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@lxorguk.ukuu.org.uk>
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@lxorguk.ukuu.org.uk>
34 Cleaned up for 2.3.x because we broke SMP now.
35 20000208 Alan Cox <alan@lxorguk.ukuu.org.uk>
37 Check up pass for 2.5. Nothing significant changed
38 20021009 Alan Cox <alan@lxorguk.ukuu.org.uk>
40 Fixed zero fill corner case
41 20030104 Alan Cox <alan@lxorguk.ukuu.org.uk>
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@lxorguk.ukuu.org.uk).\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/string.h>
121 #include <linux/errno.h>
122 #include <linux/spinlock.h>
123 #include <linux/ethtool.h>
124 #include <linux/delay.h>
125 #include <linux/bitops.h>
127 #include <asm/uaccess.h>
130 #include <linux/netdevice.h>
131 #include <linux/etherdevice.h>
132 #include <linux/skbuff.h>
133 #include <linux/init.h>
138 * The boilerplate probe code.
141 static int io = 0x280;
143 static int mem_start;
146 * el1_probe: - probe for a 3c501
147 * @dev: The device structure passed in to probe.
149 * This can be called from two places. The network layer will probe using
150 * a device structure passed in with the probe information completed. For a
151 * modular driver we use #init_module to fill in our own structure and probe
154 * Returns 0 on success. ENXIO if asked not to probe and ENODEV if asked to
155 * probe and failing to find anything.
158 struct net_device * __init el1_probe(int unit)
160 struct net_device *dev = alloc_etherdev(sizeof(struct net_local));
161 static unsigned ports[] = { 0x280, 0x300, 0};
166 return ERR_PTR(-ENOMEM);
169 sprintf(dev->name, "eth%d", unit);
170 netdev_boot_setup_check(dev);
173 mem_start = dev->mem_start & 7;
176 if (io > 0x1ff) { /* Check a single specified location. */
177 err = el1_probe1(dev, io);
178 } else if (io != 0) {
179 err = -ENXIO; /* Don't probe at all. */
181 for (port = ports; *port && el1_probe1(dev, *port); port++)
188 err = register_netdev(dev);
193 release_region(dev->base_addr, EL1_IO_EXTENT);
199 static const struct net_device_ops el_netdev_ops = {
201 .ndo_stop = el1_close,
202 .ndo_start_xmit = el_start_xmit,
203 .ndo_tx_timeout = el_timeout,
204 .ndo_set_multicast_list = set_multicast_list,
205 .ndo_change_mtu = eth_change_mtu,
206 .ndo_set_mac_address = eth_mac_addr,
207 .ndo_validate_addr = eth_validate_addr,
212 * @dev: The device structure to use
213 * @ioaddr: An I/O address to probe at.
215 * The actual probe. This is iterated over by #el1_probe in order to
216 * check all the applicable device locations.
218 * Returns 0 for a success, in which case the device is activated,
219 * EAGAIN if the IRQ is in use by another driver, and ENODEV if the
220 * board cannot be found.
223 static int __init el1_probe1(struct net_device *dev, int ioaddr)
225 struct net_local *lp;
226 const char *mname; /* Vendor name */
227 unsigned char station_addr[6];
232 * Reserve I/O resource for exclusive use by this driver
235 if (!request_region(ioaddr, EL1_IO_EXTENT, DRV_NAME))
239 * Read the station address PROM data from the special port.
242 for (i = 0; i < 6; i++) {
243 outw(i, ioaddr + EL1_DATAPTR);
244 station_addr[i] = inb(ioaddr + EL1_SAPROM);
247 * Check the first three octets of the S.A. for 3Com's prefix, or
248 * for the Sager NP943 prefix.
251 if (station_addr[0] == 0x02 && station_addr[1] == 0x60 &&
252 station_addr[2] == 0x8c)
254 else if (station_addr[0] == 0x00 && station_addr[1] == 0x80 &&
255 station_addr[2] == 0xC8)
258 release_region(ioaddr, EL1_IO_EXTENT);
263 * We auto-IRQ by shutting off the interrupt line and letting it
270 unsigned long irq_mask;
272 irq_mask = probe_irq_on();
273 inb(RX_STATUS); /* Clear pending interrupts. */
275 outb(AX_LOOP + 1, AX_CMD);
280 autoirq = probe_irq_off(irq_mask);
283 pr_warning("%s probe at %#x failed to detect IRQ line.\n",
285 release_region(ioaddr, EL1_IO_EXTENT);
290 outb(AX_RESET+AX_LOOP, AX_CMD); /* Loopback mode. */
291 dev->base_addr = ioaddr;
292 memcpy(dev->dev_addr, station_addr, ETH_ALEN);
295 el_debug = mem_start & 0x7;
299 pr_info("%s: %s EtherLink at %#lx, using %sIRQ %d.\n",
300 dev->name, mname, dev->base_addr,
301 autoirq ? "auto":"assigned ", dev->irq);
303 #ifdef CONFIG_IP_MULTICAST
304 pr_warning("WARNING: Use of the 3c501 in a multicast kernel is NOT recommended.\n");
308 pr_debug("%s", version);
310 lp = netdev_priv(dev);
311 memset(lp, 0, sizeof(struct net_local));
312 spin_lock_init(&lp->lock);
315 * The EL1-specific entries in the device structure.
318 dev->netdev_ops = &el_netdev_ops;
319 dev->watchdog_timeo = HZ;
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 pr_debug("%s: Doing el_open()...\n", dev->name);
347 retval = request_irq(dev->irq, el_interrupt, 0, dev->name, dev);
351 spin_lock_irqsave(&lp->lock, flags);
353 spin_unlock_irqrestore(&lp->lock, flags);
355 lp->txing = 0; /* Board in RX mode */
356 outb(AX_RX, AX_CMD); /* Aux control, irq and receive enabled */
357 netif_start_queue(dev);
363 * @dev: The 3c501 card that has timed out
365 * Attempt to restart the board. This is basically a mixture of extreme
366 * violence and prayer
370 static void el_timeout(struct net_device *dev)
372 struct net_local *lp = netdev_priv(dev);
373 int ioaddr = dev->base_addr;
376 pr_debug("%s: transmit timed out, txsr %#2x axsr=%02x rxsr=%02x.\n",
377 dev->name, inb(TX_STATUS),
378 inb(AX_STATUS), inb(RX_STATUS));
379 dev->stats.tx_errors++;
380 outb(TX_NORM, TX_CMD);
381 outb(RX_NORM, RX_CMD);
382 outb(AX_OFF, AX_CMD); /* Just trigger a false interrupt. */
383 outb(AX_RX, AX_CMD); /* Aux control, irq and receive enabled */
384 lp->txing = 0; /* Ripped back in to RX */
385 netif_wake_queue(dev);
391 * @skb: The packet that is queued to be sent
392 * @dev: The 3c501 card we want to throw it down
394 * Attempt to send a packet to a 3c501 card. There are some interesting
395 * catches here because the 3c501 is an extremely old and therefore
396 * stupid piece of technology.
398 * If we are handling an interrupt on the other CPU we cannot load a packet
399 * as we may still be attempting to retrieve the last RX packet buffer.
401 * When a transmit times out we dump the card into control mode and just
402 * start again. It happens enough that it isnt worth logging.
404 * We avoid holding the spin locks when doing the packet load to the board.
405 * The device is very slow, and its DMA mode is even slower. If we held the
406 * lock while loading 1500 bytes onto the controller we would drop a lot of
407 * serial port characters. This requires we do extra locking, but we have
411 static netdev_tx_t el_start_xmit(struct sk_buff *skb, struct net_device *dev)
413 struct net_local *lp = netdev_priv(dev);
414 int ioaddr = dev->base_addr;
418 * Avoid incoming interrupts between us flipping txing and flipping
419 * mode as the driver assumes txing is a faithful indicator of card
423 spin_lock_irqsave(&lp->lock, flags);
426 * Avoid timer-based retransmission conflicts.
429 netif_stop_queue(dev);
435 unsigned char *buf = skb->data;
438 pad = ETH_ZLEN - len;
440 gp_start = 0x800 - (len + pad);
442 lp->tx_pkt_start = gp_start;
445 dev->stats.tx_bytes += skb->len;
448 * Command mode with status cleared should [in theory]
449 * mean no more interrupts can be pending on the card.
452 outb_p(AX_SYS, AX_CMD);
460 * Turn interrupts back on while we spend a pleasant
461 * afternoon loading bytes into the board
464 spin_unlock_irqrestore(&lp->lock, flags);
466 /* Set rx packet area to 0. */
467 outw(0x00, RX_BUF_CLR);
468 /* aim - packet will be loaded into buffer start */
469 outw(gp_start, GP_LOW);
470 /* load buffer (usual thing each byte increments the pointer) */
471 outsb(DATAPORT, buf, len);
473 while (pad--) /* Zero fill buffer tail */
476 /* the board reuses the same register */
477 outw(gp_start, GP_LOW);
479 if (lp->loading != 2) {
480 /* fire ... Trigger xmit. */
481 outb(AX_XMIT, AX_CMD);
484 pr_debug(" queued xmit.\n");
488 /* A receive upset our load, despite our best efforts */
490 pr_debug("%s: burped during tx load.\n", dev->name);
491 spin_lock_irqsave(&lp->lock, flags);
497 * @irq: Interrupt number
498 * @dev_id: The 3c501 that burped
500 * Handle the ether interface interrupts. The 3c501 needs a lot more
501 * hand holding than most cards. In particular we get a transmit interrupt
502 * with a collision error because the board firmware isnt capable of rewinding
503 * its own transmit buffer pointers. It can however count to 16 for us.
505 * On the receive side the card is also very dumb. It has no buffering to
506 * speak of. We simply pull the packet out of its PIO buffer (which is slow)
507 * and queue it for the kernel. Then we reset the card for the next packet.
509 * We sometimes get surprise interrupts late both because the SMP IRQ delivery
510 * is message passing and because the card sometimes seems to deliver late. I
511 * think if it is part way through a receive and the mode is changed it carries
512 * on receiving and sends us an interrupt. We have to band aid all these cases
513 * to get a sensible 150kBytes/second performance. Even then you want a small
517 static irqreturn_t el_interrupt(int irq, void *dev_id)
519 struct net_device *dev = dev_id;
520 struct net_local *lp;
522 int axsr; /* Aux. status reg. */
524 ioaddr = dev->base_addr;
525 lp = netdev_priv(dev);
527 spin_lock(&lp->lock);
533 axsr = inb(AX_STATUS);
540 pr_debug("%s: el_interrupt() aux=%#02x\n", dev->name, axsr);
542 if (lp->loading == 1 && !lp->txing)
543 pr_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.
551 int txsr = inb(TX_STATUS);
553 if (lp->loading == 1) {
555 pr_debug("%s: Interrupt while loading [txsr=%02x gp=%04x rp=%04x]\n",
556 dev->name, txsr, inw(GP_LOW), inw(RX_LOW));
560 spin_unlock(&lp->lock);
564 pr_debug("%s: txsr=%02x gp=%04x rp=%04x\n", dev->name,
565 txsr, inw(GP_LOW), inw(RX_LOW));
567 if ((axsr & 0x80) && (txsr & TX_READY) == 0) {
569 * FIXME: is there a logic to whether to keep
570 * on trying or reset immediately ?
573 pr_debug("%s: Unusual interrupt during Tx, txsr=%02x axsr=%02x gp=%03x rp=%03x.\n",
574 dev->name, txsr, axsr,
575 inw(ioaddr + EL1_DATAPTR),
576 inw(ioaddr + EL1_RXPTR));
578 netif_wake_queue(dev);
579 } else if (txsr & TX_16COLLISIONS) {
584 pr_debug("%s: Transmit failed 16 times, Ethernet jammed?\n", dev->name);
585 outb(AX_SYS, AX_CMD);
587 dev->stats.tx_aborted_errors++;
588 netif_wake_queue(dev);
589 } else if (txsr & TX_COLLISION) {
595 pr_debug("%s: retransmitting after a collision.\n", dev->name);
597 * Poor little chip can't reset its own start
601 outb(AX_SYS, AX_CMD);
602 outw(lp->tx_pkt_start, GP_LOW);
603 outb(AX_XMIT, AX_CMD);
604 dev->stats.collisions++;
605 spin_unlock(&lp->lock);
609 * It worked.. we will now fall through and receive
611 dev->stats.tx_packets++;
613 pr_debug("%s: Tx succeeded %s\n", dev->name,
614 (txsr & TX_RDY) ? "." : "but tx is busy!");
616 * This is safe the interrupt is atomic WRT itself.
619 /* In case more to transmit */
620 netif_wake_queue(dev);
627 int rxsr = inb(RX_STATUS);
629 pr_debug("%s: rxsr=%02x txsr=%02x rp=%04x\n",
630 dev->name, rxsr, inb(TX_STATUS), inw(RX_LOW));
632 * Just reading rx_status fixes most errors.
634 if (rxsr & RX_MISSED)
635 dev->stats.rx_missed_errors++;
636 else if (rxsr & RX_RUNT) {
637 /* Handled to avoid board lock-up. */
638 dev->stats.rx_length_errors++;
640 pr_debug("%s: runt.\n", dev->name);
641 } else if (rxsr & RX_GOOD) {
648 * Nothing? Something is broken!
651 pr_debug("%s: No packet seen, rxsr=%02x **resetting 3c501***\n",
658 * Move into receive mode
662 outw(0x00, RX_BUF_CLR);
663 inb(RX_STATUS); /* Be certain that interrupts are cleared. */
665 spin_unlock(&lp->lock);
673 * @dev: Device to pull the packets from
675 * We have a good packet. Well, not really "good", just mostly not broken.
676 * We must check everything to see if it is good. In particular we occasionally
677 * get wild packet sizes from the card. If the packet seems sane we PIO it
678 * off the card and queue it for the protocol layers.
681 static void el_receive(struct net_device *dev)
683 int ioaddr = dev->base_addr;
687 pkt_len = inw(RX_LOW);
690 pr_debug(" el_receive %d.\n", pkt_len);
692 if (pkt_len < 60 || pkt_len > 1536) {
694 pr_debug("%s: bogus packet, length=%d\n",
696 dev->stats.rx_over_errors++;
701 * Command mode so we can empty the buffer
704 outb(AX_SYS, AX_CMD);
705 skb = dev_alloc_skb(pkt_len+2);
713 pr_info("%s: Memory squeeze, dropping packet.\n", dev->name);
714 dev->stats.rx_dropped++;
717 skb_reserve(skb, 2); /* Force 16 byte alignment */
719 * The read increments through the bytes. The interrupt
720 * handler will fix the pointer when it returns to
723 insb(DATAPORT, skb_put(skb, pkt_len), pkt_len);
724 skb->protocol = eth_type_trans(skb, dev);
726 dev->stats.rx_packets++;
727 dev->stats.rx_bytes += pkt_len;
732 * el_reset: Reset a 3c501 card
733 * @dev: The 3c501 card about to get zapped
735 * Even resetting a 3c501 isnt simple. When you activate reset it loses all
736 * its configuration. You must hold the lock when doing this. The function
737 * cannot take the lock itself as it is callable from the irq handler.
740 static void el_reset(struct net_device *dev)
742 struct net_local *lp = netdev_priv(dev);
743 int ioaddr = dev->base_addr;
746 pr_info("3c501 reset...\n");
747 outb(AX_RESET, AX_CMD); /* Reset the chip */
748 /* Aux control, irq and loopback enabled */
749 outb(AX_LOOP, AX_CMD);
752 for (i = 0; i < 6; i++) /* Set the station address. */
753 outb(dev->dev_addr[i], ioaddr + i);
756 outw(0, RX_BUF_CLR); /* Set rx packet area to 0. */
757 outb(TX_NORM, TX_CMD); /* tx irq on done, collision */
758 outb(RX_NORM, RX_CMD); /* Set Rx commands. */
759 inb(RX_STATUS); /* Clear status. */
766 * @dev: 3c501 card to shut down
768 * Close a 3c501 card. The IFF_UP flag has been cleared by the user via
769 * the SIOCSIFFLAGS ioctl. We stop any further transmissions being queued,
770 * and then disable the interrupts. Finally we reset the chip. The effects
771 * of the rest will be cleaned up by #el1_open. Always returns 0 indicating
775 static int el1_close(struct net_device *dev)
777 int ioaddr = dev->base_addr;
780 pr_info("%s: Shutting down Ethernet card at %#x.\n",
783 netif_stop_queue(dev);
786 * Free and disable the IRQ.
789 free_irq(dev->irq, dev);
790 outb(AX_RESET, AX_CMD); /* Reset the chip */
796 * set_multicast_list:
797 * @dev: The device to adjust
799 * Set or clear the multicast filter for this adaptor to use the best-effort
800 * filtering supported. The 3c501 supports only three modes of filtering.
801 * It always receives broadcasts and packets for itself. You can choose to
802 * optionally receive all packets, or all multicast packets on top of this.
805 static void set_multicast_list(struct net_device *dev)
807 int ioaddr = dev->base_addr;
809 if (dev->flags & IFF_PROMISC) {
810 outb(RX_PROM, RX_CMD);
812 } else if (!netdev_mc_empty(dev) || dev->flags & IFF_ALLMULTI) {
813 /* Multicast or all multicast is the same */
814 outb(RX_MULT, RX_CMD);
815 inb(RX_STATUS); /* Clear status. */
817 outb(RX_NORM, RX_CMD);
823 static void netdev_get_drvinfo(struct net_device *dev,
824 struct ethtool_drvinfo *info)
826 strcpy(info->driver, DRV_NAME);
827 strcpy(info->version, DRV_VERSION);
828 sprintf(info->bus_info, "ISA 0x%lx", dev->base_addr);
831 static u32 netdev_get_msglevel(struct net_device *dev)
836 static void netdev_set_msglevel(struct net_device *dev, u32 level)
841 static const struct ethtool_ops netdev_ethtool_ops = {
842 .get_drvinfo = netdev_get_drvinfo,
843 .get_msglevel = netdev_get_msglevel,
844 .set_msglevel = netdev_set_msglevel,
849 static struct net_device *dev_3c501;
851 module_param(io, int, 0);
852 module_param(irq, int, 0);
853 MODULE_PARM_DESC(io, "EtherLink I/O base address");
854 MODULE_PARM_DESC(irq, "EtherLink IRQ number");
859 * When the driver is loaded as a module this function is called. We fake up
860 * a device structure with the base I/O and interrupt set as if it were being
861 * called from Space.c. This minimises the extra code that would otherwise
864 * Returns 0 for success or -EIO if a card is not found. Returning an error
865 * here also causes the module to be unloaded
868 int __init init_module(void)
870 dev_3c501 = el1_probe(-1);
871 if (IS_ERR(dev_3c501))
872 return PTR_ERR(dev_3c501);
879 * The module is being unloaded. We unhook our network device from the system
880 * and then free up the resources we took when the card was found.
883 void __exit cleanup_module(void)
885 struct net_device *dev = dev_3c501;
886 unregister_netdev(dev);
887 release_region(dev->base_addr, EL1_IO_EXTENT);
893 MODULE_AUTHOR("Donald Becker, Alan Cox");
894 MODULE_DESCRIPTION("Support for the ancient 3Com 3c501 ethernet card");
895 MODULE_LICENSE("GPL");