[v4,11/32] sound: usb: card: Introduce USB SND platform op callbacks
Commit Message
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.
Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
---
sound/usb/card.c | 36 ++++++++++++++++++++++++++++++++++++
sound/usb/card.h | 20 ++++++++++++++++++++
2 files changed, 56 insertions(+)
Comments
On Tue, 25 Jul 2023 04:33:55 +0200,
Wesley Cheng wrote:
>
> 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.
>
> Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
> ---
> sound/usb/card.c | 36 ++++++++++++++++++++++++++++++++++++
> sound/usb/card.h | 20 ++++++++++++++++++++
> 2 files changed, 56 insertions(+)
>
> diff --git a/sound/usb/card.c b/sound/usb/card.c
> index f6e99ced8068..9365d1e17836 100644
> --- a/sound/usb/card.c
> +++ b/sound/usb/card.c
> @@ -117,6 +117,30 @@ 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;
> +
> +int snd_usb_register_platform_ops(struct snd_usb_platform_ops *ops)
> +{
> + if (platform_ops)
> + return -EEXIST;
> + mutex_lock(®ister_mutex);
> + platform_ops = ops;
> + mutex_unlock(®ister_mutex);
The check should be inside register_mutex lock, too.
Otherwise it's racy.
> --- a/sound/usb/card.h
> +++ b/sound/usb/card.h
> @@ -207,4 +207,24 @@ 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);
> +};
Don't we need resume_cb? Even if it's unused for your platform, it'd
make sense to be a pair.
> +#if IS_ENABLED(CONFIG_SND_USB_AUDIO)
> +int snd_usb_register_platform_ops(struct snd_usb_platform_ops *ops);
> +int snd_usb_unregister_platform_ops(void);
> +#else
> +static int snd_usb_register_platform_ops(struct snd_usb_platform_ops *ops)
> +{
> + return -EOPNOTSUPP;
> +}
> +
> +static int snd_usb_unregister_platform_ops(void)
> +{
> + return -EOPNOTSUPP;
> +}
> +#endif /* IS_ENABLED(CONFIG_SND_USB_AUDIO) */
Any need for dummy function definitions? I thought those exported
functions are always with CONFIG_SND_USB_AUDIO enabled?
IOW, are they use of those functions without USB audio driver?
thanks,
Takashi
@@ -117,6 +117,30 @@ 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;
+
+int snd_usb_register_platform_ops(struct snd_usb_platform_ops *ops)
+{
+ if (platform_ops)
+ return -EEXIST;
+
+ mutex_lock(®ister_mutex);
+ platform_ops = ops;
+ mutex_unlock(®ister_mutex);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(snd_usb_register_platform_ops);
+
+int snd_usb_unregister_platform_ops(void)
+{
+ mutex_lock(®ister_mutex);
+ platform_ops = NULL;
+ mutex_unlock(®ister_mutex);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(snd_usb_unregister_platform_ops);
/*
* disconnect streams
@@ -908,7 +932,11 @@ 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:
@@ -945,6 +973,9 @@ 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;
@@ -1086,6 +1117,11 @@ 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;
}
@@ -207,4 +207,24 @@ 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);
+};
+
+#if IS_ENABLED(CONFIG_SND_USB_AUDIO)
+int snd_usb_register_platform_ops(struct snd_usb_platform_ops *ops);
+int snd_usb_unregister_platform_ops(void);
+#else
+static int snd_usb_register_platform_ops(struct snd_usb_platform_ops *ops)
+{
+ return -EOPNOTSUPP;
+}
+
+static int snd_usb_unregister_platform_ops(void)
+{
+ return -EOPNOTSUPP;
+}
+#endif /* IS_ENABLED(CONFIG_SND_USB_AUDIO) */
#endif /* __USBAUDIO_CARD_H */