Linux 2.6.34-rc3

[pohmelfs.git] / drivers / net / arm / ks8695net.c

/*
 * Micrel KS8695 (Centaur) Ethernet.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * Copyright 2008 Simtec Electronics
 *                Daniel Silverstone <dsilvers@simtec.co.uk>
 *                Vincent Sanders <vince@simtec.co.uk>
 */

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

#include <asm/irq.h>

#include <mach/regs-switch.h>
#include <mach/regs-misc.h>
#include <asm/mach/irq.h>
#include <mach/regs-irq.h>

#include "ks8695net.h"

#define MODULENAME      "ks8695_ether"
#define MODULEVERSION   "1.02"

/*
 * Transmit and device reset timeout, default 5 seconds.
 */
static int watchdog = 5000;

/* Hardware structures */

/**
 *      struct rx_ring_desc - Receive descriptor ring element
 *      @status: The status of the descriptor element (E.g. who owns it)
 *      @length: The number of bytes in the block pointed to by data_ptr
 *      @data_ptr: The physical address of the data block to receive into
 *      @next_desc: The physical address of the next descriptor element.
 */
struct rx_ring_desc {
        __le32  status;
        __le32  length;
        __le32  data_ptr;
        __le32  next_desc;
};

/**
 *      struct tx_ring_desc - Transmit descriptor ring element
 *      @owner: Who owns the descriptor
 *      @status: The number of bytes in the block pointed to by data_ptr
 *      @data_ptr: The physical address of the data block to receive into
 *      @next_desc: The physical address of the next descriptor element.
 */
struct tx_ring_desc {
        __le32  owner;
        __le32  status;
        __le32  data_ptr;
        __le32  next_desc;
};

/**
 *      struct ks8695_skbuff - sk_buff wrapper for rx/tx rings.
 *      @skb: The buffer in the ring
 *      @dma_ptr: The mapped DMA pointer of the buffer
 *      @length: The number of bytes mapped to dma_ptr
 */
struct ks8695_skbuff {
        struct sk_buff  *skb;
        dma_addr_t      dma_ptr;
        u32             length;
};

/* Private device structure */

#define MAX_TX_DESC 8
#define MAX_TX_DESC_MASK 0x7
#define MAX_RX_DESC 16
#define MAX_RX_DESC_MASK 0xf

/*napi_weight have better more than rx DMA buffers*/
#define NAPI_WEIGHT   64

#define MAX_RXBUF_SIZE 0x700

#define TX_RING_DMA_SIZE (sizeof(struct tx_ring_desc) * MAX_TX_DESC)
#define RX_RING_DMA_SIZE (sizeof(struct rx_ring_desc) * MAX_RX_DESC)
#define RING_DMA_SIZE (TX_RING_DMA_SIZE + RX_RING_DMA_SIZE)

/**
 *      enum ks8695_dtype - Device type
 *      @KS8695_DTYPE_WAN: This device is a WAN interface
 *      @KS8695_DTYPE_LAN: This device is a LAN interface
 *      @KS8695_DTYPE_HPNA: This device is an HPNA interface
 */
enum ks8695_dtype {
        KS8695_DTYPE_WAN,
        KS8695_DTYPE_LAN,
        KS8695_DTYPE_HPNA,
};

/**
 *      struct ks8695_priv - Private data for the KS8695 Ethernet
 *      @in_suspend: Flag to indicate if we're suspending/resuming
 *      @ndev: The net_device for this interface
 *      @dev: The platform device object for this interface
 *      @dtype: The type of this device
 *      @io_regs: The ioremapped registers for this interface
 *      @napi : Add support NAPI for Rx
 *      @rx_irq_name: The textual name of the RX IRQ from the platform data
 *      @tx_irq_name: The textual name of the TX IRQ from the platform data
 *      @link_irq_name: The textual name of the link IRQ from the
 *                      platform data if available
 *      @rx_irq: The IRQ number for the RX IRQ
 *      @tx_irq: The IRQ number for the TX IRQ
 *      @link_irq: The IRQ number for the link IRQ if available
 *      @regs_req: The resource request for the registers region
 *      @phyiface_req: The resource request for the phy/switch region
 *                     if available
 *      @phyiface_regs: The ioremapped registers for the phy/switch if available
 *      @ring_base: The base pointer of the dma coherent memory for the rings
 *      @ring_base_dma: The DMA mapped equivalent of ring_base
 *      @tx_ring: The pointer in ring_base of the TX ring
 *      @tx_ring_used: The number of slots in the TX ring which are occupied
 *      @tx_ring_next_slot: The next slot to fill in the TX ring
 *      @tx_ring_dma: The DMA mapped equivalent of tx_ring
 *      @tx_buffers: The sk_buff mappings for the TX ring
 *      @txq_lock: A lock to protect the tx_buffers tx_ring_used etc variables
 *      @rx_ring: The pointer in ring_base of the RX ring
 *      @rx_ring_dma: The DMA mapped equivalent of rx_ring
 *      @rx_buffers: The sk_buff mappings for the RX ring
 *      @next_rx_desc_read: The next RX descriptor to read from on IRQ
 *      @rx_lock: A lock to protect Rx irq function
 *      @msg_enable: The flags for which messages to emit
 */
struct ks8695_priv {
        int in_suspend;
        struct net_device *ndev;
        struct device *dev;
        enum ks8695_dtype dtype;
        void __iomem *io_regs;

        struct napi_struct      napi;

        const char *rx_irq_name, *tx_irq_name, *link_irq_name;
        int rx_irq, tx_irq, link_irq;

        struct resource *regs_req, *phyiface_req;
        void __iomem *phyiface_regs;

        void *ring_base;
        dma_addr_t ring_base_dma;

        struct tx_ring_desc *tx_ring;
        int tx_ring_used;
        int tx_ring_next_slot;
        dma_addr_t tx_ring_dma;
        struct ks8695_skbuff tx_buffers[MAX_TX_DESC];
        spinlock_t txq_lock;

        struct rx_ring_desc *rx_ring;
        dma_addr_t rx_ring_dma;
        struct ks8695_skbuff rx_buffers[MAX_RX_DESC];
        int next_rx_desc_read;
        spinlock_t rx_lock;

        int msg_enable;
};

/* Register access */

/**
 *      ks8695_readreg - Read from a KS8695 ethernet register
 *      @ksp: The device to read from
 *      @reg: The register to read
 */
static inline u32
ks8695_readreg(struct ks8695_priv *ksp, int reg)
{
        return readl(ksp->io_regs + reg);
}

/**
 *      ks8695_writereg - Write to a KS8695 ethernet register
 *      @ksp: The device to write to
 *      @reg: The register to write
 *      @value: The value to write to the register
 */
static inline void
ks8695_writereg(struct ks8695_priv *ksp, int reg, u32 value)
{
        writel(value, ksp->io_regs + reg);
}

/* Utility functions */

/**
 *      ks8695_port_type - Retrieve port-type as user-friendly string
 *      @ksp: The device to return the type for
 *
 *      Returns a string indicating which of the WAN, LAN or HPNA
 *      ports this device is likely to represent.
 */
static const char *
ks8695_port_type(struct ks8695_priv *ksp)
{
        switch (ksp->dtype) {
        case KS8695_DTYPE_LAN:
                return "LAN";
        case KS8695_DTYPE_WAN:
                return "WAN";
        case KS8695_DTYPE_HPNA:
                return "HPNA";
        }

        return "UNKNOWN";
}

/**
 *      ks8695_update_mac - Update the MAC registers in the device
 *      @ksp: The device to update
 *
 *      Updates the MAC registers in the KS8695 device from the address in the
 *      net_device structure associated with this interface.
 */
static void
ks8695_update_mac(struct ks8695_priv *ksp)
{
        /* Update the HW with the MAC from the net_device */
        struct net_device *ndev = ksp->ndev;
        u32 machigh, maclow;

        maclow  = ((ndev->dev_addr[2] << 24) | (ndev->dev_addr[3] << 16) |
                   (ndev->dev_addr[4] <<  8) | (ndev->dev_addr[5] <<  0));
        machigh = ((ndev->dev_addr[0] <<  8) | (ndev->dev_addr[1] <<  0));

        ks8695_writereg(ksp, KS8695_MAL, maclow);
        ks8695_writereg(ksp, KS8695_MAH, machigh);

}

/**
 *      ks8695_refill_rxbuffers - Re-fill the RX buffer ring
 *      @ksp: The device to refill
 *
 *      Iterates the RX ring of the device looking for empty slots.
 *      For each empty slot, we allocate and map a new SKB and give it
 *      to the hardware.
 *      This can be called from interrupt context safely.
 */
static void
ks8695_refill_rxbuffers(struct ks8695_priv *ksp)
{
        /* Run around the RX ring, filling in any missing sk_buff's */
        int buff_n;

        for (buff_n = 0; buff_n < MAX_RX_DESC; ++buff_n) {
                if (!ksp->rx_buffers[buff_n].skb) {
                        struct sk_buff *skb = dev_alloc_skb(MAX_RXBUF_SIZE);
                        dma_addr_t mapping;

                        ksp->rx_buffers[buff_n].skb = skb;
                        if (skb == NULL) {
                                /* Failed to allocate one, perhaps
                                 * we'll try again later.
                                 */
                                break;
                        }

                        mapping = dma_map_single(ksp->dev, skb->data,
                                                 MAX_RXBUF_SIZE,
                                                 DMA_FROM_DEVICE);
                        if (unlikely(dma_mapping_error(ksp->dev, mapping))) {
                                /* Failed to DMA map this SKB, try later */
                                dev_kfree_skb_irq(skb);
                                ksp->rx_buffers[buff_n].skb = NULL;
                                break;
                        }
                        ksp->rx_buffers[buff_n].dma_ptr = mapping;
                        skb->dev = ksp->ndev;
                        ksp->rx_buffers[buff_n].length = MAX_RXBUF_SIZE;

                        /* Record this into the DMA ring */
                        ksp->rx_ring[buff_n].data_ptr = cpu_to_le32(mapping);
                        ksp->rx_ring[buff_n].length =
                                cpu_to_le32(MAX_RXBUF_SIZE);

                        wmb();

                        /* And give ownership over to the hardware */
                        ksp->rx_ring[buff_n].status = cpu_to_le32(RDES_OWN);
                }
        }
}

/* Maximum number of multicast addresses which the KS8695 HW supports */
#define KS8695_NR_ADDRESSES     16

/**
 *      ks8695_init_partial_multicast - Init the mcast addr registers
 *      @ksp: The device to initialise
 *      @addr: The multicast address list to use
 *      @nr_addr: The number of addresses in the list
 *
 *      This routine is a helper for ks8695_set_multicast - it writes
 *      the additional-address registers in the KS8695 ethernet device
 *      and cleans up any others left behind.
 */
static void
ks8695_init_partial_multicast(struct ks8695_priv *ksp,
                              struct net_device *ndev)
{
        u32 low, high;
        int i;
        struct dev_mc_list *dmi;

        i = 0;
        netdev_for_each_mc_addr(dmi, ndev) {
                /* Ran out of space in chip? */
                BUG_ON(i == KS8695_NR_ADDRESSES);

                low = (dmi->dmi_addr[2] << 24) | (dmi->dmi_addr[3] << 16) |
                      (dmi->dmi_addr[4] << 8) | (dmi->dmi_addr[5]);
                high = (dmi->dmi_addr[0] << 8) | (dmi->dmi_addr[1]);

                ks8695_writereg(ksp, KS8695_AAL_(i), low);
                ks8695_writereg(ksp, KS8695_AAH_(i), AAH_E | high);
                i++;
        }

        /* Clear the remaining Additional Station Addresses */
        for (; i < KS8695_NR_ADDRESSES; i++) {
                ks8695_writereg(ksp, KS8695_AAL_(i), 0);
                ks8695_writereg(ksp, KS8695_AAH_(i), 0);
        }
}

/* Interrupt handling */

/**
 *      ks8695_tx_irq - Transmit IRQ handler
 *      @irq: The IRQ which went off (ignored)
 *      @dev_id: The net_device for the interrupt
 *
 *      Process the TX ring, clearing out any transmitted slots.
 *      Allows the net_device to pass us new packets once slots are
 *      freed.
 */
static irqreturn_t
ks8695_tx_irq(int irq, void *dev_id)
{
        struct net_device *ndev = (struct net_device *)dev_id;
        struct ks8695_priv *ksp = netdev_priv(ndev);
        int buff_n;

        for (buff_n = 0; buff_n < MAX_TX_DESC; ++buff_n) {
                if (ksp->tx_buffers[buff_n].skb &&
                    !(ksp->tx_ring[buff_n].owner & cpu_to_le32(TDES_OWN))) {
                        rmb();
                        /* An SKB which is not owned by HW is present */
                        /* Update the stats for the net_device */
                        ndev->stats.tx_packets++;
                        ndev->stats.tx_bytes += ksp->tx_buffers[buff_n].length;

                        /* Free the packet from the ring */
                        ksp->tx_ring[buff_n].data_ptr = 0;

                        /* Free the sk_buff */
                        dma_unmap_single(ksp->dev,
                                         ksp->tx_buffers[buff_n].dma_ptr,
                                         ksp->tx_buffers[buff_n].length,
                                         DMA_TO_DEVICE);
                        dev_kfree_skb_irq(ksp->tx_buffers[buff_n].skb);
                        ksp->tx_buffers[buff_n].skb = NULL;
                        ksp->tx_ring_used--;
                }
        }

        netif_wake_queue(ndev);

        return IRQ_HANDLED;
}

/**
 *      ks8695_get_rx_enable_bit - Get rx interrupt enable/status bit
 *      @ksp: Private data for the KS8695 Ethernet
 *
 *    For KS8695 document:
 *    Interrupt Enable Register (offset 0xE204)
 *        Bit29 : WAN MAC Receive Interrupt Enable
 *        Bit16 : LAN MAC Receive Interrupt Enable
 *    Interrupt Status Register (Offset 0xF208)
 *        Bit29: WAN MAC Receive Status
 *        Bit16: LAN MAC Receive Status
 *    So, this Rx interrrupt enable/status bit number is equal
 *    as Rx IRQ number.
 */
static inline u32 ks8695_get_rx_enable_bit(struct ks8695_priv *ksp)
{
        return ksp->rx_irq;
}

/**
 *      ks8695_rx_irq - Receive IRQ handler
 *      @irq: The IRQ which went off (ignored)
 *      @dev_id: The net_device for the interrupt
 *
 *      Inform NAPI that packet reception needs to be scheduled
 */

static irqreturn_t
ks8695_rx_irq(int irq, void *dev_id)
{
        struct net_device *ndev = (struct net_device *)dev_id;
        struct ks8695_priv *ksp = netdev_priv(ndev);

        spin_lock(&ksp->rx_lock);

        if (napi_schedule_prep(&ksp->napi)) {
                unsigned long status = readl(KS8695_IRQ_VA + KS8695_INTEN);
                unsigned long mask_bit = 1 << ks8695_get_rx_enable_bit(ksp);
                /*disable rx interrupt*/
                status &= ~mask_bit;
                writel(status , KS8695_IRQ_VA + KS8695_INTEN);
                __napi_schedule(&ksp->napi);
        }

        spin_unlock(&ksp->rx_lock);
        return IRQ_HANDLED;
}

/**
 *      ks8695_rx - Receive packets called by NAPI poll method
 *      @ksp: Private data for the KS8695 Ethernet
 *      @budget: Number of packets allowed to process
 */
static int ks8695_rx(struct ks8695_priv *ksp, int budget)
{
        struct net_device *ndev = ksp->ndev;
        struct sk_buff *skb;
        int buff_n;
        u32 flags;
        int pktlen;
        int received = 0;

        buff_n = ksp->next_rx_desc_read;
        while (received < budget
                        && ksp->rx_buffers[buff_n].skb
                        && (!(ksp->rx_ring[buff_n].status &
                                        cpu_to_le32(RDES_OWN)))) {
                        rmb();
                        flags = le32_to_cpu(ksp->rx_ring[buff_n].status);

                        /* Found an SKB which we own, this means we
                         * received a packet
                         */
                        if ((flags & (RDES_FS | RDES_LS)) !=
                            (RDES_FS | RDES_LS)) {
                                /* This packet is not the first and
                                 * the last segment.  Therefore it is
                                 * a "spanning" packet and we can't
                                 * handle it
                                 */
                                goto rx_failure;
                        }

                        if (flags & (RDES_ES | RDES_RE)) {
                                /* It's an error packet */
                                ndev->stats.rx_errors++;
                                if (flags & RDES_TL)
                                        ndev->stats.rx_length_errors++;
                                if (flags & RDES_RF)
                                        ndev->stats.rx_length_errors++;
                                if (flags & RDES_CE)
                                        ndev->stats.rx_crc_errors++;
                                if (flags & RDES_RE)
                                        ndev->stats.rx_missed_errors++;

                                goto rx_failure;
                        }

                        pktlen = flags & RDES_FLEN;
                        pktlen -= 4; /* Drop the CRC */

                        /* Retrieve the sk_buff */
                        skb = ksp->rx_buffers[buff_n].skb;

                        /* Clear it from the ring */
                        ksp->rx_buffers[buff_n].skb = NULL;
                        ksp->rx_ring[buff_n].data_ptr = 0;

                        /* Unmap the SKB */
                        dma_unmap_single(ksp->dev,
                                         ksp->rx_buffers[buff_n].dma_ptr,
                                         ksp->rx_buffers[buff_n].length,
                                         DMA_FROM_DEVICE);

                        /* Relinquish the SKB to the network layer */
                        skb_put(skb, pktlen);
                        skb->protocol = eth_type_trans(skb, ndev);
                        netif_receive_skb(skb);

                        /* Record stats */
                        ndev->stats.rx_packets++;
                        ndev->stats.rx_bytes += pktlen;
                        goto rx_finished;

rx_failure:
                        /* This ring entry is an error, but we can
                         * re-use the skb
                         */
                        /* Give the ring entry back to the hardware */
                        ksp->rx_ring[buff_n].status = cpu_to_le32(RDES_OWN);
rx_finished:
                        received++;
                        buff_n = (buff_n + 1) & MAX_RX_DESC_MASK;
        }

        /* And note which RX descriptor we last did */
        ksp->next_rx_desc_read = buff_n;

        /* And refill the buffers */
        ks8695_refill_rxbuffers(ksp);

        /* Kick the RX DMA engine, in case it became suspended */
        ks8695_writereg(ksp, KS8695_DRSC, 0);

        return received;
}


/**
 *      ks8695_poll - Receive packet by NAPI poll method
 *      @ksp: Private data for the KS8695 Ethernet
 *      @budget: The remaining number packets for network subsystem
 *
 *     Invoked by the network core when it requests for new
 *     packets from the driver
 */
static int ks8695_poll(struct napi_struct *napi, int budget)
{
        struct ks8695_priv *ksp = container_of(napi, struct ks8695_priv, napi);
        unsigned long  work_done;

        unsigned long isr = readl(KS8695_IRQ_VA + KS8695_INTEN);
        unsigned long mask_bit = 1 << ks8695_get_rx_enable_bit(ksp);

        work_done = ks8695_rx(ksp, budget);

        if (work_done < budget) {
                unsigned long flags;
                spin_lock_irqsave(&ksp->rx_lock, flags);
                __napi_complete(napi);
                /*enable rx interrupt*/
                writel(isr | mask_bit, KS8695_IRQ_VA + KS8695_INTEN);
                spin_unlock_irqrestore(&ksp->rx_lock, flags);
        }
        return work_done;
}

/**
 *      ks8695_link_irq - Link change IRQ handler
 *      @irq: The IRQ which went off (ignored)
 *      @dev_id: The net_device for the interrupt
 *
 *      The WAN interface can generate an IRQ when the link changes,
 *      report this to the net layer and the user.
 */
static irqreturn_t
ks8695_link_irq(int irq, void *dev_id)
{
        struct net_device *ndev = (struct net_device *)dev_id;
        struct ks8695_priv *ksp = netdev_priv(ndev);
        u32 ctrl;

        ctrl = readl(ksp->phyiface_regs + KS8695_WMC);
        if (ctrl & WMC_WLS) {
                netif_carrier_on(ndev);
                if (netif_msg_link(ksp))
                        dev_info(ksp->dev,
                                 "%s: Link is now up (10%sMbps/%s-duplex)\n",
                                 ndev->name,
                                 (ctrl & WMC_WSS) ? "0" : "",
                                 (ctrl & WMC_WDS) ? "Full" : "Half");
        } else {
                netif_carrier_off(ndev);
                if (netif_msg_link(ksp))
                        dev_info(ksp->dev, "%s: Link is now down.\n",
                                 ndev->name);
        }

        return IRQ_HANDLED;
}


/* KS8695 Device functions */

/**
 *      ks8695_reset - Reset a KS8695 ethernet interface
 *      @ksp: The interface to reset
 *
 *      Perform an engine reset of the interface and re-program it
 *      with sensible defaults.
 */
static void
ks8695_reset(struct ks8695_priv *ksp)
{
        int reset_timeout = watchdog;
        /* Issue the reset via the TX DMA control register */
        ks8695_writereg(ksp, KS8695_DTXC, DTXC_TRST);
        while (reset_timeout--) {
                if (!(ks8695_readreg(ksp, KS8695_DTXC) & DTXC_TRST))
                        break;
                msleep(1);
        }

        if (reset_timeout < 0) {
                dev_crit(ksp->dev,
                         "Timeout waiting for DMA engines to reset\n");
                /* And blithely carry on */
        }

        /* Definitely wait long enough before attempting to program
         * the engines
         */
        msleep(10);

        /* RX: unicast and broadcast */
        ks8695_writereg(ksp, KS8695_DRXC, DRXC_RU | DRXC_RB);
        /* TX: pad and add CRC */
        ks8695_writereg(ksp, KS8695_DTXC, DTXC_TEP | DTXC_TAC);
}

/**
 *      ks8695_shutdown - Shut down a KS8695 ethernet interface
 *      @ksp: The interface to shut down
 *
 *      This disables packet RX/TX, cleans up IRQs, drains the rings,
 *      and basically places the interface into a clean shutdown
 *      state.
 */
static void
ks8695_shutdown(struct ks8695_priv *ksp)
{
        u32 ctrl;
        int buff_n;

        /* Disable packet transmission */
        ctrl = ks8695_readreg(ksp, KS8695_DTXC);
        ks8695_writereg(ksp, KS8695_DTXC, ctrl & ~DTXC_TE);

        /* Disable packet reception */
        ctrl = ks8695_readreg(ksp, KS8695_DRXC);
        ks8695_writereg(ksp, KS8695_DRXC, ctrl & ~DRXC_RE);

        /* Release the IRQs */
        free_irq(ksp->rx_irq, ksp->ndev);
        free_irq(ksp->tx_irq, ksp->ndev);
        if (ksp->link_irq != -1)
                free_irq(ksp->link_irq, ksp->ndev);

        /* Throw away any pending TX packets */
        for (buff_n = 0; buff_n < MAX_TX_DESC; ++buff_n) {
                if (ksp->tx_buffers[buff_n].skb) {
                        /* Remove this SKB from the TX ring */
                        ksp->tx_ring[buff_n].owner = 0;
                        ksp->tx_ring[buff_n].status = 0;
                        ksp->tx_ring[buff_n].data_ptr = 0;

                        /* Unmap and bin this SKB */
                        dma_unmap_single(ksp->dev,
                                         ksp->tx_buffers[buff_n].dma_ptr,
                                         ksp->tx_buffers[buff_n].length,
                                         DMA_TO_DEVICE);
                        dev_kfree_skb_irq(ksp->tx_buffers[buff_n].skb);
                        ksp->tx_buffers[buff_n].skb = NULL;
                }
        }

        /* Purge the RX buffers */
        for (buff_n = 0; buff_n < MAX_RX_DESC; ++buff_n) {
                if (ksp->rx_buffers[buff_n].skb) {
                        /* Remove the SKB from the RX ring */
                        ksp->rx_ring[buff_n].status = 0;
                        ksp->rx_ring[buff_n].data_ptr = 0;

                        /* Unmap and bin the SKB */
                        dma_unmap_single(ksp->dev,
                                         ksp->rx_buffers[buff_n].dma_ptr,
                                         ksp->rx_buffers[buff_n].length,
                                         DMA_FROM_DEVICE);
                        dev_kfree_skb_irq(ksp->rx_buffers[buff_n].skb);
                        ksp->rx_buffers[buff_n].skb = NULL;
                }
        }
}


/**
 *      ks8695_setup_irq - IRQ setup helper function
 *      @irq: The IRQ number to claim
 *      @irq_name: The name to give the IRQ claimant
 *      @handler: The function to call to handle the IRQ
 *      @ndev: The net_device to pass in as the dev_id argument to the handler
 *
 *      Return 0 on success.
 */
static int
ks8695_setup_irq(int irq, const char *irq_name,
                 irq_handler_t handler, struct net_device *ndev)
{
        int ret;

        ret = request_irq(irq, handler, IRQF_SHARED, irq_name, ndev);

        if (ret) {
                dev_err(&ndev->dev, "failure to request IRQ %d\n", irq);
                return ret;
        }

        return 0;
}

/**
 *      ks8695_init_net - Initialise a KS8695 ethernet interface
 *      @ksp: The interface to initialise
 *
 *      This routine fills the RX ring, initialises the DMA engines,
 *      allocates the IRQs and then starts the packet TX and RX
 *      engines.
 */
static int
ks8695_init_net(struct ks8695_priv *ksp)
{
        int ret;
        u32 ctrl;

        ks8695_refill_rxbuffers(ksp);

        /* Initialise the DMA engines */
        ks8695_writereg(ksp, KS8695_RDLB, (u32) ksp->rx_ring_dma);
        ks8695_writereg(ksp, KS8695_TDLB, (u32) ksp->tx_ring_dma);

        /* Request the IRQs */
        ret = ks8695_setup_irq(ksp->rx_irq, ksp->rx_irq_name,
                               ks8695_rx_irq, ksp->ndev);
        if (ret)
                return ret;
        ret = ks8695_setup_irq(ksp->tx_irq, ksp->tx_irq_name,
                               ks8695_tx_irq, ksp->ndev);
        if (ret)
                return ret;
        if (ksp->link_irq != -1) {
                ret = ks8695_setup_irq(ksp->link_irq, ksp->link_irq_name,
                                       ks8695_link_irq, ksp->ndev);
                if (ret)
                        return ret;
        }

        /* Set up the ring indices */
        ksp->next_rx_desc_read = 0;
        ksp->tx_ring_next_slot = 0;
        ksp->tx_ring_used = 0;

        /* Bring up transmission */
        ctrl = ks8695_readreg(ksp, KS8695_DTXC);
        /* Enable packet transmission */
        ks8695_writereg(ksp, KS8695_DTXC, ctrl | DTXC_TE);

        /* Bring up the reception */
        ctrl = ks8695_readreg(ksp, KS8695_DRXC);
        /* Enable packet reception */
        ks8695_writereg(ksp, KS8695_DRXC, ctrl | DRXC_RE);
        /* And start the DMA engine */
        ks8695_writereg(ksp, KS8695_DRSC, 0);

        /* All done */
        return 0;
}

/**
 *      ks8695_release_device - HW resource release for KS8695 e-net
 *      @ksp: The device to be freed
 *
 *      This unallocates io memory regions, dma-coherent regions etc
 *      which were allocated in ks8695_probe.
 */
static void
ks8695_release_device(struct ks8695_priv *ksp)
{
        /* Unmap the registers */
        iounmap(ksp->io_regs);
        if (ksp->phyiface_regs)
                iounmap(ksp->phyiface_regs);

        /* And release the request */
        release_resource(ksp->regs_req);
        kfree(ksp->regs_req);
        if (ksp->phyiface_req) {
                release_resource(ksp->phyiface_req);
                kfree(ksp->phyiface_req);
        }

        /* Free the ring buffers */
        dma_free_coherent(ksp->dev, RING_DMA_SIZE,
                          ksp->ring_base, ksp->ring_base_dma);
}

/* Ethtool support */

/**
 *      ks8695_get_msglevel - Get the messages enabled for emission
 *      @ndev: The network device to read from
 */
static u32
ks8695_get_msglevel(struct net_device *ndev)
{
        struct ks8695_priv *ksp = netdev_priv(ndev);

        return ksp->msg_enable;
}

/**
 *      ks8695_set_msglevel - Set the messages enabled for emission
 *      @ndev: The network device to configure
 *      @value: The messages to set for emission
 */
static void
ks8695_set_msglevel(struct net_device *ndev, u32 value)
{
        struct ks8695_priv *ksp = netdev_priv(ndev);

        ksp->msg_enable = value;
}

/**
 *      ks8695_get_settings - Get device-specific settings.
 *      @ndev: The network device to read settings from
 *      @cmd: The ethtool structure to read into
 */
static int
ks8695_get_settings(struct net_device *ndev, struct ethtool_cmd *cmd)
{
        struct ks8695_priv *ksp = netdev_priv(ndev);
        u32 ctrl;

        /* All ports on the KS8695 support these... */
        cmd->supported = (SUPPORTED_10baseT_Half | SUPPORTED_10baseT_Full |
                          SUPPORTED_100baseT_Half | SUPPORTED_100baseT_Full |
                          SUPPORTED_TP | SUPPORTED_MII);
        cmd->transceiver = XCVR_INTERNAL;

        /* Port specific extras */
        switch (ksp->dtype) {
        case KS8695_DTYPE_HPNA:
                cmd->phy_address = 0;
                /* not supported for HPNA */
                cmd->autoneg = AUTONEG_DISABLE;

                /* BUG: Erm, dtype hpna implies no phy regs */
                /*
                ctrl = readl(KS8695_MISC_VA + KS8695_HMC);
                cmd->speed = (ctrl & HMC_HSS) ? SPEED_100 : SPEED_10;
                cmd->duplex = (ctrl & HMC_HDS) ? DUPLEX_FULL : DUPLEX_HALF;
                */
                return -EOPNOTSUPP;
        case KS8695_DTYPE_WAN:
                cmd->advertising = ADVERTISED_TP | ADVERTISED_MII;
                cmd->port = PORT_MII;
                cmd->supported |= (SUPPORTED_Autoneg | SUPPORTED_Pause);
                cmd->phy_address = 0;

                ctrl = readl(ksp->phyiface_regs + KS8695_WMC);
                if ((ctrl & WMC_WAND) == 0) {
                        /* auto-negotiation is enabled */
                        cmd->advertising |= ADVERTISED_Autoneg;
                        if (ctrl & WMC_WANA100F)
                                cmd->advertising |= ADVERTISED_100baseT_Full;
                        if (ctrl & WMC_WANA100H)
                                cmd->advertising |= ADVERTISED_100baseT_Half;
                        if (ctrl & WMC_WANA10F)
                                cmd->advertising |= ADVERTISED_10baseT_Full;
                        if (ctrl & WMC_WANA10H)
                                cmd->advertising |= ADVERTISED_10baseT_Half;
                        if (ctrl & WMC_WANAP)
                                cmd->advertising |= ADVERTISED_Pause;
                        cmd->autoneg = AUTONEG_ENABLE;

                        cmd->speed = (ctrl & WMC_WSS) ? SPEED_100 : SPEED_10;
                        cmd->duplex = (ctrl & WMC_WDS) ?
                                DUPLEX_FULL : DUPLEX_HALF;
                } else {
                        /* auto-negotiation is disabled */
                        cmd->autoneg = AUTONEG_DISABLE;

                        cmd->speed = (ctrl & WMC_WANF100) ?
                                SPEED_100 : SPEED_10;
                        cmd->duplex = (ctrl & WMC_WANFF) ?
                                DUPLEX_FULL : DUPLEX_HALF;
                }
                break;
        case KS8695_DTYPE_LAN:
                return -EOPNOTSUPP;
        }

        return 0;
}

/**
 *      ks8695_set_settings - Set device-specific settings.
 *      @ndev: The network device to configure
 *      @cmd: The settings to configure
 */
static int
ks8695_set_settings(struct net_device *ndev, struct ethtool_cmd *cmd)
{
        struct ks8695_priv *ksp = netdev_priv(ndev);
        u32 ctrl;

        if ((cmd->speed != SPEED_10) && (cmd->speed != SPEED_100))
                return -EINVAL;
        if ((cmd->duplex != DUPLEX_HALF) && (cmd->duplex != DUPLEX_FULL))
                return -EINVAL;
        if (cmd->port != PORT_MII)
                return -EINVAL;
        if (cmd->transceiver != XCVR_INTERNAL)
                return -EINVAL;
        if ((cmd->autoneg != AUTONEG_DISABLE) &&
            (cmd->autoneg != AUTONEG_ENABLE))
                return -EINVAL;

        if (cmd->autoneg == AUTONEG_ENABLE) {
                if ((cmd->advertising & (ADVERTISED_10baseT_Half |
                                ADVERTISED_10baseT_Full |
                                ADVERTISED_100baseT_Half |
                                ADVERTISED_100baseT_Full)) == 0)
                        return -EINVAL;

                switch (ksp->dtype) {
                case KS8695_DTYPE_HPNA:
                        /* HPNA does not support auto-negotiation. */
                        return -EINVAL;
                case KS8695_DTYPE_WAN:
                        ctrl = readl(ksp->phyiface_regs + KS8695_WMC);

                        ctrl &= ~(WMC_WAND | WMC_WANA100F | WMC_WANA100H |
                                  WMC_WANA10F | WMC_WANA10H);
                        if (cmd->advertising & ADVERTISED_100baseT_Full)
                                ctrl |= WMC_WANA100F;
                        if (cmd->advertising & ADVERTISED_100baseT_Half)
                                ctrl |= WMC_WANA100H;
                        if (cmd->advertising & ADVERTISED_10baseT_Full)
                                ctrl |= WMC_WANA10F;
                        if (cmd->advertising & ADVERTISED_10baseT_Half)
                                ctrl |= WMC_WANA10H;

                        /* force a re-negotiation */
                        ctrl |= WMC_WANR;
                        writel(ctrl, ksp->phyiface_regs + KS8695_WMC);
                        break;
                case KS8695_DTYPE_LAN:
                        return -EOPNOTSUPP;
                }

        } else {
                switch (ksp->dtype) {
                case KS8695_DTYPE_HPNA:
                        /* BUG: dtype_hpna implies no phy registers */
                        /*
                        ctrl = __raw_readl(KS8695_MISC_VA + KS8695_HMC);

                        ctrl &= ~(HMC_HSS | HMC_HDS);
                        if (cmd->speed == SPEED_100)
                                ctrl |= HMC_HSS;
                        if (cmd->duplex == DUPLEX_FULL)
                                ctrl |= HMC_HDS;

                        __raw_writel(ctrl, KS8695_MISC_VA + KS8695_HMC);
                        */
                        return -EOPNOTSUPP;
                case KS8695_DTYPE_WAN:
                        ctrl = readl(ksp->phyiface_regs + KS8695_WMC);

                        /* disable auto-negotiation */
                        ctrl |= WMC_WAND;
                        ctrl &= ~(WMC_WANF100 | WMC_WANFF);

                        if (cmd->speed == SPEED_100)
                                ctrl |= WMC_WANF100;
                        if (cmd->duplex == DUPLEX_FULL)
                                ctrl |= WMC_WANFF;

                        writel(ctrl, ksp->phyiface_regs + KS8695_WMC);
                        break;
                case KS8695_DTYPE_LAN:
                        return -EOPNOTSUPP;
                }
        }

        return 0;
}

/**
 *      ks8695_nwayreset - Restart the autonegotiation on the port.
 *      @ndev: The network device to restart autoneotiation on
 */
static int
ks8695_nwayreset(struct net_device *ndev)
{
        struct ks8695_priv *ksp = netdev_priv(ndev);
        u32 ctrl;

        switch (ksp->dtype) {
        case KS8695_DTYPE_HPNA:
                /* No phy means no autonegotiation on hpna */
                return -EINVAL;
        case KS8695_DTYPE_WAN:
                ctrl = readl(ksp->phyiface_regs + KS8695_WMC);

                if ((ctrl & WMC_WAND) == 0)
                        writel(ctrl | WMC_WANR,
                               ksp->phyiface_regs + KS8695_WMC);
                else
                        /* auto-negotiation not enabled */
                        return -EINVAL;
                break;
        case KS8695_DTYPE_LAN:
                return -EOPNOTSUPP;
        }

        return 0;
}

/**
 *      ks8695_get_link - Retrieve link status of network interface
 *      @ndev: The network interface to retrive the link status of.
 */
static u32
ks8695_get_link(struct net_device *ndev)
{
        struct ks8695_priv *ksp = netdev_priv(ndev);
        u32 ctrl;

        switch (ksp->dtype) {
        case KS8695_DTYPE_HPNA:
                /* HPNA always has link */
                return 1;
        case KS8695_DTYPE_WAN:
                /* WAN we can read the PHY for */
                ctrl = readl(ksp->phyiface_regs + KS8695_WMC);
                return ctrl & WMC_WLS;
        case KS8695_DTYPE_LAN:
                return -EOPNOTSUPP;
        }
        return 0;
}

/**
 *      ks8695_get_pause - Retrieve network pause/flow-control advertising
 *      @ndev: The device to retrieve settings from
 *      @param: The structure to fill out with the information
 */
static void
ks8695_get_pause(struct net_device *ndev, struct ethtool_pauseparam *param)
{
        struct ks8695_priv *ksp = netdev_priv(ndev);
        u32 ctrl;

        switch (ksp->dtype) {
        case KS8695_DTYPE_HPNA:
                /* No phy link on hpna to configure */
                return;
        case KS8695_DTYPE_WAN:
                ctrl = readl(ksp->phyiface_regs + KS8695_WMC);

                /* advertise Pause */
                param->autoneg = (ctrl & WMC_WANAP);

                /* current Rx Flow-control */
                ctrl = ks8695_readreg(ksp, KS8695_DRXC);
                param->rx_pause = (ctrl & DRXC_RFCE);

                /* current Tx Flow-control */
                ctrl = ks8695_readreg(ksp, KS8695_DTXC);
                param->tx_pause = (ctrl & DTXC_TFCE);
                break;
        case KS8695_DTYPE_LAN:
                /* The LAN's "phy" is a direct-attached switch */
                return;
        }
}

/**
 *      ks8695_set_pause - Configure pause/flow-control
 *      @ndev: The device to configure
 *      @param: The pause parameters to set
 *
 *      TODO: Implement this
 */
static int
ks8695_set_pause(struct net_device *ndev, struct ethtool_pauseparam *param)
{
        return -EOPNOTSUPP;
}

/**
 *      ks8695_get_drvinfo - Retrieve driver information
 *      @ndev: The network device to retrieve info about
 *      @info: The info structure to fill out.
 */
static void
ks8695_get_drvinfo(struct net_device *ndev, struct ethtool_drvinfo *info)
{
        strlcpy(info->driver, MODULENAME, sizeof(info->driver));
        strlcpy(info->version, MODULEVERSION, sizeof(info->version));
        strlcpy(info->bus_info, dev_name(ndev->dev.parent),
                sizeof(info->bus_info));
}

static const struct ethtool_ops ks8695_ethtool_ops = {
        .get_msglevel   = ks8695_get_msglevel,
        .set_msglevel   = ks8695_set_msglevel,
        .get_settings   = ks8695_get_settings,
        .set_settings   = ks8695_set_settings,
        .nway_reset     = ks8695_nwayreset,
        .get_link       = ks8695_get_link,
        .get_pauseparam = ks8695_get_pause,
        .set_pauseparam = ks8695_set_pause,
        .get_drvinfo    = ks8695_get_drvinfo,
};

/* Network device interface functions */

/**
 *      ks8695_set_mac - Update MAC in net dev and HW
 *      @ndev: The network device to update
 *      @addr: The new MAC address to set
 */
static int
ks8695_set_mac(struct net_device *ndev, void *addr)
{
        struct ks8695_priv *ksp = netdev_priv(ndev);
        struct sockaddr *address = addr;

        if (!is_valid_ether_addr(address->sa_data))
                return -EADDRNOTAVAIL;

        memcpy(ndev->dev_addr, address->sa_data, ndev->addr_len);

        ks8695_update_mac(ksp);

        dev_dbg(ksp->dev, "%s: Updated MAC address to %pM\n",
                ndev->name, ndev->dev_addr);

        return 0;
}

/**
 *      ks8695_set_multicast - Set up the multicast behaviour of the interface
 *      @ndev: The net_device to configure
 *
 *      This routine, called by the net layer, configures promiscuity
 *      and multicast reception behaviour for the interface.
 */
static void
ks8695_set_multicast(struct net_device *ndev)
{
        struct ks8695_priv *ksp = netdev_priv(ndev);
        u32 ctrl;

        ctrl = ks8695_readreg(ksp, KS8695_DRXC);

        if (ndev->flags & IFF_PROMISC) {
                /* enable promiscuous mode */
                ctrl |= DRXC_RA;
        } else if (ndev->flags & ~IFF_PROMISC) {
                /* disable promiscuous mode */
                ctrl &= ~DRXC_RA;
        }

        if (ndev->flags & IFF_ALLMULTI) {
                /* enable all multicast mode */
                ctrl |= DRXC_RM;
        } else if (netdev_mc_count(ndev) > KS8695_NR_ADDRESSES) {
                /* more specific multicast addresses than can be
                 * handled in hardware
                 */
                ctrl |= DRXC_RM;
        } else {
                /* enable specific multicasts */
                ctrl &= ~DRXC_RM;
                ks8695_init_partial_multicast(ksp, ndev);
        }

        ks8695_writereg(ksp, KS8695_DRXC, ctrl);
}

/**
 *      ks8695_timeout - Handle a network tx/rx timeout.
 *      @ndev: The net_device which timed out.
 *
 *      A network transaction timed out, reset the device.
 */
static void
ks8695_timeout(struct net_device *ndev)
{
        struct ks8695_priv *ksp = netdev_priv(ndev);

        netif_stop_queue(ndev);
        ks8695_shutdown(ksp);

        ks8695_reset(ksp);

        ks8695_update_mac(ksp);

        /* We ignore the return from this since it managed to init
         * before it probably will be okay to init again.
         */
        ks8695_init_net(ksp);

        /* Reconfigure promiscuity etc */
        ks8695_set_multicast(ndev);

        /* And start the TX queue once more */
        netif_start_queue(ndev);
}

/**
 *      ks8695_start_xmit - Start a packet transmission
 *      @skb: The packet to transmit
 *      @ndev: The network device to send the packet on
 *
 *      This routine, called by the net layer, takes ownership of the
 *      sk_buff and adds it to the TX ring. It then kicks the TX DMA
 *      engine to ensure transmission begins.
 */
static int
ks8695_start_xmit(struct sk_buff *skb, struct net_device *ndev)
{
        struct ks8695_priv *ksp = netdev_priv(ndev);
        int buff_n;
        dma_addr_t dmap;

        spin_lock_irq(&ksp->txq_lock);

        if (ksp->tx_ring_used == MAX_TX_DESC) {
                /* Somehow we got entered when we have no room */
                spin_unlock_irq(&ksp->txq_lock);
                return NETDEV_TX_BUSY;
        }

        buff_n = ksp->tx_ring_next_slot;

        BUG_ON(ksp->tx_buffers[buff_n].skb);

        dmap = dma_map_single(ksp->dev, skb->data, skb->len, DMA_TO_DEVICE);
        if (unlikely(dma_mapping_error(ksp->dev, dmap))) {
                /* Failed to DMA map this SKB, give it back for now */
                spin_unlock_irq(&ksp->txq_lock);
                dev_dbg(ksp->dev, "%s: Could not map DMA memory for "\
                        "transmission, trying later\n", ndev->name);
                return NETDEV_TX_BUSY;
        }

        ksp->tx_buffers[buff_n].dma_ptr = dmap;
        /* Mapped okay, store the buffer pointer and length for later */
        ksp->tx_buffers[buff_n].skb = skb;
        ksp->tx_buffers[buff_n].length = skb->len;

        /* Fill out the TX descriptor */
        ksp->tx_ring[buff_n].data_ptr =
                cpu_to_le32(ksp->tx_buffers[buff_n].dma_ptr);
        ksp->tx_ring[buff_n].status =
                cpu_to_le32(TDES_IC | TDES_FS | TDES_LS |
                            (skb->len & TDES_TBS));

        wmb();

        /* Hand it over to the hardware */
        ksp->tx_ring[buff_n].owner = cpu_to_le32(TDES_OWN);

        if (++ksp->tx_ring_used == MAX_TX_DESC)
                netif_stop_queue(ndev);

        ndev->trans_start = jiffies;

        /* Kick the TX DMA in case it decided to go IDLE */
        ks8695_writereg(ksp, KS8695_DTSC, 0);

        /* And update the next ring slot */
        ksp->tx_ring_next_slot = (buff_n + 1) & MAX_TX_DESC_MASK;

        spin_unlock_irq(&ksp->txq_lock);
        return NETDEV_TX_OK;
}

/**
 *      ks8695_stop - Stop (shutdown) a KS8695 ethernet interface
 *      @ndev: The net_device to stop
 *
 *      This disables the TX queue and cleans up a KS8695 ethernet
 *      device.
 */
static int
ks8695_stop(struct net_device *ndev)
{
        struct ks8695_priv *ksp = netdev_priv(ndev);

        netif_stop_queue(ndev);
        napi_disable(&ksp->napi);

        ks8695_shutdown(ksp);

        return 0;
}

/**
 *      ks8695_open - Open (bring up) a KS8695 ethernet interface
 *      @ndev: The net_device to open
 *
 *      This resets, configures the MAC, initialises the RX ring and
 *      DMA engines and starts the TX queue for a KS8695 ethernet
 *      device.
 */
static int
ks8695_open(struct net_device *ndev)
{
        struct ks8695_priv *ksp = netdev_priv(ndev);
        int ret;

        if (!is_valid_ether_addr(ndev->dev_addr))
                return -EADDRNOTAVAIL;

        ks8695_reset(ksp);

        ks8695_update_mac(ksp);

        ret = ks8695_init_net(ksp);
        if (ret) {
                ks8695_shutdown(ksp);
                return ret;
        }

        napi_enable(&ksp->napi);
        netif_start_queue(ndev);

        return 0;
}

/* Platform device driver */

/**
 *      ks8695_init_switch - Init LAN switch to known good defaults.
 *      @ksp: The device to initialise
 *
 *      This initialises the LAN switch in the KS8695 to a known-good
 *      set of defaults.
 */
static void __devinit
ks8695_init_switch(struct ks8695_priv *ksp)
{
        u32 ctrl;

        /* Default value for SEC0 according to datasheet */
        ctrl = 0x40819e00;

        /* LED0 = Speed  LED1 = Link/Activity */
        ctrl &= ~(SEC0_LLED1S | SEC0_LLED0S);
        ctrl |= (LLED0S_LINK | LLED1S_LINK_ACTIVITY);

        /* Enable Switch */
        ctrl |= SEC0_ENABLE;

        writel(ctrl, ksp->phyiface_regs + KS8695_SEC0);

        /* Defaults for SEC1 */
        writel(0x9400100, ksp->phyiface_regs + KS8695_SEC1);
}

/**
 *      ks8695_init_wan_phy - Initialise the WAN PHY to sensible defaults
 *      @ksp: The device to initialise
 *
 *      This initialises a KS8695's WAN phy to sensible values for
 *      autonegotiation etc.
 */
static void __devinit
ks8695_init_wan_phy(struct ks8695_priv *ksp)
{
        u32 ctrl;

        /* Support auto-negotiation */
        ctrl = (WMC_WANAP | WMC_WANA100F | WMC_WANA100H |
                WMC_WANA10F | WMC_WANA10H);

        /* LED0 = Activity , LED1 = Link */
        ctrl |= (WLED0S_ACTIVITY | WLED1S_LINK);

        /* Restart Auto-negotiation */
        ctrl |= WMC_WANR;

        writel(ctrl, ksp->phyiface_regs + KS8695_WMC);

        writel(0, ksp->phyiface_regs + KS8695_WPPM);
        writel(0, ksp->phyiface_regs + KS8695_PPS);
}

static const struct net_device_ops ks8695_netdev_ops = {
        .ndo_open               = ks8695_open,
        .ndo_stop               = ks8695_stop,
        .ndo_start_xmit         = ks8695_start_xmit,
        .ndo_tx_timeout         = ks8695_timeout,
        .ndo_set_mac_address    = ks8695_set_mac,
        .ndo_validate_addr      = eth_validate_addr,
        .ndo_set_multicast_list = ks8695_set_multicast,
};

/**
 *      ks8695_probe - Probe and initialise a KS8695 ethernet interface
 *      @pdev: The platform device to probe
 *
 *      Initialise a KS8695 ethernet device from platform data.
 *
 *      This driver requires at least one IORESOURCE_MEM for the
 *      registers and two IORESOURCE_IRQ for the RX and TX IRQs
 *      respectively. It can optionally take an additional
 *      IORESOURCE_MEM for the switch or phy in the case of the lan or
 *      wan ports, and an IORESOURCE_IRQ for the link IRQ for the wan
 *      port.
 */
static int __devinit
ks8695_probe(struct platform_device *pdev)
{
        struct ks8695_priv *ksp;
        struct net_device *ndev;
        struct resource *regs_res, *phyiface_res;
        struct resource *rxirq_res, *txirq_res, *linkirq_res;
        int ret = 0;
        int buff_n;
        u32 machigh, maclow;

        /* Initialise a net_device */
        ndev = alloc_etherdev(sizeof(struct ks8695_priv));
        if (!ndev) {
                dev_err(&pdev->dev, "could not allocate device.\n");
                return -ENOMEM;
        }

        SET_NETDEV_DEV(ndev, &pdev->dev);

        dev_dbg(&pdev->dev, "ks8695_probe() called\n");

        /* Configure our private structure a little */
        ksp = netdev_priv(ndev);
        memset(ksp, 0, sizeof(struct ks8695_priv));

        ksp->dev = &pdev->dev;
        ksp->ndev = ndev;
        ksp->msg_enable = NETIF_MSG_LINK;

        /* Retrieve resources */
        regs_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        phyiface_res = platform_get_resource(pdev, IORESOURCE_MEM, 1);

        rxirq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
        txirq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 1);
        linkirq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 2);

        if (!(regs_res && rxirq_res && txirq_res)) {
                dev_err(ksp->dev, "insufficient resources\n");
                ret = -ENOENT;
                goto failure;
        }

        ksp->regs_req = request_mem_region(regs_res->start,
                                           resource_size(regs_res),
                                           pdev->name);

        if (!ksp->regs_req) {
                dev_err(ksp->dev, "cannot claim register space\n");
                ret = -EIO;
                goto failure;
        }

        ksp->io_regs = ioremap(regs_res->start, resource_size(regs_res));

        if (!ksp->io_regs) {
                dev_err(ksp->dev, "failed to ioremap registers\n");
                ret = -EINVAL;
                goto failure;
        }

        if (phyiface_res) {
                ksp->phyiface_req =
                        request_mem_region(phyiface_res->start,
                                           resource_size(phyiface_res),
                                           phyiface_res->name);

                if (!ksp->phyiface_req) {
                        dev_err(ksp->dev,
                                "cannot claim switch register space\n");
                        ret = -EIO;
                        goto failure;
                }

                ksp->phyiface_regs = ioremap(phyiface_res->start,
                                             resource_size(phyiface_res));

                if (!ksp->phyiface_regs) {
                        dev_err(ksp->dev,
                                "failed to ioremap switch registers\n");
                        ret = -EINVAL;
                        goto failure;
                }
        }

        ksp->rx_irq = rxirq_res->start;
        ksp->rx_irq_name = rxirq_res->name ? rxirq_res->name : "Ethernet RX";
        ksp->tx_irq = txirq_res->start;
        ksp->tx_irq_name = txirq_res->name ? txirq_res->name : "Ethernet TX";
        ksp->link_irq = (linkirq_res ? linkirq_res->start : -1);
        ksp->link_irq_name = (linkirq_res && linkirq_res->name) ?
                linkirq_res->name : "Ethernet Link";

        /* driver system setup */
        ndev->netdev_ops = &ks8695_netdev_ops;
        SET_ETHTOOL_OPS(ndev, &ks8695_ethtool_ops);
        ndev->watchdog_timeo     = msecs_to_jiffies(watchdog);

        netif_napi_add(ndev, &ksp->napi, ks8695_poll, NAPI_WEIGHT);

        /* Retrieve the default MAC addr from the chip. */
        /* The bootloader should have left it in there for us. */

        machigh = ks8695_readreg(ksp, KS8695_MAH);
        maclow = ks8695_readreg(ksp, KS8695_MAL);

        ndev->dev_addr[0] = (machigh >> 8) & 0xFF;
        ndev->dev_addr[1] = machigh & 0xFF;
        ndev->dev_addr[2] = (maclow >> 24) & 0xFF;
        ndev->dev_addr[3] = (maclow >> 16) & 0xFF;
        ndev->dev_addr[4] = (maclow >> 8) & 0xFF;
        ndev->dev_addr[5] = maclow & 0xFF;

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

        /* In order to be efficient memory-wise, we allocate both
         * rings in one go.
         */
        ksp->ring_base = dma_alloc_coherent(&pdev->dev, RING_DMA_SIZE,
                                            &ksp->ring_base_dma, GFP_KERNEL);
        if (!ksp->ring_base) {
                ret = -ENOMEM;
                goto failure;
        }

        /* Specify the TX DMA ring buffer */
        ksp->tx_ring = ksp->ring_base;
        ksp->tx_ring_dma = ksp->ring_base_dma;

        /* And initialise the queue's lock */
        spin_lock_init(&ksp->txq_lock);
        spin_lock_init(&ksp->rx_lock);

        /* Specify the RX DMA ring buffer */
        ksp->rx_ring = ksp->ring_base + TX_RING_DMA_SIZE;
        ksp->rx_ring_dma = ksp->ring_base_dma + TX_RING_DMA_SIZE;

        /* Zero the descriptor rings */
        memset(ksp->tx_ring, 0, TX_RING_DMA_SIZE);
        memset(ksp->rx_ring, 0, RX_RING_DMA_SIZE);

        /* Build the rings */
        for (buff_n = 0; buff_n < MAX_TX_DESC; ++buff_n) {
                ksp->tx_ring[buff_n].next_desc =
                        cpu_to_le32(ksp->tx_ring_dma +
                                    (sizeof(struct tx_ring_desc) *
                                     ((buff_n + 1) & MAX_TX_DESC_MASK)));
        }

        for (buff_n = 0; buff_n < MAX_RX_DESC; ++buff_n) {
                ksp->rx_ring[buff_n].next_desc =
                        cpu_to_le32(ksp->rx_ring_dma +
                                    (sizeof(struct rx_ring_desc) *
                                     ((buff_n + 1) & MAX_RX_DESC_MASK)));
        }

        /* Initialise the port (physically) */
        if (ksp->phyiface_regs && ksp->link_irq == -1) {
                ks8695_init_switch(ksp);
                ksp->dtype = KS8695_DTYPE_LAN;
        } else if (ksp->phyiface_regs && ksp->link_irq != -1) {
                ks8695_init_wan_phy(ksp);
                ksp->dtype = KS8695_DTYPE_WAN;
        } else {
                /* No initialisation since HPNA does not have a PHY */
                ksp->dtype = KS8695_DTYPE_HPNA;
        }

        /* And bring up the net_device with the net core */
        platform_set_drvdata(pdev, ndev);
        ret = register_netdev(ndev);

        if (ret == 0) {
                dev_info(ksp->dev, "ks8695 ethernet (%s) MAC: %pM\n",
                         ks8695_port_type(ksp), ndev->dev_addr);
        } else {
                /* Report the failure to register the net_device */
                dev_err(ksp->dev, "ks8695net: failed to register netdev.\n");
                goto failure;
        }

        /* All is well */
        return 0;

        /* Error exit path */
failure:
        ks8695_release_device(ksp);
        free_netdev(ndev);

        return ret;
}

/**
 *      ks8695_drv_suspend - Suspend a KS8695 ethernet platform device.
 *      @pdev: The device to suspend
 *      @state: The suspend state
 *
 *      This routine detaches and shuts down a KS8695 ethernet device.
 */
static int
ks8695_drv_suspend(struct platform_device *pdev, pm_message_t state)
{
        struct net_device *ndev = platform_get_drvdata(pdev);
        struct ks8695_priv *ksp = netdev_priv(ndev);

        ksp->in_suspend = 1;

        if (netif_running(ndev)) {
                netif_device_detach(ndev);
                ks8695_shutdown(ksp);
        }

        return 0;
}

/**
 *      ks8695_drv_resume - Resume a KS8695 ethernet platform device.
 *      @pdev: The device to resume
 *
 *      This routine re-initialises and re-attaches a KS8695 ethernet
 *      device.
 */
static int
ks8695_drv_resume(struct platform_device *pdev)
{
        struct net_device *ndev = platform_get_drvdata(pdev);
        struct ks8695_priv *ksp = netdev_priv(ndev);

        if (netif_running(ndev)) {
                ks8695_reset(ksp);
                ks8695_init_net(ksp);
                ks8695_set_multicast(ndev);
                netif_device_attach(ndev);
        }

        ksp->in_suspend = 0;

        return 0;
}

/**
 *      ks8695_drv_remove - Remove a KS8695 net device on driver unload.
 *      @pdev: The platform device to remove
 *
 *      This unregisters and releases a KS8695 ethernet device.
 */
static int __devexit
ks8695_drv_remove(struct platform_device *pdev)
{
        struct net_device *ndev = platform_get_drvdata(pdev);
        struct ks8695_priv *ksp = netdev_priv(ndev);

        platform_set_drvdata(pdev, NULL);
        netif_napi_del(&ksp->napi);

        unregister_netdev(ndev);
        ks8695_release_device(ksp);
        free_netdev(ndev);

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

static struct platform_driver ks8695_driver = {
        .driver = {
                .name   = MODULENAME,
                .owner  = THIS_MODULE,
        },
        .probe          = ks8695_probe,
        .remove         = __devexit_p(ks8695_drv_remove),
        .suspend        = ks8695_drv_suspend,
        .resume         = ks8695_drv_resume,
};

/* Module interface */

static int __init
ks8695_init(void)
{
        printk(KERN_INFO "%s Ethernet driver, V%s\n",
               MODULENAME, MODULEVERSION);

        return platform_driver_register(&ks8695_driver);
}

static void __exit
ks8695_cleanup(void)
{
        platform_driver_unregister(&ks8695_driver);
}

module_init(ks8695_init);
module_exit(ks8695_cleanup);

MODULE_AUTHOR("Simtec Electronics")
MODULE_DESCRIPTION("Micrel KS8695 (Centaur) Ethernet driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:" MODULENAME);

module_param(watchdog, int, 0400);
MODULE_PARM_DESC(watchdog, "transmit timeout in milliseconds");