Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 952 insertions, 0 deletions

diff --git a/drivers/net/atp.c b/drivers/net/atp.c
new file mode 100644
index 000000000000..bfa674ed4494
--- /dev/null
+++ b/drivers/net/atp.c
@@ -0,0 +1,952 @@
+/* atp.c: Attached (pocket) ethernet adapter driver for linux. */
+/*
+	This is a driver for commonly OEM pocket (parallel port)
+	ethernet adapters based on the Realtek RTL8002 and RTL8012 chips.
+
+	Written 1993-2000 by Donald Becker.
+
+	This software may be used and distributed according to the terms of
+	the GNU General Public License (GPL), incorporated herein by reference.
+	Drivers based on or derived from this code fall under the GPL and must
+	retain the authorship, copyright and license notice.  This file is not
+	a complete program and may only be used when the entire operating
+	system is licensed under the GPL.
+
+	Copyright 1993 United States Government as represented by the Director,
+	National Security Agency.  Copyright 1994-2000 retained by the original
+	author, Donald Becker. The timer-based reset code was supplied in 1995
+	by Bill Carlson, wwc@super.org.
+
+	The author may be reached as becker@scyld.com, or C/O
+	Scyld Computing Corporation
+	410 Severn Ave., Suite 210
+	Annapolis MD 21403
+
+	Support information and updates available at
+	http://www.scyld.com/network/atp.html
+
+
+	Modular support/softnet added by Alan Cox.
+	_bit abuse fixed up by Alan Cox
+
+*/
+
+static const char versionA[] =
+"atp.c:v1.09=ac 2002/10/01 Donald Becker <becker@scyld.com>\n";
+static const char versionB[] =
+"  http://www.scyld.com/network/atp.html\n";
+
+/* The user-configurable values.
+   These may be modified when a driver module is loaded.*/
+
+static int debug = 1; 			/* 1 normal messages, 0 quiet .. 7 verbose. */
+#define net_debug debug
+
+/* Maximum events (Rx packets, etc.) to handle at each interrupt. */
+static int max_interrupt_work = 15;
+
+#define NUM_UNITS 2
+/* The standard set of ISA module parameters. */
+static int io[NUM_UNITS];
+static int irq[NUM_UNITS];
+static int xcvr[NUM_UNITS]; 			/* The data transfer mode. */
+
+/* Operational parameters that are set at compile time. */
+
+/* Time in jiffies before concluding the transmitter is hung. */
+#define TX_TIMEOUT  (400*HZ/1000)
+
+/*
+	This file is a device driver for the RealTek (aka AT-Lan-Tec) pocket
+	ethernet adapter.  This is a common low-cost OEM pocket ethernet
+	adapter, sold under many names.
+
+  Sources:
+	This driver was written from the packet driver assembly code provided by
+	Vincent Bono of AT-Lan-Tec.	 Ever try to figure out how a complicated
+	device works just from the assembly code?  It ain't pretty.  The following
+	description is written based on guesses and writing lots of special-purpose
+	code to test my theorized operation.
+
+	In 1997 Realtek made available the documentation for the second generation
+	RTL8012 chip, which has lead to several driver improvements.
+	  http://www.realtek.com.tw/cn/cn.html
+
+					Theory of Operation
+
+	The RTL8002 adapter seems to be built around a custom spin of the SEEQ
+	controller core.  It probably has a 16K or 64K internal packet buffer, of
+	which the first 4K is devoted to transmit and the rest to receive.
+	The controller maintains the queue of received packet and the packet buffer
+	access pointer internally, with only 'reset to beginning' and 'skip to next
+	packet' commands visible.  The transmit packet queue holds two (or more?)
+	packets: both 'retransmit this packet' (due to collision) and 'transmit next
+	packet' commands must be started by hand.
+
+	The station address is stored in a standard bit-serial EEPROM which must be
+	read (ughh) by the device driver.  (Provisions have been made for
+	substituting a 74S288 PROM, but I haven't gotten reports of any models
+	using it.)  Unlike built-in devices, a pocket adapter can temporarily lose
+	power without indication to the device driver.  The major effect is that
+	the station address, receive filter (promiscuous, etc.) and transceiver
+	must be reset.
+
+	The controller itself has 16 registers, some of which use only the lower
+	bits.  The registers are read and written 4 bits at a time.  The four bit
+	register address is presented on the data lines along with a few additional
+	timing and control bits.  The data is then read from status port or written
+	to the data port.
+
+	Correction: the controller has two banks of 16 registers.  The second
+	bank contains only the multicast filter table (now used) and the EEPROM
+	access registers.
+
+	Since the bulk data transfer of the actual packets through the slow
+	parallel port dominates the driver's running time, four distinct data
+	(non-register) transfer modes are provided by the adapter, two in each
+	direction.  In the first mode timing for the nibble transfers is
+	provided through the data port.  In the second mode the same timing is
+	provided through the control port.  In either case the data is read from
+	the status port and written to the data port, just as it is accessing
+	registers.
+
+	In addition to the basic data transfer methods, several more are modes are
+	created by adding some delay by doing multiple reads of the data to allow
+	it to stabilize.  This delay seems to be needed on most machines.
+
+	The data transfer mode is stored in the 'dev->if_port' field.  Its default
+	value is '4'.  It may be overridden at boot-time using the third parameter
+	to the "ether=..." initialization.
+
+	The header file <atp.h> provides inline functions that encapsulate the
+	register and data access methods.  These functions are hand-tuned to
+	generate reasonable object code.  This header file also documents my
+	interpretations of the device registers.
+*/
+
+#include <linux/kernel.h>
+#include <linux/module.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/errno.h>
+#include <linux/init.h>
+#include <linux/crc32.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/skbuff.h>
+#include <linux/spinlock.h>
+#include <linux/delay.h>
+#include <linux/bitops.h>
+
+#include <asm/system.h>
+#include <asm/io.h>
+#include <asm/dma.h>
+
+#include "atp.h"
+
+MODULE_AUTHOR("Donald Becker <becker@scyld.com>");
+MODULE_DESCRIPTION("RealTek RTL8002/8012 parallel port Ethernet driver");
+MODULE_LICENSE("GPL");
+
+module_param(max_interrupt_work, int, 0);
+module_param(debug, int, 0);
+module_param_array(io, int, NULL, 0);
+module_param_array(irq, int, NULL, 0);
+module_param_array(xcvr, int, NULL, 0);
+MODULE_PARM_DESC(max_interrupt_work, "ATP maximum events handled per interrupt");
+MODULE_PARM_DESC(debug, "ATP debug level (0-7)");
+MODULE_PARM_DESC(io, "ATP I/O base address(es)");
+MODULE_PARM_DESC(irq, "ATP IRQ number(s)");
+MODULE_PARM_DESC(xcvr, "ATP transceiver(s) (0=internal, 1=external)");
+
+/* The number of low I/O ports used by the ethercard. */
+#define ETHERCARD_TOTAL_SIZE	3
+
+/* Sequence to switch an 8012 from printer mux to ethernet mode. */
+static char mux_8012[] = { 0xff, 0xf7, 0xff, 0xfb, 0xf3, 0xfb, 0xff, 0xf7,};
+
+struct net_local {
+    spinlock_t lock;
+    struct net_device *next_module;
+    struct net_device_stats stats;
+    struct timer_list timer;	/* Media selection timer. */
+    long last_rx_time;		/* Last Rx, in jiffies, to handle Rx hang. */
+    int saved_tx_size;
+    unsigned int tx_unit_busy:1;
+    unsigned char re_tx,	/* Number of packet retransmissions. */
+		addr_mode,		/* Current Rx filter e.g. promiscuous, etc. */
+		pac_cnt_in_tx_buf,
+		chip_type;
+};
+
+/* This code, written by wwc@super.org, resets the adapter every
+   TIMED_CHECKER ticks.  This recovers from an unknown error which
+   hangs the device. */
+#define TIMED_CHECKER (HZ/4)
+#ifdef TIMED_CHECKER
+#include <linux/timer.h>
+static void atp_timed_checker(unsigned long ignored);
+#endif
+
+/* Index to functions, as function prototypes. */
+
+static int atp_probe1(long ioaddr);
+static void get_node_ID(struct net_device *dev);
+static unsigned short eeprom_op(long ioaddr, unsigned int cmd);
+static int net_open(struct net_device *dev);
+static void hardware_init(struct net_device *dev);
+static void write_packet(long ioaddr, int length, unsigned char *packet, int pad, int mode);
+static void trigger_send(long ioaddr, int length);
+static int	atp_send_packet(struct sk_buff *skb, struct net_device *dev);
+static irqreturn_t atp_interrupt(int irq, void *dev_id, struct pt_regs *regs);
+static void net_rx(struct net_device *dev);
+static void read_block(long ioaddr, int length, unsigned char *buffer, int data_mode);
+static int net_close(struct net_device *dev);
+static struct net_device_stats *net_get_stats(struct net_device *dev);
+static void set_rx_mode_8002(struct net_device *dev);
+static void set_rx_mode_8012(struct net_device *dev);
+static void tx_timeout(struct net_device *dev);
+
+
+/* A list of all installed ATP devices, for removing the driver module. */
+static struct net_device *root_atp_dev;
+
+/* Check for a network adapter 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).
+   
+   FIXME: we should use the parport layer for this
+   */
+static int __init atp_init(void)
+{
+	int *port, ports[] = {0x378, 0x278, 0x3bc, 0};
+	int base_addr = io[0];
+
+	if (base_addr > 0x1ff)		/* Check a single specified location. */
+		return atp_probe1(base_addr);
+	else if (base_addr == 1)	/* Don't probe at all. */
+		return -ENXIO;
+
+	for (port = ports; *port; port++) {
+		long ioaddr = *port;
+		outb(0x57, ioaddr + PAR_DATA);
+		if (inb(ioaddr + PAR_DATA) != 0x57)
+			continue;
+		if (atp_probe1(ioaddr) == 0)
+			return 0;
+	}
+
+	return -ENODEV;
+}
+
+static int __init atp_probe1(long ioaddr)
+{
+	struct net_device *dev = NULL;
+	struct net_local *lp;
+	int saved_ctrl_reg, status, i;
+	int res;
+
+	outb(0xff, ioaddr + PAR_DATA);
+	/* Save the original value of the Control register, in case we guessed
+	   wrong. */
+	saved_ctrl_reg = inb(ioaddr + PAR_CONTROL);
+	if (net_debug > 3)
+		printk("atp: Control register was %#2.2x.\n", saved_ctrl_reg);
+	/* IRQEN=0, SLCTB=high INITB=high, AUTOFDB=high, STBB=high. */
+	outb(0x04, ioaddr + PAR_CONTROL);
+#ifndef final_version
+	if (net_debug > 3) {
+		/* Turn off the printer multiplexer on the 8012. */
+		for (i = 0; i < 8; i++)
+			outb(mux_8012[i], ioaddr + PAR_DATA);
+		write_reg(ioaddr, MODSEL, 0x00);
+		printk("atp: Registers are ");
+		for (i = 0; i < 32; i++)
+			printk(" %2.2x", read_nibble(ioaddr, i));
+		printk(".\n");
+	}
+#endif
+	/* Turn off the printer multiplexer on the 8012. */
+	for (i = 0; i < 8; i++)
+		outb(mux_8012[i], ioaddr + PAR_DATA);
+	write_reg_high(ioaddr, CMR1, CMR1h_RESET);
+	/* udelay() here? */
+	status = read_nibble(ioaddr, CMR1);
+
+	if (net_debug > 3) {
+		printk(KERN_DEBUG "atp: Status nibble was %#2.2x..", status);
+		for (i = 0; i < 32; i++)
+			printk(" %2.2x", read_nibble(ioaddr, i));
+		printk("\n");
+	}
+
+	if ((status & 0x78) != 0x08) {
+		/* The pocket adapter probe failed, restore the control register. */
+		outb(saved_ctrl_reg, ioaddr + PAR_CONTROL);
+		return -ENODEV;
+	}
+	status = read_nibble(ioaddr, CMR2_h);
+	if ((status & 0x78) != 0x10) {
+		outb(saved_ctrl_reg, ioaddr + PAR_CONTROL);
+		return -ENODEV;
+	}
+
+	dev = alloc_etherdev(sizeof(struct net_local));
+	if (!dev)
+		return -ENOMEM;
+	SET_MODULE_OWNER(dev);
+
+	/* Find the IRQ used by triggering an interrupt. */
+	write_reg_byte(ioaddr, CMR2, 0x01);			/* No accept mode, IRQ out. */
+	write_reg_high(ioaddr, CMR1, CMR1h_RxENABLE | CMR1h_TxENABLE);	/* Enable Tx and Rx. */
+
+	/* Omit autoIRQ routine for now. Use "table lookup" instead.  Uhgggh. */
+	if (irq[0])
+		dev->irq = irq[0];
+	else if (ioaddr == 0x378)
+		dev->irq = 7;
+	else
+		dev->irq = 5;
+	write_reg_high(ioaddr, CMR1, CMR1h_TxRxOFF); /* Disable Tx and Rx units. */
+	write_reg(ioaddr, CMR2, CMR2_NULL);
+
+	dev->base_addr = ioaddr;
+
+	/* Read the station address PROM.  */
+	get_node_ID(dev);
+
+#ifndef MODULE
+	if (net_debug)
+		printk(KERN_INFO "%s" KERN_INFO "%s", versionA, versionB);
+#endif
+
+	printk(KERN_NOTICE "%s: Pocket adapter found at %#3lx, IRQ %d, SAPROM "
+		   "%02X:%02X:%02X:%02X:%02X:%02X.\n", dev->name, dev->base_addr,
+		   dev->irq, dev->dev_addr[0], dev->dev_addr[1], dev->dev_addr[2],
+		   dev->dev_addr[3], dev->dev_addr[4], dev->dev_addr[5]);
+
+	/* Reset the ethernet hardware and activate the printer pass-through. */
+	write_reg_high(ioaddr, CMR1, CMR1h_RESET | CMR1h_MUX);
+
+	lp = netdev_priv(dev);
+	lp->chip_type = RTL8002;
+	lp->addr_mode = CMR2h_Normal;
+	spin_lock_init(&lp->lock);
+
+	/* For the ATP adapter the "if_port" is really the data transfer mode. */
+	if (xcvr[0])
+		dev->if_port = xcvr[0];
+	else
+		dev->if_port = (dev->mem_start & 0xf) ? (dev->mem_start & 0x7) : 4;
+	if (dev->mem_end & 0xf)
+		net_debug = dev->mem_end & 7;
+
+	dev->open		= net_open;
+	dev->stop		= net_close;
+	dev->hard_start_xmit	= atp_send_packet;
+	dev->get_stats		= net_get_stats;
+	dev->set_multicast_list =
+	  lp->chip_type == RTL8002 ? &set_rx_mode_8002 : &set_rx_mode_8012;
+	dev->tx_timeout		= tx_timeout;
+	dev->watchdog_timeo	= TX_TIMEOUT;
+
+	res = register_netdev(dev);
+	if (res) {
+		free_netdev(dev);
+		return res;
+	}
+
+	lp->next_module = root_atp_dev;
+	root_atp_dev = dev;
+
+	return 0;
+}
+
+/* Read the station address PROM, usually a word-wide EEPROM. */
+static void __init get_node_ID(struct net_device *dev)
+{
+	long ioaddr = dev->base_addr;
+	int sa_offset = 0;
+	int i;
+
+	write_reg(ioaddr, CMR2, CMR2_EEPROM);	  /* Point to the EEPROM control registers. */
+
+	/* Some adapters have the station address at offset 15 instead of offset
+	   zero.  Check for it, and fix it if needed. */
+	if (eeprom_op(ioaddr, EE_READ(0)) == 0xffff)
+		sa_offset = 15;
+
+	for (i = 0; i < 3; i++)
+		((u16 *)dev->dev_addr)[i] =
+			be16_to_cpu(eeprom_op(ioaddr, EE_READ(sa_offset + i)));
+
+	write_reg(ioaddr, CMR2, CMR2_NULL);
+}
+
+/*
+  An EEPROM read command starts by shifting out 0x60+address, and then
+  shifting in the serial data. See the NatSemi databook for details.
+ *		   ________________
+ * CS : __|
+ *			   ___	   ___
+ * CLK: ______|	  |___|	  |
+ *		 __ _______ _______
+ * DI :	 __X_______X_______X
+ * DO :	 _________X_______X
+ */
+
+static unsigned short __init eeprom_op(long ioaddr, u32 cmd)
+{
+	unsigned eedata_out = 0;
+	int num_bits = EE_CMD_SIZE;
+
+	while (--num_bits >= 0) {
+		char outval = (cmd & (1<<num_bits)) ? EE_DATA_WRITE : 0;
+		write_reg_high(ioaddr, PROM_CMD, outval | EE_CLK_LOW);
+		write_reg_high(ioaddr, PROM_CMD, outval | EE_CLK_HIGH);
+		eedata_out <<= 1;
+		if (read_nibble(ioaddr, PROM_DATA) & EE_DATA_READ)
+			eedata_out++;
+	}
+	write_reg_high(ioaddr, PROM_CMD, EE_CLK_LOW & ~EE_CS);
+	return eedata_out;
+}
+
+
+/* Open/initialize the board.  This is called (in the current kernel)
+   sometime after booting when the 'ifconfig' program is run.
+
+   This routine sets 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.
+
+   This is an attachable device: if there is no dev->priv entry then it wasn't
+   probed for at boot-time, and we need to probe for it again.
+   */
+static int net_open(struct net_device *dev)
+{
+	struct net_local *lp = netdev_priv(dev);
+	int ret;
+
+	/* The interrupt line is turned off (tri-stated) when the device isn't in
+	   use.  That's especially important for "attached" interfaces where the
+	   port or interrupt may be shared. */
+	ret = request_irq(dev->irq, &atp_interrupt, 0, dev->name, dev);
+	if (ret)
+		return ret;
+
+	hardware_init(dev);
+
+	init_timer(&lp->timer);
+	lp->timer.expires = jiffies + TIMED_CHECKER;
+	lp->timer.data = (unsigned long)dev;
+	lp->timer.function = &atp_timed_checker;    /* timer handler */
+	add_timer(&lp->timer);
+
+	netif_start_queue(dev);
+	return 0;
+}
+
+/* This routine resets the hardware.  We initialize everything, assuming that
+   the hardware may have been temporarily detached. */
+static void hardware_init(struct net_device *dev)
+{
+	struct net_local *lp = netdev_priv(dev);
+	long ioaddr = dev->base_addr;
+    int i;
+
+	/* Turn off the printer multiplexer on the 8012. */
+	for (i = 0; i < 8; i++)
+		outb(mux_8012[i], ioaddr + PAR_DATA);
+	write_reg_high(ioaddr, CMR1, CMR1h_RESET);
+
+    for (i = 0; i < 6; i++)
+		write_reg_byte(ioaddr, PAR0 + i, dev->dev_addr[i]);
+
+	write_reg_high(ioaddr, CMR2, lp->addr_mode);
+
+	if (net_debug > 2) {
+		printk(KERN_DEBUG "%s: Reset: current Rx mode %d.\n", dev->name,
+			   (read_nibble(ioaddr, CMR2_h) >> 3) & 0x0f);
+	}
+
+    write_reg(ioaddr, CMR2, CMR2_IRQOUT);
+    write_reg_high(ioaddr, CMR1, CMR1h_RxENABLE | CMR1h_TxENABLE);
+
+	/* Enable the interrupt line from the serial port. */
+	outb(Ctrl_SelData + Ctrl_IRQEN, ioaddr + PAR_CONTROL);
+
+	/* Unmask the interesting interrupts. */
+    write_reg(ioaddr, IMR, ISR_RxOK | ISR_TxErr | ISR_TxOK);
+    write_reg_high(ioaddr, IMR, ISRh_RxErr);
+
+	lp->tx_unit_busy = 0;
+    lp->pac_cnt_in_tx_buf = 0;
+	lp->saved_tx_size = 0;
+}
+
+static void trigger_send(long ioaddr, int length)
+{
+	write_reg_byte(ioaddr, TxCNT0, length & 0xff);
+	write_reg(ioaddr, TxCNT1, length >> 8);
+	write_reg(ioaddr, CMR1, CMR1_Xmit);
+}
+
+static void write_packet(long ioaddr, int length, unsigned char *packet, int pad_len, int data_mode)
+{
+    if (length & 1)
+    {
+    	length++;
+    	pad_len++;
+    }
+
+    outb(EOC+MAR, ioaddr + PAR_DATA);
+    if ((data_mode & 1) == 0) {
+		/* Write the packet out, starting with the write addr. */
+		outb(WrAddr+MAR, ioaddr + PAR_DATA);
+		do {
+			write_byte_mode0(ioaddr, *packet++);
+		} while (--length > pad_len) ;
+		do {
+			write_byte_mode0(ioaddr, 0);
+		} while (--length > 0) ;
+    } else {
+		/* Write the packet out in slow mode. */
+		unsigned char outbyte = *packet++;
+
+		outb(Ctrl_LNibWrite + Ctrl_IRQEN, ioaddr + PAR_CONTROL);
+		outb(WrAddr+MAR, ioaddr + PAR_DATA);
+
+		outb((outbyte & 0x0f)|0x40, ioaddr + PAR_DATA);
+		outb(outbyte & 0x0f, ioaddr + PAR_DATA);
+		outbyte >>= 4;
+		outb(outbyte & 0x0f, ioaddr + PAR_DATA);
+		outb(Ctrl_HNibWrite + Ctrl_IRQEN, ioaddr + PAR_CONTROL);
+		while (--length > pad_len)
+			write_byte_mode1(ioaddr, *packet++);
+		while (--length > 0)
+			write_byte_mode1(ioaddr, 0);
+    }
+    /* Terminate the Tx frame.  End of write: ECB. */
+    outb(0xff, ioaddr + PAR_DATA);
+    outb(Ctrl_HNibWrite | Ctrl_SelData | Ctrl_IRQEN, ioaddr + PAR_CONTROL);
+}
+
+static void tx_timeout(struct net_device *dev)
+{
+	struct net_local *np = netdev_priv(dev);
+	long ioaddr = dev->base_addr;
+
+	printk(KERN_WARNING "%s: Transmit timed out, %s?\n", dev->name,
+		   inb(ioaddr + PAR_CONTROL) & 0x10 ? "network cable problem"
+		   :  "IRQ conflict");
+	np->stats.tx_errors++;
+	/* Try to restart the adapter. */
+	hardware_init(dev);
+	dev->trans_start = jiffies;
+	netif_wake_queue(dev);
+	np->stats.tx_errors++;
+}
+
+static int atp_send_packet(struct sk_buff *skb, struct net_device *dev)
+{
+	struct net_local *lp = netdev_priv(dev);
+	long ioaddr = dev->base_addr;
+	int length;
+	unsigned long flags;
+
+	length = ETH_ZLEN < skb->len ? skb->len : ETH_ZLEN;
+
+	netif_stop_queue(dev);
+
+	/* Disable interrupts by writing 0x00 to the Interrupt Mask Register.
+	   This sequence must not be interrupted by an incoming packet. */
+
+	spin_lock_irqsave(&lp->lock, flags);
+	write_reg(ioaddr, IMR, 0);
+	write_reg_high(ioaddr, IMR, 0);
+	spin_unlock_irqrestore(&lp->lock, flags);
+
+	write_packet(ioaddr, length, skb->data, length-skb->len, dev->if_port);
+
+	lp->pac_cnt_in_tx_buf++;
+	if (lp->tx_unit_busy == 0) {
+		trigger_send(ioaddr, length);
+		lp->saved_tx_size = 0; 				/* Redundant */
+		lp->re_tx = 0;
+		lp->tx_unit_busy = 1;
+	} else
+		lp->saved_tx_size = length;
+	/* Re-enable the LPT interrupts. */
+	write_reg(ioaddr, IMR, ISR_RxOK | ISR_TxErr | ISR_TxOK);
+	write_reg_high(ioaddr, IMR, ISRh_RxErr);
+
+	dev->trans_start = jiffies;
+	dev_kfree_skb (skb);
+	return 0;
+}
+
+
+/* The typical workload of the driver:
+   Handle the network interface interrupts. */
+static irqreturn_t
+atp_interrupt(int irq, void *dev_instance, struct pt_regs * regs)
+{
+	struct net_device *dev = (struct net_device *)dev_instance;
+	struct net_local *lp;
+	long ioaddr;
+	static int num_tx_since_rx;
+	int boguscount = max_interrupt_work;
+	int handled = 0;
+
+	if (dev == NULL) {
+		printk(KERN_ERR "ATP_interrupt(): irq %d for unknown device.\n", irq);
+		return IRQ_NONE;
+	}
+	ioaddr = dev->base_addr;
+	lp = netdev_priv(dev);
+
+	spin_lock(&lp->lock);
+
+	/* Disable additional spurious interrupts. */
+	outb(Ctrl_SelData, ioaddr + PAR_CONTROL);
+
+	/* The adapter's output is currently the IRQ line, switch it to data. */
+	write_reg(ioaddr, CMR2, CMR2_NULL);
+	write_reg(ioaddr, IMR, 0);
+
+	if (net_debug > 5) printk(KERN_DEBUG "%s: In interrupt ", dev->name);
+    while (--boguscount > 0) {
+		int status = read_nibble(ioaddr, ISR);
+		if (net_debug > 5) printk("loop status %02x..", status);
+
+		if (status & (ISR_RxOK<<3)) {
+			handled = 1;
+			write_reg(ioaddr, ISR, ISR_RxOK); /* Clear the Rx interrupt. */
+			do {
+				int read_status = read_nibble(ioaddr, CMR1);
+				if (net_debug > 6)
+					printk("handling Rx packet %02x..", read_status);
+				/* We acknowledged the normal Rx interrupt, so if the interrupt
+				   is still outstanding we must have a Rx error. */
+				if (read_status & (CMR1_IRQ << 3)) { /* Overrun. */
+					lp->stats.rx_over_errors++;
+					/* Set to no-accept mode long enough to remove a packet. */
+					write_reg_high(ioaddr, CMR2, CMR2h_OFF);
+					net_rx(dev);
+					/* Clear the interrupt and return to normal Rx mode. */
+					write_reg_high(ioaddr, ISR, ISRh_RxErr);
+					write_reg_high(ioaddr, CMR2, lp->addr_mode);
+				} else if ((read_status & (CMR1_BufEnb << 3)) == 0) {
+					net_rx(dev);
+					num_tx_since_rx = 0;
+				} else
+					break;
+			} while (--boguscount > 0);
+		} else if (status & ((ISR_TxErr + ISR_TxOK)<<3)) {
+			handled = 1;
+			if (net_debug > 6)  printk("handling Tx done..");
+			/* Clear the Tx interrupt.  We should check for too many failures
+			   and reinitialize the adapter. */
+			write_reg(ioaddr, ISR, ISR_TxErr + ISR_TxOK);
+			if (status & (ISR_TxErr<<3)) {
+				lp->stats.collisions++;
+				if (++lp->re_tx > 15) {
+					lp->stats.tx_aborted_errors++;
+					hardware_init(dev);
+					break;
+				}
+				/* Attempt to retransmit. */
+				if (net_debug > 6)  printk("attempting to ReTx");
+				write_reg(ioaddr, CMR1, CMR1_ReXmit + CMR1_Xmit);
+			} else {
+				/* Finish up the transmit. */
+				lp->stats.tx_packets++;
+				lp->pac_cnt_in_tx_buf--;
+				if ( lp->saved_tx_size) {
+					trigger_send(ioaddr, lp->saved_tx_size);
+					lp->saved_tx_size = 0;
+					lp->re_tx = 0;
+				} else
+					lp->tx_unit_busy = 0;
+				netif_wake_queue(dev);	/* Inform upper layers. */
+			}
+			num_tx_since_rx++;
+		} else if (num_tx_since_rx > 8
+				   && time_after(jiffies, dev->last_rx + HZ)) {
+			if (net_debug > 2)
+				printk(KERN_DEBUG "%s: Missed packet? No Rx after %d Tx and "
+					   "%ld jiffies status %02x  CMR1 %02x.\n", dev->name,
+					   num_tx_since_rx, jiffies - dev->last_rx, status,
+					   (read_nibble(ioaddr, CMR1) >> 3) & 15);
+			lp->stats.rx_missed_errors++;
+			hardware_init(dev);
+			num_tx_since_rx = 0;
+			break;
+		} else
+			break;
+    }
+
+	/* This following code fixes a rare (and very difficult to track down)
+	   problem where the adapter forgets its ethernet address. */
+	{
+		int i;
+		for (i = 0; i < 6; i++)
+			write_reg_byte(ioaddr, PAR0 + i, dev->dev_addr[i]);
+#if 0 && defined(TIMED_CHECKER)
+		mod_timer(&lp->timer, jiffies + TIMED_CHECKER);
+#endif
+	}
+
+	/* Tell the adapter that it can go back to using the output line as IRQ. */
+    write_reg(ioaddr, CMR2, CMR2_IRQOUT);
+	/* Enable the physical interrupt line, which is sure to be low until.. */
+	outb(Ctrl_SelData + Ctrl_IRQEN, ioaddr + PAR_CONTROL);
+	/* .. we enable the interrupt sources. */
+	write_reg(ioaddr, IMR, ISR_RxOK | ISR_TxErr | ISR_TxOK);
+	write_reg_high(ioaddr, IMR, ISRh_RxErr); 			/* Hmmm, really needed? */
+
+	spin_unlock(&lp->lock);
+
+	if (net_debug > 5) printk("exiting interrupt.\n");
+	return IRQ_RETVAL(handled);
+}
+
+#ifdef TIMED_CHECKER
+/* This following code fixes a rare (and very difficult to track down)
+   problem where the adapter forgets its ethernet address. */
+static void atp_timed_checker(unsigned long data)
+{
+	struct net_device *dev = (struct net_device *)data;
+	long ioaddr = dev->base_addr;
+	struct net_local *lp = netdev_priv(dev);
+	int tickssofar = jiffies - lp->last_rx_time;
+	int i;
+
+	spin_lock(&lp->lock);
+	if (tickssofar > 2*HZ) {
+#if 1
+		for (i = 0; i < 6; i++)
+			write_reg_byte(ioaddr, PAR0 + i, dev->dev_addr[i]);
+		lp->last_rx_time = jiffies;
+#else
+		for (i = 0; i < 6; i++)
+			if (read_cmd_byte(ioaddr, PAR0 + i) != atp_timed_dev->dev_addr[i])
+				{
+			struct net_local *lp = netdev_priv(atp_timed_dev);
+			write_reg_byte(ioaddr, PAR0 + i, atp_timed_dev->dev_addr[i]);
+			if (i == 2)
+			  lp->stats.tx_errors++;
+			else if (i == 3)
+			  lp->stats.tx_dropped++;
+			else if (i == 4)
+			  lp->stats.collisions++;
+			else
+			  lp->stats.rx_errors++;
+		  }
+#endif
+	}
+	spin_unlock(&lp->lock);
+	lp->timer.expires = jiffies + TIMED_CHECKER;
+	add_timer(&lp->timer);
+}
+#endif
+
+/* 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);
+	long ioaddr = dev->base_addr;
+	struct rx_header rx_head;
+
+	/* Process the received packet. */
+	outb(EOC+MAR, ioaddr + PAR_DATA);
+	read_block(ioaddr, 8, (unsigned char*)&rx_head, dev->if_port);
+	if (net_debug > 5)
+		printk(KERN_DEBUG " rx_count %04x %04x %04x %04x..", rx_head.pad,
+			   rx_head.rx_count, rx_head.rx_status, rx_head.cur_addr);
+	if ((rx_head.rx_status & 0x77) != 0x01) {
+		lp->stats.rx_errors++;
+		if (rx_head.rx_status & 0x0004) lp->stats.rx_frame_errors++;
+		else if (rx_head.rx_status & 0x0002) lp->stats.rx_crc_errors++;
+		if (net_debug > 3)
+			printk(KERN_DEBUG "%s: Unknown ATP Rx error %04x.\n",
+				   dev->name, rx_head.rx_status);
+		if  (rx_head.rx_status & 0x0020) {
+			lp->stats.rx_fifo_errors++;
+			write_reg_high(ioaddr, CMR1, CMR1h_TxENABLE);
+			write_reg_high(ioaddr, CMR1, CMR1h_RxENABLE | CMR1h_TxENABLE);
+		} else if (rx_head.rx_status & 0x0050)
+			hardware_init(dev);
+		return;
+	} else {
+		/* Malloc up new buffer. The "-4" omits the FCS (CRC). */
+		int pkt_len = (rx_head.rx_count & 0x7ff) - 4;
+		struct sk_buff *skb;
+
+		skb = dev_alloc_skb(pkt_len + 2);
+		if (skb == NULL) {
+			printk(KERN_ERR "%s: Memory squeeze, dropping packet.\n",
+				   dev->name);
+			lp->stats.rx_dropped++;
+			goto done;
+		}
+		skb->dev = dev;
+
+		skb_reserve(skb, 2);	/* Align IP on 16 byte boundaries */
+		read_block(ioaddr, pkt_len, skb_put(skb,pkt_len), dev->if_port);
+		skb->protocol = eth_type_trans(skb, dev);
+		netif_rx(skb);
+		dev->last_rx = jiffies;
+		lp->stats.rx_packets++;
+		lp->stats.rx_bytes += pkt_len;
+	}
+ done:
+	write_reg(ioaddr, CMR1, CMR1_NextPkt);
+	lp->last_rx_time = jiffies;
+	return;
+}
+
+static void read_block(long ioaddr, int length, unsigned char *p, int data_mode)
+{
+
+	if (data_mode <= 3) { /* Mode 0 or 1 */
+		outb(Ctrl_LNibRead, ioaddr + PAR_CONTROL);
+		outb(length == 8  ?  RdAddr | HNib | MAR  :  RdAddr | MAR,
+			 ioaddr + PAR_DATA);
+		if (data_mode <= 1) { /* Mode 0 or 1 */
+			do  *p++ = read_byte_mode0(ioaddr);  while (--length > 0);
+		} else	/* Mode 2 or 3 */
+			do  *p++ = read_byte_mode2(ioaddr);  while (--length > 0);
+	} else if (data_mode <= 5)
+		do      *p++ = read_byte_mode4(ioaddr);  while (--length > 0);
+	else
+		do      *p++ = read_byte_mode6(ioaddr);  while (--length > 0);
+
+    outb(EOC+HNib+MAR, ioaddr + PAR_DATA);
+	outb(Ctrl_SelData, ioaddr + PAR_CONTROL);
+}
+
+/* The inverse routine to net_open(). */
+static int
+net_close(struct net_device *dev)
+{
+	struct net_local *lp = netdev_priv(dev);
+	long ioaddr = dev->base_addr;
+
+	netif_stop_queue(dev);
+
+	del_timer_sync(&lp->timer);
+
+	/* Flush the Tx and disable Rx here. */
+	lp->addr_mode = CMR2h_OFF;
+	write_reg_high(ioaddr, CMR2, CMR2h_OFF);
+
+	/* Free the IRQ line. */
+	outb(0x00, ioaddr + PAR_CONTROL);
+	free_irq(dev->irq, dev);
+
+	/* Reset the ethernet hardware and activate the printer pass-through. */
+	write_reg_high(ioaddr, CMR1, CMR1h_RESET | CMR1h_MUX);
+	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);
+	return &lp->stats;
+}
+
+/*
+ *	Set or clear the multicast filter for this adapter.
+ */
+
+static void set_rx_mode_8002(struct net_device *dev)
+{
+	struct net_local *lp = netdev_priv(dev);
+	long ioaddr = dev->base_addr;
+
+	if ( dev->mc_count > 0 || (dev->flags & (IFF_ALLMULTI|IFF_PROMISC))) {
+		/* We must make the kernel realise we had to move
+		 *	into promisc mode or we start all out war on
+		 *	the cable. - AC
+		 */
+		dev->flags|=IFF_PROMISC;
+		lp->addr_mode = CMR2h_PROMISC;
+	} else
+		lp->addr_mode = CMR2h_Normal;
+	write_reg_high(ioaddr, CMR2, lp->addr_mode);
+}
+
+static void set_rx_mode_8012(struct net_device *dev)
+{
+	struct net_local *lp = netdev_priv(dev);
+	long ioaddr = dev->base_addr;
+	unsigned char new_mode, mc_filter[8]; /* Multicast hash filter */
+	int i;
+
+	if (dev->flags & IFF_PROMISC) {			/* Set promiscuous. */
+		new_mode = CMR2h_PROMISC;
+	} else if ((dev->mc_count > 1000)  ||  (dev->flags & IFF_ALLMULTI)) {
+		/* Too many to filter perfectly -- accept all multicasts. */
+		memset(mc_filter, 0xff, sizeof(mc_filter));
+		new_mode = CMR2h_Normal;
+	} else {
+		struct dev_mc_list *mclist;
+
+		memset(mc_filter, 0, sizeof(mc_filter));
+		for (i = 0, mclist = dev->mc_list; mclist && i < dev->mc_count;
+			 i++, mclist = mclist->next)
+		{
+			int filterbit = ether_crc_le(ETH_ALEN, mclist->dmi_addr) & 0x3f;
+			mc_filter[filterbit >> 5] |= 1 << (filterbit & 31);
+		}
+		new_mode = CMR2h_Normal;
+	}
+	lp->addr_mode = new_mode;
+    write_reg(ioaddr, CMR2, CMR2_IRQOUT | 0x04); /* Switch to page 1. */
+    for (i = 0; i < 8; i++)
+		write_reg_byte(ioaddr, i, mc_filter[i]);
+	if (net_debug > 2 || 1) {
+		lp->addr_mode = 1;
+		printk(KERN_DEBUG "%s: Mode %d, setting multicast filter to",
+			   dev->name, lp->addr_mode);
+		for (i = 0; i < 8; i++)
+			printk(" %2.2x", mc_filter[i]);
+		printk(".\n");
+	}
+
+	write_reg_high(ioaddr, CMR2, lp->addr_mode);
+    write_reg(ioaddr, CMR2, CMR2_IRQOUT); /* Switch back to page 0 */
+}
+
+static int __init atp_init_module(void) {
+	if (debug)					/* Emit version even if no cards detected. */
+		printk(KERN_INFO "%s" KERN_INFO "%s", versionA, versionB);
+	return atp_init();
+}
+
+static void __exit atp_cleanup_module(void) {
+	struct net_device *next_dev;
+
+	while (root_atp_dev) {
+		next_dev = ((struct net_local *)root_atp_dev->priv)->next_module;
+		unregister_netdev(root_atp_dev);
+		/* No need to release_region(), since we never snarf it. */
+		free_netdev(root_atp_dev);
+		root_atp_dev = next_dev;
+	}
+}
+
+module_init(atp_init_module);
+module_exit(atp_cleanup_module);