On 8/29/24 21:40, Wesley Cheng wrote:
> USB SND needs to know how the USB offload path is being routed. This would
> allow for applications to open the corresponding sound card and pcm device
> when it wants to take the audio offload path. This callback should return
> the mapped indexes based on the USB SND device information.
>
> Signed-off-by: Wesley Cheng <quic_wcheng@xxxxxxxxxxx>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
> diff --git a/include/sound/soc-usb.h b/include/sound/soc-usb.h
> index 5c788cbfa82e..86876098a2b7 100644
> --- a/include/sound/soc-usb.h
> +++ b/include/sound/soc-usb.h
> @@ -36,6 +36,7 @@ struct snd_soc_usb_device {
> * @list - list head for SND SOC struct list
> * @component - reference to ASoC component
> * @connection_status_cb - callback to notify connection events
> + * @update_offload_route_info - callback to fetch mapped ASoC device
nit-pick: explain that 'route' refers to the (card, device) pair and
isn't related to the concept of DAPM route.
> * @priv_data - driver data
> **/
> struct snd_soc_usb {
> @@ -44,6 +45,9 @@ struct snd_soc_usb {
> int (*connection_status_cb)(struct snd_soc_usb *usb,
> struct snd_soc_usb_device *sdev,
> bool connected);
> + int (*update_offload_route_info)(struct snd_soc_component *component,
> + int card, int pcm, int direction,
> + long *route);
nit-pick: also explain the format used for the (card, device) pair
stored in the long
> void *priv_data;
> };
>
> @@ -59,6 +63,8 @@ void *snd_soc_usb_find_priv_data(struct device *dev);
> int snd_soc_usb_setup_offload_jack(struct snd_soc_component *component,
> struct snd_soc_jack *jack);
> int snd_soc_usb_disable_offload_jack(struct snd_soc_component *component);
> +int snd_soc_usb_update_offload_route(struct device *dev, int card, int pcm,
> + int direction, long *route);
>
> struct snd_soc_usb *snd_soc_usb_allocate_port(struct snd_soc_component *component,
> void *data);
> @@ -101,6 +107,12 @@ static inline int snd_soc_usb_disable_offload_jack(struct snd_soc_component *com
> return 0;
> }
>
> +static int snd_soc_usb_update_offload_route(struct device *dev, int card, int pcm,
> + int direction, long *route)
> +{
> + return -ENODEV;
> +}
> +
> static inline struct snd_soc_usb *
> snd_soc_usb_allocate_port(struct snd_soc_component *component, void *data)
> {
> diff --git a/sound/soc/soc-usb.c b/sound/soc/soc-usb.c
> index 3d5354298206..de249e8a28cb 100644
> --- a/sound/soc/soc-usb.c
> +++ b/sound/soc/soc-usb.c
> @@ -117,6 +117,37 @@ int snd_soc_usb_disable_offload_jack(struct snd_soc_component *component)
> }
> EXPORT_SYMBOL_GPL(snd_soc_usb_disable_offload_jack);
>
> +/**
> + * snd_soc_usb_update_offload_route - Find active USB offload path
> + * @dev - USB device to get offload status
> + * @card - USB card index
> + * @pcm - USB PCM device index
> + * @direction - playback or capture direction
> + * @route - pointer to route output array
> + *
> + * Fetch the current status for the USB SND card and PCM device indexes
> + * specified.
> + */
> +int snd_soc_usb_update_offload_route(struct device *dev, int card, int pcm,
> + int direction, long *route)
> +{
> + struct snd_soc_usb *ctx;
> + int ret;
> +
> + ctx = snd_soc_find_usb_ctx(dev);
> + if (!ctx)
> + return -ENODEV;
> +
> + mutex_lock(&ctx_mutex);
> + if (ctx && ctx->update_offload_route_info)
> + ret = ctx->update_offload_route_info(ctx->component, card, pcm,
> + direction, route);
> + mutex_unlock(&ctx_mutex);
> +
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(snd_soc_usb_update_offload_route);
> +
> /**
> * snd_soc_usb_find_priv_data() - Retrieve private data stored
> * @dev: device reference
