 0;
}

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

static void macb_handle_link_change(struct net_device *dev)
{
        struct macb *bp = netdev_priv(dev);
        struct phy_device *phydev = bp->phy_dev;
        unsigned long flags;

        int status_change = 0;

        spin_lock_irqsave(&bp->lock, flags);

        if (phydev->link) {
                if ((bp->speed != phydev->speed) ||
                    (bp->duplex != phydev->duplex)) {
                        u32 reg;

                        reg = macb_readl(bp, NCFGR);
                        reg &= ~(MACB_BIT(SPD) | MACB_BIT(FD));
                        if (macb_is_gem(bp))
                                reg &= ~GEM_BIT(GBE);

                        if (phydev->duplex)
                                reg |= MACB_BIT(FD);
                        if (phydev->speed == SPEED_100)
                                reg |= MACB_BIT(SPD);
                        if (phydev->speed == SPEED_1000)
                                reg |= GEM_BIT(GBE);

                        macb_or_gem_writel(bp, NCFGR, reg);

                        bp->speed = phydev->speed;
                        bp->duplex = phydev->duplex;
                        status_change = 1;
                }
        }

        if (phydev->link != bp->link) {
                if (!phydev->link) {
                        bp->speed = 0;
                        bp->duplex = -1;
                }
                bp->link = phydev->link;

                status_change = 1;
        }

        spin_unlock_irqrestore(&bp->lock, flags);

        if (status_change) {
                if (phydev->link) {
                        netif_carrier_on(dev);
                        netdev_info(dev, "link up (%d/%s)\n",
                                    phydev->speed,
                                    phydev->duplex == DUPLEX_FULL ?
                                    "Full" : "Half");
                } else {
                        netif_carrier_off(dev);
                        netdev_info(dev, "link down\n");
                }
        }
}

/* based on au1000_eth. c*/
static int macb_mii_probe(struct net_device *dev)
{
        struct macb *bp = netdev_priv(dev);
        struct macb_platform_data *pdata;
        struct phy_device *phydev;
        int phy_irq;
        int ret;

        phydev = phy_find_first(bp->mii_bus);
        if (!phydev) {
                netdev_err(dev, "no PHY found\n");
                return -ENXIO;
        }

        pdata = dev_get_platdata(&bp->pdev->dev);
        if (pdata && gpio_is_valid(pdata->phy_irq_pin)) {
                ret = devm_gpio_request(&bp->pdev->dev, pdata->phy_irq_pin, "phy int");
                if (!ret) {
                        phy_irq = gpio_to_irq(pdata->phy_irq_pin);
                        phydev->irq = (phy_irq < 0) ? PHY_POLL : phy_irq;
                }
        }

        /* attach the mac to the phy */
        ret = phy_connect_direct(dev, phydev, &macb_handle_link_change,
                                 bp->phy_interface);
        if (ret) {
                netdev_err(dev, "Could not attach to PHY\n");
                return ret;
        }

        /* mask with MAC supported features */
        if (macb_is_gem(bp))
                phydev->supported &= PHY_GBIT_FEATURES;
        else
                phydev->supported &= PHY_BASIC_FEATURES;

        phydev->advertising = phydev->supported;

        bp->link = 0;
        bp->speed = 0;
        bp->duplex = -1;
        bp->phy_dev = phydev;

        return 0;
}

int macb_mii_init(struct macb *bp)
{
        struct macb_platform_data *pdata;
        struct device_node *np;
        int err = -ENXIO, i;

        /* Enable management port */
        macb_writel(bp, NCR, MACB_BIT(MPE));

        bp->mii_bus = mdiobus_alloc();
        if (bp->mii_bus == NULL) {
                err = -ENOMEM;
                goto err_out;
        }

        bp->mii_bus->name = "MACB_mii_bus";
        bp->mii_bus->read = &macb_mdio_read;
        bp->mii_bus->write = &macb_mdio_write;
        bp->mii_bus->reset = &macb_mdio_reset;
        snprintf(bp->mii_bus->id, MII_BUS_ID_SIZE, "%s-%x",
                bp->pdev->name, bp->pdev->id);
        bp->mii_bus->priv = bp;
        bp->mii_bus->parent = &bp->dev->dev;
        pdata = dev_get_platdata(&bp->pdev->dev);

        bp->mii_bus->irq = kmalloc(sizeof(int)*PHY_MAX_ADDR, GFP_KERNEL);
        if (!bp->mii_bus->irq) {
                err = -ENOMEM;
                goto err_out_free_mdiobus;
        }

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

        np = bp->pdev->dev.of_node;
        if (np) {
                /* try dt phy registration */
                err = of_mdiobus_register(bp->mii_bus, np);

                /* fallback to standard phy registration if no phy were
                   found during dt phy registration */
                if (!err && !phy_find_first(bp->mii_bus)) {
                        for (i = 0; i < PHY_MAX_ADDR; i++) {
                                struct phy_device *phydev;

                                phydev = mdiobus_scan(bp->mii_bus, i);
                                if (IS_ERR(phydev)) {
                                        err = PTR_ERR(phydev);
                                        break;
                                }
                        }

                        if (err)
                                goto err_out_unregister_bus;
                }
        } else {
                for (i = 0; i < PHY_MAX_ADDR; i++)
                        bp->mii_bus->irq[i] = PHY_POLL;

                if (pdata)
                        bp->mii_bus->phy_mask = pdata->phy_mask;

                err = mdiobus_register(bp->mii_bus);
        }

        if (err)
                goto err_out_free_mdio_irq;

        err = macb_mii_probe(bp->dev);
        if (err)
                goto err_out_unregister_bus;

        return 0;

err_out_unregister_bus:
        mdiobus_unregister(bp->mii_bus);
err_out_free_mdio_irq:
        kfree(bp->mii_bus->irq);
err_out_free_mdiobus:
        mdiobus_free(bp->mii_bus);
err_out:
        return err;
}
EXPORT_SYMBOL_GPL(macb_mii_init);

static void macb_update_stats(struct macb *bp)
{
        u32 __iomem *reg = bp->regs + MACB_PFR;
        u32 *p = &bp->hw_stats.macb.rx_pause_frames;
        u32 *end = &bp->hw_stats.macb.tx_pause_frames + 1;

        WARN_ON((unsigned long)(end - p - 1) != (MACB_TPF - MACB_PFR) / 4);

        for(; p < end; p++, reg++)
                *p += __raw_readl(reg);
}

static int macb_halt_tx(struct macb *bp)
{
        unsigned long   halt_time, timeout;
        u32             status;

        macb_writel(bp, NCR, macb_readl(bp, NCR) | MACB_BIT(THALT));

        timeout = jiffies + usecs_to_jiffies(MACB_HALT_TIMEOUT);
        do {
                halt_time = jiffies;
                status = macb_readl(bp, TSR);
                if (!(status & MACB_BIT(TGO)))
                        return 0;

                usleep_range(10, 250);
        } while (time_before(halt_time, timeout));

        return -ETIMEDOUT;
}

static void macb_tx_error_task(struct work_struct *work)
{
        struct macb     *bp = container_of(work, struct macb, tx_error_task);
        struct macb_tx_skb      *tx_skb;
        struct sk_buff          *skb;
        unsigned int            tail;

        netdev_vdbg(bp->dev, "macb_tx_error_task: t = %u, h = %u\n",
                    bp->tx_tail, bp->tx_head);

        /* Make sure nobody is trying to queue up new packets */
        netif_stop_queue(bp->dev);

        /*
         * Stop transmission now
         * (in case we have just queued new packets)
         */
        if (macb_halt_tx(bp))
                /* Just complain for now, reinitializing TX path can be good */
                netdev_err(bp->dev, "BUG: halt tx timed out\n");

        /* No need for the lock here as nobody will interrupt us anymore */

        /*
         * Treat frames in TX queue including the ones that caused the error.
         * Free transmit buffers in upper layer.
         */
        for (tail = bp->tx_tail; tail != bp->tx_head; tail++) {
                struct macb_dma_desc    *desc;
                u32                     ctrl;

                desc = macb_tx_desc(bp, tail);
                ctrl = desc->ctrl;
                tx_skb = macb_tx_skb(bp, tail);
                skb = tx_skb->skb;

                if (ctrl & MACB_BIT(TX_USED)) {
                        netdev_vdbg(bp->dev, "txerr skb %u (data %p) TX complete\n",
                                    macb_tx_ring_wrap(tail), skb->data);
                        bp->stats.tx_packets++;
                        bp->stats.tx_bytes += skb->len;
                } else {
                        /*
                         * "Buffers exhausted mid-frame" errors may only happen
                         * if the driver is buggy, so complain loudly about those.
                         * Statistics are updated by hardware.
                         */
                        if (ctrl & MACB_BIT(TX_BUF_EXHAUSTED))
                                netdev_err(bp->dev,
                                           "BUG: TX buffers exhausted mid-frame\n");

                        desc->ctrl = ctrl | MACB_BIT(TX_USED);
                }

                dma_unmap_single(&bp->pdev->dev, tx_skb->mapping, skb->len,
                                 DMA_TO_DEVICE);
                tx_skb->skb = NULL;
                dev_kfree_skb(skb);
        }

        /* Make descriptor updates visible to hardware */
        wmb();

        /* Reinitialize the TX desc queue */
        macb_writel(bp, TBQP, bp->tx_ring_dma);
        /* Make TX ring reflect state of hardware */
        bp->tx_head = bp->tx_tail = 0;

        /* Now we are ready to start transmission again */
        netif_wake_queue(bp->dev);

        /* Housework before enabling TX IRQ */
        macb_writel(bp, TSR, macb_readl(bp, TSR));
        macb_writel(bp, IER, MACB_TX_INT_FLAGS);
}

static void macb_tx_interrupt(struct macb *bp)
{
        unsigned int tail;
        unsigned int head;
        u32 status;

        status = macb_readl(bp, TSR);
        macb_writel(bp, TSR, status);

        if (bp->caps & MACB_CAPS_ISR_CLEAR_ON_WRITE)
                macb_writel(bp, ISR, MACB_BIT(TCOMP));

        netdev_vdbg(bp->dev, "macb_tx_interrupt status = 0x%03lx\n",
                (unsigned long)status);

        head = bp->tx_head;
        for (tail = bp->tx_tail; tail != head; tail++) {
                struct macb_tx_skb      *tx_skb;
                struct sk_buff          *skb;
                struct macb_dma_desc    *desc;
                u32                     ctrl;

                desc = macb_tx_desc(bp, tail);

                /* Make hw descriptor updates visible to CPU */
                rmb();

                ctrl = desc->ctrl;

                if (!(ctrl & MACB_BIT(TX_USED)))
                        break;

                tx_skb = macb_tx_skb(bp, tail);
                skb = tx_skb->skb;

                netdev_vdbg(bp->dev, "skb %u (data %p) TX complete\n",
                        macb_tx_ring_wrap(tail), skb->data);
                dma_unmap_single(&bp->pdev->dev, tx_skb->mapping, skb->len,
                                 DMA_TO_DEVICE);
                bp->stats.tx_packets++;
                bp->stats.tx_bytes += skb->len;
                tx_skb->skb = NULL;
                dev_kfree_skb_irq(skb);
        }

        bp->tx_tail = tail;
        if (netif_queue_stopped(bp->dev)
                        && CIRC_CNT(bp->tx_head, bp->tx_tail,
                                    TX_RING_SIZE) <= MACB_TX_WAKEUP_THRESH)
                netif_wake_queue(bp->dev);
}

static void gem_rx_refill(struct macb *bp)
{
        unsigned int            entry;
        struct sk_buff          *skb;
        struct macb_dma_desc    *desc;
        dma_addr_t              paddr;

        while (CIRC_SPACE(bp->rx_prepared_head, bp->rx_tail, RX_RING_SIZE) > 0) {
                u32 addr, ctrl;

                entry = macb_rx_ring_wrap(bp->rx_prepared_head);
                desc = &bp->rx_ring[entry];

                /* Make hw descriptor updates visible to CPU */
                rmb();

                addr = desc->addr;
                ctrl = desc->ctrl;
                bp->rx_prepared_head++;

                if ((addr & MACB_BIT(RX_USED)))
                        continue;

                if (bp->rx_skbuff[entry] == NULL) {
                        /* allocate sk_buff for this free entry in ring */
                        skb = netdev_alloc_skb(bp->dev, bp->rx_buffer_size);
                        if (unlikely(skb == NULL)) {
                                netdev_err(bp->dev,
                                           "Unable to allocate sk_buff\n");
                                break;
                        }
                        bp->rx_skbuff[entry] = skb;

                        /* now fill corresponding descriptor entry */
                        paddr = dma_map_single(&bp->pdev->dev, skb->data,
                                               bp->rx_buffer_size, DMA_FROM_DEVICE);

                        if (entry == RX_RING_SIZE - 1)
                                paddr |= MACB_BIT(RX_WRAP);
                        bp->rx_ring[entry].addr = paddr;
                        bp->rx_ring[entry].ctrl = 0;

                        /* properly align Ethernet header */
                        skb_reserve(skb, NET_IP_ALIGN);
                }
        }

        /* Make descriptor updates visible to hardware */
        wmb();

        netdev_vdbg(bp->dev, "rx ring: prepared head %d, tail %d\n",
                   bp->rx_prepared_head, bp->rx_tail);
}

/* Mark DMA descriptors from begin up to and not including end as unused */
static void discard_partial_frame(struct macb *bp, unsigned int begin,
                                  unsigned int end)
{
        unsigned int frag;

        for (frag = begin; frag != end; frag++) {
                struct macb_dma_desc *desc = macb_rx_desc(bp, frag);
                desc->addr &= ~MACB_BIT(RX_USED);
        }

        /* Make descriptor updates visible to hardware */
        wmb();

        /*
         * When this happens, the hardware stats registers for
         * whatever caused this is updated, so we don't have to record
         * anything.
         */
}

static int gem_rx(struct macb *bp, int budget)
{
        unsigned int            len;
        unsigned int            entry;
        struct sk_buff          *skb;
        struct macb_dma_desc    *desc;
        int                     count = 0;

        while (count < budget) {
                u32 addr, ctrl;

                entry = macb_rx_ring_wrap(bp->rx_tail);
                desc = &bp->rx_ring[entry];

                /* Make hw descriptor updates visible to CPU */
                rmb();

                addr = desc->addr;
                ctrl = desc->ctrl;

                if (!(addr & MACB_BIT(RX_USED)))
                        break;

                desc->addr &= ~MACB_BIT(RX_USED);
                bp->rx_tail++;
                count++;

                if (!(ctrl & MACB_BIT(RX_SOF) && ctrl & MACB_BIT(RX_EOF))) {
                        netdev_err(bp->dev,
                                   "not whole frame pointed by descriptor\n");
                        bp->stats.rx_dropped++;
                        break;
                }
                skb = bp->rx_skbuff[entry];
                if (unlikely(!skb)) {
                        netdev_err(bp->dev,
                                   "inconsistent Rx descriptor chain\n");
                        bp->stats.rx_dropped++;
                        break;
                }
                /* now everything is ready for receiving packet */
                bp->rx_skbuff[entry] = NULL;
                len = MACB_BFEXT(RX_FRMLEN, ctrl);

                netdev_vdbg(bp->dev, "gem_rx %u (len %u)\n", entry, len);

                skb_put(skb, len);
                addr = MACB_BF(RX_WADDR, MACB_BFEXT(RX_WADDR, addr));
                dma_unmap_single(&bp->pdev->dev, addr,
                                 len, DMA_FROM_DEVICE);

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

                bp->stats.rx_packets++;
                bp->stats.rx_bytes += skb->len;

#if defined(DEBUG) && defined(VERBOSE_DEBUG)
                netdev_vdbg(bp->dev, "received skb of length %u, csum: %08x\n",
                            skb->len, skb->csum);
                print_hex_dump(KERN_DEBUG, " mac: ", DUMP_PREFIX_ADDRESS, 16, 1,
                               skb->mac_header, 16, true);
                print_hex_dump(KERN_DEBUG, "data: ", DUMP_PREFIX_ADDRESS, 16, 1,
                               skb->data, 32, true);
#endif

                netif_receive_skb(skb);
        }

        gem_rx_refill(bp);

        return count;
}

static int macb_rx_frame(struct macb *bp, unsigned int first_frag,
                         unsigned int last_frag)
{
        unsigned int len;
        unsigned int frag;
        unsigned int offset;
        struct sk_buff *skb;
        struct macb_dma_desc *desc;

        desc = macb_rx_desc(bp, last_frag);
        len = MACB_BFEXT(RX_FRMLEN, desc->ctrl);

        netdev_vdbg(bp->dev, "macb_rx_frame frags %u - %u (len %u)\n",
                macb_rx_ring_wrap(first_frag),
                macb_rx_ring_wrap(last_frag), len);

        /*
         * The ethernet header starts NET_IP_ALIGN bytes into the
         * first buffer. Since the header is 14 bytes, this makes the
         * payload word-aligned.
         *
         * Instead of calling skb_reserve(NET_IP_ALIGN), we just copy
         * the two padding bytes into the skb so that we avoid hitting
         * the slowpath in memcpy(), and pull them off afterwards.
         */
        skb = netdev_alloc_skb(bp->dev, len + NET_IP_ALIGN);
        if (!skb) {
                bp->stats.rx_dropped++;
                for (frag = first_frag; ; frag++) {
                        desc = macb_rx_desc(bp, frag);
                        desc->addr &= ~MACB_BIT(RX_USED);
                        if (frag == last_frag)
                                break;
                }

                /* Make descriptor updates visible to hardware */
                wmb();

                return 1;
        }

        offset = 0;
        len += NET_IP_ALIGN;
        skb_checksum_none_assert(skb);
        skb_put(skb, len);

        for (frag = first_frag; ; frag++) {
                unsigned int frag_len = bp->rx_buffer_size;

                if (offset + frag_len > len) {
                        BUG_ON(frag != last_frag);
                        frag_len = len - offset;
                }
                skb_copy_to_linear_data_offset(skb, offset,
                                macb_rx_buffer(bp, frag), frag_len);
                offset += bp->rx_buffer_size;
                desc = macb_rx_desc(bp, frag);
                desc->addr &= ~MACB_BIT(RX_USED);

                if (frag == last_frag)
                        break;
        }

        /* Make descriptor updates visible to hardware */
        wmb();

        __skb_pull(skb, NET_IP_ALIGN);
        skb->protocol = eth_type_trans(skb, bp->dev);

        bp->stats.rx_packets++;
        bp->stats.rx_bytes += skb->len;
        netdev_vdbg(bp->dev, "received skb of length %u, csum: %08x\n",
                   skb->len, skb->csum);
        netif_receive_skb(skb);

        return 0;
}

static int macb_rx(struct macb *bp, int budget)
{
        int received = 0;
        unsigned int tail;
        int first_frag = -1;

        for (tail = bp->rx_tail; budget > 0; tail++) {
                struct macb_dma_desc *desc = macb_rx_desc(bp, tail);
                u32 addr, ctrl;

                /* Make hw descriptor updates visible to CPU */
                rmb();

                addr = desc->addr;
                ctrl = desc->ctrl;

                if (!(addr & MACB_BIT(RX_USED)))
                        break;

                if (ctrl & MACB_BIT(RX_SOF)) {
                        if (first_frag != -1)
                                discard_partial_frame(bp, first_frag, tail);
                        first_frag = tail;
                }

                if (ctrl & MACB_BIT(RX_EOF)) {
                        int dropped;
                        BUG_ON(first_frag == -1);

                        dropped = macb_rx_frame(bp, first_frag, tail);
                        first_frag = -1;
                        if (!dropped) {
                                received++;
                                budget--;
                        }
                }
        }

        if (first_frag != -1)
                bp->rx_tail = first_frag;
        else
                bp->rx_tail = tail;

        return received;
}

static int macb_poll(struct napi_struct *napi, int budget)
{
        struct macb *bp = container_of(napi, struct macb, napi);
        int work_done;
        u32 status;

        status = macb_readl(bp, RSR);
        macb_writel(bp, RSR, status);

        work_done = 0;

        netdev_vdbg(bp->dev, "poll: status = %08lx, budget = %d\n",
                   (unsigned long)status, budget);

        work_done = bp->macbgem_ops.mog_rx(bp, budget);
        if (work_done < budget) {
                napi_complete(napi);

                /*
                 * We've done what we can to clean the buffers. Make sure we
                 * get notified when new packets arrive.
                 */
                macb_writel(bp, IER, MACB_RX_INT_FLAGS);

                /* Packets received while interrupts were disabled */
                status = macb_readl(bp, RSR);
                if (unlikely(status))
                        napi_reschedule(napi);
        }

        /* TODO: Handle errors */

        return work_done;
}

static irqreturn_t macb_interrupt(int irq, void *dev_id)
{
        struct net_device *dev = dev_id;
        struct macb *bp = netdev_priv(dev);
        u32 status;

        status = macb_readl(bp, ISR);

        if (unlikely(!status))
                return IRQ_NONE;

        spin_lock(&bp->lock);

        while (status) {
                /* close possible race with dev_close */
                if (unlikely(!netif_running(dev))) {
                        macb_writel(bp, IDR, -1);
                        break;
                }

                netdev_vdbg(bp->dev, "isr = 0x%08lx\n", (unsigned long)status);

                if (status & MACB_RX_INT_FLAGS) {
                        /*
                         * There's no point taking any more interrupts
                         * until we have processed the buffers. The
                         * scheduling call may fail if the poll routine
                         * is already scheduled, so disable interrupts
                         * now.
                         */
                        macb_writel(bp, IDR, MACB_RX_INT_FLAGS);
                        if (bp->caps & MACB_CAPS_ISR_CLEAR_ON_WRITE)
                                macb_writel(bp, ISR, MACB_BIT(RCOMP));

                        if (napi_schedule_prep(&bp->napi)) {
                                netdev_vdbg(bp->dev, "scheduling RX softirq\n");
                                __napi_schedule(&bp->napi);
                        }
                }

                if (unlikely(status & (MACB_TX_ERR_FLAGS))) {
                        macb_writel(bp, IDR, MACB_TX_INT_FLAGS);
                        schedule_work(&bp->tx_error_task);
                        break;
                }

                if (status & MACB_BIT(TCOMP))
                        macb_tx_interrupt(bp);

                /*
                 * Link change detection isn't possible with RMII, so we'll
                 * add that if/when we get our hands on a full-blown MII PHY.
                 */

                if (status & MACB_BIT(ISR_ROVR)) {
                        /* We missed at least one packet */
                        if (macb_is_gem(bp))
                                bp->hw_stats.gem.rx_overruns++;
                        else
                                bp->hw_stats.macb.rx_overruns++;
                }

                if (status & MACB_BIT(HRESP)) {
                        /*
                         * TODO: Reset the hardware, and maybe move the
                         * netdev_err to a lower-priority context as well
                         * (work queue?)
                         */
                        netdev_err(dev, "DMA bus error: HRESP not OK\n");
                }

                status = macb_readl(bp, ISR);
        }

        spin_unlock(&bp->lock);

        return IRQ_HANDLED;
}

#ifdef CONFIG_NET_POLL_CONTROLLER
/*
 * Polling receive - used by netconsole and other diagnostic tools
 * to allow network i/o with interrupts disabled.
 */
static void macb_poll_controller(struct net_device *dev)
{
        unsigned long flags;

        local_irq_save(flags);
        macb_interrupt(dev->irq, dev);
        local_irq_restore(flags);
}
#endif

static int macb_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
        struct macb *bp = netdev_priv(dev);
        dma_addr_t mapping;
        unsigned int len, entry;
        struct macb_dma_desc *desc;
        struct macb_tx_skb *tx_skb;
        u32 ctrl;
        unsigned long flags;

#if defined(DEBUG) && defined(VERBOSE_DEBUG)
        netdev_vdbg(bp->dev,
                   "start_xmit: len %u head %p data %p tail %p end %p\n",
                   skb->len, skb->head, skb->data,
                   skb_tail_pointer(skb), skb_end_pointer(skb));
        print_hex_dump(KERN_DEBUG, "data: ", DUMP_PREFIX_OFFSET, 16, 1,
                       skb->data, 16, true);
#endif

        len = skb->len;
        spin_lock_irqsave(&bp->lock, flags);

        /* This is a hard error, log it. */
        if (CIRC_SPACE(bp->tx_head, bp->tx_tail, TX_RING_SIZE) < 1) {
                netif_stop_queue(dev);
                spin_unlock_irqrestore(&bp->lock, flags);
                netdev_err(bp->dev, "BUG! Tx Ring full when queue awake!\n");
                netdev_dbg(bp->dev, "tx_head = %u, tx_tail = %u\n",
                           bp->tx_head, bp->tx_tail);
                return NETDEV_TX_BUSY;
        }

        entry = macb_tx_ring_wrap(bp->tx_head);
        bp->tx_head++;
        netdev_vdbg(bp->dev, "Allocated ring entry %u\n", entry);
        mapping = dma_map_single(&bp->pdev->dev, skb->data,
                                 len, DMA_TO_DEVICE);

        tx_skb = &bp->tx_skb[entry];
        tx_skb->skb = skb;

        tx_skb->mapping = mapping;
        netdev_vdbg(bp->dev, "Mapped skb data %p to DMA addr %08lx\n",
                   skb->data, (unsigned long)mapping);

        ctrl = MACB_BF(TX_FRMLEN, len);
        ctrl |= MACB_BIT(TX_LAST);
        if (entry == (TX_RING_SIZE - 1))
                ctrl |= MACB_BIT(TX_WRAP);

        desc = &bp->tx_ring[entry];
        desc->addr = mapping;
        desc->ctrl = ctrl;

        /* Make newly initialized descriptor visible to hardware */
        wmb();

        skb_tx_timestamp(skb);

        macb_writel(bp, NCR, macb_readl(bp, NCR) | MACB_BIT(TSTART));

        if (CIRC_SPACE(bp->tx_head, bp->tx_tail, TX_RING_SIZE) < 1)
                netif_stop_queue(dev);

        spin_unlock_irqrestore(&bp->lock, flags);

        return NETDEV_TX_OK;
}

static void macb_init_rx_buffer_size(struct macb *bp, size_t size)
{
        if (!macb_is_gem(bp)) {
                bp->rx_buffer_size = MACB_RX_BUFFER_SIZE;
        } else {
                bp->rx_buffer_size = size;

                if (bp->rx_buffer_size % RX_BUFFER_MULTIPLE) {
                        netdev_dbg(bp->dev,
                                    "RX buffer must be multiple of %d bytes, expanding\n",
                                    RX_BUFFER_MULTIPLE);
                        bp->rx_buffer_size =
                                roundup(bp->rx_buffer_size, RX_BUFFER_MULTIPLE);
                }
        }

        netdev_dbg(bp->dev, "mtu [%u] rx_buffer_size [%Zu]\n",
                   bp->dev->mtu, bp->rx_buffer_size);
}

static void gem_free_rx_buffers(struct macb *bp)
{
        struct sk_buff          *skb;
        struct macb_dma_desc    *desc;
        dma_addr_t              addr;
        int i;

        if (!bp->rx_skbuff)
                return;

        for (i = 0; i < RX_RING_SIZE; i++) {
                skb = bp->rx_skbuff[i];

                if (skb == NULL)
                        continue;

                desc = &bp->rx_ring[i];
                addr = MACB_BF(RX_WADDR, MACB_BFEXT(RX_WADDR, desc->addr));
                dma_unmap_single(&bp->pdev->dev, addr, skb->len,
                                 DMA_FROM_DEVICE);
                dev_kfree_skb_any(skb);
                skb = NULL;
        }

        kfree(bp->rx_skbuff);
        bp->rx_skbuff = NULL;
}

static void macb_free_rx_buffers(struct macb *bp)
{
        if (bp->rx_buffers) {
                dma_free_coherent(&bp->pdev->dev,
                                  RX_RING_SIZE * bp->rx_buffer_size,
                                  bp->rx_buffers, bp->rx_buffers_dma);
                bp->rx_buffers = NULL;
        }
}

static void macb_free_consistent(struct macb *bp)
{
        if (bp->tx_skb) {
                kfree(bp->tx_skb);
                bp->tx_skb = NULL;
        }
        bp->macbgem_ops.mog_free_rx_buffers(bp);
        if (bp->rx_ring) {
                dma_free_coherent(&bp->pdev->dev, RX_RING_BYTES,
                                  bp->rx_ring, bp->rx_ring_dma);
                bp->rx_ring = NULL;
        }
        if (bp->tx_ring) {
                dma_free_coherent(&bp->pdev->dev, TX_RING_BYTES,
                                  bp->tx_ring, bp->tx_ring_dma);
                bp->tx_ring = NULL;
        }
}

static int gem_alloc_rx_buffers(struct macb *bp)
{
        int size;

        size = RX_RING_SIZE * sizeof(struct sk_buff *);
        bp->rx_skbuff = kzalloc(size, GFP_KERNEL);
        if (!bp->rx_skbuff)
                return -ENOMEM;
        else
                netdev_dbg(bp->dev,
                           "Allocated %d RX struct sk_buff entries at %p\n",
                           RX_RING_SIZE, bp->rx_skbuff);
        return 0;
}

static int macb_alloc_rx_buffers(struct macb *bp)
{
        int size;

        size = RX_RING_SIZE * bp->rx_buffer_size;
        bp->rx_buffers = dma_alloc_coherent(&bp->pdev->dev, size,
                                            &bp->rx_buffers_dma, GFP_KERNEL);
        if (!bp->rx_buffers)
                return -ENOMEM;
        else
                netdev_dbg(bp->dev,
                           "Allocated RX buffers of %d bytes at %08lx (mapped %p)\n",
                           size, (unsigned long)bp->rx_buffers_dma, bp->rx_buffers);
        return 0;
}

static int macb_alloc_consistent(struct macb *bp)
{
        int size;

        size = TX_RING_SIZE * sizeof(struct macb_tx_skb);
        bp->tx_skb = kmalloc(size, GFP_KERNEL);
        if (!bp->tx_skb)
                goto out_err;

        size = RX_RING_BYTES;
        bp->rx_ring = dma_alloc_coherent(&bp->pdev->dev, size,
                                         &bp->rx_ring_dma, GFP_KERNEL);
        if (!bp->rx_ring)
                goto out_err;
        netdev_dbg(bp->dev,
                   "Allocated RX ring of %d bytes at %08lx (mapped %p)\n",
                   size, (unsigned long)bp->rx_ring_dma, bp->rx_ring);

        size = TX_RING_BYTES;
        bp->tx_ring = dma_alloc_coherent(&bp->pdev->dev, size,
                                         &bp->tx_ring_dma, GFP_KERNEL);
        if (!bp->tx_ring)
                goto out_err;
        netdev_dbg(bp->dev,
                   "Allocated TX ring of %d bytes at %08lx (mapped %p)\n",
                   size, (unsigned long)bp->tx_ring_dma, bp->tx_ring);

        if (bp->macbgem_ops.mog_alloc_rx_buffers(bp))
                goto out_err;

        return 0;

out_err:
        macb_free_consistent(bp);
        return -ENOMEM;
}

static void gem_init_rings(struct macb *bp)
{
        int i;

        for (i = 0; i < TX_RING_SIZE; i++) {
                bp->tx_ring[i].addr = 0;
                bp->tx_ring[i].ctrl = MACB_BIT(TX_USED);
        }
        bp->tx_ring[TX_RING_SIZE - 1].ctrl |= MACB_BIT(TX_WRAP);

        bp->rx_tail = bp->rx_prepared_head = bp->tx_head = bp->tx_tail = 0;

        gem_rx_refill(bp);
}

static void macb_init_rings(struct macb *bp)
{
        int i;
        dma_addr_t addr;

        addr = bp->rx_buffers_dma;
        for (i = 0; i < RX_RING_SIZE; i++) {
                bp->rx_ring[i].addr = addr;
                bp->rx_ring[i].ctrl = 0;
                addr += bp->rx_buffer_size;
        }
        bp->rx_ring[RX_RING_SIZE - 1].addr |= MACB_BIT(RX_WRAP);

        for (i = 0; i < TX_RING_SIZE; i++) {
                bp->tx_ring[i].addr = 0;
                bp->tx_ring[i].ctrl = MACB_BIT(TX_USED);
        }
        bp->tx_ring[TX_RING_SIZE - 1].ctrl |= MACB_BIT(TX_WRAP);

        bp->rx_tail = bp->tx_head = bp->tx_tail = 0;
}

static void macb_reset_hw(struct macb *bp)
{
        /*
         * Disable RX and TX (XXX: Should we halt the transmission
         * more gracefully?)
         */
        macb_writel(bp, NCR, 0);

        /* Clear the stats registers (XXX: Update stats first?) */
        macb_writel(bp, NCR, MACB_BIT(CLRSTAT));

        /* Clear all status flags */
        macb_writel(bp, TSR, -1);
        macb_writel(bp, RSR, -1);

        /* Disable all interrupts */
        macb_writel(bp, IDR, -1);
        macb_readl(bp, ISR);
}

static u32 gem_mdc_clk_div(struct macb *bp)
{
        u32 config;
        unsigned long pclk_hz = clk_get_rate(bp->pclk);

        if (pclk_hz <= 20000000)
                config = GEM_BF(CLK, GEM_CLK_DIV8);
        else if (pclk_hz <= 40000000)
                config = GEM_BF(CLK, GEM_CLK_DIV16);
        else if (pclk_hz <= 80000000)
                config = GEM_BF(CLK, GEM_CLK_DIV32);
        else if (pclk_hz <= 120000000)
                config = GEM_BF(CLK, GEM_CLK_DIV48);
        else if (pclk_hz <= 160000000)
                config = GEM_BF(CLK, GEM_CLK_DIV64);
        else
                config = GEM_BF(CLK, GEM_CLK_DIV96);

        return config;
}

static u32 macb_mdc_clk_div(struct macb *bp)
{
        u32 config;
        unsigned long pclk_hz;

        if (macb_is_gem(bp))
                return gem_mdc_clk_div(bp);

        pclk_hz = clk_get_rate(bp->pclk);
        if (pclk_hz <= 20000000)
                config = MACB_BF(CLK, MACB_CLK_DIV8);
        else if (pclk_hz <= 40000000)
                config = MACB_BF(CLK, MACB_CLK_DIV16);
        else if (pclk_hz <= 80000000)
                config = MACB_BF(CLK, MACB_CLK_DIV32);
        else
                config = MACB_BF(CLK, MACB_CLK_DIV64);

        return config;
}

/*
 * Get the DMA bus width field of the network configuration register that we
 * should program.  We find the width from decoding the design configuration
 * register to find the maximum supported data bus width.
 */
static u32 macb_dbw(struct macb *bp)
{
        if (!macb_is_gem(bp))
                return 0;

        switch (GEM_BFEXT(DBWDEF, gem_readl(bp, DCFG1))) {
        case 4:
                return GEM_BF(DBW, GEM_DBW128);
        case 2:
                return GEM_BF(DBW, GEM_DBW64);
        case 1:
        default:
                return GEM_BF(DBW, GEM_DBW32);
        }
}

/*
 * Configure the receive DMA engine
 * - use the correct receive buffer size
 * - set the possibility to use INCR16 bursts
 *   (if not supported by FIFO, it will fallback to default)
 * - set both rx/tx packet buffers to full memory size
 * These are configurable parameters for GEM.
 */
static void macb_configure_dma(struct macb *bp)
{
        u32 dmacfg;

        if (macb_is_gem(bp)) {
                dmacfg = gem_readl(bp, DMACFG) & ~GEM_BF(RXBS, -1L);
                dmacfg |= GEM_BF(RXBS, bp->rx_buffer_size / RX_BUFFER_MULTIPLE);
                dmacfg |= GEM_BF(FBLDO, 16);
                dmacfg |= GEM_BIT(TXPBMS) | GEM_BF(RXBMS, -1L);
                dmacfg &= ~GEM_BIT(ENDIA);
                gem_writel(bp, DMACFG, dmacfg);
        }
}

/*
 * Configure peripheral capacities according to integration options used
 */
static void macb_configure_caps(struct macb *bp)
{
        if (macb_is_gem(bp)) {
                if (GEM_BFEXT(IRQCOR, gem_readl(bp, DCFG1)) == 0)
                        bp->caps |= MACB_CAPS_ISR_CLEAR_ON_WRITE;
        }
}

static void macb_init_hw(struct macb *bp)
{
        u32 config;

        macb_reset_hw(bp);
        macb_set_hwaddr(bp);

        config = macb_mdc_clk_div(bp);
        config |= MACB_BF(RBOF, NET_IP_ALIGN);  /* Make eth data aligned */
        config |= MACB_BIT(PAE);                /* PAuse Enable */
        config |= MACB_BIT(DRFCS);              /* Discard Rx FCS */
        config |= MACB_BIT(BIG);                /* Receive oversized frames */
        if (bp->dev->flags & IFF_PROMISC)
                config |= MACB_BIT(CAF);        /* Copy All Frames */
        if (!(bp->dev->flags & IFF_BROADCAST))
                config |= MACB_BIT(NBC);        /* No BroadCast */
        config |= macb_dbw(bp);
        macb_writel(bp, NCFGR, config);
        bp->speed = SPEED_10;
        bp->duplex = DUPLEX_HALF;

        macb_configure_dma(bp);
        macb_configure_caps(bp);

        /* Initialize TX and RX buffers */
        macb_writel(bp, RBQP, bp->rx_ring_dma);
        macb_writel(bp, TBQP, bp->tx_ring_dma);

        /* Enable TX and RX */
        macb_writel(bp, NCR, MACB_BIT(RE) | MACB_BIT(TE) | MACB_BIT(MPE));

        /* Enable interrupts */
        macb_writel(bp, IER, (MACB_RX_INT_FLAGS
                              | MACB_TX_INT_FLAGS
                              | MACB_BIT(HRESP)));

}

/*
 * The hash address register is 64 bits long and takes up two
 * locations in the memory map.  The least significant bits are stored
 * in EMAC_HSL and the most significant bits in EMAC_HSH.
 *
 * The unicast hash enable and the multicast hash enable bits in the
 * network configuration register enable the reception of hash matched
 * frames. The destination address is reduced to a 6 bit index into
 * the 64 bit hash register using the following hash function.  The
 * hash function is an exclusive or of every sixth bit of the
 * destination address.
 *
 * hi[5] = da[5] ^ da[11] ^ da[17] ^ da[23] ^ da[29] ^ da[35] ^ da[41] ^ da[47]
 * hi[4] = da[4] ^ da[10] ^ da[16] ^ da[22] ^ da[28] ^ da[34] ^ da[40] ^ da[46]
 * hi[3] = da[3] ^ da[09] ^ da[15] ^ da[21] ^ da[27] ^ da[33] ^ da[39] ^ da[45]
 * hi[2] = da[2] ^ da[08] ^ da[14] ^ da[20] ^ da[26] ^ da[32] ^ da[38] ^ da[44]
 * hi[1] = da[1] ^ da[07] ^ da[13] ^ da[19] ^ da[25] ^ da[31] ^ da[37] ^ da[43]
 * hi[0] = da[0] ^ da[06] ^ da[12] ^ da[18] ^ da[24] ^ da[30] ^ da[36] ^ da[42]
 *
 * da[0] represents the least significant bit of the first byte
 * received, that is, the multicast/unicast indicator, and da[47]
 * represents the most significant bit of the last byte received.  If
 * the hash index, hi[n], points to a bit that is set in the hash
 * register then the frame will be matched according to whether the
 * frame is multicast or unicast.  A multicast match will be signalled
 * if the multicast hash enable bit is set, da[0] is 1 and the hash
 * index points to a bit set in the hash register.  A unicast match
 * will be signalled if the unicast hash enable bit is set, da[0] is 0
 * and the hash index points to a bit set in the hash register.  To
 * receive all multicast frames, the hash register should be set with
 * all ones and the multicast hash enable bit should be set in the
 * network configuration register.
 */

static inline int hash_bit_value(int bitnr, __u8 *addr)
{
        if (addr[bitnr / 8] & (1 << (bitnr % 8)))
                return 1;
        return 0;
}

/*
 * Return the hash index value for the specified address.
 */
static int hash_get_index(__u8 *addr)
{
        int i, j, bitval;
        int hash_index = 0;

        for (j = 0; j < 6; j++) {
                for (i = 0, bitval = 0; i < 8; i++)
                        bitval ^= hash_bit_value(i*6 + j, addr);

                hash_index |= (bitval << j);
        }

        return hash_index;
}

/*
 * Add multicast addresses to the internal multicast-hash table.
 */
static void macb_sethashtable(struct net_device *dev)
{
        struct netdev_hw_addr *ha;
        unsigned long mc_filter[2];
        unsigned int bitnr;
        struct macb *bp = netdev_priv(dev);

        mc_filter[0] = mc_filter[1] = 0;

        netdev_for_each_mc_addr(ha, dev) {
                bitnr = hash_get_index(ha->addr);
                mc_filter[bitnr >> 5] |= 1 << (bitnr & 31);
        }

        macb_or_gem_writel(bp, HRB, mc_filter[0]);
        macb_or_gem_writel(bp, HRT, mc_filter[1]);
}

/*
 * Enable/Disable promiscuous and multicast modes.
 */
void macb_set_rx_mode(struct net_device *dev)
{
        unsigned long cfg;
        struct macb *bp = netdev_priv(dev);

        cfg = macb_readl(bp, NCFGR);

        if (dev->flags & IFF_PROMISC)
                /* Enable promiscuous mode */
                cfg |= MACB_BIT(CAF);
        else if (dev->flags & (~IFF_PROMISC))
                 /* Disable promiscuous mode */
                cfg &= ~MACB_BIT(CAF);

        if (dev->flags & IFF_ALLMULTI) {
                /* Enable all multicast mode */
                macb_or_gem_writel(bp, HRB, -1);
                macb_or_gem_writel(bp, HRT, -1);
                cfg |= MACB_BIT(NCFGR_MTI);
        } else if (!netdev_mc_empty(dev)) {
                /* Enable specific multicasts */
                macb_sethashtable(dev);
                cfg |= MACB_BIT(NCFGR_MTI);
        } else if (dev->flags & (~IFF_ALLMULTI)) {
                /* Disable all multicast mode */
                macb_or_gem_writel(bp, HRB, 0);
                macb_or_gem_writel(bp, HRT, 0);
                cfg &= ~MACB_BIT(NCFGR_MTI);
        }

        macb_writel(bp, NCFGR, cfg);
}
EXPORT_SYMBOL_GPL(macb_set_rx_mode);

static int macb_open(struct net_device *dev)
{
        struct macb *bp = netdev_priv(dev);
        size_t bufsz = dev->mtu + ETH_HLEN + ETH_FCS_LEN + NET_IP_ALIGN;
        int err;

        netdev_dbg(bp->dev, "open\n");

        /* carrier starts down */
        netif_carrier_off(dev);

        /* if the phy is not yet register, retry later*/
        if (!bp->phy_dev)
                return -EAGAIN;

        /* RX buffers initialization */
        macb_init_rx_buffer_size(bp, bufsz);

        err = macb_alloc_consistent(bp);
        if (err) {
                netdev_err(dev, "Unable to allocate DMA memory (error %d)\n",
                           err);
                return err;
        }

        napi_enable(&bp->napi);

        bp->macbgem_ops.mog_init_rings(bp);
        macb_init_hw(bp);

        /* schedule a link state check */
        phy_start(bp->phy_dev);

        netif_start_queue(dev);

        return 0;
}

static int macb_close(struct net_device *dev)
{
        struct macb *bp = netdev_priv(dev);
        unsigned long flags;

        netif_stop_queue(dev);
        napi_disable(&bp->napi);

        if (bp->phy_dev)
                phy_stop(bp->phy_dev);

        spin_lock_irqsave(&bp->lock, flags);
        macb_reset_hw(bp);
        netif_carrier_off(dev);
        spin_unlock_irqrestore(&bp->lock, flags);

        macb_free_consistent(bp);

        return 0;
}

static void gem_update_stats(struct macb *bp)
{
        u32 __iomem *reg = bp->regs + GEM_OTX;
        u32 *p = &bp->hw_stats.gem.tx_octets_31_0;
        u32 *end = &bp->hw_stats.gem.rx_udp_checksum_errors + 1;

        for (; p < end; p++, reg++)
                *p += __raw_readl(reg);
}

static struct net_device_stats *gem_get_stats(struct macb *bp)
{
        struct gem_stats *hwstat = &bp->hw_stats.gem;
        struct net_device_stats *nstat = &bp->stats;

        gem_update_stats(bp);

        nstat->rx_errors = (hwstat->rx_frame_check_sequence_errors +
                            hwstat->rx_alignment_errors +
                            hwstat->rx_resource_errors +
                            hwstat->rx_overruns +
                            hwstat->rx_oversize_frames +
                            hwstat->rx_jabbers +
                            hwstat->rx_undersized_frames +
                            hwstat->rx_length_field_frame_errors);
        nstat->tx_errors = (hwstat->tx_late_collisions +
                            hwstat->tx_excessive_collisions +
                            hwstat->tx_underrun +
                            hwstat->tx_carrier_sense_errors);
        nstat->multicast = hwstat->rx_multicast_frames;
        nstat->collisions = (hwstat->tx_single_collision_frames +
                             hwstat->tx_multiple_collision_frames +
                             hwstat->tx_excessive_collisions);
        nstat->rx_length_errors = (hwstat->rx_oversize_frames +
                                   hwstat->rx_jabbers +
                                   hwstat->rx_undersized_frames +
                                   hwstat->rx_length_field_frame_errors);
        nstat->rx_over_errors = hwstat->rx_resource_errors;
        nstat->rx_crc_errors = hwstat->rx_frame_check_sequence_errors;
        nstat->rx_frame_errors = hwstat->rx_alignment_errors;
        nstat->rx_fifo_errors = hwstat->rx_overruns;
        nstat->tx_aborted_errors = hwstat->tx_excessive_collisions;
        nstat->tx_carrier_errors = hwstat->tx_carrier_sense_errors;
        nstat->tx_fifo_errors = hwstat->tx_underrun;

        return nstat;
}

struct net_device_stats *macb_get_stats(struct net_device *dev)
{
        struct macb *bp = netdev_priv(dev);
        struct net_device_stats *nstat = &bp->stats;
        struct macb_stats *hwstat = &bp->hw_stats.macb;

        if (macb_is_gem(bp))
                return gem_get_stats(bp);

        /* read stats from hardware */
        macb_update_stats(bp);

        /* Convert HW stats into netdevice stats */
        nstat->rx_errors = (hwstat->rx_fcs_errors +
                            hwstat->rx_align_errors +
                            hwstat->rx_resource_errors +
                            hwstat->rx_overruns +
                            hwstat->rx_oversize_pkts +
                            hwstat->rx_jabbers +
                            hwstat->rx_undersize_pkts +
                            hwstat->sqe_test_errors +
                            hwstat->rx_length_mismatch);
        nstat->tx_errors = (hwstat->tx_late_cols +
                            hwstat->tx_excessive_cols +
                            hwstat->tx_underruns +
                            hwstat->tx_carrier_errors);
        nstat->collisions = (hwstat->tx_single_cols +
                             hwstat->tx_multiple_cols +
                             hwstat->tx_excessive_cols);
        nstat->rx_length_errors = (hwstat->rx_oversize_pkts +
                                   hwstat->rx_jabbers +
                                   hwstat->rx_undersize_pkts +
                                   hwstat->rx_length_mismatch);
        nstat->rx_over_errors = hwstat->rx_resource_errors +
                                   hwstat->rx_overruns;
        nstat->rx_crc_errors = hwstat->rx_fcs_errors;
        nstat->rx_frame_errors = hwstat->rx_align_errors;
        nstat->rx_fifo_errors = hwstat->rx_overruns;
        /* XXX: What does "missed" mean? */
        nstat->tx_aborted_errors = hwstat->tx_excessive_cols;
        nstat->tx_carrier_errors = hwstat->tx_carrier_errors;
        nstat->tx_fifo_errors = hwstat->tx_underruns;
        /* Don't know about heartbeat or window errors... */

        return nstat;
}
EXPORT_SYMBOL_GPL(macb_get_stats);

static int macb_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
{
        struct macb *bp = netdev_priv(dev);
        struct phy_device *phydev = bp->phy_dev;

        if (!phydev)
                return -ENODEV;

        return phy_ethtool_gset(phydev, cmd);
}

static int macb_set_settings(struct net_device *dev, struct ethtool_cmd *cmd)
{
        struct macb *bp = netdev_priv(dev);
        struct phy_device *phydev = bp->phy_dev;

        if (!phydev)
                return -ENODEV;

        return phy_ethtool_sset(phydev, cmd);
}

static int macb_get_regs_len(struct net_device *netdev)
{
        return MACB_GREGS_NBR * sizeof(u32);
}

static void macb_get_regs(struct net_device *dev, struct ethtool_regs *regs,
                          void *p)
{
        struct macb *bp = netdev_priv(dev);
        unsigned int tail, head;
        u32 *regs_buff = p;

        regs->version = (macb_readl(bp, MID) & ((1 << MACB_REV_SIZE) - 1))
                        | MACB_GREGS_VERSION;

        tail = macb_tx_ring_wrap(bp->tx_tail);
        head = macb_tx_ring_wrap(bp->tx_head);

        regs_buff[0]  = macb_readl(bp, NCR);
        regs_buff[1]  = macb_or_gem_readl(bp, NCFGR);
        regs_buff[2]  = macb_readl(bp, NSR);
        regs_buff[3]  = macb_readl(bp, TSR);
        regs_buff[4]  = macb_readl(bp, RBQP);
        regs_buff[5]  = macb_readl(bp, TBQP);
        regs_buff[6]  = macb_readl(bp, RSR);
        regs_buff[7]  = macb_readl(bp, IMR);

        regs_buff[8]  = tail;
        regs_buff[9]  = head;
        regs_buff[10] = macb_tx_dma(bp, tail);
        regs_buff[11] = macb_tx_dma(bp, head);

        if (macb_is_gem(bp)) {
                regs_buff[12] = gem_readl(bp, USRIO);
                regs_buff[13] = gem_readl(bp, DMACFG);
        }
}

const struct ethtool_ops macb_ethtool_ops = {
        .get_settings           = macb_get_settings,
        .set_settings           = macb_set_settings,
        .get_regs_len           = macb_get_regs_len,
        .get_regs               = macb_get_regs,
        .get_link               = ethtool_op_get_link,
        .get_ts_info            = ethtool_op_get_ts_info,
};
EXPORT_SYMBOL_GPL(macb_ethtool_ops);

int macb_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
{
        struct macb *bp = netdev_priv(dev);
        struct phy_device *phydev = bp->phy_dev;

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

        if (!phydev)
                return -ENODEV;

        return phy_mii_ioctl(phydev, rq, cmd);
}
EXPORT_SYMBOL_GPL(macb_ioctl);

static const struct net_device_ops macb_netdev_ops = {
        .ndo_open               = macb_open,
        .ndo_stop               = macb_close,
        .ndo_start_xmit         = macb_start_xmit,
        .ndo_set_rx_mode        = macb_set_rx_mode,
        .ndo_get_stats          = macb_get_stats,
        .ndo_do_ioctl           = macb_ioctl,
        .ndo_validate_addr      = eth_validate_addr,
        .ndo_change_mtu         = eth_change_mtu,
        .ndo_set_mac_address    = eth_mac_addr,
#ifdef CONFIG_NET_POLL_CONTROLLER
        .ndo_poll_controller    = macb_poll_controller,
#endif
};

#if defined(CONFIG_OF)
static const struct of_device_id macb_dt_ids[] = {
        { .compatible = "cdns,at32ap7000-macb" },
        { .compatible = "cdns,at91sam9260-macb" },
        { .compatible = "cdns,macb" },
        { .compatible = "cdns,pc302-gem" },
        { .compatible = "cdns,gem" },
        { /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, macb_dt_ids);
#endif

static int __init macb_probe(struct platform_device *pdev)
{
        struct macb_platform_data *pdata;
        struct resource *regs;
        struct net_device *dev;
        struct macb *bp;
        struct phy_device *phydev;
        u32 config;
        int err = -ENXIO;
        struct pinctrl *pinctrl;
        const char *mac;

        regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (!regs) {
                dev_err(&pdev->dev, "no mmio resource defined\n");
                goto err_out;
        }

        pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
        if (IS_ERR(pinctrl)) {
                err = PTR_ERR(pinctrl);
                if (err == -EPROBE_DEFER)
                        goto err_out;

                dev_warn(&pdev->dev, "No pinctrl provided\n");
        }

        err = -ENOMEM;
        dev = alloc_etherdev(sizeof(*bp));
        if (!dev)
                goto err_out;

        SET_NETDEV_DEV(dev, &pdev->dev);

        /* TODO: Actually, we have some interesting features... */
        dev->features |= 0;

        bp = netdev_priv(dev);
        bp->pdev = pdev;
        bp->dev = dev;

        spin_lock_init(&bp->lock);
        INIT_WORK(&bp->tx_error_task, macb_tx_error_task);

        bp->pclk = clk_get(&pdev->dev, "pclk");
        if (IS_ERR(bp->pclk)) {
                dev_err(&pdev->dev, "failed to get macb_clk\n");
                goto err_out_free_dev;
        }
        clk_prepare_enable(bp->pclk);

        bp->hclk = clk_get(&pdev->dev, "hclk");
        if (IS_ERR(bp->hclk)) {
                dev_err(&pdev->dev, "failed to get hclk\n");
                goto err_out_put_pclk;
        }
        clk_prepare_enable(bp->hclk);

        bp->regs = ioremap(regs->start, resource_size(regs));
        if (!bp->regs) {
                dev_err(&pdev->dev, "failed to map registers, aborting.\n");
                err = -ENOMEM;
                goto err_out_disable_clocks;
        }

        dev->irq = platform_get_irq(pdev, 0);
        err = request_irq(dev->irq, macb_interrupt, 0, dev->name, dev);
        if (err) {
                dev_err(&pdev->dev, "Unable to request IRQ %d (error %d)\n",
                        dev->irq, err);
                goto err_out_iounmap;
        }

        dev->netdev_ops = &macb_netdev_ops;
        netif_napi_add(dev, &bp->napi, macb_poll, 64);
        dev->ethtool_ops = &macb_ethtool_ops;

        dev->base_addr = regs->start;

        /* setup appropriated routines according to adapter type */
        if (macb_is_gem(bp)) {
                bp->macbgem_ops.mog_alloc_rx_buffers = gem_alloc_rx_buffers;
                bp->macbgem_ops.mog_free_rx_buffers = gem_free_rx_buffers;
                bp->macbgem_ops.mog_init_rings = gem_init_rings;
                bp->macbgem_ops.mog_rx = gem_rx;
        } else {
                bp->macbgem_ops.mog_alloc_rx_buffers = macb_alloc_rx_buffers;
                bp->macbgem_ops.mog_free_rx_buffers = macb_free_rx_buffers;
                bp->macbgem_ops.mog_init_rings = macb_init_rings;
                bp->macbgem_ops.mog_rx = macb_rx;
        }

        /* Set MII management clock divider */
        config = macb_mdc_clk_div(bp);
        config |= macb_dbw(bp);
        macb_writel(bp, NCFGR, config);

        mac = of_get_mac_address(pdev->dev.of_node);
        if (mac)
                memcpy(bp->dev->dev_addr, mac, ETH_ALEN);
        else
                macb_get_hwaddr(bp);

        err = of_get_phy_mode(pdev->dev.of_node);
        if (err < 0) {
                pdata = dev_get_platdata(&pdev->dev);
                if (pdata && pdata->is_rmii)
                        bp->phy_interface = PHY_INTERFACE_MODE_RMII;
                else
                        bp->phy_interface = PHY_INTERFACE_MODE_MII;
        } else {
                bp->phy_interface = err;
        }

        if (bp->phy_interface == PHY_INTERFACE_MODE_RGMII)
                macb_or_gem_writel(bp, USRIO, GEM_BIT(RGMII));
        else if (bp->phy_interface == PHY_INTERFACE_MODE_RMII)
#if defined(CONFIG_ARCH_AT91)
                macb_or_gem_writel(bp, USRIO, (MACB_BIT(RMII) |
                                               MACB_BIT(CLKEN)));
#else
                macb_or_gem_writel(bp, USRIO, 0);
#endif
        else
#if defined(CONFIG_ARCH_AT91)
                macb_or_gem_writel(bp, USRIO, MACB_BIT(CLKEN));
#else
                macb_or_gem_writel(bp, USRIO, MACB_BIT(MII));
#endif

        err = register_netdev(dev);
        if (err) {
                dev_err(&pdev->dev, "Cannot register net device, aborting.\n");
                goto err_out_free_irq;
        }

        err = macb_mii_init(bp);
        if (err)
                goto err_out_unregister_netdev;

        platform_set_drvdata(pdev, dev);

        netif_carrier_off(dev);

        netdev_info(dev, "Cadence %s at 0x%08lx irq %d (%pM)\n",
                    macb_is_gem(bp) ? "GEM" : "MACB", dev->base_addr,
                    dev->irq, dev->dev_addr);

        phydev = bp->phy_dev;
        netdev_info(dev, "attached PHY driver [%s] (mii_bus:phy_addr=%s, irq=%d)\n",
                    phydev->drv->name, dev_name(&phydev->dev), phydev->irq);

        return 0;

err_out_unregister_netdev:
        unregister_netdev(dev);
err_out_free_irq:
        free_irq(dev->irq, dev);
err_out_iounmap:
        iounmap(bp->regs);
err_out_disable_clocks:
        clk_disable_unprepare(bp->hclk);
        clk_put(bp->hclk);
        clk_disable_unprepare(bp->pclk);
err_out_put_pclk:
        clk_put(bp->pclk);
err_out_free_dev:
        free_netdev(dev);
err_out:
        return err;
}

static int __exit macb_remove(struct platform_device *pdev)
{
        struct net_device *dev;
        struct macb *bp;

        dev = platform_get_drvdata(pdev);

        if (dev) {
                bp = netdev_priv(dev);
                if (bp->phy_dev)
                        phy_disconnect(bp->phy_dev);
                mdiobus_unregister(bp->mii_bus);
                kfree(bp->mii_bus->irq);
                mdiobus_free(bp->mii_bus);
                unregister_netdev(dev);
                free_irq(dev->irq, dev);
                iounmap(bp->regs);
                clk_disable_unprepare(bp->hclk);
                clk_put(bp->hclk);
                clk_disable_unprepare(bp->pclk);
                clk_put(bp->pclk);
                free_netdev(dev);
        }

        return 0;
}

#ifdef CONFIG_PM
static int macb_suspend(struct platform_device *pdev, pm_message_t state)
{
        struct net_device *netdev = platform_get_drvdata(pdev);
        struct macb *bp = netdev_priv(netdev);

        netif_carrier_off(netdev);
        netif_device_detach(netdev);

        clk_disable_unprepare(bp->hclk);
        clk_disable_unprepare(bp->pclk);

        return 0;
}

static int macb_resume(struct platform_device *pdev)
{
        struct net_device *netdev = platform_get_drvdata(pdev);
        struct macb *bp = netdev_priv(netdev);

        clk_prepare_enable(bp->pclk);
        clk_prepare_enable(bp->hclk);

        netif_device_attach(netdev);

        return 0;
}
#else
#define macb_suspend    NULL
#define macb_resume     NULL
#endif

static struct platform_driver macb_driver = {
        .remove         = __exit_p(macb_remove),
        .suspend        = macb_suspend,
        .resume         = macb_resume,
        .driver         = {
                .name           = "macb",
                .owner  = THIS_MODULE,
                .of_match_table = of_match_ptr(macb_dt_ids),
        },
};

module_platform_driver_probe(macb_driver, macb_probe);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Cadence MACB/GEM Ethernet driver");
MODULE_AUTHOR("Haavard Skinnemoen (Atmel)");
MODULE_ALIAS("platform:macb");