xref: /linux/sound/usb/6fire/pcm.c (revision 60e13231561b3a4c5269bfa1ef6c0569ad6f28ec)
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  * Version:	0.3.0
9  * Copyright:	(C) Torsten Schenk
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License as published by
13  * the Free Software Foundation; either version 2 of the License, or
14  * (at your option) any later version.
15  */
16 
17 #include "pcm.h"
18 #include "chip.h"
19 #include "comm.h"
20 #include "control.h"
21 
22 enum {
23 	OUT_N_CHANNELS = 6, IN_N_CHANNELS = 4
24 };
25 
26 /* keep next two synced with
27  * FW_EP_W_MAX_PACKET_SIZE[] and RATES_MAX_PACKET_SIZE
28  * and CONTROL_RATE_XXX in control.h */
29 static const int rates_in_packet_size[] = { 228, 228, 420, 420, 404, 404 };
30 static const int rates_out_packet_size[] = { 228, 228, 420, 420, 604, 604 };
31 static const int rates[] = { 44100, 48000, 88200, 96000, 176400, 192000 };
32 static const int rates_alsaid[] = {
33 	SNDRV_PCM_RATE_44100, SNDRV_PCM_RATE_48000,
34 	SNDRV_PCM_RATE_88200, SNDRV_PCM_RATE_96000,
35 	SNDRV_PCM_RATE_176400, SNDRV_PCM_RATE_192000 };
36 
37 enum { /* settings for pcm */
38 	OUT_EP = 6, IN_EP = 2, MAX_BUFSIZE = 128 * 1024
39 };
40 
41 enum { /* pcm streaming states */
42 	STREAM_DISABLED, /* no pcm streaming */
43 	STREAM_STARTING, /* pcm streaming requested, waiting to become ready */
44 	STREAM_RUNNING, /* pcm streaming running */
45 	STREAM_STOPPING
46 };
47 
48 static const struct snd_pcm_hardware pcm_hw = {
49 	.info = SNDRV_PCM_INFO_MMAP |
50 		SNDRV_PCM_INFO_INTERLEAVED |
51 		SNDRV_PCM_INFO_BLOCK_TRANSFER |
52 		SNDRV_PCM_INFO_MMAP_VALID |
53 		SNDRV_PCM_INFO_BATCH,
54 
55 	.formats = SNDRV_PCM_FMTBIT_S24_LE | SNDRV_PCM_FMTBIT_S32_LE,
56 
57 	.rates = SNDRV_PCM_RATE_44100 |
58 		SNDRV_PCM_RATE_48000 |
59 		SNDRV_PCM_RATE_88200 |
60 		SNDRV_PCM_RATE_96000 |
61 		SNDRV_PCM_RATE_176400 |
62 		SNDRV_PCM_RATE_192000,
63 
64 	.rate_min = 44100,
65 	.rate_max = 192000,
66 	.channels_min = 1,
67 	.channels_max = 0, /* set in pcm_open, depending on capture/playback */
68 	.buffer_bytes_max = MAX_BUFSIZE,
69 	.period_bytes_min = PCM_N_PACKETS_PER_URB * (PCM_MAX_PACKET_SIZE - 4),
70 	.period_bytes_max = MAX_BUFSIZE,
71 	.periods_min = 2,
72 	.periods_max = 1024
73 };
74 
75 static int usb6fire_pcm_set_rate(struct pcm_runtime *rt)
76 {
77 	int ret;
78 	struct control_runtime *ctrl_rt = rt->chip->control;
79 
80 	ctrl_rt->usb_streaming = false;
81 	ret = ctrl_rt->update_streaming(ctrl_rt);
82 	if (ret < 0) {
83 		snd_printk(KERN_ERR PREFIX "error stopping streaming while "
84 				"setting samplerate %d.\n", rates[rt->rate]);
85 		return ret;
86 	}
87 
88 	ret = ctrl_rt->set_rate(ctrl_rt, rt->rate);
89 	if (ret < 0) {
90 		snd_printk(KERN_ERR PREFIX "error setting samplerate %d.\n",
91 				rates[rt->rate]);
92 		return ret;
93 	}
94 
95 	ret = ctrl_rt->set_channels(ctrl_rt, OUT_N_CHANNELS, IN_N_CHANNELS,
96 			false, false);
97 	if (ret < 0) {
98 		snd_printk(KERN_ERR PREFIX "error initializing channels "
99 				"while setting samplerate %d.\n",
100 				rates[rt->rate]);
101 		return ret;
102 	}
103 
104 	ctrl_rt->usb_streaming = true;
105 	ret = ctrl_rt->update_streaming(ctrl_rt);
106 	if (ret < 0) {
107 		snd_printk(KERN_ERR PREFIX "error starting streaming while "
108 				"setting samplerate %d.\n", rates[rt->rate]);
109 		return ret;
110 	}
111 
112 	rt->in_n_analog = IN_N_CHANNELS;
113 	rt->out_n_analog = OUT_N_CHANNELS;
114 	rt->in_packet_size = rates_in_packet_size[rt->rate];
115 	rt->out_packet_size = rates_out_packet_size[rt->rate];
116 	return 0;
117 }
118 
119 static struct pcm_substream *usb6fire_pcm_get_substream(
120 		struct snd_pcm_substream *alsa_sub)
121 {
122 	struct pcm_runtime *rt = snd_pcm_substream_chip(alsa_sub);
123 
124 	if (alsa_sub->stream == SNDRV_PCM_STREAM_PLAYBACK)
125 		return &rt->playback;
126 	else if (alsa_sub->stream == SNDRV_PCM_STREAM_CAPTURE)
127 		return &rt->capture;
128 	snd_printk(KERN_ERR PREFIX "error getting pcm substream slot.\n");
129 	return NULL;
130 }
131 
132 /* call with stream_mutex locked */
133 static void usb6fire_pcm_stream_stop(struct pcm_runtime *rt)
134 {
135 	int i;
136 	struct control_runtime *ctrl_rt = rt->chip->control;
137 
138 	if (rt->stream_state != STREAM_DISABLED) {
139 		for (i = 0; i < PCM_N_URBS; i++) {
140 			usb_kill_urb(&rt->in_urbs[i].instance);
141 			usb_kill_urb(&rt->out_urbs[i].instance);
142 		}
143 		ctrl_rt->usb_streaming = false;
144 		ctrl_rt->update_streaming(ctrl_rt);
145 		rt->stream_state = STREAM_DISABLED;
146 	}
147 }
148 
149 /* call with stream_mutex locked */
150 static int usb6fire_pcm_stream_start(struct pcm_runtime *rt)
151 {
152 	int ret;
153 	int i;
154 	int k;
155 	struct usb_iso_packet_descriptor *packet;
156 
157 	if (rt->stream_state == STREAM_DISABLED) {
158 		/* submit our in urbs */
159 		rt->stream_wait_cond = false;
160 		rt->stream_state = STREAM_STARTING;
161 		for (i = 0; i < PCM_N_URBS; i++) {
162 			for (k = 0; k < PCM_N_PACKETS_PER_URB; k++) {
163 				packet = &rt->in_urbs[i].packets[k];
164 				packet->offset = k * rt->in_packet_size;
165 				packet->length = rt->in_packet_size;
166 				packet->actual_length = 0;
167 				packet->status = 0;
168 			}
169 			ret = usb_submit_urb(&rt->in_urbs[i].instance,
170 					GFP_ATOMIC);
171 			if (ret) {
172 				usb6fire_pcm_stream_stop(rt);
173 				return ret;
174 			}
175 		}
176 
177 		/* wait for first out urb to return (sent in in urb handler) */
178 		wait_event_timeout(rt->stream_wait_queue, rt->stream_wait_cond,
179 				HZ);
180 		if (rt->stream_wait_cond)
181 			rt->stream_state = STREAM_RUNNING;
182 		else {
183 			usb6fire_pcm_stream_stop(rt);
184 			return -EIO;
185 		}
186 	}
187 	return 0;
188 }
189 
190 /* call with substream locked */
191 static void usb6fire_pcm_capture(struct pcm_substream *sub, struct pcm_urb *urb)
192 {
193 	int i;
194 	int frame;
195 	int frame_count;
196 	unsigned int total_length = 0;
197 	struct pcm_runtime *rt = snd_pcm_substream_chip(sub->instance);
198 	struct snd_pcm_runtime *alsa_rt = sub->instance->runtime;
199 	u32 *src = NULL;
200 	u32 *dest = (u32 *) (alsa_rt->dma_area + sub->dma_off
201 			* (alsa_rt->frame_bits >> 3));
202 	u32 *dest_end = (u32 *) (alsa_rt->dma_area + alsa_rt->buffer_size
203 			* (alsa_rt->frame_bits >> 3));
204 	int bytes_per_frame = alsa_rt->channels << 2;
205 
206 	for (i = 0; i < PCM_N_PACKETS_PER_URB; i++) {
207 		/* at least 4 header bytes for valid packet.
208 		 * after that: 32 bits per sample for analog channels */
209 		if (urb->packets[i].actual_length > 4)
210 			frame_count = (urb->packets[i].actual_length - 4)
211 					/ (rt->in_n_analog << 2);
212 		else
213 			frame_count = 0;
214 
215 		if (alsa_rt->format == SNDRV_PCM_FORMAT_S24_LE)
216 			src = (u32 *) (urb->buffer + total_length);
217 		else if (alsa_rt->format == SNDRV_PCM_FORMAT_S32_LE)
218 			src = (u32 *) (urb->buffer - 1 + total_length);
219 		else
220 			return;
221 		src++; /* skip leading 4 bytes of every packet */
222 		total_length += urb->packets[i].length;
223 		for (frame = 0; frame < frame_count; frame++) {
224 			memcpy(dest, src, bytes_per_frame);
225 			dest += alsa_rt->channels;
226 			src += rt->in_n_analog;
227 			sub->dma_off++;
228 			sub->period_off++;
229 			if (dest == dest_end) {
230 				sub->dma_off = 0;
231 				dest = (u32 *) alsa_rt->dma_area;
232 			}
233 		}
234 	}
235 }
236 
237 /* call with substream locked */
238 static void usb6fire_pcm_playback(struct pcm_substream *sub,
239 		struct pcm_urb *urb)
240 {
241 	int i;
242 	int frame;
243 	int frame_count;
244 	struct pcm_runtime *rt = snd_pcm_substream_chip(sub->instance);
245 	struct snd_pcm_runtime *alsa_rt = sub->instance->runtime;
246 	u32 *src = (u32 *) (alsa_rt->dma_area + sub->dma_off
247 			* (alsa_rt->frame_bits >> 3));
248 	u32 *src_end = (u32 *) (alsa_rt->dma_area + alsa_rt->buffer_size
249 			* (alsa_rt->frame_bits >> 3));
250 	u32 *dest;
251 	int bytes_per_frame = alsa_rt->channels << 2;
252 
253 	if (alsa_rt->format == SNDRV_PCM_FORMAT_S32_LE)
254 		dest = (u32 *) (urb->buffer - 1);
255 	else if (alsa_rt->format == SNDRV_PCM_FORMAT_S24_LE)
256 		dest = (u32 *) (urb->buffer);
257 	else {
258 		snd_printk(KERN_ERR PREFIX "Unknown sample format.");
259 		return;
260 	}
261 
262 	for (i = 0; i < PCM_N_PACKETS_PER_URB; i++) {
263 		/* at least 4 header bytes for valid packet.
264 		 * after that: 32 bits per sample for analog channels */
265 		if (urb->packets[i].length > 4)
266 			frame_count = (urb->packets[i].length - 4)
267 					/ (rt->out_n_analog << 2);
268 		else
269 			frame_count = 0;
270 		dest++; /* skip leading 4 bytes of every frame */
271 		for (frame = 0; frame < frame_count; frame++) {
272 			memcpy(dest, src, bytes_per_frame);
273 			src += alsa_rt->channels;
274 			dest += rt->out_n_analog;
275 			sub->dma_off++;
276 			sub->period_off++;
277 			if (src == src_end) {
278 				src = (u32 *) alsa_rt->dma_area;
279 				sub->dma_off = 0;
280 			}
281 		}
282 	}
283 }
284 
285 static void usb6fire_pcm_in_urb_handler(struct urb *usb_urb)
286 {
287 	struct pcm_urb *in_urb = usb_urb->context;
288 	struct pcm_urb *out_urb = in_urb->peer;
289 	struct pcm_runtime *rt = in_urb->chip->pcm;
290 	struct pcm_substream *sub;
291 	unsigned long flags;
292 	int total_length = 0;
293 	int frame_count;
294 	int frame;
295 	int channel;
296 	int i;
297 	u8 *dest;
298 
299 	if (usb_urb->status || rt->panic || rt->stream_state == STREAM_STOPPING)
300 		return;
301 	for (i = 0; i < PCM_N_PACKETS_PER_URB; i++)
302 		if (in_urb->packets[i].status) {
303 			rt->panic = true;
304 			return;
305 		}
306 
307 	if (rt->stream_state == STREAM_DISABLED) {
308 		snd_printk(KERN_ERR PREFIX "internal error: "
309 				"stream disabled in in-urb handler.\n");
310 		return;
311 	}
312 
313 	/* receive our capture data */
314 	sub = &rt->capture;
315 	spin_lock_irqsave(&sub->lock, flags);
316 	if (sub->active) {
317 		usb6fire_pcm_capture(sub, in_urb);
318 		if (sub->period_off >= sub->instance->runtime->period_size) {
319 			sub->period_off %= sub->instance->runtime->period_size;
320 			spin_unlock_irqrestore(&sub->lock, flags);
321 			snd_pcm_period_elapsed(sub->instance);
322 		} else
323 			spin_unlock_irqrestore(&sub->lock, flags);
324 	} else
325 		spin_unlock_irqrestore(&sub->lock, flags);
326 
327 	/* setup out urb structure */
328 	for (i = 0; i < PCM_N_PACKETS_PER_URB; i++) {
329 		out_urb->packets[i].offset = total_length;
330 		out_urb->packets[i].length = (in_urb->packets[i].actual_length
331 				- 4) / (rt->in_n_analog << 2)
332 				* (rt->out_n_analog << 2) + 4;
333 		out_urb->packets[i].status = 0;
334 		total_length += out_urb->packets[i].length;
335 	}
336 	memset(out_urb->buffer, 0, total_length);
337 
338 	/* now send our playback data (if a free out urb was found) */
339 	sub = &rt->playback;
340 	spin_lock_irqsave(&sub->lock, flags);
341 	if (sub->active) {
342 		usb6fire_pcm_playback(sub, out_urb);
343 		if (sub->period_off >= sub->instance->runtime->period_size) {
344 			sub->period_off %= sub->instance->runtime->period_size;
345 			spin_unlock_irqrestore(&sub->lock, flags);
346 			snd_pcm_period_elapsed(sub->instance);
347 		} else
348 			spin_unlock_irqrestore(&sub->lock, flags);
349 	} else
350 		spin_unlock_irqrestore(&sub->lock, flags);
351 
352 	/* setup the 4th byte of each sample (0x40 for analog channels) */
353 	dest = out_urb->buffer;
354 	for (i = 0; i < PCM_N_PACKETS_PER_URB; i++)
355 		if (out_urb->packets[i].length >= 4) {
356 			frame_count = (out_urb->packets[i].length - 4)
357 					/ (rt->out_n_analog << 2);
358 			*(dest++) = 0xaa;
359 			*(dest++) = 0xaa;
360 			*(dest++) = frame_count;
361 			*(dest++) = 0x00;
362 			for (frame = 0; frame < frame_count; frame++)
363 				for (channel = 0;
364 						channel < rt->out_n_analog;
365 						channel++) {
366 					dest += 3; /* skip sample data */
367 					*(dest++) = 0x40;
368 				}
369 		}
370 	usb_submit_urb(&out_urb->instance, GFP_ATOMIC);
371 	usb_submit_urb(&in_urb->instance, GFP_ATOMIC);
372 }
373 
374 static void usb6fire_pcm_out_urb_handler(struct urb *usb_urb)
375 {
376 	struct pcm_urb *urb = usb_urb->context;
377 	struct pcm_runtime *rt = urb->chip->pcm;
378 
379 	if (rt->stream_state == STREAM_STARTING) {
380 		rt->stream_wait_cond = true;
381 		wake_up(&rt->stream_wait_queue);
382 	}
383 }
384 
385 static int usb6fire_pcm_open(struct snd_pcm_substream *alsa_sub)
386 {
387 	struct pcm_runtime *rt = snd_pcm_substream_chip(alsa_sub);
388 	struct pcm_substream *sub = NULL;
389 	struct snd_pcm_runtime *alsa_rt = alsa_sub->runtime;
390 
391 	if (rt->panic)
392 		return -EPIPE;
393 
394 	mutex_lock(&rt->stream_mutex);
395 	alsa_rt->hw = pcm_hw;
396 
397 	if (alsa_sub->stream == SNDRV_PCM_STREAM_PLAYBACK) {
398 		if (rt->rate < ARRAY_SIZE(rates))
399 			alsa_rt->hw.rates = rates_alsaid[rt->rate];
400 		alsa_rt->hw.channels_max = OUT_N_CHANNELS;
401 		sub = &rt->playback;
402 	} else if (alsa_sub->stream == SNDRV_PCM_STREAM_CAPTURE) {
403 		if (rt->rate < ARRAY_SIZE(rates))
404 			alsa_rt->hw.rates = rates_alsaid[rt->rate];
405 		alsa_rt->hw.channels_max = IN_N_CHANNELS;
406 		sub = &rt->capture;
407 	}
408 
409 	if (!sub) {
410 		mutex_unlock(&rt->stream_mutex);
411 		snd_printk(KERN_ERR PREFIX "invalid stream type.\n");
412 		return -EINVAL;
413 	}
414 
415 	sub->instance = alsa_sub;
416 	sub->active = false;
417 	mutex_unlock(&rt->stream_mutex);
418 	return 0;
419 }
420 
421 static int usb6fire_pcm_close(struct snd_pcm_substream *alsa_sub)
422 {
423 	struct pcm_runtime *rt = snd_pcm_substream_chip(alsa_sub);
424 	struct pcm_substream *sub = usb6fire_pcm_get_substream(alsa_sub);
425 	unsigned long flags;
426 
427 	if (rt->panic)
428 		return 0;
429 
430 	mutex_lock(&rt->stream_mutex);
431 	if (sub) {
432 		/* deactivate substream */
433 		spin_lock_irqsave(&sub->lock, flags);
434 		sub->instance = NULL;
435 		sub->active = false;
436 		spin_unlock_irqrestore(&sub->lock, flags);
437 
438 		/* all substreams closed? if so, stop streaming */
439 		if (!rt->playback.instance && !rt->capture.instance) {
440 			usb6fire_pcm_stream_stop(rt);
441 			rt->rate = ARRAY_SIZE(rates);
442 		}
443 	}
444 	mutex_unlock(&rt->stream_mutex);
445 	return 0;
446 }
447 
448 static int usb6fire_pcm_hw_params(struct snd_pcm_substream *alsa_sub,
449 		struct snd_pcm_hw_params *hw_params)
450 {
451 	return snd_pcm_lib_malloc_pages(alsa_sub,
452 			params_buffer_bytes(hw_params));
453 }
454 
455 static int usb6fire_pcm_hw_free(struct snd_pcm_substream *alsa_sub)
456 {
457 	return snd_pcm_lib_free_pages(alsa_sub);
458 }
459 
460 static int usb6fire_pcm_prepare(struct snd_pcm_substream *alsa_sub)
461 {
462 	struct pcm_runtime *rt = snd_pcm_substream_chip(alsa_sub);
463 	struct pcm_substream *sub = usb6fire_pcm_get_substream(alsa_sub);
464 	struct snd_pcm_runtime *alsa_rt = alsa_sub->runtime;
465 	int ret;
466 
467 	if (rt->panic)
468 		return -EPIPE;
469 	if (!sub)
470 		return -ENODEV;
471 
472 	mutex_lock(&rt->stream_mutex);
473 	sub->dma_off = 0;
474 	sub->period_off = 0;
475 
476 	if (rt->stream_state == STREAM_DISABLED) {
477 		for (rt->rate = 0; rt->rate < ARRAY_SIZE(rates); rt->rate++)
478 			if (alsa_rt->rate == rates[rt->rate])
479 				break;
480 		if (rt->rate == ARRAY_SIZE(rates)) {
481 			mutex_unlock(&rt->stream_mutex);
482 			snd_printk("invalid rate %d in prepare.\n",
483 					alsa_rt->rate);
484 			return -EINVAL;
485 		}
486 
487 		ret = usb6fire_pcm_set_rate(rt);
488 		if (ret) {
489 			mutex_unlock(&rt->stream_mutex);
490 			return ret;
491 		}
492 		ret = usb6fire_pcm_stream_start(rt);
493 		if (ret) {
494 			mutex_unlock(&rt->stream_mutex);
495 			snd_printk(KERN_ERR PREFIX
496 					"could not start pcm stream.\n");
497 			return ret;
498 		}
499 	}
500 	mutex_unlock(&rt->stream_mutex);
501 	return 0;
502 }
503 
504 static int usb6fire_pcm_trigger(struct snd_pcm_substream *alsa_sub, int cmd)
505 {
506 	struct pcm_substream *sub = usb6fire_pcm_get_substream(alsa_sub);
507 	struct pcm_runtime *rt = snd_pcm_substream_chip(alsa_sub);
508 	unsigned long flags;
509 
510 	if (rt->panic)
511 		return -EPIPE;
512 	if (!sub)
513 		return -ENODEV;
514 
515 	switch (cmd) {
516 	case SNDRV_PCM_TRIGGER_START:
517 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
518 		spin_lock_irqsave(&sub->lock, flags);
519 		sub->active = true;
520 		spin_unlock_irqrestore(&sub->lock, flags);
521 		return 0;
522 
523 	case SNDRV_PCM_TRIGGER_STOP:
524 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
525 		spin_lock_irqsave(&sub->lock, flags);
526 		sub->active = false;
527 		spin_unlock_irqrestore(&sub->lock, flags);
528 		return 0;
529 
530 	default:
531 		return -EINVAL;
532 	}
533 }
534 
535 static snd_pcm_uframes_t usb6fire_pcm_pointer(
536 		struct snd_pcm_substream *alsa_sub)
537 {
538 	struct pcm_substream *sub = usb6fire_pcm_get_substream(alsa_sub);
539 	struct pcm_runtime *rt = snd_pcm_substream_chip(alsa_sub);
540 	unsigned long flags;
541 	snd_pcm_uframes_t ret;
542 
543 	if (rt->panic || !sub)
544 		return SNDRV_PCM_STATE_XRUN;
545 
546 	spin_lock_irqsave(&sub->lock, flags);
547 	ret = sub->dma_off;
548 	spin_unlock_irqrestore(&sub->lock, flags);
549 	return ret;
550 }
551 
552 static struct snd_pcm_ops pcm_ops = {
553 	.open = usb6fire_pcm_open,
554 	.close = usb6fire_pcm_close,
555 	.ioctl = snd_pcm_lib_ioctl,
556 	.hw_params = usb6fire_pcm_hw_params,
557 	.hw_free = usb6fire_pcm_hw_free,
558 	.prepare = usb6fire_pcm_prepare,
559 	.trigger = usb6fire_pcm_trigger,
560 	.pointer = usb6fire_pcm_pointer,
561 };
562 
563 static void __devinit usb6fire_pcm_init_urb(struct pcm_urb *urb,
564 		struct sfire_chip *chip, bool in, int ep,
565 		void (*handler)(struct urb *))
566 {
567 	urb->chip = chip;
568 	usb_init_urb(&urb->instance);
569 	urb->instance.transfer_buffer = urb->buffer;
570 	urb->instance.transfer_buffer_length =
571 			PCM_N_PACKETS_PER_URB * PCM_MAX_PACKET_SIZE;
572 	urb->instance.dev = chip->dev;
573 	urb->instance.pipe = in ? usb_rcvisocpipe(chip->dev, ep)
574 			: usb_sndisocpipe(chip->dev, ep);
575 	urb->instance.interval = 1;
576 	urb->instance.transfer_flags = URB_ISO_ASAP;
577 	urb->instance.complete = handler;
578 	urb->instance.context = urb;
579 	urb->instance.number_of_packets = PCM_N_PACKETS_PER_URB;
580 }
581 
582 int __devinit usb6fire_pcm_init(struct sfire_chip *chip)
583 {
584 	int i;
585 	int ret;
586 	struct snd_pcm *pcm;
587 	struct pcm_runtime *rt =
588 			kzalloc(sizeof(struct pcm_runtime), GFP_KERNEL);
589 
590 	if (!rt)
591 		return -ENOMEM;
592 
593 	rt->chip = chip;
594 	rt->stream_state = STREAM_DISABLED;
595 	rt->rate = ARRAY_SIZE(rates);
596 	init_waitqueue_head(&rt->stream_wait_queue);
597 	mutex_init(&rt->stream_mutex);
598 
599 	spin_lock_init(&rt->playback.lock);
600 	spin_lock_init(&rt->capture.lock);
601 
602 	for (i = 0; i < PCM_N_URBS; i++) {
603 		usb6fire_pcm_init_urb(&rt->in_urbs[i], chip, true, IN_EP,
604 				usb6fire_pcm_in_urb_handler);
605 		usb6fire_pcm_init_urb(&rt->out_urbs[i], chip, false, OUT_EP,
606 				usb6fire_pcm_out_urb_handler);
607 
608 		rt->in_urbs[i].peer = &rt->out_urbs[i];
609 		rt->out_urbs[i].peer = &rt->in_urbs[i];
610 	}
611 
612 	ret = snd_pcm_new(chip->card, "DMX6FireUSB", 0, 1, 1, &pcm);
613 	if (ret < 0) {
614 		kfree(rt);
615 		snd_printk(KERN_ERR PREFIX "cannot create pcm instance.\n");
616 		return ret;
617 	}
618 
619 	pcm->private_data = rt;
620 	strcpy(pcm->name, "DMX 6Fire USB");
621 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &pcm_ops);
622 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &pcm_ops);
623 
624 	ret = snd_pcm_lib_preallocate_pages_for_all(pcm,
625 			SNDRV_DMA_TYPE_CONTINUOUS,
626 			snd_dma_continuous_data(GFP_KERNEL),
627 			MAX_BUFSIZE, MAX_BUFSIZE);
628 	if (ret) {
629 		kfree(rt);
630 		snd_printk(KERN_ERR PREFIX
631 				"error preallocating pcm buffers.\n");
632 		return ret;
633 	}
634 	rt->instance = pcm;
635 
636 	chip->pcm = rt;
637 	return 0;
638 }
639 
640 void usb6fire_pcm_abort(struct sfire_chip *chip)
641 {
642 	struct pcm_runtime *rt = chip->pcm;
643 	int i;
644 
645 	if (rt) {
646 		rt->panic = true;
647 
648 		if (rt->playback.instance)
649 			snd_pcm_stop(rt->playback.instance,
650 					SNDRV_PCM_STATE_XRUN);
651 		if (rt->capture.instance)
652 			snd_pcm_stop(rt->capture.instance,
653 					SNDRV_PCM_STATE_XRUN);
654 
655 		for (i = 0; i < PCM_N_URBS; i++) {
656 			usb_poison_urb(&rt->in_urbs[i].instance);
657 			usb_poison_urb(&rt->out_urbs[i].instance);
658 		}
659 
660 	}
661 }
662 
663 void usb6fire_pcm_destroy(struct sfire_chip *chip)
664 {
665 	kfree(chip->pcm);
666 	chip->pcm = NULL;
667 }
668