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
  46 #include <acpi/acpi.h>
  47
  48
  49 #define _COMPONENT          ACPI_HARDWARE
  50          ACPI_MODULE_NAME    ("hwacpi")
  51
  52
  53 /******************************************************************************
  54  *
  55  * FUNCTION:    acpi_hw_initialize
  56  *
  57  * PARAMETERS:  None
  58  *
  59  * RETURN:      Status
  60  *
  61  * DESCRIPTION: Initialize and validate various ACPI registers
  62  *
  63  ******************************************************************************/
  64
  65 acpi_status
  66 acpi_hw_initialize (
  67         void)
  68 {
  69         acpi_status                     status;
  70
  71
  72         ACPI_FUNCTION_TRACE ("hw_initialize");
  73
  74
  75         /* We must have the ACPI tables by the time we get here */
  76
  77         if (!acpi_gbl_FADT) {
  78                 ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "A FADT is not loaded\n"));
  79
  80                 return_ACPI_STATUS (AE_NO_ACPI_TABLES);
  81         }
  82
  83         /* Sanity check the FADT for valid values */
  84
  85         status = acpi_ut_validate_fadt ();
  86         if (ACPI_FAILURE (status)) {
  87                 return_ACPI_STATUS (status);
  88         }
  89
  90         return_ACPI_STATUS (AE_OK);
  91 }
  92
  93
  94 /******************************************************************************
  95  *
  96  * FUNCTION:    acpi_hw_set_mode
  97  *
  98  * PARAMETERS:  Mode            - SYS_MODE_ACPI or SYS_MODE_LEGACY
  99  *
 100  * RETURN:      Status
 101  *
 102  * DESCRIPTION: Transitions the system into the requested mode.
 103  *
 104  ******************************************************************************/
 105
 106 acpi_status
 107 acpi_hw_set_mode (
 108         u32                             mode)
 109 {
 110
 111         acpi_status                     status;
 112         u32                             retry;
 113
 114
 115         ACPI_FUNCTION_TRACE ("hw_set_mode");
 116
 117         /*
 118          * ACPI 2.0 clarified that if SMI_CMD in FADT is zero,
 119          * system does not support mode transition.
 120          */
 121         if (!acpi_gbl_FADT->smi_cmd) {
 122                 ACPI_REPORT_ERROR (("No SMI_CMD in FADT, mode transition failed.\n"));
 123                 return_ACPI_STATUS (AE_NO_HARDWARE_RESPONSE);
 124         }
 125
 126         /*
 127          * ACPI 2.0 clarified the meaning of ACPI_ENABLE and ACPI_DISABLE
 128          * in FADT: If it is zero, enabling or disabling is not supported.
 129          * As old systems may have used zero for mode transition,
 130          * we make sure both the numbers are zero to determine these
 131          * transitions are not supported.
 132          */
 133         if (!acpi_gbl_FADT->acpi_enable && !acpi_gbl_FADT->acpi_disable) {
 134                 ACPI_REPORT_ERROR (("No ACPI mode transition supported in this system (enable/disable both zero)\n"));
 135                 return_ACPI_STATUS (AE_OK);
 136         }
 137
 138         switch (mode) {
 139         case ACPI_SYS_MODE_ACPI:
 140
 141                 /* BIOS should have disabled ALL fixed and GP events */
 142
 143                 status = acpi_os_write_port (acpi_gbl_FADT->smi_cmd,
 144                                   (u32) acpi_gbl_FADT->acpi_enable, 8);
 145                 ACPI_DEBUG_PRINT ((ACPI_DB_INFO, "Attempting to enable ACPI mode\n"));
 146                 break;
 147
 148         case ACPI_SYS_MODE_LEGACY:
 149
 150                 /*
 151                  * BIOS should clear all fixed status bits and restore fixed event
 152                  * enable bits to default
 153                  */
 154                 status = acpi_os_write_port (acpi_gbl_FADT->smi_cmd,
 155                                  (u32) acpi_gbl_FADT->acpi_disable, 8);
 156                 ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
 157                                  "Attempting to enable Legacy (non-ACPI) mode\n"));
 158                 break;
 159
 160         default:
 161                 return_ACPI_STATUS (AE_BAD_PARAMETER);
 162         }
 163
 164         if (ACPI_FAILURE (status)) {
 165                 ACPI_REPORT_ERROR (("Could not write mode change, %s\n", acpi_format_exception (status)));
 166                 return_ACPI_STATUS (status);
 167         }
 168
 169         /*
 170          * Some hardware takes a LONG time to switch modes. Give them 3 sec to
 171          * do so, but allow faster systems to proceed more quickly.
 172          */
 173         retry = 3000;
 174         while (retry) {
 175                 if (acpi_hw_get_mode() == mode) {
 176                         ACPI_DEBUG_PRINT ((ACPI_DB_INFO, "Mode %X successfully enabled\n", mode));
 177                         return_ACPI_STATUS (AE_OK);
 178                 }
 179                 acpi_os_stall(1000);
 180                 retry--;
 181         }
 182
 183         ACPI_REPORT_ERROR (("Hardware never changed modes\n"));
 184         return_ACPI_STATUS (AE_NO_HARDWARE_RESPONSE);
 185 }
 186
 187
 188 /******************************************************************************
 189  *
 190  * FUNCTION:    acpi_hw_get_mode
 191  *
 192  * PARAMETERS:  none
 193  *
 194  * RETURN:      SYS_MODE_ACPI or SYS_MODE_LEGACY
 195  *
 196  * DESCRIPTION: Return current operating state of system.  Determined by
 197  *              querying the SCI_EN bit.
 198  *
 199  ******************************************************************************/
 200
 201 u32
 202 acpi_hw_get_mode (void)
 203 {
 204         acpi_status                     status;
 205         u32                             value;
 206
 207
 208         ACPI_FUNCTION_TRACE ("hw_get_mode");
 209
 210
 211         /*
 212          * ACPI 2.0 clarified that if SMI_CMD in FADT is zero,
 213          * system does not support mode transition.
 214          */
 215         if (!acpi_gbl_FADT->smi_cmd) {
 216                 return_VALUE (ACPI_SYS_MODE_ACPI);
 217         }
 218
 219         status = acpi_get_register (ACPI_BITREG_SCI_ENABLE, &value, ACPI_MTX_LOCK);
 220         if (ACPI_FAILURE (status)) {
 221                 return_VALUE (ACPI_SYS_MODE_LEGACY);
 222         }
 223
 224         if (value) {
 225                 return_VALUE (ACPI_SYS_MODE_ACPI);
 226         }
 227         else {
 228                 return_VALUE (ACPI_SYS_MODE_LEGACY);
 229         }
 230 }