1 2 /****************************************************************************** 3 * 4 * Module Name: hwacpi - ACPI Hardware Initialization/Mode Interface 5 * 6 *****************************************************************************/ 7 8 /* 9 * Copyright (C) 2000 - 2012, 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 #if (!ACPI_REDUCED_HARDWARE) /* Entire module */ 52 /****************************************************************************** 53 * 54 * FUNCTION: acpi_hw_set_mode 55 * 56 * PARAMETERS: mode - SYS_MODE_ACPI or SYS_MODE_LEGACY 57 * 58 * RETURN: Status 59 * 60 * DESCRIPTION: Transitions the system into the requested mode. 61 * 62 ******************************************************************************/ 63 acpi_status acpi_hw_set_mode(u32 mode) 64 { 65 66 acpi_status status; 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 " 90 "(enable/disable both zero)")); 91 return_ACPI_STATUS(AE_OK); 92 } 93 94 switch (mode) { 95 case ACPI_SYS_MODE_ACPI: 96 97 /* BIOS should have disabled ALL fixed and GP events */ 98 99 status = acpi_hw_write_port(acpi_gbl_FADT.smi_command, 100 (u32) acpi_gbl_FADT.acpi_enable, 8); 101 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 102 "Attempting to enable ACPI mode\n")); 103 break; 104 105 case ACPI_SYS_MODE_LEGACY: 106 107 /* 108 * BIOS should clear all fixed status bits and restore fixed event 109 * enable bits to default 110 */ 111 status = acpi_hw_write_port(acpi_gbl_FADT.smi_command, 112 (u32) acpi_gbl_FADT.acpi_disable, 113 8); 114 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 115 "Attempting to enable Legacy (non-ACPI) mode\n")); 116 break; 117 118 default: 119 return_ACPI_STATUS(AE_BAD_PARAMETER); 120 } 121 122 if (ACPI_FAILURE(status)) { 123 ACPI_EXCEPTION((AE_INFO, status, 124 "Could not write ACPI mode change")); 125 return_ACPI_STATUS(status); 126 } 127 128 return_ACPI_STATUS(AE_OK); 129 } 130 131 /******************************************************************************* 132 * 133 * FUNCTION: acpi_hw_get_mode 134 * 135 * PARAMETERS: none 136 * 137 * RETURN: SYS_MODE_ACPI or SYS_MODE_LEGACY 138 * 139 * DESCRIPTION: Return current operating state of system. Determined by 140 * querying the SCI_EN bit. 141 * 142 ******************************************************************************/ 143 144 u32 acpi_hw_get_mode(void) 145 { 146 acpi_status status; 147 u32 value; 148 149 ACPI_FUNCTION_TRACE(hw_get_mode); 150 151 /* 152 * ACPI 2.0 clarified that if SMI_CMD in FADT is zero, 153 * system does not support mode transition. 154 */ 155 if (!acpi_gbl_FADT.smi_command) { 156 return_UINT32(ACPI_SYS_MODE_ACPI); 157 } 158 159 status = acpi_read_bit_register(ACPI_BITREG_SCI_ENABLE, &value); 160 if (ACPI_FAILURE(status)) { 161 return_UINT32(ACPI_SYS_MODE_LEGACY); 162 } 163 164 if (value) { 165 return_UINT32(ACPI_SYS_MODE_ACPI); 166 } else { 167 return_UINT32(ACPI_SYS_MODE_LEGACY); 168 } 169 } 170 171 #endif /* !ACPI_REDUCED_HARDWARE */ 172