x86: Add support for building up an NHLT structure

The Intel Non-High-Definition-Audio Link Table (NHLT) table describes the
audio codecs and connections in a system. Various devices can contribute
information to produce the table.

Add functions to allow adding to the structure that is eventually written
to the ACPI tables. Also add the device-tree bindings.
Signed-off-by: NSimon Glass <sjg@chromium.org>

arch/x86/include/asm/acpi_nhlt.h

+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright 2020 Google LLC
+ *
+ * Modified from coreboot nhlt.h
+ */
+
+#ifndef _NHLT_H_
+#define _NHLT_H_
+
+struct acpi_ctx;
+struct nhlt;
+struct nhlt_endpoint;
+struct nhlt_format;
+struct nhlt_format_config;
+
+/*
+ * Non HD Audio ACPI support. This table is typically used for Intel Smart
+ * Sound Technology DSP. It provides a way to encode opaque settings in
+ * the ACPI tables.
+ *
+ * While the structure fields of the NHLT structs are exposed below
+ * the SoC/chipset code should be the only other user manipulating the
+ * fields directly aside from the library itself.
+ *
+ * The NHLT table consists of endpoints which in turn contain different
+ * supporting stream formats. Each endpoint may contain a device specific
+ * configuration payload as well as each stream format.
+ *
+ * Most code should use the SoC variants of the functions because
+ * there is required logic needed to be performed by the SoC. The SoC
+ * code should be abstracting the inner details of these functions that
+ * specically apply to NHLT objects for that SoC.
+ *
+ * An example sequence:
+ *
+ * nhlt = nhlt_init()
+ * ep = nhlt_add_endpoint()
+ * nhlt_endpoint_append_config(ep)
+ * nhlt_endpoint_add_formats(ep)
+ * nhlt_soc_serialise()
+ */
+
+/* Obtain an nhlt object for adding endpoints. Returns NULL on error. */
+struct nhlt *nhlt_init(void);
+
+/* Return the size of the NHLT table including ACPI 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;
+	u16 vid;
+	u16 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.
+ *
+ * generic nhlt_add_endpoint() is called by the SoC code to provide
+ * the specific assumptions/uses for NHLT for that platform. All fields
+ * are the NHLT enumerations found within this header file.
+ */
+struct nhlt_endpoint *nhlt_add_endpoint(struct nhlt *nhlt, int link_type,
+					int device_type, int dir,
+					u16 vid, u16 did);
+
+/*
+ * Append blob of configuration to the endpoint proper. Returns 0 on
+ * success, < 0 on error. A copy of the configuration is made so any
+ * resources pointed to by config can be freed after the call.
+ */
+int nhlt_endpoint_append_config(struct nhlt_endpoint *endpoint,
+				const void *config, size_t config_sz);
+
+/* Add a format type to the provided endpoint. Returns NULL on error. */
+struct nhlt_format *nhlt_add_format(struct nhlt_endpoint *endpoint,
+				    int num_channels, int sample_freq_khz,
+				    int container_bits_per_sample,
+				    int valid_bits_per_sample,
+				    u32 speaker_mask);
+
+/*
+ * Append blob of configuration to the format proper. Returns 0 on
+ * success, < 0 on error. A copy of the configuration is made so any
+ * resources pointed to by config can be freed after the call.
+ */
+int nhlt_format_append_config(struct nhlt_format *format, const void *config,
+			      size_t config_sz);
+
+/*
+ * Add num_formats described by formats to the endpoint. This function
+ * effectively wraps nhlt_add_format() and nhlt_format_config() using the
+ * data found in each nhlt_format_config object. Returns 0 on success, < 0
+ * on error.
+ */
+int nhlt_endpoint_add_formats(struct nhlt_endpoint *endpoint,
+			      const struct nhlt_format_config *formats,
+			      size_t num_formats);
+
+/*
+ * Increment the instance id for a given link type. This function is
+ * used for marking a device being completely added to the NHLT object.
+ * Subsequent endpoints added to the nhlt object with the same link type
+ * will use incremented instance id.
+ */
+void nhlt_next_instance(struct nhlt *nhlt, int link_type);
+
+/*
+ * Serialize NHLT object to ACPI table. Take in the beginning address of where
+ * the table will reside and return the address of the next ACPI table. On
+ * error 0 will be returned. The NHLT object is no longer valid after this
+ * function is called.
+ */
+uintptr_t nhlt_serialise(struct nhlt *nhlt, uintptr_t acpi_addr);
+
+/*
+ * Serialize NHLT object to ACPI table. Take in the beginning address of where
+ * the table will reside oem_id and oem_table_id and return the address of the
+ * next ACPI table. On error 0 will be returned. The NHLT object is no longer
+ * valid after this function is called.
+ */
+int nhlt_serialise_oem_overrides(struct acpi_ctx *ctx, struct nhlt *nhlt,
+				 const char *oem_id, const char *oem_table_id,
+				 u32 oem_revision);
+
+int nhlt_setup(struct nhlt *nhlt, ofnode node);
+
+/* Link and device types. */
+enum {
+	NHLT_LINK_HDA,
+	NHLT_LINK_DSP,
+	NHLT_LINK_PDM,
+	NHLT_LINK_SSP,
+	NHLT_MAX_LINK_TYPES,
+};
+
+enum {
+	NHLT_SSP_DEV_BT, /* Bluetooth */
+	NHLT_SSP_DEV_MODEM,
+	NHLT_SSP_DEV_FM,
+	NHLT_SSP_DEV_RESERVED,
+	NHLT_SSP_DEV_I2S = 4,
+};
+
+enum {
+	NHLT_PDM_DEV,
+};
+
+/* Endpoint direction. */
+enum {
+	NHLT_DIR_RENDER,
+	NHLT_DIR_CAPTURE,
+	NHLT_DIR_BIDIRECTIONAL,
+};
+
+/*
+ * Channel mask for an endpoint. While they are prefixed with 'SPEAKER' the
+ * channel masks are also used for capture devices
+ */
+enum {
+	SPEAKER_FRONT_LEFT =		BIT(0),
+	SPEAKER_FRONT_RIGHT =		BIT(1),
+	SPEAKER_FRONT_CENTER =		BIT(2),
+	SPEAKER_LOW_FREQUENCY =		BIT(3),
+	SPEAKER_BACK_LEFT =		BIT(4),
+	SPEAKER_BACK_RIGHT =		BIT(5),
+	SPEAKER_FRONT_LEFT_OF_CENTER =	BIT(6),
+	SPEAKER_FRONT_RIGHT_OF_CENTER =	BIT(7),
+	SPEAKER_BACK_CENTER =		BIT(8),
+	SPEAKER_SIDE_LEFT =		BIT(9),
+	SPEAKER_SIDE_RIGHT =		BIT(10),
+	SPEAKER_TOP_CENTER =		BIT(11),
+	SPEAKER_TOP_FRONT_LEFT =	BIT(12),
+	SPEAKER_TOP_FRONT_CENTER =	BIT(13),
+	SPEAKER_TOP_FRONT_RIGHT =	BIT(14),
+	SPEAKER_TOP_BACK_LEFT =		BIT(15),
+	SPEAKER_TOP_BACK_CENTER =	BIT(16),
+	SPEAKER_TOP_BACK_RIGHT =	BIT(17),
+};
+
+/*
+ * Supporting structures. Only SoC/chipset and the library code directly should
+ * be manipulating these structures
+ */
+struct sub_format {
+	u32 data1;
+	u16 data2;
+	u16 data3;
+	u8 data4[8];
+};
+
+struct nhlt_specific_config {
+	u32 size;
+	void *capabilities;
+};
+
+struct nhlt_waveform {
+	u16 tag;
+	u16 num_channels;
+	u32 samples_per_second;
+	u32 bytes_per_second;
+	u16 block_align;
+	u16 bits_per_sample;
+	u16 extra_size;
+	u16 valid_bits_per_sample;
+	u32 channel_mask;
+	struct sub_format sub_format;
+};
+
+struct nhlt_format {
+	struct nhlt_waveform waveform;
+	struct nhlt_specific_config config;
+};
+
+/*
+ * This struct is used by nhlt_endpoint_add_formats() for easily adding
+ * waveform formats with associated settings file.
+ */
+struct nhlt_format_config {
+	int num_channels;
+	int sample_freq_khz;
+	int container_bits_per_sample;
+	int valid_bits_per_sample;
+	u32 speaker_mask;
+	const char *settings_file;
+};
+
+/* Arbitrary max number of formats per endpoint. */
+#define MAX_FORMATS 2
+struct nhlt_endpoint {
+	u32 length;
+	u8 link_type;
+	u8 instance_id;
+	u16 vendor_id;
+	u16 device_id;
+	u16 revision_id;
+	u32 subsystem_id;
+	u8 device_type;
+	u8 direction;
+	u8 virtual_bus_id;
+	struct nhlt_specific_config config;
+	u8 num_formats;
+	struct nhlt_format formats[MAX_FORMATS];
+};
+
+#define MAX_ENDPOINTS 8
+struct nhlt {
+	u32 subsystem_id;
+	u8 num_endpoints;
+	struct nhlt_endpoint endpoints[MAX_ENDPOINTS];
+	u8 current_instance_id[NHLT_MAX_LINK_TYPES];
+};
+
+struct nhlt_tdm_config {
+	u8 virtual_slot;
+	u8 config_type;
+};
+
+enum {
+	NHLT_TDM_BASIC,
+	NHLT_TDM_MIC_ARRAY,
+};
+
+struct nhlt_dmic_array_config {
+	struct nhlt_tdm_config tdm_config;
+	u8 array_type;
+};
+
+/*
+ * Microphone array definitions may be found here:
+ * https://msdn.microsoft.com/en-us/library/windows/hardware/dn613960%28v=vs.85%29.aspx
+ */
+enum {
+	NHLT_MIC_ARRAY_2CH_SMALL = 0xa,
+	NHLT_MIC_ARRAY_2CH_BIG = 0xb,
+	NHLT_MIC_ARRAY_4CH_1ST_GEOM = 0xc,
+	NHLT_MIC_ARRAY_4CH_L_SHAPED = 0xd,
+	NHLT_MIC_ARRAY_4CH_2ND_GEOM = 0xe,
+	NHLT_MIC_ARRAY_VENDOR_DEFINED = 0xf,
+};
+
+#endif

arch/x86/lib/Makefile

@@ -22,6 +22,7 @@ obj-y	+= init_helpers.o
 obj-y	+= interrupts.o
 obj-y	+= lpc-uclass.o
 obj-y	+= mpspec.o
+obj-$(CONFIG_$(SPL_TPL_)ACPIGEN) += acpi_nhlt.o
 obj-y	+= northbridge-uclass.o
 obj-$(CONFIG_I8259_PIC) += i8259.o
 obj-$(CONFIG_I8254_TIMER) += i8254.o

arch/x86/lib/acpi_nhlt.c

+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2020 Google LLC
+ *
+ * Modified from coreboot nhlt.c
+ */
+
+#define LOG_CATEGORY	LOGC_ACPI
+
+#include <common.h>
+#include <binman.h>
+#include <dm.h>
+#include <log.h>
+#include <malloc.h>
+#include <tables_csum.h>
+#include <acpi/acpi_table.h>
+#include <asm/acpi_nhlt.h>
+#include <asm/unaligned.h>
+#include <dm/acpi.h>
+
+#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,
+	.data2 = 0x0000,
+	.data3 = 0x0010,
+	.data4 = { 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71 },
+};
+
+struct nhlt *nhlt_init(void)
+{
+	struct nhlt *nhlt;
+
+	nhlt = malloc(sizeof(*nhlt));
+
+	if (!nhlt)
+		return NULL;
+
+	memset(nhlt, 0, sizeof(*nhlt));
+	nhlt->subsystem_id = NHLT_SSID;
+
+	return nhlt;
+}
+
+struct nhlt_endpoint *nhlt_add_endpoint(struct nhlt *nhlt, int link_type,
+					int device_type, int dir,
+					u16 vid, u16 did)
+{
+	struct nhlt_endpoint *endp;
+
+	if (link_type < NHLT_LINK_HDA || link_type >= NHLT_MAX_LINK_TYPES)
+		return NULL;
+
+	if (nhlt->num_endpoints >= MAX_ENDPOINTS)
+		return NULL;
+
+	endp = &nhlt->endpoints[nhlt->num_endpoints];
+
+	endp->link_type = link_type;
+	endp->instance_id = nhlt->current_instance_id[link_type];
+	endp->vendor_id = vid;
+	endp->device_id = did;
+	endp->revision_id = NHLT_RID;
+	endp->subsystem_id = nhlt->subsystem_id;
+	endp->device_type = device_type;
+	endp->direction = dir;
+	endp->virtual_bus_id = DEFAULT_VIRTUAL_BUS_ID;
+
+	nhlt->num_endpoints++;
+
+	return endp;
+}
+
+static int append_specific_config(struct nhlt_specific_config *spec_cfg,
+				  const void *config, size_t config_sz)
+{
+	size_t new_sz;
+	void *new_cfg;
+
+	new_sz = spec_cfg->size + config_sz;
+	new_cfg = malloc(new_sz);
+	if (!new_cfg)
+		return -ENOMEM;
+
+	/* Append new config */
+	memcpy(new_cfg, spec_cfg->capabilities, spec_cfg->size);
+	memcpy(new_cfg + spec_cfg->size, config, config_sz);
+
+	free(spec_cfg->capabilities);
+
+	/* Update with new config data */
+	spec_cfg->size = new_sz;
+	spec_cfg->capabilities = new_cfg;
+
+	return 0;
+}
+
+int nhlt_endpoint_append_config(struct nhlt_endpoint *endp, const void *config,
+				size_t config_sz)
+{
+	return append_specific_config(&endp->config, config, config_sz);
+}
+
+struct nhlt_format *nhlt_add_format(struct nhlt_endpoint *endp,
+				    int num_channels, int sample_freq_khz,
+				    int container_bits_per_sample,
+				    int valid_bits_per_sample,
+				    uint32_t speaker_mask)
+{
+	struct nhlt_format *fmt;
+	struct nhlt_waveform *wave;
+
+	if (endp->num_formats >= MAX_FORMATS)
+		return NULL;
+
+	fmt = &endp->formats[endp->num_formats];
+	wave = &fmt->waveform;
+
+	wave->tag = WAVEFORMAT_TAG;
+	wave->num_channels = num_channels;
+	wave->samples_per_second = sample_freq_khz * 1000;
+	wave->bits_per_sample = container_bits_per_sample;
+	wave->extra_size = sizeof(wave->valid_bits_per_sample);
+	wave->extra_size += sizeof(wave->channel_mask);
+	wave->extra_size += sizeof(wave->sub_format);
+	wave->valid_bits_per_sample = valid_bits_per_sample;
+	wave->channel_mask = speaker_mask;
+	memcpy(&wave->sub_format, &pcm_subformat, sizeof(wave->sub_format));
+
+	/* Calculate the dervied fields */
+	wave->block_align = wave->num_channels * wave->bits_per_sample / 8;
+	wave->bytes_per_second = wave->block_align * wave->samples_per_second;
+
+	endp->num_formats++;
+
+	return fmt;
+}
+
+int nhlt_format_append_config(struct nhlt_format *fmt, const void *config,
+			      size_t config_sz)
+{
+	return append_specific_config(&fmt->config, config, config_sz);
+}
+
+int nhlt_endpoint_add_formats(struct nhlt_endpoint *endp,
+			      const struct nhlt_format_config *formats,
+			      size_t num_formats)
+{
+	ofnode node;
+	size_t i;
+
+	node = binman_section_find_node("private-files");
+
+	for (i = 0; i < num_formats; i++) {
+		const struct nhlt_format_config *cfg = &formats[i];
+		struct nhlt_format *fmt;
+		void *data;
+		int size;
+		int ret;
+
+		fmt = nhlt_add_format(endp, cfg->num_channels,
+				      cfg->sample_freq_khz,
+				      cfg->container_bits_per_sample,
+				      cfg->valid_bits_per_sample,
+				      cfg->speaker_mask);
+		if (!fmt)
+			return -ENOSPC;
+
+		if (!cfg->settings_file)
+			continue;
+
+		ret = binman_entry_map(node, cfg->settings_file, &data, &size);
+		if (ret) {
+			log_warning("Failed to find settings file %s\n",
+				    cfg->settings_file);
+			return log_msg_ret("settings", ret);
+		}
+
+		ret = nhlt_format_append_config(fmt, data, size);
+		if (ret)
+			return log_msg_ret("append", ret);
+	}
+
+	return 0;
+}
+
+void nhlt_next_instance(struct nhlt *nhlt, int link_type)
+{
+	if (link_type < NHLT_LINK_HDA || link_type >= NHLT_MAX_LINK_TYPES)
+		return;
+
+	nhlt->current_instance_id[link_type]++;
+}
+
+static size_t calc_specific_config_size(struct nhlt_specific_config *cfg)
+{
+	return sizeof(cfg->size) + cfg->size;
+}
+
+static size_t calc_format_size(struct nhlt_format *fmt)
+{
+	size_t sz = 0;
+
+	/* Wave format first */
+	sz += sizeof(fmt->waveform.tag);
+	sz += sizeof(fmt->waveform.num_channels);
+	sz += sizeof(fmt->waveform.samples_per_second);
+	sz += sizeof(fmt->waveform.bytes_per_second);
+	sz += sizeof(fmt->waveform.block_align);
+	sz += sizeof(fmt->waveform.bits_per_sample);
+	sz += sizeof(fmt->waveform.extra_size);
+	sz += sizeof(fmt->waveform.valid_bits_per_sample);
+	sz += sizeof(fmt->waveform.channel_mask);
+	sz += sizeof(fmt->waveform.sub_format);
+
+	sz += calc_specific_config_size(&fmt->config);
+
+	return sz;
+}
+
+static size_t calc_endpoint_size(struct nhlt_endpoint *endp)
+{
+	int i;
+	size_t sz = 0;
+
+	sz += sizeof(endp->length) + sizeof(endp->link_type);
+	sz += sizeof(endp->instance_id) + sizeof(endp->vendor_id);
+	sz += sizeof(endp->device_id) + sizeof(endp->revision_id);
+	sz += sizeof(endp->subsystem_id) + sizeof(endp->device_type);
+	sz += sizeof(endp->direction) + sizeof(endp->virtual_bus_id);
+	sz += calc_specific_config_size(&endp->config);
+	sz += sizeof(endp->num_formats);
+
+	for (i = 0; i < endp->num_formats; i++)
+		sz += calc_format_size(&endp->formats[i]);
+
+	/* Adjust endpoint length to reflect current configuration */
+	endp->length = sz;
+
+	return sz;
+}
+
+static size_t calc_endpoints_size(struct nhlt *nhlt)
+{
+	size_t sz = 0;
+	int i;
+
+	for (i = 0; i < nhlt->num_endpoints; i++)
+		sz += calc_endpoint_size(&nhlt->endpoints[i]);
+
+	return sz;
+}
+
+static size_t calc_size(struct nhlt *nhlt)
+{
+	return sizeof(nhlt->num_endpoints) + calc_endpoints_size(nhlt);
+}
+
+size_t nhlt_current_size(struct nhlt *nhlt)
+{
+	return calc_size(nhlt) + sizeof(struct acpi_table_header);
+}
+
+static void nhlt_free_resources(struct nhlt *nhlt)
+{
+	int i, j;
+
+	/* Free all specific configs */
+	for (i = 0; i < nhlt->num_endpoints; i++) {
+		struct nhlt_endpoint *endp = &nhlt->endpoints[i];
+
+		free(endp->config.capabilities);
+		for (j = 0; j < endp->num_formats; j++) {
+			struct nhlt_format *fmt = &endp->formats[j];
+
+			free(fmt->config.capabilities);
+		}
+	}
+
+	/* Free nhlt object proper */
+	free(nhlt);
+}
+
+struct cursor {
+	u8 *buf;
+};
+
+static void ser8(struct cursor *cur, uint val)
+{
+	*cur->buf = val;
+	cur->buf += sizeof(val);
+}
+
+static void ser16(struct cursor *cur, uint val)
+{
+	put_unaligned_le16(val, cur->buf);
+	cur->buf += sizeof(val);
+}
+
+static void ser32(struct cursor *cur, uint val)
+{
+	put_unaligned_le32(val, cur->buf);
+	cur->buf += sizeof(val);
+}
+
+static void serblob(struct cursor *cur, void *from, size_t sz)
+{
+	memcpy(cur->buf, from, sz);
+	cur->buf += sz;
+}
+
+static void serialise_specific_config(struct nhlt_specific_config *cfg,
+				      struct cursor *cur)
+{
+	ser32(cur, cfg->size);
+	serblob(cur, cfg->capabilities, cfg->size);
+}
+
+static void serialise_waveform(struct nhlt_waveform *wave, struct cursor *cur)
+{
+	ser16(cur, wave->tag);
+	ser16(cur, wave->num_channels);
+	ser32(cur, wave->samples_per_second);
+	ser32(cur, wave->bytes_per_second);
+	ser16(cur, wave->block_align);
+	ser16(cur, wave->bits_per_sample);
+	ser16(cur, wave->extra_size);
+	ser16(cur, wave->valid_bits_per_sample);
+	ser32(cur, wave->channel_mask);
+	ser32(cur, wave->sub_format.data1);
+	ser16(cur, wave->sub_format.data2);
+	ser16(cur, wave->sub_format.data3);
+	serblob(cur, wave->sub_format.data4, sizeof(wave->sub_format.data4));
+}
+
+static void serialise_format(struct nhlt_format *fmt, struct cursor *cur)
+{
+	serialise_waveform(&fmt->waveform, cur);
+	serialise_specific_config(&fmt->config, cur);
+}
+
+static void serialise_endpoint(struct nhlt_endpoint *endp, struct cursor *cur)
+{
+	int i;
+
+	ser32(cur, endp->length);
+	ser8(cur, endp->link_type);
+	ser8(cur, endp->instance_id);
+	ser16(cur, endp->vendor_id);
+	ser16(cur, endp->device_id);
+	ser16(cur, endp->revision_id);
+	ser32(cur, endp->subsystem_id);
+	ser8(cur, endp->device_type);
+	ser8(cur, endp->direction);
+	ser8(cur, endp->virtual_bus_id);
+	serialise_specific_config(&endp->config, cur);
+	ser8(cur, endp->num_formats);
+
+	for (i = 0; i < endp->num_formats; i++)
+		serialise_format(&endp->formats[i], cur);
+}
+
+static void nhlt_serialise_endpoints(struct nhlt *nhlt, struct cursor *cur)
+{
+	int i;
+
+	ser8(cur, nhlt->num_endpoints);
+
+	for (i = 0; i < nhlt->num_endpoints; i++)
+		serialise_endpoint(&nhlt->endpoints[i], cur);
+}
+
+int nhlt_serialise_oem_overrides(struct acpi_ctx *ctx, struct nhlt *nhlt,
+				 const char *oem_id, const char *oem_table_id,
+				 uint32_t oem_revision)
+{
+	struct cursor cur;
+	struct acpi_table_header *header;
+	size_t sz;
+	size_t oem_id_len;
+	size_t oem_table_id_len;
+	int ret;
+
+	log_info("ACPI:    * NHLT\n");
+	sz = nhlt_current_size(nhlt);
+
+	/* Create header */
+	header = (void *)ctx->current;
+	memset(header, '\0', sizeof(struct acpi_table_header));
+	acpi_fill_header(header, "NHLT");
+	header->length = sz;
+	header->revision = acpi_get_table_revision(ACPITAB_NHLT);
+
+	if (oem_id) {
+		oem_id_len = min((int)strlen(oem_id), 6);
+		memcpy(header->oem_id, oem_id, oem_id_len);
+	}
+	if (oem_table_id) {
+		oem_table_id_len = min((int)strlen(oem_table_id), 8);
+		memcpy(header->oem_table_id, oem_table_id, oem_table_id_len);
+	}
+	header->oem_revision = oem_revision;
+
+	cur.buf = (void *)(header + 1);
+	nhlt_serialise_endpoints(nhlt, &cur);
+
+	header->checksum = table_compute_checksum(header, sz);
+	nhlt_free_resources(nhlt);
+
+	ret = acpi_add_table(ctx, ctx->current);
+	if (ret)
+		return log_msg_ret("add", ret);
+	acpi_inc_align(ctx, sz);
+
+	return 0;
+}
+
+static int _nhlt_add_single_endpoint(struct nhlt *nhlt, int virtual_bus_id,
+				     const struct nhlt_endp_descriptor *epd)
+{
+	struct nhlt_endpoint *endp;
+	int ret;
+
+	endp = nhlt_add_endpoint(nhlt, epd->link, epd->device, epd->direction,
+				 epd->vid, epd->did);
+	if (!endp)
+		return -EINVAL;
+
+	endp->virtual_bus_id = virtual_bus_id;
+
+	ret = nhlt_endpoint_append_config(endp, epd->cfg, epd->cfg_size);
+	if (ret)
+		return ret;
+
+	ret = nhlt_endpoint_add_formats(endp, epd->formats, epd->num_formats);
+	if (ret)
+		return log_msg_ret("formats", ret);
+
+	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;
+	int ret;
+
+	for (i = 0; i < num_epds; i++) {
+		ret = _nhlt_add_single_endpoint(nhlt, virtual_bus_id, &epds[i]);
+		if (ret)
+			return log_ret(ret);
+	}
+
+	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;
+}