1/* atp.c: Attached (pocket) ethernet adapter driver for linux. */
  2/*
  3	This is a driver for commonly OEM pocket (parallel port)
  4	ethernet adapters based on the Realtek RTL8002 and RTL8012 chips.
  5
  6	Written 1993-2000 by Donald Becker.
  7
  8	This software may be used and distributed according to the terms of
  9	the GNU General Public License (GPL), incorporated herein by reference.
 10	Drivers based on or derived from this code fall under the GPL and must
 11	retain the authorship, copyright and license notice.  This file is not
 12	a complete program and may only be used when the entire operating
 13	system is licensed under the GPL.
 14
 15	Copyright 1993 United States Government as represented by the Director,
 16	National Security Agency.  Copyright 1994-2000 retained by the original
 17	author, Donald Becker. The timer-based reset code was supplied in 1995
 18	by Bill Carlson, wwc@super.org.
 19
 20	The author may be reached as becker@scyld.com, or C/O
 21	Scyld Computing Corporation
 22	410 Severn Ave., Suite 210
 23	Annapolis MD 21403
 24
 25	Support information and updates available at
 26	http://www.scyld.com/network/atp.html
 27
 28
 29	Modular support/softnet added by Alan Cox.
 30	_bit abuse fixed up by Alan Cox
 31
 32*/
 33
 34static const char version[] =
 35"atp.c:v1.09=ac 2002/10/01 Donald Becker <becker@scyld.com>\n";
 36
 37/* The user-configurable values.
 38   These may be modified when a driver module is loaded.*/
 39
 40static int debug = 1; 			/* 1 normal messages, 0 quiet .. 7 verbose. */
 41#define net_debug debug
 42
 43/* Maximum events (Rx packets, etc.) to handle at each interrupt. */
 44static int max_interrupt_work = 15;
 45
 46#define NUM_UNITS 2
 47/* The standard set of ISA module parameters. */
 48static int io[NUM_UNITS];
 49static int irq[NUM_UNITS];
 50static int xcvr[NUM_UNITS]; 			/* The data transfer mode. */
 51
 52/* Operational parameters that are set at compile time. */
 53
 54/* Time in jiffies before concluding the transmitter is hung. */
 55#define TX_TIMEOUT  (400*HZ/1000)
 56
 57/*
 58	This file is a device driver for the RealTek (aka AT-Lan-Tec) pocket
 59	ethernet adapter.  This is a common low-cost OEM pocket ethernet
 60	adapter, sold under many names.
 61
 62  Sources:
 63	This driver was written from the packet driver assembly code provided by
 64	Vincent Bono of AT-Lan-Tec.	 Ever try to figure out how a complicated
 65	device works just from the assembly code?  It ain't pretty.  The following
 66	description is written based on guesses and writing lots of special-purpose
 67	code to test my theorized operation.
 68
 69	In 1997 Realtek made available the documentation for the second generation
 70	RTL8012 chip, which has lead to several driver improvements.
 71	  http://www.realtek.com.tw/
 72
 73					Theory of Operation
 74
 75	The RTL8002 adapter seems to be built around a custom spin of the SEEQ
 76	controller core.  It probably has a 16K or 64K internal packet buffer, of
 77	which the first 4K is devoted to transmit and the rest to receive.
 78	The controller maintains the queue of received packet and the packet buffer
 79	access pointer internally, with only 'reset to beginning' and 'skip to next
 80	packet' commands visible.  The transmit packet queue holds two (or more?)
 81	packets: both 'retransmit this packet' (due to collision) and 'transmit next
 82	packet' commands must be started by hand.
 83
 84	The station address is stored in a standard bit-serial EEPROM which must be
 85	read (ughh) by the device driver.  (Provisions have been made for
 86	substituting a 74S288 PROM, but I haven't gotten reports of any models
 87	using it.)  Unlike built-in devices, a pocket adapter can temporarily lose
 88	power without indication to the device driver.  The major effect is that
 89	the station address, receive filter (promiscuous, etc.) and transceiver
 90	must be reset.
 91
 92	The controller itself has 16 registers, some of which use only the lower
 93	bits.  The registers are read and written 4 bits at a time.  The four bit
 94	register address is presented on the data lines along with a few additional
 95	timing and control bits.  The data is then read from status port or written
 96	to the data port.
 97
 98	Correction: the controller has two banks of 16 registers.  The second
 99	bank contains only the multicast filter table (now used) and the EEPROM
100	access registers.
101
102	Since the bulk data transfer of the actual packets through the slow
103	parallel port dominates the driver's running time, four distinct data
104	(non-register) transfer modes are provided by the adapter, two in each
105	direction.  In the first mode timing for the nibble transfers is
106	provided through the data port.  In the second mode the same timing is
107	provided through the control port.  In either case the data is read from
108	the status port and written to the data port, just as it is accessing
109	registers.
110
111	In addition to the basic data transfer methods, several more are modes are
112	created by adding some delay by doing multiple reads of the data to allow
113	it to stabilize.  This delay seems to be needed on most machines.
114
115	The data transfer mode is stored in the 'dev->if_port' field.  Its default
116	value is '4'.  It may be overridden at boot-time using the third parameter
117	to the "ether=..." initialization.
118
119	The header file <atp.h> provides inline functions that encapsulate the
120	register and data access methods.  These functions are hand-tuned to
121	generate reasonable object code.  This header file also documents my
122	interpretations of the device registers.
123*/
124
125#include <linux/kernel.h>
126#include <linux/module.h>
127#include <linux/types.h>
128#include <linux/fcntl.h>
129#include <linux/interrupt.h>
130#include <linux/ioport.h>
131#include <linux/in.h>
132#include <linux/string.h>
133#include <linux/errno.h>
134#include <linux/init.h>
135#include <linux/crc32.h>
136#include <linux/netdevice.h>
137#include <linux/etherdevice.h>
138#include <linux/skbuff.h>
139#include <linux/spinlock.h>
140#include <linux/delay.h>
141#include <linux/bitops.h>
142
143#include <asm/io.h>
144#include <asm/dma.h>
145
146#include "atp.h"
147
148MODULE_AUTHOR("Donald Becker <becker@scyld.com>");
149MODULE_DESCRIPTION("RealTek RTL8002/8012 parallel port Ethernet driver");
150MODULE_LICENSE("GPL");
151
152module_param(max_interrupt_work, int, 0);
153module_param(debug, int, 0);
154module_param_hw_array(io, int, ioport, NULL, 0);
155module_param_hw_array(irq, int, irq, NULL, 0);
156module_param_array(xcvr, int, NULL, 0);
157MODULE_PARM_DESC(max_interrupt_work, "ATP maximum events handled per interrupt");
158MODULE_PARM_DESC(debug, "ATP debug level (0-7)");
159MODULE_PARM_DESC(io, "ATP I/O base address(es)");
160MODULE_PARM_DESC(irq, "ATP IRQ number(s)");
161MODULE_PARM_DESC(xcvr, "ATP transceiver(s) (0=internal, 1=external)");
162
163/* The number of low I/O ports used by the ethercard. */
164#define ETHERCARD_TOTAL_SIZE	3
165
166/* Sequence to switch an 8012 from printer mux to ethernet mode. */
167static char mux_8012[] = { 0xff, 0xf7, 0xff, 0xfb, 0xf3, 0xfb, 0xff, 0xf7,};
168
169struct net_local {
170    spinlock_t lock;
171    struct net_device *next_module;
172    struct timer_list timer;	/* Media selection timer. */
173    struct net_device *dev;	/* Timer dev. */
174    unsigned long last_rx_time;	/* Last Rx, in jiffies, to handle Rx hang. */
175    int saved_tx_size;
176    unsigned int tx_unit_busy:1;
177    unsigned char re_tx,	/* Number of packet retransmissions. */
178		addr_mode,		/* Current Rx filter e.g. promiscuous, etc. */
179		pac_cnt_in_tx_buf;
180};
181
182/* This code, written by wwc@super.org, resets the adapter every
183   TIMED_CHECKER ticks.  This recovers from an unknown error which
184   hangs the device. */
185#define TIMED_CHECKER (HZ/4)
186#ifdef TIMED_CHECKER
187#include <linux/timer.h>
188static void atp_timed_checker(struct timer_list *t);
189#endif
190
191/* Index to functions, as function prototypes. */
192
193static int atp_probe1(long ioaddr);
194static void get_node_ID(struct net_device *dev);
195static unsigned short eeprom_op(long ioaddr, unsigned int cmd);
196static int net_open(struct net_device *dev);
197static void hardware_init(struct net_device *dev);
198static void write_packet(long ioaddr, int length, unsigned char *packet, int pad, int mode);
199static void trigger_send(long ioaddr, int length);
200static netdev_tx_t atp_send_packet(struct sk_buff *skb,
201				   struct net_device *dev);
202static irqreturn_t atp_interrupt(int irq, void *dev_id);
203static void net_rx(struct net_device *dev);
204static void read_block(long ioaddr, int length, unsigned char *buffer, int data_mode);
205static int net_close(struct net_device *dev);
206static void set_rx_mode(struct net_device *dev);
207static void tx_timeout(struct net_device *dev, unsigned int txqueue);
208
209
210/* A list of all installed ATP devices, for removing the driver module. */
211static struct net_device *root_atp_dev;
212
213/* Check for a network adapter of this type, and return '0' iff one exists.
214   If dev->base_addr == 0, probe all likely locations.
215   If dev->base_addr == 1, always return failure.
216   If dev->base_addr == 2, allocate space for the device and return success
217   (detachable devices only).
218
219   FIXME: we should use the parport layer for this
220   */
221static int __init atp_init(void)
222{
223	int *port, ports[] = {0x378, 0x278, 0x3bc, 0};
224	int base_addr = io[0];
225
226	if (base_addr > 0x1ff)		/* Check a single specified location. */
227		return atp_probe1(base_addr);
228	else if (base_addr == 1)	/* Don't probe at all. */
229		return -ENXIO;
230
231	for (port = ports; *port; port++) {
232		long ioaddr = *port;
233		outb(0x57, ioaddr + PAR_DATA);
234		if (inb(ioaddr + PAR_DATA) != 0x57)
235			continue;
236		if (atp_probe1(ioaddr) == 0)
237			return 0;
238	}
239
240	return -ENODEV;
241}
242
243static const struct net_device_ops atp_netdev_ops = {
244	.ndo_open		= net_open,
245	.ndo_stop		= net_close,
246	.ndo_start_xmit		= atp_send_packet,
247	.ndo_set_rx_mode	= set_rx_mode,
248	.ndo_tx_timeout		= tx_timeout,
249	.ndo_set_mac_address 	= eth_mac_addr,
250	.ndo_validate_addr	= eth_validate_addr,
251};
252
253static int __init atp_probe1(long ioaddr)
254{
255	struct net_device *dev = NULL;
256	struct net_local *lp;
257	int saved_ctrl_reg, status, i;
258	int res;
259
260	outb(0xff, ioaddr + PAR_DATA);
261	/* Save the original value of the Control register, in case we guessed
262	   wrong. */
263	saved_ctrl_reg = inb(ioaddr + PAR_CONTROL);
264	if (net_debug > 3)
265		printk("atp: Control register was %#2.2x.\n", saved_ctrl_reg);
266	/* IRQEN=0, SLCTB=high INITB=high, AUTOFDB=high, STBB=high. */
267	outb(0x04, ioaddr + PAR_CONTROL);
268#ifndef final_version
269	if (net_debug > 3) {
270		/* Turn off the printer multiplexer on the 8012. */
271		for (i = 0; i < 8; i++)
272			outb(mux_8012[i], ioaddr + PAR_DATA);
273		write_reg(ioaddr, MODSEL, 0x00);
274		printk("atp: Registers are ");
275		for (i = 0; i < 32; i++)
276			printk(" %2.2x", read_nibble(ioaddr, i));
277		printk(".\n");
278	}
279#endif
280	/* Turn off the printer multiplexer on the 8012. */
281	for (i = 0; i < 8; i++)
282		outb(mux_8012[i], ioaddr + PAR_DATA);
283	write_reg_high(ioaddr, CMR1, CMR1h_RESET);
284	/* udelay() here? */
285	status = read_nibble(ioaddr, CMR1);
286
287	if (net_debug > 3) {
288		printk(KERN_DEBUG "atp: Status nibble was %#2.2x..", status);
289		for (i = 0; i < 32; i++)
290			printk(" %2.2x", read_nibble(ioaddr, i));
291		printk("\n");
292	}
293
294	if ((status & 0x78) != 0x08) {
295		/* The pocket adapter probe failed, restore the control register. */
296		outb(saved_ctrl_reg, ioaddr + PAR_CONTROL);
297		return -ENODEV;
298	}
299	status = read_nibble(ioaddr, CMR2_h);
300	if ((status & 0x78) != 0x10) {
301		outb(saved_ctrl_reg, ioaddr + PAR_CONTROL);
302		return -ENODEV;
303	}
304
305	dev = alloc_etherdev(sizeof(struct net_local));
306	if (!dev)
307		return -ENOMEM;
308
309	/* Find the IRQ used by triggering an interrupt. */
310	write_reg_byte(ioaddr, CMR2, 0x01);			/* No accept mode, IRQ out. */
311	write_reg_high(ioaddr, CMR1, CMR1h_RxENABLE | CMR1h_TxENABLE);	/* Enable Tx and Rx. */
312
313	/* Omit autoIRQ routine for now. Use "table lookup" instead.  Uhgggh. */
314	if (irq[0])
315		dev->irq = irq[0];
316	else if (ioaddr == 0x378)
317		dev->irq = 7;
318	else
319		dev->irq = 5;
320	write_reg_high(ioaddr, CMR1, CMR1h_TxRxOFF); /* Disable Tx and Rx units. */
321	write_reg(ioaddr, CMR2, CMR2_NULL);
322
323	dev->base_addr = ioaddr;
324
325	/* Read the station address PROM.  */
326	get_node_ID(dev);
327
328#ifndef MODULE
329	if (net_debug)
330		printk(KERN_INFO "%s", version);
331#endif
332
333	printk(KERN_NOTICE "%s: Pocket adapter found at %#3lx, IRQ %d, "
334	       "SAPROM %pM.\n",
335	       dev->name, dev->base_addr, dev->irq, dev->dev_addr);
336
337	/* Reset the ethernet hardware and activate the printer pass-through. */
338	write_reg_high(ioaddr, CMR1, CMR1h_RESET | CMR1h_MUX);
339
340	lp = netdev_priv(dev);
341	lp->addr_mode = CMR2h_Normal;
342	spin_lock_init(&lp->lock);
343
344	/* For the ATP adapter the "if_port" is really the data transfer mode. */
345	if (xcvr[0])
346		dev->if_port = xcvr[0];
347	else
348		dev->if_port = (dev->mem_start & 0xf) ? (dev->mem_start & 0x7) : 4;
349	if (dev->mem_end & 0xf)
350		net_debug = dev->mem_end & 7;
351
352	dev->netdev_ops 	= &atp_netdev_ops;
353	dev->watchdog_timeo	= TX_TIMEOUT;
354
355	res = register_netdev(dev);
356	if (res) {
357		free_netdev(dev);
358		return res;
359	}
360
361	lp->next_module = root_atp_dev;
362	root_atp_dev = dev;
363
364	return 0;
365}
366
367/* Read the station address PROM, usually a word-wide EEPROM. */
368static void __init get_node_ID(struct net_device *dev)
369{
370	long ioaddr = dev->base_addr;
371	__be16 addr[ETH_ALEN / 2];
372	int sa_offset = 0;
373	int i;
374
375	write_reg(ioaddr, CMR2, CMR2_EEPROM);	  /* Point to the EEPROM control registers. */
376
377	/* Some adapters have the station address at offset 15 instead of offset
378	   zero.  Check for it, and fix it if needed. */
379	if (eeprom_op(ioaddr, EE_READ(0)) == 0xffff)
380		sa_offset = 15;
381
382	for (i = 0; i < 3; i++)
383		addr[i] =
384			cpu_to_be16(eeprom_op(ioaddr, EE_READ(sa_offset + i)));
385	eth_hw_addr_set(dev, (u8 *)addr);
386
387	write_reg(ioaddr, CMR2, CMR2_NULL);
388}
389
390/*
391  An EEPROM read command starts by shifting out 0x60+address, and then
392  shifting in the serial data. See the NatSemi databook for details.
393 *		   ________________
394 * CS : __|
395 *			   ___	   ___
396 * CLK: ______|	  |___|	  |
397 *		 __ _______ _______
398 * DI :	 __X_______X_______X
399 * DO :	 _________X_______X
400 */
401
402static unsigned short __init eeprom_op(long ioaddr, u32 cmd)
403{
404	unsigned eedata_out = 0;
405	int num_bits = EE_CMD_SIZE;
406
407	while (--num_bits >= 0) {
408		char outval = (cmd & (1<<num_bits)) ? EE_DATA_WRITE : 0;
409		write_reg_high(ioaddr, PROM_CMD, outval | EE_CLK_LOW);
410		write_reg_high(ioaddr, PROM_CMD, outval | EE_CLK_HIGH);
411		eedata_out <<= 1;
412		if (read_nibble(ioaddr, PROM_DATA) & EE_DATA_READ)
413			eedata_out++;
414	}
415	write_reg_high(ioaddr, PROM_CMD, EE_CLK_LOW & ~EE_CS);
416	return eedata_out;
417}
418
419
420/* Open/initialize the board.  This is called (in the current kernel)
421   sometime after booting when the 'ifconfig' program is run.
422
423   This routine sets everything up anew at each open, even
424   registers that "should" only need to be set once at boot, so that
425   there is non-reboot way to recover if something goes wrong.
426
427   This is an attachable device: if there is no private entry then it wasn't
428   probed for at boot-time, and we need to probe for it again.
429   */
430static int net_open(struct net_device *dev)
431{
432	struct net_local *lp = netdev_priv(dev);
433	int ret;
434
435	/* The interrupt line is turned off (tri-stated) when the device isn't in
436	   use.  That's especially important for "attached" interfaces where the
437	   port or interrupt may be shared. */
438	ret = request_irq(dev->irq, atp_interrupt, 0, dev->name, dev);
439	if (ret)
440		return ret;
441
442	hardware_init(dev);
443
444	lp->dev = dev;
445	timer_setup(&lp->timer, atp_timed_checker, 0);
446	lp->timer.expires = jiffies + TIMED_CHECKER;
447	add_timer(&lp->timer);
448
449	netif_start_queue(dev);
450	return 0;
451}
452
453/* This routine resets the hardware.  We initialize everything, assuming that
454   the hardware may have been temporarily detached. */
455static void hardware_init(struct net_device *dev)
456{
457	struct net_local *lp = netdev_priv(dev);
458	long ioaddr = dev->base_addr;
459	int i;
460
461	/* Turn off the printer multiplexer on the 8012. */
462	for (i = 0; i < 8; i++)
463		outb(mux_8012[i], ioaddr + PAR_DATA);
464	write_reg_high(ioaddr, CMR1, CMR1h_RESET);
465
466	for (i = 0; i < 6; i++)
467		write_reg_byte(ioaddr, PAR0 + i, dev->dev_addr[i]);
468
469	write_reg_high(ioaddr, CMR2, lp->addr_mode);
470
471	if (net_debug > 2) {
472		printk(KERN_DEBUG "%s: Reset: current Rx mode %d.\n", dev->name,
473			   (read_nibble(ioaddr, CMR2_h) >> 3) & 0x0f);
474	}
475
476	write_reg(ioaddr, CMR2, CMR2_IRQOUT);
477	write_reg_high(ioaddr, CMR1, CMR1h_RxENABLE | CMR1h_TxENABLE);
478
479	/* Enable the interrupt line from the serial port. */
480	outb(Ctrl_SelData + Ctrl_IRQEN, ioaddr + PAR_CONTROL);
481
482	/* Unmask the interesting interrupts. */
483	write_reg(ioaddr, IMR, ISR_RxOK | ISR_TxErr | ISR_TxOK);
484	write_reg_high(ioaddr, IMR, ISRh_RxErr);
485
486	lp->tx_unit_busy = 0;
487	lp->pac_cnt_in_tx_buf = 0;
488	lp->saved_tx_size = 0;
489}
490
491static void trigger_send(long ioaddr, int length)
492{
493	write_reg_byte(ioaddr, TxCNT0, length & 0xff);
494	write_reg(ioaddr, TxCNT1, length >> 8);
495	write_reg(ioaddr, CMR1, CMR1_Xmit);
496}
497
498static void write_packet(long ioaddr, int length, unsigned char *packet, int pad_len, int data_mode)
499{
500    if (length & 1)
501    {
502	length++;
503	pad_len++;
504    }
505
506    outb(EOC+MAR, ioaddr + PAR_DATA);
507    if ((data_mode & 1) == 0) {
508		/* Write the packet out, starting with the write addr. */
509		outb(WrAddr+MAR, ioaddr + PAR_DATA);
510		do {
511			write_byte_mode0(ioaddr, *packet++);
512		} while (--length > pad_len) ;
513		do {
514			write_byte_mode0(ioaddr, 0);
515		} while (--length > 0) ;
516    } else {
517		/* Write the packet out in slow mode. */
518		unsigned char outbyte = *packet++;
519
520		outb(Ctrl_LNibWrite + Ctrl_IRQEN, ioaddr + PAR_CONTROL);
521		outb(WrAddr+MAR, ioaddr + PAR_DATA);
522
523		outb((outbyte & 0x0f)|0x40, ioaddr + PAR_DATA);
524		outb(outbyte & 0x0f, ioaddr + PAR_DATA);
525		outbyte >>= 4;
526		outb(outbyte & 0x0f, ioaddr + PAR_DATA);
527		outb(Ctrl_HNibWrite + Ctrl_IRQEN, ioaddr + PAR_CONTROL);
528		while (--length > pad_len)
529			write_byte_mode1(ioaddr, *packet++);
530		while (--length > 0)
531			write_byte_mode1(ioaddr, 0);
532    }
533    /* Terminate the Tx frame.  End of write: ECB. */
534    outb(0xff, ioaddr + PAR_DATA);
535    outb(Ctrl_HNibWrite | Ctrl_SelData | Ctrl_IRQEN, ioaddr + PAR_CONTROL);
536}
537
538static void tx_timeout(struct net_device *dev, unsigned int txqueue)
539{
540	long ioaddr = dev->base_addr;
541
542	printk(KERN_WARNING "%s: Transmit timed out, %s?\n", dev->name,
543		   inb(ioaddr + PAR_CONTROL) & 0x10 ? "network cable problem"
544		   :  "IRQ conflict");
545	dev->stats.tx_errors++;
546	/* Try to restart the adapter. */
547	hardware_init(dev);
548	netif_trans_update(dev); /* prevent tx timeout */
549	netif_wake_queue(dev);
550	dev->stats.tx_errors++;
551}
552
553static netdev_tx_t atp_send_packet(struct sk_buff *skb,
554				   struct net_device *dev)
555{
556	struct net_local *lp = netdev_priv(dev);
557	long ioaddr = dev->base_addr;
558	int length;
559	unsigned long flags;
560
561	length = ETH_ZLEN < skb->len ? skb->len : ETH_ZLEN;
562
563	netif_stop_queue(dev);
564
565	/* Disable interrupts by writing 0x00 to the Interrupt Mask Register.
566	   This sequence must not be interrupted by an incoming packet. */
567
568	spin_lock_irqsave(&lp->lock, flags);
569	write_reg(ioaddr, IMR, 0);
570	write_reg_high(ioaddr, IMR, 0);
571	spin_unlock_irqrestore(&lp->lock, flags);
572
573	write_packet(ioaddr, length, skb->data, length-skb->len, dev->if_port);
574
575	lp->pac_cnt_in_tx_buf++;
576	if (lp->tx_unit_busy == 0) {
577		trigger_send(ioaddr, length);
578		lp->saved_tx_size = 0; 				/* Redundant */
579		lp->re_tx = 0;
580		lp->tx_unit_busy = 1;
581	} else
582		lp->saved_tx_size = length;
583	/* Re-enable the LPT interrupts. */
584	write_reg(ioaddr, IMR, ISR_RxOK | ISR_TxErr | ISR_TxOK);
585	write_reg_high(ioaddr, IMR, ISRh_RxErr);
586
587	dev_kfree_skb (skb);
588	return NETDEV_TX_OK;
589}
590
591
592/* The typical workload of the driver:
593   Handle the network interface interrupts. */
594static irqreturn_t atp_interrupt(int irq, void *dev_instance)
595{
596	struct net_device *dev = dev_instance;
597	struct net_local *lp;
598	long ioaddr;
599	static int num_tx_since_rx;
600	int boguscount = max_interrupt_work;
601	int handled = 0;
602
603	ioaddr = dev->base_addr;
604	lp = netdev_priv(dev);
605
606	spin_lock(&lp->lock);
607
608	/* Disable additional spurious interrupts. */
609	outb(Ctrl_SelData, ioaddr + PAR_CONTROL);
610
611	/* The adapter's output is currently the IRQ line, switch it to data. */
612	write_reg(ioaddr, CMR2, CMR2_NULL);
613	write_reg(ioaddr, IMR, 0);
614
615	if (net_debug > 5)
616		printk(KERN_DEBUG "%s: In interrupt ", dev->name);
617	while (--boguscount > 0) {
618		int status = read_nibble(ioaddr, ISR);
619		if (net_debug > 5)
620			printk("loop status %02x..", status);
621
622		if (status & (ISR_RxOK<<3)) {
623			handled = 1;
624			write_reg(ioaddr, ISR, ISR_RxOK); /* Clear the Rx interrupt. */
625			do {
626				int read_status = read_nibble(ioaddr, CMR1);
627				if (net_debug > 6)
628					printk("handling Rx packet %02x..", read_status);
629				/* We acknowledged the normal Rx interrupt, so if the interrupt
630				   is still outstanding we must have a Rx error. */
631				if (read_status & (CMR1_IRQ << 3)) { /* Overrun. */
632					dev->stats.rx_over_errors++;
633					/* Set to no-accept mode long enough to remove a packet. */
634					write_reg_high(ioaddr, CMR2, CMR2h_OFF);
635					net_rx(dev);
636					/* Clear the interrupt and return to normal Rx mode. */
637					write_reg_high(ioaddr, ISR, ISRh_RxErr);
638					write_reg_high(ioaddr, CMR2, lp->addr_mode);
639				} else if ((read_status & (CMR1_BufEnb << 3)) == 0) {
640					net_rx(dev);
641					num_tx_since_rx = 0;
642				} else
643					break;
644			} while (--boguscount > 0);
645		} else if (status & ((ISR_TxErr + ISR_TxOK)<<3)) {
646			handled = 1;
647			if (net_debug > 6)
648				printk("handling Tx done..");
649			/* Clear the Tx interrupt.  We should check for too many failures
650			   and reinitialize the adapter. */
651			write_reg(ioaddr, ISR, ISR_TxErr + ISR_TxOK);
652			if (status & (ISR_TxErr<<3)) {
653				dev->stats.collisions++;
654				if (++lp->re_tx > 15) {
655					dev->stats.tx_aborted_errors++;
656					hardware_init(dev);
657					break;
658				}
659				/* Attempt to retransmit. */
660				if (net_debug > 6)  printk("attempting to ReTx");
661				write_reg(ioaddr, CMR1, CMR1_ReXmit + CMR1_Xmit);
662			} else {
663				/* Finish up the transmit. */
664				dev->stats.tx_packets++;
665				lp->pac_cnt_in_tx_buf--;
666				if ( lp->saved_tx_size) {
667					trigger_send(ioaddr, lp->saved_tx_size);
668					lp->saved_tx_size = 0;
669					lp->re_tx = 0;
670				} else
671					lp->tx_unit_busy = 0;
672				netif_wake_queue(dev);	/* Inform upper layers. */
673			}
674			num_tx_since_rx++;
675		} else if (num_tx_since_rx > 8 &&
676			   time_after(jiffies, lp->last_rx_time + HZ)) {
677			if (net_debug > 2)
678				printk(KERN_DEBUG "%s: Missed packet? No Rx after %d Tx and "
679					   "%ld jiffies status %02x  CMR1 %02x.\n", dev->name,
680					   num_tx_since_rx, jiffies - lp->last_rx_time, status,
681					   (read_nibble(ioaddr, CMR1) >> 3) & 15);
682			dev->stats.rx_missed_errors++;
683			hardware_init(dev);
684			num_tx_since_rx = 0;
685			break;
686		} else
687			break;
688	}
689
690	/* This following code fixes a rare (and very difficult to track down)
691	   problem where the adapter forgets its ethernet address. */
692	{
693		int i;
694		for (i = 0; i < 6; i++)
695			write_reg_byte(ioaddr, PAR0 + i, dev->dev_addr[i]);
696#if 0 && defined(TIMED_CHECKER)
697		mod_timer(&lp->timer, jiffies + TIMED_CHECKER);
698#endif
699	}
700
701	/* Tell the adapter that it can go back to using the output line as IRQ. */
702	write_reg(ioaddr, CMR2, CMR2_IRQOUT);
703	/* Enable the physical interrupt line, which is sure to be low until.. */
704	outb(Ctrl_SelData + Ctrl_IRQEN, ioaddr + PAR_CONTROL);
705	/* .. we enable the interrupt sources. */
706	write_reg(ioaddr, IMR, ISR_RxOK | ISR_TxErr | ISR_TxOK);
707	write_reg_high(ioaddr, IMR, ISRh_RxErr); 			/* Hmmm, really needed? */
708
709	spin_unlock(&lp->lock);
710
711	if (net_debug > 5) printk("exiting interrupt.\n");
712	return IRQ_RETVAL(handled);
713}
714
715#ifdef TIMED_CHECKER
716/* This following code fixes a rare (and very difficult to track down)
717   problem where the adapter forgets its ethernet address. */
718static void atp_timed_checker(struct timer_list *t)
719{
720	struct net_local *lp = from_timer(lp, t, timer);
721	struct net_device *dev = lp->dev;
722	long ioaddr = dev->base_addr;
723	int tickssofar = jiffies - lp->last_rx_time;
724	int i;
725
726	spin_lock(&lp->lock);
727	if (tickssofar > 2*HZ) {
728#if 1
729		for (i = 0; i < 6; i++)
730			write_reg_byte(ioaddr, PAR0 + i, dev->dev_addr[i]);
731		lp->last_rx_time = jiffies;
732#else
733		for (i = 0; i < 6; i++)
734			if (read_cmd_byte(ioaddr, PAR0 + i) != atp_timed_dev->dev_addr[i])
735				{
736			struct net_local *lp = netdev_priv(atp_timed_dev);
737			write_reg_byte(ioaddr, PAR0 + i, atp_timed_dev->dev_addr[i]);
738			if (i == 2)
739			  dev->stats.tx_errors++;
740			else if (i == 3)
741			  dev->stats.tx_dropped++;
742			else if (i == 4)
743			  dev->stats.collisions++;
744			else
745			  dev->stats.rx_errors++;
746		  }
747#endif
748	}
749	spin_unlock(&lp->lock);
750	lp->timer.expires = jiffies + TIMED_CHECKER;
751	add_timer(&lp->timer);
752}
753#endif
754
755/* We have a good packet(s), get it/them out of the buffers. */
756static void net_rx(struct net_device *dev)
757{
758	struct net_local *lp = netdev_priv(dev);
759	long ioaddr = dev->base_addr;
760	struct rx_header rx_head;
761
762	/* Process the received packet. */
763	outb(EOC+MAR, ioaddr + PAR_DATA);
764	read_block(ioaddr, 8, (unsigned char*)&rx_head, dev->if_port);
765	if (net_debug > 5)
766		printk(KERN_DEBUG " rx_count %04x %04x %04x %04x..", rx_head.pad,
767			   rx_head.rx_count, rx_head.rx_status, rx_head.cur_addr);
768	if ((rx_head.rx_status & 0x77) != 0x01) {
769		dev->stats.rx_errors++;
770		if (rx_head.rx_status & 0x0004) dev->stats.rx_frame_errors++;
771		else if (rx_head.rx_status & 0x0002) dev->stats.rx_crc_errors++;
772		if (net_debug > 3)
773			printk(KERN_DEBUG "%s: Unknown ATP Rx error %04x.\n",
774				   dev->name, rx_head.rx_status);
775		if  (rx_head.rx_status & 0x0020) {
776			dev->stats.rx_fifo_errors++;
777			write_reg_high(ioaddr, CMR1, CMR1h_TxENABLE);
778			write_reg_high(ioaddr, CMR1, CMR1h_RxENABLE | CMR1h_TxENABLE);
779		} else if (rx_head.rx_status & 0x0050)
780			hardware_init(dev);
781		return;
782	} else {
783		/* Malloc up new buffer. The "-4" omits the FCS (CRC). */
784		int pkt_len = (rx_head.rx_count & 0x7ff) - 4;
785		struct sk_buff *skb;
786
787		skb = netdev_alloc_skb(dev, pkt_len + 2);
788		if (skb == NULL) {
789			dev->stats.rx_dropped++;
790			goto done;
791		}
792
793		skb_reserve(skb, 2);	/* Align IP on 16 byte boundaries */
794		read_block(ioaddr, pkt_len, skb_put(skb,pkt_len), dev->if_port);
795		skb->protocol = eth_type_trans(skb, dev);
796		netif_rx(skb);
797		dev->stats.rx_packets++;
798		dev->stats.rx_bytes += pkt_len;
799	}
800 done:
801	write_reg(ioaddr, CMR1, CMR1_NextPkt);
802	lp->last_rx_time = jiffies;
803}
804
805static void read_block(long ioaddr, int length, unsigned char *p, int data_mode)
806{
807	if (data_mode <= 3) { /* Mode 0 or 1 */
808		outb(Ctrl_LNibRead, ioaddr + PAR_CONTROL);
809		outb(length == 8  ?  RdAddr | HNib | MAR  :  RdAddr | MAR,
810			 ioaddr + PAR_DATA);
811		if (data_mode <= 1) { /* Mode 0 or 1 */
812			do { *p++ = read_byte_mode0(ioaddr); } while (--length > 0);
813		} else { /* Mode 2 or 3 */
814			do { *p++ = read_byte_mode2(ioaddr); } while (--length > 0);
815		}
816	} else if (data_mode <= 5) {
817		do { *p++ = read_byte_mode4(ioaddr); } while (--length > 0);
818	} else {
819		do { *p++ = read_byte_mode6(ioaddr); } while (--length > 0);
820	}
821
822	outb(EOC+HNib+MAR, ioaddr + PAR_DATA);
823	outb(Ctrl_SelData, ioaddr + PAR_CONTROL);
824}
825
826/* The inverse routine to net_open(). */
827static int
828net_close(struct net_device *dev)
829{
830	struct net_local *lp = netdev_priv(dev);
831	long ioaddr = dev->base_addr;
832
833	netif_stop_queue(dev);
834
835	del_timer_sync(&lp->timer);
836
837	/* Flush the Tx and disable Rx here. */
838	lp->addr_mode = CMR2h_OFF;
839	write_reg_high(ioaddr, CMR2, CMR2h_OFF);
840
841	/* Free the IRQ line. */
842	outb(0x00, ioaddr + PAR_CONTROL);
843	free_irq(dev->irq, dev);
844
845	/* Reset the ethernet hardware and activate the printer pass-through. */
846	write_reg_high(ioaddr, CMR1, CMR1h_RESET | CMR1h_MUX);
847	return 0;
848}
849
850/*
851 *	Set or clear the multicast filter for this adapter.
852 */
853
854static void set_rx_mode(struct net_device *dev)
855{
856	struct net_local *lp = netdev_priv(dev);
857	long ioaddr = dev->base_addr;
858
859	if (!netdev_mc_empty(dev) || (dev->flags & (IFF_ALLMULTI|IFF_PROMISC)))
860		lp->addr_mode = CMR2h_PROMISC;
861	else
862		lp->addr_mode = CMR2h_Normal;
863	write_reg_high(ioaddr, CMR2, lp->addr_mode);
864}
865
866static int __init atp_init_module(void) {
867	if (debug)					/* Emit version even if no cards detected. */
868		printk(KERN_INFO "%s", version);
869	return atp_init();
870}
871
872static void __exit atp_cleanup_module(void) {
873	struct net_device *next_dev;
874
875	while (root_atp_dev) {
876		struct net_local *atp_local = netdev_priv(root_atp_dev);
877		next_dev = atp_local->next_module;
878		unregister_netdev(root_atp_dev);
879		/* No need to release_region(), since we never snarf it. */
880		free_netdev(root_atp_dev);
881		root_atp_dev = next_dev;
882	}
883}
884
885module_init(atp_init_module);
886module_exit(atp_cleanup_module);