drivers/acpi/acpica/hwacpi.c

   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 /******************************************************************************
  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  ******************************************************************************/
  62 acpi_status acpi_hw_set_mode(u32 mode)
  63 {
  64
  65         acpi_status status;
  66
  67         ACPI_FUNCTION_TRACE(hw_set_mode);
  68
  69         /*
  70          * ACPI 2.0 clarified that if SMI_CMD in FADT is zero,
  71          * system does not support mode transition.
  72          */
  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);
  77         }
  78
  79         /*
  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.
  85          */
  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 "
  89                             "(enable/disable both zero)"));
  90                 return_ACPI_STATUS(AE_OK);
  91         }
  92
  93         switch (mode) {
  94         case ACPI_SYS_MODE_ACPI:
  95
  96                 /* BIOS should have disabled ALL fixed and GP events */
  97
  98                 status = acpi_hw_write_port(acpi_gbl_FADT.smi_command,
  99                                             (u32) acpi_gbl_FADT.acpi_enable, 8);
 100                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 101                                   "Attempting to enable ACPI mode\n"));
 102                 break;
 103
 104         case ACPI_SYS_MODE_LEGACY:
 105
 106                 /*
 107                  * BIOS should clear all fixed status bits and restore fixed event
 108                  * enable bits to default
 109                  */
 110                 status = acpi_hw_write_port(acpi_gbl_FADT.smi_command,
 111                                             (u32) acpi_gbl_FADT.acpi_disable,
 112                                             8);
 113                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 114                                   "Attempting to enable Legacy (non-ACPI) mode\n"));
 115                 break;
 116
 117         default:
 118                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 119         }
 120
 121         if (ACPI_FAILURE(status)) {
 122                 ACPI_EXCEPTION((AE_INFO, status,
 123                                 "Could not write ACPI mode change"));
 124                 return_ACPI_STATUS(status);
 125         }
 126
 127         return_ACPI_STATUS(AE_OK);
 128 }
 129
 130 /*******************************************************************************
 131  *
 132  * FUNCTION:    acpi_hw_get_mode
 133  *
 134  * PARAMETERS:  none
 135  *
 136  * RETURN:      SYS_MODE_ACPI or SYS_MODE_LEGACY
 137  *
 138  * DESCRIPTION: Return current operating state of system.  Determined by
 139  *              querying the SCI_EN bit.
 140  *
 141  ******************************************************************************/
 142
 143 u32 acpi_hw_get_mode(void)
 144 {
 145         acpi_status status;
 146         u32 value;
 147
 148         ACPI_FUNCTION_TRACE(hw_get_mode);
 149
 150         /*
 151          * ACPI 2.0 clarified that if SMI_CMD in FADT is zero,
 152          * system does not support mode transition.
 153          */
 154         if (!acpi_gbl_FADT.smi_command) {
 155                 return_UINT32(ACPI_SYS_MODE_ACPI);
 156         }
 157
 158         status = acpi_read_bit_register(ACPI_BITREG_SCI_ENABLE, &value);
 159         if (ACPI_FAILURE(status)) {
 160                 return_UINT32(ACPI_SYS_MODE_LEGACY);
 161         }
 162
 163         if (value) {
 164                 return_UINT32(ACPI_SYS_MODE_ACPI);
 165         } else {
 166                 return_UINT32(ACPI_SYS_MODE_LEGACY);
 167         }
 168 }