ltpc.c

LINUX 2.6.17.4的源码

		printk("ltpc_hard_header called for device %s\n",
			dev->name);
	return 0;
}

static int ltpc_poll_counter;

static void ltpc_poll(unsigned long l)
{
	struct net_device *dev = (struct net_device *) l;

	del_timer(&ltpc_timer);

	if(debug & DEBUG_VERBOSE) {
		if (!ltpc_poll_counter) {
			ltpc_poll_counter = 50;
			printk("ltpc poll is alive\n");
		}
		ltpc_poll_counter--;
	}
  
	if (!dev)
		return;  /* we've been downed */

	/* poll 20 times per second */
	idle(dev);
	ltpc_timer.expires = jiffies + HZ/20;
	
	add_timer(&ltpc_timer);
}

/* DDP to LLAP translation */

static int ltpc_xmit(struct sk_buff *skb, struct net_device *dev)
{
	/* in kernel 1.3.xx, on entry skb->data points to ddp header,
	 * and skb->len is the length of the ddp data + ddp header
	 */

	struct net_device_stats *stats = &((struct ltpc_private *)dev->priv)->stats;

	int i;
	struct lt_sendlap cbuf;

	cbuf.command = LT_SENDLAP;
	cbuf.dnode = skb->data[0];
	cbuf.laptype = skb->data[2];
	skb_pull(skb,3);	/* skip past LLAP header */
	cbuf.length = skb->len;	/* this is host order */
	skb->h.raw=skb->data;

	if(debug & DEBUG_UPPER) {
		printk("command ");
		for(i=0;i<6;i++)
			printk("%02x ",((unsigned char *)&cbuf)[i]);
		printk("\n");
	}

	do_write(dev,&cbuf,sizeof(cbuf),skb->h.raw,skb->len);

	if(debug & DEBUG_UPPER) {
		printk("sent %d ddp bytes\n",skb->len);
		for(i=0;i<skb->len;i++) printk("%02x ",skb->h.raw[i]);
		printk("\n");
	}

	stats->tx_packets++;
	stats->tx_bytes+=skb->len;

	dev_kfree_skb(skb);
	return 0;
}

static struct net_device_stats *ltpc_get_stats(struct net_device *dev)
{
	struct net_device_stats *stats = &((struct ltpc_private *) dev->priv)->stats;
	return stats;
}

/* initialization stuff */
  
static int __init ltpc_probe_dma(int base, int dma)
{
	int want = (dma == 3) ? 2 : (dma == 1) ? 1 : 3;
  	unsigned long timeout;
  	unsigned long f;
  
  	if (want & 1) {
		if (request_dma(1,"ltpc")) {
			want &= ~1;
		} else {
			f=claim_dma_lock();
			disable_dma(1);
			clear_dma_ff(1);
			set_dma_mode(1,DMA_MODE_WRITE);
			set_dma_addr(1,virt_to_bus(ltdmabuf));
			set_dma_count(1,sizeof(struct lt_mem));
			enable_dma(1);
			release_dma_lock(f);
		}
	}
	if (want & 2) {
		if (request_dma(3,"ltpc")) {
			want &= ~2;
		} else {
			f=claim_dma_lock();
			disable_dma(3);
			clear_dma_ff(3);
			set_dma_mode(3,DMA_MODE_WRITE);
			set_dma_addr(3,virt_to_bus(ltdmabuf));
			set_dma_count(3,sizeof(struct lt_mem));
			enable_dma(3);
			release_dma_lock(f);
		}
	}
	/* set up request */

	/* FIXME -- do timings better! */

	ltdmabuf[0] = LT_READMEM;
	ltdmabuf[1] = 1;  /* mailbox */
	ltdmabuf[2] = 0; ltdmabuf[3] = 0;  /* address */
	ltdmabuf[4] = 0; ltdmabuf[5] = 1;  /* read 0x0100 bytes */
	ltdmabuf[6] = 0; /* dunno if this is necessary */

	inb_p(io+1);
	inb_p(io+0);
	timeout = jiffies+100*HZ/100;
	while(time_before(jiffies, timeout)) {
		if ( 0xfa == inb_p(io+6) ) break;
	}

	inb_p(io+3);
	inb_p(io+2);
	while(time_before(jiffies, timeout)) {
		if ( 0xfb == inb_p(io+6) ) break;
	}

	/* release the other dma channel (if we opened both of them) */

	if ((want & 2) && (get_dma_residue(3)==sizeof(struct lt_mem))) {
		want &= ~2;
		free_dma(3);
	}

	if ((want & 1) && (get_dma_residue(1)==sizeof(struct lt_mem))) {
		want &= ~1;
		free_dma(1);
	}

	if (!want)
		return 0;

	return (want & 2) ? 3 : 1;
}

struct net_device * __init ltpc_probe(void)
{
	struct net_device *dev;
	int err = -ENOMEM;
	int x=0,y=0;
	int autoirq;
	unsigned long f;
	unsigned long timeout;

	dev = alloc_ltalkdev(sizeof(struct ltpc_private));
	if (!dev)
		goto out;

	SET_MODULE_OWNER(dev);

	/* probe for the I/O port address */
	
	if (io != 0x240 && request_region(0x220,8,"ltpc")) {
		x = inb_p(0x220+6);
		if ( (x!=0xff) && (x>=0xf0) ) {
			io = 0x220;
			goto got_port;
		}
		release_region(0x220,8);
	}
	if (io != 0x220 && request_region(0x240,8,"ltpc")) {
		y = inb_p(0x240+6);
		if ( (y!=0xff) && (y>=0xf0) ){ 
			io = 0x240;
			goto got_port;
		}
		release_region(0x240,8);
	} 

	/* give up in despair */
	printk(KERN_ERR "LocalTalk card not found; 220 = %02x, 240 = %02x.\n", x,y);
	err = -ENODEV;
	goto out1;

 got_port:
	/* probe for the IRQ line */
	if (irq < 2) {
		unsigned long irq_mask;

		irq_mask = probe_irq_on();
		/* reset the interrupt line */
		inb_p(io+7);
		inb_p(io+7);
		/* trigger an interrupt (I hope) */
		inb_p(io+6);
		mdelay(2);
		autoirq = probe_irq_off(irq_mask);

		if (autoirq == 0) {
			printk(KERN_ERR "ltpc: probe at %#x failed to detect IRQ line.\n", io);
		} else {
			irq = autoirq;
		}
	}

	/* allocate a DMA buffer */
	ltdmabuf = (unsigned char *) dma_mem_alloc(1000);
	if (!ltdmabuf) {
		printk(KERN_ERR "ltpc: mem alloc failed\n");
		err = -ENOMEM;
		goto out2;
	}

	ltdmacbuf = &ltdmabuf[800];

	if(debug & DEBUG_VERBOSE) {
		printk("ltdmabuf pointer %08lx\n",(unsigned long) ltdmabuf);
	}

	/* reset the card */

	inb_p(io+1);
	inb_p(io+3);

	msleep(20);

	inb_p(io+0);
	inb_p(io+2);
	inb_p(io+7); /* clear reset */
	inb_p(io+4); 
	inb_p(io+5);
	inb_p(io+5); /* enable dma */
	inb_p(io+6); /* tri-state interrupt line */

	ssleep(1);
	
	/* now, figure out which dma channel we're using, unless it's
	   already been specified */
	/* well, 0 is a legal DMA channel, but the LTPC card doesn't
	   use it... */
	dma = ltpc_probe_dma(io, dma);
	if (!dma) {  /* no dma channel */
		printk(KERN_ERR "No DMA channel found on ltpc card.\n");
		err = -ENODEV;
		goto out3;
	}

	/* print out friendly message */
	if(irq)
		printk(KERN_INFO "Apple/Farallon LocalTalk-PC card at %03x, IR%d, DMA%d.\n",io,irq,dma);
	else
		printk(KERN_INFO "Apple/Farallon LocalTalk-PC card at %03x, DMA%d.  Using polled mode.\n",io,dma);

	/* Fill in the fields of the device structure with ethernet-generic values. */
	dev->hard_start_xmit = ltpc_xmit;
	dev->hard_header = ltpc_hard_header;
	dev->get_stats = ltpc_get_stats;

	/* add the ltpc-specific things */
	dev->do_ioctl = &ltpc_ioctl;

	dev->set_multicast_list = &set_multicast_list;
	dev->mc_list = NULL;
	dev->base_addr = io;
	dev->irq = irq;
	dev->dma = dma;

	/* the card will want to send a result at this point */
	/* (I think... leaving out this part makes the kernel crash,
           so I put it back in...) */

	f=claim_dma_lock();
	disable_dma(dma);
	clear_dma_ff(dma);
	set_dma_mode(dma,DMA_MODE_READ);
	set_dma_addr(dma,virt_to_bus(ltdmabuf));
	set_dma_count(dma,0x100);
	enable_dma(dma);
	release_dma_lock(f);

	(void) inb_p(io+3);
	(void) inb_p(io+2);
	timeout = jiffies+100*HZ/100;

	while(time_before(jiffies, timeout)) {
		if( 0xf9 == inb_p(io+6))
			break;
		schedule();
	}

	if(debug & DEBUG_VERBOSE) {
		printk("setting up timer and irq\n");
	}

	/* grab it and don't let go :-) */
	if (irq && request_irq( irq, &ltpc_interrupt, 0, "ltpc", dev) >= 0)
	{
		(void) inb_p(io+7);  /* enable interrupts from board */
		(void) inb_p(io+7);  /* and reset irq line */
	} else {
		if( irq )
			printk(KERN_ERR "ltpc: IRQ already in use, using polled mode.\n");
		dev->irq = 0;
		/* polled mode -- 20 times per second */
		/* this is really, really slow... should it poll more often? */
		init_timer(&ltpc_timer);
		ltpc_timer.function=ltpc_poll;
		ltpc_timer.data = (unsigned long) dev;

		ltpc_timer.expires = jiffies + HZ/20;
		add_timer(&ltpc_timer);
	}
	err = register_netdev(dev);
	if (err)
		goto out4;

	return NULL;
out4:
	del_timer_sync(&ltpc_timer);
	if (dev->irq)
		free_irq(dev->irq, dev);
out3:
	free_pages((unsigned long)ltdmabuf, get_order(1000));
out2:
	release_region(io, 8);
out1:
	free_netdev(dev);
out:
	return ERR_PTR(err);
}

#ifndef MODULE
/* handles "ltpc=io,irq,dma" kernel command lines */
static int __init ltpc_setup(char *str)
{
	int ints[5];

	str = get_options(str, ARRAY_SIZE(ints), ints);

	if (ints[0] == 0) {
		if (str && !strncmp(str, "auto", 4)) {
			/* do nothing :-) */
		}
		else {
			/* usage message */
			printk (KERN_ERR
				"ltpc: usage: ltpc=auto|iobase[,irq[,dma]]\n");
			return 0;
		}
	} else {
		io = ints[1];
		if (ints[0] > 1) {
			irq = ints[2];
		}
		if (ints[0] > 2) {
			dma = ints[3];
		}
		/* ignore any other paramters */
	}
	return 1;
}

__setup("ltpc=", ltpc_setup);
#endif /* MODULE */

static struct net_device *dev_ltpc;

#ifdef MODULE

MODULE_LICENSE("GPL");
module_param(debug, int, 0);
module_param(io, int, 0);
module_param(irq, int, 0);
module_param(dma, int, 0);


int __init init_module(void)
{
        if(io == 0)
		printk(KERN_NOTICE
		       "ltpc: Autoprobing is not recommended for modules\n");

	dev_ltpc = ltpc_probe();
	if (IS_ERR(dev_ltpc))
		return PTR_ERR(dev_ltpc);
	return 0;
}
#endif

static void __exit ltpc_cleanup(void)
{

	if(debug & DEBUG_VERBOSE) printk("unregister_netdev\n");
	unregister_netdev(dev_ltpc);

	ltpc_timer.data = 0;  /* signal the poll routine that we're done */

	del_timer_sync(&ltpc_timer);

	if(debug & DEBUG_VERBOSE) printk("freeing irq\n");

	if (dev_ltpc->irq)
		free_irq(dev_ltpc->irq, dev_ltpc);

	if(debug & DEBUG_VERBOSE) printk("freeing dma\n");

	if (dev_ltpc->dma)
		free_dma(dev_ltpc->dma);

	if(debug & DEBUG_VERBOSE) printk("freeing ioaddr\n");

	if (dev_ltpc->base_addr)
		release_region(dev_ltpc->base_addr,8);

	free_netdev(dev_ltpc);

	if(debug & DEBUG_VERBOSE) printk("free_pages\n");

	free_pages( (unsigned long) ltdmabuf, get_order(1000));

	if(debug & DEBUG_VERBOSE) printk("returning from cleanup_module\n");
}

module_exit(ltpc_cleanup);