[POWERPC] Don't use HOSTCFLAGS in BOOTCFLAGS
[linux-ginger.git] / drivers / acpi / hardware / hwacpi.c
blob6031ca13dd2f2b9c73b66abb56aca71edd5f1d3b
2 /******************************************************************************
4 * Module Name: hwacpi - ACPI Hardware Initialization/Mode Interface
6 *****************************************************************************/
8 /*
9 * Copyright (C) 2000 - 2007, R. Byron Moore
10 * All rights reserved.
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.
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.
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.
45 #include <acpi/acpi.h>
47 #define _COMPONENT ACPI_HARDWARE
48 ACPI_MODULE_NAME("hwacpi")
50 /******************************************************************************
52 * FUNCTION: acpi_hw_set_mode
54 * PARAMETERS: Mode - SYS_MODE_ACPI or SYS_MODE_LEGACY
56 * RETURN: Status
58 * DESCRIPTION: Transitions the system into the requested mode.
60 ******************************************************************************/
61 acpi_status acpi_hw_set_mode(u32 mode)
64 acpi_status status;
65 u32 retry;
67 ACPI_FUNCTION_TRACE(hw_set_mode);
70 * ACPI 2.0 clarified that if SMI_CMD in FADT is zero,
71 * system does not support mode transition.
73 if (!acpi_gbl_FADT.smi_command) {
74 ACPI_ERROR((AE_INFO,
75 "No SMI_CMD in FADT, mode transition failed"));
76 return_ACPI_STATUS(AE_NO_HARDWARE_RESPONSE);
80 * ACPI 2.0 clarified the meaning of ACPI_ENABLE and ACPI_DISABLE
81 * in FADT: If it is zero, enabling or disabling is not supported.
82 * As old systems may have used zero for mode transition,
83 * we make sure both the numbers are zero to determine these
84 * transitions are not supported.
86 if (!acpi_gbl_FADT.acpi_enable && !acpi_gbl_FADT.acpi_disable) {
87 ACPI_ERROR((AE_INFO,
88 "No ACPI mode transition supported in this system (enable/disable both zero)"));
89 return_ACPI_STATUS(AE_OK);
92 switch (mode) {
93 case ACPI_SYS_MODE_ACPI:
95 /* BIOS should have disabled ALL fixed and GP events */
97 status = acpi_os_write_port(acpi_gbl_FADT.smi_command,
98 (u32) acpi_gbl_FADT.acpi_enable, 8);
99 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
100 "Attempting to enable ACPI mode\n"));
101 break;
103 case ACPI_SYS_MODE_LEGACY:
106 * BIOS should clear all fixed status bits and restore fixed event
107 * enable bits to default
109 status = acpi_os_write_port(acpi_gbl_FADT.smi_command,
110 (u32) acpi_gbl_FADT.acpi_disable,
112 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
113 "Attempting to enable Legacy (non-ACPI) mode\n"));
114 break;
116 default:
117 return_ACPI_STATUS(AE_BAD_PARAMETER);
120 if (ACPI_FAILURE(status)) {
121 ACPI_EXCEPTION((AE_INFO, status,
122 "Could not write ACPI mode change"));
123 return_ACPI_STATUS(status);
127 * Some hardware takes a LONG time to switch modes. Give them 3 sec to
128 * do so, but allow faster systems to proceed more quickly.
130 retry = 3000;
131 while (retry) {
132 if (acpi_hw_get_mode() == mode) {
133 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
134 "Mode %X successfully enabled\n",
135 mode));
136 return_ACPI_STATUS(AE_OK);
138 acpi_os_stall(1000);
139 retry--;
142 ACPI_ERROR((AE_INFO, "Hardware did not change modes"));
143 return_ACPI_STATUS(AE_NO_HARDWARE_RESPONSE);
146 /*******************************************************************************
148 * FUNCTION: acpi_hw_get_mode
150 * PARAMETERS: none
152 * RETURN: SYS_MODE_ACPI or SYS_MODE_LEGACY
154 * DESCRIPTION: Return current operating state of system. Determined by
155 * querying the SCI_EN bit.
157 ******************************************************************************/
159 u32 acpi_hw_get_mode(void)
161 acpi_status status;
162 u32 value;
164 ACPI_FUNCTION_TRACE(hw_get_mode);
167 * ACPI 2.0 clarified that if SMI_CMD in FADT is zero,
168 * system does not support mode transition.
170 if (!acpi_gbl_FADT.smi_command) {
171 return_UINT32(ACPI_SYS_MODE_ACPI);
174 status = acpi_get_register(ACPI_BITREG_SCI_ENABLE, &value);
175 if (ACPI_FAILURE(status)) {
176 return_UINT32(ACPI_SYS_MODE_LEGACY);
179 if (value) {
180 return_UINT32(ACPI_SYS_MODE_ACPI);
181 } else {
182 return_UINT32(ACPI_SYS_MODE_LEGACY);