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
11static u32 pcm_buffer_ms = 160;
12module_param(pcm_buffer_ms, uint, 0644);
13MODULE_PARM_DESC(pcm_buffer_ms, "PCM substream buffer time in milliseconds");
14
15static u32 pcm_periods_min = 2;
16module_param(pcm_periods_min, uint, 0644);
17MODULE_PARM_DESC(pcm_periods_min, "Minimum number of PCM periods");
18
19static u32 pcm_periods_max = 16;
20module_param(pcm_periods_max, uint, 0644);
21MODULE_PARM_DESC(pcm_periods_max, "Maximum number of PCM periods");
22
23static u32 pcm_period_ms_min = 10;
24module_param(pcm_period_ms_min, uint, 0644);
25MODULE_PARM_DESC(pcm_period_ms_min, "Minimum PCM period time in milliseconds");
26
27static u32 pcm_period_ms_max = 80;
28module_param(pcm_period_ms_max, uint, 0644);
29MODULE_PARM_DESC(pcm_period_ms_max, "Maximum PCM period time in milliseconds");
30
31/* Map for converting VirtIO format to ALSA format. */
32static 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. */
62struct virtsnd_v2a_rate {
63	unsigned int alsa_bit;
64	unsigned int rate;
65};
66
67static 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 */
91static 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 */
218struct 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 */
238struct 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 */
264int 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 */
308static 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 */
325int 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
390on_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 */
403int 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 */
494void 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