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 - 2006, 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_REPORT_ERROR(("No FADT is present\n"));
  72                 return_ACPI_STATUS(AE_NO_ACPI_TABLES);
  73         }
  74
  75         /* Sanity check the FADT for valid values */
  76
  77         status = acpi_ut_validate_fadt();
  78         if (ACPI_FAILURE(status)) {
  79                 return_ACPI_STATUS(status);
  80         }
  81
  82         return_ACPI_STATUS(AE_OK);
  83 }
  84
  85 /******************************************************************************
  86  *
  87  * FUNCTION:    acpi_hw_set_mode
  88  *
  89  * PARAMETERS:  Mode            - SYS_MODE_ACPI or SYS_MODE_LEGACY
  90  *
  91  * RETURN:      Status
  92  *
  93  * DESCRIPTION: Transitions the system into the requested mode.
  94  *
  95  ******************************************************************************/
  96
  97 acpi_status acpi_hw_set_mode(u32 mode)
  98 {
  99
 100         acpi_status status;
 101         u32 retry;
 102
 103         ACPI_FUNCTION_TRACE("hw_set_mode");
 104
 105         /*
 106          * ACPI 2.0 clarified that if SMI_CMD in FADT is zero,
 107          * system does not support mode transition.
 108          */
 109         if (!acpi_gbl_FADT->smi_cmd) {
 110                 ACPI_REPORT_ERROR(("No SMI_CMD in FADT, mode transition failed\n"));
 111                 return_ACPI_STATUS(AE_NO_HARDWARE_RESPONSE);
 112         }
 113
 114         /*
 115          * ACPI 2.0 clarified the meaning of ACPI_ENABLE and ACPI_DISABLE
 116          * in FADT: If it is zero, enabling or disabling is not supported.
 117          * As old systems may have used zero for mode transition,
 118          * we make sure both the numbers are zero to determine these
 119          * transitions are not supported.
 120          */
 121         if (!acpi_gbl_FADT->acpi_enable && !acpi_gbl_FADT->acpi_disable) {
 122                 ACPI_REPORT_ERROR(("No ACPI mode transition supported in this system (enable/disable both zero)\n"));
 123                 return_ACPI_STATUS(AE_OK);
 124         }
 125
 126         switch (mode) {
 127         case ACPI_SYS_MODE_ACPI:
 128
 129                 /* BIOS should have disabled ALL fixed and GP events */
 130
 131                 status = acpi_os_write_port(acpi_gbl_FADT->smi_cmd,
 132                                             (u32) acpi_gbl_FADT->acpi_enable,
 133                                             8);
 134                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 135                                   "Attempting to enable ACPI mode\n"));
 136                 break;
 137
 138         case ACPI_SYS_MODE_LEGACY:
 139
 140                 /*
 141                  * BIOS should clear all fixed status bits and restore fixed event
 142                  * enable bits to default
 143                  */
 144                 status = acpi_os_write_port(acpi_gbl_FADT->smi_cmd,
 145                                             (u32) acpi_gbl_FADT->acpi_disable,
 146                                             8);
 147                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 148                                   "Attempting to enable Legacy (non-ACPI) mode\n"));
 149                 break;
 150
 151         default:
 152                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 153         }
 154
 155         if (ACPI_FAILURE(status)) {
 156                 ACPI_REPORT_ERROR(("Could not write mode change, %s\n",
 157                                    acpi_format_exception(status)));
 158                 return_ACPI_STATUS(status);
 159         }
 160
 161         /*
 162          * Some hardware takes a LONG time to switch modes. Give them 3 sec to
 163          * do so, but allow faster systems to proceed more quickly.
 164          */
 165         retry = 3000;
 166         while (retry) {
 167                 if (acpi_hw_get_mode() == mode) {
 168                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 169                                           "Mode %X successfully enabled\n",
 170                                           mode));
 171                         return_ACPI_STATUS(AE_OK);
 172                 }
 173                 acpi_os_stall(1000);
 174                 retry--;
 175         }
 176
 177         ACPI_REPORT_ERROR(("Hardware never changed modes\n"));
 178         return_ACPI_STATUS(AE_NO_HARDWARE_RESPONSE);
 179 }
 180
 181 /*******************************************************************************
 182  *
 183  * FUNCTION:    acpi_hw_get_mode
 184  *
 185  * PARAMETERS:  none
 186  *
 187  * RETURN:      SYS_MODE_ACPI or SYS_MODE_LEGACY
 188  *
 189  * DESCRIPTION: Return current operating state of system.  Determined by
 190  *              querying the SCI_EN bit.
 191  *
 192  ******************************************************************************/
 193
 194 u32 acpi_hw_get_mode(void)
 195 {
 196         acpi_status status;
 197         u32 value;
 198
 199         ACPI_FUNCTION_TRACE("hw_get_mode");
 200
 201         /*
 202          * ACPI 2.0 clarified that if SMI_CMD in FADT is zero,
 203          * system does not support mode transition.
 204          */
 205         if (!acpi_gbl_FADT->smi_cmd) {
 206                 return_UINT32(ACPI_SYS_MODE_ACPI);
 207         }
 208
 209         status =
 210             acpi_get_register(ACPI_BITREG_SCI_ENABLE, &value, ACPI_MTX_LOCK);
 211         if (ACPI_FAILURE(status)) {
 212                 return_UINT32(ACPI_SYS_MODE_LEGACY);
 213         }
 214
 215         if (value) {
 216                 return_UINT32(ACPI_SYS_MODE_ACPI);
 217         } else {
 218                 return_UINT32(ACPI_SYS_MODE_LEGACY);
 219         }
 220 }