xref: /linux/drivers/media/usb/em28xx/em28xx-audio.c (revision 93df8a1ed6231727c5db94a80b1a6bd5ee67cec3)
1 /*
2  *  Empiatech em28x1 audio extension
3  *
4  *  Copyright (C) 2006 Markus Rechberger <mrechberger@gmail.com>
5  *
6  *  Copyright (C) 2007-2014 Mauro Carvalho Chehab
7  *	- Port to work with the in-kernel driver
8  *	- Cleanups, fixes, alsa-controls, etc.
9  *
10  *  This driver is based on my previous au600 usb pstn audio driver
11  *  and inherits all the copyrights
12  *
13  *  This program is free software; you can redistribute it and/or modify
14  *  it under the terms of the GNU General Public License as published by
15  *  the Free Software Foundation; either version 2 of the License, or
16  *  (at your option) any later version.
17  *
18  *  This program is distributed in the hope that it will be useful,
19  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
20  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
21  *  GNU General Public License for more details.
22  *
23  *  You should have received a copy of the GNU General Public License
24  *  along with this program; if not, write to the Free Software
25  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
26  */
27 
28 #include <linux/kernel.h>
29 #include <linux/usb.h>
30 #include <linux/init.h>
31 #include <linux/sound.h>
32 #include <linux/spinlock.h>
33 #include <linux/soundcard.h>
34 #include <linux/slab.h>
35 #include <linux/vmalloc.h>
36 #include <linux/proc_fs.h>
37 #include <linux/module.h>
38 #include <sound/core.h>
39 #include <sound/pcm.h>
40 #include <sound/pcm_params.h>
41 #include <sound/info.h>
42 #include <sound/initval.h>
43 #include <sound/control.h>
44 #include <sound/tlv.h>
45 #include <sound/ac97_codec.h>
46 #include <media/v4l2-common.h>
47 #include "em28xx.h"
48 
49 static int debug;
50 module_param(debug, int, 0644);
51 MODULE_PARM_DESC(debug, "activates debug info");
52 
53 #define EM28XX_MAX_AUDIO_BUFS		5
54 #define EM28XX_MIN_AUDIO_PACKETS	64
55 
56 #define dprintk(fmt, arg...) do {					\
57 	    if (debug)							\
58 		printk(KERN_INFO "em28xx-audio %s: " fmt,		\
59 				  __func__, ##arg);		\
60 	} while (0)
61 
62 static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;
63 
64 static int em28xx_deinit_isoc_audio(struct em28xx *dev)
65 {
66 	int i;
67 
68 	dprintk("Stopping isoc\n");
69 	for (i = 0; i < dev->adev.num_urb; i++) {
70 		struct urb *urb = dev->adev.urb[i];
71 
72 		if (!irqs_disabled())
73 			usb_kill_urb(urb);
74 		else
75 			usb_unlink_urb(urb);
76 	}
77 
78 	return 0;
79 }
80 
81 static void em28xx_audio_isocirq(struct urb *urb)
82 {
83 	struct em28xx            *dev = urb->context;
84 	int                      i;
85 	unsigned int             oldptr;
86 	int                      period_elapsed = 0;
87 	int                      status;
88 	unsigned char            *cp;
89 	unsigned int             stride;
90 	struct snd_pcm_substream *substream;
91 	struct snd_pcm_runtime   *runtime;
92 
93 	if (dev->disconnected) {
94 		dprintk("device disconnected while streaming. URB status=%d.\n", urb->status);
95 		atomic_set(&dev->adev.stream_started, 0);
96 		return;
97 	}
98 
99 	switch (urb->status) {
100 	case 0:             /* success */
101 	case -ETIMEDOUT:    /* NAK */
102 		break;
103 	case -ECONNRESET:   /* kill */
104 	case -ENOENT:
105 	case -ESHUTDOWN:
106 		return;
107 	default:            /* error */
108 		dprintk("urb completition error %d.\n", urb->status);
109 		break;
110 	}
111 
112 	if (atomic_read(&dev->adev.stream_started) == 0)
113 		return;
114 
115 	if (dev->adev.capture_pcm_substream) {
116 		substream = dev->adev.capture_pcm_substream;
117 		runtime = substream->runtime;
118 		stride = runtime->frame_bits >> 3;
119 
120 		for (i = 0; i < urb->number_of_packets; i++) {
121 			int length =
122 			    urb->iso_frame_desc[i].actual_length / stride;
123 			cp = (unsigned char *)urb->transfer_buffer +
124 			    urb->iso_frame_desc[i].offset;
125 
126 			if (!length)
127 				continue;
128 
129 			oldptr = dev->adev.hwptr_done_capture;
130 			if (oldptr + length >= runtime->buffer_size) {
131 				unsigned int cnt =
132 				    runtime->buffer_size - oldptr;
133 				memcpy(runtime->dma_area + oldptr * stride, cp,
134 				       cnt * stride);
135 				memcpy(runtime->dma_area, cp + cnt * stride,
136 				       length * stride - cnt * stride);
137 			} else {
138 				memcpy(runtime->dma_area + oldptr * stride, cp,
139 				       length * stride);
140 			}
141 
142 			snd_pcm_stream_lock(substream);
143 
144 			dev->adev.hwptr_done_capture += length;
145 			if (dev->adev.hwptr_done_capture >=
146 			    runtime->buffer_size)
147 				dev->adev.hwptr_done_capture -=
148 				    runtime->buffer_size;
149 
150 			dev->adev.capture_transfer_done += length;
151 			if (dev->adev.capture_transfer_done >=
152 			    runtime->period_size) {
153 				dev->adev.capture_transfer_done -=
154 				    runtime->period_size;
155 				period_elapsed = 1;
156 			}
157 
158 			snd_pcm_stream_unlock(substream);
159 		}
160 		if (period_elapsed)
161 			snd_pcm_period_elapsed(substream);
162 	}
163 	urb->status = 0;
164 
165 	status = usb_submit_urb(urb, GFP_ATOMIC);
166 	if (status < 0)
167 		em28xx_errdev("resubmit of audio urb failed (error=%i)\n",
168 			      status);
169 	return;
170 }
171 
172 static int em28xx_init_audio_isoc(struct em28xx *dev)
173 {
174 	int       i, errCode;
175 
176 	dprintk("Starting isoc transfers\n");
177 
178 	/* Start streaming */
179 	for (i = 0; i < dev->adev.num_urb; i++) {
180 		memset(dev->adev.transfer_buffer[i], 0x80,
181 		       dev->adev.urb[i]->transfer_buffer_length);
182 
183 		errCode = usb_submit_urb(dev->adev.urb[i], GFP_ATOMIC);
184 		if (errCode) {
185 			em28xx_errdev("submit of audio urb failed (error=%i)\n",
186 				      errCode);
187 			em28xx_deinit_isoc_audio(dev);
188 			atomic_set(&dev->adev.stream_started, 0);
189 			return errCode;
190 		}
191 
192 	}
193 
194 	return 0;
195 }
196 
197 static int snd_pcm_alloc_vmalloc_buffer(struct snd_pcm_substream *subs,
198 					size_t size)
199 {
200 	struct snd_pcm_runtime *runtime = subs->runtime;
201 
202 	dprintk("Allocating vbuffer\n");
203 	if (runtime->dma_area) {
204 		if (runtime->dma_bytes > size)
205 			return 0;
206 
207 		vfree(runtime->dma_area);
208 	}
209 	runtime->dma_area = vmalloc(size);
210 	if (!runtime->dma_area)
211 		return -ENOMEM;
212 
213 	runtime->dma_bytes = size;
214 
215 	return 0;
216 }
217 
218 static struct snd_pcm_hardware snd_em28xx_hw_capture = {
219 	.info = SNDRV_PCM_INFO_BLOCK_TRANSFER |
220 		SNDRV_PCM_INFO_MMAP           |
221 		SNDRV_PCM_INFO_INTERLEAVED    |
222 		SNDRV_PCM_INFO_BATCH	      |
223 		SNDRV_PCM_INFO_MMAP_VALID,
224 
225 	.formats = SNDRV_PCM_FMTBIT_S16_LE,
226 
227 	.rates = SNDRV_PCM_RATE_48000,
228 
229 	.rate_min = 48000,
230 	.rate_max = 48000,
231 	.channels_min = 2,
232 	.channels_max = 2,
233 	.buffer_bytes_max = 62720 * 8,	/* just about the value in usbaudio.c */
234 
235 	/*
236 	 * The period is 12.288 bytes. Allow a 10% of variation along its
237 	 * value, in order to avoid overruns/underruns due to some clock
238 	 * drift.
239 	 *
240 	 * FIXME: This period assumes 64 packets, and a 48000 PCM rate.
241 	 * Calculate it dynamically.
242 	 */
243 	.period_bytes_min = 11059,
244 	.period_bytes_max = 13516,
245 
246 	.periods_min = 2,
247 	.periods_max = 98,		/* 12544, */
248 };
249 
250 static int snd_em28xx_capture_open(struct snd_pcm_substream *substream)
251 {
252 	struct em28xx *dev = snd_pcm_substream_chip(substream);
253 	struct snd_pcm_runtime *runtime = substream->runtime;
254 	int nonblock, ret = 0;
255 
256 	if (!dev) {
257 		em28xx_err("BUG: em28xx can't find device struct."
258 				" Can't proceed with open\n");
259 		return -ENODEV;
260 	}
261 
262 	if (dev->disconnected)
263 		return -ENODEV;
264 
265 	dprintk("opening device and trying to acquire exclusive lock\n");
266 
267 	nonblock = !!(substream->f_flags & O_NONBLOCK);
268 	if (nonblock) {
269 		if (!mutex_trylock(&dev->lock))
270 			return -EAGAIN;
271 	} else
272 		mutex_lock(&dev->lock);
273 
274 	runtime->hw = snd_em28xx_hw_capture;
275 
276 	if (dev->adev.users == 0) {
277 		if (dev->alt == 0 || dev->is_audio_only) {
278 			if (dev->is_audio_only)
279 				/* audio is on a separate interface */
280 				dev->alt = 1;
281 			else
282 				/* audio is on the same interface as video */
283 				dev->alt = 7;
284 				/*
285 				 * FIXME: The intention seems to be to select
286 				 * the alt setting with the largest
287 				 * wMaxPacketSize for the video endpoint.
288 				 * At least dev->alt should be used instead, but
289 				 * we should probably not touch it at all if it
290 				 * is already >0, because wMaxPacketSize of the
291 				 * audio endpoints seems to be the same for all.
292 				 */
293 			dprintk("changing alternate number on interface %d to %d\n",
294 				dev->ifnum, dev->alt);
295 			usb_set_interface(dev->udev, dev->ifnum, dev->alt);
296 		}
297 
298 		/* Sets volume, mute, etc */
299 		dev->mute = 0;
300 		ret = em28xx_audio_analog_set(dev);
301 		if (ret < 0)
302 			goto err;
303 	}
304 
305 	kref_get(&dev->ref);
306 	dev->adev.users++;
307 	mutex_unlock(&dev->lock);
308 
309 	/* Dynamically adjust the period size */
310 	snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
311 	snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_PERIOD_BYTES,
312 				     dev->adev.period * 95 / 100,
313 				     dev->adev.period * 105 / 100);
314 
315 	dev->adev.capture_pcm_substream = substream;
316 
317 	return 0;
318 err:
319 	mutex_unlock(&dev->lock);
320 
321 	em28xx_err("Error while configuring em28xx mixer\n");
322 	return ret;
323 }
324 
325 static int snd_em28xx_pcm_close(struct snd_pcm_substream *substream)
326 {
327 	struct em28xx *dev = snd_pcm_substream_chip(substream);
328 
329 	dprintk("closing device\n");
330 
331 	dev->mute = 1;
332 	mutex_lock(&dev->lock);
333 	dev->adev.users--;
334 	if (atomic_read(&dev->adev.stream_started) > 0) {
335 		atomic_set(&dev->adev.stream_started, 0);
336 		schedule_work(&dev->adev.wq_trigger);
337 	}
338 
339 	em28xx_audio_analog_set(dev);
340 	if (substream->runtime->dma_area) {
341 		dprintk("freeing\n");
342 		vfree(substream->runtime->dma_area);
343 		substream->runtime->dma_area = NULL;
344 	}
345 	mutex_unlock(&dev->lock);
346 	kref_put(&dev->ref, em28xx_free_device);
347 
348 	return 0;
349 }
350 
351 static int snd_em28xx_hw_capture_params(struct snd_pcm_substream *substream,
352 					struct snd_pcm_hw_params *hw_params)
353 {
354 	int ret;
355 	struct em28xx *dev = snd_pcm_substream_chip(substream);
356 
357 	if (dev->disconnected)
358 		return -ENODEV;
359 
360 	dprintk("Setting capture parameters\n");
361 
362 	ret = snd_pcm_alloc_vmalloc_buffer(substream,
363 					   params_buffer_bytes(hw_params));
364 	if (ret < 0)
365 		return ret;
366 #if 0
367 	/* TODO: set up em28xx audio chip to deliver the correct audio format,
368 	   current default is 48000hz multiplexed => 96000hz mono
369 	   which shouldn't matter since analogue TV only supports mono */
370 	unsigned int channels, rate, format;
371 
372 	format = params_format(hw_params);
373 	rate = params_rate(hw_params);
374 	channels = params_channels(hw_params);
375 #endif
376 
377 	return 0;
378 }
379 
380 static int snd_em28xx_hw_capture_free(struct snd_pcm_substream *substream)
381 {
382 	struct em28xx *dev = snd_pcm_substream_chip(substream);
383 	struct em28xx_audio *adev = &dev->adev;
384 
385 	dprintk("Stop capture, if needed\n");
386 
387 	if (atomic_read(&adev->stream_started) > 0) {
388 		atomic_set(&adev->stream_started, 0);
389 		schedule_work(&adev->wq_trigger);
390 	}
391 
392 	return 0;
393 }
394 
395 static int snd_em28xx_prepare(struct snd_pcm_substream *substream)
396 {
397 	struct em28xx *dev = snd_pcm_substream_chip(substream);
398 
399 	if (dev->disconnected)
400 		return -ENODEV;
401 
402 	dev->adev.hwptr_done_capture = 0;
403 	dev->adev.capture_transfer_done = 0;
404 
405 	return 0;
406 }
407 
408 static void audio_trigger(struct work_struct *work)
409 {
410 	struct em28xx_audio *adev =
411 			    container_of(work, struct em28xx_audio, wq_trigger);
412 	struct em28xx *dev = container_of(adev, struct em28xx, adev);
413 
414 	if (atomic_read(&adev->stream_started)) {
415 		dprintk("starting capture");
416 		em28xx_init_audio_isoc(dev);
417 	} else {
418 		dprintk("stopping capture");
419 		em28xx_deinit_isoc_audio(dev);
420 	}
421 }
422 
423 static int snd_em28xx_capture_trigger(struct snd_pcm_substream *substream,
424 				      int cmd)
425 {
426 	struct em28xx *dev = snd_pcm_substream_chip(substream);
427 	int retval = 0;
428 
429 	if (dev->disconnected)
430 		return -ENODEV;
431 
432 	switch (cmd) {
433 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: /* fall through */
434 	case SNDRV_PCM_TRIGGER_RESUME: /* fall through */
435 	case SNDRV_PCM_TRIGGER_START:
436 		atomic_set(&dev->adev.stream_started, 1);
437 		break;
438 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH: /* fall through */
439 	case SNDRV_PCM_TRIGGER_SUSPEND: /* fall through */
440 	case SNDRV_PCM_TRIGGER_STOP:
441 		atomic_set(&dev->adev.stream_started, 0);
442 		break;
443 	default:
444 		retval = -EINVAL;
445 	}
446 	schedule_work(&dev->adev.wq_trigger);
447 	return retval;
448 }
449 
450 static snd_pcm_uframes_t snd_em28xx_capture_pointer(struct snd_pcm_substream
451 						    *substream)
452 {
453 	unsigned long flags;
454 	struct em28xx *dev;
455 	snd_pcm_uframes_t hwptr_done;
456 
457 	dev = snd_pcm_substream_chip(substream);
458 	if (dev->disconnected)
459 		return SNDRV_PCM_POS_XRUN;
460 
461 	spin_lock_irqsave(&dev->adev.slock, flags);
462 	hwptr_done = dev->adev.hwptr_done_capture;
463 	spin_unlock_irqrestore(&dev->adev.slock, flags);
464 
465 	return hwptr_done;
466 }
467 
468 static struct page *snd_pcm_get_vmalloc_page(struct snd_pcm_substream *subs,
469 					     unsigned long offset)
470 {
471 	void *pageptr = subs->runtime->dma_area + offset;
472 
473 	return vmalloc_to_page(pageptr);
474 }
475 
476 /*
477  * AC97 volume control support
478  */
479 static int em28xx_vol_info(struct snd_kcontrol *kcontrol,
480 			   struct snd_ctl_elem_info *info)
481 {
482 	struct em28xx *dev = snd_kcontrol_chip(kcontrol);
483 
484 	if (dev->disconnected)
485 		return -ENODEV;
486 
487 	info->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
488 	info->count = 2;
489 	info->value.integer.min = 0;
490 	info->value.integer.max = 0x1f;
491 
492 	return 0;
493 }
494 
495 static int em28xx_vol_put(struct snd_kcontrol *kcontrol,
496 			  struct snd_ctl_elem_value *value)
497 {
498 	struct em28xx *dev = snd_kcontrol_chip(kcontrol);
499 	struct snd_pcm_substream *substream = dev->adev.capture_pcm_substream;
500 	u16 val = (0x1f - (value->value.integer.value[0] & 0x1f)) |
501 		  (0x1f - (value->value.integer.value[1] & 0x1f)) << 8;
502 	int nonblock = 0;
503 	int rc;
504 
505 	if (dev->disconnected)
506 		return -ENODEV;
507 
508 	if (substream)
509 		nonblock = !!(substream->f_flags & O_NONBLOCK);
510 	if (nonblock) {
511 		if (!mutex_trylock(&dev->lock))
512 			return -EAGAIN;
513 	} else
514 		mutex_lock(&dev->lock);
515 	rc = em28xx_read_ac97(dev, kcontrol->private_value);
516 	if (rc < 0)
517 		goto err;
518 
519 	val |= rc & 0x8000;	/* Preserve the mute flag */
520 
521 	rc = em28xx_write_ac97(dev, kcontrol->private_value, val);
522 	if (rc < 0)
523 		goto err;
524 
525 	dprintk("%sleft vol %d, right vol %d (0x%04x) to ac97 volume control 0x%04x\n",
526 		(val & 0x8000) ? "muted " : "",
527 		0x1f - ((val >> 8) & 0x1f), 0x1f - (val & 0x1f),
528 		val, (int)kcontrol->private_value);
529 
530 err:
531 	mutex_unlock(&dev->lock);
532 	return rc;
533 }
534 
535 static int em28xx_vol_get(struct snd_kcontrol *kcontrol,
536 			  struct snd_ctl_elem_value *value)
537 {
538 	struct em28xx *dev = snd_kcontrol_chip(kcontrol);
539 	struct snd_pcm_substream *substream = dev->adev.capture_pcm_substream;
540 	int nonblock = 0;
541 	int val;
542 
543 	if (dev->disconnected)
544 		return -ENODEV;
545 
546 	if (substream)
547 		nonblock = !!(substream->f_flags & O_NONBLOCK);
548 	if (nonblock) {
549 		if (!mutex_trylock(&dev->lock))
550 			return -EAGAIN;
551 	} else
552 		mutex_lock(&dev->lock);
553 	val = em28xx_read_ac97(dev, kcontrol->private_value);
554 	mutex_unlock(&dev->lock);
555 	if (val < 0)
556 		return val;
557 
558 	dprintk("%sleft vol %d, right vol %d (0x%04x) from ac97 volume control 0x%04x\n",
559 		(val & 0x8000) ? "muted " : "",
560 		0x1f - ((val >> 8) & 0x1f), 0x1f - (val & 0x1f),
561 		val, (int)kcontrol->private_value);
562 
563 	value->value.integer.value[0] = 0x1f - (val & 0x1f);
564 	value->value.integer.value[1] = 0x1f - ((val << 8) & 0x1f);
565 
566 	return 0;
567 }
568 
569 static int em28xx_vol_put_mute(struct snd_kcontrol *kcontrol,
570 			       struct snd_ctl_elem_value *value)
571 {
572 	struct em28xx *dev = snd_kcontrol_chip(kcontrol);
573 	u16 val = value->value.integer.value[0];
574 	struct snd_pcm_substream *substream = dev->adev.capture_pcm_substream;
575 	int nonblock = 0;
576 	int rc;
577 
578 	if (dev->disconnected)
579 		return -ENODEV;
580 
581 	if (substream)
582 		nonblock = !!(substream->f_flags & O_NONBLOCK);
583 	if (nonblock) {
584 		if (!mutex_trylock(&dev->lock))
585 			return -EAGAIN;
586 	} else
587 		mutex_lock(&dev->lock);
588 	rc = em28xx_read_ac97(dev, kcontrol->private_value);
589 	if (rc < 0)
590 		goto err;
591 
592 	if (val)
593 		rc &= 0x1f1f;
594 	else
595 		rc |= 0x8000;
596 
597 	rc = em28xx_write_ac97(dev, kcontrol->private_value, rc);
598 	if (rc < 0)
599 		goto err;
600 
601 	dprintk("%sleft vol %d, right vol %d (0x%04x) to ac97 volume control 0x%04x\n",
602 		(val & 0x8000) ? "muted " : "",
603 		0x1f - ((val >> 8) & 0x1f), 0x1f - (val & 0x1f),
604 		val, (int)kcontrol->private_value);
605 
606 err:
607 	mutex_unlock(&dev->lock);
608 	return rc;
609 }
610 
611 static int em28xx_vol_get_mute(struct snd_kcontrol *kcontrol,
612 			       struct snd_ctl_elem_value *value)
613 {
614 	struct em28xx *dev = snd_kcontrol_chip(kcontrol);
615 	struct snd_pcm_substream *substream = dev->adev.capture_pcm_substream;
616 	int nonblock = 0;
617 	int val;
618 
619 	if (dev->disconnected)
620 		return -ENODEV;
621 
622 	if (substream)
623 		nonblock = !!(substream->f_flags & O_NONBLOCK);
624 	if (nonblock) {
625 		if (!mutex_trylock(&dev->lock))
626 			return -EAGAIN;
627 	} else
628 		mutex_lock(&dev->lock);
629 	val = em28xx_read_ac97(dev, kcontrol->private_value);
630 	mutex_unlock(&dev->lock);
631 	if (val < 0)
632 		return val;
633 
634 	if (val & 0x8000)
635 		value->value.integer.value[0] = 0;
636 	else
637 		value->value.integer.value[0] = 1;
638 
639 	dprintk("%sleft vol %d, right vol %d (0x%04x) from ac97 volume control 0x%04x\n",
640 		(val & 0x8000) ? "muted " : "",
641 		0x1f - ((val >> 8) & 0x1f), 0x1f - (val & 0x1f),
642 		val, (int)kcontrol->private_value);
643 
644 	return 0;
645 }
646 
647 static const DECLARE_TLV_DB_SCALE(em28xx_db_scale, -3450, 150, 0);
648 
649 static int em28xx_cvol_new(struct snd_card *card, struct em28xx *dev,
650 			   char *name, int id)
651 {
652 	int err;
653 	char ctl_name[44];
654 	struct snd_kcontrol *kctl;
655 	struct snd_kcontrol_new tmp;
656 
657 	memset(&tmp, 0, sizeof(tmp));
658 	tmp.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
659 	tmp.private_value = id,
660 	tmp.name  = ctl_name,
661 
662 	/* Add Mute Control */
663 	sprintf(ctl_name, "%s Switch", name);
664 	tmp.get  = em28xx_vol_get_mute;
665 	tmp.put  = em28xx_vol_put_mute;
666 	tmp.info = snd_ctl_boolean_mono_info;
667 	kctl = snd_ctl_new1(&tmp, dev);
668 	err = snd_ctl_add(card, kctl);
669 	if (err < 0)
670 		return err;
671 	dprintk("Added control %s for ac97 volume control 0x%04x\n",
672 		ctl_name, id);
673 
674 	memset(&tmp, 0, sizeof(tmp));
675 	tmp.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
676 	tmp.private_value = id,
677 	tmp.name  = ctl_name,
678 
679 	/* Add Volume Control */
680 	sprintf(ctl_name, "%s Volume", name);
681 	tmp.get   = em28xx_vol_get;
682 	tmp.put   = em28xx_vol_put;
683 	tmp.info  = em28xx_vol_info;
684 	tmp.tlv.p = em28xx_db_scale,
685 	kctl = snd_ctl_new1(&tmp, dev);
686 	err = snd_ctl_add(card, kctl);
687 	if (err < 0)
688 		return err;
689 	dprintk("Added control %s for ac97 volume control 0x%04x\n",
690 		ctl_name, id);
691 
692 	return 0;
693 }
694 
695 /*
696  * register/unregister code and data
697  */
698 static struct snd_pcm_ops snd_em28xx_pcm_capture = {
699 	.open      = snd_em28xx_capture_open,
700 	.close     = snd_em28xx_pcm_close,
701 	.ioctl     = snd_pcm_lib_ioctl,
702 	.hw_params = snd_em28xx_hw_capture_params,
703 	.hw_free   = snd_em28xx_hw_capture_free,
704 	.prepare   = snd_em28xx_prepare,
705 	.trigger   = snd_em28xx_capture_trigger,
706 	.pointer   = snd_em28xx_capture_pointer,
707 	.page      = snd_pcm_get_vmalloc_page,
708 };
709 
710 static void em28xx_audio_free_urb(struct em28xx *dev)
711 {
712 	int i;
713 
714 	for (i = 0; i < dev->adev.num_urb; i++) {
715 		struct urb *urb = dev->adev.urb[i];
716 
717 		if (!urb)
718 			continue;
719 
720 		usb_free_coherent(dev->udev, urb->transfer_buffer_length,
721 				  dev->adev.transfer_buffer[i],
722 				  urb->transfer_dma);
723 
724 		usb_free_urb(urb);
725 	}
726 	kfree(dev->adev.urb);
727 	kfree(dev->adev.transfer_buffer);
728 	dev->adev.num_urb = 0;
729 }
730 
731 /* high bandwidth multiplier, as encoded in highspeed endpoint descriptors */
732 static int em28xx_audio_ep_packet_size(struct usb_device *udev,
733 				       struct usb_endpoint_descriptor *e)
734 {
735 	int size = le16_to_cpu(e->wMaxPacketSize);
736 
737 	if (udev->speed == USB_SPEED_HIGH)
738 		return (size & 0x7ff) *  (1 + (((size) >> 11) & 0x03));
739 
740 	return size & 0x7ff;
741 }
742 
743 static int em28xx_audio_urb_init(struct em28xx *dev)
744 {
745 	struct usb_interface *intf;
746 	struct usb_endpoint_descriptor *e, *ep = NULL;
747 	int                 i, ep_size, interval, num_urb, npackets;
748 	int		    urb_size, bytes_per_transfer;
749 	u8 alt;
750 
751 	if (dev->ifnum)
752 		alt = 1;
753 	else
754 		alt = 7;
755 
756 	intf = usb_ifnum_to_if(dev->udev, dev->ifnum);
757 
758 	if (intf->num_altsetting <= alt) {
759 		em28xx_errdev("alt %d doesn't exist on interface %d\n",
760 			      dev->ifnum, alt);
761 		return -ENODEV;
762 	}
763 
764 	for (i = 0; i < intf->altsetting[alt].desc.bNumEndpoints; i++) {
765 		e = &intf->altsetting[alt].endpoint[i].desc;
766 		if (!usb_endpoint_dir_in(e))
767 			continue;
768 		if (e->bEndpointAddress == EM28XX_EP_AUDIO) {
769 			ep = e;
770 			break;
771 		}
772 	}
773 
774 	if (!ep) {
775 		em28xx_errdev("Couldn't find an audio endpoint");
776 		return -ENODEV;
777 	}
778 
779 	ep_size = em28xx_audio_ep_packet_size(dev->udev, ep);
780 	interval = 1 << (ep->bInterval - 1);
781 
782 	em28xx_info("Endpoint 0x%02x %s on intf %d alt %d interval = %d, size %d\n",
783 		    EM28XX_EP_AUDIO, usb_speed_string(dev->udev->speed),
784 		     dev->ifnum, alt,
785 		     interval,
786 		     ep_size);
787 
788 	/* Calculate the number and size of URBs to better fit the audio samples */
789 
790 	/*
791 	 * Estimate the number of bytes per DMA transfer.
792 	 *
793 	 * This is given by the bit rate (for now, only 48000 Hz) multiplied
794 	 * by 2 channels and 2 bytes/sample divided by the number of microframe
795 	 * intervals and by the microframe rate (125 us)
796 	 */
797 	bytes_per_transfer = DIV_ROUND_UP(48000 * 2 * 2, 125 * interval);
798 
799 	/*
800 	 * Estimate the number of transfer URBs. Don't let it go past the
801 	 * maximum number of URBs that is known to be supported by the device.
802 	 */
803 	num_urb = DIV_ROUND_UP(bytes_per_transfer, ep_size);
804 	if (num_urb > EM28XX_MAX_AUDIO_BUFS)
805 		num_urb = EM28XX_MAX_AUDIO_BUFS;
806 
807 	/*
808 	 * Now that we know the number of bytes per transfer and the number of
809 	 * URBs, estimate the typical size of an URB, in order to adjust the
810 	 * minimal number of packets.
811 	 */
812 	urb_size = bytes_per_transfer / num_urb;
813 
814 	/*
815 	 * Now, calculate the amount of audio packets to be filled on each
816 	 * URB. In order to preserve the old behaviour, use a minimal
817 	 * threshold for this value.
818 	 */
819 	npackets = EM28XX_MIN_AUDIO_PACKETS;
820 	if (urb_size > ep_size * npackets)
821 		npackets = DIV_ROUND_UP(urb_size, ep_size);
822 
823 	em28xx_info("Number of URBs: %d, with %d packets and %d size\n",
824 		    num_urb, npackets, urb_size);
825 
826 	/* Estimate the bytes per period */
827 	dev->adev.period = urb_size * npackets;
828 
829 	/* Allocate space to store the number of URBs to be used */
830 
831 	dev->adev.transfer_buffer = kcalloc(num_urb,
832 					    sizeof(*dev->adev.transfer_buffer),
833 					    GFP_ATOMIC);
834 	if (!dev->adev.transfer_buffer) {
835 		return -ENOMEM;
836 	}
837 
838 	dev->adev.urb = kcalloc(num_urb, sizeof(*dev->adev.urb), GFP_ATOMIC);
839 	if (!dev->adev.urb) {
840 		kfree(dev->adev.transfer_buffer);
841 		return -ENOMEM;
842 	}
843 
844 	/* Alloc memory for each URB and for each transfer buffer */
845 	dev->adev.num_urb = num_urb;
846 	for (i = 0; i < num_urb; i++) {
847 		struct urb *urb;
848 		int j, k;
849 		void *buf;
850 
851 		urb = usb_alloc_urb(npackets, GFP_ATOMIC);
852 		if (!urb) {
853 			em28xx_errdev("usb_alloc_urb failed!\n");
854 			em28xx_audio_free_urb(dev);
855 			return -ENOMEM;
856 		}
857 		dev->adev.urb[i] = urb;
858 
859 		buf = usb_alloc_coherent(dev->udev, npackets * ep_size, GFP_ATOMIC,
860 					 &urb->transfer_dma);
861 		if (!buf) {
862 			em28xx_errdev("usb_alloc_coherent failed!\n");
863 			em28xx_audio_free_urb(dev);
864 			return -ENOMEM;
865 		}
866 		dev->adev.transfer_buffer[i] = buf;
867 
868 		urb->dev = dev->udev;
869 		urb->context = dev;
870 		urb->pipe = usb_rcvisocpipe(dev->udev, EM28XX_EP_AUDIO);
871 		urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
872 		urb->transfer_buffer = buf;
873 		urb->interval = interval;
874 		urb->complete = em28xx_audio_isocirq;
875 		urb->number_of_packets = npackets;
876 		urb->transfer_buffer_length = ep_size * npackets;
877 
878 		for (j = k = 0; j < npackets; j++, k += ep_size) {
879 			urb->iso_frame_desc[j].offset = k;
880 			urb->iso_frame_desc[j].length = ep_size;
881 		}
882 	}
883 
884 	return 0;
885 }
886 
887 static int em28xx_audio_init(struct em28xx *dev)
888 {
889 	struct em28xx_audio *adev = &dev->adev;
890 	struct snd_pcm      *pcm;
891 	struct snd_card     *card;
892 	static int          devnr;
893 	int		    err;
894 
895 	if (dev->usb_audio_type != EM28XX_USB_AUDIO_VENDOR) {
896 		/* This device does not support the extension (in this case
897 		   the device is expecting the snd-usb-audio module or
898 		   doesn't have analog audio support at all) */
899 		return 0;
900 	}
901 
902 	em28xx_info("Binding audio extension\n");
903 
904 	kref_get(&dev->ref);
905 
906 	printk(KERN_INFO "em28xx-audio.c: Copyright (C) 2006 Markus "
907 			 "Rechberger\n");
908 	printk(KERN_INFO
909 	       "em28xx-audio.c: Copyright (C) 2007-2014 Mauro Carvalho Chehab\n");
910 
911 	err = snd_card_new(&dev->udev->dev, index[devnr], "Em28xx Audio",
912 			   THIS_MODULE, 0, &card);
913 	if (err < 0)
914 		return err;
915 
916 	spin_lock_init(&adev->slock);
917 	adev->sndcard = card;
918 	adev->udev = dev->udev;
919 
920 	err = snd_pcm_new(card, "Em28xx Audio", 0, 0, 1, &pcm);
921 	if (err < 0)
922 		goto card_free;
923 
924 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &snd_em28xx_pcm_capture);
925 	pcm->info_flags = 0;
926 	pcm->private_data = dev;
927 	strcpy(pcm->name, "Empia 28xx Capture");
928 
929 	strcpy(card->driver, "Em28xx-Audio");
930 	strcpy(card->shortname, "Em28xx Audio");
931 	strcpy(card->longname, "Empia Em28xx Audio");
932 
933 	INIT_WORK(&adev->wq_trigger, audio_trigger);
934 
935 	if (dev->audio_mode.ac97 != EM28XX_NO_AC97) {
936 		em28xx_cvol_new(card, dev, "Video", AC97_VIDEO);
937 		em28xx_cvol_new(card, dev, "Line In", AC97_LINE);
938 		em28xx_cvol_new(card, dev, "Phone", AC97_PHONE);
939 		em28xx_cvol_new(card, dev, "Microphone", AC97_MIC);
940 		em28xx_cvol_new(card, dev, "CD", AC97_CD);
941 		em28xx_cvol_new(card, dev, "AUX", AC97_AUX);
942 		em28xx_cvol_new(card, dev, "PCM", AC97_PCM);
943 
944 		em28xx_cvol_new(card, dev, "Master", AC97_MASTER);
945 		em28xx_cvol_new(card, dev, "Line", AC97_HEADPHONE);
946 		em28xx_cvol_new(card, dev, "Mono", AC97_MASTER_MONO);
947 		em28xx_cvol_new(card, dev, "LFE", AC97_CENTER_LFE_MASTER);
948 		em28xx_cvol_new(card, dev, "Surround", AC97_SURROUND_MASTER);
949 	}
950 
951 	err = em28xx_audio_urb_init(dev);
952 	if (err)
953 		goto card_free;
954 
955 	err = snd_card_register(card);
956 	if (err < 0)
957 		goto urb_free;
958 
959 	em28xx_info("Audio extension successfully initialized\n");
960 	return 0;
961 
962 urb_free:
963 	em28xx_audio_free_urb(dev);
964 
965 card_free:
966 	snd_card_free(card);
967 	adev->sndcard = NULL;
968 
969 	return err;
970 }
971 
972 static int em28xx_audio_fini(struct em28xx *dev)
973 {
974 	if (dev == NULL)
975 		return 0;
976 
977 	if (dev->usb_audio_type != EM28XX_USB_AUDIO_VENDOR) {
978 		/* This device does not support the extension (in this case
979 		   the device is expecting the snd-usb-audio module or
980 		   doesn't have analog audio support at all) */
981 		return 0;
982 	}
983 
984 	em28xx_info("Closing audio extension\n");
985 
986 	if (dev->adev.sndcard) {
987 		snd_card_disconnect(dev->adev.sndcard);
988 		flush_work(&dev->adev.wq_trigger);
989 
990 		em28xx_audio_free_urb(dev);
991 
992 		snd_card_free(dev->adev.sndcard);
993 		dev->adev.sndcard = NULL;
994 	}
995 
996 	kref_put(&dev->ref, em28xx_free_device);
997 	return 0;
998 }
999 
1000 static int em28xx_audio_suspend(struct em28xx *dev)
1001 {
1002 	if (dev == NULL)
1003 		return 0;
1004 
1005 	if (dev->usb_audio_type != EM28XX_USB_AUDIO_VENDOR)
1006 		return 0;
1007 
1008 	em28xx_info("Suspending audio extension\n");
1009 	em28xx_deinit_isoc_audio(dev);
1010 	atomic_set(&dev->adev.stream_started, 0);
1011 	return 0;
1012 }
1013 
1014 static int em28xx_audio_resume(struct em28xx *dev)
1015 {
1016 	if (dev == NULL)
1017 		return 0;
1018 
1019 	if (dev->usb_audio_type != EM28XX_USB_AUDIO_VENDOR)
1020 		return 0;
1021 
1022 	em28xx_info("Resuming audio extension\n");
1023 	/* Nothing to do other than schedule_work() ?? */
1024 	schedule_work(&dev->adev.wq_trigger);
1025 	return 0;
1026 }
1027 
1028 static struct em28xx_ops audio_ops = {
1029 	.id   = EM28XX_AUDIO,
1030 	.name = "Em28xx Audio Extension",
1031 	.init = em28xx_audio_init,
1032 	.fini = em28xx_audio_fini,
1033 	.suspend = em28xx_audio_suspend,
1034 	.resume = em28xx_audio_resume,
1035 };
1036 
1037 static int __init em28xx_alsa_register(void)
1038 {
1039 	return em28xx_register_extension(&audio_ops);
1040 }
1041 
1042 static void __exit em28xx_alsa_unregister(void)
1043 {
1044 	em28xx_unregister_extension(&audio_ops);
1045 }
1046 
1047 MODULE_LICENSE("GPL");
1048 MODULE_AUTHOR("Markus Rechberger <mrechberger@gmail.com>");
1049 MODULE_AUTHOR("Mauro Carvalho Chehab");
1050 MODULE_DESCRIPTION(DRIVER_DESC " - audio interface");
1051 MODULE_VERSION(EM28XX_VERSION);
1052 
1053 module_init(em28xx_alsa_register);
1054 module_exit(em28xx_alsa_unregister);
1055