ALSA: virtio: build PCM devices and substream hardware descriptors

Like the HDA specification, the virtio sound device specification links PCM substreams, jacks and PCM channel maps into functional groups. For each discovered group, a PCM device is created, the number of which coincides with the group number. Introduce the module parameters for setting the hardware buffer parameters: pcm_buffer_ms [=160] pcm_periods_min [=2] pcm_periods_max [=16] pcm_period_ms_min [=10] pcm_period_ms_max [=80] Signed-off-by: Anton Yakovlev <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Takashi Iwai <[email protected]>
niw · Mar 7, 2021 · 29b96bf · 29b96bf
1 parent 9d45e51
commit 29b96bf
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Showing 5 changed files with 581 additions and 1 deletion.
diff --git a/sound/virtio/Makefile b/sound/virtio/Makefile
@@ -4,5 +4,6 @@ obj-$(CONFIG_SND_VIRTIO) += virtio_snd.o
 
 virtio_snd-objs := \
 	virtio_card.o \
-	virtio_ctl_msg.o
+	virtio_ctl_msg.o \
+	virtio_pcm.o
 
diff --git a/sound/virtio/virtio_card.c b/sound/virtio/virtio_card.c
@@ -209,6 +209,16 @@ static int virtsnd_build_devs(struct virtio_snd *snd)
 			 VIRTIO_SND_CARD_NAME " at %s/%s",
 			 dev_name(dev->parent), dev_name(dev));
 
+	rc = virtsnd_pcm_parse_cfg(snd);
+	if (rc)
+		return rc;
+
+	if (snd->nsubstreams) {
+		rc = virtsnd_pcm_build_devs(snd);
+		if (rc)
+			return rc;
+	}
+
 	return snd_card_register(snd->card);
 }
 
@@ -237,6 +247,9 @@ static int virtsnd_validate(struct virtio_device *vdev)
 		return -EINVAL;
 	}
 
+	if (virtsnd_pcm_validate(vdev))
+		return -EINVAL;
+
 	return 0;
 }
 
@@ -259,6 +272,7 @@ static int virtsnd_probe(struct virtio_device *vdev)
 
 	snd->vdev = vdev;
 	INIT_LIST_HEAD(&snd->ctl_msgs);
+	INIT_LIST_HEAD(&snd->pcm_list);
 
 	vdev->priv = snd;
 
@@ -293,6 +307,7 @@ static int virtsnd_probe(struct virtio_device *vdev)
 static void virtsnd_remove(struct virtio_device *vdev)
 {
 	struct virtio_snd *snd = vdev->priv;
+	unsigned int i;
 
 	virtsnd_disable_event_vq(snd);
 	virtsnd_ctl_msg_cancel_all(snd);
@@ -303,6 +318,9 @@ static void virtsnd_remove(struct virtio_device *vdev)
 	vdev->config->del_vqs(vdev);
 	vdev->config->reset(vdev);
 
+	for (i = 0; snd->substreams && i < snd->nsubstreams; ++i)
+		cancel_work_sync(&snd->substreams[i].elapsed_period);
+
 	kfree(snd->event_msgs);
 }
 

diff --git a/sound/virtio/virtio_card.h b/sound/virtio/virtio_card.h
@@ -12,9 +12,13 @@
 #include <uapi/linux/virtio_snd.h>
 
 #include "virtio_ctl_msg.h"
+#include "virtio_pcm.h"
 
 #define VIRTIO_SND_CARD_DRIVER	"virtio-snd"
 #define VIRTIO_SND_CARD_NAME	"VirtIO SoundCard"
+#define VIRTIO_SND_PCM_NAME	"VirtIO PCM"
+
+struct virtio_pcm_substream;
 
 /**
  * struct virtio_snd_queue - Virtqueue wrapper structure.
@@ -33,13 +37,19 @@ struct virtio_snd_queue {
  * @card: ALSA sound card.
  * @ctl_msgs: Pending control request list.
  * @event_msgs: Device events.
+ * @pcm_list: VirtIO PCM device list.
+ * @substreams: VirtIO PCM substreams.
+ * @nsubstreams: Number of PCM substreams.
  */
 struct virtio_snd {
 	struct virtio_device *vdev;
 	struct virtio_snd_queue queues[VIRTIO_SND_VQ_MAX];
 	struct snd_card *card;
 	struct list_head ctl_msgs;
 	struct virtio_snd_event *event_msgs;
+	struct list_head pcm_list;
+	struct virtio_pcm_substream *substreams;
+	u32 nsubstreams;
 };
 
 /* Message completion timeout in milliseconds (module parameter). */