1 /* 3c501.c: A 3Com 3c501 Ethernet driver for Linux. */
3 Written 1992,1993,1994 Donald Becker
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.
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.
14 The original author may be reached as becker@scyld.com, or C/O
15 Scyld Computing Corporation
16 410 Severn Ave., Suite 210
19 Fixed (again!) the missing interrupt locking on TX/RX shifting.
20 Alan Cox <Alan.Cox@linux.org>
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)
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.Cox@linux.org>
34 Cleaned up for 2.3.x because we broke SMP now.
35 20000208 Alan Cox <alan@redhat.com>
37 Check up pass for 2.5. Nothing significant changed
38 20021009 Alan Cox <alan@redhat.com>
40 Fixed zero fill corner case
41 20030104 Alan Cox <alan@redhat.com>
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.
54 * DOC: 3c501 Card Notes
56 * Some notes on this thing if you have to hack it. [Alan]
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.
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
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
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.
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).
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).
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.
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.
102 #define DRV_NAME "3c501"
103 #define DRV_VERSION "2002/10/09"
106 static const char version[] =
107 DRV_NAME ".c: " DRV_VERSION " Alan Cox (alan@redhat.com).\n";
110 * Braindamage remaining:
114 #include <linux/module.h>
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>
128 #include <asm/uaccess.h>
131 #include <linux/netdevice.h>
132 #include <linux/etherdevice.h>
133 #include <linux/skbuff.h>
134 #include <linux/init.h>
139 * The boilerplate probe code.
144 static int mem_start;
147 * el1_probe: - probe for a 3c501
148 * @dev: The device structure passed in to probe.
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
155 * Returns 0 on success. ENXIO if asked not to probe and ENODEV if asked to
156 * probe and failing to find anything.
159 struct net_device * __init el1_probe(int unit)
161 struct net_device *dev = alloc_etherdev(sizeof(struct net_local));
162 static unsigned ports[] = { 0x280, 0x300, 0};
167 return ERR_PTR(-ENOMEM);
170 sprintf(dev->name, "eth%d", unit);
171 netdev_boot_setup_check(dev);
174 mem_start = dev->mem_start & 7;
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. */
182 for (port = ports; *port && el1_probe1(dev, *port); port++)
189 err = register_netdev(dev);
194 release_region(dev->base_addr, EL1_IO_EXTENT);
202 * @dev: The device structure to use
203 * @ioaddr: An I/O address to probe at.
205 * The actual probe. This is iterated over by #el1_probe in order to
206 * check all the applicable device locations.
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.
213 static int __init el1_probe1(struct net_device *dev, int ioaddr)
215 struct net_local *lp;
216 const char *mname; /* Vendor name */
217 unsigned char station_addr[6];
222 * Reserve I/O resource for exclusive use by this driver
225 if (!request_region(ioaddr, EL1_IO_EXTENT, DRV_NAME))
229 * Read the station address PROM data from the special port.
232 for (i = 0; i < 6; i++)
234 outw(i, ioaddr + EL1_DATAPTR);
235 station_addr[i] = inb(ioaddr + EL1_SAPROM);
238 * Check the first three octets of the S.A. for 3Com's prefix, or
239 * for the Sager NP943 prefix.
242 if (station_addr[0] == 0x02 && station_addr[1] == 0x60
243 && station_addr[2] == 0x8c)
246 } else if (station_addr[0] == 0x00 && station_addr[1] == 0x80
247 && station_addr[2] == 0xC8)
252 release_region(ioaddr, EL1_IO_EXTENT);
257 * We auto-IRQ by shutting off the interrupt line and letting it float
265 unsigned long irq_mask;
267 irq_mask = probe_irq_on();
268 inb(RX_STATUS); /* Clear pending interrupts. */
270 outb(AX_LOOP + 1, AX_CMD);
275 autoirq = probe_irq_off(irq_mask);
279 printk(KERN_WARNING "%s probe at %#x failed to detect IRQ line.\n",
281 release_region(ioaddr, EL1_IO_EXTENT);
286 outb(AX_RESET+AX_LOOP, AX_CMD); /* Loopback mode. */
287 dev->base_addr = ioaddr;
288 memcpy(dev->dev_addr, station_addr, ETH_ALEN);
291 el_debug = mem_start & 0x7;
295 printk(KERN_INFO "%s: %s EtherLink at %#lx, using %sIRQ %d.\n", dev->name, mname, dev->base_addr,
296 autoirq ? "auto":"assigned ", dev->irq);
298 #ifdef CONFIG_IP_MULTICAST
299 printk(KERN_WARNING "WARNING: Use of the 3c501 in a multicast kernel is NOT recommended.\n");
303 printk(KERN_DEBUG "%s", version);
305 memset(dev->priv, 0, sizeof(struct net_local));
306 lp = netdev_priv(dev);
307 spin_lock_init(&lp->lock);
310 * The EL1-specific entries in the device structure.
313 dev->open = &el_open;
314 dev->hard_start_xmit = &el_start_xmit;
315 dev->tx_timeout = &el_timeout;
316 dev->watchdog_timeo = HZ;
317 dev->stop = &el1_close;
318 dev->get_stats = &el1_get_stats;
319 dev->set_multicast_list = &set_multicast_list;
320 dev->ethtool_ops = &netdev_ethtool_ops;
326 * @dev: device that is being opened
328 * When an ifconfig is issued which changes the device flags to include
329 * IFF_UP this function is called. It is only called when the change
330 * occurs, not when the interface remains up. #el1_close will be called
333 * Returns 0 for a successful open, or -EAGAIN if someone has run off
334 * with our interrupt line.
337 static int el_open(struct net_device *dev)
340 int ioaddr = dev->base_addr;
341 struct net_local *lp = netdev_priv(dev);
345 printk(KERN_DEBUG "%s: Doing el_open()...", dev->name);
347 if ((retval = request_irq(dev->irq, &el_interrupt, 0, dev->name, dev)))
350 spin_lock_irqsave(&lp->lock, flags);
352 spin_unlock_irqrestore(&lp->lock, flags);
354 lp->txing = 0; /* Board in RX mode */
355 outb(AX_RX, AX_CMD); /* Aux control, irq and receive enabled */
356 netif_start_queue(dev);
362 * @dev: The 3c501 card that has timed out
364 * Attempt to restart the board. This is basically a mixture of extreme
365 * violence and prayer
369 static void el_timeout(struct net_device *dev)
371 struct net_local *lp = netdev_priv(dev);
372 int ioaddr = dev->base_addr;
375 printk (KERN_DEBUG "%s: transmit timed out, txsr %#2x axsr=%02x rxsr=%02x.\n",
376 dev->name, inb(TX_STATUS), inb(AX_STATUS), inb(RX_STATUS));
377 lp->stats.tx_errors++;
378 outb(TX_NORM, TX_CMD);
379 outb(RX_NORM, RX_CMD);
380 outb(AX_OFF, AX_CMD); /* Just trigger a false interrupt. */
381 outb(AX_RX, AX_CMD); /* Aux control, irq and receive enabled */
382 lp->txing = 0; /* Ripped back in to RX */
383 netif_wake_queue(dev);
389 * @skb: The packet that is queued to be sent
390 * @dev: The 3c501 card we want to throw it down
392 * Attempt to send a packet to a 3c501 card. There are some interesting
393 * catches here because the 3c501 is an extremely old and therefore
394 * stupid piece of technology.
396 * If we are handling an interrupt on the other CPU we cannot load a packet
397 * as we may still be attempting to retrieve the last RX packet buffer.
399 * When a transmit times out we dump the card into control mode and just
400 * start again. It happens enough that it isnt worth logging.
402 * We avoid holding the spin locks when doing the packet load to the board.
403 * The device is very slow, and its DMA mode is even slower. If we held the
404 * lock while loading 1500 bytes onto the controller we would drop a lot of
405 * serial port characters. This requires we do extra locking, but we have
409 static int el_start_xmit(struct sk_buff *skb, struct net_device *dev)
411 struct net_local *lp = netdev_priv(dev);
412 int ioaddr = dev->base_addr;
416 * Avoid incoming interrupts between us flipping txing and flipping
417 * mode as the driver assumes txing is a faithful indicator of card
421 spin_lock_irqsave(&lp->lock, flags);
424 * Avoid timer-based retransmission conflicts.
427 netif_stop_queue(dev);
434 unsigned char *buf = skb->data;
437 pad = ETH_ZLEN - len;
439 gp_start = 0x800 - ( len + pad );
441 lp->tx_pkt_start = gp_start;
444 lp->stats.tx_bytes += skb->len;
447 * Command mode with status cleared should [in theory]
448 * mean no more interrupts can be pending on the card.
451 outb_p(AX_SYS, AX_CMD);
459 * Turn interrupts back on while we spend a pleasant afternoon
460 * loading bytes into the board
463 spin_unlock_irqrestore(&lp->lock, flags);
465 outw(0x00, RX_BUF_CLR); /* Set rx packet area to 0. */
466 outw(gp_start, GP_LOW); /* aim - packet will be loaded into buffer start */
467 outsb(DATAPORT,buf,len); /* load buffer (usual thing each byte increments the pointer) */
469 while(pad--) /* Zero fill buffer tail */
472 outw(gp_start, GP_LOW); /* the board reuses the same register */
476 outb(AX_XMIT, AX_CMD); /* fire ... Trigger xmit. */
478 dev->trans_start = jiffies;
480 printk(KERN_DEBUG " queued xmit.\n");
484 /* A receive upset our load, despite our best efforts */
486 printk(KERN_DEBUG "%s: burped during tx load.\n", dev->name);
487 spin_lock_irqsave(&lp->lock, flags);
495 * @irq: Interrupt number
496 * @dev_id: The 3c501 that burped
498 * Handle the ether interface interrupts. The 3c501 needs a lot more
499 * hand holding than most cards. In particular we get a transmit interrupt
500 * with a collision error because the board firmware isnt capable of rewinding
501 * its own transmit buffer pointers. It can however count to 16 for us.
503 * On the receive side the card is also very dumb. It has no buffering to
504 * speak of. We simply pull the packet out of its PIO buffer (which is slow)
505 * and queue it for the kernel. Then we reset the card for the next packet.
507 * We sometimes get surprise interrupts late both because the SMP IRQ delivery
508 * is message passing and because the card sometimes seems to deliver late. I
509 * think if it is part way through a receive and the mode is changed it carries
510 * on receiving and sends us an interrupt. We have to band aid all these cases
511 * to get a sensible 150kBytes/second performance. Even then you want a small
515 static irqreturn_t el_interrupt(int irq, void *dev_id)
517 struct net_device *dev = dev_id;
518 struct net_local *lp;
520 int axsr; /* Aux. status reg. */
522 ioaddr = dev->base_addr;
523 lp = netdev_priv(dev);
525 spin_lock(&lp->lock);
531 axsr = inb(AX_STATUS);
538 printk(KERN_DEBUG "%s: el_interrupt() aux=%#02x", dev->name, axsr);
540 if(lp->loading==1 && !lp->txing)
541 printk(KERN_WARNING "%s: Inconsistent state loading while not in tx\n",
548 * Board in transmit mode. May be loading. If we are
549 * loading we shouldn't have got this.
552 int txsr = inb(TX_STATUS);
558 printk(KERN_DEBUG "%s: Interrupt while loading [", dev->name);
559 printk(KERN_DEBUG " txsr=%02x gp=%04x rp=%04x]\n", txsr, inw(GP_LOW),inw(RX_LOW));
561 lp->loading=2; /* Force a reload */
562 spin_unlock(&lp->lock);
567 printk(KERN_DEBUG " txsr=%02x gp=%04x rp=%04x", txsr, inw(GP_LOW),inw(RX_LOW));
569 if ((axsr & 0x80) && (txsr & TX_READY) == 0)
572 * FIXME: is there a logic to whether to keep on trying or
573 * reset immediately ?
576 printk(KERN_DEBUG "%s: Unusual interrupt during Tx, txsr=%02x axsr=%02x"
577 " gp=%03x rp=%03x.\n", dev->name, txsr, axsr,
578 inw(ioaddr + EL1_DATAPTR), inw(ioaddr + EL1_RXPTR));
580 netif_wake_queue(dev);
582 else if (txsr & TX_16COLLISIONS)
588 printk (KERN_DEBUG "%s: Transmit failed 16 times, Ethernet jammed?\n",dev->name);
589 outb(AX_SYS, AX_CMD);
591 lp->stats.tx_aborted_errors++;
592 netif_wake_queue(dev);
594 else if (txsr & TX_COLLISION)
601 printk(KERN_DEBUG " retransmitting after a collision.\n");
603 * Poor little chip can't reset its own start pointer
606 outb(AX_SYS, AX_CMD);
607 outw(lp->tx_pkt_start, GP_LOW);
608 outb(AX_XMIT, AX_CMD);
609 lp->stats.collisions++;
610 spin_unlock(&lp->lock);
616 * It worked.. we will now fall through and receive
618 lp->stats.tx_packets++;
620 printk(KERN_DEBUG " Tx succeeded %s\n",
621 (txsr & TX_RDY) ? "." : "but tx is busy!");
623 * This is safe the interrupt is atomic WRT itself.
627 netif_wake_queue(dev); /* In case more to transmit */
636 int rxsr = inb(RX_STATUS);
638 printk(KERN_DEBUG " rxsr=%02x txsr=%02x rp=%04x", rxsr, inb(TX_STATUS),inw(RX_LOW));
640 * Just reading rx_status fixes most errors.
642 if (rxsr & RX_MISSED)
643 lp->stats.rx_missed_errors++;
644 else if (rxsr & RX_RUNT)
645 { /* Handled to avoid board lock-up. */
646 lp->stats.rx_length_errors++;
648 printk(KERN_DEBUG " runt.\n");
650 else if (rxsr & RX_GOOD)
660 * Nothing? Something is broken!
663 printk(KERN_DEBUG "%s: No packet seen, rxsr=%02x **resetting 3c501***\n",
668 printk(KERN_DEBUG ".\n");
672 * Move into receive mode
676 outw(0x00, RX_BUF_CLR);
677 inb(RX_STATUS); /* Be certain that interrupts are cleared. */
679 spin_unlock(&lp->lock);
687 * @dev: Device to pull the packets from
689 * We have a good packet. Well, not really "good", just mostly not broken.
690 * We must check everything to see if it is good. In particular we occasionally
691 * get wild packet sizes from the card. If the packet seems sane we PIO it
692 * off the card and queue it for the protocol layers.
695 static void el_receive(struct net_device *dev)
697 struct net_local *lp = netdev_priv(dev);
698 int ioaddr = dev->base_addr;
702 pkt_len = inw(RX_LOW);
705 printk(KERN_DEBUG " el_receive %d.\n", pkt_len);
707 if ((pkt_len < 60) || (pkt_len > 1536))
710 printk(KERN_DEBUG "%s: bogus packet, length=%d\n", dev->name, pkt_len);
711 lp->stats.rx_over_errors++;
716 * Command mode so we can empty the buffer
719 outb(AX_SYS, AX_CMD);
720 skb = dev_alloc_skb(pkt_len+2);
729 printk(KERN_INFO "%s: Memory squeeze, dropping packet.\n", dev->name);
730 lp->stats.rx_dropped++;
735 skb_reserve(skb,2); /* Force 16 byte alignment */
737 * The read increments through the bytes. The interrupt
738 * handler will fix the pointer when it returns to
741 insb(DATAPORT, skb_put(skb,pkt_len), pkt_len);
742 skb->protocol=eth_type_trans(skb,dev);
744 dev->last_rx = jiffies;
745 lp->stats.rx_packets++;
746 lp->stats.rx_bytes+=pkt_len;
752 * el_reset: Reset a 3c501 card
753 * @dev: The 3c501 card about to get zapped
755 * Even resetting a 3c501 isnt simple. When you activate reset it loses all
756 * its configuration. You must hold the lock when doing this. The function
757 * cannot take the lock itself as it is callable from the irq handler.
760 static void el_reset(struct net_device *dev)
762 struct net_local *lp = netdev_priv(dev);
763 int ioaddr = dev->base_addr;
766 printk(KERN_INFO "3c501 reset...");
767 outb(AX_RESET, AX_CMD); /* Reset the chip */
768 outb(AX_LOOP, AX_CMD); /* Aux control, irq and loopback enabled */
771 for (i = 0; i < 6; i++) /* Set the station address. */
772 outb(dev->dev_addr[i], ioaddr + i);
775 outw(0, RX_BUF_CLR); /* Set rx packet area to 0. */
776 outb(TX_NORM, TX_CMD); /* tx irq on done, collision */
777 outb(RX_NORM, RX_CMD); /* Set Rx commands. */
778 inb(RX_STATUS); /* Clear status. */
785 * @dev: 3c501 card to shut down
787 * Close a 3c501 card. The IFF_UP flag has been cleared by the user via
788 * the SIOCSIFFLAGS ioctl. We stop any further transmissions being queued,
789 * and then disable the interrupts. Finally we reset the chip. The effects
790 * of the rest will be cleaned up by #el1_open. Always returns 0 indicating
794 static int el1_close(struct net_device *dev)
796 int ioaddr = dev->base_addr;
799 printk(KERN_INFO "%s: Shutting down Ethernet card at %#x.\n", dev->name, ioaddr);
801 netif_stop_queue(dev);
804 * Free and disable the IRQ.
807 free_irq(dev->irq, dev);
808 outb(AX_RESET, AX_CMD); /* Reset the chip */
815 * @dev: The card to get the statistics for
817 * In smarter devices this function is needed to pull statistics off the
818 * board itself. The 3c501 has no hardware statistics. We maintain them all
819 * so they are by definition always up to date.
821 * Returns the statistics for the card from the card private data
824 static struct net_device_stats *el1_get_stats(struct net_device *dev)
826 struct net_local *lp = netdev_priv(dev);
831 * set_multicast_list:
832 * @dev: The device to adjust
834 * Set or clear the multicast filter for this adaptor to use the best-effort
835 * filtering supported. The 3c501 supports only three modes of filtering.
836 * It always receives broadcasts and packets for itself. You can choose to
837 * optionally receive all packets, or all multicast packets on top of this.
840 static void set_multicast_list(struct net_device *dev)
842 int ioaddr = dev->base_addr;
844 if(dev->flags&IFF_PROMISC)
846 outb(RX_PROM, RX_CMD);
849 else if (dev->mc_list || dev->flags&IFF_ALLMULTI)
851 outb(RX_MULT, RX_CMD); /* Multicast or all multicast is the same */
852 inb(RX_STATUS); /* Clear status. */
856 outb(RX_NORM, RX_CMD);
862 static void netdev_get_drvinfo(struct net_device *dev,
863 struct ethtool_drvinfo *info)
865 strcpy(info->driver, DRV_NAME);
866 strcpy(info->version, DRV_VERSION);
867 sprintf(info->bus_info, "ISA 0x%lx", dev->base_addr);
870 static u32 netdev_get_msglevel(struct net_device *dev)
875 static void netdev_set_msglevel(struct net_device *dev, u32 level)
880 static const struct ethtool_ops netdev_ethtool_ops = {
881 .get_drvinfo = netdev_get_drvinfo,
882 .get_msglevel = netdev_get_msglevel,
883 .set_msglevel = netdev_set_msglevel,
888 static struct net_device *dev_3c501;
890 module_param(io, int, 0);
891 module_param(irq, int, 0);
892 MODULE_PARM_DESC(io, "EtherLink I/O base address");
893 MODULE_PARM_DESC(irq, "EtherLink IRQ number");
898 * When the driver is loaded as a module this function is called. We fake up
899 * a device structure with the base I/O and interrupt set as if it were being
900 * called from Space.c. This minimises the extra code that would otherwise
903 * Returns 0 for success or -EIO if a card is not found. Returning an error
904 * here also causes the module to be unloaded
907 int __init init_module(void)
909 dev_3c501 = el1_probe(-1);
910 if (IS_ERR(dev_3c501))
911 return PTR_ERR(dev_3c501);
918 * The module is being unloaded. We unhook our network device from the system
919 * and then free up the resources we took when the card was found.
922 void __exit cleanup_module(void)
924 struct net_device *dev = dev_3c501;
925 unregister_netdev(dev);
926 release_region(dev->base_addr, EL1_IO_EXTENT);
932 MODULE_AUTHOR("Donald Becker, Alan Cox");
933 MODULE_DESCRIPTION("Support for the ancient 3Com 3c501 ethernet card");
934 MODULE_LICENSE("GPL");