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Linux kernel mirror (for testing)
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kernel
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linux
1
2/******************************************************************************
3 *
4 * Module Name: hwacpi - ACPI Hardware Initialization/Mode Interface
5 *
6 *****************************************************************************/
7
8/*
9 * Copyright (C) 2000 - 2005, R. Byron Moore
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
46#include <acpi/acpi.h>
47
48
49#define _COMPONENT ACPI_HARDWARE
50 ACPI_MODULE_NAME ("hwacpi")
51
52
53/******************************************************************************
54 *
55 * FUNCTION: acpi_hw_initialize
56 *
57 * PARAMETERS: None
58 *
59 * RETURN: Status
60 *
61 * DESCRIPTION: Initialize and validate various ACPI registers
62 *
63 ******************************************************************************/
64
65acpi_status
66acpi_hw_initialize (
67 void)
68{
69 acpi_status status;
70
71
72 ACPI_FUNCTION_TRACE ("hw_initialize");
73
74
75 /* We must have the ACPI tables by the time we get here */
76
77 if (!acpi_gbl_FADT) {
78 ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "A FADT is not loaded\n"));
79
80 return_ACPI_STATUS (AE_NO_ACPI_TABLES);
81 }
82
83 /* Sanity check the FADT for valid values */
84
85 status = acpi_ut_validate_fadt ();
86 if (ACPI_FAILURE (status)) {
87 return_ACPI_STATUS (status);
88 }
89
90 return_ACPI_STATUS (AE_OK);
91}
92
93
94/******************************************************************************
95 *
96 * FUNCTION: acpi_hw_set_mode
97 *
98 * PARAMETERS: Mode - SYS_MODE_ACPI or SYS_MODE_LEGACY
99 *
100 * RETURN: Status
101 *
102 * DESCRIPTION: Transitions the system into the requested mode.
103 *
104 ******************************************************************************/
105
106acpi_status
107acpi_hw_set_mode (
108 u32 mode)
109{
110
111 acpi_status status;
112 u32 retry;
113
114
115 ACPI_FUNCTION_TRACE ("hw_set_mode");
116
117 /*
118 * ACPI 2.0 clarified that if SMI_CMD in FADT is zero,
119 * system does not support mode transition.
120 */
121 if (!acpi_gbl_FADT->smi_cmd) {
122 ACPI_REPORT_ERROR (("No SMI_CMD in FADT, mode transition failed.\n"));
123 return_ACPI_STATUS (AE_NO_HARDWARE_RESPONSE);
124 }
125
126 /*
127 * ACPI 2.0 clarified the meaning of ACPI_ENABLE and ACPI_DISABLE
128 * in FADT: If it is zero, enabling or disabling is not supported.
129 * As old systems may have used zero for mode transition,
130 * we make sure both the numbers are zero to determine these
131 * transitions are not supported.
132 */
133 if (!acpi_gbl_FADT->acpi_enable && !acpi_gbl_FADT->acpi_disable) {
134 ACPI_REPORT_ERROR (("No ACPI mode transition supported in this system (enable/disable both zero)\n"));
135 return_ACPI_STATUS (AE_OK);
136 }
137
138 switch (mode) {
139 case ACPI_SYS_MODE_ACPI:
140
141 /* BIOS should have disabled ALL fixed and GP events */
142
143 status = acpi_os_write_port (acpi_gbl_FADT->smi_cmd,
144 (u32) acpi_gbl_FADT->acpi_enable, 8);
145 ACPI_DEBUG_PRINT ((ACPI_DB_INFO, "Attempting to enable ACPI mode\n"));
146 break;
147
148 case ACPI_SYS_MODE_LEGACY:
149
150 /*
151 * BIOS should clear all fixed status bits and restore fixed event
152 * enable bits to default
153 */
154 status = acpi_os_write_port (acpi_gbl_FADT->smi_cmd,
155 (u32) acpi_gbl_FADT->acpi_disable, 8);
156 ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
157 "Attempting to enable Legacy (non-ACPI) mode\n"));
158 break;
159
160 default:
161 return_ACPI_STATUS (AE_BAD_PARAMETER);
162 }
163
164 if (ACPI_FAILURE (status)) {
165 ACPI_REPORT_ERROR (("Could not write mode change, %s\n", acpi_format_exception (status)));
166 return_ACPI_STATUS (status);
167 }
168
169 /*
170 * Some hardware takes a LONG time to switch modes. Give them 3 sec to
171 * do so, but allow faster systems to proceed more quickly.
172 */
173 retry = 3000;
174 while (retry) {
175 if (acpi_hw_get_mode() == mode) {
176 ACPI_DEBUG_PRINT ((ACPI_DB_INFO, "Mode %X successfully enabled\n", mode));
177 return_ACPI_STATUS (AE_OK);
178 }
179 acpi_os_stall(1000);
180 retry--;
181 }
182
183 ACPI_REPORT_ERROR (("Hardware never changed modes\n"));
184 return_ACPI_STATUS (AE_NO_HARDWARE_RESPONSE);
185}
186
187
188/******************************************************************************
189 *
190 * FUNCTION: acpi_hw_get_mode
191 *
192 * PARAMETERS: none
193 *
194 * RETURN: SYS_MODE_ACPI or SYS_MODE_LEGACY
195 *
196 * DESCRIPTION: Return current operating state of system. Determined by
197 * querying the SCI_EN bit.
198 *
199 ******************************************************************************/
200
201u32
202acpi_hw_get_mode (void)
203{
204 acpi_status status;
205 u32 value;
206
207
208 ACPI_FUNCTION_TRACE ("hw_get_mode");
209
210
211 /*
212 * ACPI 2.0 clarified that if SMI_CMD in FADT is zero,
213 * system does not support mode transition.
214 */
215 if (!acpi_gbl_FADT->smi_cmd) {
216 return_VALUE (ACPI_SYS_MODE_ACPI);
217 }
218
219 status = acpi_get_register (ACPI_BITREG_SCI_ENABLE, &value, ACPI_MTX_LOCK);
220 if (ACPI_FAILURE (status)) {
221 return_VALUE (ACPI_SYS_MODE_LEGACY);
222 }
223
224 if (value) {
225 return_VALUE (ACPI_SYS_MODE_ACPI);
226 }
227 else {
228 return_VALUE (ACPI_SYS_MODE_LEGACY);
229 }
230}