1 /****************************************************************************** 2 * 3 * Module Name: hwacpi - ACPI Hardware Initialization/Mode Interface 4 * 5 *****************************************************************************/ 6 7 /* 8 * Copyright (C) 2000 - 2017, Intel Corp. 9 * All rights reserved. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions, and the following disclaimer, 16 * without modification. 17 * 2. Redistributions in binary form must reproduce at minimum a disclaimer 18 * substantially similar to the "NO WARRANTY" disclaimer below 19 * ("Disclaimer") and any redistribution must be conditioned upon 20 * including a substantially similar Disclaimer requirement for further 21 * binary redistribution. 22 * 3. Neither the names of the above-listed copyright holders nor the names 23 * of any contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * Alternatively, this software may be distributed under the terms of the 27 * GNU General Public License ("GPL") version 2 as published by the Free 28 * Software Foundation. 29 * 30 * NO WARRANTY 31 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 32 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 33 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR 34 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 35 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 36 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 37 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 38 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 39 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 40 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 41 * POSSIBILITY OF SUCH DAMAGES. 42 */ 43 44 #include <acpi/acpi.h> 45 #include "accommon.h" 46 47 #define _COMPONENT ACPI_HARDWARE 48 ACPI_MODULE_NAME("hwacpi") 49 50 #if (!ACPI_REDUCED_HARDWARE) /* Entire module */ 51 /****************************************************************************** 52 * 53 * FUNCTION: acpi_hw_set_mode 54 * 55 * PARAMETERS: mode - SYS_MODE_ACPI or SYS_MODE_LEGACY 56 * 57 * RETURN: Status 58 * 59 * DESCRIPTION: Transitions the system into the requested mode. 60 * 61 ******************************************************************************/ 62 acpi_status acpi_hw_set_mode(u32 mode) 63 { 64 65 acpi_status status; 66 67 ACPI_FUNCTION_TRACE(hw_set_mode); 68 69 /* If the Hardware Reduced flag is set, machine is always in acpi mode */ 70 71 if (acpi_gbl_reduced_hardware) { 72 return_ACPI_STATUS(AE_OK); 73 } 74 75 /* 76 * ACPI 2.0 clarified that if SMI_CMD in FADT is zero, 77 * system does not support mode transition. 78 */ 79 if (!acpi_gbl_FADT.smi_command) { 80 ACPI_ERROR((AE_INFO, 81 "No SMI_CMD in FADT, mode transition failed")); 82 return_ACPI_STATUS(AE_NO_HARDWARE_RESPONSE); 83 } 84 85 /* 86 * ACPI 2.0 clarified the meaning of ACPI_ENABLE and ACPI_DISABLE 87 * in FADT: If it is zero, enabling or disabling is not supported. 88 * As old systems may have used zero for mode transition, 89 * we make sure both the numbers are zero to determine these 90 * transitions are not supported. 91 */ 92 if (!acpi_gbl_FADT.acpi_enable && !acpi_gbl_FADT.acpi_disable) { 93 ACPI_ERROR((AE_INFO, 94 "No ACPI mode transition supported in this system " 95 "(enable/disable both zero)")); 96 return_ACPI_STATUS(AE_OK); 97 } 98 99 switch (mode) { 100 case ACPI_SYS_MODE_ACPI: 101 102 /* BIOS should have disabled ALL fixed and GP events */ 103 104 status = acpi_hw_write_port(acpi_gbl_FADT.smi_command, 105 (u32) acpi_gbl_FADT.acpi_enable, 8); 106 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 107 "Attempting to enable ACPI mode\n")); 108 break; 109 110 case ACPI_SYS_MODE_LEGACY: 111 /* 112 * BIOS should clear all fixed status bits and restore fixed event 113 * enable bits to default 114 */ 115 status = acpi_hw_write_port(acpi_gbl_FADT.smi_command, 116 (u32)acpi_gbl_FADT.acpi_disable, 8); 117 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 118 "Attempting to enable Legacy (non-ACPI) mode\n")); 119 break; 120 121 default: 122 123 return_ACPI_STATUS(AE_BAD_PARAMETER); 124 } 125 126 if (ACPI_FAILURE(status)) { 127 ACPI_EXCEPTION((AE_INFO, status, 128 "Could not write ACPI mode change")); 129 return_ACPI_STATUS(status); 130 } 131 132 return_ACPI_STATUS(AE_OK); 133 } 134 135 /******************************************************************************* 136 * 137 * FUNCTION: acpi_hw_get_mode 138 * 139 * PARAMETERS: none 140 * 141 * RETURN: SYS_MODE_ACPI or SYS_MODE_LEGACY 142 * 143 * DESCRIPTION: Return current operating state of system. Determined by 144 * querying the SCI_EN bit. 145 * 146 ******************************************************************************/ 147 148 u32 acpi_hw_get_mode(void) 149 { 150 acpi_status status; 151 u32 value; 152 153 ACPI_FUNCTION_TRACE(hw_get_mode); 154 155 /* If the Hardware Reduced flag is set, machine is always in acpi mode */ 156 157 if (acpi_gbl_reduced_hardware) { 158 return_UINT32(ACPI_SYS_MODE_ACPI); 159 } 160 161 /* 162 * ACPI 2.0 clarified that if SMI_CMD in FADT is zero, 163 * system does not support mode transition. 164 */ 165 if (!acpi_gbl_FADT.smi_command) { 166 return_UINT32(ACPI_SYS_MODE_ACPI); 167 } 168 169 status = acpi_read_bit_register(ACPI_BITREG_SCI_ENABLE, &value); 170 if (ACPI_FAILURE(status)) { 171 return_UINT32(ACPI_SYS_MODE_LEGACY); 172 } 173 174 if (value) { 175 return_UINT32(ACPI_SYS_MODE_ACPI); 176 } else { 177 return_UINT32(ACPI_SYS_MODE_LEGACY); 178 } 179 } 180 181 #endif /* !ACPI_REDUCED_HARDWARE */ 182