LinuxLists.cc - [PATCH v7 0/3] Media Device Allocator API

2016-12-07 01:20:09

Subject: [PATCH v7 0/3] Media Device Allocator API

2016-12-07 01:20:13

Subject: [PATCH v7 1/3] media: Media Device Allocator API

Media Device Allocator API to allows multiple drivers share a media device.
Using this API, drivers can allocate a media device with the shared struct
device as the key. Once the media device is allocated by a driver, other
drivers can get a reference to it. The media device is released when all
the references are released.

Signed-off-by: Shuah Khan <[email protected]>
---
No changes since v6

Documentation/media/kapi/mc-core.rst | 37 ++++++++++
drivers/media/Makefile | 3 +-
drivers/media/media-dev-allocator.c | 133 +++++++++++++++++++++++++++++++++++
include/media/media-dev-allocator.h | 54 ++++++++++++++
4 files changed, 226 insertions(+), 1 deletion(-)
create mode 100644 drivers/media/media-dev-allocator.c
create mode 100644 include/media/media-dev-allocator.h

diff --git a/Documentation/media/kapi/mc-core.rst b/Documentation/media/kapi/mc-core.rst
index 1a738e5..4942cdd 100644
--- a/Documentation/media/kapi/mc-core.rst
+++ b/Documentation/media/kapi/mc-core.rst
@@ -257,8 +257,45 @@ Subsystems should facilitate link validation by providing subsystem specific
helper functions to provide easy access for commonly needed information, and
in the end provide a way to use driver-specific callbacks.

+Media Controller Device Allocator API
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+When media device belongs to more than one driver, the shared media device
+is allocated with the shared struct device as the key for look ups.
+
+Shared media device should stay in registered state until the last driver
+unregisters it. In addition, media device should be released when all the
+references are released. Each driver gets a reference to the media device
+during probe, when it allocates the media device. If media device is already
+allocated, allocate API bumps up the refcount and return the existing media
+device. Driver puts the reference back from its disconnect routine when it
+calls :c:func:`media_device_delete()`.
+
+Media device is unregistered and cleaned up from the kref put handler to
+ensure that the media device stays in registered state until the last driver
+unregisters the media device.
+
+**Driver Usage**
+
+Drivers should use the media-core routines to get register reference and
+call :c:func:`media_device_delete()` routine to make sure the shared media
+device delete is handled correctly.
+
+**driver probe:**
+Call :c:func:`media_device_usb_allocate()` to allocate or get a reference
+Call :c:func:`media_device_register()`, if media devnode isn't registered
+
+**driver disconnect:**
+Call :c:func:`media_device_delete()` to free the media_device. Free'ing is
+handled by the kref put handler.
+
+API Definitions
+^^^^^^^^^^^^^^^
+
.. kernel-doc:: include/media/media-device.h

.. kernel-doc:: include/media/media-devnode.h

.. kernel-doc:: include/media/media-entity.h
+
+.. kernel-doc:: include/media/media-dev-allocator.h
diff --git a/drivers/media/Makefile b/drivers/media/Makefile
index 0deaa93..7c0701d 100644
--- a/drivers/media/Makefile
+++ b/drivers/media/Makefile
@@ -6,7 +6,8 @@ ifeq ($(CONFIG_MEDIA_CEC_EDID),y)
obj-$(CONFIG_MEDIA_SUPPORT) += cec-edid.o
endif

-media-objs := media-device.o media-devnode.o media-entity.o
+media-objs := media-device.o media-devnode.o media-entity.o \
+ media-dev-allocator.o

#
# I2C drivers should come before other drivers, otherwise they'll fail
diff --git a/drivers/media/media-dev-allocator.c b/drivers/media/media-dev-allocator.c
new file mode 100644
index 0000000..0ecf152
--- /dev/null
+++ b/drivers/media/media-dev-allocator.c
@@ -0,0 +1,133 @@
+/*
+ * media-dev-allocator.c - Media Controller Device Allocator API
+ *
+ * Copyright (c) 2016 Shuah Khan <[email protected]>
+ * Copyright (c) 2016 Samsung Electronics Co., Ltd.
+ *
+ * This file is released under the GPLv2.
+ * Credits: Suggested by Laurent Pinchart <[email protected]>
+ */
+
+/*
+ * This file adds a global refcounted Media Controller Device Instance API.
+ * A system wide global media device list is managed and each media device
+ * includes a kref count. The last put on the media device releases the media
+ * device instance.
+ *
+ */
+
+#include <linux/kref.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/usb.h>
+
+#include <media/media-device.h>
+
+static LIST_HEAD(media_device_list);
+static DEFINE_MUTEX(media_device_lock);
+
+struct media_device_instance {
+ struct media_device mdev;
+ struct module *owner;
+ struct list_head list;
+ struct kref refcount;
+};
+
+static inline struct media_device_instance *
+to_media_device_instance(struct media_device *mdev)
+{
+ return container_of(mdev, struct media_device_instance, mdev);
+}
+
+static void media_device_instance_release(struct kref *kref)
+{
+ struct media_device_instance *mdi =
+ container_of(kref, struct media_device_instance, refcount);
+
+ dev_dbg(mdi->mdev.dev, "%s: mdev=%p\n", __func__, &mdi->mdev);
+
+ mutex_lock(&media_device_lock);
+
+ media_device_unregister(&mdi->mdev);
+ media_device_cleanup(&mdi->mdev);
+
+ list_del(&mdi->list);
+ mutex_unlock(&media_device_lock);
+
+ kfree(mdi);
+}
+
+/* Callers should hold media_device_lock when calling this function */
+static struct media_device *__media_device_get(struct device *dev,
+ char *module_name)
+{
+ struct media_device_instance *mdi;
+
+ list_for_each_entry(mdi, &media_device_list, list) {
+ if (mdi->mdev.dev != dev)
+ continue;
+
+ kref_get(&mdi->refcount);
+ /* get module reference for the media_device owner */
+ if (find_module(module_name) != mdi->owner &&
+ !try_module_get(mdi->owner))
+ dev_err(dev, "%s: try_module_get() error\n", __func__);
+ dev_dbg(dev, "%s: get mdev=%p module_name %s\n",
+ __func__, &mdi->mdev, module_name);
+ return &mdi->mdev;
+ }
+
+ mdi = kzalloc(sizeof(*mdi), GFP_KERNEL);
+ if (!mdi)
+ return NULL;
+
+ mdi->owner = find_module(module_name);
+ kref_init(&mdi->refcount);
+ list_add_tail(&mdi->list, &media_device_list);
+
+ dev_dbg(dev, "%s: alloc mdev=%p module_name %s\n", __func__,
+ &mdi->mdev, module_name);
+ return &mdi->mdev;
+}
+
+#if IS_ENABLED(CONFIG_USB)
+struct media_device *media_device_usb_allocate(struct usb_device *udev,
+ char *module_name)
+{
+ struct media_device *mdev;
+
+ mutex_lock(&media_device_lock);
+ mdev = __media_device_get(&udev->dev, module_name);
+ if (!mdev) {
+ mutex_unlock(&media_device_lock);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ /* check if media device is already initialized */
+ if (!mdev->dev)
+ __media_device_usb_init(mdev, udev, udev->product,
+ module_name);
+ mutex_unlock(&media_device_lock);
+ return mdev;
+}
+EXPORT_SYMBOL_GPL(media_device_usb_allocate);
+#endif
+
+void media_device_delete(struct media_device *mdev, char *module_name)
+{
+ struct media_device_instance *mdi = to_media_device_instance(mdev);
+
+ dev_dbg(mdi->mdev.dev, "%s: mdev=%p module_name %s\n",
+ __func__, &mdi->mdev, module_name);
+
+ mutex_lock(&media_device_lock);
+ /* put module reference if media_device owner is not THIS_MODULE */
+ if (mdi->owner != find_module(module_name)) {
+ module_put(mdi->owner);
+ dev_dbg(mdi->mdev.dev,
+ "%s decremented owner module reference\n", __func__);
+ }
+ mutex_unlock(&media_device_lock);
+ kref_put(&mdi->refcount, media_device_instance_release);
+}
+EXPORT_SYMBOL_GPL(media_device_delete);
diff --git a/include/media/media-dev-allocator.h b/include/media/media-dev-allocator.h
new file mode 100644
index 0000000..6731d825
--- /dev/null
+++ b/include/media/media-dev-allocator.h
@@ -0,0 +1,54 @@
+/*
+ * media-dev-allocator.h - Media Controller Device Allocator API
+ *
+ * Copyright (c) 2016 Shuah Khan <[email protected]>
+ * Copyright (c) 2016 Samsung Electronics Co., Ltd.
+ *
+ * This file is released under the GPLv2.
+ * Credits: Suggested by Laurent Pinchart <[email protected]>
+ */
+
+/*
+ * This file adds a global ref-counted Media Controller Device Instance API.
+ * A system wide global media device list is managed and each media device
+ * includes a kref count. The last put on the media device releases the media
+ * device instance.
+ */
+
+#ifndef _MEDIA_DEV_ALLOCTOR_H
+#define _MEDIA_DEV_ALLOCTOR_H
+
+struct usb_device;
+
+#ifdef CONFIG_MEDIA_CONTROLLER
+/**
+ * media_device_usb_allocate() - Allocate and return struct &media device
+ *
+ * @udev: struct &usb_device pointer
+ * @module_name: should be filled with %KBUILD_MODNAME
+ *
+ * This interface should be called to allocate a Media Device when multiple
+ * drivers share usb_device and the media device. This interface allocates
+ * &media_device structure and calls media_device_usb_init() to initialize
+ * it.
+ *
+ */
+struct media_device *media_device_usb_allocate(struct usb_device *udev,
+ char *module_name);
+/**
+ * media_device_delete() - Release media device. Calls kref_put().
+ *
+ * @mdev: struct &media_device pointer
+ * @module_name: should be filled with %KBUILD_MODNAME
+ *
+ * This interface should be called to put Media Device Instance kref.
+ */
+void media_device_delete(struct media_device *mdev, char *module_name);
+#else
+static inline struct media_device *media_device_usb_allocate(
+ struct usb_device *udev, char *module_name)
+ { return NULL; }
+static inline void media_device_delete(
+ struct media_device *mdev, char *module_name) { }
+#endif /* CONFIG_MEDIA_CONTROLLER */
+#endif
--
2.7.4

2016-12-07 01:20:24

by Shuah Khan

[permalink] [raw]

Subject: [PATCH v7 3/3] sound/usb: Use Media Controller API to share media resources

Change ALSA driver to use Media Controller API to share media resources
with DVB, and V4L2 drivers on a AU0828 media device.

Media Controller specific initialization is done after sound card is
registered. ALSA creates Media interface and entity function graph
nodes for Control, Mixer, PCM Playback, and PCM Capture devices.

snd_usb_hw_params() will call Media Controller enable source handler
interface to request the media resource. If resource request is granted,
it will release it from snd_usb_hw_free(). If resource is busy, -EBUSY is
returned.

Media specific cleanup is done in usb_audio_disconnect().

Signed-off-by: Shuah Khan <[email protected]>
---
Changes to patch 0003 since v6:
- Addressed Takashi's review comments on patch v6

sound/usb/Kconfig | 4 +
sound/usb/Makefile | 2 +
sound/usb/card.c | 14 +++
sound/usb/card.h | 3 +
sound/usb/media.c | 321 +++++++++++++++++++++++++++++++++++++++++++++++
sound/usb/media.h | 73 +++++++++++
sound/usb/mixer.h | 3 +
sound/usb/pcm.c | 29 ++++-
sound/usb/quirks-table.h | 1 +
sound/usb/stream.c | 2 +
sound/usb/usbaudio.h | 6 +
11 files changed, 453 insertions(+), 5 deletions(-)
create mode 100644 sound/usb/media.c
create mode 100644 sound/usb/media.h

diff --git a/sound/usb/Kconfig b/sound/usb/Kconfig
index a452ad7..d14bf41 100644
--- a/sound/usb/Kconfig
+++ b/sound/usb/Kconfig
@@ -15,6 +15,7 @@ config SND_USB_AUDIO
select SND_RAWMIDI
select SND_PCM
select BITREVERSE
+ select SND_USB_AUDIO_USE_MEDIA_CONTROLLER if MEDIA_CONTROLLER && (MEDIA_SUPPORT=y || MEDIA_SUPPORT=SND_USB_AUDIO)
help
Say Y here to include support for USB audio and USB MIDI
devices.
@@ -22,6 +23,9 @@ config SND_USB_AUDIO
To compile this driver as a module, choose M here: the module
will be called snd-usb-audio.

+config SND_USB_AUDIO_USE_MEDIA_CONTROLLER
+ bool
+
config SND_USB_UA101
tristate "Edirol UA-101/UA-1000 driver"
select SND_PCM
diff --git a/sound/usb/Makefile b/sound/usb/Makefile
index 2d2d122..8dca3c4 100644
--- a/sound/usb/Makefile
+++ b/sound/usb/Makefile
@@ -15,6 +15,8 @@ snd-usb-audio-objs := card.o \
quirks.o \
stream.o

+snd-usb-audio-$(CONFIG_SND_USB_AUDIO_USE_MEDIA_CONTROLLER) += media.o
+
snd-usbmidi-lib-objs := midi.o

# Toplevel Module Dependency
diff --git a/sound/usb/card.c b/sound/usb/card.c
index 2ddc034..570ff00 100644
--- a/sound/usb/card.c
+++ b/sound/usb/card.c
@@ -66,6 +66,7 @@
#include "format.h"
#include "power.h"
#include "stream.h"
+#include "media.h"

MODULE_AUTHOR("Takashi Iwai <[email protected]>");
MODULE_DESCRIPTION("USB Audio");
@@ -616,6 +617,11 @@ static int usb_audio_probe(struct usb_interface *intf,
if (err < 0)
goto __error;

+ if (quirk && quirk->media_device) {
+ /* don't want to fail when media_snd_device_create() fails */
+ media_snd_device_create(chip, intf);
+ }
+
usb_chip[chip->index] = chip;
chip->num_interfaces++;
usb_set_intfdata(intf, chip);
@@ -672,6 +678,14 @@ static void usb_audio_disconnect(struct usb_interface *intf)
list_for_each(p, &chip->midi_list) {
snd_usbmidi_disconnect(p);
}
+ /*
+ * Nice to check quirk && quirk->media_device and
+ * then call media_snd_device_delete(). Don't have
+ * access to quirk here. media_snd_device_delete()
+ * acceses mixer_list
+ */
+ media_snd_device_delete(chip);
+
/* release mixer resources */
list_for_each_entry(mixer, &chip->mixer_list, list) {
snd_usb_mixer_disconnect(mixer);
diff --git a/sound/usb/card.h b/sound/usb/card.h
index 111b0f0..6ef8e88 100644
--- a/sound/usb/card.h
+++ b/sound/usb/card.h
@@ -105,6 +105,8 @@ struct snd_usb_endpoint {
struct list_head list;
};

+struct media_ctl;
+
struct snd_usb_substream {
struct snd_usb_stream *stream;
struct usb_device *dev;
@@ -156,6 +158,7 @@ struct snd_usb_substream {
} dsd_dop;

bool trigger_tstamp_pending_update; /* trigger timestamp being updated from initial estimate */
+ struct media_ctl *media_ctl;
};

struct snd_usb_stream {
diff --git a/sound/usb/media.c b/sound/usb/media.c
new file mode 100644
index 0000000..0a8fc14
--- /dev/null
+++ b/sound/usb/media.c
@@ -0,0 +1,321 @@
+/*
+ * media.c - Media Controller specific ALSA driver code
+ *
+ * Copyright (c) 2016 Shuah Khan <[email protected]>
+ * Copyright (c) 2016 Samsung Electronics Co., Ltd.
+ *
+ * This file is released under the GPLv2.
+ */
+
+/*
+ * This file adds Media Controller support to ALSA driver
+ * to use the Media Controller API to share tuner with DVB
+ * and V4L2 drivers that control media device. Media device
+ * is created based on 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 media_snd_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 media_snd_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 media_snd_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 media_snd_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 media_snd_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 media_snd_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 media_snd_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;
+
+ /* 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)
+ goto snd_mixer_init;
+
+ mdev = media_device_usb_allocate(usbdev, KBUILD_MODNAME);
+ if (!mdev)
+ return -ENOMEM;
+
+ if (!media_devnode_is_registered(mdev->devnode)) {
+ /* register media_device */
+ ret = media_device_register(mdev);
+ if (ret) {
+ media_device_delete(mdev, KBUILD_MODNAME);
+ dev_err(&usbdev->dev,
+ "Couldn't register media device. Error: %d\n",
+ ret);
+ return ret;
+ }
+ }
+
+ /* save media device - avoid lookups */
+ chip->media_dev = mdev;
+
+snd_mixer_init:
+ /* Create media entities for mixer and control dev */
+ ret = media_snd_mixer_init(chip);
+ if (ret) {
+ dev_err(&usbdev->dev,
+ "Couldn't create media mixer entities. Error: %d\n",
+ ret);
+
+ /* clear saved media_dev */
+ chip->media_dev = NULL;
+
+ return ret;
+ }
+ return 0;
+}
+
+void media_snd_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) {
+ media_snd_stream_delete(&stream->substream[0]);
+ media_snd_stream_delete(&stream->substream[1]);
+ }
+
+ media_snd_mixer_delete(chip);
+
+ if (mdev) {
+ media_device_delete(mdev, KBUILD_MODNAME);
+ chip->media_dev = NULL;
+ }
+}
diff --git a/sound/usb/media.h b/sound/usb/media.h
new file mode 100644
index 0000000..d204375
--- /dev/null
+++ b/sound/usb/media.h
@@ -0,0 +1,73 @@
+/*
+ * media.h - Media Controller specific ALSA driver code
+ *
+ * Copyright (c) 2016 Shuah Khan <[email protected]>
+ * Copyright (c) 2016 Samsung Electronics Co., Ltd.
+ *
+ * This file is released under the GPLv2.
+ */
+
+/*
+ * This file adds Media Controller support to ALSA driver
+ * to use the Media Controller API to share tuner with DVB
+ * and V4L2 drivers that control media device. Media device
+ * is created based on existing quirks framework. Using this
+ * approach, the media controller API usage can be added for
+ * a specific device.
+ */
+#ifndef __MEDIA_H
+
+#ifdef CONFIG_SND_USB_AUDIO_USE_MEDIA_CONTROLLER
+
+#include <media/media-device.h>
+#include <media/media-entity.h>
+#include <media/media-dev-allocator.h>
+#include <sound/asound.h>
+
+struct media_ctl {
+ struct media_device *media_dev;
+ struct media_entity media_entity;
+ struct media_intf_devnode *intf_devnode;
+ struct media_link *intf_link;
+ struct media_pad media_pad;
+ struct media_pipeline media_pipe;
+};
+
+/*
+ * One source pad each for SNDRV_PCM_STREAM_CAPTURE and
+ * SNDRV_PCM_STREAM_PLAYBACK. One for sink pad to link
+ * to AUDIO Source
+ */
+#define MEDIA_MIXER_PAD_MAX (SNDRV_PCM_STREAM_LAST + 2)
+
+struct media_mixer_ctl {
+ struct media_device *media_dev;
+ struct media_entity media_entity;
+ struct media_intf_devnode *intf_devnode;
+ struct media_link *intf_link;
+ struct media_pad media_pad[MEDIA_MIXER_PAD_MAX];
+ struct media_pipeline media_pipe;
+};
+
+int media_snd_device_create(struct snd_usb_audio *chip,
+ struct usb_interface *iface);
+void media_snd_device_delete(struct snd_usb_audio *chip);
+int media_snd_stream_init(struct snd_usb_substream *subs, struct snd_pcm *pcm,
+ int stream);
+void media_snd_stream_delete(struct snd_usb_substream *subs);
+int media_snd_start_pipeline(struct snd_usb_substream *subs);
+void media_snd_stop_pipeline(struct snd_usb_substream *subs);
+#else
+static inline int media_snd_device_create(struct snd_usb_audio *chip,
+ struct usb_interface *iface)
+ { return 0; }
+static inline void media_snd_device_delete(struct snd_usb_audio *chip) { }
+static inline int media_snd_stream_init(struct snd_usb_substream *subs,
+ struct snd_pcm *pcm, int stream)
+ { return 0; }
+static inline void media_snd_stream_delete(struct snd_usb_substream *subs) { }
+static inline int media_snd_start_pipeline(struct snd_usb_substream *subs)
+ { return 0; }
+static inline void media_snd_stop_pipeline(struct snd_usb_substream *subs) { }
+#endif
+#endif /* __MEDIA_H */
diff --git a/sound/usb/mixer.h b/sound/usb/mixer.h
index 3417ef3..f378944 100644
--- a/sound/usb/mixer.h
+++ b/sound/usb/mixer.h
@@ -3,6 +3,8 @@

#include <sound/info.h>

+struct media_mixer_ctl;
+
struct usb_mixer_interface {
struct snd_usb_audio *chip;
struct usb_host_interface *hostif;
@@ -22,6 +24,7 @@ struct usb_mixer_interface {
struct urb *rc_urb;
struct usb_ctrlrequest *rc_setup_packet;
u8 rc_buffer[6];
+ struct media_mixer_ctl *media_mixer_ctl;
};

#define MAX_CHANNELS 16 /* max logical channels */
diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c
index 44d178e..2230865 100644
--- a/sound/usb/pcm.c
+++ b/sound/usb/pcm.c
@@ -35,6 +35,7 @@
#include "pcm.h"
#include "clock.h"
#include "power.h"
+#include "media.h"

#define SUBSTREAM_FLAG_DATA_EP_STARTED 0
#define SUBSTREAM_FLAG_SYNC_EP_STARTED 1
@@ -717,10 +718,14 @@ static int snd_usb_hw_params(struct snd_pcm_substream *substream,
struct audioformat *fmt;
int ret;

+ ret = media_snd_start_pipeline(subs);
+ if (ret)
+ return ret;
+
ret = snd_pcm_lib_alloc_vmalloc_buffer(substream,
params_buffer_bytes(hw_params));
if (ret < 0)
- return ret;
+ goto err_ret;

subs->pcm_format = params_format(hw_params);
subs->period_bytes = params_period_bytes(hw_params);
@@ -734,22 +739,27 @@ static int snd_usb_hw_params(struct snd_pcm_substream *substream,
dev_dbg(&subs->dev->dev,
"cannot set format: format = %#x, rate = %d, channels = %d\n",
subs->pcm_format, subs->cur_rate, subs->channels);
- return -EINVAL;
+ ret = -EINVAL;
+ goto err_ret;
}

ret = snd_usb_lock_shutdown(subs->stream->chip);
if (ret < 0)
- return ret;
+ goto err_ret;
ret = set_format(subs, fmt);
snd_usb_unlock_shutdown(subs->stream->chip);
if (ret < 0)
- return ret;
+ goto err_ret;

subs->interface = fmt->iface;
subs->altset_idx = fmt->altset_idx;
subs->need_setup_ep = true;

return 0;
+
+err_ret:
+ media_snd_stop_pipeline(subs);
+ return ret;
}

/*
@@ -761,6 +771,7 @@ static int snd_usb_hw_free(struct snd_pcm_substream *substream)
{
struct snd_usb_substream *subs = substream->runtime->private_data;

+ media_snd_stop_pipeline(subs);
subs->cur_audiofmt = NULL;
subs->cur_rate = 0;
subs->period_bytes = 0;
@@ -1221,6 +1232,7 @@ static int snd_usb_pcm_open(struct snd_pcm_substream *substream, int direction)
struct snd_usb_stream *as = snd_pcm_substream_chip(substream);
struct snd_pcm_runtime *runtime = substream->runtime;
struct snd_usb_substream *subs = &as->substream[direction];
+ int ret;

subs->interface = -1;
subs->altset_idx = 0;
@@ -1234,7 +1246,13 @@ static int snd_usb_pcm_open(struct snd_pcm_substream *substream, int direction)
subs->dsd_dop.channel = 0;
subs->dsd_dop.marker = 1;

- return setup_hw_info(runtime, subs);
+ ret = setup_hw_info(runtime, subs);
+ if (ret == 0) {
+ ret = media_snd_stream_init(subs, as->pcm, direction);
+ if (ret)
+ snd_usb_autosuspend(subs->stream->chip);
+ }
+ return ret;
}

static int snd_usb_pcm_close(struct snd_pcm_substream *substream, int direction)
@@ -1243,6 +1261,7 @@ static int snd_usb_pcm_close(struct snd_pcm_substream *substream, int direction)
struct snd_usb_substream *subs = &as->substream[direction];

stop_endpoints(subs, true);
+ media_snd_stop_pipeline(subs);

if (subs->interface >= 0 &&
!snd_usb_lock_shutdown(subs->stream->chip)) {
diff --git a/sound/usb/quirks-table.h b/sound/usb/quirks-table.h
index 8a59d47..164e249 100644
--- a/sound/usb/quirks-table.h
+++ b/sound/usb/quirks-table.h
@@ -2886,6 +2886,7 @@ YAMAHA_DEVICE(0x7010, "UB99"),
.product_name = pname, \
.ifnum = QUIRK_ANY_INTERFACE, \
.type = QUIRK_AUDIO_ALIGN_TRANSFER, \
+ .media_device = 1, \
} \
}

diff --git a/sound/usb/stream.c b/sound/usb/stream.c
index 8e9548bc..6fe7f21 100644
--- a/sound/usb/stream.c
+++ b/sound/usb/stream.c
@@ -36,6 +36,7 @@
#include "format.h"
#include "clock.h"
#include "stream.h"
+#include "media.h"

/*
* free a substream
@@ -52,6 +53,7 @@ static void free_substream(struct snd_usb_substream *subs)
kfree(fp);
}
kfree(subs->rate_list.list);
+ media_snd_stream_delete(subs);
}

diff --git a/sound/usb/usbaudio.h b/sound/usb/usbaudio.h
index 4d5c89a..89b6853 100644
--- a/sound/usb/usbaudio.h
+++ b/sound/usb/usbaudio.h
@@ -30,6 +30,9 @@
*
*/

+struct media_device;
+struct media_intf_devnode;
+
struct snd_usb_audio {
int index;
struct usb_device *dev;
@@ -61,6 +64,8 @@ struct snd_usb_audio {
bool autoclock; /* from the 'autoclock' module param */

struct usb_host_interface *ctrl_intf; /* the audio control interface */
+ struct media_device *media_dev;
+ struct media_intf_devnode *ctl_intf_media_devnode;
};

#define usb_audio_err(chip, fmt, args...) \
@@ -111,6 +116,7 @@ struct snd_usb_audio_quirk {
const char *product_name;
int16_t ifnum;
uint16_t type;
+ bool media_device;
const void *data;
};

--
2.7.4

2016-12-07 01:20:41

by Shuah Khan

[permalink] [raw]

Subject: [PATCH v7 2/3] media: change au0828 to use Media Device Allocator API

Change au0828 to use Media Device Allocator API to allocate media device
with the parent usb struct device as the key, so it can be shared with the
snd_usb_audio driver.

Signed-off-by: Shuah Khan <[email protected]>
---
No changes since v6

drivers/media/usb/au0828/au0828-core.c | 12 ++++--------
drivers/media/usb/au0828/au0828.h | 1 +
2 files changed, 5 insertions(+), 8 deletions(-)

diff --git a/drivers/media/usb/au0828/au0828-core.c b/drivers/media/usb/au0828/au0828-core.c
index bfd6482..ff1928e 100644
--- a/drivers/media/usb/au0828/au0828-core.c
+++ b/drivers/media/usb/au0828/au0828-core.c
@@ -159,9 +159,7 @@ static void au0828_unregister_media_device(struct au0828_dev *dev)
dev->media_dev->disable_source = NULL;
mutex_unlock(&mdev->graph_mutex);

- media_device_unregister(dev->media_dev);
- media_device_cleanup(dev->media_dev);
- kfree(dev->media_dev);
+ media_device_delete(dev->media_dev, KBUILD_MODNAME);
dev->media_dev = NULL;
#endif
}
@@ -214,14 +212,10 @@ static int au0828_media_device_init(struct au0828_dev *dev,
#ifdef CONFIG_MEDIA_CONTROLLER
struct media_device *mdev;

- mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
+ mdev = media_device_usb_allocate(udev, KBUILD_MODNAME);
if (!mdev)
return -ENOMEM;

- /* check if media device is already initialized */
- if (!mdev->dev)
- media_device_usb_init(mdev, udev, udev->product);
-
dev->media_dev = mdev;
#endif
return 0;
@@ -482,6 +476,8 @@ static int au0828_media_device_register(struct au0828_dev *dev,
/* register media device */
ret = media_device_register(dev->media_dev);
if (ret) {
+ media_device_delete(dev->media_dev, KBUILD_MODNAME);
+ dev->media_dev = NULL;
dev_err(&udev->dev,
"Media Device Register Error: %d\n", ret);
return ret;
diff --git a/drivers/media/usb/au0828/au0828.h b/drivers/media/usb/au0828/au0828.h
index dd7b378..4bf1b0c 100644
--- a/drivers/media/usb/au0828/au0828.h
+++ b/drivers/media/usb/au0828/au0828.h
@@ -35,6 +35,7 @@
#include <media/v4l2-ctrls.h>
#include <media/v4l2-fh.h>
#include <media/media-device.h>
+#include <media/media-dev-allocator.h>

/* DVB */
#include "demux.h"
--
2.7.4