xref: /openbmc/linux/sound/usb/usx2y/usbusx2yaudio.c (revision 842ed298)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *   US-X2Y AUDIO
4  *   Copyright (c) 2002-2004 by Karsten Wiese
5  *
6  *   based on
7  *
8  *   (Tentative) USB Audio Driver for ALSA
9  *
10  *   Main and PCM part
11  *
12  *   Copyright (c) 2002 by Takashi Iwai <tiwai@suse.de>
13  *
14  *   Many codes borrowed from audio.c by
15  *	    Alan Cox (alan@lxorguk.ukuu.org.uk)
16  *	    Thomas Sailer (sailer@ife.ee.ethz.ch)
17  */
18 
19 
20 #include <linux/interrupt.h>
21 #include <linux/slab.h>
22 #include <linux/usb.h>
23 #include <linux/moduleparam.h>
24 #include <sound/core.h>
25 #include <sound/info.h>
26 #include <sound/pcm.h>
27 #include <sound/pcm_params.h>
28 #include "usx2y.h"
29 #include "usbusx2y.h"
30 
31 #define USX2Y_NRPACKS 4			/* Default value used for nr of packs per urb.
32 					  1 to 4 have been tested ok on uhci.
33 					  To use 3 on ohci, you'd need a patch:
34 					  look for "0000425-linux-2.6.9-rc4-mm1_ohci-hcd.patch.gz" on
35 					  "https://bugtrack.alsa-project.org/alsa-bug/bug_view_page.php?bug_id=0000425"
36 					  .
37 					  1, 2 and 4 work out of the box on ohci, if I recall correctly.
38 					  Bigger is safer operation,
39 					  smaller gives lower latencies.
40 					*/
41 #define USX2Y_NRPACKS_VARIABLE y	/* If your system works ok with this module's parameter
42 					   nrpacks set to 1, you might as well comment
43 					   this #define out, and thereby produce smaller, faster code.
44 					   You'd also set USX2Y_NRPACKS to 1 then.
45 					*/
46 
47 #ifdef USX2Y_NRPACKS_VARIABLE
48  static int nrpacks = USX2Y_NRPACKS; /* number of packets per urb */
49  #define  nr_of_packs() nrpacks
50  module_param(nrpacks, int, 0444);
51  MODULE_PARM_DESC(nrpacks, "Number of packets per URB.");
52 #else
53  #define nr_of_packs() USX2Y_NRPACKS
54 #endif
55 
56 
57 static int usX2Y_urb_capt_retire(struct snd_usX2Y_substream *subs)
58 {
59 	struct urb	*urb = subs->completed_urb;
60 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
61 	unsigned char	*cp;
62 	int 		i, len, lens = 0, hwptr_done = subs->hwptr_done;
63 	struct usX2Ydev	*usX2Y = subs->usX2Y;
64 
65 	for (i = 0; i < nr_of_packs(); i++) {
66 		cp = (unsigned char*)urb->transfer_buffer + urb->iso_frame_desc[i].offset;
67 		if (urb->iso_frame_desc[i].status) { /* active? hmm, skip this */
68 			snd_printk(KERN_ERR "active frame status %i. "
69 				   "Most probably some hardware problem.\n",
70 				   urb->iso_frame_desc[i].status);
71 			return urb->iso_frame_desc[i].status;
72 		}
73 		len = urb->iso_frame_desc[i].actual_length / usX2Y->stride;
74 		if (! len) {
75 			snd_printd("0 == len ERROR!\n");
76 			continue;
77 		}
78 
79 		/* copy a data chunk */
80 		if ((hwptr_done + len) > runtime->buffer_size) {
81 			int cnt = runtime->buffer_size - hwptr_done;
82 			int blen = cnt * usX2Y->stride;
83 			memcpy(runtime->dma_area + hwptr_done * usX2Y->stride, cp, blen);
84 			memcpy(runtime->dma_area, cp + blen, len * usX2Y->stride - blen);
85 		} else {
86 			memcpy(runtime->dma_area + hwptr_done * usX2Y->stride, cp,
87 			       len * usX2Y->stride);
88 		}
89 		lens += len;
90 		if ((hwptr_done += len) >= runtime->buffer_size)
91 			hwptr_done -= runtime->buffer_size;
92 	}
93 
94 	subs->hwptr_done = hwptr_done;
95 	subs->transfer_done += lens;
96 	/* update the pointer, call callback if necessary */
97 	if (subs->transfer_done >= runtime->period_size) {
98 		subs->transfer_done -= runtime->period_size;
99 		snd_pcm_period_elapsed(subs->pcm_substream);
100 	}
101 	return 0;
102 }
103 /*
104  * prepare urb for playback data pipe
105  *
106  * we copy the data directly from the pcm buffer.
107  * the current position to be copied is held in hwptr field.
108  * since a urb can handle only a single linear buffer, if the total
109  * transferred area overflows the buffer boundary, we cannot send
110  * it directly from the buffer.  thus the data is once copied to
111  * a temporary buffer and urb points to that.
112  */
113 static int usX2Y_urb_play_prepare(struct snd_usX2Y_substream *subs,
114 				  struct urb *cap_urb,
115 				  struct urb *urb)
116 {
117 	int count, counts, pack;
118 	struct usX2Ydev *usX2Y = subs->usX2Y;
119 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
120 
121 	count = 0;
122 	for (pack = 0; pack <  nr_of_packs(); pack++) {
123 		/* calculate the size of a packet */
124 		counts = cap_urb->iso_frame_desc[pack].actual_length / usX2Y->stride;
125 		count += counts;
126 		if (counts < 43 || counts > 50) {
127 			snd_printk(KERN_ERR "should not be here with counts=%i\n", counts);
128 			return -EPIPE;
129 		}
130 		/* set up descriptor */
131 		urb->iso_frame_desc[pack].offset = pack ?
132 			urb->iso_frame_desc[pack - 1].offset +
133 			urb->iso_frame_desc[pack - 1].length :
134 			0;
135 		urb->iso_frame_desc[pack].length = cap_urb->iso_frame_desc[pack].actual_length;
136 	}
137 	if (atomic_read(&subs->state) >= state_PRERUNNING)
138 		if (subs->hwptr + count > runtime->buffer_size) {
139 			/* err, the transferred area goes over buffer boundary.
140 			 * copy the data to the temp buffer.
141 			 */
142 			int len;
143 			len = runtime->buffer_size - subs->hwptr;
144 			urb->transfer_buffer = subs->tmpbuf;
145 			memcpy(subs->tmpbuf, runtime->dma_area +
146 			       subs->hwptr * usX2Y->stride, len * usX2Y->stride);
147 			memcpy(subs->tmpbuf + len * usX2Y->stride,
148 			       runtime->dma_area, (count - len) * usX2Y->stride);
149 			subs->hwptr += count;
150 			subs->hwptr -= runtime->buffer_size;
151 		} else {
152 			/* set the buffer pointer */
153 			urb->transfer_buffer = runtime->dma_area + subs->hwptr * usX2Y->stride;
154 			if ((subs->hwptr += count) >= runtime->buffer_size)
155 				subs->hwptr -= runtime->buffer_size;
156 		}
157 	else
158 		urb->transfer_buffer = subs->tmpbuf;
159 	urb->transfer_buffer_length = count * usX2Y->stride;
160 	return 0;
161 }
162 
163 /*
164  * process after playback data complete
165  *
166  * update the current position and call callback if a period is processed.
167  */
168 static void usX2Y_urb_play_retire(struct snd_usX2Y_substream *subs, struct urb *urb)
169 {
170 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
171 	int		len = urb->actual_length / subs->usX2Y->stride;
172 
173 	subs->transfer_done += len;
174 	subs->hwptr_done +=  len;
175 	if (subs->hwptr_done >= runtime->buffer_size)
176 		subs->hwptr_done -= runtime->buffer_size;
177 	if (subs->transfer_done >= runtime->period_size) {
178 		subs->transfer_done -= runtime->period_size;
179 		snd_pcm_period_elapsed(subs->pcm_substream);
180 	}
181 }
182 
183 static int usX2Y_urb_submit(struct snd_usX2Y_substream *subs, struct urb *urb, int frame)
184 {
185 	int err;
186 	if (!urb)
187 		return -ENODEV;
188 	urb->start_frame = (frame + NRURBS * nr_of_packs());  // let hcd do rollover sanity checks
189 	urb->hcpriv = NULL;
190 	urb->dev = subs->usX2Y->dev; /* we need to set this at each time */
191 	if ((err = usb_submit_urb(urb, GFP_ATOMIC)) < 0) {
192 		snd_printk(KERN_ERR "usb_submit_urb() returned %i\n", err);
193 		return err;
194 	}
195 	return 0;
196 }
197 
198 static inline int usX2Y_usbframe_complete(struct snd_usX2Y_substream *capsubs,
199 					  struct snd_usX2Y_substream *playbacksubs,
200 					  int frame)
201 {
202 	int err, state;
203 	struct urb *urb = playbacksubs->completed_urb;
204 
205 	state = atomic_read(&playbacksubs->state);
206 	if (NULL != urb) {
207 		if (state == state_RUNNING)
208 			usX2Y_urb_play_retire(playbacksubs, urb);
209 		else if (state >= state_PRERUNNING)
210 			atomic_inc(&playbacksubs->state);
211 	} else {
212 		switch (state) {
213 		case state_STARTING1:
214 			urb = playbacksubs->urb[0];
215 			atomic_inc(&playbacksubs->state);
216 			break;
217 		case state_STARTING2:
218 			urb = playbacksubs->urb[1];
219 			atomic_inc(&playbacksubs->state);
220 			break;
221 		}
222 	}
223 	if (urb) {
224 		if ((err = usX2Y_urb_play_prepare(playbacksubs, capsubs->completed_urb, urb)) ||
225 		    (err = usX2Y_urb_submit(playbacksubs, urb, frame))) {
226 			return err;
227 		}
228 	}
229 
230 	playbacksubs->completed_urb = NULL;
231 
232 	state = atomic_read(&capsubs->state);
233 	if (state >= state_PREPARED) {
234 		if (state == state_RUNNING) {
235 			if ((err = usX2Y_urb_capt_retire(capsubs)))
236 				return err;
237 		} else if (state >= state_PRERUNNING)
238 			atomic_inc(&capsubs->state);
239 		if ((err = usX2Y_urb_submit(capsubs, capsubs->completed_urb, frame)))
240 			return err;
241 	}
242 	capsubs->completed_urb = NULL;
243 	return 0;
244 }
245 
246 
247 static void usX2Y_clients_stop(struct usX2Ydev *usX2Y)
248 {
249 	int s, u;
250 
251 	for (s = 0; s < 4; s++) {
252 		struct snd_usX2Y_substream *subs = usX2Y->subs[s];
253 		if (subs) {
254 			snd_printdd("%i %p state=%i\n", s, subs, atomic_read(&subs->state));
255 			atomic_set(&subs->state, state_STOPPED);
256 		}
257 	}
258 	for (s = 0; s < 4; s++) {
259 		struct snd_usX2Y_substream *subs = usX2Y->subs[s];
260 		if (subs) {
261 			if (atomic_read(&subs->state) >= state_PRERUNNING)
262 				snd_pcm_stop_xrun(subs->pcm_substream);
263 			for (u = 0; u < NRURBS; u++) {
264 				struct urb *urb = subs->urb[u];
265 				if (NULL != urb)
266 					snd_printdd("%i status=%i start_frame=%i\n",
267 						    u, urb->status, urb->start_frame);
268 			}
269 		}
270 	}
271 	usX2Y->prepare_subs = NULL;
272 	wake_up(&usX2Y->prepare_wait_queue);
273 }
274 
275 static void usX2Y_error_urb_status(struct usX2Ydev *usX2Y,
276 				   struct snd_usX2Y_substream *subs, struct urb *urb)
277 {
278 	snd_printk(KERN_ERR "ep=%i stalled with status=%i\n", subs->endpoint, urb->status);
279 	urb->status = 0;
280 	usX2Y_clients_stop(usX2Y);
281 }
282 
283 static void i_usX2Y_urb_complete(struct urb *urb)
284 {
285 	struct snd_usX2Y_substream *subs = urb->context;
286 	struct usX2Ydev *usX2Y = subs->usX2Y;
287 
288 	if (unlikely(atomic_read(&subs->state) < state_PREPARED)) {
289 		snd_printdd("hcd_frame=%i ep=%i%s status=%i start_frame=%i\n",
290 			    usb_get_current_frame_number(usX2Y->dev),
291 			    subs->endpoint, usb_pipein(urb->pipe) ? "in" : "out",
292 			    urb->status, urb->start_frame);
293 		return;
294 	}
295 	if (unlikely(urb->status)) {
296 		usX2Y_error_urb_status(usX2Y, subs, urb);
297 		return;
298 	}
299 
300 	subs->completed_urb = urb;
301 
302 	{
303 		struct snd_usX2Y_substream *capsubs = usX2Y->subs[SNDRV_PCM_STREAM_CAPTURE],
304 			*playbacksubs = usX2Y->subs[SNDRV_PCM_STREAM_PLAYBACK];
305 		if (capsubs->completed_urb &&
306 		    atomic_read(&capsubs->state) >= state_PREPARED &&
307 		    (playbacksubs->completed_urb ||
308 		     atomic_read(&playbacksubs->state) < state_PREPARED)) {
309 			if (!usX2Y_usbframe_complete(capsubs, playbacksubs, urb->start_frame))
310 				usX2Y->wait_iso_frame += nr_of_packs();
311 			else {
312 				snd_printdd("\n");
313 				usX2Y_clients_stop(usX2Y);
314 			}
315 		}
316 	}
317 }
318 
319 static void usX2Y_urbs_set_complete(struct usX2Ydev * usX2Y,
320 				    void (*complete)(struct urb *))
321 {
322 	int s, u;
323 	for (s = 0; s < 4; s++) {
324 		struct snd_usX2Y_substream *subs = usX2Y->subs[s];
325 		if (NULL != subs)
326 			for (u = 0; u < NRURBS; u++) {
327 				struct urb * urb = subs->urb[u];
328 				if (NULL != urb)
329 					urb->complete = complete;
330 			}
331 	}
332 }
333 
334 static void usX2Y_subs_startup_finish(struct usX2Ydev * usX2Y)
335 {
336 	usX2Y_urbs_set_complete(usX2Y, i_usX2Y_urb_complete);
337 	usX2Y->prepare_subs = NULL;
338 }
339 
340 static void i_usX2Y_subs_startup(struct urb *urb)
341 {
342 	struct snd_usX2Y_substream *subs = urb->context;
343 	struct usX2Ydev *usX2Y = subs->usX2Y;
344 	struct snd_usX2Y_substream *prepare_subs = usX2Y->prepare_subs;
345 	if (NULL != prepare_subs)
346 		if (urb->start_frame == prepare_subs->urb[0]->start_frame) {
347 			usX2Y_subs_startup_finish(usX2Y);
348 			atomic_inc(&prepare_subs->state);
349 			wake_up(&usX2Y->prepare_wait_queue);
350 		}
351 
352 	i_usX2Y_urb_complete(urb);
353 }
354 
355 static void usX2Y_subs_prepare(struct snd_usX2Y_substream *subs)
356 {
357 	snd_printdd("usX2Y_substream_prepare(%p) ep=%i urb0=%p urb1=%p\n",
358 		    subs, subs->endpoint, subs->urb[0], subs->urb[1]);
359 	/* reset the pointer */
360 	subs->hwptr = 0;
361 	subs->hwptr_done = 0;
362 	subs->transfer_done = 0;
363 }
364 
365 
366 static void usX2Y_urb_release(struct urb **urb, int free_tb)
367 {
368 	if (*urb) {
369 		usb_kill_urb(*urb);
370 		if (free_tb)
371 			kfree((*urb)->transfer_buffer);
372 		usb_free_urb(*urb);
373 		*urb = NULL;
374 	}
375 }
376 /*
377  * release a substreams urbs
378  */
379 static void usX2Y_urbs_release(struct snd_usX2Y_substream *subs)
380 {
381 	int i;
382 	snd_printdd("usX2Y_urbs_release() %i\n", subs->endpoint);
383 	for (i = 0; i < NRURBS; i++)
384 		usX2Y_urb_release(subs->urb + i,
385 				  subs != subs->usX2Y->subs[SNDRV_PCM_STREAM_PLAYBACK]);
386 
387 	kfree(subs->tmpbuf);
388 	subs->tmpbuf = NULL;
389 }
390 /*
391  * initialize a substream's urbs
392  */
393 static int usX2Y_urbs_allocate(struct snd_usX2Y_substream *subs)
394 {
395 	int i;
396 	unsigned int pipe;
397 	int is_playback = subs == subs->usX2Y->subs[SNDRV_PCM_STREAM_PLAYBACK];
398 	struct usb_device *dev = subs->usX2Y->dev;
399 
400 	pipe = is_playback ? usb_sndisocpipe(dev, subs->endpoint) :
401 			usb_rcvisocpipe(dev, subs->endpoint);
402 	subs->maxpacksize = usb_maxpacket(dev, pipe, is_playback);
403 	if (!subs->maxpacksize)
404 		return -EINVAL;
405 
406 	if (is_playback && NULL == subs->tmpbuf) {	/* allocate a temporary buffer for playback */
407 		subs->tmpbuf = kcalloc(nr_of_packs(), subs->maxpacksize, GFP_KERNEL);
408 		if (!subs->tmpbuf)
409 			return -ENOMEM;
410 	}
411 	/* allocate and initialize data urbs */
412 	for (i = 0; i < NRURBS; i++) {
413 		struct urb **purb = subs->urb + i;
414 		if (*purb) {
415 			usb_kill_urb(*purb);
416 			continue;
417 		}
418 		*purb = usb_alloc_urb(nr_of_packs(), GFP_KERNEL);
419 		if (NULL == *purb) {
420 			usX2Y_urbs_release(subs);
421 			return -ENOMEM;
422 		}
423 		if (!is_playback && !(*purb)->transfer_buffer) {
424 			/* allocate a capture buffer per urb */
425 			(*purb)->transfer_buffer =
426 				kmalloc_array(subs->maxpacksize,
427 					      nr_of_packs(), GFP_KERNEL);
428 			if (NULL == (*purb)->transfer_buffer) {
429 				usX2Y_urbs_release(subs);
430 				return -ENOMEM;
431 			}
432 		}
433 		(*purb)->dev = dev;
434 		(*purb)->pipe = pipe;
435 		(*purb)->number_of_packets = nr_of_packs();
436 		(*purb)->context = subs;
437 		(*purb)->interval = 1;
438 		(*purb)->complete = i_usX2Y_subs_startup;
439 	}
440 	return 0;
441 }
442 
443 static void usX2Y_subs_startup(struct snd_usX2Y_substream *subs)
444 {
445 	struct usX2Ydev *usX2Y = subs->usX2Y;
446 	usX2Y->prepare_subs = subs;
447 	subs->urb[0]->start_frame = -1;
448 	wmb();
449 	usX2Y_urbs_set_complete(usX2Y, i_usX2Y_subs_startup);
450 }
451 
452 static int usX2Y_urbs_start(struct snd_usX2Y_substream *subs)
453 {
454 	int i, err;
455 	struct usX2Ydev *usX2Y = subs->usX2Y;
456 
457 	if ((err = usX2Y_urbs_allocate(subs)) < 0)
458 		return err;
459 	subs->completed_urb = NULL;
460 	for (i = 0; i < 4; i++) {
461 		struct snd_usX2Y_substream *subs = usX2Y->subs[i];
462 		if (subs != NULL && atomic_read(&subs->state) >= state_PREPARED)
463 			goto start;
464 	}
465 
466  start:
467 	usX2Y_subs_startup(subs);
468 	for (i = 0; i < NRURBS; i++) {
469 		struct urb *urb = subs->urb[i];
470 		if (usb_pipein(urb->pipe)) {
471 			unsigned long pack;
472 			if (0 == i)
473 				atomic_set(&subs->state, state_STARTING3);
474 			urb->dev = usX2Y->dev;
475 			for (pack = 0; pack < nr_of_packs(); pack++) {
476 				urb->iso_frame_desc[pack].offset = subs->maxpacksize * pack;
477 				urb->iso_frame_desc[pack].length = subs->maxpacksize;
478 			}
479 			urb->transfer_buffer_length = subs->maxpacksize * nr_of_packs();
480 			if ((err = usb_submit_urb(urb, GFP_ATOMIC)) < 0) {
481 				snd_printk (KERN_ERR "cannot submit datapipe for urb %d, err = %d\n", i, err);
482 				err = -EPIPE;
483 				goto cleanup;
484 			} else
485 				if (i == 0)
486 					usX2Y->wait_iso_frame = urb->start_frame;
487 			urb->transfer_flags = 0;
488 		} else {
489 			atomic_set(&subs->state, state_STARTING1);
490 			break;
491 		}
492 	}
493 	err = 0;
494 	wait_event(usX2Y->prepare_wait_queue, NULL == usX2Y->prepare_subs);
495 	if (atomic_read(&subs->state) != state_PREPARED)
496 		err = -EPIPE;
497 
498  cleanup:
499 	if (err) {
500 		usX2Y_subs_startup_finish(usX2Y);
501 		usX2Y_clients_stop(usX2Y);		// something is completely wroong > stop evrything
502 	}
503 	return err;
504 }
505 
506 /*
507  * return the current pcm pointer.  just return the hwptr_done value.
508  */
509 static snd_pcm_uframes_t snd_usX2Y_pcm_pointer(struct snd_pcm_substream *substream)
510 {
511 	struct snd_usX2Y_substream *subs = substream->runtime->private_data;
512 	return subs->hwptr_done;
513 }
514 /*
515  * start/stop substream
516  */
517 static int snd_usX2Y_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
518 {
519 	struct snd_usX2Y_substream *subs = substream->runtime->private_data;
520 
521 	switch (cmd) {
522 	case SNDRV_PCM_TRIGGER_START:
523 		snd_printdd("snd_usX2Y_pcm_trigger(START)\n");
524 		if (atomic_read(&subs->state) == state_PREPARED &&
525 		    atomic_read(&subs->usX2Y->subs[SNDRV_PCM_STREAM_CAPTURE]->state) >= state_PREPARED) {
526 			atomic_set(&subs->state, state_PRERUNNING);
527 		} else {
528 			snd_printdd("\n");
529 			return -EPIPE;
530 		}
531 		break;
532 	case SNDRV_PCM_TRIGGER_STOP:
533 		snd_printdd("snd_usX2Y_pcm_trigger(STOP)\n");
534 		if (atomic_read(&subs->state) >= state_PRERUNNING)
535 			atomic_set(&subs->state, state_PREPARED);
536 		break;
537 	default:
538 		return -EINVAL;
539 	}
540 	return 0;
541 }
542 
543 
544 /*
545  * allocate a buffer, setup samplerate
546  *
547  * so far we use a physically linear buffer although packetize transfer
548  * doesn't need a continuous area.
549  * if sg buffer is supported on the later version of alsa, we'll follow
550  * that.
551  */
552 static const struct s_c2
553 {
554 	char c1, c2;
555 }
556 	SetRate44100[] =
557 {
558 	{ 0x14, 0x08},	// this line sets 44100, well actually a little less
559 	{ 0x18, 0x40},	// only tascam / frontier design knows the further lines .......
560 	{ 0x18, 0x42},
561 	{ 0x18, 0x45},
562 	{ 0x18, 0x46},
563 	{ 0x18, 0x48},
564 	{ 0x18, 0x4A},
565 	{ 0x18, 0x4C},
566 	{ 0x18, 0x4E},
567 	{ 0x18, 0x50},
568 	{ 0x18, 0x52},
569 	{ 0x18, 0x54},
570 	{ 0x18, 0x56},
571 	{ 0x18, 0x58},
572 	{ 0x18, 0x5A},
573 	{ 0x18, 0x5C},
574 	{ 0x18, 0x5E},
575 	{ 0x18, 0x60},
576 	{ 0x18, 0x62},
577 	{ 0x18, 0x64},
578 	{ 0x18, 0x66},
579 	{ 0x18, 0x68},
580 	{ 0x18, 0x6A},
581 	{ 0x18, 0x6C},
582 	{ 0x18, 0x6E},
583 	{ 0x18, 0x70},
584 	{ 0x18, 0x72},
585 	{ 0x18, 0x74},
586 	{ 0x18, 0x76},
587 	{ 0x18, 0x78},
588 	{ 0x18, 0x7A},
589 	{ 0x18, 0x7C},
590 	{ 0x18, 0x7E}
591 };
592 static const struct s_c2 SetRate48000[] =
593 {
594 	{ 0x14, 0x09},	// this line sets 48000, well actually a little less
595 	{ 0x18, 0x40},	// only tascam / frontier design knows the further lines .......
596 	{ 0x18, 0x42},
597 	{ 0x18, 0x45},
598 	{ 0x18, 0x46},
599 	{ 0x18, 0x48},
600 	{ 0x18, 0x4A},
601 	{ 0x18, 0x4C},
602 	{ 0x18, 0x4E},
603 	{ 0x18, 0x50},
604 	{ 0x18, 0x52},
605 	{ 0x18, 0x54},
606 	{ 0x18, 0x56},
607 	{ 0x18, 0x58},
608 	{ 0x18, 0x5A},
609 	{ 0x18, 0x5C},
610 	{ 0x18, 0x5E},
611 	{ 0x18, 0x60},
612 	{ 0x18, 0x62},
613 	{ 0x18, 0x64},
614 	{ 0x18, 0x66},
615 	{ 0x18, 0x68},
616 	{ 0x18, 0x6A},
617 	{ 0x18, 0x6C},
618 	{ 0x18, 0x6E},
619 	{ 0x18, 0x70},
620 	{ 0x18, 0x73},
621 	{ 0x18, 0x74},
622 	{ 0x18, 0x76},
623 	{ 0x18, 0x78},
624 	{ 0x18, 0x7A},
625 	{ 0x18, 0x7C},
626 	{ 0x18, 0x7E}
627 };
628 #define NOOF_SETRATE_URBS ARRAY_SIZE(SetRate48000)
629 
630 static void i_usX2Y_04Int(struct urb *urb)
631 {
632 	struct usX2Ydev *usX2Y = urb->context;
633 
634 	if (urb->status)
635 		snd_printk(KERN_ERR "snd_usX2Y_04Int() urb->status=%i\n", urb->status);
636 	if (0 == --usX2Y->US04->len)
637 		wake_up(&usX2Y->In04WaitQueue);
638 }
639 
640 static int usX2Y_rate_set(struct usX2Ydev *usX2Y, int rate)
641 {
642 	int			err = 0, i;
643 	struct snd_usX2Y_urbSeq	*us = NULL;
644 	int			*usbdata = NULL;
645 	const struct s_c2	*ra = rate == 48000 ? SetRate48000 : SetRate44100;
646 
647 	if (usX2Y->rate != rate) {
648 		us = kzalloc(sizeof(*us) + sizeof(struct urb*) * NOOF_SETRATE_URBS, GFP_KERNEL);
649 		if (NULL == us) {
650 			err = -ENOMEM;
651 			goto cleanup;
652 		}
653 		usbdata = kmalloc_array(NOOF_SETRATE_URBS, sizeof(int),
654 					GFP_KERNEL);
655 		if (NULL == usbdata) {
656 			err = -ENOMEM;
657 			goto cleanup;
658 		}
659 		for (i = 0; i < NOOF_SETRATE_URBS; ++i) {
660 			if (NULL == (us->urb[i] = usb_alloc_urb(0, GFP_KERNEL))) {
661 				err = -ENOMEM;
662 				goto cleanup;
663 			}
664 			((char*)(usbdata + i))[0] = ra[i].c1;
665 			((char*)(usbdata + i))[1] = ra[i].c2;
666 			usb_fill_bulk_urb(us->urb[i], usX2Y->dev, usb_sndbulkpipe(usX2Y->dev, 4),
667 					  usbdata + i, 2, i_usX2Y_04Int, usX2Y);
668 		}
669 		err = usb_urb_ep_type_check(us->urb[0]);
670 		if (err < 0)
671 			goto cleanup;
672 		us->submitted =	0;
673 		us->len =	NOOF_SETRATE_URBS;
674 		usX2Y->US04 =	us;
675 		wait_event_timeout(usX2Y->In04WaitQueue, 0 == us->len, HZ);
676 		usX2Y->US04 =	NULL;
677 		if (us->len)
678 			err = -ENODEV;
679 	cleanup:
680 		if (us) {
681 			us->submitted =	2*NOOF_SETRATE_URBS;
682 			for (i = 0; i < NOOF_SETRATE_URBS; ++i) {
683 				struct urb *urb = us->urb[i];
684 				if (!urb)
685 					continue;
686 				if (urb->status) {
687 					if (!err)
688 						err = -ENODEV;
689 					usb_kill_urb(urb);
690 				}
691 				usb_free_urb(urb);
692 			}
693 			usX2Y->US04 = NULL;
694 			kfree(usbdata);
695 			kfree(us);
696 			if (!err)
697 				usX2Y->rate = rate;
698 		}
699 	}
700 
701 	return err;
702 }
703 
704 
705 static int usX2Y_format_set(struct usX2Ydev *usX2Y, snd_pcm_format_t format)
706 {
707 	int alternate, err;
708 	struct list_head* p;
709 	if (format == SNDRV_PCM_FORMAT_S24_3LE) {
710 		alternate = 2;
711 		usX2Y->stride = 6;
712 	} else {
713 		alternate = 1;
714 		usX2Y->stride = 4;
715 	}
716 	list_for_each(p, &usX2Y->midi_list) {
717 		snd_usbmidi_input_stop(p);
718 	}
719 	usb_kill_urb(usX2Y->In04urb);
720 	if ((err = usb_set_interface(usX2Y->dev, 0, alternate))) {
721 		snd_printk(KERN_ERR "usb_set_interface error \n");
722 		return err;
723 	}
724 	usX2Y->In04urb->dev = usX2Y->dev;
725 	err = usb_submit_urb(usX2Y->In04urb, GFP_KERNEL);
726 	list_for_each(p, &usX2Y->midi_list) {
727 		snd_usbmidi_input_start(p);
728 	}
729 	usX2Y->format = format;
730 	usX2Y->rate = 0;
731 	return err;
732 }
733 
734 
735 static int snd_usX2Y_pcm_hw_params(struct snd_pcm_substream *substream,
736 				   struct snd_pcm_hw_params *hw_params)
737 {
738 	int			err = 0;
739 	unsigned int		rate = params_rate(hw_params);
740 	snd_pcm_format_t	format = params_format(hw_params);
741 	struct snd_card *card = substream->pstr->pcm->card;
742 	struct usX2Ydev	*dev = usX2Y(card);
743 	int i;
744 
745 	mutex_lock(&usX2Y(card)->pcm_mutex);
746 	snd_printdd("snd_usX2Y_hw_params(%p, %p)\n", substream, hw_params);
747 	/* all pcm substreams off one usX2Y have to operate at the same
748 	 * rate & format
749 	 */
750 	for (i = 0; i < dev->pcm_devs * 2; i++) {
751 		struct snd_usX2Y_substream *subs = dev->subs[i];
752 		struct snd_pcm_substream *test_substream;
753 
754 		if (!subs)
755 			continue;
756 		test_substream = subs->pcm_substream;
757 		if (!test_substream || test_substream == substream ||
758 		    !test_substream->runtime)
759 			continue;
760 		if ((test_substream->runtime->format &&
761 		     test_substream->runtime->format != format) ||
762 		    (test_substream->runtime->rate &&
763 		     test_substream->runtime->rate != rate)) {
764 			err = -EINVAL;
765 			goto error;
766 		}
767 	}
768 
769  error:
770 	mutex_unlock(&usX2Y(card)->pcm_mutex);
771 	return err;
772 }
773 
774 /*
775  * free the buffer
776  */
777 static int snd_usX2Y_pcm_hw_free(struct snd_pcm_substream *substream)
778 {
779 	struct snd_pcm_runtime *runtime = substream->runtime;
780 	struct snd_usX2Y_substream *subs = runtime->private_data;
781 	mutex_lock(&subs->usX2Y->pcm_mutex);
782 	snd_printdd("snd_usX2Y_hw_free(%p)\n", substream);
783 
784 	if (SNDRV_PCM_STREAM_PLAYBACK == substream->stream) {
785 		struct snd_usX2Y_substream *cap_subs = subs->usX2Y->subs[SNDRV_PCM_STREAM_CAPTURE];
786 		atomic_set(&subs->state, state_STOPPED);
787 		usX2Y_urbs_release(subs);
788 		if (!cap_subs->pcm_substream ||
789 		    !cap_subs->pcm_substream->runtime ||
790 		    !cap_subs->pcm_substream->runtime->status ||
791 		    cap_subs->pcm_substream->runtime->status->state < SNDRV_PCM_STATE_PREPARED) {
792 			atomic_set(&cap_subs->state, state_STOPPED);
793 			usX2Y_urbs_release(cap_subs);
794 		}
795 	} else {
796 		struct snd_usX2Y_substream *playback_subs = subs->usX2Y->subs[SNDRV_PCM_STREAM_PLAYBACK];
797 		if (atomic_read(&playback_subs->state) < state_PREPARED) {
798 			atomic_set(&subs->state, state_STOPPED);
799 			usX2Y_urbs_release(subs);
800 		}
801 	}
802 	mutex_unlock(&subs->usX2Y->pcm_mutex);
803 	return 0;
804 }
805 /*
806  * prepare callback
807  *
808  * set format and initialize urbs
809  */
810 static int snd_usX2Y_pcm_prepare(struct snd_pcm_substream *substream)
811 {
812 	struct snd_pcm_runtime *runtime = substream->runtime;
813 	struct snd_usX2Y_substream *subs = runtime->private_data;
814 	struct usX2Ydev *usX2Y = subs->usX2Y;
815 	struct snd_usX2Y_substream *capsubs = subs->usX2Y->subs[SNDRV_PCM_STREAM_CAPTURE];
816 	int err = 0;
817 	snd_printdd("snd_usX2Y_pcm_prepare(%p)\n", substream);
818 
819 	mutex_lock(&usX2Y->pcm_mutex);
820 	usX2Y_subs_prepare(subs);
821 // Start hardware streams
822 // SyncStream first....
823 	if (atomic_read(&capsubs->state) < state_PREPARED) {
824 		if (usX2Y->format != runtime->format)
825 			if ((err = usX2Y_format_set(usX2Y, runtime->format)) < 0)
826 				goto up_prepare_mutex;
827 		if (usX2Y->rate != runtime->rate)
828 			if ((err = usX2Y_rate_set(usX2Y, runtime->rate)) < 0)
829 				goto up_prepare_mutex;
830 		snd_printdd("starting capture pipe for %s\n", subs == capsubs ? "self" : "playpipe");
831 		if (0 > (err = usX2Y_urbs_start(capsubs)))
832 			goto up_prepare_mutex;
833 	}
834 
835 	if (subs != capsubs && atomic_read(&subs->state) < state_PREPARED)
836 		err = usX2Y_urbs_start(subs);
837 
838  up_prepare_mutex:
839 	mutex_unlock(&usX2Y->pcm_mutex);
840 	return err;
841 }
842 
843 static const struct snd_pcm_hardware snd_usX2Y_2c =
844 {
845 	.info =			(SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_INTERLEAVED |
846 				 SNDRV_PCM_INFO_BLOCK_TRANSFER |
847 				 SNDRV_PCM_INFO_MMAP_VALID |
848 				 SNDRV_PCM_INFO_BATCH),
849 	.formats =                 SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S24_3LE,
850 	.rates =                   SNDRV_PCM_RATE_44100 | SNDRV_PCM_RATE_48000,
851 	.rate_min =                44100,
852 	.rate_max =                48000,
853 	.channels_min =            2,
854 	.channels_max =            2,
855 	.buffer_bytes_max =	(2*128*1024),
856 	.period_bytes_min =	64,
857 	.period_bytes_max =	(128*1024),
858 	.periods_min =		2,
859 	.periods_max =		1024,
860 	.fifo_size =              0
861 };
862 
863 
864 
865 static int snd_usX2Y_pcm_open(struct snd_pcm_substream *substream)
866 {
867 	struct snd_usX2Y_substream	*subs = ((struct snd_usX2Y_substream **)
868 					 snd_pcm_substream_chip(substream))[substream->stream];
869 	struct snd_pcm_runtime	*runtime = substream->runtime;
870 
871 	if (subs->usX2Y->chip_status & USX2Y_STAT_CHIP_MMAP_PCM_URBS)
872 		return -EBUSY;
873 
874 	runtime->hw = snd_usX2Y_2c;
875 	runtime->private_data = subs;
876 	subs->pcm_substream = substream;
877 	snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_PERIOD_TIME, 1000, 200000);
878 	return 0;
879 }
880 
881 
882 
883 static int snd_usX2Y_pcm_close(struct snd_pcm_substream *substream)
884 {
885 	struct snd_pcm_runtime *runtime = substream->runtime;
886 	struct snd_usX2Y_substream *subs = runtime->private_data;
887 
888 	subs->pcm_substream = NULL;
889 
890 	return 0;
891 }
892 
893 
894 static const struct snd_pcm_ops snd_usX2Y_pcm_ops =
895 {
896 	.open =		snd_usX2Y_pcm_open,
897 	.close =	snd_usX2Y_pcm_close,
898 	.hw_params =	snd_usX2Y_pcm_hw_params,
899 	.hw_free =	snd_usX2Y_pcm_hw_free,
900 	.prepare =	snd_usX2Y_pcm_prepare,
901 	.trigger =	snd_usX2Y_pcm_trigger,
902 	.pointer =	snd_usX2Y_pcm_pointer,
903 };
904 
905 
906 /*
907  * free a usb stream instance
908  */
909 static void usX2Y_audio_stream_free(struct snd_usX2Y_substream **usX2Y_substream)
910 {
911 	int stream;
912 
913 	for_each_pcm_streams(stream) {
914 		kfree(usX2Y_substream[stream]);
915 		usX2Y_substream[stream] = NULL;
916 	}
917 }
918 
919 static void snd_usX2Y_pcm_private_free(struct snd_pcm *pcm)
920 {
921 	struct snd_usX2Y_substream **usX2Y_stream = pcm->private_data;
922 	if (usX2Y_stream)
923 		usX2Y_audio_stream_free(usX2Y_stream);
924 }
925 
926 static int usX2Y_audio_stream_new(struct snd_card *card, int playback_endpoint, int capture_endpoint)
927 {
928 	struct snd_pcm *pcm;
929 	int err, i;
930 	struct snd_usX2Y_substream **usX2Y_substream =
931 		usX2Y(card)->subs + 2 * usX2Y(card)->pcm_devs;
932 
933 	for (i = playback_endpoint ? SNDRV_PCM_STREAM_PLAYBACK : SNDRV_PCM_STREAM_CAPTURE;
934 	     i <= SNDRV_PCM_STREAM_CAPTURE; ++i) {
935 		usX2Y_substream[i] = kzalloc(sizeof(struct snd_usX2Y_substream), GFP_KERNEL);
936 		if (!usX2Y_substream[i])
937 			return -ENOMEM;
938 
939 		usX2Y_substream[i]->usX2Y = usX2Y(card);
940 	}
941 
942 	if (playback_endpoint)
943 		usX2Y_substream[SNDRV_PCM_STREAM_PLAYBACK]->endpoint = playback_endpoint;
944 	usX2Y_substream[SNDRV_PCM_STREAM_CAPTURE]->endpoint = capture_endpoint;
945 
946 	err = snd_pcm_new(card, NAME_ALLCAPS" Audio", usX2Y(card)->pcm_devs,
947 			  playback_endpoint ? 1 : 0, 1,
948 			  &pcm);
949 	if (err < 0) {
950 		usX2Y_audio_stream_free(usX2Y_substream);
951 		return err;
952 	}
953 
954 	if (playback_endpoint)
955 		snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &snd_usX2Y_pcm_ops);
956 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &snd_usX2Y_pcm_ops);
957 
958 	pcm->private_data = usX2Y_substream;
959 	pcm->private_free = snd_usX2Y_pcm_private_free;
960 	pcm->info_flags = 0;
961 
962 	sprintf(pcm->name, NAME_ALLCAPS" Audio #%d", usX2Y(card)->pcm_devs);
963 
964 	if (playback_endpoint) {
965 		snd_pcm_set_managed_buffer(pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream,
966 					   SNDRV_DMA_TYPE_CONTINUOUS,
967 					   NULL,
968 					   64*1024, 128*1024);
969 	}
970 
971 	snd_pcm_set_managed_buffer(pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream,
972 				   SNDRV_DMA_TYPE_CONTINUOUS,
973 				   NULL,
974 				   64*1024, 128*1024);
975 	usX2Y(card)->pcm_devs++;
976 
977 	return 0;
978 }
979 
980 /*
981  * create a chip instance and set its names.
982  */
983 int usX2Y_audio_create(struct snd_card *card)
984 {
985 	int err = 0;
986 
987 	INIT_LIST_HEAD(&usX2Y(card)->pcm_list);
988 
989 	if (0 > (err = usX2Y_audio_stream_new(card, 0xA, 0x8)))
990 		return err;
991 	if (le16_to_cpu(usX2Y(card)->dev->descriptor.idProduct) == USB_ID_US428)
992 	     if (0 > (err = usX2Y_audio_stream_new(card, 0, 0xA)))
993 		     return err;
994 	if (le16_to_cpu(usX2Y(card)->dev->descriptor.idProduct) != USB_ID_US122)
995 		err = usX2Y_rate_set(usX2Y(card), 44100);	// Lets us428 recognize output-volume settings, disturbs us122.
996 	return err;
997 }
998