Allow for different platforms to be notified on USB SND connect/disconnect seqeunces. This allows for platform USB SND modules to properly initialize and populate internal structures with references to the USB SND chip device.
Change-Id: I4d67c6cb48b3672d82e7f8f471e0c9121164031f Signed-off-by: Wesley Cheng quic_wcheng@quicinc.com --- sound/usb/card.c | 53 ++++++++++++++++++++++++++++++++++++++++++++++++ sound/usb/card.h | 9 ++++++++ 2 files changed, 62 insertions(+)
diff --git a/sound/usb/card.c b/sound/usb/card.c index 1b2edc0fd2e9..ca4f3bc1b42d 100644 --- a/sound/usb/card.c +++ b/sound/usb/card.c @@ -118,6 +118,42 @@ MODULE_PARM_DESC(skip_validation, "Skip unit descriptor validation (default: no) static DEFINE_MUTEX(register_mutex); static struct snd_usb_audio *usb_chip[SNDRV_CARDS]; static struct usb_driver usb_audio_driver; +static struct snd_usb_platform_ops *platform_ops; + +/* + * Register platform specific operations that will be notified on events + * which occur in USB SND. The platform driver can utilize this path to + * enable features, such as USB audio offloading, which allows for audio data + * to be queued by an audio DSP. + * + * Only one set of platform operations can be registered to USB SND. The + * platform register operation is protected by the register_mutex. + */ +int snd_usb_register_platform_ops(struct snd_usb_platform_ops *ops) +{ + guard(mutex)(®ister_mutex); + if (platform_ops) + return -EEXIST; + + platform_ops = ops; + return 0; +} +EXPORT_SYMBOL_GPL(snd_usb_register_platform_ops); + +/* + * Unregisters the current set of platform operations. This allows for + * a new set to be registered if required. + * + * The platform unregister operation is protected by the register_mutex. + */ +int snd_usb_unregister_platform_ops(void) +{ + guard(mutex)(®ister_mutex); + platform_ops = NULL; + + return 0; +} +EXPORT_SYMBOL_GPL(snd_usb_unregister_platform_ops);
/* * disconnect streams @@ -910,7 +946,11 @@ static int usb_audio_probe(struct usb_interface *intf, chip->num_interfaces++; usb_set_intfdata(intf, chip); atomic_dec(&chip->active); + + if (platform_ops && platform_ops->connect_cb) + platform_ops->connect_cb(chip); mutex_unlock(®ister_mutex); + return 0;
__error: @@ -947,6 +987,9 @@ static void usb_audio_disconnect(struct usb_interface *intf) card = chip->card;
mutex_lock(®ister_mutex); + if (platform_ops && platform_ops->disconnect_cb) + platform_ops->disconnect_cb(chip); + if (atomic_inc_return(&chip->shutdown) == 1) { struct snd_usb_stream *as; struct snd_usb_endpoint *ep; @@ -1090,6 +1133,11 @@ static int usb_audio_suspend(struct usb_interface *intf, pm_message_t message) chip->system_suspend = chip->num_suspended_intf; }
+ mutex_lock(®ister_mutex); + if (platform_ops && platform_ops->suspend_cb) + platform_ops->suspend_cb(intf, message); + mutex_unlock(®ister_mutex); + return 0; }
@@ -1130,6 +1178,11 @@ static int usb_audio_resume(struct usb_interface *intf)
snd_usb_midi_v2_resume_all(chip);
+ mutex_lock(®ister_mutex); + if (platform_ops && platform_ops->resume_cb) + platform_ops->resume_cb(intf); + mutex_unlock(®ister_mutex); + out: if (chip->num_suspended_intf == chip->system_suspend) { snd_power_change_state(chip->card, SNDRV_CTL_POWER_D0); diff --git a/sound/usb/card.h b/sound/usb/card.h index 6ec95b2edf86..2884912adc96 100644 --- a/sound/usb/card.h +++ b/sound/usb/card.h @@ -207,4 +207,13 @@ struct snd_usb_stream { struct list_head list; };
+struct snd_usb_platform_ops { + void (*connect_cb)(struct snd_usb_audio *chip); + void (*disconnect_cb)(struct snd_usb_audio *chip); + void (*suspend_cb)(struct usb_interface *intf, pm_message_t message); + void (*resume_cb)(struct usb_interface *intf); +}; + +int snd_usb_register_platform_ops(struct snd_usb_platform_ops *ops); +int snd_usb_unregister_platform_ops(void); #endif /* __USBAUDIO_CARD_H */