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 /* Local Prototypes */
  55 static acpi_status
  56 acpi_hw_read_multiple(u32 *value,
  57                       struct acpi_generic_address *register_a,
  58                       struct acpi_generic_address *register_b);
  59
  60 static acpi_status
  61 acpi_hw_write_multiple(u32 value,
  62                        struct acpi_generic_address *register_a,
  63                        struct acpi_generic_address *register_b);
  64
  65 /*******************************************************************************
  66  *
  67  * FUNCTION:    acpi_hw_clear_acpi_status
  68  *
  69  * PARAMETERS:  None
  70  *
  71  * RETURN:      Status
  72  *
  73  * DESCRIPTION: Clears all fixed and general purpose status bits
  74  *
  75  ******************************************************************************/
  76
  77 acpi_status acpi_hw_clear_acpi_status(void)
  78 {
  79         acpi_status status;
  80         acpi_cpu_flags lock_flags = 0;
  81
  82         ACPI_FUNCTION_TRACE(hw_clear_acpi_status);
  83
  84         ACPI_DEBUG_PRINT((ACPI_DB_IO, "About to write %04X to %0llX\n",
  85                           ACPI_BITMASK_ALL_FIXED_STATUS,
  86                           acpi_gbl_xpm1a_status.address));
  87
  88         lock_flags = acpi_os_acquire_lock(acpi_gbl_hardware_lock);
  89
  90         /* Clear the fixed events in PM1 A/B */
  91
  92         status = acpi_hw_register_write(ACPI_REGISTER_PM1_STATUS,
  93                                         ACPI_BITMASK_ALL_FIXED_STATUS);
  94         if (ACPI_FAILURE(status)) {
  95                 goto unlock_and_exit;
  96         }
  97
  98         /* Clear the GPE Bits in all GPE registers in all GPE blocks */
  99
 100         status = acpi_ev_walk_gpe_list(acpi_hw_clear_gpe_block, NULL);
 101
 102       unlock_and_exit:
 103         acpi_os_release_lock(acpi_gbl_hardware_lock, lock_flags);
 104         return_ACPI_STATUS(status);
 105 }
 106
 107 /*******************************************************************************
 108  *
 109  * FUNCTION:    acpi_hw_get_register_bit_mask
 110  *
 111  * PARAMETERS:  register_id         - Index of ACPI Register to access
 112  *
 113  * RETURN:      The bitmask to be used when accessing the register
 114  *
 115  * DESCRIPTION: Map register_id into a register bitmask.
 116  *
 117  ******************************************************************************/
 118
 119 struct acpi_bit_register_info *acpi_hw_get_bit_register_info(u32 register_id)
 120 {
 121         ACPI_FUNCTION_ENTRY();
 122
 123         if (register_id > ACPI_BITREG_MAX) {
 124                 ACPI_ERROR((AE_INFO, "Invalid BitRegister ID: %X",
 125                             register_id));
 126                 return (NULL);
 127         }
 128
 129         return (&acpi_gbl_bit_register_info[register_id]);
 130 }
 131
 132 /******************************************************************************
 133  *
 134  * FUNCTION:    acpi_hw_register_read
 135  *
 136  * PARAMETERS:  register_id         - ACPI Register ID
 137  *              return_value        - Where the register value is returned
 138  *
 139  * RETURN:      Status and the value read.
 140  *
 141  * DESCRIPTION: Read from the specified ACPI register
 142  *
 143  ******************************************************************************/
 144 acpi_status
 145 acpi_hw_register_read(u32 register_id, u32 * return_value)
 146 {
 147         u32 value = 0;
 148         acpi_status status;
 149
 150         ACPI_FUNCTION_TRACE(hw_register_read);
 151
 152         switch (register_id) {
 153         case ACPI_REGISTER_PM1_STATUS:  /* PM1 A/B: 16-bit access each */
 154
 155                 status = acpi_hw_read_multiple(&value,
 156                                                &acpi_gbl_xpm1a_status,
 157                                                &acpi_gbl_xpm1b_status);
 158                 break;
 159
 160         case ACPI_REGISTER_PM1_ENABLE:  /* PM1 A/B: 16-bit access each */
 161
 162                 status = acpi_hw_read_multiple(&value,
 163                                                &acpi_gbl_xpm1a_enable,
 164                                                &acpi_gbl_xpm1b_enable);
 165                 break;
 166
 167         case ACPI_REGISTER_PM1_CONTROL: /* PM1 A/B: 16-bit access each */
 168
 169                 status = acpi_hw_read_multiple(&value,
 170                                                &acpi_gbl_FADT.
 171                                                xpm1a_control_block,
 172                                                &acpi_gbl_FADT.
 173                                                xpm1b_control_block);
 174                 break;
 175
 176         case ACPI_REGISTER_PM2_CONTROL: /* 8-bit access */
 177
 178                 status = acpi_read(&value, &acpi_gbl_FADT.xpm2_control_block);
 179                 break;
 180
 181         case ACPI_REGISTER_PM_TIMER:    /* 32-bit access */
 182
 183                 status = acpi_read(&value, &acpi_gbl_FADT.xpm_timer_block);
 184                 break;
 185
 186         case ACPI_REGISTER_SMI_COMMAND_BLOCK:   /* 8-bit access */
 187
 188                 status =
 189                     acpi_os_read_port(acpi_gbl_FADT.smi_command, &value, 8);
 190                 break;
 191
 192         default:
 193                 ACPI_ERROR((AE_INFO, "Unknown Register ID: %X", register_id));
 194                 status = AE_BAD_PARAMETER;
 195                 break;
 196         }
 197
 198         if (ACPI_SUCCESS(status)) {
 199                 *return_value = value;
 200         }
 201
 202         return_ACPI_STATUS(status);
 203 }
 204
 205 /******************************************************************************
 206  *
 207  * FUNCTION:    acpi_hw_register_write
 208  *
 209  * PARAMETERS:  register_id         - ACPI Register ID
 210  *              Value               - The value to write
 211  *
 212  * RETURN:      Status
 213  *
 214  * DESCRIPTION: Write to the specified ACPI register
 215  *
 216  * NOTE: In accordance with the ACPI specification, this function automatically
 217  * preserves the value of the following bits, meaning that these bits cannot be
 218  * changed via this interface:
 219  *
 220  * PM1_CONTROL[0] = SCI_EN
 221  * PM1_CONTROL[9]
 222  * PM1_STATUS[11]
 223  *
 224  * ACPI References:
 225  * 1) Hardware Ignored Bits: When software writes to a register with ignored
 226  *      bit fields, it preserves the ignored bit fields
 227  * 2) SCI_EN: OSPM always preserves this bit position
 228  *
 229  ******************************************************************************/
 230
 231 acpi_status acpi_hw_register_write(u32 register_id, u32 value)
 232 {
 233         acpi_status status;
 234         u32 read_value;
 235
 236         ACPI_FUNCTION_TRACE(hw_register_write);
 237
 238         switch (register_id) {
 239         case ACPI_REGISTER_PM1_STATUS:  /* PM1 A/B: 16-bit access each */
 240
 241                 /* Perform a read first to preserve certain bits (per ACPI spec) */
 242
 243                 status = acpi_hw_read_multiple(&read_value,
 244                                                &acpi_gbl_xpm1a_status,
 245                                                &acpi_gbl_xpm1b_status);
 246                 if (ACPI_FAILURE(status)) {
 247                         goto exit;
 248                 }
 249
 250                 /* Insert the bits to be preserved */
 251
 252                 ACPI_INSERT_BITS(value, ACPI_PM1_STATUS_PRESERVED_BITS,
 253                                  read_value);
 254
 255                 /* Now we can write the data */
 256
 257                 status = acpi_hw_write_multiple(value,
 258                                                 &acpi_gbl_xpm1a_status,
 259                                                 &acpi_gbl_xpm1b_status);
 260                 break;
 261
 262         case ACPI_REGISTER_PM1_ENABLE:  /* PM1 A/B: 16-bit access */
 263
 264                 status = acpi_hw_write_multiple(value,
 265                                                 &acpi_gbl_xpm1a_enable,
 266                                                 &acpi_gbl_xpm1b_enable);
 267                 break;
 268
 269         case ACPI_REGISTER_PM1_CONTROL: /* PM1 A/B: 16-bit access each */
 270
 271                 /*
 272                  * Perform a read first to preserve certain bits (per ACPI spec)
 273                  * Note: This includes SCI_EN, we never want to change this bit
 274                  */
 275                 status = acpi_hw_read_multiple(&read_value,
 276                                                &acpi_gbl_FADT.
 277                                                xpm1a_control_block,
 278                                                &acpi_gbl_FADT.
 279                                                xpm1b_control_block);
 280                 if (ACPI_FAILURE(status)) {
 281                         goto exit;
 282                 }
 283
 284                 /* Insert the bits to be preserved */
 285
 286                 ACPI_INSERT_BITS(value, ACPI_PM1_CONTROL_PRESERVED_BITS,
 287                                  read_value);
 288
 289                 /* Now we can write the data */
 290
 291                 status = acpi_hw_write_multiple(value,
 292                                                 &acpi_gbl_FADT.
 293                                                 xpm1a_control_block,
 294                                                 &acpi_gbl_FADT.
 295                                                 xpm1b_control_block);
 296                 break;
 297
 298         case ACPI_REGISTER_PM1A_CONTROL:        /* 16-bit access */
 299
 300                 status = acpi_write(value, &acpi_gbl_FADT.xpm1a_control_block);
 301                 break;
 302
 303         case ACPI_REGISTER_PM1B_CONTROL:        /* 16-bit access */
 304
 305                 status = acpi_write(value, &acpi_gbl_FADT.xpm1b_control_block);
 306                 break;
 307
 308         case ACPI_REGISTER_PM2_CONTROL: /* 8-bit access */
 309
 310                 status = acpi_write(value, &acpi_gbl_FADT.xpm2_control_block);
 311                 break;
 312
 313         case ACPI_REGISTER_PM_TIMER:    /* 32-bit access */
 314
 315                 status = acpi_write(value, &acpi_gbl_FADT.xpm_timer_block);
 316                 break;
 317
 318         case ACPI_REGISTER_SMI_COMMAND_BLOCK:   /* 8-bit access */
 319
 320                 /* SMI_CMD is currently always in IO space */
 321
 322                 status =
 323                     acpi_os_write_port(acpi_gbl_FADT.smi_command, value, 8);
 324                 break;
 325
 326         default:
 327                 ACPI_ERROR((AE_INFO, "Unknown Register ID: %X", register_id));
 328                 status = AE_BAD_PARAMETER;
 329                 break;
 330         }
 331
 332       exit:
 333         return_ACPI_STATUS(status);
 334 }
 335
 336 /******************************************************************************
 337  *
 338  * FUNCTION:    acpi_hw_read_multiple
 339  *
 340  * PARAMETERS:  Value               - Where the register value is returned
 341  *              register_a           - First ACPI register (required)
 342  *              register_b           - Second ACPI register (optional)
 343  *
 344  * RETURN:      Status
 345  *
 346  * DESCRIPTION: Read from the specified two-part ACPI register (such as PM1 A/B)
 347  *
 348  ******************************************************************************/
 349
 350 static acpi_status
 351 acpi_hw_read_multiple(u32 *value,
 352                       struct acpi_generic_address *register_a,
 353                       struct acpi_generic_address *register_b)
 354 {
 355         u32 value_a = 0;
 356         u32 value_b = 0;
 357         acpi_status status;
 358
 359         /* The first register is always required */
 360
 361         status = acpi_read(&value_a, register_a);
 362         if (ACPI_FAILURE(status)) {
 363                 return (status);
 364         }
 365
 366         /* Second register is optional */
 367
 368         if (register_b->address) {
 369                 status = acpi_read(&value_b, register_b);
 370                 if (ACPI_FAILURE(status)) {
 371                         return (status);
 372                 }
 373         }
 374
 375         /* Shift the B bits above the A bits */
 376
 377         *value = value_a | (value_b << register_a->bit_width);
 378         return (AE_OK);
 379 }
 380
 381 /******************************************************************************
 382  *
 383  * FUNCTION:    acpi_hw_write_multiple
 384  *
 385  * PARAMETERS:  Value               - The value to write
 386  *              register_a           - First ACPI register (required)
 387  *              register_b           - Second ACPI register (optional)
 388  *
 389  * RETURN:      Status
 390  *
 391  * DESCRIPTION: Write to the specified two-part ACPI register (such as PM1 A/B)
 392  *
 393  ******************************************************************************/
 394
 395 static acpi_status
 396 acpi_hw_write_multiple(u32 value,
 397                        struct acpi_generic_address *register_a,
 398                        struct acpi_generic_address *register_b)
 399 {
 400         acpi_status status;
 401
 402         /* The first register is always required */
 403
 404         status = acpi_write(value, register_a);
 405         if (ACPI_FAILURE(status)) {
 406                 return (status);
 407         }
 408
 409         /* Second register is optional */
 410
 411         if (register_b->address) {
 412
 413                 /* Normalize the B bits before write */
 414
 415                 status = acpi_write(value >> register_a->bit_width, register_b);
 416         }
 417
 418         return (status);
 419 }