net: Delete isa-skeleton net driver

/* 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);

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;

	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;

	return dev;

out:

	free_netdev(dev);

	return ERR_PTR(err);

}

#endif

static const struct net_device_ops netcard_netdev_ops = {

	.ndo_open		= net_open,

	.ndo_stop		= net_close,

	.ndo_start_xmit		= net_send_packet,

	.ndo_get_stats		= net_get_stats,

	.ndo_set_multicast_list	= set_multicast_list,

	.ndo_tx_timeout		= net_tx_timeout,

	.ndo_validate_addr	= eth_validate_addr,

	.ndo_set_mac_address	= eth_mac_addr,

	.ndo_change_mtu		= eth_change_mtu,

};

/*

 * 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++)

		dev->dev_addr[i] = inb(ioaddr + i);

	printk("%pM", dev->dev_addr);

	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->netdev_ops		= &netcard_netdev_ops;

        dev->watchdog_timeo	= MY_TX_TIMEOUT;

	err = register_netdev(dev);

	if (err)

		goto out2;

	return 0;

out2:

#ifdef jumpered_dma

	free_dma(dev->dma);

#endif

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.

	 */

	unsigned long flags;

	spin_lock_irqsave(&np->lock, flags);

	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_irqrestore(&np->lock, flags);

#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 NETDEV_TX_OK;

}

#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 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++;

	}

#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);

			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) ||

		 netdev_mc_count(dev) > HW_MAX_ADDRS)

	{

		/* Disable promiscuous mode, use normal mode. */

		hardware_set_filter(NULL);

		outw(MULTICAST, ioaddr);

	}

	else if (!netdev_mc_empty(dev))

	{

		/* Walk the address list, and load the filter */

		hardware_set_filter(dev);

		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) {

		this_device = dev;

		return 0;

	}

	free_netdev(dev);

	return -ENXIO;

}

void

cleanup_module(void)

{

	unregister_netdev(this_device);

	cleanup_card(this_device);

	free_netdev(this_device);

}

#endif /* MODULE */