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
49ACPI_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 ******************************************************************************/
63acpi_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
144u32 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