ALSA: virtio: introduce PCM channel map support
Enumerate all available PCM channel maps and create ALSA controls.
Signed-off-by: Anton Yakovlev <anton.yakovlev@opensynergy.com>
Link: https://lore.kernel.org/r/20210302164709.3142702-9-anton.yakovlev@opensynergy.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/virtio/virtio_chmap.c b/sound/virtio/virtio_chmap.c
new file mode 100644
index 0000000..5bc9249
--- /dev/null
+++ b/sound/virtio/virtio_chmap.c
@@ -0,0 +1,219 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * virtio-snd: Virtio sound device
+ * Copyright (C) 2021 OpenSynergy GmbH
+ */
+#include <linux/virtio_config.h>
+
+#include "virtio_card.h"
+
+/* VirtIO->ALSA channel position map */
+static const u8 g_v2a_position_map[] = {
+ [VIRTIO_SND_CHMAP_NONE] = SNDRV_CHMAP_UNKNOWN,
+ [VIRTIO_SND_CHMAP_NA] = SNDRV_CHMAP_NA,
+ [VIRTIO_SND_CHMAP_MONO] = SNDRV_CHMAP_MONO,
+ [VIRTIO_SND_CHMAP_FL] = SNDRV_CHMAP_FL,
+ [VIRTIO_SND_CHMAP_FR] = SNDRV_CHMAP_FR,
+ [VIRTIO_SND_CHMAP_RL] = SNDRV_CHMAP_RL,
+ [VIRTIO_SND_CHMAP_RR] = SNDRV_CHMAP_RR,
+ [VIRTIO_SND_CHMAP_FC] = SNDRV_CHMAP_FC,
+ [VIRTIO_SND_CHMAP_LFE] = SNDRV_CHMAP_LFE,
+ [VIRTIO_SND_CHMAP_SL] = SNDRV_CHMAP_SL,
+ [VIRTIO_SND_CHMAP_SR] = SNDRV_CHMAP_SR,
+ [VIRTIO_SND_CHMAP_RC] = SNDRV_CHMAP_RC,
+ [VIRTIO_SND_CHMAP_FLC] = SNDRV_CHMAP_FLC,
+ [VIRTIO_SND_CHMAP_FRC] = SNDRV_CHMAP_FRC,
+ [VIRTIO_SND_CHMAP_RLC] = SNDRV_CHMAP_RLC,
+ [VIRTIO_SND_CHMAP_RRC] = SNDRV_CHMAP_RRC,
+ [VIRTIO_SND_CHMAP_FLW] = SNDRV_CHMAP_FLW,
+ [VIRTIO_SND_CHMAP_FRW] = SNDRV_CHMAP_FRW,
+ [VIRTIO_SND_CHMAP_FLH] = SNDRV_CHMAP_FLH,
+ [VIRTIO_SND_CHMAP_FCH] = SNDRV_CHMAP_FCH,
+ [VIRTIO_SND_CHMAP_FRH] = SNDRV_CHMAP_FRH,
+ [VIRTIO_SND_CHMAP_TC] = SNDRV_CHMAP_TC,
+ [VIRTIO_SND_CHMAP_TFL] = SNDRV_CHMAP_TFL,
+ [VIRTIO_SND_CHMAP_TFR] = SNDRV_CHMAP_TFR,
+ [VIRTIO_SND_CHMAP_TFC] = SNDRV_CHMAP_TFC,
+ [VIRTIO_SND_CHMAP_TRL] = SNDRV_CHMAP_TRL,
+ [VIRTIO_SND_CHMAP_TRR] = SNDRV_CHMAP_TRR,
+ [VIRTIO_SND_CHMAP_TRC] = SNDRV_CHMAP_TRC,
+ [VIRTIO_SND_CHMAP_TFLC] = SNDRV_CHMAP_TFLC,
+ [VIRTIO_SND_CHMAP_TFRC] = SNDRV_CHMAP_TFRC,
+ [VIRTIO_SND_CHMAP_TSL] = SNDRV_CHMAP_TSL,
+ [VIRTIO_SND_CHMAP_TSR] = SNDRV_CHMAP_TSR,
+ [VIRTIO_SND_CHMAP_LLFE] = SNDRV_CHMAP_LLFE,
+ [VIRTIO_SND_CHMAP_RLFE] = SNDRV_CHMAP_RLFE,
+ [VIRTIO_SND_CHMAP_BC] = SNDRV_CHMAP_BC,
+ [VIRTIO_SND_CHMAP_BLC] = SNDRV_CHMAP_BLC,
+ [VIRTIO_SND_CHMAP_BRC] = SNDRV_CHMAP_BRC
+};
+
+/**
+ * virtsnd_chmap_parse_cfg() - Parse the channel map configuration.
+ * @snd: VirtIO sound device.
+ *
+ * This function is called during initial device initialization.
+ *
+ * Context: Any context that permits to sleep.
+ * Return: 0 on success, -errno on failure.
+ */
+int virtsnd_chmap_parse_cfg(struct virtio_snd *snd)
+{
+ struct virtio_device *vdev = snd->vdev;
+ u32 i;
+ int rc;
+
+ virtio_cread_le(vdev, struct virtio_snd_config, chmaps, &snd->nchmaps);
+ if (!snd->nchmaps)
+ return 0;
+
+ snd->chmaps = devm_kcalloc(&vdev->dev, snd->nchmaps,
+ sizeof(*snd->chmaps), GFP_KERNEL);
+ if (!snd->chmaps)
+ return -ENOMEM;
+
+ rc = virtsnd_ctl_query_info(snd, VIRTIO_SND_R_CHMAP_INFO, 0,
+ snd->nchmaps, sizeof(*snd->chmaps),
+ snd->chmaps);
+ if (rc)
+ return rc;
+
+ /* Count the number of channel maps per each PCM device/stream. */
+ for (i = 0; i < snd->nchmaps; ++i) {
+ struct virtio_snd_chmap_info *info = &snd->chmaps[i];
+ u32 nid = le32_to_cpu(info->hdr.hda_fn_nid);
+ struct virtio_pcm *vpcm;
+ struct virtio_pcm_stream *vs;
+
+ vpcm = virtsnd_pcm_find_or_create(snd, nid);
+ if (IS_ERR(vpcm))
+ return PTR_ERR(vpcm);
+
+ switch (info->direction) {
+ case VIRTIO_SND_D_OUTPUT:
+ vs = &vpcm->streams[SNDRV_PCM_STREAM_PLAYBACK];
+ break;
+ case VIRTIO_SND_D_INPUT:
+ vs = &vpcm->streams[SNDRV_PCM_STREAM_CAPTURE];
+ break;
+ default:
+ dev_err(&vdev->dev,
+ "chmap #%u: unknown direction (%u)\n", i,
+ info->direction);
+ return -EINVAL;
+ }
+
+ vs->nchmaps++;
+ }
+
+ return 0;
+}
+
+/**
+ * virtsnd_chmap_add_ctls() - Create an ALSA control for channel maps.
+ * @pcm: ALSA PCM device.
+ * @direction: PCM stream direction (SNDRV_PCM_STREAM_XXX).
+ * @vs: VirtIO PCM stream.
+ *
+ * Context: Any context.
+ * Return: 0 on success, -errno on failure.
+ */
+static int virtsnd_chmap_add_ctls(struct snd_pcm *pcm, int direction,
+ struct virtio_pcm_stream *vs)
+{
+ u32 i;
+ int max_channels = 0;
+
+ for (i = 0; i < vs->nchmaps; i++)
+ if (max_channels < vs->chmaps[i].channels)
+ max_channels = vs->chmaps[i].channels;
+
+ return snd_pcm_add_chmap_ctls(pcm, direction, vs->chmaps, max_channels,
+ 0, NULL);
+}
+
+/**
+ * virtsnd_chmap_build_devs() - Build ALSA controls for channel maps.
+ * @snd: VirtIO sound device.
+ *
+ * Context: Any context.
+ * Return: 0 on success, -errno on failure.
+ */
+int virtsnd_chmap_build_devs(struct virtio_snd *snd)
+{
+ struct virtio_device *vdev = snd->vdev;
+ struct virtio_pcm *vpcm;
+ struct virtio_pcm_stream *vs;
+ u32 i;
+ int rc;
+
+ /* Allocate channel map elements per each PCM device/stream. */
+ list_for_each_entry(vpcm, &snd->pcm_list, list) {
+ for (i = 0; i < ARRAY_SIZE(vpcm->streams); ++i) {
+ vs = &vpcm->streams[i];
+
+ if (!vs->nchmaps)
+ continue;
+
+ vs->chmaps = devm_kcalloc(&vdev->dev, vs->nchmaps + 1,
+ sizeof(*vs->chmaps),
+ GFP_KERNEL);
+ if (!vs->chmaps)
+ return -ENOMEM;
+
+ vs->nchmaps = 0;
+ }
+ }
+
+ /* Initialize channel maps per each PCM device/stream. */
+ for (i = 0; i < snd->nchmaps; ++i) {
+ struct virtio_snd_chmap_info *info = &snd->chmaps[i];
+ unsigned int channels = info->channels;
+ unsigned int ch;
+ struct snd_pcm_chmap_elem *chmap;
+
+ vpcm = virtsnd_pcm_find(snd, le32_to_cpu(info->hdr.hda_fn_nid));
+ if (IS_ERR(vpcm))
+ return PTR_ERR(vpcm);
+
+ if (info->direction == VIRTIO_SND_D_OUTPUT)
+ vs = &vpcm->streams[SNDRV_PCM_STREAM_PLAYBACK];
+ else
+ vs = &vpcm->streams[SNDRV_PCM_STREAM_CAPTURE];
+
+ chmap = &vs->chmaps[vs->nchmaps++];
+
+ if (channels > ARRAY_SIZE(chmap->map))
+ channels = ARRAY_SIZE(chmap->map);
+
+ chmap->channels = channels;
+
+ for (ch = 0; ch < channels; ++ch) {
+ u8 position = info->positions[ch];
+
+ if (position >= ARRAY_SIZE(g_v2a_position_map))
+ return -EINVAL;
+
+ chmap->map[ch] = g_v2a_position_map[position];
+ }
+ }
+
+ /* Create an ALSA control per each PCM device/stream. */
+ list_for_each_entry(vpcm, &snd->pcm_list, list) {
+ if (!vpcm->pcm)
+ continue;
+
+ for (i = 0; i < ARRAY_SIZE(vpcm->streams); ++i) {
+ vs = &vpcm->streams[i];
+
+ if (!vs->nchmaps)
+ continue;
+
+ rc = virtsnd_chmap_add_ctls(vpcm->pcm, i, vs);
+ if (rc)
+ return rc;
+ }
+ }
+
+ return 0;
+}
