xref: /linux/sound/virtio/virtio_pcm.c (revision 0ea5c948cb64bab5bc7a5516774eb8536f05aa0d)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * virtio-snd: Virtio sound device
4  * Copyright (C) 2021 OpenSynergy GmbH
5  */
6 #include <linux/moduleparam.h>
7 #include <linux/virtio_config.h>
8 
9 #include "virtio_card.h"
10 
11 static u32 pcm_buffer_ms = 160;
12 module_param(pcm_buffer_ms, uint, 0644);
13 MODULE_PARM_DESC(pcm_buffer_ms, "PCM substream buffer time in milliseconds");
14 
15 static u32 pcm_periods_min = 2;
16 module_param(pcm_periods_min, uint, 0644);
17 MODULE_PARM_DESC(pcm_periods_min, "Minimum number of PCM periods");
18 
19 static u32 pcm_periods_max = 16;
20 module_param(pcm_periods_max, uint, 0644);
21 MODULE_PARM_DESC(pcm_periods_max, "Maximum number of PCM periods");
22 
23 static u32 pcm_period_ms_min = 10;
24 module_param(pcm_period_ms_min, uint, 0644);
25 MODULE_PARM_DESC(pcm_period_ms_min, "Minimum PCM period time in milliseconds");
26 
27 static u32 pcm_period_ms_max = 80;
28 module_param(pcm_period_ms_max, uint, 0644);
29 MODULE_PARM_DESC(pcm_period_ms_max, "Maximum PCM period time in milliseconds");
30 
31 /* Map for converting VirtIO format to ALSA format. */
32 static const snd_pcm_format_t g_v2a_format_map[] = {
33 	[VIRTIO_SND_PCM_FMT_IMA_ADPCM] = SNDRV_PCM_FORMAT_IMA_ADPCM,
34 	[VIRTIO_SND_PCM_FMT_MU_LAW] = SNDRV_PCM_FORMAT_MU_LAW,
35 	[VIRTIO_SND_PCM_FMT_A_LAW] = SNDRV_PCM_FORMAT_A_LAW,
36 	[VIRTIO_SND_PCM_FMT_S8] = SNDRV_PCM_FORMAT_S8,
37 	[VIRTIO_SND_PCM_FMT_U8] = SNDRV_PCM_FORMAT_U8,
38 	[VIRTIO_SND_PCM_FMT_S16] = SNDRV_PCM_FORMAT_S16_LE,
39 	[VIRTIO_SND_PCM_FMT_U16] = SNDRV_PCM_FORMAT_U16_LE,
40 	[VIRTIO_SND_PCM_FMT_S18_3] = SNDRV_PCM_FORMAT_S18_3LE,
41 	[VIRTIO_SND_PCM_FMT_U18_3] = SNDRV_PCM_FORMAT_U18_3LE,
42 	[VIRTIO_SND_PCM_FMT_S20_3] = SNDRV_PCM_FORMAT_S20_3LE,
43 	[VIRTIO_SND_PCM_FMT_U20_3] = SNDRV_PCM_FORMAT_U20_3LE,
44 	[VIRTIO_SND_PCM_FMT_S24_3] = SNDRV_PCM_FORMAT_S24_3LE,
45 	[VIRTIO_SND_PCM_FMT_U24_3] = SNDRV_PCM_FORMAT_U24_3LE,
46 	[VIRTIO_SND_PCM_FMT_S20] = SNDRV_PCM_FORMAT_S20_LE,
47 	[VIRTIO_SND_PCM_FMT_U20] = SNDRV_PCM_FORMAT_U20_LE,
48 	[VIRTIO_SND_PCM_FMT_S24] = SNDRV_PCM_FORMAT_S24_LE,
49 	[VIRTIO_SND_PCM_FMT_U24] = SNDRV_PCM_FORMAT_U24_LE,
50 	[VIRTIO_SND_PCM_FMT_S32] = SNDRV_PCM_FORMAT_S32_LE,
51 	[VIRTIO_SND_PCM_FMT_U32] = SNDRV_PCM_FORMAT_U32_LE,
52 	[VIRTIO_SND_PCM_FMT_FLOAT] = SNDRV_PCM_FORMAT_FLOAT_LE,
53 	[VIRTIO_SND_PCM_FMT_FLOAT64] = SNDRV_PCM_FORMAT_FLOAT64_LE,
54 	[VIRTIO_SND_PCM_FMT_DSD_U8] = SNDRV_PCM_FORMAT_DSD_U8,
55 	[VIRTIO_SND_PCM_FMT_DSD_U16] = SNDRV_PCM_FORMAT_DSD_U16_LE,
56 	[VIRTIO_SND_PCM_FMT_DSD_U32] = SNDRV_PCM_FORMAT_DSD_U32_LE,
57 	[VIRTIO_SND_PCM_FMT_IEC958_SUBFRAME] =
58 		SNDRV_PCM_FORMAT_IEC958_SUBFRAME_LE
59 };
60 
61 /* Map for converting VirtIO frame rate to ALSA frame rate. */
62 struct virtsnd_v2a_rate {
63 	unsigned int alsa_bit;
64 	unsigned int rate;
65 };
66 
67 static const struct virtsnd_v2a_rate g_v2a_rate_map[] = {
68 	[VIRTIO_SND_PCM_RATE_5512] = { SNDRV_PCM_RATE_5512, 5512 },
69 	[VIRTIO_SND_PCM_RATE_8000] = { SNDRV_PCM_RATE_8000, 8000 },
70 	[VIRTIO_SND_PCM_RATE_11025] = { SNDRV_PCM_RATE_11025, 11025 },
71 	[VIRTIO_SND_PCM_RATE_16000] = { SNDRV_PCM_RATE_16000, 16000 },
72 	[VIRTIO_SND_PCM_RATE_22050] = { SNDRV_PCM_RATE_22050, 22050 },
73 	[VIRTIO_SND_PCM_RATE_32000] = { SNDRV_PCM_RATE_32000, 32000 },
74 	[VIRTIO_SND_PCM_RATE_44100] = { SNDRV_PCM_RATE_44100, 44100 },
75 	[VIRTIO_SND_PCM_RATE_48000] = { SNDRV_PCM_RATE_48000, 48000 },
76 	[VIRTIO_SND_PCM_RATE_64000] = { SNDRV_PCM_RATE_64000, 64000 },
77 	[VIRTIO_SND_PCM_RATE_88200] = { SNDRV_PCM_RATE_88200, 88200 },
78 	[VIRTIO_SND_PCM_RATE_96000] = { SNDRV_PCM_RATE_96000, 96000 },
79 	[VIRTIO_SND_PCM_RATE_176400] = { SNDRV_PCM_RATE_176400, 176400 },
80 	[VIRTIO_SND_PCM_RATE_192000] = { SNDRV_PCM_RATE_192000, 192000 }
81 };
82 
83 /**
84  * virtsnd_pcm_build_hw() - Parse substream config and build HW descriptor.
85  * @vss: VirtIO substream.
86  * @info: VirtIO substream information entry.
87  *
88  * Context: Any context.
89  * Return: 0 on success, -EINVAL if configuration is invalid.
90  */
virtsnd_pcm_build_hw(struct virtio_pcm_substream * vss,struct virtio_snd_pcm_info * info)91 static int virtsnd_pcm_build_hw(struct virtio_pcm_substream *vss,
92 				struct virtio_snd_pcm_info *info)
93 {
94 	struct virtio_device *vdev = vss->snd->vdev;
95 	unsigned int i;
96 	u64 values;
97 	size_t sample_max = 0;
98 	size_t sample_min = 0;
99 
100 	vss->features = le32_to_cpu(info->features);
101 
102 	/*
103 	 * TODO: set SNDRV_PCM_INFO_{BATCH,BLOCK_TRANSFER} if device supports
104 	 * only message-based transport.
105 	 */
106 	vss->hw.info =
107 		SNDRV_PCM_INFO_MMAP |
108 		SNDRV_PCM_INFO_MMAP_VALID |
109 		SNDRV_PCM_INFO_BATCH |
110 		SNDRV_PCM_INFO_BLOCK_TRANSFER |
111 		SNDRV_PCM_INFO_INTERLEAVED |
112 		SNDRV_PCM_INFO_PAUSE |
113 		SNDRV_PCM_INFO_NO_REWINDS |
114 		SNDRV_PCM_INFO_SYNC_APPLPTR;
115 
116 	if (!info->channels_min || info->channels_min > info->channels_max) {
117 		dev_err(&vdev->dev,
118 			"SID %u: invalid channel range [%u %u]\n",
119 			vss->sid, info->channels_min, info->channels_max);
120 		return -EINVAL;
121 	}
122 
123 	vss->hw.channels_min = info->channels_min;
124 	vss->hw.channels_max = info->channels_max;
125 
126 	values = le64_to_cpu(info->formats);
127 
128 	vss->hw.formats = 0;
129 
130 	for (i = 0; i < ARRAY_SIZE(g_v2a_format_map); ++i)
131 		if (values & (1ULL << i)) {
132 			snd_pcm_format_t alsa_fmt = g_v2a_format_map[i];
133 			int bytes = snd_pcm_format_physical_width(alsa_fmt) / 8;
134 
135 			if (!sample_min || sample_min > bytes)
136 				sample_min = bytes;
137 
138 			if (sample_max < bytes)
139 				sample_max = bytes;
140 
141 			vss->hw.formats |= pcm_format_to_bits(alsa_fmt);
142 		}
143 
144 	if (!vss->hw.formats) {
145 		dev_err(&vdev->dev,
146 			"SID %u: no supported PCM sample formats found\n",
147 			vss->sid);
148 		return -EINVAL;
149 	}
150 
151 	values = le64_to_cpu(info->rates);
152 
153 	vss->hw.rates = 0;
154 
155 	for (i = 0; i < ARRAY_SIZE(g_v2a_rate_map); ++i)
156 		if (values & (1ULL << i)) {
157 			if (!vss->hw.rate_min ||
158 			    vss->hw.rate_min > g_v2a_rate_map[i].rate)
159 				vss->hw.rate_min = g_v2a_rate_map[i].rate;
160 
161 			if (vss->hw.rate_max < g_v2a_rate_map[i].rate)
162 				vss->hw.rate_max = g_v2a_rate_map[i].rate;
163 
164 			vss->hw.rates |= g_v2a_rate_map[i].alsa_bit;
165 		}
166 
167 	if (!vss->hw.rates) {
168 		dev_err(&vdev->dev,
169 			"SID %u: no supported PCM frame rates found\n",
170 			vss->sid);
171 		return -EINVAL;
172 	}
173 
174 	vss->hw.periods_min = pcm_periods_min;
175 	vss->hw.periods_max = pcm_periods_max;
176 
177 	/*
178 	 * We must ensure that there is enough space in the buffer to store
179 	 * pcm_buffer_ms ms for the combination (Cmax, Smax, Rmax), where:
180 	 *   Cmax = maximum supported number of channels,
181 	 *   Smax = maximum supported sample size in bytes,
182 	 *   Rmax = maximum supported frame rate.
183 	 */
184 	vss->hw.buffer_bytes_max =
185 		PAGE_ALIGN(sample_max * vss->hw.channels_max * pcm_buffer_ms *
186 			   (vss->hw.rate_max / MSEC_PER_SEC));
187 
188 	/*
189 	 * We must ensure that the minimum period size is enough to store
190 	 * pcm_period_ms_min ms for the combination (Cmin, Smin, Rmin), where:
191 	 *   Cmin = minimum supported number of channels,
192 	 *   Smin = minimum supported sample size in bytes,
193 	 *   Rmin = minimum supported frame rate.
194 	 */
195 	vss->hw.period_bytes_min =
196 		sample_min * vss->hw.channels_min * pcm_period_ms_min *
197 		(vss->hw.rate_min / MSEC_PER_SEC);
198 
199 	/*
200 	 * We must ensure that the maximum period size is enough to store
201 	 * pcm_period_ms_max ms for the combination (Cmax, Smax, Rmax).
202 	 */
203 	vss->hw.period_bytes_max =
204 		sample_max * vss->hw.channels_max * pcm_period_ms_max *
205 		(vss->hw.rate_max / MSEC_PER_SEC);
206 
207 	return 0;
208 }
209 
210 /**
211  * virtsnd_pcm_find() - Find the PCM device for the specified node ID.
212  * @snd: VirtIO sound device.
213  * @nid: Function node ID.
214  *
215  * Context: Any context.
216  * Return: a pointer to the PCM device or ERR_PTR(-ENOENT).
217  */
virtsnd_pcm_find(struct virtio_snd * snd,u32 nid)218 struct virtio_pcm *virtsnd_pcm_find(struct virtio_snd *snd, u32 nid)
219 {
220 	struct virtio_pcm *vpcm;
221 
222 	list_for_each_entry(vpcm, &snd->pcm_list, list)
223 		if (vpcm->nid == nid)
224 			return vpcm;
225 
226 	return ERR_PTR(-ENOENT);
227 }
228 
229 /**
230  * virtsnd_pcm_find_or_create() - Find or create the PCM device for the
231  *                                specified node ID.
232  * @snd: VirtIO sound device.
233  * @nid: Function node ID.
234  *
235  * Context: Any context that permits to sleep.
236  * Return: a pointer to the PCM device or ERR_PTR(-errno).
237  */
virtsnd_pcm_find_or_create(struct virtio_snd * snd,u32 nid)238 struct virtio_pcm *virtsnd_pcm_find_or_create(struct virtio_snd *snd, u32 nid)
239 {
240 	struct virtio_device *vdev = snd->vdev;
241 	struct virtio_pcm *vpcm;
242 
243 	vpcm = virtsnd_pcm_find(snd, nid);
244 	if (!IS_ERR(vpcm))
245 		return vpcm;
246 
247 	vpcm = devm_kzalloc(&vdev->dev, sizeof(*vpcm), GFP_KERNEL);
248 	if (!vpcm)
249 		return ERR_PTR(-ENOMEM);
250 
251 	vpcm->nid = nid;
252 	list_add_tail(&vpcm->list, &snd->pcm_list);
253 
254 	return vpcm;
255 }
256 
257 /**
258  * virtsnd_pcm_validate() - Validate if the device can be started.
259  * @vdev: VirtIO parent device.
260  *
261  * Context: Any context.
262  * Return: 0 on success, -EINVAL on failure.
263  */
virtsnd_pcm_validate(struct virtio_device * vdev)264 int virtsnd_pcm_validate(struct virtio_device *vdev)
265 {
266 	if (pcm_periods_min < 2 || pcm_periods_min > pcm_periods_max) {
267 		dev_err(&vdev->dev,
268 			"invalid range [%u %u] of the number of PCM periods\n",
269 			pcm_periods_min, pcm_periods_max);
270 		return -EINVAL;
271 	}
272 
273 	if (!pcm_period_ms_min || pcm_period_ms_min > pcm_period_ms_max) {
274 		dev_err(&vdev->dev,
275 			"invalid range [%u %u] of the size of the PCM period\n",
276 			pcm_period_ms_min, pcm_period_ms_max);
277 		return -EINVAL;
278 	}
279 
280 	if (pcm_buffer_ms < pcm_periods_min * pcm_period_ms_min) {
281 		dev_err(&vdev->dev,
282 			"pcm_buffer_ms(=%u) value cannot be < %u ms\n",
283 			pcm_buffer_ms, pcm_periods_min * pcm_period_ms_min);
284 		return -EINVAL;
285 	}
286 
287 	if (pcm_period_ms_max > pcm_buffer_ms / 2) {
288 		dev_err(&vdev->dev,
289 			"pcm_period_ms_max(=%u) value cannot be > %u ms\n",
290 			pcm_period_ms_max, pcm_buffer_ms / 2);
291 		return -EINVAL;
292 	}
293 
294 	return 0;
295 }
296 
297 /**
298  * virtsnd_pcm_period_elapsed() - Kernel work function to handle the elapsed
299  *                                period state.
300  * @work: Elapsed period work.
301  *
302  * The main purpose of this function is to call snd_pcm_period_elapsed() in
303  * a process context, not in an interrupt context. This is necessary because PCM
304  * devices operate in non-atomic mode.
305  *
306  * Context: Process context.
307  */
virtsnd_pcm_period_elapsed(struct work_struct * work)308 static void virtsnd_pcm_period_elapsed(struct work_struct *work)
309 {
310 	struct virtio_pcm_substream *vss =
311 		container_of(work, struct virtio_pcm_substream, elapsed_period);
312 
313 	snd_pcm_period_elapsed(vss->substream);
314 }
315 
316 /**
317  * virtsnd_pcm_parse_cfg() - Parse the stream configuration.
318  * @snd: VirtIO sound device.
319  *
320  * This function is called during initial device initialization.
321  *
322  * Context: Any context that permits to sleep.
323  * Return: 0 on success, -errno on failure.
324  */
virtsnd_pcm_parse_cfg(struct virtio_snd * snd)325 int virtsnd_pcm_parse_cfg(struct virtio_snd *snd)
326 {
327 	struct virtio_device *vdev = snd->vdev;
328 	struct virtio_snd_pcm_info *info;
329 	u32 i;
330 	int rc;
331 
332 	virtio_cread_le(vdev, struct virtio_snd_config, streams,
333 			&snd->nsubstreams);
334 	if (!snd->nsubstreams)
335 		return 0;
336 
337 	snd->substreams = devm_kcalloc(&vdev->dev, snd->nsubstreams,
338 				       sizeof(*snd->substreams), GFP_KERNEL);
339 	if (!snd->substreams)
340 		return -ENOMEM;
341 
342 	info = kcalloc(snd->nsubstreams, sizeof(*info), GFP_KERNEL);
343 	if (!info)
344 		return -ENOMEM;
345 
346 	rc = virtsnd_ctl_query_info(snd, VIRTIO_SND_R_PCM_INFO, 0,
347 				    snd->nsubstreams, sizeof(*info), info);
348 	if (rc)
349 		goto on_exit;
350 
351 	for (i = 0; i < snd->nsubstreams; ++i) {
352 		struct virtio_pcm_substream *vss = &snd->substreams[i];
353 		struct virtio_pcm *vpcm;
354 
355 		vss->snd = snd;
356 		vss->sid = i;
357 		INIT_WORK(&vss->elapsed_period, virtsnd_pcm_period_elapsed);
358 		init_waitqueue_head(&vss->msg_empty);
359 		spin_lock_init(&vss->lock);
360 
361 		rc = virtsnd_pcm_build_hw(vss, &info[i]);
362 		if (rc)
363 			goto on_exit;
364 
365 		vss->nid = le32_to_cpu(info[i].hdr.hda_fn_nid);
366 
367 		vpcm = virtsnd_pcm_find_or_create(snd, vss->nid);
368 		if (IS_ERR(vpcm)) {
369 			rc = PTR_ERR(vpcm);
370 			goto on_exit;
371 		}
372 
373 		switch (info[i].direction) {
374 		case VIRTIO_SND_D_OUTPUT:
375 			vss->direction = SNDRV_PCM_STREAM_PLAYBACK;
376 			break;
377 		case VIRTIO_SND_D_INPUT:
378 			vss->direction = SNDRV_PCM_STREAM_CAPTURE;
379 			break;
380 		default:
381 			dev_err(&vdev->dev, "SID %u: unknown direction (%u)\n",
382 				vss->sid, info[i].direction);
383 			rc = -EINVAL;
384 			goto on_exit;
385 		}
386 
387 		vpcm->streams[vss->direction].nsubstreams++;
388 	}
389 
390 on_exit:
391 	kfree(info);
392 
393 	return rc;
394 }
395 
396 /**
397  * virtsnd_pcm_build_devs() - Build ALSA PCM devices.
398  * @snd: VirtIO sound device.
399  *
400  * Context: Any context that permits to sleep.
401  * Return: 0 on success, -errno on failure.
402  */
virtsnd_pcm_build_devs(struct virtio_snd * snd)403 int virtsnd_pcm_build_devs(struct virtio_snd *snd)
404 {
405 	struct virtio_device *vdev = snd->vdev;
406 	struct virtio_pcm *vpcm;
407 	u32 i;
408 	int rc;
409 
410 	list_for_each_entry(vpcm, &snd->pcm_list, list) {
411 		unsigned int npbs =
412 			vpcm->streams[SNDRV_PCM_STREAM_PLAYBACK].nsubstreams;
413 		unsigned int ncps =
414 			vpcm->streams[SNDRV_PCM_STREAM_CAPTURE].nsubstreams;
415 
416 		if (!npbs && !ncps)
417 			continue;
418 
419 		rc = snd_pcm_new(snd->card, VIRTIO_SND_CARD_DRIVER, vpcm->nid,
420 				 npbs, ncps, &vpcm->pcm);
421 		if (rc) {
422 			dev_err(&vdev->dev, "snd_pcm_new[%u] failed: %d\n",
423 				vpcm->nid, rc);
424 			return rc;
425 		}
426 
427 		vpcm->pcm->info_flags = 0;
428 		vpcm->pcm->dev_class = SNDRV_PCM_CLASS_GENERIC;
429 		vpcm->pcm->dev_subclass = SNDRV_PCM_SUBCLASS_GENERIC_MIX;
430 		snprintf(vpcm->pcm->name, sizeof(vpcm->pcm->name),
431 			 VIRTIO_SND_PCM_NAME " %u", vpcm->pcm->device);
432 		vpcm->pcm->private_data = vpcm;
433 		vpcm->pcm->nonatomic = true;
434 
435 		for (i = 0; i < ARRAY_SIZE(vpcm->streams); ++i) {
436 			struct virtio_pcm_stream *stream = &vpcm->streams[i];
437 
438 			if (!stream->nsubstreams)
439 				continue;
440 
441 			stream->substreams =
442 				devm_kcalloc(&vdev->dev, stream->nsubstreams,
443 					     sizeof(*stream->substreams),
444 					     GFP_KERNEL);
445 			if (!stream->substreams)
446 				return -ENOMEM;
447 
448 			stream->nsubstreams = 0;
449 		}
450 	}
451 
452 	for (i = 0; i < snd->nsubstreams; ++i) {
453 		struct virtio_pcm_stream *vs;
454 		struct virtio_pcm_substream *vss = &snd->substreams[i];
455 
456 		vpcm = virtsnd_pcm_find(snd, vss->nid);
457 		if (IS_ERR(vpcm))
458 			return PTR_ERR(vpcm);
459 
460 		vs = &vpcm->streams[vss->direction];
461 		vs->substreams[vs->nsubstreams++] = vss;
462 	}
463 
464 	list_for_each_entry(vpcm, &snd->pcm_list, list) {
465 		for (i = 0; i < ARRAY_SIZE(vpcm->streams); ++i) {
466 			struct virtio_pcm_stream *vs = &vpcm->streams[i];
467 			struct snd_pcm_str *ks = &vpcm->pcm->streams[i];
468 			struct snd_pcm_substream *kss;
469 
470 			if (!vs->nsubstreams)
471 				continue;
472 
473 			for (kss = ks->substream; kss; kss = kss->next)
474 				vs->substreams[kss->number]->substream = kss;
475 
476 			snd_pcm_set_ops(vpcm->pcm, i, &virtsnd_pcm_ops[i]);
477 		}
478 
479 		snd_pcm_set_managed_buffer_all(vpcm->pcm,
480 					       SNDRV_DMA_TYPE_VMALLOC, NULL,
481 					       0, 0);
482 	}
483 
484 	return 0;
485 }
486 
487 /**
488  * virtsnd_pcm_event() - Handle the PCM device event notification.
489  * @snd: VirtIO sound device.
490  * @event: VirtIO sound event.
491  *
492  * Context: Interrupt context.
493  */
virtsnd_pcm_event(struct virtio_snd * snd,struct virtio_snd_event * event)494 void virtsnd_pcm_event(struct virtio_snd *snd, struct virtio_snd_event *event)
495 {
496 	struct virtio_pcm_substream *vss;
497 	u32 sid = le32_to_cpu(event->data);
498 
499 	if (sid >= snd->nsubstreams)
500 		return;
501 
502 	vss = &snd->substreams[sid];
503 
504 	switch (le32_to_cpu(event->hdr.code)) {
505 	case VIRTIO_SND_EVT_PCM_PERIOD_ELAPSED:
506 		/* TODO: deal with shmem elapsed period */
507 		break;
508 	case VIRTIO_SND_EVT_PCM_XRUN:
509 		spin_lock(&vss->lock);
510 		if (vss->xfer_enabled)
511 			vss->xfer_xrun = true;
512 		spin_unlock(&vss->lock);
513 		break;
514 	}
515 }
516