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