3c509.c

讲述linux的初始化过程

	return word;
}


static int
el3_open(struct net_device *dev)
{
	int ioaddr = dev->base_addr;
	int i;

	outw(TxReset, ioaddr + EL3_CMD);
	outw(RxReset, ioaddr + EL3_CMD);
	outw(SetStatusEnb | 0x00, ioaddr + EL3_CMD);

	i = request_irq(dev->irq, &el3_interrupt, 0, dev->name, dev);
	if (i) return i;

	EL3WINDOW(0);
	if (el3_debug > 3)
		printk("%s: Opening, IRQ %d	 status@%x %4.4x.\n", dev->name,
			   dev->irq, ioaddr + EL3_STATUS, inw(ioaddr + EL3_STATUS));

	/* Activate board: this is probably unnecessary. */
	outw(0x0001, ioaddr + 4);

	/* Set the IRQ line. */
	outw((dev->irq << 12) | 0x0f00, ioaddr + WN0_IRQ);

	/* Set the station address in window 2 each time opened. */
	EL3WINDOW(2);

	for (i = 0; i < 6; i++)
		outb(dev->dev_addr[i], ioaddr + i);

	if (dev->if_port == 3)
		/* Start the thinnet transceiver. We should really wait 50ms...*/
		outw(StartCoax, ioaddr + EL3_CMD);
	else if (dev->if_port == 0) {
		/* 10baseT interface, enabled link beat and jabber check. */
		EL3WINDOW(4);
		outw(inw(ioaddr + WN4_MEDIA) | MEDIA_TP, ioaddr + WN4_MEDIA);
	}

	/* Switch to the stats window, and clear all stats by reading. */
	outw(StatsDisable, ioaddr + EL3_CMD);
	EL3WINDOW(6);
	for (i = 0; i < 9; i++)
		inb(ioaddr + i);
	inw(ioaddr + 10);
	inw(ioaddr + 12);

	/* Switch to register set 1 for normal use. */
	EL3WINDOW(1);

	/* Accept b-case and phys addr only. */
	outw(SetRxFilter | RxStation | RxBroadcast, ioaddr + EL3_CMD);
	outw(StatsEnable, ioaddr + EL3_CMD); /* Turn on statistics. */

	netif_start_queue(dev);

	outw(RxEnable, ioaddr + EL3_CMD); /* Enable the receiver. */
	outw(TxEnable, ioaddr + EL3_CMD); /* Enable transmitter. */
	/* Allow status bits to be seen. */
	outw(SetStatusEnb | 0xff, ioaddr + EL3_CMD);
	/* Ack all pending events, and set active indicator mask. */
	outw(AckIntr | IntLatch | TxAvailable | RxEarly | IntReq,
		 ioaddr + EL3_CMD);
	outw(SetIntrEnb | IntLatch|TxAvailable|TxComplete|RxComplete|StatsFull,
		 ioaddr + EL3_CMD);

	if (el3_debug > 3)
		printk("%s: Opened 3c509  IRQ %d  status %4.4x.\n",
			   dev->name, dev->irq, inw(ioaddr + EL3_STATUS));

	return 0;
}

static void
el3_tx_timeout (struct net_device *dev)
{
	struct el3_private *lp = (struct el3_private *)dev->priv;
	int ioaddr = dev->base_addr;

	/* Transmitter timeout, serious problems. */
	printk("%s: transmit timed out, Tx_status %2.2x status %4.4x "
		   "Tx FIFO room %d.\n",
		   dev->name, inb(ioaddr + TX_STATUS), inw(ioaddr + EL3_STATUS),
		   inw(ioaddr + TX_FREE));
	lp->stats.tx_errors++;
	dev->trans_start = jiffies;
	/* Issue TX_RESET and TX_START commands. */
	outw(TxReset, ioaddr + EL3_CMD);
	outw(TxEnable, ioaddr + EL3_CMD);
	netif_wake_queue(dev);
}


static int
el3_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct el3_private *lp = (struct el3_private *)dev->priv;
	int ioaddr = dev->base_addr;
	unsigned long flags;

	netif_stop_queue (dev);

	lp->stats.tx_bytes += skb->len;
	
	if (el3_debug > 4) {
		printk("%s: el3_start_xmit(length = %u) called, status %4.4x.\n",
			   dev->name, skb->len, inw(ioaddr + EL3_STATUS));
	}
#if 0
#ifndef final_version
	{	/* Error-checking code, delete someday. */
		ushort status = inw(ioaddr + EL3_STATUS);
		if (status & 0x0001 		/* IRQ line active, missed one. */
			&& inw(ioaddr + EL3_STATUS) & 1) { 			/* Make sure. */
			printk("%s: Missed interrupt, status then %04x now %04x"
				   "  Tx %2.2x Rx %4.4x.\n", dev->name, status,
				   inw(ioaddr + EL3_STATUS), inb(ioaddr + TX_STATUS),
				   inw(ioaddr + RX_STATUS));
			/* Fake interrupt trigger by masking, acknowledge interrupts. */
			outw(SetStatusEnb | 0x00, ioaddr + EL3_CMD);
			outw(AckIntr | IntLatch | TxAvailable | RxEarly | IntReq,
				 ioaddr + EL3_CMD);
			outw(SetStatusEnb | 0xff, ioaddr + EL3_CMD);
		}
	}
#endif
#endif
	/*
	 *	We lock the driver against other processors. Note
	 *	we don't need to lock versus the IRQ as we suspended
	 *	that. This means that we lose the ability to take
	 *	an RX during a TX upload. That sucks a bit with SMP
	 *	on an original 3c509 (2K buffer)
	 *
	 *	Using disable_irq stops us crapping on other
	 *	time sensitive devices.
	 */

    	spin_lock_irqsave(&lp->lock, flags);
	    
	/* Put out the doubleword header... */
	outw(skb->len, ioaddr + TX_FIFO);
	outw(0x00, ioaddr + TX_FIFO);
	/* ... and the packet rounded to a doubleword. */
#ifdef  __powerpc__
	outsl_unswapped(ioaddr + TX_FIFO, skb->data, (skb->len + 3) >> 2);
#else
	outsl(ioaddr + TX_FIFO, skb->data, (skb->len + 3) >> 2);
#endif

	dev->trans_start = jiffies;
	if (inw(ioaddr + TX_FREE) > 1536)
		netif_start_queue(dev);
	else
		/* Interrupt us when the FIFO has room for max-sized packet. */
		outw(SetTxThreshold + 1536, ioaddr + EL3_CMD);

	spin_unlock_irqrestore(&lp->lock, flags);

	dev_kfree_skb (skb);

	/* Clear the Tx status stack. */
	{
		short tx_status;
		int i = 4;

		while (--i > 0	&&	(tx_status = inb(ioaddr + TX_STATUS)) > 0) {
			if (tx_status & 0x38) lp->stats.tx_aborted_errors++;
			if (tx_status & 0x30) outw(TxReset, ioaddr + EL3_CMD);
			if (tx_status & 0x3C) outw(TxEnable, ioaddr + EL3_CMD);
			outb(0x00, ioaddr + TX_STATUS); /* Pop the status stack. */
		}
	}
	return 0;
}

/* The EL3 interrupt handler. */
static void
el3_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
	struct net_device *dev = (struct net_device *)dev_id;
	struct el3_private *lp;
	int ioaddr, status;
	int i = max_interrupt_work;

	if (dev == NULL) {
		printk ("el3_interrupt(): irq %d for unknown device.\n", irq);
		return;
	}

	lp = (struct el3_private *)dev->priv;
	spin_lock(&lp->lock);

	ioaddr = dev->base_addr;

	if (el3_debug > 4) {
		status = inw(ioaddr + EL3_STATUS);
		printk("%s: interrupt, status %4.4x.\n", dev->name, status);
	}

	while ((status = inw(ioaddr + EL3_STATUS)) &
		   (IntLatch | RxComplete | StatsFull)) {

		if (status & RxComplete)
			el3_rx(dev);

		if (status & TxAvailable) {
			if (el3_debug > 5)
				printk("	TX room bit was handled.\n");
			/* There's room in the FIFO for a full-sized packet. */
			outw(AckIntr | TxAvailable, ioaddr + EL3_CMD);
			netif_wake_queue (dev);
		}
		if (status & (AdapterFailure | RxEarly | StatsFull | TxComplete)) {
			/* Handle all uncommon interrupts. */
			if (status & StatsFull)				/* Empty statistics. */
				update_stats(dev);
			if (status & RxEarly) {				/* Rx early is unused. */
				el3_rx(dev);
				outw(AckIntr | RxEarly, ioaddr + EL3_CMD);
			}
			if (status & TxComplete) {			/* Really Tx error. */
				struct el3_private *lp = (struct el3_private *)dev->priv;
				short tx_status;
				int i = 4;

				while (--i>0 && (tx_status = inb(ioaddr + TX_STATUS)) > 0) {
					if (tx_status & 0x38) lp->stats.tx_aborted_errors++;
					if (tx_status & 0x30) outw(TxReset, ioaddr + EL3_CMD);
					if (tx_status & 0x3C) outw(TxEnable, ioaddr + EL3_CMD);
					outb(0x00, ioaddr + TX_STATUS); /* Pop the status stack. */
				}
			}
			if (status & AdapterFailure) {
				/* Adapter failure requires Rx reset and reinit. */
				outw(RxReset, ioaddr + EL3_CMD);
				/* Set the Rx filter to the current state. */
				outw(SetRxFilter | RxStation | RxBroadcast
					 | (dev->flags & IFF_ALLMULTI ? RxMulticast : 0)
					 | (dev->flags & IFF_PROMISC ? RxProm : 0),
					 ioaddr + EL3_CMD);
				outw(RxEnable, ioaddr + EL3_CMD); /* Re-enable the receiver. */
				outw(AckIntr | AdapterFailure, ioaddr + EL3_CMD);
			}
		}

		if (--i < 0) {
			printk("%s: Infinite loop in interrupt, status %4.4x.\n",
				   dev->name, status);
			/* Clear all interrupts. */
			outw(AckIntr | 0xFF, ioaddr + EL3_CMD);
			break;
		}
		/* Acknowledge the IRQ. */
		outw(AckIntr | IntReq | IntLatch, ioaddr + EL3_CMD); /* Ack IRQ */
	}

	if (el3_debug > 4) {
		printk("%s: exiting interrupt, status %4.4x.\n", dev->name,
			   inw(ioaddr + EL3_STATUS));
	}
	spin_unlock(&lp->lock);
	return;
}


static struct net_device_stats *
el3_get_stats(struct net_device *dev)
{
	struct el3_private *lp = (struct el3_private *)dev->priv;
	unsigned long flags;

	/*
	 *	This is fast enough not to bother with disable IRQ
	 *	stuff.
	 */
	 
	spin_lock_irqsave(&lp->lock, flags);
	update_stats(dev);
	spin_unlock_irqrestore(&lp->lock, flags);
	return &lp->stats;
}

/*  Update statistics.  We change to register window 6, so this should be run
	single-threaded if the device is active. This is expected to be a rare
	operation, and it's simpler for the rest of the driver to assume that
	window 1 is always valid rather than use a special window-state variable.
	*/
static void update_stats(struct net_device *dev)
{
	struct el3_private *lp = (struct el3_private *)dev->priv;
	int ioaddr = dev->base_addr;

	if (el3_debug > 5)
		printk("   Updating the statistics.\n");
	/* Turn off statistics updates while reading. */
	outw(StatsDisable, ioaddr + EL3_CMD);
	/* Switch to the stats window, and read everything. */
	EL3WINDOW(6);
	lp->stats.tx_carrier_errors 	+= inb(ioaddr + 0);
	lp->stats.tx_heartbeat_errors	+= inb(ioaddr + 1);
	/* Multiple collisions. */	   inb(ioaddr + 2);
	lp->stats.collisions		+= inb(ioaddr + 3);
	lp->stats.tx_window_errors	+= inb(ioaddr + 4);
	lp->stats.rx_fifo_errors	+= inb(ioaddr + 5);
	lp->stats.tx_packets		+= inb(ioaddr + 6);
	/* Rx packets	*/		   inb(ioaddr + 7);
	/* Tx deferrals */		   inb(ioaddr + 8);
	inw(ioaddr + 10);	/* Total Rx and Tx octets. */
	inw(ioaddr + 12);

	/* Back to window 1, and turn statistics back on. */
	EL3WINDOW(1);
	outw(StatsEnable, ioaddr + EL3_CMD);
	return;
}

static int
el3_rx(struct net_device *dev)
{
	struct el3_private *lp = (struct el3_private *)dev->priv;
	int ioaddr = dev->base_addr;
	short rx_status;

	if (el3_debug > 5)
		printk("   In rx_packet(), status %4.4x, rx_status %4.4x.\n",
			   inw(ioaddr+EL3_STATUS), inw(ioaddr+RX_STATUS));
	while ((rx_status = inw(ioaddr + RX_STATUS)) > 0) {
		if (rx_status & 0x4000) { /* Error, update stats. */
			short error = rx_status & 0x3800;

			outw(RxDiscard, ioaddr + EL3_CMD);
			lp->stats.rx_errors++;
			switch (error) {
			case 0x0000:		lp->stats.rx_over_errors++; break;
			case 0x0800:		lp->stats.rx_length_errors++; break;
			case 0x1000:		lp->stats.rx_frame_errors++; break;
			case 0x1800:		lp->stats.rx_length_errors++; break;
			case 0x2000:		lp->stats.rx_frame_errors++; break;
			case 0x2800:		lp->stats.rx_crc_errors++; break;
			}
		} else {
			short pkt_len = rx_status & 0x7ff;
			struct sk_buff *skb;

			skb = dev_alloc_skb(pkt_len+5);
			lp->stats.rx_bytes += pkt_len;
			if (el3_debug > 4)
				printk("Receiving packet size %d status %4.4x.\n",
					   pkt_len, rx_status);
			if (skb != NULL) {
				skb->dev = dev;
				skb_reserve(skb, 2);     /* Align IP on 16 byte */

				/* 'skb->data' points to the start of sk_buff data area. */
#ifdef  __powerpc__
				insl_unswapped(ioaddr+RX_FIFO, skb_put(skb,pkt_len),
							   (pkt_len + 3) >> 2);
#else
				insl(ioaddr + RX_FIFO, skb_put(skb,pkt_len),
					 (pkt_len + 3) >> 2);
#endif

				outw(RxDiscard, ioaddr + EL3_CMD); /* Pop top Rx packet. */
				skb->protocol = eth_type_trans(skb,dev);
				netif_rx(skb);
				lp->stats.rx_packets++;
				continue;
			}
			outw(RxDiscard, ioaddr + EL3_CMD);
			lp->stats.rx_dropped++;
			if (el3_debug)
				printk("%s: Couldn't allocate a sk_buff of size %d.\n",
					   dev->name, pkt_len);
		}
		inw(ioaddr + EL3_STATUS); 				/* Delay. */
		while (inw(ioaddr + EL3_STATUS) & 0x1000)
			printk(KERN_DEBUG "	Waiting for 3c509 to discard packet, status %x.\n",
				   inw(ioaddr + EL3_STATUS) );
	}

	return 0;
}

/*
 *     Set or clear the multicast filter for this adaptor.
 */
static void
set_multicast_list(struct net_device *dev)
{
	unsigned long flags;
	struct el3_private *lp = (struct el3_private *)dev->priv;
	int ioaddr = dev->base_addr;

	if (el3_debug > 1) {
		static int old = 0;
		if (old != dev->mc_count) {
			old = dev->mc_count;
			printk("%s: Setting Rx mode to %d addresses.\n", dev->name, dev->mc_count);
		}
	}
	spin_lock_irqsave(&lp->lock, flags);
	if (dev->flags&IFF_PROMISC) {
		outw(SetRxFilter | RxStation | RxMulticast | RxBroadcast | RxProm,
			 ioaddr + EL3_CMD);
	}
	else if (dev->mc_count || (dev->flags&IFF_ALLMULTI)) {
		outw(SetRxFilter | RxStation | RxMulticast | RxBroadcast, ioaddr + EL3_CMD);
	}
	else
                outw(SetRxFilter | RxStation | RxBroadcast, ioaddr + EL3_CMD);
	spin_unlock_irqrestore(&lp->lock, flags);
}

static int
el3_close(struct net_device *dev)
{
	int ioaddr = dev->base_addr;

	if (el3_debug > 2)
		printk("%s: Shutting down ethercard.\n", dev->name);

	netif_stop_queue(dev);

	/* Turn off statistics ASAP.  We update lp->stats below. */
	outw(StatsDisable, ioaddr + EL3_CMD);

	/* Disable the receiver and transmitter. */
	outw(RxDisable, ioaddr + EL3_CMD);
	outw(TxDisable, ioaddr + EL3_CMD);

	if (dev->if_port == 3)
		/* Turn off thinnet power.  Green! */
		outw(StopCoax, ioaddr + EL3_CMD);
	else if (dev->if_port == 0) {
		/* Disable link beat and jabber, if_port may change ere next open(). */
		EL3WINDOW(4);
		outw(inw(ioaddr + WN4_MEDIA) & ~MEDIA_TP, ioaddr + WN4_MEDIA);
	}

	free_irq(dev->irq, dev);
	/* Switching back to window 0 disables the IRQ. */
	EL3WINDOW(0);
	/* But we explicitly zero the IRQ line select anyway. */
	outw(0x0f00, ioaddr + WN0_IRQ);

	update_stats(dev);
	return 0;
}

#ifdef MODULE
/* Parameters that may be passed into the module. */
static int debug = -1;
static int irq[] = {-1, -1, -1, -1, -1, -1, -1, -1};
static int xcvr[] = {-1, -1, -1, -1, -1, -1, -1, -1};

MODULE_PARM(debug,"i");
MODULE_PARM(irq,"1-8i");
MODULE_PARM(xcvr,"1-8i");
MODULE_PARM(max_interrupt_work, "i");
#ifdef __ISAPNP__
MODULE_PARM(nopnp, "i");
#endif

int
init_module(void)
{
	int el3_cards = 0;

	if (debug >= 0)
		el3_debug = debug;

	el3_root_dev = NULL;
	while (el3_probe(0) == 0) {
		if (irq[el3_cards] > 1)
			el3_root_dev->irq = irq[el3_cards];
		if (xcvr[el3_cards] >= 0)
			el3_root_dev->if_port = xcvr[el3_cards];
		el3_cards++;
	}

	return el3_cards ? 0 : -ENODEV;
}

void
cleanup_module(void)
{
	struct net_device *next_dev;

	/* No need to check MOD_IN_USE, as sys_delete_module() checks. */
	while (el3_root_dev) {
		struct el3_private *lp = (struct el3_private *)el3_root_dev->priv;
#ifdef CONFIG_MCA		
		if(lp->mca_slot!=-1)
			mca_mark_as_unused(lp->mca_slot);
#endif			
		next_dev = lp->next_dev;
		unregister_netdev(el3_root_dev);
		release_region(el3_root_dev->base_addr, EL3_IO_EXTENT);
		kfree(el3_root_dev);
		el3_root_dev = next_dev;
	}
}
#endif /* MODULE */

/*
 * Local variables:
 *  compile-command: "gcc -DMODULE -D__KERNEL__ -Wall -Wstrict-prototypes -O6 -c 3c509.c"
 *  version-control: t
 *  kept-new-versions: 5
 *  tab-width: 4
 * End:
 */