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- /* 3c501.c: A 3Com 3c501 ethernet driver for linux. */
- /*
- Written 1992,1993,1994 Donald Becker
-
- Copyright 1993 United States Government as represented by the
- Director, National Security Agency. This software may be used and
- distributed according to the terms of the GNU Public License,
- incorporated herein by reference.
-
- This is a device driver for the 3Com Etherlink 3c501.
- Do not purchase this card, even as a joke. It's performance is horrible,
- and it breaks in many ways.
-
- The author may be reached as becker@CESDIS.gsfc.nasa.gov, or C/O
- Center of Excellence in Space Data and Information Sciences
- Code 930.5, Goddard Space Flight Center, Greenbelt MD 20771
-
- Fixed (again!) the missing interrupt locking on TX/RX shifting.
- Alan Cox <Alan.Cox@linux.org>
-
- Some notes on this thing if you have to hack it. [Alan]
-
- 1] Some documentation is available from 3Com. Due to the boards age
- standard responses when you ask for this will range from 'be serious'
- to 'give it to a museum'. The documentation is incomplete and mostly
- of historical interest anyway.
-
- 2] The basic system is a single buffer which can be used to receive or
- transmit a packet. A third command mode exists when you are setting
- things up.
-
- 3] If it's transmitting it's not receiving and vice versa. In fact the
- time to get the board back into useful state after an operation is
- quite large.
-
- 4] The driver works by keeping the board in receive mode waiting for a
- packet to arrive. When one arrives it is copied out of the buffer
- and delivered to the kernel. The card is reloaded and off we go.
-
- 5] When transmitting dev->tbusy is set and the card is reset (from
- receive mode) [possibly losing a packet just received] to command
- mode. A packet is loaded and transmit mode triggered. The interrupt
- handler runs different code for transmit interrupts and can handle
- returning to receive mode or retransmissions (yes you have to help
- out with those too).
-
- Problems:
- There are a wide variety of undocumented error returns from the card
- and you basically have to kick the board and pray if they turn up. Most
- only occur under extreme load or if you do something the board doesn't
- like (eg touching a register at the wrong time).
-
- The driver is less efficient than it could be. It switches through
- receive mode even if more transmits are queued. If this worries you buy
- a real ethernet card.
-
- The combination of slow receive restart and no real multicast
- filter makes the board unusable with a kernel compiled for IP
- multicasting in a real multicast environment. Thats down to the board,
- but even with no multicast programs running a multicast IP kernel is
- in group 224.0.0.1 and you will therefore be listening to all multicasts.
- One nv conference running over that ethernet and you can give up.
-
- 2/8/95 (invid@msen.com)
-
- Removed calls to init_etherdev since they are no longer needed, and
- cleaned up modularization just a bit. The driver still allows only
- the default address for cards when loaded as a module, but that's
- really less braindead than anyone using a 3c501 board. :)
- */
-
- static char *version =
- "3c501.c: 9/23/94 Donald Becker (becker@cesdis.gsfc.nasa.gov).\n";
-
- /*
- Braindamage remaining:
- The 3c501 board.
- */
-
- #include <linux/config.h>
- #ifdef MODULE
- #include <linux/module.h>
- #include <linux/version.h>
- #else
- #define MOD_INC_USE_COUNT
- #define MOD_DEC_USE_COUNT
- #endif
-
- #include <linux/kernel.h>
- #include <linux/sched.h>
- #include <linux/ptrace.h>
- #include <linux/fcntl.h>
- #include <linux/ioport.h>
- #include <linux/interrupt.h>
- #include <linux/malloc.h>
- #include <linux/string.h>
- #include <linux/ioport.h>
- #include <linux/errno.h>
-
- #include <asm/bitops.h>
- #include <asm/io.h>
-
- #include <linux/netdevice.h>
- #include <linux/etherdevice.h>
- #include <linux/skbuff.h>
-
- /* A zero-terminated list of I/O addresses to be probed.
- The 3c501 can be at many locations, but here are the popular ones. */
- static unsigned int netcard_portlist[] =
- { 0x280, 0x300, 0};
-
-
- /* Index to functions. */
- int el1_probe(struct device *dev);
- static int el1_probe1(struct device *dev, int ioaddr);
- static int el_open(struct device *dev);
- static int el_start_xmit(struct sk_buff *skb, struct device *dev);
- static void el_interrupt(int irq, struct pt_regs *regs);
- static void el_receive(struct device *dev);
- static void el_reset(struct device *dev);
- static int el1_close(struct device *dev);
- static struct enet_statistics *el1_get_stats(struct device *dev);
- static void set_multicast_list(struct device *dev, int num_addrs, void *addrs);
-
- #define EL1_IO_EXTENT 16
-
- #ifndef EL_DEBUG
- #define EL_DEBUG 2 /* use 0 for production, 1 for devel., >2 for debug */
- #endif /* Anything above 5 is wordy death! */
- static int el_debug = EL_DEBUG;
-
- /* Board-specific info in dev->priv. */
- struct net_local {
- struct enet_statistics stats;
- int tx_pkt_start; /* The length of the current Tx packet. */
- int collisions; /* Tx collisions this packet */
- };
-
-
- #define RX_STATUS (ioaddr + 0x06)
- #define RX_CMD RX_STATUS
- #define TX_STATUS (ioaddr + 0x07)
- #define TX_CMD TX_STATUS
- #define GP_LOW (ioaddr + 0x08)
- #define GP_HIGH (ioaddr + 0x09)
- #define RX_BUF_CLR (ioaddr + 0x0A)
- #define RX_LOW (ioaddr + 0x0A)
- #define RX_HIGH (ioaddr + 0x0B)
- #define SAPROM (ioaddr + 0x0C)
- #define AX_STATUS (ioaddr + 0x0E)
- #define AX_CMD AX_STATUS
- #define DATAPORT (ioaddr + 0x0F)
- #define TX_RDY 0x08 /* In TX_STATUS */
-
- #define EL1_DATAPTR 0x08
- #define EL1_RXPTR 0x0A
- #define EL1_SAPROM 0x0C
- #define EL1_DATAPORT 0x0f
-
- /* Writes to the ax command register. */
- #define AX_OFF 0x00 /* Irq off, buffer access on */
- #define AX_SYS 0x40 /* Load the buffer */
- #define AX_XMIT 0x44 /* Transmit a packet */
- #define AX_RX 0x48 /* Receive a packet */
- #define AX_LOOP 0x0C /* Loopback mode */
- #define AX_RESET 0x80
-
- /* Normal receive mode written to RX_STATUS. We must intr on short packets
- to avoid bogus rx lockups. */
- #define RX_NORM 0xA8 /* 0x68 == all addrs, 0xA8 only to me. */
- #define RX_PROM 0x68 /* Senior Prom, uhmm promiscuous mode. */
- #define RX_MULT 0xE8 /* Accept multicast packets. */
- #define TX_NORM 0x0A /* Interrupt on everything that might hang the chip */
-
- /* TX_STATUS register. */
- #define TX_COLLISION 0x02
- #define TX_16COLLISIONS 0x04
- #define TX_READY 0x08
-
- #define RX_RUNT 0x08
- #define RX_MISSED 0x01 /* Missed a packet due to 3c501 braindamage. */
- #define RX_GOOD 0x30 /* Good packet 0x20, or simple overflow 0x10. */
-
-
- /* The boilerplate probe code. */
- #ifdef HAVE_DEVLIST
- struct netdev_entry el1_drv =
- {"3c501", el1_probe1, EL1_IO_EXTENT, netcard_portlist};
- #else
- int
- el1_probe(struct device *dev)
- {
- int i;
- int base_addr = dev ? dev->base_addr : 0;
-
- if (base_addr > 0x1ff) /* Check a single specified location. */
- return el1_probe1(dev, base_addr);
- else if (base_addr != 0) /* Don't probe at all. */
- return ENXIO;
-
- for (i = 0; netcard_portlist[i]; i++) {
- int ioaddr = netcard_portlist[i];
- if (check_region(ioaddr, EL1_IO_EXTENT))
- continue;
- if (el1_probe1(dev, ioaddr) == 0)
- return 0;
- }
-
- return ENODEV;
- }
- #endif
-
- /* The actual probe. */
- static int
- el1_probe1(struct device *dev, int ioaddr)
- {
- #ifndef MODULE
-
- char *mname; /* Vendor name */
- unsigned char station_addr[6];
- int autoirq = 0;
- int i;
-
- /* Read the station address PROM data from the special port. */
- for (i = 0; i < 6; i++) {
- outw(i, ioaddr + EL1_DATAPTR);
- station_addr[i] = inb(ioaddr + EL1_SAPROM);
- }
- /* Check the first three octets of the S.A. for 3Com's prefix, or
- for the Sager NP943 prefix. */
- if (station_addr[0] == 0x02 && station_addr[1] == 0x60
- && station_addr[2] == 0x8c) {
- mname = "3c501";
- } else if (station_addr[0] == 0x00 && station_addr[1] == 0x80
- && station_addr[2] == 0xC8) {
- mname = "NP943";
- } else
- return ENODEV;
-
- /* Grab the region so we can find the another board if autoIRQ fails. */
- request_region(ioaddr, EL1_IO_EXTENT,"3c501");
-
- /* We auto-IRQ by shutting off the interrupt line and letting it float
- high. */
- if (dev->irq < 2) {
-
- autoirq_setup(2);
-
- inb(RX_STATUS); /* Clear pending interrupts. */
- inb(TX_STATUS);
- outb(AX_LOOP + 1, AX_CMD);
-
- outb(0x00, AX_CMD);
-
- autoirq = autoirq_report(1);
-
- if (autoirq == 0) {
- printk("%s probe at %#x failed to detect IRQ line.\n",
- mname, ioaddr);
- return EAGAIN;
- }
- }
-
- outb(AX_RESET+AX_LOOP, AX_CMD); /* Loopback mode. */
-
- dev->base_addr = ioaddr;
- memcpy(dev->dev_addr, station_addr, ETH_ALEN);
- if (dev->mem_start & 0xf)
- el_debug = dev->mem_start & 0x7;
- if (autoirq)
- dev->irq = autoirq;
-
- printk("%s: %s EtherLink at %#lx, using %sIRQ %d.\n",
- dev->name, mname, dev->base_addr,
- autoirq ? "auto":"assigned ", dev->irq);
-
- #ifdef CONFIG_IP_MULTICAST
- printk("WARNING: Use of the 3c501 in a multicast kernel is NOT recommended.\n");
- #endif
-
- if (el_debug)
- printk("%s", version);
-
- /* Initialize the device structure. */
- if (dev->priv == NULL)
- dev->priv = kmalloc(sizeof(struct net_local), GFP_KERNEL);
- memset(dev->priv, 0, sizeof(struct net_local));
-
- /* The EL1-specific entries in the device structure. */
- dev->open = &el_open;
- dev->hard_start_xmit = &el_start_xmit;
- dev->stop = &el1_close;
- dev->get_stats = &el1_get_stats;
- dev->set_multicast_list = &set_multicast_list;
- /* Setup the generic properties */
- ether_setup(dev);
-
- #endif /* !MODULE */
- return 0;
- }
-
- /* Open/initialize the board. */
- static int
- el_open(struct device *dev)
- {
- int ioaddr = dev->base_addr;
-
- if (el_debug > 2)
- printk("%s: Doing el_open()...", dev->name);
-
- if (request_irq(dev->irq, &el_interrupt, 0, "3c501")) {
- return -EAGAIN;
- }
- irq2dev_map[dev->irq] = dev;
-
- el_reset(dev);
-
- dev->start = 1;
-
- outb(AX_RX, AX_CMD); /* Aux control, irq and receive enabled */
- MOD_INC_USE_COUNT;
- return 0;
- }
-
- static int
- el_start_xmit(struct sk_buff *skb, struct device *dev)
- {
- struct net_local *lp = (struct net_local *)dev->priv;
- int ioaddr = dev->base_addr;
- unsigned long flags;
-
- if (dev->tbusy) {
- if (jiffies - dev->trans_start < 20) {
- if (el_debug > 2)
- printk(" transmitter busy, deferred.\n");
- return 1;
- }
- if (el_debug)
- printk ("%s: transmit timed out, txsr %#2x axsr=%02x rxsr=%02x.\n",
- dev->name, inb(TX_STATUS), inb(AX_STATUS), inb(RX_STATUS));
- lp->stats.tx_errors++;
- outb(TX_NORM, TX_CMD);
- outb(RX_NORM, RX_CMD);
- outb(AX_OFF, AX_CMD); /* Just trigger a false interrupt. */
- outb(AX_RX, AX_CMD); /* Aux control, irq and receive enabled */
- dev->tbusy = 0;
- dev->trans_start = jiffies;
- }
-
- if (skb == NULL) {
- dev_tint(dev);
- return 0;
- }
-
- save_flags(flags);
- /* Avoid incoming interrupts between us flipping tbusy and flipping
- mode as the driver assumes tbusy is a faithful indicator of card
- state */
- cli();
- /* Avoid timer-based retransmission conflicts. */
- if (set_bit(0, (void*)&dev->tbusy) != 0)
- {
- restore_flags(flags);
- printk("%s: Transmitter access conflict.\n", dev->name);
- }
- else {
- int gp_start = 0x800 - (ETH_ZLEN < skb->len ? skb->len : ETH_ZLEN);
- unsigned char *buf = skb->data;
-
- lp->tx_pkt_start = gp_start;
- lp->collisions = 0;
-
- /*
- * Command mode with status cleared should [in theory]
- * mean no more interrupts can be pending on the card.
- */
- outb(AX_SYS, AX_CMD);
- inb(RX_STATUS);
- inb(TX_STATUS);
- /*
- * Turn interrupts back on while we spend a pleasant afternoon
- * loading bytes into the board
- */
- restore_flags(flags);
- outw(0x00, RX_BUF_CLR); /* Set rx packet area to 0. */
- outw(gp_start, GP_LOW); /* aim - packet will be loaded into buffer start */
- outsb(DATAPORT,buf,skb->len); /* load buffer (usual thing each byte increments the pointer) */
- outw(gp_start, GP_LOW); /* the board reuses the same register */
- outb(AX_XMIT, AX_CMD); /* fire ... Trigger xmit. */
- dev->trans_start = jiffies;
- }
-
- if (el_debug > 2)
- printk(" queued xmit.\n");
- dev_kfree_skb (skb, FREE_WRITE);
- return 0;
- }
-
-
- /* The typical workload of the driver:
- Handle the ether interface interrupts. */
- static void
- el_interrupt(int irq, struct pt_regs *regs)
- {
- struct device *dev = (struct device *)(irq2dev_map[irq]);
- struct net_local *lp;
- int ioaddr;
- int axsr; /* Aux. status reg. */
-
- if (dev == NULL || dev->irq != irq) {
- printk ("3c501 driver: irq %d for unknown device.\n", irq);
- return;
- }
-
- ioaddr = dev->base_addr;
- lp = (struct net_local *)dev->priv;
- axsr = inb(AX_STATUS);
-
- if (el_debug > 3)
- printk("%s: el_interrupt() aux=%#02x", dev->name, axsr);
- if (dev->interrupt)
- printk("%s: Reentering the interrupt driver!\n", dev->name);
- dev->interrupt = 1;
-
- if (dev->tbusy) {
-
- /*
- * Board in transmit mode.
- */
-
- int txsr = inb(TX_STATUS);
-
- if (el_debug > 6)
- printk(" txsr=%02x gp=%04x rp=%04x", txsr, inw(GP_LOW),
- inw(RX_LOW));
-
- if ((axsr & 0x80) && (txsr & TX_READY) == 0) {
- /*
- * FIXME: is there a logic to whether to keep on trying or
- * reset immediately ?
- */
- printk("%s: Unusual interrupt during Tx, txsr=%02x axsr=%02x"
- " gp=%03x rp=%03x.\n", dev->name, txsr, axsr,
- inw(ioaddr + EL1_DATAPTR), inw(ioaddr + EL1_RXPTR));
- dev->tbusy = 0;
- mark_bh(NET_BH);
- } else if (txsr & TX_16COLLISIONS) {
- /*
- * Timed out
- */
- if (el_debug)
- printk("%s: Transmit failed 16 times, ethernet jammed?\n",
- dev->name);
- outb(AX_SYS, AX_CMD);
- lp->stats.tx_aborted_errors++;
- } else if (txsr & TX_COLLISION) { /* Retrigger xmit. */
- if (el_debug > 6)
- printk(" retransmitting after a collision.\n");
- /*
- * Poor little chip can't reset its own start pointer
- */
- outb(AX_SYS, AX_CMD);
- outw(lp->tx_pkt_start, GP_LOW);
- outb(AX_XMIT, AX_CMD);
- lp->stats.collisions++;
- dev->interrupt = 0;
- return;
- } else {
- /*
- * It worked.. we will now fall through and receive
- */
- lp->stats.tx_packets++;
- if (el_debug > 6)
- printk(" Tx succeeded %s\n",
- (txsr & TX_RDY) ? "." : "but tx is busy!");
- /*
- * This is safe the interrupt is atomic WRT itself.
- */
- dev->tbusy = 0;
- mark_bh(NET_BH); /* In case more to transmit */
- }
- } else {
-
- /*
- * In receive mode.
- */
-
- int rxsr = inb(RX_STATUS);
- if (el_debug > 5)
- printk(" rxsr=%02x txsr=%02x rp=%04x", rxsr, inb(TX_STATUS),
- inw(RX_LOW));
-
- /*
- * Just reading rx_status fixes most errors.
- */
- if (rxsr & RX_MISSED)
- lp->stats.rx_missed_errors++;
- if (rxsr & RX_RUNT) { /* Handled to avoid board lock-up. */
- lp->stats.rx_length_errors++;
- if (el_debug > 5) printk(" runt.\n");
- } else if (rxsr & RX_GOOD) {
- /*
- * Receive worked.
- */
- el_receive(dev);
- } else { /* Nothing? Something is broken! */
- if (el_debug > 2)
- printk("%s: No packet seen, rxsr=%02x **resetting 3c501***\n",
- dev->name, rxsr);
- el_reset(dev);
- }
- if (el_debug > 3)
- printk(".\n");
- }
-
- /*
- * Move into receive mode
- */
- outb(AX_RX, AX_CMD);
- outw(0x00, RX_BUF_CLR);
- inb(RX_STATUS); /* Be certain that interrupts are cleared. */
- inb(TX_STATUS);
- dev->interrupt = 0;
- return;
- }
-
-
- /* We have a good packet. Well, not really "good", just mostly not broken.
- We must check everything to see if it is good. */
- static void
- el_receive(struct device *dev)
- {
- struct net_local *lp = (struct net_local *)dev->priv;
- int ioaddr = dev->base_addr;
- int pkt_len;
- struct sk_buff *skb;
-
- pkt_len = inw(RX_LOW);
-
- if (el_debug > 4)
- printk(" el_receive %d.\n", pkt_len);
-
- if ((pkt_len < 60) || (pkt_len > 1536)) {
- if (el_debug)
- printk("%s: bogus packet, length=%d\n", dev->name, pkt_len);
- lp->stats.rx_over_errors++;
- return;
- }
-
- /*
- * Command mode so we can empty the buffer
- */
-
- outb(AX_SYS, AX_CMD);
-
- skb = alloc_skb(pkt_len, GFP_ATOMIC);
- /*
- * Start of frame
- */
- outw(0x00, GP_LOW);
- if (skb == NULL) {
- printk("%s: Memory squeeze, dropping packet.\n", dev->name);
- lp->stats.rx_dropped++;
- return;
- } else {
- skb->len = pkt_len;
- skb->dev = dev;
-
- /*
- * The read increments through the bytes. The interrupt
- * handler will fix the pointer when it returns to
- * receive mode.
- */
-
- insb(DATAPORT, skb->data, pkt_len);
-
- netif_rx(skb);
- lp->stats.rx_packets++;
- }
- return;
- }
-
- static void
- el_reset(struct device *dev)
- {
- int ioaddr = dev->base_addr;
-
- if (el_debug> 2)
- printk("3c501 reset...");
- outb(AX_RESET, AX_CMD); /* Reset the chip */
- outb(AX_LOOP, AX_CMD); /* Aux control, irq and loopback enabled */
- {
- int i;
- for (i = 0; i < 6; i++) /* Set the station address. */
- outb(dev->dev_addr[i], ioaddr + i);
- }
-
- outw(0, RX_BUF_CLR); /* Set rx packet area to 0. */
- cli(); /* Avoid glitch on writes to CMD regs */
- outb(TX_NORM, TX_CMD); /* tx irq on done, collision */
- outb(RX_NORM, RX_CMD); /* Set Rx commands. */
- inb(RX_STATUS); /* Clear status. */
- inb(TX_STATUS);
- dev->interrupt = 0;
- dev->tbusy = 0;
- sti();
- }
-
- static int
- el1_close(struct device *dev)
- {
- int ioaddr = dev->base_addr;
-
- if (el_debug > 2)
- printk("%s: Shutting down ethercard at %#x.\n", dev->name, ioaddr);
-
- dev->tbusy = 1;
- dev->start = 0;
-
- /* Free and disable the IRQ. */
- free_irq(dev->irq);
- outb(AX_RESET, AX_CMD); /* Reset the chip */
- irq2dev_map[dev->irq] = 0;
-
- MOD_DEC_USE_COUNT;
- return 0;
- }
-
- static struct enet_statistics *
- el1_get_stats(struct device *dev)
- {
- struct net_local *lp = (struct net_local *)dev->priv;
- return &lp->stats;
- }
-
- /* Set or clear the multicast filter for this adaptor.
- num_addrs == -1 Promiscuous mode, receive all packets
- num_addrs == 0 Normal mode, clear multicast list
- num_addrs > 0 Multicast mode, receive normal and MC packets, and do
- best-effort filtering.
- */
- static void
- set_multicast_list(struct device *dev, int num_addrs, void *addrs)
- {
- int ioaddr = dev->base_addr;
-
- if (num_addrs > 0) {
- outb(RX_MULT, RX_CMD);
- inb(RX_STATUS); /* Clear status. */
- } else if (num_addrs < 0) {
- outb(RX_PROM, RX_CMD);
- inb(RX_STATUS);
- } else {
- outb(RX_NORM, RX_CMD);
- inb(RX_STATUS);
- }
- }
- #ifdef MODULE
- char kernel_version[] = UTS_RELEASE;
- static struct device dev_3c501 = {
- " " /*"3c501"*/,
- 0, 0, 0, 0,
- 0x280, 5,
- 0, 0, 0, NULL, el1_probe };
-
- int io=0x280;
- int irq=5;
-
- int
- init_module(void)
- {
- dev_3c501.irq=irq;
- dev_3c501.base_addr=io;
- if (register_netdev(&dev_3c501) != 0)
- return -EIO;
- return 0;
- }
-
- void
- cleanup_module(void)
- {
- /* No need to check MOD_IN_USE, as sys_delete_module() checks. */
- unregister_netdev(&dev_3c501);
-
- /* Free up the private structure, or leak memory :-) */
- kfree(dev_3c501.priv);
- dev_3c501.priv = NULL; /* gets re-allocated by el1_probe1 */
-
- /* If we don't do this, we can't re-insmod it later. */
- release_region(dev_3c501.base_addr, EL1_IO_EXTENT);
- }
- #endif /* MODULE */
-
- /*
- * Local variables:
- * compile-command: "gcc -D__KERNEL__ -Wall -Wstrict-prototypes -O6 -fomit-frame-pointer -m486 -c -o 3c501.o 3c501.c"
- * kept-new-versions: 5
- * End:
- */
-