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 nonblock, 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 	nonblock = !!(substream->f_flags & O_NONBLOCK);
269 	if (nonblock) {
270 		if (!mutex_trylock(&dev->lock))
271 		return -EAGAIN;
272 	} else
273 		mutex_lock(&dev->lock);
274 
275 	runtime->hw = snd_em28xx_hw_capture;
276 
277 	if (dev->adev.users == 0) {
278 		if (dev->alt == 0 || dev->is_audio_only) {
279 			if (dev->is_audio_only)
280 				/* audio is on a separate interface */
281 				dev->alt = 1;
282 			else
283 				/* audio is on the same interface as video */
284 				dev->alt = 7;
285 				/*
286 				 * FIXME: The intention seems to be to select
287 				 * the alt setting with the largest
288 				 * wMaxPacketSize for the video endpoint.
289 				 * At least dev->alt should be used instead, but
290 				 * we should probably not touch it at all if it
291 				 * is already >0, because wMaxPacketSize of the
292 				 * audio endpoints seems to be the same for all.
293 				 */
294 			dprintk("changing alternate number on interface %d to %d\n",
295 				dev->ifnum, dev->alt);
296 			usb_set_interface(dev->udev, dev->ifnum, dev->alt);
297 		}
298 
299 		/* Sets volume, mute, etc */
300 		dev->mute = 0;
301 		ret = em28xx_audio_analog_set(dev);
302 		if (ret < 0)
303 			goto err;
304 	}
305 
306 	kref_get(&dev->ref);
307 	dev->adev.users++;
308 	mutex_unlock(&dev->lock);
309 
310 	/* Dynamically adjust the period size */
311 	snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
312 	snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_PERIOD_BYTES,
313 				     dev->adev.period * 95 / 100,
314 				     dev->adev.period * 105 / 100);
315 
316 	dev->adev.capture_pcm_substream = substream;
317 
318 	return 0;
319 err:
320 	mutex_unlock(&dev->lock);
321 
322 	em28xx_err("Error while configuring em28xx mixer\n");
323 	return ret;
324 }
325 
326 static int snd_em28xx_pcm_close(struct snd_pcm_substream *substream)
327 {
328 	struct em28xx *dev = snd_pcm_substream_chip(substream);
329 
330 	dprintk("closing device\n");
331 
332 	dev->mute = 1;
333 	mutex_lock(&dev->lock);
334 	dev->adev.users--;
335 	if (atomic_read(&dev->stream_started) > 0) {
336 		atomic_set(&dev->stream_started, 0);
337 		schedule_work(&dev->wq_trigger);
338 	}
339 
340 	em28xx_audio_analog_set(dev);
341 	if (substream->runtime->dma_area) {
342 		dprintk("freeing\n");
343 		vfree(substream->runtime->dma_area);
344 		substream->runtime->dma_area = NULL;
345 	}
346 	mutex_unlock(&dev->lock);
347 	kref_put(&dev->ref, em28xx_free_device);
348 
349 	return 0;
350 }
351 
352 static int snd_em28xx_hw_capture_params(struct snd_pcm_substream *substream,
353 					struct snd_pcm_hw_params *hw_params)
354 {
355 	int ret;
356 	struct em28xx *dev = snd_pcm_substream_chip(substream);
357 
358 	if (dev->disconnected)
359 		return -ENODEV;
360 
361 	dprintk("Setting capture parameters\n");
362 
363 	ret = snd_pcm_alloc_vmalloc_buffer(substream,
364 				params_buffer_bytes(hw_params));
365 	if (ret < 0)
366 		return ret;
367 #if 0
368 	/* TODO: set up em28xx audio chip to deliver the correct audio format,
369 	   current default is 48000hz multiplexed => 96000hz mono
370 	   which shouldn't matter since analogue TV only supports mono */
371 	unsigned int channels, rate, format;
372 
373 	format = params_format(hw_params);
374 	rate = params_rate(hw_params);
375 	channels = params_channels(hw_params);
376 #endif
377 
378 	return 0;
379 }
380 
381 static int snd_em28xx_hw_capture_free(struct snd_pcm_substream *substream)
382 {
383 	struct em28xx *dev = snd_pcm_substream_chip(substream);
384 
385 	dprintk("Stop capture, if needed\n");
386 
387 	if (atomic_read(&dev->stream_started) > 0) {
388 		atomic_set(&dev->stream_started, 0);
389 		schedule_work(&dev->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 *dev = container_of(work, struct em28xx, wq_trigger);
411 
412 	if (atomic_read(&dev->stream_started)) {
413 		dprintk("starting capture");
414 		em28xx_init_audio_isoc(dev);
415 	} else {
416 		dprintk("stopping capture");
417 		em28xx_deinit_isoc_audio(dev);
418 	}
419 }
420 
421 static int snd_em28xx_capture_trigger(struct snd_pcm_substream *substream,
422 				      int cmd)
423 {
424 	struct em28xx *dev = snd_pcm_substream_chip(substream);
425 	int retval = 0;
426 
427 	if (dev->disconnected)
428 		return -ENODEV;
429 
430 	switch (cmd) {
431 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: /* fall through */
432 	case SNDRV_PCM_TRIGGER_RESUME: /* fall through */
433 	case SNDRV_PCM_TRIGGER_START:
434 		atomic_set(&dev->stream_started, 1);
435 		break;
436 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH: /* fall through */
437 	case SNDRV_PCM_TRIGGER_SUSPEND: /* fall through */
438 	case SNDRV_PCM_TRIGGER_STOP:
439 		atomic_set(&dev->stream_started, 0);
440 		break;
441 	default:
442 		retval = -EINVAL;
443 	}
444 	schedule_work(&dev->wq_trigger);
445 	return retval;
446 }
447 
448 static snd_pcm_uframes_t snd_em28xx_capture_pointer(struct snd_pcm_substream
449 						    *substream)
450 {
451 	unsigned long flags;
452 	struct em28xx *dev;
453 	snd_pcm_uframes_t hwptr_done;
454 
455 	dev = snd_pcm_substream_chip(substream);
456 	if (dev->disconnected)
457 		return SNDRV_PCM_POS_XRUN;
458 
459 	spin_lock_irqsave(&dev->adev.slock, flags);
460 	hwptr_done = dev->adev.hwptr_done_capture;
461 	spin_unlock_irqrestore(&dev->adev.slock, flags);
462 
463 	return hwptr_done;
464 }
465 
466 static struct page *snd_pcm_get_vmalloc_page(struct snd_pcm_substream *subs,
467 					     unsigned long offset)
468 {
469 	void *pageptr = subs->runtime->dma_area + offset;
470 
471 	return vmalloc_to_page(pageptr);
472 }
473 
474 /*
475  * AC97 volume control support
476  */
477 static int em28xx_vol_info(struct snd_kcontrol *kcontrol,
478 				struct snd_ctl_elem_info *info)
479 {
480 	struct em28xx *dev = snd_kcontrol_chip(kcontrol);
481 
482 	if (dev->disconnected)
483 		return -ENODEV;
484 
485 	info->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
486 	info->count = 2;
487 	info->value.integer.min = 0;
488 	info->value.integer.max = 0x1f;
489 
490 	return 0;
491 }
492 
493 static int em28xx_vol_put(struct snd_kcontrol *kcontrol,
494 			       struct snd_ctl_elem_value *value)
495 {
496 	struct em28xx *dev = snd_kcontrol_chip(kcontrol);
497 	struct snd_pcm_substream *substream = dev->adev.capture_pcm_substream;
498 	u16 val = (0x1f - (value->value.integer.value[0] & 0x1f)) |
499 		  (0x1f - (value->value.integer.value[1] & 0x1f)) << 8;
500 	int nonblock = 0;
501 	int rc;
502 
503 	if (dev->disconnected)
504 		return -ENODEV;
505 
506 	if (substream)
507 		nonblock = !!(substream->f_flags & O_NONBLOCK);
508 	if (nonblock) {
509 		if (!mutex_trylock(&dev->lock))
510 			return -EAGAIN;
511 	} else
512 		mutex_lock(&dev->lock);
513 	rc = em28xx_read_ac97(dev, kcontrol->private_value);
514 	if (rc < 0)
515 		goto err;
516 
517 	val |= rc & 0x8000;	/* Preserve the mute flag */
518 
519 	rc = em28xx_write_ac97(dev, kcontrol->private_value, val);
520 	if (rc < 0)
521 		goto err;
522 
523 	dprintk("%sleft vol %d, right vol %d (0x%04x) to ac97 volume control 0x%04x\n",
524 		(val & 0x8000) ? "muted " : "",
525 		0x1f - ((val >> 8) & 0x1f), 0x1f - (val & 0x1f),
526 		val, (int)kcontrol->private_value);
527 
528 err:
529 	mutex_unlock(&dev->lock);
530 	return rc;
531 }
532 
533 static int em28xx_vol_get(struct snd_kcontrol *kcontrol,
534 			       struct snd_ctl_elem_value *value)
535 {
536 	struct em28xx *dev = snd_kcontrol_chip(kcontrol);
537 	struct snd_pcm_substream *substream = dev->adev.capture_pcm_substream;
538 	int nonblock = 0;
539 	int val;
540 
541 	if (dev->disconnected)
542 		return -ENODEV;
543 
544 	if (substream)
545 		nonblock = !!(substream->f_flags & O_NONBLOCK);
546 	if (nonblock) {
547 		if (!mutex_trylock(&dev->lock))
548 			return -EAGAIN;
549 	} else
550 		mutex_lock(&dev->lock);
551 	val = em28xx_read_ac97(dev, kcontrol->private_value);
552 	mutex_unlock(&dev->lock);
553 	if (val < 0)
554 		return val;
555 
556 	dprintk("%sleft vol %d, right vol %d (0x%04x) from ac97 volume control 0x%04x\n",
557 		(val & 0x8000) ? "muted " : "",
558 		0x1f - ((val >> 8) & 0x1f), 0x1f - (val & 0x1f),
559 		val, (int)kcontrol->private_value);
560 
561 	value->value.integer.value[0] = 0x1f - (val & 0x1f);
562 	value->value.integer.value[1] = 0x1f - ((val << 8) & 0x1f);
563 
564 	return 0;
565 }
566 
567 static int em28xx_vol_put_mute(struct snd_kcontrol *kcontrol,
568 			       struct snd_ctl_elem_value *value)
569 {
570 	struct em28xx *dev = snd_kcontrol_chip(kcontrol);
571 	u16 val = value->value.integer.value[0];
572 	struct snd_pcm_substream *substream = dev->adev.capture_pcm_substream;
573 	int nonblock = 0;
574 	int rc;
575 
576 	if (dev->disconnected)
577 		return -ENODEV;
578 
579 	if (substream)
580 		nonblock = !!(substream->f_flags & O_NONBLOCK);
581 	if (nonblock) {
582 		if (!mutex_trylock(&dev->lock))
583 			return -EAGAIN;
584 	} else
585 		mutex_lock(&dev->lock);
586 	rc = em28xx_read_ac97(dev, kcontrol->private_value);
587 	if (rc < 0)
588 		goto err;
589 
590 	if (val)
591 		rc &= 0x1f1f;
592 	else
593 		rc |= 0x8000;
594 
595 	rc = em28xx_write_ac97(dev, kcontrol->private_value, rc);
596 	if (rc < 0)
597 		goto err;
598 
599 	dprintk("%sleft vol %d, right vol %d (0x%04x) to ac97 volume control 0x%04x\n",
600 		(val & 0x8000) ? "muted " : "",
601 		0x1f - ((val >> 8) & 0x1f), 0x1f - (val & 0x1f),
602 		val, (int)kcontrol->private_value);
603 
604 err:
605 	mutex_unlock(&dev->lock);
606 	return rc;
607 }
608 
609 static int em28xx_vol_get_mute(struct snd_kcontrol *kcontrol,
610 			       struct snd_ctl_elem_value *value)
611 {
612 	struct em28xx *dev = snd_kcontrol_chip(kcontrol);
613 	struct snd_pcm_substream *substream = dev->adev.capture_pcm_substream;
614 	int nonblock = 0;
615 	int val;
616 
617 	if (dev->disconnected)
618 		return -ENODEV;
619 
620 	if (substream)
621 		nonblock = !!(substream->f_flags & O_NONBLOCK);
622 	if (nonblock) {
623 		if (!mutex_trylock(&dev->lock))
624 			return -EAGAIN;
625 	} else
626 		mutex_lock(&dev->lock);
627 	val = em28xx_read_ac97(dev, kcontrol->private_value);
628 	mutex_unlock(&dev->lock);
629 	if (val < 0)
630 		return val;
631 
632 	if (val & 0x8000)
633 		value->value.integer.value[0] = 0;
634 	else
635 		value->value.integer.value[0] = 1;
636 
637 	dprintk("%sleft vol %d, right vol %d (0x%04x) from ac97 volume control 0x%04x\n",
638 		(val & 0x8000) ? "muted " : "",
639 		0x1f - ((val >> 8) & 0x1f), 0x1f - (val & 0x1f),
640 		val, (int)kcontrol->private_value);
641 
642 	return 0;
643 }
644 
645 static const DECLARE_TLV_DB_SCALE(em28xx_db_scale, -3450, 150, 0);
646 
647 static int em28xx_cvol_new(struct snd_card *card, struct em28xx *dev,
648 			   char *name, int id)
649 {
650 	int err;
651 	char ctl_name[44];
652 	struct snd_kcontrol *kctl;
653 	struct snd_kcontrol_new tmp;
654 
655 	memset (&tmp, 0, sizeof(tmp));
656 	tmp.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
657 	tmp.private_value = id,
658 	tmp.name  = ctl_name,
659 
660 	/* Add Mute Control */
661 	sprintf(ctl_name, "%s Switch", name);
662 	tmp.get  = em28xx_vol_get_mute;
663 	tmp.put  = em28xx_vol_put_mute;
664 	tmp.info = snd_ctl_boolean_mono_info;
665 	kctl = snd_ctl_new1(&tmp, dev);
666 	err = snd_ctl_add(card, kctl);
667 	if (err < 0)
668 		return err;
669 	dprintk("Added control %s for ac97 volume control 0x%04x\n",
670 		ctl_name, id);
671 
672 	memset (&tmp, 0, sizeof(tmp));
673 	tmp.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
674 	tmp.private_value = id,
675 	tmp.name  = ctl_name,
676 
677 	/* Add Volume Control */
678 	sprintf(ctl_name, "%s Volume", name);
679 	tmp.get   = em28xx_vol_get;
680 	tmp.put   = em28xx_vol_put;
681 	tmp.info  = em28xx_vol_info;
682 	tmp.tlv.p = em28xx_db_scale,
683 	kctl = snd_ctl_new1(&tmp, dev);
684 	err = snd_ctl_add(card, kctl);
685 	if (err < 0)
686 		return err;
687 	dprintk("Added control %s for ac97 volume control 0x%04x\n",
688 		ctl_name, id);
689 
690 	return 0;
691 }
692 
693 /*
694  * register/unregister code and data
695  */
696 static struct snd_pcm_ops snd_em28xx_pcm_capture = {
697 	.open      = snd_em28xx_capture_open,
698 	.close     = snd_em28xx_pcm_close,
699 	.ioctl     = snd_pcm_lib_ioctl,
700 	.hw_params = snd_em28xx_hw_capture_params,
701 	.hw_free   = snd_em28xx_hw_capture_free,
702 	.prepare   = snd_em28xx_prepare,
703 	.trigger   = snd_em28xx_capture_trigger,
704 	.pointer   = snd_em28xx_capture_pointer,
705 	.page      = snd_pcm_get_vmalloc_page,
706 };
707 
708 static void em28xx_audio_free_urb(struct em28xx *dev)
709 {
710 	int i;
711 
712 	for (i = 0; i < dev->adev.num_urb; i++) {
713 		struct urb *urb = dev->adev.urb[i];
714 
715 		if (!urb)
716 			continue;
717 
718 		usb_free_coherent(dev->udev, urb->transfer_buffer_length,
719 				  dev->adev.transfer_buffer[i],
720 				  urb->transfer_dma);
721 
722 		usb_free_urb(urb);
723 	}
724 	kfree(dev->adev.urb);
725 	kfree(dev->adev.transfer_buffer);
726 	dev->adev.num_urb = 0;
727 }
728 
729 /* high bandwidth multiplier, as encoded in highspeed endpoint descriptors */
730 static int em28xx_audio_ep_packet_size(struct usb_device *udev,
731 					struct usb_endpoint_descriptor *e)
732 {
733 	int size = le16_to_cpu(e->wMaxPacketSize);
734 
735 	if (udev->speed == USB_SPEED_HIGH)
736 		return (size & 0x7ff) *  (1 + (((size) >> 11) & 0x03));
737 
738 	return size & 0x7ff;
739 }
740 
741 static int em28xx_audio_urb_init(struct em28xx *dev)
742 {
743 	struct usb_interface *intf;
744 	struct usb_endpoint_descriptor *e, *ep = NULL;
745 	int                 i, ep_size, interval, num_urb, npackets;
746 	int		    urb_size, bytes_per_transfer;
747 	u8 alt;
748 
749 	if (dev->ifnum)
750 		alt = 1;
751 	else
752 		alt = 7;
753 
754 	intf = usb_ifnum_to_if(dev->udev, dev->ifnum);
755 
756 	if (intf->num_altsetting <= alt) {
757 		em28xx_errdev("alt %d doesn't exist on interface %d\n",
758 			      dev->ifnum, alt);
759 		return -ENODEV;
760 	}
761 
762 	for (i = 0; i < intf->altsetting[alt].desc.bNumEndpoints; i++) {
763 		e = &intf->altsetting[alt].endpoint[i].desc;
764 		if (!usb_endpoint_dir_in(e))
765 			continue;
766 		if (e->bEndpointAddress == EM28XX_EP_AUDIO) {
767 			ep = e;
768 			break;
769 		}
770 	}
771 
772 	if (!ep) {
773 		em28xx_errdev("Couldn't find an audio endpoint");
774 		return -ENODEV;
775 	}
776 
777 	ep_size = em28xx_audio_ep_packet_size(dev->udev, ep);
778 	interval = 1 << (ep->bInterval - 1);
779 
780 	em28xx_info("Endpoint 0x%02x %s on intf %d alt %d interval = %d, size %d\n",
781 		     EM28XX_EP_AUDIO, usb_speed_string(dev->udev->speed),
782 		     dev->ifnum, alt,
783 		     interval,
784 		     ep_size);
785 
786 	/* Calculate the number and size of URBs to better fit the audio samples */
787 
788 	/*
789 	 * Estimate the number of bytes per DMA transfer.
790 	 *
791 	 * This is given by the bit rate (for now, only 48000 Hz) multiplied
792 	 * by 2 channels and 2 bytes/sample divided by the number of microframe
793 	 * intervals and by the microframe rate (125 us)
794 	 */
795 	bytes_per_transfer = DIV_ROUND_UP(48000 * 2 * 2, 125 * interval);
796 
797 	/*
798 	 * Estimate the number of transfer URBs. Don't let it go past the
799 	 * maximum number of URBs that is known to be supported by the device.
800 	 */
801 	num_urb = DIV_ROUND_UP(bytes_per_transfer, ep_size);
802 	if (num_urb > EM28XX_MAX_AUDIO_BUFS)
803 		num_urb = EM28XX_MAX_AUDIO_BUFS;
804 
805 	/*
806 	 * Now that we know the number of bytes per transfer and the number of
807 	 * URBs, estimate the typical size of an URB, in order to adjust the
808 	 * minimal number of packets.
809 	 */
810 	urb_size = bytes_per_transfer / num_urb;
811 
812 	/*
813 	 * Now, calculate the amount of audio packets to be filled on each
814 	 * URB. In order to preserve the old behaviour, use a minimal
815 	 * threshold for this value.
816 	 */
817 	npackets = EM28XX_MIN_AUDIO_PACKETS;
818 	if (urb_size > ep_size * npackets)
819 		npackets = DIV_ROUND_UP(urb_size, ep_size);
820 
821 	em28xx_info("Number of URBs: %d, with %d packets and %d size",
822 		    num_urb, npackets, urb_size);
823 
824 	/* Estimate the bytes per period */
825 	dev->adev.period = urb_size * npackets;
826 
827 	/* Allocate space to store the number of URBs to be used */
828 
829 	dev->adev.transfer_buffer = kcalloc(num_urb,
830 					    sizeof(*dev->adev.transfer_buffer),
831 					    GFP_ATOMIC);
832 	if (!dev->adev.transfer_buffer) {
833 		return -ENOMEM;
834 	}
835 
836 	dev->adev.urb = kcalloc(num_urb, sizeof(*dev->adev.urb), GFP_ATOMIC);
837 	if (!dev->adev.urb) {
838 		kfree(dev->adev.transfer_buffer);
839 		return -ENOMEM;
840 	}
841 
842 	/* Alloc memory for each URB and for each transfer buffer */
843 	dev->adev.num_urb = num_urb;
844 	for (i = 0; i < num_urb; i++) {
845 		struct urb *urb;
846 		int j, k;
847 		void *buf;
848 
849 		urb = usb_alloc_urb(npackets, GFP_ATOMIC);
850 		if (!urb) {
851 			em28xx_errdev("usb_alloc_urb failed!\n");
852 			em28xx_audio_free_urb(dev);
853 			return -ENOMEM;
854 		}
855 		dev->adev.urb[i] = urb;
856 
857 		buf = usb_alloc_coherent(dev->udev, npackets * ep_size, GFP_ATOMIC,
858 					 &urb->transfer_dma);
859 		if (!buf) {
860 			em28xx_errdev("usb_alloc_coherent failed!\n");
861 			em28xx_audio_free_urb(dev);
862 			return -ENOMEM;
863 		}
864 		dev->adev.transfer_buffer[i] = buf;
865 
866 		urb->dev = dev->udev;
867 		urb->context = dev;
868 		urb->pipe = usb_rcvisocpipe(dev->udev, EM28XX_EP_AUDIO);
869 		urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
870 		urb->transfer_buffer = buf;
871 		urb->interval = interval;
872 		urb->complete = em28xx_audio_isocirq;
873 		urb->number_of_packets = npackets;
874 		urb->transfer_buffer_length = ep_size * npackets;
875 
876 		for (j = k = 0; j < npackets; j++, k += ep_size) {
877 			urb->iso_frame_desc[j].offset = k;
878 			urb->iso_frame_desc[j].length = ep_size;
879 		}
880 	}
881 
882 	return 0;
883 }
884 
885 static int em28xx_audio_init(struct em28xx *dev)
886 {
887 	struct em28xx_audio *adev = &dev->adev;
888 	struct snd_pcm      *pcm;
889 	struct snd_card     *card;
890 	static int          devnr;
891 	int		    err;
892 
893 	if (!dev->has_alsa_audio) {
894 		/* This device does not support the extension (in this case
895 		   the device is expecting the snd-usb-audio module or
896 		   doesn't have analog audio support at all) */
897 		return 0;
898 	}
899 
900 	em28xx_info("Binding audio extension\n");
901 
902 	kref_get(&dev->ref);
903 
904 	printk(KERN_INFO "em28xx-audio.c: Copyright (C) 2006 Markus "
905 			 "Rechberger\n");
906 	printk(KERN_INFO
907 	       "em28xx-audio.c: Copyright (C) 2007-2014 Mauro Carvalho Chehab\n");
908 
909 	err = snd_card_new(&dev->udev->dev, index[devnr], "Em28xx Audio",
910 			   THIS_MODULE, 0, &card);
911 	if (err < 0)
912 		return err;
913 
914 	spin_lock_init(&adev->slock);
915 	adev->sndcard = card;
916 	adev->udev = dev->udev;
917 
918 	err = snd_pcm_new(card, "Em28xx Audio", 0, 0, 1, &pcm);
919 	if (err < 0)
920 		goto card_free;
921 
922 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &snd_em28xx_pcm_capture);
923 	pcm->info_flags = 0;
924 	pcm->private_data = dev;
925 	strcpy(pcm->name, "Empia 28xx Capture");
926 
927 	strcpy(card->driver, "Em28xx-Audio");
928 	strcpy(card->shortname, "Em28xx Audio");
929 	strcpy(card->longname, "Empia Em28xx Audio");
930 
931 	INIT_WORK(&dev->wq_trigger, audio_trigger);
932 
933 	if (dev->audio_mode.ac97 != EM28XX_NO_AC97) {
934 		em28xx_cvol_new(card, dev, "Video", AC97_VIDEO);
935 		em28xx_cvol_new(card, dev, "Line In", AC97_LINE);
936 		em28xx_cvol_new(card, dev, "Phone", AC97_PHONE);
937 		em28xx_cvol_new(card, dev, "Microphone", AC97_MIC);
938 		em28xx_cvol_new(card, dev, "CD", AC97_CD);
939 		em28xx_cvol_new(card, dev, "AUX", AC97_AUX);
940 		em28xx_cvol_new(card, dev, "PCM", AC97_PCM);
941 
942 		em28xx_cvol_new(card, dev, "Master", AC97_MASTER);
943 		em28xx_cvol_new(card, dev, "Line", AC97_HEADPHONE);
944 		em28xx_cvol_new(card, dev, "Mono", AC97_MASTER_MONO);
945 		em28xx_cvol_new(card, dev, "LFE", AC97_CENTER_LFE_MASTER);
946 		em28xx_cvol_new(card, dev, "Surround", AC97_SURROUND_MASTER);
947 	}
948 
949 	err = em28xx_audio_urb_init(dev);
950 	if (err)
951 		goto card_free;
952 
953 	err = snd_card_register(card);
954 	if (err < 0)
955 		goto urb_free;
956 
957 	em28xx_info("Audio extension successfully initialized\n");
958 	return 0;
959 
960 urb_free:
961 	em28xx_audio_free_urb(dev);
962 
963 card_free:
964 	snd_card_free(card);
965 	adev->sndcard = NULL;
966 
967 	return err;
968 }
969 
970 static int em28xx_audio_fini(struct em28xx *dev)
971 {
972 	if (dev == NULL)
973 		return 0;
974 
975 	if (!dev->has_alsa_audio) {
976 		/* This device does not support the extension (in this case
977 		   the device is expecting the snd-usb-audio module or
978 		   doesn't have analog audio support at all) */
979 		return 0;
980 	}
981 
982 	em28xx_info("Closing audio extension");
983 
984 	if (dev->adev.sndcard) {
985 		snd_card_disconnect(dev->adev.sndcard);
986 		flush_work(&dev->wq_trigger);
987 
988 		em28xx_audio_free_urb(dev);
989 
990 		snd_card_free(dev->adev.sndcard);
991 		dev->adev.sndcard = NULL;
992 	}
993 
994 	kref_put(&dev->ref, em28xx_free_device);
995 	return 0;
996 }
997 
998 static int em28xx_audio_suspend(struct em28xx *dev)
999 {
1000 	if (dev == NULL)
1001 		return 0;
1002 
1003 	if (!dev->has_alsa_audio)
1004 		return 0;
1005 
1006 	em28xx_info("Suspending audio extension");
1007 	em28xx_deinit_isoc_audio(dev);
1008 	atomic_set(&dev->stream_started, 0);
1009 	return 0;
1010 }
1011 
1012 static int em28xx_audio_resume(struct em28xx *dev)
1013 {
1014 	if (dev == NULL)
1015 		return 0;
1016 
1017 	if (!dev->has_alsa_audio)
1018 		return 0;
1019 
1020 	em28xx_info("Resuming audio extension");
1021 	/* Nothing to do other than schedule_work() ?? */
1022 	schedule_work(&dev->wq_trigger);
1023 	return 0;
1024 }
1025 
1026 static struct em28xx_ops audio_ops = {
1027 	.id   = EM28XX_AUDIO,
1028 	.name = "Em28xx Audio Extension",
1029 	.init = em28xx_audio_init,
1030 	.fini = em28xx_audio_fini,
1031 	.suspend = em28xx_audio_suspend,
1032 	.resume = em28xx_audio_resume,
1033 };
1034 
1035 static int __init em28xx_alsa_register(void)
1036 {
1037 	return em28xx_register_extension(&audio_ops);
1038 }
1039 
1040 static void __exit em28xx_alsa_unregister(void)
1041 {
1042 	em28xx_unregister_extension(&audio_ops);
1043 }
1044 
1045 MODULE_LICENSE("GPL");
1046 MODULE_AUTHOR("Markus Rechberger <mrechberger@gmail.com>");
1047 MODULE_AUTHOR("Mauro Carvalho Chehab");
1048 MODULE_DESCRIPTION(DRIVER_DESC " - audio interface");
1049 MODULE_VERSION(EM28XX_VERSION);
1050 
1051 module_init(em28xx_alsa_register);
1052 module_exit(em28xx_alsa_unregister);
1053