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![Erik Schmauss](/assets/img/avatar_default.png)
Signed-off-by: Erik Schmauss <erik.schmauss@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
147 lines
3.8 KiB
C
147 lines
3.8 KiB
C
// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
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/******************************************************************************
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*
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* Module Name: hwacpi - ACPI Hardware Initialization/Mode Interface
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*
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* Copyright (C) 2000 - 2018, Intel Corp.
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*
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*****************************************************************************/
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#include <acpi/acpi.h>
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#include "accommon.h"
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#define _COMPONENT ACPI_HARDWARE
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ACPI_MODULE_NAME("hwacpi")
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#if (!ACPI_REDUCED_HARDWARE) /* Entire module */
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/******************************************************************************
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*
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* FUNCTION: acpi_hw_set_mode
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*
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* PARAMETERS: mode - SYS_MODE_ACPI or SYS_MODE_LEGACY
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*
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* RETURN: Status
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*
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* DESCRIPTION: Transitions the system into the requested mode.
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*
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******************************************************************************/
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acpi_status acpi_hw_set_mode(u32 mode)
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{
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acpi_status status;
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ACPI_FUNCTION_TRACE(hw_set_mode);
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/* If the Hardware Reduced flag is set, machine is always in acpi mode */
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if (acpi_gbl_reduced_hardware) {
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return_ACPI_STATUS(AE_OK);
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}
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/*
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* ACPI 2.0 clarified that if SMI_CMD in FADT is zero,
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* system does not support mode transition.
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*/
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if (!acpi_gbl_FADT.smi_command) {
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ACPI_ERROR((AE_INFO,
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"No SMI_CMD in FADT, mode transition failed"));
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return_ACPI_STATUS(AE_NO_HARDWARE_RESPONSE);
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}
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/*
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* ACPI 2.0 clarified the meaning of ACPI_ENABLE and ACPI_DISABLE
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* in FADT: If it is zero, enabling or disabling is not supported.
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* As old systems may have used zero for mode transition,
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* we make sure both the numbers are zero to determine these
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* transitions are not supported.
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*/
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if (!acpi_gbl_FADT.acpi_enable && !acpi_gbl_FADT.acpi_disable) {
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ACPI_ERROR((AE_INFO,
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"No ACPI mode transition supported in this system "
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"(enable/disable both zero)"));
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return_ACPI_STATUS(AE_OK);
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}
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switch (mode) {
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case ACPI_SYS_MODE_ACPI:
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/* BIOS should have disabled ALL fixed and GP events */
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status = acpi_hw_write_port(acpi_gbl_FADT.smi_command,
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(u32) acpi_gbl_FADT.acpi_enable, 8);
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ACPI_DEBUG_PRINT((ACPI_DB_INFO,
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"Attempting to enable ACPI mode\n"));
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break;
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case ACPI_SYS_MODE_LEGACY:
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/*
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* BIOS should clear all fixed status bits and restore fixed event
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* enable bits to default
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*/
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status = acpi_hw_write_port(acpi_gbl_FADT.smi_command,
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(u32)acpi_gbl_FADT.acpi_disable, 8);
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ACPI_DEBUG_PRINT((ACPI_DB_INFO,
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"Attempting to enable Legacy (non-ACPI) mode\n"));
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break;
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default:
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return_ACPI_STATUS(AE_BAD_PARAMETER);
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}
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if (ACPI_FAILURE(status)) {
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ACPI_EXCEPTION((AE_INFO, status,
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"Could not write ACPI mode change"));
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return_ACPI_STATUS(status);
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}
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return_ACPI_STATUS(AE_OK);
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}
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/*******************************************************************************
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*
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* FUNCTION: acpi_hw_get_mode
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*
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* PARAMETERS: none
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*
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* RETURN: SYS_MODE_ACPI or SYS_MODE_LEGACY
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*
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* DESCRIPTION: Return current operating state of system. Determined by
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* querying the SCI_EN bit.
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*
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******************************************************************************/
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u32 acpi_hw_get_mode(void)
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{
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acpi_status status;
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u32 value;
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ACPI_FUNCTION_TRACE(hw_get_mode);
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/* If the Hardware Reduced flag is set, machine is always in acpi mode */
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if (acpi_gbl_reduced_hardware) {
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return_UINT32(ACPI_SYS_MODE_ACPI);
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}
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/*
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* ACPI 2.0 clarified that if SMI_CMD in FADT is zero,
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* system does not support mode transition.
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*/
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if (!acpi_gbl_FADT.smi_command) {
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return_UINT32(ACPI_SYS_MODE_ACPI);
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}
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status = acpi_read_bit_register(ACPI_BITREG_SCI_ENABLE, &value);
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if (ACPI_FAILURE(status)) {
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return_UINT32(ACPI_SYS_MODE_LEGACY);
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}
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if (value) {
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return_UINT32(ACPI_SYS_MODE_ACPI);
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} else {
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return_UINT32(ACPI_SYS_MODE_LEGACY);
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}
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}
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#endif /* !ACPI_REDUCED_HARDWARE */
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