ACPI: NHLT: Introduce API for the table

The table is composed of a range of endpoints with each describing
audio formats they support. Most of the operations involve iterating
over elements of the table and filtering them. Simplify the process by
implementing range of getters.

While the acpi_nhlt_endpoint_mic_count() stands out a bit, it is a
critical component for any AudioDSP driver to know how many digital
microphones it is dealing with.

Signed-off-by: Cezary Rojewski <cezary.rojewski@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 181 insertions, 0 deletions

diff --git a/include/acpi/nhlt.h b/include/acpi/nhlt.h
new file mode 100644
index 000000000000..7c394e7bc2bb
--- /dev/null
+++ b/include/acpi/nhlt.h
@@ -0,0 +1,181 @@
+/* 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>
+ */
+
+#ifndef __ACPI_NHLT_H__
+#define __ACPI_NHLT_H__
+
+#include <linux/acpi.h>
+#include <linux/kconfig.h>
+#include <linux/overflow.h>
+#include <linux/types.h>
+
+#define __acpi_nhlt_endpoint_config(ep)		((void *)((ep) + 1))
+#define __acpi_nhlt_config_caps(cfg)		((void *)((cfg) + 1))
+
+/**
+ * acpi_nhlt_endpoint_fmtscfg - Get the formats configuration space.
+ * @ep:		the endpoint to retrieve the space for.
+ *
+ * Return: A pointer to the formats configuration space.
+ */
+static inline struct acpi_nhlt2_formats_config *
+acpi_nhlt_endpoint_fmtscfg(const struct acpi_nhlt2_endpoint *ep)
+{
+	struct acpi_nhlt_config *cfg = __acpi_nhlt_endpoint_config(ep);
+
+	return (struct acpi_nhlt2_formats_config *)((u8 *)(cfg + 1) + cfg->capabilities_size);
+}
+
+#define __acpi_nhlt_first_endpoint(tb) \
+	((void *)(tb + 1))
+
+#define __acpi_nhlt_next_endpoint(ep) \
+	((void *)((u8 *)(ep) + (ep)->length))
+
+#define __acpi_nhlt_get_endpoint(tb, ep, i) \
+	((i) ? __acpi_nhlt_next_endpoint(ep) : __acpi_nhlt_first_endpoint(tb))
+
+#define __acpi_nhlt_first_fmtcfg(fmts) \
+	((void *)(fmts + 1))
+
+#define __acpi_nhlt_next_fmtcfg(fmt) \
+	((void *)((u8 *)((fmt) + 1) + (fmt)->config.capabilities_size))
+
+#define __acpi_nhlt_get_fmtcfg(fmts, fmt, i) \
+	((i) ? __acpi_nhlt_next_fmtcfg(fmt) : __acpi_nhlt_first_fmtcfg(fmts))
+
+/*
+ * The for_each_nhlt_*() macros rely on an iterator to deal with the
+ * variable length of each endpoint structure and the possible presence
+ * of an OED-Config used by Windows only.
+ */
+
+/**
+ * for_each_nhlt_endpoint - Iterate over endpoints in a NHLT table.
+ * @tb:		the pointer to a NHLT table.
+ * @ep:		the pointer to endpoint to use as loop cursor.
+ */
+#define for_each_nhlt_endpoint(tb, ep)					\
+	for (unsigned int __i = 0;					\
+	     __i < (tb)->endpoints_count &&				\
+		(ep = __acpi_nhlt_get_endpoint(tb, ep, __i));		\
+	     __i++)
+
+/**
+ * for_each_nhlt_fmtcfg - Iterate over format configurations.
+ * @fmts:	the pointer to formats configuration space.
+ * @fmt:	the pointer to format to use as loop cursor.
+ */
+#define for_each_nhlt_fmtcfg(fmts, fmt)					\
+	for (unsigned int __i = 0;					\
+	     __i < (fmts)->formats_count &&				\
+		(fmt = __acpi_nhlt_get_fmtcfg(fmts, fmt, __i));	\
+	     __i++)
+
+/**
+ * for_each_nhlt_endpoint_fmtcfg - Iterate over format configurations in an endpoint.
+ * @ep:		the pointer to an endpoint.
+ * @fmt:	the pointer to format to use as loop cursor.
+ */
+#define for_each_nhlt_endpoint_fmtcfg(ep, fmt) \
+	for_each_nhlt_fmtcfg(acpi_nhlt_endpoint_fmtscfg(ep), fmt)
+
+#if IS_ENABLED(CONFIG_ACPI_NHLT)
+
+/*
+ * System-wide pointer to the first NHLT table.
+ *
+ * A sound driver may utilize acpi_nhlt_get/put_gbl_table() on its
+ * initialization and removal respectively to avoid excessive mapping
+ * and unmapping of the memory occupied by the table between streaming
+ * operations.
+ */
+
+acpi_status acpi_nhlt_get_gbl_table(void);
+void acpi_nhlt_put_gbl_table(void);
+
+bool acpi_nhlt_endpoint_match(const struct acpi_nhlt2_endpoint *ep,
+			      int link_type, int dev_type, int dir, int bus_id);
+struct acpi_nhlt2_endpoint *
+acpi_nhlt_tb_find_endpoint(const struct acpi_table_nhlt2 *tb,
+			   int link_type, int dev_type, int dir, int bus_id);
+struct acpi_nhlt2_endpoint *
+acpi_nhlt_find_endpoint(int link_type, int dev_type, int dir, int bus_id);
+struct acpi_nhlt2_format_config *
+acpi_nhlt_endpoint_find_fmtcfg(const struct acpi_nhlt2_endpoint *ep,
+			       u16 ch, u32 rate, u16 vbps, u16 bps);
+struct acpi_nhlt2_format_config *
+acpi_nhlt_tb_find_fmtcfg(const struct acpi_table_nhlt2 *tb,
+			 int link_type, int dev_type, int dir, int bus_id,
+			 u16 ch, u32 rate, u16 vpbs, u16 bps);
+struct acpi_nhlt2_format_config *
+acpi_nhlt_find_fmtcfg(int link_type, int dev_type, int dir, int bus_id,
+		      u16 ch, u32 rate, u16 vpbs, u16 bps);
+int acpi_nhlt_endpoint_mic_count(const struct acpi_nhlt2_endpoint *ep);
+
+#else /* !CONFIG_ACPI_NHLT */
+
+static inline acpi_status acpi_nhlt_get_gbl_table(void)
+{
+	return AE_NOT_FOUND;
+}
+
+static inline void acpi_nhlt_put_gbl_table(void)
+{
+}
+
+static inline bool
+acpi_nhlt_endpoint_match(const struct acpi_nhlt2_endpoint *ep,
+			 int link_type, int dev_type, int dir, int bus_id)
+{
+	return false;
+}
+
+static inline struct acpi_nhlt2_endpoint *
+acpi_nhlt_tb_find_endpoint(const struct acpi_table_nhlt2 *tb,
+			   int link_type, int dev_type, int dir, int bus_id)
+{
+	return NULL;
+}
+
+static inline struct acpi_nhlt2_format_config *
+acpi_nhlt_endpoint_find_fmtcfg(const struct acpi_nhlt2_endpoint *ep,
+			       u16 ch, u32 rate, u16 vbps, u16 bps)
+{
+	return NULL;
+}
+
+static inline struct acpi_nhlt2_format_config *
+acpi_nhlt_tb_find_fmtcfg(const struct acpi_table_nhlt2 *tb,
+			 int link_type, int dev_type, int dir, int bus_id,
+			 u16 ch, u32 rate, u16 vpbs, u16 bps)
+{
+	return NULL;
+}
+
+static inline int acpi_nhlt_endpoint_mic_count(const struct acpi_nhlt2_endpoint *ep)
+{
+	return 0;
+}
+
+static inline struct acpi_nhlt2_endpoint *
+acpi_nhlt_find_endpoint(int link_type, int dev_type, int dir, int bus_id)
+{
+	return NULL;
+}
+
+static inline struct acpi_nhlt2_format_config *
+acpi_nhlt_find_fmtcfg(int link_type, int dev_type, int dir, int bus_id,
+		      u16 ch, u32 rate, u16 vpbs, u16 bps)
+{
+	return NULL;
+}
+
+#endif /* CONFIG_ACPI_NHLT */
+
+#endif /* __ACPI_NHLT_H__ */