[alsa-devel] [PATCH MC Next Gen v2 2/3] sound/usb: Create media mixer function and control interface entities
Takashi Iwai
tiwai at suse.de
Thu Oct 22 09:16:25 CEST 2015
On Wed, 21 Oct 2015 01:25:15 +0200,
Shuah Khan wrote:
>
> Add support for creating MEDIA_ENT_F_AUDIO_MIXER entity for
> each mixer and a MEDIA_INTF_T_ALSA_CONTROL control interface
> entity that links to mixer entities. MEDIA_INTF_T_ALSA_CONTROL
> entity corresponds to the control device for the card.
>
> Signed-off-by: Shuah Khan <shuahkh at osg.samsung.com>
> ---
> sound/usb/card.c | 5 +++
> sound/usb/media.c | 89 ++++++++++++++++++++++++++++++++++++++++++++++++++++
> sound/usb/media.h | 20 ++++++++++++
> sound/usb/mixer.h | 1 +
> sound/usb/usbaudio.h | 1 +
> 5 files changed, 116 insertions(+)
>
> diff --git a/sound/usb/card.c b/sound/usb/card.c
> index 469d2bf..d004cb4 100644
> --- a/sound/usb/card.c
> +++ b/sound/usb/card.c
> @@ -560,6 +560,9 @@ static int usb_audio_probe(struct usb_interface *intf,
> if (err < 0)
> goto __error;
>
> + /* Create media entities for mixer and control dev */
> + media_mixer_init(chip);
> +
> usb_chip[chip->index] = chip;
> chip->num_interfaces++;
> chip->probing = 0;
> @@ -616,6 +619,8 @@ static void usb_audio_disconnect(struct usb_interface *intf)
> list_for_each(p, &chip->midi_list) {
> snd_usbmidi_disconnect(p);
> }
> + /* delete mixer media resources */
> + media_mixer_delete(chip);
> /* release mixer resources */
> list_for_each_entry(mixer, &chip->mixer_list, list) {
> snd_usb_mixer_disconnect(mixer);
> diff --git a/sound/usb/media.c b/sound/usb/media.c
> index 0cbfee6..a26ea8b 100644
> --- a/sound/usb/media.c
> +++ b/sound/usb/media.c
> @@ -199,4 +199,93 @@ void media_stop_pipeline(struct snd_usb_substream *subs)
> if (mctl)
> media_disable_source(mctl);
> }
> +
> +int 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;
> + struct media_mixer_ctl *mctl;
> + u32 intf_type = MEDIA_INTF_T_ALSA_CONTROL;
> + int ret;
> +
> + mdev = media_device_find_devres(&chip->dev->dev);
> + if (!mdev)
> + return -ENODEV;
> +
> + ctl_intf = (struct media_intf_devnode *) chip->ctl_intf_media_devnode;
Why do we need cast? Can't chip->ctl_intf_media_devnode itself be
struct media_intf_devndoe pointer?
> + if (!ctl_intf) {
> + ctl_intf = (void *) media_devnode_create(mdev,
> + intf_type, 0,
> + MAJOR(ctl_dev->devt),
> + MINOR(ctl_dev->devt));
> + if (!ctl_intf)
> + return -ENOMEM;
> + }
Is chip->ctl_intf_media_devnode assigned anywhere at all?
Not directly related with this patchset: the above uses
media_devnode_create(), which I assume it's a device-file
(major:minor) specific. What if sound hardware with multiple codecs
and so on in general?
> +
> + list_for_each_entry(mixer, &chip->mixer_list, list) {
> +
> + if (mixer->media_mixer_ctl)
> + continue;
> +
> + /* allocate media_ctl */
> + mctl = kzalloc(sizeof(struct media_ctl), GFP_KERNEL);
> + if (!mctl)
> + return -ENOMEM;
> +
> + mixer->media_mixer_ctl = (void *) mctl;
> + 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_init(&mctl->media_entity, MEDIA_MIXER_PAD_MAX,
> + mctl->media_pad);
> + ret = media_device_register_entity(mctl->media_dev,
> + &mctl->media_entity);
> + if (ret)
> + return ret;
Will the last (unfinished) mctl be freed properly in the error path?
> + 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);
> + return -ENOMEM;
Ditto.
> + }
> + mctl->intf_devnode = ctl_intf;
> + }
> + return 0;
> +}
> +
> +void media_mixer_delete(struct snd_usb_audio *chip)
> +{
> + struct usb_mixer_interface *mixer;
> + struct media_device *mdev;
> +
> + mdev = media_device_find_devres(&chip->dev->dev);
> + if (!mdev)
> + return;
> +
> + list_for_each_entry(mixer, &chip->mixer_list, list) {
> + struct media_mixer_ctl *mctl;
> +
> + mctl = (struct media_mixer_ctl *) mixer->media_mixer_ctl;
> + if (!mixer->media_mixer_ctl)
> + continue;
> +
> + media_entity_remove_links(&mctl->media_entity);
> + media_device_unregister_entity(&mctl->media_entity);
> + media_entity_cleanup(&mctl->media_entity);
> + mctl->media_dev = NULL;
> + mctl->intf_devnode = NULL;
> + kfree(mctl);
The previous two NULL are superfluous as we'll free them immediately.
thanks,
Takashi
> + mixer->media_mixer_ctl = NULL;
> + }
> + media_devnode_remove(chip->ctl_intf_media_devnode);
> +}
> +
> #endif
> diff --git a/sound/usb/media.h b/sound/usb/media.h
> index cdcfb80..8268e52 100644
> --- a/sound/usb/media.h
> +++ b/sound/usb/media.h
> @@ -20,6 +20,7 @@
> #ifdef USE_MEDIA_CONTROLLER
> #include <media/media-device.h>
> #include <media/media-entity.h>
> +#include <sound/asound.h>
>
> struct media_ctl {
> struct media_device *media_dev;
> @@ -30,6 +31,21 @@ struct media_ctl {
> 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_device_init(struct snd_usb_audio *chip, struct usb_interface *iface);
> void media_device_delete(struct usb_interface *iface);
> int media_stream_init(struct snd_usb_substream *subs, struct snd_pcm *pcm,
> @@ -37,6 +53,8 @@ int media_stream_init(struct snd_usb_substream *subs, struct snd_pcm *pcm,
> void media_stream_delete(struct snd_usb_substream *subs);
> int media_start_pipeline(struct snd_usb_substream *subs);
> void media_stop_pipeline(struct snd_usb_substream *subs);
> +int media_mixer_init(struct snd_usb_audio *chip);
> +void media_mixer_delete(struct snd_usb_audio *chip);
> #else
> static inline int media_device_init(struct snd_usb_audio *chip,
> struct usb_interface *iface)
> @@ -49,5 +67,7 @@ static inline void media_stream_delete(struct snd_usb_substream *subs) { }
> static inline int media_start_pipeline(struct snd_usb_substream *subs)
> { return 0; }
> static inline void media_stop_pipeline(struct snd_usb_substream *subs) { }
> +static int media_mixer_init(struct snd_usb_audio *chip) { return 0; }
> +static void media_mixer_delete(struct snd_usb_audio *chip) { }
> #endif
> #endif /* __MEDIA_H */
> diff --git a/sound/usb/mixer.h b/sound/usb/mixer.h
> index d3268f0..9d62a9e 100644
> --- a/sound/usb/mixer.h
> +++ b/sound/usb/mixer.h
> @@ -22,6 +22,7 @@ struct usb_mixer_interface {
> struct urb *rc_urb;
> struct usb_ctrlrequest *rc_setup_packet;
> u8 rc_buffer[6];
> + void *media_mixer_ctl;
> };
>
> #define MAX_CHANNELS 16 /* max logical channels */
> diff --git a/sound/usb/usbaudio.h b/sound/usb/usbaudio.h
> index c2dbf1d..b2be7c3 100644
> --- a/sound/usb/usbaudio.h
> +++ b/sound/usb/usbaudio.h
> @@ -59,6 +59,7 @@ struct snd_usb_audio {
> bool autoclock; /* from the 'autoclock' module param */
>
> struct usb_host_interface *ctrl_intf; /* the audio control interface */
> + void *ctl_intf_media_devnode;
> };
>
> #define usb_audio_err(chip, fmt, args...) \
> --
> 2.1.4
>
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