aboutsummaryrefslogtreecommitdiff
path: root/drivers/media/dvb/frontends/lgdt330x.c
blob: c990d35a13dcdf2617d7efb65d7ea782735b9939 (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
/*
 *    Support for LGDT3302 and LGDT3303 - VSB/QAM
 *
 *    Copyright (C) 2005 Wilson Michaels <wilsonmichaels@earthlink.net>
 *
 *    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., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

/*
 *                      NOTES ABOUT THIS DRIVER
 *
 * This Linux driver supports:
 *   DViCO FusionHDTV 3 Gold-Q
 *   DViCO FusionHDTV 3 Gold-T
 *   DViCO FusionHDTV 5 Gold
 *   DViCO FusionHDTV 5 Lite
 *   DViCO FusionHDTV 5 USB Gold
 *   Air2PC/AirStar 2 ATSC 3rd generation (HD5000)
 *   pcHDTV HD5500
 *
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <asm/byteorder.h>

#include "dvb_frontend.h"
#include "dvb_math.h"
#include "lgdt330x_priv.h"
#include "lgdt330x.h"

/* Use Equalizer Mean Squared Error instead of Phaser Tracker MSE */
/* #define USE_EQMSE */

static int debug;
module_param(debug, int, 0644);
MODULE_PARM_DESC(debug,"Turn on/off lgdt330x frontend debugging (default:off).");
#define dprintk(args...) \
do { \
if (debug) printk(KERN_DEBUG "lgdt330x: " args); \
} while (0)

struct lgdt330x_state
{
	struct i2c_adapter* i2c;

	/* Configuration settings */
	const struct lgdt330x_config* config;

	struct dvb_frontend frontend;

	/* Demodulator private data */
	fe_modulation_t current_modulation;
	u32 snr; /* Result of last SNR calculation */

	/* Tuner private data */
	u32 current_frequency;
};

static int i2c_write_demod_bytes (struct lgdt330x_state* state,
				  u8 *buf, /* data bytes to send */
				  int len  /* number of bytes to send */ )
{
	struct i2c_msg msg =
		{ .addr = state->config->demod_address,
		  .flags = 0,
		  .buf = buf,
		  .len = 2 };
	int i;
	int err;

	for (i=0; i<len-1; i+=2){
		if ((err = i2c_transfer(state->i2c, &msg, 1)) != 1) {
			printk(KERN_WARNING "lgdt330x: %s error (addr %02x <- %02x, err = %i)\n", __func__, msg.buf[0], msg.buf[1], err);
			if (err < 0)
				return err;
			else
				return -EREMOTEIO;
		}
		msg.buf += 2;
	}
	return 0;
}

/*
 * This routine writes the register (reg) to the demod bus
 * then reads the data returned for (len) bytes.
 */

static u8 i2c_read_demod_bytes (struct lgdt330x_state* state,
			       enum I2C_REG reg, u8* buf, int len)
{
	u8 wr [] = { reg };
	struct i2c_msg msg [] = {
		{ .addr = state->config->demod_address,
		  .flags = 0, .buf = wr,  .len = 1 },
		{ .addr = state->config->demod_address,
		  .flags = I2C_M_RD, .buf = buf, .len = len },
	};
	int ret;
	ret = i2c_transfer(state->i2c, msg, 2);
	if (ret != 2) {
		printk(KERN_WARNING "lgdt330x: %s: addr 0x%02x select 0x%02x error (ret == %i)\n", __func__, state->config->demod_address, reg, ret);
	} else {
		ret = 0;
	}
	return ret;
}

/* Software reset */
static int lgdt3302_SwReset(struct lgdt330x_state* state)
{
	u8 ret;
	u8 reset[] = {
		IRQ_MASK,
		0x00 /* bit 6 is active low software reset
		      *	bits 5-0 are 1 to mask interrupts */
	};

	ret = i2c_write_demod_bytes(state,
				    reset, sizeof(reset));
	if (ret == 0) {

		/* force reset high (inactive) and unmask interrupts */
		reset[1] = 0x7f;
		ret = i2c_write_demod_bytes(state,
					    reset, sizeof(reset));
	}
	return ret;
}

static int lgdt3303_SwReset(struct lgdt330x_state* state)
{
	u8 ret;
	u8 reset[] = {
		0x02,
		0x00 /* bit 0 is active low software reset */
	};

	ret = i2c_write_demod_bytes(state,
				    reset, sizeof(reset));
	if (ret == 0) {

		/* force reset high (inactive) */
		reset[1] = 0x01;
		ret = i2c_write_demod_bytes(state,
					    reset, sizeof(reset));
	}
	return ret;
}

static int lgdt330x_SwReset(struct lgdt330x_state* state)
{
	switch (state->config->demod_chip) {
	case LGDT3302:
		return lgdt3302_SwReset(state);
	case LGDT3303:
		return lgdt3303_SwReset(state);
	default:
		return -ENODEV;
	}
}

static int lgdt330x_init(struct dvb_frontend* fe)
{
	/* Hardware reset is done using gpio[0] of cx23880x chip.
	 * I'd like to do it here, but don't know how to find chip address.
	 * cx88-cards.c arranges for the reset bit to be inactive (high).
	 * Maybe there needs to be a callable function in cx88-core or
	 * the caller of this function needs to do it. */

	/*
	 * Array of byte pairs <address, value>
	 * to initialize each different chip
	 */
	static u8 lgdt3302_init_data[] = {
		/* Use 50MHz parameter values from spec sheet since xtal is 50 */
		/* Change the value of NCOCTFV[25:0] of carrier
		   recovery center frequency register */
		VSB_CARRIER_FREQ0, 0x00,
		VSB_CARRIER_FREQ1, 0x87,
		VSB_CARRIER_FREQ2, 0x8e,
		VSB_CARRIER_FREQ3, 0x01,
		/* Change the TPCLK pin polarity
		   data is valid on falling clock */
		DEMUX_CONTROL, 0xfb,
		/* Change the value of IFBW[11:0] of
		   AGC IF/RF loop filter bandwidth register */
		AGC_RF_BANDWIDTH0, 0x40,
		AGC_RF_BANDWIDTH1, 0x93,
		AGC_RF_BANDWIDTH2, 0x00,
		/* Change the value of bit 6, 'nINAGCBY' and
		   'NSSEL[1:0] of ACG function control register 2 */
		AGC_FUNC_CTRL2, 0xc6,
		/* Change the value of bit 6 'RFFIX'
		   of AGC function control register 3 */
		AGC_FUNC_CTRL3, 0x40,
		/* Set the value of 'INLVTHD' register 0x2a/0x2c
		   to 0x7fe */
		AGC_DELAY0, 0x07,
		AGC_DELAY2, 0xfe,
		/* Change the value of IAGCBW[15:8]
		   of inner AGC loop filter bandwidth */
		AGC_LOOP_BANDWIDTH0, 0x08,
		AGC_LOOP_BANDWIDTH1, 0x9a
	};

	static u8 lgdt3303_init_data[] = {
		0x4c, 0x14
	};

	static u8 flip_1_lgdt3303_init_data[] = {
		0x4c, 0x14,
		0x87, 0xf3
	};

	static u8 flip_2_lgdt3303_init_data[] = {
		0x4c, 0x14,
		0x87, 0xda
	};

	struct lgdt330x_state* state = fe->demodulator_priv;
	char  *chip_name;
	int    err;

	switch (state->config->demod_chip) {
	case LGDT3302:
		chip_name = "LGDT3302";
		err = i2c_write_demod_bytes(state, lgdt3302_init_data,
					    sizeof(lgdt3302_init_data));
		break;
	case LGDT3303:
		chip_name = "LGDT3303";
		switch (state->config->clock_polarity_flip) {
		case 2:
			err = i2c_write_demod_bytes(state,
					flip_2_lgdt3303_init_data,
					sizeof(flip_2_lgdt3303_init_data));
			break;
		case 1:
			err = i2c_write_demod_bytes(state,
					flip_1_lgdt3303_init_data,
					sizeof(flip_1_lgdt3303_init_data));
			break;
		case 0:
		default:
			err = i2c_write_demod_bytes(state, lgdt3303_init_data,
						    sizeof(lgdt3303_init_data));
		}
		break;
	default:
		chip_name = "undefined";
		printk (KERN_WARNING "Only LGDT3302 and LGDT3303 are supported chips.\n");
		err = -ENODEV;
	}
	dprintk("%s entered as %s\n", __func__, chip_name);
	if (err < 0)
		return err;
	return lgdt330x_SwReset(state);
}

static int lgdt330x_read_ber(struct dvb_frontend* fe, u32* ber)
{
	*ber = 0; /* Not supplied by the demod chips */
	return 0;
}

static int lgdt330x_read_ucblocks(struct dvb_frontend* fe, u32* ucblocks)
{
	struct lgdt330x_state* state = fe->demodulator_priv;
	int err;
	u8 buf[2];

	*ucblocks = 0;

	switch (state->config->demod_chip) {
	case LGDT3302:
		err = i2c_read_demod_bytes(state, LGDT3302_PACKET_ERR_COUNTER1,
					   buf, sizeof(buf));
		break;
	case LGDT3303:
		err = i2c_read_demod_bytes(state, LGDT3303_PACKET_ERR_COUNTER1,
					   buf, sizeof(buf));
		break;
	default:
		printk(KERN_WARNING
		       "Only LGDT3302 and LGDT3303 are supported chips.\n");
		err = -ENODEV;
	}
	if (err < 0)
		return err;

	*ucblocks = (buf[0] << 8) | buf[1];
	return 0;
}

static int lgdt330x_set_parameters(struct dvb_frontend *fe)
{
	struct dtv_frontend_properties *p = &fe->dtv_property_cache;
	/*
	 * Array of byte pairs <address, value>
	 * to initialize 8VSB for lgdt3303 chip 50 MHz IF
	 */
	static u8 lgdt3303_8vsb_44_data[] = {
		0x04, 0x00,
		0x0d, 0x40,
		0x0e, 0x87,
		0x0f, 0x8e,
		0x10, 0x01,
		0x47, 0x8b };

	/*
	 * Array of byte pairs <address, value>
	 * to initialize QAM for lgdt3303 chip
	 */
	static u8 lgdt3303_qam_data[] = {
		0x04, 0x00,
		0x0d, 0x00,
		0x0e, 0x00,
		0x0f, 0x00,
		0x10, 0x00,
		0x51, 0x63,
		0x47, 0x66,
		0x48, 0x66,
		0x4d, 0x1a,
		0x49, 0x08,
		0x4a, 0x9b };

	struct lgdt330x_state* state = fe->demodulator_priv;

	static u8 top_ctrl_cfg[]   = { TOP_CONTROL, 0x03 };

	int err = 0;
	/* Change only if we are actually changing the modulation */
	if (state->current_modulation != p->modulation) {
		switch (p->modulation) {
		case VSB_8:
			dprintk("%s: VSB_8 MODE\n", __func__);

			/* Select VSB mode */
			top_ctrl_cfg[1] = 0x03;

			/* Select ANT connector if supported by card */
			if (state->config->pll_rf_set)
				state->config->pll_rf_set(fe, 1);

			if (state->config->demod_chip == LGDT3303) {
				err = i2c_write_demod_bytes(state, lgdt3303_8vsb_44_data,
							    sizeof(lgdt3303_8vsb_44_data));
			}
			break;

		case QAM_64:
			dprintk("%s: QAM_64 MODE\n", __func__);

			/* Select QAM_64 mode */
			top_ctrl_cfg[1] = 0x00;

			/* Select CABLE connector if supported by card */
			if (state->config->pll_rf_set)
				state->config->pll_rf_set(fe, 0);

			if (state->config->demod_chip == LGDT3303) {
				err = i2c_write_demod_bytes(state, lgdt3303_qam_data,
											sizeof(lgdt3303_qam_data));
			}
			break;

		case QAM_256:
			dprintk("%s: QAM_256 MODE\n", __func__);

			/* Select QAM_256 mode */
			top_ctrl_cfg[1] = 0x01;

			/* Select CABLE connector if supported by card */
			if (state->config->pll_rf_set)
				state->config->pll_rf_set(fe, 0);

			if (state->config->demod_chip == LGDT3303) {
				err = i2c_write_demod_bytes(state, lgdt3303_qam_data,
											sizeof(lgdt3303_qam_data));
			}
			break;
		default:
			printk(KERN_WARNING "lgdt330x: %s: Modulation type(%d) UNSUPPORTED\n", __func__, p->modulation);
			return -1;
		}
		if (err < 0)
			printk(KERN_WARNING "lgdt330x: %s: error blasting "
			       "bytes to lgdt3303 for modulation type(%d)\n",
			       __func__, p->modulation);

		/*
		 * select serial or parallel MPEG harware interface
		 * Serial:   0x04 for LGDT3302 or 0x40 for LGDT3303
		 * Parallel: 0x00
		 */
		top_ctrl_cfg[1] |= state->config->serial_mpeg;

		/* Select the requested mode */
		i2c_write_demod_bytes(state, top_ctrl_cfg,
				      sizeof(top_ctrl_cfg));
		if (state->config->set_ts_params)
			state->config->set_ts_params(fe, 0);
		state->current_modulation = p->modulation;
	}

	/* Tune to the specified frequency */
	if (fe->ops.tuner_ops.set_params) {
		fe->ops.tuner_ops.set_params(fe);
		if (fe->ops.i2c_gate_ctrl) fe->ops.i2c_gate_ctrl(fe, 0);
	}

	/* Keep track of the new frequency */
	/* FIXME this is the wrong way to do this...           */
	/* The tuner is shared with the video4linux analog API */
	state->current_frequency = p->frequency;

	lgdt330x_SwReset(state);
	return 0;
}

static int lgdt330x_get_frontend(struct dvb_frontend *fe)
{
	struct dtv_frontend_properties *p = &fe->dtv_property_cache;
	struct lgdt330x_state *state = fe->demodulator_priv;
	p->frequency = state->current_frequency;
	return 0;
}

static int lgdt3302_read_status(struct dvb_frontend* fe, fe_status_t* status)
{
	struct lgdt330x_state* state = fe->demodulator_priv;
	u8 buf[3];

	*status = 0; /* Reset status result */

	/* AGC status register */
	i2c_read_demod_bytes(state, AGC_STATUS, buf, 1);
	dprintk("%s: AGC_STATUS = 0x%02x\n", __func__, buf[0]);
	if ((buf[0] & 0x0c) == 0x8){
		/* Test signal does not exist flag */
		/* as well as the AGC lock flag.   */
		*status |= FE_HAS_SIGNAL;
	}

	/*
	 * You must set the Mask bits to 1 in the IRQ_MASK in order
	 * to see that status bit in the IRQ_STATUS register.
	 * This is done in SwReset();
	 */
	/* signal status */
	i2c_read_demod_bytes(state, TOP_CONTROL, buf, sizeof(buf));
	dprintk("%s: TOP_CONTROL = 0x%02x, IRO_MASK = 0x%02x, IRQ_STATUS = 0x%02x\n", __func__, buf[0], buf[1], buf[2]);


	/* sync status */
	if ((buf[2] & 0x03) == 0x01) {
		*status |= FE_HAS_SYNC;
	}

	/* FEC error status */
	if ((buf[2] & 0x0c) == 0x08) {
		*status |= FE_HAS_LOCK;
		*status |= FE_HAS_VITERBI;
	}

	/* Carrier Recovery Lock Status Register */
	i2c_read_demod_bytes(state, CARRIER_LOCK, buf, 1);
	dprintk("%s: CARRIER_LOCK = 0x%02x\n", __func__, buf[0]);
	switch (state->current_modulation) {
	case QAM_256:
	case QAM_64:
		/* Need to understand why there are 3 lock levels here */
		if ((buf[0] & 0x07) == 0x07)
			*status |= FE_HAS_CARRIER;
		break;
	case VSB_8:
		if ((buf[0] & 0x80) == 0x80)
			*status |= FE_HAS_CARRIER;
		break;
	default:
		printk(KERN_WARNING "lgdt330x: %s: Modulation set to unsupported value\n", __func__);
	}

	return 0;
}

static int lgdt3303_read_status(struct dvb_frontend* fe, fe_status_t* status)
{
	struct lgdt330x_state* state = fe->demodulator_priv;
	int err;
	u8 buf[3];

	*status = 0; /* Reset status result */

	/* lgdt3303 AGC status register */
	err = i2c_read_demod_bytes(state, 0x58, buf, 1);
	if (err < 0)
		return err;

	dprintk("%s: AGC_STATUS = 0x%02x\n", __func__, buf[0]);
	if ((buf[0] & 0x21) == 0x01){
		/* Test input signal does not exist flag */
		/* as well as the AGC lock flag.   */
		*status |= FE_HAS_SIGNAL;
	}

	/* Carrier Recovery Lock Status Register */
	i2c_read_demod_bytes(state, CARRIER_LOCK, buf, 1);
	dprintk("%s: CARRIER_LOCK = 0x%02x\n", __func__, buf[0]);
	switch (state->current_modulation) {
	case QAM_256:
	case QAM_64:
		/* Need to understand why there are 3 lock levels here */
		if ((buf[0] & 0x07) == 0x07)
			*status |= FE_HAS_CARRIER;
		else
			break;
		i2c_read_demod_bytes(state, 0x8a, buf, 1);
		if ((buf[0] & 0x04) == 0x04)
			*status |= FE_HAS_SYNC;
		if ((buf[0] & 0x01) == 0x01)
			*status |= FE_HAS_LOCK;
		if ((buf[0] & 0x08) == 0x08)
			*status |= FE_HAS_VITERBI;
		break;
	case VSB_8:
		if ((buf[0] & 0x80) == 0x80)
			*status |= FE_HAS_CARRIER;
		else
			break;
		i2c_read_demod_bytes(state, 0x38, buf, 1);
		if ((buf[0] & 0x02) == 0x00)
			*status |= FE_HAS_SYNC;
		if ((buf[0] & 0x01) == 0x01) {
			*status |= FE_HAS_LOCK;
			*status |= FE_HAS_VITERBI;
		}
		break;
	default:
		printk(KERN_WARNING "lgdt330x: %s: Modulation set to unsupported value\n", __func__);
	}
	return 0;
}

/* Calculate SNR estimation (scaled by 2^24)

   8-VSB SNR equations from LGDT3302 and LGDT3303 datasheets, QAM
   equations from LGDT3303 datasheet.  VSB is the same between the '02
   and '03, so maybe QAM is too?  Perhaps someone with a newer datasheet
   that has QAM information could verify?

   For 8-VSB: (two ways, take your pick)
   LGDT3302:
     SNR_EQ = 10 * log10(25 * 24^2 / EQ_MSE)
   LGDT3303:
     SNR_EQ = 10 * log10(25 * 32^2 / EQ_MSE)
   LGDT3302 & LGDT3303:
     SNR_PT = 10 * log10(25 * 32^2 / PT_MSE)  (we use this one)
   For 64-QAM:
     SNR    = 10 * log10( 688128   / MSEQAM)
   For 256-QAM:
     SNR    = 10 * log10( 696320   / MSEQAM)

   We re-write the snr equation as:
     SNR * 2^24 = 10*(c - intlog10(MSE))
   Where for 256-QAM, c = log10(696320) * 2^24, and so on. */

static u32 calculate_snr(u32 mse, u32 c)
{
	if (mse == 0) /* No signal */
		return 0;

	mse = intlog10(mse);
	if (mse > c) {
		/* Negative SNR, which is possible, but realisticly the
		demod will lose lock before the signal gets this bad.  The
		API only allows for unsigned values, so just return 0 */
		return 0;
	}
	return 10*(c - mse);
}

static int lgdt3302_read_snr(struct dvb_frontend* fe, u16* snr)
{
	struct lgdt330x_state* state = (struct lgdt330x_state*) fe->demodulator_priv;
	u8 buf[5];	/* read data buffer */
	u32 noise;	/* noise value */
	u32 c;		/* per-modulation SNR calculation constant */

	switch(state->current_modulation) {
	case VSB_8:
		i2c_read_demod_bytes(state, LGDT3302_EQPH_ERR0, buf, 5);
#ifdef USE_EQMSE
		/* Use Equalizer Mean-Square Error Register */
		/* SNR for ranges from -15.61 to +41.58 */
		noise = ((buf[0] & 7) << 16) | (buf[1] << 8) | buf[2];
		c = 69765745; /* log10(25*24^2)*2^24 */
#else
		/* Use Phase Tracker Mean-Square Error Register */
		/* SNR for ranges from -13.11 to +44.08 */
		noise = ((buf[0] & 7<<3) << 13) | (buf[3] << 8) | buf[4];
		c = 73957994; /* log10(25*32^2)*2^24 */
#endif
		break;
	case QAM_64:
	case QAM_256:
		i2c_read_demod_bytes(state, CARRIER_MSEQAM1, buf, 2);
		noise = ((buf[0] & 3) << 8) | buf[1];
		c = state->current_modulation == QAM_64 ? 97939837 : 98026066;
		/* log10(688128)*2^24 and log10(696320)*2^24 */
		break;
	default:
		printk(KERN_ERR "lgdt330x: %s: Modulation set to unsupported value\n",
		       __func__);
		return -EREMOTEIO; /* return -EDRIVER_IS_GIBBERED; */
	}

	state->snr = calculate_snr(noise, c);
	*snr = (state->snr) >> 16; /* Convert from 8.24 fixed-point to 8.8 */

	dprintk("%s: noise = 0x%08x, snr = %d.%02d dB\n", __func__, noise,
		state->snr >> 24, (((state->snr>>8) & 0xffff) * 100) >> 16);

	return 0;
}

static int lgdt3303_read_snr(struct dvb_frontend* fe, u16* snr)
{
	struct lgdt330x_state* state = (struct lgdt330x_state*) fe->demodulator_priv;
	u8 buf[5];	/* read data buffer */
	u32 noise;	/* noise value */
	u32 c;		/* per-modulation SNR calculation constant */

	switch(state->current_modulation) {
	case VSB_8:
		i2c_read_demod_bytes(state, LGDT3303_EQPH_ERR0, buf, 5);
#ifdef USE_EQMSE
		/* Use Equalizer Mean-Square Error Register */
		/* SNR for ranges from -16.12 to +44.08 */
		noise = ((buf[0] & 0x78) << 13) | (buf[1] << 8) | buf[2];
		c = 73957994; /* log10(25*32^2)*2^24 */
#else
		/* Use Phase Tracker Mean-Square Error Register */
		/* SNR for ranges from -13.11 to +44.08 */
		noise = ((buf[0] & 7) << 16) | (buf[3] << 8) | buf[4];
		c = 73957994; /* log10(25*32^2)*2^24 */
#endif
		break;
	case QAM_64:
	case QAM_256:
		i2c_read_demod_bytes(state, CARRIER_MSEQAM1, buf, 2);
		noise = (buf[0] << 8) | buf[1];
		c = state->current_modulation == QAM_64 ? 97939837 : 98026066;
		/* log10(688128)*2^24 and log10(696320)*2^24 */
		break;
	default:
		printk(KERN_ERR "lgdt330x: %s: Modulation set to unsupported value\n",
		       __func__);
		return -EREMOTEIO; /* return -EDRIVER_IS_GIBBERED; */
	}

	state->snr = calculate_snr(noise, c);
	*snr = (state->snr) >> 16; /* Convert from 8.24 fixed-point to 8.8 */

	dprintk("%s: noise = 0x%08x, snr = %d.%02d dB\n", __func__, noise,
		state->snr >> 24, (((state->snr >> 8) & 0xffff) * 100) >> 16);

	return 0;
}

static int lgdt330x_read_signal_strength(struct dvb_frontend* fe, u16* strength)
{
	/* Calculate Strength from SNR up to 35dB */
	/* Even though the SNR can go higher than 35dB, there is some comfort */
	/* factor in having a range of strong signals that can show at 100%   */
	struct lgdt330x_state* state = (struct lgdt330x_state*) fe->demodulator_priv;
	u16 snr;
	int ret;

	ret = fe->ops.read_snr(fe, &snr);
	if (ret != 0)
		return ret;
	/* Rather than use the 8.8 value snr, use state->snr which is 8.24 */
	/* scale the range 0 - 35*2^24 into 0 - 65535 */
	if (state->snr >= 8960 * 0x10000)
		*strength = 0xffff;
	else
		*strength = state->snr / 8960;

	return 0;
}

static int lgdt330x_get_tune_settings(struct dvb_frontend* fe, struct dvb_frontend_tune_settings* fe_tune_settings)
{
	/* I have no idea about this - it may not be needed */
	fe_tune_settings->min_delay_ms = 500;
	fe_tune_settings->step_size = 0;
	fe_tune_settings->max_drift = 0;
	return 0;
}

static void lgdt330x_release(struct dvb_frontend* fe)
{
	struct lgdt330x_state* state = (struct lgdt330x_state*) fe->demodulator_priv;
	kfree(state);
}

static struct dvb_frontend_ops lgdt3302_ops;
static struct dvb_frontend_ops lgdt3303_ops;

struct dvb_frontend* lgdt330x_attach(const struct lgdt330x_config* config,
				     struct i2c_adapter* i2c)
{
	struct lgdt330x_state* state = NULL;
	u8 buf[1];

	/* Allocate memory for the internal state */
	state = kzalloc(sizeof(struct lgdt330x_state), GFP_KERNEL);
	if (state == NULL)
		goto error;

	/* Setup the state */
	state->config = config;
	state->i2c = i2c;

	/* Create dvb_frontend */
	switch (config->demod_chip) {
	case LGDT3302:
		memcpy(&state->frontend.ops, &lgdt3302_ops, sizeof(struct dvb_frontend_ops));
		break;
	case LGDT3303:
		memcpy(&state->frontend.ops, &lgdt3303_ops, sizeof(struct dvb_frontend_ops));
		break;
	default:
		goto error;
	}
	state->frontend.demodulator_priv = state;

	/* Verify communication with demod chip */
	if (i2c_read_demod_bytes(state, 2, buf, 1))
		goto error;

	state->current_frequency = -1;
	state->current_modulation = -1;

	return &state->frontend;

error:
	kfree(state);
	dprintk("%s: ERROR\n",__func__);
	return NULL;
}

static struct dvb_frontend_ops lgdt3302_ops = {
	.delsys = { SYS_ATSC, SYS_DVBC_ANNEX_B },
	.info = {
		.name= "LG Electronics LGDT3302 VSB/QAM Frontend",
		.frequency_min= 54000000,
		.frequency_max= 858000000,
		.frequency_stepsize= 62500,
		.symbol_rate_min    = 5056941,	/* QAM 64 */
		.symbol_rate_max    = 10762000,	/* VSB 8  */
		.caps = FE_CAN_QAM_64 | FE_CAN_QAM_256 | FE_CAN_8VSB
	},
	.init                 = lgdt330x_init,
	.set_frontend         = lgdt330x_set_parameters,
	.get_frontend         = lgdt330x_get_frontend,
	.get_tune_settings    = lgdt330x_get_tune_settings,
	.read_status          = lgdt3302_read_status,
	.read_ber             = lgdt330x_read_ber,
	.read_signal_strength = lgdt330x_read_signal_strength,
	.read_snr             = lgdt3302_read_snr,
	.read_ucblocks        = lgdt330x_read_ucblocks,
	.release              = lgdt330x_release,
};

static struct dvb_frontend_ops lgdt3303_ops = {
	.delsys = { SYS_ATSC, SYS_DVBC_ANNEX_B },
	.info = {
		.name= "LG Electronics LGDT3303 VSB/QAM Frontend",
		.frequency_min= 54000000,
		.frequency_max= 858000000,
		.frequency_stepsize= 62500,
		.symbol_rate_min    = 5056941,	/* QAM 64 */
		.symbol_rate_max    = 10762000,	/* VSB 8  */
		.caps = FE_CAN_QAM_64 | FE_CAN_QAM_256 | FE_CAN_8VSB
	},
	.init                 = lgdt330x_init,
	.set_frontend         = lgdt330x_set_parameters,
	.get_frontend         = lgdt330x_get_frontend,
	.get_tune_settings    = lgdt330x_get_tune_settings,
	.read_status          = lgdt3303_read_status,
	.read_ber             = lgdt330x_read_ber,
	.read_signal_strength = lgdt330x_read_signal_strength,
	.read_snr             = lgdt3303_read_snr,
	.read_ucblocks        = lgdt330x_read_ucblocks,
	.release              = lgdt330x_release,
};

MODULE_DESCRIPTION("LGDT330X (ATSC 8VSB & ITU-T J.83 AnnexB 64/256 QAM) Demodulator Driver");
MODULE_AUTHOR("Wilson Michaels");
MODULE_LICENSE("GPL");

EXPORT_SYMBOL(lgdt330x_attach);

/*
 * Local variables:
 * c-basic-offset: 8
 * End:
 */