ltpc.c

内核linux2.4.20,可跟rtlinux3.2打补丁 组成实时linux系统,编译内核

	}

	memset(dev->priv, 0, sizeof(struct ltpc_private));
	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;

	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 */

	idle(dev);
	ltpc_timer.expires = jiffies+5;
	
	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 = 0;
  	int timeout;
  	unsigned long f;
  
  	if (!request_dma(1,"ltpc")) {
  		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);
		dma|=1;
	}
	if (!request_dma(3,"ltpc")) {
		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);
		dma|=2;
	}

	/* 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 ( (dma&0x2) && (get_dma_residue(3)==sizeof(struct lt_mem)) ){
		dma&=1;
		free_dma(3);
	}
  
	if ( (dma&0x1) && (get_dma_residue(1)==sizeof(struct lt_mem)) ){
		dma&=0x2;
		free_dma(1);
	}

	/* fix up dma number */
	dma|=1;

	return dma;
}

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

	SET_MODULE_OWNER(dev);

	save_flags(flags);

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

	if(io) {
		/* found it, now grab it */
		request_region(io,8,"ltpc");
	} else {
		/* give up in despair */
		printk ("LocalTalk card not found; 220 = %02x, 240 = %02x.\n",
			x,y);
		restore_flags(flags);
		return -1;
	}

	/* probe for the IRQ line */
	if (irq < 2) {
		autoirq_setup(2);

		/* reset the interrupt line */
		inb_p(io+7);
		inb_p(io+7);
		/* trigger an interrupt (I hope) */
		inb_p(io+6);

		autoirq = autoirq_report(1);

		if (autoirq == 0) {
			printk("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) ltdmacbuf = &ltdmabuf[800];

	if (!ltdmabuf) {
		printk("ltpc: mem alloc failed\n");
		restore_flags(flags);
		return(-1);
	}

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

	/* reset the card */

	inb_p(io+1);
	inb_p(io+3);
	timeout = jiffies+2*HZ/100;
	while(time_before(jiffies, timeout)) ; /* hold it in reset for a coupla jiffies */
	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 */

	timeout = jiffies+100*HZ/100;
	
	while(time_before(jiffies, timeout)) {
		/* wait for the card to complete initialization */
	}
 
	/* 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... */
	if (dma == 0) {
		dma = ltpc_probe_dma(io);
		if (!dma) {  /* no dma channel */
			printk("No DMA channel found on ltpc card.\n");
			restore_flags(flags);
			return -1;
		}
	}

	/* print out friendly message */

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

	/* seems more logical to do this *after* probing the card... */
	err = ltpc_init(dev);
	if (err) return err;

	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;
	}

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

	if (irq) {
		/* grab it and don't let go :-) */
		(void) request_irq( irq, &ltpc_interrupt, 0, "ltpc", dev);
		(void) inb_p(io+7);  /* enable interrupts from board */
		(void) inb_p(io+7);  /* and reset irq line */
	} else {
		/* 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 + 5;
		add_timer(&ltpc_timer);
		restore_flags(flags); 
	}

	return 0;
}

#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_PARM(debug, "i");
MODULE_PARM(io, "i");
MODULE_PARM(irq, "i");
MODULE_PARM(dma, "i");


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

	/* Find a name for this unit */
	dev_ltpc.init = ltpc_probe;
	err=dev_alloc_name(&dev_ltpc,"lt%d");
	
	if(err<0)
		return err;

	if ((result = register_netdev(&dev_ltpc)) != 0) {
		printk(KERN_DEBUG "could not register Localtalk-PC device\n");
		return result;
	} else {
		if(debug&DEBUG_VERBOSE) printk("0 from register_netdev\n");
		return 0;
	}
}
#endif

static void __exit ltpc_cleanup(void)
{
	long timeout;

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

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

	if(dev_ltpc.irq) {
		free_irq(dev_ltpc.irq,&dev_ltpc);
		dev_ltpc.irq = 0;
	}

	if(del_timer(&ltpc_timer)) 
	{
		/* either the poll was never started, or a poll is in process */
		if(debug&DEBUG_VERBOSE) printk("waiting\n");
		/* if it's in process, wait a bit for it to finish */
		timeout = jiffies+HZ; 
		add_timer(&ltpc_timer);
		while(del_timer(&ltpc_timer) && time_after(timeout, jiffies))
		{
			add_timer(&ltpc_timer);
			schedule();
		}
	}

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

	if(dev_ltpc.dma) {
		free_dma(dev_ltpc.dma);
		dev_ltpc.dma = 0;
	}

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

	if(dev_ltpc.base_addr) {
		release_region(dev_ltpc.base_addr,8);
		dev_ltpc.base_addr = 0;
	}

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

	free_pages( (unsigned long) ltdmabuf, get_order(1000));
	ltdmabuf=NULL;
	ltdmacbuf=NULL;

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

	unregister_netdev(&dev_ltpc);

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

module_exit(ltpc_cleanup);