1/******************************************************************************
2 *
3 * Module Name: hwacpi - ACPI Hardware Initialization/Mode Interface
4 *
5 *****************************************************************************/
6
7/*
8 * Copyright (C) 2000 - 2015, 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#include <acpi/acpi.h>
45#include "accommon.h"
46
47#define _COMPONENT          ACPI_HARDWARE
48ACPI_MODULE_NAME("hwacpi")
49
50#if (!ACPI_REDUCED_HARDWARE)	/* Entire module */
51/******************************************************************************
52 *
53 * FUNCTION:    acpi_hw_set_mode
54 *
55 * PARAMETERS:  mode            - SYS_MODE_ACPI or SYS_MODE_LEGACY
56 *
57 * RETURN:      Status
58 *
59 * DESCRIPTION: Transitions the system into the requested mode.
60 *
61 ******************************************************************************/
62acpi_status acpi_hw_set_mode(u32 mode)
63{
64
65	acpi_status status;
66
67	ACPI_FUNCTION_TRACE(hw_set_mode);
68
69	/* If the Hardware Reduced flag is set, machine is always in acpi mode */
70
71	if (acpi_gbl_reduced_hardware) {
72		return_ACPI_STATUS(AE_OK);
73	}
74
75	/*
76	 * ACPI 2.0 clarified that if SMI_CMD in FADT is zero,
77	 * system does not support mode transition.
78	 */
79	if (!acpi_gbl_FADT.smi_command) {
80		ACPI_ERROR((AE_INFO,
81			    "No SMI_CMD in FADT, mode transition failed"));
82		return_ACPI_STATUS(AE_NO_HARDWARE_RESPONSE);
83	}
84
85	/*
86	 * ACPI 2.0 clarified the meaning of ACPI_ENABLE and ACPI_DISABLE
87	 * in FADT: If it is zero, enabling or disabling is not supported.
88	 * As old systems may have used zero for mode transition,
89	 * we make sure both the numbers are zero to determine these
90	 * transitions are not supported.
91	 */
92	if (!acpi_gbl_FADT.acpi_enable && !acpi_gbl_FADT.acpi_disable) {
93		ACPI_ERROR((AE_INFO,
94			    "No ACPI mode transition supported in this system "
95			    "(enable/disable both zero)"));
96		return_ACPI_STATUS(AE_OK);
97	}
98
99	switch (mode) {
100	case ACPI_SYS_MODE_ACPI:
101
102		/* BIOS should have disabled ALL fixed and GP events */
103
104		status = acpi_hw_write_port(acpi_gbl_FADT.smi_command,
105					    (u32) acpi_gbl_FADT.acpi_enable, 8);
106		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
107				  "Attempting to enable ACPI mode\n"));
108		break;
109
110	case ACPI_SYS_MODE_LEGACY:
111		/*
112		 * BIOS should clear all fixed status bits and restore fixed event
113		 * enable bits to default
114		 */
115		status = acpi_hw_write_port(acpi_gbl_FADT.smi_command,
116					    (u32)acpi_gbl_FADT.acpi_disable, 8);
117		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
118				  "Attempting to enable Legacy (non-ACPI) mode\n"));
119		break;
120
121	default:
122
123		return_ACPI_STATUS(AE_BAD_PARAMETER);
124	}
125
126	if (ACPI_FAILURE(status)) {
127		ACPI_EXCEPTION((AE_INFO, status,
128				"Could not write ACPI mode change"));
129		return_ACPI_STATUS(status);
130	}
131
132	return_ACPI_STATUS(AE_OK);
133}
134
135/*******************************************************************************
136 *
137 * FUNCTION:    acpi_hw_get_mode
138 *
139 * PARAMETERS:  none
140 *
141 * RETURN:      SYS_MODE_ACPI or SYS_MODE_LEGACY
142 *
143 * DESCRIPTION: Return current operating state of system. Determined by
144 *              querying the SCI_EN bit.
145 *
146 ******************************************************************************/
147
148u32 acpi_hw_get_mode(void)
149{
150	acpi_status status;
151	u32 value;
152
153	ACPI_FUNCTION_TRACE(hw_get_mode);
154
155	/* If the Hardware Reduced flag is set, machine is always in acpi mode */
156
157	if (acpi_gbl_reduced_hardware) {
158		return_UINT32(ACPI_SYS_MODE_ACPI);
159	}
160
161	/*
162	 * ACPI 2.0 clarified that if SMI_CMD in FADT is zero,
163	 * system does not support mode transition.
164	 */
165	if (!acpi_gbl_FADT.smi_command) {
166		return_UINT32(ACPI_SYS_MODE_ACPI);
167	}
168
169	status = acpi_read_bit_register(ACPI_BITREG_SCI_ENABLE, &value);
170	if (ACPI_FAILURE(status)) {
171		return_UINT32(ACPI_SYS_MODE_LEGACY);
172	}
173
174	if (value) {
175		return_UINT32(ACPI_SYS_MODE_ACPI);
176	} else {
177		return_UINT32(ACPI_SYS_MODE_LEGACY);
178	}
179}
180
181#endif				/* !ACPI_REDUCED_HARDWARE */
182