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 */
33 * acpigen_get_current() - Get the current ACPI code output pointer
35 * @ctx: ACPI context pointer
36 * @return output pointer
38 u8 *acpigen_get_current(struct acpi_ctx *ctx);
41 * acpigen_emit_byte() - Emit a byte to the ACPI code
43 * @ctx: ACPI context pointer
44 * @data: Value to output
46 void acpigen_emit_byte(struct acpi_ctx *ctx, uint data);
49 * acpigen_emit_word() - Emit a 16-bit word to the ACPI code
51 * @ctx: ACPI context pointer
52 * @data: Value to output
54 void acpigen_emit_word(struct acpi_ctx *ctx, uint data);
57 * acpigen_emit_dword() - Emit a 32-bit 'double word' to the ACPI code
59 * @ctx: ACPI context pointer
60 * @data: Value to output
62 void acpigen_emit_dword(struct acpi_ctx *ctx, uint data);
65 * acpigen_emit_stream() - Emit a stream of bytes
67 * @ctx: ACPI context pointer
68 * @data: Data to output
69 * @size: Size of data in bytes
71 void acpigen_emit_stream(struct acpi_ctx *ctx, const char *data, int size);
74 * acpigen_emit_string() - Emit a string
76 * Emit a string with a null terminator
78 * @ctx: ACPI context pointer
79 * @str: String to output, or NULL for an empty string
81 void acpigen_emit_string(struct acpi_ctx *ctx, const char *str);
84 * acpigen_write_len_f() - Write a 'forward' length placeholder
86 * This adds space for a length value in the ACPI stream and pushes the current
87 * position (before the length) on the stack. After calling this you can write
88 * some data and then call acpigen_pop_len() to update the length value.
92 * acpigen_write_len_f() ------\
93 * acpigen_write...() |
94 * acpigen_write...() |
95 * acpigen_write_len_f() --\ |
96 * acpigen_write...() | |
97 * acpigen_write...() | |
98 * acpigen_pop_len() ------/ |
99 * acpigen_write...() |
100 * acpigen_pop_len() ----------/
102 * See ACPI 6.3 section 20.2.4 Package Length Encoding
104 * This implementation always uses a 3-byte packet length for simplicity. It
105 * could be adjusted to support other lengths.
107 * @ctx: ACPI context pointer
109 void acpigen_write_len_f(struct acpi_ctx *ctx);
112 * acpigen_pop_len() - Update the previously stacked length placeholder
114 * Call this after the data for the block has been written. It updates the
115 * top length value in the stack and pops it off.
117 * @ctx: ACPI context pointer
119 void acpigen_pop_len(struct acpi_ctx *ctx);
122 * acpigen_write_package() - Start writing a package
124 * A package collects together a number of elements in the ACPI code. To write
127 * acpigen_write_package(ctx, 3);
131 * If you don't know the number of elements in advance, acpigen_write_package()
132 * returns a pointer to the value so you can update it later:
134 * char *num_elements = acpigen_write_package(ctx, 0);
136 * *num_elements += 1;
138 * *num_elements += 1;
141 * @ctx: ACPI context pointer
142 * @nr_el: Number of elements (0 if not known)
143 * @returns pointer to the number of elements, which can be updated by the
146 char *acpigen_write_package(struct acpi_ctx *ctx, int nr_el);
149 * acpigen_write_integer() - Write an integer
151 * This writes an operation (BYTE_OP, WORD_OP, DWORD_OP, QWORD_OP depending on
152 * the integer size) and an integer value. Note that WORD means 16 bits in ACPI.
154 * @ctx: ACPI context pointer
155 * @data: Integer to write
157 void acpigen_write_integer(struct acpi_ctx *ctx, u64 data);
160 * acpigen_write_string() - Write a string
162 * This writes a STRING_PREFIX followed by a null-terminated string
164 * @ctx: ACPI context pointer
165 * @str: String to write
167 void acpigen_write_string(struct acpi_ctx *ctx, const char *str);