xref: /linux/sound/usb/hiface/pcm.c (revision cf21f328fcafacf4f96e7a30ef9dceede1076378)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Linux driver for M2Tech hiFace compatible devices
4  *
5  * Copyright 2012-2013 (C) M2TECH S.r.l and Amarula Solutions B.V.
6  *
7  * Authors:  Michael Trimarchi <michael@amarulasolutions.com>
8  *           Antonio Ospite <ao2@amarulasolutions.com>
9  *
10  * The driver is based on the work done in TerraTec DMX 6Fire USB
11  */
12 
13 #include <linux/slab.h>
14 #include <sound/pcm.h>
15 
16 #include "pcm.h"
17 #include "chip.h"
18 
19 #define OUT_EP          0x2
20 #define PCM_N_URBS      8
21 #define PCM_PACKET_SIZE 4096
22 #define PCM_BUFFER_SIZE (2 * PCM_N_URBS * PCM_PACKET_SIZE)
23 
24 struct pcm_urb {
25 	struct hiface_chip *chip;
26 
27 	struct urb instance;
28 	struct usb_anchor submitted;
29 	u8 *buffer;
30 };
31 
32 struct pcm_substream {
33 	spinlock_t lock;
34 	struct snd_pcm_substream *instance;
35 
36 	bool active;
37 	snd_pcm_uframes_t dma_off;    /* current position in alsa dma_area */
38 	snd_pcm_uframes_t period_off; /* current position in current period */
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 struct pcm_runtime {
49 	struct hiface_chip *chip;
50 	struct snd_pcm *instance;
51 
52 	struct pcm_substream playback;
53 	bool panic; /* if set driver won't do anymore pcm on device */
54 
55 	struct pcm_urb out_urbs[PCM_N_URBS];
56 
57 	struct mutex stream_mutex;
58 	u8 stream_state; /* one of STREAM_XXX */
59 	u8 extra_freq;
60 	wait_queue_head_t stream_wait_queue;
61 	bool stream_wait_cond;
62 };
63 
64 static const unsigned int rates[] = { 44100, 48000, 88200, 96000, 176400, 192000,
65 				      352800, 384000 };
66 static const struct snd_pcm_hw_constraint_list constraints_extra_rates = {
67 	.count = ARRAY_SIZE(rates),
68 	.list = rates,
69 	.mask = 0,
70 };
71 
72 static const struct snd_pcm_hardware pcm_hw = {
73 	.info = SNDRV_PCM_INFO_MMAP |
74 		SNDRV_PCM_INFO_INTERLEAVED |
75 		SNDRV_PCM_INFO_BLOCK_TRANSFER |
76 		SNDRV_PCM_INFO_PAUSE |
77 		SNDRV_PCM_INFO_MMAP_VALID |
78 		SNDRV_PCM_INFO_BATCH,
79 
80 	.formats = SNDRV_PCM_FMTBIT_S32_LE,
81 
82 	.rates = SNDRV_PCM_RATE_44100 |
83 		SNDRV_PCM_RATE_48000 |
84 		SNDRV_PCM_RATE_88200 |
85 		SNDRV_PCM_RATE_96000 |
86 		SNDRV_PCM_RATE_176400 |
87 		SNDRV_PCM_RATE_192000,
88 
89 	.rate_min = 44100,
90 	.rate_max = 192000, /* changes in hiface_pcm_open to support extra rates */
91 	.channels_min = 2,
92 	.channels_max = 2,
93 	.buffer_bytes_max = PCM_BUFFER_SIZE,
94 	.period_bytes_min = PCM_PACKET_SIZE,
95 	.period_bytes_max = PCM_BUFFER_SIZE,
96 	.periods_min = 2,
97 	.periods_max = 1024
98 };
99 
100 /* message values used to change the sample rate */
101 #define HIFACE_SET_RATE_REQUEST 0xb0
102 
103 #define HIFACE_RATE_44100  0x43
104 #define HIFACE_RATE_48000  0x4b
105 #define HIFACE_RATE_88200  0x42
106 #define HIFACE_RATE_96000  0x4a
107 #define HIFACE_RATE_176400 0x40
108 #define HIFACE_RATE_192000 0x48
109 #define HIFACE_RATE_352800 0x58
110 #define HIFACE_RATE_384000 0x68
111 
112 static int hiface_pcm_set_rate(struct pcm_runtime *rt, unsigned int rate)
113 {
114 	struct usb_device *device = rt->chip->dev;
115 	u16 rate_value;
116 	int ret;
117 
118 	/* We are already sure that the rate is supported here thanks to
119 	 * ALSA constraints
120 	 */
121 	switch (rate) {
122 	case 44100:
123 		rate_value = HIFACE_RATE_44100;
124 		break;
125 	case 48000:
126 		rate_value = HIFACE_RATE_48000;
127 		break;
128 	case 88200:
129 		rate_value = HIFACE_RATE_88200;
130 		break;
131 	case 96000:
132 		rate_value = HIFACE_RATE_96000;
133 		break;
134 	case 176400:
135 		rate_value = HIFACE_RATE_176400;
136 		break;
137 	case 192000:
138 		rate_value = HIFACE_RATE_192000;
139 		break;
140 	case 352800:
141 		rate_value = HIFACE_RATE_352800;
142 		break;
143 	case 384000:
144 		rate_value = HIFACE_RATE_384000;
145 		break;
146 	default:
147 		dev_err(&device->dev, "Unsupported rate %d\n", rate);
148 		return -EINVAL;
149 	}
150 
151 	/*
152 	 * USBIO: Vendor 0xb0(wValue=0x0043, wIndex=0x0000)
153 	 * 43 b0 43 00 00 00 00 00
154 	 * USBIO: Vendor 0xb0(wValue=0x004b, wIndex=0x0000)
155 	 * 43 b0 4b 00 00 00 00 00
156 	 * This control message doesn't have any ack from the
157 	 * other side
158 	 */
159 	ret = usb_control_msg_send(device, 0,
160 				   HIFACE_SET_RATE_REQUEST,
161 				   USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_OTHER,
162 				   rate_value, 0, NULL, 0, 100, GFP_KERNEL);
163 	if (ret)
164 		dev_err(&device->dev, "Error setting samplerate %d.\n", rate);
165 
166 	return ret;
167 }
168 
169 static struct pcm_substream *hiface_pcm_get_substream(struct snd_pcm_substream
170 						      *alsa_sub)
171 {
172 	struct pcm_runtime *rt = snd_pcm_substream_chip(alsa_sub);
173 	struct device *device = &rt->chip->dev->dev;
174 
175 	if (alsa_sub->stream == SNDRV_PCM_STREAM_PLAYBACK)
176 		return &rt->playback;
177 
178 	dev_err(device, "Error getting pcm substream slot.\n");
179 	return NULL;
180 }
181 
182 /* call with stream_mutex locked */
183 static void hiface_pcm_stream_stop(struct pcm_runtime *rt)
184 {
185 	int i, time;
186 
187 	if (rt->stream_state != STREAM_DISABLED) {
188 		rt->stream_state = STREAM_STOPPING;
189 
190 		for (i = 0; i < PCM_N_URBS; i++) {
191 			time = usb_wait_anchor_empty_timeout(
192 					&rt->out_urbs[i].submitted, 100);
193 			if (!time)
194 				usb_kill_anchored_urbs(
195 					&rt->out_urbs[i].submitted);
196 			usb_kill_urb(&rt->out_urbs[i].instance);
197 		}
198 
199 		rt->stream_state = STREAM_DISABLED;
200 	}
201 }
202 
203 /* call with stream_mutex locked */
204 static int hiface_pcm_stream_start(struct pcm_runtime *rt)
205 {
206 	int ret = 0;
207 	int i;
208 
209 	if (rt->stream_state == STREAM_DISABLED) {
210 
211 		/* reset panic state when starting a new stream */
212 		rt->panic = false;
213 
214 		/* submit our out urbs zero init */
215 		rt->stream_state = STREAM_STARTING;
216 		for (i = 0; i < PCM_N_URBS; i++) {
217 			memset(rt->out_urbs[i].buffer, 0, PCM_PACKET_SIZE);
218 			usb_anchor_urb(&rt->out_urbs[i].instance,
219 				       &rt->out_urbs[i].submitted);
220 			ret = usb_submit_urb(&rt->out_urbs[i].instance,
221 					     GFP_ATOMIC);
222 			if (ret) {
223 				hiface_pcm_stream_stop(rt);
224 				return ret;
225 			}
226 		}
227 
228 		/* wait for first out urb to return (sent in urb handler) */
229 		wait_event_timeout(rt->stream_wait_queue, rt->stream_wait_cond,
230 				   HZ);
231 		if (rt->stream_wait_cond) {
232 			struct device *device = &rt->chip->dev->dev;
233 			dev_dbg(device, "%s: Stream is running wakeup event\n",
234 				 __func__);
235 			rt->stream_state = STREAM_RUNNING;
236 		} else {
237 			hiface_pcm_stream_stop(rt);
238 			return -EIO;
239 		}
240 	}
241 	return ret;
242 }
243 
244 /* The hardware wants word-swapped 32-bit values */
245 static void memcpy_swahw32(u8 *dest, u8 *src, unsigned int n)
246 {
247 	unsigned int i;
248 
249 	for (i = 0; i < n / 4; i++)
250 		((u32 *)dest)[i] = swahw32(((u32 *)src)[i]);
251 }
252 
253 /* call with substream locked */
254 /* returns true if a period elapsed */
255 static bool hiface_pcm_playback(struct pcm_substream *sub, struct pcm_urb *urb)
256 {
257 	struct snd_pcm_runtime *alsa_rt = sub->instance->runtime;
258 	struct device *device = &urb->chip->dev->dev;
259 	u8 *source;
260 	unsigned int pcm_buffer_size;
261 
262 	WARN_ON(alsa_rt->format != SNDRV_PCM_FORMAT_S32_LE);
263 
264 	pcm_buffer_size = snd_pcm_lib_buffer_bytes(sub->instance);
265 
266 	if (sub->dma_off + PCM_PACKET_SIZE <= pcm_buffer_size) {
267 		dev_dbg(device, "%s: (1) buffer_size %#x dma_offset %#x\n", __func__,
268 			 (unsigned int) pcm_buffer_size,
269 			 (unsigned int) sub->dma_off);
270 
271 		source = alsa_rt->dma_area + sub->dma_off;
272 		memcpy_swahw32(urb->buffer, source, PCM_PACKET_SIZE);
273 	} else {
274 		/* wrap around at end of ring buffer */
275 		unsigned int len;
276 
277 		dev_dbg(device, "%s: (2) buffer_size %#x dma_offset %#x\n", __func__,
278 			 (unsigned int) pcm_buffer_size,
279 			 (unsigned int) sub->dma_off);
280 
281 		len = pcm_buffer_size - sub->dma_off;
282 
283 		source = alsa_rt->dma_area + sub->dma_off;
284 		memcpy_swahw32(urb->buffer, source, len);
285 
286 		source = alsa_rt->dma_area;
287 		memcpy_swahw32(urb->buffer + len, source,
288 			       PCM_PACKET_SIZE - len);
289 	}
290 	sub->dma_off += PCM_PACKET_SIZE;
291 	if (sub->dma_off >= pcm_buffer_size)
292 		sub->dma_off -= pcm_buffer_size;
293 
294 	sub->period_off += PCM_PACKET_SIZE;
295 	if (sub->period_off >= alsa_rt->period_size) {
296 		sub->period_off %= alsa_rt->period_size;
297 		return true;
298 	}
299 	return false;
300 }
301 
302 static void hiface_pcm_out_urb_handler(struct urb *usb_urb)
303 {
304 	struct pcm_urb *out_urb = usb_urb->context;
305 	struct pcm_runtime *rt = out_urb->chip->pcm;
306 	struct pcm_substream *sub;
307 	bool do_period_elapsed = false;
308 	unsigned long flags;
309 	int ret;
310 
311 	if (rt->panic || rt->stream_state == STREAM_STOPPING)
312 		return;
313 
314 	if (unlikely(usb_urb->status == -ENOENT ||	/* unlinked */
315 		     usb_urb->status == -ENODEV ||	/* device removed */
316 		     usb_urb->status == -ECONNRESET ||	/* unlinked */
317 		     usb_urb->status == -ESHUTDOWN)) {	/* device disabled */
318 		goto out_fail;
319 	}
320 
321 	if (rt->stream_state == STREAM_STARTING) {
322 		rt->stream_wait_cond = true;
323 		wake_up(&rt->stream_wait_queue);
324 	}
325 
326 	/* now send our playback data (if a free out urb was found) */
327 	sub = &rt->playback;
328 	spin_lock_irqsave(&sub->lock, flags);
329 	if (sub->active)
330 		do_period_elapsed = hiface_pcm_playback(sub, out_urb);
331 	else
332 		memset(out_urb->buffer, 0, PCM_PACKET_SIZE);
333 
334 	spin_unlock_irqrestore(&sub->lock, flags);
335 
336 	if (do_period_elapsed)
337 		snd_pcm_period_elapsed(sub->instance);
338 
339 	ret = usb_submit_urb(&out_urb->instance, GFP_ATOMIC);
340 	if (ret < 0)
341 		goto out_fail;
342 
343 	return;
344 
345 out_fail:
346 	rt->panic = true;
347 }
348 
349 static int hiface_pcm_open(struct snd_pcm_substream *alsa_sub)
350 {
351 	struct pcm_runtime *rt = snd_pcm_substream_chip(alsa_sub);
352 	struct pcm_substream *sub = NULL;
353 	struct snd_pcm_runtime *alsa_rt = alsa_sub->runtime;
354 	int ret;
355 
356 	if (rt->panic)
357 		return -EPIPE;
358 
359 	mutex_lock(&rt->stream_mutex);
360 	alsa_rt->hw = pcm_hw;
361 
362 	if (alsa_sub->stream == SNDRV_PCM_STREAM_PLAYBACK)
363 		sub = &rt->playback;
364 
365 	if (!sub) {
366 		struct device *device = &rt->chip->dev->dev;
367 		mutex_unlock(&rt->stream_mutex);
368 		dev_err(device, "Invalid stream type\n");
369 		return -EINVAL;
370 	}
371 
372 	if (rt->extra_freq) {
373 		alsa_rt->hw.rates |= SNDRV_PCM_RATE_KNOT;
374 		alsa_rt->hw.rate_max = 384000;
375 
376 		/* explicit constraints needed as we added SNDRV_PCM_RATE_KNOT */
377 		ret = snd_pcm_hw_constraint_list(alsa_sub->runtime, 0,
378 						 SNDRV_PCM_HW_PARAM_RATE,
379 						 &constraints_extra_rates);
380 		if (ret < 0) {
381 			mutex_unlock(&rt->stream_mutex);
382 			return ret;
383 		}
384 	}
385 
386 	sub->instance = alsa_sub;
387 	sub->active = false;
388 	mutex_unlock(&rt->stream_mutex);
389 	return 0;
390 }
391 
392 static int hiface_pcm_close(struct snd_pcm_substream *alsa_sub)
393 {
394 	struct pcm_runtime *rt = snd_pcm_substream_chip(alsa_sub);
395 	struct pcm_substream *sub = hiface_pcm_get_substream(alsa_sub);
396 	unsigned long flags;
397 
398 	if (rt->panic)
399 		return 0;
400 
401 	mutex_lock(&rt->stream_mutex);
402 	if (sub) {
403 		hiface_pcm_stream_stop(rt);
404 
405 		/* deactivate substream */
406 		spin_lock_irqsave(&sub->lock, flags);
407 		sub->instance = NULL;
408 		sub->active = false;
409 		spin_unlock_irqrestore(&sub->lock, flags);
410 
411 	}
412 	mutex_unlock(&rt->stream_mutex);
413 	return 0;
414 }
415 
416 static int hiface_pcm_prepare(struct snd_pcm_substream *alsa_sub)
417 {
418 	struct pcm_runtime *rt = snd_pcm_substream_chip(alsa_sub);
419 	struct pcm_substream *sub = hiface_pcm_get_substream(alsa_sub);
420 	struct snd_pcm_runtime *alsa_rt = alsa_sub->runtime;
421 	int ret;
422 
423 	if (rt->panic)
424 		return -EPIPE;
425 	if (!sub)
426 		return -ENODEV;
427 
428 	mutex_lock(&rt->stream_mutex);
429 
430 	hiface_pcm_stream_stop(rt);
431 
432 	sub->dma_off = 0;
433 	sub->period_off = 0;
434 
435 	if (rt->stream_state == STREAM_DISABLED) {
436 
437 		ret = hiface_pcm_set_rate(rt, alsa_rt->rate);
438 		if (ret) {
439 			mutex_unlock(&rt->stream_mutex);
440 			return ret;
441 		}
442 		ret = hiface_pcm_stream_start(rt);
443 		if (ret) {
444 			mutex_unlock(&rt->stream_mutex);
445 			return ret;
446 		}
447 	}
448 	mutex_unlock(&rt->stream_mutex);
449 	return 0;
450 }
451 
452 static int hiface_pcm_trigger(struct snd_pcm_substream *alsa_sub, int cmd)
453 {
454 	struct pcm_substream *sub = hiface_pcm_get_substream(alsa_sub);
455 	struct pcm_runtime *rt = snd_pcm_substream_chip(alsa_sub);
456 
457 	if (rt->panic)
458 		return -EPIPE;
459 	if (!sub)
460 		return -ENODEV;
461 
462 	switch (cmd) {
463 	case SNDRV_PCM_TRIGGER_START:
464 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
465 		spin_lock_irq(&sub->lock);
466 		sub->active = true;
467 		spin_unlock_irq(&sub->lock);
468 		return 0;
469 
470 	case SNDRV_PCM_TRIGGER_STOP:
471 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
472 		spin_lock_irq(&sub->lock);
473 		sub->active = false;
474 		spin_unlock_irq(&sub->lock);
475 		return 0;
476 
477 	default:
478 		return -EINVAL;
479 	}
480 }
481 
482 static snd_pcm_uframes_t hiface_pcm_pointer(struct snd_pcm_substream *alsa_sub)
483 {
484 	struct pcm_substream *sub = hiface_pcm_get_substream(alsa_sub);
485 	struct pcm_runtime *rt = snd_pcm_substream_chip(alsa_sub);
486 	unsigned long flags;
487 	snd_pcm_uframes_t dma_offset;
488 
489 	if (rt->panic || !sub)
490 		return SNDRV_PCM_POS_XRUN;
491 
492 	spin_lock_irqsave(&sub->lock, flags);
493 	dma_offset = sub->dma_off;
494 	spin_unlock_irqrestore(&sub->lock, flags);
495 	return bytes_to_frames(alsa_sub->runtime, dma_offset);
496 }
497 
498 static const struct snd_pcm_ops pcm_ops = {
499 	.open = hiface_pcm_open,
500 	.close = hiface_pcm_close,
501 	.prepare = hiface_pcm_prepare,
502 	.trigger = hiface_pcm_trigger,
503 	.pointer = hiface_pcm_pointer,
504 };
505 
506 static int hiface_pcm_init_urb(struct pcm_urb *urb,
507 			       struct hiface_chip *chip,
508 			       unsigned int ep,
509 			       void (*handler)(struct urb *))
510 {
511 	urb->chip = chip;
512 	usb_init_urb(&urb->instance);
513 
514 	urb->buffer = kzalloc(PCM_PACKET_SIZE, GFP_KERNEL);
515 	if (!urb->buffer)
516 		return -ENOMEM;
517 
518 	usb_fill_bulk_urb(&urb->instance, chip->dev,
519 			  usb_sndbulkpipe(chip->dev, ep), (void *)urb->buffer,
520 			  PCM_PACKET_SIZE, handler, urb);
521 	if (usb_urb_ep_type_check(&urb->instance))
522 		return -EINVAL;
523 	init_usb_anchor(&urb->submitted);
524 
525 	return 0;
526 }
527 
528 void hiface_pcm_abort(struct hiface_chip *chip)
529 {
530 	struct pcm_runtime *rt = chip->pcm;
531 
532 	if (rt) {
533 		rt->panic = true;
534 
535 		mutex_lock(&rt->stream_mutex);
536 		hiface_pcm_stream_stop(rt);
537 		mutex_unlock(&rt->stream_mutex);
538 	}
539 }
540 
541 static void hiface_pcm_destroy(struct hiface_chip *chip)
542 {
543 	struct pcm_runtime *rt = chip->pcm;
544 	int i;
545 
546 	for (i = 0; i < PCM_N_URBS; i++)
547 		kfree(rt->out_urbs[i].buffer);
548 
549 	kfree(chip->pcm);
550 	chip->pcm = NULL;
551 }
552 
553 static void hiface_pcm_free(struct snd_pcm *pcm)
554 {
555 	struct pcm_runtime *rt = pcm->private_data;
556 
557 	if (rt)
558 		hiface_pcm_destroy(rt->chip);
559 }
560 
561 int hiface_pcm_init(struct hiface_chip *chip, u8 extra_freq)
562 {
563 	int i;
564 	int ret;
565 	struct snd_pcm *pcm;
566 	struct pcm_runtime *rt;
567 
568 	rt = kzalloc(sizeof(*rt), GFP_KERNEL);
569 	if (!rt)
570 		return -ENOMEM;
571 
572 	rt->chip = chip;
573 	rt->stream_state = STREAM_DISABLED;
574 	if (extra_freq)
575 		rt->extra_freq = 1;
576 
577 	init_waitqueue_head(&rt->stream_wait_queue);
578 	mutex_init(&rt->stream_mutex);
579 	spin_lock_init(&rt->playback.lock);
580 
581 	for (i = 0; i < PCM_N_URBS; i++) {
582 		ret = hiface_pcm_init_urb(&rt->out_urbs[i], chip, OUT_EP,
583 				    hiface_pcm_out_urb_handler);
584 		if (ret < 0)
585 			goto error;
586 	}
587 
588 	ret = snd_pcm_new(chip->card, "USB-SPDIF Audio", 0, 1, 0, &pcm);
589 	if (ret < 0) {
590 		dev_err(&chip->dev->dev, "Cannot create pcm instance\n");
591 		goto error;
592 	}
593 
594 	pcm->private_data = rt;
595 	pcm->private_free = hiface_pcm_free;
596 
597 	strscpy(pcm->name, "USB-SPDIF Audio", sizeof(pcm->name));
598 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &pcm_ops);
599 	snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_VMALLOC,
600 				       NULL, 0, 0);
601 
602 	rt->instance = pcm;
603 
604 	chip->pcm = rt;
605 	return 0;
606 
607 error:
608 	for (i = 0; i < PCM_N_URBS; i++)
609 		kfree(rt->out_urbs[i].buffer);
610 	kfree(rt);
611 	return ret;
612 }
613