Initial import

1 files changed, 1285 insertions, 0 deletions

diff --git a/drivers/net/appletalk/ltpc.c b/drivers/net/appletalk/ltpc.c
new file mode 100644
index 000000000..01e2ac55c
--- /dev/null
+++ b/drivers/net/appletalk/ltpc.c
@@ -0,0 +1,1285 @@
+/***    ltpc.c -- a driver for the LocalTalk PC card.
+ *
+ *      Copyright (c) 1995,1996 Bradford W. Johnson <johns393@maroon.tc.umn.edu>
+ *
+ *      This software may be used and distributed according to the terms
+ *      of the GNU General Public License, incorporated herein by reference.
+ *
+ *      This is ALPHA code at best.  It may not work for you.  It may
+ *      damage your equipment.  It may damage your relations with other
+ *      users of your network.  Use it at your own risk!
+ *
+ *      Based in part on:
+ *      skeleton.c      by Donald Becker
+ *      dummy.c         by Nick Holloway and Alan Cox
+ *      loopback.c      by Ross Biro, Fred van Kampen, Donald Becker
+ *      the netatalk source code (UMICH)
+ *      lots of work on the card...
+ *
+ *      I do not have access to the (proprietary) SDK that goes with the card.
+ *      If you do, I don't want to know about it, and you can probably write
+ *      a better driver yourself anyway.  This does mean that the pieces that
+ *      talk to the card are guesswork on my part, so use at your own risk!
+ *
+ *      This is my first try at writing Linux networking code, and is also
+ *      guesswork.  Again, use at your own risk!  (Although on this part, I'd
+ *      welcome suggestions)
+ *
+ *      This is a loadable kernel module which seems to work at my site
+ *      consisting of a 1.2.13 linux box running netatalk 1.3.3, and with
+ *      the kernel support from 1.3.3b2 including patches routing.patch
+ *      and ddp.disappears.from.chooser.  In order to run it, you will need
+ *      to patch ddp.c and aarp.c in the kernel, but only a little...
+ *
+ *      I'm fairly confident that while this is arguably badly written, the
+ *      problems that people experience will be "higher level", that is, with
+ *      complications in the netatalk code.  The driver itself doesn't do
+ *      anything terribly complicated -- it pretends to be an ether device
+ *      as far as netatalk is concerned, strips the DDP data out of the ether
+ *      frame and builds a LLAP packet to send out the card.  In the other
+ *      direction, it receives LLAP frames from the card and builds a fake
+ *      ether packet that it then tosses up to the networking code.  You can
+ *      argue (correctly) that this is an ugly way to do things, but it
+ *      requires a minimal amount of fooling with the code in ddp.c and aarp.c.
+ *
+ *      The card will do a lot more than is used here -- I *think* it has the
+ *      layers up through ATP.  Even if you knew how that part works (which I
+ *      don't) it would be a big job to carve up the kernel ddp code to insert
+ *      things at a higher level, and probably a bad idea...
+ *
+ *      There are a number of other cards that do LocalTalk on the PC.  If
+ *      nobody finds any insurmountable (at the netatalk level) problems
+ *      here, this driver should encourage people to put some work into the
+ *      other cards (some of which I gather are still commercially available)
+ *      and also to put hooks for LocalTalk into the official ddp code.
+ *
+ *      I welcome comments and suggestions.  This is my first try at Linux
+ *      networking stuff, and there are probably lots of things that I did
+ *      suboptimally.  
+ *
+ ***/
+
+/***
+ *
+ * $Log: ltpc.c,v $
+ * Revision 1.1.2.1  2000/03/01 05:35:07  jgarzik
+ * at and tr cleanup
+ *
+ * Revision 1.8  1997/01/28 05:44:54  bradford
+ * Clean up for non-module a little.
+ * Hacked about a bit to clean things up - Alan Cox 
+ * Probably broken it from the origina 1.8
+ *
+
+ * 1998/11/09: David Huggins-Daines <dhd@debian.org>
+ * Cleaned up the initialization code to use the standard autoirq methods,
+   and to probe for things in the standard order of i/o, irq, dma.  This
+   removes the "reset the reset" hack, because I couldn't figure out an
+   easy way to get the card to trigger an interrupt after it.
+ * Added support for passing configuration parameters on the kernel command
+   line and through insmod
+ * Changed the device name from "ltalk0" to "lt0", both to conform with the
+   other localtalk driver, and to clear up the inconsistency between the
+   module and the non-module versions of the driver :-)
+ * Added a bunch of comments (I was going to make some enums for the state
+   codes and the register offsets, but I'm still not sure exactly what their
+   semantics are)
+ * Don't poll anymore in interrupt-driven mode
+ * It seems to work as a module now (as of 2.1.127), but I don't think
+   I'm responsible for that...
+
+ *
+ * Revision 1.7  1996/12/12 03:42:33  bradford
+ * DMA alloc cribbed from 3c505.c.
+ *
+ * Revision 1.6  1996/12/12 03:18:58  bradford
+ * Added virt_to_bus; works in 2.1.13.
+ *
+ * Revision 1.5  1996/12/12 03:13:22  root
+ * xmitQel initialization -- think through better though.
+ *
+ * Revision 1.4  1996/06/18 14:55:55  root
+ * Change names to ltpc. Tabs. Took a shot at dma alloc,
+ * although more needs to be done eventually.
+ *
+ * Revision 1.3  1996/05/22 14:59:39  root
+ * Change dev->open, dev->close to track dummy.c in 1.99.(around 7)
+ *
+ * Revision 1.2  1996/05/22 14:58:24  root
+ * Change tabs mostly.
+ *
+ * Revision 1.1  1996/04/23 04:45:09  root
+ * Initial revision
+ *
+ * Revision 0.16  1996/03/05 15:59:56  root
+ * Change ARPHRD_LOCALTLK definition to the "real" one.
+ *
+ * Revision 0.15  1996/03/05 06:28:30  root
+ * Changes for kernel 1.3.70.  Still need a few patches to kernel, but
+ * it's getting closer.
+ *
+ * Revision 0.14  1996/02/25 17:38:32  root
+ * More cleanups.  Removed query to card on get_stats.
+ *
+ * Revision 0.13  1996/02/21  16:27:40  root
+ * Refix debug_print_skb.  Fix mac.raw gotcha that appeared in 1.3.65.
+ * Clean up receive code a little.
+ *
+ * Revision 0.12  1996/02/19  16:34:53  root
+ * Fix debug_print_skb.  Kludge outgoing snet to 0 when using startup
+ * range.  Change debug to mask: 1 for verbose, 2 for higher level stuff
+ * including packet printing, 4 for lower level (card i/o) stuff.
+ *
+ * Revision 0.11  1996/02/12  15:53:38  root
+ * Added router sends (requires new aarp.c patch)
+ *
+ * Revision 0.10  1996/02/11  00:19:35  root
+ * Change source LTALK_LOGGING debug switch to insmod ... debug=2.
+ *
+ * Revision 0.9  1996/02/10  23:59:35  root
+ * Fixed those fixes for 1.2 -- DANGER!  The at.h that comes with netatalk
+ * has a *different* definition of struct sockaddr_at than the Linux kernel
+ * does.  This is an "insidious and invidious" bug...
+ * (Actually the preceding comment is false -- it's the atalk.h in the
+ * ancient atalk-0.06 that's the problem)
+ *
+ * Revision 0.8  1996/02/10 19:09:00  root
+ * Merge 1.3 changes.  Tested OK under 1.3.60.
+ *
+ * Revision 0.7  1996/02/10 17:56:56  root
+ * Added debug=1 parameter on insmod for debugging prints.  Tried
+ * to fix timer unload on rmmod, but I don't think that's the problem.
+ *
+ * Revision 0.6  1995/12/31  19:01:09  root
+ * Clean up rmmod, irq comments per feedback from Corin Anderson (Thanks Corey!)
+ * Clean up initial probing -- sometimes the card wakes up latched in reset.
+ *
+ * Revision 0.5  1995/12/22  06:03:44  root
+ * Added comments in front and cleaned up a bit.
+ * This version sent out to people.
+ *
+ * Revision 0.4  1995/12/18  03:46:44  root
+ * Return shortDDP to longDDP fake to 0/0.  Added command structs.
+ *
+ ***/
+
+/* ltpc jumpers are:
+*
+*	Interrupts -- set at most one.  If none are set, the driver uses
+*	polled mode.  Because the card was developed in the XT era, the
+*	original documentation refers to IRQ2.  Since you'll be running
+*	this on an AT (or later) class machine, that really means IRQ9.
+*
+*	SW1	IRQ 4
+*	SW2	IRQ 3
+*	SW3	IRQ 9 (2 in original card documentation only applies to XT)
+*
+*
+*	DMA -- choose DMA 1 or 3, and set both corresponding switches.
+*
+*	SW4	DMA 3
+*	SW5	DMA 1
+*	SW6	DMA 3
+*	SW7	DMA 1
+*
+*
+*	I/O address -- choose one.  
+*
+*	SW8	220 / 240
+*/
+
+/*	To have some stuff logged, do 
+*	insmod ltpc.o debug=1
+*
+*	For a whole bunch of stuff, use higher numbers.
+*
+*	The default is 0, i.e. no messages except for the probe results.
+*/
+
+/* insmod-tweakable variables */
+static int debug;
+#define DEBUG_VERBOSE 1
+#define DEBUG_UPPER 2
+#define DEBUG_LOWER 4
+
+static int io;
+static int irq;
+static int dma;
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/fcntl.h>
+#include <linux/interrupt.h>
+#include <linux/ptrace.h>
+#include <linux/ioport.h>
+#include <linux/spinlock.h>
+#include <linux/in.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/skbuff.h>
+#include <linux/if_arp.h>
+#include <linux/if_ltalk.h>
+#include <linux/delay.h>
+#include <linux/timer.h>
+#include <linux/atalk.h>
+#include <linux/bitops.h>
+#include <linux/gfp.h>
+
+#include <asm/dma.h>
+#include <asm/io.h>
+
+/* our stuff */
+#include "ltpc.h"
+
+static DEFINE_SPINLOCK(txqueue_lock);
+static DEFINE_SPINLOCK(mbox_lock);
+
+/* function prototypes */
+static int do_read(struct net_device *dev, void *cbuf, int cbuflen,
+	void *dbuf, int dbuflen);
+static int sendup_buffer (struct net_device *dev);
+
+/* Dma Memory related stuff, cribbed directly from 3c505.c */
+
+static unsigned long dma_mem_alloc(int size)
+{
+        int order = get_order(size);
+
+        return __get_dma_pages(GFP_KERNEL, order);
+}
+
+/* DMA data buffer, DMA command buffer */
+static unsigned char *ltdmabuf;
+static unsigned char *ltdmacbuf;
+
+/* private struct, holds our appletalk address */
+
+struct ltpc_private
+{
+	struct atalk_addr my_addr;
+};
+
+/* transmit queue element struct */
+
+struct xmitQel {
+	struct xmitQel *next;
+	/* command buffer */
+	unsigned char *cbuf;
+	short cbuflen;
+	/* data buffer */
+	unsigned char *dbuf;
+	short dbuflen;
+	unsigned char QWrite;	/* read or write data */
+	unsigned char mailbox;
+};
+
+/* the transmit queue itself */
+
+static struct xmitQel *xmQhd, *xmQtl;
+
+static void enQ(struct xmitQel *qel)
+{
+	unsigned long flags;
+	qel->next = NULL;
+	
+	spin_lock_irqsave(&txqueue_lock, flags);
+	if (xmQtl) {
+		xmQtl->next = qel;
+	} else {
+		xmQhd = qel;
+	}
+	xmQtl = qel;
+	spin_unlock_irqrestore(&txqueue_lock, flags);
+
+	if (debug & DEBUG_LOWER)
+		printk("enqueued a 0x%02x command\n",qel->cbuf[0]);
+}
+
+static struct xmitQel *deQ(void)
+{
+	unsigned long flags;
+	int i;
+	struct xmitQel *qel=NULL;
+	
+	spin_lock_irqsave(&txqueue_lock, flags);
+	if (xmQhd) {
+		qel = xmQhd;
+		xmQhd = qel->next;
+		if(!xmQhd) xmQtl = NULL;
+	}
+	spin_unlock_irqrestore(&txqueue_lock, flags);
+
+	if ((debug & DEBUG_LOWER) && qel) {
+		int n;
+		printk(KERN_DEBUG "ltpc: dequeued command ");
+		n = qel->cbuflen;
+		if (n>100) n=100;
+		for(i=0;i<n;i++) printk("%02x ",qel->cbuf[i]);
+		printk("\n");
+	}
+
+	return qel;
+}
+
+/* and... the queue elements we'll be using */
+static struct xmitQel qels[16];
+
+/* and their corresponding mailboxes */
+static unsigned char mailbox[16];
+static unsigned char mboxinuse[16] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
+
+static int wait_timeout(struct net_device *dev, int c)
+{
+	/* returns true if it stayed c */
+	/* this uses base+6, but it's ok */
+	int i;
+
+	/* twenty second or so total */
+
+	for(i=0;i<200000;i++) {
+		if ( c != inb_p(dev->base_addr+6) ) return 0;
+		udelay(100);
+	}
+	return 1; /* timed out */
+}
+
+/* get the first free mailbox */
+
+static int getmbox(void)
+{
+	unsigned long flags;
+	int i;
+
+	spin_lock_irqsave(&mbox_lock, flags);
+	for(i=1;i<16;i++) if(!mboxinuse[i]) {
+		mboxinuse[i]=1;
+		spin_unlock_irqrestore(&mbox_lock, flags);
+		return i;
+	}
+	spin_unlock_irqrestore(&mbox_lock, flags);
+	return 0;
+}
+
+/* read a command from the card */
+static void handlefc(struct net_device *dev)
+{
+	/* called *only* from idle, non-reentrant */
+	int dma = dev->dma;
+	int base = dev->base_addr;
+	unsigned long flags;
+
+
+	flags=claim_dma_lock();
+	disable_dma(dma);
+	clear_dma_ff(dma);
+	set_dma_mode(dma,DMA_MODE_READ);
+	set_dma_addr(dma,virt_to_bus(ltdmacbuf));
+	set_dma_count(dma,50);
+	enable_dma(dma);
+	release_dma_lock(flags);
+
+	inb_p(base+3);
+	inb_p(base+2);
+
+	if ( wait_timeout(dev,0xfc) ) printk("timed out in handlefc\n");
+}
+
+/* read data from the card */
+static void handlefd(struct net_device *dev)
+{
+	int dma = dev->dma;
+	int base = dev->base_addr;
+	unsigned long flags;
+
+	flags=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,800);
+	enable_dma(dma);
+	release_dma_lock(flags);
+
+	inb_p(base+3);
+	inb_p(base+2);
+
+	if ( wait_timeout(dev,0xfd) ) printk("timed out in handlefd\n");
+	sendup_buffer(dev);
+} 
+
+static void handlewrite(struct net_device *dev)
+{
+	/* called *only* from idle, non-reentrant */
+	/* on entry, 0xfb and ltdmabuf holds data */
+	int dma = dev->dma;
+	int base = dev->base_addr;
+	unsigned long flags;
+	
+	flags=claim_dma_lock();
+	disable_dma(dma);
+	clear_dma_ff(dma);
+	set_dma_mode(dma,DMA_MODE_WRITE);
+	set_dma_addr(dma,virt_to_bus(ltdmabuf));
+	set_dma_count(dma,800);
+	enable_dma(dma);
+	release_dma_lock(flags);
+	
+	inb_p(base+3);
+	inb_p(base+2);
+
+	if ( wait_timeout(dev,0xfb) ) {
+		flags=claim_dma_lock();
+		printk("timed out in handlewrite, dma res %d\n",
+			get_dma_residue(dev->dma) );
+		release_dma_lock(flags);
+	}
+}
+
+static void handleread(struct net_device *dev)
+{
+	/* on entry, 0xfb */
+	/* on exit, ltdmabuf holds data */
+	int dma = dev->dma;
+	int base = dev->base_addr;
+	unsigned long flags;
+
+	
+	flags=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,800);
+	enable_dma(dma);
+	release_dma_lock(flags);
+
+	inb_p(base+3);
+	inb_p(base+2);
+	if ( wait_timeout(dev,0xfb) ) printk("timed out in handleread\n");
+}
+
+static void handlecommand(struct net_device *dev)
+{
+	/* on entry, 0xfa and ltdmacbuf holds command */
+	int dma = dev->dma;
+	int base = dev->base_addr;
+	unsigned long flags;
+
+	flags=claim_dma_lock();
+	disable_dma(dma);
+	clear_dma_ff(dma);
+	set_dma_mode(dma,DMA_MODE_WRITE);
+	set_dma_addr(dma,virt_to_bus(ltdmacbuf));
+	set_dma_count(dma,50);
+	enable_dma(dma);
+	release_dma_lock(flags);
+	inb_p(base+3);
+	inb_p(base+2);
+	if ( wait_timeout(dev,0xfa) ) printk("timed out in handlecommand\n");
+} 
+
+/* ready made command for getting the result from the card */
+static unsigned char rescbuf[2] = {LT_GETRESULT,0};
+static unsigned char resdbuf[2];
+
+static int QInIdle;
+
+/* idle expects to be called with the IRQ line high -- either because of
+ * an interrupt, or because the line is tri-stated
+ */
+
+static void idle(struct net_device *dev)
+{
+	unsigned long flags;
+	int state;
+	/* FIXME This is initialized to shut the warning up, but I need to
+	 * think this through again.
+	 */
+	struct xmitQel *q = NULL;
+	int oops;
+	int i;
+	int base = dev->base_addr;
+
+	spin_lock_irqsave(&txqueue_lock, flags);
+	if(QInIdle) {
+		spin_unlock_irqrestore(&txqueue_lock, flags);
+		return;
+	}
+	QInIdle = 1;
+	spin_unlock_irqrestore(&txqueue_lock, flags);
+
+	/* this tri-states the IRQ line */
+	(void) inb_p(base+6);
+
+	oops = 100;
+
+loop:
+	if (0>oops--) { 
+		printk("idle: looped too many times\n");
+		goto done;
+	}
+
+	state = inb_p(base+6);
+	if (state != inb_p(base+6)) goto loop;
+
+	switch(state) {
+		case 0xfc:
+			/* incoming command */
+			if (debug & DEBUG_LOWER) printk("idle: fc\n");
+			handlefc(dev); 
+			break;
+		case 0xfd:
+			/* incoming data */
+			if(debug & DEBUG_LOWER) printk("idle: fd\n");
+			handlefd(dev); 
+			break;
+		case 0xf9:
+			/* result ready */
+			if (debug & DEBUG_LOWER) printk("idle: f9\n");
+			if(!mboxinuse[0]) {
+				mboxinuse[0] = 1;
+				qels[0].cbuf = rescbuf;
+				qels[0].cbuflen = 2;
+				qels[0].dbuf = resdbuf;
+				qels[0].dbuflen = 2;
+				qels[0].QWrite = 0;
+				qels[0].mailbox = 0;
+				enQ(&qels[0]);
+			}
+			inb_p(dev->base_addr+1);
+			inb_p(dev->base_addr+0);
+			if( wait_timeout(dev,0xf9) )
+				printk("timed out idle f9\n");
+			break;
+		case 0xf8:
+			/* ?? */
+			if (xmQhd) {
+				inb_p(dev->base_addr+1);
+				inb_p(dev->base_addr+0);
+				if(wait_timeout(dev,0xf8) )
+					printk("timed out idle f8\n");
+			} else {
+				goto done;
+			}
+			break;
+		case 0xfa:
+			/* waiting for command */
+			if(debug & DEBUG_LOWER) printk("idle: fa\n");
+			if (xmQhd) {
+				q=deQ();
+				memcpy(ltdmacbuf,q->cbuf,q->cbuflen);
+				ltdmacbuf[1] = q->mailbox;
+				if (debug>1) { 
+					int n;
+					printk("ltpc: sent command     ");
+					n = q->cbuflen;
+					if (n>100) n=100;
+					for(i=0;i<n;i++)
+						printk("%02x ",ltdmacbuf[i]);
+					printk("\n");
+				}
+				handlecommand(dev);
+					if(0xfa==inb_p(base+6)) {
+						/* we timed out, so return */
+						goto done;
+					} 
+			} else {
+				/* we don't seem to have a command */
+				if (!mboxinuse[0]) {
+					mboxinuse[0] = 1;
+					qels[0].cbuf = rescbuf;
+					qels[0].cbuflen = 2;
+					qels[0].dbuf = resdbuf;
+					qels[0].dbuflen = 2;
+					qels[0].QWrite = 0;
+					qels[0].mailbox = 0;
+					enQ(&qels[0]);
+				} else {
+					printk("trouble: response command already queued\n");
+					goto done;
+				}
+			} 
+			break;
+		case 0Xfb:
+			/* data transfer ready */
+			if(debug & DEBUG_LOWER) printk("idle: fb\n");
+			if(q->QWrite) {
+				memcpy(ltdmabuf,q->dbuf,q->dbuflen);
+				handlewrite(dev);
+			} else {
+				handleread(dev);
+				/* non-zero mailbox numbers are for
+				   commmands, 0 is for GETRESULT
+				   requests */
+				if(q->mailbox) {
+					memcpy(q->dbuf,ltdmabuf,q->dbuflen);
+				} else { 
+					/* this was a result */
+					mailbox[ 0x0f & ltdmabuf[0] ] = ltdmabuf[1];
+					mboxinuse[0]=0;
+				}
+			}
+			break;
+	}
+	goto loop;
+
+done:
+	QInIdle=0;
+
+	/* now set the interrupts back as appropriate */
+	/* the first read takes it out of tri-state (but still high) */
+	/* the second resets it */
+	/* note that after this point, any read of base+6 will
+	   trigger an interrupt */
+
+	if (dev->irq) {
+		inb_p(base+7);
+		inb_p(base+7);
+	}
+}
+
+
+static int do_write(struct net_device *dev, void *cbuf, int cbuflen,
+	void *dbuf, int dbuflen)
+{
+
+	int i = getmbox();
+	int ret;
+
+	if(i) {
+		qels[i].cbuf = cbuf;
+		qels[i].cbuflen = cbuflen;
+		qels[i].dbuf = dbuf;
+		qels[i].dbuflen = dbuflen;
+		qels[i].QWrite = 1;
+		qels[i].mailbox = i;  /* this should be initted rather */
+		enQ(&qels[i]);
+		idle(dev);
+		ret = mailbox[i];
+		mboxinuse[i]=0;
+		return ret;
+	}
+	printk("ltpc: could not allocate mbox\n");
+	return -1;
+}
+
+static int do_read(struct net_device *dev, void *cbuf, int cbuflen,
+	void *dbuf, int dbuflen)
+{
+
+	int i = getmbox();
+	int ret;
+
+	if(i) {
+		qels[i].cbuf = cbuf;
+		qels[i].cbuflen = cbuflen;
+		qels[i].dbuf = dbuf;
+		qels[i].dbuflen = dbuflen;
+		qels[i].QWrite = 0;
+		qels[i].mailbox = i;  /* this should be initted rather */
+		enQ(&qels[i]);
+		idle(dev);
+		ret = mailbox[i];
+		mboxinuse[i]=0;
+		return ret;
+	}
+	printk("ltpc: could not allocate mbox\n");
+	return -1;
+}
+
+/* end of idle handlers -- what should be seen is do_read, do_write */
+
+static struct timer_list ltpc_timer;
+
+static netdev_tx_t ltpc_xmit(struct sk_buff *skb, struct net_device *dev);
+
+static int read_30 ( struct net_device *dev)
+{
+	lt_command c;
+	c.getflags.command = LT_GETFLAGS;
+	return do_read(dev, &c, sizeof(c.getflags),&c,0);
+}
+
+static int set_30 (struct net_device *dev,int x)
+{
+	lt_command c;
+	c.setflags.command = LT_SETFLAGS;
+	c.setflags.flags = x;
+	return do_write(dev, &c, sizeof(c.setflags),&c,0);
+}
+
+/* LLAP to DDP translation */
+
+static int sendup_buffer (struct net_device *dev)
+{
+	/* on entry, command is in ltdmacbuf, data in ltdmabuf */
+	/* called from idle, non-reentrant */
+
+	int dnode, snode, llaptype, len; 
+	int sklen;
+	struct sk_buff *skb;
+	struct lt_rcvlap *ltc = (struct lt_rcvlap *) ltdmacbuf;
+
+	if (ltc->command != LT_RCVLAP) {
+		printk("unknown command 0x%02x from ltpc card\n",ltc->command);
+		return -1;
+	}
+	dnode = ltc->dnode;
+	snode = ltc->snode;
+	llaptype = ltc->laptype;
+	len = ltc->length; 
+
+	sklen = len;
+	if (llaptype == 1) 
+		sklen += 8;  /* correct for short ddp */
+	if(sklen > 800) {
+		printk(KERN_INFO "%s: nonsense length in ltpc command 0x14: 0x%08x\n",
+			dev->name,sklen);
+		return -1;
+	}
+
+	if ( (llaptype==0) || (llaptype>2) ) {
+		printk(KERN_INFO "%s: unknown LLAP type: %d\n",dev->name,llaptype);
+		return -1;
+	}
+
+
+	skb = dev_alloc_skb(3+sklen);
+	if (skb == NULL) 
+	{
+		printk("%s: dropping packet due to memory squeeze.\n",
+			dev->name);
+		return -1;
+	}
+	skb->dev = dev;
+
+	if (sklen > len)
+		skb_reserve(skb,8);
+	skb_put(skb,len+3);
+	skb->protocol = htons(ETH_P_LOCALTALK);
+	/* add LLAP header */
+	skb->data[0] = dnode;
+	skb->data[1] = snode;
+	skb->data[2] = llaptype;
+	skb_reset_mac_header(skb);	/* save pointer to llap header */
+	skb_pull(skb,3);
+
+	/* copy ddp(s,e)hdr + contents */
+	skb_copy_to_linear_data(skb, ltdmabuf, len);
+
+	skb_reset_transport_header(skb);
+
+	dev->stats.rx_packets++;
+	dev->stats.rx_bytes += skb->len;
+
+	/* toss it onwards */
+	netif_rx(skb);
+	return 0;
+}
+
+/* the handler for the board interrupt */
+ 
+static irqreturn_t
+ltpc_interrupt(int irq, void *dev_id)
+{
+	struct net_device *dev = dev_id;
+
+	if (dev==NULL) {
+		printk("ltpc_interrupt: unknown device.\n");
+		return IRQ_NONE;
+	}
+
+	inb_p(dev->base_addr+6);  /* disable further interrupts from board */
+
+	idle(dev); /* handle whatever is coming in */
+ 
+	/* idle re-enables interrupts from board */ 
+
+	return IRQ_HANDLED;
+}
+
+/***
+ *
+ *    The ioctls that the driver responds to are:
+ *
+ *    SIOCSIFADDR -- do probe using the passed node hint.
+ *    SIOCGIFADDR -- return net, node.
+ *
+ *    some of this stuff should be done elsewhere.
+ *
+ ***/
+
+static int ltpc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
+{
+	struct sockaddr_at *sa = (struct sockaddr_at *) &ifr->ifr_addr;
+	/* we'll keep the localtalk node address in dev->pa_addr */
+	struct ltpc_private *ltpc_priv = netdev_priv(dev);
+	struct atalk_addr *aa = &ltpc_priv->my_addr;
+	struct lt_init c;
+	int ltflags;
+
+	if(debug & DEBUG_VERBOSE) printk("ltpc_ioctl called\n");
+
+	switch(cmd) {
+		case SIOCSIFADDR:
+
+			aa->s_net  = sa->sat_addr.s_net;
+      
+			/* this does the probe and returns the node addr */
+			c.command = LT_INIT;
+			c.hint = sa->sat_addr.s_node;
+
+			aa->s_node = do_read(dev,&c,sizeof(c),&c,0);
+
+			/* get all llap frames raw */
+			ltflags = read_30(dev);
+			ltflags |= LT_FLAG_ALLLAP;
+			set_30 (dev,ltflags);  
+
+			dev->broadcast[0] = 0xFF;
+			dev->dev_addr[0] = aa->s_node;
+
+			dev->addr_len=1;
+   
+			return 0;
+
+		case SIOCGIFADDR:
+
+			sa->sat_addr.s_net = aa->s_net;
+			sa->sat_addr.s_node = aa->s_node;
+
+			return 0;
+
+		default: 
+			return -EINVAL;
+	}
+}
+
+static void set_multicast_list(struct net_device *dev)
+{
+	/* This needs to be present to keep netatalk happy. */
+	/* Actually netatalk needs fixing! */
+}
+
+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 netdev_tx_t 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
+	 */
+	int i;
+	struct lt_sendlap cbuf;
+	unsigned char *hdr;
+
+	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_reset_transport_header(skb);
+
+	if(debug & DEBUG_UPPER) {
+		printk("command ");
+		for(i=0;i<6;i++)
+			printk("%02x ",((unsigned char *)&cbuf)[i]);
+		printk("\n");
+	}
+
+	hdr = skb_transport_header(skb);
+	do_write(dev, &cbuf, sizeof(cbuf), hdr, skb->len);
+
+	if(debug & DEBUG_UPPER) {
+		printk("sent %d ddp bytes\n",skb->len);
+		for (i = 0; i < skb->len; i++)
+			printk("%02x ", hdr[i]);
+		printk("\n");
+	}
+
+	dev->stats.tx_packets++;
+	dev->stats.tx_bytes += skb->len;
+
+	dev_kfree_skb(skb);
+	return NETDEV_TX_OK;
+}
+
+/* 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;
+}
+
+static const struct net_device_ops ltpc_netdev = {
+	.ndo_start_xmit		= ltpc_xmit,
+	.ndo_do_ioctl		= ltpc_ioctl,
+	.ndo_set_rx_mode	= set_multicast_list,
+};
+
+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;
+
+	/* 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);
+
+	dev->netdev_ops = &ltpc_netdev;
+	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 parameters */
+	}
+	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);
+
+
+static int __init ltpc_module_init(void)
+{
+        if(io == 0)
+		printk(KERN_NOTICE
+		       "ltpc: Autoprobing is not recommended for modules\n");
+
+	dev_ltpc = ltpc_probe();
+	return PTR_ERR_OR_ZERO(dev_ltpc);
+}
+module_init(ltpc_module_init);
+#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);