diff mbox series

[v9,20/34] ALSA: usb-audio: Check for support for requested audio format

Message ID 20231017200109.11407-21-quic_wcheng@quicinc.com
State New
Headers
Series Introduce QC USB SND audio offloading support |

Commit Message

Wesley Cheng Oct. 17, 2023, 8 p.m. UTC 
  Allow for checks on a specific USB audio device to see if a requested PCM
format is supported.  This is needed for support for when playback is
initiated by the ASoC USB backend path.

Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
---
 sound/usb/card.c | 40 ++++++++++++++++++++++++++++++++++++++++
 sound/usb/card.h | 11 +++++++++++
 2 files changed, 51 insertions(+)

Comments

Pierre-Louis Bossart Oct. 17, 2023, 10:29 p.m. UTC | #1 
On 10/17/23 15:00, Wesley Cheng wrote:
> Allow for checks on a specific USB audio device to see if a requested PCM
> format is supported.  This is needed for support for when playback is

This is needed for support when playback is

> initiated by the ASoC USB backend path.
> 
> Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
> ---
>  sound/usb/card.c | 40 ++++++++++++++++++++++++++++++++++++++++
>  sound/usb/card.h | 11 +++++++++++
>  2 files changed, 51 insertions(+)
> 
> diff --git a/sound/usb/card.c b/sound/usb/card.c
> index c0b312e264bf..88f431917c15 100644
> --- a/sound/usb/card.c
> +++ b/sound/usb/card.c
> @@ -162,6 +162,46 @@ int snd_usb_unregister_platform_ops(void)
>  }
>  EXPORT_SYMBOL_GPL(snd_usb_unregister_platform_ops);
>  
> +/*
> + * Checks to see if requested audio profile, i.e sample rate, # of
> + * channels, etc... is supported by the substream associated to the
> + * USB audio device.
> + */
> +struct snd_usb_stream *snd_usb_find_suppported_substream(int card_idx,
> +			struct snd_pcm_hw_params *params, int direction)
> +{
> +	struct snd_usb_audio *chip;
> +	struct snd_usb_substream *subs = NULL;

useless init?

> +	struct snd_usb_stream *as;
> +	const struct audioformat *fmt;
> +
> +	/*
> +	 * Register mutex is held when populating and clearing usb_chip
> +	 * array.
> +	 */
> +	mutex_lock(&register_mutex);
> +	chip = usb_chip[card_idx];
> +	if (!chip) {
> +		mutex_unlock(&register_mutex);
> +		return NULL;
> +	}
> +
> +	if (enable[card_idx]) {
> +		list_for_each_entry(as, &chip->pcm_list, list) {
> +			subs = &as->substream[direction];
> +			fmt = snd_usb_find_substream_format(subs, params);
> +			if (fmt) {
> +				mutex_unlock(&register_mutex);
> +				return as;
> +			}
> +		}
> +	}
> +	mutex_unlock(&register_mutex);
> +
> +	return NULL;
> +}
> +EXPORT_SYMBOL_GPL(snd_usb_find_suppported_substream);
> +
>  /*
>   * disconnect streams
>   * called from usb_audio_disconnect()
> diff --git a/sound/usb/card.h b/sound/usb/card.h
> index 2884912adc96..e26292363cf0 100644
> --- a/sound/usb/card.h
> +++ b/sound/usb/card.h
> @@ -216,4 +216,15 @@ struct snd_usb_platform_ops {
>  
>  int snd_usb_register_platform_ops(struct snd_usb_platform_ops *ops);
>  int snd_usb_unregister_platform_ops(void);
> +
> +#if IS_ENABLED(CONFIG_SND_USB_AUDIO)
> +struct snd_usb_stream *snd_usb_find_suppported_substream(int card_idx,
> +			struct snd_pcm_hw_params *params, int direction);
> +#else
> +static struct snd_usb_stream *snd_usb_find_suppported_substream(int card_idx,
> +			struct snd_pcm_hw_params *params, int direction)
> +{
> +	return NULL;
> +}
> +#endif /* IS_ENABLED(CONFIG_SND_USB_AUDIO) */
>  #endif /* __USBAUDIO_CARD_H */
Wesley Cheng Oct. 18, 2023, 8:21 p.m. UTC | #2 
Hi Pierre,

On 10/17/2023 3:29 PM, Pierre-Louis Bossart wrote:
> 
> 
> On 10/17/23 15:00, Wesley Cheng wrote:
>> Allow for checks on a specific USB audio device to see if a requested PCM
>> format is supported.  This is needed for support for when playback is
> 
> This is needed for support when playback is
> 

Will fix this typo

>> initiated by the ASoC USB backend path.
>>
>> Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
>> ---
>>   sound/usb/card.c | 40 ++++++++++++++++++++++++++++++++++++++++
>>   sound/usb/card.h | 11 +++++++++++
>>   2 files changed, 51 insertions(+)
>>
>> diff --git a/sound/usb/card.c b/sound/usb/card.c
>> index c0b312e264bf..88f431917c15 100644
>> --- a/sound/usb/card.c
>> +++ b/sound/usb/card.c
>> @@ -162,6 +162,46 @@ int snd_usb_unregister_platform_ops(void)
>>   }
>>   EXPORT_SYMBOL_GPL(snd_usb_unregister_platform_ops);
>>   
>> +/*
>> + * Checks to see if requested audio profile, i.e sample rate, # of
>> + * channels, etc... is supported by the substream associated to the
>> + * USB audio device.
>> + */
>> +struct snd_usb_stream *snd_usb_find_suppported_substream(int card_idx,
>> +			struct snd_pcm_hw_params *params, int direction)
>> +{
>> +	struct snd_usb_audio *chip;
>> +	struct snd_usb_substream *subs = NULL;
> 
> useless init?
> 

Agreed.

Thanks
Wesley Cheng
diff mbox series

Patch

diff --git a/sound/usb/card.c b/sound/usb/card.c
index c0b312e264bf..88f431917c15 100644
--- a/sound/usb/card.c
+++ b/sound/usb/card.c
@@ -162,6 +162,46 @@  int snd_usb_unregister_platform_ops(void)
 }
 EXPORT_SYMBOL_GPL(snd_usb_unregister_platform_ops);
 
+/*
+ * Checks to see if requested audio profile, i.e sample rate, # of
+ * channels, etc... is supported by the substream associated to the
+ * USB audio device.
+ */
+struct snd_usb_stream *snd_usb_find_suppported_substream(int card_idx,
+			struct snd_pcm_hw_params *params, int direction)
+{
+	struct snd_usb_audio *chip;
+	struct snd_usb_substream *subs = NULL;
+	struct snd_usb_stream *as;
+	const struct audioformat *fmt;
+
+	/*
+	 * Register mutex is held when populating and clearing usb_chip
+	 * array.
+	 */
+	mutex_lock(&register_mutex);
+	chip = usb_chip[card_idx];
+	if (!chip) {
+		mutex_unlock(&register_mutex);
+		return NULL;
+	}
+
+	if (enable[card_idx]) {
+		list_for_each_entry(as, &chip->pcm_list, list) {
+			subs = &as->substream[direction];
+			fmt = snd_usb_find_substream_format(subs, params);
+			if (fmt) {
+				mutex_unlock(&register_mutex);
+				return as;
+			}
+		}
+	}
+	mutex_unlock(&register_mutex);
+
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(snd_usb_find_suppported_substream);
+
 /*
  * disconnect streams
  * called from usb_audio_disconnect()
diff --git a/sound/usb/card.h b/sound/usb/card.h
index 2884912adc96..e26292363cf0 100644
--- a/sound/usb/card.h
+++ b/sound/usb/card.h
@@ -216,4 +216,15 @@  struct snd_usb_platform_ops {
 
 int snd_usb_register_platform_ops(struct snd_usb_platform_ops *ops);
 int snd_usb_unregister_platform_ops(void);
+
+#if IS_ENABLED(CONFIG_SND_USB_AUDIO)
+struct snd_usb_stream *snd_usb_find_suppported_substream(int card_idx,
+			struct snd_pcm_hw_params *params, int direction);
+#else
+static struct snd_usb_stream *snd_usb_find_suppported_substream(int card_idx,
+			struct snd_pcm_hw_params *params, int direction)
+{
+	return NULL;
+}
+#endif /* IS_ENABLED(CONFIG_SND_USB_AUDIO) */
 #endif /* __USBAUDIO_CARD_H */