1/*
2 *	de620.c $Revision: 1.40 $ BETA
3 *
4 *
5 *	Linux driver for the D-Link DE-620 Ethernet pocket adapter.
6 *
7 *	Portions (C) Copyright 1993, 1994 by Bjorn Ekwall <bj0rn@blox.se>
8 *
9 *	Based on adapter information gathered from DOS packetdriver
10 *	sources from D-Link Inc:  (Special thanks to Henry Ngai of D-Link.)
11 *		Portions (C) Copyright D-Link SYSTEM Inc. 1991, 1992
12 *		Copyright, 1988, Russell Nelson, Crynwr Software
13 *
14 *	Adapted to the sample network driver core for linux,
15 *	written by: Donald Becker <becker@super.org>
16 *		(Now at <becker@scyld.com>)
17 *
18 *	Valuable assistance from:
19 *		J. Joshua Kopper <kopper@rtsg.mot.com>
20 *		Olav Kvittem <Olav.Kvittem@uninett.no>
21 *		Germano Caronni <caronni@nessie.cs.id.ethz.ch>
22 *		Jeremy Fitzhardinge <jeremy@suite.sw.oz.au>
23 *
24 *****************************************************************************/
25/*
26 *	This program is free software; you can redistribute it and/or modify
27 *	it under the terms of the GNU General Public License as published by
28 *	the Free Software Foundation; either version 2, or (at your option)
29 *	any later version.
30 *
31 *	This program is distributed in the hope that it will be useful,
32 *	but WITHOUT ANY WARRANTY; without even the implied warranty of
33 *	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
34 *	GNU General Public License for more details.
35 *
36 *	You should have received a copy of the GNU General Public License
37 *	along with this program; if not, write to the Free Software
38 *	Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
39 *
40 *****************************************************************************/
41static const char version[] =
42	"de620.c: $Revision: 1.40 $,  Bjorn Ekwall <bj0rn@blox.se>\n";
43
44/***********************************************************************
45 *
46 * "Tuning" section.
47 *
48 * Compile-time options: (see below for descriptions)
49 * -DDE620_IO=0x378	(lpt1)
50 * -DDE620_IRQ=7	(lpt1)
51 * -DSHUTDOWN_WHEN_LOST
52 * -DCOUNT_LOOPS
53 * -DLOWSPEED
54 * -DREAD_DELAY
55 * -DWRITE_DELAY
56 */
57
58/*
59 * This driver assumes that the printer port is a "normal",
60 * dumb, uni-directional port!
61 * If your port is "fancy" in any way, please try to set it to "normal"
62 * with your BIOS setup.  I have no access to machines with bi-directional
63 * ports, so I can't test such a driver :-(
64 * (Yes, I _know_ it is possible to use DE620 with bidirectional ports...)
65 *
66 * There are some clones of DE620 out there, with different names.
67 * If the current driver does not recognize a clone, try to change
68 * the following #define to:
69 *
70 * #define DE620_CLONE 1
71 */
72#define DE620_CLONE 0
73
74/*
75 * If the adapter has problems with high speeds, enable this #define
76 * otherwise full printerport speed will be attempted.
77 *
78 * You can tune the READ_DELAY/WRITE_DELAY below if you enable LOWSPEED
79 *
80#define LOWSPEED
81 */
82
83#ifndef READ_DELAY
84#define READ_DELAY 100	/* adapter internal read delay in 100ns units */
85#endif
86
87#ifndef WRITE_DELAY
88#define WRITE_DELAY 100	/* adapter internal write delay in 100ns units */
89#endif
90
91/*
92 * Enable this #define if you want the adapter to do a "ifconfig down" on
93 * itself when we have detected that something is possibly wrong with it.
94 * The default behaviour is to retry with "adapter_init()" until success.
95 * This should be used for debugging purposes only.
96 *
97#define SHUTDOWN_WHEN_LOST
98 */
99
100#ifdef LOWSPEED
101/*
102 * Enable this #define if you want to see debugging output that show how long
103 * we have to wait before the DE-620 is ready for the next read/write/command.
104 *
105#define COUNT_LOOPS
106 */
107#endif
108
109#include <linux/module.h>
110#include <linux/kernel.h>
111#include <linux/types.h>
112#include <linux/fcntl.h>
113#include <linux/string.h>
114#include <linux/interrupt.h>
115#include <linux/ioport.h>
116#include <linux/in.h>
117#include <linux/errno.h>
118#include <linux/init.h>
119#include <linux/inet.h>
120#include <linux/netdevice.h>
121#include <linux/etherdevice.h>
122#include <linux/skbuff.h>
123
124#include <asm/io.h>
125#include <asm/system.h>
126
127/* Constant definitions for the DE-620 registers, commands and bits */
128#include "de620.h"
129
130typedef unsigned char byte;
131
132/*******************************************************
133 *                                                     *
134 * Definition of D-Link DE-620 Ethernet Pocket adapter *
135 * See also "de620.h"                                  *
136 *                                                     *
137 *******************************************************/
138#ifndef DE620_IO /* Compile-time configurable */
139#define DE620_IO 0x378
140#endif
141
142#ifndef DE620_IRQ /* Compile-time configurable */
143#define DE620_IRQ	7
144#endif
145
146#define DATA_PORT	(dev->base_addr)
147#define STATUS_PORT	(dev->base_addr + 1)
148#define COMMAND_PORT	(dev->base_addr + 2)
149
150#define RUNT 60		/* Too small Ethernet packet */
151#define GIANT 1514	/* largest legal size packet, no fcs */
152
153/*
154 * Force media with insmod:
155 *	insmod de620.o bnc=1
156 * or
157 *	insmod de620.o utp=1
158 *
159 * Force io and/or irq with insmod:
160 *	insmod de620.o io=0x378 irq=7
161 *
162 * Make a clone skip the Ethernet-address range check:
163 *	insmod de620.o clone=1
164 */
165static int bnc;
166static int utp;
167static int io  = DE620_IO;
168static int irq = DE620_IRQ;
169static int clone = DE620_CLONE;
170
171static spinlock_t de620_lock;
172
173module_param(bnc, int, 0);
174module_param(utp, int, 0);
175module_param(io, int, 0);
176module_param(irq, int, 0);
177module_param(clone, int, 0);
178MODULE_PARM_DESC(bnc, "DE-620 set BNC medium (0-1)");
179MODULE_PARM_DESC(utp, "DE-620 set UTP medium (0-1)");
180MODULE_PARM_DESC(io, "DE-620 I/O base address,required");
181MODULE_PARM_DESC(irq, "DE-620 IRQ number,required");
182MODULE_PARM_DESC(clone, "Check also for non-D-Link DE-620 clones (0-1)");
183
184/***********************************************
185 *                                             *
186 * Index to functions, as function prototypes. *
187 *                                             *
188 ***********************************************/
189
190/*
191 * Routines used internally. (See also "convenience macros.. below")
192 */
193
194/* Put in the device structure. */
195static int	de620_open(struct net_device *);
196static int	de620_close(struct net_device *);
197static void	de620_set_multicast_list(struct net_device *);
198static int	de620_start_xmit(struct sk_buff *, struct net_device *);
199
200/* Dispatch from interrupts. */
201static irqreturn_t de620_interrupt(int, void *);
202static int	de620_rx_intr(struct net_device *);
203
204/* Initialization */
205static int	adapter_init(struct net_device *);
206static int	read_eeprom(struct net_device *);
207
208
209/*
210 * D-Link driver variables:
211 */
212#define SCR_DEF NIBBLEMODE |INTON | SLEEP | AUTOTX
213#define	TCR_DEF RXPB			/* not used: | TXSUCINT | T16INT */
214#define DE620_RX_START_PAGE 12		/* 12 pages (=3k) reserved for tx */
215#define DEF_NIC_CMD IRQEN | ICEN | DS1
216
217static volatile byte	NIC_Cmd;
218static volatile byte	next_rx_page;
219static byte		first_rx_page;
220static byte		last_rx_page;
221static byte		EIPRegister;
222
223static struct nic {
224	byte	NodeID[6];
225	byte	RAM_Size;
226	byte	Model;
227	byte	Media;
228	byte	SCR;
229} nic_data;
230
231/**********************************************************
232 *                                                        *
233 * Convenience macros/functions for D-Link DE-620 adapter *
234 *                                                        *
235 **********************************************************/
236#define de620_tx_buffs(dd) (inb(STATUS_PORT) & (TXBF0 | TXBF1))
237#define de620_flip_ds(dd) NIC_Cmd ^= DS0 | DS1; outb(NIC_Cmd, COMMAND_PORT);
238
239/* Check for ready-status, and return a nibble (high 4 bits) for data input */
240#ifdef COUNT_LOOPS
241static int tot_cnt;
242#endif
243static inline byte
244de620_ready(struct net_device *dev)
245{
246	byte value;
247	register short int cnt = 0;
248
249	while ((((value = inb(STATUS_PORT)) & READY) == 0) && (cnt <= 1000))
250		++cnt;
251
252#ifdef COUNT_LOOPS
253	tot_cnt += cnt;
254#endif
255	return value & 0xf0; /* nibble */
256}
257
258static inline void
259de620_send_command(struct net_device *dev, byte cmd)
260{
261	de620_ready(dev);
262	if (cmd == W_DUMMY)
263		outb(NIC_Cmd, COMMAND_PORT);
264
265	outb(cmd, DATA_PORT);
266
267	outb(NIC_Cmd ^ CS0, COMMAND_PORT);
268	de620_ready(dev);
269	outb(NIC_Cmd, COMMAND_PORT);
270}
271
272static inline void
273de620_put_byte(struct net_device *dev, byte value)
274{
275	/* The de620_ready() makes 7 loops, on the average, on a DX2/66 */
276	de620_ready(dev);
277	outb(value, DATA_PORT);
278	de620_flip_ds(dev);
279}
280
281static inline byte
282de620_read_byte(struct net_device *dev)
283{
284	byte value;
285
286	/* The de620_ready() makes 7 loops, on the average, on a DX2/66 */
287	value = de620_ready(dev); /* High nibble */
288	de620_flip_ds(dev);
289	value |= de620_ready(dev) >> 4; /* Low nibble */
290	return value;
291}
292
293static inline void
294de620_write_block(struct net_device *dev, byte *buffer, int count, int pad)
295{
296#ifndef LOWSPEED
297	byte uflip = NIC_Cmd ^ (DS0 | DS1);
298	byte dflip = NIC_Cmd;
299#else /* LOWSPEED */
300#ifdef COUNT_LOOPS
301	int bytes = count;
302#endif /* COUNT_LOOPS */
303#endif /* LOWSPEED */
304
305#ifdef LOWSPEED
306#ifdef COUNT_LOOPS
307	tot_cnt = 0;
308#endif /* COUNT_LOOPS */
309	/* No further optimization useful, the limit is in the adapter. */
310	for ( ; count > 0; --count, ++buffer) {
311		de620_put_byte(dev,*buffer);
312	}
313	for ( count = pad ; count > 0; --count, ++buffer) {
314		de620_put_byte(dev, 0);
315	}
316	de620_send_command(dev,W_DUMMY);
317#ifdef COUNT_LOOPS
318	/* trial debug output: loops per byte in de620_ready() */
319	printk("WRITE(%d)\n", tot_cnt/((bytes?bytes:1)));
320#endif /* COUNT_LOOPS */
321#else /* not LOWSPEED */
322	for ( ; count > 0; count -=2) {
323		outb(*buffer++, DATA_PORT);
324		outb(uflip, COMMAND_PORT);
325		outb(*buffer++, DATA_PORT);
326		outb(dflip, COMMAND_PORT);
327	}
328	de620_send_command(dev,W_DUMMY);
329#endif /* LOWSPEED */
330}
331
332static inline void
333de620_read_block(struct net_device *dev, byte *data, int count)
334{
335#ifndef LOWSPEED
336	byte value;
337	byte uflip = NIC_Cmd ^ (DS0 | DS1);
338	byte dflip = NIC_Cmd;
339#else /* LOWSPEED */
340#ifdef COUNT_LOOPS
341	int bytes = count;
342
343	tot_cnt = 0;
344#endif /* COUNT_LOOPS */
345#endif /* LOWSPEED */
346
347#ifdef LOWSPEED
348	/* No further optimization useful, the limit is in the adapter. */
349	while (count-- > 0) {
350		*data++ = de620_read_byte(dev);
351		de620_flip_ds(dev);
352	}
353#ifdef COUNT_LOOPS
354	/* trial debug output: loops per byte in de620_ready() */
355	printk("READ(%d)\n", tot_cnt/(2*(bytes?bytes:1)));
356#endif /* COUNT_LOOPS */
357#else /* not LOWSPEED */
358	while (count-- > 0) {
359		value = inb(STATUS_PORT) & 0xf0; /* High nibble */
360		outb(uflip, COMMAND_PORT);
361		*data++ = value | inb(STATUS_PORT) >> 4; /* Low nibble */
362		outb(dflip , COMMAND_PORT);
363	}
364#endif /* LOWSPEED */
365}
366
367static inline void
368de620_set_delay(struct net_device *dev)
369{
370	de620_ready(dev);
371	outb(W_DFR, DATA_PORT);
372	outb(NIC_Cmd ^ CS0, COMMAND_PORT);
373
374	de620_ready(dev);
375#ifdef LOWSPEED
376	outb(WRITE_DELAY, DATA_PORT);
377#else
378	outb(0, DATA_PORT);
379#endif
380	de620_flip_ds(dev);
381
382	de620_ready(dev);
383#ifdef LOWSPEED
384	outb(READ_DELAY, DATA_PORT);
385#else
386	outb(0, DATA_PORT);
387#endif
388	de620_flip_ds(dev);
389}
390
391static inline void
392de620_set_register(struct net_device *dev, byte reg, byte value)
393{
394	de620_ready(dev);
395	outb(reg, DATA_PORT);
396	outb(NIC_Cmd ^ CS0, COMMAND_PORT);
397
398	de620_put_byte(dev, value);
399}
400
401static inline byte
402de620_get_register(struct net_device *dev, byte reg)
403{
404	byte value;
405
406	de620_send_command(dev,reg);
407	value = de620_read_byte(dev);
408	de620_send_command(dev,W_DUMMY);
409
410	return value;
411}
412
413/*********************************************************************
414 *
415 * Open/initialize the board.
416 *
417 * This routine should set everything up anew at each open, even
418 * registers that "should" only need to be set once at boot, so that
419 * there is a non-reboot way to recover if something goes wrong.
420 *
421 */
422static int de620_open(struct net_device *dev)
423{
424	int ret = request_irq(dev->irq, de620_interrupt, 0, dev->name, dev);
425	if (ret) {
426		printk (KERN_ERR "%s: unable to get IRQ %d\n", dev->name, dev->irq);
427		return ret;
428	}
429
430	if (adapter_init(dev)) {
431		ret = -EIO;
432		goto out_free_irq;
433	}
434
435	netif_start_queue(dev);
436	return 0;
437
438out_free_irq:
439	free_irq(dev->irq, dev);
440	return ret;
441}
442
443/************************************************
444 *
445 * The inverse routine to de620_open().
446 *
447 */
448
449static int de620_close(struct net_device *dev)
450{
451	netif_stop_queue(dev);
452	/* disable recv */
453	de620_set_register(dev, W_TCR, RXOFF);
454	free_irq(dev->irq, dev);
455	return 0;
456}
457
458/*********************************************
459 *
460 * Set or clear the multicast filter for this adaptor.
461 * (no real multicast implemented for the DE-620, but she can be promiscuous...)
462 *
463 */
464
465static void de620_set_multicast_list(struct net_device *dev)
466{
467	if (!netdev_mc_empty(dev) || dev->flags&(IFF_ALLMULTI|IFF_PROMISC))
468	{ /* Enable promiscuous mode */
469		de620_set_register(dev, W_TCR, (TCR_DEF & ~RXPBM) | RXALL);
470	}
471	else
472	{ /* Disable promiscuous mode, use normal mode */
473		de620_set_register(dev, W_TCR, TCR_DEF);
474	}
475}
476
477/*******************************************************
478 *
479 * Handle timeouts on transmit
480 */
481
482static void de620_timeout(struct net_device *dev)
483{
484	printk(KERN_WARNING "%s: transmit timed out, %s?\n", dev->name, "network cable problem");
485	/* Restart the adapter. */
486	if (!adapter_init(dev)) /* maybe close it */
487		netif_wake_queue(dev);
488}
489
490/*******************************************************
491 *
492 * Copy a buffer to the adapter transmit page memory.
493 * Start sending.
494 */
495static int de620_start_xmit(struct sk_buff *skb, struct net_device *dev)
496{
497	unsigned long flags;
498	int len;
499	byte *buffer = skb->data;
500	byte using_txbuf;
501
502	using_txbuf = de620_tx_buffs(dev); /* Peek at the adapter */
503
504	netif_stop_queue(dev);
505
506
507	if ((len = skb->len) < RUNT)
508		len = RUNT;
509	if (len & 1) /* send an even number of bytes */
510		++len;
511
512	/* Start real output */
513
514	spin_lock_irqsave(&de620_lock, flags);
515	pr_debug("de620_start_xmit: len=%d, bufs 0x%02x\n",
516		(int)skb->len, using_txbuf);
517
518	/* select a free tx buffer. if there is one... */
519	switch (using_txbuf) {
520	default: /* both are free: use TXBF0 */
521	case TXBF1: /* use TXBF0 */
522		de620_send_command(dev,W_CR | RW0);
523		using_txbuf |= TXBF0;
524		break;
525
526	case TXBF0: /* use TXBF1 */
527		de620_send_command(dev,W_CR | RW1);
528		using_txbuf |= TXBF1;
529		break;
530
531	case (TXBF0 | TXBF1): /* NONE!!! */
532		printk(KERN_WARNING "%s: No tx-buffer available!\n", dev->name);
533		spin_unlock_irqrestore(&de620_lock, flags);
534		return NETDEV_TX_BUSY;
535	}
536	de620_write_block(dev, buffer, skb->len, len-skb->len);
537
538	if(!(using_txbuf == (TXBF0 | TXBF1)))
539		netif_wake_queue(dev);
540
541	dev->stats.tx_packets++;
542	spin_unlock_irqrestore(&de620_lock, flags);
543	dev_kfree_skb (skb);
544	return NETDEV_TX_OK;
545}
546
547/*****************************************************
548 *
549 * Handle the network interface interrupts.
550 *
551 */
552static irqreturn_t
553de620_interrupt(int irq_in, void *dev_id)
554{
555	struct net_device *dev = dev_id;
556	byte irq_status;
557	int bogus_count = 0;
558	int again = 0;
559
560	spin_lock(&de620_lock);
561
562	/* Read the status register (_not_ the status port) */
563	irq_status = de620_get_register(dev, R_STS);
564
565	pr_debug("de620_interrupt (%2.2X)\n", irq_status);
566
567	if (irq_status & RXGOOD) {
568		do {
569			again = de620_rx_intr(dev);
570			pr_debug("again=%d\n", again);
571		}
572		while (again && (++bogus_count < 100));
573	}
574
575	if(de620_tx_buffs(dev) != (TXBF0 | TXBF1))
576		netif_wake_queue(dev);
577
578	spin_unlock(&de620_lock);
579	return IRQ_HANDLED;
580}
581
582/**************************************
583 *
584 * Get a packet from the adapter
585 *
586 * Send it "upstairs"
587 *
588 */
589static int de620_rx_intr(struct net_device *dev)
590{
591	struct header_buf {
592		byte		status;
593		byte		Rx_NextPage;
594		unsigned short	Rx_ByteCount;
595	} header_buf;
596	struct sk_buff *skb;
597	int size;
598	byte *buffer;
599	byte pagelink;
600	byte curr_page;
601
602	pr_debug("de620_rx_intr: next_rx_page = %d\n", next_rx_page);
603
604	/* Tell the adapter that we are going to read data, and from where */
605	de620_send_command(dev, W_CR | RRN);
606	de620_set_register(dev, W_RSA1, next_rx_page);
607	de620_set_register(dev, W_RSA0, 0);
608
609	/* Deep breath, and away we goooooo */
610	de620_read_block(dev, (byte *)&header_buf, sizeof(struct header_buf));
611	pr_debug("page status=0x%02x, nextpage=%d, packetsize=%d\n",
612		header_buf.status, header_buf.Rx_NextPage,
613		header_buf.Rx_ByteCount);
614
615	/* Plausible page header? */
616	pagelink = header_buf.Rx_NextPage;
617	if ((pagelink < first_rx_page) || (last_rx_page < pagelink)) {
618		/* Ouch... Forget it! Skip all and start afresh... */
619		printk(KERN_WARNING "%s: Ring overrun? Restoring...\n", dev->name);
620		/* You win some, you lose some. And sometimes plenty... */
621		adapter_init(dev);
622		netif_wake_queue(dev);
623		dev->stats.rx_over_errors++;
624		return 0;
625	}
626
627	/* OK, this look good, so far. Let's see if it's consistent... */
628	/* Let's compute the start of the next packet, based on where we are */
629	pagelink = next_rx_page +
630		((header_buf.Rx_ByteCount + (4 - 1 + 0x100)) >> 8);
631
632	/* Are we going to wrap around the page counter? */
633	if (pagelink > last_rx_page)
634		pagelink -= (last_rx_page - first_rx_page + 1);
635
636	/* Is the _computed_ next page number equal to what the adapter says? */
637	if (pagelink != header_buf.Rx_NextPage) {
638		/* Naah, we'll skip this packet. Probably bogus data as well */
639		printk(KERN_WARNING "%s: Page link out of sync! Restoring...\n", dev->name);
640		next_rx_page = header_buf.Rx_NextPage; /* at least a try... */
641		de620_send_command(dev, W_DUMMY);
642		de620_set_register(dev, W_NPRF, next_rx_page);
643		dev->stats.rx_over_errors++;
644		return 0;
645	}
646	next_rx_page = pagelink;
647
648	size = header_buf.Rx_ByteCount - 4;
649	if ((size < RUNT) || (GIANT < size)) {
650		printk(KERN_WARNING "%s: Illegal packet size: %d!\n", dev->name, size);
651	}
652	else { /* Good packet? */
653		skb = dev_alloc_skb(size+2);
654		if (skb == NULL) { /* Yeah, but no place to put it... */
655			printk(KERN_WARNING "%s: Couldn't allocate a sk_buff of size %d.\n", dev->name, size);
656			dev->stats.rx_dropped++;
657		}
658		else { /* Yep! Go get it! */
659			skb_reserve(skb,2);	/* Align */
660			/* skb->data points to the start of sk_buff data area */
661			buffer = skb_put(skb,size);
662			/* copy the packet into the buffer */
663			de620_read_block(dev, buffer, size);
664			pr_debug("Read %d bytes\n", size);
665			skb->protocol=eth_type_trans(skb,dev);
666			netif_rx(skb); /* deliver it "upstairs" */
667			/* count all receives */
668			dev->stats.rx_packets++;
669			dev->stats.rx_bytes += size;
670		}
671	}
672
673	/* Let's peek ahead to see if we have read the last current packet */
674	/* NOTE! We're _not_ checking the 'EMPTY'-flag! This seems better... */
675	curr_page = de620_get_register(dev, R_CPR);
676	de620_set_register(dev, W_NPRF, next_rx_page);
677	pr_debug("next_rx_page=%d CPR=%d\n", next_rx_page, curr_page);
678
679	return next_rx_page != curr_page; /* That was slightly tricky... */
680}
681
682/*********************************************
683 *
684 * Reset the adapter to a known state
685 *
686 */
687static int adapter_init(struct net_device *dev)
688{
689	int i;
690	static int was_down;
691
692	if ((nic_data.Model == 3) || (nic_data.Model == 0)) { /* CT */
693		EIPRegister = NCTL0;
694		if (nic_data.Media != 1)
695			EIPRegister |= NIS0;	/* not BNC */
696	}
697	else if (nic_data.Model == 2) { /* UTP */
698		EIPRegister = NCTL0 | NIS0;
699	}
700
701	if (utp)
702		EIPRegister = NCTL0 | NIS0;
703	if (bnc)
704		EIPRegister = NCTL0;
705
706	de620_send_command(dev, W_CR | RNOP | CLEAR);
707	de620_send_command(dev, W_CR | RNOP);
708
709	de620_set_register(dev, W_SCR, SCR_DEF);
710	/* disable recv to wait init */
711	de620_set_register(dev, W_TCR, RXOFF);
712
713	/* Set the node ID in the adapter */
714	for (i = 0; i < 6; ++i) { /* W_PARn = 0xaa + n */
715		de620_set_register(dev, W_PAR0 + i, dev->dev_addr[i]);
716	}
717
718	de620_set_register(dev, W_EIP, EIPRegister);
719
720	next_rx_page = first_rx_page = DE620_RX_START_PAGE;
721	if (nic_data.RAM_Size)
722		last_rx_page = nic_data.RAM_Size - 1;
723	else /* 64k RAM */
724		last_rx_page = 255;
725
726	de620_set_register(dev, W_SPR, first_rx_page); /* Start Page Register*/
727	de620_set_register(dev, W_EPR, last_rx_page);  /* End Page Register */
728	de620_set_register(dev, W_CPR, first_rx_page);/*Current Page Register*/
729	de620_send_command(dev, W_NPR | first_rx_page); /* Next Page Register*/
730	de620_send_command(dev, W_DUMMY);
731	de620_set_delay(dev);
732
733	/* Final sanity check: Anybody out there? */
734	/* Let's hope some bits from the statusregister make a good check */
735#define CHECK_MASK (  0 | TXSUC |  T16  |  0  | RXCRC | RXSHORT |  0  |  0  )
736#define CHECK_OK   (  0 |   0   |  0    |  0  |   0   |   0     |  0  |  0  )
737        /* success:   X     0      0       X      0       0        X     X  */
738        /* ignore:   EEDI                RXGOOD                   COLS  LNKS*/
739
740	if (((i = de620_get_register(dev, R_STS)) & CHECK_MASK) != CHECK_OK) {
741		printk(KERN_ERR "%s: Something has happened to the DE-620!  Please check it"
742#ifdef SHUTDOWN_WHEN_LOST
743			" and do a new ifconfig"
744#endif
745			"! (%02x)\n", dev->name, i);
746#ifdef SHUTDOWN_WHEN_LOST
747		/* Goodbye, cruel world... */
748		dev->flags &= ~IFF_UP;
749		de620_close(dev);
750#endif
751		was_down = 1;
752		return 1; /* failed */
753	}
754	if (was_down) {
755		printk(KERN_WARNING "%s: Thanks, I feel much better now!\n", dev->name);
756		was_down = 0;
757	}
758
759	/* All OK, go ahead... */
760	de620_set_register(dev, W_TCR, TCR_DEF);
761
762	return 0; /* all ok */
763}
764
765static const struct net_device_ops de620_netdev_ops = {
766	.ndo_open 		= de620_open,
767	.ndo_stop 		= de620_close,
768	.ndo_start_xmit 	= de620_start_xmit,
769	.ndo_tx_timeout 	= de620_timeout,
770	.ndo_set_rx_mode	= de620_set_multicast_list,
771	.ndo_change_mtu		= eth_change_mtu,
772	.ndo_set_mac_address 	= eth_mac_addr,
773	.ndo_validate_addr	= eth_validate_addr,
774};
775
776/******************************************************************************
777 *
778 * Only start-up code below
779 *
780 */
781/****************************************
782 *
783 * Check if there is a DE-620 connected
784 */
785struct net_device * __init de620_probe(int unit)
786{
787	byte checkbyte = 0xa5;
788	struct net_device *dev;
789	int err = -ENOMEM;
790	int i;
791
792	dev = alloc_etherdev(0);
793	if (!dev)
794		goto out;
795
796	spin_lock_init(&de620_lock);
797
798	/*
799	 * This is where the base_addr and irq gets set.
800	 * Tunable at compile-time and insmod-time
801	 */
802	dev->base_addr = io;
803	dev->irq       = irq;
804
805	/* allow overriding parameters on command line */
806	if (unit >= 0) {
807		sprintf(dev->name, "eth%d", unit);
808		netdev_boot_setup_check(dev);
809	}
810
811	pr_debug("%s", version);
812
813	printk(KERN_INFO "D-Link DE-620 pocket adapter");
814
815	if (!request_region(dev->base_addr, 3, "de620")) {
816		printk(" io 0x%3lX, which is busy.\n", dev->base_addr);
817		err = -EBUSY;
818		goto out1;
819	}
820
821	/* Initially, configure basic nibble mode, so we can read the EEPROM */
822	NIC_Cmd = DEF_NIC_CMD;
823	de620_set_register(dev, W_EIP, EIPRegister);
824
825	/* Anybody out there? */
826	de620_set_register(dev, W_CPR, checkbyte);
827	checkbyte = de620_get_register(dev, R_CPR);
828
829	if ((checkbyte != 0xa5) || (read_eeprom(dev) != 0)) {
830		printk(" not identified in the printer port\n");
831		err = -ENODEV;
832		goto out2;
833	}
834
835	/* else, got it! */
836	dev->dev_addr[0] = nic_data.NodeID[0];
837	for (i = 1; i < ETH_ALEN; i++) {
838		dev->dev_addr[i] = nic_data.NodeID[i];
839		dev->broadcast[i] = 0xff;
840	}
841
842	printk(", Ethernet Address: %pM", dev->dev_addr);
843
844	printk(" (%dk RAM,",
845		(nic_data.RAM_Size) ? (nic_data.RAM_Size >> 2) : 64);
846
847	if (nic_data.Media == 1)
848		printk(" BNC)\n");
849	else
850		printk(" UTP)\n");
851
852	dev->netdev_ops = &de620_netdev_ops;
853	dev->watchdog_timeo	= HZ*2;
854
855	/* base_addr and irq are already set, see above! */
856
857	/* dump eeprom */
858	pr_debug("\nEEPROM contents:\n"
859		"RAM_Size = 0x%02X\n"
860		"NodeID = %pM\n"
861		"Model = %d\n"
862		"Media = %d\n"
863		"SCR = 0x%02x\n", nic_data.RAM_Size, nic_data.NodeID,
864		nic_data.Model, nic_data.Media, nic_data.SCR);
865
866	err = register_netdev(dev);
867	if (err)
868		goto out2;
869	return dev;
870
871out2:
872	release_region(dev->base_addr, 3);
873out1:
874	free_netdev(dev);
875out:
876	return ERR_PTR(err);
877}
878
879/**********************************
880 *
881 * Read info from on-board EEPROM
882 *
883 * Note: Bitwise serial I/O to/from the EEPROM vi the status _register_!
884 */
885#define sendit(dev,data) de620_set_register(dev, W_EIP, data | EIPRegister);
886
887static unsigned short __init ReadAWord(struct net_device *dev, int from)
888{
889	unsigned short data;
890	int nbits;
891
892	/* cs   [__~~] SET SEND STATE */
893	/* di   [____]                */
894	/* sck  [_~~_]                */
895	sendit(dev, 0); sendit(dev, 1); sendit(dev, 5); sendit(dev, 4);
896
897	/* Send the 9-bit address from where we want to read the 16-bit word */
898	for (nbits = 9; nbits > 0; --nbits, from <<= 1) {
899		if (from & 0x0100) { /* bit set? */
900			/* cs    [~~~~] SEND 1 */
901			/* di    [~~~~]        */
902			/* sck   [_~~_]        */
903			sendit(dev, 6); sendit(dev, 7); sendit(dev, 7); sendit(dev, 6);
904		}
905		else {
906			/* cs    [~~~~] SEND 0 */
907			/* di    [____]        */
908			/* sck   [_~~_]        */
909			sendit(dev, 4); sendit(dev, 5); sendit(dev, 5); sendit(dev, 4);
910		}
911	}
912
913	/* Shift in the 16-bit word. The bits appear serially in EEDI (=0x80) */
914	for (data = 0, nbits = 16; nbits > 0; --nbits) {
915		/* cs    [~~~~] SEND 0 */
916		/* di    [____]        */
917		/* sck   [_~~_]        */
918		sendit(dev, 4); sendit(dev, 5); sendit(dev, 5); sendit(dev, 4);
919		data = (data << 1) | ((de620_get_register(dev, R_STS) & EEDI) >> 7);
920	}
921	/* cs    [____] RESET SEND STATE */
922	/* di    [____]                  */
923	/* sck   [_~~_]                  */
924	sendit(dev, 0); sendit(dev, 1); sendit(dev, 1); sendit(dev, 0);
925
926	return data;
927}
928
929static int __init read_eeprom(struct net_device *dev)
930{
931	unsigned short wrd;
932
933	/* D-Link Ethernet addresses are in the series  00:80:c8:7X:XX:XX:XX */
934	wrd = ReadAWord(dev, 0x1aa);	/* bytes 0 + 1 of NodeID */
935	if (!clone && (wrd != htons(0x0080))) /* Valid D-Link ether sequence? */
936		return -1; /* Nope, not a DE-620 */
937	nic_data.NodeID[0] = wrd & 0xff;
938	nic_data.NodeID[1] = wrd >> 8;
939
940	wrd = ReadAWord(dev, 0x1ab);	/* bytes 2 + 3 of NodeID */
941	if (!clone && ((wrd & 0xff) != 0xc8)) /* Valid D-Link ether sequence? */
942		return -1; /* Nope, not a DE-620 */
943	nic_data.NodeID[2] = wrd & 0xff;
944	nic_data.NodeID[3] = wrd >> 8;
945
946	wrd = ReadAWord(dev, 0x1ac);	/* bytes 4 + 5 of NodeID */
947	nic_data.NodeID[4] = wrd & 0xff;
948	nic_data.NodeID[5] = wrd >> 8;
949
950	wrd = ReadAWord(dev, 0x1ad);	/* RAM size in pages (256 bytes). 0 = 64k */
951	nic_data.RAM_Size = (wrd >> 8);
952
953	wrd = ReadAWord(dev, 0x1ae);	/* hardware model (CT = 3) */
954	nic_data.Model = (wrd & 0xff);
955
956	wrd = ReadAWord(dev, 0x1af); /* media (indicates BNC/UTP) */
957	nic_data.Media = (wrd & 0xff);
958
959	wrd = ReadAWord(dev, 0x1a8); /* System Configuration Register */
960	nic_data.SCR = (wrd >> 8);
961
962	return 0; /* no errors */
963}
964
965/******************************************************************************
966 *
967 * Loadable module skeleton
968 *
969 */
970#ifdef MODULE
971static struct net_device *de620_dev;
972
973int __init init_module(void)
974{
975	de620_dev = de620_probe(-1);
976	if (IS_ERR(de620_dev))
977		return PTR_ERR(de620_dev);
978	return 0;
979}
980
981void cleanup_module(void)
982{
983	unregister_netdev(de620_dev);
984	release_region(de620_dev->base_addr, 3);
985	free_netdev(de620_dev);
986}
987#endif /* MODULE */
988MODULE_LICENSE("GPL");
989