linux/drivers/acpi/acpica/exfield.c

// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/******************************************************************************
 *
 * Module Name: exfield - AML execution - field_unit read/write
 *
 * Copyright (C) 2000 - 2023, Intel Corp.
 *
 *****************************************************************************/

#include <acpi/acpi.h>
#include "accommon.h"
#include "acdispat.h"
#include "acinterp.h"
#include "amlcode.h"

#define _COMPONENT …
ACPI_MODULE_NAME("exfield")

/*
 * This table maps the various Attrib protocols to the byte transfer
 * length. Used for the generic serial bus.
 */
#define ACPI_INVALID_PROTOCOL_ID …
#define ACPI_MAX_PROTOCOL_ID …
static const u8 acpi_protocol_lengths[] = …;

#define PCC_MASTER_SUBSPACE …

/*
 * The following macros determine a given offset is a COMD field.
 * According to the specification, generic subspaces (types 0-2) contains a
 * 2-byte COMD field at offset 4 and master subspaces (type 3) contains a 4-byte
 * COMD field starting at offset 12.
 */
#define GENERIC_SUBSPACE_COMMAND(a) …
#define MASTER_SUBSPACE_COMMAND(a) …

/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_get_protocol_buffer_length
 *
 * PARAMETERS:  protocol_id     - The type of the protocol indicated by region
 *                                field access attributes
 *              return_length   - Where the protocol byte transfer length is
 *                                returned
 *
 * RETURN:      Status and decoded byte transfer length
 *
 * DESCRIPTION: This routine returns the length of the generic_serial_bus
 *              protocol bytes
 *
 ******************************************************************************/

acpi_status
acpi_ex_get_protocol_buffer_length(u32 protocol_id, u32 *return_length)
{ … }

/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_read_data_from_field
 *
 * PARAMETERS:  walk_state          - Current execution state
 *              obj_desc            - The named field
 *              ret_buffer_desc     - Where the return data object is stored
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Read from a named field. Returns either an Integer or a
 *              Buffer, depending on the size of the field and whether if a
 *              field is created by the create_field() operator.
 *
 ******************************************************************************/

acpi_status
acpi_ex_read_data_from_field(struct acpi_walk_state *walk_state,
			     union acpi_operand_object *obj_desc,
			     union acpi_operand_object **ret_buffer_desc)
{ … }

/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_write_data_to_field
 *
 * PARAMETERS:  source_desc         - Contains data to write
 *              obj_desc            - The named field
 *              result_desc         - Where the return value is returned, if any
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Write to a named field
 *
 ******************************************************************************/

acpi_status
acpi_ex_write_data_to_field(union acpi_operand_object *source_desc,
			    union acpi_operand_object *obj_desc,
			    union acpi_operand_object **result_desc)
{ … }