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1 /* 3c501.c: A 3Com 3c501 Ethernet driver for Linux. */
2 /*
3     Written 1992,1993,1994  Donald Becker
4 
5     Copyright 1993 United States Government as represented by the
6     Director, National Security Agency.  This software may be used and
7     distributed according to the terms of the GNU General Public License,
8     incorporated herein by reference.
9 
10     This is a device driver for the 3Com Etherlink 3c501.
11     Do not purchase this card, even as a joke.  It's performance is horrible,
12     and it breaks in many ways.
13 
14     The original author may be reached as becker@scyld.com, or C/O
15 	Scyld Computing Corporation
16 	410 Severn Ave., Suite 210
17 	Annapolis MD 21403
18 
19     Fixed (again!) the missing interrupt locking on TX/RX shifting.
20 	Alan Cox <alan@lxorguk.ukuu.org.uk>
21 
22     Removed calls to init_etherdev since they are no longer needed, and
23     cleaned up modularization just a bit. The driver still allows only
24     the default address for cards when loaded as a module, but that's
25     really less braindead than anyone using a 3c501 board. :)
26 		    19950208 (invid@msen.com)
27 
28     Added traps for interrupts hitting the window as we clear and TX load
29     the board. Now getting 150K/second FTP with a 3c501 card. Still playing
30     with a TX-TX optimisation to see if we can touch 180-200K/second as seems
31     theoretically maximum.
32 		19950402 Alan Cox <alan@lxorguk.ukuu.org.uk>
33 
34     Cleaned up for 2.3.x because we broke SMP now.
35 		20000208 Alan Cox <alan@lxorguk.ukuu.org.uk>
36 
37     Check up pass for 2.5. Nothing significant changed
38 		20021009 Alan Cox <alan@lxorguk.ukuu.org.uk>
39 
40     Fixed zero fill corner case
41 		20030104 Alan Cox <alan@lxorguk.ukuu.org.uk>
42 
43 
44    For the avoidance of doubt the "preferred form" of this code is one which
45    is in an open non patent encumbered format. Where cryptographic key signing
46    forms part of the process of creating an executable the information
47    including keys needed to generate an equivalently functional executable
48    are deemed to be part of the source code.
49 
50 */
51 
52 
53 /**
54  * DOC: 3c501 Card Notes
55  *
56  *  Some notes on this thing if you have to hack it.  [Alan]
57  *
58  *  Some documentation is available from 3Com. Due to the boards age
59  *  standard responses when you ask for this will range from 'be serious'
60  *  to 'give it to a museum'. The documentation is incomplete and mostly
61  *  of historical interest anyway.
62  *
63  *  The basic system is a single buffer which can be used to receive or
64  *  transmit a packet. A third command mode exists when you are setting
65  *  things up.
66  *
67  *  If it's transmitting it's not receiving and vice versa. In fact the
68  *  time to get the board back into useful state after an operation is
69  *  quite large.
70  *
71  *  The driver works by keeping the board in receive mode waiting for a
72  *  packet to arrive. When one arrives it is copied out of the buffer
73  *  and delivered to the kernel. The card is reloaded and off we go.
74  *
75  *  When transmitting lp->txing is set and the card is reset (from
76  *  receive mode) [possibly losing a packet just received] to command
77  *  mode. A packet is loaded and transmit mode triggered. The interrupt
78  *  handler runs different code for transmit interrupts and can handle
79  *  returning to receive mode or retransmissions (yes you have to help
80  *  out with those too).
81  *
82  * DOC: Problems
83  *
84  *  There are a wide variety of undocumented error returns from the card
85  *  and you basically have to kick the board and pray if they turn up. Most
86  *  only occur under extreme load or if you do something the board doesn't
87  *  like (eg touching a register at the wrong time).
88  *
89  *  The driver is less efficient than it could be. It switches through
90  *  receive mode even if more transmits are queued. If this worries you buy
91  *  a real Ethernet card.
92  *
93  *  The combination of slow receive restart and no real multicast
94  *  filter makes the board unusable with a kernel compiled for IP
95  *  multicasting in a real multicast environment. That's down to the board,
96  *  but even with no multicast programs running a multicast IP kernel is
97  *  in group 224.0.0.1 and you will therefore be listening to all multicasts.
98  *  One nv conference running over that Ethernet and you can give up.
99  *
100  */
101 
102 #define DRV_NAME	"3c501"
103 #define DRV_VERSION	"2002/10/09"
104 
105 
106 static const char version[] =
107 	DRV_NAME ".c: " DRV_VERSION " Alan Cox (alan@lxorguk.ukuu.org.uk).\n";
108 
109 /*
110  *	Braindamage remaining:
111  *	The 3c501 board.
112  */
113 
114 #include <linux/module.h>
115 
116 #include <linux/kernel.h>
117 #include <linux/fcntl.h>
118 #include <linux/ioport.h>
119 #include <linux/interrupt.h>
120 #include <linux/slab.h>
121 #include <linux/string.h>
122 #include <linux/errno.h>
123 #include <linux/spinlock.h>
124 #include <linux/ethtool.h>
125 #include <linux/delay.h>
126 #include <linux/bitops.h>
127 
128 #include <asm/uaccess.h>
129 #include <asm/io.h>
130 
131 #include <linux/netdevice.h>
132 #include <linux/etherdevice.h>
133 #include <linux/skbuff.h>
134 #include <linux/init.h>
135 
136 #include "3c501.h"
137 
138 /*
139  *	The boilerplate probe code.
140  */
141 
142 static int io = 0x280;
143 static int irq = 5;
144 static int mem_start;
145 
146 /**
147  * el1_probe:		-	probe for a 3c501
148  * @dev: The device structure passed in to probe.
149  *
150  * This can be called from two places. The network layer will probe using
151  * a device structure passed in with the probe information completed. For a
152  * modular driver we use #init_module to fill in our own structure and probe
153  * for it.
154  *
155  * Returns 0 on success. ENXIO if asked not to probe and ENODEV if asked to
156  * probe and failing to find anything.
157  */
158 
el1_probe(int unit)159 struct net_device * __init el1_probe(int unit)
160 {
161 	struct net_device *dev = alloc_etherdev(sizeof(struct net_local));
162 	static unsigned ports[] = { 0x280, 0x300, 0};
163 	unsigned *port;
164 	int err = 0;
165 
166 	if (!dev)
167 		return ERR_PTR(-ENOMEM);
168 
169 	if (unit >= 0) {
170 		sprintf(dev->name, "eth%d", unit);
171 		netdev_boot_setup_check(dev);
172 		io = dev->base_addr;
173 		irq = dev->irq;
174 		mem_start = dev->mem_start & 7;
175 	}
176 
177 	if (io > 0x1ff) {	/* Check a single specified location. */
178 		err = el1_probe1(dev, io);
179 	} else if (io != 0) {
180 		err = -ENXIO;		/* Don't probe at all. */
181 	} else {
182 		for (port = ports; *port && el1_probe1(dev, *port); port++)
183 			;
184 		if (!*port)
185 			err = -ENODEV;
186 	}
187 	if (err)
188 		goto out;
189 	err = register_netdev(dev);
190 	if (err)
191 		goto out1;
192 	return dev;
193 out1:
194 	release_region(dev->base_addr, EL1_IO_EXTENT);
195 out:
196 	free_netdev(dev);
197 	return ERR_PTR(err);
198 }
199 
200 /**
201  *	el1_probe1:
202  *	@dev: The device structure to use
203  *	@ioaddr: An I/O address to probe at.
204  *
205  *	The actual probe. This is iterated over by #el1_probe in order to
206  *	check all the applicable device locations.
207  *
208  *	Returns 0 for a success, in which case the device is activated,
209  *	EAGAIN if the IRQ is in use by another driver, and ENODEV if the
210  *	board cannot be found.
211  */
212 
el1_probe1(struct net_device * dev,int ioaddr)213 static int __init el1_probe1(struct net_device *dev, int ioaddr)
214 {
215 	struct net_local *lp;
216 	const char *mname;		/* Vendor name */
217 	unsigned char station_addr[6];
218 	int autoirq = 0;
219 	int i;
220 
221 	/*
222 	 *	Reserve I/O resource for exclusive use by this driver
223 	 */
224 
225 	if (!request_region(ioaddr, EL1_IO_EXTENT, DRV_NAME))
226 		return -ENODEV;
227 
228 	/*
229 	 *	Read the station address PROM data from the special port.
230 	 */
231 
232 	for (i = 0; i < 6; i++) {
233 		outw(i, ioaddr + EL1_DATAPTR);
234 		station_addr[i] = inb(ioaddr + EL1_SAPROM);
235 	}
236 	/*
237 	 *	Check the first three octets of the S.A. for 3Com's prefix, or
238 	 *	for the Sager NP943 prefix.
239 	 */
240 
241 	if (station_addr[0] == 0x02  &&  station_addr[1] == 0x60
242 						&& station_addr[2] == 0x8c)
243 		mname = "3c501";
244 	else if (station_addr[0] == 0x00  &&  station_addr[1] == 0x80
245 						&& station_addr[2] == 0xC8)
246 		mname = "NP943";
247 	else {
248 		release_region(ioaddr, EL1_IO_EXTENT);
249 		return -ENODEV;
250 	}
251 
252 	/*
253 	 *	We auto-IRQ by shutting off the interrupt line and letting it
254 	 *	float high.
255 	 */
256 
257 	dev->irq = irq;
258 
259 	if (dev->irq < 2) {
260 		unsigned long irq_mask;
261 
262 		irq_mask = probe_irq_on();
263 		inb(RX_STATUS);		/* Clear pending interrupts. */
264 		inb(TX_STATUS);
265 		outb(AX_LOOP + 1, AX_CMD);
266 
267 		outb(0x00, AX_CMD);
268 
269 		mdelay(20);
270 		autoirq = probe_irq_off(irq_mask);
271 
272 		if (autoirq == 0) {
273 			printk(KERN_WARNING "%s probe at %#x failed to detect IRQ line.\n",
274 				mname, ioaddr);
275 			release_region(ioaddr, EL1_IO_EXTENT);
276 			return -EAGAIN;
277 		}
278 	}
279 
280 	outb(AX_RESET+AX_LOOP, AX_CMD);			/* Loopback mode. */
281 	dev->base_addr = ioaddr;
282 	memcpy(dev->dev_addr, station_addr, ETH_ALEN);
283 
284 	if (mem_start & 0xf)
285 		el_debug = mem_start & 0x7;
286 	if (autoirq)
287 		dev->irq = autoirq;
288 
289 	printk(KERN_INFO "%s: %s EtherLink at %#lx, using %sIRQ %d.\n",
290 			dev->name, mname, dev->base_addr,
291 			autoirq ? "auto":"assigned ", dev->irq);
292 
293 #ifdef CONFIG_IP_MULTICAST
294 	printk(KERN_WARNING "WARNING: Use of the 3c501 in a multicast kernel is NOT recommended.\n");
295 #endif
296 
297 	if (el_debug)
298 		printk(KERN_DEBUG "%s", version);
299 
300 	lp = netdev_priv(dev);
301 	memset(lp, 0, sizeof(struct net_local));
302 	spin_lock_init(&lp->lock);
303 
304 	/*
305 	 *	The EL1-specific entries in the device structure.
306 	 */
307 
308 	dev->open = &el_open;
309 	dev->hard_start_xmit = &el_start_xmit;
310 	dev->tx_timeout = &el_timeout;
311 	dev->watchdog_timeo = HZ;
312 	dev->stop = &el1_close;
313 	dev->set_multicast_list = &set_multicast_list;
314 	dev->ethtool_ops = &netdev_ethtool_ops;
315 	return 0;
316 }
317 
318 /**
319  *	el1_open:
320  *	@dev: device that is being opened
321  *
322  *	When an ifconfig is issued which changes the device flags to include
323  *	IFF_UP this function is called. It is only called when the change
324  *	occurs, not when the interface remains up. #el1_close will be called
325  *	when it goes down.
326  *
327  *	Returns 0 for a successful open, or -EAGAIN if someone has run off
328  *	with our interrupt line.
329  */
330 
el_open(struct net_device * dev)331 static int el_open(struct net_device *dev)
332 {
333 	int retval;
334 	int ioaddr = dev->base_addr;
335 	struct net_local *lp = netdev_priv(dev);
336 	unsigned long flags;
337 
338 	if (el_debug > 2)
339 		printk(KERN_DEBUG "%s: Doing el_open()...", dev->name);
340 
341 	retval = request_irq(dev->irq, &el_interrupt, 0, dev->name, dev);
342 	if (retval)
343 		return retval;
344 
345 	spin_lock_irqsave(&lp->lock, flags);
346 	el_reset(dev);
347 	spin_unlock_irqrestore(&lp->lock, flags);
348 
349 	lp->txing = 0;		/* Board in RX mode */
350 	outb(AX_RX, AX_CMD);	/* Aux control, irq and receive enabled */
351 	netif_start_queue(dev);
352 	return 0;
353 }
354 
355 /**
356  * el_timeout:
357  * @dev: The 3c501 card that has timed out
358  *
359  * Attempt to restart the board. This is basically a mixture of extreme
360  * violence and prayer
361  *
362  */
363 
el_timeout(struct net_device * dev)364 static void el_timeout(struct net_device *dev)
365 {
366 	struct net_local *lp = netdev_priv(dev);
367 	int ioaddr = dev->base_addr;
368 
369 	if (el_debug)
370 		printk(KERN_DEBUG "%s: transmit timed out, txsr %#2x axsr=%02x rxsr=%02x.\n",
371 			dev->name, inb(TX_STATUS),
372 			inb(AX_STATUS), inb(RX_STATUS));
373 	dev->stats.tx_errors++;
374 	outb(TX_NORM, TX_CMD);
375 	outb(RX_NORM, RX_CMD);
376 	outb(AX_OFF, AX_CMD);	/* Just trigger a false interrupt. */
377 	outb(AX_RX, AX_CMD);	/* Aux control, irq and receive enabled */
378 	lp->txing = 0;		/* Ripped back in to RX */
379 	netif_wake_queue(dev);
380 }
381 
382 
383 /**
384  * el_start_xmit:
385  * @skb: The packet that is queued to be sent
386  * @dev: The 3c501 card we want to throw it down
387  *
388  * Attempt to send a packet to a 3c501 card. There are some interesting
389  * catches here because the 3c501 is an extremely old and therefore
390  * stupid piece of technology.
391  *
392  * If we are handling an interrupt on the other CPU we cannot load a packet
393  * as we may still be attempting to retrieve the last RX packet buffer.
394  *
395  * When a transmit times out we dump the card into control mode and just
396  * start again. It happens enough that it isnt worth logging.
397  *
398  * We avoid holding the spin locks when doing the packet load to the board.
399  * The device is very slow, and its DMA mode is even slower. If we held the
400  * lock while loading 1500 bytes onto the controller we would drop a lot of
401  * serial port characters. This requires we do extra locking, but we have
402  * no real choice.
403  */
404 
el_start_xmit(struct sk_buff * skb,struct net_device * dev)405 static int el_start_xmit(struct sk_buff *skb, struct net_device *dev)
406 {
407 	struct net_local *lp = netdev_priv(dev);
408 	int ioaddr = dev->base_addr;
409 	unsigned long flags;
410 
411 	/*
412 	 *	Avoid incoming interrupts between us flipping txing and flipping
413 	 *	mode as the driver assumes txing is a faithful indicator of card
414 	 *	state
415 	 */
416 
417 	spin_lock_irqsave(&lp->lock, flags);
418 
419 	/*
420 	 *	Avoid timer-based retransmission conflicts.
421 	 */
422 
423 	netif_stop_queue(dev);
424 
425 	do {
426 		int len = skb->len;
427 		int pad = 0;
428 		int gp_start;
429 		unsigned char *buf = skb->data;
430 
431 		if (len < ETH_ZLEN)
432 			pad = ETH_ZLEN - len;
433 
434 		gp_start = 0x800 - (len + pad);
435 
436 		lp->tx_pkt_start = gp_start;
437 		lp->collisions = 0;
438 
439 		dev->stats.tx_bytes += skb->len;
440 
441 		/*
442 		 *	Command mode with status cleared should [in theory]
443 		 *	mean no more interrupts can be pending on the card.
444 		 */
445 
446 		outb_p(AX_SYS, AX_CMD);
447 		inb_p(RX_STATUS);
448 		inb_p(TX_STATUS);
449 
450 		lp->loading = 1;
451 		lp->txing = 1;
452 
453 		/*
454 		 *	Turn interrupts back on while we spend a pleasant
455 		 *	afternoon loading bytes into the board
456 		 */
457 
458 		spin_unlock_irqrestore(&lp->lock, flags);
459 
460 		/* Set rx packet area to 0. */
461 		outw(0x00, RX_BUF_CLR);
462 		/* aim - packet will be loaded into buffer start */
463 		outw(gp_start, GP_LOW);
464 		/* load buffer (usual thing each byte increments the pointer) */
465 		outsb(DATAPORT, buf, len);
466 		if (pad) {
467 			while (pad--)		/* Zero fill buffer tail */
468 				outb(0, DATAPORT);
469 		}
470 		/* the board reuses the same register */
471 		outw(gp_start, GP_LOW);
472 
473 		if (lp->loading != 2) {
474 			/* fire ... Trigger xmit.  */
475 			outb(AX_XMIT, AX_CMD);
476 			lp->loading = 0;
477 			dev->trans_start = jiffies;
478 			if (el_debug > 2)
479 				printk(KERN_DEBUG " queued xmit.\n");
480 			dev_kfree_skb(skb);
481 			return 0;
482 		}
483 		/* A receive upset our load, despite our best efforts */
484 		if (el_debug > 2)
485 			printk(KERN_DEBUG "%s: burped during tx load.\n",
486 				dev->name);
487 		spin_lock_irqsave(&lp->lock, flags);
488 	} while (1);
489 }
490 
491 /**
492  * el_interrupt:
493  * @irq: Interrupt number
494  * @dev_id: The 3c501 that burped
495  *
496  * Handle the ether interface interrupts. The 3c501 needs a lot more
497  * hand holding than most cards. In particular we get a transmit interrupt
498  * with a collision error because the board firmware isnt capable of rewinding
499  * its own transmit buffer pointers. It can however count to 16 for us.
500  *
501  * On the receive side the card is also very dumb. It has no buffering to
502  * speak of. We simply pull the packet out of its PIO buffer (which is slow)
503  * and queue it for the kernel. Then we reset the card for the next packet.
504  *
505  * We sometimes get surprise interrupts late both because the SMP IRQ delivery
506  * is message passing and because the card sometimes seems to deliver late. I
507  * think if it is part way through a receive and the mode is changed it carries
508  * on receiving and sends us an interrupt. We have to band aid all these cases
509  * to get a sensible 150kBytes/second performance. Even then you want a small
510  * TCP window.
511  */
512 
el_interrupt(int irq,void * dev_id)513 static irqreturn_t el_interrupt(int irq, void *dev_id)
514 {
515 	struct net_device *dev = dev_id;
516 	struct net_local *lp;
517 	int ioaddr;
518 	int axsr;			/* Aux. status reg. */
519 
520 	ioaddr = dev->base_addr;
521 	lp = netdev_priv(dev);
522 
523 	spin_lock(&lp->lock);
524 
525 	/*
526 	 *	What happened ?
527 	 */
528 
529 	axsr = inb(AX_STATUS);
530 
531 	/*
532 	 *	Log it
533 	 */
534 
535 	if (el_debug > 3)
536 		printk(KERN_DEBUG "%s: el_interrupt() aux=%#02x",
537 							dev->name, axsr);
538 
539 	if (lp->loading == 1 && !lp->txing)
540 		printk(KERN_WARNING "%s: Inconsistent state loading while not in tx\n",
541 			dev->name);
542 
543 	if (lp->txing) {
544 		/*
545 		 *	Board in transmit mode. May be loading. If we are
546 		 *	loading we shouldn't have got this.
547 		 */
548 		int txsr = inb(TX_STATUS);
549 
550 		if (lp->loading == 1) {
551 			if (el_debug > 2) {
552 				printk(KERN_DEBUG "%s: Interrupt while loading [",
553 					dev->name);
554 				printk(" txsr=%02x gp=%04x rp=%04x]\n",
555 					txsr, inw(GP_LOW), inw(RX_LOW));
556 			}
557 			/* Force a reload */
558 			lp->loading = 2;
559 			spin_unlock(&lp->lock);
560 			goto out;
561 		}
562 		if (el_debug > 6)
563 			printk(KERN_DEBUG " txsr=%02x gp=%04x rp=%04x",
564 					txsr, inw(GP_LOW), inw(RX_LOW));
565 
566 		if ((axsr & 0x80) && (txsr & TX_READY) == 0) {
567 			/*
568 			 *	FIXME: is there a logic to whether to keep
569 			 *	on trying or reset immediately ?
570 			 */
571 			if (el_debug > 1)
572 				printk(KERN_DEBUG "%s: Unusual interrupt during Tx, txsr=%02x axsr=%02x gp=%03x rp=%03x.\n",
573 					dev->name, txsr, axsr,
574 					inw(ioaddr + EL1_DATAPTR),
575 					inw(ioaddr + EL1_RXPTR));
576 			lp->txing = 0;
577 			netif_wake_queue(dev);
578 		} else if (txsr & TX_16COLLISIONS) {
579 			/*
580 			 *	Timed out
581 			 */
582 			if (el_debug)
583 				printk(KERN_DEBUG "%s: Transmit failed 16 times, Ethernet jammed?\n", dev->name);
584 			outb(AX_SYS, AX_CMD);
585 			lp->txing = 0;
586 			dev->stats.tx_aborted_errors++;
587 			netif_wake_queue(dev);
588 		} else if (txsr & TX_COLLISION) {
589 			/*
590 			 *	Retrigger xmit.
591 			 */
592 
593 			if (el_debug > 6)
594 				printk(KERN_DEBUG " retransmitting after a collision.\n");
595 			/*
596 			 *	Poor little chip can't reset its own start
597 			 *	pointer
598 			 */
599 
600 			outb(AX_SYS, AX_CMD);
601 			outw(lp->tx_pkt_start, GP_LOW);
602 			outb(AX_XMIT, AX_CMD);
603 			dev->stats.collisions++;
604 			spin_unlock(&lp->lock);
605 			goto out;
606 		} else {
607 			/*
608 			 *	It worked.. we will now fall through and receive
609 			 */
610 			dev->stats.tx_packets++;
611 			if (el_debug > 6)
612 				printk(KERN_DEBUG " Tx succeeded %s\n",
613 					(txsr & TX_RDY) ? "." :
614 							"but tx is busy!");
615 			/*
616 			 *	This is safe the interrupt is atomic WRT itself.
617 			 */
618 			lp->txing = 0;
619 			/* In case more to transmit */
620 			netif_wake_queue(dev);
621 		}
622 	} else {
623 		/*
624 		 *	In receive mode.
625 		 */
626 
627 		int rxsr = inb(RX_STATUS);
628 		if (el_debug > 5)
629 			printk(KERN_DEBUG " rxsr=%02x txsr=%02x rp=%04x", rxsr, inb(TX_STATUS), inw(RX_LOW));
630 		/*
631 		 *	Just reading rx_status fixes most errors.
632 		 */
633 		if (rxsr & RX_MISSED)
634 			dev->stats.rx_missed_errors++;
635 		else if (rxsr & RX_RUNT) {
636 			/* Handled to avoid board lock-up. */
637 			dev->stats.rx_length_errors++;
638 			if (el_debug > 5)
639 				printk(KERN_DEBUG " runt.\n");
640 		} else if (rxsr & RX_GOOD) {
641 			/*
642 			 *	Receive worked.
643 			 */
644 			el_receive(dev);
645 		} else {
646 			/*
647 			 *	Nothing?  Something is broken!
648 			 */
649 			if (el_debug > 2)
650 				printk(KERN_DEBUG "%s: No packet seen, rxsr=%02x **resetting 3c501***\n",
651 					dev->name, rxsr);
652 			el_reset(dev);
653 		}
654 		if (el_debug > 3)
655 			printk(KERN_DEBUG ".\n");
656 	}
657 
658 	/*
659 	 *	Move into receive mode
660 	 */
661 
662 	outb(AX_RX, AX_CMD);
663 	outw(0x00, RX_BUF_CLR);
664 	inb(RX_STATUS);		/* Be certain that interrupts are cleared. */
665 	inb(TX_STATUS);
666 	spin_unlock(&lp->lock);
667 out:
668 	return IRQ_HANDLED;
669 }
670 
671 
672 /**
673  * el_receive:
674  * @dev: Device to pull the packets from
675  *
676  * We have a good packet. Well, not really "good", just mostly not broken.
677  * We must check everything to see if it is good. In particular we occasionally
678  * get wild packet sizes from the card. If the packet seems sane we PIO it
679  * off the card and queue it for the protocol layers.
680  */
681 
el_receive(struct net_device * dev)682 static void el_receive(struct net_device *dev)
683 {
684 	int ioaddr = dev->base_addr;
685 	int pkt_len;
686 	struct sk_buff *skb;
687 
688 	pkt_len = inw(RX_LOW);
689 
690 	if (el_debug > 4)
691 		printk(KERN_DEBUG " el_receive %d.\n", pkt_len);
692 
693 	if (pkt_len < 60 || pkt_len > 1536) {
694 		if (el_debug)
695 			printk(KERN_DEBUG "%s: bogus packet, length=%d\n",
696 						dev->name, pkt_len);
697 		dev->stats.rx_over_errors++;
698 		return;
699 	}
700 
701 	/*
702 	 *	Command mode so we can empty the buffer
703 	 */
704 
705 	outb(AX_SYS, AX_CMD);
706 	skb = dev_alloc_skb(pkt_len+2);
707 
708 	/*
709 	 *	Start of frame
710 	 */
711 
712 	outw(0x00, GP_LOW);
713 	if (skb == NULL) {
714 		printk(KERN_INFO "%s: Memory squeeze, dropping packet.\n",
715 								dev->name);
716 		dev->stats.rx_dropped++;
717 		return;
718 	} else {
719 		skb_reserve(skb, 2);	/* Force 16 byte alignment */
720 		/*
721 		 *	The read increments through the bytes. The interrupt
722 		 *	handler will fix the pointer when it returns to
723 		 *	receive mode.
724 		 */
725 		insb(DATAPORT, skb_put(skb, pkt_len), pkt_len);
726 		skb->protocol = eth_type_trans(skb, dev);
727 		netif_rx(skb);
728 		dev->stats.rx_packets++;
729 		dev->stats.rx_bytes += pkt_len;
730 	}
731 	return;
732 }
733 
734 /**
735  * el_reset: Reset a 3c501 card
736  * @dev: The 3c501 card about to get zapped
737  *
738  * Even resetting a 3c501 isnt simple. When you activate reset it loses all
739  * its configuration. You must hold the lock when doing this. The function
740  * cannot take the lock itself as it is callable from the irq handler.
741  */
742 
el_reset(struct net_device * dev)743 static void  el_reset(struct net_device *dev)
744 {
745 	struct net_local *lp = netdev_priv(dev);
746 	int ioaddr = dev->base_addr;
747 
748 	if (el_debug > 2)
749 		printk(KERN_INFO "3c501 reset...");
750 	outb(AX_RESET, AX_CMD);		/* Reset the chip */
751 	/* Aux control, irq and loopback enabled */
752 	outb(AX_LOOP, AX_CMD);
753 	{
754 		int i;
755 		for (i = 0; i < 6; i++)	/* Set the station address. */
756 			outb(dev->dev_addr[i], ioaddr + i);
757 	}
758 
759 	outw(0, RX_BUF_CLR);		/* Set rx packet area to 0. */
760 	outb(TX_NORM, TX_CMD);		/* tx irq on done, collision */
761 	outb(RX_NORM, RX_CMD);		/* Set Rx commands. */
762 	inb(RX_STATUS);			/* Clear status. */
763 	inb(TX_STATUS);
764 	lp->txing = 0;
765 }
766 
767 /**
768  * el1_close:
769  * @dev: 3c501 card to shut down
770  *
771  * Close a 3c501 card. The IFF_UP flag has been cleared by the user via
772  * the SIOCSIFFLAGS ioctl. We stop any further transmissions being queued,
773  * and then disable the interrupts. Finally we reset the chip. The effects
774  * of the rest will be cleaned up by #el1_open. Always returns 0 indicating
775  * a success.
776  */
777 
el1_close(struct net_device * dev)778 static int el1_close(struct net_device *dev)
779 {
780 	int ioaddr = dev->base_addr;
781 
782 	if (el_debug > 2)
783 		printk(KERN_INFO "%s: Shutting down Ethernet card at %#x.\n",
784 						dev->name, ioaddr);
785 
786 	netif_stop_queue(dev);
787 
788 	/*
789 	 *	Free and disable the IRQ.
790 	 */
791 
792 	free_irq(dev->irq, dev);
793 	outb(AX_RESET, AX_CMD);		/* Reset the chip */
794 
795 	return 0;
796 }
797 
798 /**
799  * set_multicast_list:
800  * @dev: The device to adjust
801  *
802  * Set or clear the multicast filter for this adaptor to use the best-effort
803  * filtering supported. The 3c501 supports only three modes of filtering.
804  * It always receives broadcasts and packets for itself. You can choose to
805  * optionally receive all packets, or all multicast packets on top of this.
806  */
807 
set_multicast_list(struct net_device * dev)808 static void set_multicast_list(struct net_device *dev)
809 {
810 	int ioaddr = dev->base_addr;
811 
812 	if (dev->flags & IFF_PROMISC) {
813 		outb(RX_PROM, RX_CMD);
814 		inb(RX_STATUS);
815 	} else if (dev->mc_list || dev->flags & IFF_ALLMULTI) {
816 		/* Multicast or all multicast is the same */
817 		outb(RX_MULT, RX_CMD);
818 		inb(RX_STATUS);		/* Clear status. */
819 	} else {
820 		outb(RX_NORM, RX_CMD);
821 		inb(RX_STATUS);
822 	}
823 }
824 
825 
netdev_get_drvinfo(struct net_device * dev,struct ethtool_drvinfo * info)826 static void netdev_get_drvinfo(struct net_device *dev,
827 			       struct ethtool_drvinfo *info)
828 {
829 	strcpy(info->driver, DRV_NAME);
830 	strcpy(info->version, DRV_VERSION);
831 	sprintf(info->bus_info, "ISA 0x%lx", dev->base_addr);
832 }
833 
netdev_get_msglevel(struct net_device * dev)834 static u32 netdev_get_msglevel(struct net_device *dev)
835 {
836 	return debug;
837 }
838 
netdev_set_msglevel(struct net_device * dev,u32 level)839 static void netdev_set_msglevel(struct net_device *dev, u32 level)
840 {
841 	debug = level;
842 }
843 
844 static const struct ethtool_ops netdev_ethtool_ops = {
845 	.get_drvinfo		= netdev_get_drvinfo,
846 	.get_msglevel		= netdev_get_msglevel,
847 	.set_msglevel		= netdev_set_msglevel,
848 };
849 
850 #ifdef MODULE
851 
852 static struct net_device *dev_3c501;
853 
854 module_param(io, int, 0);
855 module_param(irq, int, 0);
856 MODULE_PARM_DESC(io, "EtherLink I/O base address");
857 MODULE_PARM_DESC(irq, "EtherLink IRQ number");
858 
859 /**
860  * init_module:
861  *
862  * When the driver is loaded as a module this function is called. We fake up
863  * a device structure with the base I/O and interrupt set as if it were being
864  * called from Space.c. This minimises the extra code that would otherwise
865  * be required.
866  *
867  * Returns 0 for success or -EIO if a card is not found. Returning an error
868  * here also causes the module to be unloaded
869  */
870 
init_module(void)871 int __init init_module(void)
872 {
873 	dev_3c501 = el1_probe(-1);
874 	if (IS_ERR(dev_3c501))
875 		return PTR_ERR(dev_3c501);
876 	return 0;
877 }
878 
879 /**
880  * cleanup_module:
881  *
882  * The module is being unloaded. We unhook our network device from the system
883  * and then free up the resources we took when the card was found.
884  */
885 
cleanup_module(void)886 void __exit cleanup_module(void)
887 {
888 	struct net_device *dev = dev_3c501;
889 	unregister_netdev(dev);
890 	release_region(dev->base_addr, EL1_IO_EXTENT);
891 	free_netdev(dev);
892 }
893 
894 #endif /* MODULE */
895 
896 MODULE_AUTHOR("Donald Becker, Alan Cox");
897 MODULE_DESCRIPTION("Support for the ancient 3Com 3c501 ethernet card");
898 MODULE_LICENSE("GPL");
899 
900