lib/nhlt: add helper functions for adding endpoints

In order to ease the porting of supporting NHLT endpoints
introduce a nhlt_endpoint_descriptor structure as well as
corresponding helper functions.

Change-Id: I68edaf681b4e60502f6ddbbd04de21d8aa072296
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/15486
Reviewed-by: Furquan Shaikh <furquan@google.com>
Tested-by: build bot (Jenkins)

src/include/nhlt.h

@@ -57,6 +57,43 @@ struct nhlt *nhlt_init(void);
 /* Return the size of the NHLT table including APCI header. */
 size_t nhlt_current_size(struct nhlt *nhlt);
 
+/*
+ * Helper functions for adding NHLT devices utilizing an nhlt_endp_descriptor
+ * to drive the logic.
+ */
+
+struct nhlt_endp_descriptor {
+	/* NHLT endpoint types. */
+	int link;
+	int device;
+	int direction;
+	uint16_t vid;
+	uint16_t did;
+	/* Optional endpoint specific configuration data. */
+	const void *cfg;
+	size_t cfg_size;
+	/* Formats supported for endpoint. */
+	const struct nhlt_format_config *formats;
+	size_t num_formats;
+};
+
+/*
+ * Add the number of endpoints described by each descriptor. The virtual bus
+ * id for each descriptor is the default value of 0.
+ * Returns < 0 on error, 0 on success.
+ */
+int nhlt_add_endpoints(struct nhlt *nhlt,
+			const struct nhlt_endp_descriptor *epds,
+			size_t num_epds);
+
+/*
+ * Add the number of endpoints associated with a single NHLT SSP instance id.
+ * Each endpoint described in the endpoint descriptor array uses the provided
+ * virtual bus id. Returns < 0 on error, 0 on success.
+ */
+int nhlt_add_ssp_endpoints(struct nhlt *nhlt, int virtual_bus_id,
+		const struct nhlt_endp_descriptor *epds, size_t num_epds);
+
 /*
  * Add endpoint to NHLT object. Returns NULL on error.
  *

src/lib/nhlt.c

@@ -24,6 +24,7 @@
 #define NHLT_RID 1
 #define NHLT_SSID 1
 #define WAVEFORMAT_TAG 0xfffe
+#define DEFAULT_VIRTUAL_BUS_ID 0
 
 static const struct sub_format pcm_subformat = {
 	.data1 = 0x00000001,
@@ -68,7 +69,7 @@ struct nhlt_endpoint *nhlt_add_endpoint(struct nhlt *nhlt, int link_type,
 	endp->subsystem_id = NHLT_SSID;
 	endp->device_type = device_type;
 	endp->direction = dir;
-	endp->virtual_bus_id = 0;
+	endp->virtual_bus_id = DEFAULT_VIRTUAL_BUS_ID;
 
 	nhlt->num_endpoints++;
 
@@ -437,3 +438,60 @@ uintptr_t nhlt_serialize_oem_overrides(struct nhlt *nhlt,
 
 	return acpi_addr;
 }
+
+static int _nhlt_add_single_endpoint(struct nhlt *nhlt, int virtual_bus_id,
+					const struct nhlt_endp_descriptor *epd)
+{
+	struct nhlt_endpoint *endp;
+
+	endp = nhlt_add_endpoint(nhlt, epd->link, epd->device, epd->direction,
+				epd->vid, epd->did);
+
+	if (endp == NULL)
+		return -1;
+
+	endp->virtual_bus_id = virtual_bus_id;
+
+	if (nhlt_endpoint_append_config(endp, epd->cfg, epd->cfg_size))
+		return -1;
+
+	if (nhlt_endpoint_add_formats(endp, epd->formats, epd->num_formats))
+		return -1;
+
+	return 0;
+}
+
+static int _nhlt_add_endpoints(struct nhlt *nhlt, int virtual_bus_id,
+			const struct nhlt_endp_descriptor *epds,
+			size_t num_epds)
+{
+	size_t i;
+
+	for (i = 0; i < num_epds; i++)
+		if (_nhlt_add_single_endpoint(nhlt, virtual_bus_id, &epds[i]))
+			return -1;
+
+	return 0;
+}
+
+int nhlt_add_endpoints(struct nhlt *nhlt,
+			const struct nhlt_endp_descriptor *epds,
+			size_t num_epds)
+{
+	int ret;
+	ret = _nhlt_add_endpoints(nhlt, DEFAULT_VIRTUAL_BUS_ID, epds, num_epds);
+	return ret;
+}
+
+int nhlt_add_ssp_endpoints(struct nhlt *nhlt, int virtual_bus_id,
+		const struct nhlt_endp_descriptor *epds, size_t num_epds)
+{
+	int ret;
+
+	ret = _nhlt_add_endpoints(nhlt, virtual_bus_id, epds, num_epds);
+
+	if (!ret)
+		nhlt_next_instance(nhlt, NHLT_LINK_SSP);
+
+	return ret;
+}