xref: /linux/drivers/media/dvb-frontends/stv0297.c (revision ab52c59103002b49f2455371e4b9c56ba3ef1781)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3     Driver for STV0297 demodulator
4 
5     Copyright (C) 2004 Andrew de Quincey <adq_dvb@lidskialf.net>
6     Copyright (C) 2003-2004 Dennis Noermann <dennis.noermann@noernet.de>
7 
8 */
9 
10 #include <linux/init.h>
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/string.h>
14 #include <linux/delay.h>
15 #include <linux/jiffies.h>
16 #include <linux/slab.h>
17 
18 #include <media/dvb_frontend.h>
19 #include "stv0297.h"
20 
21 struct stv0297_state {
22 	struct i2c_adapter *i2c;
23 	const struct stv0297_config *config;
24 	struct dvb_frontend frontend;
25 
26 	unsigned long last_ber;
27 	unsigned long base_freq;
28 };
29 
30 #if 1
31 #define dprintk(x...) printk(x)
32 #else
33 #define dprintk(x...)
34 #endif
35 
36 #define STV0297_CLOCK_KHZ   28900
37 
38 
39 static int stv0297_writereg(struct stv0297_state *state, u8 reg, u8 data)
40 {
41 	int ret;
42 	u8 buf[] = { reg, data };
43 	struct i2c_msg msg = {.addr = state->config->demod_address,.flags = 0,.buf = buf,.len = 2 };
44 
45 	ret = i2c_transfer(state->i2c, &msg, 1);
46 
47 	if (ret != 1)
48 		dprintk("%s: writereg error (reg == 0x%02x, val == 0x%02x, ret == %i)\n",
49 			__func__, reg, data, ret);
50 
51 	return (ret != 1) ? -1 : 0;
52 }
53 
54 static int stv0297_readreg(struct stv0297_state *state, u8 reg)
55 {
56 	int ret;
57 	u8 b0[] = { reg };
58 	u8 b1[] = { 0 };
59 	struct i2c_msg msg[] = { {.addr = state->config->demod_address,.flags = 0,.buf = b0,.len = 1},
60 				 {.addr = state->config->demod_address,.flags = I2C_M_RD,.buf = b1,.len = 1}
61 			       };
62 
63 	// this device needs a STOP between the register and data
64 	if (state->config->stop_during_read) {
65 		if ((ret = i2c_transfer(state->i2c, &msg[0], 1)) != 1) {
66 			dprintk("%s: readreg error (reg == 0x%02x, ret == %i)\n", __func__, reg, ret);
67 			return -1;
68 		}
69 		if ((ret = i2c_transfer(state->i2c, &msg[1], 1)) != 1) {
70 			dprintk("%s: readreg error (reg == 0x%02x, ret == %i)\n", __func__, reg, ret);
71 			return -1;
72 		}
73 	} else {
74 		if ((ret = i2c_transfer(state->i2c, msg, 2)) != 2) {
75 			dprintk("%s: readreg error (reg == 0x%02x, ret == %i)\n", __func__, reg, ret);
76 			return -1;
77 		}
78 	}
79 
80 	return b1[0];
81 }
82 
83 static int stv0297_writereg_mask(struct stv0297_state *state, u8 reg, u8 mask, u8 data)
84 {
85 	int val;
86 
87 	val = stv0297_readreg(state, reg);
88 	val &= ~mask;
89 	val |= (data & mask);
90 	stv0297_writereg(state, reg, val);
91 
92 	return 0;
93 }
94 
95 static int stv0297_readregs(struct stv0297_state *state, u8 reg1, u8 * b, u8 len)
96 {
97 	int ret;
98 	struct i2c_msg msg[] = { {.addr = state->config->demod_address,.flags = 0,.buf =
99 				  &reg1,.len = 1},
100 	{.addr = state->config->demod_address,.flags = I2C_M_RD,.buf = b,.len = len}
101 	};
102 
103 	// this device needs a STOP between the register and data
104 	if (state->config->stop_during_read) {
105 		if ((ret = i2c_transfer(state->i2c, &msg[0], 1)) != 1) {
106 			dprintk("%s: readreg error (reg == 0x%02x, ret == %i)\n", __func__, reg1, ret);
107 			return -1;
108 		}
109 		if ((ret = i2c_transfer(state->i2c, &msg[1], 1)) != 1) {
110 			dprintk("%s: readreg error (reg == 0x%02x, ret == %i)\n", __func__, reg1, ret);
111 			return -1;
112 		}
113 	} else {
114 		if ((ret = i2c_transfer(state->i2c, msg, 2)) != 2) {
115 			dprintk("%s: readreg error (reg == 0x%02x, ret == %i)\n", __func__, reg1, ret);
116 			return -1;
117 		}
118 	}
119 
120 	return 0;
121 }
122 
123 static u32 stv0297_get_symbolrate(struct stv0297_state *state)
124 {
125 	u64 tmp;
126 
127 	tmp = (u64)(stv0297_readreg(state, 0x55)
128 		    | (stv0297_readreg(state, 0x56) << 8)
129 		    | (stv0297_readreg(state, 0x57) << 16)
130 		    | (stv0297_readreg(state, 0x58) << 24));
131 
132 	tmp *= STV0297_CLOCK_KHZ;
133 	tmp >>= 32;
134 
135 	return (u32) tmp;
136 }
137 
138 static void stv0297_set_symbolrate(struct stv0297_state *state, u32 srate)
139 {
140 	long tmp;
141 
142 	tmp = 131072L * srate;	/* 131072 = 2^17  */
143 	tmp = tmp / (STV0297_CLOCK_KHZ / 4);	/* 1/4 = 2^-2 */
144 	tmp = tmp * 8192L;	/* 8192 = 2^13 */
145 
146 	stv0297_writereg(state, 0x55, (unsigned char) (tmp & 0xFF));
147 	stv0297_writereg(state, 0x56, (unsigned char) (tmp >> 8));
148 	stv0297_writereg(state, 0x57, (unsigned char) (tmp >> 16));
149 	stv0297_writereg(state, 0x58, (unsigned char) (tmp >> 24));
150 }
151 
152 static void stv0297_set_sweeprate(struct stv0297_state *state, short fshift, long symrate)
153 {
154 	long tmp;
155 
156 	tmp = (long) fshift *262144L;	/* 262144 = 2*18 */
157 	tmp /= symrate;
158 	tmp *= 1024;		/* 1024 = 2*10   */
159 
160 	// adjust
161 	if (tmp >= 0) {
162 		tmp += 500000;
163 	} else {
164 		tmp -= 500000;
165 	}
166 	tmp /= 1000000;
167 
168 	stv0297_writereg(state, 0x60, tmp & 0xFF);
169 	stv0297_writereg_mask(state, 0x69, 0xF0, (tmp >> 4) & 0xf0);
170 }
171 
172 static void stv0297_set_carrieroffset(struct stv0297_state *state, long offset)
173 {
174 	long tmp;
175 
176 	/* symrate is hardcoded to 10000 */
177 	tmp = offset * 26844L;	/* (2**28)/10000 */
178 	if (tmp < 0)
179 		tmp += 0x10000000;
180 	tmp &= 0x0FFFFFFF;
181 
182 	stv0297_writereg(state, 0x66, (unsigned char) (tmp & 0xFF));
183 	stv0297_writereg(state, 0x67, (unsigned char) (tmp >> 8));
184 	stv0297_writereg(state, 0x68, (unsigned char) (tmp >> 16));
185 	stv0297_writereg_mask(state, 0x69, 0x0F, (tmp >> 24) & 0x0f);
186 }
187 
188 /*
189 static long stv0297_get_carrieroffset(struct stv0297_state *state)
190 {
191 	s64 tmp;
192 
193 	stv0297_writereg(state, 0x6B, 0x00);
194 
195 	tmp = stv0297_readreg(state, 0x66);
196 	tmp |= (stv0297_readreg(state, 0x67) << 8);
197 	tmp |= (stv0297_readreg(state, 0x68) << 16);
198 	tmp |= (stv0297_readreg(state, 0x69) & 0x0F) << 24;
199 
200 	tmp *= stv0297_get_symbolrate(state);
201 	tmp >>= 28;
202 
203 	return (s32) tmp;
204 }
205 */
206 
207 static void stv0297_set_initialdemodfreq(struct stv0297_state *state, long freq)
208 {
209 	s32 tmp;
210 
211 	if (freq > 10000)
212 		freq -= STV0297_CLOCK_KHZ;
213 
214 	tmp = (STV0297_CLOCK_KHZ * 1000) / (1 << 16);
215 	tmp = (freq * 1000) / tmp;
216 	if (tmp > 0xffff)
217 		tmp = 0xffff;
218 
219 	stv0297_writereg_mask(state, 0x25, 0x80, 0x80);
220 	stv0297_writereg(state, 0x21, tmp >> 8);
221 	stv0297_writereg(state, 0x20, tmp);
222 }
223 
224 static int stv0297_set_qam(struct stv0297_state *state,
225 			   enum fe_modulation modulation)
226 {
227 	int val = 0;
228 
229 	switch (modulation) {
230 	case QAM_16:
231 		val = 0;
232 		break;
233 
234 	case QAM_32:
235 		val = 1;
236 		break;
237 
238 	case QAM_64:
239 		val = 4;
240 		break;
241 
242 	case QAM_128:
243 		val = 2;
244 		break;
245 
246 	case QAM_256:
247 		val = 3;
248 		break;
249 
250 	default:
251 		return -EINVAL;
252 	}
253 
254 	stv0297_writereg_mask(state, 0x00, 0x70, val << 4);
255 
256 	return 0;
257 }
258 
259 static int stv0297_set_inversion(struct stv0297_state *state,
260 				 enum fe_spectral_inversion inversion)
261 {
262 	int val = 0;
263 
264 	switch (inversion) {
265 	case INVERSION_OFF:
266 		val = 0;
267 		break;
268 
269 	case INVERSION_ON:
270 		val = 1;
271 		break;
272 
273 	default:
274 		return -EINVAL;
275 	}
276 
277 	stv0297_writereg_mask(state, 0x83, 0x08, val << 3);
278 
279 	return 0;
280 }
281 
282 static int stv0297_i2c_gate_ctrl(struct dvb_frontend *fe, int enable)
283 {
284 	struct stv0297_state *state = fe->demodulator_priv;
285 
286 	if (enable) {
287 		stv0297_writereg(state, 0x87, 0x78);
288 		stv0297_writereg(state, 0x86, 0xc8);
289 	}
290 
291 	return 0;
292 }
293 
294 static int stv0297_init(struct dvb_frontend *fe)
295 {
296 	struct stv0297_state *state = fe->demodulator_priv;
297 	int i;
298 
299 	/* load init table */
300 	for (i=0; !(state->config->inittab[i] == 0xff && state->config->inittab[i+1] == 0xff); i+=2)
301 		stv0297_writereg(state, state->config->inittab[i], state->config->inittab[i+1]);
302 	msleep(200);
303 
304 	state->last_ber = 0;
305 
306 	return 0;
307 }
308 
309 static int stv0297_sleep(struct dvb_frontend *fe)
310 {
311 	struct stv0297_state *state = fe->demodulator_priv;
312 
313 	stv0297_writereg_mask(state, 0x80, 1, 1);
314 
315 	return 0;
316 }
317 
318 static int stv0297_read_status(struct dvb_frontend *fe,
319 			       enum fe_status *status)
320 {
321 	struct stv0297_state *state = fe->demodulator_priv;
322 
323 	u8 sync = stv0297_readreg(state, 0xDF);
324 
325 	*status = 0;
326 	if (sync & 0x80)
327 		*status |=
328 			FE_HAS_SYNC | FE_HAS_SIGNAL | FE_HAS_CARRIER | FE_HAS_VITERBI | FE_HAS_LOCK;
329 	return 0;
330 }
331 
332 static int stv0297_read_ber(struct dvb_frontend *fe, u32 * ber)
333 {
334 	struct stv0297_state *state = fe->demodulator_priv;
335 	u8 BER[3];
336 
337 	stv0297_readregs(state, 0xA0, BER, 3);
338 	if (!(BER[0] & 0x80)) {
339 		state->last_ber = BER[2] << 8 | BER[1];
340 		stv0297_writereg_mask(state, 0xA0, 0x80, 0x80);
341 	}
342 
343 	*ber = state->last_ber;
344 
345 	return 0;
346 }
347 
348 
349 static int stv0297_read_signal_strength(struct dvb_frontend *fe, u16 * strength)
350 {
351 	struct stv0297_state *state = fe->demodulator_priv;
352 	u8 STRENGTH[3];
353 	u16 tmp;
354 
355 	stv0297_readregs(state, 0x41, STRENGTH, 3);
356 	tmp = (STRENGTH[1] & 0x03) << 8 | STRENGTH[0];
357 	if (STRENGTH[2] & 0x20) {
358 		if (tmp < 0x200)
359 			tmp = 0;
360 		else
361 			tmp = tmp - 0x200;
362 	} else {
363 		if (tmp > 0x1ff)
364 			tmp = 0;
365 		else
366 			tmp = 0x1ff - tmp;
367 	}
368 	*strength = (tmp << 7) | (tmp >> 2);
369 	return 0;
370 }
371 
372 static int stv0297_read_snr(struct dvb_frontend *fe, u16 * snr)
373 {
374 	struct stv0297_state *state = fe->demodulator_priv;
375 	u8 SNR[2];
376 
377 	stv0297_readregs(state, 0x07, SNR, 2);
378 	*snr = SNR[1] << 8 | SNR[0];
379 
380 	return 0;
381 }
382 
383 static int stv0297_read_ucblocks(struct dvb_frontend *fe, u32 * ucblocks)
384 {
385 	struct stv0297_state *state = fe->demodulator_priv;
386 
387 	stv0297_writereg_mask(state, 0xDF, 0x03, 0x03); /* freeze the counters */
388 
389 	*ucblocks = (stv0297_readreg(state, 0xD5) << 8)
390 		| stv0297_readreg(state, 0xD4);
391 
392 	stv0297_writereg_mask(state, 0xDF, 0x03, 0x02); /* clear the counters */
393 	stv0297_writereg_mask(state, 0xDF, 0x03, 0x01); /* re-enable the counters */
394 
395 	return 0;
396 }
397 
398 static int stv0297_set_frontend(struct dvb_frontend *fe)
399 {
400 	struct dtv_frontend_properties *p = &fe->dtv_property_cache;
401 	struct stv0297_state *state = fe->demodulator_priv;
402 	int u_threshold;
403 	int initial_u;
404 	int blind_u;
405 	int delay;
406 	int sweeprate;
407 	int carrieroffset;
408 	unsigned long timeout;
409 	enum fe_spectral_inversion inversion;
410 
411 	switch (p->modulation) {
412 	case QAM_16:
413 	case QAM_32:
414 	case QAM_64:
415 		delay = 100;
416 		sweeprate = 1000;
417 		break;
418 
419 	case QAM_128:
420 	case QAM_256:
421 		delay = 200;
422 		sweeprate = 500;
423 		break;
424 
425 	default:
426 		return -EINVAL;
427 	}
428 
429 	// determine inversion dependent parameters
430 	inversion = p->inversion;
431 	if (state->config->invert)
432 		inversion = (inversion == INVERSION_ON) ? INVERSION_OFF : INVERSION_ON;
433 	carrieroffset = -330;
434 	switch (inversion) {
435 	case INVERSION_OFF:
436 		break;
437 
438 	case INVERSION_ON:
439 		sweeprate = -sweeprate;
440 		carrieroffset = -carrieroffset;
441 		break;
442 
443 	default:
444 		return -EINVAL;
445 	}
446 
447 	stv0297_init(fe);
448 	if (fe->ops.tuner_ops.set_params) {
449 		fe->ops.tuner_ops.set_params(fe);
450 		if (fe->ops.i2c_gate_ctrl) fe->ops.i2c_gate_ctrl(fe, 0);
451 	}
452 
453 	/* clear software interrupts */
454 	stv0297_writereg(state, 0x82, 0x0);
455 
456 	/* set initial demodulation frequency */
457 	stv0297_set_initialdemodfreq(state, 7250);
458 
459 	/* setup AGC */
460 	stv0297_writereg_mask(state, 0x43, 0x10, 0x00);
461 	stv0297_writereg(state, 0x41, 0x00);
462 	stv0297_writereg_mask(state, 0x42, 0x03, 0x01);
463 	stv0297_writereg_mask(state, 0x36, 0x60, 0x00);
464 	stv0297_writereg_mask(state, 0x36, 0x18, 0x00);
465 	stv0297_writereg_mask(state, 0x71, 0x80, 0x80);
466 	stv0297_writereg(state, 0x72, 0x00);
467 	stv0297_writereg(state, 0x73, 0x00);
468 	stv0297_writereg_mask(state, 0x74, 0x0F, 0x00);
469 	stv0297_writereg_mask(state, 0x43, 0x08, 0x00);
470 	stv0297_writereg_mask(state, 0x71, 0x80, 0x00);
471 
472 	/* setup STL */
473 	stv0297_writereg_mask(state, 0x5a, 0x20, 0x20);
474 	stv0297_writereg_mask(state, 0x5b, 0x02, 0x02);
475 	stv0297_writereg_mask(state, 0x5b, 0x02, 0x00);
476 	stv0297_writereg_mask(state, 0x5b, 0x01, 0x00);
477 	stv0297_writereg_mask(state, 0x5a, 0x40, 0x40);
478 
479 	/* disable frequency sweep */
480 	stv0297_writereg_mask(state, 0x6a, 0x01, 0x00);
481 
482 	/* reset deinterleaver */
483 	stv0297_writereg_mask(state, 0x81, 0x01, 0x01);
484 	stv0297_writereg_mask(state, 0x81, 0x01, 0x00);
485 
486 	/* ??? */
487 	stv0297_writereg_mask(state, 0x83, 0x20, 0x20);
488 	stv0297_writereg_mask(state, 0x83, 0x20, 0x00);
489 
490 	/* reset equaliser */
491 	u_threshold = stv0297_readreg(state, 0x00) & 0xf;
492 	initial_u = stv0297_readreg(state, 0x01) >> 4;
493 	blind_u = stv0297_readreg(state, 0x01) & 0xf;
494 	stv0297_writereg_mask(state, 0x84, 0x01, 0x01);
495 	stv0297_writereg_mask(state, 0x84, 0x01, 0x00);
496 	stv0297_writereg_mask(state, 0x00, 0x0f, u_threshold);
497 	stv0297_writereg_mask(state, 0x01, 0xf0, initial_u << 4);
498 	stv0297_writereg_mask(state, 0x01, 0x0f, blind_u);
499 
500 	/* data comes from internal A/D */
501 	stv0297_writereg_mask(state, 0x87, 0x80, 0x00);
502 
503 	/* clear phase registers */
504 	stv0297_writereg(state, 0x63, 0x00);
505 	stv0297_writereg(state, 0x64, 0x00);
506 	stv0297_writereg(state, 0x65, 0x00);
507 	stv0297_writereg(state, 0x66, 0x00);
508 	stv0297_writereg(state, 0x67, 0x00);
509 	stv0297_writereg(state, 0x68, 0x00);
510 	stv0297_writereg_mask(state, 0x69, 0x0f, 0x00);
511 
512 	/* set parameters */
513 	stv0297_set_qam(state, p->modulation);
514 	stv0297_set_symbolrate(state, p->symbol_rate / 1000);
515 	stv0297_set_sweeprate(state, sweeprate, p->symbol_rate / 1000);
516 	stv0297_set_carrieroffset(state, carrieroffset);
517 	stv0297_set_inversion(state, inversion);
518 
519 	/* kick off lock */
520 	/* Disable corner detection for higher QAMs */
521 	if (p->modulation == QAM_128 ||
522 		p->modulation == QAM_256)
523 		stv0297_writereg_mask(state, 0x88, 0x08, 0x00);
524 	else
525 		stv0297_writereg_mask(state, 0x88, 0x08, 0x08);
526 
527 	stv0297_writereg_mask(state, 0x5a, 0x20, 0x00);
528 	stv0297_writereg_mask(state, 0x6a, 0x01, 0x01);
529 	stv0297_writereg_mask(state, 0x43, 0x40, 0x40);
530 	stv0297_writereg_mask(state, 0x5b, 0x30, 0x00);
531 	stv0297_writereg_mask(state, 0x03, 0x0c, 0x0c);
532 	stv0297_writereg_mask(state, 0x03, 0x03, 0x03);
533 	stv0297_writereg_mask(state, 0x43, 0x10, 0x10);
534 
535 	/* wait for WGAGC lock */
536 	timeout = jiffies + msecs_to_jiffies(2000);
537 	while (time_before(jiffies, timeout)) {
538 		msleep(10);
539 		if (stv0297_readreg(state, 0x43) & 0x08)
540 			break;
541 	}
542 	if (time_after(jiffies, timeout)) {
543 		goto timeout;
544 	}
545 	msleep(20);
546 
547 	/* wait for equaliser partial convergence */
548 	timeout = jiffies + msecs_to_jiffies(500);
549 	while (time_before(jiffies, timeout)) {
550 		msleep(10);
551 
552 		if (stv0297_readreg(state, 0x82) & 0x04) {
553 			break;
554 		}
555 	}
556 	if (time_after(jiffies, timeout)) {
557 		goto timeout;
558 	}
559 
560 	/* wait for equaliser full convergence */
561 	timeout = jiffies + msecs_to_jiffies(delay);
562 	while (time_before(jiffies, timeout)) {
563 		msleep(10);
564 
565 		if (stv0297_readreg(state, 0x82) & 0x08) {
566 			break;
567 		}
568 	}
569 	if (time_after(jiffies, timeout)) {
570 		goto timeout;
571 	}
572 
573 	/* disable sweep */
574 	stv0297_writereg_mask(state, 0x6a, 1, 0);
575 	stv0297_writereg_mask(state, 0x88, 8, 0);
576 
577 	/* wait for main lock */
578 	timeout = jiffies + msecs_to_jiffies(20);
579 	while (time_before(jiffies, timeout)) {
580 		msleep(10);
581 
582 		if (stv0297_readreg(state, 0xDF) & 0x80) {
583 			break;
584 		}
585 	}
586 	if (time_after(jiffies, timeout)) {
587 		goto timeout;
588 	}
589 	msleep(100);
590 
591 	/* is it still locked after that delay? */
592 	if (!(stv0297_readreg(state, 0xDF) & 0x80)) {
593 		goto timeout;
594 	}
595 
596 	/* success!! */
597 	stv0297_writereg_mask(state, 0x5a, 0x40, 0x00);
598 	state->base_freq = p->frequency;
599 	return 0;
600 
601 timeout:
602 	stv0297_writereg_mask(state, 0x6a, 0x01, 0x00);
603 	return 0;
604 }
605 
606 static int stv0297_get_frontend(struct dvb_frontend *fe,
607 				struct dtv_frontend_properties *p)
608 {
609 	struct stv0297_state *state = fe->demodulator_priv;
610 	int reg_00, reg_83;
611 
612 	reg_00 = stv0297_readreg(state, 0x00);
613 	reg_83 = stv0297_readreg(state, 0x83);
614 
615 	p->frequency = state->base_freq;
616 	p->inversion = (reg_83 & 0x08) ? INVERSION_ON : INVERSION_OFF;
617 	if (state->config->invert)
618 		p->inversion = (p->inversion == INVERSION_ON) ? INVERSION_OFF : INVERSION_ON;
619 	p->symbol_rate = stv0297_get_symbolrate(state) * 1000;
620 	p->fec_inner = FEC_NONE;
621 
622 	switch ((reg_00 >> 4) & 0x7) {
623 	case 0:
624 		p->modulation = QAM_16;
625 		break;
626 	case 1:
627 		p->modulation = QAM_32;
628 		break;
629 	case 2:
630 		p->modulation = QAM_128;
631 		break;
632 	case 3:
633 		p->modulation = QAM_256;
634 		break;
635 	case 4:
636 		p->modulation = QAM_64;
637 		break;
638 	}
639 
640 	return 0;
641 }
642 
643 static void stv0297_release(struct dvb_frontend *fe)
644 {
645 	struct stv0297_state *state = fe->demodulator_priv;
646 	kfree(state);
647 }
648 
649 static const struct dvb_frontend_ops stv0297_ops;
650 
651 struct dvb_frontend *stv0297_attach(const struct stv0297_config *config,
652 				    struct i2c_adapter *i2c)
653 {
654 	struct stv0297_state *state = NULL;
655 
656 	/* allocate memory for the internal state */
657 	state = kzalloc(sizeof(struct stv0297_state), GFP_KERNEL);
658 	if (state == NULL)
659 		goto error;
660 
661 	/* setup the state */
662 	state->config = config;
663 	state->i2c = i2c;
664 	state->last_ber = 0;
665 	state->base_freq = 0;
666 
667 	/* check if the demod is there */
668 	if ((stv0297_readreg(state, 0x80) & 0x70) != 0x20)
669 		goto error;
670 
671 	/* create dvb_frontend */
672 	memcpy(&state->frontend.ops, &stv0297_ops, sizeof(struct dvb_frontend_ops));
673 	state->frontend.demodulator_priv = state;
674 	return &state->frontend;
675 
676 error:
677 	kfree(state);
678 	return NULL;
679 }
680 
681 static const struct dvb_frontend_ops stv0297_ops = {
682 	.delsys = { SYS_DVBC_ANNEX_A },
683 	.info = {
684 		 .name = "ST STV0297 DVB-C",
685 		 .frequency_min_hz = 47 * MHz,
686 		 .frequency_max_hz = 862 * MHz,
687 		 .frequency_stepsize_hz = 62500,
688 		 .symbol_rate_min = 870000,
689 		 .symbol_rate_max = 11700000,
690 		 .caps = FE_CAN_QAM_16 | FE_CAN_QAM_32 | FE_CAN_QAM_64 |
691 		 FE_CAN_QAM_128 | FE_CAN_QAM_256 | FE_CAN_FEC_AUTO},
692 
693 	.release = stv0297_release,
694 
695 	.init = stv0297_init,
696 	.sleep = stv0297_sleep,
697 	.i2c_gate_ctrl = stv0297_i2c_gate_ctrl,
698 
699 	.set_frontend = stv0297_set_frontend,
700 	.get_frontend = stv0297_get_frontend,
701 
702 	.read_status = stv0297_read_status,
703 	.read_ber = stv0297_read_ber,
704 	.read_signal_strength = stv0297_read_signal_strength,
705 	.read_snr = stv0297_read_snr,
706 	.read_ucblocks = stv0297_read_ucblocks,
707 };
708 
709 MODULE_DESCRIPTION("ST STV0297 DVB-C Demodulator driver");
710 MODULE_AUTHOR("Dennis Noermann and Andrew de Quincey");
711 MODULE_LICENSE("GPL");
712 
713 EXPORT_SYMBOL_GPL(stv0297_attach);
714