1 /* SPDX-License-Identifier: GPL-2.0 */
3 * Core ACPI (Advanced Configuration and Power Interface) support
5 * Copyright 2019 Google LLC
7 * Modified from coreboot file acpigen.h
10 #ifndef __ACPI_ACPIGEN_H
11 #define __ACPI_ACPIGEN_H
13 #include <linux/types.h>
17 /* Top 4 bits of the value used to indicate a three-byte length value */
18 #define ACPI_PKG_LEN_3_BYTES 0x80
20 /* ACPI Op/Prefix codes */
32 DUAL_NAME_PREFIX = 0x2e,
33 MULTI_NAME_PREFIX = 0x2f,
38 * acpigen_get_current() - Get the current ACPI code output pointer
40 * @ctx: ACPI context pointer
41 * @return output pointer
43 u8 *acpigen_get_current(struct acpi_ctx *ctx);
46 * acpigen_emit_byte() - Emit a byte to the ACPI code
48 * @ctx: ACPI context pointer
49 * @data: Value to output
51 void acpigen_emit_byte(struct acpi_ctx *ctx, uint data);
54 * acpigen_emit_word() - Emit a 16-bit word to the ACPI code
56 * @ctx: ACPI context pointer
57 * @data: Value to output
59 void acpigen_emit_word(struct acpi_ctx *ctx, uint data);
62 * acpigen_emit_dword() - Emit a 32-bit 'double word' to the ACPI code
64 * @ctx: ACPI context pointer
65 * @data: Value to output
67 void acpigen_emit_dword(struct acpi_ctx *ctx, uint data);
70 * acpigen_emit_stream() - Emit a stream of bytes
72 * @ctx: ACPI context pointer
73 * @data: Data to output
74 * @size: Size of data in bytes
76 void acpigen_emit_stream(struct acpi_ctx *ctx, const char *data, int size);
79 * acpigen_emit_string() - Emit a string
81 * Emit a string with a null terminator
83 * @ctx: ACPI context pointer
84 * @str: String to output, or NULL for an empty string
86 void acpigen_emit_string(struct acpi_ctx *ctx, const char *str);
89 * acpigen_write_len_f() - Write a 'forward' length placeholder
91 * This adds space for a length value in the ACPI stream and pushes the current
92 * position (before the length) on the stack. After calling this you can write
93 * some data and then call acpigen_pop_len() to update the length value.
97 * acpigen_write_len_f() ------\
98 * acpigen_write...() |
99 * acpigen_write...() |
100 * acpigen_write_len_f() --\ |
101 * acpigen_write...() | |
102 * acpigen_write...() | |
103 * acpigen_pop_len() ------/ |
104 * acpigen_write...() |
105 * acpigen_pop_len() ----------/
107 * See ACPI 6.3 section 20.2.4 Package Length Encoding
109 * This implementation always uses a 3-byte packet length for simplicity. It
110 * could be adjusted to support other lengths.
112 * @ctx: ACPI context pointer
114 void acpigen_write_len_f(struct acpi_ctx *ctx);
117 * acpigen_pop_len() - Update the previously stacked length placeholder
119 * Call this after the data for the block has been written. It updates the
120 * top length value in the stack and pops it off.
122 * @ctx: ACPI context pointer
124 void acpigen_pop_len(struct acpi_ctx *ctx);
127 * acpigen_write_package() - Start writing a package
129 * A package collects together a number of elements in the ACPI code. To write
132 * acpigen_write_package(ctx, 3);
136 * If you don't know the number of elements in advance, acpigen_write_package()
137 * returns a pointer to the value so you can update it later:
139 * char *num_elements = acpigen_write_package(ctx, 0);
141 * *num_elements += 1;
143 * *num_elements += 1;
146 * @ctx: ACPI context pointer
147 * @nr_el: Number of elements (0 if not known)
148 * @returns pointer to the number of elements, which can be updated by the
151 char *acpigen_write_package(struct acpi_ctx *ctx, int nr_el);
154 * acpigen_write_integer() - Write an integer
156 * This writes an operation (BYTE_OP, WORD_OP, DWORD_OP, QWORD_OP depending on
157 * the integer size) and an integer value. Note that WORD means 16 bits in ACPI.
159 * @ctx: ACPI context pointer
160 * @data: Integer to write
162 void acpigen_write_integer(struct acpi_ctx *ctx, u64 data);
165 * acpigen_write_string() - Write a string
167 * This writes a STRING_PREFIX followed by a null-terminated string
169 * @ctx: ACPI context pointer
170 * @str: String to write
172 void acpigen_write_string(struct acpi_ctx *ctx, const char *str);
175 * acpigen_emit_namestring() - Emit an ACPI name
177 * This writes out an ACPI name or path in the required special format. It does
178 * not add the NAME_OP prefix.
180 * @ctx: ACPI context pointer
181 * @namepath: Name / path to emit
183 void acpigen_emit_namestring(struct acpi_ctx *ctx, const char *namepath);
186 * acpigen_write_name() - Write out an ACPI name
188 * This writes out an ACPI name or path in the required special format with a
191 * @ctx: ACPI context pointer
192 * @namepath: Name / path to emit
194 void acpigen_write_name(struct acpi_ctx *ctx, const char *namepath);
197 * acpigen_write_uuid() - Write a UUID
199 * This writes out a UUID in the format used by ACPI, with a BUFFER_OP prefix.
201 * @ctx: ACPI context pointer
202 * @uuid: UUID to write in the form aabbccdd-eeff-gghh-iijj-kkllmmnnoopp
203 * @return 0 if OK, -EINVAL if the format is incorrect
205 int acpigen_write_uuid(struct acpi_ctx *ctx, const char *uuid);