Import of Linus's Linux 1.1.68

1 files changed, 988 insertions, 0 deletions

diff --git a/drivers/net/de620.c b/drivers/net/de620.c
new file mode 100644
index 000000000..e3cb9a307
--- /dev/null
+++ b/drivers/net/de620.c
@@ -0,0 +1,988 @@
+/*
+ *	de620.c $Revision: 1.31 $ BETA
+ *
+ *
+ *	Linux driver for the D-Link DE-620 Ethernet pocket adapter.
+ *
+ *	Portions (C) Copyright 1993, 1994 by Bjorn Ekwall <bj0rn@blox.se>
+ *
+ *	Based on adapter information gathered from DOS packetdriver
+ *	sources from D-Link Inc:  (Special thanks to Henry Ngai of D-Link.)
+ *		Portions (C) Copyright D-Link SYSTEM Inc. 1991, 1992
+ *		Copyright, 1988, Russell Nelson, Crynwr Software
+ *
+ *	Adapted to the sample network driver core for linux,
+ *	written by: Donald Becker <becker@super.org>
+ *		(Now at <becker@cesdis.gsfc.nasa.gov>
+ *
+ *	Valuable assistance from:
+ *		J. Joshua Kopper <kopper@rtsg.mot.com>
+ *		Olav Kvittem <Olav.Kvittem@uninett.no>
+ *		Germano Caronni <caronni@nessie.cs.id.ethz.ch>
+ *		Jeremy Fitzhardinge <jeremy@suite.sw.oz.au>
+ *
+ *****************************************************************************/
+/*
+ *	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, 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.
+ *
+ *	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., 675 Mass Ave, Cambridge, MA 02139, USA. 
+ *
+ *****************************************************************************/
+static char *version =
+	"de620.c: $Revision: 1.31 $,  Bjorn Ekwall <bj0rn@blox.se>\n";
+
+/***********************************************************************
+ *
+ * "Tuning" section.
+ *
+ * Compile-time options: (see below for descriptions)
+ * -DDE620_IO=0x378	(lpt1)
+ * -DDE620_IRQ=7	(lpt1)
+ * -DDE602_DEBUG=...
+ * -DSHUTDOWN_WHEN_LOST
+ * -DCOUNT_LOOPS
+ * -DLOWSPEED
+ * -DREAD_DELAY
+ * -DWRITE_DELAY
+ */
+
+/*
+ * If the adapter has problems with high speeds, enable this #define
+ * otherwise full printerport speed will be attempted.
+ *
+ * You can tune the READ_DELAY/WRITE_DELAY below if you enable LOWSPEED
+ *
+#define LOWSPEED
+ */
+
+#ifndef READ_DELAY
+#define READ_DELAY 100	/* adapter internal read delay in 100ns units */
+#endif
+
+#ifndef WRITE_DELAY
+#define WRITE_DELAY 100	/* adapter internal write delay in 100ns units */
+#endif
+
+/*
+ * Enable this #define if you want the adapter to do a "ifconfig down" on
+ * itself when we have detected that something is possibly wrong with it.
+ * The default behaviour is to retry with "adapter_init()" until success.
+ * This should be used for debugging purposes only.
+ *
+#define SHUTDOWN_WHEN_LOST
+ */
+
+/*
+ * Enable debugging by "-DDE620_DEBUG=3" when compiling,
+ * OR in "./CONFIG"
+ * OR by enabling the following #define
+ *
+ * use 0 for production, 1 for verification, >2 for debug
+ *
+#define DE620_DEBUG 3
+ */
+
+#ifdef LOWSPEED
+/*
+ * Enable this #define if you want to see debugging output that show how long
+ * we have to wait before the DE-620 is ready for the next read/write/command.
+ *
+#define COUNT_LOOPS
+ */
+#endif
+
+#include <linux/config.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/types.h>
+#include <linux/fcntl.h>
+#include <linux/string.h>
+#include <linux/interrupt.h>
+#include <asm/io.h>
+#include <linux/in.h>
+#include <linux/ptrace.h>
+#include <asm/system.h>
+#include <linux/errno.h>
+
+#include <linux/inet.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/skbuff.h>
+
+#ifdef MODULE
+#include <linux/module.h>
+#include "../../tools/version.h"
+#endif
+
+/* Constant definitions for the DE-620 registers, commands and bits */
+#include "de620.h"
+
+#define netstats enet_statistics
+typedef unsigned char byte;
+
+/*******************************************************
+ *                                                     *
+ * Definition of D-Link DE-620 Ethernet Pocket adapter *
+ * See also "de620.h"                                  *
+ *                                                     *
+ *******************************************************/
+#ifndef DE620_IO /* Compile-time configurable */
+#define DE620_IO 0x378
+#endif
+
+#ifndef DE620_IRQ /* Compile-time configurable */
+#define DE620_IRQ	7
+#endif
+
+#define DATA_PORT	(DE620_IO)
+#define STATUS_PORT	(DE620_IO + 1)
+#define COMMAND_PORT	(DE620_IO + 2)
+
+#define RUNT 60		/* Too small Ethernet packet */
+#define GIANT 1514	/* largest legal size packet, no fcs */
+
+#ifdef DE620_DEBUG /* Compile-time configurable */
+#define PRINTK(x) if (de620_debug >= 2) printk x
+#else
+#define DE620_DEBUG 0
+#define PRINTK(x) /**/
+#endif
+
+/***********************************************
+ *                                             *
+ * Index to functions, as function prototypes. *
+ *                                             *
+ ***********************************************/
+
+/*
+ * Routines used internally. (See also "convenience macros.. below")
+ */
+
+/* Put in the device structure. */
+static int	de620_open(struct device *);
+static int	de620_close(struct device *);
+static struct netstats *get_stats(struct device *);
+static void	de620_set_multicast_list(struct device *, int, void *);
+static int	de620_start_xmit(struct sk_buff *, struct device *);
+
+/* Dispatch from interrupts. */
+static void	de620_interrupt(int);
+static int	de620_rx_intr(struct device *);
+
+/* Initialization */
+static int	adapter_init(struct device *);
+int		de620_probe(struct device *);
+static int	read_eeprom(void);
+
+
+/*
+ * D-Link driver variables:
+ */
+#define SCR_DEF NIBBLEMODE |INTON | SLEEP | AUTOTX
+#define	TCR_DEF RXPB			/* not used: | TXSUCINT | T16INT */
+#define DE620_RX_START_PAGE 12		/* 12 pages (=3k) reserved for tx */
+#define DEF_NIC_CMD IRQEN | ICEN | DS1
+
+extern struct device *irq2dev_map[16];
+unsigned int de620_debug = DE620_DEBUG;
+
+static volatile byte	NIC_Cmd;
+static volatile byte	next_rx_page;
+static byte		first_rx_page;
+static byte		last_rx_page;
+static byte		EIPRegister;
+
+static struct nic {
+	byte	NodeID[6];
+	byte	RAM_Size;
+	byte	Model;
+	byte	Media;
+	byte	SCR;
+} nic_data;
+
+/**********************************************************
+ *                                                        *
+ * Convenience macros/functions for D-Link DE-620 adapter *
+ *                                                        *
+ **********************************************************/
+#define de620_tx_buffs() (inb(STATUS_PORT) & (TXBF0 | TXBF1))
+#define de620_flip_ds() NIC_Cmd ^= DS0 | DS1; outb(NIC_Cmd, COMMAND_PORT);
+
+/* Check for ready-status, and return a nibble (high 4 bits) for data input */
+#ifdef COUNT_LOOPS
+static int tot_cnt;
+#endif
+static inline byte
+de620_ready(void)
+{
+	byte value;
+	register short int cnt = 0;
+
+	while ((((value = inb(STATUS_PORT)) & READY) == 0) && (cnt <= 1000))
+		++cnt;
+
+#ifdef COUNT_LOOPS
+	tot_cnt += cnt;
+#endif
+	return value & 0xf0; /* nibble */
+}
+
+static inline void
+de620_send_command(byte cmd)
+{
+	de620_ready();
+	if (cmd == W_DUMMY)
+		outb(NIC_Cmd, COMMAND_PORT);
+
+	outb(cmd, DATA_PORT);
+
+	outb(NIC_Cmd ^ CS0, COMMAND_PORT);
+	de620_ready();
+	outb(NIC_Cmd, COMMAND_PORT);
+}
+
+static inline void
+de620_put_byte(byte value)
+{
+	/* The de620_ready() makes 7 loops, on the average, on a DX2/66 */
+	de620_ready();
+	outb(value, DATA_PORT);
+	de620_flip_ds();
+}
+
+static inline byte
+de620_read_byte(void)
+{
+	byte value;
+
+	/* The de620_ready() makes 7 loops, on the average, on a DX2/66 */
+	value = de620_ready(); /* High nibble */
+	de620_flip_ds();
+	value |= de620_ready() >> 4; /* Low nibble */
+	return value;
+}
+
+static inline void
+de620_write_block(byte *buffer, int count)
+{
+#ifndef LOWSPEED
+	byte uflip = NIC_Cmd ^ (DS0 | DS1);
+	byte dflip = NIC_Cmd;
+#else /* LOWSPEED */
+#ifdef COUNT_LOOPS
+	int bytes = count;
+#endif /* COUNT_LOOPS */
+#endif /* LOWSPEED */
+
+#ifdef LOWSPEED
+#ifdef COUNT_LOOPS
+	tot_cnt = 0;
+#endif /* COUNT_LOOPS */
+	/* No further optimization useful, the limit is in the adapter. */
+	for ( ; count > 0; --count, ++buffer) {
+		de620_put_byte(*buffer);
+	}
+	de620_send_command(W_DUMMY);
+#ifdef COUNT_LOOPS
+	/* trial debug output: loops per byte in de620_ready() */
+	printk("WRITE(%d)\n", tot_cnt/((bytes?bytes:1)));
+#endif /* COUNT_LOOPS */
+#else /* not LOWSPEED */
+	for ( ; count > 0; count -=2) {
+		outb(*buffer++, DATA_PORT);
+		outb(uflip, COMMAND_PORT);
+		outb(*buffer++, DATA_PORT);
+		outb(dflip, COMMAND_PORT);
+	}
+	de620_send_command(W_DUMMY);
+#endif /* LOWSPEED */
+}
+
+static inline void
+de620_read_block(byte *data, int count)
+{
+#ifndef LOWSPEED
+	byte value;
+	byte uflip = NIC_Cmd ^ (DS0 | DS1);
+	byte dflip = NIC_Cmd;
+#else /* LOWSPEED */
+#ifdef COUNT_LOOPS
+	int bytes = count;
+
+	tot_cnt = 0;
+#endif /* COUNT_LOOPS */
+#endif /* LOWSPEED */
+
+#ifdef LOWSPEED
+	/* No further optimization useful, the limit is in the adapter. */
+	while (count-- > 0) {
+		*data++ = de620_read_byte();
+		de620_flip_ds();
+	}
+#ifdef COUNT_LOOPS
+	/* trial debug output: loops per byte in de620_ready() */
+	printk("READ(%d)\n", tot_cnt/(2*(bytes?bytes:1)));
+#endif /* COUNT_LOOPS */
+#else /* not LOWSPEED */
+	while (count-- > 0) {
+		value = inb(STATUS_PORT) & 0xf0; /* High nibble */
+		outb(uflip, COMMAND_PORT);
+		*data++ = value | inb(STATUS_PORT) >> 4; /* Low nibble */
+		outb(dflip , COMMAND_PORT);
+	}
+#endif /* LOWSPEED */
+}
+
+static inline void
+de620_set_delay(void)
+{
+	de620_ready();
+	outb(W_DFR, DATA_PORT);
+	outb(NIC_Cmd ^ CS0, COMMAND_PORT);
+
+	de620_ready();
+#ifdef LOWSPEED
+	outb(WRITE_DELAY, DATA_PORT);
+#else
+	outb(0, DATA_PORT);
+#endif
+	de620_flip_ds();
+
+	de620_ready();
+#ifdef LOWSPEED
+	outb(READ_DELAY, DATA_PORT);
+#else
+	outb(0, DATA_PORT);
+#endif
+	de620_flip_ds();
+}
+
+static inline void
+de620_set_register(byte reg, byte value)
+{
+	de620_ready();
+	outb(reg, DATA_PORT);
+	outb(NIC_Cmd ^ CS0, COMMAND_PORT);
+
+	de620_put_byte(value);
+}
+
+static inline byte
+de620_get_register(byte reg)
+{
+	byte value;
+
+	de620_send_command(reg);
+	value = de620_read_byte();
+	de620_send_command(W_DUMMY);
+
+	return value;
+}
+
+/*********************************************************************
+ *
+ * Open/initialize the board.
+ *
+ * This routine should set everything up anew at each open, even
+ * registers that "should" only need to be set once at boot, so that
+ * there is a non-reboot way to recover if something goes wrong.
+ *
+ */
+static int
+de620_open(struct device *dev)
+{
+	if (request_irq(DE620_IRQ, de620_interrupt, 0, "de620")) {
+		printk ("%s: unable to get IRQ %d\n", dev->name, DE620_IRQ);
+		return 1;
+	}
+	irq2dev_map[DE620_IRQ] = dev;
+
+#ifdef MODULE
+	MOD_INC_USE_COUNT;
+#endif
+	if (adapter_init(dev)) {
+		return 1;
+	}
+	dev->start = 1;
+	return 0;
+}
+
+/************************************************
+ *
+ * The inverse routine to de620_open().
+ *
+ */
+static int
+de620_close(struct device *dev)
+{
+	/* disable recv */
+	de620_set_register(W_TCR, RXOFF);
+
+	free_irq(DE620_IRQ);
+	irq2dev_map[DE620_IRQ] = NULL;
+
+	dev->start = 0;
+#ifdef MODULE
+	MOD_DEC_USE_COUNT;
+#endif
+	return 0;
+}
+
+/*********************************************
+ *
+ * Return current statistics
+ *
+ */
+static struct netstats *
+get_stats(struct device *dev)
+{
+	return (struct netstats *)(dev->priv);
+}
+
+/*********************************************
+ *
+ * Set or clear the multicast filter for this adaptor.
+ * (no real multicast implemented for the DE-620, but she can be promiscuous...)
+ *
+ * num_addrs == -1	Promiscuous mode, receive all packets
+ * num_addrs == 0	Normal mode, clear multicast list
+ * num_addrs > 0	Multicast mode, receive normal and MC packets, and do
+ *			best-effort filtering.
+ */
+static void
+de620_set_multicast_list(struct device *dev, int num_addrs, void *addrs)
+{
+	if (num_addrs) { /* Enable promiscuous mode */
+		de620_set_register(W_TCR, (TCR_DEF & ~RXPBM) | RXALL);
+	}
+	else { /* Disable promiscuous mode, use normal mode */
+		de620_set_register(W_TCR, TCR_DEF);
+	}
+}
+
+/*******************************************************
+ *
+ * Copy a buffer to the adapter transmit page memory.
+ * Start sending.
+ */
+static int
+de620_start_xmit(struct sk_buff *skb, struct device *dev)
+{
+	unsigned long flags;
+	int len;
+	int tickssofar;
+	byte *buffer = skb->data;
+	byte using_txbuf;
+
+	/*
+	 * If some higher layer thinks we've missed a
+	 * tx-done interrupt we are passed NULL.
+	 * Caution: dev_tint() handles the cli()/sti() itself.
+	 */
+
+	if (skb == NULL) {
+		dev_tint(dev);
+		return 0;
+	}
+
+	using_txbuf = de620_tx_buffs(); /* Peek at the adapter */
+	dev->tbusy = (using_txbuf == (TXBF0 | TXBF1)); /* Boolean! */
+
+	if (dev->tbusy) {	/* Do timeouts, to avoid hangs. */
+		tickssofar = jiffies - dev->trans_start;
+
+		if (tickssofar < 5)
+			return 1;
+
+		/* else */
+		printk("%s: transmit timed out (%d), %s?\n",
+			dev->name,
+			tickssofar,
+			"network cable problem"
+			);
+		/* Restart the adapter. */
+		if (adapter_init(dev)) /* maybe close it */
+			return 1;
+	}
+
+	if ((len = skb->len) < RUNT)
+		len = RUNT;
+	if (len & 1) /* send an even number of bytes */
+		++len;
+
+	/* Start real output */
+	save_flags(flags);
+	cli();
+
+	PRINTK(("de620_start_xmit: len=%d, bufs 0x%02x\n",
+		(int)skb->len, using_txbuf));
+
+	/* select a free tx buffer. if there is one... */
+	switch (using_txbuf) {
+	default: /* both are free: use TXBF0 */
+	case TXBF1: /* use TXBF0 */
+		de620_send_command(W_CR | RW0);
+		using_txbuf |= TXBF0;
+		break;
+
+	case TXBF0: /* use TXBF1 */
+		de620_send_command(W_CR | RW1);
+		using_txbuf |= TXBF1;
+		break;
+
+	case (TXBF0 | TXBF1): /* NONE!!! */
+		printk("de620: Ouch! No tx-buffer available!\n");
+		restore_flags(flags);
+		return 1;
+		break;
+	}
+	de620_write_block(buffer, len);
+
+	dev->trans_start = jiffies;
+	dev->tbusy = (using_txbuf == (TXBF0 | TXBF1)); /* Boolean! */
+
+	((struct netstats *)(dev->priv))->tx_packets++;
+	
+	restore_flags(flags); /* interrupts maybe back on */
+	
+	dev_kfree_skb (skb, FREE_WRITE);
+
+	return 0;
+}
+
+/*****************************************************
+ *
+ * Handle the network interface interrupts.
+ *
+ */
+static void
+de620_interrupt(int reg_ptr)
+{
+	int irq = -(((struct pt_regs *)reg_ptr)->orig_eax+2);
+	struct device *dev = irq2dev_map[irq];
+	byte irq_status;
+	int bogus_count = 0;
+	int again = 0;
+
+	/* This might be deleted now, no crummy drivers present :-) Or..? */
+	if ((dev == NULL) || (DE620_IRQ != irq)) {
+		printk("%s: bogus interrupt %d\n", dev?dev->name:"DE620", irq);
+		return;
+	}
+
+	cli();
+	dev->interrupt = 1;
+
+	/* Read the status register (_not_ the status port) */
+	irq_status = de620_get_register(R_STS);
+
+	PRINTK(("de620_interrupt (%2.2X)\n", irq_status));
+
+	if (irq_status & RXGOOD) {
+		do {
+			again = de620_rx_intr(dev);
+			PRINTK(("again=%d\n", again));
+		}
+		while (again && (++bogus_count < 100));
+	}
+
+	dev->tbusy = (de620_tx_buffs() == (TXBF0 | TXBF1)); /* Boolean! */
+
+	dev->interrupt = 0;
+	sti();
+	return;
+}
+
+/**************************************
+ *
+ * Get a packet from the adapter
+ *
+ * Send it "upstairs"
+ *
+ */
+static int
+de620_rx_intr(struct device *dev)
+{
+	struct header_buf {
+		byte		status;
+		byte		Rx_NextPage;
+		unsigned short	Rx_ByteCount;
+	} header_buf;
+	struct sk_buff *skb;
+	int size;
+	byte *buffer;
+	byte pagelink;
+	byte curr_page;
+
+	PRINTK(("de620_rx_intr: next_rx_page = %d\n", next_rx_page));
+
+	/* Tell the adapter that we are going to read data, and from where */
+	de620_send_command(W_CR | RRN);
+	de620_set_register(W_RSA1, next_rx_page);
+	de620_set_register(W_RSA0, 0);
+
+	/* Deep breath, and away we goooooo */
+	de620_read_block((byte *)&header_buf, sizeof(struct header_buf));
+	PRINTK(("page status=0x%02x, nextpage=%d, packetsize=%d\n",
+	header_buf.status, header_buf.Rx_NextPage, header_buf.Rx_ByteCount));
+
+	/* Plausible page header? */
+	pagelink = header_buf.Rx_NextPage;
+	if ((pagelink < first_rx_page) || (last_rx_page < pagelink)) {
+		/* Ouch... Forget it! Skip all and start afresh... */
+		printk("%s: Ring overrun? Restoring...\n", dev->name);
+		/* You win some, you loose some. And sometimes plenty... */
+		adapter_init(dev);
+		((struct netstats *)(dev->priv))->rx_over_errors++;
+		return 0;
+	}
+
+	/* OK, this look good, so far. Let's see if it's consistent... */
+	/* Let's compute the start of the next packet, based on where we are */
+	pagelink = next_rx_page +
+		((header_buf.Rx_ByteCount + (4 - 1 + 0x100)) >> 8);
+
+	/* Are we going to wrap around the page counter? */
+	if (pagelink > last_rx_page)
+		pagelink -= (last_rx_page - first_rx_page + 1);
+
+	/* Is the _computed_ next page number equal to what the adapter says? */
+	if (pagelink != header_buf.Rx_NextPage) {
+		/* Naah, we'll skip this packet. Probably bogus data as well */
+		printk("%s: Page link out of sync! Restoring...\n", dev->name);
+		next_rx_page = header_buf.Rx_NextPage; /* at least a try... */
+		de620_send_command(W_DUMMY);
+		de620_set_register(W_NPRF, next_rx_page);
+		((struct netstats *)(dev->priv))->rx_over_errors++;
+		return 0;
+	}
+	next_rx_page = pagelink;
+
+	size = header_buf.Rx_ByteCount - 4;
+	if ((size < RUNT) || (GIANT < size)) {
+		printk("%s: Illegal packet size: %d!\n", dev->name, size);
+	}
+	else { /* Good packet? */
+		skb = alloc_skb(size, GFP_ATOMIC);
+		if (skb == NULL) { /* Yeah, but no place to put it... */
+			printk("%s: Couldn't allocate a sk_buff of size %d.\n",
+				dev->name, size);
+			((struct netstats *)(dev->priv))->rx_dropped++;
+		}
+		else { /* Yep! Go get it! */
+			skb->len = size; skb->dev = dev; skb->free = 1;
+			/* skb->data points to the start of sk_buff data area */
+			buffer = skb->data;
+			/* copy the packet into the buffer */
+			de620_read_block(buffer, size);
+			PRINTK(("Read %d bytes\n", size));
+			netif_rx(skb); /* deliver it "upstairs" */
+			/* count all receives */
+			((struct netstats *)(dev->priv))->rx_packets++;
+		}
+	}
+
+	/* Let's peek ahead to see if we have read the last current packet */
+	/* NOTE! We're _not_ checking the 'EMPTY'-flag! This seems better... */
+	curr_page = de620_get_register(R_CPR);
+	de620_set_register(W_NPRF, next_rx_page);
+	PRINTK(("next_rx_page=%d CPR=%d\n", next_rx_page, curr_page));
+
+	return (next_rx_page != curr_page); /* That was slightly tricky... */
+}
+
+/*********************************************
+ *
+ * Reset the adapter to a known state
+ *
+ */
+static int
+adapter_init(struct device *dev)
+{
+	int i;
+	static int was_down = 0;
+
+	if ((nic_data.Model == 3) || (nic_data.Model == 0)) { /* CT */
+		EIPRegister = NCTL0;
+		if (nic_data.Media != 1)
+			EIPRegister |= NIS0;	/* not BNC */
+	}
+	else if (nic_data.Model == 2) { /* UTP */
+		EIPRegister = NCTL0 | NIS0;
+	}
+
+	de620_send_command(W_CR | RNOP | CLEAR);
+	de620_send_command(W_CR | RNOP);
+
+	de620_set_register(W_SCR, SCR_DEF);
+	/* disable recv to wait init */
+	de620_set_register(W_TCR, RXOFF);
+
+	/* Set the node ID in the adapter */
+	for (i = 0; i < 6; ++i) { /* W_PARn = 0xaa + n */
+		de620_set_register(W_PAR0 + i, dev->dev_addr[i]);
+	}
+
+	de620_set_register(W_EIP, EIPRegister);
+
+	next_rx_page = first_rx_page = DE620_RX_START_PAGE;
+	if (nic_data.RAM_Size)
+		last_rx_page = nic_data.RAM_Size - 1;
+	else /* 64k RAM */
+		last_rx_page = 255;
+
+	de620_set_register(W_SPR, first_rx_page); /* Start Page Register */
+	de620_set_register(W_EPR, last_rx_page);  /* End Page Register */
+	de620_set_register(W_CPR, first_rx_page); /* Current Page Register */
+	de620_send_command(W_NPR | first_rx_page); /* Next Page Register */
+	de620_send_command(W_DUMMY);
+	de620_set_delay();
+
+	/* Final sanity check: Anybody out there? */
+	/* Let's hope some bits from the statusregister make a good check */
+#define CHECK_MASK (  0 | TXSUC |  T16  |  0  | RXCRC | RXSHORT |  0  |  0  )
+#define CHECK_OK   (  0 |   0   |  0    |  0  |   0   |   0     |  0  |  0  )
+        /* success:   X     0      0       X      0       0        X     X  */
+        /* ignore:   EEDI                RXGOOD                   COLS  LNKS*/
+
+	if (((i = de620_get_register(R_STS)) & CHECK_MASK) != CHECK_OK) {
+		printk("Something has happened to the DE-620!  Please check it"
+#ifdef SHUTDOWN_WHEN_LOST
+			" and do a new ifconfig"
+#endif
+			"! (%02x)\n", i);
+#ifdef SHUTDOWN_WHEN_LOST
+		/* Goodbye, cruel world... */
+		dev->flags &= ~IFF_UP;
+		de620_close(dev);
+#endif
+		was_down = 1;
+		return 1; /* failed */
+	}
+	if (was_down) {
+		printk("Thanks, I feel much better now!\n");
+		was_down = 0;
+	}
+
+	/* All OK, go ahead... */
+	de620_set_register(W_TCR, TCR_DEF);
+
+	return 0; /* all ok */
+}
+
+/******************************************************************************
+ *
+ * Only start-up code below
+ *
+ */
+/****************************************
+ *
+ * Check if there is a DE-620 connected
+ */
+int
+de620_probe(struct device *dev)
+{
+	static struct netstats de620_netstats;
+	int i;
+	byte checkbyte = 0xa5;
+
+	if (de620_debug)
+		printk(version);
+
+	printk("D-Link DE-620 pocket adapter");
+
+	/* Initially, configure basic nibble mode, so we can read the EEPROM */
+	NIC_Cmd = DEF_NIC_CMD;
+	de620_set_register(W_EIP, EIPRegister);
+
+	/* Anybody out there? */
+	de620_set_register(W_CPR, checkbyte);
+	checkbyte = de620_get_register(R_CPR);
+
+	if ((checkbyte != 0xa5) || (read_eeprom() != 0)) {
+		printk(" not identified in the printer port\n");
+		return ENODEV;
+	}
+
+	/* else, got it! */
+	printk(", Ethernet Address: %2.2X",
+		dev->dev_addr[0] = nic_data.NodeID[0]);
+	for (i = 1; i < ETH_ALEN; i++) {
+		printk(":%2.2X", dev->dev_addr[i] = nic_data.NodeID[i]);
+		dev->broadcast[i] = 0xff;
+	}
+
+	printk(" (%dk RAM,",
+		(nic_data.RAM_Size) ? (nic_data.RAM_Size >> 2) : 64);
+
+	if (nic_data.Media == 1)
+		printk(" BNC)\n");
+	else
+		printk(" UTP)\n");
+
+	/* Initialize the device structure. */
+	/*dev->priv = kmalloc(sizeof(struct netstats), GFP_KERNEL);*/
+	dev->priv = &de620_netstats;
+
+	memset(dev->priv, 0, sizeof(struct netstats));
+	dev->get_stats = get_stats;
+	dev->open = de620_open;
+	dev->stop = de620_close;
+	dev->hard_start_xmit = &de620_start_xmit;
+	dev->set_multicast_list = &de620_set_multicast_list;
+	dev->base_addr = DE620_IO;
+	dev->irq = DE620_IRQ;
+
+	ether_setup(dev);
+	
+	/* dump eeprom */
+	if (de620_debug) {
+		printk("\nEEPROM contents:\n");
+		printk("RAM_Size = 0x%02X\n", nic_data.RAM_Size);
+		printk("NodeID = %02X:%02X:%02X:%02X:%02X:%02X\n",
+			nic_data.NodeID[0], nic_data.NodeID[1],
+			nic_data.NodeID[2], nic_data.NodeID[3],
+			nic_data.NodeID[4], nic_data.NodeID[5]);
+		printk("Model = %d\n", nic_data.Model);
+		printk("Media = %d\n", nic_data.Media);
+		printk("SCR = 0x%02x\n", nic_data.SCR);
+	}
+
+	return 0;
+}
+
+/**********************************
+ *
+ * Read info from on-board EEPROM
+ *
+ * Note: Bitwise serial I/O to/from the EEPROM vi the status _register_!
+ */
+#define sendit(data) de620_set_register(W_EIP, data | EIPRegister);
+
+static unsigned short
+ReadAWord(int from)
+{
+	unsigned short data;
+	int nbits;
+
+	/* cs   [__~~] SET SEND STATE */
+	/* di   [____]                */
+	/* sck  [_~~_]                */
+	sendit(0); sendit(1); sendit(5); sendit(4);
+
+	/* Send the 9-bit address from where we want to read the 16-bit word */
+	for (nbits = 9; nbits > 0; --nbits, from <<= 1) {
+		if (from & 0x0100) { /* bit set? */
+			/* cs    [~~~~] SEND 1 */
+			/* di    [~~~~]        */
+			/* sck   [_~~_]        */
+			sendit(6); sendit(7); sendit(7); sendit(6);
+		}
+		else {
+			/* cs    [~~~~] SEND 0 */
+			/* di    [____]        */
+			/* sck   [_~~_]        */
+			sendit(4); sendit(5); sendit(5); sendit(4);
+		}
+	}
+
+	/* Shift in the 16-bit word. The bits appear serially in EEDI (=0x80) */
+	for (data = 0, nbits = 16; nbits > 0; --nbits) {
+		/* cs    [~~~~] SEND 0 */
+		/* di    [____]        */
+		/* sck   [_~~_]        */
+		sendit(4); sendit(5); sendit(5); sendit(4);
+		data = (data << 1) | ((de620_get_register(R_STS) & EEDI) >> 7);
+	}
+	/* cs    [____] RESET SEND STATE */
+	/* di    [____]                  */
+	/* sck   [_~~_]                  */
+	sendit(0); sendit(1); sendit(1); sendit(0);
+
+	return data;
+}
+
+static int
+read_eeprom(void)
+{
+	unsigned short wrd;
+
+	/* D-Link Ethernet addresses are in the series  00:80:c8:7X:XX:XX:XX */
+	wrd = ReadAWord(0x1aa);	/* bytes 0 + 1 of NodeID */
+	if (wrd != htons(0x0080)) /* Valid D-Link ether sequence? */
+		return -1; /* Nope, not a DE-620 */
+	nic_data.NodeID[0] = wrd & 0xff;
+	nic_data.NodeID[1] = wrd >> 8;
+
+	wrd = ReadAWord(0x1ab);	/* bytes 2 + 3 of NodeID */
+	if ((wrd & 0xff) != 0xc8) /* Valid D-Link ether sequence? */
+		return -1; /* Nope, not a DE-620 */
+	nic_data.NodeID[2] = wrd & 0xff;
+	nic_data.NodeID[3] = wrd >> 8;
+
+	wrd = ReadAWord(0x1ac);	/* bytes 4 + 5 of NodeID */
+	nic_data.NodeID[4] = wrd & 0xff;
+	nic_data.NodeID[5] = wrd >> 8;
+
+	wrd = ReadAWord(0x1ad);	/* RAM size in pages (256 bytes). 0 = 64k */
+	nic_data.RAM_Size = (wrd >> 8);
+
+	wrd = ReadAWord(0x1ae);	/* hardware model (CT = 3) */
+	nic_data.Model = (wrd & 0xff);
+
+	wrd = ReadAWord(0x1af); /* media (indicates BNC/UTP) */
+	nic_data.Media = (wrd & 0xff);
+
+	wrd = ReadAWord(0x1a8); /* System Configuration Register */
+	nic_data.SCR = (wrd >> 8);
+
+	return 0; /* no errors */
+}
+
+/******************************************************************************
+ *
+ * Loadable module skeleton
+ *
+ */
+#ifdef MODULE
+char kernel_version[] = UTS_RELEASE;
+static char nullname[8];
+static struct device de620_dev = {
+	nullname, 0, 0, 0, 0, 0, 0, 0, 0, 0, NULL, de620_probe };
+
+int
+init_module(void)
+{
+	if (register_netdev(&de620_dev) != 0)
+		return -EIO;
+	return 0;
+}
+
+void
+cleanup_module(void)
+{
+	if (MOD_IN_USE)
+		printk("de620: device busy, remove delayed\n");
+	else
+		unregister_netdev(&de620_dev);
+}
+#endif /* MODULE */
+
+/*
+ * (add '-DMODULE' when compiling as loadable module)
+ *
+ * compile-command:
+ *	gcc -D__KERNEL__ -Wall -Wstrict-prototypes -O2 \
+ *	 -fomit-frame-pointer -m486 \
+ *	-I/usr/src/linux/include -I../../net/inet -c de620.c
+ */