Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 1569 insertions, 0 deletions

diff --git a/drivers/net/gt96100eth.c b/drivers/net/gt96100eth.c
new file mode 100644
index 000000000000..666cfbbcf6d9
--- /dev/null
+++ b/drivers/net/gt96100eth.c
@@ -0,0 +1,1569 @@
+/*
+ * Copyright 2000, 2001 MontaVista Software Inc.
+ * Author: MontaVista Software, Inc.
+ *         	stevel@mvista.com or source@mvista.com
+ *
+ *  This program is free software; you can distribute it and/or modify it
+ *  under the terms of the GNU General Public License (Version 2) as
+ *  published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope 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.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
+ *
+ * Ethernet driver for the MIPS GT96100 Advanced Communication Controller.
+ * 
+ *  Revision history
+ *    
+ *    11.11.2001  Moved to 2.4.14, ppopov@mvista.com.  Modified driver to add
+ *                proper gt96100A support.
+ *    12.05.2001  Moved eth port 0 to irq 3 (mapped to GT_SERINT0 on EV96100A)
+ *                in order for both ports to work. Also cleaned up boot
+ *                option support (mac address string parsing), fleshed out
+ *                gt96100_cleanup_module(), and other general code cleanups
+ *                <stevel@mvista.com>.
+ */
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/timer.h>
+#include <linux/errno.h>
+#include <linux/in.h>
+#include <linux/ioport.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/pci.h>
+#include <linux/init.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/skbuff.h>
+#include <linux/delay.h>
+#include <linux/ctype.h>
+#include <linux/bitops.h>
+
+#include <asm/irq.h>
+#include <asm/io.h>
+
+#define DESC_BE 1
+#define DESC_DATA_BE 1
+
+#define GT96100_DEBUG 2
+
+#include "gt96100eth.h"
+
+// prototypes
+static void* dmaalloc(size_t size, dma_addr_t *dma_handle);
+static void dmafree(size_t size, void *vaddr);
+static void gt96100_delay(int msec);
+static int gt96100_add_hash_entry(struct net_device *dev,
+				  unsigned char* addr);
+static void read_mib_counters(struct gt96100_private *gp);
+static int read_MII(int phy_addr, u32 reg);
+static int write_MII(int phy_addr, u32 reg, u16 data);
+static int gt96100_init_module(void);
+static void gt96100_cleanup_module(void);
+static void dump_MII(int dbg_lvl, struct net_device *dev);
+static void dump_tx_desc(int dbg_lvl, struct net_device *dev, int i);
+static void dump_rx_desc(int dbg_lvl, struct net_device *dev, int i);
+static void dump_skb(int dbg_lvl, struct net_device *dev,
+		     struct sk_buff *skb);
+static void dump_hw_addr(int dbg_lvl, struct net_device *dev,
+			 const char* pfx, unsigned char* addr_str);
+static void update_stats(struct gt96100_private *gp);
+static void abort(struct net_device *dev, u32 abort_bits);
+static void hard_stop(struct net_device *dev);
+static void enable_ether_irq(struct net_device *dev);
+static void disable_ether_irq(struct net_device *dev);
+static int gt96100_probe1(struct pci_dev *pci, int port_num);
+static void reset_tx(struct net_device *dev);
+static void reset_rx(struct net_device *dev);
+static int gt96100_check_tx_consistent(struct gt96100_private *gp);
+static int gt96100_init(struct net_device *dev);
+static int gt96100_open(struct net_device *dev);
+static int gt96100_close(struct net_device *dev);
+static int gt96100_tx(struct sk_buff *skb, struct net_device *dev);
+static int gt96100_rx(struct net_device *dev, u32 status);
+static irqreturn_t gt96100_interrupt(int irq, void *dev_id, struct pt_regs *regs);
+static void gt96100_tx_timeout(struct net_device *dev);
+static void gt96100_set_rx_mode(struct net_device *dev);
+static struct net_device_stats* gt96100_get_stats(struct net_device *dev);
+
+extern char * __init prom_getcmdline(void);
+
+static int max_interrupt_work = 32;
+
+#define nibswap(x) ((((x) >> 4) & 0x0f) | (((x) << 4) & 0xf0))
+
+#define RUN_AT(x) (jiffies + (x))
+
+// For reading/writing 32-bit words and half-words from/to DMA memory
+#ifdef DESC_BE
+#define cpu_to_dma32 cpu_to_be32
+#define dma32_to_cpu be32_to_cpu
+#define cpu_to_dma16 cpu_to_be16
+#define dma16_to_cpu be16_to_cpu
+#else
+#define cpu_to_dma32 cpu_to_le32
+#define dma32_to_cpu le32_to_cpu
+#define cpu_to_dma16 cpu_to_le16
+#define dma16_to_cpu le16_to_cpu
+#endif
+
+static char mac0[18] = "00.02.03.04.05.06";
+static char mac1[18] = "00.01.02.03.04.05";
+MODULE_PARM(mac0, "c18");
+MODULE_PARM(mac1, "c18");
+MODULE_PARM_DESC(mac0, "MAC address for GT96100 ethernet port 0");
+MODULE_PARM_DESC(mac1, "MAC address for GT96100 ethernet port 1");
+
+/*
+ * Info for the GT96100 ethernet controller's ports.
+ */
+static struct gt96100_if_t {
+	struct net_device *dev;
+	unsigned int  iobase;   // IO Base address of this port
+	int           irq;      // IRQ number of this port
+	char         *mac_str;
+} gt96100_iflist[NUM_INTERFACES] = {
+	{
+		NULL,
+		GT96100_ETH0_BASE, GT96100_ETHER0_IRQ,
+		mac0
+	},
+	{
+		NULL,
+		GT96100_ETH1_BASE, GT96100_ETHER1_IRQ,
+		mac1
+	}
+};
+
+static inline const char*
+chip_name(int chip_rev)
+{
+	switch (chip_rev) {
+	case REV_GT96100:
+		return "GT96100";
+	case REV_GT96100A_1:
+	case REV_GT96100A:
+		return "GT96100A";
+	default:
+		return "Unknown GT96100";
+	}
+}
+
+/*
+  DMA memory allocation, derived from pci_alloc_consistent.
+*/
+static void * dmaalloc(size_t size, dma_addr_t *dma_handle)
+{
+	void *ret;
+	
+	ret = (void *)__get_free_pages(GFP_ATOMIC | GFP_DMA, get_order(size));
+	
+	if (ret != NULL) {
+		dma_cache_inv((unsigned long)ret, size);
+		if (dma_handle != NULL)
+			*dma_handle = virt_to_phys(ret);
+
+		/* bump virtual address up to non-cached area */
+		ret = (void*)KSEG1ADDR(ret);
+	}
+
+	return ret;
+}
+
+static void dmafree(size_t size, void *vaddr)
+{
+	vaddr = (void*)KSEG0ADDR(vaddr);
+	free_pages((unsigned long)vaddr, get_order(size));
+}
+
+static void gt96100_delay(int ms)
+{
+	if (in_interrupt())
+		return;
+	else
+		msleep_interruptible(ms);
+}
+
+static int
+parse_mac_addr(struct net_device *dev, char* macstr)
+{
+	int i, j;
+	unsigned char result, value;
+	
+	for (i=0; i<6; i++) {
+		result = 0;
+		if (i != 5 && *(macstr+2) != '.') {
+			err(__FILE__ "invalid mac address format: %d %c\n",
+			    i, *(macstr+2));
+			return -EINVAL;
+		}
+		
+		for (j=0; j<2; j++) {
+			if (isxdigit(*macstr) &&
+			    (value = isdigit(*macstr) ? *macstr-'0' : 
+			     toupper(*macstr)-'A'+10) < 16) {
+				result = result*16 + value;
+				macstr++;
+			} else {
+				err(__FILE__ "invalid mac address "
+				    "character: %c\n", *macstr);
+				return -EINVAL;
+			}
+		}
+
+		macstr++; // step over '.'
+		dev->dev_addr[i] = result;
+	}
+
+	return 0;
+}
+
+
+static int
+read_MII(int phy_addr, u32 reg)
+{
+	int timedout = 20;
+	u32 smir = smirOpCode | (phy_addr << smirPhyAdBit) |
+		(reg << smirRegAdBit);
+
+	// wait for last operation to complete
+	while (GT96100_READ(GT96100_ETH_SMI_REG) & smirBusy) {
+		// snooze for 1 msec and check again
+		gt96100_delay(1);
+
+		if (--timedout == 0) {
+			printk(KERN_ERR "%s: busy timeout!!\n", __FUNCTION__);
+			return -ENODEV;
+		}
+	}
+    
+	GT96100_WRITE(GT96100_ETH_SMI_REG, smir);
+
+	timedout = 20;
+	// wait for read to complete
+	while (!((smir = GT96100_READ(GT96100_ETH_SMI_REG)) & smirReadValid)) {
+		// snooze for 1 msec and check again
+		gt96100_delay(1);
+	
+		if (--timedout == 0) {
+			printk(KERN_ERR "%s: timeout!!\n", __FUNCTION__);
+			return -ENODEV;
+		}
+	}
+
+	return (int)(smir & smirDataMask);
+}
+
+static void
+dump_tx_desc(int dbg_lvl, struct net_device *dev, int i)
+{
+	struct gt96100_private *gp = netdev_priv(dev);
+	gt96100_td_t *td = &gp->tx_ring[i];
+
+	dbg(dbg_lvl, "Tx descriptor at 0x%08lx:\n", virt_to_phys(td));
+	dbg(dbg_lvl,
+	    "    cmdstat=%04x, byte_cnt=%04x, buff_ptr=%04x, next=%04x\n",
+	    dma32_to_cpu(td->cmdstat),
+	    dma16_to_cpu(td->byte_cnt),
+	    dma32_to_cpu(td->buff_ptr),
+	    dma32_to_cpu(td->next));
+}
+
+static void
+dump_rx_desc(int dbg_lvl, struct net_device *dev, int i)
+{
+	struct gt96100_private *gp = netdev_priv(dev);
+	gt96100_rd_t *rd = &gp->rx_ring[i];
+
+	dbg(dbg_lvl, "Rx descriptor at 0x%08lx:\n", virt_to_phys(rd));
+	dbg(dbg_lvl, "    cmdstat=%04x, buff_sz=%04x, byte_cnt=%04x, "
+	    "buff_ptr=%04x, next=%04x\n",
+	    dma32_to_cpu(rd->cmdstat),
+	    dma16_to_cpu(rd->buff_sz),
+	    dma16_to_cpu(rd->byte_cnt),
+	    dma32_to_cpu(rd->buff_ptr),
+	    dma32_to_cpu(rd->next));
+}
+
+static int
+write_MII(int phy_addr, u32 reg, u16 data)
+{
+	int timedout = 20;
+	u32 smir = (phy_addr << smirPhyAdBit) |
+		(reg << smirRegAdBit) | data;
+
+	// wait for last operation to complete
+	while (GT96100_READ(GT96100_ETH_SMI_REG) & smirBusy) {
+		// snooze for 1 msec and check again
+		gt96100_delay(1);
+	
+		if (--timedout == 0) {
+			printk(KERN_ERR "%s: busy timeout!!\n", __FUNCTION__);
+			return -1;
+		}
+	}
+
+	GT96100_WRITE(GT96100_ETH_SMI_REG, smir);
+	return 0;
+}
+
+static void
+dump_MII(int dbg_lvl, struct net_device *dev)
+{
+	int i, val;
+	struct gt96100_private *gp = netdev_priv(dev);
+    
+	if (dbg_lvl <= GT96100_DEBUG) {
+		for (i=0; i<7; i++) {
+			if ((val = read_MII(gp->phy_addr, i)) >= 0)
+				printk("MII Reg %d=%x\n", i, val);
+		}
+		for (i=16; i<21; i++) {
+			if ((val = read_MII(gp->phy_addr, i)) >= 0)
+				printk("MII Reg %d=%x\n", i, val);
+		}
+	}
+}
+
+static void
+dump_hw_addr(int dbg_lvl, struct net_device *dev, const char* pfx,
+	     unsigned char* addr_str)
+{
+	int i;
+	char buf[100], octet[5];
+    
+	if (dbg_lvl <= GT96100_DEBUG) {
+		strcpy(buf, pfx);
+		for (i = 0; i < 6; i++) {
+			sprintf(octet, "%2.2x%s",
+				addr_str[i], i<5 ? ":" : "\n");
+			strcat(buf, octet);
+		}
+		info("%s", buf);
+	}
+}
+
+
+static void
+dump_skb(int dbg_lvl, struct net_device *dev, struct sk_buff *skb)
+{
+	int i;
+	unsigned char* skbdata;
+    
+	if (dbg_lvl <= GT96100_DEBUG) {
+		dbg(dbg_lvl, "%s: skb=%p, skb->data=%p, skb->len=%d\n",
+		    __FUNCTION__, skb, skb->data, skb->len);
+
+		skbdata = (unsigned char*)KSEG1ADDR(skb->data);
+    
+		for (i=0; i<skb->len; i++) {
+			if (!(i % 16))
+				printk(KERN_DEBUG "\n   %3.3x: %2.2x,",
+				       i, skbdata[i]);
+			else
+				printk(KERN_DEBUG "%2.2x,", skbdata[i]);
+		}
+		printk(KERN_DEBUG "\n");
+	}
+}
+
+
+static int
+gt96100_add_hash_entry(struct net_device *dev, unsigned char* addr)
+{
+	struct gt96100_private *gp = netdev_priv(dev);
+	//u16 hashResult, stmp;
+	//unsigned char ctmp, hash_ea[6];
+	u32 tblEntry1, tblEntry0, *tblEntryAddr;
+	int i;
+
+	tblEntry1 = hteValid | hteRD;
+	tblEntry1 |= (u32)addr[5] << 3;
+	tblEntry1 |= (u32)addr[4] << 11;
+	tblEntry1 |= (u32)addr[3] << 19;
+	tblEntry1 |= ((u32)addr[2] & 0x1f) << 27;
+	dbg(3, "%s: tblEntry1=%x\n", __FUNCTION__, tblEntry1);
+	tblEntry0 = ((u32)addr[2] >> 5) & 0x07;
+	tblEntry0 |= (u32)addr[1] << 3;
+	tblEntry0 |= (u32)addr[0] << 11;
+	dbg(3, "%s: tblEntry0=%x\n", __FUNCTION__, tblEntry0);
+
+#if 0
+
+	for (i=0; i<6; i++) {
+		// nibble swap
+		ctmp = nibswap(addr[i]);
+		// invert every nibble
+		hash_ea[i] = ((ctmp&1)<<3) | ((ctmp&8)>>3) |
+			((ctmp&2)<<1) | ((ctmp&4)>>1);
+		hash_ea[i] |= ((ctmp&0x10)<<3) | ((ctmp&0x80)>>3) |
+			((ctmp&0x20)<<1) | ((ctmp&0x40)>>1);
+	}
+
+	dump_hw_addr(3, dev, "%s: nib swap/invt addr=", __FUNCTION__, hash_ea);
+    
+	if (gp->hash_mode == 0) {
+		hashResult = ((u16)hash_ea[0] & 0xfc) << 7;
+		stmp = ((u16)hash_ea[0] & 0x03) |
+			(((u16)hash_ea[1] & 0x7f) << 2);
+		stmp ^= (((u16)hash_ea[1] >> 7) & 0x01) |
+			((u16)hash_ea[2] << 1);
+		stmp ^= (u16)hash_ea[3] | (((u16)hash_ea[4] & 1) << 8);
+		hashResult |= stmp;
+	} else {
+		return -1; // don't support hash mode 1
+	}
+
+	dbg(3, "%s: hashResult=%x\n", __FUNCTION__, hashResult);
+
+	tblEntryAddr =
+		(u32 *)(&gp->hash_table[((u32)hashResult & 0x7ff) << 3]);
+    
+	dbg(3, "%s: tblEntryAddr=%p\n", tblEntryAddr, __FUNCTION__);
+
+	for (i=0; i<HASH_HOP_NUMBER; i++) {
+		if ((*tblEntryAddr & hteValid) &&
+		    !(*tblEntryAddr & hteSkip)) {
+			// This entry is already occupied, go to next entry
+			tblEntryAddr += 2;
+			dbg(3, "%s: skipping to %p\n", __FUNCTION__, 
+			    tblEntryAddr);
+		} else {
+			memset(tblEntryAddr, 0, 8);
+			tblEntryAddr[1] = cpu_to_dma32(tblEntry1);
+			tblEntryAddr[0] = cpu_to_dma32(tblEntry0);
+			break;
+		}
+	}
+
+	if (i >= HASH_HOP_NUMBER) {
+		err("%s: expired!\n", __FUNCTION__);
+		return -1; // Couldn't find an unused entry
+	}
+
+#else
+
+	tblEntryAddr = (u32 *)gp->hash_table;
+	for (i=0; i<RX_HASH_TABLE_SIZE/4; i+=2) {
+		tblEntryAddr[i+1] = cpu_to_dma32(tblEntry1);
+		tblEntryAddr[i] = cpu_to_dma32(tblEntry0);
+	}
+
+#endif
+    
+	return 0;
+}
+
+
+static void
+read_mib_counters(struct gt96100_private *gp)
+{
+	u32* mib_regs = (u32*)&gp->mib;
+	int i;
+    
+	for (i=0; i<sizeof(mib_counters_t)/sizeof(u32); i++)
+		mib_regs[i] = GT96100ETH_READ(gp, GT96100_ETH_MIB_COUNT_BASE +
+					      i*sizeof(u32));
+}
+
+
+static void
+update_stats(struct gt96100_private *gp)
+{
+	mib_counters_t *mib = &gp->mib;
+	struct net_device_stats *stats = &gp->stats;
+    
+	read_mib_counters(gp);
+    
+	stats->rx_packets = mib->totalFramesReceived;
+	stats->tx_packets = mib->framesSent;
+	stats->rx_bytes = mib->totalByteReceived;
+	stats->tx_bytes = mib->byteSent;
+	stats->rx_errors = mib->totalFramesReceived - mib->framesReceived;
+	//the tx error counters are incremented by the ISR
+	//rx_dropped incremented by gt96100_rx
+	//tx_dropped incremented by gt96100_tx
+	stats->multicast = mib->multicastFramesReceived;
+	// collisions incremented by gt96100_tx_complete
+	stats->rx_length_errors = mib->oversizeFrames + mib->fragments;
+	// The RxError condition means the Rx DMA encountered a
+	// CPU owned descriptor, which, if things are working as
+	// they should, means the Rx ring has overflowed.
+	stats->rx_over_errors = mib->macRxError;
+	stats->rx_crc_errors = mib->cRCError;
+}
+
+static void
+abort(struct net_device *dev, u32 abort_bits)
+{
+	struct gt96100_private *gp = netdev_priv(dev);
+	int timedout = 100; // wait up to 100 msec for hard stop to complete
+
+	dbg(3, "%s\n", __FUNCTION__);
+
+	// Return if neither Rx or Tx abort bits are set
+	if (!(abort_bits & (sdcmrAR | sdcmrAT)))
+		return;
+
+	// make sure only the Rx/Tx abort bits are set
+	abort_bits &= (sdcmrAR | sdcmrAT);
+    
+	spin_lock(&gp->lock);
+
+	// abort any Rx/Tx DMA immediately
+	GT96100ETH_WRITE(gp, GT96100_ETH_SDMA_COMM, abort_bits);
+
+	dbg(3, "%s: SDMA comm = %x\n", __FUNCTION__,
+	    GT96100ETH_READ(gp, GT96100_ETH_SDMA_COMM));
+
+	// wait for abort to complete
+	while (GT96100ETH_READ(gp, GT96100_ETH_SDMA_COMM) & abort_bits) {
+		// snooze for 1 msec and check again
+		gt96100_delay(1);
+	
+		if (--timedout == 0) {
+			err("%s: timeout!!\n", __FUNCTION__);
+			break;
+		}
+	}
+
+	spin_unlock(&gp->lock);
+}
+
+
+static void
+hard_stop(struct net_device *dev)
+{
+	struct gt96100_private *gp = netdev_priv(dev);
+
+	dbg(3, "%s\n", __FUNCTION__);
+
+	disable_ether_irq(dev);
+
+	abort(dev, sdcmrAR | sdcmrAT);
+
+	// disable port
+	GT96100ETH_WRITE(gp, GT96100_ETH_PORT_CONFIG, 0);
+}
+
+
+static void
+enable_ether_irq(struct net_device *dev)
+{
+	struct gt96100_private *gp = netdev_priv(dev);
+	u32 intMask;
+	/*
+	 * route ethernet interrupt to GT_SERINT0 for port 0,
+	 * GT_INT0 for port 1.
+	 */
+	int intr_mask_reg = (gp->port_num == 0) ?
+		GT96100_SERINT0_MASK : GT96100_INT0_HIGH_MASK;
+	
+	if (gp->chip_rev >= REV_GT96100A_1) {
+		intMask = icrTxBufferLow | icrTxEndLow |
+			icrTxErrorLow  | icrRxOVR | icrTxUdr |
+			icrRxBufferQ0 | icrRxErrorQ0 |
+			icrMIIPhySTC | icrEtherIntSum;
+	}
+	else {
+		intMask = icrTxBufferLow | icrTxEndLow |
+			icrTxErrorLow  | icrRxOVR | icrTxUdr |
+			icrRxBuffer | icrRxError |
+			icrMIIPhySTC | icrEtherIntSum;
+	}
+	
+	// unmask interrupts
+	GT96100ETH_WRITE(gp, GT96100_ETH_INT_MASK, intMask);
+    
+	intMask = GT96100_READ(intr_mask_reg);
+	intMask |= 1<<gp->port_num;
+	GT96100_WRITE(intr_mask_reg, intMask);
+}
+
+static void
+disable_ether_irq(struct net_device *dev)
+{
+	struct gt96100_private *gp = netdev_priv(dev);
+	u32 intMask;
+	int intr_mask_reg = (gp->port_num == 0) ?
+		GT96100_SERINT0_MASK : GT96100_INT0_HIGH_MASK;
+
+	intMask = GT96100_READ(intr_mask_reg);
+	intMask &= ~(1<<gp->port_num);
+	GT96100_WRITE(intr_mask_reg, intMask);
+    
+	GT96100ETH_WRITE(gp, GT96100_ETH_INT_MASK, 0);
+}
+
+
+/*
+ * Init GT96100 ethernet controller driver
+ */
+static int gt96100_init_module(void)
+{
+	struct pci_dev *pci;
+	int i, retval=0;
+	u32 cpuConfig;
+
+	/*
+	 * Stupid probe because this really isn't a PCI device
+	 */
+	if (!(pci = pci_find_device(PCI_VENDOR_ID_MARVELL,
+	                            PCI_DEVICE_ID_MARVELL_GT96100, NULL)) &&
+	    !(pci = pci_find_device(PCI_VENDOR_ID_MARVELL,
+		                    PCI_DEVICE_ID_MARVELL_GT96100A, NULL))) {
+		printk(KERN_ERR __FILE__ ": GT96100 not found!\n");
+		return -ENODEV;
+	}
+
+	cpuConfig = GT96100_READ(GT96100_CPU_INTERF_CONFIG);
+	if (cpuConfig & (1<<12)) {
+		printk(KERN_ERR __FILE__
+		       ": must be in Big Endian mode!\n");
+		return -ENODEV;
+	}
+
+	for (i=0; i < NUM_INTERFACES; i++)
+		retval |= gt96100_probe1(pci, i);
+
+	return retval;
+}
+
+static int __init gt96100_probe1(struct pci_dev *pci, int port_num)
+{
+	struct gt96100_private *gp = NULL;
+	struct gt96100_if_t *gtif = &gt96100_iflist[port_num];
+	int phy_addr, phy_id1, phy_id2;
+	u32 phyAD;
+	int retval;
+	unsigned char chip_rev;
+	struct net_device *dev = NULL;
+    
+	if (gtif->irq < 0) {
+		printk(KERN_ERR "%s: irq unknown - probing not supported\n",
+		      __FUNCTION__);
+		return -ENODEV;
+	}
+    
+	pci_read_config_byte(pci, PCI_REVISION_ID, &chip_rev);
+
+	if (chip_rev >= REV_GT96100A_1) {
+		phyAD = GT96100_READ(GT96100_ETH_PHY_ADDR_REG);
+		phy_addr = (phyAD >> (5*port_num)) & 0x1f;
+	} else {
+		/*
+		 * not sure what's this about -- probably a gt bug
+		 */
+		phy_addr = port_num;
+		phyAD = GT96100_READ(GT96100_ETH_PHY_ADDR_REG);
+		phyAD &= ~(0x1f << (port_num*5));
+		phyAD |= phy_addr << (port_num*5);
+		GT96100_WRITE(GT96100_ETH_PHY_ADDR_REG, phyAD);
+	}
+	
+	// probe for the external PHY
+	if ((phy_id1 = read_MII(phy_addr, 2)) <= 0 ||
+	    (phy_id2 = read_MII(phy_addr, 3)) <= 0) {
+		printk(KERN_ERR "%s: no PHY found on MII%d\n", __FUNCTION__, port_num);
+		return -ENODEV;
+	}
+	
+	if (!request_region(gtif->iobase, GT96100_ETH_IO_SIZE, "GT96100ETH")) {
+		printk(KERN_ERR "%s: request_region failed\n", __FUNCTION__);
+		return -EBUSY;
+	}
+
+	dev = alloc_etherdev(sizeof(struct gt96100_private));
+	if (!dev)
+		goto out;
+	gtif->dev = dev;
+	
+	/* private struct aligned and zeroed by alloc_etherdev */
+	/* Fill in the 'dev' fields. */
+	dev->base_addr = gtif->iobase;
+	dev->irq = gtif->irq;
+
+	if ((retval = parse_mac_addr(dev, gtif->mac_str))) {
+		err("%s: MAC address parse failed\n", __FUNCTION__);
+		retval = -EINVAL;
+		goto out1;
+	}
+
+	gp = netdev_priv(dev);
+
+	memset(gp, 0, sizeof(*gp)); // clear it
+
+	gp->port_num = port_num;
+	gp->io_size = GT96100_ETH_IO_SIZE;
+	gp->port_offset = port_num * GT96100_ETH_IO_SIZE;
+	gp->phy_addr = phy_addr;
+	gp->chip_rev = chip_rev;
+
+	info("%s found at 0x%x, irq %d\n",
+	     chip_name(gp->chip_rev), gtif->iobase, gtif->irq);
+	dump_hw_addr(0, dev, "HW Address ", dev->dev_addr);
+	info("%s chip revision=%d\n", chip_name(gp->chip_rev), gp->chip_rev);
+	info("%s ethernet port %d\n", chip_name(gp->chip_rev), gp->port_num);
+	info("external PHY ID1=0x%04x, ID2=0x%04x\n", phy_id1, phy_id2);
+
+	// Allocate Rx and Tx descriptor rings
+	if (gp->rx_ring == NULL) {
+		// All descriptors in ring must be 16-byte aligned
+		gp->rx_ring = dmaalloc(sizeof(gt96100_rd_t) * RX_RING_SIZE
+				       + sizeof(gt96100_td_t) * TX_RING_SIZE,
+				       &gp->rx_ring_dma);
+		if (gp->rx_ring == NULL) {
+			retval = -ENOMEM;
+			goto out1;
+		}
+	
+		gp->tx_ring = (gt96100_td_t *)(gp->rx_ring + RX_RING_SIZE);
+		gp->tx_ring_dma =
+			gp->rx_ring_dma + sizeof(gt96100_rd_t) * RX_RING_SIZE;
+	}
+    
+	// Allocate the Rx Data Buffers
+	if (gp->rx_buff == NULL) {
+		gp->rx_buff = dmaalloc(PKT_BUF_SZ*RX_RING_SIZE,
+				       &gp->rx_buff_dma);
+		if (gp->rx_buff == NULL) {
+			retval = -ENOMEM;
+			goto out2;
+		}
+	}
+    
+	dbg(3, "%s: rx_ring=%p, tx_ring=%p\n", __FUNCTION__,
+	    gp->rx_ring, gp->tx_ring);
+
+	// Allocate Rx Hash Table
+	if (gp->hash_table == NULL) {
+		gp->hash_table = (char*)dmaalloc(RX_HASH_TABLE_SIZE,
+						 &gp->hash_table_dma);
+		if (gp->hash_table == NULL) {
+			retval = -ENOMEM;
+			goto out3;
+		}
+	}
+    
+	dbg(3, "%s: hash=%p\n", __FUNCTION__, gp->hash_table);
+
+	spin_lock_init(&gp->lock);
+    
+	dev->open = gt96100_open;
+	dev->hard_start_xmit = gt96100_tx;
+	dev->stop = gt96100_close;
+	dev->get_stats = gt96100_get_stats;
+	//dev->do_ioctl = gt96100_ioctl;
+	dev->set_multicast_list = gt96100_set_rx_mode;
+	dev->tx_timeout = gt96100_tx_timeout;
+	dev->watchdog_timeo = GT96100ETH_TX_TIMEOUT;
+
+	retval = register_netdev(dev);
+	if (retval)
+		goto out4;
+	return 0;
+
+out4:
+	dmafree(RX_HASH_TABLE_SIZE, gp->hash_table_dma);
+out3:
+	dmafree(PKT_BUF_SZ*RX_RING_SIZE, gp->rx_buff);
+out2:
+	dmafree(sizeof(gt96100_rd_t) * RX_RING_SIZE
+		+ sizeof(gt96100_td_t) * TX_RING_SIZE,
+		gp->rx_ring);
+out1:
+	free_netdev (dev);
+out:
+	release_region(gtif->iobase, GT96100_ETH_IO_SIZE);
+
+	err("%s failed.  Returns %d\n", __FUNCTION__, retval);
+	return retval;
+}
+
+
+static void
+reset_tx(struct net_device *dev)
+{
+	struct gt96100_private *gp = netdev_priv(dev);
+	int i;
+
+	abort(dev, sdcmrAT);
+
+	for (i=0; i<TX_RING_SIZE; i++) {
+		if (gp->tx_skbuff[i]) {
+			if (in_interrupt())
+				dev_kfree_skb_irq(gp->tx_skbuff[i]);
+			else
+				dev_kfree_skb(gp->tx_skbuff[i]);
+			gp->tx_skbuff[i] = NULL;
+		}
+
+		gp->tx_ring[i].cmdstat = 0; // CPU owns
+		gp->tx_ring[i].byte_cnt = 0;
+		gp->tx_ring[i].buff_ptr = 0;
+		gp->tx_ring[i].next =
+			cpu_to_dma32(gp->tx_ring_dma +
+				     sizeof(gt96100_td_t) * (i+1));
+		dump_tx_desc(4, dev, i);
+	}
+	/* Wrap the ring. */
+	gp->tx_ring[i-1].next = cpu_to_dma32(gp->tx_ring_dma);
+    
+	// setup only the lowest priority TxCDP reg
+	GT96100ETH_WRITE(gp, GT96100_ETH_CURR_TX_DESC_PTR0, gp->tx_ring_dma);
+	GT96100ETH_WRITE(gp, GT96100_ETH_CURR_TX_DESC_PTR1, 0);
+
+	// init Tx indeces and pkt counter
+	gp->tx_next_in = gp->tx_next_out = 0;
+	gp->tx_count = 0;
+
+}
+
+static void
+reset_rx(struct net_device *dev)
+{
+	struct gt96100_private *gp = netdev_priv(dev);
+	int i;
+
+	abort(dev, sdcmrAR);
+    
+	for (i=0; i<RX_RING_SIZE; i++) {
+		gp->rx_ring[i].next =
+			cpu_to_dma32(gp->rx_ring_dma +
+				     sizeof(gt96100_rd_t) * (i+1));
+		gp->rx_ring[i].buff_ptr =
+			cpu_to_dma32(gp->rx_buff_dma + i*PKT_BUF_SZ);
+		gp->rx_ring[i].buff_sz = cpu_to_dma16(PKT_BUF_SZ);
+		// Give ownership to device, set first and last, enable intr
+		gp->rx_ring[i].cmdstat =
+			cpu_to_dma32((u32)(rxFirst | rxLast | rxOwn | rxEI));
+		dump_rx_desc(4, dev, i);
+	}
+	/* Wrap the ring. */
+	gp->rx_ring[i-1].next = cpu_to_dma32(gp->rx_ring_dma);
+
+	// Setup only the lowest priority RxFDP and RxCDP regs
+	for (i=0; i<4; i++) {
+		if (i == 0) {
+			GT96100ETH_WRITE(gp, GT96100_ETH_1ST_RX_DESC_PTR0,
+					 gp->rx_ring_dma);
+			GT96100ETH_WRITE(gp, GT96100_ETH_CURR_RX_DESC_PTR0,
+					 gp->rx_ring_dma);
+		} else {
+			GT96100ETH_WRITE(gp,
+					 GT96100_ETH_1ST_RX_DESC_PTR0 + i*4,
+					 0);
+			GT96100ETH_WRITE(gp,
+					 GT96100_ETH_CURR_RX_DESC_PTR0 + i*4,
+					 0);
+		}
+	}
+
+	// init Rx NextOut index
+	gp->rx_next_out = 0;
+}
+
+
+// Returns 1 if the Tx counter and indeces don't gel
+static int
+gt96100_check_tx_consistent(struct gt96100_private *gp)
+{
+	int diff = gp->tx_next_in - gp->tx_next_out;
+
+	diff = diff<0 ? TX_RING_SIZE + diff : diff;
+	diff = gp->tx_count == TX_RING_SIZE ? diff + TX_RING_SIZE : diff;
+    
+	return (diff != gp->tx_count);
+}
+
+static int
+gt96100_init(struct net_device *dev)
+{
+	struct gt96100_private *gp = netdev_priv(dev);
+	u32 tmp;
+	u16 mii_reg;
+    
+	dbg(3, "%s: dev=%p\n", __FUNCTION__, dev);
+	dbg(3, "%s: scs10_lo=%4x, scs10_hi=%4x\n", __FUNCTION__, 
+	    GT96100_READ(0x8), GT96100_READ(0x10));
+	dbg(3, "%s: scs32_lo=%4x, scs32_hi=%4x\n", __FUNCTION__,
+	    GT96100_READ(0x18), GT96100_READ(0x20));
+    
+	// Stop and disable Port
+	hard_stop(dev);
+    
+	// Setup CIU Arbiter
+	tmp = GT96100_READ(GT96100_CIU_ARBITER_CONFIG);
+	tmp |= (0x0c << (gp->port_num*2)); // set Ether DMA req priority to hi
+#ifndef DESC_BE
+	tmp &= ~(1<<31);                   // set desc endianess to little
+#else
+	tmp |= (1<<31);
+#endif
+	GT96100_WRITE(GT96100_CIU_ARBITER_CONFIG, tmp);
+	dbg(3, "%s: CIU Config=%x/%x\n", __FUNCTION__, 
+	    tmp, GT96100_READ(GT96100_CIU_ARBITER_CONFIG));
+
+	// Set routing.
+	tmp = GT96100_READ(GT96100_ROUTE_MAIN) & (0x3f << 18);
+	tmp |= (0x07 << (18 + gp->port_num*3));
+	GT96100_WRITE(GT96100_ROUTE_MAIN, tmp);
+
+	/* set MII as peripheral func */
+	tmp = GT96100_READ(GT96100_GPP_CONFIG2);
+	tmp |= 0x7fff << (gp->port_num*16);
+	GT96100_WRITE(GT96100_GPP_CONFIG2, tmp);
+	
+	/* Set up MII port pin directions */
+	tmp = GT96100_READ(GT96100_GPP_IO2);
+	tmp |= 0x003d << (gp->port_num*16);
+	GT96100_WRITE(GT96100_GPP_IO2, tmp);
+
+	// Set-up hash table
+	memset(gp->hash_table, 0, RX_HASH_TABLE_SIZE); // clear it
+	gp->hash_mode = 0;
+	// Add a single entry to hash table - our ethernet address
+	gt96100_add_hash_entry(dev, dev->dev_addr);
+	// Set-up DMA ptr to hash table
+	GT96100ETH_WRITE(gp, GT96100_ETH_HASH_TBL_PTR, gp->hash_table_dma);
+	dbg(3, "%s: Hash Tbl Ptr=%x\n", __FUNCTION__,
+	    GT96100ETH_READ(gp, GT96100_ETH_HASH_TBL_PTR));
+
+	// Setup Tx
+	reset_tx(dev);
+
+	dbg(3, "%s: Curr Tx Desc Ptr0=%x\n", __FUNCTION__,
+	    GT96100ETH_READ(gp, GT96100_ETH_CURR_TX_DESC_PTR0));
+
+	// Setup Rx
+	reset_rx(dev);
+
+	dbg(3, "%s: 1st/Curr Rx Desc Ptr0=%x/%x\n", __FUNCTION__,
+	    GT96100ETH_READ(gp, GT96100_ETH_1ST_RX_DESC_PTR0),
+	    GT96100ETH_READ(gp, GT96100_ETH_CURR_RX_DESC_PTR0));
+
+	// eth port config register
+	GT96100ETH_WRITE(gp, GT96100_ETH_PORT_CONFIG_EXT,
+			 pcxrFCTL | pcxrFCTLen | pcxrFLP | pcxrDPLXen);
+
+	mii_reg = read_MII(gp->phy_addr, 0x11); /* int enable register */
+	mii_reg |= 2;  /* enable mii interrupt */
+	write_MII(gp->phy_addr, 0x11, mii_reg);
+	
+	dbg(3, "%s: PhyAD=%x\n", __FUNCTION__,
+	    GT96100_READ(GT96100_ETH_PHY_ADDR_REG));
+
+	// setup DMA
+
+	// We want the Rx/Tx DMA to write/read data to/from memory in
+	// Big Endian mode. Also set DMA Burst Size to 8 64Bit words.
+#ifdef DESC_DATA_BE
+	GT96100ETH_WRITE(gp, GT96100_ETH_SDMA_CONFIG,
+			 (0xf<<sdcrRCBit) | sdcrRIFB | (3<<sdcrBSZBit));
+#else
+	GT96100ETH_WRITE(gp, GT96100_ETH_SDMA_CONFIG,
+			 sdcrBLMR | sdcrBLMT |
+			 (0xf<<sdcrRCBit) | sdcrRIFB | (3<<sdcrBSZBit));
+#endif
+	dbg(3, "%s: SDMA Config=%x\n", __FUNCTION__,
+	    GT96100ETH_READ(gp, GT96100_ETH_SDMA_CONFIG));
+
+	// start Rx DMA
+	GT96100ETH_WRITE(gp, GT96100_ETH_SDMA_COMM, sdcmrERD);
+	dbg(3, "%s: SDMA Comm=%x\n", __FUNCTION__,
+	    GT96100ETH_READ(gp, GT96100_ETH_SDMA_COMM));
+    
+	// enable this port (set hash size to 1/2K)
+	GT96100ETH_WRITE(gp, GT96100_ETH_PORT_CONFIG, pcrEN | pcrHS);
+	dbg(3, "%s: Port Config=%x\n", __FUNCTION__,
+	    GT96100ETH_READ(gp, GT96100_ETH_PORT_CONFIG));
+    
+	/*
+	 * Disable all Type-of-Service queueing. All Rx packets will be
+	 * treated normally and will be sent to the lowest priority
+	 * queue.
+	 *
+	 * Disable flow-control for now. FIXME: support flow control?
+	 */
+
+	// clear all the MIB ctr regs
+	GT96100ETH_WRITE(gp, GT96100_ETH_PORT_CONFIG_EXT,
+			 pcxrFCTL | pcxrFCTLen | pcxrFLP |
+			 pcxrPRIOrxOverride);
+	read_mib_counters(gp);
+	GT96100ETH_WRITE(gp, GT96100_ETH_PORT_CONFIG_EXT,
+			 pcxrFCTL | pcxrFCTLen | pcxrFLP |
+			 pcxrPRIOrxOverride | pcxrMIBclrMode);
+    
+	dbg(3, "%s: Port Config Ext=%x\n", __FUNCTION__,
+	    GT96100ETH_READ(gp, GT96100_ETH_PORT_CONFIG_EXT));
+
+	netif_start_queue(dev);
+
+	dump_MII(4, dev);
+
+	// enable interrupts
+	enable_ether_irq(dev);
+
+	// we should now be receiving frames
+	return 0;
+}
+
+
+static int
+gt96100_open(struct net_device *dev)
+{
+	int retval;
+    
+	dbg(2, "%s: dev=%p\n", __FUNCTION__, dev);
+
+	// Initialize and startup the GT-96100 ethernet port
+	if ((retval = gt96100_init(dev))) {
+		err("error in gt96100_init\n");
+		free_irq(dev->irq, dev);
+		return retval;
+	}
+
+	if ((retval = request_irq(dev->irq, &gt96100_interrupt,
+				  SA_SHIRQ, dev->name, dev))) {
+		err("unable to get IRQ %d\n", dev->irq);
+		return retval;
+	}
+	
+	dbg(2, "%s: Initialization done.\n", __FUNCTION__);
+
+	return 0;
+}
+
+static int
+gt96100_close(struct net_device *dev)
+{
+	dbg(3, "%s: dev=%p\n", __FUNCTION__, dev);
+
+	// stop the device
+	if (netif_device_present(dev)) {
+		netif_stop_queue(dev);
+		hard_stop(dev);
+	}
+
+	free_irq(dev->irq, dev);
+    
+	return 0;
+}
+
+
+static int
+gt96100_tx(struct sk_buff *skb, struct net_device *dev)
+{
+	struct gt96100_private *gp = netdev_priv(dev);
+	unsigned long flags;
+	int nextIn;
+
+	spin_lock_irqsave(&gp->lock, flags);
+
+	nextIn = gp->tx_next_in;
+
+	dbg(3, "%s: nextIn=%d\n", __FUNCTION__, nextIn);
+    
+	if (gp->tx_count >= TX_RING_SIZE) {
+		warn("Tx Ring full, pkt dropped.\n");
+		gp->stats.tx_dropped++;
+		spin_unlock_irqrestore(&gp->lock, flags);
+		return 1;
+	}
+    
+	if (!(gp->last_psr & psrLink)) {
+		err("%s: Link down, pkt dropped.\n", __FUNCTION__);
+		gp->stats.tx_dropped++;
+		spin_unlock_irqrestore(&gp->lock, flags);
+		return 1;
+	}
+    
+	if (dma32_to_cpu(gp->tx_ring[nextIn].cmdstat) & txOwn) {
+		err("%s: device owns descriptor, pkt dropped.\n", __FUNCTION__);
+		gp->stats.tx_dropped++;
+		// stop the queue, so Tx timeout can fix it
+		netif_stop_queue(dev);
+		spin_unlock_irqrestore(&gp->lock, flags);
+		return 1;
+	}
+    
+	// Prepare the Descriptor at tx_next_in
+	gp->tx_skbuff[nextIn] = skb;
+	gp->tx_ring[nextIn].byte_cnt = cpu_to_dma16(skb->len);
+	gp->tx_ring[nextIn].buff_ptr = cpu_to_dma32(virt_to_phys(skb->data));
+	// make sure packet gets written back to memory
+	dma_cache_wback_inv((unsigned long)(skb->data), skb->len);
+	// Give ownership to device, set first and last desc, enable interrupt
+	// Setting of ownership bit must be *last*!
+	gp->tx_ring[nextIn].cmdstat =
+		cpu_to_dma32((u32)(txOwn | txGenCRC | txEI |
+				   txPad | txFirst | txLast));
+    
+	dump_tx_desc(4, dev, nextIn);
+	dump_skb(4, dev, skb);
+
+	// increment tx_next_in with wrap
+	gp->tx_next_in = (nextIn + 1) % TX_RING_SIZE;
+	// If DMA is stopped, restart
+	if (!(GT96100ETH_READ(gp, GT96100_ETH_PORT_STATUS) & psrTxLow))
+		GT96100ETH_WRITE(gp, GT96100_ETH_SDMA_COMM,
+				 sdcmrERD | sdcmrTXDL);
+
+	// increment count and stop queue if full
+	if (++gp->tx_count == TX_RING_SIZE) {
+		gp->tx_full = 1;
+		netif_stop_queue(dev);
+		dbg(2, "Tx Ring now full, queue stopped.\n");
+	}
+    
+	dev->trans_start = jiffies;
+	spin_unlock_irqrestore(&gp->lock, flags);
+
+	return 0;
+}
+
+
+static int
+gt96100_rx(struct net_device *dev, u32 status)
+{
+	struct gt96100_private *gp = netdev_priv(dev);
+	struct sk_buff *skb;
+	int pkt_len, nextOut, cdp;
+	gt96100_rd_t *rd;
+	u32 cmdstat;
+    
+	dbg(3, "%s: dev=%p, status=%x\n", __FUNCTION__, dev, status);
+
+	cdp = (GT96100ETH_READ(gp, GT96100_ETH_1ST_RX_DESC_PTR0)
+	       - gp->rx_ring_dma) / sizeof(gt96100_rd_t);
+
+	// Continue until we reach 1st descriptor pointer
+	for (nextOut = gp->rx_next_out; nextOut != cdp;
+	     nextOut = (nextOut + 1) % RX_RING_SIZE) {
+	
+		if (--gp->intr_work_done == 0)
+			break;
+
+		rd = &gp->rx_ring[nextOut];
+		cmdstat = dma32_to_cpu(rd->cmdstat);
+	
+		dbg(4, "%s: Rx desc cmdstat=%x, nextOut=%d\n", __FUNCTION__,
+		    cmdstat, nextOut);
+
+		if (cmdstat & (u32)rxOwn) {
+			//err("%s: device owns descriptor!\n", __FUNCTION__);
+			// DMA is not finished updating descriptor???
+			// Leave and come back later to pick-up where
+			// we left off.
+			break;
+		}
+
+		// Drop this received pkt if there were any errors
+		if (((cmdstat & (u32)(rxErrorSummary)) &&
+		     (cmdstat & (u32)(rxFirst))) || (status & icrRxError)) {
+			// update the detailed rx error counters that
+			// are not covered by the MIB counters.
+			if (cmdstat & (u32)rxOverrun)
+				gp->stats.rx_fifo_errors++;
+			cmdstat |= (u32)rxOwn;
+			rd->cmdstat = cpu_to_dma32(cmdstat);
+			continue;
+		}
+
+		/*
+		 * Must be first and last (ie only) descriptor of packet. We
+		 * ignore (drop) any packets that do not fit in one descriptor.
+		 * Every descriptor's receive buffer is large enough to hold
+		 * the maximum 802.3 frame size, so a multi-descriptor packet
+		 * indicates an error. Most if not all corrupted packets will
+		 * have already been dropped by the above check for the
+		 * rxErrorSummary status bit.
+		 */
+		if (!(cmdstat & (u32)rxFirst) || !(cmdstat & (u32)rxLast)) {
+			if (cmdstat & (u32)rxFirst) {
+				/*
+				 * This is the first descriptor of a
+				 * multi-descriptor packet. It isn't corrupted
+				 * because the above check for rxErrorSummary
+				 * would have dropped it already, so what's
+				 * the deal with this packet? Good question,
+				 * let's dump it out.
+				 */
+				err("%s: desc not first and last!\n", __FUNCTION__);
+				dump_rx_desc(0, dev, nextOut);
+			}
+			cmdstat |= (u32)rxOwn;
+			rd->cmdstat = cpu_to_dma32(cmdstat);
+			// continue to drop every descriptor of this packet
+			continue;
+		}
+	
+		pkt_len = dma16_to_cpu(rd->byte_cnt);
+	
+		/* Create new skb. */
+		skb = dev_alloc_skb(pkt_len+2);
+		if (skb == NULL) {
+			err("%s: Memory squeeze, dropping packet.\n", __FUNCTION__);
+			gp->stats.rx_dropped++;
+			cmdstat |= (u32)rxOwn;
+			rd->cmdstat = cpu_to_dma32(cmdstat);
+			continue;
+		}
+		skb->dev = dev;
+		skb_reserve(skb, 2);   /* 16 byte IP header align */
+		memcpy(skb_put(skb, pkt_len),
+		       &gp->rx_buff[nextOut*PKT_BUF_SZ], pkt_len);
+		skb->protocol = eth_type_trans(skb, dev);
+		dump_skb(4, dev, skb);
+	
+		netif_rx(skb);        /* pass the packet to upper layers */
+		dev->last_rx = jiffies;
+
+		// now we can release ownership of this desc back to device
+		cmdstat |= (u32)rxOwn;
+		rd->cmdstat = cpu_to_dma32(cmdstat);
+	}
+    
+	if (nextOut == gp->rx_next_out)
+		dbg(3, "%s: RxCDP did not increment?\n", __FUNCTION__);
+
+	gp->rx_next_out = nextOut;
+	return 0;
+}
+
+
+static void
+gt96100_tx_complete(struct net_device *dev, u32 status)
+{
+	struct gt96100_private *gp = netdev_priv(dev);
+	int nextOut, cdp;
+	gt96100_td_t *td;
+	u32 cmdstat;
+
+	cdp = (GT96100ETH_READ(gp, GT96100_ETH_CURR_TX_DESC_PTR0)
+	       - gp->tx_ring_dma) / sizeof(gt96100_td_t);
+    
+	// Continue until we reach the current descriptor pointer
+	for (nextOut = gp->tx_next_out; nextOut != cdp;
+	     nextOut = (nextOut + 1) % TX_RING_SIZE) {
+	
+		if (--gp->intr_work_done == 0)
+			break;
+
+		td = &gp->tx_ring[nextOut];
+		cmdstat = dma32_to_cpu(td->cmdstat);
+	
+		dbg(3, "%s: Tx desc cmdstat=%x, nextOut=%d\n", __FUNCTION__,
+		    cmdstat, nextOut);
+	
+		if (cmdstat & (u32)txOwn) {
+			/*
+			 * DMA is not finished writing descriptor???
+			 * Leave and come back later to pick-up where
+			 * we left off.
+			 */
+			break;
+		}
+	
+		// increment Tx error stats
+		if (cmdstat & (u32)txErrorSummary) {
+			dbg(2, "%s: Tx error, cmdstat = %x\n", __FUNCTION__,
+			    cmdstat);
+			gp->stats.tx_errors++;
+			if (cmdstat & (u32)txReTxLimit)
+				gp->stats.tx_aborted_errors++;
+			if (cmdstat & (u32)txUnderrun)
+				gp->stats.tx_fifo_errors++;
+			if (cmdstat & (u32)txLateCollision)
+				gp->stats.tx_window_errors++;
+		}
+	
+		if (cmdstat & (u32)txCollision)
+			gp->stats.collisions +=
+				(u32)((cmdstat & txReTxCntMask) >>
+				      txReTxCntBit);
+
+		// Wake the queue if the ring was full
+		if (gp->tx_full) {
+			gp->tx_full = 0;
+			if (gp->last_psr & psrLink) {
+				netif_wake_queue(dev);
+				dbg(2, "%s: Tx Ring was full, queue waked\n",
+				    __FUNCTION__);
+			}
+		}
+	
+		// decrement tx ring buffer count
+		if (gp->tx_count) gp->tx_count--;
+	
+		// free the skb
+		if (gp->tx_skbuff[nextOut]) {
+			dbg(3, "%s: good Tx, skb=%p\n", __FUNCTION__,
+			    gp->tx_skbuff[nextOut]);
+			dev_kfree_skb_irq(gp->tx_skbuff[nextOut]);
+			gp->tx_skbuff[nextOut] = NULL;
+		} else {
+			err("%s: no skb!\n", __FUNCTION__);
+		}
+	}
+
+	gp->tx_next_out = nextOut;
+
+	if (gt96100_check_tx_consistent(gp)) {
+		err("%s: Tx queue inconsistent!\n", __FUNCTION__);
+	}
+    
+	if ((status & icrTxEndLow) && gp->tx_count != 0) {
+		// we must restart the DMA
+		dbg(3, "%s: Restarting Tx DMA\n", __FUNCTION__);
+		GT96100ETH_WRITE(gp, GT96100_ETH_SDMA_COMM,
+				 sdcmrERD | sdcmrTXDL);
+	}
+}
+
+
+static irqreturn_t
+gt96100_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+{
+	struct net_device *dev = (struct net_device *)dev_id;
+	struct gt96100_private *gp = netdev_priv(dev);
+	u32 status;
+    	int handled = 0;
+
+	if (dev == NULL) {
+		err("%s: null dev ptr\n", __FUNCTION__);
+		return IRQ_NONE;
+	}
+
+	dbg(3, "%s: entry, icr=%x\n", __FUNCTION__,
+	    GT96100ETH_READ(gp, GT96100_ETH_INT_CAUSE));
+
+	spin_lock(&gp->lock);
+
+	gp->intr_work_done = max_interrupt_work;
+
+	while (gp->intr_work_done > 0) {
+
+		status = GT96100ETH_READ(gp, GT96100_ETH_INT_CAUSE);
+		// ACK interrupts
+		GT96100ETH_WRITE(gp, GT96100_ETH_INT_CAUSE, ~status);
+
+		if ((status & icrEtherIntSum) == 0 &&
+		    !(status & (icrTxBufferLow|icrTxBufferHigh|icrRxBuffer)))
+			break;
+
+		handled = 1;
+
+		if (status & icrMIIPhySTC) {
+			u32 psr = GT96100ETH_READ(gp, GT96100_ETH_PORT_STATUS);
+			if (gp->last_psr != psr) {
+				dbg(0, "port status:\n");
+				dbg(0, "    %s MBit/s, %s-duplex, "
+				    "flow-control %s, link is %s,\n",
+				    psr & psrSpeed ? "100":"10",
+				    psr & psrDuplex ? "full":"half",
+				    psr & psrFctl ? "disabled":"enabled",
+				    psr & psrLink ? "up":"down");
+				dbg(0, "    TxLowQ is %s, TxHighQ is %s, "
+				    "Transmitter is %s\n",
+				    psr & psrTxLow ? "running":"stopped",
+				    psr & psrTxHigh ? "running":"stopped",
+				    psr & psrTxInProg ? "on":"off");
+		
+				if ((psr & psrLink) && !gp->tx_full &&
+				    netif_queue_stopped(dev)) {
+					dbg(0, "%s: Link up, waking queue.\n",
+					    __FUNCTION__);
+					netif_wake_queue(dev);
+				} else if (!(psr & psrLink) &&
+					   !netif_queue_stopped(dev)) {
+					dbg(0, "%s: Link down, stopping queue.\n",
+					    __FUNCTION__);
+					netif_stop_queue(dev);
+				}
+
+				gp->last_psr = psr;
+			}
+
+			if (--gp->intr_work_done == 0)
+				break;
+		}
+	
+		if (status & (icrTxBufferLow | icrTxEndLow))
+			gt96100_tx_complete(dev, status);
+
+		if (status & (icrRxBuffer | icrRxError)) {
+			gt96100_rx(dev, status);
+		}
+	
+		// Now check TX errors (RX errors were handled in gt96100_rx)
+		if (status & icrTxErrorLow) {
+			err("%s: Tx resource error\n", __FUNCTION__);
+			if (--gp->intr_work_done == 0)
+				break;
+		}
+	
+		if (status & icrTxUdr) {
+			err("%s: Tx underrun error\n", __FUNCTION__);
+			if (--gp->intr_work_done == 0)
+				break;
+		}
+	}
+
+	if (gp->intr_work_done == 0) {
+		// ACK any remaining pending interrupts
+		GT96100ETH_WRITE(gp, GT96100_ETH_INT_CAUSE, 0);
+		dbg(3, "%s: hit max work\n", __FUNCTION__);
+	}
+    
+	dbg(3, "%s: exit, icr=%x\n", __FUNCTION__,
+	    GT96100ETH_READ(gp, GT96100_ETH_INT_CAUSE));
+
+	spin_unlock(&gp->lock);
+	return IRQ_RETVAL(handled);
+}
+
+
+static void
+gt96100_tx_timeout(struct net_device *dev)
+{
+	struct gt96100_private *gp = netdev_priv(dev);
+	unsigned long flags;
+    
+	spin_lock_irqsave(&gp->lock, flags);
+    
+	if (!(gp->last_psr & psrLink)) {
+		err("tx_timeout: link down.\n");
+		spin_unlock_irqrestore(&gp->lock, flags);
+	} else {
+		if (gt96100_check_tx_consistent(gp))
+			err("tx_timeout: Tx ring error.\n");
+
+		disable_ether_irq(dev);
+		spin_unlock_irqrestore(&gp->lock, flags);
+		reset_tx(dev);
+		enable_ether_irq(dev);
+	
+		netif_wake_queue(dev);
+	}
+}
+
+
+static void
+gt96100_set_rx_mode(struct net_device *dev)
+{
+	struct gt96100_private *gp = netdev_priv(dev);
+	unsigned long flags;
+	//struct dev_mc_list *mcptr;
+    
+	dbg(3, "%s: dev=%p, flags=%x\n", __FUNCTION__, dev, dev->flags);
+
+	// stop the Receiver DMA
+	abort(dev, sdcmrAR);
+
+	spin_lock_irqsave(&gp->lock, flags);
+
+	if (dev->flags & IFF_PROMISC) {
+		GT96100ETH_WRITE(gp, GT96100_ETH_PORT_CONFIG,
+				 pcrEN | pcrHS | pcrPM);
+	}
+
+#if 0
+	/*
+	  FIXME: currently multicast doesn't work - need to get hash table
+	  working first.
+	*/
+	if (dev->mc_count) {
+		// clear hash table
+		memset(gp->hash_table, 0, RX_HASH_TABLE_SIZE);
+		// Add our ethernet address
+		gt96100_add_hash_entry(dev, dev->dev_addr);
+
+		for (mcptr = dev->mc_list; mcptr; mcptr = mcptr->next) {
+			dump_hw_addr(2, dev, __FUNCTION__ ": addr=",
+				     mcptr->dmi_addr);
+			gt96100_add_hash_entry(dev, mcptr->dmi_addr);
+		}
+	}
+#endif
+    
+	// restart Rx DMA
+	GT96100ETH_WRITE(gp, GT96100_ETH_SDMA_COMM, sdcmrERD);
+
+	spin_unlock_irqrestore(&gp->lock, flags);
+}
+
+static struct net_device_stats *
+gt96100_get_stats(struct net_device *dev)
+{
+	struct gt96100_private *gp = netdev_priv(dev);
+	unsigned long flags;
+
+	dbg(3, "%s: dev=%p\n", __FUNCTION__, dev);
+
+	if (netif_device_present(dev)) {
+		spin_lock_irqsave (&gp->lock, flags);
+		update_stats(gp);
+		spin_unlock_irqrestore (&gp->lock, flags);
+	}
+
+	return &gp->stats;
+}
+
+static void gt96100_cleanup_module(void)
+{
+	int i;
+	for (i=0; i<NUM_INTERFACES; i++) {
+		struct gt96100_if_t *gtif = &gt96100_iflist[i];
+		if (gtif->dev != NULL) {
+			struct gt96100_private *gp = (struct gt96100_private *)
+				netdev_priv(gtif->dev);
+			unregister_netdev(gtif->dev);
+			dmafree(RX_HASH_TABLE_SIZE, gp->hash_table_dma);
+			dmafree(PKT_BUF_SZ*RX_RING_SIZE, gp->rx_buff);
+			dmafree(sizeof(gt96100_rd_t) * RX_RING_SIZE
+				+ sizeof(gt96100_td_t) * TX_RING_SIZE,
+				gp->rx_ring);
+			free_netdev(gtif->dev);
+			release_region(gtif->iobase, gp->io_size);
+		}
+	}
+}
+
+static int __init gt96100_setup(char *options)
+{
+	char *this_opt;
+
+	if (!options || !*options)
+		return 0;
+
+	while ((this_opt = strsep (&options, ",")) != NULL) {
+		if (!*this_opt)
+			continue;
+		if (!strncmp(this_opt, "mac0:", 5)) {
+			memcpy(mac0, this_opt+5, 17);
+			mac0[17]= '\0';
+		} else if (!strncmp(this_opt, "mac1:", 5)) {
+			memcpy(mac1, this_opt+5, 17);
+			mac1[17]= '\0';
+		}
+	}
+
+	return 1;
+}
+
+__setup("gt96100eth=", gt96100_setup);
+
+module_init(gt96100_init_module);
+module_exit(gt96100_cleanup_module);
+
+MODULE_AUTHOR("Steve Longerbeam <stevel@mvista.com>");
+MODULE_DESCRIPTION("GT96100 Ethernet driver");