1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3     Conexant 22702 DVB OFDM demodulator driver
4 
5     based on:
6 	Alps TDMB7 DVB OFDM demodulator driver
7 
8     Copyright (C) 2001-2002 Convergence Integrated Media GmbH
9 	  Holger Waechtler <holger@convergence.de>
10 
11     Copyright (C) 2004 Steven Toth <stoth@linuxtv.org>
12 
13 
14 */
15 
16 #include <linux/kernel.h>
17 #include <linux/init.h>
18 #include <linux/module.h>
19 #include <linux/string.h>
20 #include <linux/slab.h>
21 #include <linux/delay.h>
22 #include <media/dvb_frontend.h>
23 #include "cx22702.h"
24 
25 struct cx22702_state {
26 
27 	struct i2c_adapter *i2c;
28 
29 	/* configuration settings */
30 	const struct cx22702_config *config;
31 
32 	struct dvb_frontend frontend;
33 
34 	/* previous uncorrected block counter */
35 	u8 prevUCBlocks;
36 };
37 
38 static int debug;
39 module_param(debug, int, 0644);
40 MODULE_PARM_DESC(debug, "Enable verbose debug messages");
41 
42 #define dprintk	if (debug) printk
43 
44 /* Register values to initialise the demod */
45 static const u8 init_tab[] = {
46 	0x00, 0x00, /* Stop acquisition */
47 	0x0B, 0x06,
48 	0x09, 0x01,
49 	0x0D, 0x41,
50 	0x16, 0x32,
51 	0x20, 0x0A,
52 	0x21, 0x17,
53 	0x24, 0x3e,
54 	0x26, 0xff,
55 	0x27, 0x10,
56 	0x28, 0x00,
57 	0x29, 0x00,
58 	0x2a, 0x10,
59 	0x2b, 0x00,
60 	0x2c, 0x10,
61 	0x2d, 0x00,
62 	0x48, 0xd4,
63 	0x49, 0x56,
64 	0x6b, 0x1e,
65 	0xc8, 0x02,
66 	0xf9, 0x00,
67 	0xfa, 0x00,
68 	0xfb, 0x00,
69 	0xfc, 0x00,
70 	0xfd, 0x00,
71 };
72 
73 static int cx22702_writereg(struct cx22702_state *state, u8 reg, u8 data)
74 {
75 	int ret;
76 	u8 buf[] = { reg, data };
77 	struct i2c_msg msg = {
78 		.addr = state->config->demod_address, .flags = 0,
79 			.buf = buf, .len = 2 };
80 
81 	ret = i2c_transfer(state->i2c, &msg, 1);
82 
83 	if (unlikely(ret != 1)) {
84 		printk(KERN_ERR
85 			"%s: error (reg == 0x%02x, val == 0x%02x, ret == %i)\n",
86 			__func__, reg, data, ret);
87 		return -1;
88 	}
89 
90 	return 0;
91 }
92 
93 static u8 cx22702_readreg(struct cx22702_state *state, u8 reg)
94 {
95 	int ret;
96 	u8 data;
97 
98 	struct i2c_msg msg[] = {
99 		{ .addr = state->config->demod_address, .flags = 0,
100 			.buf = &reg, .len = 1 },
101 		{ .addr = state->config->demod_address, .flags = I2C_M_RD,
102 			.buf = &data, .len = 1 } };
103 
104 	ret = i2c_transfer(state->i2c, msg, 2);
105 
106 	if (unlikely(ret != 2)) {
107 		printk(KERN_ERR "%s: error (reg == 0x%02x, ret == %i)\n",
108 			__func__, reg, ret);
109 		return 0;
110 	}
111 
112 	return data;
113 }
114 
115 static int cx22702_set_inversion(struct cx22702_state *state, int inversion)
116 {
117 	u8 val;
118 
119 	val = cx22702_readreg(state, 0x0C);
120 	switch (inversion) {
121 	case INVERSION_AUTO:
122 		return -EOPNOTSUPP;
123 	case INVERSION_ON:
124 		val |= 0x01;
125 		break;
126 	case INVERSION_OFF:
127 		val &= 0xfe;
128 		break;
129 	default:
130 		return -EINVAL;
131 	}
132 	return cx22702_writereg(state, 0x0C, val);
133 }
134 
135 /* Retrieve the demod settings */
136 static int cx22702_get_tps(struct cx22702_state *state,
137 			   struct dtv_frontend_properties *p)
138 {
139 	u8 val;
140 
141 	/* Make sure the TPS regs are valid */
142 	if (!(cx22702_readreg(state, 0x0A) & 0x20))
143 		return -EAGAIN;
144 
145 	val = cx22702_readreg(state, 0x01);
146 	switch ((val & 0x18) >> 3) {
147 	case 0:
148 		p->modulation = QPSK;
149 		break;
150 	case 1:
151 		p->modulation = QAM_16;
152 		break;
153 	case 2:
154 		p->modulation = QAM_64;
155 		break;
156 	}
157 	switch (val & 0x07) {
158 	case 0:
159 		p->hierarchy = HIERARCHY_NONE;
160 		break;
161 	case 1:
162 		p->hierarchy = HIERARCHY_1;
163 		break;
164 	case 2:
165 		p->hierarchy = HIERARCHY_2;
166 		break;
167 	case 3:
168 		p->hierarchy = HIERARCHY_4;
169 		break;
170 	}
171 
172 
173 	val = cx22702_readreg(state, 0x02);
174 	switch ((val & 0x38) >> 3) {
175 	case 0:
176 		p->code_rate_HP = FEC_1_2;
177 		break;
178 	case 1:
179 		p->code_rate_HP = FEC_2_3;
180 		break;
181 	case 2:
182 		p->code_rate_HP = FEC_3_4;
183 		break;
184 	case 3:
185 		p->code_rate_HP = FEC_5_6;
186 		break;
187 	case 4:
188 		p->code_rate_HP = FEC_7_8;
189 		break;
190 	}
191 	switch (val & 0x07) {
192 	case 0:
193 		p->code_rate_LP = FEC_1_2;
194 		break;
195 	case 1:
196 		p->code_rate_LP = FEC_2_3;
197 		break;
198 	case 2:
199 		p->code_rate_LP = FEC_3_4;
200 		break;
201 	case 3:
202 		p->code_rate_LP = FEC_5_6;
203 		break;
204 	case 4:
205 		p->code_rate_LP = FEC_7_8;
206 		break;
207 	}
208 
209 	val = cx22702_readreg(state, 0x03);
210 	switch ((val & 0x0c) >> 2) {
211 	case 0:
212 		p->guard_interval = GUARD_INTERVAL_1_32;
213 		break;
214 	case 1:
215 		p->guard_interval = GUARD_INTERVAL_1_16;
216 		break;
217 	case 2:
218 		p->guard_interval = GUARD_INTERVAL_1_8;
219 		break;
220 	case 3:
221 		p->guard_interval = GUARD_INTERVAL_1_4;
222 		break;
223 	}
224 	switch (val & 0x03) {
225 	case 0:
226 		p->transmission_mode = TRANSMISSION_MODE_2K;
227 		break;
228 	case 1:
229 		p->transmission_mode = TRANSMISSION_MODE_8K;
230 		break;
231 	}
232 
233 	return 0;
234 }
235 
236 static int cx22702_i2c_gate_ctrl(struct dvb_frontend *fe, int enable)
237 {
238 	struct cx22702_state *state = fe->demodulator_priv;
239 	u8 val;
240 
241 	dprintk("%s(%d)\n", __func__, enable);
242 	val = cx22702_readreg(state, 0x0D);
243 	if (enable)
244 		val &= 0xfe;
245 	else
246 		val |= 0x01;
247 	return cx22702_writereg(state, 0x0D, val);
248 }
249 
250 /* Talk to the demod, set the FEC, GUARD, QAM settings etc */
251 static int cx22702_set_tps(struct dvb_frontend *fe)
252 {
253 	struct dtv_frontend_properties *p = &fe->dtv_property_cache;
254 	u8 val;
255 	struct cx22702_state *state = fe->demodulator_priv;
256 
257 	if (fe->ops.tuner_ops.set_params) {
258 		fe->ops.tuner_ops.set_params(fe);
259 		if (fe->ops.i2c_gate_ctrl)
260 			fe->ops.i2c_gate_ctrl(fe, 0);
261 	}
262 
263 	/* set inversion */
264 	cx22702_set_inversion(state, p->inversion);
265 
266 	/* set bandwidth */
267 	val = cx22702_readreg(state, 0x0C) & 0xcf;
268 	switch (p->bandwidth_hz) {
269 	case 6000000:
270 		val |= 0x20;
271 		break;
272 	case 7000000:
273 		val |= 0x10;
274 		break;
275 	case 8000000:
276 		break;
277 	default:
278 		dprintk("%s: invalid bandwidth\n", __func__);
279 		return -EINVAL;
280 	}
281 	cx22702_writereg(state, 0x0C, val);
282 
283 	p->code_rate_LP = FEC_AUTO; /* temp hack as manual not working */
284 
285 	/* use auto configuration? */
286 	if ((p->hierarchy == HIERARCHY_AUTO) ||
287 	   (p->modulation == QAM_AUTO) ||
288 	   (p->code_rate_HP == FEC_AUTO) ||
289 	   (p->code_rate_LP == FEC_AUTO) ||
290 	   (p->guard_interval == GUARD_INTERVAL_AUTO) ||
291 	   (p->transmission_mode == TRANSMISSION_MODE_AUTO)) {
292 
293 		/* TPS Source - use hardware driven values */
294 		cx22702_writereg(state, 0x06, 0x10);
295 		cx22702_writereg(state, 0x07, 0x9);
296 		cx22702_writereg(state, 0x08, 0xC1);
297 		cx22702_writereg(state, 0x0B, cx22702_readreg(state, 0x0B)
298 			& 0xfc);
299 		cx22702_writereg(state, 0x0C,
300 			(cx22702_readreg(state, 0x0C) & 0xBF) | 0x40);
301 		cx22702_writereg(state, 0x00, 0x01); /* Begin acquisition */
302 		dprintk("%s: Autodetecting\n", __func__);
303 		return 0;
304 	}
305 
306 	/* manually programmed values */
307 	switch (p->modulation) {		/* mask 0x18 */
308 	case QPSK:
309 		val = 0x00;
310 		break;
311 	case QAM_16:
312 		val = 0x08;
313 		break;
314 	case QAM_64:
315 		val = 0x10;
316 		break;
317 	default:
318 		dprintk("%s: invalid modulation\n", __func__);
319 		return -EINVAL;
320 	}
321 	switch (p->hierarchy) {	/* mask 0x07 */
322 	case HIERARCHY_NONE:
323 		break;
324 	case HIERARCHY_1:
325 		val |= 0x01;
326 		break;
327 	case HIERARCHY_2:
328 		val |= 0x02;
329 		break;
330 	case HIERARCHY_4:
331 		val |= 0x03;
332 		break;
333 	default:
334 		dprintk("%s: invalid hierarchy\n", __func__);
335 		return -EINVAL;
336 	}
337 	cx22702_writereg(state, 0x06, val);
338 
339 	switch (p->code_rate_HP) {		/* mask 0x38 */
340 	case FEC_NONE:
341 	case FEC_1_2:
342 		val = 0x00;
343 		break;
344 	case FEC_2_3:
345 		val = 0x08;
346 		break;
347 	case FEC_3_4:
348 		val = 0x10;
349 		break;
350 	case FEC_5_6:
351 		val = 0x18;
352 		break;
353 	case FEC_7_8:
354 		val = 0x20;
355 		break;
356 	default:
357 		dprintk("%s: invalid code_rate_HP\n", __func__);
358 		return -EINVAL;
359 	}
360 	switch (p->code_rate_LP) {		/* mask 0x07 */
361 	case FEC_NONE:
362 	case FEC_1_2:
363 		break;
364 	case FEC_2_3:
365 		val |= 0x01;
366 		break;
367 	case FEC_3_4:
368 		val |= 0x02;
369 		break;
370 	case FEC_5_6:
371 		val |= 0x03;
372 		break;
373 	case FEC_7_8:
374 		val |= 0x04;
375 		break;
376 	default:
377 		dprintk("%s: invalid code_rate_LP\n", __func__);
378 		return -EINVAL;
379 	}
380 	cx22702_writereg(state, 0x07, val);
381 
382 	switch (p->guard_interval) {		/* mask 0x0c */
383 	case GUARD_INTERVAL_1_32:
384 		val = 0x00;
385 		break;
386 	case GUARD_INTERVAL_1_16:
387 		val = 0x04;
388 		break;
389 	case GUARD_INTERVAL_1_8:
390 		val = 0x08;
391 		break;
392 	case GUARD_INTERVAL_1_4:
393 		val = 0x0c;
394 		break;
395 	default:
396 		dprintk("%s: invalid guard_interval\n", __func__);
397 		return -EINVAL;
398 	}
399 	switch (p->transmission_mode) {		/* mask 0x03 */
400 	case TRANSMISSION_MODE_2K:
401 		break;
402 	case TRANSMISSION_MODE_8K:
403 		val |= 0x1;
404 		break;
405 	default:
406 		dprintk("%s: invalid transmission_mode\n", __func__);
407 		return -EINVAL;
408 	}
409 	cx22702_writereg(state, 0x08, val);
410 	cx22702_writereg(state, 0x0B,
411 		(cx22702_readreg(state, 0x0B) & 0xfc) | 0x02);
412 	cx22702_writereg(state, 0x0C,
413 		(cx22702_readreg(state, 0x0C) & 0xBF) | 0x40);
414 
415 	/* Begin channel acquisition */
416 	cx22702_writereg(state, 0x00, 0x01);
417 
418 	return 0;
419 }
420 
421 /* Reset the demod hardware and reset all of the configuration registers
422    to a default state. */
423 static int cx22702_init(struct dvb_frontend *fe)
424 {
425 	int i;
426 	struct cx22702_state *state = fe->demodulator_priv;
427 
428 	cx22702_writereg(state, 0x00, 0x02);
429 
430 	msleep(10);
431 
432 	for (i = 0; i < ARRAY_SIZE(init_tab); i += 2)
433 		cx22702_writereg(state, init_tab[i], init_tab[i + 1]);
434 
435 	cx22702_writereg(state, 0xf8, (state->config->output_mode << 1)
436 		& 0x02);
437 
438 	cx22702_i2c_gate_ctrl(fe, 0);
439 
440 	return 0;
441 }
442 
443 static int cx22702_read_status(struct dvb_frontend *fe, enum fe_status *status)
444 {
445 	struct cx22702_state *state = fe->demodulator_priv;
446 	u8 reg0A;
447 	u8 reg23;
448 
449 	*status = 0;
450 
451 	reg0A = cx22702_readreg(state, 0x0A);
452 	reg23 = cx22702_readreg(state, 0x23);
453 
454 	dprintk("%s: status demod=0x%02x agc=0x%02x\n"
455 		, __func__, reg0A, reg23);
456 
457 	if (reg0A & 0x10) {
458 		*status |= FE_HAS_LOCK;
459 		*status |= FE_HAS_VITERBI;
460 		*status |= FE_HAS_SYNC;
461 	}
462 
463 	if (reg0A & 0x20)
464 		*status |= FE_HAS_CARRIER;
465 
466 	if (reg23 < 0xf0)
467 		*status |= FE_HAS_SIGNAL;
468 
469 	return 0;
470 }
471 
472 static int cx22702_read_ber(struct dvb_frontend *fe, u32 *ber)
473 {
474 	struct cx22702_state *state = fe->demodulator_priv;
475 
476 	if (cx22702_readreg(state, 0xE4) & 0x02) {
477 		/* Realtime statistics */
478 		*ber = (cx22702_readreg(state, 0xDE) & 0x7F) << 7
479 			| (cx22702_readreg(state, 0xDF) & 0x7F);
480 	} else {
481 		/* Averagtine statistics */
482 		*ber = (cx22702_readreg(state, 0xDE) & 0x7F) << 7
483 			| cx22702_readreg(state, 0xDF);
484 	}
485 
486 	return 0;
487 }
488 
489 static int cx22702_read_signal_strength(struct dvb_frontend *fe,
490 	u16 *signal_strength)
491 {
492 	struct cx22702_state *state = fe->demodulator_priv;
493 	u8 reg23;
494 
495 	/*
496 	 * Experience suggests that the strength signal register works as
497 	 * follows:
498 	 * - In the absence of signal, value is 0xff.
499 	 * - In the presence of a weak signal, bit 7 is set, not sure what
500 	 *   the lower 7 bits mean.
501 	 * - In the presence of a strong signal, the register holds a 7-bit
502 	 *   value (bit 7 is cleared), with greater values standing for
503 	 *   weaker signals.
504 	 */
505 	reg23 = cx22702_readreg(state, 0x23);
506 	if (reg23 & 0x80) {
507 		*signal_strength = 0;
508 	} else {
509 		reg23 = ~reg23 & 0x7f;
510 		/* Scale to 16 bit */
511 		*signal_strength = (reg23 << 9) | (reg23 << 2) | (reg23 >> 5);
512 	}
513 
514 	return 0;
515 }
516 
517 static int cx22702_read_snr(struct dvb_frontend *fe, u16 *snr)
518 {
519 	struct cx22702_state *state = fe->demodulator_priv;
520 
521 	u16 rs_ber;
522 	if (cx22702_readreg(state, 0xE4) & 0x02) {
523 		/* Realtime statistics */
524 		rs_ber = (cx22702_readreg(state, 0xDE) & 0x7F) << 7
525 			| (cx22702_readreg(state, 0xDF) & 0x7F);
526 	} else {
527 		/* Averagine statistics */
528 		rs_ber = (cx22702_readreg(state, 0xDE) & 0x7F) << 8
529 			| cx22702_readreg(state, 0xDF);
530 	}
531 	*snr = ~rs_ber;
532 
533 	return 0;
534 }
535 
536 static int cx22702_read_ucblocks(struct dvb_frontend *fe, u32 *ucblocks)
537 {
538 	struct cx22702_state *state = fe->demodulator_priv;
539 
540 	u8 _ucblocks;
541 
542 	/* RS Uncorrectable Packet Count then reset */
543 	_ucblocks = cx22702_readreg(state, 0xE3);
544 	if (state->prevUCBlocks < _ucblocks)
545 		*ucblocks = (_ucblocks - state->prevUCBlocks);
546 	else
547 		*ucblocks = state->prevUCBlocks - _ucblocks;
548 	state->prevUCBlocks = _ucblocks;
549 
550 	return 0;
551 }
552 
553 static int cx22702_get_frontend(struct dvb_frontend *fe,
554 				struct dtv_frontend_properties *c)
555 {
556 	struct cx22702_state *state = fe->demodulator_priv;
557 
558 	u8 reg0C = cx22702_readreg(state, 0x0C);
559 
560 	c->inversion = reg0C & 0x1 ? INVERSION_ON : INVERSION_OFF;
561 	return cx22702_get_tps(state, c);
562 }
563 
564 static int cx22702_get_tune_settings(struct dvb_frontend *fe,
565 	struct dvb_frontend_tune_settings *tune)
566 {
567 	tune->min_delay_ms = 1000;
568 	return 0;
569 }
570 
571 static void cx22702_release(struct dvb_frontend *fe)
572 {
573 	struct cx22702_state *state = fe->demodulator_priv;
574 	kfree(state);
575 }
576 
577 static const struct dvb_frontend_ops cx22702_ops;
578 
579 struct dvb_frontend *cx22702_attach(const struct cx22702_config *config,
580 	struct i2c_adapter *i2c)
581 {
582 	struct cx22702_state *state = NULL;
583 
584 	/* allocate memory for the internal state */
585 	state = kzalloc(sizeof(struct cx22702_state), GFP_KERNEL);
586 	if (state == NULL)
587 		goto error;
588 
589 	/* setup the state */
590 	state->config = config;
591 	state->i2c = i2c;
592 
593 	/* check if the demod is there */
594 	if (cx22702_readreg(state, 0x1f) != 0x3)
595 		goto error;
596 
597 	/* create dvb_frontend */
598 	memcpy(&state->frontend.ops, &cx22702_ops,
599 		sizeof(struct dvb_frontend_ops));
600 	state->frontend.demodulator_priv = state;
601 	return &state->frontend;
602 
603 error:
604 	kfree(state);
605 	return NULL;
606 }
607 EXPORT_SYMBOL(cx22702_attach);
608 
609 static const struct dvb_frontend_ops cx22702_ops = {
610 	.delsys = { SYS_DVBT },
611 	.info = {
612 		.name			= "Conexant CX22702 DVB-T",
613 		.frequency_min_hz	= 177 * MHz,
614 		.frequency_max_hz	= 858 * MHz,
615 		.frequency_stepsize_hz	= 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