// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0 /****************************************************************************** * * Module Name: hwacpi - ACPI Hardware Initialization/Mode Interface * * Copyright (C) 2000 - 2019, 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 */