2 /******************************************************************************
4 * Module Name: hwacpi - ACPI Hardware Initialization/Mode Interface
6 *****************************************************************************/
9 * Copyright (C) 2000 - 2005, R. Byron Moore
10 * All rights reserved.
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13 * modification, are permitted provided that the following conditions
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16 * notice, this list of conditions, and the following disclaimer,
17 * without modification.
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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.
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.
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33 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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46 #include <acpi/acpi.h>
49 #define _COMPONENT ACPI_HARDWARE
50 ACPI_MODULE_NAME ("hwacpi")
53 /******************************************************************************
55 * FUNCTION: acpi_hw_initialize
61 * DESCRIPTION: Initialize and validate the various ACPI registers defined in
64 ******************************************************************************/
73 ACPI_FUNCTION_TRACE ("hw_initialize");
76 /* We must have the ACPI tables by the time we get here */
79 ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "No FADT is present\n"));
81 return_ACPI_STATUS (AE_NO_ACPI_TABLES);
84 /* Sanity check the FADT for valid values */
86 status = acpi_ut_validate_fadt ();
87 if (ACPI_FAILURE (status)) {
88 return_ACPI_STATUS (status);
91 return_ACPI_STATUS (AE_OK);
95 /******************************************************************************
97 * FUNCTION: acpi_hw_set_mode
99 * PARAMETERS: Mode - SYS_MODE_ACPI or SYS_MODE_LEGACY
103 * DESCRIPTION: Transitions the system into the requested mode.
105 ******************************************************************************/
116 ACPI_FUNCTION_TRACE ("hw_set_mode");
119 * ACPI 2.0 clarified that if SMI_CMD in FADT is zero,
120 * system does not support mode transition.
122 if (!acpi_gbl_FADT->smi_cmd) {
123 ACPI_REPORT_ERROR (("No SMI_CMD in FADT, mode transition failed.\n"));
124 return_ACPI_STATUS (AE_NO_HARDWARE_RESPONSE);
128 * ACPI 2.0 clarified the meaning of ACPI_ENABLE and ACPI_DISABLE
129 * in FADT: If it is zero, enabling or disabling is not supported.
130 * As old systems may have used zero for mode transition,
131 * we make sure both the numbers are zero to determine these
132 * transitions are not supported.
134 if (!acpi_gbl_FADT->acpi_enable && !acpi_gbl_FADT->acpi_disable) {
136 "No ACPI mode transition supported in this system (enable/disable both zero)\n"));
137 return_ACPI_STATUS (AE_OK);
141 case ACPI_SYS_MODE_ACPI:
143 /* BIOS should have disabled ALL fixed and GP events */
145 status = acpi_os_write_port (acpi_gbl_FADT->smi_cmd,
146 (u32) acpi_gbl_FADT->acpi_enable, 8);
147 ACPI_DEBUG_PRINT ((ACPI_DB_INFO, "Attempting to enable ACPI mode\n"));
150 case ACPI_SYS_MODE_LEGACY:
153 * BIOS should clear all fixed status bits and restore fixed event
154 * enable bits to default
156 status = acpi_os_write_port (acpi_gbl_FADT->smi_cmd,
157 (u32) acpi_gbl_FADT->acpi_disable, 8);
158 ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
159 "Attempting to enable Legacy (non-ACPI) mode\n"));
163 return_ACPI_STATUS (AE_BAD_PARAMETER);
166 if (ACPI_FAILURE (status)) {
167 ACPI_REPORT_ERROR (("Could not write mode change, %s\n",
168 acpi_format_exception (status)));
169 return_ACPI_STATUS (status);
173 * Some hardware takes a LONG time to switch modes. Give them 3 sec to
174 * do so, but allow faster systems to proceed more quickly.
178 if (acpi_hw_get_mode() == mode) {
179 ACPI_DEBUG_PRINT ((ACPI_DB_INFO, "Mode %X successfully enabled\n",
181 return_ACPI_STATUS (AE_OK);
187 ACPI_REPORT_ERROR (("Hardware never changed modes\n"));
188 return_ACPI_STATUS (AE_NO_HARDWARE_RESPONSE);
192 /*******************************************************************************
194 * FUNCTION: acpi_hw_get_mode
198 * RETURN: SYS_MODE_ACPI or SYS_MODE_LEGACY
200 * DESCRIPTION: Return current operating state of system. Determined by
201 * querying the SCI_EN bit.
203 ******************************************************************************/
213 ACPI_FUNCTION_TRACE ("hw_get_mode");
217 * ACPI 2.0 clarified that if SMI_CMD in FADT is zero,
218 * system does not support mode transition.
220 if (!acpi_gbl_FADT->smi_cmd) {
221 return_VALUE (ACPI_SYS_MODE_ACPI);
224 status = acpi_get_register (ACPI_BITREG_SCI_ENABLE, &value, ACPI_MTX_LOCK);
225 if (ACPI_FAILURE (status)) {
226 return_VALUE (ACPI_SYS_MODE_LEGACY);
230 return_VALUE (ACPI_SYS_MODE_ACPI);
233 return_VALUE (ACPI_SYS_MODE_LEGACY);