1 files changed, 327 insertions, 0 deletions

diff --git a/sound/usb/media.c b/sound/usb/media.c
new file mode 100644
index 0000000000..d48db6f3ae
--- /dev/null
+++ b/sound/usb/media.c
@@ -0,0 +1,327 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * media.c - Media Controller specific ALSA driver code
+ *
+ * Copyright (c) 2019 Shuah Khan <shuah@kernel.org>
+ *
+ */
+
+/*
+ * This file adds Media Controller support to the ALSA driver
+ * to use the Media Controller API to share the tuner with DVB
+ * and V4L2 drivers that control the media device.
+ *
+ * The media device is created based on the existing quirks framework.
+ * Using this approach, the media controller API usage can be added for
+ * a specific device.
+ */
+
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <linux/usb.h>
+
+#include <sound/pcm.h>
+#include <sound/core.h>
+
+#include "usbaudio.h"
+#include "card.h"
+#include "mixer.h"
+#include "media.h"
+
+int snd_media_stream_init(struct snd_usb_substream *subs, struct snd_pcm *pcm,
+			  int stream)
+{
+	struct media_device *mdev;
+	struct media_ctl *mctl;
+	struct device *pcm_dev = pcm->streams[stream].dev;
+	u32 intf_type;
+	int ret = 0;
+	u16 mixer_pad;
+	struct media_entity *entity;
+
+	mdev = subs->stream->chip->media_dev;
+	if (!mdev)
+		return 0;
+
+	if (subs->media_ctl)
+		return 0;
+
+	/* allocate media_ctl */
+	mctl = kzalloc(sizeof(*mctl), GFP_KERNEL);
+	if (!mctl)
+		return -ENOMEM;
+
+	mctl->media_dev = mdev;
+	if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		intf_type = MEDIA_INTF_T_ALSA_PCM_PLAYBACK;
+		mctl->media_entity.function = MEDIA_ENT_F_AUDIO_PLAYBACK;
+		mctl->media_pad.flags = MEDIA_PAD_FL_SOURCE;
+		mixer_pad = 1;
+	} else {
+		intf_type = MEDIA_INTF_T_ALSA_PCM_CAPTURE;
+		mctl->media_entity.function = MEDIA_ENT_F_AUDIO_CAPTURE;
+		mctl->media_pad.flags = MEDIA_PAD_FL_SINK;
+		mixer_pad = 2;
+	}
+	mctl->media_entity.name = pcm->name;
+	media_entity_pads_init(&mctl->media_entity, 1, &mctl->media_pad);
+	ret =  media_device_register_entity(mctl->media_dev,
+					    &mctl->media_entity);
+	if (ret)
+		goto free_mctl;
+
+	mctl->intf_devnode = media_devnode_create(mdev, intf_type, 0,
+						  MAJOR(pcm_dev->devt),
+						  MINOR(pcm_dev->devt));
+	if (!mctl->intf_devnode) {
+		ret = -ENOMEM;
+		goto unregister_entity;
+	}
+	mctl->intf_link = media_create_intf_link(&mctl->media_entity,
+						 &mctl->intf_devnode->intf,
+						 MEDIA_LNK_FL_ENABLED);
+	if (!mctl->intf_link) {
+		ret = -ENOMEM;
+		goto devnode_remove;
+	}
+
+	/* create link between mixer and audio */
+	media_device_for_each_entity(entity, mdev) {
+		switch (entity->function) {
+		case MEDIA_ENT_F_AUDIO_MIXER:
+			ret = media_create_pad_link(entity, mixer_pad,
+						    &mctl->media_entity, 0,
+						    MEDIA_LNK_FL_ENABLED);
+			if (ret)
+				goto remove_intf_link;
+			break;
+		}
+	}
+
+	subs->media_ctl = mctl;
+	return 0;
+
+remove_intf_link:
+	media_remove_intf_link(mctl->intf_link);
+devnode_remove:
+	media_devnode_remove(mctl->intf_devnode);
+unregister_entity:
+	media_device_unregister_entity(&mctl->media_entity);
+free_mctl:
+	kfree(mctl);
+	return ret;
+}
+
+void snd_media_stream_delete(struct snd_usb_substream *subs)
+{
+	struct media_ctl *mctl = subs->media_ctl;
+
+	if (mctl) {
+		struct media_device *mdev;
+
+		mdev = mctl->media_dev;
+		if (mdev && media_devnode_is_registered(mdev->devnode)) {
+			media_devnode_remove(mctl->intf_devnode);
+			media_device_unregister_entity(&mctl->media_entity);
+			media_entity_cleanup(&mctl->media_entity);
+		}
+		kfree(mctl);
+		subs->media_ctl = NULL;
+	}
+}
+
+int snd_media_start_pipeline(struct snd_usb_substream *subs)
+{
+	struct media_ctl *mctl = subs->media_ctl;
+	int ret = 0;
+
+	if (!mctl)
+		return 0;
+
+	mutex_lock(&mctl->media_dev->graph_mutex);
+	if (mctl->media_dev->enable_source)
+		ret = mctl->media_dev->enable_source(&mctl->media_entity,
+						     &mctl->media_pipe);
+	mutex_unlock(&mctl->media_dev->graph_mutex);
+	return ret;
+}
+
+void snd_media_stop_pipeline(struct snd_usb_substream *subs)
+{
+	struct media_ctl *mctl = subs->media_ctl;
+
+	if (!mctl)
+		return;
+
+	mutex_lock(&mctl->media_dev->graph_mutex);
+	if (mctl->media_dev->disable_source)
+		mctl->media_dev->disable_source(&mctl->media_entity);
+	mutex_unlock(&mctl->media_dev->graph_mutex);
+}
+
+static int snd_media_mixer_init(struct snd_usb_audio *chip)
+{
+	struct device *ctl_dev = chip->card->ctl_dev;
+	struct media_intf_devnode *ctl_intf;
+	struct usb_mixer_interface *mixer;
+	struct media_device *mdev = chip->media_dev;
+	struct media_mixer_ctl *mctl;
+	u32 intf_type = MEDIA_INTF_T_ALSA_CONTROL;
+	int ret;
+
+	if (!mdev)
+		return -ENODEV;
+
+	ctl_intf = chip->ctl_intf_media_devnode;
+	if (!ctl_intf) {
+		ctl_intf = media_devnode_create(mdev, intf_type, 0,
+						MAJOR(ctl_dev->devt),
+						MINOR(ctl_dev->devt));
+		if (!ctl_intf)
+			return -ENOMEM;
+		chip->ctl_intf_media_devnode = ctl_intf;
+	}
+
+	list_for_each_entry(mixer, &chip->mixer_list, list) {
+
+		if (mixer->media_mixer_ctl)
+			continue;
+
+		/* allocate media_mixer_ctl */
+		mctl = kzalloc(sizeof(*mctl), GFP_KERNEL);
+		if (!mctl)
+			return -ENOMEM;
+
+		mctl->media_dev = mdev;
+		mctl->media_entity.function = MEDIA_ENT_F_AUDIO_MIXER;
+		mctl->media_entity.name = chip->card->mixername;
+		mctl->media_pad[0].flags = MEDIA_PAD_FL_SINK;
+		mctl->media_pad[1].flags = MEDIA_PAD_FL_SOURCE;
+		mctl->media_pad[2].flags = MEDIA_PAD_FL_SOURCE;
+		media_entity_pads_init(&mctl->media_entity, MEDIA_MIXER_PAD_MAX,
+				  mctl->media_pad);
+		ret =  media_device_register_entity(mctl->media_dev,
+						    &mctl->media_entity);
+		if (ret) {
+			kfree(mctl);
+			return ret;
+		}
+
+		mctl->intf_link = media_create_intf_link(&mctl->media_entity,
+							 &ctl_intf->intf,
+							 MEDIA_LNK_FL_ENABLED);
+		if (!mctl->intf_link) {
+			media_device_unregister_entity(&mctl->media_entity);
+			media_entity_cleanup(&mctl->media_entity);
+			kfree(mctl);
+			return -ENOMEM;
+		}
+		mctl->intf_devnode = ctl_intf;
+		mixer->media_mixer_ctl = mctl;
+	}
+	return 0;
+}
+
+static void snd_media_mixer_delete(struct snd_usb_audio *chip)
+{
+	struct usb_mixer_interface *mixer;
+	struct media_device *mdev = chip->media_dev;
+
+	if (!mdev)
+		return;
+
+	list_for_each_entry(mixer, &chip->mixer_list, list) {
+		struct media_mixer_ctl *mctl;
+
+		mctl = mixer->media_mixer_ctl;
+		if (!mixer->media_mixer_ctl)
+			continue;
+
+		if (media_devnode_is_registered(mdev->devnode)) {
+			media_device_unregister_entity(&mctl->media_entity);
+			media_entity_cleanup(&mctl->media_entity);
+		}
+		kfree(mctl);
+		mixer->media_mixer_ctl = NULL;
+	}
+	if (media_devnode_is_registered(mdev->devnode))
+		media_devnode_remove(chip->ctl_intf_media_devnode);
+	chip->ctl_intf_media_devnode = NULL;
+}
+
+int snd_media_device_create(struct snd_usb_audio *chip,
+			struct usb_interface *iface)
+{
+	struct media_device *mdev;
+	struct usb_device *usbdev = interface_to_usbdev(iface);
+	int ret = 0;
+
+	/* usb-audio driver is probed for each usb interface, and
+	 * there are multiple interfaces per device. Avoid calling
+	 * media_device_usb_allocate() each time usb_audio_probe()
+	 * is called. Do it only once.
+	 */
+	if (chip->media_dev) {
+		mdev = chip->media_dev;
+		goto snd_mixer_init;
+	}
+
+	mdev = media_device_usb_allocate(usbdev, KBUILD_MODNAME, THIS_MODULE);
+	if (IS_ERR(mdev))
+		return -ENOMEM;
+
+	/* save media device - avoid lookups */
+	chip->media_dev = mdev;
+
+snd_mixer_init:
+	/* Create media entities for mixer and control dev */
+	ret = snd_media_mixer_init(chip);
+	/* media_device might be registered, print error and continue */
+	if (ret)
+		dev_err(&usbdev->dev,
+			"Couldn't create media mixer entities. Error: %d\n",
+			ret);
+
+	if (!media_devnode_is_registered(mdev->devnode)) {
+		/* don't register if snd_media_mixer_init() failed */
+		if (ret)
+			goto create_fail;
+
+		/* register media_device */
+		ret = media_device_register(mdev);
+create_fail:
+		if (ret) {
+			snd_media_mixer_delete(chip);
+			media_device_delete(mdev, KBUILD_MODNAME, THIS_MODULE);
+			/* clear saved media_dev */
+			chip->media_dev = NULL;
+			dev_err(&usbdev->dev,
+				"Couldn't register media device. Error: %d\n",
+				ret);
+			return ret;
+		}
+	}
+
+	return ret;
+}
+
+void snd_media_device_delete(struct snd_usb_audio *chip)
+{
+	struct media_device *mdev = chip->media_dev;
+	struct snd_usb_stream *stream;
+
+	/* release resources */
+	list_for_each_entry(stream, &chip->pcm_list, list) {
+		snd_media_stream_delete(&stream->substream[0]);
+		snd_media_stream_delete(&stream->substream[1]);
+	}
+
+	snd_media_mixer_delete(chip);
+
+	if (mdev) {
+		media_device_delete(mdev, KBUILD_MODNAME, THIS_MODULE);
+		chip->media_dev = NULL;
+	}
+}