1 2 /****************************************************************************** 3 * 4 * Module Name: hwacpi - ACPI Hardware Initialization/Mode Interface 5 * 6 *****************************************************************************/ 7 8 /* 9 * Copyright (C) 2000 - 2011, Intel Corp. 10 * All rights reserved. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions, and the following disclaimer, 17 * without modification. 18 * 2. Redistributions in binary form must reproduce at minimum a disclaimer 19 * substantially similar to the "NO WARRANTY" disclaimer below 20 * ("Disclaimer") and any redistribution must be conditioned upon 21 * including a substantially similar Disclaimer requirement for further 22 * binary redistribution. 23 * 3. Neither the names of the above-listed copyright holders nor the names 24 * of any contributors may be used to endorse or promote products derived 25 * from this software without specific prior written permission. 26 * 27 * Alternatively, this software may be distributed under the terms of the 28 * GNU General Public License ("GPL") version 2 as published by the Free 29 * Software Foundation. 30 * 31 * NO WARRANTY 32 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 33 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 34 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR 35 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 36 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 37 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 38 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 39 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 40 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 41 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 42 * POSSIBILITY OF SUCH DAMAGES. 43 */ 44 45 #define __HWACPI_C__ 46 47 #include "acpi.h" 48 #include "accommon.h" 49 50 51 #define _COMPONENT ACPI_HARDWARE 52 ACPI_MODULE_NAME ("hwacpi") 53 54 55 /****************************************************************************** 56 * 57 * FUNCTION: AcpiHwSetMode 58 * 59 * PARAMETERS: Mode - SYS_MODE_ACPI or SYS_MODE_LEGACY 60 * 61 * RETURN: Status 62 * 63 * DESCRIPTION: Transitions the system into the requested mode. 64 * 65 ******************************************************************************/ 66 67 ACPI_STATUS 68 AcpiHwSetMode ( 69 UINT32 Mode) 70 { 71 72 ACPI_STATUS Status; 73 UINT32 Retry; 74 75 76 ACPI_FUNCTION_TRACE (HwSetMode); 77 78 /* 79 * ACPI 2.0 clarified that if SMI_CMD in FADT is zero, 80 * system does not support mode transition. 81 */ 82 if (!AcpiGbl_FADT.SmiCommand) 83 { 84 ACPI_ERROR ((AE_INFO, "No SMI_CMD in FADT, mode transition failed")); 85 return_ACPI_STATUS (AE_NO_HARDWARE_RESPONSE); 86 } 87 88 /* 89 * ACPI 2.0 clarified the meaning of ACPI_ENABLE and ACPI_DISABLE 90 * in FADT: If it is zero, enabling or disabling is not supported. 91 * As old systems may have used zero for mode transition, 92 * we make sure both the numbers are zero to determine these 93 * transitions are not supported. 94 */ 95 if (!AcpiGbl_FADT.AcpiEnable && !AcpiGbl_FADT.AcpiDisable) 96 { 97 ACPI_ERROR ((AE_INFO, 98 "No ACPI mode transition supported in this system " 99 "(enable/disable both zero)")); 100 return_ACPI_STATUS (AE_OK); 101 } 102 103 switch (Mode) 104 { 105 case ACPI_SYS_MODE_ACPI: 106 107 /* BIOS should have disabled ALL fixed and GP events */ 108 109 Status = AcpiHwWritePort (AcpiGbl_FADT.SmiCommand, 110 (UINT32) AcpiGbl_FADT.AcpiEnable, 8); 111 ACPI_DEBUG_PRINT ((ACPI_DB_INFO, "Attempting to enable ACPI mode\n")); 112 break; 113 114 case ACPI_SYS_MODE_LEGACY: 115 116 /* 117 * BIOS should clear all fixed status bits and restore fixed event 118 * enable bits to default 119 */ 120 Status = AcpiHwWritePort (AcpiGbl_FADT.SmiCommand, 121 (UINT32) AcpiGbl_FADT.AcpiDisable, 8); 122 ACPI_DEBUG_PRINT ((ACPI_DB_INFO, 123 "Attempting to enable Legacy (non-ACPI) mode\n")); 124 break; 125 126 default: 127 return_ACPI_STATUS (AE_BAD_PARAMETER); 128 } 129 130 if (ACPI_FAILURE (Status)) 131 { 132 ACPI_EXCEPTION ((AE_INFO, Status, 133 "Could not write ACPI mode change")); 134 return_ACPI_STATUS (Status); 135 } 136 137 /* 138 * Some hardware takes a LONG time to switch modes. Give them 3 sec to 139 * do so, but allow faster systems to proceed more quickly. 140 */ 141 Retry = 3000; 142 while (Retry) 143 { 144 if (AcpiHwGetMode() == Mode) 145 { 146 ACPI_DEBUG_PRINT ((ACPI_DB_INFO, "Mode %X successfully enabled\n", 147 Mode)); 148 return_ACPI_STATUS (AE_OK); 149 } 150 AcpiOsStall(1000); 151 Retry--; 152 } 153 154 ACPI_ERROR ((AE_INFO, "Hardware did not change modes")); 155 return_ACPI_STATUS (AE_NO_HARDWARE_RESPONSE); 156 } 157 158 159 /******************************************************************************* 160 * 161 * FUNCTION: AcpiHwGetMode 162 * 163 * PARAMETERS: none 164 * 165 * RETURN: SYS_MODE_ACPI or SYS_MODE_LEGACY 166 * 167 * DESCRIPTION: Return current operating state of system. Determined by 168 * querying the SCI_EN bit. 169 * 170 ******************************************************************************/ 171 172 UINT32 173 AcpiHwGetMode ( 174 void) 175 { 176 ACPI_STATUS Status; 177 UINT32 Value; 178 179 180 ACPI_FUNCTION_TRACE (HwGetMode); 181 182 183 /* 184 * ACPI 2.0 clarified that if SMI_CMD in FADT is zero, 185 * system does not support mode transition. 186 */ 187 if (!AcpiGbl_FADT.SmiCommand) 188 { 189 return_UINT32 (ACPI_SYS_MODE_ACPI); 190 } 191 192 Status = AcpiReadBitRegister (ACPI_BITREG_SCI_ENABLE, &Value); 193 if (ACPI_FAILURE (Status)) 194 { 195 return_UINT32 (ACPI_SYS_MODE_LEGACY); 196 } 197 198 if (Value) 199 { 200 return_UINT32 (ACPI_SYS_MODE_ACPI); 201 } 202 else 203 { 204 return_UINT32 (ACPI_SYS_MODE_LEGACY); 205 } 206 } 207