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1 /*
2     Conexant 22702 DVB OFDM demodulator driver
3 
4     based on:
5 	Alps TDMB7 DVB OFDM demodulator driver
6 
7     Copyright (C) 2001-2002 Convergence Integrated Media GmbH
8 	  Holger Waechtler <holger@convergence.de>
9 
10     Copyright (C) 2004 Steven Toth <stoth@linuxtv.org>
11 
12     This program is free software; you can redistribute it and/or modify
13     it under the terms of the GNU General Public License as published by
14     the Free Software Foundation; either version 2 of the License, or
15     (at your option) any later version.
16 
17     This program is distributed in the hope that it will be useful,
18     but WITHOUT ANY WARRANTY; without even the implied warranty of
19     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20     GNU General Public License for more details.
21 
22     You should have received a copy of the GNU General Public License
23     along with this program; if not, write to the Free Software
24     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
25 
26 */
27 
28 #include <linux/kernel.h>
29 #include <linux/init.h>
30 #include <linux/module.h>
31 #include <linux/string.h>
32 #include <linux/slab.h>
33 #include <linux/delay.h>
34 #include "dvb_frontend.h"
35 #include "cx22702.h"
36 
37 struct cx22702_state {
38 
39 	struct i2c_adapter *i2c;
40 
41 	/* configuration settings */
42 	const struct cx22702_config *config;
43 
44 	struct dvb_frontend frontend;
45 
46 	/* previous uncorrected block counter */
47 	u8 prevUCBlocks;
48 };
49 
50 static int debug;
51 module_param(debug, int, 0644);
52 MODULE_PARM_DESC(debug, "Enable verbose debug messages");
53 
54 #define dprintk	if (debug) printk
55 
56 /* Register values to initialise the demod */
57 static u8 init_tab[] = {
58 	0x00, 0x00, /* Stop aquisition */
59 	0x0B, 0x06,
60 	0x09, 0x01,
61 	0x0D, 0x41,
62 	0x16, 0x32,
63 	0x20, 0x0A,
64 	0x21, 0x17,
65 	0x24, 0x3e,
66 	0x26, 0xff,
67 	0x27, 0x10,
68 	0x28, 0x00,
69 	0x29, 0x00,
70 	0x2a, 0x10,
71 	0x2b, 0x00,
72 	0x2c, 0x10,
73 	0x2d, 0x00,
74 	0x48, 0xd4,
75 	0x49, 0x56,
76 	0x6b, 0x1e,
77 	0xc8, 0x02,
78 	0xf9, 0x00,
79 	0xfa, 0x00,
80 	0xfb, 0x00,
81 	0xfc, 0x00,
82 	0xfd, 0x00,
83 };
84 
cx22702_writereg(struct cx22702_state * state,u8 reg,u8 data)85 static int cx22702_writereg(struct cx22702_state *state, u8 reg, u8 data)
86 {
87 	int ret;
88 	u8 buf[] = { reg, data };
89 	struct i2c_msg msg = {
90 		.addr = state->config->demod_address, .flags = 0,
91 			.buf = buf, .len = 2 };
92 
93 	ret = i2c_transfer(state->i2c, &msg, 1);
94 
95 	if (ret != 1)
96 		printk(KERN_ERR
97 			"%s: error (reg == 0x%02x, val == 0x%02x, ret == %i)\n",
98 			__func__, reg, data, ret);
99 
100 	return (ret != 1) ? -1 : 0;
101 }
102 
cx22702_readreg(struct cx22702_state * state,u8 reg)103 static u8 cx22702_readreg(struct cx22702_state *state, u8 reg)
104 {
105 	int ret;
106 	u8 b0[] = { reg };
107 	u8 b1[] = { 0 };
108 
109 	struct i2c_msg msg[] = {
110 		{ .addr = state->config->demod_address, .flags = 0,
111 			.buf = b0, .len = 1 },
112 		{ .addr = state->config->demod_address, .flags = I2C_M_RD,
113 			.buf = b1, .len = 1 } };
114 
115 	ret = i2c_transfer(state->i2c, msg, 2);
116 
117 	if (ret != 2)
118 		printk(KERN_ERR "%s: readreg error (ret == %i)\n",
119 			__func__, ret);
120 
121 	return b1[0];
122 }
123 
cx22702_set_inversion(struct cx22702_state * state,int inversion)124 static int cx22702_set_inversion(struct cx22702_state *state, int inversion)
125 {
126 	u8 val;
127 
128 	switch (inversion) {
129 	case INVERSION_AUTO:
130 		return -EOPNOTSUPP;
131 	case INVERSION_ON:
132 		val = cx22702_readreg(state, 0x0C);
133 		return cx22702_writereg(state, 0x0C, val | 0x01);
134 	case INVERSION_OFF:
135 		val = cx22702_readreg(state, 0x0C);
136 		return cx22702_writereg(state, 0x0C, val & 0xfe);
137 	default:
138 		return -EINVAL;
139 	}
140 
141 }
142 
143 /* Retrieve the demod settings */
cx22702_get_tps(struct cx22702_state * state,struct dvb_ofdm_parameters * p)144 static int cx22702_get_tps(struct cx22702_state *state,
145 	struct dvb_ofdm_parameters *p)
146 {
147 	u8 val;
148 
149 	/* Make sure the TPS regs are valid */
150 	if (!(cx22702_readreg(state, 0x0A) & 0x20))
151 		return -EAGAIN;
152 
153 	val = cx22702_readreg(state, 0x01);
154 	switch ((val & 0x18) >> 3) {
155 	case 0:
156 		p->constellation = QPSK;
157 		break;
158 	case 1:
159 		p->constellation = QAM_16;
160 		break;
161 	case 2:
162 		p->constellation = QAM_64;
163 		break;
164 	}
165 	switch (val & 0x07) {
166 	case 0:
167 		p->hierarchy_information = HIERARCHY_NONE;
168 		break;
169 	case 1:
170 		p->hierarchy_information = HIERARCHY_1;
171 		break;
172 	case 2:
173 		p->hierarchy_information = HIERARCHY_2;
174 		break;
175 	case 3:
176 		p->hierarchy_information = HIERARCHY_4;
177 		break;
178 	}
179 
180 
181 	val = cx22702_readreg(state, 0x02);
182 	switch ((val & 0x38) >> 3) {
183 	case 0:
184 		p->code_rate_HP = FEC_1_2;
185 		break;
186 	case 1:
187 		p->code_rate_HP = FEC_2_3;
188 		break;
189 	case 2:
190 		p->code_rate_HP = FEC_3_4;
191 		break;
192 	case 3:
193 		p->code_rate_HP = FEC_5_6;
194 		break;
195 	case 4:
196 		p->code_rate_HP = FEC_7_8;
197 		break;
198 	}
199 	switch (val & 0x07) {
200 	case 0:
201 		p->code_rate_LP = FEC_1_2;
202 		break;
203 	case 1:
204 		p->code_rate_LP = FEC_2_3;
205 		break;
206 	case 2:
207 		p->code_rate_LP = FEC_3_4;
208 		break;
209 	case 3:
210 		p->code_rate_LP = FEC_5_6;
211 		break;
212 	case 4:
213 		p->code_rate_LP = FEC_7_8;
214 		break;
215 	}
216 
217 	val = cx22702_readreg(state, 0x03);
218 	switch ((val & 0x0c) >> 2) {
219 	case 0:
220 		p->guard_interval = GUARD_INTERVAL_1_32;
221 		break;
222 	case 1:
223 		p->guard_interval = GUARD_INTERVAL_1_16;
224 		break;
225 	case 2:
226 		p->guard_interval = GUARD_INTERVAL_1_8;
227 		break;
228 	case 3:
229 		p->guard_interval = GUARD_INTERVAL_1_4;
230 		break;
231 	}
232 	switch (val & 0x03) {
233 	case 0:
234 		p->transmission_mode = TRANSMISSION_MODE_2K;
235 		break;
236 	case 1:
237 		p->transmission_mode = TRANSMISSION_MODE_8K;
238 		break;
239 	}
240 
241 	return 0;
242 }
243 
cx22702_i2c_gate_ctrl(struct dvb_frontend * fe,int enable)244 static int cx22702_i2c_gate_ctrl(struct dvb_frontend *fe, int enable)
245 {
246 	struct cx22702_state *state = fe->demodulator_priv;
247 	dprintk("%s(%d)\n", __func__, enable);
248 	if (enable)
249 		return cx22702_writereg(state, 0x0D,
250 			cx22702_readreg(state, 0x0D) & 0xfe);
251 	else
252 		return cx22702_writereg(state, 0x0D,
253 			cx22702_readreg(state, 0x0D) | 1);
254 }
255 
256 /* Talk to the demod, set the FEC, GUARD, QAM settings etc */
cx22702_set_tps(struct dvb_frontend * fe,struct dvb_frontend_parameters * p)257 static int cx22702_set_tps(struct dvb_frontend *fe,
258 	struct dvb_frontend_parameters *p)
259 {
260 	u8 val;
261 	struct cx22702_state *state = fe->demodulator_priv;
262 
263 	if (fe->ops.tuner_ops.set_params) {
264 		fe->ops.tuner_ops.set_params(fe, p);
265 		if (fe->ops.i2c_gate_ctrl)
266 			fe->ops.i2c_gate_ctrl(fe, 0);
267 	}
268 
269 	/* set inversion */
270 	cx22702_set_inversion(state, p->inversion);
271 
272 	/* set bandwidth */
273 	switch (p->u.ofdm.bandwidth) {
274 	case BANDWIDTH_6_MHZ:
275 		cx22702_writereg(state, 0x0C,
276 			(cx22702_readreg(state, 0x0C) & 0xcf) | 0x20);
277 		break;
278 	case BANDWIDTH_7_MHZ:
279 		cx22702_writereg(state, 0x0C,
280 			(cx22702_readreg(state, 0x0C) & 0xcf) | 0x10);
281 		break;
282 	case BANDWIDTH_8_MHZ:
283 		cx22702_writereg(state, 0x0C,
284 			cx22702_readreg(state, 0x0C) & 0xcf);
285 		break;
286 	default:
287 		dprintk("%s: invalid bandwidth\n", __func__);
288 		return -EINVAL;
289 	}
290 
291 	p->u.ofdm.code_rate_LP = FEC_AUTO; /* temp hack as manual not working */
292 
293 	/* use auto configuration? */
294 	if ((p->u.ofdm.hierarchy_information == HIERARCHY_AUTO) ||
295 	   (p->u.ofdm.constellation == QAM_AUTO) ||
296 	   (p->u.ofdm.code_rate_HP == FEC_AUTO) ||
297 	   (p->u.ofdm.code_rate_LP == FEC_AUTO) ||
298 	   (p->u.ofdm.guard_interval == GUARD_INTERVAL_AUTO) ||
299 	   (p->u.ofdm.transmission_mode == TRANSMISSION_MODE_AUTO)) {
300 
301 		/* TPS Source - use hardware driven values */
302 		cx22702_writereg(state, 0x06, 0x10);
303 		cx22702_writereg(state, 0x07, 0x9);
304 		cx22702_writereg(state, 0x08, 0xC1);
305 		cx22702_writereg(state, 0x0B, cx22702_readreg(state, 0x0B)
306 			& 0xfc);
307 		cx22702_writereg(state, 0x0C,
308 			(cx22702_readreg(state, 0x0C) & 0xBF) | 0x40);
309 		cx22702_writereg(state, 0x00, 0x01); /* Begin aquisition */
310 		dprintk("%s: Autodetecting\n", __func__);
311 		return 0;
312 	}
313 
314 	/* manually programmed values */
315 	val = 0;
316 	switch (p->u.ofdm.constellation) {
317 	case QPSK:
318 		val = (val & 0xe7);
319 		break;
320 	case QAM_16:
321 		val = (val & 0xe7) | 0x08;
322 		break;
323 	case QAM_64:
324 		val = (val & 0xe7) | 0x10;
325 		break;
326 	default:
327 		dprintk("%s: invalid constellation\n", __func__);
328 		return -EINVAL;
329 	}
330 	switch (p->u.ofdm.hierarchy_information) {
331 	case HIERARCHY_NONE:
332 		val = (val & 0xf8);
333 		break;
334 	case HIERARCHY_1:
335 		val = (val & 0xf8) | 1;
336 		break;
337 	case HIERARCHY_2:
338 		val = (val & 0xf8) | 2;
339 		break;
340 	case HIERARCHY_4:
341 		val = (val & 0xf8) | 3;
342 		break;
343 	default:
344 		dprintk("%s: invalid hierarchy\n", __func__);
345 		return -EINVAL;
346 	}
347 	cx22702_writereg(state, 0x06, val);
348 
349 	val = 0;
350 	switch (p->u.ofdm.code_rate_HP) {
351 	case FEC_NONE:
352 	case FEC_1_2:
353 		val = (val & 0xc7);
354 		break;
355 	case FEC_2_3:
356 		val = (val & 0xc7) | 0x08;
357 		break;
358 	case FEC_3_4:
359 		val = (val & 0xc7) | 0x10;
360 		break;
361 	case FEC_5_6:
362 		val = (val & 0xc7) | 0x18;
363 		break;
364 	case FEC_7_8:
365 		val = (val & 0xc7) | 0x20;
366 		break;
367 	default:
368 		dprintk("%s: invalid code_rate_HP\n", __func__);
369 		return -EINVAL;
370 	}
371 	switch (p->u.ofdm.code_rate_LP) {
372 	case FEC_NONE:
373 	case FEC_1_2:
374 		val = (val & 0xf8);
375 		break;
376 	case FEC_2_3:
377 		val = (val & 0xf8) | 1;
378 		break;
379 	case FEC_3_4:
380 		val = (val & 0xf8) | 2;
381 		break;
382 	case FEC_5_6:
383 		val = (val & 0xf8) | 3;
384 		break;
385 	case FEC_7_8:
386 		val = (val & 0xf8) | 4;
387 		break;
388 	default:
389 		dprintk("%s: invalid code_rate_LP\n", __func__);
390 		return -EINVAL;
391 	}
392 	cx22702_writereg(state, 0x07, val);
393 
394 	val = 0;
395 	switch (p->u.ofdm.guard_interval) {
396 	case GUARD_INTERVAL_1_32:
397 		val = (val & 0xf3);
398 		break;
399 	case GUARD_INTERVAL_1_16:
400 		val = (val & 0xf3) | 0x04;
401 		break;
402 	case GUARD_INTERVAL_1_8:
403 		val = (val & 0xf3) | 0x08;
404 		break;
405 	case GUARD_INTERVAL_1_4:
406 		val = (val & 0xf3) | 0x0c;
407 		break;
408 	default:
409 		dprintk("%s: invalid guard_interval\n", __func__);
410 		return -EINVAL;
411 	}
412 	switch (p->u.ofdm.transmission_mode) {
413 	case TRANSMISSION_MODE_2K:
414 		val = (val & 0xfc);
415 		break;
416 	case TRANSMISSION_MODE_8K:
417 		val = (val & 0xfc) | 1;
418 		break;
419 	default:
420 		dprintk("%s: invalid transmission_mode\n", __func__);
421 		return -EINVAL;
422 	}
423 	cx22702_writereg(state, 0x08, val);
424 	cx22702_writereg(state, 0x0B,
425 		(cx22702_readreg(state, 0x0B) & 0xfc) | 0x02);
426 	cx22702_writereg(state, 0x0C,
427 		(cx22702_readreg(state, 0x0C) & 0xBF) | 0x40);
428 
429 	/* Begin channel aquisition */
430 	cx22702_writereg(state, 0x00, 0x01);
431 
432 	return 0;
433 }
434 
435 /* Reset the demod hardware and reset all of the configuration registers
436    to a default state. */
cx22702_init(struct dvb_frontend * fe)437 static int cx22702_init(struct dvb_frontend *fe)
438 {
439 	int i;
440 	struct cx22702_state *state = fe->demodulator_priv;
441 
442 	cx22702_writereg(state, 0x00, 0x02);
443 
444 	msleep(10);
445 
446 	for (i = 0; i < ARRAY_SIZE(init_tab); i += 2)
447 		cx22702_writereg(state, init_tab[i], init_tab[i + 1]);
448 
449 	cx22702_writereg(state, 0xf8, (state->config->output_mode << 1)
450 		& 0x02);
451 
452 	cx22702_i2c_gate_ctrl(fe, 0);
453 
454 	return 0;
455 }
456 
cx22702_read_status(struct dvb_frontend * fe,fe_status_t * status)457 static int cx22702_read_status(struct dvb_frontend *fe, fe_status_t *status)
458 {
459 	struct cx22702_state *state = fe->demodulator_priv;
460 	u8 reg0A;
461 	u8 reg23;
462 
463 	*status = 0;
464 
465 	reg0A = cx22702_readreg(state, 0x0A);
466 	reg23 = cx22702_readreg(state, 0x23);
467 
468 	dprintk("%s: status demod=0x%02x agc=0x%02x\n"
469 		, __func__, reg0A, reg23);
470 
471 	if (reg0A & 0x10) {
472 		*status |= FE_HAS_LOCK;
473 		*status |= FE_HAS_VITERBI;
474 		*status |= FE_HAS_SYNC;
475 	}
476 
477 	if (reg0A & 0x20)
478 		*status |= FE_HAS_CARRIER;
479 
480 	if (reg23 < 0xf0)
481 		*status |= FE_HAS_SIGNAL;
482 
483 	return 0;
484 }
485 
cx22702_read_ber(struct dvb_frontend * fe,u32 * ber)486 static int cx22702_read_ber(struct dvb_frontend *fe, u32 *ber)
487 {
488 	struct cx22702_state *state = fe->demodulator_priv;
489 
490 	if (cx22702_readreg(state, 0xE4) & 0x02) {
491 		/* Realtime statistics */
492 		*ber = (cx22702_readreg(state, 0xDE) & 0x7F) << 7
493 			| (cx22702_readreg(state, 0xDF) & 0x7F);
494 	} else {
495 		/* Averagtine statistics */
496 		*ber = (cx22702_readreg(state, 0xDE) & 0x7F) << 7
497 			| cx22702_readreg(state, 0xDF);
498 	}
499 
500 	return 0;
501 }
502 
cx22702_read_signal_strength(struct dvb_frontend * fe,u16 * signal_strength)503 static int cx22702_read_signal_strength(struct dvb_frontend *fe,
504 	u16 *signal_strength)
505 {
506 	struct cx22702_state *state = fe->demodulator_priv;
507 
508 	u16 rs_ber = 0;
509 	rs_ber = cx22702_readreg(state, 0x23);
510 	*signal_strength = (rs_ber << 8) | rs_ber;
511 
512 	return 0;
513 }
514 
cx22702_read_snr(struct dvb_frontend * fe,u16 * snr)515 static int cx22702_read_snr(struct dvb_frontend *fe, u16 *snr)
516 {
517 	struct cx22702_state *state = fe->demodulator_priv;
518 
519 	u16 rs_ber = 0;
520 	if (cx22702_readreg(state, 0xE4) & 0x02) {
521 		/* Realtime statistics */
522 		rs_ber = (cx22702_readreg(state, 0xDE) & 0x7F) << 7
523 			| (cx22702_readreg(state, 0xDF) & 0x7F);
524 	} else {
525 		/* Averagine statistics */
526 		rs_ber = (cx22702_readreg(state, 0xDE) & 0x7F) << 8
527 			| cx22702_readreg(state, 0xDF);
528 	}
529 	*snr = ~rs_ber;
530 
531 	return 0;
532 }
533 
cx22702_read_ucblocks(struct dvb_frontend * fe,u32 * ucblocks)534 static int cx22702_read_ucblocks(struct dvb_frontend *fe, u32 *ucblocks)
535 {
536 	struct cx22702_state *state = fe->demodulator_priv;
537 
538 	u8 _ucblocks;
539 
540 	/* RS Uncorrectable Packet Count then reset */
541 	_ucblocks = cx22702_readreg(state, 0xE3);
542 	if (state->prevUCBlocks < _ucblocks)
543 		*ucblocks = (_ucblocks - state->prevUCBlocks);
544 	else
545 		*ucblocks = state->prevUCBlocks - _ucblocks;
546 	state->prevUCBlocks = _ucblocks;
547 
548 	return 0;
549 }
550 
cx22702_get_frontend(struct dvb_frontend * fe,struct dvb_frontend_parameters * p)551 static int cx22702_get_frontend(struct dvb_frontend *fe,
552 	struct dvb_frontend_parameters *p)
553 {
554 	struct cx22702_state *state = fe->demodulator_priv;
555 
556 	u8 reg0C = cx22702_readreg(state, 0x0C);
557 
558 	p->inversion = reg0C & 0x1 ? INVERSION_ON : INVERSION_OFF;
559 	return cx22702_get_tps(state, &p->u.ofdm);
560 }
561 
cx22702_get_tune_settings(struct dvb_frontend * fe,struct dvb_frontend_tune_settings * tune)562 static int cx22702_get_tune_settings(struct dvb_frontend *fe,
563 	struct dvb_frontend_tune_settings *tune)
564 {
565 	tune->min_delay_ms = 1000;
566 	return 0;
567 }
568 
cx22702_release(struct dvb_frontend * fe)569 static void cx22702_release(struct dvb_frontend *fe)
570 {
571 	struct cx22702_state *state = fe->demodulator_priv;
572 	kfree(state);
573 }
574 
575 static struct dvb_frontend_ops cx22702_ops;
576 
cx22702_attach(const struct cx22702_config * config,struct i2c_adapter * i2c)577 struct dvb_frontend *cx22702_attach(const struct cx22702_config *config,
578 	struct i2c_adapter *i2c)
579 {
580 	struct cx22702_state *state = NULL;
581 
582 	/* allocate memory for the internal state */
583 	state = kmalloc(sizeof(struct cx22702_state), GFP_KERNEL);
584 	if (state == NULL)
585 		goto error;
586 
587 	/* setup the state */
588 	state->config = config;
589 	state->i2c = i2c;
590 	state->prevUCBlocks = 0;
591 
592 	/* check if the demod is there */
593 	if (cx22702_readreg(state, 0x1f) != 0x3)
594 		goto error;
595 
596 	/* create dvb_frontend */
597 	memcpy(&state->frontend.ops, &cx22702_ops,
598 		sizeof(struct dvb_frontend_ops));
599 	state->frontend.demodulator_priv = state;
600 	return &state->frontend;
601 
602 error:
603 	kfree(state);
604 	return NULL;
605 }
606 EXPORT_SYMBOL(cx22702_attach);
607 
608 static struct dvb_frontend_ops cx22702_ops = {
609 
610 	.info = {
611 		.name			= "Conexant CX22702 DVB-T",
612 		.type			= FE_OFDM,
613 		.frequency_min		= 177000000,
614 		.frequency_max		= 858000000,
615 		.frequency_stepsize	= 166666,
616 		.caps = FE_CAN_FEC_1_2 | FE_CAN_FEC_2_3 | FE_CAN_FEC_3_4 |
617 		FE_CAN_FEC_5_6 | FE_CAN_FEC_7_8 | FE_CAN_FEC_AUTO |
618 		FE_CAN_QPSK | FE_CAN_QAM_16 | FE_CAN_QAM_64 | FE_CAN_QAM_AUTO |
619 		FE_CAN_HIERARCHY_AUTO | FE_CAN_GUARD_INTERVAL_AUTO |
620 		FE_CAN_TRANSMISSION_MODE_AUTO | FE_CAN_RECOVER
621 	},
622 
623 	.release = cx22702_release,
624 
625 	.init = cx22702_init,
626 	.i2c_gate_ctrl = cx22702_i2c_gate_ctrl,
627 
628 	.set_frontend = cx22702_set_tps,
629 	.get_frontend = cx22702_get_frontend,
630 	.get_tune_settings = cx22702_get_tune_settings,
631 
632 	.read_status = cx22702_read_status,
633 	.read_ber = cx22702_read_ber,
634 	.read_signal_strength = cx22702_read_signal_strength,
635 	.read_snr = cx22702_read_snr,
636 	.read_ucblocks = cx22702_read_ucblocks,
637 };
638 
639 MODULE_DESCRIPTION("Conexant CX22702 DVB-T Demodulator driver");
640 MODULE_AUTHOR("Steven Toth");
641 MODULE_LICENSE("GPL");
642