1 /*
2     Driver for STV0297 demodulator
3 
4     Copyright (C) 2004 Andrew de Quincey <adq_dvb@lidskialf.net>
5     Copyright (C) 2003-2004 Dennis Noermann <dennis.noermann@noernet.de>
6 
7     This program is free software; you can redistribute it and/or modify
8     it under the terms of the GNU General Public License as published by
9     the Free Software Foundation; either version 2 of the License, or
10     (at your option) any later version.
11 
12     This program is distributed in the hope that it will be useful,
13     but WITHOUT ANY WARRANTY; without even the implied warranty of
14     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15     GNU General Public License for more details.
16 
17     You should have received a copy of the GNU General Public License
18     along with this program; if not, write to the Free Software
19     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 */
21 
22 #include <linux/init.h>
23 #include <linux/kernel.h>
24 #include <linux/module.h>
25 #include <linux/string.h>
26 #include <linux/delay.h>
27 #include <linux/jiffies.h>
28 #include <linux/slab.h>
29 
30 #include "dvb_frontend.h"
31 #include "stv0297.h"
32 
33 struct stv0297_state {
34 	struct i2c_adapter *i2c;
35 	const struct stv0297_config *config;
36 	struct dvb_frontend frontend;
37 
38 	unsigned long last_ber;
39 	unsigned long base_freq;
40 };
41 
42 #if 1
43 #define dprintk(x...) printk(x)
44 #else
45 #define dprintk(x...)
46 #endif
47 
48 #define STV0297_CLOCK_KHZ   28900
49 
50 
51 static int stv0297_writereg(struct stv0297_state *state, u8 reg, u8 data)
52 {
53 	int ret;
54 	u8 buf[] = { reg, data };
55 	struct i2c_msg msg = {.addr = state->config->demod_address,.flags = 0,.buf = buf,.len = 2 };
56 
57 	ret = i2c_transfer(state->i2c, &msg, 1);
58 
59 	if (ret != 1)
60 		dprintk("%s: writereg error (reg == 0x%02x, val == 0x%02x, "
61 			"ret == %i)\n", __func__, reg, data, ret);
62 
63 	return (ret != 1) ? -1 : 0;
64 }
65 
66 static int stv0297_readreg(struct stv0297_state *state, u8 reg)
67 {
68 	int ret;
69 	u8 b0[] = { reg };
70 	u8 b1[] = { 0 };
71 	struct i2c_msg msg[] = { {.addr = state->config->demod_address,.flags = 0,.buf = b0,.len = 1},
72 				 {.addr = state->config->demod_address,.flags = I2C_M_RD,.buf = b1,.len = 1}
73 			       };
74 
75 	// this device needs a STOP between the register and data
76 	if (state->config->stop_during_read) {
77 		if ((ret = i2c_transfer(state->i2c, &msg[0], 1)) != 1) {
78 			dprintk("%s: readreg error (reg == 0x%02x, ret == %i)\n", __func__, reg, ret);
79 			return -1;
80 		}
81 		if ((ret = i2c_transfer(state->i2c, &msg[1], 1)) != 1) {
82 			dprintk("%s: readreg error (reg == 0x%02x, ret == %i)\n", __func__, reg, ret);
83 			return -1;
84 		}
85 	} else {
86 		if ((ret = i2c_transfer(state->i2c, msg, 2)) != 2) {
87 			dprintk("%s: readreg error (reg == 0x%02x, ret == %i)\n", __func__, reg, ret);
88 			return -1;
89 		}
90 	}
91 
92 	return b1[0];
93 }
94 
95 static int stv0297_writereg_mask(struct stv0297_state *state, u8 reg, u8 mask, u8 data)
96 {
97 	int val;
98 
99 	val = stv0297_readreg(state, reg);
100 	val &= ~mask;
101 	val |= (data & mask);
102 	stv0297_writereg(state, reg, val);
103 
104 	return 0;
105 }
106 
107 static int stv0297_readregs(struct stv0297_state *state, u8 reg1, u8 * b, u8 len)
108 {
109 	int ret;
110 	struct i2c_msg msg[] = { {.addr = state->config->demod_address,.flags = 0,.buf =
111 				  &reg1,.len = 1},
112 	{.addr = state->config->demod_address,.flags = I2C_M_RD,.buf = b,.len = len}
113 	};
114 
115 	// this device needs a STOP between the register and data
116 	if (state->config->stop_during_read) {
117 		if ((ret = i2c_transfer(state->i2c, &msg[0], 1)) != 1) {
118 			dprintk("%s: readreg error (reg == 0x%02x, ret == %i)\n", __func__, reg1, ret);
119 			return -1;
120 		}
121 		if ((ret = i2c_transfer(state->i2c, &msg[1], 1)) != 1) {
122 			dprintk("%s: readreg error (reg == 0x%02x, ret == %i)\n", __func__, reg1, ret);
123 			return -1;
124 		}
125 	} else {
126 		if ((ret = i2c_transfer(state->i2c, msg, 2)) != 2) {
127 			dprintk("%s: readreg error (reg == 0x%02x, ret == %i)\n", __func__, reg1, ret);
128 			return -1;
129 		}
130 	}
131 
132 	return 0;
133 }
134 
135 static u32 stv0297_get_symbolrate(struct stv0297_state *state)
136 {
137 	u64 tmp;
138 
139 	tmp = stv0297_readreg(state, 0x55);
140 	tmp |= stv0297_readreg(state, 0x56) << 8;
141 	tmp |= stv0297_readreg(state, 0x57) << 16;
142 	tmp |= stv0297_readreg(state, 0x58) << 24;
143 
144 	tmp *= STV0297_CLOCK_KHZ;
145 	tmp >>= 32;
146 
147 	return (u32) tmp;
148 }
149 
150 static void stv0297_set_symbolrate(struct stv0297_state *state, u32 srate)
151 {
152 	long tmp;
153 
154 	tmp = 131072L * srate;	/* 131072 = 2^17  */
155 	tmp = tmp / (STV0297_CLOCK_KHZ / 4);	/* 1/4 = 2^-2 */
156 	tmp = tmp * 8192L;	/* 8192 = 2^13 */
157 
158 	stv0297_writereg(state, 0x55, (unsigned char) (tmp & 0xFF));
159 	stv0297_writereg(state, 0x56, (unsigned char) (tmp >> 8));
160 	stv0297_writereg(state, 0x57, (unsigned char) (tmp >> 16));
161 	stv0297_writereg(state, 0x58, (unsigned char) (tmp >> 24));
162 }
163 
164 static void stv0297_set_sweeprate(struct stv0297_state *state, short fshift, long symrate)
165 {
166 	long tmp;
167 
168 	tmp = (long) fshift *262144L;	/* 262144 = 2*18 */
169 	tmp /= symrate;
170 	tmp *= 1024;		/* 1024 = 2*10   */
171 
172 	// adjust
173 	if (tmp >= 0) {
174 		tmp += 500000;
175 	} else {
176 		tmp -= 500000;
177 	}
178 	tmp /= 1000000;
179 
180 	stv0297_writereg(state, 0x60, tmp & 0xFF);
181 	stv0297_writereg_mask(state, 0x69, 0xF0, (tmp >> 4) & 0xf0);
182 }
183 
184 static void stv0297_set_carrieroffset(struct stv0297_state *state, long offset)
185 {
186 	long tmp;
187 
188 	/* symrate is hardcoded to 10000 */
189 	tmp = offset * 26844L;	/* (2**28)/10000 */
190 	if (tmp < 0)
191 		tmp += 0x10000000;
192 	tmp &= 0x0FFFFFFF;
193 
194 	stv0297_writereg(state, 0x66, (unsigned char) (tmp & 0xFF));
195 	stv0297_writereg(state, 0x67, (unsigned char) (tmp >> 8));
196 	stv0297_writereg(state, 0x68, (unsigned char) (tmp >> 16));
197 	stv0297_writereg_mask(state, 0x69, 0x0F, (tmp >> 24) & 0x0f);
198 }
199 
200 /*
201 static long stv0297_get_carrieroffset(struct stv0297_state *state)
202 {
203 	s64 tmp;
204 
205 	stv0297_writereg(state, 0x6B, 0x00);
206 
207 	tmp = stv0297_readreg(state, 0x66);
208 	tmp |= (stv0297_readreg(state, 0x67) << 8);
209 	tmp |= (stv0297_readreg(state, 0x68) << 16);
210 	tmp |= (stv0297_readreg(state, 0x69) & 0x0F) << 24;
211 
212 	tmp *= stv0297_get_symbolrate(state);
213 	tmp >>= 28;
214 
215 	return (s32) tmp;
216 }
217 */
218 
219 static void stv0297_set_initialdemodfreq(struct stv0297_state *state, long freq)
220 {
221 	s32 tmp;
222 
223 	if (freq > 10000)
224 		freq -= STV0297_CLOCK_KHZ;
225 
226 	tmp = (STV0297_CLOCK_KHZ * 1000) / (1 << 16);
227 	tmp = (freq * 1000) / tmp;
228 	if (tmp > 0xffff)
229 		tmp = 0xffff;
230 
231 	stv0297_writereg_mask(state, 0x25, 0x80, 0x80);
232 	stv0297_writereg(state, 0x21, tmp >> 8);
233 	stv0297_writereg(state, 0x20, tmp);
234 }
235 
236 static int stv0297_set_qam(struct stv0297_state *state, fe_modulation_t modulation)
237 {
238 	int val = 0;
239 
240 	switch (modulation) {
241 	case QAM_16:
242 		val = 0;
243 		break;
244 
245 	case QAM_32:
246 		val = 1;
247 		break;
248 
249 	case QAM_64:
250 		val = 4;
251 		break;
252 
253 	case QAM_128:
254 		val = 2;
255 		break;
256 
257 	case QAM_256:
258 		val = 3;
259 		break;
260 
261 	default:
262 		return -EINVAL;
263 	}
264 
265 	stv0297_writereg_mask(state, 0x00, 0x70, val << 4);
266 
267 	return 0;
268 }
269 
270 static int stv0297_set_inversion(struct stv0297_state *state, fe_spectral_inversion_t inversion)
271 {
272 	int val = 0;
273 
274 	switch (inversion) {
275 	case INVERSION_OFF:
276 		val = 0;
277 		break;
278 
279 	case INVERSION_ON:
280 		val = 1;
281 		break;
282 
283 	default:
284 		return -EINVAL;
285 	}
286 
287 	stv0297_writereg_mask(state, 0x83, 0x08, val << 3);
288 
289 	return 0;
290 }
291 
292 static int stv0297_i2c_gate_ctrl(struct dvb_frontend *fe, int enable)
293 {
294 	struct stv0297_state *state = fe->demodulator_priv;
295 
296 	if (enable) {
297 		stv0297_writereg(state, 0x87, 0x78);
298 		stv0297_writereg(state, 0x86, 0xc8);
299 	}
300 
301 	return 0;
302 }
303 
304 static int stv0297_init(struct dvb_frontend *fe)
305 {
306 	struct stv0297_state *state = fe->demodulator_priv;
307 	int i;
308 
309 	/* load init table */
310 	for (i=0; !(state->config->inittab[i] == 0xff && state->config->inittab[i+1] == 0xff); i+=2)
311 		stv0297_writereg(state, state->config->inittab[i], state->config->inittab[i+1]);
312 	msleep(200);
313 
314 	state->last_ber = 0;
315 
316 	return 0;
317 }
318 
319 static int stv0297_sleep(struct dvb_frontend *fe)
320 {
321 	struct stv0297_state *state = fe->demodulator_priv;
322 
323 	stv0297_writereg_mask(state, 0x80, 1, 1);
324 
325 	return 0;
326 }
327 
328 static int stv0297_read_status(struct dvb_frontend *fe, fe_status_t * status)
329 {
330 	struct stv0297_state *state = fe->demodulator_priv;
331 
332 	u8 sync = stv0297_readreg(state, 0xDF);
333 
334 	*status = 0;
335 	if (sync & 0x80)
336 		*status |=
337 			FE_HAS_SYNC | FE_HAS_SIGNAL | FE_HAS_CARRIER | FE_HAS_VITERBI | FE_HAS_LOCK;
338 	return 0;
339 }
340 
341 static int stv0297_read_ber(struct dvb_frontend *fe, u32 * ber)
342 {
343 	struct stv0297_state *state = fe->demodulator_priv;
344 	u8 BER[3];
345 
346 	stv0297_readregs(state, 0xA0, BER, 3);
347 	if (!(BER[0] & 0x80)) {
348 		state->last_ber = BER[2] << 8 | BER[1];
349 		stv0297_writereg_mask(state, 0xA0, 0x80, 0x80);
350 	}
351 
352 	*ber = state->last_ber;
353 
354 	return 0;
355 }
356 
357 
358 static int stv0297_read_signal_strength(struct dvb_frontend *fe, u16 * strength)
359 {
360 	struct stv0297_state *state = fe->demodulator_priv;
361 	u8 STRENGTH[3];
362 	u16 tmp;
363 
364 	stv0297_readregs(state, 0x41, STRENGTH, 3);
365 	tmp = (STRENGTH[1] & 0x03) << 8 | STRENGTH[0];
366 	if (STRENGTH[2] & 0x20) {
367 		if (tmp < 0x200)
368 			tmp = 0;
369 		else
370 			tmp = tmp - 0x200;
371 	} else {
372 		if (tmp > 0x1ff)
373 			tmp = 0;
374 		else
375 			tmp = 0x1ff - tmp;
376 	}
377 	*strength = (tmp << 7) | (tmp >> 2);
378 	return 0;
379 }
380 
381 static int stv0297_read_snr(struct dvb_frontend *fe, u16 * snr)
382 {
383 	struct stv0297_state *state = fe->demodulator_priv;
384 	u8 SNR[2];
385 
386 	stv0297_readregs(state, 0x07, SNR, 2);
387 	*snr = SNR[1] << 8 | SNR[0];
388 
389 	return 0;
390 }
391 
392 static int stv0297_read_ucblocks(struct dvb_frontend *fe, u32 * ucblocks)
393 {
394 	struct stv0297_state *state = fe->demodulator_priv;
395 
396 	stv0297_writereg_mask(state, 0xDF, 0x03, 0x03); /* freeze the counters */
397 
398 	*ucblocks = (stv0297_readreg(state, 0xD5) << 8)
399 		| stv0297_readreg(state, 0xD4);
400 
401 	stv0297_writereg_mask(state, 0xDF, 0x03, 0x02); /* clear the counters */
402 	stv0297_writereg_mask(state, 0xDF, 0x03, 0x01); /* re-enable the counters */
403 
404 	return 0;
405 }
406 
407 static int stv0297_set_frontend(struct dvb_frontend *fe)
408 {
409 	struct dtv_frontend_properties *p = &fe->dtv_property_cache;
410 	struct stv0297_state *state = fe->demodulator_priv;
411 	int u_threshold;
412 	int initial_u;
413 	int blind_u;
414 	int delay;
415 	int sweeprate;
416 	int carrieroffset;
417 	unsigned long timeout;
418 	fe_spectral_inversion_t inversion;
419 
420 	switch (p->modulation) {
421 	case QAM_16:
422 	case QAM_32:
423 	case QAM_64:
424 		delay = 100;
425 		sweeprate = 1000;
426 		break;
427 
428 	case QAM_128:
429 	case QAM_256:
430 		delay = 200;
431 		sweeprate = 500;
432 		break;
433 
434 	default:
435 		return -EINVAL;
436 	}
437 
438 	// determine inversion dependent parameters
439 	inversion = p->inversion;
440 	if (state->config->invert)
441 		inversion = (inversion == INVERSION_ON) ? INVERSION_OFF : INVERSION_ON;
442 	carrieroffset = -330;
443 	switch (inversion) {
444 	case INVERSION_OFF:
445 		break;
446 
447 	case INVERSION_ON:
448 		sweeprate = -sweeprate;
449 		carrieroffset = -carrieroffset;
450 		break;
451 
452 	default:
453 		return -EINVAL;
454 	}
455 
456 	stv0297_init(fe);
457 	if (fe->ops.tuner_ops.set_params) {
458 		fe->ops.tuner_ops.set_params(fe);
459 		if (fe->ops.i2c_gate_ctrl) fe->ops.i2c_gate_ctrl(fe, 0);
460 	}
461 
462 	/* clear software interrupts */
463 	stv0297_writereg(state, 0x82, 0x0);
464 
465 	/* set initial demodulation frequency */
466 	stv0297_set_initialdemodfreq(state, 7250);
467 
468 	/* setup AGC */
469 	stv0297_writereg_mask(state, 0x43, 0x10, 0x00);
470 	stv0297_writereg(state, 0x41, 0x00);
471 	stv0297_writereg_mask(state, 0x42, 0x03, 0x01);
472 	stv0297_writereg_mask(state, 0x36, 0x60, 0x00);
473 	stv0297_writereg_mask(state, 0x36, 0x18, 0x00);
474 	stv0297_writereg_mask(state, 0x71, 0x80, 0x80);
475 	stv0297_writereg(state, 0x72, 0x00);
476 	stv0297_writereg(state, 0x73, 0x00);
477 	stv0297_writereg_mask(state, 0x74, 0x0F, 0x00);
478 	stv0297_writereg_mask(state, 0x43, 0x08, 0x00);
479 	stv0297_writereg_mask(state, 0x71, 0x80, 0x00);
480 
481 	/* setup STL */
482 	stv0297_writereg_mask(state, 0x5a, 0x20, 0x20);
483 	stv0297_writereg_mask(state, 0x5b, 0x02, 0x02);
484 	stv0297_writereg_mask(state, 0x5b, 0x02, 0x00);
485 	stv0297_writereg_mask(state, 0x5b, 0x01, 0x00);
486 	stv0297_writereg_mask(state, 0x5a, 0x40, 0x40);
487 
488 	/* disable frequency sweep */
489 	stv0297_writereg_mask(state, 0x6a, 0x01, 0x00);
490 
491 	/* reset deinterleaver */
492 	stv0297_writereg_mask(state, 0x81, 0x01, 0x01);
493 	stv0297_writereg_mask(state, 0x81, 0x01, 0x00);
494 
495 	/* ??? */
496 	stv0297_writereg_mask(state, 0x83, 0x20, 0x20);
497 	stv0297_writereg_mask(state, 0x83, 0x20, 0x00);
498 
499 	/* reset equaliser */
500 	u_threshold = stv0297_readreg(state, 0x00) & 0xf;
501 	initial_u = stv0297_readreg(state, 0x01) >> 4;
502 	blind_u = stv0297_readreg(state, 0x01) & 0xf;
503 	stv0297_writereg_mask(state, 0x84, 0x01, 0x01);
504 	stv0297_writereg_mask(state, 0x84, 0x01, 0x00);
505 	stv0297_writereg_mask(state, 0x00, 0x0f, u_threshold);
506 	stv0297_writereg_mask(state, 0x01, 0xf0, initial_u << 4);
507 	stv0297_writereg_mask(state, 0x01, 0x0f, blind_u);
508 
509 	/* data comes from internal A/D */
510 	stv0297_writereg_mask(state, 0x87, 0x80, 0x00);
511 
512 	/* clear phase registers */
513 	stv0297_writereg(state, 0x63, 0x00);
514 	stv0297_writereg(state, 0x64, 0x00);
515 	stv0297_writereg(state, 0x65, 0x00);
516 	stv0297_writereg(state, 0x66, 0x00);
517 	stv0297_writereg(state, 0x67, 0x00);
518 	stv0297_writereg(state, 0x68, 0x00);
519 	stv0297_writereg_mask(state, 0x69, 0x0f, 0x00);
520 
521 	/* set parameters */
522 	stv0297_set_qam(state, p->modulation);
523 	stv0297_set_symbolrate(state, p->symbol_rate / 1000);
524 	stv0297_set_sweeprate(state, sweeprate, p->symbol_rate / 1000);
525 	stv0297_set_carrieroffset(state, carrieroffset);
526 	stv0297_set_inversion(state, inversion);
527 
528 	/* kick off lock */
529 	/* Disable corner detection for higher QAMs */
530 	if (p->modulation == QAM_128 ||
531 		p->modulation == QAM_256)
532 		stv0297_writereg_mask(state, 0x88, 0x08, 0x00);
533 	else
534 		stv0297_writereg_mask(state, 0x88, 0x08, 0x08);
535 
536 	stv0297_writereg_mask(state, 0x5a, 0x20, 0x00);
537 	stv0297_writereg_mask(state, 0x6a, 0x01, 0x01);
538 	stv0297_writereg_mask(state, 0x43, 0x40, 0x40);
539 	stv0297_writereg_mask(state, 0x5b, 0x30, 0x00);
540 	stv0297_writereg_mask(state, 0x03, 0x0c, 0x0c);
541 	stv0297_writereg_mask(state, 0x03, 0x03, 0x03);
542 	stv0297_writereg_mask(state, 0x43, 0x10, 0x10);
543 
544 	/* wait for WGAGC lock */
545 	timeout = jiffies + msecs_to_jiffies(2000);
546 	while (time_before(jiffies, timeout)) {
547 		msleep(10);
548 		if (stv0297_readreg(state, 0x43) & 0x08)
549 			break;
550 	}
551 	if (time_after(jiffies, timeout)) {
552 		goto timeout;
553 	}
554 	msleep(20);
555 
556 	/* wait for equaliser partial convergence */
557 	timeout = jiffies + msecs_to_jiffies(500);
558 	while (time_before(jiffies, timeout)) {
559 		msleep(10);
560 
561 		if (stv0297_readreg(state, 0x82) & 0x04) {
562 			break;
563 		}
564 	}
565 	if (time_after(jiffies, timeout)) {
566 		goto timeout;
567 	}
568 
569 	/* wait for equaliser full convergence */
570 	timeout = jiffies + msecs_to_jiffies(delay);
571 	while (time_before(jiffies, timeout)) {
572 		msleep(10);
573 
574 		if (stv0297_readreg(state, 0x82) & 0x08) {
575 			break;
576 		}
577 	}
578 	if (time_after(jiffies, timeout)) {
579 		goto timeout;
580 	}
581 
582 	/* disable sweep */
583 	stv0297_writereg_mask(state, 0x6a, 1, 0);
584 	stv0297_writereg_mask(state, 0x88, 8, 0);
585 
586 	/* wait for main lock */
587 	timeout = jiffies + msecs_to_jiffies(20);
588 	while (time_before(jiffies, timeout)) {
589 		msleep(10);
590 
591 		if (stv0297_readreg(state, 0xDF) & 0x80) {
592 			break;
593 		}
594 	}
595 	if (time_after(jiffies, timeout)) {
596 		goto timeout;
597 	}
598 	msleep(100);
599 
600 	/* is it still locked after that delay? */
601 	if (!(stv0297_readreg(state, 0xDF) & 0x80)) {
602 		goto timeout;
603 	}
604 
605 	/* success!! */
606 	stv0297_writereg_mask(state, 0x5a, 0x40, 0x00);
607 	state->base_freq = p->frequency;
608 	return 0;
609 
610 timeout:
611 	stv0297_writereg_mask(state, 0x6a, 0x01, 0x00);
612 	return 0;
613 }
614 
615 static int stv0297_get_frontend(struct dvb_frontend *fe)
616 {
617 	struct dtv_frontend_properties *p = &fe->dtv_property_cache;
618 	struct stv0297_state *state = fe->demodulator_priv;
619 	int reg_00, reg_83;
620 
621 	reg_00 = stv0297_readreg(state, 0x00);
622 	reg_83 = stv0297_readreg(state, 0x83);
623 
624 	p->frequency = state->base_freq;
625 	p->inversion = (reg_83 & 0x08) ? INVERSION_ON : INVERSION_OFF;
626 	if (state->config->invert)
627 		p->inversion = (p->inversion == INVERSION_ON) ? INVERSION_OFF : INVERSION_ON;
628 	p->symbol_rate = stv0297_get_symbolrate(state) * 1000;
629 	p->fec_inner = FEC_NONE;
630 
631 	switch ((reg_00 >> 4) & 0x7) {
632 	case 0:
633 		p->modulation = QAM_16;
634 		break;
635 	case 1:
636 		p->modulation = QAM_32;
637 		break;
638 	case 2:
639 		p->modulation = QAM_128;
640 		break;
641 	case 3:
642 		p->modulation = QAM_256;
643 		break;
644 	case 4:
645 		p->modulation = QAM_64;
646 		break;
647 	}
648 
649 	return 0;
650 }
651 
652 static void stv0297_release(struct dvb_frontend *fe)
653 {
654 	struct stv0297_state *state = fe->demodulator_priv;
655 	kfree(state);
656 }
657 
658 static struct dvb_frontend_ops stv0297_ops;
659 
660 struct dvb_frontend *stv0297_attach(const struct stv0297_config *config,
661 				    struct i2c_adapter *i2c)
662 {
663 	struct stv0297_state *state = NULL;
664 
665 	/* allocate memory for the internal state */
666 	state = kzalloc(sizeof(struct stv0297_state), GFP_KERNEL);
667 	if (state == NULL)
668 		goto error;
669 
670 	/* setup the state */
671 	state->config = config;
672 	state->i2c = i2c;
673 	state->last_ber = 0;
674 	state->base_freq = 0;
675 
676 	/* check if the demod is there */
677 	if ((stv0297_readreg(state, 0x80) & 0x70) != 0x20)
678 		goto error;
679 
680 	/* create dvb_frontend */
681 	memcpy(&state->frontend.ops, &stv0297_ops, sizeof(struct dvb_frontend_ops));
682 	state->frontend.demodulator_priv = state;
683 	return &state->frontend;
684 
685 error:
686 	kfree(state);
687 	return NULL;
688 }
689 
690 static struct dvb_frontend_ops stv0297_ops = {
691 	.delsys = { SYS_DVBC_ANNEX_A },
692 	.info = {
693 		 .name = "ST STV0297 DVB-C",
694 		 .frequency_min = 47000000,
695 		 .frequency_max = 862000000,
696 		 .frequency_stepsize = 62500,
697 		 .symbol_rate_min = 870000,
698 		 .symbol_rate_max = 11700000,
699 		 .caps = FE_CAN_QAM_16 | FE_CAN_QAM_32 | FE_CAN_QAM_64 |
700 		 FE_CAN_QAM_128 | FE_CAN_QAM_256 | FE_CAN_FEC_AUTO},
701 
702 	.release = stv0297_release,
703 
704 	.init = stv0297_init,
705 	.sleep = stv0297_sleep,
706 	.i2c_gate_ctrl = stv0297_i2c_gate_ctrl,
707 
708 	.set_frontend = stv0297_set_frontend,
709 	.get_frontend = stv0297_get_frontend,
710 
711 	.read_status = stv0297_read_status,
712 	.read_ber = stv0297_read_ber,
713 	.read_signal_strength = stv0297_read_signal_strength,
714 	.read_snr = stv0297_read_snr,
715 	.read_ucblocks = stv0297_read_ucblocks,
716 };
717 
718 MODULE_DESCRIPTION("ST STV0297 DVB-C Demodulator driver");
719 MODULE_AUTHOR("Dennis Noermann and Andrew de Quincey");
720 MODULE_LICENSE("GPL");
721 
722 EXPORT_SYMBOL(stv0297_attach);
723