[PATCH v16 31/50] ASoC: usb: Add PCM format check API for USB backend

@@ -39,6 +39,8 @@ struct snd_soc_usb {
 
 #if IS_ENABLED(CONFIG_SND_SOC_USB)
 const char *snd_soc_usb_get_components_tag(bool playback);
+int snd_soc_usb_find_format(int card_idx, struct snd_pcm_hw_params *params,
+			int direction);
 
 int snd_soc_usb_connect(struct device *usbdev, struct snd_soc_usb_device *sdev);
 int snd_soc_usb_disconnect(struct device *usbdev, struct snd_soc_usb_device *sdev);

@@ -55,6 +57,13 @@ static inline const char *snd_soc_usb_get_components_tag(bool playback)
 	return "";
 }
 
+static inline int snd_soc_usb_find_format(int card_idx,
+					  struct snd_pcm_hw_params *params,
+					  int direction)
+{
+	return -EINVAL;
+}
+
 static inline int snd_soc_usb_connect(struct device *usbdev,
 					struct snd_soc_usb_device *sdev)
 {

@@ -80,6 +80,31 @@ void *snd_soc_usb_find_priv_data(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(snd_soc_usb_find_priv_data);
 
+/**
+ * snd_soc_usb_find_format() - Check if audio format is supported
+ * @card_idx: USB sound chip array index
+ * @params: PCM parameters
+ * @direction: capture or playback
+ *
+ * Ensure that a requested audio profile from the ASoC side is able to be
+ * supported by the USB device.
+ *
+ * Return 0 on success, negative on error.
+ *
+ */
+int snd_soc_usb_find_format(int card_idx, struct snd_pcm_hw_params *params,
+			int direction)
+{
+	struct snd_usb_stream *as;
+
+	as = snd_usb_find_suppported_substream(card_idx, params, direction);
+	if (!as)
+		return -EOPNOTSUPP;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_soc_usb_find_format);
+
 /**
  * snd_soc_usb_allocate_port() - allocate a SOC USB device
  * @component: USB DPCM backend DAI component