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->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->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->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 	/*
237 	 * The period is 12.288 bytes. Allow a 10% of variation along its
238 	 * value, in order to avoid overruns/underruns due to some clock
239 	 * drift.
240 	 *
241 	 * FIXME: This period assumes 64 packets, and a 48000 PCM rate.
242 	 * Calculate it dynamically.
243 	 */
244 	.period_bytes_min = 11059,
245 	.period_bytes_max = 13516,
246 
247 	.periods_min = 2,
248 	.periods_max = 98,		/* 12544, */
249 };
250 
251 static int snd_em28xx_capture_open(struct snd_pcm_substream *substream)
252 {
253 	struct em28xx *dev = snd_pcm_substream_chip(substream);
254 	struct snd_pcm_runtime *runtime = substream->runtime;
255 	int ret = 0;
256 
257 	if (!dev) {
258 		em28xx_err("BUG: em28xx can't find device struct."
259 				" Can't proceed with open\n");
260 		return -ENODEV;
261 	}
262 
263 	if (dev->disconnected)
264 		return -ENODEV;
265 
266 	dprintk("opening device and trying to acquire exclusive lock\n");
267 
268 	runtime->hw = snd_em28xx_hw_capture;
269 	if ((dev->alt == 0 || dev->is_audio_only) && dev->adev.users == 0) {
270 		int nonblock = !!(substream->f_flags & O_NONBLOCK);
271 
272 		if (nonblock) {
273 			if (!mutex_trylock(&dev->lock))
274 				return -EAGAIN;
275 		} else
276 			mutex_lock(&dev->lock);
277 		if (dev->is_audio_only)
278 			/* vendor audio is on a separate interface */
279 			dev->alt = 1;
280 		else
281 			/* vendor audio is on the same interface as video */
282 			dev->alt = 7;
283 			/*
284 			 * FIXME: The intention seems to be to select the alt
285 			 * setting with the largest wMaxPacketSize for the video
286 			 * endpoint.
287 			 * At least dev->alt should be used instead, but we
288 			 * should probably not touch it at all if it is
289 			 * already >0, because wMaxPacketSize of the audio
290 			 * endpoints seems to be the same for all.
291 			 */
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 		/* Sets volume, mute, etc */
298 		dev->mute = 0;
299 		ret = em28xx_audio_analog_set(dev);
300 		if (ret < 0)
301 			goto err;
302 
303 		dev->adev.users++;
304 		mutex_unlock(&dev->lock);
305 	}
306 
307 	/* Dynamically adjust the period size */
308 	snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
309 	snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_PERIOD_BYTES,
310 				     dev->adev.period * 95 / 100,
311 				     dev->adev.period * 105 / 100);
312 
313 	dev->adev.capture_pcm_substream = substream;
314 
315 	return 0;
316 err:
317 	mutex_unlock(&dev->lock);
318 
319 	em28xx_err("Error while configuring em28xx mixer\n");
320 	return ret;
321 }
322 
323 static int snd_em28xx_pcm_close(struct snd_pcm_substream *substream)
324 {
325 	struct em28xx *dev = snd_pcm_substream_chip(substream);
326 
327 	dprintk("closing device\n");
328 
329 	dev->mute = 1;
330 	mutex_lock(&dev->lock);
331 	dev->adev.users--;
332 	if (atomic_read(&dev->stream_started) > 0) {
333 		atomic_set(&dev->stream_started, 0);
334 		schedule_work(&dev->wq_trigger);
335 	}
336 
337 	em28xx_audio_analog_set(dev);
338 	if (substream->runtime->dma_area) {
339 		dprintk("freeing\n");
340 		vfree(substream->runtime->dma_area);
341 		substream->runtime->dma_area = NULL;
342 	}
343 	mutex_unlock(&dev->lock);
344 
345 	return 0;
346 }
347 
348 static int snd_em28xx_hw_capture_params(struct snd_pcm_substream *substream,
349 					struct snd_pcm_hw_params *hw_params)
350 {
351 	int ret;
352 	struct em28xx *dev = snd_pcm_substream_chip(substream);
353 
354 	if (dev->disconnected)
355 		return -ENODEV;
356 
357 	dprintk("Setting capture parameters\n");
358 
359 	ret = snd_pcm_alloc_vmalloc_buffer(substream,
360 				params_buffer_bytes(hw_params));
361 	if (ret < 0)
362 		return ret;
363 #if 0
364 	/* TODO: set up em28xx audio chip to deliver the correct audio format,
365 	   current default is 48000hz multiplexed => 96000hz mono
366 	   which shouldn't matter since analogue TV only supports mono */
367 	unsigned int channels, rate, format;
368 
369 	format = params_format(hw_params);
370 	rate = params_rate(hw_params);
371 	channels = params_channels(hw_params);
372 #endif
373 
374 	return 0;
375 }
376 
377 static int snd_em28xx_hw_capture_free(struct snd_pcm_substream *substream)
378 {
379 	struct em28xx *dev = snd_pcm_substream_chip(substream);
380 
381 	dprintk("Stop capture, if needed\n");
382 
383 	if (atomic_read(&dev->stream_started) > 0) {
384 		atomic_set(&dev->stream_started, 0);
385 		schedule_work(&dev->wq_trigger);
386 	}
387 
388 	return 0;
389 }
390 
391 static int snd_em28xx_prepare(struct snd_pcm_substream *substream)
392 {
393 	struct em28xx *dev = snd_pcm_substream_chip(substream);
394 
395 	if (dev->disconnected)
396 		return -ENODEV;
397 
398 	dev->adev.hwptr_done_capture = 0;
399 	dev->adev.capture_transfer_done = 0;
400 
401 	return 0;
402 }
403 
404 static void audio_trigger(struct work_struct *work)
405 {
406 	struct em28xx *dev = container_of(work, struct em28xx, wq_trigger);
407 
408 	if (atomic_read(&dev->stream_started)) {
409 		dprintk("starting capture");
410 		em28xx_init_audio_isoc(dev);
411 	} else {
412 		dprintk("stopping capture");
413 		em28xx_deinit_isoc_audio(dev);
414 	}
415 }
416 
417 static int snd_em28xx_capture_trigger(struct snd_pcm_substream *substream,
418 				      int cmd)
419 {
420 	struct em28xx *dev = snd_pcm_substream_chip(substream);
421 	int retval = 0;
422 
423 	if (dev->disconnected)
424 		return -ENODEV;
425 
426 	switch (cmd) {
427 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: /* fall through */
428 	case SNDRV_PCM_TRIGGER_RESUME: /* fall through */
429 	case SNDRV_PCM_TRIGGER_START:
430 		atomic_set(&dev->stream_started, 1);
431 		break;
432 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH: /* fall through */
433 	case SNDRV_PCM_TRIGGER_SUSPEND: /* fall through */
434 	case SNDRV_PCM_TRIGGER_STOP:
435 		atomic_set(&dev->stream_started, 0);
436 		break;
437 	default:
438 		retval = -EINVAL;
439 	}
440 	schedule_work(&dev->wq_trigger);
441 	return retval;
442 }
443 
444 static snd_pcm_uframes_t snd_em28xx_capture_pointer(struct snd_pcm_substream
445 						    *substream)
446 {
447 	unsigned long flags;
448 	struct em28xx *dev;
449 	snd_pcm_uframes_t hwptr_done;
450 
451 	dev = snd_pcm_substream_chip(substream);
452 	if (dev->disconnected)
453 		return SNDRV_PCM_POS_XRUN;
454 
455 	spin_lock_irqsave(&dev->adev.slock, flags);
456 	hwptr_done = dev->adev.hwptr_done_capture;
457 	spin_unlock_irqrestore(&dev->adev.slock, flags);
458 
459 	return hwptr_done;
460 }
461 
462 static struct page *snd_pcm_get_vmalloc_page(struct snd_pcm_substream *subs,
463 					     unsigned long offset)
464 {
465 	void *pageptr = subs->runtime->dma_area + offset;
466 
467 	return vmalloc_to_page(pageptr);
468 }
469 
470 /*
471  * AC97 volume control support
472  */
473 static int em28xx_vol_info(struct snd_kcontrol *kcontrol,
474 				struct snd_ctl_elem_info *info)
475 {
476 	struct em28xx *dev = snd_kcontrol_chip(kcontrol);
477 
478 	if (dev->disconnected)
479 		return -ENODEV;
480 
481 	info->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
482 	info->count = 2;
483 	info->value.integer.min = 0;
484 	info->value.integer.max = 0x1f;
485 
486 	return 0;
487 }
488 
489 static int em28xx_vol_put(struct snd_kcontrol *kcontrol,
490 			       struct snd_ctl_elem_value *value)
491 {
492 	struct em28xx *dev = snd_kcontrol_chip(kcontrol);
493 	struct snd_pcm_substream *substream = dev->adev.capture_pcm_substream;
494 	u16 val = (0x1f - (value->value.integer.value[0] & 0x1f)) |
495 		  (0x1f - (value->value.integer.value[1] & 0x1f)) << 8;
496 	int nonblock = 0;
497 	int rc;
498 
499 	if (dev->disconnected)
500 		return -ENODEV;
501 
502 	if (substream)
503 		nonblock = !!(substream->f_flags & O_NONBLOCK);
504 	if (nonblock) {
505 		if (!mutex_trylock(&dev->lock))
506 			return -EAGAIN;
507 	} else
508 		mutex_lock(&dev->lock);
509 	rc = em28xx_read_ac97(dev, kcontrol->private_value);
510 	if (rc < 0)
511 		goto err;
512 
513 	val |= rc & 0x8000;	/* Preserve the mute flag */
514 
515 	rc = em28xx_write_ac97(dev, kcontrol->private_value, val);
516 	if (rc < 0)
517 		goto err;
518 
519 	dprintk("%sleft vol %d, right vol %d (0x%04x) to ac97 volume control 0x%04x\n",
520 		(val & 0x8000) ? "muted " : "",
521 		0x1f - ((val >> 8) & 0x1f), 0x1f - (val & 0x1f),
522 		val, (int)kcontrol->private_value);
523 
524 err:
525 	mutex_unlock(&dev->lock);
526 	return rc;
527 }
528 
529 static int em28xx_vol_get(struct snd_kcontrol *kcontrol,
530 			       struct snd_ctl_elem_value *value)
531 {
532 	struct em28xx *dev = snd_kcontrol_chip(kcontrol);
533 	struct snd_pcm_substream *substream = dev->adev.capture_pcm_substream;
534 	int nonblock = 0;
535 	int val;
536 
537 	if (dev->disconnected)
538 		return -ENODEV;
539 
540 	if (substream)
541 		nonblock = !!(substream->f_flags & O_NONBLOCK);
542 	if (nonblock) {
543 		if (!mutex_trylock(&dev->lock))
544 			return -EAGAIN;
545 	} else
546 		mutex_lock(&dev->lock);
547 	val = em28xx_read_ac97(dev, kcontrol->private_value);
548 	mutex_unlock(&dev->lock);
549 	if (val < 0)
550 		return val;
551 
552 	dprintk("%sleft vol %d, right vol %d (0x%04x) from ac97 volume control 0x%04x\n",
553 		(val & 0x8000) ? "muted " : "",
554 		0x1f - ((val >> 8) & 0x1f), 0x1f - (val & 0x1f),
555 		val, (int)kcontrol->private_value);
556 
557 	value->value.integer.value[0] = 0x1f - (val & 0x1f);
558 	value->value.integer.value[1] = 0x1f - ((val << 8) & 0x1f);
559 
560 	return 0;
561 }
562 
563 static int em28xx_vol_put_mute(struct snd_kcontrol *kcontrol,
564 			       struct snd_ctl_elem_value *value)
565 {
566 	struct em28xx *dev = snd_kcontrol_chip(kcontrol);
567 	u16 val = value->value.integer.value[0];
568 	struct snd_pcm_substream *substream = dev->adev.capture_pcm_substream;
569 	int nonblock = 0;
570 	int rc;
571 
572 	if (dev->disconnected)
573 		return -ENODEV;
574 
575 	if (substream)
576 		nonblock = !!(substream->f_flags & O_NONBLOCK);
577 	if (nonblock) {
578 		if (!mutex_trylock(&dev->lock))
579 			return -EAGAIN;
580 	} else
581 		mutex_lock(&dev->lock);
582 	rc = em28xx_read_ac97(dev, kcontrol->private_value);
583 	if (rc < 0)
584 		goto err;
585 
586 	if (val)
587 		rc &= 0x1f1f;
588 	else
589 		rc |= 0x8000;
590 
591 	rc = em28xx_write_ac97(dev, kcontrol->private_value, rc);
592 	if (rc < 0)
593 		goto err;
594 
595 	dprintk("%sleft vol %d, right vol %d (0x%04x) to ac97 volume control 0x%04x\n",
596 		(val & 0x8000) ? "muted " : "",
597 		0x1f - ((val >> 8) & 0x1f), 0x1f - (val & 0x1f),
598 		val, (int)kcontrol->private_value);
599 
600 err:
601 	mutex_unlock(&dev->lock);
602 	return rc;
603 }
604 
605 static int em28xx_vol_get_mute(struct snd_kcontrol *kcontrol,
606 			       struct snd_ctl_elem_value *value)
607 {
608 	struct em28xx *dev = snd_kcontrol_chip(kcontrol);
609 	struct snd_pcm_substream *substream = dev->adev.capture_pcm_substream;
610 	int nonblock = 0;
611 	int val;
612 
613 	if (dev->disconnected)
614 		return -ENODEV;
615 
616 	if (substream)
617 		nonblock = !!(substream->f_flags & O_NONBLOCK);
618 	if (nonblock) {
619 		if (!mutex_trylock(&dev->lock))
620 			return -EAGAIN;
621 	} else
622 		mutex_lock(&dev->lock);
623 	val = em28xx_read_ac97(dev, kcontrol->private_value);
624 	mutex_unlock(&dev->lock);
625 	if (val < 0)
626 		return val;
627 
628 	if (val & 0x8000)
629 		value->value.integer.value[0] = 0;
630 	else
631 		value->value.integer.value[0] = 1;
632 
633 	dprintk("%sleft vol %d, right vol %d (0x%04x) from ac97 volume control 0x%04x\n",
634 		(val & 0x8000) ? "muted " : "",
635 		0x1f - ((val >> 8) & 0x1f), 0x1f - (val & 0x1f),
636 		val, (int)kcontrol->private_value);
637 
638 	return 0;
639 }
640 
641 static const DECLARE_TLV_DB_SCALE(em28xx_db_scale, -3450, 150, 0);
642 
643 static int em28xx_cvol_new(struct snd_card *card, struct em28xx *dev,
644 			   char *name, int id)
645 {
646 	int err;
647 	char ctl_name[44];
648 	struct snd_kcontrol *kctl;
649 	struct snd_kcontrol_new tmp;
650 
651 	memset (&tmp, 0, sizeof(tmp));
652 	tmp.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
653 	tmp.private_value = id,
654 	tmp.name  = ctl_name,
655 
656 	/* Add Mute Control */
657 	sprintf(ctl_name, "%s Switch", name);
658 	tmp.get  = em28xx_vol_get_mute;
659 	tmp.put  = em28xx_vol_put_mute;
660 	tmp.info = snd_ctl_boolean_mono_info;
661 	kctl = snd_ctl_new1(&tmp, dev);
662 	err = snd_ctl_add(card, kctl);
663 	if (err < 0)
664 		return err;
665 	dprintk("Added control %s for ac97 volume control 0x%04x\n",
666 		ctl_name, id);
667 
668 	memset (&tmp, 0, sizeof(tmp));
669 	tmp.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
670 	tmp.private_value = id,
671 	tmp.name  = ctl_name,
672 
673 	/* Add Volume Control */
674 	sprintf(ctl_name, "%s Volume", name);
675 	tmp.get   = em28xx_vol_get;
676 	tmp.put   = em28xx_vol_put;
677 	tmp.info  = em28xx_vol_info;
678 	tmp.tlv.p = em28xx_db_scale,
679 	kctl = snd_ctl_new1(&tmp, dev);
680 	err = snd_ctl_add(card, kctl);
681 	if (err < 0)
682 		return err;
683 	dprintk("Added control %s for ac97 volume control 0x%04x\n",
684 		ctl_name, id);
685 
686 	return 0;
687 }
688 
689 /*
690  * register/unregister code and data
691  */
692 static struct snd_pcm_ops snd_em28xx_pcm_capture = {
693 	.open      = snd_em28xx_capture_open,
694 	.close     = snd_em28xx_pcm_close,
695 	.ioctl     = snd_pcm_lib_ioctl,
696 	.hw_params = snd_em28xx_hw_capture_params,
697 	.hw_free   = snd_em28xx_hw_capture_free,
698 	.prepare   = snd_em28xx_prepare,
699 	.trigger   = snd_em28xx_capture_trigger,
700 	.pointer   = snd_em28xx_capture_pointer,
701 	.page      = snd_pcm_get_vmalloc_page,
702 };
703 
704 static void em28xx_audio_free_urb(struct em28xx *dev)
705 {
706 	int i;
707 
708 	for (i = 0; i < dev->adev.num_urb; i++) {
709 		struct urb *urb = dev->adev.urb[i];
710 
711 		if (!urb)
712 			continue;
713 
714 		usb_free_coherent(dev->udev, urb->transfer_buffer_length,
715 				  dev->adev.transfer_buffer[i],
716 				  urb->transfer_dma);
717 
718 		usb_free_urb(urb);
719 	}
720 	kfree(dev->adev.urb);
721 	kfree(dev->adev.transfer_buffer);
722 	dev->adev.num_urb = 0;
723 }
724 
725 /* high bandwidth multiplier, as encoded in highspeed endpoint descriptors */
726 static int em28xx_audio_ep_packet_size(struct usb_device *udev,
727 					struct usb_endpoint_descriptor *e)
728 {
729 	int size = le16_to_cpu(e->wMaxPacketSize);
730 
731 	if (udev->speed == USB_SPEED_HIGH)
732 		return (size & 0x7ff) *  (1 + (((size) >> 11) & 0x03));
733 
734 	return size & 0x7ff;
735 }
736 
737 static int em28xx_audio_urb_init(struct em28xx *dev)
738 {
739 	struct usb_interface *intf;
740 	struct usb_endpoint_descriptor *e, *ep = NULL;
741 	int                 i, ep_size, interval, num_urb, npackets;
742 	int		    urb_size, bytes_per_transfer;
743 	u8 alt;
744 
745 	if (dev->ifnum)
746 		alt = 1;
747 	else
748 		alt = 7;
749 
750 	intf = usb_ifnum_to_if(dev->udev, dev->ifnum);
751 
752 	if (intf->num_altsetting <= alt) {
753 		em28xx_errdev("alt %d doesn't exist on interface %d\n",
754 			      dev->ifnum, alt);
755 		return -ENODEV;
756 	}
757 
758 	for (i = 0; i < intf->altsetting[alt].desc.bNumEndpoints; i++) {
759 		e = &intf->altsetting[alt].endpoint[i].desc;
760 		if (!usb_endpoint_dir_in(e))
761 			continue;
762 		if (e->bEndpointAddress == EM28XX_EP_AUDIO) {
763 			ep = e;
764 			break;
765 		}
766 	}
767 
768 	if (!ep) {
769 		em28xx_errdev("Couldn't find an audio endpoint");
770 		return -ENODEV;
771 	}
772 
773 	ep_size = em28xx_audio_ep_packet_size(dev->udev, ep);
774 	interval = 1 << (ep->bInterval - 1);
775 
776 	em28xx_info("Endpoint 0x%02x %s on intf %d alt %d interval = %d, size %d\n",
777 		     EM28XX_EP_AUDIO, usb_speed_string(dev->udev->speed),
778 		     dev->ifnum, alt,
779 		     interval,
780 		     ep_size);
781 
782 	/* Calculate the number and size of URBs to better fit the audio samples */
783 
784 	/*
785 	 * Estimate the number of bytes per DMA transfer.
786 	 *
787 	 * This is given by the bit rate (for now, only 48000 Hz) multiplied
788 	 * by 2 channels and 2 bytes/sample divided by the number of microframe
789 	 * intervals and by the microframe rate (125 us)
790 	 */
791 	bytes_per_transfer = DIV_ROUND_UP(48000 * 2 * 2, 125 * interval);
792 
793 	/*
794 	 * Estimate the number of transfer URBs. Don't let it go past the
795 	 * maximum number of URBs that is known to be supported by the device.
796 	 */
797 	num_urb = DIV_ROUND_UP(bytes_per_transfer, ep_size);
798 	if (num_urb > EM28XX_MAX_AUDIO_BUFS)
799 		num_urb = EM28XX_MAX_AUDIO_BUFS;
800 
801 	/*
802 	 * Now that we know the number of bytes per transfer and the number of
803 	 * URBs, estimate the typical size of an URB, in order to adjust the
804 	 * minimal number of packets.
805 	 */
806 	urb_size = bytes_per_transfer / num_urb;
807 
808 	/*
809 	 * Now, calculate the amount of audio packets to be filled on each
810 	 * URB. In order to preserve the old behaviour, use a minimal
811 	 * threshold for this value.
812 	 */
813 	npackets = EM28XX_MIN_AUDIO_PACKETS;
814 	if (urb_size > ep_size * npackets)
815 		npackets = DIV_ROUND_UP(urb_size, ep_size);
816 
817 	em28xx_info("Number of URBs: %d, with %d packets and %d size",
818 		    num_urb, npackets, urb_size);
819 
820 	/* Estimate the bytes per period */
821 	dev->adev.period = urb_size * npackets;
822 
823 	/* Allocate space to store the number of URBs to be used */
824 
825 	dev->adev.transfer_buffer = kcalloc(num_urb,
826 					    sizeof(*dev->adev.transfer_buffer),
827 					    GFP_ATOMIC);
828 	if (!dev->adev.transfer_buffer) {
829 		return -ENOMEM;
830 	}
831 
832 	dev->adev.urb = kcalloc(num_urb, sizeof(*dev->adev.urb), GFP_ATOMIC);
833 	if (!dev->adev.urb) {
834 		kfree(dev->adev.transfer_buffer);
835 		return -ENOMEM;
836 	}
837 
838 	/* Alloc memory for each URB and for each transfer buffer */
839 	dev->adev.num_urb = num_urb;
840 	for (i = 0; i < num_urb; i++) {
841 		struct urb *urb;
842 		int j, k;
843 		void *buf;
844 
845 		urb = usb_alloc_urb(npackets, GFP_ATOMIC);
846 		if (!urb) {
847 			em28xx_errdev("usb_alloc_urb failed!\n");
848 			em28xx_audio_free_urb(dev);
849 			return -ENOMEM;
850 		}
851 		dev->adev.urb[i] = urb;
852 
853 		buf = usb_alloc_coherent(dev->udev, npackets * ep_size, GFP_ATOMIC,
854 					 &urb->transfer_dma);
855 		if (!buf) {
856 			em28xx_errdev("usb_alloc_coherent failed!\n");
857 			em28xx_audio_free_urb(dev);
858 			return -ENOMEM;
859 		}
860 		dev->adev.transfer_buffer[i] = buf;
861 
862 		urb->dev = dev->udev;
863 		urb->context = dev;
864 		urb->pipe = usb_rcvisocpipe(dev->udev, EM28XX_EP_AUDIO);
865 		urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
866 		urb->transfer_buffer = buf;
867 		urb->interval = interval;
868 		urb->complete = em28xx_audio_isocirq;
869 		urb->number_of_packets = npackets;
870 		urb->transfer_buffer_length = ep_size * npackets;
871 
872 		for (j = k = 0; j < npackets; j++, k += ep_size) {
873 			urb->iso_frame_desc[j].offset = k;
874 			urb->iso_frame_desc[j].length = ep_size;
875 		}
876 	}
877 
878 	return 0;
879 }
880 
881 static int em28xx_audio_init(struct em28xx *dev)
882 {
883 	struct em28xx_audio *adev = &dev->adev;
884 	struct snd_pcm      *pcm;
885 	struct snd_card     *card;
886 	static int          devnr;
887 	int		    err;
888 
889 	if (!dev->has_alsa_audio) {
890 		/* This device does not support the extension (in this case
891 		   the device is expecting the snd-usb-audio module or
892 		   doesn't have analog audio support at all) */
893 		return 0;
894 	}
895 
896 	em28xx_info("Binding audio extension\n");
897 
898 	printk(KERN_INFO "em28xx-audio.c: Copyright (C) 2006 Markus "
899 			 "Rechberger\n");
900 	printk(KERN_INFO
901 	       "em28xx-audio.c: Copyright (C) 2007-2014 Mauro Carvalho Chehab\n");
902 
903 	err = snd_card_create(index[devnr], "Em28xx Audio", THIS_MODULE, 0,
904 			      &card);
905 	if (err < 0)
906 		return err;
907 
908 	spin_lock_init(&adev->slock);
909 	adev->sndcard = card;
910 	adev->udev = dev->udev;
911 
912 	err = snd_pcm_new(card, "Em28xx Audio", 0, 0, 1, &pcm);
913 	if (err < 0)
914 		goto card_free;
915 
916 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &snd_em28xx_pcm_capture);
917 	pcm->info_flags = 0;
918 	pcm->private_data = dev;
919 	strcpy(pcm->name, "Empia 28xx Capture");
920 
921 	snd_card_set_dev(card, &dev->udev->dev);
922 	strcpy(card->driver, "Em28xx-Audio");
923 	strcpy(card->shortname, "Em28xx Audio");
924 	strcpy(card->longname, "Empia Em28xx Audio");
925 
926 	INIT_WORK(&dev->wq_trigger, audio_trigger);
927 
928 	if (dev->audio_mode.ac97 != EM28XX_NO_AC97) {
929 		em28xx_cvol_new(card, dev, "Video", AC97_VIDEO);
930 		em28xx_cvol_new(card, dev, "Line In", AC97_LINE);
931 		em28xx_cvol_new(card, dev, "Phone", AC97_PHONE);
932 		em28xx_cvol_new(card, dev, "Microphone", AC97_MIC);
933 		em28xx_cvol_new(card, dev, "CD", AC97_CD);
934 		em28xx_cvol_new(card, dev, "AUX", AC97_AUX);
935 		em28xx_cvol_new(card, dev, "PCM", AC97_PCM);
936 
937 		em28xx_cvol_new(card, dev, "Master", AC97_MASTER);
938 		em28xx_cvol_new(card, dev, "Line", AC97_HEADPHONE);
939 		em28xx_cvol_new(card, dev, "Mono", AC97_MASTER_MONO);
940 		em28xx_cvol_new(card, dev, "LFE", AC97_CENTER_LFE_MASTER);
941 		em28xx_cvol_new(card, dev, "Surround", AC97_SURROUND_MASTER);
942 	}
943 
944 	err = em28xx_audio_urb_init(dev);
945 	if (err)
946 		goto card_free;
947 
948 	err = snd_card_register(card);
949 	if (err < 0)
950 		goto urb_free;
951 
952 	em28xx_info("Audio extension successfully initialized\n");
953 	return 0;
954 
955 urb_free:
956 	em28xx_audio_free_urb(dev);
957 
958 card_free:
959 	snd_card_free(card);
960 	adev->sndcard = NULL;
961 
962 	return err;
963 }
964 
965 static int em28xx_audio_fini(struct em28xx *dev)
966 {
967 	if (dev == NULL)
968 		return 0;
969 
970 	if (dev->has_alsa_audio != 1) {
971 		/* This device does not support the extension (in this case
972 		   the device is expecting the snd-usb-audio module or
973 		   doesn't have analog audio support at all) */
974 		return 0;
975 	}
976 
977 	em28xx_info("Closing audio extension");
978 
979 	if (dev->adev.sndcard) {
980 		snd_card_disconnect(dev->adev.sndcard);
981 		flush_work(&dev->wq_trigger);
982 
983 		em28xx_audio_free_urb(dev);
984 
985 		snd_card_free(dev->adev.sndcard);
986 		dev->adev.sndcard = NULL;
987 	}
988 
989 	return 0;
990 }
991 
992 static struct em28xx_ops audio_ops = {
993 	.id   = EM28XX_AUDIO,
994 	.name = "Em28xx Audio Extension",
995 	.init = em28xx_audio_init,
996 	.fini = em28xx_audio_fini,
997 };
998 
999 static int __init em28xx_alsa_register(void)
1000 {
1001 	return em28xx_register_extension(&audio_ops);
1002 }
1003 
1004 static void __exit em28xx_alsa_unregister(void)
1005 {
1006 	em28xx_unregister_extension(&audio_ops);
1007 }
1008 
1009 MODULE_LICENSE("GPL");
1010 MODULE_AUTHOR("Markus Rechberger <mrechberger@gmail.com>");
1011 MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@redhat.com>");
1012 MODULE_DESCRIPTION(DRIVER_DESC " - audio interface");
1013 MODULE_VERSION(EM28XX_VERSION);
1014 
1015 module_init(em28xx_alsa_register);
1016 module_exit(em28xx_alsa_unregister);
1017