xref: /openbmc/linux/sound/usb/6fire/pcm.c (revision 65417d9f)
1 /*
2  * Linux driver for TerraTec DMX 6Fire USB
3  *
4  * PCM driver
5  *
6  * Author:	Torsten Schenk <torsten.schenk@zoho.com>
7  * Created:	Jan 01, 2011
8  * Copyright:	(C) Torsten Schenk
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License as published by
12  * the Free Software Foundation; either version 2 of the License, or
13  * (at your option) any later version.
14  */
15 
16 #include "pcm.h"
17 #include "chip.h"
18 #include "comm.h"
19 #include "control.h"
20 
21 enum {
22 	OUT_N_CHANNELS = 6, IN_N_CHANNELS = 4
23 };
24 
25 /* keep next two synced with
26  * FW_EP_W_MAX_PACKET_SIZE[] and RATES_MAX_PACKET_SIZE
27  * and CONTROL_RATE_XXX in control.h */
28 static const int rates_in_packet_size[] = { 228, 228, 420, 420, 404, 404 };
29 static const int rates_out_packet_size[] = { 228, 228, 420, 420, 604, 604 };
30 static const int rates[] = { 44100, 48000, 88200, 96000, 176400, 192000 };
31 static const int rates_alsaid[] = {
32 	SNDRV_PCM_RATE_44100, SNDRV_PCM_RATE_48000,
33 	SNDRV_PCM_RATE_88200, SNDRV_PCM_RATE_96000,
34 	SNDRV_PCM_RATE_176400, SNDRV_PCM_RATE_192000 };
35 
36 enum { /* settings for pcm */
37 	OUT_EP = 6, IN_EP = 2, MAX_BUFSIZE = 128 * 1024
38 };
39 
40 enum { /* pcm streaming states */
41 	STREAM_DISABLED, /* no pcm streaming */
42 	STREAM_STARTING, /* pcm streaming requested, waiting to become ready */
43 	STREAM_RUNNING, /* pcm streaming running */
44 	STREAM_STOPPING
45 };
46 
47 static const struct snd_pcm_hardware pcm_hw = {
48 	.info = SNDRV_PCM_INFO_MMAP |
49 		SNDRV_PCM_INFO_INTERLEAVED |
50 		SNDRV_PCM_INFO_BLOCK_TRANSFER |
51 		SNDRV_PCM_INFO_MMAP_VALID |
52 		SNDRV_PCM_INFO_BATCH,
53 
54 	.formats = SNDRV_PCM_FMTBIT_S24_LE | SNDRV_PCM_FMTBIT_S32_LE,
55 
56 	.rates = SNDRV_PCM_RATE_44100 |
57 		SNDRV_PCM_RATE_48000 |
58 		SNDRV_PCM_RATE_88200 |
59 		SNDRV_PCM_RATE_96000 |
60 		SNDRV_PCM_RATE_176400 |
61 		SNDRV_PCM_RATE_192000,
62 
63 	.rate_min = 44100,
64 	.rate_max = 192000,
65 	.channels_min = 1,
66 	.channels_max = 0, /* set in pcm_open, depending on capture/playback */
67 	.buffer_bytes_max = MAX_BUFSIZE,
68 	.period_bytes_min = PCM_N_PACKETS_PER_URB * (PCM_MAX_PACKET_SIZE - 4),
69 	.period_bytes_max = MAX_BUFSIZE,
70 	.periods_min = 2,
71 	.periods_max = 1024
72 };
73 
74 static int usb6fire_pcm_set_rate(struct pcm_runtime *rt)
75 {
76 	int ret;
77 	struct control_runtime *ctrl_rt = rt->chip->control;
78 
79 	ctrl_rt->usb_streaming = false;
80 	ret = ctrl_rt->update_streaming(ctrl_rt);
81 	if (ret < 0) {
82 		dev_err(&rt->chip->dev->dev,
83 			"error stopping streaming while setting samplerate %d.\n",
84 			rates[rt->rate]);
85 		return ret;
86 	}
87 
88 	ret = ctrl_rt->set_rate(ctrl_rt, rt->rate);
89 	if (ret < 0) {
90 		dev_err(&rt->chip->dev->dev,
91 			"error setting samplerate %d.\n",
92 			rates[rt->rate]);
93 		return ret;
94 	}
95 
96 	ret = ctrl_rt->set_channels(ctrl_rt, OUT_N_CHANNELS, IN_N_CHANNELS,
97 			false, false);
98 	if (ret < 0) {
99 		dev_err(&rt->chip->dev->dev,
100 			"error initializing channels while setting samplerate %d.\n",
101 			rates[rt->rate]);
102 		return ret;
103 	}
104 
105 	ctrl_rt->usb_streaming = true;
106 	ret = ctrl_rt->update_streaming(ctrl_rt);
107 	if (ret < 0) {
108 		dev_err(&rt->chip->dev->dev,
109 			"error starting streaming while setting samplerate %d.\n",
110 			rates[rt->rate]);
111 		return ret;
112 	}
113 
114 	rt->in_n_analog = IN_N_CHANNELS;
115 	rt->out_n_analog = OUT_N_CHANNELS;
116 	rt->in_packet_size = rates_in_packet_size[rt->rate];
117 	rt->out_packet_size = rates_out_packet_size[rt->rate];
118 	return 0;
119 }
120 
121 static struct pcm_substream *usb6fire_pcm_get_substream(
122 		struct snd_pcm_substream *alsa_sub)
123 {
124 	struct pcm_runtime *rt = snd_pcm_substream_chip(alsa_sub);
125 
126 	if (alsa_sub->stream == SNDRV_PCM_STREAM_PLAYBACK)
127 		return &rt->playback;
128 	else if (alsa_sub->stream == SNDRV_PCM_STREAM_CAPTURE)
129 		return &rt->capture;
130 	dev_err(&rt->chip->dev->dev, "error getting pcm substream slot.\n");
131 	return NULL;
132 }
133 
134 /* call with stream_mutex locked */
135 static void usb6fire_pcm_stream_stop(struct pcm_runtime *rt)
136 {
137 	int i;
138 	struct control_runtime *ctrl_rt = rt->chip->control;
139 
140 	if (rt->stream_state != STREAM_DISABLED) {
141 
142 		rt->stream_state = STREAM_STOPPING;
143 
144 		for (i = 0; i < PCM_N_URBS; i++) {
145 			usb_kill_urb(&rt->in_urbs[i].instance);
146 			usb_kill_urb(&rt->out_urbs[i].instance);
147 		}
148 		ctrl_rt->usb_streaming = false;
149 		ctrl_rt->update_streaming(ctrl_rt);
150 		rt->stream_state = STREAM_DISABLED;
151 	}
152 }
153 
154 /* call with stream_mutex locked */
155 static int usb6fire_pcm_stream_start(struct pcm_runtime *rt)
156 {
157 	int ret;
158 	int i;
159 	int k;
160 	struct usb_iso_packet_descriptor *packet;
161 
162 	if (rt->stream_state == STREAM_DISABLED) {
163 		/* submit our in urbs */
164 		rt->stream_wait_cond = false;
165 		rt->stream_state = STREAM_STARTING;
166 		for (i = 0; i < PCM_N_URBS; i++) {
167 			for (k = 0; k < PCM_N_PACKETS_PER_URB; k++) {
168 				packet = &rt->in_urbs[i].packets[k];
169 				packet->offset = k * rt->in_packet_size;
170 				packet->length = rt->in_packet_size;
171 				packet->actual_length = 0;
172 				packet->status = 0;
173 			}
174 			ret = usb_submit_urb(&rt->in_urbs[i].instance,
175 					GFP_ATOMIC);
176 			if (ret) {
177 				usb6fire_pcm_stream_stop(rt);
178 				return ret;
179 			}
180 		}
181 
182 		/* wait for first out urb to return (sent in in urb handler) */
183 		wait_event_timeout(rt->stream_wait_queue, rt->stream_wait_cond,
184 				HZ);
185 		if (rt->stream_wait_cond)
186 			rt->stream_state = STREAM_RUNNING;
187 		else {
188 			usb6fire_pcm_stream_stop(rt);
189 			return -EIO;
190 		}
191 	}
192 	return 0;
193 }
194 
195 /* call with substream locked */
196 static void usb6fire_pcm_capture(struct pcm_substream *sub, struct pcm_urb *urb)
197 {
198 	int i;
199 	int frame;
200 	int frame_count;
201 	unsigned int total_length = 0;
202 	struct pcm_runtime *rt = snd_pcm_substream_chip(sub->instance);
203 	struct snd_pcm_runtime *alsa_rt = sub->instance->runtime;
204 	u32 *src = NULL;
205 	u32 *dest = (u32 *) (alsa_rt->dma_area + sub->dma_off
206 			* (alsa_rt->frame_bits >> 3));
207 	u32 *dest_end = (u32 *) (alsa_rt->dma_area + alsa_rt->buffer_size
208 			* (alsa_rt->frame_bits >> 3));
209 	int bytes_per_frame = alsa_rt->channels << 2;
210 
211 	for (i = 0; i < PCM_N_PACKETS_PER_URB; i++) {
212 		/* at least 4 header bytes for valid packet.
213 		 * after that: 32 bits per sample for analog channels */
214 		if (urb->packets[i].actual_length > 4)
215 			frame_count = (urb->packets[i].actual_length - 4)
216 					/ (rt->in_n_analog << 2);
217 		else
218 			frame_count = 0;
219 
220 		if (alsa_rt->format == SNDRV_PCM_FORMAT_S24_LE)
221 			src = (u32 *) (urb->buffer + total_length);
222 		else if (alsa_rt->format == SNDRV_PCM_FORMAT_S32_LE)
223 			src = (u32 *) (urb->buffer - 1 + total_length);
224 		else
225 			return;
226 		src++; /* skip leading 4 bytes of every packet */
227 		total_length += urb->packets[i].length;
228 		for (frame = 0; frame < frame_count; frame++) {
229 			memcpy(dest, src, bytes_per_frame);
230 			dest += alsa_rt->channels;
231 			src += rt->in_n_analog;
232 			sub->dma_off++;
233 			sub->period_off++;
234 			if (dest == dest_end) {
235 				sub->dma_off = 0;
236 				dest = (u32 *) alsa_rt->dma_area;
237 			}
238 		}
239 	}
240 }
241 
242 /* call with substream locked */
243 static void usb6fire_pcm_playback(struct pcm_substream *sub,
244 		struct pcm_urb *urb)
245 {
246 	int i;
247 	int frame;
248 	int frame_count;
249 	struct pcm_runtime *rt = snd_pcm_substream_chip(sub->instance);
250 	struct snd_pcm_runtime *alsa_rt = sub->instance->runtime;
251 	u32 *src = (u32 *) (alsa_rt->dma_area + sub->dma_off
252 			* (alsa_rt->frame_bits >> 3));
253 	u32 *src_end = (u32 *) (alsa_rt->dma_area + alsa_rt->buffer_size
254 			* (alsa_rt->frame_bits >> 3));
255 	u32 *dest;
256 	int bytes_per_frame = alsa_rt->channels << 2;
257 
258 	if (alsa_rt->format == SNDRV_PCM_FORMAT_S32_LE)
259 		dest = (u32 *) (urb->buffer - 1);
260 	else if (alsa_rt->format == SNDRV_PCM_FORMAT_S24_LE)
261 		dest = (u32 *) (urb->buffer);
262 	else {
263 		dev_err(&rt->chip->dev->dev, "Unknown sample format.");
264 		return;
265 	}
266 
267 	for (i = 0; i < PCM_N_PACKETS_PER_URB; i++) {
268 		/* at least 4 header bytes for valid packet.
269 		 * after that: 32 bits per sample for analog channels */
270 		if (urb->packets[i].length > 4)
271 			frame_count = (urb->packets[i].length - 4)
272 					/ (rt->out_n_analog << 2);
273 		else
274 			frame_count = 0;
275 		dest++; /* skip leading 4 bytes of every frame */
276 		for (frame = 0; frame < frame_count; frame++) {
277 			memcpy(dest, src, bytes_per_frame);
278 			src += alsa_rt->channels;
279 			dest += rt->out_n_analog;
280 			sub->dma_off++;
281 			sub->period_off++;
282 			if (src == src_end) {
283 				src = (u32 *) alsa_rt->dma_area;
284 				sub->dma_off = 0;
285 			}
286 		}
287 	}
288 }
289 
290 static void usb6fire_pcm_in_urb_handler(struct urb *usb_urb)
291 {
292 	struct pcm_urb *in_urb = usb_urb->context;
293 	struct pcm_urb *out_urb = in_urb->peer;
294 	struct pcm_runtime *rt = in_urb->chip->pcm;
295 	struct pcm_substream *sub;
296 	unsigned long flags;
297 	int total_length = 0;
298 	int frame_count;
299 	int frame;
300 	int channel;
301 	int i;
302 	u8 *dest;
303 
304 	if (usb_urb->status || rt->panic || rt->stream_state == STREAM_STOPPING)
305 		return;
306 	for (i = 0; i < PCM_N_PACKETS_PER_URB; i++)
307 		if (in_urb->packets[i].status) {
308 			rt->panic = true;
309 			return;
310 		}
311 
312 	if (rt->stream_state == STREAM_DISABLED) {
313 		dev_err(&rt->chip->dev->dev,
314 			"internal error: stream disabled in in-urb handler.\n");
315 		return;
316 	}
317 
318 	/* receive our capture data */
319 	sub = &rt->capture;
320 	spin_lock_irqsave(&sub->lock, flags);
321 	if (sub->active) {
322 		usb6fire_pcm_capture(sub, in_urb);
323 		if (sub->period_off >= sub->instance->runtime->period_size) {
324 			sub->period_off %= sub->instance->runtime->period_size;
325 			spin_unlock_irqrestore(&sub->lock, flags);
326 			snd_pcm_period_elapsed(sub->instance);
327 		} else
328 			spin_unlock_irqrestore(&sub->lock, flags);
329 	} else
330 		spin_unlock_irqrestore(&sub->lock, flags);
331 
332 	/* setup out urb structure */
333 	for (i = 0; i < PCM_N_PACKETS_PER_URB; i++) {
334 		out_urb->packets[i].offset = total_length;
335 		out_urb->packets[i].length = (in_urb->packets[i].actual_length
336 				- 4) / (rt->in_n_analog << 2)
337 				* (rt->out_n_analog << 2) + 4;
338 		out_urb->packets[i].status = 0;
339 		total_length += out_urb->packets[i].length;
340 	}
341 	memset(out_urb->buffer, 0, total_length);
342 
343 	/* now send our playback data (if a free out urb was found) */
344 	sub = &rt->playback;
345 	spin_lock_irqsave(&sub->lock, flags);
346 	if (sub->active) {
347 		usb6fire_pcm_playback(sub, out_urb);
348 		if (sub->period_off >= sub->instance->runtime->period_size) {
349 			sub->period_off %= sub->instance->runtime->period_size;
350 			spin_unlock_irqrestore(&sub->lock, flags);
351 			snd_pcm_period_elapsed(sub->instance);
352 		} else
353 			spin_unlock_irqrestore(&sub->lock, flags);
354 	} else
355 		spin_unlock_irqrestore(&sub->lock, flags);
356 
357 	/* setup the 4th byte of each sample (0x40 for analog channels) */
358 	dest = out_urb->buffer;
359 	for (i = 0; i < PCM_N_PACKETS_PER_URB; i++)
360 		if (out_urb->packets[i].length >= 4) {
361 			frame_count = (out_urb->packets[i].length - 4)
362 					/ (rt->out_n_analog << 2);
363 			*(dest++) = 0xaa;
364 			*(dest++) = 0xaa;
365 			*(dest++) = frame_count;
366 			*(dest++) = 0x00;
367 			for (frame = 0; frame < frame_count; frame++)
368 				for (channel = 0;
369 						channel < rt->out_n_analog;
370 						channel++) {
371 					dest += 3; /* skip sample data */
372 					*(dest++) = 0x40;
373 				}
374 		}
375 	usb_submit_urb(&out_urb->instance, GFP_ATOMIC);
376 	usb_submit_urb(&in_urb->instance, GFP_ATOMIC);
377 }
378 
379 static void usb6fire_pcm_out_urb_handler(struct urb *usb_urb)
380 {
381 	struct pcm_urb *urb = usb_urb->context;
382 	struct pcm_runtime *rt = urb->chip->pcm;
383 
384 	if (rt->stream_state == STREAM_STARTING) {
385 		rt->stream_wait_cond = true;
386 		wake_up(&rt->stream_wait_queue);
387 	}
388 }
389 
390 static int usb6fire_pcm_open(struct snd_pcm_substream *alsa_sub)
391 {
392 	struct pcm_runtime *rt = snd_pcm_substream_chip(alsa_sub);
393 	struct pcm_substream *sub = NULL;
394 	struct snd_pcm_runtime *alsa_rt = alsa_sub->runtime;
395 
396 	if (rt->panic)
397 		return -EPIPE;
398 
399 	mutex_lock(&rt->stream_mutex);
400 	alsa_rt->hw = pcm_hw;
401 
402 	if (alsa_sub->stream == SNDRV_PCM_STREAM_PLAYBACK) {
403 		if (rt->rate < ARRAY_SIZE(rates))
404 			alsa_rt->hw.rates = rates_alsaid[rt->rate];
405 		alsa_rt->hw.channels_max = OUT_N_CHANNELS;
406 		sub = &rt->playback;
407 	} else if (alsa_sub->stream == SNDRV_PCM_STREAM_CAPTURE) {
408 		if (rt->rate < ARRAY_SIZE(rates))
409 			alsa_rt->hw.rates = rates_alsaid[rt->rate];
410 		alsa_rt->hw.channels_max = IN_N_CHANNELS;
411 		sub = &rt->capture;
412 	}
413 
414 	if (!sub) {
415 		mutex_unlock(&rt->stream_mutex);
416 		dev_err(&rt->chip->dev->dev, "invalid stream type.\n");
417 		return -EINVAL;
418 	}
419 
420 	sub->instance = alsa_sub;
421 	sub->active = false;
422 	mutex_unlock(&rt->stream_mutex);
423 	return 0;
424 }
425 
426 static int usb6fire_pcm_close(struct snd_pcm_substream *alsa_sub)
427 {
428 	struct pcm_runtime *rt = snd_pcm_substream_chip(alsa_sub);
429 	struct pcm_substream *sub = usb6fire_pcm_get_substream(alsa_sub);
430 	unsigned long flags;
431 
432 	if (rt->panic)
433 		return 0;
434 
435 	mutex_lock(&rt->stream_mutex);
436 	if (sub) {
437 		/* deactivate substream */
438 		spin_lock_irqsave(&sub->lock, flags);
439 		sub->instance = NULL;
440 		sub->active = false;
441 		spin_unlock_irqrestore(&sub->lock, flags);
442 
443 		/* all substreams closed? if so, stop streaming */
444 		if (!rt->playback.instance && !rt->capture.instance) {
445 			usb6fire_pcm_stream_stop(rt);
446 			rt->rate = ARRAY_SIZE(rates);
447 		}
448 	}
449 	mutex_unlock(&rt->stream_mutex);
450 	return 0;
451 }
452 
453 static int usb6fire_pcm_hw_params(struct snd_pcm_substream *alsa_sub,
454 		struct snd_pcm_hw_params *hw_params)
455 {
456 	return snd_pcm_lib_alloc_vmalloc_buffer(alsa_sub,
457 						params_buffer_bytes(hw_params));
458 }
459 
460 static int usb6fire_pcm_hw_free(struct snd_pcm_substream *alsa_sub)
461 {
462 	return snd_pcm_lib_free_vmalloc_buffer(alsa_sub);
463 }
464 
465 static int usb6fire_pcm_prepare(struct snd_pcm_substream *alsa_sub)
466 {
467 	struct pcm_runtime *rt = snd_pcm_substream_chip(alsa_sub);
468 	struct pcm_substream *sub = usb6fire_pcm_get_substream(alsa_sub);
469 	struct snd_pcm_runtime *alsa_rt = alsa_sub->runtime;
470 	int ret;
471 
472 	if (rt->panic)
473 		return -EPIPE;
474 	if (!sub)
475 		return -ENODEV;
476 
477 	mutex_lock(&rt->stream_mutex);
478 	sub->dma_off = 0;
479 	sub->period_off = 0;
480 
481 	if (rt->stream_state == STREAM_DISABLED) {
482 		for (rt->rate = 0; rt->rate < ARRAY_SIZE(rates); rt->rate++)
483 			if (alsa_rt->rate == rates[rt->rate])
484 				break;
485 		if (rt->rate == ARRAY_SIZE(rates)) {
486 			mutex_unlock(&rt->stream_mutex);
487 			dev_err(&rt->chip->dev->dev,
488 				"invalid rate %d in prepare.\n",
489 				alsa_rt->rate);
490 			return -EINVAL;
491 		}
492 
493 		ret = usb6fire_pcm_set_rate(rt);
494 		if (ret) {
495 			mutex_unlock(&rt->stream_mutex);
496 			return ret;
497 		}
498 		ret = usb6fire_pcm_stream_start(rt);
499 		if (ret) {
500 			mutex_unlock(&rt->stream_mutex);
501 			dev_err(&rt->chip->dev->dev,
502 				"could not start pcm stream.\n");
503 			return ret;
504 		}
505 	}
506 	mutex_unlock(&rt->stream_mutex);
507 	return 0;
508 }
509 
510 static int usb6fire_pcm_trigger(struct snd_pcm_substream *alsa_sub, int cmd)
511 {
512 	struct pcm_substream *sub = usb6fire_pcm_get_substream(alsa_sub);
513 	struct pcm_runtime *rt = snd_pcm_substream_chip(alsa_sub);
514 	unsigned long flags;
515 
516 	if (rt->panic)
517 		return -EPIPE;
518 	if (!sub)
519 		return -ENODEV;
520 
521 	switch (cmd) {
522 	case SNDRV_PCM_TRIGGER_START:
523 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
524 		spin_lock_irqsave(&sub->lock, flags);
525 		sub->active = true;
526 		spin_unlock_irqrestore(&sub->lock, flags);
527 		return 0;
528 
529 	case SNDRV_PCM_TRIGGER_STOP:
530 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
531 		spin_lock_irqsave(&sub->lock, flags);
532 		sub->active = false;
533 		spin_unlock_irqrestore(&sub->lock, flags);
534 		return 0;
535 
536 	default:
537 		return -EINVAL;
538 	}
539 }
540 
541 static snd_pcm_uframes_t usb6fire_pcm_pointer(
542 		struct snd_pcm_substream *alsa_sub)
543 {
544 	struct pcm_substream *sub = usb6fire_pcm_get_substream(alsa_sub);
545 	struct pcm_runtime *rt = snd_pcm_substream_chip(alsa_sub);
546 	unsigned long flags;
547 	snd_pcm_uframes_t ret;
548 
549 	if (rt->panic || !sub)
550 		return SNDRV_PCM_POS_XRUN;
551 
552 	spin_lock_irqsave(&sub->lock, flags);
553 	ret = sub->dma_off;
554 	spin_unlock_irqrestore(&sub->lock, flags);
555 	return ret;
556 }
557 
558 static const struct snd_pcm_ops pcm_ops = {
559 	.open = usb6fire_pcm_open,
560 	.close = usb6fire_pcm_close,
561 	.ioctl = snd_pcm_lib_ioctl,
562 	.hw_params = usb6fire_pcm_hw_params,
563 	.hw_free = usb6fire_pcm_hw_free,
564 	.prepare = usb6fire_pcm_prepare,
565 	.trigger = usb6fire_pcm_trigger,
566 	.pointer = usb6fire_pcm_pointer,
567 	.page = snd_pcm_lib_get_vmalloc_page,
568 	.mmap = snd_pcm_lib_mmap_vmalloc,
569 };
570 
571 static void usb6fire_pcm_init_urb(struct pcm_urb *urb,
572 				  struct sfire_chip *chip, bool in, int ep,
573 				  void (*handler)(struct urb *))
574 {
575 	urb->chip = chip;
576 	usb_init_urb(&urb->instance);
577 	urb->instance.transfer_buffer = urb->buffer;
578 	urb->instance.transfer_buffer_length =
579 			PCM_N_PACKETS_PER_URB * PCM_MAX_PACKET_SIZE;
580 	urb->instance.dev = chip->dev;
581 	urb->instance.pipe = in ? usb_rcvisocpipe(chip->dev, ep)
582 			: usb_sndisocpipe(chip->dev, ep);
583 	urb->instance.interval = 1;
584 	urb->instance.complete = handler;
585 	urb->instance.context = urb;
586 	urb->instance.number_of_packets = PCM_N_PACKETS_PER_URB;
587 }
588 
589 static int usb6fire_pcm_buffers_init(struct pcm_runtime *rt)
590 {
591 	int i;
592 
593 	for (i = 0; i < PCM_N_URBS; i++) {
594 		rt->out_urbs[i].buffer = kzalloc(PCM_N_PACKETS_PER_URB
595 				* PCM_MAX_PACKET_SIZE, GFP_KERNEL);
596 		if (!rt->out_urbs[i].buffer)
597 			return -ENOMEM;
598 		rt->in_urbs[i].buffer = kzalloc(PCM_N_PACKETS_PER_URB
599 				* PCM_MAX_PACKET_SIZE, GFP_KERNEL);
600 		if (!rt->in_urbs[i].buffer)
601 			return -ENOMEM;
602 	}
603 	return 0;
604 }
605 
606 static void usb6fire_pcm_buffers_destroy(struct pcm_runtime *rt)
607 {
608 	int i;
609 
610 	for (i = 0; i < PCM_N_URBS; i++) {
611 		kfree(rt->out_urbs[i].buffer);
612 		kfree(rt->in_urbs[i].buffer);
613 	}
614 }
615 
616 int usb6fire_pcm_init(struct sfire_chip *chip)
617 {
618 	int i;
619 	int ret;
620 	struct snd_pcm *pcm;
621 	struct pcm_runtime *rt =
622 			kzalloc(sizeof(struct pcm_runtime), GFP_KERNEL);
623 
624 	if (!rt)
625 		return -ENOMEM;
626 
627 	ret = usb6fire_pcm_buffers_init(rt);
628 	if (ret) {
629 		usb6fire_pcm_buffers_destroy(rt);
630 		kfree(rt);
631 		return ret;
632 	}
633 
634 	rt->chip = chip;
635 	rt->stream_state = STREAM_DISABLED;
636 	rt->rate = ARRAY_SIZE(rates);
637 	init_waitqueue_head(&rt->stream_wait_queue);
638 	mutex_init(&rt->stream_mutex);
639 
640 	spin_lock_init(&rt->playback.lock);
641 	spin_lock_init(&rt->capture.lock);
642 
643 	for (i = 0; i < PCM_N_URBS; i++) {
644 		usb6fire_pcm_init_urb(&rt->in_urbs[i], chip, true, IN_EP,
645 				usb6fire_pcm_in_urb_handler);
646 		usb6fire_pcm_init_urb(&rt->out_urbs[i], chip, false, OUT_EP,
647 				usb6fire_pcm_out_urb_handler);
648 
649 		rt->in_urbs[i].peer = &rt->out_urbs[i];
650 		rt->out_urbs[i].peer = &rt->in_urbs[i];
651 	}
652 
653 	ret = snd_pcm_new(chip->card, "DMX6FireUSB", 0, 1, 1, &pcm);
654 	if (ret < 0) {
655 		usb6fire_pcm_buffers_destroy(rt);
656 		kfree(rt);
657 		dev_err(&chip->dev->dev, "cannot create pcm instance.\n");
658 		return ret;
659 	}
660 
661 	pcm->private_data = rt;
662 	strcpy(pcm->name, "DMX 6Fire USB");
663 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &pcm_ops);
664 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &pcm_ops);
665 
666 	if (ret) {
667 		usb6fire_pcm_buffers_destroy(rt);
668 		kfree(rt);
669 		dev_err(&chip->dev->dev,
670 			"error preallocating pcm buffers.\n");
671 		return ret;
672 	}
673 	rt->instance = pcm;
674 
675 	chip->pcm = rt;
676 	return 0;
677 }
678 
679 void usb6fire_pcm_abort(struct sfire_chip *chip)
680 {
681 	struct pcm_runtime *rt = chip->pcm;
682 	int i;
683 
684 	if (rt) {
685 		rt->panic = true;
686 
687 		if (rt->playback.instance)
688 			snd_pcm_stop_xrun(rt->playback.instance);
689 
690 		if (rt->capture.instance)
691 			snd_pcm_stop_xrun(rt->capture.instance);
692 
693 		for (i = 0; i < PCM_N_URBS; i++) {
694 			usb_poison_urb(&rt->in_urbs[i].instance);
695 			usb_poison_urb(&rt->out_urbs[i].instance);
696 		}
697 
698 	}
699 }
700 
701 void usb6fire_pcm_destroy(struct sfire_chip *chip)
702 {
703 	struct pcm_runtime *rt = chip->pcm;
704 
705 	usb6fire_pcm_buffers_destroy(rt);
706 	kfree(rt);
707 	chip->pcm = NULL;
708 }
709