1 /****************************************************************************** 2 * 3 * Module Name: hwacpi - ACPI Hardware Initialization/Mode Interface 4 * 5 *****************************************************************************/ 6 7 /* 8 * Copyright (C) 2000 - 2012, 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 /* 70 * ACPI 2.0 clarified that if SMI_CMD in FADT is zero, 71 * system does not support mode transition. 72 */ 73 if (!acpi_gbl_FADT.smi_command) { 74 ACPI_ERROR((AE_INFO, 75 "No SMI_CMD in FADT, mode transition failed")); 76 return_ACPI_STATUS(AE_NO_HARDWARE_RESPONSE); 77 } 78 79 /* 80 * ACPI 2.0 clarified the meaning of ACPI_ENABLE and ACPI_DISABLE 81 * in FADT: If it is zero, enabling or disabling is not supported. 82 * As old systems may have used zero for mode transition, 83 * we make sure both the numbers are zero to determine these 84 * transitions are not supported. 85 */ 86 if (!acpi_gbl_FADT.acpi_enable && !acpi_gbl_FADT.acpi_disable) { 87 ACPI_ERROR((AE_INFO, 88 "No ACPI mode transition supported in this system " 89 "(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_hw_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_hw_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 return_ACPI_STATUS(AE_OK); 128 } 129 130 /******************************************************************************* 131 * 132 * FUNCTION: acpi_hw_get_mode 133 * 134 * PARAMETERS: none 135 * 136 * RETURN: SYS_MODE_ACPI or SYS_MODE_LEGACY 137 * 138 * DESCRIPTION: Return current operating state of system. Determined by 139 * querying the SCI_EN bit. 140 * 141 ******************************************************************************/ 142 143 u32 acpi_hw_get_mode(void) 144 { 145 acpi_status status; 146 u32 value; 147 148 ACPI_FUNCTION_TRACE(hw_get_mode); 149 150 /* 151 * ACPI 2.0 clarified that if SMI_CMD in FADT is zero, 152 * system does not support mode transition. 153 */ 154 if (!acpi_gbl_FADT.smi_command) { 155 return_UINT32(ACPI_SYS_MODE_ACPI); 156 } 157 158 status = acpi_read_bit_register(ACPI_BITREG_SCI_ENABLE, &value); 159 if (ACPI_FAILURE(status)) { 160 return_UINT32(ACPI_SYS_MODE_LEGACY); 161 } 162 163 if (value) { 164 return_UINT32(ACPI_SYS_MODE_ACPI); 165 } else { 166 return_UINT32(ACPI_SYS_MODE_LEGACY); 167 } 168 } 169 170 #endif /* !ACPI_REDUCED_HARDWARE */ 171