1 2 /****************************************************************************** 3 * 4 * Module Name: hwacpi - ACPI Hardware Initialization/Mode Interface 5 * 6 *****************************************************************************/ 7 8 /* 9 * Copyright (C) 2000 - 2008, 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 #include <acpi/acpi.h> 46 #include "accommon.h" 47 48 #define _COMPONENT ACPI_HARDWARE 49 ACPI_MODULE_NAME("hwacpi") 50 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 u32 retry; 67 68 ACPI_FUNCTION_TRACE(hw_set_mode); 69 70 /* 71 * ACPI 2.0 clarified that if SMI_CMD in FADT is zero, 72 * system does not support mode transition. 73 */ 74 if (!acpi_gbl_FADT.smi_command) { 75 ACPI_ERROR((AE_INFO, 76 "No SMI_CMD in FADT, mode transition failed")); 77 return_ACPI_STATUS(AE_NO_HARDWARE_RESPONSE); 78 } 79 80 /* 81 * ACPI 2.0 clarified the meaning of ACPI_ENABLE and ACPI_DISABLE 82 * in FADT: If it is zero, enabling or disabling is not supported. 83 * As old systems may have used zero for mode transition, 84 * we make sure both the numbers are zero to determine these 85 * transitions are not supported. 86 */ 87 if (!acpi_gbl_FADT.acpi_enable && !acpi_gbl_FADT.acpi_disable) { 88 ACPI_ERROR((AE_INFO, 89 "No ACPI mode transition supported in this system (enable/disable both zero)")); 90 return_ACPI_STATUS(AE_OK); 91 } 92 93 switch (mode) { 94 case ACPI_SYS_MODE_ACPI: 95 96 /* BIOS should have disabled ALL fixed and GP events */ 97 98 status = acpi_os_write_port(acpi_gbl_FADT.smi_command, 99 (u32) acpi_gbl_FADT.acpi_enable, 8); 100 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 101 "Attempting to enable ACPI mode\n")); 102 break; 103 104 case ACPI_SYS_MODE_LEGACY: 105 106 /* 107 * BIOS should clear all fixed status bits and restore fixed event 108 * enable bits to default 109 */ 110 status = acpi_os_write_port(acpi_gbl_FADT.smi_command, 111 (u32) acpi_gbl_FADT.acpi_disable, 112 8); 113 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 114 "Attempting to enable Legacy (non-ACPI) mode\n")); 115 break; 116 117 default: 118 return_ACPI_STATUS(AE_BAD_PARAMETER); 119 } 120 121 if (ACPI_FAILURE(status)) { 122 ACPI_EXCEPTION((AE_INFO, status, 123 "Could not write ACPI mode change")); 124 return_ACPI_STATUS(status); 125 } 126 127 /* 128 * Some hardware takes a LONG time to switch modes. Give them 3 sec to 129 * do so, but allow faster systems to proceed more quickly. 130 */ 131 retry = 3000; 132 while (retry) { 133 if (acpi_hw_get_mode() == mode) { 134 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 135 "Mode %X successfully enabled\n", 136 mode)); 137 return_ACPI_STATUS(AE_OK); 138 } 139 acpi_os_stall(1000); 140 retry--; 141 } 142 143 ACPI_ERROR((AE_INFO, "Hardware did not change modes")); 144 return_ACPI_STATUS(AE_NO_HARDWARE_RESPONSE); 145 } 146 147 /******************************************************************************* 148 * 149 * FUNCTION: acpi_hw_get_mode 150 * 151 * PARAMETERS: none 152 * 153 * RETURN: SYS_MODE_ACPI or SYS_MODE_LEGACY 154 * 155 * DESCRIPTION: Return current operating state of system. Determined by 156 * querying the SCI_EN bit. 157 * 158 ******************************************************************************/ 159 160 u32 acpi_hw_get_mode(void) 161 { 162 acpi_status status; 163 u32 value; 164 165 ACPI_FUNCTION_TRACE(hw_get_mode); 166 167 /* 168 * ACPI 2.0 clarified that if SMI_CMD in FADT is zero, 169 * system does not support mode transition. 170 */ 171 if (!acpi_gbl_FADT.smi_command) { 172 return_UINT32(ACPI_SYS_MODE_ACPI); 173 } 174 175 status = acpi_get_register(ACPI_BITREG_SCI_ENABLE, &value); 176 if (ACPI_FAILURE(status)) { 177 return_UINT32(ACPI_SYS_MODE_LEGACY); 178 } 179 180 if (value) { 181 return_UINT32(ACPI_SYS_MODE_ACPI); 182 } else { 183 return_UINT32(ACPI_SYS_MODE_LEGACY); 184 } 185 } 186