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  1/*
  2 *  Conexant Cx231xx audio extension
  3 *
  4 *  Copyright (C) 2008 <srinivasa.deevi at conexant dot com>
  5 *       Based on em28xx driver
  6 *
  7 *
  8 *  This program is free software; you can redistribute it and/or modify
  9 *  it under the terms of the GNU General Public License as published by
 10 *  the Free Software Foundation; either version 2 of the License, or
 11 *  (at your option) any later version.
 12 *
 13 *  This program is distributed in the hope that it will be useful,
 14 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 15 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 16 *  GNU General Public License for more details.
 17 *
 18 *  You should have received a copy of the GNU General Public License
 19 *  along with this program; if not, write to the Free Software
 20 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 21 */
 22
 23#include <linux/kernel.h>
 24#include <linux/usb.h>
 25#include <linux/init.h>
 26#include <linux/sound.h>
 27#include <linux/spinlock.h>
 28#include <linux/soundcard.h>
 29#include <linux/slab.h>
 30#include <linux/vmalloc.h>
 31#include <linux/proc_fs.h>
 32#include <linux/module.h>
 33#include <sound/core.h>
 34#include <sound/pcm.h>
 35#include <sound/pcm_params.h>
 36#include <sound/info.h>
 37#include <sound/initval.h>
 38#include <sound/control.h>
 39#include <media/v4l2-common.h>
 40#include "cx231xx.h"
 41
 42static int debug;
 43module_param(debug, int, 0644);
 44MODULE_PARM_DESC(debug, "activates debug info");
 45
 46#define dprintk(fmt, arg...) do {					\
 47		if (debug)						\
 48			printk(KERN_INFO "cx231xx-audio %s: " fmt,	\
 49				__func__, ##arg); 			\
 50	} while (0)
 51
 52static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;
 53
 54static int cx231xx_isoc_audio_deinit(struct cx231xx *dev)
 55{
 56	int i;
 57
 58	dprintk("Stopping isoc\n");
 59
 60	for (i = 0; i < CX231XX_AUDIO_BUFS; i++) {
 61		if (dev->adev.urb[i]) {
 62			if (!irqs_disabled())
 63				usb_kill_urb(dev->adev.urb[i]);
 64			else
 65				usb_unlink_urb(dev->adev.urb[i]);
 66
 67			usb_free_urb(dev->adev.urb[i]);
 68			dev->adev.urb[i] = NULL;
 69
 70			kfree(dev->adev.transfer_buffer[i]);
 71			dev->adev.transfer_buffer[i] = NULL;
 72		}
 73	}
 74
 75	return 0;
 76}
 77
 78static int cx231xx_bulk_audio_deinit(struct cx231xx *dev)
 79{
 80	int i;
 81
 82	dprintk("Stopping bulk\n");
 83
 84	for (i = 0; i < CX231XX_AUDIO_BUFS; i++) {
 85		if (dev->adev.urb[i]) {
 86			if (!irqs_disabled())
 87				usb_kill_urb(dev->adev.urb[i]);
 88			else
 89				usb_unlink_urb(dev->adev.urb[i]);
 90
 91			usb_free_urb(dev->adev.urb[i]);
 92			dev->adev.urb[i] = NULL;
 93
 94			kfree(dev->adev.transfer_buffer[i]);
 95			dev->adev.transfer_buffer[i] = NULL;
 96		}
 97	}
 98
 99	return 0;
100}
101
102static void cx231xx_audio_isocirq(struct urb *urb)
103{
104	struct cx231xx *dev = urb->context;
105	int i;
106	unsigned int oldptr;
107	int period_elapsed = 0;
108	int status;
109	unsigned char *cp;
110	unsigned int stride;
111	struct snd_pcm_substream *substream;
112	struct snd_pcm_runtime *runtime;
113
114	if (dev->state & DEV_DISCONNECTED)
115		return;
116
117	switch (urb->status) {
118	case 0:		/* success */
119	case -ETIMEDOUT:	/* NAK */
120		break;
121	case -ECONNRESET:	/* kill */
122	case -ENOENT:
123	case -ESHUTDOWN:
124		return;
125	default:		/* error */
126		dprintk("urb completition error %d.\n", urb->status);
127		break;
128	}
129
130	if (atomic_read(&dev->stream_started) == 0)
131		return;
132
133	if (dev->adev.capture_pcm_substream) {
134		substream = dev->adev.capture_pcm_substream;
135		runtime = substream->runtime;
136		stride = runtime->frame_bits >> 3;
137
138		for (i = 0; i < urb->number_of_packets; i++) {
139			int length = urb->iso_frame_desc[i].actual_length /
140				     stride;
141			cp = (unsigned char *)urb->transfer_buffer +
142					      urb->iso_frame_desc[i].offset;
143
144			if (!length)
145				continue;
146
147			oldptr = dev->adev.hwptr_done_capture;
148			if (oldptr + length >= runtime->buffer_size) {
149				unsigned int cnt;
150
151				cnt = runtime->buffer_size - oldptr;
152				memcpy(runtime->dma_area + oldptr * stride, cp,
153				       cnt * stride);
154				memcpy(runtime->dma_area, cp + cnt * stride,
155				       length * stride - cnt * stride);
156			} else {
157				memcpy(runtime->dma_area + oldptr * stride, cp,
158				       length * stride);
159			}
160
161			snd_pcm_stream_lock(substream);
162
163			dev->adev.hwptr_done_capture += length;
164			if (dev->adev.hwptr_done_capture >=
165						runtime->buffer_size)
166				dev->adev.hwptr_done_capture -=
167						runtime->buffer_size;
168
169			dev->adev.capture_transfer_done += length;
170			if (dev->adev.capture_transfer_done >=
171				runtime->period_size) {
172				dev->adev.capture_transfer_done -=
173						runtime->period_size;
174				period_elapsed = 1;
175			}
176			snd_pcm_stream_unlock(substream);
177		}
178		if (period_elapsed)
179			snd_pcm_period_elapsed(substream);
180	}
181	urb->status = 0;
182
183	status = usb_submit_urb(urb, GFP_ATOMIC);
184	if (status < 0) {
185		cx231xx_errdev("resubmit of audio urb failed (error=%i)\n",
186			       status);
187	}
188	return;
189}
190
191static void cx231xx_audio_bulkirq(struct urb *urb)
192{
193	struct cx231xx *dev = urb->context;
194	unsigned int oldptr;
195	int period_elapsed = 0;
196	int status;
197	unsigned char *cp;
198	unsigned int stride;
199	struct snd_pcm_substream *substream;
200	struct snd_pcm_runtime *runtime;
201
202	if (dev->state & DEV_DISCONNECTED)
203		return;
204
205	switch (urb->status) {
206	case 0:		/* success */
207	case -ETIMEDOUT:	/* NAK */
208		break;
209	case -ECONNRESET:	/* kill */
210	case -ENOENT:
211	case -ESHUTDOWN:
212		return;
213	default:		/* error */
214		dprintk("urb completition error %d.\n", urb->status);
215		break;
216	}
217
218	if (atomic_read(&dev->stream_started) == 0)
219		return;
220
221	if (dev->adev.capture_pcm_substream) {
222		substream = dev->adev.capture_pcm_substream;
223		runtime = substream->runtime;
224		stride = runtime->frame_bits >> 3;
225
226		if (1) {
227			int length = urb->actual_length /
228				     stride;
229			cp = (unsigned char *)urb->transfer_buffer;
230
231			oldptr = dev->adev.hwptr_done_capture;
232			if (oldptr + length >= runtime->buffer_size) {
233				unsigned int cnt;
234
235				cnt = runtime->buffer_size - oldptr;
236				memcpy(runtime->dma_area + oldptr * stride, cp,
237				       cnt * stride);
238				memcpy(runtime->dma_area, cp + cnt * stride,
239				       length * stride - cnt * stride);
240			} else {
241				memcpy(runtime->dma_area + oldptr * stride, cp,
242				       length * stride);
243			}
244
245			snd_pcm_stream_lock(substream);
246
247			dev->adev.hwptr_done_capture += length;
248			if (dev->adev.hwptr_done_capture >=
249						runtime->buffer_size)
250				dev->adev.hwptr_done_capture -=
251						runtime->buffer_size;
252
253			dev->adev.capture_transfer_done += length;
254			if (dev->adev.capture_transfer_done >=
255				runtime->period_size) {
256				dev->adev.capture_transfer_done -=
257						runtime->period_size;
258				period_elapsed = 1;
259			}
260			snd_pcm_stream_unlock(substream);
261		}
262		if (period_elapsed)
263			snd_pcm_period_elapsed(substream);
264	}
265	urb->status = 0;
266
267	status = usb_submit_urb(urb, GFP_ATOMIC);
268	if (status < 0) {
269		cx231xx_errdev("resubmit of audio urb failed (error=%i)\n",
270			       status);
271	}
272	return;
273}
274
275static int cx231xx_init_audio_isoc(struct cx231xx *dev)
276{
277	int i, errCode;
278	int sb_size;
279
280	cx231xx_info("%s: Starting ISO AUDIO transfers\n", __func__);
281
282	if (dev->state & DEV_DISCONNECTED)
283		return -ENODEV;
284
285	sb_size = CX231XX_ISO_NUM_AUDIO_PACKETS * dev->adev.max_pkt_size;
286
287	for (i = 0; i < CX231XX_AUDIO_BUFS; i++) {
288		struct urb *urb;
289		int j, k;
290
291		dev->adev.transfer_buffer[i] = kmalloc(sb_size, GFP_ATOMIC);
292		if (!dev->adev.transfer_buffer[i])
293			return -ENOMEM;
294
295		memset(dev->adev.transfer_buffer[i], 0x80, sb_size);
296		urb = usb_alloc_urb(CX231XX_ISO_NUM_AUDIO_PACKETS, GFP_ATOMIC);
297		if (!urb) {
298			cx231xx_errdev("usb_alloc_urb failed!\n");
299			for (j = 0; j < i; j++) {
300				usb_free_urb(dev->adev.urb[j]);
301				kfree(dev->adev.transfer_buffer[j]);
302			}
303			return -ENOMEM;
304		}
305
306		urb->dev = dev->udev;
307		urb->context = dev;
308		urb->pipe = usb_rcvisocpipe(dev->udev,
309						dev->adev.end_point_addr);
310		urb->transfer_flags = URB_ISO_ASAP;
311		urb->transfer_buffer = dev->adev.transfer_buffer[i];
312		urb->interval = 1;
313		urb->complete = cx231xx_audio_isocirq;
314		urb->number_of_packets = CX231XX_ISO_NUM_AUDIO_PACKETS;
315		urb->transfer_buffer_length = sb_size;
316
317		for (j = k = 0; j < CX231XX_ISO_NUM_AUDIO_PACKETS;
318			j++, k += dev->adev.max_pkt_size) {
319			urb->iso_frame_desc[j].offset = k;
320			urb->iso_frame_desc[j].length = dev->adev.max_pkt_size;
321		}
322		dev->adev.urb[i] = urb;
323	}
324
325	for (i = 0; i < CX231XX_AUDIO_BUFS; i++) {
326		errCode = usb_submit_urb(dev->adev.urb[i], GFP_ATOMIC);
327		if (errCode < 0) {
328			cx231xx_isoc_audio_deinit(dev);
329			return errCode;
330		}
331	}
332
333	return errCode;
334}
335
336static int cx231xx_init_audio_bulk(struct cx231xx *dev)
337{
338	int i, errCode;
339	int sb_size;
340
341	cx231xx_info("%s: Starting BULK AUDIO transfers\n", __func__);
342
343	if (dev->state & DEV_DISCONNECTED)
344		return -ENODEV;
345
346	sb_size = CX231XX_NUM_AUDIO_PACKETS * dev->adev.max_pkt_size;
347
348	for (i = 0; i < CX231XX_AUDIO_BUFS; i++) {
349		struct urb *urb;
350		int j;
351
352		dev->adev.transfer_buffer[i] = kmalloc(sb_size, GFP_ATOMIC);
353		if (!dev->adev.transfer_buffer[i])
354			return -ENOMEM;
355
356		memset(dev->adev.transfer_buffer[i], 0x80, sb_size);
357		urb = usb_alloc_urb(CX231XX_NUM_AUDIO_PACKETS, GFP_ATOMIC);
358		if (!urb) {
359			cx231xx_errdev("usb_alloc_urb failed!\n");
360			for (j = 0; j < i; j++) {
361				usb_free_urb(dev->adev.urb[j]);
362				kfree(dev->adev.transfer_buffer[j]);
363			}
364			return -ENOMEM;
365		}
366
367		urb->dev = dev->udev;
368		urb->context = dev;
369		urb->pipe = usb_rcvbulkpipe(dev->udev,
370						dev->adev.end_point_addr);
371		urb->transfer_flags = 0;
372		urb->transfer_buffer = dev->adev.transfer_buffer[i];
373		urb->complete = cx231xx_audio_bulkirq;
374		urb->transfer_buffer_length = sb_size;
375
376		dev->adev.urb[i] = urb;
377
378	}
379
380	for (i = 0; i < CX231XX_AUDIO_BUFS; i++) {
381		errCode = usb_submit_urb(dev->adev.urb[i], GFP_ATOMIC);
382		if (errCode < 0) {
383			cx231xx_bulk_audio_deinit(dev);
384			return errCode;
385		}
386	}
387
388	return errCode;
389}
390
391static int snd_pcm_alloc_vmalloc_buffer(struct snd_pcm_substream *subs,
392					size_t size)
393{
394	struct snd_pcm_runtime *runtime = subs->runtime;
395
396	dprintk("Allocating vbuffer\n");
397	if (runtime->dma_area) {
398		if (runtime->dma_bytes > size)
399			return 0;
400
401		vfree(runtime->dma_area);
402	}
403	runtime->dma_area = vmalloc(size);
404	if (!runtime->dma_area)
405		return -ENOMEM;
406
407	runtime->dma_bytes = size;
408
409	return 0;
410}
411
412static struct snd_pcm_hardware snd_cx231xx_hw_capture = {
413	.info = SNDRV_PCM_INFO_BLOCK_TRANSFER 	|
414	    SNDRV_PCM_INFO_MMAP 		|
415	    SNDRV_PCM_INFO_INTERLEAVED 		|
416	    SNDRV_PCM_INFO_MMAP_VALID,
417
418	.formats = SNDRV_PCM_FMTBIT_S16_LE,
419
420	.rates = SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_KNOT,
421
422	.rate_min = 48000,
423	.rate_max = 48000,
424	.channels_min = 2,
425	.channels_max = 2,
426	.buffer_bytes_max = 62720 * 8,	/* just about the value in usbaudio.c */
427	.period_bytes_min = 64,		/* 12544/2, */
428	.period_bytes_max = 12544,
429	.periods_min = 2,
430	.periods_max = 98,		/* 12544, */
431};
432
433static int snd_cx231xx_capture_open(struct snd_pcm_substream *substream)
434{
435	struct cx231xx *dev = snd_pcm_substream_chip(substream);
436	struct snd_pcm_runtime *runtime = substream->runtime;
437	int ret = 0;
438
439	dprintk("opening device and trying to acquire exclusive lock\n");
440
441	if (!dev) {
442		cx231xx_errdev("BUG: cx231xx can't find device struct."
443			       " Can't proceed with open\n");
444		return -ENODEV;
445	}
446
447	if (dev->state & DEV_DISCONNECTED) {
448		cx231xx_errdev("Can't open. the device was removed.\n");
449		return -ENODEV;
450	}
451
452	/* Sets volume, mute, etc */
453	dev->mute = 0;
454
455	/* set alternate setting for audio interface */
456	/* 1 - 48000 samples per sec */
457	mutex_lock(&dev->lock);
458	if (dev->USE_ISO)
459		ret = cx231xx_set_alt_setting(dev, INDEX_AUDIO, 1);
460	else
461		ret = cx231xx_set_alt_setting(dev, INDEX_AUDIO, 0);
462	mutex_unlock(&dev->lock);
463	if (ret < 0) {
464		cx231xx_errdev("failed to set alternate setting !\n");
465
466		return ret;
467	}
468
469	runtime->hw = snd_cx231xx_hw_capture;
470
471	mutex_lock(&dev->lock);
472	/* inform hardware to start streaming */
473	ret = cx231xx_capture_start(dev, 1, Audio);
474
475	dev->adev.users++;
476	mutex_unlock(&dev->lock);
477
478	snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
479	dev->adev.capture_pcm_substream = substream;
480	runtime->private_data = dev;
481
482	return 0;
483}
484
485static int snd_cx231xx_pcm_close(struct snd_pcm_substream *substream)
486{
487	int ret;
488	struct cx231xx *dev = snd_pcm_substream_chip(substream);
489
490	dprintk("closing device\n");
491
492	/* inform hardware to stop streaming */
493	mutex_lock(&dev->lock);
494	ret = cx231xx_capture_start(dev, 0, Audio);
495
496	/* set alternate setting for audio interface */
497	/* 1 - 48000 samples per sec */
498	ret = cx231xx_set_alt_setting(dev, INDEX_AUDIO, 0);
499	if (ret < 0) {
500		cx231xx_errdev("failed to set alternate setting !\n");
501
502		mutex_unlock(&dev->lock);
503		return ret;
504	}
505
506	dev->mute = 1;
507	dev->adev.users--;
508	mutex_unlock(&dev->lock);
509
510	if (dev->adev.users == 0 && dev->adev.shutdown == 1) {
511		dprintk("audio users: %d\n", dev->adev.users);
512		dprintk("disabling audio stream!\n");
513		dev->adev.shutdown = 0;
514		dprintk("released lock\n");
515		if (atomic_read(&dev->stream_started) > 0) {
516			atomic_set(&dev->stream_started, 0);
517			schedule_work(&dev->wq_trigger);
518		}
519	}
520	return 0;
521}
522
523static int snd_cx231xx_hw_capture_params(struct snd_pcm_substream *substream,
524					 struct snd_pcm_hw_params *hw_params)
525{
526	int ret;
527
528	dprintk("Setting capture parameters\n");
529
530	ret = snd_pcm_alloc_vmalloc_buffer(substream,
531					   params_buffer_bytes(hw_params));
532#if 0
533	/* TODO: set up cx231xx audio chip to deliver the correct audio format,
534	   current default is 48000hz multiplexed => 96000hz mono
535	   which shouldn't matter since analogue TV only supports mono */
536	unsigned int channels, rate, format;
537
538	format = params_format(hw_params);
539	rate = params_rate(hw_params);
540	channels = params_channels(hw_params);
541#endif
542
543	return ret;
544}
545
546static int snd_cx231xx_hw_capture_free(struct snd_pcm_substream *substream)
547{
548	struct cx231xx *dev = snd_pcm_substream_chip(substream);
549
550	dprintk("Stop capture, if needed\n");
551
552	if (atomic_read(&dev->stream_started) > 0) {
553		atomic_set(&dev->stream_started, 0);
554		schedule_work(&dev->wq_trigger);
555	}
556
557	return 0;
558}
559
560static int snd_cx231xx_prepare(struct snd_pcm_substream *substream)
561{
562	struct cx231xx *dev = snd_pcm_substream_chip(substream);
563
564	dev->adev.hwptr_done_capture = 0;
565	dev->adev.capture_transfer_done = 0;
566
567	return 0;
568}
569
570static void audio_trigger(struct work_struct *work)
571{
572	struct cx231xx *dev = container_of(work, struct cx231xx, wq_trigger);
573
574	if (atomic_read(&dev->stream_started)) {
575		dprintk("starting capture");
576		if (is_fw_load(dev) == 0)
577			cx25840_call(dev, core, load_fw);
578		if (dev->USE_ISO)
579			cx231xx_init_audio_isoc(dev);
580		else
581			cx231xx_init_audio_bulk(dev);
582	} else {
583		dprintk("stopping capture");
584		cx231xx_isoc_audio_deinit(dev);
585	}
586}
587
588static int snd_cx231xx_capture_trigger(struct snd_pcm_substream *substream,
589				       int cmd)
590{
591	struct cx231xx *dev = snd_pcm_substream_chip(substream);
592	int retval = 0;
593
594	if (dev->state & DEV_DISCONNECTED)
595		return -ENODEV;
596
597	spin_lock(&dev->adev.slock);
598	switch (cmd) {
599	case SNDRV_PCM_TRIGGER_START:
600		atomic_set(&dev->stream_started, 1);
601		break;
602	case SNDRV_PCM_TRIGGER_STOP:
603		atomic_set(&dev->stream_started, 0);
604		break;
605	default:
606		retval = -EINVAL;
607		break;
608	}
609	spin_unlock(&dev->adev.slock);
610
611	schedule_work(&dev->wq_trigger);
612
613	return retval;
614}
615
616static snd_pcm_uframes_t snd_cx231xx_capture_pointer(struct snd_pcm_substream
617						     *substream)
618{
619	struct cx231xx *dev;
620	unsigned long flags;
621	snd_pcm_uframes_t hwptr_done;
622
623	dev = snd_pcm_substream_chip(substream);
624
625	spin_lock_irqsave(&dev->adev.slock, flags);
626	hwptr_done = dev->adev.hwptr_done_capture;
627	spin_unlock_irqrestore(&dev->adev.slock, flags);
628
629	return hwptr_done;
630}
631
632static struct page *snd_pcm_get_vmalloc_page(struct snd_pcm_substream *subs,
633					     unsigned long offset)
634{
635	void *pageptr = subs->runtime->dma_area + offset;
636
637	return vmalloc_to_page(pageptr);
638}
639
640static struct snd_pcm_ops snd_cx231xx_pcm_capture = {
641	.open = snd_cx231xx_capture_open,
642	.close = snd_cx231xx_pcm_close,
643	.ioctl = snd_pcm_lib_ioctl,
644	.hw_params = snd_cx231xx_hw_capture_params,
645	.hw_free = snd_cx231xx_hw_capture_free,
646	.prepare = snd_cx231xx_prepare,
647	.trigger = snd_cx231xx_capture_trigger,
648	.pointer = snd_cx231xx_capture_pointer,
649	.page = snd_pcm_get_vmalloc_page,
650};
651
652static int cx231xx_audio_init(struct cx231xx *dev)
653{
654	struct cx231xx_audio *adev = &dev->adev;
655	struct snd_pcm *pcm;
656	struct snd_card *card;
657	static int devnr;
658	int err;
659	struct usb_interface *uif;
660	int i, isoc_pipe = 0;
661
662	if (dev->has_alsa_audio != 1) {
663		/* This device does not support the extension (in this case
664		   the device is expecting the snd-usb-audio module or
665		   doesn't have analog audio support at all) */
666		return 0;
667	}
668
669	cx231xx_info("cx231xx-audio.c: probing for cx231xx "
670		     "non standard usbaudio\n");
671
672	err = snd_card_create(index[devnr], "Cx231xx Audio", THIS_MODULE,
673			      0, &card);
674	if (err < 0)
675		return err;
676
677	spin_lock_init(&adev->slock);
678	err = snd_pcm_new(card, "Cx231xx Audio", 0, 0, 1, &pcm);
679	if (err < 0) {
680		snd_card_free(card);
681		return err;
682	}
683
684	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE,
685			&snd_cx231xx_pcm_capture);
686	pcm->info_flags = 0;
687	pcm->private_data = dev;
688	strcpy(pcm->name, "Conexant cx231xx Capture");
689	snd_card_set_dev(card, &dev->udev->dev);
690	strcpy(card->driver, "Cx231xx-Audio");
691	strcpy(card->shortname, "Cx231xx Audio");
692	strcpy(card->longname, "Conexant cx231xx Audio");
693
694	INIT_WORK(&dev->wq_trigger, audio_trigger);
695
696	err = snd_card_register(card);
697	if (err < 0) {
698		snd_card_free(card);
699		return err;
700	}
701	adev->sndcard = card;
702	adev->udev = dev->udev;
703
704	/* compute alternate max packet sizes for Audio */
705	uif =
706	    dev->udev->actconfig->interface[dev->current_pcb_config.
707					    hs_config_info[0].interface_info.
708					    audio_index + 1];
709
710	adev->end_point_addr =
711	    le16_to_cpu(uif->altsetting[0].endpoint[isoc_pipe].desc.
712			bEndpointAddress);
713
714	adev->num_alt = uif->num_altsetting;
715	cx231xx_info("EndPoint Addr 0x%x, Alternate settings: %i\n",
716		     adev->end_point_addr, adev->num_alt);
717	adev->alt_max_pkt_size = kmalloc(32 * adev->num_alt, GFP_KERNEL);
718
719	if (adev->alt_max_pkt_size == NULL) {
720		cx231xx_errdev("out of memory!\n");
721		return -ENOMEM;
722	}
723
724	for (i = 0; i < adev->num_alt; i++) {
725		u16 tmp =
726		    le16_to_cpu(uif->altsetting[i].endpoint[isoc_pipe].desc.
727				wMaxPacketSize);
728		adev->alt_max_pkt_size[i] =
729		    (tmp & 0x07ff) * (((tmp & 0x1800) >> 11) + 1);
730		cx231xx_info("Alternate setting %i, max size= %i\n", i,
731			     adev->alt_max_pkt_size[i]);
732	}
733
734	return 0;
735}
736
737static int cx231xx_audio_fini(struct cx231xx *dev)
738{
739	if (dev == NULL)
740		return 0;
741
742	if (dev->has_alsa_audio != 1) {
743		/* This device does not support the extension (in this case
744		   the device is expecting the snd-usb-audio module or
745		   doesn't have analog audio support at all) */
746		return 0;
747	}
748
749	if (dev->adev.sndcard) {
750		snd_card_free(dev->adev.sndcard);
751		kfree(dev->adev.alt_max_pkt_size);
752		dev->adev.sndcard = NULL;
753	}
754
755	return 0;
756}
757
758static struct cx231xx_ops audio_ops = {
759	.id = CX231XX_AUDIO,
760	.name = "Cx231xx Audio Extension",
761	.init = cx231xx_audio_init,
762	.fini = cx231xx_audio_fini,
763};
764
765static int __init cx231xx_alsa_register(void)
766{
767	return cx231xx_register_extension(&audio_ops);
768}
769
770static void __exit cx231xx_alsa_unregister(void)
771{
772	cx231xx_unregister_extension(&audio_ops);
773}
774
775MODULE_LICENSE("GPL");
776MODULE_AUTHOR("Srinivasa Deevi <srinivasa.deevi@conexant.com>");
777MODULE_DESCRIPTION("Cx231xx Audio driver");
778
779module_init(cx231xx_alsa_register);
780module_exit(cx231xx_alsa_unregister);