1
2 /******************************************************************************
3 *
4 * Module Name: hwacpi - ACPI Hardware Initialization/Mode Interface
5 *
6 *****************************************************************************/
7
8 /*
9 * Copyright (C) 2000 - 2011, 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 #define __HWACPI_C__
46
47 #include "acpi.h"
48 #include "accommon.h"
49
50
51 #define _COMPONENT ACPI_HARDWARE
52 ACPI_MODULE_NAME ("hwacpi")
53
54
55 /******************************************************************************
56 *
57 * FUNCTION: AcpiHwSetMode
58 *
59 * PARAMETERS: Mode - SYS_MODE_ACPI or SYS_MODE_LEGACY
60 *
61 * RETURN: Status
62 *
63 * DESCRIPTION: Transitions the system into the requested mode.
64 *
65 ******************************************************************************/
66
67 ACPI_STATUS
68 AcpiHwSetMode (
69 UINT32 Mode)
70 {
71
72 ACPI_STATUS Status;
73 UINT32 Retry;
74
75
76 ACPI_FUNCTION_TRACE (HwSetMode);
77
78 /*
79 * ACPI 2.0 clarified that if SMI_CMD in FADT is zero,
80 * system does not support mode transition.
81 */
82 if (!AcpiGbl_FADT.SmiCommand)
83 {
84 ACPI_ERROR ((AE_INFO, "No SMI_CMD in FADT, mode transition failed"));
85 return_ACPI_STATUS (AE_NO_HARDWARE_RESPONSE);
86 }
87
88 /*
89 * ACPI 2.0 clarified the meaning of ACPI_ENABLE and ACPI_DISABLE
90 * in FADT: If it is zero, enabling or disabling is not supported.
91 * As old systems may have used zero for mode transition,
92 * we make sure both the numbers are zero to determine these
93 * transitions are not supported.
94 */
95 if (!AcpiGbl_FADT.AcpiEnable && !AcpiGbl_FADT.AcpiDisable)
96 {
97 ACPI_ERROR ((AE_INFO,
98 "No ACPI mode transition supported in this system "
99 "(enable/disable both zero)"));
100 return_ACPI_STATUS (AE_OK);
101 }
102
103 switch (Mode)
104 {
105 case ACPI_SYS_MODE_ACPI:
106
107 /* BIOS should have disabled ALL fixed and GP events */
108
109 Status = AcpiHwWritePort (AcpiGbl_FADT.SmiCommand,
110 (UINT32) AcpiGbl_FADT.AcpiEnable, 8);
111 ACPI_DEBUG_PRINT ((ACPI_DB_INFO, "Attempting to enable ACPI mode\n"));
112 break;
113
114 case ACPI_SYS_MODE_LEGACY:
115
116 /*
117 * BIOS should clear all fixed status bits and restore fixed event
118 * enable bits to default
119 */
120 Status = AcpiHwWritePort (AcpiGbl_FADT.SmiCommand,
121 (UINT32) AcpiGbl_FADT.AcpiDisable, 8);
122 ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
123 "Attempting to enable Legacy (non-ACPI) mode\n"));
124 break;
125
126 default:
127 return_ACPI_STATUS (AE_BAD_PARAMETER);
128 }
129
130 if (ACPI_FAILURE (Status))
131 {
132 ACPI_EXCEPTION ((AE_INFO, Status,
133 "Could not write ACPI mode change"));
134 return_ACPI_STATUS (Status);
135 }
136
137 /*
138 * Some hardware takes a LONG time to switch modes. Give them 3 sec to
139 * do so, but allow faster systems to proceed more quickly.
140 */
141 Retry = 3000;
142 while (Retry)
143 {
144 if (AcpiHwGetMode() == Mode)
145 {
146 ACPI_DEBUG_PRINT ((ACPI_DB_INFO, "Mode %X successfully enabled\n",
147 Mode));
148 return_ACPI_STATUS (AE_OK);
149 }
150 AcpiOsStall(1000);
151 Retry--;
152 }
153
154 ACPI_ERROR ((AE_INFO, "Hardware did not change modes"));
155 return_ACPI_STATUS (AE_NO_HARDWARE_RESPONSE);
156 }
157
158
159 /*******************************************************************************
160 *
161 * FUNCTION: AcpiHwGetMode
162 *
163 * PARAMETERS: none
164 *
165 * RETURN: SYS_MODE_ACPI or SYS_MODE_LEGACY
166 *
167 * DESCRIPTION: Return current operating state of system. Determined by
168 * querying the SCI_EN bit.
169 *
170 ******************************************************************************/
171
172 UINT32
173 AcpiHwGetMode (
174 void)
175 {
176 ACPI_STATUS Status;
177 UINT32 Value;
178
179
180 ACPI_FUNCTION_TRACE (HwGetMode);
181
182
183 /*
184 * ACPI 2.0 clarified that if SMI_CMD in FADT is zero,
185 * system does not support mode transition.
186 */
187 if (!AcpiGbl_FADT.SmiCommand)
188 {
189 return_UINT32 (ACPI_SYS_MODE_ACPI);
190 }
191
192 Status = AcpiReadBitRegister (ACPI_BITREG_SCI_ENABLE, &Value);
193 if (ACPI_FAILURE (Status))
194 {
195 return_UINT32 (ACPI_SYS_MODE_LEGACY);
196 }
197
198 if (Value)
199 {
200 return_UINT32 (ACPI_SYS_MODE_ACPI);
201 }
202 else
203 {
204 return_UINT32 (ACPI_SYS_MODE_LEGACY);
205 }
206 }