drivers/acpi/hardware/hwacpi.c

   1
   2 /******************************************************************************
   3  *
   4  * Module Name: hwacpi - ACPI Hardware Initialization/Mode Interface
   5  *
   6  *****************************************************************************/
   7
   8 /*
   9  * Copyright (C) 2000 - 2005, R. Byron Moore
  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
  47 #define _COMPONENT          ACPI_HARDWARE
  48 ACPI_MODULE_NAME("hwacpi")
  49
  50 /******************************************************************************
  51  *
  52  * FUNCTION:    acpi_hw_initialize
  53  *
  54  * PARAMETERS:  None
  55  *
  56  * RETURN:      Status
  57  *
  58  * DESCRIPTION: Initialize and validate the various ACPI registers defined in
  59  *              the FADT.
  60  *
  61  ******************************************************************************/
  62 acpi_status acpi_hw_initialize(void)
  63 {
  64         acpi_status status;
  65
  66         ACPI_FUNCTION_TRACE("hw_initialize");
  67
  68         /* We must have the ACPI tables by the time we get here */
  69
  70         if (!acpi_gbl_FADT) {
  71                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "No FADT is present\n"));
  72
  73                 return_ACPI_STATUS(AE_NO_ACPI_TABLES);
  74         }
  75
  76         /* Sanity check the FADT for valid values */
  77
  78         status = acpi_ut_validate_fadt();
  79         if (ACPI_FAILURE(status)) {
  80                 return_ACPI_STATUS(status);
  81         }
  82
  83         return_ACPI_STATUS(AE_OK);
  84 }
  85
  86 /******************************************************************************
  87  *
  88  * FUNCTION:    acpi_hw_set_mode
  89  *
  90  * PARAMETERS:  Mode            - SYS_MODE_ACPI or SYS_MODE_LEGACY
  91  *
  92  * RETURN:      Status
  93  *
  94  * DESCRIPTION: Transitions the system into the requested mode.
  95  *
  96  ******************************************************************************/
  97
  98 acpi_status acpi_hw_set_mode(u32 mode)
  99 {
 100
 101         acpi_status status;
 102         u32 retry;
 103
 104         ACPI_FUNCTION_TRACE("hw_set_mode");
 105
 106         /*
 107          * ACPI 2.0 clarified that if SMI_CMD in FADT is zero,
 108          * system does not support mode transition.
 109          */
 110         if (!acpi_gbl_FADT->smi_cmd) {
 111                 ACPI_REPORT_ERROR(("No SMI_CMD in FADT, mode transition failed.\n"));
 112                 return_ACPI_STATUS(AE_NO_HARDWARE_RESPONSE);
 113         }
 114
 115         /*
 116          * ACPI 2.0 clarified the meaning of ACPI_ENABLE and ACPI_DISABLE
 117          * in FADT: If it is zero, enabling or disabling is not supported.
 118          * As old systems may have used zero for mode transition,
 119          * we make sure both the numbers are zero to determine these
 120          * transitions are not supported.
 121          */
 122         if (!acpi_gbl_FADT->acpi_enable && !acpi_gbl_FADT->acpi_disable) {
 123                 ACPI_REPORT_ERROR(("No ACPI mode transition supported in this system (enable/disable both zero)\n"));
 124                 return_ACPI_STATUS(AE_OK);
 125         }
 126
 127         switch (mode) {
 128         case ACPI_SYS_MODE_ACPI:
 129
 130                 /* BIOS should have disabled ALL fixed and GP events */
 131
 132                 status = acpi_os_write_port(acpi_gbl_FADT->smi_cmd,
 133                                             (u32) acpi_gbl_FADT->acpi_enable,
 134                                             8);
 135                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 136                                   "Attempting to enable ACPI mode\n"));
 137                 break;
 138
 139         case ACPI_SYS_MODE_LEGACY:
 140
 141                 /*
 142                  * BIOS should clear all fixed status bits and restore fixed event
 143                  * enable bits to default
 144                  */
 145                 status = acpi_os_write_port(acpi_gbl_FADT->smi_cmd,
 146                                             (u32) acpi_gbl_FADT->acpi_disable,
 147                                             8);
 148                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 149                                   "Attempting to enable Legacy (non-ACPI) mode\n"));
 150                 break;
 151
 152         default:
 153                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 154         }
 155
 156         if (ACPI_FAILURE(status)) {
 157                 ACPI_REPORT_ERROR(("Could not write mode change, %s\n",
 158                                    acpi_format_exception(status)));
 159                 return_ACPI_STATUS(status);
 160         }
 161
 162         /*
 163          * Some hardware takes a LONG time to switch modes. Give them 3 sec to
 164          * do so, but allow faster systems to proceed more quickly.
 165          */
 166         retry = 3000;
 167         while (retry) {
 168                 if (acpi_hw_get_mode() == mode) {
 169                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 170                                           "Mode %X successfully enabled\n",
 171                                           mode));
 172                         return_ACPI_STATUS(AE_OK);
 173                 }
 174                 acpi_os_stall(1000);
 175                 retry--;
 176         }
 177
 178         ACPI_REPORT_ERROR(("Hardware never changed modes\n"));
 179         return_ACPI_STATUS(AE_NO_HARDWARE_RESPONSE);
 180 }
 181
 182 /*******************************************************************************
 183  *
 184  * FUNCTION:    acpi_hw_get_mode
 185  *
 186  * PARAMETERS:  none
 187  *
 188  * RETURN:      SYS_MODE_ACPI or SYS_MODE_LEGACY
 189  *
 190  * DESCRIPTION: Return current operating state of system.  Determined by
 191  *              querying the SCI_EN bit.
 192  *
 193  ******************************************************************************/
 194
 195 u32 acpi_hw_get_mode(void)
 196 {
 197         acpi_status status;
 198         u32 value;
 199
 200         ACPI_FUNCTION_TRACE("hw_get_mode");
 201
 202         /*
 203          * ACPI 2.0 clarified that if SMI_CMD in FADT is zero,
 204          * system does not support mode transition.
 205          */
 206         if (!acpi_gbl_FADT->smi_cmd) {
 207                 return_VALUE(ACPI_SYS_MODE_ACPI);
 208         }
 209
 210         status =
 211             acpi_get_register(ACPI_BITREG_SCI_ENABLE, &value, ACPI_MTX_LOCK);
 212         if (ACPI_FAILURE(status)) {
 213                 return_VALUE(ACPI_SYS_MODE_LEGACY);
 214         }
 215
 216         if (value) {
 217                 return_VALUE(ACPI_SYS_MODE_ACPI);
 218         } else {
 219                 return_VALUE(ACPI_SYS_MODE_LEGACY);
 220         }
 221 }