drivers/acpi/acpica/hwregs.c

   1
   2 /*******************************************************************************
   3  *
   4  * Module Name: hwregs - Read/write access functions for the various ACPI
   5  *                       control and status registers.
   6  *
   7  ******************************************************************************/
   8
   9 /*
  10  * Copyright (C) 2000 - 2008, Intel Corp.
  11  * All rights reserved.
  12  *
  13  * Redistribution and use in source and binary forms, with or without
  14  * modification, are permitted provided that the following conditions
  15  * are met:
  16  * 1. Redistributions of source code must retain the above copyright
  17  *    notice, this list of conditions, and the following disclaimer,
  18  *    without modification.
  19  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
  20  *    substantially similar to the "NO WARRANTY" disclaimer below
  21  *    ("Disclaimer") and any redistribution must be conditioned upon
  22  *    including a substantially similar Disclaimer requirement for further
  23  *    binary redistribution.
  24  * 3. Neither the names of the above-listed copyright holders nor the names
  25  *    of any contributors may be used to endorse or promote products derived
  26  *    from this software without specific prior written permission.
  27  *
  28  * Alternatively, this software may be distributed under the terms of the
  29  * GNU General Public License ("GPL") version 2 as published by the Free
  30  * Software Foundation.
  31  *
  32  * NO WARRANTY
  33  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  34  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  35  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
  36  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  37  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  38  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  39  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  40  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  41  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  42  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  43  * POSSIBILITY OF SUCH DAMAGES.
  44  */
  45
  46 #include <acpi/acpi.h>
  47 #include "accommon.h"
  48 #include "acnamesp.h"
  49 #include "acevents.h"
  50
  51 #define _COMPONENT          ACPI_HARDWARE
  52 ACPI_MODULE_NAME("hwregs")
  53
  54 /*******************************************************************************
  55  *
  56  * FUNCTION:    acpi_hw_clear_acpi_status
  57  *
  58  * PARAMETERS:  None
  59  *
  60  * RETURN:      Status
  61  *
  62  * DESCRIPTION: Clears all fixed and general purpose status bits
  63  *              THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED
  64  *
  65  ******************************************************************************/
  66 acpi_status acpi_hw_clear_acpi_status(void)
  67 {
  68         acpi_status status;
  69         acpi_cpu_flags lock_flags = 0;
  70
  71         ACPI_FUNCTION_TRACE(hw_clear_acpi_status);
  72
  73         ACPI_DEBUG_PRINT((ACPI_DB_IO, "About to write %04X to %04X\n",
  74                           ACPI_BITMASK_ALL_FIXED_STATUS,
  75                           (u16) acpi_gbl_xpm1a_status.address));
  76
  77         lock_flags = acpi_os_acquire_lock(acpi_gbl_hardware_lock);
  78
  79         /* Clear the fixed events */
  80
  81         status = acpi_hw_register_write(ACPI_REGISTER_PM1_STATUS,
  82                                         ACPI_BITMASK_ALL_FIXED_STATUS);
  83         if (ACPI_FAILURE(status)) {
  84                 goto unlock_and_exit;
  85         }
  86
  87         /* Write PM1B register if present */
  88
  89         if (acpi_gbl_xpm1b_status.address) {
  90                 status = acpi_write(ACPI_BITMASK_ALL_FIXED_STATUS,
  91                                     &acpi_gbl_xpm1b_status);
  92                 if (ACPI_FAILURE(status)) {
  93                         goto unlock_and_exit;
  94                 }
  95         }
  96
  97         /* Clear the GPE Bits in all GPE registers in all GPE blocks */
  98
  99         status = acpi_ev_walk_gpe_list(acpi_hw_clear_gpe_block, NULL);
 100
 101       unlock_and_exit:
 102         acpi_os_release_lock(acpi_gbl_hardware_lock, lock_flags);
 103         return_ACPI_STATUS(status);
 104 }
 105
 106 /*******************************************************************************
 107  *
 108  * FUNCTION:    acpi_hw_get_register_bit_mask
 109  *
 110  * PARAMETERS:  register_id         - Index of ACPI Register to access
 111  *
 112  * RETURN:      The bitmask to be used when accessing the register
 113  *
 114  * DESCRIPTION: Map register_id into a register bitmask.
 115  *
 116  ******************************************************************************/
 117
 118 struct acpi_bit_register_info *acpi_hw_get_bit_register_info(u32 register_id)
 119 {
 120         ACPI_FUNCTION_ENTRY();
 121
 122         if (register_id > ACPI_BITREG_MAX) {
 123                 ACPI_ERROR((AE_INFO, "Invalid BitRegister ID: %X",
 124                             register_id));
 125                 return (NULL);
 126         }
 127
 128         return (&acpi_gbl_bit_register_info[register_id]);
 129 }
 130
 131 /******************************************************************************
 132  *
 133  * FUNCTION:    acpi_hw_register_read
 134  *
 135  * PARAMETERS:  register_id         - ACPI Register ID
 136  *              return_value        - Where the register value is returned
 137  *
 138  * RETURN:      Status and the value read.
 139  *
 140  * DESCRIPTION: Read from the specified ACPI register
 141  *
 142  ******************************************************************************/
 143 acpi_status
 144 acpi_hw_register_read(u32 register_id, u32 * return_value)
 145 {
 146         u32 value1 = 0;
 147         u32 value2 = 0;
 148         acpi_status status;
 149
 150         ACPI_FUNCTION_TRACE(hw_register_read);
 151
 152         switch (register_id) {
 153         case ACPI_REGISTER_PM1_STATUS:  /* 16-bit access */
 154
 155                 status = acpi_read(&value1, &acpi_gbl_xpm1a_status);
 156                 if (ACPI_FAILURE(status)) {
 157                         goto exit;
 158                 }
 159
 160                 /* PM1B is optional */
 161
 162                 status = acpi_read(&value2, &acpi_gbl_xpm1b_status);
 163                 value1 |= value2;
 164                 break;
 165
 166         case ACPI_REGISTER_PM1_ENABLE:  /* 16-bit access */
 167
 168                 status = acpi_read(&value1, &acpi_gbl_xpm1a_enable);
 169                 if (ACPI_FAILURE(status)) {
 170                         goto exit;
 171                 }
 172
 173                 /* PM1B is optional */
 174
 175                 status = acpi_read(&value2, &acpi_gbl_xpm1b_enable);
 176                 value1 |= value2;
 177                 break;
 178
 179         case ACPI_REGISTER_PM1_CONTROL: /* 16-bit access */
 180
 181                 status = acpi_read(&value1, &acpi_gbl_FADT.xpm1a_control_block);
 182                 if (ACPI_FAILURE(status)) {
 183                         goto exit;
 184                 }
 185
 186                 status = acpi_read(&value2, &acpi_gbl_FADT.xpm1b_control_block);
 187                 value1 |= value2;
 188                 break;
 189
 190         case ACPI_REGISTER_PM2_CONTROL: /* 8-bit access */
 191
 192                 status = acpi_read(&value1, &acpi_gbl_FADT.xpm2_control_block);
 193                 break;
 194
 195         case ACPI_REGISTER_PM_TIMER:    /* 32-bit access */
 196
 197                 status = acpi_read(&value1, &acpi_gbl_FADT.xpm_timer_block);
 198                 break;
 199
 200         case ACPI_REGISTER_SMI_COMMAND_BLOCK:   /* 8-bit access */
 201
 202                 status =
 203                     acpi_os_read_port(acpi_gbl_FADT.smi_command, &value1, 8);
 204                 break;
 205
 206         default:
 207                 ACPI_ERROR((AE_INFO, "Unknown Register ID: %X", register_id));
 208                 status = AE_BAD_PARAMETER;
 209                 break;
 210         }
 211
 212       exit:
 213
 214         if (ACPI_SUCCESS(status)) {
 215                 *return_value = value1;
 216         }
 217
 218         return_ACPI_STATUS(status);
 219 }
 220
 221 /******************************************************************************
 222  *
 223  * FUNCTION:    acpi_hw_register_write
 224  *
 225  * PARAMETERS:  register_id         - ACPI Register ID
 226  *              Value               - The value to write
 227  *
 228  * RETURN:      Status
 229  *
 230  * DESCRIPTION: Write to the specified ACPI register
 231  *
 232  * NOTE: In accordance with the ACPI specification, this function automatically
 233  * preserves the value of the following bits, meaning that these bits cannot be
 234  * changed via this interface:
 235  *
 236  * PM1_CONTROL[0] = SCI_EN
 237  * PM1_CONTROL[9]
 238  * PM1_STATUS[11]
 239  *
 240  * ACPI References:
 241  * 1) Hardware Ignored Bits: When software writes to a register with ignored
 242  *      bit fields, it preserves the ignored bit fields
 243  * 2) SCI_EN: OSPM always preserves this bit position
 244  *
 245  ******************************************************************************/
 246
 247 acpi_status acpi_hw_register_write(u32 register_id, u32 value)
 248 {
 249         acpi_status status;
 250         u32 read_value;
 251
 252         ACPI_FUNCTION_TRACE(hw_register_write);
 253
 254         switch (register_id) {
 255         case ACPI_REGISTER_PM1_STATUS:  /* 16-bit access */
 256
 257                 /* Perform a read first to preserve certain bits (per ACPI spec) */
 258
 259                 status = acpi_hw_register_read(ACPI_REGISTER_PM1_STATUS,
 260                                                &read_value);
 261                 if (ACPI_FAILURE(status)) {
 262                         goto exit;
 263                 }
 264
 265                 /* Insert the bits to be preserved */
 266
 267                 ACPI_INSERT_BITS(value, ACPI_PM1_STATUS_PRESERVED_BITS,
 268                                  read_value);
 269
 270                 /* Now we can write the data */
 271
 272                 status = acpi_write(value, &acpi_gbl_xpm1a_status);
 273                 if (ACPI_FAILURE(status)) {
 274                         goto exit;
 275                 }
 276
 277                 /* PM1B is optional */
 278
 279                 status = acpi_write(value, &acpi_gbl_xpm1b_status);
 280                 break;
 281
 282         case ACPI_REGISTER_PM1_ENABLE:  /* 16-bit access */
 283
 284                 status = acpi_write(value, &acpi_gbl_xpm1a_enable);
 285                 if (ACPI_FAILURE(status)) {
 286                         goto exit;
 287                 }
 288
 289                 /* PM1B is optional */
 290
 291                 status = acpi_write(value, &acpi_gbl_xpm1b_enable);
 292                 break;
 293
 294         case ACPI_REGISTER_PM1_CONTROL: /* 16-bit access */
 295
 296                 /*
 297                  * Perform a read first to preserve certain bits (per ACPI spec)
 298                  */
 299                 status = acpi_hw_register_read(ACPI_REGISTER_PM1_CONTROL,
 300                                                &read_value);
 301                 if (ACPI_FAILURE(status)) {
 302                         goto exit;
 303                 }
 304
 305                 /* Insert the bits to be preserved */
 306
 307                 ACPI_INSERT_BITS(value, ACPI_PM1_CONTROL_PRESERVED_BITS,
 308                                  read_value);
 309
 310                 /* Now we can write the data */
 311
 312                 status = acpi_write(value, &acpi_gbl_FADT.xpm1a_control_block);
 313                 if (ACPI_FAILURE(status)) {
 314                         goto exit;
 315                 }
 316
 317                 status = acpi_write(value, &acpi_gbl_FADT.xpm1b_control_block);
 318                 break;
 319
 320         case ACPI_REGISTER_PM1A_CONTROL:        /* 16-bit access */
 321
 322                 status = acpi_write(value, &acpi_gbl_FADT.xpm1a_control_block);
 323                 break;
 324
 325         case ACPI_REGISTER_PM1B_CONTROL:        /* 16-bit access */
 326
 327                 status = acpi_write(value, &acpi_gbl_FADT.xpm1b_control_block);
 328                 break;
 329
 330         case ACPI_REGISTER_PM2_CONTROL: /* 8-bit access */
 331
 332                 status = acpi_write(value, &acpi_gbl_FADT.xpm2_control_block);
 333                 break;
 334
 335         case ACPI_REGISTER_PM_TIMER:    /* 32-bit access */
 336
 337                 status = acpi_write(value, &acpi_gbl_FADT.xpm_timer_block);
 338                 break;
 339
 340         case ACPI_REGISTER_SMI_COMMAND_BLOCK:   /* 8-bit access */
 341
 342                 /* SMI_CMD is currently always in IO space */
 343
 344                 status =
 345                     acpi_os_write_port(acpi_gbl_FADT.smi_command, value, 8);
 346                 break;
 347
 348         default:
 349                 status = AE_BAD_PARAMETER;
 350                 break;
 351         }
 352
 353       exit:
 354         return_ACPI_STATUS(status);
 355 }