1 /******************************************************************************
2 *
3 * Module Name: hwacpi - ACPI Hardware Initialization/Mode Interface
4 *
5 *****************************************************************************/
6
7 /*
8 * Copyright (C) 2000 - 2014, 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 #define __HWACPI_C__
45
46 #include "acpi.h"
47 #include "accommon.h"
48
49
50 #define _COMPONENT ACPI_HARDWARE
51 ACPI_MODULE_NAME ("hwacpi")
52
53
54 #if (!ACPI_REDUCED_HARDWARE) /* Entire module */
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 /* If the Hardware Reduced flag is set, machine is always in acpi mode */
80
81 if (AcpiGbl_ReducedHardware)
82 {
83 return_ACPI_STATUS (AE_OK);
84 }
85
86 /*
87 * ACPI 2.0 clarified that if SMI_CMD in FADT is zero,
88 * system does not support mode transition.
89 */
90 if (!AcpiGbl_FADT.SmiCommand)
91 {
92 ACPI_ERROR ((AE_INFO, "No SMI_CMD in FADT, mode transition failed"));
93 return_ACPI_STATUS (AE_NO_HARDWARE_RESPONSE);
94 }
95
96 /*
97 * ACPI 2.0 clarified the meaning of ACPI_ENABLE and ACPI_DISABLE
98 * in FADT: If it is zero, enabling or disabling is not supported.
99 * As old systems may have used zero for mode transition,
100 * we make sure both the numbers are zero to determine these
101 * transitions are not supported.
102 */
103 if (!AcpiGbl_FADT.AcpiEnable && !AcpiGbl_FADT.AcpiDisable)
104 {
105 ACPI_ERROR ((AE_INFO,
106 "No ACPI mode transition supported in this system "
107 "(enable/disable both zero)"));
108 return_ACPI_STATUS (AE_OK);
109 }
110
111 switch (Mode)
112 {
113 case ACPI_SYS_MODE_ACPI:
114
115 /* BIOS should have disabled ALL fixed and GP events */
116
117 Status = AcpiHwWritePort (AcpiGbl_FADT.SmiCommand,
118 (UINT32) AcpiGbl_FADT.AcpiEnable, 8);
119 ACPI_DEBUG_PRINT ((ACPI_DB_INFO, "Attempting to enable ACPI mode\n"));
120 break;
121
122 case ACPI_SYS_MODE_LEGACY:
123 /*
124 * BIOS should clear all fixed status bits and restore fixed event
125 * enable bits to default
126 */
127 Status = AcpiHwWritePort (AcpiGbl_FADT.SmiCommand,
128 (UINT32) AcpiGbl_FADT.AcpiDisable, 8);
129 ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
130 "Attempting to enable Legacy (non-ACPI) mode\n"));
131 break;
132
133 default:
134
135 return_ACPI_STATUS (AE_BAD_PARAMETER);
136 }
137
138 if (ACPI_FAILURE (Status))
139 {
140 ACPI_EXCEPTION ((AE_INFO, Status,
141 "Could not write ACPI mode change"));
142 return_ACPI_STATUS (Status);
143 }
144
145 /*
146 * Some hardware takes a LONG time to switch modes. Give them 3 sec to
147 * do so, but allow faster systems to proceed more quickly.
148 */
149 Retry = 3000;
150 while (Retry)
151 {
152 if (AcpiHwGetMode () == Mode)
153 {
154 ACPI_DEBUG_PRINT ((ACPI_DB_INFO, "Mode %X successfully enabled\n",
155 Mode));
156 return_ACPI_STATUS (AE_OK);
157 }
158 AcpiOsStall (ACPI_USEC_PER_MSEC);
159 Retry--;
160 }
161
162 ACPI_ERROR ((AE_INFO, "Hardware did not change modes"));
163 return_ACPI_STATUS (AE_NO_HARDWARE_RESPONSE);
164 }
165
166
167 /*******************************************************************************
168 *
169 * FUNCTION: AcpiHwGetMode
170 *
171 * PARAMETERS: none
172 *
173 * RETURN: SYS_MODE_ACPI or SYS_MODE_LEGACY
174 *
175 * DESCRIPTION: Return current operating state of system. Determined by
176 * querying the SCI_EN bit.
177 *
178 ******************************************************************************/
179
180 UINT32
181 AcpiHwGetMode (
182 void)
183 {
184 ACPI_STATUS Status;
185 UINT32 Value;
186
187
188 ACPI_FUNCTION_TRACE (HwGetMode);
189
190
191 /* If the Hardware Reduced flag is set, machine is always in acpi mode */
192
193 if (AcpiGbl_ReducedHardware)
194 {
195 return_UINT32 (ACPI_SYS_MODE_ACPI);
196 }
197
198 /*
199 * ACPI 2.0 clarified that if SMI_CMD in FADT is zero,
200 * system does not support mode transition.
201 */
202 if (!AcpiGbl_FADT.SmiCommand)
203 {
204 return_UINT32 (ACPI_SYS_MODE_ACPI);
205 }
206
207 Status = AcpiReadBitRegister (ACPI_BITREG_SCI_ENABLE, &Value);
208 if (ACPI_FAILURE (Status))
209 {
210 return_UINT32 (ACPI_SYS_MODE_LEGACY);
211 }
212
213 if (Value)
214 {
215 return_UINT32 (ACPI_SYS_MODE_ACPI);
216 }
217 else
218 {
219 return_UINT32 (ACPI_SYS_MODE_LEGACY);
220 }
221 }
222
223 #endif /* !ACPI_REDUCED_HARDWARE */