ALSA: hda: intel-nhlt: add intel_nhlt_ssp_device_type() function

Add a helper function intel_nhlt_ssp_device_type() to detect the type
of specific SSP port. The result is nhlt_device_type enum type which
could be NHLT_DEVICE_BT or NHLT_DEVICE_I2S.

Signed-off-by: Brent Lu <[e-mail]>
Reviewed-by: Péter Ujfalusi <[e-mail]>
Reviewed-by: Pierre-Louis Bossart <[e-mail]>
Reviewed-by: Bard Liao <[e-mail]>
Signed-off-by: Peter Ujfalusi <[e-mail]>
Signed-off-by: Takashi Iwai <[e-mail]>
Message-ID: <[e-mail]>

include/sound/intel-nhlt.h

···
 			     u32 bus_id, u8 link_type, u8 vbps, u8 bps,
 			     u8 num_ch, u32 rate, u8 dir, u8 dev_type);
 
+int intel_nhlt_ssp_device_type(struct device *dev, struct nhlt_acpi_table *nhlt,
+			       u8 virtual_bus_id);
+
 #else
 
 static inline struct nhlt_acpi_table *intel_nhlt_init(struct device *dev)
···
 			     u8 num_ch, u32 rate, u8 dir, u8 dev_type)
 {
 	return NULL;
+}
+
+static inline int intel_nhlt_ssp_device_type(struct device *dev,
+					     struct nhlt_acpi_table *nhlt,
+					     u8 virtual_bus_id)
+{
+	return -EINVAL;
 }
 
 #endif

sound/hda/intel-nhlt.c

···
 	return NULL;
 }
 EXPORT_SYMBOL(intel_nhlt_get_endpoint_blob);
+
+int intel_nhlt_ssp_device_type(struct device *dev, struct nhlt_acpi_table *nhlt,
+			       u8 virtual_bus_id)
+{
+	struct nhlt_endpoint *epnt;
+	int i;
+
+	if (!nhlt)
+		return -EINVAL;
+
+	epnt = (struct nhlt_endpoint *)nhlt->desc;
+	for (i = 0; i < nhlt->endpoint_count; i++) {
+		/* for SSP link the virtual bus id is the SSP port number */
+		if (epnt->linktype == NHLT_LINK_SSP &&
+		    epnt->virtual_bus_id == virtual_bus_id) {
+			dev_dbg(dev, "SSP%d: dev_type=%d\n", virtual_bus_id,
+				epnt->device_type);
+			return epnt->device_type;
+		}
+
+		epnt = (struct nhlt_endpoint *)((u8 *)epnt + epnt->length);
+	}
+
+	return -EINVAL;
+}
+EXPORT_SYMBOL(intel_nhlt_ssp_device_type);