drivers/bus/acpi/hardware/hwacpi.c

   1
   2 /******************************************************************************
   3  *
   4  * Module Name: hwacpi - ACPI Hardware Initialization/Mode Interface
   5  *              $Revision$
   6  *
   7  *****************************************************************************/
   8
   9 /*
  10  *  Copyright (C) 2000, 2001 R. Byron Moore
  11  *
  12  *  This program is free software; you can redistribute it and/or modify
  13  *  it under the terms of the GNU General Public License as published by
  14  *  the Free Software Foundation; either version 2 of the License, or
  15  *  (at your option) any later version.
  16  *
  17  *  This program is distributed in the hope that it will be useful,
  18  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  *  GNU General Public License for more details.
  21  *
  22  *  You should have received a copy of the GNU General Public License
  23  *  along with this program; if not, write to the Free Software
  24  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  25  */
  26
  27
  28 #include "acpi.h"
  29 #include "achware.h"
  30
  31
  32 #define _COMPONENT          ACPI_HARDWARE
  33          MODULE_NAME         ("hwacpi")
  34
  35
  36 /******************************************************************************
  37  *
  38  * FUNCTION:    Acpi_hw_initialize
  39  *
  40  * PARAMETERS:  None
  41  *
  42  * RETURN:      Status
  43  *
  44  * DESCRIPTION: Initialize and validate various ACPI registers
  45  *
  46  ******************************************************************************/
  47
  48 ACPI_STATUS
  49 acpi_hw_initialize (
  50         void)
  51 {
  52         ACPI_STATUS             status = AE_OK;
  53         u32                     index;
  54
  55
  56         /* We must have the ACPI tables by the time we get here */
  57
  58         if (!acpi_gbl_FADT) {
  59                 acpi_gbl_restore_acpi_chipset = FALSE;
  60
  61                 return (AE_NO_ACPI_TABLES);
  62         }
  63
  64         /* Must support *some* mode! */
  65 /*
  66         if (!(System_flags & SYS_MODES_MASK))
  67         {
  68                 Restore_acpi_chipset = FALSE;
  69
  70                 return (AE_ERROR);
  71         }
  72
  73 */
  74
  75
  76         switch (acpi_gbl_system_flags & SYS_MODES_MASK) {
  77                 /* Identify current ACPI/legacy mode   */
  78
  79         case (SYS_MODE_ACPI):
  80
  81                 acpi_gbl_original_mode = SYS_MODE_ACPI;
  82                 break;
  83
  84
  85         case (SYS_MODE_LEGACY):
  86
  87                 acpi_gbl_original_mode = SYS_MODE_LEGACY;
  88                 break;
  89
  90
  91         case (SYS_MODE_ACPI | SYS_MODE_LEGACY):
  92
  93                 if (acpi_hw_get_mode () == SYS_MODE_ACPI) {
  94                         acpi_gbl_original_mode = SYS_MODE_ACPI;
  95                 }
  96                 else {
  97                         acpi_gbl_original_mode = SYS_MODE_LEGACY;
  98                 }
  99
 100                 break;
 101         }
 102
 103
 104         if (acpi_gbl_system_flags & SYS_MODE_ACPI) {
 105                 /* Target system supports ACPI mode */
 106
 107                 /*
 108                  * The purpose of this code is to save the initial state
 109                  * of the ACPI event enable registers. An exit function will be
 110                  * registered which will restore this state when the application
 111                  * exits. The exit function will also clear all of the ACPI event
 112                  * status bits prior to restoring the original mode.
 113                  *
 114                  * The location of the PM1a_evt_blk enable registers is defined as the
 115                  * base of PM1a_evt_blk + DIV_2(PM1a_evt_blk_length). Since the spec further
 116                  * fully defines the PM1a_evt_blk to be a total of 4 bytes, the offset
 117                  * for the enable registers is always 2 from the base. It is hard
 118                  * coded here. If this changes in the spec, this code will need to
 119                  * be modified. The PM1b_evt_blk behaves as expected.
 120                  */
 121
 122                 acpi_gbl_pm1_enable_register_save = (u16) acpi_hw_register_read (ACPI_MTX_LOCK, PM1_EN);
 123
 124
 125                 /*
 126                  * The GPEs behave similarly, except that the length of the register
 127                  * block is not fixed, so the buffer must be allocated with malloc
 128                  */
 129
 130                 if (ACPI_VALID_ADDRESS (acpi_gbl_FADT->Xgpe0blk.address) &&
 131                         acpi_gbl_FADT->gpe0blk_len) {
 132                         /* GPE0 specified in FADT  */
 133
 134                         acpi_gbl_gpe0enable_register_save =
 135                                 acpi_cm_allocate (DIV_2 (acpi_gbl_FADT->gpe0blk_len));
 136                         if (!acpi_gbl_gpe0enable_register_save) {
 137                                 return (AE_NO_MEMORY);
 138                         }
 139
 140                         /* Save state of GPE0 enable bits */
 141
 142                         for (index = 0; index < DIV_2 (acpi_gbl_FADT->gpe0blk_len); index++) {
 143                                 acpi_gbl_gpe0enable_register_save[index] =
 144                                         (u8) acpi_hw_register_read (ACPI_MTX_LOCK, GPE0_EN_BLOCK | index);
 145                         }
 146                 }
 147
 148                 else {
 149                         acpi_gbl_gpe0enable_register_save = NULL;
 150                 }
 151
 152                 if (ACPI_VALID_ADDRESS (acpi_gbl_FADT->Xgpe1_blk.address) &&
 153                         acpi_gbl_FADT->gpe1_blk_len) {
 154                         /* GPE1 defined */
 155
 156                         acpi_gbl_gpe1_enable_register_save =
 157                                 acpi_cm_allocate (DIV_2 (acpi_gbl_FADT->gpe1_blk_len));
 158                         if (!acpi_gbl_gpe1_enable_register_save) {
 159                                 return (AE_NO_MEMORY);
 160                         }
 161
 162                         /* save state of GPE1 enable bits */
 163
 164                         for (index = 0; index < DIV_2 (acpi_gbl_FADT->gpe1_blk_len); index++) {
 165                                 acpi_gbl_gpe1_enable_register_save[index] =
 166                                         (u8) acpi_hw_register_read (ACPI_MTX_LOCK, GPE1_EN_BLOCK | index);
 167                         }
 168                 }
 169
 170                 else {
 171                         acpi_gbl_gpe1_enable_register_save = NULL;
 172                 }
 173         }
 174
 175         return (status);
 176 }
 177
 178
 179 /******************************************************************************
 180  *
 181  * FUNCTION:    Acpi_hw_set_mode
 182  *
 183  * PARAMETERS:  Mode            - SYS_MODE_ACPI or SYS_MODE_LEGACY
 184  *
 185  * RETURN:      Status
 186  *
 187  * DESCRIPTION: Transitions the system into the requested mode or does nothing
 188  *              if the system is already in that mode.
 189  *
 190  ******************************************************************************/
 191
 192 ACPI_STATUS
 193 acpi_hw_set_mode (
 194         u32                     mode)
 195 {
 196
 197         ACPI_STATUS             status = AE_NO_HARDWARE_RESPONSE;
 198
 199
 200         if (mode == SYS_MODE_ACPI) {
 201                 /* BIOS should have disabled ALL fixed and GP events */
 202
 203                 acpi_os_out8 (acpi_gbl_FADT->smi_cmd, acpi_gbl_FADT->acpi_enable);
 204         }
 205
 206         else if (mode == SYS_MODE_LEGACY) {
 207                 /*
 208                  * BIOS should clear all fixed status bits and restore fixed event
 209                  * enable bits to default
 210                  */
 211
 212                 acpi_os_out8 (acpi_gbl_FADT->smi_cmd, acpi_gbl_FADT->acpi_disable);
 213         }
 214
 215         if (acpi_hw_get_mode () == mode) {
 216                 status = AE_OK;
 217         }
 218
 219         return (status);
 220 }
 221
 222
 223 /******************************************************************************
 224  *
 225  * FUNCTION:    Acpi_hw_get_mode
 226  *
 227  * PARAMETERS:  none
 228  *
 229  * RETURN:      SYS_MODE_ACPI or SYS_MODE_LEGACY
 230  *
 231  * DESCRIPTION: Return current operating state of system.  Determined by
 232  *              querying the SCI_EN bit.
 233  *
 234  ******************************************************************************/
 235
 236 u32
 237 acpi_hw_get_mode (void)
 238 {
 239
 240
 241         if (acpi_hw_register_bit_access (ACPI_READ, ACPI_MTX_LOCK, SCI_EN)) {
 242                 return (SYS_MODE_ACPI);
 243         }
 244         else {
 245                 return (SYS_MODE_LEGACY);
 246         }
 247 }
 248
 249 /******************************************************************************
 250  *
 251  * FUNCTION:    Acpi_hw_get_mode_capabilities
 252  *
 253  * PARAMETERS:  none
 254  *
 255  * RETURN:      logical OR of SYS_MODE_ACPI and SYS_MODE_LEGACY determined at initial
 256  *              system state.
 257  *
 258  * DESCRIPTION: Returns capablities of system
 259  *
 260  ******************************************************************************/
 261
 262 u32
 263 acpi_hw_get_mode_capabilities (void)
 264 {
 265
 266
 267         if (!(acpi_gbl_system_flags & SYS_MODES_MASK)) {
 268                 if (acpi_hw_get_mode () == SYS_MODE_LEGACY) {
 269                         /*
 270                          * Assume that if this call is being made, Acpi_init has been called
 271                          * and ACPI support has been established by the presence of the
 272                          * tables.  Therefore since we're in SYS_MODE_LEGACY, the system
 273                          * must support both modes
 274                          */
 275
 276                         acpi_gbl_system_flags |= (SYS_MODE_ACPI | SYS_MODE_LEGACY);
 277                 }
 278
 279                 else {
 280                         /* TBD: [Investigate] !!! this may be unsafe... */
 281                         /*
 282                          * system is is ACPI mode, so try to switch back to LEGACY to see if
 283                          * it is supported
 284                          */
 285                         acpi_hw_set_mode (SYS_MODE_LEGACY);
 286
 287                         if (acpi_hw_get_mode () == SYS_MODE_LEGACY) {
 288                                 /* Now in SYS_MODE_LEGACY, so both are supported */
 289
 290                                 acpi_gbl_system_flags |= (SYS_MODE_ACPI | SYS_MODE_LEGACY);
 291                                 acpi_hw_set_mode (SYS_MODE_ACPI);
 292                         }
 293
 294                         else {
 295                                 /* Still in SYS_MODE_ACPI so this must be an ACPI only system */
 296
 297                                 acpi_gbl_system_flags |= SYS_MODE_ACPI;
 298                         }
 299                 }
 300         }
 301
 302         return (acpi_gbl_system_flags & SYS_MODES_MASK);
 303 }
 304
 305