xref: /linux/drivers/media/dvb-frontends/nxt6000.c (revision 58e16d792a6a8c6b750f637a4649967fcac853dc)
1  // SPDX-License-Identifier: GPL-2.0-or-later
2  /*
3  	NxtWave Communications - NXT6000 demodulator driver
4  
5      Copyright (C) 2002-2003 Florian Schirmer <jolt@tuxbox.org>
6      Copyright (C) 2003 Paul Andreassen <paul@andreassen.com.au>
7  
8  */
9  
10  #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11  
12  #include <linux/init.h>
13  #include <linux/kernel.h>
14  #include <linux/module.h>
15  #include <linux/string.h>
16  #include <linux/slab.h>
17  
18  #include <media/dvb_frontend.h>
19  #include "nxt6000_priv.h"
20  #include "nxt6000.h"
21  
22  
23  
24  struct nxt6000_state {
25  	struct i2c_adapter* i2c;
26  	/* configuration settings */
27  	const struct nxt6000_config* config;
28  	struct dvb_frontend frontend;
29  };
30  
31  static int debug;
32  #define dprintk(fmt, arg...) do {					\
33  	if (debug)							\
34  		printk(KERN_DEBUG pr_fmt("%s: " fmt),			\
35  		       __func__, ##arg);				\
36  } while (0)
37  
38  static int nxt6000_writereg(struct nxt6000_state* state, u8 reg, u8 data)
39  {
40  	u8 buf[] = { reg, data };
41  	struct i2c_msg msg = {.addr = state->config->demod_address,.flags = 0,.buf = buf,.len = 2 };
42  	int ret;
43  
44  	if ((ret = i2c_transfer(state->i2c, &msg, 1)) != 1)
45  		dprintk("nxt6000: nxt6000_write error (reg: 0x%02X, data: 0x%02X, ret: %d)\n", reg, data, ret);
46  
47  	return (ret != 1) ? -EIO : 0;
48  }
49  
50  static u8 nxt6000_readreg(struct nxt6000_state* state, u8 reg)
51  {
52  	int ret;
53  	u8 b0[] = { reg };
54  	u8 b1[] = { 0 };
55  	struct i2c_msg msgs[] = {
56  		{.addr = state->config->demod_address,.flags = 0,.buf = b0,.len = 1},
57  		{.addr = state->config->demod_address,.flags = I2C_M_RD,.buf = b1,.len = 1}
58  	};
59  
60  	ret = i2c_transfer(state->i2c, msgs, 2);
61  
62  	if (ret != 2)
63  		dprintk("nxt6000: nxt6000_read error (reg: 0x%02X, ret: %d)\n", reg, ret);
64  
65  	return b1[0];
66  }
67  
68  static void nxt6000_reset(struct nxt6000_state* state)
69  {
70  	u8 val;
71  
72  	val = nxt6000_readreg(state, OFDM_COR_CTL);
73  
74  	nxt6000_writereg(state, OFDM_COR_CTL, val & ~COREACT);
75  	nxt6000_writereg(state, OFDM_COR_CTL, val | COREACT);
76  }
77  
78  static int nxt6000_set_bandwidth(struct nxt6000_state *state, u32 bandwidth)
79  {
80  	u16 nominal_rate;
81  	int result;
82  
83  	switch (bandwidth) {
84  	case 6000000:
85  		nominal_rate = 0x55B7;
86  		break;
87  
88  	case 7000000:
89  		nominal_rate = 0x6400;
90  		break;
91  
92  	case 8000000:
93  		nominal_rate = 0x7249;
94  		break;
95  
96  	default:
97  		return -EINVAL;
98  	}
99  
100  	if ((result = nxt6000_writereg(state, OFDM_TRL_NOMINALRATE_1, nominal_rate & 0xFF)) < 0)
101  		return result;
102  
103  	return nxt6000_writereg(state, OFDM_TRL_NOMINALRATE_2, (nominal_rate >> 8) & 0xFF);
104  }
105  
106  static int nxt6000_set_guard_interval(struct nxt6000_state *state,
107  				      enum fe_guard_interval guard_interval)
108  {
109  	switch (guard_interval) {
110  
111  	case GUARD_INTERVAL_1_32:
112  		return nxt6000_writereg(state, OFDM_COR_MODEGUARD, 0x00 | (nxt6000_readreg(state, OFDM_COR_MODEGUARD) & ~0x03));
113  
114  	case GUARD_INTERVAL_1_16:
115  		return nxt6000_writereg(state, OFDM_COR_MODEGUARD, 0x01 | (nxt6000_readreg(state, OFDM_COR_MODEGUARD) & ~0x03));
116  
117  	case GUARD_INTERVAL_AUTO:
118  	case GUARD_INTERVAL_1_8:
119  		return nxt6000_writereg(state, OFDM_COR_MODEGUARD, 0x02 | (nxt6000_readreg(state, OFDM_COR_MODEGUARD) & ~0x03));
120  
121  	case GUARD_INTERVAL_1_4:
122  		return nxt6000_writereg(state, OFDM_COR_MODEGUARD, 0x03 | (nxt6000_readreg(state, OFDM_COR_MODEGUARD) & ~0x03));
123  
124  	default:
125  		return -EINVAL;
126  	}
127  }
128  
129  static int nxt6000_set_inversion(struct nxt6000_state *state,
130  				 enum fe_spectral_inversion inversion)
131  {
132  	switch (inversion) {
133  
134  	case INVERSION_OFF:
135  		return nxt6000_writereg(state, OFDM_ITB_CTL, 0x00);
136  
137  	case INVERSION_ON:
138  		return nxt6000_writereg(state, OFDM_ITB_CTL, ITBINV);
139  
140  	default:
141  		return -EINVAL;
142  
143  	}
144  }
145  
146  static int
147  nxt6000_set_transmission_mode(struct nxt6000_state *state,
148  			      enum fe_transmit_mode transmission_mode)
149  {
150  	int result;
151  
152  	switch (transmission_mode) {
153  
154  	case TRANSMISSION_MODE_2K:
155  		if ((result = nxt6000_writereg(state, EN_DMD_RACQ, 0x00 | (nxt6000_readreg(state, EN_DMD_RACQ) & ~0x03))) < 0)
156  			return result;
157  
158  		return nxt6000_writereg(state, OFDM_COR_MODEGUARD, (0x00 << 2) | (nxt6000_readreg(state, OFDM_COR_MODEGUARD) & ~0x04));
159  
160  	case TRANSMISSION_MODE_8K:
161  	case TRANSMISSION_MODE_AUTO:
162  		if ((result = nxt6000_writereg(state, EN_DMD_RACQ, 0x02 | (nxt6000_readreg(state, EN_DMD_RACQ) & ~0x03))) < 0)
163  			return result;
164  
165  		return nxt6000_writereg(state, OFDM_COR_MODEGUARD, (0x01 << 2) | (nxt6000_readreg(state, OFDM_COR_MODEGUARD) & ~0x04));
166  
167  	default:
168  		return -EINVAL;
169  
170  	}
171  }
172  
173  static void nxt6000_setup(struct dvb_frontend* fe)
174  {
175  	struct nxt6000_state* state = fe->demodulator_priv;
176  
177  	nxt6000_writereg(state, RS_COR_SYNC_PARAM, SYNC_PARAM);
178  	nxt6000_writereg(state, BER_CTRL, /*(1 << 2) | */ (0x01 << 1) | 0x01);
179  	nxt6000_writereg(state, VIT_BERTIME_2, 0x00);  // BER Timer = 0x000200 * 256 = 131072 bits
180  	nxt6000_writereg(state, VIT_BERTIME_1, 0x02);  //
181  	nxt6000_writereg(state, VIT_BERTIME_0, 0x00);  //
182  	nxt6000_writereg(state, VIT_COR_INTEN, 0x98); // Enable BER interrupts
183  	nxt6000_writereg(state, VIT_COR_CTL, 0x82);   // Enable BER measurement
184  	nxt6000_writereg(state, VIT_COR_CTL, VIT_COR_RESYNC | 0x02 );
185  	nxt6000_writereg(state, OFDM_COR_CTL, (0x01 << 5) | (nxt6000_readreg(state, OFDM_COR_CTL) & 0x0F));
186  	nxt6000_writereg(state, OFDM_COR_MODEGUARD, FORCEMODE8K | 0x02);
187  	nxt6000_writereg(state, OFDM_AGC_CTL, AGCLAST | INITIAL_AGC_BW);
188  	nxt6000_writereg(state, OFDM_ITB_FREQ_1, 0x06);
189  	nxt6000_writereg(state, OFDM_ITB_FREQ_2, 0x31);
190  	nxt6000_writereg(state, OFDM_CAS_CTL, (0x01 << 7) | (0x02 << 3) | 0x04);
191  	nxt6000_writereg(state, CAS_FREQ, 0xBB);	/* CHECKME */
192  	nxt6000_writereg(state, OFDM_SYR_CTL, 1 << 2);
193  	nxt6000_writereg(state, OFDM_PPM_CTL_1, PPM256);
194  	nxt6000_writereg(state, OFDM_TRL_NOMINALRATE_1, 0x49);
195  	nxt6000_writereg(state, OFDM_TRL_NOMINALRATE_2, 0x72);
196  	nxt6000_writereg(state, ANALOG_CONTROL_0, 1 << 5);
197  	nxt6000_writereg(state, EN_DMD_RACQ, (1 << 7) | (3 << 4) | 2);
198  	nxt6000_writereg(state, DIAG_CONFIG, TB_SET);
199  
200  	if (state->config->clock_inversion)
201  		nxt6000_writereg(state, SUB_DIAG_MODE_SEL, CLKINVERSION);
202  	else
203  		nxt6000_writereg(state, SUB_DIAG_MODE_SEL, 0);
204  
205  	nxt6000_writereg(state, TS_FORMAT, 0);
206  }
207  
208  static void nxt6000_dump_status(struct nxt6000_state *state)
209  {
210  	u8 val;
211  
212  #if 0
213  	pr_info("RS_COR_STAT: 0x%02X\n",
214  		nxt6000_readreg(fe, RS_COR_STAT));
215  	pr_info("VIT_SYNC_STATUS: 0x%02X\n",
216  		nxt6000_readreg(fe, VIT_SYNC_STATUS));
217  	pr_info("OFDM_COR_STAT: 0x%02X\n",
218  		nxt6000_readreg(fe, OFDM_COR_STAT));
219  	pr_info("OFDM_SYR_STAT: 0x%02X\n",
220  		nxt6000_readreg(fe, OFDM_SYR_STAT));
221  	pr_info("OFDM_TPS_RCVD_1: 0x%02X\n",
222  		nxt6000_readreg(fe, OFDM_TPS_RCVD_1));
223  	pr_info("OFDM_TPS_RCVD_2: 0x%02X\n",
224  		nxt6000_readreg(fe, OFDM_TPS_RCVD_2));
225  	pr_info("OFDM_TPS_RCVD_3: 0x%02X\n",
226  		nxt6000_readreg(fe, OFDM_TPS_RCVD_3));
227  	pr_info("OFDM_TPS_RCVD_4: 0x%02X\n",
228  		nxt6000_readreg(fe, OFDM_TPS_RCVD_4));
229  	pr_info("OFDM_TPS_RESERVED_1: 0x%02X\n",
230  		nxt6000_readreg(fe, OFDM_TPS_RESERVED_1));
231  	pr_info("OFDM_TPS_RESERVED_2: 0x%02X\n",
232  		nxt6000_readreg(fe, OFDM_TPS_RESERVED_2));
233  #endif
234  	pr_info("NXT6000 status:");
235  
236  	val = nxt6000_readreg(state, RS_COR_STAT);
237  
238  	pr_cont(" DATA DESCR LOCK: %d,", val & 0x01);
239  	pr_cont(" DATA SYNC LOCK: %d,", (val >> 1) & 0x01);
240  
241  	val = nxt6000_readreg(state, VIT_SYNC_STATUS);
242  
243  	pr_cont(" VITERBI LOCK: %d,", (val >> 7) & 0x01);
244  
245  	switch ((val >> 4) & 0x07) {
246  
247  	case 0x00:
248  		pr_cont(" VITERBI CODERATE: 1/2,");
249  		break;
250  
251  	case 0x01:
252  		pr_cont(" VITERBI CODERATE: 2/3,");
253  		break;
254  
255  	case 0x02:
256  		pr_cont(" VITERBI CODERATE: 3/4,");
257  		break;
258  
259  	case 0x03:
260  		pr_cont(" VITERBI CODERATE: 5/6,");
261  		break;
262  
263  	case 0x04:
264  		pr_cont(" VITERBI CODERATE: 7/8,");
265  		break;
266  
267  	default:
268  		pr_cont(" VITERBI CODERATE: Reserved,");
269  
270  	}
271  
272  	val = nxt6000_readreg(state, OFDM_COR_STAT);
273  
274  	pr_cont(" CHCTrack: %d,", (val >> 7) & 0x01);
275  	pr_cont(" TPSLock: %d,", (val >> 6) & 0x01);
276  	pr_cont(" SYRLock: %d,", (val >> 5) & 0x01);
277  	pr_cont(" AGCLock: %d,", (val >> 4) & 0x01);
278  
279  	switch (val & 0x0F) {
280  
281  	case 0x00:
282  		pr_cont(" CoreState: IDLE,");
283  		break;
284  
285  	case 0x02:
286  		pr_cont(" CoreState: WAIT_AGC,");
287  		break;
288  
289  	case 0x03:
290  		pr_cont(" CoreState: WAIT_SYR,");
291  		break;
292  
293  	case 0x04:
294  		pr_cont(" CoreState: WAIT_PPM,");
295  		break;
296  
297  	case 0x01:
298  		pr_cont(" CoreState: WAIT_TRL,");
299  		break;
300  
301  	case 0x05:
302  		pr_cont(" CoreState: WAIT_TPS,");
303  		break;
304  
305  	case 0x06:
306  		pr_cont(" CoreState: MONITOR_TPS,");
307  		break;
308  
309  	default:
310  		pr_cont(" CoreState: Reserved,");
311  
312  	}
313  
314  	val = nxt6000_readreg(state, OFDM_SYR_STAT);
315  
316  	pr_cont(" SYRLock: %d,", (val >> 4) & 0x01);
317  	pr_cont(" SYRMode: %s,", (val >> 2) & 0x01 ? "8K" : "2K");
318  
319  	switch ((val >> 4) & 0x03) {
320  
321  	case 0x00:
322  		pr_cont(" SYRGuard: 1/32,");
323  		break;
324  
325  	case 0x01:
326  		pr_cont(" SYRGuard: 1/16,");
327  		break;
328  
329  	case 0x02:
330  		pr_cont(" SYRGuard: 1/8,");
331  		break;
332  
333  	case 0x03:
334  		pr_cont(" SYRGuard: 1/4,");
335  		break;
336  	}
337  
338  	val = nxt6000_readreg(state, OFDM_TPS_RCVD_3);
339  
340  	switch ((val >> 4) & 0x07) {
341  
342  	case 0x00:
343  		pr_cont(" TPSLP: 1/2,");
344  		break;
345  
346  	case 0x01:
347  		pr_cont(" TPSLP: 2/3,");
348  		break;
349  
350  	case 0x02:
351  		pr_cont(" TPSLP: 3/4,");
352  		break;
353  
354  	case 0x03:
355  		pr_cont(" TPSLP: 5/6,");
356  		break;
357  
358  	case 0x04:
359  		pr_cont(" TPSLP: 7/8,");
360  		break;
361  
362  	default:
363  		pr_cont(" TPSLP: Reserved,");
364  
365  	}
366  
367  	switch (val & 0x07) {
368  
369  	case 0x00:
370  		pr_cont(" TPSHP: 1/2,");
371  		break;
372  
373  	case 0x01:
374  		pr_cont(" TPSHP: 2/3,");
375  		break;
376  
377  	case 0x02:
378  		pr_cont(" TPSHP: 3/4,");
379  		break;
380  
381  	case 0x03:
382  		pr_cont(" TPSHP: 5/6,");
383  		break;
384  
385  	case 0x04:
386  		pr_cont(" TPSHP: 7/8,");
387  		break;
388  
389  	default:
390  		pr_cont(" TPSHP: Reserved,");
391  
392  	}
393  
394  	val = nxt6000_readreg(state, OFDM_TPS_RCVD_4);
395  
396  	pr_cont(" TPSMode: %s,", val & 0x01 ? "8K" : "2K");
397  
398  	switch ((val >> 4) & 0x03) {
399  
400  	case 0x00:
401  		pr_cont(" TPSGuard: 1/32,");
402  		break;
403  
404  	case 0x01:
405  		pr_cont(" TPSGuard: 1/16,");
406  		break;
407  
408  	case 0x02:
409  		pr_cont(" TPSGuard: 1/8,");
410  		break;
411  
412  	case 0x03:
413  		pr_cont(" TPSGuard: 1/4,");
414  		break;
415  
416  	}
417  
418  	/* Strange magic required to gain access to RF_AGC_STATUS */
419  	nxt6000_readreg(state, RF_AGC_VAL_1);
420  	val = nxt6000_readreg(state, RF_AGC_STATUS);
421  	val = nxt6000_readreg(state, RF_AGC_STATUS);
422  
423  	pr_cont(" RF AGC LOCK: %d,", (val >> 4) & 0x01);
424  	pr_cont("\n");
425  }
426  
427  static int nxt6000_read_status(struct dvb_frontend *fe, enum fe_status *status)
428  {
429  	u8 core_status;
430  	struct nxt6000_state* state = fe->demodulator_priv;
431  
432  	*status = 0;
433  
434  	core_status = nxt6000_readreg(state, OFDM_COR_STAT);
435  
436  	if (core_status & AGCLOCKED)
437  		*status |= FE_HAS_SIGNAL;
438  
439  	if (nxt6000_readreg(state, OFDM_SYR_STAT) & GI14_SYR_LOCK)
440  		*status |= FE_HAS_CARRIER;
441  
442  	if (nxt6000_readreg(state, VIT_SYNC_STATUS) & VITINSYNC)
443  		*status |= FE_HAS_VITERBI;
444  
445  	if (nxt6000_readreg(state, RS_COR_STAT) & RSCORESTATUS)
446  		*status |= FE_HAS_SYNC;
447  
448  	if ((core_status & TPSLOCKED) && (*status == (FE_HAS_SIGNAL | FE_HAS_CARRIER | FE_HAS_VITERBI | FE_HAS_SYNC)))
449  		*status |= FE_HAS_LOCK;
450  
451  	if (debug)
452  		nxt6000_dump_status(state);
453  
454  	return 0;
455  }
456  
457  static int nxt6000_init(struct dvb_frontend* fe)
458  {
459  	struct nxt6000_state* state = fe->demodulator_priv;
460  
461  	nxt6000_reset(state);
462  	nxt6000_setup(fe);
463  
464  	return 0;
465  }
466  
467  static int nxt6000_set_frontend(struct dvb_frontend *fe)
468  {
469  	struct dtv_frontend_properties *p = &fe->dtv_property_cache;
470  	struct nxt6000_state* state = fe->demodulator_priv;
471  	int result;
472  
473  	if (fe->ops.tuner_ops.set_params) {
474  		fe->ops.tuner_ops.set_params(fe);
475  		if (fe->ops.i2c_gate_ctrl) fe->ops.i2c_gate_ctrl(fe, 0);
476  	}
477  
478  	result = nxt6000_set_bandwidth(state, p->bandwidth_hz);
479  	if (result < 0)
480  		return result;
481  
482  	result = nxt6000_set_guard_interval(state, p->guard_interval);
483  	if (result < 0)
484  		return result;
485  
486  	result = nxt6000_set_transmission_mode(state, p->transmission_mode);
487  	if (result < 0)
488  		return result;
489  
490  	result = nxt6000_set_inversion(state, p->inversion);
491  	if (result < 0)
492  		return result;
493  
494  	msleep(500);
495  	return 0;
496  }
497  
498  static void nxt6000_release(struct dvb_frontend* fe)
499  {
500  	struct nxt6000_state* state = fe->demodulator_priv;
501  	kfree(state);
502  }
503  
504  static int nxt6000_read_snr(struct dvb_frontend* fe, u16* snr)
505  {
506  	struct nxt6000_state* state = fe->demodulator_priv;
507  
508  	*snr = nxt6000_readreg( state, OFDM_CHC_SNR) / 8;
509  
510  	return 0;
511  }
512  
513  static int nxt6000_read_ber(struct dvb_frontend* fe, u32* ber)
514  {
515  	struct nxt6000_state* state = fe->demodulator_priv;
516  
517  	nxt6000_writereg( state, VIT_COR_INTSTAT, 0x18 );
518  
519  	*ber = (nxt6000_readreg( state, VIT_BER_1 ) << 8 ) |
520  		nxt6000_readreg( state, VIT_BER_0 );
521  
522  	nxt6000_writereg( state, VIT_COR_INTSTAT, 0x18); // Clear BER Done interrupts
523  
524  	return 0;
525  }
526  
527  static int nxt6000_read_signal_strength(struct dvb_frontend* fe, u16* signal_strength)
528  {
529  	struct nxt6000_state* state = fe->demodulator_priv;
530  
531  	*signal_strength = (short) (511 -
532  		(nxt6000_readreg(state, AGC_GAIN_1) +
533  		((nxt6000_readreg(state, AGC_GAIN_2) & 0x03) << 8)));
534  
535  	return 0;
536  }
537  
538  static int nxt6000_fe_get_tune_settings(struct dvb_frontend* fe, struct dvb_frontend_tune_settings *tune)
539  {
540  	tune->min_delay_ms = 500;
541  	return 0;
542  }
543  
544  static int nxt6000_i2c_gate_ctrl(struct dvb_frontend* fe, int enable)
545  {
546  	struct nxt6000_state* state = fe->demodulator_priv;
547  
548  	if (enable) {
549  		return nxt6000_writereg(state, ENABLE_TUNER_IIC, 0x01);
550  	} else {
551  		return nxt6000_writereg(state, ENABLE_TUNER_IIC, 0x00);
552  	}
553  }
554  
555  static const struct dvb_frontend_ops nxt6000_ops;
556  
557  struct dvb_frontend* nxt6000_attach(const struct nxt6000_config* config,
558  				    struct i2c_adapter* i2c)
559  {
560  	struct nxt6000_state* state = NULL;
561  
562  	/* allocate memory for the internal state */
563  	state = kzalloc(sizeof(struct nxt6000_state), GFP_KERNEL);
564  	if (state == NULL) goto error;
565  
566  	/* setup the state */
567  	state->config = config;
568  	state->i2c = i2c;
569  
570  	/* check if the demod is there */
571  	if (nxt6000_readreg(state, OFDM_MSC_REV) != NXT6000ASICDEVICE) goto error;
572  
573  	/* create dvb_frontend */
574  	memcpy(&state->frontend.ops, &nxt6000_ops, sizeof(struct dvb_frontend_ops));
575  	state->frontend.demodulator_priv = state;
576  	return &state->frontend;
577  
578  error:
579  	kfree(state);
580  	return NULL;
581  }
582  
583  static const struct dvb_frontend_ops nxt6000_ops = {
584  	.delsys = { SYS_DVBT },
585  	.info = {
586  		.name = "NxtWave NXT6000 DVB-T",
587  		.frequency_min_hz = 0,
588  		.frequency_max_hz = 863250 * kHz,
589  		.frequency_stepsize_hz = 62500,
590  		/*.frequency_tolerance = *//* FIXME: 12% of SR */
591  		.symbol_rate_min = 0,	/* FIXME */
592  		.symbol_rate_max = 9360000,	/* FIXME */
593  		.symbol_rate_tolerance = 4000,
594  		.caps = FE_CAN_FEC_1_2 | FE_CAN_FEC_2_3 | FE_CAN_FEC_3_4 |
595  			FE_CAN_FEC_4_5 | FE_CAN_FEC_5_6 | FE_CAN_FEC_6_7 |
596  			FE_CAN_FEC_7_8 | FE_CAN_FEC_8_9 | FE_CAN_FEC_AUTO |
597  			FE_CAN_QAM_16 | FE_CAN_QAM_64 | FE_CAN_QAM_AUTO |
598  			FE_CAN_TRANSMISSION_MODE_AUTO | FE_CAN_GUARD_INTERVAL_AUTO |
599  			FE_CAN_HIERARCHY_AUTO,
600  	},
601  
602  	.release = nxt6000_release,
603  
604  	.init = nxt6000_init,
605  	.i2c_gate_ctrl = nxt6000_i2c_gate_ctrl,
606  
607  	.get_tune_settings = nxt6000_fe_get_tune_settings,
608  
609  	.set_frontend = nxt6000_set_frontend,
610  
611  	.read_status = nxt6000_read_status,
612  	.read_ber = nxt6000_read_ber,
613  	.read_signal_strength = nxt6000_read_signal_strength,
614  	.read_snr = nxt6000_read_snr,
615  };
616  
617  module_param(debug, int, 0644);
618  MODULE_PARM_DESC(debug, "Turn on/off frontend debugging (default:off).");
619  
620  MODULE_DESCRIPTION("NxtWave NXT6000 DVB-T demodulator driver");
621  MODULE_AUTHOR("Florian Schirmer");
622  MODULE_LICENSE("GPL");
623  
624  EXPORT_SYMBOL(nxt6000_attach);
625