1 files changed, 289 insertions, 0 deletions
diff --git a/drivers/acpi/nhlt.c b/drivers/acpi/nhlt.c
new file mode 100644
index 000000000000..dc1bd0df9228
--- /dev/null
+++ b/drivers/acpi/nhlt.c
@@ -0,0 +1,289 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright(c) 2023-2024 Intel Corporation
+ *
+ * Authors: Cezary Rojewski <cezary.rojewski@intel.com>
+ *          Amadeusz Slawinski <amadeuszx.slawinski@linux.intel.com>
+ */
+
+#define pr_fmt(fmt) "ACPI: NHLT: " fmt
+
+#include <linux/acpi.h>
+#include <linux/errno.h>
+#include <linux/export.h>
+#include <linux/minmax.h>
+#include <linux/printk.h>
+#include <linux/types.h>
+#include <acpi/nhlt.h>
+
+static struct acpi_table_nhlt *acpi_gbl_nhlt;
+
+static struct acpi_table_nhlt empty_nhlt = {
+	.header = {
+		.signature = ACPI_SIG_NHLT,
+	},
+};
+
+/**
+ * acpi_nhlt_get_gbl_table - Retrieve a pointer to the first NHLT table.
+ *
+ * If there is no NHLT in the system, acpi_gbl_nhlt will instead point to an
+ * empty table.
+ *
+ * Return: ACPI status code of the operation.
+ */
+acpi_status acpi_nhlt_get_gbl_table(void)
+{
+	acpi_status status;
+
+	status = acpi_get_table(ACPI_SIG_NHLT, 0, (struct acpi_table_header **)(&acpi_gbl_nhlt));
+	if (!acpi_gbl_nhlt)
+		acpi_gbl_nhlt = &empty_nhlt;
+	return status;
+}
+EXPORT_SYMBOL_GPL(acpi_nhlt_get_gbl_table);
+
+/**
+ * acpi_nhlt_put_gbl_table - Release the global NHLT table.
+ */
+void acpi_nhlt_put_gbl_table(void)
+{
+	acpi_put_table((struct acpi_table_header *)acpi_gbl_nhlt);
+}
+EXPORT_SYMBOL_GPL(acpi_nhlt_put_gbl_table);
+
+/**
+ * acpi_nhlt_endpoint_match - Verify if an endpoint matches criteria.
+ * @ep:			the endpoint to check.
+ * @link_type:		the hardware link type, e.g.: PDM or SSP.
+ * @dev_type:		the device type.
+ * @dir:		stream direction.
+ * @bus_id:		the ID of virtual bus hosting the endpoint.
+ *
+ * Either of @link_type, @dev_type, @dir or @bus_id may be set to a negative
+ * value to ignore the parameter when matching.
+ *
+ * Return: %true if endpoint matches specified criteria or %false otherwise.
+ */
+bool acpi_nhlt_endpoint_match(const struct acpi_nhlt_endpoint *ep,
+			      int link_type, int dev_type, int dir, int bus_id)
+{
+	return ep &&
+	       (link_type < 0 || ep->link_type == link_type) &&
+	       (dev_type < 0 || ep->device_type == dev_type) &&
+	       (bus_id < 0 || ep->virtual_bus_id == bus_id) &&
+	       (dir < 0 || ep->direction == dir);
+}
+EXPORT_SYMBOL_GPL(acpi_nhlt_endpoint_match);
+
+/**
+ * acpi_nhlt_tb_find_endpoint - Search a NHLT table for an endpoint.
+ * @tb:			the table to search.
+ * @link_type:		the hardware link type, e.g.: PDM or SSP.
+ * @dev_type:		the device type.
+ * @dir:		stream direction.
+ * @bus_id:		the ID of virtual bus hosting the endpoint.
+ *
+ * Either of @link_type, @dev_type, @dir or @bus_id may be set to a negative
+ * value to ignore the parameter during the search.
+ *
+ * Return: A pointer to endpoint matching the criteria, %NULL if not found or
+ * an ERR_PTR() otherwise.
+ */
+struct acpi_nhlt_endpoint *
+acpi_nhlt_tb_find_endpoint(const struct acpi_table_nhlt *tb,
+			   int link_type, int dev_type, int dir, int bus_id)
+{
+	struct acpi_nhlt_endpoint *ep;
+
+	for_each_nhlt_endpoint(tb, ep)
+		if (acpi_nhlt_endpoint_match(ep, link_type, dev_type, dir, bus_id))
+			return ep;
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(acpi_nhlt_tb_find_endpoint);
+
+/**
+ * acpi_nhlt_find_endpoint - Search all NHLT tables for an endpoint.
+ * @link_type:		the hardware link type, e.g.: PDM or SSP.
+ * @dev_type:		the device type.
+ * @dir:		stream direction.
+ * @bus_id:		the ID of virtual bus hosting the endpoint.
+ *
+ * Either of @link_type, @dev_type, @dir or @bus_id may be set to a negative
+ * value to ignore the parameter during the search.
+ *
+ * Return: A pointer to endpoint matching the criteria, %NULL if not found or
+ * an ERR_PTR() otherwise.
+ */
+struct acpi_nhlt_endpoint *
+acpi_nhlt_find_endpoint(int link_type, int dev_type, int dir, int bus_id)
+{
+	/* TODO: Currently limited to table of index 0. */
+	return acpi_nhlt_tb_find_endpoint(acpi_gbl_nhlt, link_type, dev_type, dir, bus_id);
+}
+EXPORT_SYMBOL_GPL(acpi_nhlt_find_endpoint);
+
+/**
+ * acpi_nhlt_endpoint_find_fmtcfg - Search endpoint's formats configuration space
+ *                                  for a specific format.
+ * @ep:			the endpoint to search.
+ * @ch:			number of channels.
+ * @rate:		samples per second.
+ * @vbps:		valid bits per sample.
+ * @bps:		bits per sample.
+ *
+ * Return: A pointer to format matching the criteria, %NULL if not found or
+ * an ERR_PTR() otherwise.
+ */
+struct acpi_nhlt_format_config *
+acpi_nhlt_endpoint_find_fmtcfg(const struct acpi_nhlt_endpoint *ep,
+			       u16 ch, u32 rate, u16 vbps, u16 bps)
+{
+	struct acpi_nhlt_wave_formatext *wav;
+	struct acpi_nhlt_format_config *fmt;
+
+	for_each_nhlt_endpoint_fmtcfg(ep, fmt) {
+		wav = &fmt->format;
+
+		if (wav->valid_bits_per_sample == vbps &&
+		    wav->samples_per_sec == rate &&
+		    wav->bits_per_sample == bps &&
+		    wav->channel_count == ch)
+			return fmt;
+	}
+
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(acpi_nhlt_endpoint_find_fmtcfg);
+
+/**
+ * acpi_nhlt_tb_find_fmtcfg - Search a NHLT table for a specific format.
+ * @tb:			the table to search.
+ * @link_type:		the hardware link type, e.g.: PDM or SSP.
+ * @dev_type:		the device type.
+ * @dir:		stream direction.
+ * @bus_id:		the ID of virtual bus hosting the endpoint.
+ *
+ * @ch:			number of channels.
+ * @rate:		samples per second.
+ * @vbps:		valid bits per sample.
+ * @bps:		bits per sample.
+ *
+ * Either of @link_type, @dev_type, @dir or @bus_id may be set to a negative
+ * value to ignore the parameter during the search.
+ *
+ * Return: A pointer to format matching the criteria, %NULL if not found or
+ * an ERR_PTR() otherwise.
+ */
+struct acpi_nhlt_format_config *
+acpi_nhlt_tb_find_fmtcfg(const struct acpi_table_nhlt *tb,
+			 int link_type, int dev_type, int dir, int bus_id,
+			 u16 ch, u32 rate, u16 vbps, u16 bps)
+{
+	struct acpi_nhlt_format_config *fmt;
+	struct acpi_nhlt_endpoint *ep;
+
+	for_each_nhlt_endpoint(tb, ep) {
+		if (!acpi_nhlt_endpoint_match(ep, link_type, dev_type, dir, bus_id))
+			continue;
+
+		fmt = acpi_nhlt_endpoint_find_fmtcfg(ep, ch, rate, vbps, bps);
+		if (fmt)
+			return fmt;
+	}
+
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(acpi_nhlt_tb_find_fmtcfg);
+
+/**
+ * acpi_nhlt_find_fmtcfg - Search all NHLT tables for a specific format.
+ * @link_type:		the hardware link type, e.g.: PDM or SSP.
+ * @dev_type:		the device type.
+ * @dir:		stream direction.
+ * @bus_id:		the ID of virtual bus hosting the endpoint.
+ *
+ * @ch:			number of channels.
+ * @rate:		samples per second.
+ * @vbps:		valid bits per sample.
+ * @bps:		bits per sample.
+ *
+ * Either of @link_type, @dev_type, @dir or @bus_id may be set to a negative
+ * value to ignore the parameter during the search.
+ *
+ * Return: A pointer to format matching the criteria, %NULL if not found or
+ * an ERR_PTR() otherwise.
+ */
+struct acpi_nhlt_format_config *
+acpi_nhlt_find_fmtcfg(int link_type, int dev_type, int dir, int bus_id,
+		      u16 ch, u32 rate, u16 vbps, u16 bps)
+{
+	/* TODO: Currently limited to table of index 0. */
+	return acpi_nhlt_tb_find_fmtcfg(acpi_gbl_nhlt, link_type, dev_type, dir, bus_id,
+					ch, rate, vbps, bps);
+}
+EXPORT_SYMBOL_GPL(acpi_nhlt_find_fmtcfg);
+
+static bool acpi_nhlt_config_is_micdevice(struct acpi_nhlt_config *cfg)
+{
+	return cfg->capabilities_size >= sizeof(struct acpi_nhlt_micdevice_config);
+}
+
+static bool acpi_nhlt_config_is_vendor_micdevice(struct acpi_nhlt_config *cfg)
+{
+	struct acpi_nhlt_vendor_micdevice_config *devcfg = __acpi_nhlt_config_caps(cfg);
+
+	return cfg->capabilities_size >= sizeof(*devcfg) &&
+	       cfg->capabilities_size == struct_size(devcfg, mics, devcfg->mics_count);
+}
+
+/**
+ * acpi_nhlt_endpoint_mic_count - Retrieve number of digital microphones for a PDM endpoint.
+ * @ep:			the endpoint to return microphones count for.
+ *
+ * Return: A number of microphones or an error code if an invalid endpoint is provided.
+ */
+int acpi_nhlt_endpoint_mic_count(const struct acpi_nhlt_endpoint *ep)
+{
+	union acpi_nhlt_device_config *devcfg;
+	struct acpi_nhlt_format_config *fmt;
+	struct acpi_nhlt_config *cfg;
+	u16 max_ch = 0;
+
+	if (!ep || ep->link_type != ACPI_NHLT_LINKTYPE_PDM)
+		return -EINVAL;
+
+	/* Find max number of channels based on formats configuration. */
+	for_each_nhlt_endpoint_fmtcfg(ep, fmt)
+		max_ch = max(fmt->format.channel_count, max_ch);
+
+	cfg = __acpi_nhlt_endpoint_config(ep);
+	devcfg = __acpi_nhlt_config_caps(cfg);
+
+	/* If @ep is not a mic array, fallback to channels count. */
+	if (!acpi_nhlt_config_is_micdevice(cfg) ||
+	    devcfg->gen.config_type != ACPI_NHLT_CONFIGTYPE_MICARRAY)
+		return max_ch;
+
+	switch (devcfg->mic.array_type) {
+	case ACPI_NHLT_ARRAYTYPE_LINEAR2_SMALL:
+	case ACPI_NHLT_ARRAYTYPE_LINEAR2_BIG:
+		return 2;
+
+	case ACPI_NHLT_ARRAYTYPE_LINEAR4_GEO1:
+	case ACPI_NHLT_ARRAYTYPE_PLANAR4_LSHAPED:
+	case ACPI_NHLT_ARRAYTYPE_LINEAR4_GEO2:
+		return 4;
+
+	case ACPI_NHLT_ARRAYTYPE_VENDOR:
+		if (!acpi_nhlt_config_is_vendor_micdevice(cfg))
+			return -EINVAL;
+		return devcfg->vendor_mic.mics_count;
+
+	default:
+		pr_warn("undefined mic array type: %#x\n", devcfg->mic.array_type);
+		return max_ch;
+	}
+}
+EXPORT_SYMBOL_GPL(acpi_nhlt_endpoint_mic_count);