aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/media/dvb/frontends/cx24110.c
blob: 71b54094bda8a6a1d6745e81e0b6340c96be92d0 (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
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
/*
    cx24110 - Single Chip Satellite Channel Receiver driver module

    Copyright (C) 2002 Peter Hettkamp <peter.hettkamp@htp-tel.de> based on
    work
    Copyright (C) 1999 Convergence Integrated Media GmbH <ralph@convergence.de>

    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.

*/

#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>

#include "dvb_frontend.h"
#include "cx24110.h"


struct cx24110_state {

	struct i2c_adapter* i2c;

	struct dvb_frontend_ops ops;

	const struct cx24110_config* config;

	struct dvb_frontend frontend;

	u32 lastber;
	u32 lastbler;
	u32 lastesn0;
};

static int debug;
#define dprintk(args...) \
	do { \
		if (debug) printk(KERN_DEBUG "cx24110: " args); \
	} while (0)

static struct {u8 reg; u8 data;} cx24110_regdata[]=
                      /* Comments beginning with @ denote this value should
                         be the default */
        {{0x09,0x01}, /* SoftResetAll */
         {0x09,0x00}, /* release reset */
         {0x01,0xe8}, /* MSB of code rate 27.5MS/s */
         {0x02,0x17}, /* middle byte " */
         {0x03,0x29}, /* LSB         " */
         {0x05,0x03}, /* @ DVB mode, standard code rate 3/4 */
         {0x06,0xa5}, /* @ PLL 60MHz */
         {0x07,0x01}, /* @ Fclk, i.e. sampling clock, 60MHz */
         {0x0a,0x00}, /* @ partial chip disables, do not set */
         {0x0b,0x01}, /* set output clock in gapped mode, start signal low
                         active for first byte */
         {0x0c,0x11}, /* no parity bytes, large hold time, serial data out */
         {0x0d,0x6f}, /* @ RS Sync/Unsync thresholds */
         {0x10,0x40}, /* chip doc is misleading here: write bit 6 as 1
                         to avoid starting the BER counter. Reset the
                         CRC test bit. Finite counting selected */
         {0x15,0xff}, /* @ size of the limited time window for RS BER
                         estimation. It is <value>*256 RS blocks, this
                         gives approx. 2.6 sec at 27.5MS/s, rate 3/4 */
         {0x16,0x00}, /* @ enable all RS output ports */
         {0x17,0x04}, /* @ time window allowed for the RS to sync */
         {0x18,0xae}, /* @ allow all standard DVB code rates to be scanned
                         for automatically */
                      /* leave the current code rate and normalization
                         registers as they are after reset... */
         {0x21,0x10}, /* @ during AutoAcq, search each viterbi setting
                         only once */
         {0x23,0x18}, /* @ size of the limited time window for Viterbi BER
                         estimation. It is <value>*65536 channel bits, i.e.
                         approx. 38ms at 27.5MS/s, rate 3/4 */
         {0x24,0x24}, /* do not trigger Viterbi CRC test. Finite count window */
                      /* leave front-end AGC parameters at default values */
                      /* leave decimation AGC parameters at default values */
         {0x35,0x40}, /* disable all interrupts. They are not connected anyway */
         {0x36,0xff}, /* clear all interrupt pending flags */
         {0x37,0x00}, /* @ fully enable AutoAcqq state machine */
         {0x38,0x07}, /* @ enable fade recovery, but not autostart AutoAcq */
                      /* leave the equalizer parameters on their default values */
                      /* leave the final AGC parameters on their default values */
         {0x41,0x00}, /* @ MSB of front-end derotator frequency */
         {0x42,0x00}, /* @ middle bytes " */
         {0x43,0x00}, /* @ LSB          " */
                      /* leave the carrier tracking loop parameters on default */
                      /* leave the bit timing loop parameters at gefault */
         {0x56,0x4d}, /* set the filtune voltage to 2.7V, as recommended by */
                      /* the cx24108 data sheet for symbol rates above 15MS/s */
         {0x57,0x00}, /* @ Filter sigma delta enabled, positive */
         {0x61,0x95}, /* GPIO pins 1-4 have special function */
         {0x62,0x05}, /* GPIO pin 5 has special function, pin 6 is GPIO */
         {0x63,0x00}, /* All GPIO pins use CMOS output characteristics */
         {0x64,0x20}, /* GPIO 6 is input, all others are outputs */
         {0x6d,0x30}, /* tuner auto mode clock freq 62kHz */
         {0x70,0x15}, /* use auto mode, tuner word is 21 bits long */
         {0x73,0x00}, /* @ disable several demod bypasses */
         {0x74,0x00}, /* @  " */
         {0x75,0x00}  /* @  " */
                      /* the remaining registers are for SEC */
	};


static int cx24110_writereg (struct cx24110_state* state, int reg, int data)
{
        u8 buf [] = { reg, data };
	struct i2c_msg msg = { .addr = state->config->demod_address, .flags = 0, .buf = buf, .len = 2 };
	int err;

        if ((err = i2c_transfer(state->i2c, &msg, 1)) != 1) {
		dprintk ("%s: writereg error (err == %i, reg == 0x%02x,"
			 " data == 0x%02x)\n", __FUNCTION__, err, reg, data);
		return -EREMOTEIO;
	}

        return 0;
}

static int cx24110_readreg (struct cx24110_state* state, u8 reg)
{
	int ret;
	u8 b0 [] = { reg };
	u8 b1 [] = { 0 };
	struct i2c_msg msg [] = { { .addr = state->config->demod_address, .flags = 0, .buf = b0, .len = 1 },
			   { .addr = state->config->demod_address, .flags = I2C_M_RD, .buf = b1, .len = 1 } };

	ret = i2c_transfer(state->i2c, msg, 2);

	if (ret != 2) return ret;

	return b1[0];
}

static int cx24110_set_inversion (struct cx24110_state* state, fe_spectral_inversion_t inversion)
{
/* fixme (low): error handling */

	switch (inversion) {
	case INVERSION_OFF:
                cx24110_writereg(state,0x37,cx24110_readreg(state,0x37)|0x1);
                /* AcqSpectrInvDis on. No idea why someone should want this */
                cx24110_writereg(state,0x5,cx24110_readreg(state,0x5)&0xf7);
                /* Initial value 0 at start of acq */
                cx24110_writereg(state,0x22,cx24110_readreg(state,0x22)&0xef);
                /* current value 0 */
                /* The cx24110 manual tells us this reg is read-only.
                   But what the heck... set it ayways */
                break;
	case INVERSION_ON:
                cx24110_writereg(state,0x37,cx24110_readreg(state,0x37)|0x1);
                /* AcqSpectrInvDis on. No idea why someone should want this */
                cx24110_writereg(state,0x5,cx24110_readreg(state,0x5)|0x08);
                /* Initial value 1 at start of acq */
                cx24110_writereg(state,0x22,cx24110_readreg(state,0x22)|0x10);
                /* current value 1 */
                break;
	case INVERSION_AUTO:
                cx24110_writereg(state,0x37,cx24110_readreg(state,0x37)&0xfe);
                /* AcqSpectrInvDis off. Leave initial & current states as is */
                break;
	default:
		return -EINVAL;
	}

	return 0;
}

static int cx24110_set_fec (struct cx24110_state* state, fe_code_rate_t fec)
{
/* fixme (low): error handling */

        static const int rate[]={-1,1,2,3,5,7,-1};
        static const int g1[]={-1,0x01,0x02,0x05,0x15,0x45,-1};
        static const int g2[]={-1,0x01,0x03,0x06,0x1a,0x7a,-1};

        /* Well, the AutoAcq engine of the cx24106 and 24110 automatically
           searches all enabled viterbi rates, and can handle non-standard
           rates as well. */

        if (fec>FEC_AUTO)
                fec=FEC_AUTO;

        if (fec==FEC_AUTO) { /* (re-)establish AutoAcq behaviour */
		cx24110_writereg(state,0x37,cx24110_readreg(state,0x37)&0xdf);
		/* clear AcqVitDis bit */
		cx24110_writereg(state,0x18,0xae);
		/* allow all DVB standard code rates */
		cx24110_writereg(state,0x05,(cx24110_readreg(state,0x05)&0xf0)|0x3);
		/* set nominal Viterbi rate 3/4 */
		cx24110_writereg(state,0x22,(cx24110_readreg(state,0x22)&0xf0)|0x3);
		/* set current Viterbi rate 3/4 */
		cx24110_writereg(state,0x1a,0x05); cx24110_writereg(state,0x1b,0x06);
		/* set the puncture registers for code rate 3/4 */
		return 0;
        } else {
		cx24110_writereg(state,0x37,cx24110_readreg(state,0x37)|0x20);
		/* set AcqVitDis bit */
		if(rate[fec]>0) {
			cx24110_writereg(state,0x05,(cx24110_readreg(state,0x05)&0xf0)|rate[fec]);
			/* set nominal Viterbi rate */
			cx24110_writereg(state,0x22,(cx24110_readreg(state,0x22)&0xf0)|rate[fec]);
			/* set current Viterbi rate */
			cx24110_writereg(state,0x1a,g1[fec]);
			cx24110_writereg(state,0x1b,g2[fec]);
			/* not sure if this is the right way: I always used AutoAcq mode */
           } else
		   return -EOPNOTSUPP;
/* fixme (low): which is the correct return code? */
        };
	return 0;
}

static fe_code_rate_t cx24110_get_fec (struct cx24110_state* state)
{
	int i;

	i=cx24110_readreg(state,0x22)&0x0f;
	if(!(i&0x08)) {
		return FEC_1_2 + i - 1;
	} else {
/* fixme (low): a special code rate has been selected. In theory, we need to
   return a denominator value, a numerator value, and a pair of puncture
   maps to correctly describe this mode. But this should never happen in
   practice, because it cannot be set by cx24110_get_fec. */
	   return FEC_NONE;
	}
}

static int cx24110_set_symbolrate (struct cx24110_state* state, u32 srate)
{
/* fixme (low): add error handling */
        u32 ratio;
        u32 tmp, fclk, BDRI;

        static const u32 bands[]={5000000UL,15000000UL,90999000UL/2};
        int i;

dprintk("cx24110 debug: entering %s(%d)\n",__FUNCTION__,srate);
        if (srate>90999000UL/2)
                srate=90999000UL/2;
        if (srate<500000)
                srate=500000;

        for(i=0;(i<sizeof(bands)/sizeof(bands[0]))&&(srate>bands[i]);i++)
		;
        /* first, check which sample rate is appropriate: 45, 60 80 or 90 MHz,
           and set the PLL accordingly (R07[1:0] Fclk, R06[7:4] PLLmult,
           R06[3:0] PLLphaseDetGain */
        tmp=cx24110_readreg(state,0x07)&0xfc;
        if(srate<90999000UL/4) { /* sample rate 45MHz*/
		cx24110_writereg(state,0x07,tmp);
		cx24110_writereg(state,0x06,0x78);
		fclk=90999000UL/2;
        } else if(srate<60666000UL/2) { /* sample rate 60MHz */
		cx24110_writereg(state,0x07,tmp|0x1);
		cx24110_writereg(state,0x06,0xa5);
		fclk=60666000UL;
        } else if(srate<80888000UL/2) { /* sample rate 80MHz */
		cx24110_writereg(state,0x07,tmp|0x2);
		cx24110_writereg(state,0x06,0x87);
		fclk=80888000UL;
        } else { /* sample rate 90MHz */
		cx24110_writereg(state,0x07,tmp|0x3);
		cx24110_writereg(state,0x06,0x78);
		fclk=90999000UL;
        };
        dprintk("cx24110 debug: fclk %d Hz\n",fclk);
        /* we need to divide two integers with approx. 27 bits in 32 bit
           arithmetic giving a 25 bit result */
        /* the maximum dividend is 90999000/2, 0x02b6446c, this number is
           also the most complex divisor. Hence, the dividend has,
           assuming 32bit unsigned arithmetic, 6 clear bits on top, the
           divisor 2 unused bits at the bottom. Also, the quotient is
           always less than 1/2. Borrowed from VES1893.c, of course */

        tmp=srate<<6;
        BDRI=fclk>>2;
        ratio=(tmp/BDRI);

        tmp=(tmp%BDRI)<<8;
        ratio=(ratio<<8)+(tmp/BDRI);

        tmp=(tmp%BDRI)<<8;
        ratio=(ratio<<8)+(tmp/BDRI);

        tmp=(tmp%BDRI)<<1;
        ratio=(ratio<<1)+(tmp/BDRI);

        dprintk("srate= %d (range %d, up to %d)\n", srate,i,bands[i]);
        dprintk("fclk = %d\n", fclk);
        dprintk("ratio= %08x\n", ratio);

        cx24110_writereg(state, 0x1, (ratio>>16)&0xff);
        cx24110_writereg(state, 0x2, (ratio>>8)&0xff);
        cx24110_writereg(state, 0x3, (ratio)&0xff);

        return 0;

}

int cx24110_pll_write (struct dvb_frontend* fe, u32 data)
{
	struct cx24110_state *state = fe->demodulator_priv;

/* tuner data is 21 bits long, must be left-aligned in data */
/* tuner cx24108 is written through a dedicated 3wire interface on the demod chip */
/* FIXME (low): add error handling, avoid infinite loops if HW fails... */

	dprintk("cx24110 debug: cx24108_write(%8.8x)\n",data);

        cx24110_writereg(state,0x6d,0x30); /* auto mode at 62kHz */
        cx24110_writereg(state,0x70,0x15); /* auto mode 21 bits */

        /* if the auto tuner writer is still busy, clear it out */
        while (cx24110_readreg(state,0x6d)&0x80)
		cx24110_writereg(state,0x72,0);

        /* write the topmost 8 bits */
        cx24110_writereg(state,0x72,(data>>24)&0xff);

        /* wait for the send to be completed */
        while ((cx24110_readreg(state,0x6d)&0xc0)==0x80)
		;

        /* send another 8 bytes */
        cx24110_writereg(state,0x72,(data>>16)&0xff);
        while ((cx24110_readreg(state,0x6d)&0xc0)==0x80)
		;

        /* and the topmost 5 bits of this byte */
        cx24110_writereg(state,0x72,(data>>8)&0xff);
        while ((cx24110_readreg(state,0x6d)&0xc0)==0x80)
		;

        /* now strobe the enable line once */
        cx24110_writereg(state,0x6d,0x32);
        cx24110_writereg(state,0x6d,0x30);

        return 0;
}

static int cx24110_initfe(struct dvb_frontend* fe)
{
	struct cx24110_state *state = fe->demodulator_priv;
/* fixme (low): error handling */
        int i;

	dprintk("%s: init chip\n", __FUNCTION__);

        for(i=0;i<sizeof(cx24110_regdata)/sizeof(cx24110_regdata[0]);i++) {
		cx24110_writereg(state, cx24110_regdata[i].reg, cx24110_regdata[i].data);
        };

	if (state->config->pll_init) state->config->pll_init(fe);

	return 0;
}

static int cx24110_set_voltage (struct dvb_frontend* fe, fe_sec_voltage_t voltage)
{
	struct cx24110_state *state = fe->demodulator_priv;

	switch (voltage) {
	case SEC_VOLTAGE_13:
		return cx24110_writereg(state,0x76,(cx24110_readreg(state,0x76)&0x3b)|0xc0);
	case SEC_VOLTAGE_18:
		return cx24110_writereg(state,0x76,(cx24110_readreg(state,0x76)&0x3b)|0x40);
	default:
		return -EINVAL;
	};
}

static int cx24110_diseqc_send_burst(struct dvb_frontend* fe, fe_sec_mini_cmd_t burst)
{
	int rv, bit, i;
	struct cx24110_state *state = fe->demodulator_priv;

	if (burst == SEC_MINI_A)
		bit = 0x00;
	else if (burst == SEC_MINI_B)
		bit = 0x08;
	else
		return -EINVAL;

	rv = cx24110_readreg(state, 0x77);
	cx24110_writereg(state, 0x77, rv | 0x04);

	rv = cx24110_readreg(state, 0x76);
	cx24110_writereg(state, 0x76, ((rv & 0x90) | 0x40 | bit));
	for (i = 500; i-- > 0 && !(cx24110_readreg(state,0x76)&0x40) ; )
              ; /* wait for LNB ready */

	return 0;
}

static int cx24110_send_diseqc_msg(struct dvb_frontend* fe,
				   struct dvb_diseqc_master_cmd *cmd)
{
	int i, rv;
	struct cx24110_state *state = fe->demodulator_priv;

	for (i = 0; i < cmd->msg_len; i++)
		cx24110_writereg(state, 0x79 + i, cmd->msg[i]);

	rv = cx24110_readreg(state, 0x77);
	cx24110_writereg(state, 0x77, rv & ~0x04);
	msleep(30); /* reportedly fixes switching problems */

	rv = cx24110_readreg(state, 0x76);

	cx24110_writereg(state, 0x76, ((rv & 0x90) | 0x40) | ((cmd->msg_len-3) & 3));
	for (i=500; i-- > 0 && !(cx24110_readreg(state,0x76)&0x40);)
		; /* wait for LNB ready */

	return 0;
}

static int cx24110_read_status(struct dvb_frontend* fe, fe_status_t* status)
{
	struct cx24110_state *state = fe->demodulator_priv;

	int sync = cx24110_readreg (state, 0x55);

	*status = 0;

	if (sync & 0x10)
		*status |= FE_HAS_SIGNAL;

	if (sync & 0x08)
		*status |= FE_HAS_CARRIER;

	sync = cx24110_readreg (state, 0x08);

	if (sync & 0x40)
		*status |= FE_HAS_VITERBI;

	if (sync & 0x20)
		*status |= FE_HAS_SYNC;

	if ((sync & 0x60) == 0x60)
		*status |= FE_HAS_LOCK;

	return 0;
}

static int cx24110_read_ber(struct dvb_frontend* fe, u32* ber)
{
	struct cx24110_state *state = fe->demodulator_priv;

	/* fixme (maybe): value range is 16 bit. Scale? */
	if(cx24110_readreg(state,0x24)&0x10) {
		/* the Viterbi error counter has finished one counting window */
		cx24110_writereg(state,0x24,0x04); /* select the ber reg */
		state->lastber=cx24110_readreg(state,0x25)|
			(cx24110_readreg(state,0x26)<<8);
		cx24110_writereg(state,0x24,0x04); /* start new count window */
		cx24110_writereg(state,0x24,0x14);
	}
	*ber = state->lastber;

	return 0;
}

static int cx24110_read_signal_strength(struct dvb_frontend* fe, u16* signal_strength)
{
	struct cx24110_state *state = fe->demodulator_priv;

/* no provision in hardware. Read the frontend AGC accumulator. No idea how to scale this, but I know it is 2s complement */
	u8 signal = cx24110_readreg (state, 0x27)+128;
	*signal_strength = (signal << 8) | signal;

	return 0;
}

static int cx24110_read_snr(struct dvb_frontend* fe, u16* snr)
{
	struct cx24110_state *state = fe->demodulator_priv;

	/* no provision in hardware. Can be computed from the Es/N0 estimator, but I don't know how. */
	if(cx24110_readreg(state,0x6a)&0x80) {
		/* the Es/N0 error counter has finished one counting window */
		state->lastesn0=cx24110_readreg(state,0x69)|
			(cx24110_readreg(state,0x68)<<8);
		cx24110_writereg(state,0x6a,0x84); /* start new count window */
	}
	*snr = state->lastesn0;

	return 0;
}

static int cx24110_read_ucblocks(struct dvb_frontend* fe, u32* ucblocks)
{
	struct cx24110_state *state = fe->demodulator_priv;
	u32 lastbyer;

	if(cx24110_readreg(state,0x10)&0x40) {
		/* the RS error counter has finished one counting window */
		cx24110_writereg(state,0x10,0x60); /* select the byer reg */
		lastbyer=cx24110_readreg(state,0x12)|
			(cx24110_readreg(state,0x13)<<8)|
			(cx24110_readreg(state,0x14)<<16);
		cx24110_writereg(state,0x10,0x70); /* select the bler reg */
		state->lastbler=cx24110_readreg(state,0x12)|
			(cx24110_readreg(state,0x13)<<8)|
			(cx24110_readreg(state,0x14)<<16);
		cx24110_writereg(state,0x10,0x20); /* start new count window */
	}
	*ucblocks = state->lastbler;

	return 0;
}

static int cx24110_set_frontend(struct dvb_frontend* fe, struct dvb_frontend_parameters *p)
{
	struct cx24110_state *state = fe->demodulator_priv;

	state->config->pll_set(fe, p);
	cx24110_set_inversion (state, p->inversion);
	cx24110_set_fec (state, p->u.qpsk.fec_inner);
	cx24110_set_symbolrate (state, p->u.qpsk.symbol_rate);
	cx24110_writereg(state,0x04,0x05); /* start aquisition */

	return 0;
}

static int cx24110_get_frontend(struct dvb_frontend* fe, struct dvb_frontend_parameters *p)
{
	struct cx24110_state *state = fe->demodulator_priv;
	s32 afc; unsigned sclk;

/* cannot read back tuner settings (freq). Need to have some private storage */

	sclk = cx24110_readreg (state, 0x07) & 0x03;
/* ok, real AFC (FEDR) freq. is afc/2^24*fsamp, fsamp=45/60/80/90MHz.
 * Need 64 bit arithmetic. Is thiss possible in the kernel? */
	if (sclk==0) sclk=90999000L/2L;
	else if (sclk==1) sclk=60666000L;
	else if (sclk==2) sclk=80888000L;
	else sclk=90999000L;
	sclk>>=8;
	afc = sclk*(cx24110_readreg (state, 0x44)&0x1f)+
	      ((sclk*cx24110_readreg (state, 0x45))>>8)+
	      ((sclk*cx24110_readreg (state, 0x46))>>16);

	p->frequency += afc;
	p->inversion = (cx24110_readreg (state, 0x22) & 0x10) ?
				INVERSION_ON : INVERSION_OFF;
	p->u.qpsk.fec_inner = cx24110_get_fec (state);

	return 0;
}

static int cx24110_set_tone(struct dvb_frontend* fe, fe_sec_tone_mode_t tone)
{
	struct cx24110_state *state = fe->demodulator_priv;

	return cx24110_writereg(state,0x76,(cx24110_readreg(state,0x76)&~0x10)|(((tone==SEC_TONE_ON))?0x10:0));
}

static void cx24110_release(struct dvb_frontend* fe)
{
	struct cx24110_state* state = fe->demodulator_priv;
	kfree(state);
}

static struct dvb_frontend_ops cx24110_ops;

struct dvb_frontend* cx24110_attach(const struct cx24110_config* config,
				    struct i2c_adapter* i2c)
{
	struct cx24110_state* state = NULL;
	int ret;

	/* allocate memory for the internal state */
	state = kmalloc(sizeof(struct cx24110_state), GFP_KERNEL);
	if (state == NULL) goto error;

	/* setup the state */
	state->config = config;
	state->i2c = i2c;
	memcpy(&state->ops, &cx24110_ops, sizeof(struct dvb_frontend_ops));
	state->lastber = 0;
	state->lastbler = 0;
	state->lastesn0 = 0;

	/* check if the demod is there */
	ret = cx24110_readreg(state, 0x00);
	if ((ret != 0x5a) && (ret != 0x69)) goto error;

	/* create dvb_frontend */
	state->frontend.ops = &state->ops;
	state->frontend.demodulator_priv = state;
	return &state->frontend;

error:
	kfree(state);
	return NULL;
}

static struct dvb_frontend_ops cx24110_ops = {

	.info = {
		.name = "Conexant CX24110 DVB-S",
		.type = FE_QPSK,
		.frequency_min = 950000,
		.frequency_max = 2150000,
		.frequency_stepsize = 1011,  /* kHz for QPSK frontends */
		.frequency_tolerance = 29500,
		.symbol_rate_min = 1000000,
		.symbol_rate_max = 45000000,
		.caps = FE_CAN_INVERSION_AUTO |
			FE_CAN_FEC_1_2 | FE_CAN_FEC_2_3 | FE_CAN_FEC_3_4 |
			FE_CAN_FEC_5_6 | FE_CAN_FEC_7_8 | FE_CAN_FEC_AUTO |
			FE_CAN_QPSK | FE_CAN_RECOVER
	},

	.release = cx24110_release,

	.init = cx24110_initfe,
	.set_frontend = cx24110_set_frontend,
	.get_frontend = cx24110_get_frontend,
	.read_status = cx24110_read_status,
	.read_ber = cx24110_read_ber,
	.read_signal_strength = cx24110_read_signal_strength,
	.read_snr = cx24110_read_snr,
	.read_ucblocks = cx24110_read_ucblocks,

	.diseqc_send_master_cmd = cx24110_send_diseqc_msg,
	.set_tone = cx24110_set_tone,
	.set_voltage = cx24110_set_voltage,
	.diseqc_send_burst = cx24110_diseqc_send_burst,
};

module_param(debug, int, 0644);
MODULE_PARM_DESC(debug, "Turn on/off frontend debugging (default:off).");

MODULE_DESCRIPTION("Conexant CX24110 DVB-S Demodulator driver");
MODULE_AUTHOR("Peter Hettkamp");
MODULE_LICENSE("GPL");

EXPORT_SYMBOL(cx24110_attach);
EXPORT_SYMBOL(cx24110_pll_write);