aboutsummaryrefslogblamecommitdiffstats
path: root/drivers/net/arm/am79c961a.c
blob: 877891a29aaac297fcf88542c8ea6159d97f1377 (plain) (tree)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
















                                                                       

                            




                              



                         
                                  
 
                         
                   
                       


















































                                                                                 
                                              




































































































































































































                                                                                                                 
                                  
                                      

                                                   
                                       

                                                     
 
                                                                 


























































































































































































































































































































































































                                                                                                  
                                                     
 

                                                                



                               



                                                            




                                                      

                                        






                                                  

                                             



















                                                             
                               
                                                                      
 

                          


















                                                            


                                                                  
                                                             


                                                                               
                         
         








                                             










                                                 
                          
/*
 *  linux/drivers/net/am79c961.c
 *
 *  by Russell King <rmk@arm.linux.org.uk> 1995-2001.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Derived from various things including skeleton.c
 *
 * This is a special driver for the am79c961A Lance chip used in the
 * Intel (formally Digital Equipment Corp) EBSA110 platform.  Please
 * note that this can not be built as a module (it doesn't make sense).
 */
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/crc32.h>
#include <linux/bitops.h>
#include <linux/platform_device.h>

#include <asm/hardware.h>
#include <asm/io.h>
#include <asm/system.h>

#define TX_BUFFERS 15
#define RX_BUFFERS 25

#include "am79c961a.h"

static irqreturn_t
am79c961_interrupt (int irq, void *dev_id, struct pt_regs *regs);

static unsigned int net_debug = NET_DEBUG;

static const char version[] =
	"am79c961 ethernet driver (C) 1995-2001 Russell King v0.04\n";

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

#ifdef __arm__
static void write_rreg(u_long base, u_int reg, u_int val)
{
	__asm__(
	"str%?h	%1, [%2]	@ NET_RAP\n\t"
	"str%?h	%0, [%2, #-4]	@ NET_RDP"
	:
	: "r" (val), "r" (reg), "r" (ISAIO_BASE + 0x0464));
}

static inline unsigned short read_rreg(u_long base_addr, u_int reg)
{
	unsigned short v;
	__asm__(
	"str%?h	%1, [%2]	@ NET_RAP\n\t"
	"ldr%?h	%0, [%2, #-4]	@ NET_RDP"
	: "=r" (v)
	: "r" (reg), "r" (ISAIO_BASE + 0x0464));
	return v;
}

static inline void write_ireg(u_long base, u_int reg, u_int val)
{
	__asm__(
	"str%?h	%1, [%2]	@ NET_RAP\n\t"
	"str%?h	%0, [%2, #8]	@ NET_IDP"
	:
	: "r" (val), "r" (reg), "r" (ISAIO_BASE + 0x0464));
}

static inline unsigned short read_ireg(u_long base_addr, u_int reg)
{
	u_short v;
	__asm__(
	"str%?h	%1, [%2]	@ NAT_RAP\n\t"
	"ldr%?h	%0, [%2, #8]	@ NET_IDP\n\t"
	: "=r" (v)
	: "r" (reg), "r" (ISAIO_BASE + 0x0464));
	return v;
}

#define am_writeword(dev,off,val) __raw_writew(val, ISAMEM_BASE + ((off) << 1))
#define am_readword(dev,off)      __raw_readw(ISAMEM_BASE + ((off) << 1))

static inline void
am_writebuffer(struct net_device *dev, u_int offset, unsigned char *buf, unsigned int length)
{
	offset = ISAMEM_BASE + (offset << 1);
	length = (length + 1) & ~1;
	if ((int)buf & 2) {
		__asm__ __volatile__("str%?h	%2, [%0], #4"
		 : "=&r" (offset) : "0" (offset), "r" (buf[0] | (buf[1] << 8)));
		buf += 2;
		length -= 2;
	}
	while (length > 8) {
		unsigned int tmp, tmp2;
		__asm__ __volatile__(
			"ldm%?ia	%1!, {%2, %3}\n\t"
			"str%?h	%2, [%0], #4\n\t"
			"mov%?	%2, %2, lsr #16\n\t"
			"str%?h	%2, [%0], #4\n\t"
			"str%?h	%3, [%0], #4\n\t"
			"mov%?	%3, %3, lsr #16\n\t"
			"str%?h	%3, [%0], #4"
		: "=&r" (offset), "=&r" (buf), "=r" (tmp), "=r" (tmp2)
		: "0" (offset), "1" (buf));
		length -= 8;
	}
	while (length > 0) {
		__asm__ __volatile__("str%?h	%2, [%0], #4"
		 : "=&r" (offset) : "0" (offset), "r" (buf[0] | (buf[1] << 8)));
		buf += 2;
		length -= 2;
	}
}

static inline void
am_readbuffer(struct net_device *dev, u_int offset, unsigned char *buf, unsigned int length)
{
	offset = ISAMEM_BASE + (offset << 1);
	length = (length + 1) & ~1;
	if ((int)buf & 2) {
		unsigned int tmp;
		__asm__ __volatile__(
			"ldr%?h	%2, [%0], #4\n\t"
			"str%?b	%2, [%1], #1\n\t"
			"mov%?	%2, %2, lsr #8\n\t"
			"str%?b	%2, [%1], #1"
		: "=&r" (offset), "=&r" (buf), "=r" (tmp): "0" (offset), "1" (buf));
		length -= 2;
	}
	while (length > 8) {
		unsigned int tmp, tmp2, tmp3;
		__asm__ __volatile__(
			"ldr%?h	%2, [%0], #4\n\t"
			"ldr%?h	%3, [%0], #4\n\t"
			"orr%?	%2, %2, %3, lsl #16\n\t"
			"ldr%?h	%3, [%0], #4\n\t"
			"ldr%?h	%4, [%0], #4\n\t"
			"orr%?	%3, %3, %4, lsl #16\n\t"
			"stm%?ia	%1!, {%2, %3}"
		: "=&r" (offset), "=&r" (buf), "=r" (tmp), "=r" (tmp2), "=r" (tmp3)
		: "0" (offset), "1" (buf));
		length -= 8;
	}
	while (length > 0) {
		unsigned int tmp;
		__asm__ __volatile__(
			"ldr%?h	%2, [%0], #4\n\t"
			"str%?b	%2, [%1], #1\n\t"
			"mov%?	%2, %2, lsr #8\n\t"
			"str%?b	%2, [%1], #1"
		: "=&r" (offset), "=&r" (buf), "=r" (tmp) : "0" (offset), "1" (buf));
		length -= 2;
	}
}
#else
#error Not compatible
#endif

static int
am79c961_ramtest(struct net_device *dev, unsigned int val)
{
	unsigned char *buffer = kmalloc (65536, GFP_KERNEL);
	int i, error = 0, errorcount = 0;

	if (!buffer)
		return 0;
	memset (buffer, val, 65536);
	am_writebuffer(dev, 0, buffer, 65536);
	memset (buffer, val ^ 255, 65536);
	am_readbuffer(dev, 0, buffer, 65536);
	for (i = 0; i < 65536; i++) {
		if (buffer[i] != val && !error) {
			printk ("%s: buffer error (%02X %02X) %05X - ", dev->name, val, buffer[i], i);
			error = 1;
			errorcount ++;
		} else if (error && buffer[i] == val) {
			printk ("%05X\n", i);
			error = 0;
		}
	}
	if (error)
		printk ("10000\n");
	kfree (buffer);
	return errorcount;
}

static void
am79c961_init_for_open(struct net_device *dev)
{
	struct dev_priv *priv = netdev_priv(dev);
	unsigned long flags;
	unsigned char *p;
	u_int hdr_addr, first_free_addr;
	int i;

	/*
	 * Stop the chip.
	 */
	spin_lock_irqsave(priv->chip_lock, flags);
	write_rreg (dev->base_addr, CSR0, CSR0_BABL|CSR0_CERR|CSR0_MISS|CSR0_MERR|CSR0_TINT|CSR0_RINT|CSR0_STOP);
	spin_unlock_irqrestore(priv->chip_lock, flags);

	write_ireg (dev->base_addr, 5, 0x00a0); /* Receive address LED */
	write_ireg (dev->base_addr, 6, 0x0081); /* Collision LED */
	write_ireg (dev->base_addr, 7, 0x0090); /* XMIT LED */
	write_ireg (dev->base_addr, 2, 0x0000); /* MODE register selects media */

	for (i = LADRL; i <= LADRH; i++)
		write_rreg (dev->base_addr, i, 0);

	for (i = PADRL, p = dev->dev_addr; i <= PADRH; i++, p += 2)
		write_rreg (dev->base_addr, i, p[0] | (p[1] << 8));

	i = MODE_PORT_10BT;
	if (dev->flags & IFF_PROMISC)
		i |= MODE_PROMISC;

	write_rreg (dev->base_addr, MODE, i);
	write_rreg (dev->base_addr, POLLINT, 0);
	write_rreg (dev->base_addr, SIZERXR, -RX_BUFFERS);
	write_rreg (dev->base_addr, SIZETXR, -TX_BUFFERS);

	first_free_addr = RX_BUFFERS * 8 + TX_BUFFERS * 8 + 16;
	hdr_addr = 0;

	priv->rxhead = 0;
	priv->rxtail = 0;
	priv->rxhdr = hdr_addr;

	for (i = 0; i < RX_BUFFERS; i++) {
		priv->rxbuffer[i] = first_free_addr;
		am_writeword (dev, hdr_addr, first_free_addr);
		am_writeword (dev, hdr_addr + 2, RMD_OWN);
		am_writeword (dev, hdr_addr + 4, (-1600));
		am_writeword (dev, hdr_addr + 6, 0);
		first_free_addr += 1600;
		hdr_addr += 8;
	}
	priv->txhead = 0;
	priv->txtail = 0;
	priv->txhdr = hdr_addr;
	for (i = 0; i < TX_BUFFERS; i++) {
		priv->txbuffer[i] = first_free_addr;
		am_writeword (dev, hdr_addr, first_free_addr);
		am_writeword (dev, hdr_addr + 2, TMD_STP|TMD_ENP);
		am_writeword (dev, hdr_addr + 4, 0xf000);
		am_writeword (dev, hdr_addr + 6, 0);
		first_free_addr += 1600;
		hdr_addr += 8;
	}

	write_rreg (dev->base_addr, BASERXL, priv->rxhdr);
	write_rreg (dev->base_addr, BASERXH, 0);
	write_rreg (dev->base_addr, BASETXL, priv->txhdr);
	write_rreg (dev->base_addr, BASERXH, 0);
	write_rreg (dev->base_addr, CSR0, CSR0_STOP);
	write_rreg (dev->base_addr, CSR3, CSR3_IDONM|CSR3_BABLM|CSR3_DXSUFLO);
	write_rreg (dev->base_addr, CSR4, CSR4_APAD_XMIT|CSR4_MFCOM|CSR4_RCVCCOM|CSR4_TXSTRTM|CSR4_JABM);
	write_rreg (dev->base_addr, CSR0, CSR0_IENA|CSR0_STRT);
}

static void am79c961_timer(unsigned long data)
{
	struct net_device *dev = (struct net_device *)data;
	struct dev_priv *priv = netdev_priv(dev);
	unsigned int lnkstat, carrier;

	lnkstat = read_ireg(dev->base_addr, ISALED0) & ISALED0_LNKST;
	carrier = netif_carrier_ok(dev);

	if (lnkstat && !carrier) {
		netif_carrier_on(dev);
		printk("%s: link up\n", dev->name);
	} else if (!lnkstat && carrier) {
		netif_carrier_off(dev);
		printk("%s: link down\n", dev->name);
	}

	mod_timer(&priv->timer, jiffies + msecs_to_jiffies(500));
}

/*
 * Open/initialize the board.
 */
static int
am79c961_open(struct net_device *dev)
{
	struct dev_priv *priv = netdev_priv(dev);
	int ret;

	memset (&priv->stats, 0, sizeof (priv->stats));

	ret = request_irq(dev->irq, am79c961_interrupt, 0, dev->name, dev);
	if (ret)
		return ret;

	am79c961_init_for_open(dev);

	netif_carrier_off(dev);

	priv->timer.expires = jiffies;
	add_timer(&priv->timer);

	netif_start_queue(dev);

	return 0;
}

/*
 * The inverse routine to am79c961_open().
 */
static int
am79c961_close(struct net_device *dev)
{
	struct dev_priv *priv = netdev_priv(dev);
	unsigned long flags;

	del_timer_sync(&priv->timer);

	netif_stop_queue(dev);
	netif_carrier_off(dev);

	spin_lock_irqsave(priv->chip_lock, flags);
	write_rreg (dev->base_addr, CSR0, CSR0_STOP);
	write_rreg (dev->base_addr, CSR3, CSR3_MASKALL);
	spin_unlock_irqrestore(priv->chip_lock, flags);

	free_irq (dev->irq, dev);

	return 0;
}

/*
 * Get the current statistics.
 */
static struct net_device_stats *am79c961_getstats (struct net_device *dev)
{
	struct dev_priv *priv = netdev_priv(dev);
	return &priv->stats;
}

static void am79c961_mc_hash(struct dev_mc_list *dmi, unsigned short *hash)
{
	if (dmi->dmi_addrlen == ETH_ALEN && dmi->dmi_addr[0] & 0x01) {
		int idx, bit;
		u32 crc;

		crc = ether_crc_le(ETH_ALEN, dmi->dmi_addr);

		idx = crc >> 30;
		bit = (crc >> 26) & 15;

		hash[idx] |= 1 << bit;
	}
}

/*
 * Set or clear promiscuous/multicast mode filter for this adapter.
 */
static void am79c961_setmulticastlist (struct net_device *dev)
{
	struct dev_priv *priv = netdev_priv(dev);
	unsigned long flags;
	unsigned short multi_hash[4], mode;
	int i, stopped;

	mode = MODE_PORT_10BT;

	if (dev->flags & IFF_PROMISC) {
		mode |= MODE_PROMISC;
	} else if (dev->flags & IFF_ALLMULTI) {
		memset(multi_hash, 0xff, sizeof(multi_hash));
	} else {
		struct dev_mc_list *dmi;

		memset(multi_hash, 0x00, sizeof(multi_hash));

		for (dmi = dev->mc_list; dmi; dmi = dmi->next)
			am79c961_mc_hash(dmi, multi_hash);
	}

	spin_lock_irqsave(priv->chip_lock, flags);

	stopped = read_rreg(dev->base_addr, CSR0) & CSR0_STOP;

	if (!stopped) {
		/*
		 * Put the chip into suspend mode
		 */
		write_rreg(dev->base_addr, CTRL1, CTRL1_SPND);

		/*
		 * Spin waiting for chip to report suspend mode
		 */
		while ((read_rreg(dev->base_addr, CTRL1) & CTRL1_SPND) == 0) {
			spin_unlock_irqrestore(priv->chip_lock, flags);
			nop();
			spin_lock_irqsave(priv->chip_lock, flags);
		}
	}

	/*
	 * Update the multicast hash table
	 */
	for (i = 0; i < sizeof(multi_hash) / sizeof(multi_hash[0]); i++)
		write_rreg(dev->base_addr, i + LADRL, multi_hash[i]);

	/*
	 * Write the mode register
	 */
	write_rreg(dev->base_addr, MODE, mode);

	if (!stopped) {
		/*
		 * Put the chip back into running mode
		 */
		write_rreg(dev->base_addr, CTRL1, 0);
	}

	spin_unlock_irqrestore(priv->chip_lock, flags);
}

static void am79c961_timeout(struct net_device *dev)
{
	printk(KERN_WARNING "%s: transmit timed out, network cable problem?\n",
		dev->name);

	/*
	 * ought to do some setup of the tx side here
	 */

	netif_wake_queue(dev);
}

/*
 * Transmit a packet
 */
static int
am79c961_sendpacket(struct sk_buff *skb, struct net_device *dev)
{
	struct dev_priv *priv = netdev_priv(dev);
	unsigned int hdraddr, bufaddr;
	unsigned int head;
	unsigned long flags;

	head = priv->txhead;
	hdraddr = priv->txhdr + (head << 3);
	bufaddr = priv->txbuffer[head];
	head += 1;
	if (head >= TX_BUFFERS)
		head = 0;

	am_writebuffer (dev, bufaddr, skb->data, skb->len);
	am_writeword (dev, hdraddr + 4, -skb->len);
	am_writeword (dev, hdraddr + 2, TMD_OWN|TMD_STP|TMD_ENP);
	priv->txhead = head;

	spin_lock_irqsave(priv->chip_lock, flags);
	write_rreg (dev->base_addr, CSR0, CSR0_TDMD|CSR0_IENA);
	dev->trans_start = jiffies;
	spin_unlock_irqrestore(priv->chip_lock, flags);

	/*
	 * If the next packet is owned by the ethernet device,
	 * then the tx ring is full and we can't add another
	 * packet.
	 */
	if (am_readword(dev, priv->txhdr + (priv->txhead << 3) + 2) & TMD_OWN)
		netif_stop_queue(dev);

	dev_kfree_skb(skb);

	return 0;
}

/*
 * If we have a good packet(s), get it/them out of the buffers.
 */
static void
am79c961_rx(struct net_device *dev, struct dev_priv *priv)
{
	do {
		struct sk_buff *skb;
		u_int hdraddr;
		u_int pktaddr;
		u_int status;
		int len;

		hdraddr = priv->rxhdr + (priv->rxtail << 3);
		pktaddr = priv->rxbuffer[priv->rxtail];

		status = am_readword (dev, hdraddr + 2);
		if (status & RMD_OWN) /* do we own it? */
			break;

		priv->rxtail ++;
		if (priv->rxtail >= RX_BUFFERS)
			priv->rxtail = 0;

		if ((status & (RMD_ERR|RMD_STP|RMD_ENP)) != (RMD_STP|RMD_ENP)) {
			am_writeword (dev, hdraddr + 2, RMD_OWN);
			priv->stats.rx_errors ++;
			if (status & RMD_ERR) {
				if (status & RMD_FRAM)
					priv->stats.rx_frame_errors ++;
				if (status & RMD_CRC)
					priv->stats.rx_crc_errors ++;
			} else if (status & RMD_STP)
				priv->stats.rx_length_errors ++;
			continue;
		}

		len = am_readword(dev, hdraddr + 6);
		skb = dev_alloc_skb(len + 2);

		if (skb) {
			skb->dev = dev;
			skb_reserve(skb, 2);

			am_readbuffer(dev, pktaddr, skb_put(skb, len), len);
			am_writeword(dev, hdraddr + 2, RMD_OWN);
			skb->protocol = eth_type_trans(skb, dev);
			netif_rx(skb);
			dev->last_rx = jiffies;
			priv->stats.rx_bytes += len;
			priv->stats.rx_packets ++;
		} else {
			am_writeword (dev, hdraddr + 2, RMD_OWN);
			printk (KERN_WARNING "%s: memory squeeze, dropping packet.\n", dev->name);
			priv->stats.rx_dropped ++;
			break;
		}
	} while (1);
}

/*
 * Update stats for the transmitted packet
 */
static void
am79c961_tx(struct net_device *dev, struct dev_priv *priv)
{
	do {
		short len;
		u_int hdraddr;
		u_int status;

		hdraddr = priv->txhdr + (priv->txtail << 3);
		status = am_readword (dev, hdraddr + 2);
		if (status & TMD_OWN)
			break;

		priv->txtail ++;
		if (priv->txtail >= TX_BUFFERS)
			priv->txtail = 0;

		if (status & TMD_ERR) {
			u_int status2;

			priv->stats.tx_errors ++;

			status2 = am_readword (dev, hdraddr + 6);

			/*
			 * Clear the error byte
			 */
			am_writeword (dev, hdraddr + 6, 0);

			if (status2 & TST_RTRY)
				priv->stats.collisions += 16;
			if (status2 & TST_LCOL)
				priv->stats.tx_window_errors ++;
			if (status2 & TST_LCAR)
				priv->stats.tx_carrier_errors ++;
			if (status2 & TST_UFLO)
				priv->stats.tx_fifo_errors ++;
			continue;
		}
		priv->stats.tx_packets ++;
		len = am_readword (dev, hdraddr + 4);
		priv->stats.tx_bytes += -len;
	} while (priv->txtail != priv->txhead);

	netif_wake_queue(dev);
}

static irqreturn_t
am79c961_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
	struct net_device *dev = (struct net_device *)dev_id;
	struct dev_priv *priv = netdev_priv(dev);
	u_int status, n = 100;
	int handled = 0;

	do {
		status = read_rreg(dev->base_addr, CSR0);
		write_rreg(dev->base_addr, CSR0, status &
			   (CSR0_IENA|CSR0_TINT|CSR0_RINT|
			    CSR0_MERR|CSR0_MISS|CSR0_CERR|CSR0_BABL));

		if (status & CSR0_RINT) {
			handled = 1;
			am79c961_rx(dev, priv);
		}
		if (status & CSR0_TINT) {
			handled = 1;
			am79c961_tx(dev, priv);
		}
		if (status & CSR0_MISS) {
			handled = 1;
			priv->stats.rx_dropped ++;
		}
		if (status & CSR0_CERR) {
			handled = 1;
			mod_timer(&priv->timer, jiffies);
		}
	} while (--n && status & (CSR0_RINT | CSR0_TINT));

	return IRQ_RETVAL(handled);
}

#ifdef CONFIG_NET_POLL_CONTROLLER
static void am79c961_poll_controller(struct net_device *dev)
{
	unsigned long flags;
	local_irq_save(flags);
	am79c961_interrupt(dev->irq, dev, NULL);
	local_irq_restore(flags);
}
#endif

/*
 * Initialise the chip.  Note that we always expect
 * to be entered with interrupts enabled.
 */
static int
am79c961_hw_init(struct net_device *dev)
{
	struct dev_priv *priv = netdev_priv(dev);

	spin_lock_irq(&priv->chip_lock);
	write_rreg (dev->base_addr, CSR0, CSR0_STOP);
	write_rreg (dev->base_addr, CSR3, CSR3_MASKALL);
	spin_unlock_irq(&priv->chip_lock);

	am79c961_ramtest(dev, 0x66);
	am79c961_ramtest(dev, 0x99);

	return 0;
}

static void __init am79c961_banner(void)
{
	static unsigned version_printed;

	if (net_debug && version_printed++ == 0)
		printk(KERN_INFO "%s", version);
}

static int __init am79c961_probe(struct device *_dev)
{
	struct platform_device *pdev = to_platform_device(_dev);
	struct resource *res;
	struct net_device *dev;
	struct dev_priv *priv;
	int i, ret;

	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
	if (!res)
		return -ENODEV;

	dev = alloc_etherdev(sizeof(struct dev_priv));
	ret = -ENOMEM;
	if (!dev)
		goto out;

	SET_NETDEV_DEV(dev, &pdev->dev);

	priv = netdev_priv(dev);

	/*
	 * Fixed address and IRQ lines here.
	 * The PNP initialisation should have been
	 * done by the ether bootp loader.
	 */
	dev->base_addr = res->start;
	dev->irq = platform_get_irq(pdev, 0);

    	ret = -ENODEV;
	if (!request_region(dev->base_addr, 0x18, dev->name))
		goto nodev;

	/*
	 * Reset the device.
	 */
	inb(dev->base_addr + NET_RESET);
	udelay(5);

	/*
	 * Check the manufacturer part of the
	 * ether address.
	 */
	if (inb(dev->base_addr) != 0x08 ||
	    inb(dev->base_addr + 2) != 0x00 ||
	    inb(dev->base_addr + 4) != 0x2b)
	    	goto release;

	for (i = 0; i < 6; i++)
		dev->dev_addr[i] = inb(dev->base_addr + i * 2) & 0xff;

	am79c961_banner();

	spin_lock_init(&priv->chip_lock);
	init_timer(&priv->timer);
	priv->timer.data = (unsigned long)dev;
	priv->timer.function = am79c961_timer;

	if (am79c961_hw_init(dev))
		goto release;

	dev->open		= am79c961_open;
	dev->stop		= am79c961_close;
	dev->hard_start_xmit	= am79c961_sendpacket;
	dev->get_stats		= am79c961_getstats;
	dev->set_multicast_list	= am79c961_setmulticastlist;
	dev->tx_timeout		= am79c961_timeout;
#ifdef CONFIG_NET_POLL_CONTROLLER
	dev->poll_controller	= am79c961_poll_controller;
#endif

	ret = register_netdev(dev);
	if (ret == 0) {
		printk(KERN_INFO "%s: ether address ", dev->name);

		/* Retrive and print the ethernet address. */
		for (i = 0; i < 6; i++)
			printk (i == 5 ? "%02x\n" : "%02x:", dev->dev_addr[i]);

		return 0;
	}

release:
	release_region(dev->base_addr, 0x18);
nodev:
	free_netdev(dev);
out:
	return ret;
}

static struct device_driver am79c961_driver = {
	.name		= "am79c961",
	.bus		= &platform_bus_type,
	.probe		= am79c961_probe,
};

static int __init am79c961_init(void)
{
	return driver_register(&am79c961_driver);
}

__initcall(am79c961_init);