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.
142 static int io
= 0x280;
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
++) {
233 outw(i
, ioaddr
+ EL1_DATAPTR
);
234 station_addr
[i
] = inb(ioaddr
+ EL1_SAPROM
);
237 * Check the first three octets of the S.A. for 3Com's prefix, or
238 * for the Sager NP943 prefix.
241 if (station_addr
[0] == 0x02 && station_addr
[1] == 0x60
242 && station_addr
[2] == 0x8c)
244 else if (station_addr
[0] == 0x00 && station_addr
[1] == 0x80
245 && station_addr
[2] == 0xC8)
248 release_region(ioaddr
, EL1_IO_EXTENT
);
253 * We auto-IRQ by shutting off the interrupt line and letting it
260 unsigned long irq_mask
;
262 irq_mask
= probe_irq_on();
263 inb(RX_STATUS
); /* Clear pending interrupts. */
265 outb(AX_LOOP
+ 1, AX_CMD
);
270 autoirq
= probe_irq_off(irq_mask
);
273 printk(KERN_WARNING
"%s probe at %#x failed to detect IRQ line.\n",
275 release_region(ioaddr
, EL1_IO_EXTENT
);
280 outb(AX_RESET
+AX_LOOP
, AX_CMD
); /* Loopback mode. */
281 dev
->base_addr
= ioaddr
;
282 memcpy(dev
->dev_addr
, station_addr
, ETH_ALEN
);
285 el_debug
= mem_start
& 0x7;
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
);
293 #ifdef CONFIG_IP_MULTICAST
294 printk(KERN_WARNING
"WARNING: Use of the 3c501 in a multicast kernel is NOT recommended.\n");
298 printk(KERN_DEBUG
"%s", version
);
300 memset(dev
->priv
, 0, sizeof(struct net_local
));
301 lp
= netdev_priv(dev
);
302 spin_lock_init(&lp
->lock
);
305 * The EL1-specific entries in the device structure.
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
;
320 * @dev: device that is being opened
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
327 * Returns 0 for a successful open, or -EAGAIN if someone has run off
328 * with our interrupt line.
331 static int el_open(struct net_device
*dev
)
334 int ioaddr
= dev
->base_addr
;
335 struct net_local
*lp
= netdev_priv(dev
);
339 printk(KERN_DEBUG
"%s: Doing el_open()...", dev
->name
);
341 retval
= request_irq(dev
->irq
, &el_interrupt
, 0, dev
->name
, dev
);
345 spin_lock_irqsave(&lp
->lock
, flags
);
347 spin_unlock_irqrestore(&lp
->lock
, flags
);
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
);
357 * @dev: The 3c501 card that has timed out
359 * Attempt to restart the board. This is basically a mixture of extreme
360 * violence and prayer
364 static void el_timeout(struct net_device
*dev
)
366 struct net_local
*lp
= netdev_priv(dev
);
367 int ioaddr
= dev
->base_addr
;
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
);
385 * @skb: The packet that is queued to be sent
386 * @dev: The 3c501 card we want to throw it down
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.
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.
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.
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
405 static int el_start_xmit(struct sk_buff
*skb
, struct net_device
*dev
)
407 struct net_local
*lp
= netdev_priv(dev
);
408 int ioaddr
= dev
->base_addr
;
412 * Avoid incoming interrupts between us flipping txing and flipping
413 * mode as the driver assumes txing is a faithful indicator of card
417 spin_lock_irqsave(&lp
->lock
, flags
);
420 * Avoid timer-based retransmission conflicts.
423 netif_stop_queue(dev
);
429 unsigned char *buf
= skb
->data
;
432 pad
= ETH_ZLEN
- len
;
434 gp_start
= 0x800 - (len
+ pad
);
436 lp
->tx_pkt_start
= gp_start
;
439 dev
->stats
.tx_bytes
+= skb
->len
;
442 * Command mode with status cleared should [in theory]
443 * mean no more interrupts can be pending on the card.
446 outb_p(AX_SYS
, AX_CMD
);
454 * Turn interrupts back on while we spend a pleasant
455 * afternoon loading bytes into the board
458 spin_unlock_irqrestore(&lp
->lock
, flags
);
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
);
467 while (pad
--) /* Zero fill buffer tail */
470 /* the board reuses the same register */
471 outw(gp_start
, GP_LOW
);
473 if (lp
->loading
!= 2) {
474 /* fire ... Trigger xmit. */
475 outb(AX_XMIT
, AX_CMD
);
477 dev
->trans_start
= jiffies
;
479 printk(KERN_DEBUG
" queued xmit.\n");
483 /* A receive upset our load, despite our best efforts */
485 printk(KERN_DEBUG
"%s: burped during tx load.\n",
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",
541 if (lp
->loading
== 1 && !lp
->txing
)
542 printk(KERN_WARNING
"%s: Inconsistent state loading while not in tx\n",
547 * Board in transmit mode. May be loading. If we are
548 * loading we shouldn't have got this.
550 int txsr
= inb(TX_STATUS
);
552 if (lp
->loading
== 1) {
554 printk(KERN_DEBUG
"%s: Interrupt while loading [",
556 printk(" txsr=%02x gp=%04x rp=%04x]\n",
557 txsr
, inw(GP_LOW
), inw(RX_LOW
));
561 spin_unlock(&lp
->lock
);
565 printk(KERN_DEBUG
" txsr=%02x gp=%04x rp=%04x",
566 txsr
, inw(GP_LOW
), inw(RX_LOW
));
568 if ((axsr
& 0x80) && (txsr
& TX_READY
) == 0) {
570 * FIXME: is there a logic to whether to keep
571 * on trying or reset immediately ?
574 printk(KERN_DEBUG
"%s: Unusual interrupt during Tx, txsr=%02x axsr=%02x gp=%03x rp=%03x.\n",
575 dev
->name
, txsr
, axsr
,
576 inw(ioaddr
+ EL1_DATAPTR
),
577 inw(ioaddr
+ EL1_RXPTR
));
579 netif_wake_queue(dev
);
580 } else if (txsr
& TX_16COLLISIONS
) {
585 printk(KERN_DEBUG
"%s: Transmit failed 16 times, Ethernet jammed?\n", dev
->name
);
586 outb(AX_SYS
, AX_CMD
);
588 dev
->stats
.tx_aborted_errors
++;
589 netif_wake_queue(dev
);
590 } else if (txsr
& TX_COLLISION
) {
596 printk(KERN_DEBUG
" retransmitting after a collision.\n");
598 * Poor little chip can't reset its own start
602 outb(AX_SYS
, AX_CMD
);
603 outw(lp
->tx_pkt_start
, GP_LOW
);
604 outb(AX_XMIT
, AX_CMD
);
605 dev
->stats
.collisions
++;
606 spin_unlock(&lp
->lock
);
610 * It worked.. we will now fall through and receive
612 dev
->stats
.tx_packets
++;
614 printk(KERN_DEBUG
" Tx succeeded %s\n",
615 (txsr
& TX_RDY
) ? "." : "but tx is busy!");
617 * This is safe the interrupt is atomic WRT itself.
620 /* In case more to transmit */
621 netif_wake_queue(dev
);
628 int rxsr
= inb(RX_STATUS
);
630 printk(KERN_DEBUG
" rxsr=%02x txsr=%02x rp=%04x", 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 printk(KERN_DEBUG
" runt.\n");
641 } else if (rxsr
& RX_GOOD
) {
648 * Nothing? Something is broken!
651 printk(KERN_DEBUG
"%s: No packet seen, rxsr=%02x **resetting 3c501***\n",
656 printk(KERN_DEBUG
".\n");
660 * Move into receive mode
664 outw(0x00, RX_BUF_CLR
);
665 inb(RX_STATUS
); /* Be certain that interrupts are cleared. */
667 spin_unlock(&lp
->lock
);
675 * @dev: Device to pull the packets from
677 * We have a good packet. Well, not really "good", just mostly not broken.
678 * We must check everything to see if it is good. In particular we occasionally
679 * get wild packet sizes from the card. If the packet seems sane we PIO it
680 * off the card and queue it for the protocol layers.
683 static void el_receive(struct net_device
*dev
)
685 int ioaddr
= dev
->base_addr
;
689 pkt_len
= inw(RX_LOW
);
692 printk(KERN_DEBUG
" el_receive %d.\n", pkt_len
);
694 if (pkt_len
< 60 || pkt_len
> 1536) {
696 printk(KERN_DEBUG
"%s: bogus packet, length=%d\n", dev
->name
, pkt_len
);
697 dev
->stats
.rx_over_errors
++;
702 * Command mode so we can empty the buffer
705 outb(AX_SYS
, AX_CMD
);
706 skb
= dev_alloc_skb(pkt_len
+2);
714 printk(KERN_INFO
"%s: Memory squeeze, dropping packet.\n", dev
->name
);
715 dev
->stats
.rx_dropped
++;
718 skb_reserve(skb
, 2); /* Force 16 byte alignment */
720 * The read increments through the bytes. The interrupt
721 * handler will fix the pointer when it returns to
724 insb(DATAPORT
, skb_put(skb
, pkt_len
), pkt_len
);
725 skb
->protocol
= eth_type_trans(skb
, dev
);
727 dev
->last_rx
= jiffies
;
728 dev
->stats
.rx_packets
++;
729 dev
->stats
.rx_bytes
+= pkt_len
;
735 * el_reset: Reset a 3c501 card
736 * @dev: The 3c501 card about to get zapped
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.
743 static void el_reset(struct net_device
*dev
)
745 struct net_local
*lp
= netdev_priv(dev
);
746 int ioaddr
= dev
->base_addr
;
749 printk(KERN_INFO
"3c501 reset...");
750 outb(AX_RESET
, AX_CMD
); /* Reset the chip */
751 outb(AX_LOOP
, AX_CMD
); /* Aux control, irq and loopback enabled */
754 for (i
= 0; i
< 6; i
++) /* Set the station address. */
755 outb(dev
->dev_addr
[i
], ioaddr
+ i
);
758 outw(0, RX_BUF_CLR
); /* Set rx packet area to 0. */
759 outb(TX_NORM
, TX_CMD
); /* tx irq on done, collision */
760 outb(RX_NORM
, RX_CMD
); /* Set Rx commands. */
761 inb(RX_STATUS
); /* Clear status. */
768 * @dev: 3c501 card to shut down
770 * Close a 3c501 card. The IFF_UP flag has been cleared by the user via
771 * the SIOCSIFFLAGS ioctl. We stop any further transmissions being queued,
772 * and then disable the interrupts. Finally we reset the chip. The effects
773 * of the rest will be cleaned up by #el1_open. Always returns 0 indicating
777 static int el1_close(struct net_device
*dev
)
779 int ioaddr
= dev
->base_addr
;
782 printk(KERN_INFO
"%s: Shutting down Ethernet card at %#x.\n",
785 netif_stop_queue(dev
);
788 * Free and disable the IRQ.
791 free_irq(dev
->irq
, dev
);
792 outb(AX_RESET
, AX_CMD
); /* Reset the chip */
798 * set_multicast_list:
799 * @dev: The device to adjust
801 * Set or clear the multicast filter for this adaptor to use the best-effort
802 * filtering supported. The 3c501 supports only three modes of filtering.
803 * It always receives broadcasts and packets for itself. You can choose to
804 * optionally receive all packets, or all multicast packets on top of this.
807 static void set_multicast_list(struct net_device
*dev
)
809 int ioaddr
= dev
->base_addr
;
811 if (dev
->flags
& IFF_PROMISC
) {
812 outb(RX_PROM
, RX_CMD
);
814 } else if (dev
->mc_list
|| dev
->flags
& IFF_ALLMULTI
) {
815 /* Multicast or all multicast is the same */
816 outb(RX_MULT
, RX_CMD
);
817 inb(RX_STATUS
); /* Clear status. */
819 outb(RX_NORM
, RX_CMD
);
825 static void netdev_get_drvinfo(struct net_device
*dev
,
826 struct ethtool_drvinfo
*info
)
828 strcpy(info
->driver
, DRV_NAME
);
829 strcpy(info
->version
, DRV_VERSION
);
830 sprintf(info
->bus_info
, "ISA 0x%lx", dev
->base_addr
);
833 static u32
netdev_get_msglevel(struct net_device
*dev
)
838 static void netdev_set_msglevel(struct net_device
*dev
, u32 level
)
843 static const struct ethtool_ops netdev_ethtool_ops
= {
844 .get_drvinfo
= netdev_get_drvinfo
,
845 .get_msglevel
= netdev_get_msglevel
,
846 .set_msglevel
= netdev_set_msglevel
,
851 static struct net_device
*dev_3c501
;
853 module_param(io
, int, 0);
854 module_param(irq
, int, 0);
855 MODULE_PARM_DESC(io
, "EtherLink I/O base address");
856 MODULE_PARM_DESC(irq
, "EtherLink IRQ number");
861 * When the driver is loaded as a module this function is called. We fake up
862 * a device structure with the base I/O and interrupt set as if it were being
863 * called from Space.c. This minimises the extra code that would otherwise
866 * Returns 0 for success or -EIO if a card is not found. Returning an error
867 * here also causes the module to be unloaded
870 int __init
init_module(void)
872 dev_3c501
= el1_probe(-1);
873 if (IS_ERR(dev_3c501
))
874 return PTR_ERR(dev_3c501
);
881 * The module is being unloaded. We unhook our network device from the system
882 * and then free up the resources we took when the card was found.
885 void __exit
cleanup_module(void)
887 struct net_device
*dev
= dev_3c501
;
888 unregister_netdev(dev
);
889 release_region(dev
->base_addr
, EL1_IO_EXTENT
);
895 MODULE_AUTHOR("Donald Becker, Alan Cox");
896 MODULE_DESCRIPTION("Support for the ancient 3Com 3c501 ethernet card");
897 MODULE_LICENSE("GPL");