aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/gpu/drm/i915/dvo_ns2501.c
blob: 441630434d34742b38d938e5ba6bee0fa6faa965 (plain) (blame)
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
/*
 *
 * Copyright (c) 2012 Gilles Dartiguelongue, Thomas Richter
 *
 * All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sub license, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 */

#include "dvo.h"
#include "i915_reg.h"
#include "i915_drv.h"

#define NS2501_VID 0x1305
#define NS2501_DID 0x6726

#define NS2501_VID_LO 0x00
#define NS2501_VID_HI 0x01
#define NS2501_DID_LO 0x02
#define NS2501_DID_HI 0x03
#define NS2501_REV 0x04
#define NS2501_RSVD 0x05
#define NS2501_FREQ_LO 0x06
#define NS2501_FREQ_HI 0x07

#define NS2501_REG8 0x08
#define NS2501_8_VEN (1<<5)
#define NS2501_8_HEN (1<<4)
#define NS2501_8_DSEL (1<<3)
#define NS2501_8_BPAS (1<<2)
#define NS2501_8_RSVD (1<<1)
#define NS2501_8_PD (1<<0)

#define NS2501_REG9 0x09
#define NS2501_9_VLOW (1<<7)
#define NS2501_9_MSEL_MASK (0x7<<4)
#define NS2501_9_TSEL (1<<3)
#define NS2501_9_RSEN (1<<2)
#define NS2501_9_RSVD (1<<1)
#define NS2501_9_MDI (1<<0)

#define NS2501_REGC 0x0c

enum {
	MODE_640x480,
	MODE_800x600,
	MODE_1024x768,
};

struct ns2501_reg {
	 uint8_t offset;
	 uint8_t value;
};

/*
 * Magic values based on what the BIOS on
 * Fujitsu-Siemens Lifebook S6010 programs (1024x768 panel).
 */
static const struct ns2501_reg regs_1024x768[][86] = {
	[MODE_640x480] = {
		[0] = { .offset = 0x0a, .value = 0x81, },
		[1] = { .offset = 0x18, .value = 0x07, },
		[2] = { .offset = 0x19, .value = 0x00, },
		[3] = { .offset = 0x1a, .value = 0x00, },
		[4] = { .offset = 0x1b, .value = 0x11, },
		[5] = { .offset = 0x1c, .value = 0x54, },
		[6] = { .offset = 0x1d, .value = 0x03, },
		[7] = { .offset = 0x1e, .value = 0x02, },
		[8] = { .offset = 0xf3, .value = 0x90, },
		[9] = { .offset = 0xf9, .value = 0x00, },
		[10] = { .offset = 0xc1, .value = 0x90, },
		[11] = { .offset = 0xc2, .value = 0x00, },
		[12] = { .offset = 0xc3, .value = 0x0f, },
		[13] = { .offset = 0xc4, .value = 0x03, },
		[14] = { .offset = 0xc5, .value = 0x16, },
		[15] = { .offset = 0xc6, .value = 0x00, },
		[16] = { .offset = 0xc7, .value = 0x02, },
		[17] = { .offset = 0xc8, .value = 0x02, },
		[18] = { .offset = 0xf4, .value = 0x00, },
		[19] = { .offset = 0x80, .value = 0xff, },
		[20] = { .offset = 0x81, .value = 0x07, },
		[21] = { .offset = 0x82, .value = 0x3d, },
		[22] = { .offset = 0x83, .value = 0x05, },
		[23] = { .offset = 0x94, .value = 0x00, },
		[24] = { .offset = 0x95, .value = 0x00, },
		[25] = { .offset = 0x96, .value = 0x05, },
		[26] = { .offset = 0x97, .value = 0x00, },
		[27] = { .offset = 0x9a, .value = 0x88, },
		[28] = { .offset = 0x9b, .value = 0x00, },
		[29] = { .offset = 0x98, .value = 0x00, },
		[30] = { .offset = 0x99, .value = 0x00, },
		[31] = { .offset = 0xf7, .value = 0x88, },
		[32] = { .offset = 0xf8, .value = 0x0a, },
		[33] = { .offset = 0x9c, .value = 0x24, },
		[34] = { .offset = 0x9d, .value = 0x00, },
		[35] = { .offset = 0x9e, .value = 0x25, },
		[36] = { .offset = 0x9f, .value = 0x03, },
		[37] = { .offset = 0xa0, .value = 0x28, },
		[38] = { .offset = 0xa1, .value = 0x01, },
		[39] = { .offset = 0xa2, .value = 0x28, },
		[40] = { .offset = 0xa3, .value = 0x05, },
		[41] = { .offset = 0xb6, .value = 0x09, },
		[42] = { .offset = 0xb8, .value = 0x00, },
		[43] = { .offset = 0xb9, .value = 0xa0, },
		[44] = { .offset = 0xba, .value = 0x00, },
		[45] = { .offset = 0xbb, .value = 0x20, },
		[46] = { .offset = 0x10, .value = 0x00, },
		[47] = { .offset = 0x11, .value = 0xa0, },
		[48] = { .offset = 0x12, .value = 0x02, },
		[49] = { .offset = 0x20, .value = 0x00, },
		[50] = { .offset = 0x22, .value = 0x00, },
		[51] = { .offset = 0x23, .value = 0x00, },
		[52] = { .offset = 0x24, .value = 0x00, },
		[53] = { .offset = 0x25, .value = 0x00, },
		[54] = { .offset = 0x8c, .value = 0x10, },
		[55] = { .offset = 0x8d, .value = 0x02, },
		[56] = { .offset = 0x8e, .value = 0x10, },
		[57] = { .offset = 0x8f, .value = 0x00, },
		[58] = { .offset = 0x90, .value = 0xff, },
		[59] = { .offset = 0x91, .value = 0x07, },
		[60] = { .offset = 0x92, .value = 0xa0, },
		[61] = { .offset = 0x93, .value = 0x02, },
		[62] = { .offset = 0xa5, .value = 0x00, },
		[63] = { .offset = 0xa6, .value = 0x00, },
		[64] = { .offset = 0xa7, .value = 0x00, },
		[65] = { .offset = 0xa8, .value = 0x00, },
		[66] = { .offset = 0xa9, .value = 0x04, },
		[67] = { .offset = 0xaa, .value = 0x70, },
		[68] = { .offset = 0xab, .value = 0x4f, },
		[69] = { .offset = 0xac, .value = 0x00, },
		[70] = { .offset = 0xa4, .value = 0x84, },
		[71] = { .offset = 0x7e, .value = 0x18, },
		[72] = { .offset = 0x84, .value = 0x00, },
		[73] = { .offset = 0x85, .value = 0x00, },
		[74] = { .offset = 0x86, .value = 0x00, },
		[75] = { .offset = 0x87, .value = 0x00, },
		[76] = { .offset = 0x88, .value = 0x00, },
		[77] = { .offset = 0x89, .value = 0x00, },
		[78] = { .offset = 0x8a, .value = 0x00, },
		[79] = { .offset = 0x8b, .value = 0x00, },
		[80] = { .offset = 0x26, .value = 0x00, },
		[81] = { .offset = 0x27, .value = 0x00, },
		[82] = { .offset = 0xad, .value = 0x00, },
		[83] = { .offset = 0x08, .value = 0x30, }, /* 0x31 */
		[84] = { .offset = 0x41, .value = 0x00, },
		[85] = { .offset = 0xc0, .value = 0x05, },
	},
	[MODE_800x600] = {
		[0] = { .offset = 0x0a, .value = 0x81, },
		[1] = { .offset = 0x18, .value = 0x07, },
		[2] = { .offset = 0x19, .value = 0x00, },
		[3] = { .offset = 0x1a, .value = 0x00, },
		[4] = { .offset = 0x1b, .value = 0x19, },
		[5] = { .offset = 0x1c, .value = 0x64, },
		[6] = { .offset = 0x1d, .value = 0x02, },
		[7] = { .offset = 0x1e, .value = 0x02, },
		[8] = { .offset = 0xf3, .value = 0x90, },
		[9] = { .offset = 0xf9, .value = 0x00, },
		[10] = { .offset = 0xc1, .value = 0xd7, },
		[11] = { .offset = 0xc2, .value = 0x00, },
		[12] = { .offset = 0xc3, .value = 0xf8, },
		[13] = { .offset = 0xc4, .value = 0x03, },
		[14] = { .offset = 0xc5, .value = 0x1a, },
		[15] = { .offset = 0xc6, .value = 0x00, },
		[16] = { .offset = 0xc7, .value = 0x73, },
		[17] = { .offset = 0xc8, .value = 0x02, },
		[18] = { .offset = 0xf4, .value = 0x00, },
		[19] = { .offset = 0x80, .value = 0x27, },
		[20] = { .offset = 0x81, .value = 0x03, },
		[21] = { .offset = 0x82, .value = 0x41, },
		[22] = { .offset = 0x83, .value = 0x05, },
		[23] = { .offset = 0x94, .value = 0x00, },
		[24] = { .offset = 0x95, .value = 0x00, },
		[25] = { .offset = 0x96, .value = 0x05, },
		[26] = { .offset = 0x97, .value = 0x00, },
		[27] = { .offset = 0x9a, .value = 0x88, },
		[28] = { .offset = 0x9b, .value = 0x00, },
		[29] = { .offset = 0x98, .value = 0x00, },
		[30] = { .offset = 0x99, .value = 0x00, },
		[31] = { .offset = 0xf7, .value = 0x88, },
		[32] = { .offset = 0xf8, .value = 0x06, },
		[33] = { .offset = 0x9c, .value = 0x23, },
		[34] = { .offset = 0x9d, .value = 0x00, },
		[35] = { .offset = 0x9e, .value = 0x25, },
		[36] = { .offset = 0x9f, .value = 0x03, },
		[37] = { .offset = 0xa0, .value = 0x28, },
		[38] = { .offset = 0xa1, .value = 0x01, },
		[39] = { .offset = 0xa2, .value = 0x28, },
		[40] = { .offset = 0xa3, .value = 0x05, },
		[41] = { .offset = 0xb6, .value = 0x09, },
		[42] = { .offset = 0xb8, .value = 0x30, },
		[43] = { .offset = 0xb9, .value = 0xc8, },
		[44] = { .offset = 0xba, .value = 0x00, },
		[45] = { .offset = 0xbb, .value = 0x20, },
		[46] = { .offset = 0x10, .value = 0x20, },
		[47] = { .offset = 0x11, .value = 0xc8, },
		[48] = { .offset = 0x12, .value = 0x02, },
		[49] = { .offset = 0x20, .value = 0x00, },
		[50] = { .offset = 0x22, .value = 0x00, },
		[51] = { .offset = 0x23, .value = 0x00, },
		[52] = { .offset = 0x24, .value = 0x00, },
		[53] = { .offset = 0x25, .value = 0x00, },
		[54] = { .offset = 0x8c, .value = 0x10, },
		[55] = { .offset = 0x8d, .value = 0x02, },
		[56] = { .offset = 0x8e, .value = 0x04, },
		[57] = { .offset = 0x8f, .value = 0x00, },
		[58] = { .offset = 0x90, .value = 0xff, },
		[59] = { .offset = 0x91, .value = 0x07, },
		[60] = { .offset = 0x92, .value = 0xa0, },
		[61] = { .offset = 0x93, .value = 0x02, },
		[62] = { .offset = 0xa5, .value = 0x00, },
		[63] = { .offset = 0xa6, .value = 0x00, },
		[64] = { .offset = 0xa7, .value = 0x00, },
		[65] = { .offset = 0xa8, .value = 0x00, },
		[66] = { .offset = 0xa9, .value = 0x83, },
		[67] = { .offset = 0xaa, .value = 0x40, },
		[68] = { .offset = 0xab, .value = 0x32, },
		[69] = { .offset = 0xac, .value = 0x00, },
		[70] = { .offset = 0xa4, .value = 0x80, },
		[71] = { .offset = 0x7e, .value = 0x18, },
		[72] = { .offset = 0x84, .value = 0x00, },
		[73] = { .offset = 0x85, .value = 0x00, },
		[74] = { .offset = 0x86, .value = 0x00, },
		[75] = { .offset = 0x87, .value = 0x00, },
		[76] = { .offset = 0x88, .value = 0x00, },
		[77] = { .offset = 0x89, .value = 0x00, },
		[78] = { .offset = 0x8a, .value = 0x00, },
		[79] = { .offset = 0x8b, .value = 0x00, },
		[80] = { .offset = 0x26, .value = 0x00, },
		[81] = { .offset = 0x27, .value = 0x00, },
		[82] = { .offset = 0xad, .value = 0x00, },
		[83] = { .offset = 0x08, .value = 0x30, }, /* 0x31 */
		[84] = { .offset = 0x41, .value = 0x00, },
		[85] = { .offset = 0xc0, .value = 0x07, },
	},
	[MODE_1024x768] = {
		[0] = { .offset = 0x0a, .value = 0x81, },
		[1] = { .offset = 0x18, .value = 0x07, },
		[2] = { .offset = 0x19, .value = 0x00, },
		[3] = { .offset = 0x1a, .value = 0x00, },
		[4] = { .offset = 0x1b, .value = 0x11, },
		[5] = { .offset = 0x1c, .value = 0x54, },
		[6] = { .offset = 0x1d, .value = 0x03, },
		[7] = { .offset = 0x1e, .value = 0x02, },
		[8] = { .offset = 0xf3, .value = 0x90, },
		[9] = { .offset = 0xf9, .value = 0x00, },
		[10] = { .offset = 0xc1, .value = 0x90, },
		[11] = { .offset = 0xc2, .value = 0x00, },
		[12] = { .offset = 0xc3, .value = 0x0f, },
		[13] = { .offset = 0xc4, .value = 0x03, },
		[14] = { .offset = 0xc5, .value = 0x16, },
		[15] = { .offset = 0xc6, .value = 0x00, },
		[16] = { .offset = 0xc7, .value = 0x02, },
		[17] = { .offset = 0xc8, .value = 0x02, },
		[18] = { .offset = 0xf4, .value = 0x00, },
		[19] = { .offset = 0x80, .value = 0xff, },
		[20] = { .offset = 0x81, .value = 0x07, },
		[21] = { .offset = 0x82, .value = 0x3d, },
		[22] = { .offset = 0x83, .value = 0x05, },
		[23] = { .offset = 0x94, .value = 0x00, },
		[24] = { .offset = 0x95, .value = 0x00, },
		[25] = { .offset = 0x96, .value = 0x05, },
		[26] = { .offset = 0x97, .value = 0x00, },
		[27] = { .offset = 0x9a, .value = 0x88, },
		[28] = { .offset = 0x9b, .value = 0x00, },
		[29] = { .offset = 0x98, .value = 0x00, },
		[30] = { .offset = 0x99, .value = 0x00, },
		[31] = { .offset = 0xf7, .value = 0x88, },
		[32] = { .offset = 0xf8, .value = 0x0a, },
		[33] = { .offset = 0x9c, .value = 0x24, },
		[34] = { .offset = 0x9d, .value = 0x00, },
		[35] = { .offset = 0x9e, .value = 0x25, },
		[36] = { .offset = 0x9f, .value = 0x03, },
		[37] = { .offset = 0xa0, .value = 0x28, },
		[38] = { .offset = 0xa1, .value = 0x01, },
		[39] = { .offset = 0xa2, .value = 0x28, },
		[40] = { .offset = 0xa3, .value = 0x05, },
		[41] = { .offset = 0xb6, .value = 0x09, },
		[42] = { .offset = 0xb8, .value = 0x00, },
		[43] = { .offset = 0xb9, .value = 0xa0, },
		[44] = { .offset = 0xba, .value = 0x00, },
		[45] = { .offset = 0xbb, .value = 0x20, },
		[46] = { .offset = 0x10, .value = 0x00, },
		[47] = { .offset = 0x11, .value = 0xa0, },
		[48] = { .offset = 0x12, .value = 0x02, },
		[49] = { .offset = 0x20, .value = 0x00, },
		[50] = { .offset = 0x22, .value = 0x00, },
		[51] = { .offset = 0x23, .value = 0x00, },
		[52] = { .offset = 0x24, .value = 0x00, },
		[53] = { .offset = 0x25, .value = 0x00, },
		[54] = { .offset = 0x8c, .value = 0x10, },
		[55] = { .offset = 0x8d, .value = 0x02, },
		[56] = { .offset = 0x8e, .value = 0x10, },
		[57] = { .offset = 0x8f, .value = 0x00, },
		[58] = { .offset = 0x90, .value = 0xff, },
		[59] = { .offset = 0x91, .value = 0x07, },
		[60] = { .offset = 0x92, .value = 0xa0, },
		[61] = { .offset = 0x93, .value = 0x02, },
		[62] = { .offset = 0xa5, .value = 0x00, },
		[63] = { .offset = 0xa6, .value = 0x00, },
		[64] = { .offset = 0xa7, .value = 0x00, },
		[65] = { .offset = 0xa8, .value = 0x00, },
		[66] = { .offset = 0xa9, .value = 0x04, },
		[67] = { .offset = 0xaa, .value = 0x70, },
		[68] = { .offset = 0xab, .value = 0x4f, },
		[69] = { .offset = 0xac, .value = 0x00, },
		[70] = { .offset = 0xa4, .value = 0x84, },
		[71] = { .offset = 0x7e, .value = 0x18, },
		[72] = { .offset = 0x84, .value = 0x00, },
		[73] = { .offset = 0x85, .value = 0x00, },
		[74] = { .offset = 0x86, .value = 0x00, },
		[75] = { .offset = 0x87, .value = 0x00, },
		[76] = { .offset = 0x88, .value = 0x00, },
		[77] = { .offset = 0x89, .value = 0x00, },
		[78] = { .offset = 0x8a, .value = 0x00, },
		[79] = { .offset = 0x8b, .value = 0x00, },
		[80] = { .offset = 0x26, .value = 0x00, },
		[81] = { .offset = 0x27, .value = 0x00, },
		[82] = { .offset = 0xad, .value = 0x00, },
		[83] = { .offset = 0x08, .value = 0x34, }, /* 0x35 */
		[84] = { .offset = 0x41, .value = 0x00, },
		[85] = { .offset = 0xc0, .value = 0x01, },
	},
};

static const struct ns2501_reg regs_init[] = {
	[0] = { .offset = 0x35, .value = 0xff, },
	[1] = { .offset = 0x34, .value = 0x00, },
	[2] = { .offset = 0x08, .value = 0x30, },
};

struct ns2501_priv {
	bool quiet;
	const struct ns2501_reg *regs;
};

#define NSPTR(d) ((NS2501Ptr)(d->DriverPrivate.ptr))

/*
 * For reasons unclear to me, the ns2501 at least on the Fujitsu/Siemens
 * laptops does not react on the i2c bus unless
 * both the PLL is running and the display is configured in its native
 * resolution.
 * This function forces the DVO on, and stores the registers it touches.
 * Afterwards, registers are restored to regular values.
 *
 * This is pretty much a hack, though it works.
 * Without that, ns2501_readb and ns2501_writeb fail
 * when switching the resolution.
 */

/*
** Read a register from the ns2501.
** Returns true if successful, false otherwise.
** If it returns false, it might be wise to enable the
** DVO with the above function.
*/
static bool ns2501_readb(struct intel_dvo_device *dvo, int addr, uint8_t * ch)
{
	struct ns2501_priv *ns = dvo->dev_priv;
	struct i2c_adapter *adapter = dvo->i2c_bus;
	u8 out_buf[2];
	u8 in_buf[2];

	struct i2c_msg msgs[] = {
		{
		 .addr = dvo->slave_addr,
		 .flags = 0,
		 .len = 1,
		 .buf = out_buf,
		 },
		{
		 .addr = dvo->slave_addr,
		 .flags = I2C_M_RD,
		 .len = 1,
		 .buf = in_buf,
		 }
	};

	out_buf[0] = addr;
	out_buf[1] = 0;

	if (i2c_transfer(adapter, msgs, 2) == 2) {
		*ch = in_buf[0];
		return true;
	}

	if (!ns->quiet) {
		DRM_DEBUG_KMS
		    ("Unable to read register 0x%02x from %s:0x%02x.\n", addr,
		     adapter->name, dvo->slave_addr);
	}

	return false;
}

/*
** Write a register to the ns2501.
** Returns true if successful, false otherwise.
** If it returns false, it might be wise to enable the
** DVO with the above function.
*/
static bool ns2501_writeb(struct intel_dvo_device *dvo, int addr, uint8_t ch)
{
	struct ns2501_priv *ns = dvo->dev_priv;
	struct i2c_adapter *adapter = dvo->i2c_bus;
	uint8_t out_buf[2];

	struct i2c_msg msg = {
		.addr = dvo->slave_addr,
		.flags = 0,
		.len = 2,
		.buf = out_buf,
	};

	out_buf[0] = addr;
	out_buf[1] = ch;

	if (i2c_transfer(adapter, &msg, 1) == 1) {
		return true;
	}

	if (!ns->quiet) {
		DRM_DEBUG_KMS("Unable to write register 0x%02x to %s:%d\n",
			      addr, adapter->name, dvo->slave_addr);
	}

	return false;
}

/* National Semiconductor 2501 driver for chip on i2c bus
 * scan for the chip on the bus.
 * Hope the VBIOS initialized the PLL correctly so we can
 * talk to it. If not, it will not be seen and not detected.
 * Bummer!
 */
static bool ns2501_init(struct intel_dvo_device *dvo,
			struct i2c_adapter *adapter)
{
	/* this will detect the NS2501 chip on the specified i2c bus */
	struct ns2501_priv *ns;
	unsigned char ch;

	ns = kzalloc(sizeof(struct ns2501_priv), GFP_KERNEL);
	if (ns == NULL)
		return false;

	dvo->i2c_bus = adapter;
	dvo->dev_priv = ns;
	ns->quiet = true;

	if (!ns2501_readb(dvo, NS2501_VID_LO, &ch))
		goto out;

	if (ch != (NS2501_VID & 0xff)) {
		DRM_DEBUG_KMS("ns2501 not detected got %d: from %s Slave %d.\n",
			      ch, adapter->name, dvo->slave_addr);
		goto out;
	}

	if (!ns2501_readb(dvo, NS2501_DID_LO, &ch))
		goto out;

	if (ch != (NS2501_DID & 0xff)) {
		DRM_DEBUG_KMS("ns2501 not detected got %d: from %s Slave %d.\n",
			      ch, adapter->name, dvo->slave_addr);
		goto out;
	}
	ns->quiet = false;

	DRM_DEBUG_KMS("init ns2501 dvo controller successfully!\n");

	return true;

out:
	kfree(ns);
	return false;
}

static enum drm_connector_status ns2501_detect(struct intel_dvo_device *dvo)
{
	/*
	 * This is a Laptop display, it doesn't have hotplugging.
	 * Even if not, the detection bit of the 2501 is unreliable as
	 * it only works for some display types.
	 * It is even more unreliable as the PLL must be active for
	 * allowing reading from the chiop.
	 */
	return connector_status_connected;
}

static enum drm_mode_status ns2501_mode_valid(struct intel_dvo_device *dvo,
					      struct drm_display_mode *mode)
{
	DRM_DEBUG_KMS
	    ("is mode valid (hdisplay=%d,htotal=%d,vdisplay=%d,vtotal=%d)\n",
	     mode->hdisplay, mode->htotal, mode->vdisplay, mode->vtotal);

	/*
	 * Currently, these are all the modes I have data from.
	 * More might exist. Unclear how to find the native resolution
	 * of the panel in here so we could always accept it
	 * by disabling the scaler.
	 */
	if ((mode->hdisplay == 640 && mode->vdisplay == 480 && mode->clock == 25175) ||
	    (mode->hdisplay == 800 && mode->vdisplay == 600 && mode->clock == 40000) ||
	    (mode->hdisplay == 1024 && mode->vdisplay == 768 && mode->clock == 65000)) {
		return MODE_OK;
	} else {
		return MODE_ONE_SIZE;	/* Is this a reasonable error? */
	}
}

static void ns2501_mode_set(struct intel_dvo_device *dvo,
			    struct drm_display_mode *mode,
			    struct drm_display_mode *adjusted_mode)
{
	struct ns2501_priv *ns = (struct ns2501_priv *)(dvo->dev_priv);
	int mode_idx, i;

	DRM_DEBUG_KMS
	    ("set mode (hdisplay=%d,htotal=%d,vdisplay=%d,vtotal=%d).\n",
	     mode->hdisplay, mode->htotal, mode->vdisplay, mode->vtotal);

	if (mode->hdisplay == 640 && mode->vdisplay == 480)
		mode_idx = MODE_640x480;
	else if (mode->hdisplay == 800 && mode->vdisplay == 600)
		mode_idx = MODE_800x600;
	else if (mode->hdisplay == 1024 && mode->vdisplay == 768)
		mode_idx = MODE_1024x768;
	else
		return;

	/* Hopefully doing it every time won't hurt... */
	for (i = 0; i < ARRAY_SIZE(regs_init); i++)
		ns2501_writeb(dvo, regs_init[i].offset, regs_init[i].value);

	ns->regs = regs_1024x768[mode_idx];

	for (i = 0; i < 84; i++)
		ns2501_writeb(dvo, ns->regs[i].offset, ns->regs[i].value);
}

/* set the NS2501 power state */
static bool ns2501_get_hw_state(struct intel_dvo_device *dvo)
{
	unsigned char ch;

	if (!ns2501_readb(dvo, NS2501_REG8, &ch))
		return false;

	return ch & NS2501_8_PD;
}

/* set the NS2501 power state */
static void ns2501_dpms(struct intel_dvo_device *dvo, bool enable)
{
	struct ns2501_priv *ns = (struct ns2501_priv *)(dvo->dev_priv);

	DRM_DEBUG_KMS("Trying set the dpms of the DVO to %i\n", enable);

	if (enable) {
		if (WARN_ON(ns->regs[83].offset != 0x08 ||
			    ns->regs[84].offset != 0x41 ||
			    ns->regs[85].offset != 0xc0))
			return;

		ns2501_writeb(dvo, 0xc0, ns->regs[85].value | 0x08);

		ns2501_writeb(dvo, 0x41, ns->regs[84].value);

		ns2501_writeb(dvo, 0x34, 0x01);
		msleep(15);

		ns2501_writeb(dvo, 0x08, 0x35);
		if (!(ns->regs[83].value & NS2501_8_BPAS))
			ns2501_writeb(dvo, 0x08, 0x31);
		msleep(200);

		ns2501_writeb(dvo, 0x34, 0x03);

		ns2501_writeb(dvo, 0xc0, ns->regs[85].value);
	} else {
		ns2501_writeb(dvo, 0x34, 0x01);
		msleep(200);

		ns2501_writeb(dvo, 0x08, 0x34);
		msleep(15);

		ns2501_writeb(dvo, 0x34, 0x00);
	}
}

static void ns2501_destroy(struct intel_dvo_device *dvo)
{
	struct ns2501_priv *ns = dvo->dev_priv;

	if (ns) {
		kfree(ns);
		dvo->dev_priv = NULL;
	}
}

struct intel_dvo_dev_ops ns2501_ops = {
	.init = ns2501_init,
	.detect = ns2501_detect,
	.mode_valid = ns2501_mode_valid,
	.mode_set = ns2501_mode_set,
	.dpms = ns2501_dpms,
	.get_hw_state = ns2501_get_hw_state,
	.destroy = ns2501_destroy,
};