summaryrefslogtreecommitdiffstats
path: root/drivers/ide/via82cxxx.c
blob: 3ea1e261ece4224c784f015a1880c0d7a74b4231 (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
/*
 * $Id: via82cxxx.c,v 2.1e 2000/10/03 10:01:00 vojtech Exp $
 *
 *  Copyright (c) 2000 Vojtech Pavlik
 *
 *  Based on the work of:
 *	Michel Aubry
 *	Jeff Garzik
 *	Andre Hedrick
 *
 *  Sponsored by SuSE
 */

/*
 * VIA vt82c586 IDE driver for Linux. Supports
 *
 *   vt82c586, vt82c586a, vt82c586b, vt82c596a, vt82c596b, vt82c686a, vt8231
 *
 * southbridges, which can be found in
 *
 *  VIA Apollo VP, VPX, VPX/97, VP2, VP2/97, VP3, MVP3, MVP4
 *  VIA Apollo Pro, Pro Plus, Pro 133, Pro 133A, ProMedia 601, ProSavage 605
 *  VIA Apollo KX133, KT133
 *  AMD-640, AMD-750 IronGate
 *
 * chipsets. Supports PIO 0-5, MWDMA 0-2, SWDMA 0-2 and
 * UDMA 0-5 (includes UDMA33, 66 and 100) modes. UDMA100 isn't possible
 * on any of the supported chipsets yet.
 *
 * UDMA66 and higher modes are autodetected only in case the BIOS has enabled them.
 * To force UDMA66, use 'ide0=ata66' or 'ide1=ata66' on the kernel command line.
 */

/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 * Should you need to contact me, the author, you can do so either by
 * e-mail - mail your message to <vojtech@suse.cz>, or by paper mail:
 * Vojtech Pavlik, Ucitelska 1576, Prague 8, 182 00 Czech Republic
 */

#include <linux/config.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/timer.h>
#include <linux/mm.h>
#include <linux/ioport.h>
#include <linux/interrupt.h>
#include <linux/blkdev.h>
#include <linux/hdreg.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/ide.h>
#include <asm/io.h>

#include "ide_modes.h"

#define VIA_BM_BASE		0x20
#define VIA_IDE_ENABLE		0x40
#define VIA_IDE_CONFIG		0x41
#define VIA_FIFO_CONFIG		0x43
#define VIA_MISC_1		0x44
#define VIA_MISC_2		0x45
#define VIA_MISC_3		0x46
#define VIA_DRIVE_TIMING	0x48
#define VIA_ADDRESS_SETUP	0x4c
#define VIA_UDMA_TIMING		0x50
#define VIA_PRI_SECTOR_SIZE	0x60
#define VIA_SEC_SECTOR_SIZE	0x68

/*
 * VIA SouthBridge chips.
 */

static const struct {
	char *name;
	unsigned short id;
	unsigned char speed;
} via_isa_bridges[] = {
	{ "vt8231",	PCI_DEVICE_ID_VIA_8231,     XFER_UDMA_4 },
	{ "vt82c686a",	PCI_DEVICE_ID_VIA_82C686,   XFER_UDMA_4 },
	{ "vt82c596b",	PCI_DEVICE_ID_VIA_82C596,   XFER_UDMA_4 },
	{ "vt82c596a",	PCI_DEVICE_ID_VIA_82C596,   XFER_UDMA_2 },
	{ "vt82c586b",	PCI_DEVICE_ID_VIA_82C586_0, XFER_UDMA_2 },
	{ "vt82c586a",	PCI_DEVICE_ID_VIA_82C586_0, XFER_UDMA_2 },
	{ "vt82c586",	PCI_DEVICE_ID_VIA_82C586_0, XFER_MW_DMA_2 },
	{ "Unknown SouthBridge",	0,	    XFER_UDMA_2 },
};

static unsigned char via_config;
static unsigned char via_enabled;
static unsigned int via_ata66;

/*
 * PIO 0-5, MWDMA 0-2 and UDMA 0-5 timings (in nanoseconds).
 * These were taken from ATA/ATAPI-6 standard, rev 0a, except
 * for PIO 5, which is a nonstandard extension.
 *
 * Dilemma: 8-bit (register) PIO accesses need more relaxed timing.
 * Hopefully the chipset is taking care of that. If it doesn't
 * do so, define VIA_USE_8_BIT_TIMING to see if it helps.
 */

#ifndef XFER_PIO_5
#define XFER_PIO_5		0x0d
#endif

static const struct {
	int mode;
	char *name;
	short setup;	/* t1 */
	short active;	/* t2  or tD */
	short recover;	/* t2i or tK */
	short cycle;	/* t0 */
	short udma;	/* t2CYCTYP/2 */
} via_timing[] = {
	{ XFER_UDMA_5,    "UDMA5", 25,  70,  25, 120,  20 },
	{ XFER_UDMA_4,    "UDMA4", 25,  70,  25, 120,  30 },
	{ XFER_UDMA_3,    "UDMA3", 25,  70,  25, 120,  45 },

	{ XFER_UDMA_2,    "UDMA2", 25,  70,  25, 120,  60 },
	{ XFER_UDMA_1,    "UDMA1", 25,  70,  25, 120,  80 },
	{ XFER_UDMA_0,    "UDMA0", 25,  70,  25, 120, 120 },

	{ XFER_MW_DMA_2,  "MDMA2", 25,  70,  25, 120,   0 },
	{ XFER_MW_DMA_1,  "MDMA1", 45,  80,  50, 150,   0 },
	{ XFER_MW_DMA_0,  "MDMA0", 60, 215, 215, 480,   0 },

	{ XFER_SW_DMA_2,  "SDMA2", 60, 120, 120, 240,   0 },
	{ XFER_SW_DMA_1,  "SDMA1", 90, 240, 240, 480,   0 },
	{ XFER_SW_DMA_0,  "SDMA0",120, 480, 480, 960,   0 },

	{ XFER_PIO_5,     "PIO5",  20,  50,  30, 100,   0 },
	{ XFER_PIO_4,     "PIO4",  25,  70,  25, 120,   0 },
	{ XFER_PIO_3,     "PIO3",  30,  80,  70, 180,   0 },

#ifdef VIA_USE_8_BIT_TIMING
	{ XFER_PIO_2,     "PIO2",  30, 290,  60, 330,   0 },
	{ XFER_PIO_1,     "PIO1",  50, 290, 100, 383,   0 },
	{ XFER_PIO_0,     "PIO0",  70, 290, 300, 600,   0 },
#else
	{ XFER_PIO_2,     "PIO2",  30, 100,  90, 240,   0 },
	{ XFER_PIO_1,     "PIO1",  50, 125, 100, 383,   0 },
	{ XFER_PIO_0,     "PIO0",  70, 165, 150, 600,   0 },
#endif

	{ XFER_PIO_SLOW,  "SLOW", 120, 290, 240, 960,   0 },
	{ 0 }
};

/*
 * VIA /proc entry.
 */

#ifdef CONFIG_PROC_FS

#include <linux/stat.h>
#include <linux/proc_fs.h>

int via_proc = 0;
static struct pci_dev *bmide_dev, *isa_dev;
extern int (*via_display_info)(char *, char **, off_t, int); /* ide-proc.c */

static char *via_fifo[] = { " 1 ", "3/4", "1/2", "1/4" };
static char *via_control3[] = { "No limit", "64", "128", "192" };

#define via_print(format, arg...) p += sprintf(p, format "\n" , ## arg)
#define via_print_drive(name, format, arg...)\
	p += sprintf(p, name); for (i = 0; i < 4; i++) p += sprintf(p, format, ## arg); p += sprintf(p, "\n");

static int via_get_info(char *buffer, char **addr, off_t offset, int count)
{
	short pci_clock, speed[4], cycle[4], setup[4], active[4], recover[4], umul[4], uen[4], udma[4];
	struct pci_dev *dev = bmide_dev;
	unsigned int v, u, i, base;
	unsigned short c, size0, size1;
	unsigned char t, c0, c1;
	char *p = buffer;

	via_print("----------VIA BusMastering IDE Configuration----------------");

	via_print("Driver Version:                     2.1e");

	pci_read_config_byte(isa_dev, PCI_REVISION_ID, &t);
	via_print("South Bridge:                       VIA %s rev %#x", via_isa_bridges[via_config].name, t);

	pci_read_config_word(dev, PCI_COMMAND, &c);
	via_print("Command register:                   %#x", c);

	pci_read_config_byte(dev, PCI_LATENCY_TIMER, &t);
	via_print("Latency timer:                      %d", t);

	pci_clock = system_bus_clock();
	via_print("PCI clock:                          %dMHz", pci_clock);

	pci_read_config_byte(dev, VIA_MISC_1, &t);
	via_print("Master Read  Cycle IRDY:            %dws", (t & 64) >>6 );
	via_print("Master Write Cycle IRDY:            %dws", (t & 32) >> 5 );
	via_print("FIFO Output Data 1/2 Clock Advance: %s", (t & 16) ? "on" : "off" );
	via_print("BM IDE Status Register Read Retry:  %s", (t & 8) ? "on" : "off" );

	pci_read_config_byte(dev, VIA_MISC_3, &t);
	via_print("Max DRDY Pulse Width:               %s%s", via_control3[(t & 0x03)], (t & 0x03) ? "PCI clocks" : "");

	via_print("-----------------------Primary IDE-------Secondary IDE------");
	via_print("Read DMA FIFO flush:   %10s%20s", (t & 0x80) ? "on" : "off", (t & 0x40) ? "on" : "off" );
	via_print("End Sect. FIFO flush:  %10s%20s", (t & 0x20) ? "on" : "off", (t & 0x10) ? "on" : "off" );

	pci_read_config_byte(dev, VIA_IDE_CONFIG, &t);
	via_print("Prefetch Buffer:       %10s%20s", (t & 0x80) ? "on" : "off", (t & 0x20) ? "on" : "off" );
	via_print("Post Write Buffer:     %10s%20s", (t & 0x40) ? "on" : "off", (t & 0x10) ? "on" : "off" );

	pci_read_config_byte(dev, VIA_FIFO_CONFIG, &t);
	via_print("FIFO size:             %10d%20d", 16 - (((t >> 5) & 1) + ((t >> 6) & 1)) * 8,
							  (((t >> 5) & 1) + ((t >> 6) & 1)) * 8);
	via_print("Threshold Prim.:       %10s%20s", via_fifo[(t >> 2) & 3], via_fifo[t & 3]);

	pci_read_config_word(dev, VIA_PRI_SECTOR_SIZE, &size0);
	pci_read_config_word(dev, VIA_SEC_SECTOR_SIZE, &size1);
	via_print("Bytes Per Sector:      %10d%20d", size0 & 0xfff, size1 & 0xfff);

	pci_read_config_dword(dev, VIA_BM_BASE, &base);
	base = (base & 0xfff0) ;

	c0 = inb((unsigned short)base + 0x02);
	c1 = inb((unsigned short)base + 0x0a);

	via_print("Both channels togth:   %10s%20s", (c0 & 0x80) ? "no" : "yes", (c1 & 0x80) ? "no" : "yes" );

	via_print("-------------------drive0----drive1----drive2----drive3-----");

	via_print("BMDMA enabled: %10s%10s%10s%10s", (c0 & 0x20) ? "yes" : "no", (c0 & 0x40) ? "yes" : "no",
						     (c1 & 0x20) ? "yes" : "no", (c1 & 0x40) ? "yes" : "no" );

	pci_read_config_byte(dev, VIA_ADDRESS_SETUP, &t);
	pci_read_config_dword(dev, VIA_DRIVE_TIMING, &v);
	pci_read_config_dword(dev, VIA_UDMA_TIMING, &u);

	for (i = 0; i < 4; i++) {
		setup[i]   = ((t >>  ((3 - i) << 1)     ) & 0x3) + 1;
		active[i]  = ((v >> (((3 - i) << 3) + 4)) & 0xf) + 1;
		recover[i] = ((v >>  ((3 - i) << 3)     ) & 0xf) + 1;
		udma[i]    = ((u >>  ((3 - i) << 3)     ) & 0x7) + 2;
		umul[i]    = ((u >> (((3 - i) & 2) << 3)) & 0x8) ? 2 : 1;
		uen[i]     = ((u >> ((3 - i) << 3)) & 0x20) ? 1 : 0;
		speed[i] = uen[i] ? 20 * pci_clock * umul[i] / udma[i] :
				    20 * pci_clock / (active[i] + recover[i]);
		cycle[i] = uen[i] ? 1000 / (pci_clock * umul[i]) * udma[i] :
				    1000 / pci_clock * (active[i] + recover[i]);
	}

	via_print_drive("Transfer Mode: ", "%10s", uen[i] ? "UDMA" : "DMA/PIO");
	via_print_drive("Address Setup: ", "%8dns", (1000 / pci_clock) * setup[i]);
	via_print_drive("Active Pulse:  ", "%8dns", (1000 / pci_clock) * active[i]);
	via_print_drive("Recovery Time: ", "%8dns", (1000 / pci_clock) * recover[i]);
	via_print_drive("Cycle Time:    ", "%8dns", cycle[i]);
	via_print_drive("Transfer Rate: ", "%4d.%dMB/s", speed[i] / 10, speed[i] % 10);

	return p - buffer;	/* hoping it is less than 4K... */
}

#endif

#define FIT(v,min,max) ((v)>(max)?(max):((v)<(min)?(min):(v)))
#define ENOUGH(v,un) (((v)-1)/(un)+1)

#ifdef DEBUG
#define via_write_config_byte(dev,number,value) do {\
		printk(KERN_DEBUG "VP_IDE: Setting register %#x to %#x\n", number, value);\
		pci_write_config_byte(dev,number,value); } while (0)
#else
#define via_write_config_byte	pci_write_config_byte
#endif

static int via_set_speed(ide_drive_t *drive, byte speed)
{
	struct pci_dev *dev = HWIF(drive)->pci_dev;
	int i, T, err = 0;
	unsigned char t, setup, active, recover, cycle;

	if (drive->dn > 3) return -1;

	T = 1000 / system_bus_clock();

	if (speed > via_isa_bridges[via_config].speed)
		speed = via_isa_bridges[via_config].speed;

	for (i = 0; via_timing[i].mode && via_timing[i].mode != speed; i++);

#ifdef DEBUG
	printk(KERN_DEBUG "VP_IDE: Setting drive %d to %s\n", drive->dn, via_timing[i].name);
#endif

	setup   = ENOUGH(via_timing[i].setup,   T);
	active  = ENOUGH(via_timing[i].active,  T);
	recover = ENOUGH(via_timing[i].recover, T);
	cycle   = ENOUGH(via_timing[i].cycle,   T);

	if (active + recover < cycle) {
		active += (cycle - (active + recover)) / 2;
		recover = cycle - active;
	}

/*
 * PIO address setup
 */

	pci_read_config_byte(dev, VIA_ADDRESS_SETUP, &t);
	t = (t & ~(3 << ((3 - drive->dn) << 1))) | (FIT(setup - 1, 0, 3) << ((3 - drive->dn) << 1));
	via_write_config_byte(dev, VIA_ADDRESS_SETUP, t);

/*
 * PIO active & recover
 */

	via_write_config_byte(dev, VIA_DRIVE_TIMING + (3 - drive->dn),
		(FIT(active - 1, 0, 0xf) << 4) | FIT(recover - 1, 0, 0xf));

/*
 * UDMA cycle
 */

	switch(via_isa_bridges[via_config].speed) {
		case XFER_UDMA_2: t = via_timing[i].udma ? (0xe0 | (FIT(ENOUGH(via_timing[i].udma, T), 2, 5) - 2)) : 0x03; break;
		case XFER_UDMA_4: t = via_timing[i].udma ? (0xe8 | (FIT(ENOUGH(via_timing[i].udma, T/2), 2, 9) - 2)) : 0x0f; break;
        }

	if (via_isa_bridges[via_config].speed != XFER_MW_DMA_2)
		via_write_config_byte(dev, VIA_UDMA_TIMING + (3 - drive->dn), t);

/*
 * Drive init
 */

	if (!drive->init_speed) drive->init_speed = speed;
	if ((err = ide_config_drive_speed(drive, speed)))
		return err;
	drive->current_speed = speed;

	return 0;
}

static void config_chipset_for_pio(ide_drive_t *drive)
{
	short eide_pio_timing[] = {600, 383, 240, 180, 120, 100};
	signed char pio, ide_pio;

	if (drive->id->eide_pio_iordy > 0) {	/* Has timing table */
		for (pio = 5; pio >= 0; pio--)
			if (drive->id->eide_pio_iordy <= eide_pio_timing[pio])
				break;
	} else {				/* No timing table -> use mode capabilities */
		pio = (drive->id->eide_pio_modes & 4) ? 5 :
		      (drive->id->eide_pio_modes & 2) ? 4 :
		      (drive->id->eide_pio_modes & 1) ? 3 :
		      (drive->id->tPIO == 2) ? 2 :
		      (drive->id->tPIO == 1) ? 1 : 0;
	}

	ide_pio = ide_get_best_pio_mode(drive, 255, 5, NULL);
	pio = (pio >= ide_pio) ? pio : ide_pio;	/* Phew. What about the blacklist? */

	if (!pio) pio = (!drive->id->tPIO) ? XFER_PIO_0 : XFER_PIO_SLOW;
		else pio += XFER_PIO_0;

	/* Fixup because of broken ide-probe.c */
	drive->dn = HWIF(drive)->channel * 2 + (drive->select.b.unit & 1); 

	via_set_speed(drive, pio);
}

static void via82cxxx_tune_drive(ide_drive_t *drive, byte pio)
{
	if (pio == 255) {
		config_chipset_for_pio(drive);
		return;
	}
	
	if (pio > 5) pio = 5;
	
	via_set_speed(drive, XFER_PIO_0 + pio);
}

#ifdef CONFIG_BLK_DEV_IDEDMA

static int config_chipset_for_dma(ide_drive_t *drive)
{
	struct hd_driveid *id = drive->id;
	unsigned char ultra66 = eighty_ninty_three(drive);
	unsigned char speed =

		((id->dma_ultra & 0x0010) && ultra66) ? XFER_UDMA_4 :
		((id->dma_ultra & 0x0008) && ultra66) ? XFER_UDMA_3 :
		(id->dma_ultra & 0x0004) ? XFER_UDMA_2 :
		(id->dma_ultra & 0x0002) ? XFER_UDMA_1 :
		(id->dma_ultra & 0x0001) ? XFER_UDMA_0 :
		(id->dma_mword & 0x0004) ? XFER_MW_DMA_2 :
		(id->dma_mword & 0x0002) ? XFER_MW_DMA_1 :
		(id->dma_mword & 0x0001) ? XFER_MW_DMA_0 :
		(id->dma_1word & 0x0004) ? XFER_SW_DMA_2 :
		(id->dma_1word & 0x0002) ? XFER_SW_DMA_1 :
		(id->dma_1word & 0x0001) ? XFER_SW_DMA_0 : 0;
		
	if (!speed) return (int) ide_dma_off_quietly;

	via_set_speed(drive, speed);

	return (int) ide_dma_on;
}

/*
 * Almost a library function.
 */

static int config_drive_xfer_rate(ide_drive_t *drive)
{
	struct hd_driveid *id = drive->id;
	ide_dma_action_t dma_func = ide_dma_on;

	if (id && (id->capability & 1) && HWIF(drive)->autodma) {
		/* Consult the list of known "bad" drives */
		if (ide_dmaproc(ide_dma_bad_drive, drive)) {
			dma_func = ide_dma_off;
			goto fast_ata_pio;
		}
		dma_func = ide_dma_off_quietly;
		if (id->field_valid & 4) {
			if (id->dma_ultra & 0x002F) {
				/* Force if Capable UltraDMA */
				dma_func = config_chipset_for_dma(drive);
				if ((id->field_valid & 2) &&
				    (dma_func != ide_dma_on))
					goto try_dma_modes;
			}
		} else if (id->field_valid & 2) {
try_dma_modes:
			if (id->dma_mword & 0x0007) {
				/* Force if Capable regular DMA modes */
				dma_func = config_chipset_for_dma(drive);
				if (dma_func != ide_dma_on)
					goto no_dma_set;
			}
		} else if (ide_dmaproc(ide_dma_good_drive, drive)) {
			if (id->eide_dma_time > 150) {
				goto no_dma_set;
			}
			/* Consult the list of known "good" drives */
			dma_func = config_chipset_for_dma(drive);
			if (dma_func != ide_dma_on)
				goto no_dma_set;
		} else {
			goto fast_ata_pio;
		}
	} else if ((id->capability & 8) || (id->field_valid & 2)) {
fast_ata_pio:
		dma_func = ide_dma_off_quietly;
no_dma_set:
		config_chipset_for_pio(drive);
	}
	return HWIF(drive)->dmaproc(dma_func, drive);
}


int via82cxxx_dmaproc(ide_dma_action_t func, ide_drive_t *drive)
{
	if (func == ide_dma_check)
			return config_drive_xfer_rate(drive);
	return ide_dmaproc(func, drive);
}
#endif /* CONFIG_BLK_DEV_IDEDMA */

unsigned int __init pci_init_via82cxxx(struct pci_dev *dev, const char *name)
{
	struct pci_dev *isa = NULL;
	unsigned char f, t, m;
	unsigned int u, i;

/*
 * Find ISA bridge to see how good the IDE is.
 */

	for (via_config = 0; via_isa_bridges[via_config].id; via_config++)
		if ((isa = pci_find_device(PCI_VENDOR_ID_VIA, via_isa_bridges[via_config].id, NULL)))	
			break;
/*
 * Read revision.
 */

	if (via_isa_bridges[via_config].id == PCI_DEVICE_ID_VIA_82C586_0) {
		pci_read_config_byte(isa, PCI_REVISION_ID, &t);
		if (t < 0x30) via_config++;			/* vt82c586a */
		if (t < 0x20) via_config++;			/* vt82c586 */
	}

	if (via_isa_bridges[via_config].id == PCI_DEVICE_ID_VIA_82C596) {
		pci_read_config_byte(isa, PCI_REVISION_ID, &t);
		if (t < 0x10) via_config++;			/* vt82c596a */
	}

/*
 * Check UDMA66 mode set by BIOS.
 */

	pci_read_config_dword(dev, VIA_UDMA_TIMING, &u);

	for (i = 0; i < 4; i++) {
		pci_read_config_byte(dev, VIA_UDMA_TIMING + (3 - i), &t);
		if ((u & (0x80000 >> ((i >> 1) << 4))) && ((t & 7) < 2)) via_ata66 |= (1 << (i >> 1));
	} 

#ifdef DEBUG
	printk(KERN_DEBUG "VP_IDE: BIOS enabled ATA66: primary: %s, secondary: %s\n",
		via_ata66 & 1 ? "yes" : "no", via_ata66 & 2 ? "yes" : "no");
#endif

/*
 * Set UDMA66 double clock bits.
 */
	if (via_isa_bridges[via_config].speed == XFER_UDMA_4)
		pci_write_config_dword(dev, VIA_UDMA_TIMING, u | 0x80008);

/*
 * Set up FIFO, flush, prefetch and post-writes.
 */

	pci_read_config_dword(dev, VIA_IDE_ENABLE, &u);
	pci_read_config_byte(dev, VIA_FIFO_CONFIG, &f);
	pci_read_config_byte(dev, VIA_IDE_CONFIG, &t);
	pci_read_config_byte(dev, VIA_MISC_3, &m);

	f &= 0x90; t &= 0x0f; m &= 0x0f;

	switch (u & 3) {
		case 2: via_enabled = 1; f |= 0x06; t |= 0xc0; m |= 0xa0; break;	/* primary only, 3/4 */
		case 1: via_enabled = 2; f |= 0x69; t |= 0x30; m |= 0x50; break;	/* secondary only, 3/4 */
		case 3: via_enabled = 3;
		default:                 f |= 0x2a; t |= 0xf0; m |= 0xf0; break;	/* fifo evenly distributed */
	}

	via_write_config_byte(dev, VIA_FIFO_CONFIG, f);
	via_write_config_byte(dev, VIA_IDE_CONFIG, t);
	via_write_config_byte(dev, VIA_MISC_3, m);

/*
 * Print the boot message.
 */

	printk(KERN_INFO "VP_IDE: VIA %s IDE %s controller on pci%d:%d.%d\n",
			via_isa_bridges[via_config].name,
			via_isa_bridges[via_config].speed >= XFER_UDMA_4 ? "UDMA66" :
			via_isa_bridges[via_config].speed >= XFER_UDMA_2 ? "UDMA33" : "MWDMA16",
			dev->bus->number, PCI_SLOT(dev->devfn), PCI_FUNC(dev->devfn));
/*
 * Register /proc/ide/via entry
 */

#if defined(CONFIG_PROC_FS)
	if (!via_proc) {
		via_proc = 1;
		bmide_dev = dev;
		isa_dev = isa;
		via_display_info = &via_get_info;
	}
#endif

	return 0;
}

/*
 * Since we don't have a way to detect the 80-wire ribbon cable
 * we rely on the BIOS detection. We also check the IDENTIFY byte
 * 93 to check the drive's point of view. I think we could return
 * '1' here 
 */

unsigned int __init ata66_via82cxxx(ide_hwif_t *hwif)
{
	return ((via_enabled & via_ata66) >> hwif->channel) & 1;
}

void __init ide_init_via82cxxx(ide_hwif_t *hwif)
{
	hwif->tuneproc = &via82cxxx_tune_drive;
	hwif->speedproc = &via_set_speed;
	hwif->drives[0].autotune = 1;
	hwif->drives[1].autotune = 1;
	hwif->autodma = 0;

#ifdef CONFIG_BLK_DEV_IDEDMA
	if (hwif->dma_base) {
		hwif->dmaproc = &via82cxxx_dmaproc;
		hwif->autodma = 1;
	}
#endif /* CONFIG_BLK_DEV_IDEDMA */
}

/*
 * We allow the BM-DMA driver only work on enabled interfaces.
 */

void __init ide_dmacapable_via82cxxx(ide_hwif_t *hwif, unsigned long dmabase)
{
	if ((via_enabled >> hwif->channel) & 1)
		ide_setup_dma(hwif, dmabase, 8);
}