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 <media/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 const u8 init_tab[] = {
58 	0x00, 0x00, /* Stop acquisition */
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 
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 (unlikely(ret != 1)) {
96 		printk(KERN_ERR
97 			"%s: error (reg == 0x%02x, val == 0x%02x, ret == %i)\n",
98 			__func__, reg, data, ret);
99 		return -1;
100 	}
101 
102 	return 0;
103 }
104 
105 static u8 cx22702_readreg(struct cx22702_state *state, u8 reg)
106 {
107 	int ret;
108 	u8 data;
109 
110 	struct i2c_msg msg[] = {
111 		{ .addr = state->config->demod_address, .flags = 0,
112 			.buf = &reg, .len = 1 },
113 		{ .addr = state->config->demod_address, .flags = I2C_M_RD,
114 			.buf = &data, .len = 1 } };
115 
116 	ret = i2c_transfer(state->i2c, msg, 2);
117 
118 	if (unlikely(ret != 2)) {
119 		printk(KERN_ERR "%s: error (reg == 0x%02x, ret == %i)\n",
120 			__func__, reg, ret);
121 		return 0;
122 	}
123 
124 	return data;
125 }
126 
127 static int cx22702_set_inversion(struct cx22702_state *state, int inversion)
128 {
129 	u8 val;
130 
131 	val = cx22702_readreg(state, 0x0C);
132 	switch (inversion) {
133 	case INVERSION_AUTO:
134 		return -EOPNOTSUPP;
135 	case INVERSION_ON:
136 		val |= 0x01;
137 		break;
138 	case INVERSION_OFF:
139 		val &= 0xfe;
140 		break;
141 	default:
142 		return -EINVAL;
143 	}
144 	return cx22702_writereg(state, 0x0C, val);
145 }
146 
147 /* Retrieve the demod settings */
148 static int cx22702_get_tps(struct cx22702_state *state,
149 			   struct dtv_frontend_properties *p)
150 {
151 	u8 val;
152 
153 	/* Make sure the TPS regs are valid */
154 	if (!(cx22702_readreg(state, 0x0A) & 0x20))
155 		return -EAGAIN;
156 
157 	val = cx22702_readreg(state, 0x01);
158 	switch ((val & 0x18) >> 3) {
159 	case 0:
160 		p->modulation = QPSK;
161 		break;
162 	case 1:
163 		p->modulation = QAM_16;
164 		break;
165 	case 2:
166 		p->modulation = QAM_64;
167 		break;
168 	}
169 	switch (val & 0x07) {
170 	case 0:
171 		p->hierarchy = HIERARCHY_NONE;
172 		break;
173 	case 1:
174 		p->hierarchy = HIERARCHY_1;
175 		break;
176 	case 2:
177 		p->hierarchy = HIERARCHY_2;
178 		break;
179 	case 3:
180 		p->hierarchy = HIERARCHY_4;
181 		break;
182 	}
183 
184 
185 	val = cx22702_readreg(state, 0x02);
186 	switch ((val & 0x38) >> 3) {
187 	case 0:
188 		p->code_rate_HP = FEC_1_2;
189 		break;
190 	case 1:
191 		p->code_rate_HP = FEC_2_3;
192 		break;
193 	case 2:
194 		p->code_rate_HP = FEC_3_4;
195 		break;
196 	case 3:
197 		p->code_rate_HP = FEC_5_6;
198 		break;
199 	case 4:
200 		p->code_rate_HP = FEC_7_8;
201 		break;
202 	}
203 	switch (val & 0x07) {
204 	case 0:
205 		p->code_rate_LP = FEC_1_2;
206 		break;
207 	case 1:
208 		p->code_rate_LP = FEC_2_3;
209 		break;
210 	case 2:
211 		p->code_rate_LP = FEC_3_4;
212 		break;
213 	case 3:
214 		p->code_rate_LP = FEC_5_6;
215 		break;
216 	case 4:
217 		p->code_rate_LP = FEC_7_8;
218 		break;
219 	}
220 
221 	val = cx22702_readreg(state, 0x03);
222 	switch ((val & 0x0c) >> 2) {
223 	case 0:
224 		p->guard_interval = GUARD_INTERVAL_1_32;
225 		break;
226 	case 1:
227 		p->guard_interval = GUARD_INTERVAL_1_16;
228 		break;
229 	case 2:
230 		p->guard_interval = GUARD_INTERVAL_1_8;
231 		break;
232 	case 3:
233 		p->guard_interval = GUARD_INTERVAL_1_4;
234 		break;
235 	}
236 	switch (val & 0x03) {
237 	case 0:
238 		p->transmission_mode = TRANSMISSION_MODE_2K;
239 		break;
240 	case 1:
241 		p->transmission_mode = TRANSMISSION_MODE_8K;
242 		break;
243 	}
244 
245 	return 0;
246 }
247 
248 static int cx22702_i2c_gate_ctrl(struct dvb_frontend *fe, int enable)
249 {
250 	struct cx22702_state *state = fe->demodulator_priv;
251 	u8 val;
252 
253 	dprintk("%s(%d)\n", __func__, enable);
254 	val = cx22702_readreg(state, 0x0D);
255 	if (enable)
256 		val &= 0xfe;
257 	else
258 		val |= 0x01;
259 	return cx22702_writereg(state, 0x0D, val);
260 }
261 
262 /* Talk to the demod, set the FEC, GUARD, QAM settings etc */
263 static int cx22702_set_tps(struct dvb_frontend *fe)
264 {
265 	struct dtv_frontend_properties *p = &fe->dtv_property_cache;
266 	u8 val;
267 	struct cx22702_state *state = fe->demodulator_priv;
268 
269 	if (fe->ops.tuner_ops.set_params) {
270 		fe->ops.tuner_ops.set_params(fe);
271 		if (fe->ops.i2c_gate_ctrl)
272 			fe->ops.i2c_gate_ctrl(fe, 0);
273 	}
274 
275 	/* set inversion */
276 	cx22702_set_inversion(state, p->inversion);
277 
278 	/* set bandwidth */
279 	val = cx22702_readreg(state, 0x0C) & 0xcf;
280 	switch (p->bandwidth_hz) {
281 	case 6000000:
282 		val |= 0x20;
283 		break;
284 	case 7000000:
285 		val |= 0x10;
286 		break;
287 	case 8000000:
288 		break;
289 	default:
290 		dprintk("%s: invalid bandwidth\n", __func__);
291 		return -EINVAL;
292 	}
293 	cx22702_writereg(state, 0x0C, val);
294 
295 	p->code_rate_LP = FEC_AUTO; /* temp hack as manual not working */
296 
297 	/* use auto configuration? */
298 	if ((p->hierarchy == HIERARCHY_AUTO) ||
299 	   (p->modulation == QAM_AUTO) ||
300 	   (p->code_rate_HP == FEC_AUTO) ||
301 	   (p->code_rate_LP == FEC_AUTO) ||
302 	   (p->guard_interval == GUARD_INTERVAL_AUTO) ||
303 	   (p->transmission_mode == TRANSMISSION_MODE_AUTO)) {
304 
305 		/* TPS Source - use hardware driven values */
306 		cx22702_writereg(state, 0x06, 0x10);
307 		cx22702_writereg(state, 0x07, 0x9);
308 		cx22702_writereg(state, 0x08, 0xC1);
309 		cx22702_writereg(state, 0x0B, cx22702_readreg(state, 0x0B)
310 			& 0xfc);
311 		cx22702_writereg(state, 0x0C,
312 			(cx22702_readreg(state, 0x0C) & 0xBF) | 0x40);
313 		cx22702_writereg(state, 0x00, 0x01); /* Begin acquisition */
314 		dprintk("%s: Autodetecting\n", __func__);
315 		return 0;
316 	}
317 
318 	/* manually programmed values */
319 	switch (p->modulation) {		/* mask 0x18 */
320 	case QPSK:
321 		val = 0x00;
322 		break;
323 	case QAM_16:
324 		val = 0x08;
325 		break;
326 	case QAM_64:
327 		val = 0x10;
328 		break;
329 	default:
330 		dprintk("%s: invalid modulation\n", __func__);
331 		return -EINVAL;
332 	}
333 	switch (p->hierarchy) {	/* mask 0x07 */
334 	case HIERARCHY_NONE:
335 		break;
336 	case HIERARCHY_1:
337 		val |= 0x01;
338 		break;
339 	case HIERARCHY_2:
340 		val |= 0x02;
341 		break;
342 	case HIERARCHY_4:
343 		val |= 0x03;
344 		break;
345 	default:
346 		dprintk("%s: invalid hierarchy\n", __func__);
347 		return -EINVAL;
348 	}
349 	cx22702_writereg(state, 0x06, val);
350 
351 	switch (p->code_rate_HP) {		/* mask 0x38 */
352 	case FEC_NONE:
353 	case FEC_1_2:
354 		val = 0x00;
355 		break;
356 	case FEC_2_3:
357 		val = 0x08;
358 		break;
359 	case FEC_3_4:
360 		val = 0x10;
361 		break;
362 	case FEC_5_6:
363 		val = 0x18;
364 		break;
365 	case FEC_7_8:
366 		val = 0x20;
367 		break;
368 	default:
369 		dprintk("%s: invalid code_rate_HP\n", __func__);
370 		return -EINVAL;
371 	}
372 	switch (p->code_rate_LP) {		/* mask 0x07 */
373 	case FEC_NONE:
374 	case FEC_1_2:
375 		break;
376 	case FEC_2_3:
377 		val |= 0x01;
378 		break;
379 	case FEC_3_4:
380 		val |= 0x02;
381 		break;
382 	case FEC_5_6:
383 		val |= 0x03;
384 		break;
385 	case FEC_7_8:
386 		val |= 0x04;
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 	switch (p->guard_interval) {		/* mask 0x0c */
395 	case GUARD_INTERVAL_1_32:
396 		val = 0x00;
397 		break;
398 	case GUARD_INTERVAL_1_16:
399 		val = 0x04;
400 		break;
401 	case GUARD_INTERVAL_1_8:
402 		val = 0x08;
403 		break;
404 	case GUARD_INTERVAL_1_4:
405 		val = 0x0c;
406 		break;
407 	default:
408 		dprintk("%s: invalid guard_interval\n", __func__);
409 		return -EINVAL;
410 	}
411 	switch (p->transmission_mode) {		/* mask 0x03 */
412 	case TRANSMISSION_MODE_2K:
413 		break;
414 	case TRANSMISSION_MODE_8K:
415 		val |= 0x1;
416 		break;
417 	default:
418 		dprintk("%s: invalid transmission_mode\n", __func__);
419 		return -EINVAL;
420 	}
421 	cx22702_writereg(state, 0x08, val);
422 	cx22702_writereg(state, 0x0B,
423 		(cx22702_readreg(state, 0x0B) & 0xfc) | 0x02);
424 	cx22702_writereg(state, 0x0C,
425 		(cx22702_readreg(state, 0x0C) & 0xBF) | 0x40);
426 
427 	/* Begin channel acquisition */
428 	cx22702_writereg(state, 0x00, 0x01);
429 
430 	return 0;
431 }
432 
433 /* Reset the demod hardware and reset all of the configuration registers
434    to a default state. */
435 static int cx22702_init(struct dvb_frontend *fe)
436 {
437 	int i;
438 	struct cx22702_state *state = fe->demodulator_priv;
439 
440 	cx22702_writereg(state, 0x00, 0x02);
441 
442 	msleep(10);
443 
444 	for (i = 0; i < ARRAY_SIZE(init_tab); i += 2)
445 		cx22702_writereg(state, init_tab[i], init_tab[i + 1]);
446 
447 	cx22702_writereg(state, 0xf8, (state->config->output_mode << 1)
448 		& 0x02);
449 
450 	cx22702_i2c_gate_ctrl(fe, 0);
451 
452 	return 0;
453 }
454 
455 static int cx22702_read_status(struct dvb_frontend *fe, enum fe_status *status)
456 {
457 	struct cx22702_state *state = fe->demodulator_priv;
458 	u8 reg0A;
459 	u8 reg23;
460 
461 	*status = 0;
462 
463 	reg0A = cx22702_readreg(state, 0x0A);
464 	reg23 = cx22702_readreg(state, 0x23);
465 
466 	dprintk("%s: status demod=0x%02x agc=0x%02x\n"
467 		, __func__, reg0A, reg23);
468 
469 	if (reg0A & 0x10) {
470 		*status |= FE_HAS_LOCK;
471 		*status |= FE_HAS_VITERBI;
472 		*status |= FE_HAS_SYNC;
473 	}
474 
475 	if (reg0A & 0x20)
476 		*status |= FE_HAS_CARRIER;
477 
478 	if (reg23 < 0xf0)
479 		*status |= FE_HAS_SIGNAL;
480 
481 	return 0;
482 }
483 
484 static int cx22702_read_ber(struct dvb_frontend *fe, u32 *ber)
485 {
486 	struct cx22702_state *state = fe->demodulator_priv;
487 
488 	if (cx22702_readreg(state, 0xE4) & 0x02) {
489 		/* Realtime statistics */
490 		*ber = (cx22702_readreg(state, 0xDE) & 0x7F) << 7
491 			| (cx22702_readreg(state, 0xDF) & 0x7F);
492 	} else {
493 		/* Averagtine statistics */
494 		*ber = (cx22702_readreg(state, 0xDE) & 0x7F) << 7
495 			| cx22702_readreg(state, 0xDF);
496 	}
497 
498 	return 0;
499 }
500 
501 static int cx22702_read_signal_strength(struct dvb_frontend *fe,
502 	u16 *signal_strength)
503 {
504 	struct cx22702_state *state = fe->demodulator_priv;
505 	u8 reg23;
506 
507 	/*
508 	 * Experience suggests that the strength signal register works as
509 	 * follows:
510 	 * - In the absence of signal, value is 0xff.
511 	 * - In the presence of a weak signal, bit 7 is set, not sure what
512 	 *   the lower 7 bits mean.
513 	 * - In the presence of a strong signal, the register holds a 7-bit
514 	 *   value (bit 7 is cleared), with greater values standing for
515 	 *   weaker signals.
516 	 */
517 	reg23 = cx22702_readreg(state, 0x23);
518 	if (reg23 & 0x80) {
519 		*signal_strength = 0;
520 	} else {
521 		reg23 = ~reg23 & 0x7f;
522 		/* Scale to 16 bit */
523 		*signal_strength = (reg23 << 9) | (reg23 << 2) | (reg23 >> 5);
524 	}
525 
526 	return 0;
527 }
528 
529 static int cx22702_read_snr(struct dvb_frontend *fe, u16 *snr)
530 {
531 	struct cx22702_state *state = fe->demodulator_priv;
532 
533 	u16 rs_ber;
534 	if (cx22702_readreg(state, 0xE4) & 0x02) {
535 		/* Realtime statistics */
536 		rs_ber = (cx22702_readreg(state, 0xDE) & 0x7F) << 7
537 			| (cx22702_readreg(state, 0xDF) & 0x7F);
538 	} else {
539 		/* Averagine statistics */
540 		rs_ber = (cx22702_readreg(state, 0xDE) & 0x7F) << 8
541 			| cx22702_readreg(state, 0xDF);
542 	}
543 	*snr = ~rs_ber;
544 
545 	return 0;
546 }
547 
548 static int cx22702_read_ucblocks(struct dvb_frontend *fe, u32 *ucblocks)
549 {
550 	struct cx22702_state *state = fe->demodulator_priv;
551 
552 	u8 _ucblocks;
553 
554 	/* RS Uncorrectable Packet Count then reset */
555 	_ucblocks = cx22702_readreg(state, 0xE3);
556 	if (state->prevUCBlocks < _ucblocks)
557 		*ucblocks = (_ucblocks - state->prevUCBlocks);
558 	else
559 		*ucblocks = state->prevUCBlocks - _ucblocks;
560 	state->prevUCBlocks = _ucblocks;
561 
562 	return 0;
563 }
564 
565 static int cx22702_get_frontend(struct dvb_frontend *fe,
566 				struct dtv_frontend_properties *c)
567 {
568 	struct cx22702_state *state = fe->demodulator_priv;
569 
570 	u8 reg0C = cx22702_readreg(state, 0x0C);
571 
572 	c->inversion = reg0C & 0x1 ? INVERSION_ON : INVERSION_OFF;
573 	return cx22702_get_tps(state, c);
574 }
575 
576 static int cx22702_get_tune_settings(struct dvb_frontend *fe,
577 	struct dvb_frontend_tune_settings *tune)
578 {
579 	tune->min_delay_ms = 1000;
580 	return 0;
581 }
582 
583 static void cx22702_release(struct dvb_frontend *fe)
584 {
585 	struct cx22702_state *state = fe->demodulator_priv;
586 	kfree(state);
587 }
588 
589 static const struct dvb_frontend_ops cx22702_ops;
590 
591 struct dvb_frontend *cx22702_attach(const struct cx22702_config *config,
592 	struct i2c_adapter *i2c)
593 {
594 	struct cx22702_state *state = NULL;
595 
596 	/* allocate memory for the internal state */
597 	state = kzalloc(sizeof(struct cx22702_state), GFP_KERNEL);
598 	if (state == NULL)
599 		goto error;
600 
601 	/* setup the state */
602 	state->config = config;
603 	state->i2c = i2c;
604 
605 	/* check if the demod is there */
606 	if (cx22702_readreg(state, 0x1f) != 0x3)
607 		goto error;
608 
609 	/* create dvb_frontend */
610 	memcpy(&state->frontend.ops, &cx22702_ops,
611 		sizeof(struct dvb_frontend_ops));
612 	state->frontend.demodulator_priv = state;
613 	return &state->frontend;
614 
615 error:
616 	kfree(state);
617 	return NULL;
618 }
619 EXPORT_SYMBOL(cx22702_attach);
620 
621 static const struct dvb_frontend_ops cx22702_ops = {
622 	.delsys = { SYS_DVBT },
623 	.info = {
624 		.name			= "Conexant CX22702 DVB-T",
625 		.frequency_min_hz	= 177 * MHz,
626 		.frequency_max_hz	= 858 * MHz,
627 		.frequency_stepsize_hz	= 166666,
628 		.caps = FE_CAN_FEC_1_2 | FE_CAN_FEC_2_3 | FE_CAN_FEC_3_4 |
629 		FE_CAN_FEC_5_6 | FE_CAN_FEC_7_8 | FE_CAN_FEC_AUTO |
630 		FE_CAN_QPSK | FE_CAN_QAM_16 | FE_CAN_QAM_64 | FE_CAN_QAM_AUTO |
631 		FE_CAN_HIERARCHY_AUTO | FE_CAN_GUARD_INTERVAL_AUTO |
632 		FE_CAN_TRANSMISSION_MODE_AUTO | FE_CAN_RECOVER
633 	},
634 
635 	.release = cx22702_release,
636 
637 	.init = cx22702_init,
638 	.i2c_gate_ctrl = cx22702_i2c_gate_ctrl,
639 
640 	.set_frontend = cx22702_set_tps,
641 	.get_frontend = cx22702_get_frontend,
642 	.get_tune_settings = cx22702_get_tune_settings,
643 
644 	.read_status = cx22702_read_status,
645 	.read_ber = cx22702_read_ber,
646 	.read_signal_strength = cx22702_read_signal_strength,
647 	.read_snr = cx22702_read_snr,
648 	.read_ucblocks = cx22702_read_ucblocks,
649 };
650 
651 MODULE_DESCRIPTION("Conexant CX22702 DVB-T Demodulator driver");
652 MODULE_AUTHOR("Steven Toth");
653 MODULE_LICENSE("GPL");
654