1/*
2 *   This program is free software; you can redistribute it and/or modify
3 *   it under the terms of the GNU General Public License as published by
4 *   the Free Software Foundation; either version 2 of the License, or
5 *   (at your option) any later version.
6 *
7 *   This program is distributed in the hope that it will be useful,
8 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
9 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
10 *   GNU General Public License for more details.
11 *
12 *   You should have received a copy of the GNU General Public License
13 *   along with this program; if not, write to the Free Software
14 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
15 *
16 */
17
18#include <linux/gfp.h>
19#include <linux/init.h>
20#include <linux/ratelimit.h>
21#include <linux/usb.h>
22#include <linux/usb/audio.h>
23#include <linux/slab.h>
24
25#include <sound/core.h>
26#include <sound/pcm.h>
27#include <sound/pcm_params.h>
28
29#include "usbaudio.h"
30#include "helper.h"
31#include "card.h"
32#include "endpoint.h"
33#include "pcm.h"
34#include "quirks.h"
35
36#define EP_FLAG_RUNNING		1
37#define EP_FLAG_STOPPING	2
38
39/*
40 * snd_usb_endpoint is a model that abstracts everything related to an
41 * USB endpoint and its streaming.
42 *
43 * There are functions to activate and deactivate the streaming URBs and
44 * optional callbacks to let the pcm logic handle the actual content of the
45 * packets for playback and record. Thus, the bus streaming and the audio
46 * handlers are fully decoupled.
47 *
48 * There are two different types of endpoints in audio applications.
49 *
50 * SND_USB_ENDPOINT_TYPE_DATA handles full audio data payload for both
51 * inbound and outbound traffic.
52 *
53 * SND_USB_ENDPOINT_TYPE_SYNC endpoints are for inbound traffic only and
54 * expect the payload to carry Q10.14 / Q16.16 formatted sync information
55 * (3 or 4 bytes).
56 *
57 * Each endpoint has to be configured prior to being used by calling
58 * snd_usb_endpoint_set_params().
59 *
60 * The model incorporates a reference counting, so that multiple users
61 * can call snd_usb_endpoint_start() and snd_usb_endpoint_stop(), and
62 * only the first user will effectively start the URBs, and only the last
63 * one to stop it will tear the URBs down again.
64 */
65
66/*
67 * convert a sampling rate into our full speed format (fs/1000 in Q16.16)
68 * this will overflow at approx 524 kHz
69 */
70static inline unsigned get_usb_full_speed_rate(unsigned int rate)
71{
72	return ((rate << 13) + 62) / 125;
73}
74
75/*
76 * convert a sampling rate into USB high speed format (fs/8000 in Q16.16)
77 * this will overflow at approx 4 MHz
78 */
79static inline unsigned get_usb_high_speed_rate(unsigned int rate)
80{
81	return ((rate << 10) + 62) / 125;
82}
83
84/*
85 * release a urb data
86 */
87static void release_urb_ctx(struct snd_urb_ctx *u)
88{
89	if (u->buffer_size)
90		usb_free_coherent(u->ep->chip->dev, u->buffer_size,
91				  u->urb->transfer_buffer,
92				  u->urb->transfer_dma);
93	usb_free_urb(u->urb);
94	u->urb = NULL;
95}
96
97static const char *usb_error_string(int err)
98{
99	switch (err) {
100	case -ENODEV:
101		return "no device";
102	case -ENOENT:
103		return "endpoint not enabled";
104	case -EPIPE:
105		return "endpoint stalled";
106	case -ENOSPC:
107		return "not enough bandwidth";
108	case -ESHUTDOWN:
109		return "device disabled";
110	case -EHOSTUNREACH:
111		return "device suspended";
112	case -EINVAL:
113	case -EAGAIN:
114	case -EFBIG:
115	case -EMSGSIZE:
116		return "internal error";
117	default:
118		return "unknown error";
119	}
120}
121
122/**
123 * snd_usb_endpoint_implicit_feedback_sink: Report endpoint usage type
124 *
125 * @ep: The snd_usb_endpoint
126 *
127 * Determine whether an endpoint is driven by an implicit feedback
128 * data endpoint source.
129 */
130int snd_usb_endpoint_implicit_feedback_sink(struct snd_usb_endpoint *ep)
131{
132	return  ep->sync_master &&
133		ep->sync_master->type == SND_USB_ENDPOINT_TYPE_DATA &&
134		ep->type == SND_USB_ENDPOINT_TYPE_DATA &&
135		usb_pipeout(ep->pipe);
136}
137
138/*
139 * For streaming based on information derived from sync endpoints,
140 * prepare_outbound_urb_sizes() will call next_packet_size() to
141 * determine the number of samples to be sent in the next packet.
142 *
143 * For implicit feedback, next_packet_size() is unused.
144 */
145int snd_usb_endpoint_next_packet_size(struct snd_usb_endpoint *ep)
146{
147	unsigned long flags;
148	int ret;
149
150	if (ep->fill_max)
151		return ep->maxframesize;
152
153	spin_lock_irqsave(&ep->lock, flags);
154	ep->phase = (ep->phase & 0xffff)
155		+ (ep->freqm << ep->datainterval);
156	ret = min(ep->phase >> 16, ep->maxframesize);
157	spin_unlock_irqrestore(&ep->lock, flags);
158
159	return ret;
160}
161
162static void retire_outbound_urb(struct snd_usb_endpoint *ep,
163				struct snd_urb_ctx *urb_ctx)
164{
165	if (ep->retire_data_urb)
166		ep->retire_data_urb(ep->data_subs, urb_ctx->urb);
167}
168
169static void retire_inbound_urb(struct snd_usb_endpoint *ep,
170			       struct snd_urb_ctx *urb_ctx)
171{
172	struct urb *urb = urb_ctx->urb;
173
174	if (unlikely(ep->skip_packets > 0)) {
175		ep->skip_packets--;
176		return;
177	}
178
179	if (ep->sync_slave)
180		snd_usb_handle_sync_urb(ep->sync_slave, ep, urb);
181
182	if (ep->retire_data_urb)
183		ep->retire_data_urb(ep->data_subs, urb);
184}
185
186/*
187 * Prepare a PLAYBACK urb for submission to the bus.
188 */
189static void prepare_outbound_urb(struct snd_usb_endpoint *ep,
190				 struct snd_urb_ctx *ctx)
191{
192	int i;
193	struct urb *urb = ctx->urb;
194	unsigned char *cp = urb->transfer_buffer;
195
196	urb->dev = ep->chip->dev; /* we need to set this at each time */
197
198	switch (ep->type) {
199	case SND_USB_ENDPOINT_TYPE_DATA:
200		if (ep->prepare_data_urb) {
201			ep->prepare_data_urb(ep->data_subs, urb);
202		} else {
203			/* no data provider, so send silence */
204			unsigned int offs = 0;
205			for (i = 0; i < ctx->packets; ++i) {
206				int counts;
207
208				if (ctx->packet_size[i])
209					counts = ctx->packet_size[i];
210				else
211					counts = snd_usb_endpoint_next_packet_size(ep);
212
213				urb->iso_frame_desc[i].offset = offs * ep->stride;
214				urb->iso_frame_desc[i].length = counts * ep->stride;
215				offs += counts;
216			}
217
218			urb->number_of_packets = ctx->packets;
219			urb->transfer_buffer_length = offs * ep->stride;
220			memset(urb->transfer_buffer, ep->silence_value,
221			       offs * ep->stride);
222		}
223		break;
224
225	case SND_USB_ENDPOINT_TYPE_SYNC:
226		if (snd_usb_get_speed(ep->chip->dev) >= USB_SPEED_HIGH) {
227			/*
228			 * fill the length and offset of each urb descriptor.
229			 * the fixed 12.13 frequency is passed as 16.16 through the pipe.
230			 */
231			urb->iso_frame_desc[0].length = 4;
232			urb->iso_frame_desc[0].offset = 0;
233			cp[0] = ep->freqn;
234			cp[1] = ep->freqn >> 8;
235			cp[2] = ep->freqn >> 16;
236			cp[3] = ep->freqn >> 24;
237		} else {
238			/*
239			 * fill the length and offset of each urb descriptor.
240			 * the fixed 10.14 frequency is passed through the pipe.
241			 */
242			urb->iso_frame_desc[0].length = 3;
243			urb->iso_frame_desc[0].offset = 0;
244			cp[0] = ep->freqn >> 2;
245			cp[1] = ep->freqn >> 10;
246			cp[2] = ep->freqn >> 18;
247		}
248
249		break;
250	}
251}
252
253/*
254 * Prepare a CAPTURE or SYNC urb for submission to the bus.
255 */
256static inline void prepare_inbound_urb(struct snd_usb_endpoint *ep,
257				       struct snd_urb_ctx *urb_ctx)
258{
259	int i, offs;
260	struct urb *urb = urb_ctx->urb;
261
262	urb->dev = ep->chip->dev; /* we need to set this at each time */
263
264	switch (ep->type) {
265	case SND_USB_ENDPOINT_TYPE_DATA:
266		offs = 0;
267		for (i = 0; i < urb_ctx->packets; i++) {
268			urb->iso_frame_desc[i].offset = offs;
269			urb->iso_frame_desc[i].length = ep->curpacksize;
270			offs += ep->curpacksize;
271		}
272
273		urb->transfer_buffer_length = offs;
274		urb->number_of_packets = urb_ctx->packets;
275		break;
276
277	case SND_USB_ENDPOINT_TYPE_SYNC:
278		urb->iso_frame_desc[0].length = min(4u, ep->syncmaxsize);
279		urb->iso_frame_desc[0].offset = 0;
280		break;
281	}
282}
283
284/*
285 * Send output urbs that have been prepared previously. URBs are dequeued
286 * from ep->ready_playback_urbs and in case there there aren't any available
287 * or there are no packets that have been prepared, this function does
288 * nothing.
289 *
290 * The reason why the functionality of sending and preparing URBs is separated
291 * is that host controllers don't guarantee the order in which they return
292 * inbound and outbound packets to their submitters.
293 *
294 * This function is only used for implicit feedback endpoints. For endpoints
295 * driven by dedicated sync endpoints, URBs are immediately re-submitted
296 * from their completion handler.
297 */
298static void queue_pending_output_urbs(struct snd_usb_endpoint *ep)
299{
300	while (test_bit(EP_FLAG_RUNNING, &ep->flags)) {
301
302		unsigned long flags;
303		struct snd_usb_packet_info *uninitialized_var(packet);
304		struct snd_urb_ctx *ctx = NULL;
305		struct urb *urb;
306		int err, i;
307
308		spin_lock_irqsave(&ep->lock, flags);
309		if (ep->next_packet_read_pos != ep->next_packet_write_pos) {
310			packet = ep->next_packet + ep->next_packet_read_pos;
311			ep->next_packet_read_pos++;
312			ep->next_packet_read_pos %= MAX_URBS;
313
314			/* take URB out of FIFO */
315			if (!list_empty(&ep->ready_playback_urbs))
316				ctx = list_first_entry(&ep->ready_playback_urbs,
317					       struct snd_urb_ctx, ready_list);
318		}
319		spin_unlock_irqrestore(&ep->lock, flags);
320
321		if (ctx == NULL)
322			return;
323
324		list_del_init(&ctx->ready_list);
325		urb = ctx->urb;
326
327		/* copy over the length information */
328		for (i = 0; i < packet->packets; i++)
329			ctx->packet_size[i] = packet->packet_size[i];
330
331		/* call the data handler to fill in playback data */
332		prepare_outbound_urb(ep, ctx);
333
334		err = usb_submit_urb(ctx->urb, GFP_ATOMIC);
335		if (err < 0)
336			usb_audio_err(ep->chip,
337				"Unable to submit urb #%d: %d (urb %p)\n",
338				ctx->index, err, ctx->urb);
339		else
340			set_bit(ctx->index, &ep->active_mask);
341	}
342}
343
344/*
345 * complete callback for urbs
346 */
347static void snd_complete_urb(struct urb *urb)
348{
349	struct snd_urb_ctx *ctx = urb->context;
350	struct snd_usb_endpoint *ep = ctx->ep;
351	struct snd_pcm_substream *substream;
352	unsigned long flags;
353	int err;
354
355	if (unlikely(urb->status == -ENOENT ||		/* unlinked */
356		     urb->status == -ENODEV ||		/* device removed */
357		     urb->status == -ECONNRESET ||	/* unlinked */
358		     urb->status == -ESHUTDOWN))	/* device disabled */
359		goto exit_clear;
360	/* device disconnected */
361	if (unlikely(atomic_read(&ep->chip->shutdown)))
362		goto exit_clear;
363
364	if (usb_pipeout(ep->pipe)) {
365		retire_outbound_urb(ep, ctx);
366		/* can be stopped during retire callback */
367		if (unlikely(!test_bit(EP_FLAG_RUNNING, &ep->flags)))
368			goto exit_clear;
369
370		if (snd_usb_endpoint_implicit_feedback_sink(ep)) {
371			spin_lock_irqsave(&ep->lock, flags);
372			list_add_tail(&ctx->ready_list, &ep->ready_playback_urbs);
373			spin_unlock_irqrestore(&ep->lock, flags);
374			queue_pending_output_urbs(ep);
375
376			goto exit_clear;
377		}
378
379		prepare_outbound_urb(ep, ctx);
380	} else {
381		retire_inbound_urb(ep, ctx);
382		/* can be stopped during retire callback */
383		if (unlikely(!test_bit(EP_FLAG_RUNNING, &ep->flags)))
384			goto exit_clear;
385
386		prepare_inbound_urb(ep, ctx);
387	}
388
389	err = usb_submit_urb(urb, GFP_ATOMIC);
390	if (err == 0)
391		return;
392
393	usb_audio_err(ep->chip, "cannot submit urb (err = %d)\n", err);
394	if (ep->data_subs && ep->data_subs->pcm_substream) {
395		substream = ep->data_subs->pcm_substream;
396		snd_pcm_stop_xrun(substream);
397	}
398
399exit_clear:
400	clear_bit(ctx->index, &ep->active_mask);
401}
402
403/**
404 * snd_usb_add_endpoint: Add an endpoint to an USB audio chip
405 *
406 * @chip: The chip
407 * @alts: The USB host interface
408 * @ep_num: The number of the endpoint to use
409 * @direction: SNDRV_PCM_STREAM_PLAYBACK or SNDRV_PCM_STREAM_CAPTURE
410 * @type: SND_USB_ENDPOINT_TYPE_DATA or SND_USB_ENDPOINT_TYPE_SYNC
411 *
412 * If the requested endpoint has not been added to the given chip before,
413 * a new instance is created. Otherwise, a pointer to the previoulsy
414 * created instance is returned. In case of any error, NULL is returned.
415 *
416 * New endpoints will be added to chip->ep_list and must be freed by
417 * calling snd_usb_endpoint_free().
418 *
419 * For SND_USB_ENDPOINT_TYPE_SYNC, the caller needs to guarantee that
420 * bNumEndpoints > 1 beforehand.
421 */
422struct snd_usb_endpoint *snd_usb_add_endpoint(struct snd_usb_audio *chip,
423					      struct usb_host_interface *alts,
424					      int ep_num, int direction, int type)
425{
426	struct snd_usb_endpoint *ep;
427	int is_playback = direction == SNDRV_PCM_STREAM_PLAYBACK;
428
429	if (WARN_ON(!alts))
430		return NULL;
431
432	mutex_lock(&chip->mutex);
433
434	list_for_each_entry(ep, &chip->ep_list, list) {
435		if (ep->ep_num == ep_num &&
436		    ep->iface == alts->desc.bInterfaceNumber &&
437		    ep->altsetting == alts->desc.bAlternateSetting) {
438			usb_audio_dbg(ep->chip,
439				      "Re-using EP %x in iface %d,%d @%p\n",
440					ep_num, ep->iface, ep->altsetting, ep);
441			goto __exit_unlock;
442		}
443	}
444
445	usb_audio_dbg(chip, "Creating new %s %s endpoint #%x\n",
446		    is_playback ? "playback" : "capture",
447		    type == SND_USB_ENDPOINT_TYPE_DATA ? "data" : "sync",
448		    ep_num);
449
450	ep = kzalloc(sizeof(*ep), GFP_KERNEL);
451	if (!ep)
452		goto __exit_unlock;
453
454	ep->chip = chip;
455	spin_lock_init(&ep->lock);
456	ep->type = type;
457	ep->ep_num = ep_num;
458	ep->iface = alts->desc.bInterfaceNumber;
459	ep->altsetting = alts->desc.bAlternateSetting;
460	INIT_LIST_HEAD(&ep->ready_playback_urbs);
461	ep_num &= USB_ENDPOINT_NUMBER_MASK;
462
463	if (is_playback)
464		ep->pipe = usb_sndisocpipe(chip->dev, ep_num);
465	else
466		ep->pipe = usb_rcvisocpipe(chip->dev, ep_num);
467
468	if (type == SND_USB_ENDPOINT_TYPE_SYNC) {
469		if (get_endpoint(alts, 1)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
470		    get_endpoint(alts, 1)->bRefresh >= 1 &&
471		    get_endpoint(alts, 1)->bRefresh <= 9)
472			ep->syncinterval = get_endpoint(alts, 1)->bRefresh;
473		else if (snd_usb_get_speed(chip->dev) == USB_SPEED_FULL)
474			ep->syncinterval = 1;
475		else if (get_endpoint(alts, 1)->bInterval >= 1 &&
476			 get_endpoint(alts, 1)->bInterval <= 16)
477			ep->syncinterval = get_endpoint(alts, 1)->bInterval - 1;
478		else
479			ep->syncinterval = 3;
480
481		ep->syncmaxsize = le16_to_cpu(get_endpoint(alts, 1)->wMaxPacketSize);
482
483		if (chip->usb_id == USB_ID(0x0644, 0x8038) /* TEAC UD-H01 */ &&
484		    ep->syncmaxsize == 4)
485			ep->udh01_fb_quirk = 1;
486	}
487
488	list_add_tail(&ep->list, &chip->ep_list);
489
490__exit_unlock:
491	mutex_unlock(&chip->mutex);
492
493	return ep;
494}
495
496/*
497 *  wait until all urbs are processed.
498 */
499static int wait_clear_urbs(struct snd_usb_endpoint *ep)
500{
501	unsigned long end_time = jiffies + msecs_to_jiffies(1000);
502	int alive;
503
504	do {
505		alive = bitmap_weight(&ep->active_mask, ep->nurbs);
506		if (!alive)
507			break;
508
509		schedule_timeout_uninterruptible(1);
510	} while (time_before(jiffies, end_time));
511
512	if (alive)
513		usb_audio_err(ep->chip,
514			"timeout: still %d active urbs on EP #%x\n",
515			alive, ep->ep_num);
516	clear_bit(EP_FLAG_STOPPING, &ep->flags);
517
518	return 0;
519}
520
521/* sync the pending stop operation;
522 * this function itself doesn't trigger the stop operation
523 */
524void snd_usb_endpoint_sync_pending_stop(struct snd_usb_endpoint *ep)
525{
526	if (ep && test_bit(EP_FLAG_STOPPING, &ep->flags))
527		wait_clear_urbs(ep);
528}
529
530/*
531 * unlink active urbs.
532 */
533static int deactivate_urbs(struct snd_usb_endpoint *ep, bool force)
534{
535	unsigned int i;
536
537	if (!force && atomic_read(&ep->chip->shutdown)) /* to be sure... */
538		return -EBADFD;
539
540	clear_bit(EP_FLAG_RUNNING, &ep->flags);
541
542	INIT_LIST_HEAD(&ep->ready_playback_urbs);
543	ep->next_packet_read_pos = 0;
544	ep->next_packet_write_pos = 0;
545
546	for (i = 0; i < ep->nurbs; i++) {
547		if (test_bit(i, &ep->active_mask)) {
548			if (!test_and_set_bit(i, &ep->unlink_mask)) {
549				struct urb *u = ep->urb[i].urb;
550				usb_unlink_urb(u);
551			}
552		}
553	}
554
555	return 0;
556}
557
558/*
559 * release an endpoint's urbs
560 */
561static void release_urbs(struct snd_usb_endpoint *ep, int force)
562{
563	int i;
564
565	/* route incoming urbs to nirvana */
566	ep->retire_data_urb = NULL;
567	ep->prepare_data_urb = NULL;
568
569	/* stop urbs */
570	deactivate_urbs(ep, force);
571	wait_clear_urbs(ep);
572
573	for (i = 0; i < ep->nurbs; i++)
574		release_urb_ctx(&ep->urb[i]);
575
576	if (ep->syncbuf)
577		usb_free_coherent(ep->chip->dev, SYNC_URBS * 4,
578				  ep->syncbuf, ep->sync_dma);
579
580	ep->syncbuf = NULL;
581	ep->nurbs = 0;
582}
583
584/*
585 * configure a data endpoint
586 */
587static int data_ep_set_params(struct snd_usb_endpoint *ep,
588			      snd_pcm_format_t pcm_format,
589			      unsigned int channels,
590			      unsigned int period_bytes,
591			      unsigned int frames_per_period,
592			      unsigned int periods_per_buffer,
593			      struct audioformat *fmt,
594			      struct snd_usb_endpoint *sync_ep)
595{
596	unsigned int maxsize, minsize, packs_per_ms, max_packs_per_urb;
597	unsigned int max_packs_per_period, urbs_per_period, urb_packs;
598	unsigned int max_urbs, i;
599	int frame_bits = snd_pcm_format_physical_width(pcm_format) * channels;
600
601	if (pcm_format == SNDRV_PCM_FORMAT_DSD_U16_LE && fmt->dsd_dop) {
602		/*
603		 * When operating in DSD DOP mode, the size of a sample frame
604		 * in hardware differs from the actual physical format width
605		 * because we need to make room for the DOP markers.
606		 */
607		frame_bits += channels << 3;
608	}
609
610	ep->datainterval = fmt->datainterval;
611	ep->stride = frame_bits >> 3;
612	ep->silence_value = pcm_format == SNDRV_PCM_FORMAT_U8 ? 0x80 : 0;
613
614	/* assume max. frequency is 25% higher than nominal */
615	ep->freqmax = ep->freqn + (ep->freqn >> 2);
616	maxsize = ((ep->freqmax + 0xffff) * (frame_bits >> 3))
617				>> (16 - ep->datainterval);
618	/* but wMaxPacketSize might reduce this */
619	if (ep->maxpacksize && ep->maxpacksize < maxsize) {
620		/* whatever fits into a max. size packet */
621		maxsize = ep->maxpacksize;
622		ep->freqmax = (maxsize / (frame_bits >> 3))
623				<< (16 - ep->datainterval);
624	}
625
626	if (ep->fill_max)
627		ep->curpacksize = ep->maxpacksize;
628	else
629		ep->curpacksize = maxsize;
630
631	if (snd_usb_get_speed(ep->chip->dev) != USB_SPEED_FULL) {
632		packs_per_ms = 8 >> ep->datainterval;
633		max_packs_per_urb = MAX_PACKS_HS;
634	} else {
635		packs_per_ms = 1;
636		max_packs_per_urb = MAX_PACKS;
637	}
638	if (sync_ep && !snd_usb_endpoint_implicit_feedback_sink(ep))
639		max_packs_per_urb = min(max_packs_per_urb,
640					1U << sync_ep->syncinterval);
641	max_packs_per_urb = max(1u, max_packs_per_urb >> ep->datainterval);
642
643	/*
644	 * Capture endpoints need to use small URBs because there's no way
645	 * to tell in advance where the next period will end, and we don't
646	 * want the next URB to complete much after the period ends.
647	 *
648	 * Playback endpoints with implicit sync much use the same parameters
649	 * as their corresponding capture endpoint.
650	 */
651	if (usb_pipein(ep->pipe) ||
652			snd_usb_endpoint_implicit_feedback_sink(ep)) {
653
654		urb_packs = packs_per_ms;
655		/*
656		 * Wireless devices can poll at a max rate of once per 4ms.
657		 * For dataintervals less than 5, increase the packet count to
658		 * allow the host controller to use bursting to fill in the
659		 * gaps.
660		 */
661		if (snd_usb_get_speed(ep->chip->dev) == USB_SPEED_WIRELESS) {
662			int interval = ep->datainterval;
663			while (interval < 5) {
664				urb_packs <<= 1;
665				++interval;
666			}
667		}
668		/* make capture URBs <= 1 ms and smaller than a period */
669		urb_packs = min(max_packs_per_urb, urb_packs);
670		while (urb_packs > 1 && urb_packs * maxsize >= period_bytes)
671			urb_packs >>= 1;
672		ep->nurbs = MAX_URBS;
673
674	/*
675	 * Playback endpoints without implicit sync are adjusted so that
676	 * a period fits as evenly as possible in the smallest number of
677	 * URBs.  The total number of URBs is adjusted to the size of the
678	 * ALSA buffer, subject to the MAX_URBS and MAX_QUEUE limits.
679	 */
680	} else {
681		/* determine how small a packet can be */
682		minsize = (ep->freqn >> (16 - ep->datainterval)) *
683				(frame_bits >> 3);
684		/* with sync from device, assume it can be 12% lower */
685		if (sync_ep)
686			minsize -= minsize >> 3;
687		minsize = max(minsize, 1u);
688
689		/* how many packets will contain an entire ALSA period? */
690		max_packs_per_period = DIV_ROUND_UP(period_bytes, minsize);
691
692		/* how many URBs will contain a period? */
693		urbs_per_period = DIV_ROUND_UP(max_packs_per_period,
694				max_packs_per_urb);
695		/* how many packets are needed in each URB? */
696		urb_packs = DIV_ROUND_UP(max_packs_per_period, urbs_per_period);
697
698		/* limit the number of frames in a single URB */
699		ep->max_urb_frames = DIV_ROUND_UP(frames_per_period,
700					urbs_per_period);
701
702		/* try to use enough URBs to contain an entire ALSA buffer */
703		max_urbs = min((unsigned) MAX_URBS,
704				MAX_QUEUE * packs_per_ms / urb_packs);
705		ep->nurbs = min(max_urbs, urbs_per_period * periods_per_buffer);
706	}
707
708	/* allocate and initialize data urbs */
709	for (i = 0; i < ep->nurbs; i++) {
710		struct snd_urb_ctx *u = &ep->urb[i];
711		u->index = i;
712		u->ep = ep;
713		u->packets = urb_packs;
714		u->buffer_size = maxsize * u->packets;
715
716		if (fmt->fmt_type == UAC_FORMAT_TYPE_II)
717			u->packets++; /* for transfer delimiter */
718		u->urb = usb_alloc_urb(u->packets, GFP_KERNEL);
719		if (!u->urb)
720			goto out_of_memory;
721
722		u->urb->transfer_buffer =
723			usb_alloc_coherent(ep->chip->dev, u->buffer_size,
724					   GFP_KERNEL, &u->urb->transfer_dma);
725		if (!u->urb->transfer_buffer)
726			goto out_of_memory;
727		u->urb->pipe = ep->pipe;
728		u->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
729		u->urb->interval = 1 << ep->datainterval;
730		u->urb->context = u;
731		u->urb->complete = snd_complete_urb;
732		INIT_LIST_HEAD(&u->ready_list);
733	}
734
735	return 0;
736
737out_of_memory:
738	release_urbs(ep, 0);
739	return -ENOMEM;
740}
741
742/*
743 * configure a sync endpoint
744 */
745static int sync_ep_set_params(struct snd_usb_endpoint *ep)
746{
747	int i;
748
749	ep->syncbuf = usb_alloc_coherent(ep->chip->dev, SYNC_URBS * 4,
750					 GFP_KERNEL, &ep->sync_dma);
751	if (!ep->syncbuf)
752		return -ENOMEM;
753
754	for (i = 0; i < SYNC_URBS; i++) {
755		struct snd_urb_ctx *u = &ep->urb[i];
756		u->index = i;
757		u->ep = ep;
758		u->packets = 1;
759		u->urb = usb_alloc_urb(1, GFP_KERNEL);
760		if (!u->urb)
761			goto out_of_memory;
762		u->urb->transfer_buffer = ep->syncbuf + i * 4;
763		u->urb->transfer_dma = ep->sync_dma + i * 4;
764		u->urb->transfer_buffer_length = 4;
765		u->urb->pipe = ep->pipe;
766		u->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
767		u->urb->number_of_packets = 1;
768		u->urb->interval = 1 << ep->syncinterval;
769		u->urb->context = u;
770		u->urb->complete = snd_complete_urb;
771	}
772
773	ep->nurbs = SYNC_URBS;
774
775	return 0;
776
777out_of_memory:
778	release_urbs(ep, 0);
779	return -ENOMEM;
780}
781
782/**
783 * snd_usb_endpoint_set_params: configure an snd_usb_endpoint
784 *
785 * @ep: the snd_usb_endpoint to configure
786 * @pcm_format: the audio fomat.
787 * @channels: the number of audio channels.
788 * @period_bytes: the number of bytes in one alsa period.
789 * @period_frames: the number of frames in one alsa period.
790 * @buffer_periods: the number of periods in one alsa buffer.
791 * @rate: the frame rate.
792 * @fmt: the USB audio format information
793 * @sync_ep: the sync endpoint to use, if any
794 *
795 * Determine the number of URBs to be used on this endpoint.
796 * An endpoint must be configured before it can be started.
797 * An endpoint that is already running can not be reconfigured.
798 */
799int snd_usb_endpoint_set_params(struct snd_usb_endpoint *ep,
800				snd_pcm_format_t pcm_format,
801				unsigned int channels,
802				unsigned int period_bytes,
803				unsigned int period_frames,
804				unsigned int buffer_periods,
805				unsigned int rate,
806				struct audioformat *fmt,
807				struct snd_usb_endpoint *sync_ep)
808{
809	int err;
810
811	if (ep->use_count != 0) {
812		usb_audio_warn(ep->chip,
813			 "Unable to change format on ep #%x: already in use\n",
814			 ep->ep_num);
815		return -EBUSY;
816	}
817
818	/* release old buffers, if any */
819	release_urbs(ep, 0);
820
821	ep->datainterval = fmt->datainterval;
822	ep->maxpacksize = fmt->maxpacksize;
823	ep->fill_max = !!(fmt->attributes & UAC_EP_CS_ATTR_FILL_MAX);
824
825	if (snd_usb_get_speed(ep->chip->dev) == USB_SPEED_FULL)
826		ep->freqn = get_usb_full_speed_rate(rate);
827	else
828		ep->freqn = get_usb_high_speed_rate(rate);
829
830	/* calculate the frequency in 16.16 format */
831	ep->freqm = ep->freqn;
832	ep->freqshift = INT_MIN;
833
834	ep->phase = 0;
835
836	switch (ep->type) {
837	case  SND_USB_ENDPOINT_TYPE_DATA:
838		err = data_ep_set_params(ep, pcm_format, channels,
839					 period_bytes, period_frames,
840					 buffer_periods, fmt, sync_ep);
841		break;
842	case  SND_USB_ENDPOINT_TYPE_SYNC:
843		err = sync_ep_set_params(ep);
844		break;
845	default:
846		err = -EINVAL;
847	}
848
849	usb_audio_dbg(ep->chip,
850		"Setting params for ep #%x (type %d, %d urbs), ret=%d\n",
851		ep->ep_num, ep->type, ep->nurbs, err);
852
853	return err;
854}
855
856/**
857 * snd_usb_endpoint_start: start an snd_usb_endpoint
858 *
859 * @ep:		the endpoint to start
860 * @can_sleep:	flag indicating whether the operation is executed in
861 * 		non-atomic context
862 *
863 * A call to this function will increment the use count of the endpoint.
864 * In case it is not already running, the URBs for this endpoint will be
865 * submitted. Otherwise, this function does nothing.
866 *
867 * Must be balanced to calls of snd_usb_endpoint_stop().
868 *
869 * Returns an error if the URB submission failed, 0 in all other cases.
870 */
871int snd_usb_endpoint_start(struct snd_usb_endpoint *ep, bool can_sleep)
872{
873	int err;
874	unsigned int i;
875
876	if (atomic_read(&ep->chip->shutdown))
877		return -EBADFD;
878
879	/* already running? */
880	if (++ep->use_count != 1)
881		return 0;
882
883	/* just to be sure */
884	deactivate_urbs(ep, false);
885	if (can_sleep)
886		wait_clear_urbs(ep);
887
888	ep->active_mask = 0;
889	ep->unlink_mask = 0;
890	ep->phase = 0;
891
892	snd_usb_endpoint_start_quirk(ep);
893
894	/*
895	 * If this endpoint has a data endpoint as implicit feedback source,
896	 * don't start the urbs here. Instead, mark them all as available,
897	 * wait for the record urbs to return and queue the playback urbs
898	 * from that context.
899	 */
900
901	set_bit(EP_FLAG_RUNNING, &ep->flags);
902
903	if (snd_usb_endpoint_implicit_feedback_sink(ep)) {
904		for (i = 0; i < ep->nurbs; i++) {
905			struct snd_urb_ctx *ctx = ep->urb + i;
906			list_add_tail(&ctx->ready_list, &ep->ready_playback_urbs);
907		}
908
909		return 0;
910	}
911
912	for (i = 0; i < ep->nurbs; i++) {
913		struct urb *urb = ep->urb[i].urb;
914
915		if (snd_BUG_ON(!urb))
916			goto __error;
917
918		if (usb_pipeout(ep->pipe)) {
919			prepare_outbound_urb(ep, urb->context);
920		} else {
921			prepare_inbound_urb(ep, urb->context);
922		}
923
924		err = usb_submit_urb(urb, GFP_ATOMIC);
925		if (err < 0) {
926			usb_audio_err(ep->chip,
927				"cannot submit urb %d, error %d: %s\n",
928				i, err, usb_error_string(err));
929			goto __error;
930		}
931		set_bit(i, &ep->active_mask);
932	}
933
934	return 0;
935
936__error:
937	clear_bit(EP_FLAG_RUNNING, &ep->flags);
938	ep->use_count--;
939	deactivate_urbs(ep, false);
940	return -EPIPE;
941}
942
943/**
944 * snd_usb_endpoint_stop: stop an snd_usb_endpoint
945 *
946 * @ep: the endpoint to stop (may be NULL)
947 *
948 * A call to this function will decrement the use count of the endpoint.
949 * In case the last user has requested the endpoint stop, the URBs will
950 * actually be deactivated.
951 *
952 * Must be balanced to calls of snd_usb_endpoint_start().
953 *
954 * The caller needs to synchronize the pending stop operation via
955 * snd_usb_endpoint_sync_pending_stop().
956 */
957void snd_usb_endpoint_stop(struct snd_usb_endpoint *ep)
958{
959	if (!ep)
960		return;
961
962	if (snd_BUG_ON(ep->use_count == 0))
963		return;
964
965	if (--ep->use_count == 0) {
966		deactivate_urbs(ep, false);
967		ep->data_subs = NULL;
968		ep->sync_slave = NULL;
969		ep->retire_data_urb = NULL;
970		ep->prepare_data_urb = NULL;
971		set_bit(EP_FLAG_STOPPING, &ep->flags);
972	}
973}
974
975/**
976 * snd_usb_endpoint_deactivate: deactivate an snd_usb_endpoint
977 *
978 * @ep: the endpoint to deactivate
979 *
980 * If the endpoint is not currently in use, this functions will
981 * deactivate its associated URBs.
982 *
983 * In case of any active users, this functions does nothing.
984 */
985void snd_usb_endpoint_deactivate(struct snd_usb_endpoint *ep)
986{
987	if (!ep)
988		return;
989
990	if (ep->use_count != 0)
991		return;
992
993	deactivate_urbs(ep, true);
994	wait_clear_urbs(ep);
995}
996
997/**
998 * snd_usb_endpoint_release: Tear down an snd_usb_endpoint
999 *
1000 * @ep: the endpoint to release
1001 *
1002 * This function does not care for the endpoint's use count but will tear
1003 * down all the streaming URBs immediately.
1004 */
1005void snd_usb_endpoint_release(struct snd_usb_endpoint *ep)
1006{
1007	release_urbs(ep, 1);
1008}
1009
1010/**
1011 * snd_usb_endpoint_free: Free the resources of an snd_usb_endpoint
1012 *
1013 * @ep: the endpoint to free
1014 *
1015 * This free all resources of the given ep.
1016 */
1017void snd_usb_endpoint_free(struct snd_usb_endpoint *ep)
1018{
1019	kfree(ep);
1020}
1021
1022/**
1023 * snd_usb_handle_sync_urb: parse an USB sync packet
1024 *
1025 * @ep: the endpoint to handle the packet
1026 * @sender: the sending endpoint
1027 * @urb: the received packet
1028 *
1029 * This function is called from the context of an endpoint that received
1030 * the packet and is used to let another endpoint object handle the payload.
1031 */
1032void snd_usb_handle_sync_urb(struct snd_usb_endpoint *ep,
1033			     struct snd_usb_endpoint *sender,
1034			     const struct urb *urb)
1035{
1036	int shift;
1037	unsigned int f;
1038	unsigned long flags;
1039
1040	snd_BUG_ON(ep == sender);
1041
1042	/*
1043	 * In case the endpoint is operating in implicit feedback mode, prepare
1044	 * a new outbound URB that has the same layout as the received packet
1045	 * and add it to the list of pending urbs. queue_pending_output_urbs()
1046	 * will take care of them later.
1047	 */
1048	if (snd_usb_endpoint_implicit_feedback_sink(ep) &&
1049	    ep->use_count != 0) {
1050
1051		/* implicit feedback case */
1052		int i, bytes = 0;
1053		struct snd_urb_ctx *in_ctx;
1054		struct snd_usb_packet_info *out_packet;
1055
1056		in_ctx = urb->context;
1057
1058		/* Count overall packet size */
1059		for (i = 0; i < in_ctx->packets; i++)
1060			if (urb->iso_frame_desc[i].status == 0)
1061				bytes += urb->iso_frame_desc[i].actual_length;
1062
1063		/*
1064		 * skip empty packets. At least M-Audio's Fast Track Ultra stops
1065		 * streaming once it received a 0-byte OUT URB
1066		 */
1067		if (bytes == 0)
1068			return;
1069
1070		spin_lock_irqsave(&ep->lock, flags);
1071		out_packet = ep->next_packet + ep->next_packet_write_pos;
1072
1073		/*
1074		 * Iterate through the inbound packet and prepare the lengths
1075		 * for the output packet. The OUT packet we are about to send
1076		 * will have the same amount of payload bytes per stride as the
1077		 * IN packet we just received. Since the actual size is scaled
1078		 * by the stride, use the sender stride to calculate the length
1079		 * in case the number of channels differ between the implicitly
1080		 * fed-back endpoint and the synchronizing endpoint.
1081		 */
1082
1083		out_packet->packets = in_ctx->packets;
1084		for (i = 0; i < in_ctx->packets; i++) {
1085			if (urb->iso_frame_desc[i].status == 0)
1086				out_packet->packet_size[i] =
1087					urb->iso_frame_desc[i].actual_length / sender->stride;
1088			else
1089				out_packet->packet_size[i] = 0;
1090		}
1091
1092		ep->next_packet_write_pos++;
1093		ep->next_packet_write_pos %= MAX_URBS;
1094		spin_unlock_irqrestore(&ep->lock, flags);
1095		queue_pending_output_urbs(ep);
1096
1097		return;
1098	}
1099
1100	/*
1101	 * process after playback sync complete
1102	 *
1103	 * Full speed devices report feedback values in 10.14 format as samples
1104	 * per frame, high speed devices in 16.16 format as samples per
1105	 * microframe.
1106	 *
1107	 * Because the Audio Class 1 spec was written before USB 2.0, many high
1108	 * speed devices use a wrong interpretation, some others use an
1109	 * entirely different format.
1110	 *
1111	 * Therefore, we cannot predict what format any particular device uses
1112	 * and must detect it automatically.
1113	 */
1114
1115	if (urb->iso_frame_desc[0].status != 0 ||
1116	    urb->iso_frame_desc[0].actual_length < 3)
1117		return;
1118
1119	f = le32_to_cpup(urb->transfer_buffer);
1120	if (urb->iso_frame_desc[0].actual_length == 3)
1121		f &= 0x00ffffff;
1122	else
1123		f &= 0x0fffffff;
1124
1125	if (f == 0)
1126		return;
1127
1128	if (unlikely(sender->udh01_fb_quirk)) {
1129		/*
1130		 * The TEAC UD-H01 firmware sometimes changes the feedback value
1131		 * by +/- 0x1.0000.
1132		 */
1133		if (f < ep->freqn - 0x8000)
1134			f += 0x10000;
1135		else if (f > ep->freqn + 0x8000)
1136			f -= 0x10000;
1137	} else if (unlikely(ep->freqshift == INT_MIN)) {
1138		/*
1139		 * The first time we see a feedback value, determine its format
1140		 * by shifting it left or right until it matches the nominal
1141		 * frequency value.  This assumes that the feedback does not
1142		 * differ from the nominal value more than +50% or -25%.
1143		 */
1144		shift = 0;
1145		while (f < ep->freqn - ep->freqn / 4) {
1146			f <<= 1;
1147			shift++;
1148		}
1149		while (f > ep->freqn + ep->freqn / 2) {
1150			f >>= 1;
1151			shift--;
1152		}
1153		ep->freqshift = shift;
1154	} else if (ep->freqshift >= 0)
1155		f <<= ep->freqshift;
1156	else
1157		f >>= -ep->freqshift;
1158
1159	if (likely(f >= ep->freqn - ep->freqn / 8 && f <= ep->freqmax)) {
1160		/*
1161		 * If the frequency looks valid, set it.
1162		 * This value is referred to in prepare_playback_urb().
1163		 */
1164		spin_lock_irqsave(&ep->lock, flags);
1165		ep->freqm = f;
1166		spin_unlock_irqrestore(&ep->lock, flags);
1167	} else {
1168		/*
1169		 * Out of range; maybe the shift value is wrong.
1170		 * Reset it so that we autodetect again the next time.
1171		 */
1172		ep->freqshift = INT_MIN;
1173	}
1174}
1175
1176