1 /****************************************************************************** 2 * 3 * Module Name: hwacpi - ACPI Hardware Initialization/Mode Interface 4 * 5 *****************************************************************************/ 6 7 /* 8 * Copyright (C) 2000 - 2016, 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.h" 45 #include "accommon.h" 46 47 48 #define _COMPONENT ACPI_HARDWARE 49 ACPI_MODULE_NAME ("hwacpi") 50 51 52 #if (!ACPI_REDUCED_HARDWARE) /* Entire module */ 53 /****************************************************************************** 54 * 55 * FUNCTION: AcpiHwSetMode 56 * 57 * PARAMETERS: Mode - SYS_MODE_ACPI or SYS_MODE_LEGACY 58 * 59 * RETURN: Status 60 * 61 * DESCRIPTION: Transitions the system into the requested mode. 62 * 63 ******************************************************************************/ 64 65 ACPI_STATUS 66 AcpiHwSetMode ( 67 UINT32 Mode) 68 { 69 70 ACPI_STATUS Status; 71 UINT32 Retry; 72 73 74 ACPI_FUNCTION_TRACE (HwSetMode); 75 76 77 /* If the Hardware Reduced flag is set, machine is always in acpi mode */ 78 79 if (AcpiGbl_ReducedHardware) 80 { 81 return_ACPI_STATUS (AE_OK); 82 } 83 84 /* 85 * ACPI 2.0 clarified that if SMI_CMD in FADT is zero, 86 * system does not support mode transition. 87 */ 88 if (!AcpiGbl_FADT.SmiCommand) 89 { 90 ACPI_ERROR ((AE_INFO, "No SMI_CMD in FADT, mode transition failed")); 91 return_ACPI_STATUS (AE_NO_HARDWARE_RESPONSE); 92 } 93 94 /* 95 * ACPI 2.0 clarified the meaning of ACPI_ENABLE and ACPI_DISABLE 96 * in FADT: If it is zero, enabling or disabling is not supported. 97 * As old systems may have used zero for mode transition, 98 * we make sure both the numbers are zero to determine these 99 * transitions are not supported. 100 */ 101 if (!AcpiGbl_FADT.AcpiEnable && !AcpiGbl_FADT.AcpiDisable) 102 { 103 ACPI_ERROR ((AE_INFO, 104 "No ACPI mode transition supported in this system " 105 "(enable/disable both zero)")); 106 return_ACPI_STATUS (AE_OK); 107 } 108 109 switch (Mode) 110 { 111 case ACPI_SYS_MODE_ACPI: 112 113 /* BIOS should have disabled ALL fixed and GP events */ 114 115 Status = AcpiHwWritePort (AcpiGbl_FADT.SmiCommand, 116 (UINT32) AcpiGbl_FADT.AcpiEnable, 8); 117 ACPI_DEBUG_PRINT ((ACPI_DB_INFO, "Attempting to enable ACPI mode\n")); 118 break; 119 120 case ACPI_SYS_MODE_LEGACY: 121 /* 122 * BIOS should clear all fixed status bits and restore fixed event 123 * enable bits to default 124 */ 125 Status = AcpiHwWritePort (AcpiGbl_FADT.SmiCommand, 126 (UINT32) AcpiGbl_FADT.AcpiDisable, 8); 127 ACPI_DEBUG_PRINT ((ACPI_DB_INFO, 128 "Attempting to enable Legacy (non-ACPI) mode\n")); 129 break; 130 131 default: 132 133 return_ACPI_STATUS (AE_BAD_PARAMETER); 134 } 135 136 if (ACPI_FAILURE (Status)) 137 { 138 ACPI_EXCEPTION ((AE_INFO, Status, 139 "Could not write ACPI mode change")); 140 return_ACPI_STATUS (Status); 141 } 142 143 /* 144 * Some hardware takes a LONG time to switch modes. Give them 3 sec to 145 * do so, but allow faster systems to proceed more quickly. 146 */ 147 Retry = 3000; 148 while (Retry) 149 { 150 if (AcpiHwGetMode () == Mode) 151 { 152 ACPI_DEBUG_PRINT ((ACPI_DB_INFO, 153 "Mode %X successfully enabled\n", Mode)); 154 return_ACPI_STATUS (AE_OK); 155 } 156 AcpiOsStall (ACPI_USEC_PER_MSEC); 157 Retry--; 158 } 159 160 ACPI_ERROR ((AE_INFO, "Hardware did not change modes")); 161 return_ACPI_STATUS (AE_NO_HARDWARE_RESPONSE); 162 } 163 164 165 /******************************************************************************* 166 * 167 * FUNCTION: AcpiHwGetMode 168 * 169 * PARAMETERS: none 170 * 171 * RETURN: SYS_MODE_ACPI or SYS_MODE_LEGACY 172 * 173 * DESCRIPTION: Return current operating state of system. Determined by 174 * querying the SCI_EN bit. 175 * 176 ******************************************************************************/ 177 178 UINT32 179 AcpiHwGetMode ( 180 void) 181 { 182 ACPI_STATUS Status; 183 UINT32 Value; 184 185 186 ACPI_FUNCTION_TRACE (HwGetMode); 187 188 189 /* If the Hardware Reduced flag is set, machine is always in acpi mode */ 190 191 if (AcpiGbl_ReducedHardware) 192 { 193 return_UINT32 (ACPI_SYS_MODE_ACPI); 194 } 195 196 /* 197 * ACPI 2.0 clarified that if SMI_CMD in FADT is zero, 198 * system does not support mode transition. 199 */ 200 if (!AcpiGbl_FADT.SmiCommand) 201 { 202 return_UINT32 (ACPI_SYS_MODE_ACPI); 203 } 204 205 Status = AcpiReadBitRegister (ACPI_BITREG_SCI_ENABLE, &Value); 206 if (ACPI_FAILURE (Status)) 207 { 208 return_UINT32 (ACPI_SYS_MODE_LEGACY); 209 } 210 211 if (Value) 212 { 213 return_UINT32 (ACPI_SYS_MODE_ACPI); 214 } 215 else 216 { 217 return_UINT32 (ACPI_SYS_MODE_LEGACY); 218 } 219 } 220 221 #endif /* !ACPI_REDUCED_HARDWARE */ 222