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Diffstat (limited to 'drivers/net/isa-skeleton.c')
| -rw-r--r-- | drivers/net/isa-skeleton.c | 724 |
1 files changed, 724 insertions, 0 deletions
diff --git a/drivers/net/isa-skeleton.c b/drivers/net/isa-skeleton.c new file mode 100644 index 00000000000..50bebb55e9e --- /dev/null +++ b/drivers/net/isa-skeleton.c @@ -0,0 +1,724 @@ +/* isa-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 General Public License, incorporated herein by reference. + * + * The author may be reached as becker@scyld.com, or C/O + * Scyld Computing Corporation + * 410 Severn Ave., Suite 210 + * Annapolis MD 21403 + * + * 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 = + "isa-skeleton.c:v1.51 9/24/94 Donald Becker (becker@cesdis.gsfc.nasa.gov)\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 <linux/module.h> +#include <linux/kernel.h> +#include <linux/types.h> +#include <linux/fcntl.h> +#include <linux/interrupt.h> +#include <linux/ioport.h> +#include <linux/in.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/spinlock.h> +#include <linux/errno.h> +#include <linux/init.h> +#include <linux/netdevice.h> +#include <linux/etherdevice.h> +#include <linux/skbuff.h> +#include <linux/bitops.h> + +#include <asm/system.h> +#include <asm/io.h> +#include <asm/dma.h> + +/* + * 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[] __initdata = + { 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 + +#define MY_TX_TIMEOUT ((400*HZ)/1000) + +/* Information that need to be kept for each board. */ +struct net_local { + struct net_device_stats stats; + long open_time; /* Useless example local info. */ + + /* Tx control lock. This protects the transmit buffer ring + * state along with the "tx full" state of the driver. This + * means all netif_queue flow control actions are protected + * by this lock as well. + */ + spinlock_t lock; +}; + +/* 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. */ + +static int netcard_probe1(struct net_device *dev, int ioaddr); +static int net_open(struct net_device *dev); +static int net_send_packet(struct sk_buff *skb, struct net_device *dev); +static irqreturn_t net_interrupt(int irq, void *dev_id, struct pt_regs *regs); +static void net_rx(struct net_device *dev); +static int net_close(struct net_device *dev); +static struct net_device_stats *net_get_stats(struct net_device *dev); +static void set_multicast_list(struct net_device *dev); +static void net_tx_timeout(struct net_device *dev); + + +/* Example routines you must write ;->. */ +#define tx_done(dev) 1 +static void hardware_send_packet(short ioaddr, char *buf, int length); +static void chipset_init(struct net_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). + */ +static int __init do_netcard_probe(struct net_device *dev) +{ + int i; + int base_addr = dev->base_addr; + int irq = dev->irq; + + SET_MODULE_OWNER(dev); + + 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 (netcard_probe1(dev, ioaddr) == 0) + return 0; + dev->irq = irq; + } + + return -ENODEV; +} + +static void cleanup_card(struct net_device *dev) +{ +#ifdef jumpered_dma + free_dma(dev->dma); +#endif +#ifdef jumpered_interrupts + free_irq(dev->irq, dev); +#endif + release_region(dev->base_addr, NETCARD_IO_EXTENT); +} + +#ifndef MODULE +struct net_device * __init netcard_probe(int unit) +{ + struct net_device *dev = alloc_etherdev(sizeof(struct net_local)); + int err; + + if (!dev) + return ERR_PTR(-ENOMEM); + + sprintf(dev->name, "eth%d", unit); + netdev_boot_setup_check(dev); + + err = do_netcard_probe(dev); + if (err) + goto out; + err = register_netdev(dev); + if (err) + goto out1; + return dev; +out1: + cleanup_card(dev); +out: + free_netdev(dev); + return ERR_PTR(err); +} +#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 __init netcard_probe1(struct net_device *dev, int ioaddr) +{ + struct net_local *np; + static unsigned version_printed; + int i; + int err = -ENODEV; + + /* Grab the region so that no one else tries to probe our ioports. */ + if (!request_region(ioaddr, NETCARD_IO_EXTENT, cardname)) + return -EBUSY; + + /* + * 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) + goto out; + + 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)); + + err = -EAGAIN; +#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" */ + unsigned long irq_mask = probe_irq_on(); + /* Trigger an interrupt here. */ + + dev->irq = probe_irq_off(irq_mask); + 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, dev); + if (irqval) { + printk("%s: unable to get IRQ %d (irqval=%d).\n", + dev->name, dev->irq, irqval); + goto out; + } + } +#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); + goto out1; + } 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"); + goto out1; + } + if (request_dma(dev->dma, cardname)) { + printk("probed DMA %d allocation failed.\n", dev->dma); + goto out1; + } + } +#endif /* jumpered DMA */ + + np = netdev_priv(dev); + spin_lock_init(&np->lock); + + 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; + + dev->tx_timeout = &net_tx_timeout; + dev->watchdog_timeo = MY_TX_TIMEOUT; + return 0; +out1: +#ifdef jumpered_interrupts + free_irq(dev->irq, dev); +#endif +out: + release_region(base_addr, NETCARD_IO_EXTENT); + return err; +} + +static void net_tx_timeout(struct net_device *dev) +{ + struct net_local *np = netdev_priv(dev); + + 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); + + np->stats.tx_errors++; + + /* If we have space available to accept new transmit + * requests, wake up the queueing layer. This would + * be the case if the chipset_init() call above just + * flushes out the tx queue and empties it. + * + * If instead, the tx queue is retained then the + * netif_wake_queue() call should be placed in the + * TX completion interrupt handler of the driver instead + * of here. + */ + if (!tx_full(dev)) + netif_wake_queue(dev); +} + +/* + * 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 net_device *dev) +{ + struct net_local *np = netdev_priv(dev); + 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, dev)) { + 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, dev); + return -EAGAIN; + } + + /* Reset the hardware here. Don't forget to set the station address. */ + chipset_init(dev, 1); + outb(0x00, ioaddr); + np->open_time = jiffies; + + /* We are now ready to accept transmit requeusts from + * the queueing layer of the networking. + */ + netif_start_queue(dev); + + return 0; +} + +/* This will only be invoked if your driver is _not_ in XOFF state. + * What this means is that you need not check it, and that this + * invariant will hold if you make sure that the netif_*_queue() + * calls are done at the proper times. + */ +static int net_send_packet(struct sk_buff *skb, struct net_device *dev) +{ + struct net_local *np = netdev_priv(dev); + int ioaddr = dev->base_addr; + short length = ETH_ZLEN < skb->len ? skb->len : ETH_ZLEN; + unsigned char *buf = skb->data; + + /* If some error occurs while trying to transmit this + * packet, you should return '1' from this function. + * In such a case you _may not_ do anything to the + * SKB, it is still owned by the network queueing + * layer when an error is returned. This means you + * may not modify any SKB fields, you may not free + * the SKB, etc. + */ + +#if TX_RING + /* This is the most common case for modern hardware. + * The spinlock protects this code from the TX complete + * hardware interrupt handler. Queue flow control is + * thus managed under this lock as well. + */ + spin_lock_irq(&np->lock); + + add_to_tx_ring(np, skb, length); + dev->trans_start = jiffies; + + /* If we just used up the very last entry in the + * TX ring on this device, tell the queueing + * layer to send no more. + */ + if (tx_full(dev)) + netif_stop_queue(dev); + + /* When the TX completion hw interrupt arrives, this + * is when the transmit statistics are updated. + */ + + spin_unlock_irq(&np->lock); +#else + /* This is the case for older hardware which takes + * a single transmit buffer at a time, and it is + * just written to the device via PIO. + * + * No spin locking is needed since there is no TX complete + * event. If by chance your card does have a TX complete + * hardware IRQ then you may need to utilize np->lock here. + */ + hardware_send_packet(ioaddr, buf, length); + np->stats.tx_bytes += skb->len; + + dev->trans_start = jiffies; + + /* You might need to clean up and record Tx statistics here. */ + if (inw(ioaddr) == /*RU*/81) + np->stats.tx_aborted_errors++; + dev_kfree_skb (skb); +#endif + + return 0; +} + +#if TX_RING +/* This handles TX complete events posted by the device + * via interrupts. + */ +void net_tx(struct net_device *dev) +{ + struct net_local *np = netdev_priv(dev); + int entry; + + /* This protects us from concurrent execution of + * our dev->hard_start_xmit function above. + */ + spin_lock(&np->lock); + + entry = np->tx_old; + while (tx_entry_is_sent(np, entry)) { + struct sk_buff *skb = np->skbs[entry]; + + np->stats.tx_bytes += skb->len; + dev_kfree_skb_irq (skb); + + entry = next_tx_entry(np, entry); + } + np->tx_old = entry; + + /* If we had stopped the queue due to a "tx full" + * condition, and space has now been made available, + * wake up the queue. + */ + if (netif_queue_stopped(dev) && ! tx_full(dev)) + netif_wake_queue(dev); + + spin_unlock(&np->lock); +} +#endif + +/* + * The typical workload of the driver: + * Handle the network interface interrupts. + */ +static irqreturn_t net_interrupt(int irq, void *dev_id, struct pt_regs * regs) +{ + struct net_device *dev = dev_id; + struct net_local *np; + int ioaddr, status; + int handled = 0; + + ioaddr = dev->base_addr; + + np = netdev_priv(dev); + status = inw(ioaddr + 0); + + if (status == 0) + goto out; + handled = 1; + + if (status & RX_INTR) { + /* Got a packet(s). */ + net_rx(dev); + } +#if TX_RING + if (status & TX_INTR) { + /* Transmit complete. */ + net_tx(dev); + np->stats.tx_packets++; + netif_wake_queue(dev); + } +#endif + if (status & COUNTERS_INTR) { + /* Increment the appropriate 'localstats' field. */ + np->stats.tx_window_errors++; + } +out: + return IRQ_RETVAL(handled); +} + +/* We have a good packet(s), get it/them out of the buffers. */ +static void +net_rx(struct net_device *dev) +{ + struct net_local *lp = netdev_priv(dev); + 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; + + lp->stats.rx_bytes+=pkt_len; + + 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); + dev->last_rx = jiffies; + lp->stats.rx_packets++; + lp->stats.rx_bytes += pkt_len; + } + } while (--boguscount); + + return; +} + +/* The inverse routine to net_open(). */ +static int +net_close(struct net_device *dev) +{ + struct net_local *lp = netdev_priv(dev); + int ioaddr = dev->base_addr; + + lp->open_time = 0; + + netif_stop_queue(dev); + + /* 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, dev); + free_dma(dev->dma); + + /* Update the statistics here. */ + + return 0; + +} + +/* + * Get the current statistics. + * This may be called with the card open or closed. + */ +static struct net_device_stats *net_get_stats(struct net_device *dev) +{ + struct net_local *lp = netdev_priv(dev); + short ioaddr = dev->base_addr; + + /* Update the statistics from the device registers. */ + lp->stats.rx_missed_errors = inw(ioaddr+1); + 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 net_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 struct net_device *this_device; +static int io = 0x300; +static int irq; +static int dma; +static int mem; +MODULE_LICENSE("GPL"); + +int init_module(void) +{ + struct net_device *dev; + int result; + + if (io == 0) + printk(KERN_WARNING "%s: You shouldn't use auto-probing with insmod!\n", + cardname); + dev = alloc_etherdev(sizeof(struct net_local)); + if (!dev) + return -ENOMEM; + + /* Copy the parameters from insmod into the device structure. */ + dev->base_addr = io; + dev->irq = irq; + dev->dma = dma; + dev->mem_start = mem; + if (do_netcard_probe(dev) == 0) { + if (register_netdev(dev) == 0) + this_device = dev; + return 0; + } + cleanup_card(dev); + } + free_netdev(dev); + return -ENXIO; +} + +void +cleanup_module(void) +{ + unregister_netdev(this_device); + cleanup_card(this_device); + free_netdev(this_device); +} + +#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: + */ |