summaryrefslogtreecommitdiffstats
path: root/drivers/misc/parport_pc.c
blob: cddb1dffe15cc714bdc6e06409ace31435420e91 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
/* Low-level parallel-port routines for 8255-based PC-style hardware.
 * 
 * Authors: Phil Blundell <Philip.Blundell@pobox.com>
 *          Tim Waugh <tim@cyberelk.demon.co.uk>
 *	    Jose Renau <renau@acm.org>
 *          David Campbell <campbell@torque.net>
 *          Andrea Arcangeli
 *
 * based on work by Grant Guenther <grant@torque.net> and Phil Blundell.
 *
 * Cleaned up include files - Russell King <linux@arm.uk.linux.org>
 */

/* This driver should work with any hardware that is broadly compatible
 * with that in the IBM PC.  This applies to the majority of integrated
 * I/O chipsets that are commonly available.  The expected register
 * layout is:
 *
 *	base+0		data
 *	base+1		status
 *	base+2		control
 *
 * In addition, there are some optional registers:
 *
 *	base+3		EPP address
 *	base+4		EPP data
 *	base+0x400	ECP config A
 *	base+0x401	ECP config B
 *	base+0x402	ECP control
 *
 * All registers are 8 bits wide and read/write.  If your hardware differs
 * only in register addresses (eg because your registers are on 32-bit
 * word boundaries) then you can alter the constants in parport_pc.h to
 * accomodate this.
 */

#include <linux/config.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/kernel.h>
#include <linux/malloc.h>

#include <asm/io.h>

#include <linux/parport.h>
#include <linux/parport_pc.h>

/* Maximum number of ports to support.  It is useless to set this greater
   than PARPORT_MAX (in <linux/parport.h>).  */
#define PARPORT_PC_MAX_PORTS  8

static void parport_pc_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
	parport_generic_irq(irq, (struct parport *) dev_id, regs);
}

void parport_pc_write_epp(struct parport *p, unsigned char d)
{
	outb(d, p->base+EPPDATA);
}

unsigned char parport_pc_read_epp(struct parport *p)
{
	return inb(p->base+EPPDATA);
}

void parport_pc_write_epp_addr(struct parport *p, unsigned char d)
{
	outb(d, p->base+EPPADDR);
}

unsigned char parport_pc_read_epp_addr(struct parport *p)
{
	return inb(p->base+EPPADDR);
}

int parport_pc_check_epp_timeout(struct parport *p)
{
	if (!(inb(p->base+STATUS) & 1))
		return 0;
	parport_pc_epp_clear_timeout(p);
	return 1;
}

unsigned char parport_pc_read_configb(struct parport *p)
{
	return inb(p->base+CONFIGB);
}

void parport_pc_write_data(struct parport *p, unsigned char d)
{
	outb(d, p->base+DATA);
}

unsigned char parport_pc_read_data(struct parport *p)
{
	return inb(p->base+DATA);
}

void parport_pc_write_control(struct parport *p, unsigned char d)
{
	outb(d, p->base+CONTROL);
}

unsigned char parport_pc_read_control(struct parport *p)
{
	return inb(p->base+CONTROL);
}

unsigned char parport_pc_frob_control(struct parport *p, unsigned char mask,  unsigned char val)
{
	unsigned char old = inb(p->base+CONTROL);
	outb(((old & ~mask) ^ val), p->base+CONTROL);
	return old;
}

void parport_pc_write_status(struct parport *p, unsigned char d)
{
	outb(d, p->base+STATUS);
}

unsigned char parport_pc_read_status(struct parport *p)
{
	return inb(p->base+STATUS);
}

void parport_pc_write_econtrol(struct parport *p, unsigned char d)
{
	outb(d, p->base+ECONTROL);
}

unsigned char parport_pc_read_econtrol(struct parport *p)
{
	return inb(p->base+ECONTROL);
}

unsigned char parport_pc_frob_econtrol(struct parport *p, unsigned char mask,  unsigned char val)
{
	unsigned char old = inb(p->base+ECONTROL);
	outb(((old & ~mask) ^ val), p->base+ECONTROL);
	return old;
}

void parport_pc_change_mode(struct parport *p, int m)
{
	/* FIXME */
}

void parport_pc_write_fifo(struct parport *p, unsigned char v)
{
	outb (v, p->base+CONFIGA);
}

unsigned char parport_pc_read_fifo(struct parport *p)
{
	return inb (p->base+CONFIGA);
}

void parport_pc_disable_irq(struct parport *p)
{
	parport_pc_frob_control(p, 0x10, 0);
}

void parport_pc_enable_irq(struct parport *p)
{
	parport_pc_frob_control(p, 0x10, 0x10);
}

void parport_pc_release_resources(struct parport *p)
{
	if (p->irq != PARPORT_IRQ_NONE)
		free_irq(p->irq, p);
	release_region(p->base, p->size);
	if (p->modes & PARPORT_MODE_PCECR)
		release_region(p->base+0x400, 3);
}

int parport_pc_claim_resources(struct parport *p)
{
	int err;
	if (p->irq != PARPORT_IRQ_NONE)
		if ((err = request_irq(p->irq, parport_pc_interrupt,
				       0, p->name, p)) != 0)
			return err;
	request_region(p->base, p->size, p->name);
	if (p->modes & PARPORT_MODE_PCECR)
		request_region(p->base+0x400, 3, p->name);
	return 0;
}

void parport_pc_init_state(struct parport_state *s)
{
	s->u.pc.ctr = 0xc;
	s->u.pc.ecr = 0x0;
}

void parport_pc_save_state(struct parport *p, struct parport_state *s)
{
	s->u.pc.ctr = parport_pc_read_control(p);
	if (p->modes & PARPORT_MODE_PCECR)
		s->u.pc.ecr = parport_pc_read_econtrol(p);
}

void parport_pc_restore_state(struct parport *p, struct parport_state *s)
{
	parport_pc_write_control(p, s->u.pc.ctr);
	if (p->modes & PARPORT_MODE_PCECR)
		parport_pc_write_econtrol(p, s->u.pc.ecr);
}

size_t parport_pc_epp_read_block(struct parport *p, void *buf, size_t length)
{
	size_t got = 0;
	for (; got < length; got++) {
		*((char*)buf)++ = inb (p->base+EPPDATA);
		if (inb (p->base+STATUS) & 0x01)
			break;
	}
	return got;
}

size_t parport_pc_epp_write_block(struct parport *p, void *buf, size_t length)
{
	size_t written = 0;
	for (; written < length; written++) {
		outb (*((char*)buf)++, p->base+EPPDATA);
		if (inb (p->base+STATUS) & 0x01)
			break;
	}
	return written;
}

int parport_pc_ecp_read_block(struct parport *p, void *buf, size_t length, void (*fn)(struct parport *, void *, size_t), void *handle)
{
	return -ENOSYS; /* FIXME */
}

int parport_pc_ecp_write_block(struct parport *p, void *buf, size_t length, void (*fn)(struct parport *, void *, size_t), void *handle)
{
	return -ENOSYS; /* FIXME */
}

void parport_pc_inc_use_count(void)
{
#ifdef MODULE
	MOD_INC_USE_COUNT;
#endif
}

void parport_pc_dec_use_count(void)
{
#ifdef MODULE
	MOD_DEC_USE_COUNT;
#endif
}

static void parport_pc_fill_inode(struct inode *inode, int fill)
{
#ifdef MODULE
	if (fill)
		MOD_INC_USE_COUNT;
	else
		MOD_DEC_USE_COUNT;
#endif
}

struct parport_operations parport_pc_ops = 
{
	parport_pc_write_data,
	parport_pc_read_data,

	parport_pc_write_control,
	parport_pc_read_control,
	parport_pc_frob_control,

	parport_pc_write_econtrol,
	parport_pc_read_econtrol,
	parport_pc_frob_econtrol,

	parport_pc_write_status,
	parport_pc_read_status,

	parport_pc_write_fifo,
	parport_pc_read_fifo,
	
	parport_pc_change_mode,
	
	parport_pc_release_resources,
	parport_pc_claim_resources,
	
	parport_pc_write_epp,
	parport_pc_read_epp,
	parport_pc_write_epp_addr,
	parport_pc_read_epp_addr,
	parport_pc_check_epp_timeout,

	parport_pc_epp_write_block,
	parport_pc_epp_read_block,

	parport_pc_ecp_write_block,
	parport_pc_ecp_read_block,
	
	parport_pc_init_state,
	parport_pc_save_state,
	parport_pc_restore_state,

	parport_pc_enable_irq,
	parport_pc_disable_irq,
	parport_pc_interrupt,

	parport_pc_inc_use_count,
	parport_pc_dec_use_count,
	parport_pc_fill_inode
};

/* --- Mode detection ------------------------------------- */

/*
 * Clear TIMEOUT BIT in EPP MODE
 */
int parport_pc_epp_clear_timeout(struct parport *pb)
{
	unsigned char r;

	if (!(parport_pc_read_status(pb) & 0x01))
		return 1;

	/* To clear timeout some chips require double read */
	parport_pc_read_status(pb);
	r = parport_pc_read_status(pb);
	parport_pc_write_status(pb, r | 0x01); /* Some reset by writing 1 */
	parport_pc_write_status(pb, r & 0xfe); /* Others by writing 0 */
	r = parport_pc_read_status(pb);

	return !(r & 0x01);
}


/*
 * Checks for port existence, all ports support SPP MODE
 */
static int parport_SPP_supported(struct parport *pb)
{
	/*
	 * first clear an eventually pending EPP timeout 
	 * I (sailer@ife.ee.ethz.ch) have an SMSC chipset
	 * that does not even respond to SPP cycles if an EPP
	 * timeout is pending
	 */
	parport_pc_epp_clear_timeout(pb);

	/* Do a simple read-write test to make sure the port exists. */
	parport_pc_write_control(pb, 0xc);
	parport_pc_write_data(pb, 0xaa);
	if (parport_pc_read_data(pb) != 0xaa) return 0;
	
	parport_pc_write_data(pb, 0x55);
	if (parport_pc_read_data(pb) != 0x55) return 0;

	return PARPORT_MODE_PCSPP;
}

/* Check for ECP
 *
 * Old style XT ports alias io ports every 0x400, hence accessing ECR
 * on these cards actually accesses the CTR.
 *
 * Modern cards don't do this but reading from ECR will return 0xff
 * regardless of what is written here if the card does NOT support
 * ECP.
 *
 * We will write 0x2c to ECR and 0xcc to CTR since both of these
 * values are "safe" on the CTR since bits 6-7 of CTR are unused.
 */
static int parport_ECR_present(struct parport *pb)
{
	unsigned char r, octr = parport_pc_read_control(pb);
	unsigned char oecr = parport_pc_read_econtrol(pb);
	unsigned char tmp;

	r = parport_pc_read_control(pb);	
	if ((parport_pc_read_econtrol(pb) & 0x3) == (r & 0x3)) {
		parport_pc_write_control(pb, r ^ 0x2 ); /* Toggle bit 1 */

		r = parport_pc_read_control(pb);	
		if ((parport_pc_read_econtrol(pb) & 0x2) == (r & 0x2)) {
			parport_pc_write_control(pb, octr);
			return 0; /* Sure that no ECR register exists */
		}
	}
	
	if ((parport_pc_read_econtrol(pb) & 0x3 ) != 0x1)
		return 0;

	parport_pc_write_econtrol(pb, 0x34);
	tmp = parport_pc_read_econtrol(pb);

	parport_pc_write_econtrol(pb, oecr);
	parport_pc_write_control(pb, octr);
	
	if (tmp != 0x35)
		return 0;

	return PARPORT_MODE_PCECR;
}

static int parport_ECP_supported(struct parport *pb)
{
	int i;
	unsigned char oecr;
	
	/* If there is no ECR, we have no hope of supporting ECP. */
	if (!(pb->modes & PARPORT_MODE_PCECR))
		return 0;

	oecr = parport_pc_read_econtrol(pb);
	/*
	 * Using LGS chipset it uses ECR register, but
	 * it doesn't support ECP or FIFO MODE
	 */
	
	parport_pc_write_econtrol(pb, 0xc0); /* TEST FIFO */
	for (i=0; i < 1024 && (parport_pc_read_econtrol(pb) & 0x01); i++)
		parport_pc_write_fifo(pb, 0xaa);

	parport_pc_write_econtrol(pb, oecr);
	return (i==1024)?0:PARPORT_MODE_PCECP;
}

/* EPP mode detection
 * Theory:
 *	Bit 0 of STR is the EPP timeout bit, this bit is 0
 *	when EPP is possible and is set high when an EPP timeout
 *	occurs (EPP uses the HALT line to stop the CPU while it does
 *	the byte transfer, an EPP timeout occurs if the attached
 *	device fails to respond after 10 micro seconds).
 *
 *	This bit is cleared by either reading it (National Semi)
 *	or writing a 1 to the bit (SMC, UMC, WinBond), others ???
 *	This bit is always high in non EPP modes.
 */
static int parport_EPP_supported(struct parport *pb)
{
	/* If EPP timeout bit clear then EPP available */
	if (!parport_pc_epp_clear_timeout(pb))
		return 0;  /* No way to clear timeout */

	parport_pc_write_control(pb, parport_pc_read_control(pb) | 0x20);
	parport_pc_write_control(pb, parport_pc_read_control(pb) | 0x10);
	parport_pc_epp_clear_timeout(pb);
	
	parport_pc_read_epp(pb);
	udelay(30);  /* Wait for possible EPP timeout */
	
	if (parport_pc_read_status(pb) & 0x01) {
		parport_pc_epp_clear_timeout(pb);
		return PARPORT_MODE_PCEPP;
	}

	return 0;
}

static int parport_ECPEPP_supported(struct parport *pb)
{
	int mode;
	unsigned char oecr;

	if (!(pb->modes & PARPORT_MODE_PCECR))
		return 0;

	oecr = parport_pc_read_econtrol(pb);
	/* Search for SMC style EPP+ECP mode */
	parport_pc_write_econtrol(pb, 0x80);
	
	mode = parport_EPP_supported(pb);

	parport_pc_write_econtrol(pb, oecr);
	
	return mode?PARPORT_MODE_PCECPEPP:0;
}

/* Detect PS/2 support.
 *
 * Bit 5 (0x20) sets the PS/2 data direction; setting this high
 * allows us to read data from the data lines.  In theory we would get back
 * 0xff but any peripheral attached to the port may drag some or all of the
 * lines down to zero.  So if we get back anything that isn't the contents
 * of the data register we deem PS/2 support to be present. 
 *
 * Some SPP ports have "half PS/2" ability - you can't turn off the line
 * drivers, but an external peripheral with sufficiently beefy drivers of
 * its own can overpower them and assert its own levels onto the bus, from
 * where they can then be read back as normal.  Ports with this property
 * and the right type of device attached are likely to fail the SPP test,
 * (as they will appear to have stuck bits) and so the fact that they might
 * be misdetected here is rather academic. 
 */

static int parport_PS2_supported(struct parport *pb)
{
	int ok = 0;
	unsigned char octr = parport_pc_read_control(pb);
  
	parport_pc_epp_clear_timeout(pb);

	parport_pc_write_control(pb, octr | 0x20);  /* try to tri-state the buffer */
	
	parport_pc_write_data(pb, 0x55);
	if (parport_pc_read_data(pb) != 0x55) ok++;

	parport_pc_write_data(pb, 0xaa);
	if (parport_pc_read_data(pb) != 0xaa) ok++;
	
	parport_pc_write_control(pb, octr);          /* cancel input mode */

	return ok?PARPORT_MODE_PCPS2:0;
}

static int parport_ECPPS2_supported(struct parport *pb)
{
	int mode;
	unsigned char oecr;

	if (!(pb->modes & PARPORT_MODE_PCECR))
		return 0;

	oecr = parport_pc_read_econtrol(pb);
	parport_pc_write_econtrol(pb, 0x20);
	
	mode = parport_PS2_supported(pb);

	parport_pc_write_econtrol(pb, oecr);
	return mode?PARPORT_MODE_PCECPPS2:0;
}

/* --- IRQ detection -------------------------------------- */

/* Only if supports ECP mode */
static int programmable_irq_support(struct parport *pb)
{
	int irq, intrLine;
	unsigned char oecr = parport_pc_read_econtrol(pb);
	static const int lookup[8] = {
		PARPORT_IRQ_NONE, 7, 9, 10, 11, 14, 15, 5
	};

	parport_pc_write_econtrol(pb,0xE0); /* Configuration MODE */
	
	intrLine = (parport_pc_read_configb(pb) >> 3) & 0x07;
	irq = lookup[intrLine];

	parport_pc_write_econtrol(pb, oecr);
	return irq;
}

static int irq_probe_ECP(struct parport *pb)
{
	int irqs, i;

	sti();
	irqs = probe_irq_on();
		
	parport_pc_write_econtrol(pb, 0x00);	/* Reset FIFO */
	parport_pc_write_econtrol(pb, 0xd0);	/* TEST FIFO + nErrIntrEn */

	/* If Full FIFO sure that WriteIntrThresold is generated */
	for (i=0; i < 1024 && !(parport_pc_read_econtrol(pb) & 0x02) ; i++) 
		parport_pc_write_fifo(pb, 0xaa);
		
	pb->irq = probe_irq_off(irqs);
	parport_pc_write_econtrol(pb, 0x00);

	if (pb->irq <= 0)
		pb->irq = PARPORT_IRQ_NONE;

	return pb->irq;
}

/*
 * This detection seems that only works in National Semiconductors
 * This doesn't work in SMC, LGS, and Winbond 
 */
static int irq_probe_EPP(struct parport *pb)
{
	int irqs;
	unsigned char octr = parport_pc_read_control(pb);
	unsigned char oecr;

#ifndef ADVANCED_DETECT
	return PARPORT_IRQ_NONE;
#endif

	if (pb->modes & PARPORT_MODE_PCECR)
		oecr = parport_pc_read_econtrol(pb);

	sti();
	irqs = probe_irq_on();

	if (pb->modes & PARPORT_MODE_PCECR)
		parport_pc_frob_econtrol (pb, 0x10, 0x10);
	
	parport_pc_epp_clear_timeout(pb);
	parport_pc_frob_control (pb, 0x20, 0x20);
	parport_pc_frob_control (pb, 0x10, 0x10);
	parport_pc_epp_clear_timeout(pb);

	/* Device isn't expecting an EPP read
	 * and generates an IRQ.
	 */
	parport_pc_read_epp(pb);
	udelay(20);

	pb->irq = probe_irq_off (irqs);
	if (pb->modes & PARPORT_MODE_PCECR)
		parport_pc_write_econtrol(pb, oecr);
	parport_pc_write_control(pb, octr);

	if (pb->irq <= 0)
		pb->irq = PARPORT_IRQ_NONE;

	return pb->irq;
}

static int irq_probe_SPP(struct parport *pb)
{
	int irqs;
	unsigned char octr = parport_pc_read_control(pb);
	unsigned char oecr;

#ifndef ADVANCED_DETECT
	return PARPORT_IRQ_NONE;
#endif

	if (pb->modes & PARPORT_MODE_PCECR)
		oecr = parport_pc_read_econtrol(pb);
	probe_irq_off(probe_irq_on());	/* Clear any interrupts */
	irqs = probe_irq_on();

	if (pb->modes & PARPORT_MODE_PCECR)
		parport_pc_write_econtrol(pb, 0x10);

	parport_pc_write_data(pb,0x00);
	parport_pc_write_control(pb,0x00);
	parport_pc_write_control(pb,0x0c);
	udelay(5);
	parport_pc_write_control(pb,0x0d);
	udelay(5);
	parport_pc_write_control(pb,0x0c);
	udelay(25);
	parport_pc_write_control(pb,0x08);
	udelay(25);
	parport_pc_write_control(pb,0x0c);
	udelay(50);

	pb->irq = probe_irq_off(irqs);
	if (pb->irq <= 0)
		pb->irq = PARPORT_IRQ_NONE;	/* No interrupt detected */
	
	if (pb->modes & PARPORT_MODE_PCECR)
		parport_pc_write_econtrol(pb, oecr);
	parport_pc_write_control(pb, octr);
	return pb->irq;
}

/* We will attempt to share interrupt requests since other devices
 * such as sound cards and network cards seem to like using the
 * printer IRQs.
 *
 * When ECP is available we can autoprobe for IRQs.
 * NOTE: If we can autoprobe it, we can register the IRQ.
 */
static int parport_irq_probe(struct parport *pb)
{
	if (pb->modes & PARPORT_MODE_PCECR) {
		pb->irq = programmable_irq_support(pb);
		if (pb->irq != PARPORT_IRQ_NONE)
			goto out;
	}

	if (pb->modes & PARPORT_MODE_PCECP)
		pb->irq = irq_probe_ECP(pb);

	if (pb->irq == PARPORT_IRQ_NONE && 
	    (pb->modes & PARPORT_MODE_PCECPEPP))
		pb->irq = irq_probe_EPP(pb);

	parport_pc_epp_clear_timeout(pb);

	if (pb->irq == PARPORT_IRQ_NONE && (pb->modes & PARPORT_MODE_PCEPP))
		pb->irq = irq_probe_EPP(pb);

	parport_pc_epp_clear_timeout(pb);

	if (pb->irq == PARPORT_IRQ_NONE)
		pb->irq = irq_probe_SPP(pb);

out:
	return pb->irq;
}

/* --- Initialisation code -------------------------------- */

static int probe_one_port(unsigned long int base, int irq, int dma)
{
	struct parport tmpport, *p;
	int probedirq = PARPORT_IRQ_NONE;
	if (check_region(base, 3)) return 0;
	tmpport.base = base;
	tmpport.ops = &parport_pc_ops;
	if (!(parport_SPP_supported(&tmpport))) return 0;
       	if (!(p = parport_register_port(base, irq, dma, &parport_pc_ops))) return 0;
	p->modes = PARPORT_MODE_PCSPP | parport_PS2_supported(p);
	if (p->base != 0x3bc) {
		if (!check_region(base+0x400,3)) {
			p->modes |= parport_ECR_present(p);	
			p->modes |= parport_ECP_supported(p);
			p->modes |= parport_ECPPS2_supported(p);
		}
		if (!check_region(base+0x3, 5)) {
			p->modes |= parport_EPP_supported(p);
			p->modes |= parport_ECPEPP_supported(p);
		}
	}
	p->size = (p->modes & (PARPORT_MODE_PCEPP 
			       | PARPORT_MODE_PCECPEPP))?8:3;
	printk(KERN_INFO "%s: PC-style at 0x%lx", p->name, p->base);
	if (p->irq == PARPORT_IRQ_AUTO) {
		p->irq = PARPORT_IRQ_NONE;
		parport_irq_probe(p);
	} else if (p->irq == PARPORT_IRQ_PROBEONLY) {
		p->irq = PARPORT_IRQ_NONE;
		parport_irq_probe(p);
		probedirq = p->irq;
		p->irq = PARPORT_IRQ_NONE;
	}
	if (p->irq != PARPORT_IRQ_NONE)
		printk(", irq %d", p->irq);
	if (p->dma == PARPORT_DMA_AUTO)		
		p->dma = PARPORT_DMA_NONE;
	if (p->dma != PARPORT_DMA_NONE)
		printk(", dma %d", p->dma);
	printk(" [");
#define printmode(x) {if(p->modes&PARPORT_MODE_PC##x){printk("%s%s",f?",":"",#x);f++;}}
	{
		int f = 0;
		printmode(SPP);
		printmode(PS2);
		printmode(EPP);
		printmode(ECP);
		printmode(ECPEPP);
		printmode(ECPPS2);
	}
#undef printmode
	printk("]\n");
#ifdef	CONFIG_PROC_FS
	if (probedirq != PARPORT_IRQ_NONE) 
		printk("%s: detected irq %d; use procfs to enable interrupt-driven operation.\n", p->name, probedirq);
	parport_proc_register(p);
#endif
	p->flags |= PARPORT_FLAG_COMA;

	/* Done probing.  Now put the port into a sensible start-up state. */
	if (p->modes & PARPORT_MODE_PCECR)
		/*
		 * Put the ECP detected port in the more SPP like mode.
		 */
		parport_pc_write_econtrol(p, 0x0);
	parport_pc_write_control(p, 0xc);
	parport_pc_write_data(p, 0);

	if (parport_probe_hook)
		(*parport_probe_hook)(p);

	return 1;
}

int parport_pc_init(int *io, int *irq, int *dma)
{
	int count = 0, i = 0;
	if (io && *io) {
		/* Only probe the ports we were given. */
		do {
			count += probe_one_port(*(io++), *(irq++), *(dma++));
		} while (*io && (++i < PARPORT_PC_MAX_PORTS));
	} else {
		/* Probe all the likely ports. */
		count += probe_one_port(0x3bc, irq[0], dma[0]);
		count += probe_one_port(0x378, irq[0], dma[0]);
		count += probe_one_port(0x278, irq[0], dma[0]);
	}

	return count;
}

#ifdef MODULE
static int io[PARPORT_PC_MAX_PORTS+1] = { [0 ... PARPORT_PC_MAX_PORTS] = 0 };
static int dma[PARPORT_PC_MAX_PORTS] = { [0 ... PARPORT_PC_MAX_PORTS-1] = PARPORT_DMA_NONE };
static int irqval[PARPORT_PC_MAX_PORTS] = { [0 ... PARPORT_PC_MAX_PORTS-1] = PARPORT_IRQ_PROBEONLY };
static const char *irq[PARPORT_PC_MAX_PORTS] = { NULL, };
MODULE_PARM(io, "1-" __MODULE_STRING(PARPORT_PC_MAX_PORTS) "i");
MODULE_PARM(irq, "1-" __MODULE_STRING(PARPORT_PC_MAX_PORTS) "s");
MODULE_PARM(dma, "1-" __MODULE_STRING(PARPORT_PC_MAX_PORTS) "i");

int init_module(void)
{	
	/* Work out how many ports we have, then get parport_share to parse
	   the irq values. */
	unsigned int i;
	for (i = 0; i < PARPORT_PC_MAX_PORTS && io[i]; i++);
	parport_parse_irqs(i, irq, irqval);

	return (parport_pc_init(io, irqval, dma)?0:1);
}

void cleanup_module(void)
{
	struct parport *p = parport_enumerate(), *tmp;
	while (p) {
		tmp = p->next;
		if (p->modes & PARPORT_MODE_PCSPP) { 
			if (!(p->flags & PARPORT_FLAG_COMA)) 
				parport_quiesce(p);
#ifdef	CONFIG_PROC_FS
			parport_proc_unregister(p);
#endif
			parport_unregister_port(p);
		}
		p = tmp;
	}
}
#endif