1
2 /******************************************************************************
3 *
4 * Module Name: hwacpi - ACPI Hardware Initialization/Mode Interface
5 *
6 *****************************************************************************/
7
8 /*
9 * Copyright (C) 2000 - 2012, 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 #include <acpi/acpi.h>
46 #include "accommon.h"
47
48 #define _COMPONENT ACPI_HARDWARE
49 ACPI_MODULE_NAME("hwacpi")
50
51 #if (!ACPI_REDUCED_HARDWARE) /* Entire module */
52 /******************************************************************************
53 *
54 * FUNCTION: acpi_hw_set_mode
55 *
56 * PARAMETERS: Mode - SYS_MODE_ACPI or SYS_MODE_LEGACY
57 *
58 * RETURN: Status
59 *
60 * DESCRIPTION: Transitions the system into the requested mode.
61 *
62 ******************************************************************************/
acpi_hw_set_mode(u32 mode)63 acpi_status acpi_hw_set_mode(u32 mode)
64 {
65
66 acpi_status status;
67
68 ACPI_FUNCTION_TRACE(hw_set_mode);
69
70 /*
71 * ACPI 2.0 clarified that if SMI_CMD in FADT is zero,
72 * system does not support mode transition.
73 */
74 if (!acpi_gbl_FADT.smi_command) {
75 ACPI_ERROR((AE_INFO,
76 "No SMI_CMD in FADT, mode transition failed"));
77 return_ACPI_STATUS(AE_NO_HARDWARE_RESPONSE);
78 }
79
80 /*
81 * ACPI 2.0 clarified the meaning of ACPI_ENABLE and ACPI_DISABLE
82 * in FADT: If it is zero, enabling or disabling is not supported.
83 * As old systems may have used zero for mode transition,
84 * we make sure both the numbers are zero to determine these
85 * transitions are not supported.
86 */
87 if (!acpi_gbl_FADT.acpi_enable && !acpi_gbl_FADT.acpi_disable) {
88 ACPI_ERROR((AE_INFO,
89 "No ACPI mode transition supported in this system "
90 "(enable/disable both zero)"));
91 return_ACPI_STATUS(AE_OK);
92 }
93
94 switch (mode) {
95 case ACPI_SYS_MODE_ACPI:
96
97 /* BIOS should have disabled ALL fixed and GP events */
98
99 status = acpi_hw_write_port(acpi_gbl_FADT.smi_command,
100 (u32) acpi_gbl_FADT.acpi_enable, 8);
101 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
102 "Attempting to enable ACPI mode\n"));
103 break;
104
105 case ACPI_SYS_MODE_LEGACY:
106
107 /*
108 * BIOS should clear all fixed status bits and restore fixed event
109 * enable bits to default
110 */
111 status = acpi_hw_write_port(acpi_gbl_FADT.smi_command,
112 (u32) acpi_gbl_FADT.acpi_disable,
113 8);
114 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
115 "Attempting to enable Legacy (non-ACPI) mode\n"));
116 break;
117
118 default:
119 return_ACPI_STATUS(AE_BAD_PARAMETER);
120 }
121
122 if (ACPI_FAILURE(status)) {
123 ACPI_EXCEPTION((AE_INFO, status,
124 "Could not write ACPI mode change"));
125 return_ACPI_STATUS(status);
126 }
127
128 return_ACPI_STATUS(AE_OK);
129 }
130
131 /*******************************************************************************
132 *
133 * FUNCTION: acpi_hw_get_mode
134 *
135 * PARAMETERS: none
136 *
137 * RETURN: SYS_MODE_ACPI or SYS_MODE_LEGACY
138 *
139 * DESCRIPTION: Return current operating state of system. Determined by
140 * querying the SCI_EN bit.
141 *
142 ******************************************************************************/
143
acpi_hw_get_mode(void)144 u32 acpi_hw_get_mode(void)
145 {
146 acpi_status status;
147 u32 value;
148
149 ACPI_FUNCTION_TRACE(hw_get_mode);
150
151 /*
152 * ACPI 2.0 clarified that if SMI_CMD in FADT is zero,
153 * system does not support mode transition.
154 */
155 if (!acpi_gbl_FADT.smi_command) {
156 return_UINT32(ACPI_SYS_MODE_ACPI);
157 }
158
159 status = acpi_read_bit_register(ACPI_BITREG_SCI_ENABLE, &value);
160 if (ACPI_FAILURE(status)) {
161 return_UINT32(ACPI_SYS_MODE_LEGACY);
162 }
163
164 if (value) {
165 return_UINT32(ACPI_SYS_MODE_ACPI);
166 } else {
167 return_UINT32(ACPI_SYS_MODE_LEGACY);
168 }
169 }
170
171 #endif /* !ACPI_REDUCED_HARDWARE */
172