fec.c

/*
 * Fast Ethernet Controller (FEC) driver for Motorola MPC8xx.
 * Copyright (c) 1997 Dan Malek (dmalek@jlc.net)
 *
 * This version of the driver is specific to the FADS implementation,
 * since the board contains control registers external to the processor
 * for the control of the LevelOne LXT970 transceiver.  The MPC860T manual
 * describes connections using the internal parallel port I/O, which
 * is basically all of Port D.
 *
 * Right now, I am very wasteful with the buffers.  I allocate memory
 * pages and then divide them into 2K frame buffers.  This way I know I
 * have buffers large enough to hold one frame within one buffer descriptor.
 * Once I get this working, I will use 64 or 128 byte CPM buffers, which
 * will be much more memory efficient and will easily handle lots of
 * small packets.
 *
 * Much better multiple PHY support by Magnus Damm.
 * Copyright (c) 2000 Ericsson Radio Systems AB.
 *
 * Support for FEC controller of ColdFire processors.
 * Copyright (c) 2001-2005 Greg Ungerer (gerg@snapgear.com)
 *
 * Bug fixes and cleanup by Philippe De Muyter (phdm@macqel.be)
 * Copyright (c) 2004-2006 Macq Electronique SA.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/ptrace.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/spinlock.h>
#include <linux/workqueue.h>
#include <linux/bitops.h>

#include <asm/irq.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <asm/pgtable.h>
#include <asm/cacheflush.h>

#if defined(CONFIG_M523x) || defined(CONFIG_M527x) || \
    defined(CONFIG_M5272) || defined(CONFIG_M528x) || \
    defined(CONFIG_M520x) || defined(CONFIG_M532x)
#include <asm/coldfire.h>
#include <asm/mcfsim.h>
#include "fec.h"
#else
#include <asm/8xx_immap.h>
#include <asm/mpc8xx.h>
#include "commproc.h"
#endif

#if defined(CONFIG_FEC2)
#define	FEC_MAX_PORTS	2
#else
#define	FEC_MAX_PORTS	1
#endif

#if defined(CONFIG_FADS) || defined(CONFIG_RPXCLASSIC) || defined(CONFIG_M5272)
#define HAVE_mii_link_interrupt
#endif

/*
 * Define the fixed address of the FEC hardware.
 */
static unsigned int fec_hw[] = {
#if defined(CONFIG_M5272)
	(MCF_MBAR + 0x840),
#elif defined(CONFIG_M527x)
	(MCF_MBAR + 0x1000),
	(MCF_MBAR + 0x1800),
#elif defined(CONFIG_M523x) || defined(CONFIG_M528x)
	(MCF_MBAR + 0x1000),
#elif defined(CONFIG_M520x)
	(MCF_MBAR+0x30000),
#elif defined(CONFIG_M532x)
	(MCF_MBAR+0xfc030000),
#else
	&(((immap_t *)IMAP_ADDR)->im_cpm.cp_fec),
#endif
};

static unsigned char	fec_mac_default[] = {
	0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
};

/*
 * Some hardware gets it MAC address out of local flash memory.
 * if this is non-zero then assume it is the address to get MAC from.
 */
#if defined(CONFIG_NETtel)
#define	FEC_FLASHMAC	0xf0006006
#elif defined(CONFIG_GILBARCONAP) || defined(CONFIG_SCALES)
#define	FEC_FLASHMAC	0xf0006000
#elif defined(CONFIG_CANCam)
#define	FEC_FLASHMAC	0xf0020000
#elif defined (CONFIG_M5272C3)
#define	FEC_FLASHMAC	(0xffe04000 + 4)
#elif defined(CONFIG_MOD5272)
#define FEC_FLASHMAC 	0xffc0406b
#else
#define	FEC_FLASHMAC	0
#endif

/* Forward declarations of some structures to support different PHYs
*/

typedef struct {
	uint mii_data;
	void (*funct)(uint mii_reg, struct net_device *dev);
} phy_cmd_t;

typedef struct {
	uint id;
	char *name;

	const phy_cmd_t *config;
	const phy_cmd_t *startup;
	const phy_cmd_t *ack_int;
	const phy_cmd_t *shutdown;
} phy_info_t;

/* The number of Tx and Rx buffers.  These are allocated from the page
 * pool.  The code may assume these are power of two, so it it best
 * to keep them that size.
 * We don't need to allocate pages for the transmitter.  We just use
 * the skbuffer directly.
 */
#define FEC_ENET_RX_PAGES	8
#define FEC_ENET_RX_FRSIZE	2048
#define FEC_ENET_RX_FRPPG	(PAGE_SIZE / FEC_ENET_RX_FRSIZE)
#define RX_RING_SIZE		(FEC_ENET_RX_FRPPG * FEC_ENET_RX_PAGES)
#define FEC_ENET_TX_FRSIZE	2048
#define FEC_ENET_TX_FRPPG	(PAGE_SIZE / FEC_ENET_TX_FRSIZE)
#define TX_RING_SIZE		16	/* Must be power of two */
#define TX_RING_MOD_MASK	15	/*   for this to work */

#if (((RX_RING_SIZE + TX_RING_SIZE) * 8) > PAGE_SIZE)
#error "FEC: descriptor ring size constants too large"
#endif

/* Interrupt events/masks.
*/
#define FEC_ENET_HBERR	((uint)0x80000000)	/* Heartbeat error */
#define FEC_ENET_BABR	((uint)0x40000000)	/* Babbling receiver */
#define FEC_ENET_BABT	((uint)0x20000000)	/* Babbling transmitter */
#define FEC_ENET_GRA	((uint)0x10000000)	/* Graceful stop complete */
#define FEC_ENET_TXF	((uint)0x08000000)	/* Full frame transmitted */
#define FEC_ENET_TXB	((uint)0x04000000)	/* A buffer was transmitted */
#define FEC_ENET_RXF	((uint)0x02000000)	/* Full frame received */
#define FEC_ENET_RXB	((uint)0x01000000)	/* A buffer was received */
#define FEC_ENET_MII	((uint)0x00800000)	/* MII interrupt */
#define FEC_ENET_EBERR	((uint)0x00400000)	/* SDMA bus error */

/* The FEC stores dest/src/type, data, and checksum for receive packets.
 */
#define PKT_MAXBUF_SIZE		1518
#define PKT_MINBUF_SIZE		64
#define PKT_MAXBLR_SIZE		1520


/*
 * The 5270/5271/5280/5282/532x RX control register also contains maximum frame
 * size bits. Other FEC hardware does not, so we need to take that into
 * account when setting it.
 */
#if defined(CONFIG_M523x) || defined(CONFIG_M527x) || defined(CONFIG_M528x) || \
    defined(CONFIG_M520x) || defined(CONFIG_M532x)
#define	OPT_FRAME_SIZE	(PKT_MAXBUF_SIZE << 16)
#else
#define	OPT_FRAME_SIZE	0
#endif

/* The FEC buffer descriptors track the ring buffers.  The rx_bd_base and
 * tx_bd_base always point to the base of the buffer descriptors.  The
 * cur_rx and cur_tx point to the currently available buffer.
 * The dirty_tx tracks the current buffer that is being sent by the
 * controller.  The cur_tx and dirty_tx are equal under both completely
 * empty and completely full conditions.  The empty/ready indicator in
 * the buffer descriptor determines the actual condition.
 */
struct fec_enet_private {
	/* Hardware registers of the FEC device */
	volatile fec_t	*hwp;

	struct net_device *netdev;

	/* The saved address of a sent-in-place packet/buffer, for skfree(). */
	unsigned char *tx_bounce[TX_RING_SIZE];
	struct	sk_buff* tx_skbuff[TX_RING_SIZE];
	ushort	skb_cur;
	ushort	skb_dirty;

	/* CPM dual port RAM relative addresses.
	*/
	cbd_t	*rx_bd_base;		/* Address of Rx and Tx buffers. */
	cbd_t	*tx_bd_base;
	cbd_t	*cur_rx, *cur_tx;		/* The next free ring entry */
	cbd_t	*dirty_tx;	/* The ring entries to be free()ed. */
	uint	tx_full;
	/* hold while accessing the HW like ringbuffer for tx/rx but not MAC */
	spinlock_t hw_lock;
	/* hold while accessing the mii_list_t() elements */
	spinlock_t mii_lock;

	uint	phy_id;
	uint	phy_id_done;
	uint	phy_status;
	uint	phy_speed;
	phy_info_t const	*phy;
	struct work_struct phy_task;

	uint	sequence_done;
	uint	mii_phy_task_queued;

	uint	phy_addr;

	int	index;
	int	opened;
	int	link;
	int	old_link;
	int	full_duplex;
};

static int fec_enet_open(struct net_device *dev);
static int fec_enet_start_xmit(struct sk_buff *skb, struct net_device *dev);
static void fec_enet_mii(struct net_device *dev);
static irqreturn_t fec_enet_interrupt(int irq, void * dev_id);
static void fec_enet_tx(struct net_device *dev);
static void fec_enet_rx(struct net_device *dev);
static int fec_enet_close(struct net_device *dev);
static void set_multicast_list(struct net_device *dev);
static void fec_restart(struct net_device *dev, int duplex);
static void fec_stop(struct net_device *dev);
static void fec_set_mac_address(struct net_device *dev);


/* MII processing.  We keep this as simple as possible.  Requests are
 * placed on the list (if there is room).  When the request is finished
 * by the MII, an optional function may be called.
 */
typedef struct mii_list {
	uint	mii_regval;
	void	(*mii_func)(uint val, struct net_device *dev);
	struct	mii_list *mii_next;
} mii_list_t;

#define		NMII	20
static mii_list_t	mii_cmds[NMII];
static mii_list_t	*mii_free;
static mii_list_t	*mii_head;
static mii_list_t	*mii_tail;

static int	mii_queue(struct net_device *dev, int request,
				void (*func)(uint, struct net_device *));

/* Make MII read/write commands for the FEC.
*/
#define mk_mii_read(REG)	(0x60020000 | ((REG & 0x1f) << 18))
#define mk_mii_write(REG, VAL)	(0x50020000 | ((REG & 0x1f) << 18) | \
						(VAL & 0xffff))
#define mk_mii_end	0

/* Transmitter timeout.
*/
#define TX_TIMEOUT (2*HZ)

/* Register definitions for the PHY.
*/

#define MII_REG_CR          0  /* Control Register                         */
#define MII_REG_SR          1  /* Status Register                          */
#define MII_REG_PHYIR1      2  /* PHY Identification Register 1            */
#define MII_REG_PHYIR2      3  /* PHY Identification Register 2            */
#define MII_REG_ANAR        4  /* A-N Advertisement Register               */
#define MII_REG_ANLPAR      5  /* A-N Link Partner Ability Register        */
#define MII_REG_ANER        6  /* A-N Expansion Register                   */
#define MII_REG_ANNPTR      7  /* A-N Next Page Transmit Register          */
#define MII_REG_ANLPRNPR    8  /* A-N Link Partner Received Next Page Reg. */

/* values for phy_status */

#define PHY_CONF_ANE	0x0001  /* 1 auto-negotiation enabled */
#define PHY_CONF_LOOP	0x0002  /* 1 loopback mode enabled */
#define PHY_CONF_SPMASK	0x00f0  /* mask for speed */
#define PHY_CONF_10HDX	0x0010  /* 10 Mbit half duplex supported */
#define PHY_CONF_10FDX	0x0020  /* 10 Mbit full duplex supported */
#define PHY_CONF_100HDX	0x0040  /* 100 Mbit half duplex supported */
#define PHY_CONF_100FDX	0x0080  /* 100 Mbit full duplex supported */

#define PHY_STAT_LINK	0x0100  /* 1 up - 0 down */
#define PHY_STAT_FAULT	0x0200  /* 1 remote fault */
#define PHY_STAT_ANC	0x0400  /* 1 auto-negotiation complete	*/
#define PHY_STAT_SPMASK	0xf000  /* mask for speed */
#define PHY_STAT_10HDX	0x1000  /* 10 Mbit half duplex selected	*/
#define PHY_STAT_10FDX	0x2000  /* 10 Mbit full duplex selected	*/
#define PHY_STAT_100HDX	0x4000  /* 100 Mbit half duplex selected */
#define PHY_STAT_100FDX	0x8000  /* 100 Mbit full duplex selected */


static int
fec_enet_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct fec_enet_private *fep;
	volatile fec_t	*fecp;
	volatile cbd_t	*bdp;
	unsigned short	status;
	unsigned long flags;

	fep = netdev_priv(dev);
	fecp = (volatile fec_t*)dev->base_addr;

	if (!fep->link) {
		/* Link is down or autonegotiation is in progress. */
		return 1;
	}

	spin_lock_irqsave(&fep->hw_lock, flags);
	/* Fill in a Tx ring entry */
	bdp = fep->cur_tx;

	status = bdp->cbd_sc;
#ifndef final_version
	if (status & BD_ENET_TX_READY) {
		/* Ooops.  All transmit buffers are full.  Bail out.
		 * This should not happen, since dev->tbusy should be set.
		 */
		printk("%s: tx queue full!.\n", dev->name);
		spin_unlock_irqrestore(&fep->hw_lock, flags);
		return 1;
	}
#endif

	/* Clear all of the status flags.
	 */
	status &= ~BD_ENET_TX_STATS;

	/* Set buffer length and buffer pointer.
	*/
	bdp->cbd_bufaddr = __pa(skb->data);
	bdp->cbd_datlen = skb->len;

	/*
	 *	On some FEC implementations data must be aligned on
	 *	4-byte boundaries. Use bounce buffers to copy data
	 *	and get it aligned. Ugh.
	 */
	if (bdp->cbd_bufaddr & 0x3) {
		unsigned int index;
		index = bdp - fep->tx_bd_base;
		memcpy(fep->tx_bounce[index], (void *) bdp->cbd_bufaddr, bdp->cbd_datlen);
		bdp->cbd_bufaddr = __pa(fep->tx_bounce[index]);
	}

	/* Save skb pointer.
	*/
	fep->tx_skbuff[fep->skb_cur] = skb;

	dev->stats.tx_bytes += skb->len;
	fep->skb_cur = (fep->skb_cur+1) & TX_RING_MOD_MASK;

	/* Push the data cache so the CPM does not get stale memory
	 * data.
	 */
	flush_dcache_range((unsigned long)skb->data,
			   (unsigned long)skb->data + skb->len);

	/* Send it on its way.  Tell FEC it's ready, interrupt when done,
	 * it's the last BD of the frame, and to put the CRC on the end.
	 */

	status |= (BD_ENET_TX_READY | BD_ENET_TX_INTR
			| BD_ENET_TX_LAST | BD_ENET_TX_TC);
	bdp->cbd_sc = status;

	dev->trans_start = jiffies;

	/* Trigger transmission start */
	fecp->fec_x_des_active = 0;

	/* If this was the last BD in the ring, start at the beginning again.
	*/
	if (status & BD_ENET_TX_WRAP) {
		bdp = fep->tx_bd_base;
	} else {
		bdp++;
	}

	if (bdp == fep->dirty_tx) {
		fep->tx_full = 1;
		netif_stop_queue(dev);
	}

	fep->cur_tx = (cbd_t *)bdp;

	spin_unlock_irqrestore(&fep->hw_lock, flags);

	return 0;
}

static void
fec_timeout(struct net_device *dev)
{
	struct fec_enet_private *fep = netdev_priv(dev);

	printk("%s: transmit timed out.\n", dev->name);
	dev->stats.tx_errors++;
#ifndef final_version
	{
	int	i;
	cbd_t	*bdp;

	printk("Ring data dump: cur_tx %lx%s, dirty_tx %lx cur_rx: %lx\n",
	       (unsigned long)fep->cur_tx, fep->tx_full ? " (full)" : "",
	       (unsigned long)fep->dirty_tx,
	       (unsigned long)fep->cur_rx);

	bdp = fep->tx_bd_base;
	printk(" tx: %u buffers\n",  TX_RING_SIZE);
	for (i = 0 ; i < TX_RING_SIZE; i++) {
		printk("  %08x: %04x %04x %08x\n",
		       (uint) bdp,
		       bdp->cbd_sc,
		       bdp->cbd_datlen,
		       (int) bdp->cbd_bufaddr);
		bdp++;
	}

	bdp = fep->rx_bd_base;
	printk(" rx: %lu buffers\n",  (unsigned long) RX_RING_SIZE);
	for (i = 0 ; i < RX_RING_SIZE; i++) {
		printk("  %08x: %04x %04x %08x\n",
		       (uint) bdp,
		       bdp->cbd_sc,
		       bdp->cbd_datlen,
		       (int) bdp->cbd_bufaddr);
		bdp++;
	}
	}
#endif
	fec_restart(dev, fep->full_duplex);
	netif_wake_queue(dev);
}

/* The interrupt handler.
 * This is called from the MPC core interrupt.
 */
static irqreturn_t
fec_enet_interrupt(int irq, void * dev_id)
{
	struct	net_device *dev = dev_id;
	volatile fec_t	*fecp;
	uint	int_events;
	irqreturn_t ret = IRQ_NONE;

	fecp = (volatile fec_t*)dev->base_addr;

	/* Get the interrupt events that caused us to be here.
	*/
	do {
		int_events = fecp->fec_ievent;
		fecp->fec_ievent = int_events;

		/* Handle receive event in its own function.
		 */
		if (int_events & FEC_ENET_RXF) {
			ret = IRQ_HANDLED;
			fec_enet_rx(dev);
		}

		/* Transmit OK, or non-fatal error. Update the buffer
		   descriptors. FEC handles all errors, we just discover
		   them as part of the transmit process.
		*/
		if (int_events & FEC_ENET_TXF) {
			ret = IRQ_HANDLED;
			fec_enet_tx(dev);
		}

		if (int_events & FEC_ENET_MII) {
			ret = IRQ_HANDLED;
			fec_enet_mii(dev);
		}

	} while (int_events);

	return ret;
}


static void
fec_enet_tx(struct net_device *dev)
{
	struct	fec_enet_private *fep;
	volatile cbd_t	*bdp;
	unsigned short status;
	struct	sk_buff	*skb;

	fep = netdev_priv(dev);
	spin_lock_irq(&fep->hw_lock);
	bdp = fep->dirty_tx;

	while (((status = bdp->cbd_sc) & BD_ENET_TX_READY) == 0) {
		if (bdp == fep->cur_tx && fep->tx_full == 0) break;

		skb = fep->tx_skbuff[fep->skb_dirty];
		/* Check for errors. */
		if (status & (BD_ENET_TX_HB | BD_ENET_TX_LC |
				   BD_ENET_TX_RL | BD_ENET_TX_UN |
				   BD_ENET_TX_CSL)) {
			dev->stats.tx_errors++;
			if (status & BD_ENET_TX_HB)  /* No heartbeat */
				dev->stats.tx_heartbeat_errors++;
			if (status & BD_ENET_TX_LC)  /* Late collision */
				dev->stats.tx_window_errors++;
			if (status & BD_ENET_TX_RL)  /* Retrans limit */
				dev->stats.tx_aborted_errors++;
			if (status & BD_ENET_TX_UN)  /* Underrun */
				dev->stats.tx_fifo_errors++;
			if (status & BD_ENET_TX_CSL) /* Carrier lost */
				dev->stats.tx_carrier_errors++;
		} else {
			dev->stats.tx_packets++;
		}

#ifndef final_version
		if (status & BD_ENET_TX_READY)
			printk("HEY! Enet xmit interrupt and TX_READY.\n");
#endif
		/* Deferred means some collisions occurred during transmit,
		 * but we eventually sent the packet OK.
		 */
		if (status & BD_ENET_TX_DEF)
			dev->stats.collisions++;

		/* Free the sk buffer associated with this last transmit.
		 */
		dev_kfree_skb_any(skb);
		fep->tx_skbuff[fep->skb_dirty] = NULL;
		fep->skb_dirty = (fep->skb_dirty + 1) & TX_RING_MOD_MASK;

		/* Update pointer to next buffer descriptor to be transmitted.
		 */
		if (status & BD_ENET_TX_WRAP)
			bdp = fep->tx_bd_base;
		else
			bdp++;

		/* Since we have freed up a buffer, the ring is no longer
		 * full.
		 */
		if (fep->tx_full) {
			fep->tx_full = 0;
			if (netif_queue_stopped(dev))
				netif_wake_queue(dev);
		}
	}
	fep->dirty_tx = (cbd_t *)bdp;
	spin_unlock_irq(&fep->hw_lock);
}


/* During a receive, the cur_rx points to the current incoming buffer.
 * When we update through the ring, if the next incoming buffer has
 * not been given to the system, we just set the empty indicator,
 * effectively tossing the packet.
 */
static void
fec_enet_rx(struct net_device *dev)
{
	struct	fec_enet_private *fep;
	volatile fec_t	*fecp;
	volatile cbd_t *bdp;
	unsigned short status;
	struct	sk_buff	*skb;
	ushort	pkt_len;
	__u8 *data;

#ifdef CONFIG_M532x
	flush_cache_all();
#endif

	fep = netdev_priv(dev);
	fecp = (volatile fec_t*)dev->base_addr;

	spin_lock_irq(&fep->hw_lock);

	/* First, grab all of the stats for the incoming packet.
	 * These get messed up if we get called due to a busy condition.
	 */
	bdp = fep->cur_rx;

while (!((status = bdp->cbd_sc) & BD_ENET_RX_EMPTY)) {

#ifndef final_version
	/* Since we have allocated space to hold a complete frame,
	 * the last indicator should be set.
	 */
	if ((status & BD_ENET_RX_LAST) == 0)
		printk("FEC ENET: rcv is not +last\n");
#endif

	if (!fep->opened)
		goto rx_processing_done;

	/* Check for errors. */
	if (status & (BD_ENET_RX_LG | BD_ENET_RX_SH | BD_ENET_RX_NO |
			   BD_ENET_RX_CR | BD_ENET_RX_OV)) {
		dev->stats.rx_errors++;
		if (status & (BD_ENET_RX_LG | BD_ENET_RX_SH)) {
		/* Frame too long or too short. */
			dev->stats.rx_length_errors++;
		}
		if (status & BD_ENET_RX_NO)	/* Frame alignment */
			dev->stats.rx_frame_errors++;
		if (status & BD_ENET_RX_CR)	/* CRC Error */
			dev->stats.rx_crc_errors++;
		if (status & BD_ENET_RX_OV)	/* FIFO overrun */
			dev->stats.rx_fifo_errors++;
	}

	/* Report late collisions as a frame error.
	 * On this error, the BD is closed, but we don't know what we
	 * have in the buffer.  So, just drop this frame on the floor.
	 */
	if (status & BD_ENET_RX_CL) {
		dev->stats.rx_errors++;
		dev->stats.rx_frame_errors++;
		goto rx_processing_done;
	}

	/* Process the incoming frame.
	 */
	dev->stats.rx_packets++;
	pkt_len = bdp->cbd_datlen;
	dev->stats.rx_bytes += pkt_len;
	data = (__u8*)__va(bdp->cbd_bufaddr);

	/* This does 16 byte alignment, exactly what we need.
	 * The packet length includes FCS, but we don't want to
	 * include that when passing upstream as it messes up
	 * bridging applications.
	 */
	skb = dev_alloc_skb(pkt_len-4);

	if (skb == NULL) {
		printk("%s: Memory squeeze, dropping packet.\n", dev->name);
		dev->stats.rx_dropped++;
	} else {
		skb_put(skb,pkt_len-4);	/* Make room */
		skb_copy_to_linear_data(skb, data, pkt_len-4);
		skb->protocol=eth_type_trans(skb,dev);
		netif_rx(skb);
	}
  rx_processing_done:

	/* Clear the status flags for this buffer.
	*/
	status &= ~BD_ENET_RX_STATS;

	/* Mark the buffer empty.
	*/
	status |= BD_ENET_RX_EMPTY;
	bdp->cbd_sc = status;

	/* Update BD pointer to next entry.
	*/
	if (status & BD_ENET_RX_WRAP)
		bdp = fep->rx_bd_base;
	else
		bdp++;

#if 1
	/* Doing this here will keep the FEC running while we process
	 * incoming frames.  On a heavily loaded network, we should be
	 * able to keep up at the expense of system resources.
	 */
	fecp->fec_r_des_active = 0;
#endif
   } /* while (!((status = bdp->cbd_sc) & BD_ENET_RX_EMPTY)) */
	fep->cur_rx = (cbd_t *)bdp;

#if 0
	/* Doing this here will allow us to process all frames in the
	 * ring before the FEC is allowed to put more there.  On a heavily
	 * loaded network, some frames may be lost.  Unfortunately, this
	 * increases the interrupt overhead since we can potentially work
	 * our way back to the interrupt return only to come right back
	 * here.
	 */
	fecp->fec_r_des_active = 0;
#endif

	spin_unlock_irq(&fep->hw_lock);
}


/* called from interrupt context */
static void
fec_enet_mii(struct net_device *dev)
{
	struct	fec_enet_private *fep;
	volatile fec_t	*ep;
	mii_list_t	*mip;
	uint		mii_reg;

	fep = netdev_priv(dev);
	spin_lock_irq(&fep->mii_lock);

	ep = fep->hwp;
	mii_reg = ep->fec_mii_data;

	if ((mip = mii_head) == NULL) {
		printk("MII and no head!\n");
		goto unlock;
	}

	if (mip->mii_func != NULL)
		(*(mip->mii_func))(mii_reg, dev);

	mii_head = mip->mii_next;
	mip->mii_next = mii_free;
	mii_free = mip;

	if ((mip = mii_head) != NULL)
		ep->fec_mii_data = mip->mii_regval;

unlock:
	spin_unlock_irq(&fep->mii_lock);
}

static int
mii_queue(struct net_device *dev, int regval, void (*func)(uint, struct net_device *))
{
	struct fec_enet_private *fep;
	unsigned long	flags;
	mii_list_t	*mip;
	int		retval;

	/* Add PHY address to register command.
	*/
	fep = netdev_priv(dev);
	spin_lock_irqsave(&fep->mii_lock, flags);

	regval |= fep->phy_addr << 23;
	retval = 0;

	if ((mip = mii_free) != NULL) {
		mii_free = mip->mii_next;
		mip->mii_regval = regval;
		mip->mii_func = func;
		mip->mii_next = NULL;
		if (mii_head) {
			mii_tail->mii_next = mip;
			mii_tail = mip;
		} else {
			mii_head = mii_tail = mip;
			fep->hwp->fec_mii_data = regval;
		}
	} else {
		retval = 1;
	}

	spin_unlock_irqrestore(&fep->mii_lock, flags);
	return retval;
}

static void mii_do_cmd(struct net_device *dev, const phy_cmd_t *c)
{
	if(!c)
		return;

	for (; c->mii_data != mk_mii_end; c++)
		mii_queue(dev, c->mii_data, c->funct);
}

static void mii_parse_sr(uint mii_reg, struct net_device *dev)
{
	struct fec_enet_private *fep = netdev_priv(dev);
	volatile uint *s = &(fep->phy_status);
	uint status;

	status = *s & ~(PHY_STAT_LINK | PHY_STAT_FAULT | PHY_STAT_ANC);

	if (mii_reg & 0x0004)
		status |= PHY_STAT_LINK;
	if (mii_reg & 0x0010)
		status |= PHY_STAT_FAULT;
	if (mii_reg & 0x0020)
		status |= PHY_STAT_ANC;
	*s = status;
}

static void mii_parse_cr(uint mii_reg, struct net_device *dev)
{
	struct fec_enet_private *fep = netdev_priv(dev);
	volatile uint *s = &(fep->phy_status);
	uint status;

	status = *s & ~(PHY_CONF_ANE | PHY_CONF_LOOP);

	if (mii_reg & 0x1000)
		status |= PHY_CONF_ANE;
	if (mii_reg & 0x4000)
		status |= PHY_CONF_LOOP;
	*s = status;
}

static void mii_parse_anar(uint mii_reg, struct net_device *dev)
{
	struct fec_enet_private *fep = netdev_priv(dev);
	volatile uint *s = &(fep->phy_status);
	uint status;

	status = *s & ~(PHY_CONF_SPMASK);

	if (mii_reg & 0x0020)
		status |= PHY_CONF_10HDX;
	if (mii_reg & 0x0040)
		status |= PHY_CONF_10FDX;
	if (mii_reg & 0x0080)
		status |= PHY_CONF_100HDX;
	if (mii_reg & 0x00100)
		status |= PHY_CONF_100FDX;
	*s = status;
}

/* ------------------------------------------------------------------------- */
/* The Level one LXT970 is used by many boards				     */

#define MII_LXT970_MIRROR    16  /* Mirror register           */
#define MII_LXT970_IER       17  /* Interrupt Enable Register */
#define MII_LXT970_ISR       18  /* Interrupt Status Register */
#define MII_LXT970_CONFIG    19  /* Configuration Register    */
#define MII_LXT970_CSR       20  /* Chip Status Register      */

static void mii_parse_lxt970_csr(uint mii_reg, struct net_device *dev)
{
	struct fec_enet_private *fep = netdev_priv(dev);
	volatile uint *s = &(fep->phy_status);
	uint status;

	status = *s & ~(PHY_STAT_SPMASK);
	if (mii_reg & 0x0800) {
		if (mii_reg & 0x1000)
			status |= PHY_STAT_100FDX;
		else
			status |= PHY_STAT_100HDX;
	} else {
		if (mii_reg & 0x1000)
			status |= PHY_STAT_10FDX;
		else
			status |= PHY_STAT_10HDX;
	}
	*s = status;
}

static phy_cmd_t const phy_cmd_lxt970_config[] = {
		{ mk_mii_read(MII_REG_CR), mii_parse_cr },
		{ mk_mii_read(MII_REG_ANAR), mii_parse_anar },
		{ mk_mii_end, }
	};
static phy_cmd_t const phy_cmd_lxt970_startup[] = { /* enable interrupts */
		{ mk_mii_write(MII_LXT970_IER, 0x0002), NULL },
		{ mk_mii_write(MII_REG_CR, 0x1200), NULL }, /* autonegotiate */
		{ mk_mii_end, }
	};
static phy_cmd_t const phy_cmd_lxt970_ack_int[] = {
		/* read SR and ISR to acknowledge */
		{ mk_mii_read(MII_REG_SR), mii_parse_sr },
		{ mk_mii_read(MII_LXT970_ISR), NULL },

		/* find out the current status */
		{ mk_mii_read(MII_LXT970_CSR), mii_parse_lxt970_csr },
		{ mk_mii_end, }
	};
static phy_cmd_t const phy_cmd_lxt970_shutdown[] = { /* disable interrupts */
		{ mk_mii_write(MII_LXT970_IER, 0x0000), NULL },
		{ mk_mii_end, }
	};
static phy_info_t const phy_info_lxt970 = {
	.id = 0x07810000,
	.name = "LXT970",
	.config = phy_cmd_lxt970_config,
	.startup = phy_cmd_lxt970_startup,
	.ack_int = phy_cmd_lxt970_ack_int,
	.shutdown = phy_cmd_lxt970_shutdown
};

/* ------------------------------------------------------------------------- */
/* The Level one LXT971 is used on some of my custom boards                  */

/* register definitions for the 971 */

#define MII_LXT971_PCR       16  /* Port Control Register     */
#define MII_LXT971_SR2       17  /* Status Register 2         */
#define MII_LXT971_IER       18  /* Interrupt Enable Register */
#define MII_LXT971_ISR       19  /* Interrupt Status Register */
#define MII_LXT971_LCR       20  /* LED Control Register      */
#define MII_LXT971_TCR       30  /* Transmit Control Register */

/*
 * I had some nice ideas of running the MDIO faster...
 * The 971 should support 8MHz and I tried it, but things acted really
 * weird, so 2.5 MHz ought to be enough for anyone...
 */

static void mii_parse_lxt971_sr2(uint mii_reg, struct net_device *dev)
{
	struct fec_enet_private *fep = netdev_priv(dev);
	volatile uint *s = &(fep->phy_status);
	uint status;

	status = *s & ~(PHY_STAT_SPMASK | PHY_STAT_LINK | PHY_STAT_ANC);

	if (mii_reg & 0x0400) {
		fep->link = 1;
		status |= PHY_STAT_LINK;
	} else {
		fep->link = 0;
	}
	if (mii_reg & 0x0080)
		status |= PHY_STAT_ANC;
	if (mii_reg & 0x4000) {
		if (mii_reg & 0x0200)
			status |= PHY_STAT_100FDX;
		else
			status |= PHY_STAT_100HDX;
	} else {
		if (mii_reg & 0x0200)
			status |= PHY_STAT_10FDX;
		else
			status |= PHY_STAT_10HDX;
	}
	if (mii_reg & 0x0008)
		status |= PHY_STAT_FAULT;

	*s = status;
}

static phy_cmd_t const phy_cmd_lxt971_config[] = {
		/* limit to 10MBit because my prototype board
		 * doesn't work with 100. */
		{ mk_mii_read(MII_REG_CR), mii_parse_cr },
		{ mk_mii_read(MII_REG_ANAR), mii_parse_anar },
		{ mk_mii_read(MII_LXT971_SR2), mii_parse_lxt971_sr2 },
		{ mk_mii_end, }
	};
static phy_cmd_t const phy_cmd_lxt971_startup[] = {  /* enable interrupts */
		{ mk_mii_write(MII_LXT971_IER, 0x00f2), NULL },
		{ mk_mii_write(MII_REG_CR, 0x1200), NULL }, /* autonegotiate */
		{ mk_mii_write(MII_LXT971_LCR, 0xd422), NULL }, /* LED config */
		/* Somehow does the 971 tell me that the link is down
		 * the first read after power-up.
		 * read here to get a valid value in ack_int */
		{ mk_mii_read(MII_REG_SR), mii_parse_sr },
		{ mk_mii_end, }
	};
static phy_cmd_t const phy_cmd_lxt971_ack_int[] = {
		/* acknowledge the int before reading status ! */
		{ mk_mii_read(MII_LXT971_ISR), NULL },
		/* find out the current status */
		{ mk_mii_read(MII_REG_SR), mii_parse_sr },
		{ mk_mii_read(MII_LXT971_SR2), mii_parse_lxt971_sr2 },
		{ mk_mii_end, }
	};
static phy_cmd_t const phy_cmd_lxt971_shutdown[] = { /* disable interrupts */
		{ mk_mii_write(MII_LXT971_IER, 0x0000), NULL },
		{ mk_mii_end, }
	};
static phy_info_t const phy_info_lxt971 = {
	.id = 0x0001378e,
	.name = "LXT971",
	.config = phy_cmd_lxt971_config,
	.startup = phy_cmd_lxt971_startup,
	.ack_int = phy_cmd_lxt971_ack_int,
	.shutdown = phy_cmd_lxt971_shutdown
};

/* ------------------------------------------------------------------------- */
/* The Quality Semiconductor QS6612 is used on the RPX CLLF                  */

/* register definitions */

#define MII_QS6612_MCR       17  /* Mode Control Register      */
#define MII_QS6612_FTR       27  /* Factory Test Register      */
#define MII_QS6612_MCO       28  /* Misc. Control Register     */
#define MII_QS6612_ISR       29  /* Interrupt Source Register  */
#define MII_QS6612_IMR       30  /* Interrupt Mask Register    */
#define MII_QS6612_PCR       31  /* 100BaseTx PHY Control Reg. */

static void mii_parse_qs6612_pcr(uint mii_reg, struct net_device *dev)
{
	struct fec_enet_private *fep = netdev_priv(dev);
	volatile uint *s = &(fep->phy_status);
	uint status;

	status = *s & ~(PHY_STAT_SPMASK);

	switch((mii_reg >> 2) & 7) {
	case 1: status |= PHY_STAT_10HDX; break;
	case 2: status |= PHY_STAT_100HDX; break;
	case 5: status |= PHY_STAT_10FDX; break;
	case 6: status |= PHY_STAT_100FDX; break;
}

	*s = status;
}

static phy_cmd_t const phy_cmd_qs6612_config[] = {
		/* The PHY powers up isolated on the RPX,
		 * so send a command to allow operation.
		 */
		{ mk_mii_write(MII_QS6612_PCR, 0x0dc0), NULL },

		/* parse cr and anar to get some info */
		{ mk_mii_read(MII_REG_CR), mii_parse_cr },
		{ mk_mii_read(MII_REG_ANAR), mii_parse_anar },
		{ mk_mii_end, }
	};
static phy_cmd_t const phy_cmd_qs6612_startup[] = {  /* enable interrupts */
		{ mk_mii_write(MII_QS6612_IMR, 0x003a), NULL },
		{ mk_mii_write(MII_REG_CR, 0x1200), NULL }, /* autonegotiate */
		{ mk_mii_end, }
	};
static phy_cmd_t const phy_cmd_qs6612_ack_int[] = {
		/* we need to read ISR, SR and ANER to acknowledge */
		{ mk_mii_read(MII_QS6612_ISR), NULL },
		{ mk_mii_read(MII_REG_SR), mii_parse_sr },
		{ mk_mii_read(MII_REG_ANER), NULL },

		/* read pcr to get info */
		{ mk_mii_read(MII_QS6612_PCR), mii_parse_qs6612_pcr },
		{ mk_mii_end, }
	};
static phy_cmd_t const phy_cmd_qs6612_shutdown[] = { /* disable interrupts */
		{ mk_mii_write(MII_QS6612_IMR, 0x0000), NULL },
		{ mk_mii_end, }
	};
static phy_info_t const phy_info_qs6612 = {
	.id = 0x00181440,
	.name = "QS6612",
	.config = phy_cmd_qs6612_config,
	.startup = phy_cmd_qs6612_startup,
	.ack_int = phy_cmd_qs6612_ack_int,
	.shutdown = phy_cmd_qs6612_shutdown
};

/* ------------------------------------------------------------------------- */
/* AMD AM79C874 phy                                                          */

/* register definitions for the 874 */

#define MII_AM79C874_MFR       16  /* Miscellaneous Feature Register */
#define MII_AM79C874_ICSR      17  /* Interrupt/Status Register      */
#define MII_AM79C874_DR        18  /* Diagnostic Register            */
#define MII_AM79C874_PMLR      19  /* Power and Loopback Register    */
#define MII_AM79C874_MCR       21  /* ModeControl Register           */
#define MII_AM79C874_DC        23  /* Disconnect Counter             */
#define MII_AM79C874_REC       24  /* Recieve Error Counter          */

static void mii_parse_am79c874_dr(uint mii_reg, struct net_device *dev)
{
	struct fec_enet_private *fep = netdev_priv(dev);
	volatile uint *s = &(fep->phy_status);
	uint status;

	status = *s & ~(PHY_STAT_SPMASK | PHY_STAT_ANC);

	if (mii_reg & 0x0080)
		status |= PHY_STAT_ANC;
	if (mii_reg & 0x0400)
		status |= ((mii_reg & 0x0800) ? PHY_STAT_100FDX : PHY_STAT_100HDX);
	else
		status |= ((mii_reg & 0x0800) ? PHY_STAT_10FDX : PHY_STAT_10HDX);

	*s = status;
}

static phy_cmd_t const phy_cmd_am79c874_config[] = {
		{ mk_mii_read(MII_REG_CR), mii_parse_cr },
		{ mk_mii_read(MII_REG_ANAR), mii_parse_anar },
		{ mk_mii_read(MII_AM79C874_DR), mii_parse_am79c874_dr },
		{ mk_mii_end, }
	};
static phy_cmd_t const phy_cmd_am79c874_startup[] = {  /* enable interrupts */
		{ mk_mii_write(MII_AM79C874_ICSR, 0xff00), NULL },
		{ mk_mii_write(MII_REG_CR, 0x1200), NULL }, /* autonegotiate */
		{ mk_mii_read(MII_REG_SR), mii_parse_sr },
		{ mk_mii_end, }
	};
static phy_cmd_t const phy_cmd_am79c874_ack_int[] = {
		/* find out the current status */
		{ mk_mii_read(MII_REG_SR), mii_parse_sr },
		{ mk_mii_read(MII_AM79C874_DR), mii_parse_am79c874_dr },
		/* we only need to read ISR to acknowledge */
		{ mk_mii_read(MII_AM79C874_ICSR), NULL },
		{ mk_mii_end, }
	};
static phy_cmd_t const phy_cmd_am79c874_shutdown[] = { /* disable interrupts */
		{ mk_mii_write(MII_AM79C874_ICSR, 0x0000), NULL },
		{ mk_mii_end, }
	};
static phy_info_t const phy_info_am79c874 = {
	.id = 0x00022561,
	.name = "AM79C874",
	.config = phy_cmd_am79c874_config,
	.startup = phy_cmd_am79c874_startup,
	.ack_int = phy_cmd_am79c874_ack_int,
	.shutdown = phy_cmd_am79c874_shutdown
};


/* ------------------------------------------------------------------------- */
/* Kendin KS8721BL phy                                                       */

/* register definitions for the 8721 */

#define MII_KS8721BL_RXERCR	21
#define MII_KS8721BL_ICSR	22
#define	MII_KS8721BL_PHYCR	31

static phy_cmd_t const phy_cmd_ks8721bl_config[] = {
		{ mk_mii_read(MII_REG_CR), mii_parse_cr },
		{ mk_mii_read(MII_REG_ANAR), mii_parse_anar },
		{ mk_mii_end, }
	};
static phy_cmd_t const phy_cmd_ks8721bl_startup[] = {  /* enable interrupts */
		{ mk_mii_write(MII_KS8721BL_ICSR, 0xff00), NULL },
		{ mk_mii_write(MII_REG_CR, 0x1200), NULL }, /* autonegotiate */
		{ mk_mii_read(MII_REG_SR), mii_parse_sr },
		{ mk_mii_end, }
	};
static phy_cmd_t const phy_cmd_ks8721bl_ack_int[] = {
		/* find out the current status */
		{ mk_mii_read(MII_REG_SR), mii_parse_sr },
		/* we only need to read ISR to acknowledge */
		{ mk_mii_read(MII_KS8721BL_ICSR), NULL },
		{ mk_mii_end, }
	};
static phy_cmd_t const phy_cmd_ks8721bl_shutdown[] = { /* disable interrupts */
		{ mk_mii_write(MII_KS8721BL_ICSR, 0x0000), NULL },
		{ mk_mii_end, }
	};
static phy_info_t const phy_info_ks8721bl = {
	.id = 0x00022161,
	.name = "KS8721BL",
	.config = phy_cmd_ks8721bl_config,
	.startup = phy_cmd_ks8721bl_startup,
	.ack_int = phy_cmd_ks8721bl_ack_int,
	.shutdown = phy_cmd_ks8721bl_shutdown
};

/* ------------------------------------------------------------------------- */
/* register definitions for the DP83848 */

#define MII_DP8384X_PHYSTST    16  /* PHY Status Register */

static void mii_parse_dp8384x_sr2(uint mii_reg, struct net_device *dev)
{
	struct fec_enet_private *fep = dev->priv;
	volatile uint *s = &(fep->phy_status);

	*s &= ~(PHY_STAT_SPMASK | PHY_STAT_LINK | PHY_STAT_ANC);

	/* Link up */
	if (mii_reg & 0x0001) {
		fep->link = 1;
		*s |= PHY_STAT_LINK;
	} else
		fep->link = 0;
	/* Status of link */
	if (mii_reg & 0x0010)   /* Autonegotioation complete */
		*s |= PHY_STAT_ANC;
	if (mii_reg & 0x0002) {   /* 10MBps? */
		if (mii_reg & 0x0004)   /* Full Duplex? */
			*s |= PHY_STAT_10FDX;
		else
			*s |= PHY_STAT_10HDX;
	} else {                  /* 100 Mbps? */
		if (mii_reg & 0x0004)   /* Full Duplex? */
			*s |= PHY_STAT_100FDX;
		else
			*s |= PHY_STAT_100HDX;
	}
	if (mii_reg & 0x0008)
		*s |= PHY_STAT_FAULT;
}

static phy_info_t phy_info_dp83848= {
	0x020005c9,
	"DP83848",

	(const phy_cmd_t []) {  /* config */
		{ mk_mii_read(MII_REG_CR), mii_parse_cr },
		{ mk_mii_read(MII_REG_ANAR), mii_parse_anar },
		{ mk_mii_read(MII_DP8384X_PHYSTST), mii_parse_dp8384x_sr2 },
		{ mk_mii_end, }
	},
	(const phy_cmd_t []) {  /* startup - enable interrupts */
		{ mk_mii_write(MII_REG_CR, 0x1200), NULL }, /* autonegotiate */
		{ mk_mii_read(MII_REG_SR), mii_parse_sr },
		{ mk_mii_end, }
	},
	(const phy_cmd_t []) { /* ack_int - never happens, no interrupt */
		{ mk_mii_end, }
	},
	(const phy_cmd_t []) {  /* shutdown */
		{ mk_mii_end, }
	},
};

/* ------------------------------------------------------------------------- */

static phy_info_t const * const phy_info[] = {
	&phy_info_lxt970,
	&phy_info_lxt971,
	&phy_info_qs6612,
	&phy_info_am79c874,
	&phy_info_ks8721bl,
	&phy_info_dp83848,
	NULL
};

/* ------------------------------------------------------------------------- */
#ifdef HAVE_mii_link_interrupt
#ifdef CONFIG_RPXCLASSIC
static void
mii_link_interrupt(void *dev_id);
#else
static irqreturn_t
mii_link_interrupt(int irq, void * dev_id);
#endif
#endif

#if defined(CONFIG_M5272)
/*
 *	Code specific to Coldfire 5272 setup.
 */
static void __inline__ fec_request_intrs(struct net_device *dev)
{
	volatile unsigned long *icrp;
	static const struct idesc {
		char *name;
		unsigned short irq;
		irq_handler_t handler;
	} *idp, id[] = {
		{ "fec(RX)", 86, fec_enet_interrupt },
		{ "fec(TX)", 87, fec_enet_interrupt },
		{ "fec(OTHER)", 88, fec_enet_interrupt },
		{ "fec(MII)", 66, mii_link_interrupt },
		{ NULL },
	};

	/* Setup interrupt handlers. */
	for (idp = id; idp->name; idp++) {
		if (request_irq(idp->irq, idp->handler, IRQF_DISABLED, idp->name, dev) != 0)
			printk("FEC: Could not allocate %s IRQ(%d)!\n", idp->name, idp->irq);
	}

	/* Unmask interrupt at ColdFire 5272 SIM */
	icrp = (volatile unsigned long *) (MCF_MBAR + MCFSIM_ICR3);
	*icrp = 0x00000ddd;
	icrp = (volatile unsigned long *) (MCF_MBAR + MCFSIM_ICR1);
	*icrp = 0x0d000000;
}

static void __inline__ fec_set_mii(struct net_device *dev, struct fec_enet_private *fep)
{
	volatile fec_t *fecp;

	fecp = fep->hwp;
	fecp->fec_r_cntrl = OPT_FRAME_SIZE | 0x04;
	fecp->fec_x_cntrl = 0x00;

	/*
	 * Set MII speed to 2.5 MHz
	 * See 5272 manual section 11.5.8: MSCR
	 */
	fep->phy_speed = ((((MCF_CLK / 4) / (2500000 / 10)) + 5) / 10) * 2;
	fecp->fec_mii_speed = fep->phy_speed;

	fec_restart(dev, 0);
}

static void __inline__ fec_get_mac(struct net_device *dev)
{
	struct fec_enet_private *fep = netdev_priv(dev);
	volatile fec_t *fecp;
	unsigned char *iap, tmpaddr[ETH_ALEN];

	fecp = fep->hwp;

	if (FEC_FLASHMAC) {
		/*
		 * Get MAC address from FLASH.
		 * If it is all 1's or 0's, use the default.
		 */
		iap = (unsigned char *)FEC_FLASHMAC;
		if ((iap[0] == 0) && (iap[1] == 0) && (iap[2] == 0) &&
		    (iap[3] == 0) && (iap[4] == 0) && (iap[5] == 0))
			iap = fec_mac_default;
		if ((iap[0] == 0xff) && (iap[1] == 0xff) && (iap[2] == 0xff) &&
		    (iap[3] == 0xff) && (iap[4] == 0xff) && (iap[5] == 0xff))
			iap = fec_mac_default;
	} else {
		*((unsigned long *) &tmpaddr[0]) = fecp->fec_addr_low;
		*((unsigned short *) &tmpaddr[4]) = (fecp->fec_addr_high >> 16);
		iap = &tmpaddr[0];
	}

	memcpy(dev->dev_addr, iap, ETH_ALEN);

	/* Adjust MAC if using default MAC address */
	if (iap == fec_mac_default)
		 dev->dev_addr[ETH_ALEN-1] = fec_mac_default[ETH_ALEN-1] + fep->index;
}

static void __inline__ fec_enable_phy_intr(void)
{
}

static void __inline__ fec_disable_phy_intr(void)
{
	volatile unsigned long *icrp;
	icrp = (volatile unsigned long *) (MCF_MBAR + MCFSIM_ICR1);
	*icrp = 0x08000000;
}

static void __inline__ fec_phy_ack_intr(void)
{
	volatile unsigned long *icrp;
	/* Acknowledge the interrupt */