1// SPDX-License-Identifier: GPL-2.0+
2//
3// Empiatech em28x1 audio extension
4//
5// Copyright (C) 2006 Markus Rechberger <mrechberger@gmail.com>
6//
7// Copyright (C) 2007-2016 Mauro Carvalho Chehab
8//	- Port to work with the in-kernel driver
9//	- Cleanups, fixes, alsa-controls, etc.
10//
11// This driver is based on my previous au600 usb pstn audio driver
12// and inherits all the copyrights
13
14#include "em28xx.h"
15
16#include <linux/kernel.h>
17#include <linux/usb.h>
18#include <linux/init.h>
19#include <linux/sound.h>
20#include <linux/spinlock.h>
21#include <linux/soundcard.h>
22#include <linux/slab.h>
23#include <linux/module.h>
24#include <sound/core.h>
25#include <sound/pcm.h>
26#include <sound/pcm_params.h>
27#include <sound/info.h>
28#include <sound/initval.h>
29#include <sound/control.h>
30#include <sound/tlv.h>
31#include <sound/ac97_codec.h>
32#include <media/v4l2-common.h>
33
34static int debug;
35module_param(debug, int, 0644);
36MODULE_PARM_DESC(debug, "activates debug info");
37
38#define EM28XX_MAX_AUDIO_BUFS		5
39#define EM28XX_MIN_AUDIO_PACKETS	64
40
41#define dprintk(fmt, arg...) do {					\
42	if (debug)						\
43		dev_printk(KERN_DEBUG, &dev->intf->dev,			\
44			   "video: %s: " fmt, __func__, ## arg);	\
45} while (0)
46
47static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;
48
49static int em28xx_deinit_isoc_audio(struct em28xx *dev)
50{
51	int i;
52
53	dprintk("Stopping isoc\n");
54	for (i = 0; i < dev->adev.num_urb; i++) {
55		struct urb *urb = dev->adev.urb[i];
56
57		if (!irqs_disabled())
58			usb_kill_urb(urb);
59		else
60			usb_unlink_urb(urb);
61	}
62
63	return 0;
64}
65
66static void em28xx_audio_isocirq(struct urb *urb)
67{
68	struct em28xx            *dev = urb->context;
69	int                      i;
70	unsigned int             oldptr;
71	int                      period_elapsed = 0;
72	int                      status;
73	unsigned char            *cp;
74	unsigned int             stride;
75	struct snd_pcm_substream *substream;
76	struct snd_pcm_runtime   *runtime;
77
78	if (dev->disconnected) {
79		dprintk("device disconnected while streaming. URB status=%d.\n",
80			urb->status);
81		atomic_set(&dev->adev.stream_started, 0);
82		return;
83	}
84
85	switch (urb->status) {
86	case 0:             /* success */
87	case -ETIMEDOUT:    /* NAK */
88		break;
89	case -ECONNRESET:   /* kill */
90	case -ENOENT:
91	case -ESHUTDOWN:
92		return;
93	default:            /* error */
94		dprintk("urb completion error %d.\n", urb->status);
95		break;
96	}
97
98	if (atomic_read(&dev->adev.stream_started) == 0)
99		return;
100
101	if (dev->adev.capture_pcm_substream) {
102		substream = dev->adev.capture_pcm_substream;
103		runtime = substream->runtime;
104		stride = runtime->frame_bits >> 3;
105
106		for (i = 0; i < urb->number_of_packets; i++) {
107			unsigned long flags;
108			int length =
109			    urb->iso_frame_desc[i].actual_length / stride;
110			cp = (unsigned char *)urb->transfer_buffer +
111			    urb->iso_frame_desc[i].offset;
112
113			if (!length)
114				continue;
115
116			oldptr = dev->adev.hwptr_done_capture;
117			if (oldptr + length >= runtime->buffer_size) {
118				unsigned int cnt =
119				    runtime->buffer_size - oldptr;
120				memcpy(runtime->dma_area + oldptr * stride, cp,
121				       cnt * stride);
122				memcpy(runtime->dma_area, cp + cnt * stride,
123				       length * stride - cnt * stride);
124			} else {
125				memcpy(runtime->dma_area + oldptr * stride, cp,
126				       length * stride);
127			}
128
129			snd_pcm_stream_lock_irqsave(substream, flags);
130
131			dev->adev.hwptr_done_capture += length;
132			if (dev->adev.hwptr_done_capture >=
133			    runtime->buffer_size)
134				dev->adev.hwptr_done_capture -=
135				    runtime->buffer_size;
136
137			dev->adev.capture_transfer_done += length;
138			if (dev->adev.capture_transfer_done >=
139			    runtime->period_size) {
140				dev->adev.capture_transfer_done -=
141				    runtime->period_size;
142				period_elapsed = 1;
143			}
144
145			snd_pcm_stream_unlock_irqrestore(substream, flags);
146		}
147		if (period_elapsed)
148			snd_pcm_period_elapsed(substream);
149	}
150	urb->status = 0;
151
152	status = usb_submit_urb(urb, GFP_ATOMIC);
153	if (status < 0)
154		dev_err(&dev->intf->dev,
155			"resubmit of audio urb failed (error=%i)\n",
156			status);
157}
158
159static int em28xx_init_audio_isoc(struct em28xx *dev)
160{
161	int       i, err;
162
163	dprintk("Starting isoc transfers\n");
164
165	/* Start streaming */
166	for (i = 0; i < dev->adev.num_urb; i++) {
167		memset(dev->adev.transfer_buffer[i], 0x80,
168		       dev->adev.urb[i]->transfer_buffer_length);
169
170		err = usb_submit_urb(dev->adev.urb[i], GFP_ATOMIC);
171		if (err) {
172			dev_err(&dev->intf->dev,
173				"submit of audio urb failed (error=%i)\n",
174				err);
175			em28xx_deinit_isoc_audio(dev);
176			atomic_set(&dev->adev.stream_started, 0);
177			return err;
178		}
179	}
180
181	return 0;
182}
183
184static const struct snd_pcm_hardware snd_em28xx_hw_capture = {
185	.info = SNDRV_PCM_INFO_BLOCK_TRANSFER |
186		SNDRV_PCM_INFO_MMAP           |
187		SNDRV_PCM_INFO_INTERLEAVED    |
188		SNDRV_PCM_INFO_BATCH	      |
189		SNDRV_PCM_INFO_MMAP_VALID,
190
191	.formats = SNDRV_PCM_FMTBIT_S16_LE,
192
193	.rates = SNDRV_PCM_RATE_48000,
194
195	.rate_min = 48000,
196	.rate_max = 48000,
197	.channels_min = 2,
198	.channels_max = 2,
199	.buffer_bytes_max = 62720 * 8,	/* just about the value in usbaudio.c */
200
201	/*
202	 * The period is 12.288 bytes. Allow a 10% of variation along its
203	 * value, in order to avoid overruns/underruns due to some clock
204	 * drift.
205	 *
206	 * FIXME: This period assumes 64 packets, and a 48000 PCM rate.
207	 * Calculate it dynamically.
208	 */
209	.period_bytes_min = 11059,
210	.period_bytes_max = 13516,
211
212	.periods_min = 2,
213	.periods_max = 98,		/* 12544, */
214};
215
216static int snd_em28xx_capture_open(struct snd_pcm_substream *substream)
217{
218	struct em28xx *dev = snd_pcm_substream_chip(substream);
219	struct snd_pcm_runtime *runtime = substream->runtime;
220	int nonblock, ret = 0;
221
222	if (!dev) {
223		pr_err("em28xx-audio: BUG: em28xx can't find device struct. Can't proceed with open\n");
224		return -ENODEV;
225	}
226
227	if (dev->disconnected)
228		return -ENODEV;
229
230	dprintk("opening device and trying to acquire exclusive lock\n");
231
232	nonblock = !!(substream->f_flags & O_NONBLOCK);
233	if (nonblock) {
234		if (!mutex_trylock(&dev->lock))
235			return -EAGAIN;
236	} else {
237		mutex_lock(&dev->lock);
238	}
239
240	runtime->hw = snd_em28xx_hw_capture;
241
242	if (dev->adev.users == 0) {
243		if (!dev->alt || dev->is_audio_only) {
244			struct usb_device *udev;
245
246			udev = interface_to_usbdev(dev->intf);
247
248			if (dev->is_audio_only)
249				/* audio is on a separate interface */
250				dev->alt = 1;
251			else
252				/* audio is on the same interface as video */
253				dev->alt = 7;
254				/*
255				 * FIXME: The intention seems to be to select
256				 * the alt setting with the largest
257				 * wMaxPacketSize for the video endpoint.
258				 * At least dev->alt should be used instead, but
259				 * we should probably not touch it at all if it
260				 * is already >0, because wMaxPacketSize of the
261				 * audio endpoints seems to be the same for all.
262				 */
263			dprintk("changing alternate number on interface %d to %d\n",
264				dev->ifnum, dev->alt);
265			usb_set_interface(udev, dev->ifnum, dev->alt);
266		}
267
268		/* Sets volume, mute, etc */
269		dev->mute = 0;
270		ret = em28xx_audio_analog_set(dev);
271		if (ret < 0)
272			goto err;
273	}
274
275	kref_get(&dev->ref);
276	dev->adev.users++;
277	mutex_unlock(&dev->lock);
278
279	/* Dynamically adjust the period size */
280	snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
281	snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_PERIOD_BYTES,
282				     dev->adev.period * 95 / 100,
283				     dev->adev.period * 105 / 100);
284
285	dev->adev.capture_pcm_substream = substream;
286
287	return 0;
288err:
289	mutex_unlock(&dev->lock);
290
291	dev_err(&dev->intf->dev,
292		"Error while configuring em28xx mixer\n");
293	return ret;
294}
295
296static int snd_em28xx_pcm_close(struct snd_pcm_substream *substream)
297{
298	struct em28xx *dev = snd_pcm_substream_chip(substream);
299
300	dprintk("closing device\n");
301
302	dev->mute = 1;
303	mutex_lock(&dev->lock);
304	dev->adev.users--;
305	if (atomic_read(&dev->adev.stream_started) > 0) {
306		atomic_set(&dev->adev.stream_started, 0);
307		schedule_work(&dev->adev.wq_trigger);
308	}
309
310	em28xx_audio_analog_set(dev);
311	mutex_unlock(&dev->lock);
312	kref_put(&dev->ref, em28xx_free_device);
313
314	return 0;
315}
316
317static int snd_em28xx_prepare(struct snd_pcm_substream *substream)
318{
319	struct em28xx *dev = snd_pcm_substream_chip(substream);
320
321	if (dev->disconnected)
322		return -ENODEV;
323
324	dev->adev.hwptr_done_capture = 0;
325	dev->adev.capture_transfer_done = 0;
326
327	return 0;
328}
329
330static void audio_trigger(struct work_struct *work)
331{
332	struct em28xx_audio *adev =
333			    container_of(work, struct em28xx_audio, wq_trigger);
334	struct em28xx *dev = container_of(adev, struct em28xx, adev);
335
336	if (atomic_read(&adev->stream_started)) {
337		dprintk("starting capture");
338		em28xx_init_audio_isoc(dev);
339	} else {
340		dprintk("stopping capture");
341		em28xx_deinit_isoc_audio(dev);
342	}
343}
344
345static int snd_em28xx_capture_trigger(struct snd_pcm_substream *substream,
346				      int cmd)
347{
348	struct em28xx *dev = snd_pcm_substream_chip(substream);
349	int retval = 0;
350
351	if (dev->disconnected)
352		return -ENODEV;
353
354	switch (cmd) {
355	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
356	case SNDRV_PCM_TRIGGER_RESUME:
357	case SNDRV_PCM_TRIGGER_START:
358		atomic_set(&dev->adev.stream_started, 1);
359		break;
360	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
361	case SNDRV_PCM_TRIGGER_SUSPEND:
362	case SNDRV_PCM_TRIGGER_STOP:
363		atomic_set(&dev->adev.stream_started, 0);
364		break;
365	default:
366		retval = -EINVAL;
367	}
368	schedule_work(&dev->adev.wq_trigger);
369	return retval;
370}
371
372static snd_pcm_uframes_t snd_em28xx_capture_pointer(struct snd_pcm_substream
373						    *substream)
374{
375	unsigned long flags;
376	struct em28xx *dev;
377	snd_pcm_uframes_t hwptr_done;
378
379	dev = snd_pcm_substream_chip(substream);
380	if (dev->disconnected)
381		return SNDRV_PCM_POS_XRUN;
382
383	spin_lock_irqsave(&dev->adev.slock, flags);
384	hwptr_done = dev->adev.hwptr_done_capture;
385	spin_unlock_irqrestore(&dev->adev.slock, flags);
386
387	return hwptr_done;
388}
389
390/*
391 * AC97 volume control support
392 */
393static int em28xx_vol_info(struct snd_kcontrol *kcontrol,
394			   struct snd_ctl_elem_info *info)
395{
396	struct em28xx *dev = snd_kcontrol_chip(kcontrol);
397
398	if (dev->disconnected)
399		return -ENODEV;
400
401	info->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
402	info->count = 2;
403	info->value.integer.min = 0;
404	info->value.integer.max = 0x1f;
405
406	return 0;
407}
408
409static int em28xx_vol_put(struct snd_kcontrol *kcontrol,
410			  struct snd_ctl_elem_value *value)
411{
412	struct em28xx *dev = snd_kcontrol_chip(kcontrol);
413	struct snd_pcm_substream *substream = dev->adev.capture_pcm_substream;
414	u16 val = (0x1f - (value->value.integer.value[0] & 0x1f)) |
415		  (0x1f - (value->value.integer.value[1] & 0x1f)) << 8;
416	int nonblock = 0;
417	int rc;
418
419	if (dev->disconnected)
420		return -ENODEV;
421
422	if (substream)
423		nonblock = !!(substream->f_flags & O_NONBLOCK);
424	if (nonblock) {
425		if (!mutex_trylock(&dev->lock))
426			return -EAGAIN;
427	} else {
428		mutex_lock(&dev->lock);
429	}
430	rc = em28xx_read_ac97(dev, kcontrol->private_value);
431	if (rc < 0)
432		goto err;
433
434	val |= rc & 0x8000;	/* Preserve the mute flag */
435
436	rc = em28xx_write_ac97(dev, kcontrol->private_value, val);
437	if (rc < 0)
438		goto err;
439
440	dprintk("%sleft vol %d, right vol %d (0x%04x) to ac97 volume control 0x%04x\n",
441		(val & 0x8000) ? "muted " : "",
442		0x1f - ((val >> 8) & 0x1f), 0x1f - (val & 0x1f),
443		val, (int)kcontrol->private_value);
444
445err:
446	mutex_unlock(&dev->lock);
447	return rc;
448}
449
450static int em28xx_vol_get(struct snd_kcontrol *kcontrol,
451			  struct snd_ctl_elem_value *value)
452{
453	struct em28xx *dev = snd_kcontrol_chip(kcontrol);
454	struct snd_pcm_substream *substream = dev->adev.capture_pcm_substream;
455	int nonblock = 0;
456	int val;
457
458	if (dev->disconnected)
459		return -ENODEV;
460
461	if (substream)
462		nonblock = !!(substream->f_flags & O_NONBLOCK);
463	if (nonblock) {
464		if (!mutex_trylock(&dev->lock))
465			return -EAGAIN;
466	} else {
467		mutex_lock(&dev->lock);
468	}
469	val = em28xx_read_ac97(dev, kcontrol->private_value);
470	mutex_unlock(&dev->lock);
471	if (val < 0)
472		return val;
473
474	dprintk("%sleft vol %d, right vol %d (0x%04x) from ac97 volume control 0x%04x\n",
475		(val & 0x8000) ? "muted " : "",
476		0x1f - ((val >> 8) & 0x1f), 0x1f - (val & 0x1f),
477		val, (int)kcontrol->private_value);
478
479	value->value.integer.value[0] = 0x1f - (val & 0x1f);
480	value->value.integer.value[1] = 0x1f - ((val >> 8) & 0x1f);
481
482	return 0;
483}
484
485static int em28xx_vol_put_mute(struct snd_kcontrol *kcontrol,
486			       struct snd_ctl_elem_value *value)
487{
488	struct em28xx *dev = snd_kcontrol_chip(kcontrol);
489	u16 val = value->value.integer.value[0];
490	struct snd_pcm_substream *substream = dev->adev.capture_pcm_substream;
491	int nonblock = 0;
492	int rc;
493
494	if (dev->disconnected)
495		return -ENODEV;
496
497	if (substream)
498		nonblock = !!(substream->f_flags & O_NONBLOCK);
499	if (nonblock) {
500		if (!mutex_trylock(&dev->lock))
501			return -EAGAIN;
502	} else {
503		mutex_lock(&dev->lock);
504	}
505	rc = em28xx_read_ac97(dev, kcontrol->private_value);
506	if (rc < 0)
507		goto err;
508
509	if (val)
510		rc &= 0x1f1f;
511	else
512		rc |= 0x8000;
513
514	rc = em28xx_write_ac97(dev, kcontrol->private_value, rc);
515	if (rc < 0)
516		goto err;
517
518	dprintk("%sleft vol %d, right vol %d (0x%04x) to ac97 volume control 0x%04x\n",
519		(val & 0x8000) ? "muted " : "",
520		0x1f - ((val >> 8) & 0x1f), 0x1f - (val & 0x1f),
521		val, (int)kcontrol->private_value);
522
523err:
524	mutex_unlock(&dev->lock);
525	return rc;
526}
527
528static int em28xx_vol_get_mute(struct snd_kcontrol *kcontrol,
529			       struct snd_ctl_elem_value *value)
530{
531	struct em28xx *dev = snd_kcontrol_chip(kcontrol);
532	struct snd_pcm_substream *substream = dev->adev.capture_pcm_substream;
533	int nonblock = 0;
534	int val;
535
536	if (dev->disconnected)
537		return -ENODEV;
538
539	if (substream)
540		nonblock = !!(substream->f_flags & O_NONBLOCK);
541	if (nonblock) {
542		if (!mutex_trylock(&dev->lock))
543			return -EAGAIN;
544	} else {
545		mutex_lock(&dev->lock);
546	}
547	val = em28xx_read_ac97(dev, kcontrol->private_value);
548	mutex_unlock(&dev->lock);
549	if (val < 0)
550		return val;
551
552	if (val & 0x8000)
553		value->value.integer.value[0] = 0;
554	else
555		value->value.integer.value[0] = 1;
556
557	dprintk("%sleft vol %d, right vol %d (0x%04x) from ac97 volume control 0x%04x\n",
558		(val & 0x8000) ? "muted " : "",
559		0x1f - ((val >> 8) & 0x1f), 0x1f - (val & 0x1f),
560		val, (int)kcontrol->private_value);
561
562	return 0;
563}
564
565static const DECLARE_TLV_DB_SCALE(em28xx_db_scale, -3450, 150, 0);
566
567static int em28xx_cvol_new(struct snd_card *card, struct em28xx *dev,
568			   char *name, int id)
569{
570	int err;
571	char ctl_name[44];
572	struct snd_kcontrol *kctl;
573	struct snd_kcontrol_new tmp;
574
575	memset(&tmp, 0, sizeof(tmp));
576	tmp.iface = SNDRV_CTL_ELEM_IFACE_MIXER;
577	tmp.private_value = id;
578	tmp.name  = ctl_name;
579
580	/* Add Mute Control */
581	sprintf(ctl_name, "%s Switch", name);
582	tmp.get  = em28xx_vol_get_mute;
583	tmp.put  = em28xx_vol_put_mute;
584	tmp.info = snd_ctl_boolean_mono_info;
585	kctl = snd_ctl_new1(&tmp, dev);
586	err = snd_ctl_add(card, kctl);
587	if (err < 0)
588		return err;
589	dprintk("Added control %s for ac97 volume control 0x%04x\n",
590		ctl_name, id);
591
592	memset(&tmp, 0, sizeof(tmp));
593	tmp.iface = SNDRV_CTL_ELEM_IFACE_MIXER;
594	tmp.private_value = id;
595	tmp.name  = ctl_name;
596
597	/* Add Volume Control */
598	sprintf(ctl_name, "%s Volume", name);
599	tmp.get   = em28xx_vol_get;
600	tmp.put   = em28xx_vol_put;
601	tmp.info  = em28xx_vol_info;
602	tmp.tlv.p = em28xx_db_scale;
603	kctl = snd_ctl_new1(&tmp, dev);
604	err = snd_ctl_add(card, kctl);
605	if (err < 0)
606		return err;
607	dprintk("Added control %s for ac97 volume control 0x%04x\n",
608		ctl_name, id);
609
610	return 0;
611}
612
613/*
614 * register/unregister code and data
615 */
616static const struct snd_pcm_ops snd_em28xx_pcm_capture = {
617	.open      = snd_em28xx_capture_open,
618	.close     = snd_em28xx_pcm_close,
619	.prepare   = snd_em28xx_prepare,
620	.trigger   = snd_em28xx_capture_trigger,
621	.pointer   = snd_em28xx_capture_pointer,
622};
623
624static void em28xx_audio_free_urb(struct em28xx *dev)
625{
626	struct usb_device *udev = interface_to_usbdev(dev->intf);
627	int i;
628
629	for (i = 0; i < dev->adev.num_urb; i++) {
630		struct urb *urb = dev->adev.urb[i];
631
632		if (!urb)
633			continue;
634
635		usb_free_coherent(udev, urb->transfer_buffer_length,
636				  dev->adev.transfer_buffer[i],
637				  urb->transfer_dma);
638
639		usb_free_urb(urb);
640	}
641	kfree(dev->adev.urb);
642	kfree(dev->adev.transfer_buffer);
643	dev->adev.num_urb = 0;
644}
645
646/* high bandwidth multiplier, as encoded in highspeed endpoint descriptors */
647static int em28xx_audio_ep_packet_size(struct usb_device *udev,
648				       struct usb_endpoint_descriptor *e)
649{
650	int size = le16_to_cpu(e->wMaxPacketSize);
651
652	if (udev->speed == USB_SPEED_HIGH)
653		return (size & 0x7ff) *  (1 + (((size) >> 11) & 0x03));
654
655	return size & 0x7ff;
656}
657
658static int em28xx_audio_urb_init(struct em28xx *dev)
659{
660	struct usb_interface *intf;
661	struct usb_endpoint_descriptor *e, *ep = NULL;
662	struct usb_device *udev = interface_to_usbdev(dev->intf);
663	int                 i, ep_size, interval, num_urb, npackets;
664	int		    urb_size, bytes_per_transfer;
665	u8 alt;
666
667	if (dev->ifnum)
668		alt = 1;
669	else
670		alt = 7;
671
672	intf = usb_ifnum_to_if(udev, dev->ifnum);
673
674	if (intf->num_altsetting <= alt) {
675		dev_err(&dev->intf->dev, "alt %d doesn't exist on interface %d\n",
676			dev->ifnum, alt);
677		return -ENODEV;
678	}
679
680	for (i = 0; i < intf->altsetting[alt].desc.bNumEndpoints; i++) {
681		e = &intf->altsetting[alt].endpoint[i].desc;
682		if (!usb_endpoint_dir_in(e))
683			continue;
684		if (e->bEndpointAddress == EM28XX_EP_AUDIO) {
685			ep = e;
686			break;
687		}
688	}
689
690	if (!ep) {
691		dev_err(&dev->intf->dev, "Couldn't find an audio endpoint");
692		return -ENODEV;
693	}
694
695	ep_size = em28xx_audio_ep_packet_size(udev, ep);
696	interval = 1 << (ep->bInterval - 1);
697
698	dev_info(&dev->intf->dev,
699		 "Endpoint 0x%02x %s on intf %d alt %d interval = %d, size %d\n",
700		 EM28XX_EP_AUDIO, usb_speed_string(udev->speed),
701		 dev->ifnum, alt, interval, ep_size);
702
703	/* Calculate the number and size of URBs to better fit the audio samples */
704
705	/*
706	 * Estimate the number of bytes per DMA transfer.
707	 *
708	 * This is given by the bit rate (for now, only 48000 Hz) multiplied
709	 * by 2 channels and 2 bytes/sample divided by the number of microframe
710	 * intervals and by the microframe rate (125 us)
711	 */
712	bytes_per_transfer = DIV_ROUND_UP(48000 * 2 * 2, 125 * interval);
713
714	/*
715	 * Estimate the number of transfer URBs. Don't let it go past the
716	 * maximum number of URBs that is known to be supported by the device.
717	 */
718	num_urb = DIV_ROUND_UP(bytes_per_transfer, ep_size);
719	if (num_urb > EM28XX_MAX_AUDIO_BUFS)
720		num_urb = EM28XX_MAX_AUDIO_BUFS;
721
722	/*
723	 * Now that we know the number of bytes per transfer and the number of
724	 * URBs, estimate the typical size of an URB, in order to adjust the
725	 * minimal number of packets.
726	 */
727	urb_size = bytes_per_transfer / num_urb;
728
729	/*
730	 * Now, calculate the amount of audio packets to be filled on each
731	 * URB. In order to preserve the old behaviour, use a minimal
732	 * threshold for this value.
733	 */
734	npackets = EM28XX_MIN_AUDIO_PACKETS;
735	if (urb_size > ep_size * npackets)
736		npackets = DIV_ROUND_UP(urb_size, ep_size);
737
738	dev_info(&dev->intf->dev,
739		 "Number of URBs: %d, with %d packets and %d size\n",
740		 num_urb, npackets, urb_size);
741
742	/* Estimate the bytes per period */
743	dev->adev.period = urb_size * npackets;
744
745	/* Allocate space to store the number of URBs to be used */
746
747	dev->adev.transfer_buffer = kcalloc(num_urb,
748					    sizeof(*dev->adev.transfer_buffer),
749					    GFP_KERNEL);
750	if (!dev->adev.transfer_buffer)
751		return -ENOMEM;
752
753	dev->adev.urb = kcalloc(num_urb, sizeof(*dev->adev.urb), GFP_KERNEL);
754	if (!dev->adev.urb) {
755		kfree(dev->adev.transfer_buffer);
756		return -ENOMEM;
757	}
758
759	/* Alloc memory for each URB and for each transfer buffer */
760	dev->adev.num_urb = num_urb;
761	for (i = 0; i < num_urb; i++) {
762		struct urb *urb;
763		int j, k;
764		void *buf;
765
766		urb = usb_alloc_urb(npackets, GFP_KERNEL);
767		if (!urb) {
768			em28xx_audio_free_urb(dev);
769			return -ENOMEM;
770		}
771		dev->adev.urb[i] = urb;
772
773		buf = usb_alloc_coherent(udev, npackets * ep_size, GFP_KERNEL,
774					 &urb->transfer_dma);
775		if (!buf) {
776			dev_err(&dev->intf->dev,
777				"usb_alloc_coherent failed!\n");
778			em28xx_audio_free_urb(dev);
779			return -ENOMEM;
780		}
781		dev->adev.transfer_buffer[i] = buf;
782
783		urb->dev = udev;
784		urb->context = dev;
785		urb->pipe = usb_rcvisocpipe(udev, EM28XX_EP_AUDIO);
786		urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
787		urb->transfer_buffer = buf;
788		urb->interval = interval;
789		urb->complete = em28xx_audio_isocirq;
790		urb->number_of_packets = npackets;
791		urb->transfer_buffer_length = ep_size * npackets;
792
793		for (j = k = 0; j < npackets; j++, k += ep_size) {
794			urb->iso_frame_desc[j].offset = k;
795			urb->iso_frame_desc[j].length = ep_size;
796		}
797	}
798
799	return 0;
800}
801
802static int em28xx_audio_init(struct em28xx *dev)
803{
804	struct em28xx_audio *adev = &dev->adev;
805	struct usb_device *udev = interface_to_usbdev(dev->intf);
806	struct snd_pcm      *pcm;
807	struct snd_card     *card;
808	static int          devnr;
809	int		    err;
810
811	if (dev->usb_audio_type != EM28XX_USB_AUDIO_VENDOR) {
812		/*
813		 * This device does not support the extension (in this case
814		 * the device is expecting the snd-usb-audio module or
815		 * doesn't have analog audio support at all)
816		 */
817		return 0;
818	}
819
820	dev_info(&dev->intf->dev, "Binding audio extension\n");
821
822	kref_get(&dev->ref);
823
824	dev_info(&dev->intf->dev,
825		 "em28xx-audio.c: Copyright (C) 2006 Markus Rechberger\n");
826	dev_info(&dev->intf->dev,
827		 "em28xx-audio.c: Copyright (C) 2007-2016 Mauro Carvalho Chehab\n");
828
829	err = snd_card_new(&dev->intf->dev, index[devnr], "Em28xx Audio",
830			   THIS_MODULE, 0, &card);
831	if (err < 0)
832		return err;
833
834	spin_lock_init(&adev->slock);
835	adev->sndcard = card;
836	adev->udev = udev;
837
838	err = snd_pcm_new(card, "Em28xx Audio", 0, 0, 1, &pcm);
839	if (err < 0)
840		goto card_free;
841
842	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &snd_em28xx_pcm_capture);
843	snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_VMALLOC, NULL, 0, 0);
844	pcm->info_flags = 0;
845	pcm->private_data = dev;
846	strscpy(pcm->name, "Empia 28xx Capture", sizeof(pcm->name));
847
848	strscpy(card->driver, "Em28xx-Audio", sizeof(card->driver));
849	strscpy(card->shortname, "Em28xx Audio", sizeof(card->shortname));
850	strscpy(card->longname, "Empia Em28xx Audio", sizeof(card->longname));
851
852	INIT_WORK(&adev->wq_trigger, audio_trigger);
853
854	if (dev->audio_mode.ac97 != EM28XX_NO_AC97) {
855		em28xx_cvol_new(card, dev, "Video", AC97_VIDEO);
856		em28xx_cvol_new(card, dev, "Line In", AC97_LINE);
857		em28xx_cvol_new(card, dev, "Phone", AC97_PHONE);
858		em28xx_cvol_new(card, dev, "Microphone", AC97_MIC);
859		em28xx_cvol_new(card, dev, "CD", AC97_CD);
860		em28xx_cvol_new(card, dev, "AUX", AC97_AUX);
861		em28xx_cvol_new(card, dev, "PCM", AC97_PCM);
862
863		em28xx_cvol_new(card, dev, "Master", AC97_MASTER);
864		em28xx_cvol_new(card, dev, "Line", AC97_HEADPHONE);
865		em28xx_cvol_new(card, dev, "Mono", AC97_MASTER_MONO);
866		em28xx_cvol_new(card, dev, "LFE", AC97_CENTER_LFE_MASTER);
867		em28xx_cvol_new(card, dev, "Surround", AC97_SURROUND_MASTER);
868	}
869
870	err = em28xx_audio_urb_init(dev);
871	if (err)
872		goto card_free;
873
874	err = snd_card_register(card);
875	if (err < 0)
876		goto urb_free;
877
878	dev_info(&dev->intf->dev, "Audio extension successfully initialized\n");
879	return 0;
880
881urb_free:
882	em28xx_audio_free_urb(dev);
883
884card_free:
885	snd_card_free(card);
886	adev->sndcard = NULL;
887
888	return err;
889}
890
891static int em28xx_audio_fini(struct em28xx *dev)
892{
893	if (!dev)
894		return 0;
895
896	if (dev->usb_audio_type != EM28XX_USB_AUDIO_VENDOR) {
897		/*
898		 * This device does not support the extension (in this case
899		 * the device is expecting the snd-usb-audio module or
900		 * doesn't have analog audio support at all)
901		 */
902		return 0;
903	}
904
905	dev_info(&dev->intf->dev, "Closing audio extension\n");
906
907	if (dev->adev.sndcard) {
908		snd_card_disconnect(dev->adev.sndcard);
909		flush_work(&dev->adev.wq_trigger);
910
911		em28xx_audio_free_urb(dev);
912
913		snd_card_free(dev->adev.sndcard);
914		dev->adev.sndcard = NULL;
915	}
916
917	kref_put(&dev->ref, em28xx_free_device);
918	return 0;
919}
920
921static int em28xx_audio_suspend(struct em28xx *dev)
922{
923	if (!dev)
924		return 0;
925
926	if (dev->usb_audio_type != EM28XX_USB_AUDIO_VENDOR)
927		return 0;
928
929	dev_info(&dev->intf->dev, "Suspending audio extension\n");
930	em28xx_deinit_isoc_audio(dev);
931	atomic_set(&dev->adev.stream_started, 0);
932	return 0;
933}
934
935static int em28xx_audio_resume(struct em28xx *dev)
936{
937	if (!dev)
938		return 0;
939
940	if (dev->usb_audio_type != EM28XX_USB_AUDIO_VENDOR)
941		return 0;
942
943	dev_info(&dev->intf->dev, "Resuming audio extension\n");
944	/* Nothing to do other than schedule_work() ?? */
945	schedule_work(&dev->adev.wq_trigger);
946	return 0;
947}
948
949static struct em28xx_ops audio_ops = {
950	.id   = EM28XX_AUDIO,
951	.name = "Em28xx Audio Extension",
952	.init = em28xx_audio_init,
953	.fini = em28xx_audio_fini,
954	.suspend = em28xx_audio_suspend,
955	.resume = em28xx_audio_resume,
956};
957
958static int __init em28xx_alsa_register(void)
959{
960	return em28xx_register_extension(&audio_ops);
961}
962
963static void __exit em28xx_alsa_unregister(void)
964{
965	em28xx_unregister_extension(&audio_ops);
966}
967
968MODULE_LICENSE("GPL v2");
969MODULE_AUTHOR("Markus Rechberger <mrechberger@gmail.com>");
970MODULE_AUTHOR("Mauro Carvalho Chehab");
971MODULE_DESCRIPTION(DRIVER_DESC " - audio interface");
972MODULE_VERSION(EM28XX_VERSION);
973
974module_init(em28xx_alsa_register);
975module_exit(em28xx_alsa_unregister);
976