1 /*
2  *  drivers/media/radio/si470x/radio-si470x-common.c
3  *
4  *  Driver for radios with Silicon Labs Si470x FM Radio Receivers
5  *
6  *  Copyright (c) 2009 Tobias Lorenz <tobias.lorenz@gmx.net>
7  *  Copyright (c) 2012 Hans de Goede <hdegoede@redhat.com>
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License as published by
11  * the Free Software Foundation; either version 2 of the License, or
12  * (at your option) any later version.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  * GNU General Public License for more details.
18  */
19 
20 
21 /*
22  * History:
23  * 2008-01-12	Tobias Lorenz <tobias.lorenz@gmx.net>
24  *		Version 1.0.0
25  *		- First working version
26  * 2008-01-13	Tobias Lorenz <tobias.lorenz@gmx.net>
27  *		Version 1.0.1
28  *		- Improved error handling, every function now returns errno
29  *		- Improved multi user access (start/mute/stop)
30  *		- Channel doesn't get lost anymore after start/mute/stop
31  *		- RDS support added (polling mode via interrupt EP 1)
32  *		- marked default module parameters with *value*
33  *		- switched from bit structs to bit masks
34  *		- header file cleaned and integrated
35  * 2008-01-14	Tobias Lorenz <tobias.lorenz@gmx.net>
36  * 		Version 1.0.2
37  * 		- hex values are now lower case
38  * 		- commented USB ID for ADS/Tech moved on todo list
39  * 		- blacklisted si470x in hid-quirks.c
40  * 		- rds buffer handling functions integrated into *_work, *_read
41  * 		- rds_command in si470x_poll exchanged against simple retval
42  * 		- check for firmware version 15
43  * 		- code order and prototypes still remain the same
44  * 		- spacing and bottom of band codes remain the same
45  * 2008-01-16	Tobias Lorenz <tobias.lorenz@gmx.net>
46  *		Version 1.0.3
47  * 		- code reordered to avoid function prototypes
48  *		- switch/case defaults are now more user-friendly
49  *		- unified comment style
50  *		- applied all checkpatch.pl v1.12 suggestions
51  *		  except the warning about the too long lines with bit comments
52  *		- renamed FMRADIO to RADIO to cut line length (checkpatch.pl)
53  * 2008-01-22	Tobias Lorenz <tobias.lorenz@gmx.net>
54  *		Version 1.0.4
55  *		- avoid poss. locking when doing copy_to_user which may sleep
56  *		- RDS is automatically activated on read now
57  *		- code cleaned of unnecessary rds_commands
58  *		- USB Vendor/Product ID for ADS/Tech FM Radio Receiver verified
59  *		  (thanks to Guillaume RAMOUSSE)
60  * 2008-01-27	Tobias Lorenz <tobias.lorenz@gmx.net>
61  *		Version 1.0.5
62  *		- number of seek_retries changed to tune_timeout
63  *		- fixed problem with incomplete tune operations by own buffers
64  *		- optimization of variables and printf types
65  *		- improved error logging
66  * 2008-01-31	Tobias Lorenz <tobias.lorenz@gmx.net>
67  *		Oliver Neukum <oliver@neukum.org>
68  *		Version 1.0.6
69  *		- fixed coverity checker warnings in *_usb_driver_disconnect
70  *		- probe()/open() race by correct ordering in probe()
71  *		- DMA coherency rules by separate allocation of all buffers
72  *		- use of endianness macros
73  *		- abuse of spinlock, replaced by mutex
74  *		- racy handling of timer in disconnect,
75  *		  replaced by delayed_work
76  *		- racy interruptible_sleep_on(),
77  *		  replaced with wait_event_interruptible()
78  *		- handle signals in read()
79  * 2008-02-08	Tobias Lorenz <tobias.lorenz@gmx.net>
80  *		Oliver Neukum <oliver@neukum.org>
81  *		Version 1.0.7
82  *		- usb autosuspend support
83  *		- unplugging fixed
84  * 2008-05-07	Tobias Lorenz <tobias.lorenz@gmx.net>
85  *		Version 1.0.8
86  *		- hardware frequency seek support
87  *		- afc indication
88  *		- more safety checks, let si470x_get_freq return errno
89  *		- vidioc behavior corrected according to v4l2 spec
90  * 2008-10-20	Alexey Klimov <klimov.linux@gmail.com>
91  * 		- add support for KWorld USB FM Radio FM700
92  * 		- blacklisted KWorld radio in hid-core.c and hid-ids.h
93  * 2008-12-03	Mark Lord <mlord@pobox.com>
94  *		- add support for DealExtreme USB Radio
95  * 2009-01-31	Bob Ross <pigiron@gmx.com>
96  *		- correction of stereo detection/setting
97  *		- correction of signal strength indicator scaling
98  * 2009-01-31	Rick Bronson <rick@efn.org>
99  *		Tobias Lorenz <tobias.lorenz@gmx.net>
100  *		- add LED status output
101  *		- get HW/SW version from scratchpad
102  * 2009-06-16   Edouard Lafargue <edouard@lafargue.name>
103  *		Version 1.0.10
104  *		- add support for interrupt mode for RDS endpoint,
105  *                instead of polling.
106  *                Improves RDS reception significantly
107  */
108 
109 
110 /* kernel includes */
111 #include "radio-si470x.h"
112 
113 
114 
115 /**************************************************************************
116  * Module Parameters
117  **************************************************************************/
118 
119 /* Spacing (kHz) */
120 /* 0: 200 kHz (USA, Australia) */
121 /* 1: 100 kHz (Europe, Japan) */
122 /* 2:  50 kHz */
123 static unsigned short space = 2;
124 module_param(space, ushort, 0444);
125 MODULE_PARM_DESC(space, "Spacing: 0=200kHz 1=100kHz *2=50kHz*");
126 
127 /* De-emphasis */
128 /* 0: 75 us (USA) */
129 /* 1: 50 us (Europe, Australia, Japan) */
130 static unsigned short de = 1;
131 module_param(de, ushort, 0444);
132 MODULE_PARM_DESC(de, "De-emphasis: 0=75us *1=50us*");
133 
134 /* Tune timeout */
135 static unsigned int tune_timeout = 3000;
136 module_param(tune_timeout, uint, 0644);
137 MODULE_PARM_DESC(tune_timeout, "Tune timeout: *3000*");
138 
139 /* Seek timeout */
140 static unsigned int seek_timeout = 5000;
141 module_param(seek_timeout, uint, 0644);
142 MODULE_PARM_DESC(seek_timeout, "Seek timeout: *5000*");
143 
144 static const struct v4l2_frequency_band bands[] = {
145 	{
146 		.type = V4L2_TUNER_RADIO,
147 		.index = 0,
148 		.capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO |
149 			    V4L2_TUNER_CAP_RDS | V4L2_TUNER_CAP_RDS_BLOCK_IO |
150 			    V4L2_TUNER_CAP_FREQ_BANDS |
151 			    V4L2_TUNER_CAP_HWSEEK_BOUNDED |
152 			    V4L2_TUNER_CAP_HWSEEK_WRAP,
153 		.rangelow   =  87500 * 16,
154 		.rangehigh  = 108000 * 16,
155 		.modulation = V4L2_BAND_MODULATION_FM,
156 	},
157 	{
158 		.type = V4L2_TUNER_RADIO,
159 		.index = 1,
160 		.capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO |
161 			    V4L2_TUNER_CAP_RDS | V4L2_TUNER_CAP_RDS_BLOCK_IO |
162 			    V4L2_TUNER_CAP_FREQ_BANDS |
163 			    V4L2_TUNER_CAP_HWSEEK_BOUNDED |
164 			    V4L2_TUNER_CAP_HWSEEK_WRAP,
165 		.rangelow   =  76000 * 16,
166 		.rangehigh  = 108000 * 16,
167 		.modulation = V4L2_BAND_MODULATION_FM,
168 	},
169 	{
170 		.type = V4L2_TUNER_RADIO,
171 		.index = 2,
172 		.capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO |
173 			    V4L2_TUNER_CAP_RDS | V4L2_TUNER_CAP_RDS_BLOCK_IO |
174 			    V4L2_TUNER_CAP_FREQ_BANDS |
175 			    V4L2_TUNER_CAP_HWSEEK_BOUNDED |
176 			    V4L2_TUNER_CAP_HWSEEK_WRAP,
177 		.rangelow   =  76000 * 16,
178 		.rangehigh  =  90000 * 16,
179 		.modulation = V4L2_BAND_MODULATION_FM,
180 	},
181 };
182 
183 /**************************************************************************
184  * Generic Functions
185  **************************************************************************/
186 
187 /*
188  * si470x_set_band - set the band
189  */
190 static int si470x_set_band(struct si470x_device *radio, int band)
191 {
192 	if (radio->band == band)
193 		return 0;
194 
195 	radio->band = band;
196 	radio->registers[SYSCONFIG2] &= ~SYSCONFIG2_BAND;
197 	radio->registers[SYSCONFIG2] |= radio->band << 6;
198 	return si470x_set_register(radio, SYSCONFIG2);
199 }
200 
201 /*
202  * si470x_set_chan - set the channel
203  */
204 static int si470x_set_chan(struct si470x_device *radio, unsigned short chan)
205 {
206 	int retval;
207 	unsigned long time_left;
208 	bool timed_out = false;
209 
210 	/* start tuning */
211 	radio->registers[CHANNEL] &= ~CHANNEL_CHAN;
212 	radio->registers[CHANNEL] |= CHANNEL_TUNE | chan;
213 	retval = si470x_set_register(radio, CHANNEL);
214 	if (retval < 0)
215 		goto done;
216 
217 	/* wait till tune operation has completed */
218 	reinit_completion(&radio->completion);
219 	time_left = wait_for_completion_timeout(&radio->completion,
220 						msecs_to_jiffies(tune_timeout));
221 	if (time_left == 0)
222 		timed_out = true;
223 
224 	if ((radio->registers[STATUSRSSI] & STATUSRSSI_STC) == 0)
225 		dev_warn(&radio->videodev.dev, "tune does not complete\n");
226 	if (timed_out)
227 		dev_warn(&radio->videodev.dev,
228 			"tune timed out after %u ms\n", tune_timeout);
229 
230 	/* stop tuning */
231 	radio->registers[CHANNEL] &= ~CHANNEL_TUNE;
232 	retval = si470x_set_register(radio, CHANNEL);
233 
234 done:
235 	return retval;
236 }
237 
238 /*
239  * si470x_get_step - get channel spacing
240  */
241 static unsigned int si470x_get_step(struct si470x_device *radio)
242 {
243 	/* Spacing (kHz) */
244 	switch ((radio->registers[SYSCONFIG2] & SYSCONFIG2_SPACE) >> 4) {
245 	/* 0: 200 kHz (USA, Australia) */
246 	case 0:
247 		return 200 * 16;
248 	/* 1: 100 kHz (Europe, Japan) */
249 	case 1:
250 		return 100 * 16;
251 	/* 2:  50 kHz */
252 	default:
253 		return 50 * 16;
254 	}
255 }
256 
257 
258 /*
259  * si470x_get_freq - get the frequency
260  */
261 static int si470x_get_freq(struct si470x_device *radio, unsigned int *freq)
262 {
263 	int chan, retval;
264 
265 	/* read channel */
266 	retval = si470x_get_register(radio, READCHAN);
267 	chan = radio->registers[READCHAN] & READCHAN_READCHAN;
268 
269 	/* Frequency (MHz) = Spacing (kHz) x Channel + Bottom of Band (MHz) */
270 	*freq = chan * si470x_get_step(radio) + bands[radio->band].rangelow;
271 
272 	return retval;
273 }
274 
275 
276 /*
277  * si470x_set_freq - set the frequency
278  */
279 int si470x_set_freq(struct si470x_device *radio, unsigned int freq)
280 {
281 	unsigned short chan;
282 
283 	freq = clamp(freq, bands[radio->band].rangelow,
284 			   bands[radio->band].rangehigh);
285 	/* Chan = [ Freq (Mhz) - Bottom of Band (MHz) ] / Spacing (kHz) */
286 	chan = (freq - bands[radio->band].rangelow) / si470x_get_step(radio);
287 
288 	return si470x_set_chan(radio, chan);
289 }
290 
291 
292 /*
293  * si470x_set_seek - set seek
294  */
295 static int si470x_set_seek(struct si470x_device *radio,
296 			   const struct v4l2_hw_freq_seek *seek)
297 {
298 	int band, retval;
299 	unsigned int freq;
300 	bool timed_out = false;
301 	unsigned long time_left;
302 
303 	/* set band */
304 	if (seek->rangelow || seek->rangehigh) {
305 		for (band = 0; band < ARRAY_SIZE(bands); band++) {
306 			if (bands[band].rangelow  == seek->rangelow &&
307 			    bands[band].rangehigh == seek->rangehigh)
308 				break;
309 		}
310 		if (band == ARRAY_SIZE(bands))
311 			return -EINVAL; /* No matching band found */
312 	} else
313 		band = 1; /* If nothing is specified seek 76 - 108 Mhz */
314 
315 	if (radio->band != band) {
316 		retval = si470x_get_freq(radio, &freq);
317 		if (retval)
318 			return retval;
319 		retval = si470x_set_band(radio, band);
320 		if (retval)
321 			return retval;
322 		retval = si470x_set_freq(radio, freq);
323 		if (retval)
324 			return retval;
325 	}
326 
327 	/* start seeking */
328 	radio->registers[POWERCFG] |= POWERCFG_SEEK;
329 	if (seek->wrap_around)
330 		radio->registers[POWERCFG] &= ~POWERCFG_SKMODE;
331 	else
332 		radio->registers[POWERCFG] |= POWERCFG_SKMODE;
333 	if (seek->seek_upward)
334 		radio->registers[POWERCFG] |= POWERCFG_SEEKUP;
335 	else
336 		radio->registers[POWERCFG] &= ~POWERCFG_SEEKUP;
337 	retval = si470x_set_register(radio, POWERCFG);
338 	if (retval < 0)
339 		return retval;
340 
341 	/* wait till tune operation has completed */
342 	reinit_completion(&radio->completion);
343 	time_left = wait_for_completion_timeout(&radio->completion,
344 						msecs_to_jiffies(seek_timeout));
345 	if (time_left == 0)
346 		timed_out = true;
347 
348 	if ((radio->registers[STATUSRSSI] & STATUSRSSI_STC) == 0)
349 		dev_warn(&radio->videodev.dev, "seek does not complete\n");
350 	if (radio->registers[STATUSRSSI] & STATUSRSSI_SF)
351 		dev_warn(&radio->videodev.dev,
352 			"seek failed / band limit reached\n");
353 
354 	/* stop seeking */
355 	radio->registers[POWERCFG] &= ~POWERCFG_SEEK;
356 	retval = si470x_set_register(radio, POWERCFG);
357 
358 	/* try again, if timed out */
359 	if (retval == 0 && timed_out)
360 		return -ENODATA;
361 	return retval;
362 }
363 
364 
365 /*
366  * si470x_start - switch on radio
367  */
368 int si470x_start(struct si470x_device *radio)
369 {
370 	int retval;
371 
372 	/* powercfg */
373 	radio->registers[POWERCFG] =
374 		POWERCFG_DMUTE | POWERCFG_ENABLE | POWERCFG_RDSM;
375 	retval = si470x_set_register(radio, POWERCFG);
376 	if (retval < 0)
377 		goto done;
378 
379 	/* sysconfig 1 */
380 	radio->registers[SYSCONFIG1] =
381 		(de << 11) & SYSCONFIG1_DE;		/* DE*/
382 	retval = si470x_set_register(radio, SYSCONFIG1);
383 	if (retval < 0)
384 		goto done;
385 
386 	/* sysconfig 2 */
387 	radio->registers[SYSCONFIG2] =
388 		(0x1f  << 8) |				/* SEEKTH */
389 		((radio->band << 6) & SYSCONFIG2_BAND) |/* BAND */
390 		((space << 4) & SYSCONFIG2_SPACE) |	/* SPACE */
391 		15;					/* VOLUME (max) */
392 	retval = si470x_set_register(radio, SYSCONFIG2);
393 	if (retval < 0)
394 		goto done;
395 
396 	/* reset last channel */
397 	retval = si470x_set_chan(radio,
398 		radio->registers[CHANNEL] & CHANNEL_CHAN);
399 
400 done:
401 	return retval;
402 }
403 
404 
405 /*
406  * si470x_stop - switch off radio
407  */
408 int si470x_stop(struct si470x_device *radio)
409 {
410 	int retval;
411 
412 	/* sysconfig 1 */
413 	radio->registers[SYSCONFIG1] &= ~SYSCONFIG1_RDS;
414 	retval = si470x_set_register(radio, SYSCONFIG1);
415 	if (retval < 0)
416 		goto done;
417 
418 	/* powercfg */
419 	radio->registers[POWERCFG] &= ~POWERCFG_DMUTE;
420 	/* POWERCFG_ENABLE has to automatically go low */
421 	radio->registers[POWERCFG] |= POWERCFG_ENABLE |	POWERCFG_DISABLE;
422 	retval = si470x_set_register(radio, POWERCFG);
423 
424 done:
425 	return retval;
426 }
427 
428 
429 /*
430  * si470x_rds_on - switch on rds reception
431  */
432 static int si470x_rds_on(struct si470x_device *radio)
433 {
434 	int retval;
435 
436 	/* sysconfig 1 */
437 	radio->registers[SYSCONFIG1] |= SYSCONFIG1_RDS;
438 	retval = si470x_set_register(radio, SYSCONFIG1);
439 	if (retval < 0)
440 		radio->registers[SYSCONFIG1] &= ~SYSCONFIG1_RDS;
441 
442 	return retval;
443 }
444 
445 
446 
447 /**************************************************************************
448  * File Operations Interface
449  **************************************************************************/
450 
451 /*
452  * si470x_fops_read - read RDS data
453  */
454 static ssize_t si470x_fops_read(struct file *file, char __user *buf,
455 		size_t count, loff_t *ppos)
456 {
457 	struct si470x_device *radio = video_drvdata(file);
458 	int retval = 0;
459 	unsigned int block_count = 0;
460 
461 	/* switch on rds reception */
462 	if ((radio->registers[SYSCONFIG1] & SYSCONFIG1_RDS) == 0)
463 		si470x_rds_on(radio);
464 
465 	/* block if no new data available */
466 	while (radio->wr_index == radio->rd_index) {
467 		if (file->f_flags & O_NONBLOCK) {
468 			retval = -EWOULDBLOCK;
469 			goto done;
470 		}
471 		if (wait_event_interruptible(radio->read_queue,
472 			radio->wr_index != radio->rd_index) < 0) {
473 			retval = -EINTR;
474 			goto done;
475 		}
476 	}
477 
478 	/* calculate block count from byte count */
479 	count /= 3;
480 
481 	/* copy RDS block out of internal buffer and to user buffer */
482 	while (block_count < count) {
483 		if (radio->rd_index == radio->wr_index)
484 			break;
485 
486 		/* always transfer rds complete blocks */
487 		if (copy_to_user(buf, &radio->buffer[radio->rd_index], 3))
488 			/* retval = -EFAULT; */
489 			break;
490 
491 		/* increment and wrap read pointer */
492 		radio->rd_index += 3;
493 		if (radio->rd_index >= radio->buf_size)
494 			radio->rd_index = 0;
495 
496 		/* increment counters */
497 		block_count++;
498 		buf += 3;
499 		retval += 3;
500 	}
501 
502 done:
503 	return retval;
504 }
505 
506 
507 /*
508  * si470x_fops_poll - poll RDS data
509  */
510 static unsigned int si470x_fops_poll(struct file *file,
511 		struct poll_table_struct *pts)
512 {
513 	struct si470x_device *radio = video_drvdata(file);
514 	unsigned long req_events = poll_requested_events(pts);
515 	int retval = v4l2_ctrl_poll(file, pts);
516 
517 	if (req_events & (POLLIN | POLLRDNORM)) {
518 		/* switch on rds reception */
519 		if ((radio->registers[SYSCONFIG1] & SYSCONFIG1_RDS) == 0)
520 			si470x_rds_on(radio);
521 
522 		poll_wait(file, &radio->read_queue, pts);
523 
524 		if (radio->rd_index != radio->wr_index)
525 			retval |= POLLIN | POLLRDNORM;
526 	}
527 
528 	return retval;
529 }
530 
531 
532 /*
533  * si470x_fops - file operations interface
534  */
535 static const struct v4l2_file_operations si470x_fops = {
536 	.owner			= THIS_MODULE,
537 	.read			= si470x_fops_read,
538 	.poll			= si470x_fops_poll,
539 	.unlocked_ioctl		= video_ioctl2,
540 	.open			= si470x_fops_open,
541 	.release		= si470x_fops_release,
542 };
543 
544 
545 
546 /**************************************************************************
547  * Video4Linux Interface
548  **************************************************************************/
549 
550 
551 static int si470x_s_ctrl(struct v4l2_ctrl *ctrl)
552 {
553 	struct si470x_device *radio =
554 		container_of(ctrl->handler, struct si470x_device, hdl);
555 
556 	switch (ctrl->id) {
557 	case V4L2_CID_AUDIO_VOLUME:
558 		radio->registers[SYSCONFIG2] &= ~SYSCONFIG2_VOLUME;
559 		radio->registers[SYSCONFIG2] |= ctrl->val;
560 		return si470x_set_register(radio, SYSCONFIG2);
561 	case V4L2_CID_AUDIO_MUTE:
562 		if (ctrl->val)
563 			radio->registers[POWERCFG] &= ~POWERCFG_DMUTE;
564 		else
565 			radio->registers[POWERCFG] |= POWERCFG_DMUTE;
566 		return si470x_set_register(radio, POWERCFG);
567 	default:
568 		return -EINVAL;
569 	}
570 }
571 
572 
573 /*
574  * si470x_vidioc_g_tuner - get tuner attributes
575  */
576 static int si470x_vidioc_g_tuner(struct file *file, void *priv,
577 		struct v4l2_tuner *tuner)
578 {
579 	struct si470x_device *radio = video_drvdata(file);
580 	int retval = 0;
581 
582 	if (tuner->index != 0)
583 		return -EINVAL;
584 
585 	if (!radio->status_rssi_auto_update) {
586 		retval = si470x_get_register(radio, STATUSRSSI);
587 		if (retval < 0)
588 			return retval;
589 	}
590 
591 	/* driver constants */
592 	strcpy(tuner->name, "FM");
593 	tuner->type = V4L2_TUNER_RADIO;
594 	tuner->capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO |
595 			    V4L2_TUNER_CAP_RDS | V4L2_TUNER_CAP_RDS_BLOCK_IO |
596 			    V4L2_TUNER_CAP_HWSEEK_BOUNDED |
597 			    V4L2_TUNER_CAP_HWSEEK_WRAP;
598 	tuner->rangelow  =  76 * FREQ_MUL;
599 	tuner->rangehigh = 108 * FREQ_MUL;
600 
601 	/* stereo indicator == stereo (instead of mono) */
602 	if ((radio->registers[STATUSRSSI] & STATUSRSSI_ST) == 0)
603 		tuner->rxsubchans = V4L2_TUNER_SUB_MONO;
604 	else
605 		tuner->rxsubchans = V4L2_TUNER_SUB_STEREO;
606 	/* If there is a reliable method of detecting an RDS channel,
607 	   then this code should check for that before setting this
608 	   RDS subchannel. */
609 	tuner->rxsubchans |= V4L2_TUNER_SUB_RDS;
610 
611 	/* mono/stereo selector */
612 	if ((radio->registers[POWERCFG] & POWERCFG_MONO) == 0)
613 		tuner->audmode = V4L2_TUNER_MODE_STEREO;
614 	else
615 		tuner->audmode = V4L2_TUNER_MODE_MONO;
616 
617 	/* min is worst, max is best; signal:0..0xffff; rssi: 0..0xff */
618 	/* measured in units of dbµV in 1 db increments (max at ~75 dbµV) */
619 	tuner->signal = (radio->registers[STATUSRSSI] & STATUSRSSI_RSSI);
620 	/* the ideal factor is 0xffff/75 = 873,8 */
621 	tuner->signal = (tuner->signal * 873) + (8 * tuner->signal / 10);
622 	if (tuner->signal > 0xffff)
623 		tuner->signal = 0xffff;
624 
625 	/* automatic frequency control: -1: freq to low, 1 freq to high */
626 	/* AFCRL does only indicate that freq. differs, not if too low/high */
627 	tuner->afc = (radio->registers[STATUSRSSI] & STATUSRSSI_AFCRL) ? 1 : 0;
628 
629 	return retval;
630 }
631 
632 
633 /*
634  * si470x_vidioc_s_tuner - set tuner attributes
635  */
636 static int si470x_vidioc_s_tuner(struct file *file, void *priv,
637 		const struct v4l2_tuner *tuner)
638 {
639 	struct si470x_device *radio = video_drvdata(file);
640 
641 	if (tuner->index != 0)
642 		return -EINVAL;
643 
644 	/* mono/stereo selector */
645 	switch (tuner->audmode) {
646 	case V4L2_TUNER_MODE_MONO:
647 		radio->registers[POWERCFG] |= POWERCFG_MONO;  /* force mono */
648 		break;
649 	case V4L2_TUNER_MODE_STEREO:
650 	default:
651 		radio->registers[POWERCFG] &= ~POWERCFG_MONO; /* try stereo */
652 		break;
653 	}
654 
655 	return si470x_set_register(radio, POWERCFG);
656 }
657 
658 
659 /*
660  * si470x_vidioc_g_frequency - get tuner or modulator radio frequency
661  */
662 static int si470x_vidioc_g_frequency(struct file *file, void *priv,
663 		struct v4l2_frequency *freq)
664 {
665 	struct si470x_device *radio = video_drvdata(file);
666 
667 	if (freq->tuner != 0)
668 		return -EINVAL;
669 
670 	freq->type = V4L2_TUNER_RADIO;
671 	return si470x_get_freq(radio, &freq->frequency);
672 }
673 
674 
675 /*
676  * si470x_vidioc_s_frequency - set tuner or modulator radio frequency
677  */
678 static int si470x_vidioc_s_frequency(struct file *file, void *priv,
679 		const struct v4l2_frequency *freq)
680 {
681 	struct si470x_device *radio = video_drvdata(file);
682 	int retval;
683 
684 	if (freq->tuner != 0)
685 		return -EINVAL;
686 
687 	if (freq->frequency < bands[radio->band].rangelow ||
688 	    freq->frequency > bands[radio->band].rangehigh) {
689 		/* Switch to band 1 which covers everything we support */
690 		retval = si470x_set_band(radio, 1);
691 		if (retval)
692 			return retval;
693 	}
694 	return si470x_set_freq(radio, freq->frequency);
695 }
696 
697 
698 /*
699  * si470x_vidioc_s_hw_freq_seek - set hardware frequency seek
700  */
701 static int si470x_vidioc_s_hw_freq_seek(struct file *file, void *priv,
702 		const struct v4l2_hw_freq_seek *seek)
703 {
704 	struct si470x_device *radio = video_drvdata(file);
705 
706 	if (seek->tuner != 0)
707 		return -EINVAL;
708 
709 	if (file->f_flags & O_NONBLOCK)
710 		return -EWOULDBLOCK;
711 
712 	return si470x_set_seek(radio, seek);
713 }
714 
715 /*
716  * si470x_vidioc_enum_freq_bands - enumerate supported bands
717  */
718 static int si470x_vidioc_enum_freq_bands(struct file *file, void *priv,
719 					 struct v4l2_frequency_band *band)
720 {
721 	if (band->tuner != 0)
722 		return -EINVAL;
723 	if (band->index >= ARRAY_SIZE(bands))
724 		return -EINVAL;
725 	*band = bands[band->index];
726 	return 0;
727 }
728 
729 const struct v4l2_ctrl_ops si470x_ctrl_ops = {
730 	.s_ctrl = si470x_s_ctrl,
731 };
732 
733 /*
734  * si470x_ioctl_ops - video device ioctl operations
735  */
736 static const struct v4l2_ioctl_ops si470x_ioctl_ops = {
737 	.vidioc_querycap	= si470x_vidioc_querycap,
738 	.vidioc_g_tuner		= si470x_vidioc_g_tuner,
739 	.vidioc_s_tuner		= si470x_vidioc_s_tuner,
740 	.vidioc_g_frequency	= si470x_vidioc_g_frequency,
741 	.vidioc_s_frequency	= si470x_vidioc_s_frequency,
742 	.vidioc_s_hw_freq_seek	= si470x_vidioc_s_hw_freq_seek,
743 	.vidioc_enum_freq_bands = si470x_vidioc_enum_freq_bands,
744 	.vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
745 	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
746 };
747 
748 
749 /*
750  * si470x_viddev_template - video device interface
751  */
752 struct video_device si470x_viddev_template = {
753 	.fops			= &si470x_fops,
754 	.name			= DRIVER_NAME,
755 	.release		= video_device_release_empty,
756 	.ioctl_ops		= &si470x_ioctl_ops,
757 };
758