/* skeleton.c: A network driver outline for linux. * * Written 1993-94 by 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. * * 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 * * This file is an outline for writing a network device driver for the * the Linux operating system. * * To write (or understand) a driver, have a look at the * "loopback.c" file to get a feel of what is going on, and then * use the code below as a skeleton for the new driver. */ static const char *version = "skeleton.c:v1.51 9/24/94 Donald Becker\n"; /* * Sources: * List your sources of programming information to document that * the driver is your own creation, and give due credit to others * that contributed to the work. Remember that GNU project code * cannot use proprietary or trade secret information. Interface * definitions are generally considered non-copyrightable to the * extent that the same names and structures must be used to be * compatible. * * Finally, keep in mind that the Linux kernel is has an API, not * ABI. Proprietary object-code-only distributions are not permitted * under the GPL. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * The name of the card. Is used for messages and in the requests for * io regions, irqs and dma channels */ static const char* cardname = "netcard"; /* First, a few definitions that the brave might change. */ /* A zero-terminated list of I/O addresses to be probed. */ static unsigned int netcard_portlist[] = { 0x200, 0x240, 0x280, 0x2C0, 0x300, 0x320, 0x340, 0}; /* use 0 for production, 1 for verification, >2 for debug */ #ifndef NET_DEBUG #define NET_DEBUG 2 #endif static unsigned int net_debug = NET_DEBUG; /* The number of low I/O ports used by the ethercard. */ #define NETCARD_IO_EXTENT 32 /* Information that need to be kept for each board. */ struct net_local { struct enet_statistics stats; long open_time; /* Useless example local info. */ }; /* The station (ethernet) address prefix, used for IDing the board. */ #define SA_ADDR0 0x00 #define SA_ADDR1 0x42 #define SA_ADDR2 0x65 /* Index to functions, as function prototypes. */ extern int netcard_probe(struct device *dev); static int netcard_probe1(struct device *dev, int ioaddr); static int net_open(struct device *dev); static int net_send_packet(struct sk_buff *skb, struct device *dev); static void net_interrupt(int irq, void *dev_id, struct pt_regs *regs); static void net_rx(struct device *dev); static int net_close(struct device *dev); static struct enet_statistics *net_get_stats(struct device *dev); static void set_multicast_list(struct device *dev); /* Example routines you must write ;->. */ #define tx_done(dev) 1 extern void hardware_send_packet(short ioaddr, char *buf, int length); extern void chipset_init(struct device *dev, int startp); /* * Check for a network adaptor of this type, and return '0' iff one exists. * If dev->base_addr == 0, probe all likely locations. * If dev->base_addr == 1, always return failure. * If dev->base_addr == 2, allocate space for the device and return success * (detachable devices only). */ #ifdef HAVE_DEVLIST /* * Support for a alternate probe manager, * which will eliminate the boilerplate below. */ struct netdev_entry netcard_drv = {cardname, netcard_probe1, NETCARD_IO_EXTENT, netcard_portlist}; #else int netcard_probe(struct device *dev) { int i; int base_addr = dev ? dev->base_addr : 0; if (base_addr > 0x1ff) /* Check a single specified location. */ return netcard_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, NETCARD_IO_EXTENT)) continue; if (netcard_probe1(dev, ioaddr) == 0) return 0; } return -ENODEV; } #endif /* * This is the real probe routine. Linux has a history of friendly * device probes on the ISA bus. A good device probes avoids doing * writes, and verifies that the correct device exists and functions. */ static int netcard_probe1(struct device *dev, int ioaddr) { static unsigned version_printed = 0; int i; /* * For ethernet adaptors the first three octets of the station * address contains the manufacturer's unique code. That might * be a good probe method. Ideally you would add additional * checks. */ if (inb(ioaddr + 0) != SA_ADDR0 || inb(ioaddr + 1) != SA_ADDR1 || inb(ioaddr + 2) != SA_ADDR2) { return -ENODEV; } /* Allocate a new 'dev' if needed. */ if (dev == NULL) { /* * Don't allocate the private data here, it is done * later This makes it easier to free the memory when * this driver is used as a module. */ dev = init_etherdev(0, 0); if (dev == NULL) return -ENOMEM; } if (net_debug && version_printed++ == 0) printk(KERN_DEBUG "%s", version); printk(KERN_INFO "%s: %s found at %#3x, ", dev->name, cardname, ioaddr); /* Fill in the 'dev' fields. */ dev->base_addr = ioaddr; /* Retrieve and print the ethernet address. */ for (i = 0; i < 6; i++) printk(" %2.2x", dev->dev_addr[i] = inb(ioaddr + i)); #ifdef jumpered_interrupts /* * If this board has jumpered interrupts, allocate the * interrupt vector now. There is no point in waiting since no * other device can use the interrupt, and this marks the irq * as busy. Jumpered interrupts are typically not reported by * the boards, and we must used autoIRQ to find them. */ if (dev->irq == -1) ; /* Do nothing: a user-level program will set it. */ else if (dev->irq < 2) { /* "Auto-IRQ" */ autoirq_setup(0); /* Trigger an interrupt here. */ dev->irq = autoirq_report(0); if (net_debug >= 2) printk(" autoirq is %d", dev->irq); } else if (dev->irq == 2) /* * Fixup for users that don't know that IRQ 2 is really * IRQ9, or don't know which one to set. */ dev->irq = 9; { int irqval = request_irq(dev->irq, &net_interrupt, 0, cardname, NULL); if (irqval) { printk("%s: unable to get IRQ %d (irqval=%d).\n", dev->name, dev->irq, irqval); return -EAGAIN; } } #endif /* jumpered interrupt */ #ifdef jumpered_dma /* * If we use a jumpered DMA channel, that should be probed for * and allocated here as well. See lance.c for an example. */ if (dev->dma == 0) { if (request_dma(dev->dma, cardname)) { printk("DMA %d allocation failed.\n", dev->dma); return -EAGAIN; } else printk(", assigned DMA %d.\n", dev->dma); } else { short dma_status, new_dma_status; /* Read the DMA channel status registers. */ dma_status = ((inb(DMA1_STAT_REG) >> 4) & 0x0f) | (inb(DMA2_STAT_REG) & 0xf0); /* Trigger a DMA request, perhaps pause a bit. */ outw(0x1234, ioaddr + 8); /* Re-read the DMA status registers. */ new_dma_status = ((inb(DMA1_STAT_REG) >> 4) & 0x0f) | (inb(DMA2_STAT_REG) & 0xf0); /* * Eliminate the old and floating requests, * and DMA4 the cascade. */ new_dma_status ^= dma_status; new_dma_status &= ~0x10; for (i = 7; i > 0; i--) if (test_bit(i, &new_dma_status)) { dev->dma = i; break; } if (i <= 0) { printk("DMA probe failed.\n"); return -EAGAIN; } if (request_dma(dev->dma, cardname)) { printk("probed DMA %d allocation failed.\n", dev->dma); return -EAGAIN; } } #endif /* jumpered DMA */ /* Initialize the device structure. */ if (dev->priv == NULL) { dev->priv = kmalloc(sizeof(struct net_local), GFP_KERNEL); if (dev->priv == NULL) return -ENOMEM; } memset(dev->priv, 0, sizeof(struct net_local)); /* * Grab the region so that no one else tries to probe * our ioports. */ request_region(ioaddr, NETCARD_IO_EXTENT, cardname); dev->open = net_open; dev->stop = net_close; dev->hard_start_xmit = net_send_packet; dev->get_stats = net_get_stats; dev->set_multicast_list = &set_multicast_list; /* * Fill in the fields of the device structure with * ethernet values. */ ether_setup(dev); return 0; } /* * Open/initialize the board. This is called (in the current kernel) * sometime after booting when the 'ifconfig' program is run. * * This routine should set everything up anew at each open, even * registers that "should" only need to be set once at boot, so that * there is non-reboot way to recover if something goes wrong. */ static int net_open(struct device *dev) { struct net_local *lp = (struct net_local *)dev->priv; int ioaddr = dev->base_addr; /* * This is used if the interrupt line can turned off (shared). * See 3c503.c for an example of selecting the IRQ at config-time. */ if (request_irq(dev->irq, &net_interrupt, 0, cardname, NULL)) { return -EAGAIN; } /* * Always allocate the DMA channel after the IRQ, * and clean up on failure. */ if (request_dma(dev->dma, cardname)) { free_irq(dev->irq, NULL); return -EAGAIN; } irq2dev_map[dev->irq] = dev; /* * Reset the hardware here. Don't forget to set the * station address. */ /*chipset_init(dev, 1);*/ outb(0x00, ioaddr); lp->open_time = jiffies; dev->tbusy = 0; dev->interrupt = 0; dev->start = 1; MOD_INC_USE_COUNT; return 0; } static int net_send_packet(struct sk_buff *skb, struct device *dev) { struct net_local *lp = (struct net_local *)dev->priv; int ioaddr = dev->base_addr; if (dev->tbusy) { /* * If we get here, some higher level has decided we * are broken. There should really be a "kick me" * function call instead. */ int tickssofar = jiffies - dev->trans_start; if (tickssofar < 5) return 1; printk(KERN_WARNING "%s: transmit timed out, %s?\n", dev->name, (tx_done(dev) ? "IRQ conflict" : "network cable problem")); /* Try to restart the adaptor. */ chipset_init(dev, 1); dev->tbusy=0; dev->trans_start = jiffies; } /* * If some higher layer thinks we've missed an tx-done * interrupt we are passed NULL. Caution: dev_tint() handles * the cli()/sti() itself. */ if (skb == NULL) { dev_tint(dev); return 0; } /* * Block a timer-based transmit from overlapping. This could * better be done with atomic_swap(1, dev->tbusy), but * set_bit() works as well. */ if (set_bit(0, (void*)&dev->tbusy) != 0) printk(KERN_WARNING "%s: Transmitter access conflict.\n", dev->name); else { short length = ETH_ZLEN < skb->len ? skb->len : ETH_ZLEN; unsigned char *buf = skb->data; hardware_send_packet(ioaddr, buf, length); dev->trans_start = jiffies; } dev_kfree_skb (skb, FREE_WRITE); /* You might need to clean up and record Tx statistics here. */ if (inw(ioaddr) == /*RU*/81) lp->stats.tx_aborted_errors++; return 0; } /* * The typical workload of the driver: * Handle the network interface interrupts. */ static void net_interrupt(int irq, void *dev_id, struct pt_regs * regs) { struct device *dev = (struct device *)(irq2dev_map[irq]); struct net_local *lp; int ioaddr, status, boguscount = 0; if (dev == NULL) { printk(KERN_WARNING "%s: irq %d for unknown device.\n", cardname, irq); return; } dev->interrupt = 1; ioaddr = dev->base_addr; lp = (struct net_local *)dev->priv; status = inw(ioaddr + 0); do { if (status /*& RX_INTR*/) { /* Got a packet(s). */ net_rx(dev); } if (status /*& TX_INTR*/) { lp->stats.tx_packets++; dev->tbusy = 0; mark_bh(NET_BH); /* Inform upper layers. */ } if (status /*& COUNTERS_INTR*/) { /* Increment the appropriate 'localstats' field. */ lp->stats.tx_window_errors++; } } while (++boguscount < 20) ; dev->interrupt = 0; return; } /* We have a good packet(s), get it/them out of the buffers. */ static void net_rx(struct device *dev) { struct net_local *lp = (struct net_local *)dev->priv; int ioaddr = dev->base_addr; int boguscount = 10; do { int status = inw(ioaddr); int pkt_len = inw(ioaddr); if (pkt_len == 0) /* Read all the frames? */ break; /* Done for now */ if (status & 0x40) { /* There was an error. */ lp->stats.rx_errors++; if (status & 0x20) lp->stats.rx_frame_errors++; if (status & 0x10) lp->stats.rx_over_errors++; if (status & 0x08) lp->stats.rx_crc_errors++; if (status & 0x04) lp->stats.rx_fifo_errors++; } else { /* Malloc up new buffer. */ struct sk_buff *skb; skb = dev_alloc_skb(pkt_len); if (skb == NULL) { printk(KERN_NOTICE "%s: Memory squeeze, " "dropping packet.\n", dev->name); lp->stats.rx_dropped++; break; } skb->dev = dev; /* * 'skb->data' points to the start of sk_buff * data area. */ memcpy(skb_put(skb,pkt_len), (void*)dev->rmem_start, pkt_len); /* or */ insw(ioaddr, skb->data, (pkt_len + 1) >> 1); netif_rx(skb); lp->stats.rx_packets++; } } while (--boguscount); /* * If any worth-while packets have been received, dev_rint() * has done a mark_bh(NET_BH) for us and will work on them * when we get to the bottom-half routine. */ return; } /* The inverse routine to net_open(). */ static int net_close(struct device *dev) { struct net_local *lp = (struct net_local *)dev->priv; int ioaddr = dev->base_addr; lp->open_time = 0; dev->tbusy = 1; dev->start = 0; /* Flush the Tx and disable Rx here. */ disable_dma(dev->dma); /* If not IRQ or DMA jumpered, free up the line. */ outw(0x00, ioaddr+0); /* Release the physical interrupt line. */ free_irq(dev->irq, NULL); free_dma(dev->dma); irq2dev_map[dev->irq] = 0; /* Update the statistics here. */ MOD_DEC_USE_COUNT; return 0; } /* * Get the current statistics. * This may be called with the card open or closed. */ static struct enet_statistics * net_get_stats(struct device *dev) { struct net_local *lp = (struct net_local *)dev->priv; short ioaddr = dev->base_addr; cli(); /* Update the statistics from the device registers. */ lp->stats.rx_missed_errors = inw(ioaddr+1); sti(); 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) { short ioaddr = dev->base_addr; if (dev->flags&IFF_PROMISC) { /* Enable promiscuous mode */ outw(MULTICAST|PROMISC, ioaddr); } else if((dev->flags&IFF_ALLMULTI) || dev->mc_count > HW_MAX_ADDRS) { /* Disable promiscuous mode, use normal mode. */ hardware_set_filter(NULL); outw(MULTICAST, ioaddr); } else if(dev->mc_count) { /* Walk the address list, and load the filter */ hardware_set_filter(dev->mc_list); outw(MULTICAST, ioaddr); } else outw(0, ioaddr); } #ifdef MODULE static char devicename[9] = { 0, }; static struct device this_device = { devicename, /* will be inserted by linux/drivers/net/net_init.c */ 0, 0, 0, 0, 0, 0, /* I/O address, IRQ */ 0, 0, 0, NULL, netcard_probe }; static int io = 0x300; static int irq = 0; static int dma = 0; static int mem = 0; int init_module(void) { int result; if (io == 0) printk(KERN_WARNING "%s: You shouldn't use " "auto-probing with insmod!\n", cardname); /* Copy the parameters from insmod into the device structure. */ this_device.base_addr = io; this_device.irq = irq; this_device.dma = dma; this_device.mem_start = mem; if ((result = register_netdev(&this_device)) != 0) return result; return 0; } void cleanup_module(void) { /* No need to check MOD_IN_USE, as sys_delete_module() checks. */ unregister_netdev(&this_device); /* * If we don't do this, we can't re-insmod it later. * Release irq/dma here, when you have jumpered versions and * allocate them in net_probe1(). */ /* free_irq(this_device.irq, NULL); free_dma(this_device.dma); */ release_region(this_device.base_addr, NETCARD_IO_EXTENT); if (this_device.priv) kfree_s(this_device.priv, sizeof(struct net_local)); } #endif /* MODULE */ /* * Local variables: * compile-command: * gcc -D__KERNEL__ -Wall -Wstrict-prototypes -Wwrite-strings * -Wredundant-decls -O2 -m486 -c skeleton.c * version-control: t * kept-new-versions: 5 * tab-width: 4 * c-indent-level: 4 * End: */