Subversion Repositories Kolibri OS

Rev

Rev 1498 | Blame | Compare with Previous | Last modification | View Log | Download | RSS feed

  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.  *
  11.  * 1. Copyright Notice
  12.  *
  13.  * Some or all of this work - Copyright (c) 1999 - 2011, Intel Corp.
  14.  * All rights reserved.
  15.  *
  16.  * 2. License
  17.  *
  18.  * 2.1. This is your license from Intel Corp. under its intellectual property
  19.  * rights.  You may have additional license terms from the party that provided
  20.  * you this software, covering your right to use that party's intellectual
  21.  * property rights.
  22.  *
  23.  * 2.2. Intel grants, free of charge, to any person ("Licensee") obtaining a
  24.  * copy of the source code appearing in this file ("Covered Code") an
  25.  * irrevocable, perpetual, worldwide license under Intel's copyrights in the
  26.  * base code distributed originally by Intel ("Original Intel Code") to copy,
  27.  * make derivatives, distribute, use and display any portion of the Covered
  28.  * Code in any form, with the right to sublicense such rights; and
  29.  *
  30.  * 2.3. Intel grants Licensee a non-exclusive and non-transferable patent
  31.  * license (with the right to sublicense), under only those claims of Intel
  32.  * patents that are infringed by the Original Intel Code, to make, use, sell,
  33.  * offer to sell, and import the Covered Code and derivative works thereof
  34.  * solely to the minimum extent necessary to exercise the above copyright
  35.  * license, and in no event shall the patent license extend to any additions
  36.  * to or modifications of the Original Intel Code.  No other license or right
  37.  * is granted directly or by implication, estoppel or otherwise;
  38.  *
  39.  * The above copyright and patent license is granted only if the following
  40.  * conditions are met:
  41.  *
  42.  * 3. Conditions
  43.  *
  44.  * 3.1. Redistribution of Source with Rights to Further Distribute Source.
  45.  * Redistribution of source code of any substantial portion of the Covered
  46.  * Code or modification with rights to further distribute source must include
  47.  * the above Copyright Notice, the above License, this list of Conditions,
  48.  * and the following Disclaimer and Export Compliance provision.  In addition,
  49.  * Licensee must cause all Covered Code to which Licensee contributes to
  50.  * contain a file documenting the changes Licensee made to create that Covered
  51.  * Code and the date of any change.  Licensee must include in that file the
  52.  * documentation of any changes made by any predecessor Licensee.  Licensee
  53.  * must include a prominent statement that the modification is derived,
  54.  * directly or indirectly, from Original Intel Code.
  55.  *
  56.  * 3.2. Redistribution of Source with no Rights to Further Distribute Source.
  57.  * Redistribution of source code of any substantial portion of the Covered
  58.  * Code or modification without rights to further distribute source must
  59.  * include the following Disclaimer and Export Compliance provision in the
  60.  * documentation and/or other materials provided with distribution.  In
  61.  * addition, Licensee may not authorize further sublicense of source of any
  62.  * portion of the Covered Code, and must include terms to the effect that the
  63.  * license from Licensee to its licensee is limited to the intellectual
  64.  * property embodied in the software Licensee provides to its licensee, and
  65.  * not to intellectual property embodied in modifications its licensee may
  66.  * make.
  67.  *
  68.  * 3.3. Redistribution of Executable. Redistribution in executable form of any
  69.  * substantial portion of the Covered Code or modification must reproduce the
  70.  * above Copyright Notice, and the following Disclaimer and Export Compliance
  71.  * provision in the documentation and/or other materials provided with the
  72.  * distribution.
  73.  *
  74.  * 3.4. Intel retains all right, title, and interest in and to the Original
  75.  * Intel Code.
  76.  *
  77.  * 3.5. Neither the name Intel nor any other trademark owned or controlled by
  78.  * Intel shall be used in advertising or otherwise to promote the sale, use or
  79.  * other dealings in products derived from or relating to the Covered Code
  80.  * without prior written authorization from Intel.
  81.  *
  82.  * 4. Disclaimer and Export Compliance
  83.  *
  84.  * 4.1. INTEL MAKES NO WARRANTY OF ANY KIND REGARDING ANY SOFTWARE PROVIDED
  85.  * HERE.  ANY SOFTWARE ORIGINATING FROM INTEL OR DERIVED FROM INTEL SOFTWARE
  86.  * IS PROVIDED "AS IS," AND INTEL WILL NOT PROVIDE ANY SUPPORT,  ASSISTANCE,
  87.  * INSTALLATION, TRAINING OR OTHER SERVICES.  INTEL WILL NOT PROVIDE ANY
  88.  * UPDATES, ENHANCEMENTS OR EXTENSIONS.  INTEL SPECIFICALLY DISCLAIMS ANY
  89.  * IMPLIED WARRANTIES OF MERCHANTABILITY, NONINFRINGEMENT AND FITNESS FOR A
  90.  * PARTICULAR PURPOSE.
  91.  *
  92.  * 4.2. IN NO EVENT SHALL INTEL HAVE ANY LIABILITY TO LICENSEE, ITS LICENSEES
  93.  * OR ANY OTHER THIRD PARTY, FOR ANY LOST PROFITS, LOST DATA, LOSS OF USE OR
  94.  * COSTS OF PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, OR FOR ANY INDIRECT,
  95.  * SPECIAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THIS AGREEMENT, UNDER ANY
  96.  * CAUSE OF ACTION OR THEORY OF LIABILITY, AND IRRESPECTIVE OF WHETHER INTEL
  97.  * HAS ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES.  THESE LIMITATIONS
  98.  * SHALL APPLY NOTWITHSTANDING THE FAILURE OF THE ESSENTIAL PURPOSE OF ANY
  99.  * LIMITED REMEDY.
  100.  *
  101.  * 4.3. Licensee shall not export, either directly or indirectly, any of this
  102.  * software or system incorporating such software without first obtaining any
  103.  * required license or other approval from the U. S. Department of Commerce or
  104.  * any other agency or department of the United States Government.  In the
  105.  * event Licensee exports any such software from the United States or
  106.  * re-exports any such software from a foreign destination, Licensee shall
  107.  * ensure that the distribution and export/re-export of the software is in
  108.  * compliance with all laws, regulations, orders, or other restrictions of the
  109.  * U.S. Export Administration Regulations. Licensee agrees that neither it nor
  110.  * any of its subsidiaries will export/re-export any technical data, process,
  111.  * software, or service, directly or indirectly, to any country for which the
  112.  * United States government or any agency thereof requires an export license,
  113.  * other governmental approval, or letter of assurance, without first obtaining
  114.  * such license, approval or letter.
  115.  *
  116.  *****************************************************************************/
  117.  
  118. #define __HWREGS_C__
  119.  
  120. #include "acpi.h"
  121. #include "accommon.h"
  122. #include "acevents.h"
  123.  
  124. #define _COMPONENT          ACPI_HARDWARE
  125.         ACPI_MODULE_NAME    ("hwregs")
  126.  
  127.  
  128. /* Local Prototypes */
  129.  
  130. static ACPI_STATUS
  131. AcpiHwReadMultiple (
  132.     UINT32                  *Value,
  133.     ACPI_GENERIC_ADDRESS    *RegisterA,
  134.     ACPI_GENERIC_ADDRESS    *RegisterB);
  135.  
  136. static ACPI_STATUS
  137. AcpiHwWriteMultiple (
  138.     UINT32                  Value,
  139.     ACPI_GENERIC_ADDRESS    *RegisterA,
  140.     ACPI_GENERIC_ADDRESS    *RegisterB);
  141.  
  142.  
  143. /******************************************************************************
  144.  *
  145.  * FUNCTION:    AcpiHwValidateRegister
  146.  *
  147.  * PARAMETERS:  Reg                 - GAS register structure
  148.  *              MaxBitWidth         - Max BitWidth supported (32 or 64)
  149.  *              Address             - Pointer to where the gas->address
  150.  *                                    is returned
  151.  *
  152.  * RETURN:      Status
  153.  *
  154.  * DESCRIPTION: Validate the contents of a GAS register. Checks the GAS
  155.  *              pointer, Address, SpaceId, BitWidth, and BitOffset.
  156.  *
  157.  ******************************************************************************/
  158.  
  159. ACPI_STATUS
  160. AcpiHwValidateRegister (
  161.     ACPI_GENERIC_ADDRESS    *Reg,
  162.     UINT8                   MaxBitWidth,
  163.     UINT64                  *Address)
  164. {
  165.  
  166.     /* Must have a valid pointer to a GAS structure */
  167.  
  168.     if (!Reg)
  169.     {
  170.         return (AE_BAD_PARAMETER);
  171.     }
  172.  
  173.     /*
  174.      * Copy the target address. This handles possible alignment issues.
  175.      * Address must not be null. A null address also indicates an optional
  176.      * ACPI register that is not supported, so no error message.
  177.      */
  178.     ACPI_MOVE_64_TO_64 (Address, &Reg->Address);
  179.     if (!(*Address))
  180.     {
  181.         return (AE_BAD_ADDRESS);
  182.     }
  183.  
  184.     /* Validate the SpaceID */
  185.  
  186.     if ((Reg->SpaceId != ACPI_ADR_SPACE_SYSTEM_MEMORY) &&
  187.         (Reg->SpaceId != ACPI_ADR_SPACE_SYSTEM_IO))
  188.     {
  189.         ACPI_ERROR ((AE_INFO,
  190.             "Unsupported address space: 0x%X", Reg->SpaceId));
  191.         return (AE_SUPPORT);
  192.     }
  193.  
  194.     /* Validate the BitWidth */
  195.  
  196.     if ((Reg->BitWidth != 8) &&
  197.         (Reg->BitWidth != 16) &&
  198.         (Reg->BitWidth != 32) &&
  199.         (Reg->BitWidth != MaxBitWidth))
  200.     {
  201.         ACPI_ERROR ((AE_INFO,
  202.             "Unsupported register bit width: 0x%X", Reg->BitWidth));
  203.         return (AE_SUPPORT);
  204.     }
  205.  
  206.     /* Validate the BitOffset. Just a warning for now. */
  207.  
  208.     if (Reg->BitOffset != 0)
  209.     {
  210.         ACPI_WARNING ((AE_INFO,
  211.             "Unsupported register bit offset: 0x%X", Reg->BitOffset));
  212.     }
  213.  
  214.     return (AE_OK);
  215. }
  216.  
  217.  
  218. /******************************************************************************
  219.  *
  220.  * FUNCTION:    AcpiHwRead
  221.  *
  222.  * PARAMETERS:  Value               - Where the value is returned
  223.  *              Reg                 - GAS register structure
  224.  *
  225.  * RETURN:      Status
  226.  *
  227.  * DESCRIPTION: Read from either memory or IO space. This is a 32-bit max
  228.  *              version of AcpiRead, used internally since the overhead of
  229.  *              64-bit values is not needed.
  230.  *
  231.  * LIMITATIONS: <These limitations also apply to AcpiHwWrite>
  232.  *      BitWidth must be exactly 8, 16, or 32.
  233.  *      SpaceID must be SystemMemory or SystemIO.
  234.  *      BitOffset and AccessWidth are currently ignored, as there has
  235.  *          not been a need to implement these.
  236.  *
  237.  ******************************************************************************/
  238.  
  239. ACPI_STATUS
  240. AcpiHwRead (
  241.     UINT32                  *Value,
  242.     ACPI_GENERIC_ADDRESS    *Reg)
  243. {
  244.     UINT64                  Address;
  245.     ACPI_STATUS             Status;
  246.  
  247.  
  248.     ACPI_FUNCTION_NAME (HwRead);
  249.  
  250.  
  251.     /* Validate contents of the GAS register */
  252.  
  253.     Status = AcpiHwValidateRegister (Reg, 32, &Address);
  254.     if (ACPI_FAILURE (Status))
  255.     {
  256.         return (Status);
  257.     }
  258.  
  259.     /* Initialize entire 32-bit return value to zero */
  260.  
  261.     *Value = 0;
  262.  
  263.     /*
  264.      * Two address spaces supported: Memory or IO. PCI_Config is
  265.      * not supported here because the GAS structure is insufficient
  266.      */
  267.     if (Reg->SpaceId == ACPI_ADR_SPACE_SYSTEM_MEMORY)
  268.     {
  269.         Status = AcpiOsReadMemory ((ACPI_PHYSICAL_ADDRESS)
  270.                     Address, Value, Reg->BitWidth);
  271.     }
  272.     else /* ACPI_ADR_SPACE_SYSTEM_IO, validated earlier */
  273.     {
  274.         Status = AcpiHwReadPort ((ACPI_IO_ADDRESS)
  275.                     Address, Value, Reg->BitWidth);
  276.     }
  277.  
  278.     ACPI_DEBUG_PRINT ((ACPI_DB_IO,
  279.         "Read:  %8.8X width %2d from %8.8X%8.8X (%s)\n",
  280.         *Value, Reg->BitWidth, ACPI_FORMAT_UINT64 (Address),
  281.         AcpiUtGetRegionName (Reg->SpaceId)));
  282.  
  283.     return (Status);
  284. }
  285.  
  286.  
  287. /******************************************************************************
  288.  *
  289.  * FUNCTION:    AcpiHwWrite
  290.  *
  291.  * PARAMETERS:  Value               - Value to be written
  292.  *              Reg                 - GAS register structure
  293.  *
  294.  * RETURN:      Status
  295.  *
  296.  * DESCRIPTION: Write to either memory or IO space. This is a 32-bit max
  297.  *              version of AcpiWrite, used internally since the overhead of
  298.  *              64-bit values is not needed.
  299.  *
  300.  ******************************************************************************/
  301.  
  302. ACPI_STATUS
  303. AcpiHwWrite (
  304.     UINT32                  Value,
  305.     ACPI_GENERIC_ADDRESS    *Reg)
  306. {
  307.     UINT64                  Address;
  308.     ACPI_STATUS             Status;
  309.  
  310.  
  311.     ACPI_FUNCTION_NAME (HwWrite);
  312.  
  313.  
  314.     /* Validate contents of the GAS register */
  315.  
  316.     Status = AcpiHwValidateRegister (Reg, 32, &Address);
  317.     if (ACPI_FAILURE (Status))
  318.     {
  319.         return (Status);
  320.     }
  321.  
  322.     /*
  323.      * Two address spaces supported: Memory or IO. PCI_Config is
  324.      * not supported here because the GAS structure is insufficient
  325.      */
  326.     if (Reg->SpaceId == ACPI_ADR_SPACE_SYSTEM_MEMORY)
  327.     {
  328.         Status = AcpiOsWriteMemory ((ACPI_PHYSICAL_ADDRESS)
  329.                     Address, Value, Reg->BitWidth);
  330.     }
  331.     else /* ACPI_ADR_SPACE_SYSTEM_IO, validated earlier */
  332.     {
  333.         Status = AcpiHwWritePort ((ACPI_IO_ADDRESS)
  334.                     Address, Value, Reg->BitWidth);
  335.     }
  336.  
  337.     ACPI_DEBUG_PRINT ((ACPI_DB_IO,
  338.         "Wrote: %8.8X width %2d   to %8.8X%8.8X (%s)\n",
  339.         Value, Reg->BitWidth, ACPI_FORMAT_UINT64 (Address),
  340.         AcpiUtGetRegionName (Reg->SpaceId)));
  341.  
  342.     return (Status);
  343. }
  344.  
  345.  
  346. /*******************************************************************************
  347.  *
  348.  * FUNCTION:    AcpiHwClearAcpiStatus
  349.  *
  350.  * PARAMETERS:  None
  351.  *
  352.  * RETURN:      Status
  353.  *
  354.  * DESCRIPTION: Clears all fixed and general purpose status bits
  355.  *
  356.  ******************************************************************************/
  357.  
  358. ACPI_STATUS
  359. AcpiHwClearAcpiStatus (
  360.     void)
  361. {
  362.     ACPI_STATUS             Status;
  363.     ACPI_CPU_FLAGS          LockFlags = 0;
  364.  
  365.  
  366.     ACPI_FUNCTION_TRACE (HwClearAcpiStatus);
  367.  
  368.  
  369.     ACPI_DEBUG_PRINT ((ACPI_DB_IO, "About to write %04X to %8.8X%8.8X\n",
  370.         ACPI_BITMASK_ALL_FIXED_STATUS,
  371.         ACPI_FORMAT_UINT64 (AcpiGbl_XPm1aStatus.Address)));
  372.  
  373.     LockFlags = AcpiOsAcquireLock (AcpiGbl_HardwareLock);
  374.  
  375.     /* Clear the fixed events in PM1 A/B */
  376.  
  377.     Status = AcpiHwRegisterWrite (ACPI_REGISTER_PM1_STATUS,
  378.                 ACPI_BITMASK_ALL_FIXED_STATUS);
  379.     if (ACPI_FAILURE (Status))
  380.     {
  381.         goto UnlockAndExit;
  382.     }
  383.  
  384.     /* Clear the GPE Bits in all GPE registers in all GPE blocks */
  385.  
  386.     Status = AcpiEvWalkGpeList (AcpiHwClearGpeBlock, NULL);
  387.  
  388. UnlockAndExit:
  389.     AcpiOsReleaseLock (AcpiGbl_HardwareLock, LockFlags);
  390.     return_ACPI_STATUS (Status);
  391. }
  392.  
  393.  
  394. /*******************************************************************************
  395.  *
  396.  * FUNCTION:    AcpiHwGetRegisterBitMask
  397.  *
  398.  * PARAMETERS:  RegisterId          - Index of ACPI Register to access
  399.  *
  400.  * RETURN:      The bitmask to be used when accessing the register
  401.  *
  402.  * DESCRIPTION: Map RegisterId into a register bitmask.
  403.  *
  404.  ******************************************************************************/
  405.  
  406. ACPI_BIT_REGISTER_INFO *
  407. AcpiHwGetBitRegisterInfo (
  408.     UINT32                  RegisterId)
  409. {
  410.     ACPI_FUNCTION_ENTRY ();
  411.  
  412.  
  413.     if (RegisterId > ACPI_BITREG_MAX)
  414.     {
  415.         ACPI_ERROR ((AE_INFO, "Invalid BitRegister ID: 0x%X", RegisterId));
  416.         return (NULL);
  417.     }
  418.  
  419.     return (&AcpiGbl_BitRegisterInfo[RegisterId]);
  420. }
  421.  
  422.  
  423. /******************************************************************************
  424.  *
  425.  * FUNCTION:    AcpiHwWritePm1Control
  426.  *
  427.  * PARAMETERS:  Pm1aControl         - Value to be written to PM1A control
  428.  *              Pm1bControl         - Value to be written to PM1B control
  429.  *
  430.  * RETURN:      Status
  431.  *
  432.  * DESCRIPTION: Write the PM1 A/B control registers. These registers are
  433.  *              different than than the PM1 A/B status and enable registers
  434.  *              in that different values can be written to the A/B registers.
  435.  *              Most notably, the SLP_TYP bits can be different, as per the
  436.  *              values returned from the _Sx predefined methods.
  437.  *
  438.  ******************************************************************************/
  439.  
  440. ACPI_STATUS
  441. AcpiHwWritePm1Control (
  442.     UINT32                  Pm1aControl,
  443.     UINT32                  Pm1bControl)
  444. {
  445.     ACPI_STATUS             Status;
  446.  
  447.  
  448.     ACPI_FUNCTION_TRACE (HwWritePm1Control);
  449.  
  450.  
  451.     Status = AcpiHwWrite (Pm1aControl, &AcpiGbl_FADT.XPm1aControlBlock);
  452.     if (ACPI_FAILURE (Status))
  453.     {
  454.         return_ACPI_STATUS (Status);
  455.     }
  456.  
  457.     if (AcpiGbl_FADT.XPm1bControlBlock.Address)
  458.     {
  459.         Status = AcpiHwWrite (Pm1bControl, &AcpiGbl_FADT.XPm1bControlBlock);
  460.     }
  461.     return_ACPI_STATUS (Status);
  462. }
  463.  
  464.  
  465. /******************************************************************************
  466.  *
  467.  * FUNCTION:    AcpiHwRegisterRead
  468.  *
  469.  * PARAMETERS:  RegisterId          - ACPI Register ID
  470.  *              ReturnValue         - Where the register value is returned
  471.  *
  472.  * RETURN:      Status and the value read.
  473.  *
  474.  * DESCRIPTION: Read from the specified ACPI register
  475.  *
  476.  ******************************************************************************/
  477.  
  478. ACPI_STATUS
  479. AcpiHwRegisterRead (
  480.     UINT32                  RegisterId,
  481.     UINT32                  *ReturnValue)
  482. {
  483.     UINT32                  Value = 0;
  484.     ACPI_STATUS             Status;
  485.  
  486.  
  487.     ACPI_FUNCTION_TRACE (HwRegisterRead);
  488.  
  489.  
  490.     switch (RegisterId)
  491.     {
  492.     case ACPI_REGISTER_PM1_STATUS:           /* PM1 A/B: 16-bit access each */
  493.  
  494.         Status = AcpiHwReadMultiple (&Value,
  495.                     &AcpiGbl_XPm1aStatus,
  496.                     &AcpiGbl_XPm1bStatus);
  497.         break;
  498.  
  499.  
  500.     case ACPI_REGISTER_PM1_ENABLE:           /* PM1 A/B: 16-bit access each */
  501.  
  502.         Status = AcpiHwReadMultiple (&Value,
  503.                     &AcpiGbl_XPm1aEnable,
  504.                     &AcpiGbl_XPm1bEnable);
  505.         break;
  506.  
  507.  
  508.     case ACPI_REGISTER_PM1_CONTROL:          /* PM1 A/B: 16-bit access each */
  509.  
  510.         Status = AcpiHwReadMultiple (&Value,
  511.                     &AcpiGbl_FADT.XPm1aControlBlock,
  512.                     &AcpiGbl_FADT.XPm1bControlBlock);
  513.  
  514.         /*
  515.          * Zero the write-only bits. From the ACPI specification, "Hardware
  516.          * Write-Only Bits": "Upon reads to registers with write-only bits,
  517.          * software masks out all write-only bits."
  518.          */
  519.         Value &= ~ACPI_PM1_CONTROL_WRITEONLY_BITS;
  520.         break;
  521.  
  522.  
  523.     case ACPI_REGISTER_PM2_CONTROL:          /* 8-bit access */
  524.  
  525.         Status = AcpiHwRead (&Value, &AcpiGbl_FADT.XPm2ControlBlock);
  526.         break;
  527.  
  528.  
  529.     case ACPI_REGISTER_PM_TIMER:             /* 32-bit access */
  530.  
  531.         Status = AcpiHwRead (&Value, &AcpiGbl_FADT.XPmTimerBlock);
  532.         break;
  533.  
  534.  
  535.     case ACPI_REGISTER_SMI_COMMAND_BLOCK:    /* 8-bit access */
  536.  
  537.         Status = AcpiHwReadPort (AcpiGbl_FADT.SmiCommand, &Value, 8);
  538.         break;
  539.  
  540.  
  541.     default:
  542.         ACPI_ERROR ((AE_INFO, "Unknown Register ID: 0x%X",
  543.             RegisterId));
  544.         Status = AE_BAD_PARAMETER;
  545.         break;
  546.     }
  547.  
  548.     if (ACPI_SUCCESS (Status))
  549.     {
  550.         *ReturnValue = Value;
  551.     }
  552.  
  553.     return_ACPI_STATUS (Status);
  554. }
  555.  
  556.  
  557. /******************************************************************************
  558.  *
  559.  * FUNCTION:    AcpiHwRegisterWrite
  560.  *
  561.  * PARAMETERS:  RegisterId          - ACPI Register ID
  562.  *              Value               - The value to write
  563.  *
  564.  * RETURN:      Status
  565.  *
  566.  * DESCRIPTION: Write to the specified ACPI register
  567.  *
  568.  * NOTE: In accordance with the ACPI specification, this function automatically
  569.  * preserves the value of the following bits, meaning that these bits cannot be
  570.  * changed via this interface:
  571.  *
  572.  * PM1_CONTROL[0] = SCI_EN
  573.  * PM1_CONTROL[9]
  574.  * PM1_STATUS[11]
  575.  *
  576.  * ACPI References:
  577.  * 1) Hardware Ignored Bits: When software writes to a register with ignored
  578.  *      bit fields, it preserves the ignored bit fields
  579.  * 2) SCI_EN: OSPM always preserves this bit position
  580.  *
  581.  ******************************************************************************/
  582.  
  583. ACPI_STATUS
  584. AcpiHwRegisterWrite (
  585.     UINT32                  RegisterId,
  586.     UINT32                  Value)
  587. {
  588.     ACPI_STATUS             Status;
  589.     UINT32                  ReadValue;
  590.  
  591.  
  592.     ACPI_FUNCTION_TRACE (HwRegisterWrite);
  593.  
  594.  
  595.     switch (RegisterId)
  596.     {
  597.     case ACPI_REGISTER_PM1_STATUS:           /* PM1 A/B: 16-bit access each */
  598.         /*
  599.          * Handle the "ignored" bit in PM1 Status. According to the ACPI
  600.          * specification, ignored bits are to be preserved when writing.
  601.          * Normally, this would mean a read/modify/write sequence. However,
  602.          * preserving a bit in the status register is different. Writing a
  603.          * one clears the status, and writing a zero preserves the status.
  604.          * Therefore, we must always write zero to the ignored bit.
  605.          *
  606.          * This behavior is clarified in the ACPI 4.0 specification.
  607.          */
  608.         Value &= ~ACPI_PM1_STATUS_PRESERVED_BITS;
  609.  
  610.         Status = AcpiHwWriteMultiple (Value,
  611.                     &AcpiGbl_XPm1aStatus,
  612.                     &AcpiGbl_XPm1bStatus);
  613.         break;
  614.  
  615.  
  616.     case ACPI_REGISTER_PM1_ENABLE:           /* PM1 A/B: 16-bit access each */
  617.  
  618.         Status = AcpiHwWriteMultiple (Value,
  619.                     &AcpiGbl_XPm1aEnable,
  620.                     &AcpiGbl_XPm1bEnable);
  621.         break;
  622.  
  623.  
  624.     case ACPI_REGISTER_PM1_CONTROL:          /* PM1 A/B: 16-bit access each */
  625.  
  626.         /*
  627.          * Perform a read first to preserve certain bits (per ACPI spec)
  628.          * Note: This includes SCI_EN, we never want to change this bit
  629.          */
  630.         Status = AcpiHwReadMultiple (&ReadValue,
  631.                     &AcpiGbl_FADT.XPm1aControlBlock,
  632.                     &AcpiGbl_FADT.XPm1bControlBlock);
  633.         if (ACPI_FAILURE (Status))
  634.         {
  635.             goto Exit;
  636.         }
  637.  
  638.         /* Insert the bits to be preserved */
  639.  
  640.         ACPI_INSERT_BITS (Value, ACPI_PM1_CONTROL_PRESERVED_BITS, ReadValue);
  641.  
  642.         /* Now we can write the data */
  643.  
  644.         Status = AcpiHwWriteMultiple (Value,
  645.                     &AcpiGbl_FADT.XPm1aControlBlock,
  646.                     &AcpiGbl_FADT.XPm1bControlBlock);
  647.         break;
  648.  
  649.  
  650.     case ACPI_REGISTER_PM2_CONTROL:          /* 8-bit access */
  651.  
  652.         /*
  653.          * For control registers, all reserved bits must be preserved,
  654.          * as per the ACPI spec.
  655.          */
  656.         Status = AcpiHwRead (&ReadValue, &AcpiGbl_FADT.XPm2ControlBlock);
  657.         if (ACPI_FAILURE (Status))
  658.         {
  659.             goto Exit;
  660.         }
  661.  
  662.         /* Insert the bits to be preserved */
  663.  
  664.         ACPI_INSERT_BITS (Value, ACPI_PM2_CONTROL_PRESERVED_BITS, ReadValue);
  665.  
  666.         Status = AcpiHwWrite (Value, &AcpiGbl_FADT.XPm2ControlBlock);
  667.         break;
  668.  
  669.  
  670.     case ACPI_REGISTER_PM_TIMER:             /* 32-bit access */
  671.  
  672.         Status = AcpiHwWrite (Value, &AcpiGbl_FADT.XPmTimerBlock);
  673.         break;
  674.  
  675.  
  676.     case ACPI_REGISTER_SMI_COMMAND_BLOCK:    /* 8-bit access */
  677.  
  678.         /* SMI_CMD is currently always in IO space */
  679.  
  680.         Status = AcpiHwWritePort (AcpiGbl_FADT.SmiCommand, Value, 8);
  681.         break;
  682.  
  683.  
  684.     default:
  685.         ACPI_ERROR ((AE_INFO, "Unknown Register ID: 0x%X",
  686.             RegisterId));
  687.         Status = AE_BAD_PARAMETER;
  688.         break;
  689.     }
  690.  
  691. Exit:
  692.     return_ACPI_STATUS (Status);
  693. }
  694.  
  695.  
  696. /******************************************************************************
  697.  *
  698.  * FUNCTION:    AcpiHwReadMultiple
  699.  *
  700.  * PARAMETERS:  Value               - Where the register value is returned
  701.  *              RegisterA           - First ACPI register (required)
  702.  *              RegisterB           - Second ACPI register (optional)
  703.  *
  704.  * RETURN:      Status
  705.  *
  706.  * DESCRIPTION: Read from the specified two-part ACPI register (such as PM1 A/B)
  707.  *
  708.  ******************************************************************************/
  709.  
  710. static ACPI_STATUS
  711. AcpiHwReadMultiple (
  712.     UINT32                  *Value,
  713.     ACPI_GENERIC_ADDRESS    *RegisterA,
  714.     ACPI_GENERIC_ADDRESS    *RegisterB)
  715. {
  716.     UINT32                  ValueA = 0;
  717.     UINT32                  ValueB = 0;
  718.     ACPI_STATUS             Status;
  719.  
  720.  
  721.     /* The first register is always required */
  722.  
  723.     Status = AcpiHwRead (&ValueA, RegisterA);
  724.     if (ACPI_FAILURE (Status))
  725.     {
  726.         return (Status);
  727.     }
  728.  
  729.     /* Second register is optional */
  730.  
  731.     if (RegisterB->Address)
  732.     {
  733.         Status = AcpiHwRead (&ValueB, RegisterB);
  734.         if (ACPI_FAILURE (Status))
  735.         {
  736.             return (Status);
  737.         }
  738.     }
  739.  
  740.     /*
  741.      * OR the two return values together. No shifting or masking is necessary,
  742.      * because of how the PM1 registers are defined in the ACPI specification:
  743.      *
  744.      * "Although the bits can be split between the two register blocks (each
  745.      * register block has a unique pointer within the FADT), the bit positions
  746.      * are maintained. The register block with unimplemented bits (that is,
  747.      * those implemented in the other register block) always returns zeros,
  748.      * and writes have no side effects"
  749.      */
  750.     *Value = (ValueA | ValueB);
  751.     return (AE_OK);
  752. }
  753.  
  754.  
  755. /******************************************************************************
  756.  *
  757.  * FUNCTION:    AcpiHwWriteMultiple
  758.  *
  759.  * PARAMETERS:  Value               - The value to write
  760.  *              RegisterA           - First ACPI register (required)
  761.  *              RegisterB           - Second ACPI register (optional)
  762.  *
  763.  * RETURN:      Status
  764.  *
  765.  * DESCRIPTION: Write to the specified two-part ACPI register (such as PM1 A/B)
  766.  *
  767.  ******************************************************************************/
  768.  
  769. static ACPI_STATUS
  770. AcpiHwWriteMultiple (
  771.     UINT32                  Value,
  772.     ACPI_GENERIC_ADDRESS    *RegisterA,
  773.     ACPI_GENERIC_ADDRESS    *RegisterB)
  774. {
  775.     ACPI_STATUS             Status;
  776.  
  777.  
  778.     /* The first register is always required */
  779.  
  780.     Status = AcpiHwWrite (Value, RegisterA);
  781.     if (ACPI_FAILURE (Status))
  782.     {
  783.         return (Status);
  784.     }
  785.  
  786.     /*
  787.      * Second register is optional
  788.      *
  789.      * No bit shifting or clearing is necessary, because of how the PM1
  790.      * registers are defined in the ACPI specification:
  791.      *
  792.      * "Although the bits can be split between the two register blocks (each
  793.      * register block has a unique pointer within the FADT), the bit positions
  794.      * are maintained. The register block with unimplemented bits (that is,
  795.      * those implemented in the other register block) always returns zeros,
  796.      * and writes have no side effects"
  797.      */
  798.     if (RegisterB->Address)
  799.     {
  800.         Status = AcpiHwWrite (Value, RegisterB);
  801.     }
  802.  
  803.     return (Status);
  804. }
  805.  
  806.