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  1/*
  2 *  Empiatech em28x1 audio extension
  3 *
  4 *  Copyright (C) 2006 Markus Rechberger <mrechberger@gmail.com>
  5 *
  6 *  Copyright (C) 2007-2011 Mauro Carvalho Chehab <mchehab@redhat.com>
  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 <media/v4l2-common.h>
 46#include "em28xx.h"
 47
 48static int debug;
 49module_param(debug, int, 0644);
 50MODULE_PARM_DESC(debug, "activates debug info");
 51
 52#define dprintk(fmt, arg...) do {					\
 53	    if (debug)							\
 54		printk(KERN_INFO "em28xx-audio %s: " fmt,		\
 55				  __func__, ##arg); 		\
 56	} while (0)
 57
 58static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;
 59
 60static int em28xx_deinit_isoc_audio(struct em28xx *dev)
 61{
 62	int i;
 63
 64	dprintk("Stopping isoc\n");
 65	for (i = 0; i < EM28XX_AUDIO_BUFS; i++) {
 66		if (!irqs_disabled())
 67			usb_kill_urb(dev->adev.urb[i]);
 68		else
 69			usb_unlink_urb(dev->adev.urb[i]);
 70
 71		usb_free_urb(dev->adev.urb[i]);
 72		dev->adev.urb[i] = NULL;
 73
 74		kfree(dev->adev.transfer_buffer[i]);
 75		dev->adev.transfer_buffer[i] = NULL;
 76	}
 77
 78	return 0;
 79}
 80
 81static 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	switch (urb->status) {
 94	case 0:             /* success */
 95	case -ETIMEDOUT:    /* NAK */
 96		break;
 97	case -ECONNRESET:   /* kill */
 98	case -ENOENT:
 99	case -ESHUTDOWN:
100		return;
101	default:            /* error */
102		dprintk("urb completition error %d.\n", urb->status);
103		break;
104	}
105
106	if (atomic_read(&dev->stream_started) == 0)
107		return;
108
109	if (dev->adev.capture_pcm_substream) {
110		substream = dev->adev.capture_pcm_substream;
111		runtime = substream->runtime;
112		stride = runtime->frame_bits >> 3;
113
114		for (i = 0; i < urb->number_of_packets; i++) {
115			int length =
116			    urb->iso_frame_desc[i].actual_length / stride;
117			cp = (unsigned char *)urb->transfer_buffer +
118			    urb->iso_frame_desc[i].offset;
119
120			if (!length)
121				continue;
122
123			oldptr = dev->adev.hwptr_done_capture;
124			if (oldptr + length >= runtime->buffer_size) {
125				unsigned int cnt =
126				    runtime->buffer_size - oldptr;
127				memcpy(runtime->dma_area + oldptr * stride, cp,
128				       cnt * stride);
129				memcpy(runtime->dma_area, cp + cnt * stride,
130				       length * stride - cnt * stride);
131			} else {
132				memcpy(runtime->dma_area + oldptr * stride, cp,
133				       length * stride);
134			}
135
136			snd_pcm_stream_lock(substream);
137
138			dev->adev.hwptr_done_capture += length;
139			if (dev->adev.hwptr_done_capture >=
140			    runtime->buffer_size)
141				dev->adev.hwptr_done_capture -=
142				    runtime->buffer_size;
143
144			dev->adev.capture_transfer_done += length;
145			if (dev->adev.capture_transfer_done >=
146			    runtime->period_size) {
147				dev->adev.capture_transfer_done -=
148				    runtime->period_size;
149				period_elapsed = 1;
150			}
151
152			snd_pcm_stream_unlock(substream);
153		}
154		if (period_elapsed)
155			snd_pcm_period_elapsed(substream);
156	}
157	urb->status = 0;
158
159	status = usb_submit_urb(urb, GFP_ATOMIC);
160	if (status < 0) {
161		em28xx_errdev("resubmit of audio urb failed (error=%i)\n",
162			      status);
163	}
164	return;
165}
166
167static int em28xx_init_audio_isoc(struct em28xx *dev)
168{
169	int       i, errCode;
170	const int sb_size = EM28XX_NUM_AUDIO_PACKETS *
171			    EM28XX_AUDIO_MAX_PACKET_SIZE;
172
173	dprintk("Starting isoc transfers\n");
174
175	for (i = 0; i < EM28XX_AUDIO_BUFS; i++) {
176		struct urb *urb;
177		int j, k;
178
179		dev->adev.transfer_buffer[i] = kmalloc(sb_size, GFP_ATOMIC);
180		if (!dev->adev.transfer_buffer[i])
181			return -ENOMEM;
182
183		memset(dev->adev.transfer_buffer[i], 0x80, sb_size);
184		urb = usb_alloc_urb(EM28XX_NUM_AUDIO_PACKETS, GFP_ATOMIC);
185		if (!urb) {
186			em28xx_errdev("usb_alloc_urb failed!\n");
187			for (j = 0; j < i; j++) {
188				usb_free_urb(dev->adev.urb[j]);
189				kfree(dev->adev.transfer_buffer[j]);
190			}
191			return -ENOMEM;
192		}
193
194		urb->dev = dev->udev;
195		urb->context = dev;
196		urb->pipe = usb_rcvisocpipe(dev->udev, EM28XX_EP_AUDIO);
197		urb->transfer_flags = URB_ISO_ASAP;
198		urb->transfer_buffer = dev->adev.transfer_buffer[i];
199		urb->interval = 1;
200		urb->complete = em28xx_audio_isocirq;
201		urb->number_of_packets = EM28XX_NUM_AUDIO_PACKETS;
202		urb->transfer_buffer_length = sb_size;
203
204		for (j = k = 0; j < EM28XX_NUM_AUDIO_PACKETS;
205			     j++, k += EM28XX_AUDIO_MAX_PACKET_SIZE) {
206			urb->iso_frame_desc[j].offset = k;
207			urb->iso_frame_desc[j].length =
208			    EM28XX_AUDIO_MAX_PACKET_SIZE;
209		}
210		dev->adev.urb[i] = urb;
211	}
212
213	for (i = 0; i < EM28XX_AUDIO_BUFS; i++) {
214		errCode = usb_submit_urb(dev->adev.urb[i], GFP_ATOMIC);
215		if (errCode) {
216			em28xx_errdev("submit of audio urb failed\n");
217			em28xx_deinit_isoc_audio(dev);
218			atomic_set(&dev->stream_started, 0);
219			return errCode;
220		}
221
222	}
223
224	return 0;
225}
226
227static int snd_pcm_alloc_vmalloc_buffer(struct snd_pcm_substream *subs,
228					size_t size)
229{
230	struct snd_pcm_runtime *runtime = subs->runtime;
231
232	dprintk("Allocating vbuffer\n");
233	if (runtime->dma_area) {
234		if (runtime->dma_bytes > size)
235			return 0;
236
237		vfree(runtime->dma_area);
238	}
239	runtime->dma_area = vmalloc(size);
240	if (!runtime->dma_area)
241		return -ENOMEM;
242
243	runtime->dma_bytes = size;
244
245	return 0;
246}
247
248static struct snd_pcm_hardware snd_em28xx_hw_capture = {
249	.info = SNDRV_PCM_INFO_BLOCK_TRANSFER |
250		SNDRV_PCM_INFO_MMAP           |
251		SNDRV_PCM_INFO_INTERLEAVED    |
252		SNDRV_PCM_INFO_BATCH	      |
253		SNDRV_PCM_INFO_MMAP_VALID,
254
255	.formats = SNDRV_PCM_FMTBIT_S16_LE,
256
257	.rates = SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_KNOT,
258
259	.rate_min = 48000,
260	.rate_max = 48000,
261	.channels_min = 2,
262	.channels_max = 2,
263	.buffer_bytes_max = 62720 * 8,	/* just about the value in usbaudio.c */
264	.period_bytes_min = 64,		/* 12544/2, */
265	.period_bytes_max = 12544,
266	.periods_min = 2,
267	.periods_max = 98,		/* 12544, */
268};
269
270static int snd_em28xx_capture_open(struct snd_pcm_substream *substream)
271{
272	struct em28xx *dev = snd_pcm_substream_chip(substream);
273	struct snd_pcm_runtime *runtime = substream->runtime;
274	int ret = 0;
275
276	dprintk("opening device and trying to acquire exclusive lock\n");
277
278	if (!dev) {
279		em28xx_err("BUG: em28xx can't find device struct."
280				" Can't proceed with open\n");
281		return -ENODEV;
282	}
283
284	runtime->hw = snd_em28xx_hw_capture;
285	if ((dev->alt == 0 || dev->audio_ifnum) && dev->adev.users == 0) {
286		if (dev->audio_ifnum)
287			dev->alt = 1;
288		else
289			dev->alt = 7;
290
291		dprintk("changing alternate number on interface %d to %d\n",
292			dev->audio_ifnum, dev->alt);
293		usb_set_interface(dev->udev, dev->audio_ifnum, dev->alt);
294
295		/* Sets volume, mute, etc */
296		dev->mute = 0;
297		mutex_lock(&dev->lock);
298		ret = em28xx_audio_analog_set(dev);
299		if (ret < 0)
300			goto err;
301
302		dev->adev.users++;
303		mutex_unlock(&dev->lock);
304	}
305
306	snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
307	dev->adev.capture_pcm_substream = substream;
308	runtime->private_data = dev;
309
310	return 0;
311err:
312	mutex_unlock(&dev->lock);
313
314	em28xx_err("Error while configuring em28xx mixer\n");
315	return ret;
316}
317
318static int snd_em28xx_pcm_close(struct snd_pcm_substream *substream)
319{
320	struct em28xx *dev = snd_pcm_substream_chip(substream);
321
322	dprintk("closing device\n");
323
324	dev->mute = 1;
325	mutex_lock(&dev->lock);
326	dev->adev.users--;
327	if (atomic_read(&dev->stream_started) > 0) {
328		atomic_set(&dev->stream_started, 0);
329		schedule_work(&dev->wq_trigger);
330	}
331
332	em28xx_audio_analog_set(dev);
333	if (substream->runtime->dma_area) {
334		dprintk("freeing\n");
335		vfree(substream->runtime->dma_area);
336		substream->runtime->dma_area = NULL;
337	}
338	mutex_unlock(&dev->lock);
339
340	return 0;
341}
342
343static int snd_em28xx_hw_capture_params(struct snd_pcm_substream *substream,
344					struct snd_pcm_hw_params *hw_params)
345{
346	int ret;
347
348	dprintk("Setting capture parameters\n");
349
350	ret = snd_pcm_alloc_vmalloc_buffer(substream,
351				params_buffer_bytes(hw_params));
352	if (ret < 0)
353		return ret;
354#if 0
355	/* TODO: set up em28xx audio chip to deliver the correct audio format,
356	   current default is 48000hz multiplexed => 96000hz mono
357	   which shouldn't matter since analogue TV only supports mono */
358	unsigned int channels, rate, format;
359
360	format = params_format(hw_params);
361	rate = params_rate(hw_params);
362	channels = params_channels(hw_params);
363#endif
364
365	return 0;
366}
367
368static int snd_em28xx_hw_capture_free(struct snd_pcm_substream *substream)
369{
370	struct em28xx *dev = snd_pcm_substream_chip(substream);
371
372	dprintk("Stop capture, if needed\n");
373
374	if (atomic_read(&dev->stream_started) > 0) {
375		atomic_set(&dev->stream_started, 0);
376		schedule_work(&dev->wq_trigger);
377	}
378
379	return 0;
380}
381
382static int snd_em28xx_prepare(struct snd_pcm_substream *substream)
383{
384	struct em28xx *dev = snd_pcm_substream_chip(substream);
385
386	dev->adev.hwptr_done_capture = 0;
387	dev->adev.capture_transfer_done = 0;
388
389	return 0;
390}
391
392static void audio_trigger(struct work_struct *work)
393{
394	struct em28xx *dev = container_of(work, struct em28xx, wq_trigger);
395
396	if (atomic_read(&dev->stream_started)) {
397		dprintk("starting capture");
398		em28xx_init_audio_isoc(dev);
399	} else {
400		dprintk("stopping capture");
401		em28xx_deinit_isoc_audio(dev);
402	}
403}
404
405static int snd_em28xx_capture_trigger(struct snd_pcm_substream *substream,
406				      int cmd)
407{
408	struct em28xx *dev = snd_pcm_substream_chip(substream);
409	int retval = 0;
410
411	switch (cmd) {
412	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: /* fall through */
413	case SNDRV_PCM_TRIGGER_RESUME: /* fall through */
414	case SNDRV_PCM_TRIGGER_START:
415		atomic_set(&dev->stream_started, 1);
416		break;
417	case SNDRV_PCM_TRIGGER_PAUSE_PUSH: /* fall through */
418	case SNDRV_PCM_TRIGGER_SUSPEND: /* fall through */
419	case SNDRV_PCM_TRIGGER_STOP:
420		atomic_set(&dev->stream_started, 0);
421		break;
422	default:
423		retval = -EINVAL;
424	}
425	schedule_work(&dev->wq_trigger);
426	return retval;
427}
428
429static snd_pcm_uframes_t snd_em28xx_capture_pointer(struct snd_pcm_substream
430						    *substream)
431{
432	unsigned long flags;
433	struct em28xx *dev;
434	snd_pcm_uframes_t hwptr_done;
435
436	dev = snd_pcm_substream_chip(substream);
437	spin_lock_irqsave(&dev->adev.slock, flags);
438	hwptr_done = dev->adev.hwptr_done_capture;
439	spin_unlock_irqrestore(&dev->adev.slock, flags);
440
441	return hwptr_done;
442}
443
444static struct page *snd_pcm_get_vmalloc_page(struct snd_pcm_substream *subs,
445					     unsigned long offset)
446{
447	void *pageptr = subs->runtime->dma_area + offset;
448
449	return vmalloc_to_page(pageptr);
450}
451
452/*
453 * AC97 volume control support
454 */
455static int em28xx_vol_info(struct snd_kcontrol *kcontrol,
456				struct snd_ctl_elem_info *info)
457{
458	info->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
459	info->count = 2;
460	info->value.integer.min = 0;
461	info->value.integer.max = 0x1f;
462
463	return 0;
464}
465
466static int em28xx_vol_put(struct snd_kcontrol *kcontrol,
467			       struct snd_ctl_elem_value *value)
468{
469	struct em28xx *dev = snd_kcontrol_chip(kcontrol);
470	u16 val = (0x1f - (value->value.integer.value[0] & 0x1f)) |
471		  (0x1f - (value->value.integer.value[1] & 0x1f)) << 8;
472	int rc;
473
474	mutex_lock(&dev->lock);
475	rc = em28xx_read_ac97(dev, kcontrol->private_value);
476	if (rc < 0)
477		goto err;
478
479	val |= rc & 0x8000;	/* Preserve the mute flag */
480
481	rc = em28xx_write_ac97(dev, kcontrol->private_value, val);
482	if (rc < 0)
483		goto err;
484
485	dprintk("%sleft vol %d, right vol %d (0x%04x) to ac97 volume control 0x%04x\n",
486		(val & 0x8000) ? "muted " : "",
487		0x1f - ((val >> 8) & 0x1f), 0x1f - (val & 0x1f),
488		val, (int)kcontrol->private_value);
489
490err:
491	mutex_unlock(&dev->lock);
492	return rc;
493}
494
495static int em28xx_vol_get(struct snd_kcontrol *kcontrol,
496			       struct snd_ctl_elem_value *value)
497{
498	struct em28xx *dev = snd_kcontrol_chip(kcontrol);
499	int val;
500
501	mutex_lock(&dev->lock);
502	val = em28xx_read_ac97(dev, kcontrol->private_value);
503	mutex_unlock(&dev->lock);
504	if (val < 0)
505		return val;
506
507	dprintk("%sleft vol %d, right vol %d (0x%04x) from ac97 volume control 0x%04x\n",
508		(val & 0x8000) ? "muted " : "",
509		0x1f - ((val >> 8) & 0x1f), 0x1f - (val & 0x1f),
510		val, (int)kcontrol->private_value);
511
512	value->value.integer.value[0] = 0x1f - (val & 0x1f);
513	value->value.integer.value[1] = 0x1f - ((val << 8) & 0x1f);
514
515	return 0;
516}
517
518static int em28xx_vol_put_mute(struct snd_kcontrol *kcontrol,
519			       struct snd_ctl_elem_value *value)
520{
521	struct em28xx *dev = snd_kcontrol_chip(kcontrol);
522	u16 val = value->value.integer.value[0];
523	int rc;
524
525	mutex_lock(&dev->lock);
526	rc = em28xx_read_ac97(dev, kcontrol->private_value);
527	if (rc < 0)
528		goto err;
529
530	if (val)
531		rc &= 0x1f1f;
532	else
533		rc |= 0x8000;
534
535	rc = em28xx_write_ac97(dev, kcontrol->private_value, rc);
536	if (rc < 0)
537		goto err;
538
539	dprintk("%sleft vol %d, right vol %d (0x%04x) to ac97 volume control 0x%04x\n",
540		(val & 0x8000) ? "muted " : "",
541		0x1f - ((val >> 8) & 0x1f), 0x1f - (val & 0x1f),
542		val, (int)kcontrol->private_value);
543
544err:
545	mutex_unlock(&dev->lock);
546	return rc;
547}
548
549static int em28xx_vol_get_mute(struct snd_kcontrol *kcontrol,
550			       struct snd_ctl_elem_value *value)
551{
552	struct em28xx *dev = snd_kcontrol_chip(kcontrol);
553	int val;
554
555	mutex_lock(&dev->lock);
556	val = em28xx_read_ac97(dev, kcontrol->private_value);
557	mutex_unlock(&dev->lock);
558	if (val < 0)
559		return val;
560
561	if (val & 0x8000)
562		value->value.integer.value[0] = 0;
563	else
564		value->value.integer.value[0] = 1;
565
566	dprintk("%sleft vol %d, right vol %d (0x%04x) from ac97 volume control 0x%04x\n",
567		(val & 0x8000) ? "muted " : "",
568		0x1f - ((val >> 8) & 0x1f), 0x1f - (val & 0x1f),
569		val, (int)kcontrol->private_value);
570
571	return 0;
572}
573
574static const DECLARE_TLV_DB_SCALE(em28xx_db_scale, -3450, 150, 0);
575
576static int em28xx_cvol_new(struct snd_card *card, struct em28xx *dev,
577			   char *name, int id)
578{
579	int err;
580	char ctl_name[44];
581	struct snd_kcontrol *kctl;
582	struct snd_kcontrol_new tmp;
583
584	memset (&tmp, 0, sizeof(tmp));
585	tmp.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
586	tmp.private_value = id,
587	tmp.name  = ctl_name,
588
589	/* Add Mute Control */
590	sprintf(ctl_name, "%s Switch", name);
591	tmp.get  = em28xx_vol_get_mute;
592	tmp.put  = em28xx_vol_put_mute;
593	tmp.info = snd_ctl_boolean_mono_info;
594	kctl = snd_ctl_new1(&tmp, dev);
595	err = snd_ctl_add(card, kctl);
596	if (err < 0)
597		return err;
598	dprintk("Added control %s for ac97 volume control 0x%04x\n",
599		ctl_name, id);
600
601	memset (&tmp, 0, sizeof(tmp));
602	tmp.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
603	tmp.private_value = id,
604	tmp.name  = ctl_name,
605
606	/* Add Volume Control */
607	sprintf(ctl_name, "%s Volume", name);
608	tmp.get   = em28xx_vol_get;
609	tmp.put   = em28xx_vol_put;
610	tmp.info  = em28xx_vol_info;
611	tmp.tlv.p = em28xx_db_scale,
612	kctl = snd_ctl_new1(&tmp, dev);
613	err = snd_ctl_add(card, kctl);
614	if (err < 0)
615		return err;
616	dprintk("Added control %s for ac97 volume control 0x%04x\n",
617		ctl_name, id);
618
619	return 0;
620}
621
622/*
623 * register/unregister code and data
624 */
625static struct snd_pcm_ops snd_em28xx_pcm_capture = {
626	.open      = snd_em28xx_capture_open,
627	.close     = snd_em28xx_pcm_close,
628	.ioctl     = snd_pcm_lib_ioctl,
629	.hw_params = snd_em28xx_hw_capture_params,
630	.hw_free   = snd_em28xx_hw_capture_free,
631	.prepare   = snd_em28xx_prepare,
632	.trigger   = snd_em28xx_capture_trigger,
633	.pointer   = snd_em28xx_capture_pointer,
634	.page      = snd_pcm_get_vmalloc_page,
635};
636
637static int em28xx_audio_init(struct em28xx *dev)
638{
639	struct em28xx_audio *adev = &dev->adev;
640	struct snd_pcm      *pcm;
641	struct snd_card     *card;
642	static int          devnr;
643	int                 err;
644
645	if (!dev->has_alsa_audio || dev->audio_ifnum < 0) {
646		/* This device does not support the extension (in this case
647		   the device is expecting the snd-usb-audio module or
648		   doesn't have analog audio support at all) */
649		return 0;
650	}
651
652	printk(KERN_INFO "em28xx-audio.c: probing for em28xx Audio Vendor Class\n");
653	printk(KERN_INFO "em28xx-audio.c: Copyright (C) 2006 Markus "
654			 "Rechberger\n");
655	printk(KERN_INFO "em28xx-audio.c: Copyright (C) 2007-2011 Mauro Carvalho Chehab\n");
656
657	err = snd_card_create(index[devnr], "Em28xx Audio", THIS_MODULE, 0,
658			      &card);
659	if (err < 0)
660		return err;
661
662	spin_lock_init(&adev->slock);
663	err = snd_pcm_new(card, "Em28xx Audio", 0, 0, 1, &pcm);
664	if (err < 0) {
665		snd_card_free(card);
666		return err;
667	}
668
669	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &snd_em28xx_pcm_capture);
670	pcm->info_flags = 0;
671	pcm->private_data = dev;
672	strcpy(pcm->name, "Empia 28xx Capture");
673
674	snd_card_set_dev(card, &dev->udev->dev);
675	strcpy(card->driver, "Em28xx-Audio");
676	strcpy(card->shortname, "Em28xx Audio");
677	strcpy(card->longname, "Empia Em28xx Audio");
678
679	INIT_WORK(&dev->wq_trigger, audio_trigger);
680
681	if (dev->audio_mode.ac97 != EM28XX_NO_AC97) {
682		em28xx_cvol_new(card, dev, "Video", AC97_VIDEO_VOL);
683		em28xx_cvol_new(card, dev, "Line In", AC97_LINEIN_VOL);
684		em28xx_cvol_new(card, dev, "Phone", AC97_PHONE_VOL);
685		em28xx_cvol_new(card, dev, "Microphone", AC97_PHONE_VOL);
686		em28xx_cvol_new(card, dev, "CD", AC97_CD_VOL);
687		em28xx_cvol_new(card, dev, "AUX", AC97_AUX_VOL);
688		em28xx_cvol_new(card, dev, "PCM", AC97_PCM_OUT_VOL);
689
690		em28xx_cvol_new(card, dev, "Master", AC97_MASTER_VOL);
691		em28xx_cvol_new(card, dev, "Line", AC97_LINE_LEVEL_VOL);
692		em28xx_cvol_new(card, dev, "Mono", AC97_MASTER_MONO_VOL);
693		em28xx_cvol_new(card, dev, "LFE", AC97_LFE_MASTER_VOL);
694		em28xx_cvol_new(card, dev, "Surround", AC97_SURR_MASTER_VOL);
695	}
696
697	err = snd_card_register(card);
698	if (err < 0) {
699		snd_card_free(card);
700		return err;
701	}
702	adev->sndcard = card;
703	adev->udev = dev->udev;
704
705	return 0;
706}
707
708static int em28xx_audio_fini(struct em28xx *dev)
709{
710	if (dev == NULL)
711		return 0;
712
713	if (dev->has_alsa_audio != 1) {
714		/* This device does not support the extension (in this case
715		   the device is expecting the snd-usb-audio module or
716		   doesn't have analog audio support at all) */
717		return 0;
718	}
719
720	if (dev->adev.sndcard) {
721		snd_card_free(dev->adev.sndcard);
722		dev->adev.sndcard = NULL;
723	}
724
725	return 0;
726}
727
728static struct em28xx_ops audio_ops = {
729	.id   = EM28XX_AUDIO,
730	.name = "Em28xx Audio Extension",
731	.init = em28xx_audio_init,
732	.fini = em28xx_audio_fini,
733};
734
735static int __init em28xx_alsa_register(void)
736{
737	return em28xx_register_extension(&audio_ops);
738}
739
740static void __exit em28xx_alsa_unregister(void)
741{
742	em28xx_unregister_extension(&audio_ops);
743}
744
745MODULE_LICENSE("GPL");
746MODULE_AUTHOR("Markus Rechberger <mrechberger@gmail.com>");
747MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@redhat.com>");
748MODULE_DESCRIPTION("Em28xx Audio driver");
749
750module_init(em28xx_alsa_register);
751module_exit(em28xx_alsa_unregister);