/*******************************************************************************

 *

 * Module Name: hwregs - Read/write access functions for the various ACPI

 *                       control and status registers.

 *

 ******************************************************************************/

/*

 * Copyright (C) 2000 - 2006, R. Byron Moore

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions, and the following disclaimer,

 *    without modification.

 * 2. Redistributions in binary form must reproduce at minimum a disclaimer

 *    substantially similar to the "NO WARRANTY" disclaimer below

 *    ("Disclaimer") and any redistribution must be conditioned upon

 *    including a substantially similar Disclaimer requirement for further

 *    binary redistribution.

 * 3. Neither the names of the above-listed copyright holders nor the names

 *    of any contributors may be used to endorse or promote products derived

 *    from this software without specific prior written permission.

 *

 * Alternatively, this software may be distributed under the terms of the

 * GNU General Public License ("GPL") version 2 as published by the Free

 * Software Foundation.

 *

 * NO WARRANTY

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR

 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT

 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS

 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,

 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING

 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

 * POSSIBILITY OF SUCH DAMAGES.

 */

#include <asm/io.h>

#include <xen/init.h>

#include <xen/types.h>

#include <xen/errno.h>

#include <acpi/acpi.h>

#define _COMPONENT          ACPI_HARDWARE

ACPI_MODULE_NAME("hwregs")

/*******************************************************************************

 *

 * FUNCTION:    acpi_hw_get_register_bit_mask

 *

 * PARAMETERS:  register_id         - Index of ACPI Register to access

 *

 * RETURN:      The bitmask to be used when accessing the register

 *

 * DESCRIPTION: Map register_id into a register bitmask.

 *

 ******************************************************************************/

static struct acpi_bit_register_info *

acpi_hw_get_bit_register_info(u32 register_id)

{

  ACPI_FUNCTION_ENTRY();

  if (register_id > ACPI_BITREG_MAX) {

    ACPI_DEBUG_PRINT((AE_INFO, "Invalid BitRegister ID: %X",

          register_id));

    return (NULL);

  }

  return (&acpi_gbl_bit_register_info[register_id]);

}

/*******************************************************************************

 *

 * FUNCTION:    acpi_get_register

 *

 * PARAMETERS:  register_id     - ID of ACPI bit_register to access

 *              return_value    - Value that was read from the register

 *

 * RETURN:      Status and the value read from specified Register. Value

 *              returned is normalized to bit0 (is shifted all the way right)

 *

 * DESCRIPTION: ACPI bit_register read function.

 *

 ******************************************************************************/

acpi_status acpi_get_register(u32 register_id, u32 * return_value)

{

  u32 register_value = 0;

  struct acpi_bit_register_info *bit_reg_info;

  acpi_status status;

  ACPI_FUNCTION_TRACE(acpi_get_register);

  /* Get the info structure corresponding to the requested ACPI Register */

  bit_reg_info = acpi_hw_get_bit_register_info(register_id);

  if (!bit_reg_info) {

    return_ACPI_STATUS(AE_BAD_PARAMETER);

  }

  /* Read from the register */

  status = acpi_hw_register_read(bit_reg_info->parent_register,

               &register_value);

  if (ACPI_SUCCESS(status)) {

    /* Normalize the value that was read */

    register_value =

        ((register_value & bit_reg_info->access_bit_mask)

         >> bit_reg_info->bit_position);

    *return_value = register_value;

    ACPI_DEBUG_PRINT((ACPI_DB_IO, "Read value %8.8X register %X\n",

          register_value,

          bit_reg_info->parent_register));

  }

  return_ACPI_STATUS(status);

}

/*******************************************************************************

 *

 * FUNCTION:    acpi_set_register

 *

 * PARAMETERS:  register_id     - ID of ACPI bit_register to access

 *              Value           - (only used on write) value to write to the

 *                                Register, NOT pre-normalized to the bit pos

 *

 * RETURN:      Status

 *

 * DESCRIPTION: ACPI Bit Register write function.

 *

 ******************************************************************************/

acpi_status acpi_set_register(u32 register_id, u32 value)

{

  u32 register_value = 0;

  struct acpi_bit_register_info *bit_reg_info;

  acpi_status status;

  ACPI_FUNCTION_TRACE_U32(acpi_set_register, register_id);

  /* Get the info structure corresponding to the requested ACPI Register */

  bit_reg_info = acpi_hw_get_bit_register_info(register_id);

  if (!bit_reg_info) {

    ACPI_DEBUG_PRINT((AE_INFO, "Bad ACPI HW RegisterId: %X",

          register_id));

    return_ACPI_STATUS(AE_BAD_PARAMETER);

  }

  /* Always do a register read first so we can insert the new bits  */

  status = acpi_hw_register_read(bit_reg_info->parent_register,

               &register_value);

  if (ACPI_FAILURE(status)) {

    goto unlock_and_exit;

  }

  /*

   * Decode the Register ID

   * Register ID = [Register block ID] | [bit ID]

   *

   * Check bit ID to fine locate Register offset.

   * Check Mask to determine Register offset, and then read-write.

   */

  switch (bit_reg_info->parent_register) {

  case ACPI_REGISTER_PM1_STATUS:

    /*

     * Status Registers are different from the rest. Clear by

     * writing 1, and writing 0 has no effect. So, the only relevant

     * information is the single bit we're interested in, all others should

     * be written as 0 so they will be left unchanged.

     */

    value = ACPI_REGISTER_PREPARE_BITS(value,

               bit_reg_info->bit_position,

               bit_reg_info->

               access_bit_mask);

    if (value) {

      status = acpi_hw_register_write(ACPI_REGISTER_PM1_STATUS,

              (u16) value);

      register_value = 0;

    }

    break;

  case ACPI_REGISTER_PM1_ENABLE:

    ACPI_REGISTER_INSERT_VALUE(register_value,

             bit_reg_info->bit_position,

             bit_reg_info->access_bit_mask,

             value);

    status = acpi_hw_register_write(ACPI_REGISTER_PM1_ENABLE,

            (u16) register_value);

    break;

  case ACPI_REGISTER_PM1_CONTROL:

    /*

     * Write the PM1 Control register.

     * Note that at this level, the fact that there are actually TWO

     * registers (A and B - and B may not exist) is abstracted.

     */

    ACPI_DEBUG_PRINT((ACPI_DB_IO, "PM1 control: Read %X\n",

          register_value));

    ACPI_REGISTER_INSERT_VALUE(register_value,

             bit_reg_info->bit_position,

             bit_reg_info->access_bit_mask,

             value);

    status = acpi_hw_register_write(ACPI_REGISTER_PM1_CONTROL,

            (u16) register_value);

    break;

  case ACPI_REGISTER_PM2_CONTROL:

#if 0 /* Redundant read in original Linux code. */

    status = acpi_hw_register_read(ACPI_REGISTER_PM2_CONTROL,

                 &register_value);

    if (ACPI_FAILURE(status)) {

      goto unlock_and_exit;

    }

#endif

    ACPI_DEBUG_PRINT((ACPI_DB_IO,

          "PM2 control: Read %X from %8.8X%8.8X\n",

          register_value,

          ACPI_FORMAT_UINT64(acpi_gbl_FADT.

                 xpm2_control_block.

                 address)));

    ACPI_REGISTER_INSERT_VALUE(register_value,

             bit_reg_info->bit_position,

             bit_reg_info->access_bit_mask,

             value);

    ACPI_DEBUG_PRINT((ACPI_DB_IO,

          "About to write %4.4X to %8.8X%8.8X\n",

          register_value,

          ACPI_FORMAT_UINT64(acpi_gbl_FADT.

                 xpm2_control_block.

                 address)));

    status = acpi_hw_register_write(ACPI_REGISTER_PM2_CONTROL,

            (u8) (register_value));

    break;

  default:

    break;

  }

      unlock_and_exit:

  /* Normalize the value that was read */

  ACPI_DEBUG_EXEC(register_value =

      ((register_value & bit_reg_info->access_bit_mask) >>

       bit_reg_info->bit_position));

  ACPI_DEBUG_PRINT((ACPI_DB_IO,

        "Set bits: %8.8X actual %8.8X register %X\n", value,

        register_value, bit_reg_info->parent_register));

  return_ACPI_STATUS(status);

}

/******************************************************************************

 *

 * FUNCTION:    acpi_hw_register_read

 *

 * PARAMETERS:  register_id         - ACPI Register ID

 *              return_value        - Where the register value is returned

 *

 * RETURN:      Status and the value read.

 *

 * DESCRIPTION: Read from the specified ACPI register

 *

 ******************************************************************************/

acpi_status

acpi_hw_register_read(u32 register_id, u32 * return_value)

{

  u32 value1 = 0;

  u32 value2 = 0;

  acpi_status status;

  ACPI_FUNCTION_TRACE(hw_register_read);

  switch (register_id) {

  case ACPI_REGISTER_PM1_STATUS: /* 16-bit access */

    status =

        acpi_hw_low_level_read(16, &value1,

             &acpi_gbl_FADT.xpm1a_event_block);

    if (ACPI_FAILURE(status)) {

      goto exit;

    }

    /* PM1B is optional */

    status =

        acpi_hw_low_level_read(16, &value2,

             &acpi_gbl_FADT.xpm1b_event_block);

    value1 |= value2;

    break;

  case ACPI_REGISTER_PM1_ENABLE: /* 16-bit access */

    status =

        acpi_hw_low_level_read(16, &value1, &acpi_gbl_xpm1a_enable);

    if (ACPI_FAILURE(status)) {

      goto exit;

    }

    /* PM1B is optional */

    status =

        acpi_hw_low_level_read(16, &value2, &acpi_gbl_xpm1b_enable);

    value1 |= value2;

    break;

  case ACPI_REGISTER_PM1_CONTROL: /* 16-bit access */

    status =

        acpi_hw_low_level_read(16, &value1,

             &acpi_gbl_FADT.xpm1a_control_block);

    if (ACPI_FAILURE(status)) {

      goto exit;

    }

    status =

        acpi_hw_low_level_read(16, &value2,

             &acpi_gbl_FADT.xpm1b_control_block);

    value1 |= value2;

    break;

  case ACPI_REGISTER_PM2_CONTROL: /* 8-bit access */

    status =

        acpi_hw_low_level_read(8, &value1,

             &acpi_gbl_FADT.xpm2_control_block);

    break;

  case ACPI_REGISTER_PM_TIMER: /* 32-bit access */

    status =

        acpi_hw_low_level_read(32, &value1,

             &acpi_gbl_FADT.xpm_timer_block);

    break;

  case ACPI_REGISTER_SMI_COMMAND_BLOCK: /* 8-bit access */

    status =

        acpi_os_read_port(acpi_gbl_FADT.smi_command, &value1, 8);

    break;

  case ACPI_REGISTER_SLEEP_STATUS:

    status =

        acpi_hw_low_level_read(acpi_gbl_FADT.sleep_status.bit_width,

             &value1,

             &acpi_gbl_FADT.sleep_status);

    break;

  default:

    ACPI_DEBUG_PRINT((AE_INFO, "Unknown Register ID: %X", register_id));

    status = AE_BAD_PARAMETER;

    break;

  }

      exit:

  if (ACPI_SUCCESS(status)) {

    *return_value = value1;

  }

  return_ACPI_STATUS(status);

}

/******************************************************************************

 *

 * FUNCTION:    acpi_hw_register_write

 *

 * PARAMETERS:  register_id         - ACPI Register ID

 *              Value               - The value to write

 *

 * RETURN:      Status

 *

 * DESCRIPTION: Write to the specified ACPI register

 *

 * NOTE: In accordance with the ACPI specification, this function automatically

 * preserves the value of the following bits, meaning that these bits cannot be

 * changed via this interface:

 *

 * PM1_CONTROL[0] = SCI_EN

 * PM1_CONTROL[9]

 * PM1_STATUS[11]

 *

 * ACPI References:

 * 1) Hardware Ignored Bits: When software writes to a register with ignored

 *      bit fields, it preserves the ignored bit fields

 * 2) SCI_EN: OSPM always preserves this bit position

 *

 ******************************************************************************/

acpi_status acpi_hw_register_write(u32 register_id, u32 value)

{

  acpi_status status;

  u32 read_value;

  ACPI_FUNCTION_TRACE(hw_register_write);

  switch (register_id) {

  case ACPI_REGISTER_PM1_STATUS: /* 16-bit access */

    /* Perform a read first to preserve certain bits (per ACPI spec) */

    status = acpi_hw_register_read(ACPI_REGISTER_PM1_STATUS,

                 &read_value);

    if (ACPI_FAILURE(status)) {

      goto exit;

    }

    /* Insert the bits to be preserved */

    ACPI_INSERT_BITS(value, ACPI_PM1_STATUS_PRESERVED_BITS,

         read_value);

    /* Now we can write the data */

    status =

        acpi_hw_low_level_write(16, value,

              &acpi_gbl_FADT.xpm1a_event_block);

    if (ACPI_FAILURE(status)) {

      goto exit;

    }

    /* PM1B is optional */

    status =

        acpi_hw_low_level_write(16, value,

              &acpi_gbl_FADT.xpm1b_event_block);

    break;

  case ACPI_REGISTER_PM1_ENABLE: /* 16-bit access */

    status =

        acpi_hw_low_level_write(16, value, &acpi_gbl_xpm1a_enable);

    if (ACPI_FAILURE(status)) {

      goto exit;

    }

    /* PM1B is optional */

    status =

        acpi_hw_low_level_write(16, value, &acpi_gbl_xpm1b_enable);

    break;

  case ACPI_REGISTER_PM1_CONTROL: /* 16-bit access */

    /*

     * Perform a read first to preserve certain bits (per ACPI spec)

     */

    status = acpi_hw_register_read(ACPI_REGISTER_PM1_CONTROL,

                 &read_value);

    if (ACPI_FAILURE(status)) {

      goto exit;

    }

    /* Insert the bits to be preserved */

    ACPI_INSERT_BITS(value, ACPI_PM1_CONTROL_PRESERVED_BITS,

         read_value);

    /* Now we can write the data */

    status =

        acpi_hw_low_level_write(16, value,

              &acpi_gbl_FADT.xpm1a_control_block);

    if (ACPI_FAILURE(status)) {

      goto exit;

    }

    status =

        acpi_hw_low_level_write(16, value,

              &acpi_gbl_FADT.xpm1b_control_block);

    break;

  case ACPI_REGISTER_PM1A_CONTROL: /* 16-bit access */

    status =

        acpi_hw_low_level_write(16, value,

              &acpi_gbl_FADT.xpm1a_control_block);

    break;

  case ACPI_REGISTER_PM1B_CONTROL: /* 16-bit access */

    status =

        acpi_hw_low_level_write(16, value,

              &acpi_gbl_FADT.xpm1b_control_block);

    break;

  case ACPI_REGISTER_PM2_CONTROL: /* 8-bit access */

    status =

        acpi_hw_low_level_write(8, value,

              &acpi_gbl_FADT.xpm2_control_block);

    break;

  case ACPI_REGISTER_PM_TIMER: /* 32-bit access */

    status =

        acpi_hw_low_level_write(32, value,

              &acpi_gbl_FADT.xpm_timer_block);

    break;

  case ACPI_REGISTER_SMI_COMMAND_BLOCK: /* 8-bit access */

    /* SMI_CMD is currently always in IO space */

    status =

        acpi_os_write_port(acpi_gbl_FADT.smi_command, value, 8);

    break;

  case ACPI_REGISTER_SLEEP_CONTROL:

    status =

        acpi_hw_low_level_write(acpi_gbl_FADT.sleep_control.bit_width,

              value,

              &acpi_gbl_FADT.sleep_control);

    break;

  default:

    status = AE_BAD_PARAMETER;

    break;

  }

      exit:

  return_ACPI_STATUS(status);

}

/******************************************************************************

 *

 * FUNCTION:    acpi_hw_low_level_read

 *

 * PARAMETERS:  Width               - 8, 16, or 32

 *              Value               - Where the value is returned

 *              Reg                 - GAS register structure

 *

 * RETURN:      Status

 *

 * DESCRIPTION: Read from either memory or IO space.

 *

 ******************************************************************************/

acpi_status

acpi_hw_low_level_read(u32 width, u32 * value, struct acpi_generic_address *reg)

{

  u64 address;

  acpi_status status;

  ACPI_FUNCTION_NAME(hw_low_level_read);

  /*

   * Must have a valid pointer to a GAS structure, and

   * a non-zero address within. However, don't return an error

   * because the PM1A/B code must not fail if B isn't present.

   */

  if (!reg) {

    return (AE_OK);

  }

  /* Get a local copy of the address. Handles possible alignment issues */

  ACPI_MOVE_64_TO_64(&address, &reg->address);

  if (!address) {

    return (AE_OK);

  }

  *value = 0;

  /*

   * Two address spaces supported: Memory or IO.

   * PCI_Config is not supported here because the GAS struct is insufficient

   */

  switch (reg->space_id) {

  case ACPI_ADR_SPACE_SYSTEM_MEMORY:

    status = acpi_os_read_memory((acpi_physical_address) address,

               value, width);

    break;

  case ACPI_ADR_SPACE_SYSTEM_IO:

    status = acpi_os_read_port((acpi_io_address) address,

             value, width);

    break;

  default:

    return (AE_BAD_PARAMETER);

  }

  ACPI_DEBUG_PRINT((ACPI_DB_IO,

        "Read:  %8.8X width %2d from %8.8X%8.8X (%s)\n",

        *value, width,

        ACPI_FORMAT_UINT64(address),

        acpi_ut_get_region_name(reg->address_space_id)));

  return (status);

}

/******************************************************************************

 *

 * FUNCTION:    acpi_hw_low_level_write

 *

 * PARAMETERS:  Width               - 8, 16, or 32

 *              Value               - To be written

 *              Reg                 - GAS register structure

 *

 * RETURN:      Status

 *

 * DESCRIPTION: Write to either memory or IO space.

 *

 ******************************************************************************/

acpi_status

acpi_hw_low_level_write(u32 width, u32 value, struct acpi_generic_address * reg)

{

  u64 address;

  acpi_status status;

  ACPI_FUNCTION_NAME(hw_low_level_write);

  /*

   * Must have a valid pointer to a GAS structure, and

   * a non-zero address within. However, don't return an error

   * because the PM1A/B code must not fail if B isn't present.

   */

  if (!reg) {

    return (AE_OK);

  }

  /* Get a local copy of the address. Handles possible alignment issues */

  ACPI_MOVE_64_TO_64(&address, &reg->address);

  if (!address) {

    return (AE_OK);

  }

  /*

   * Two address spaces supported: Memory or IO.

   * PCI_Config is not supported here because the GAS struct is insufficient

   */

  switch (reg->space_id) {

  case ACPI_ADR_SPACE_SYSTEM_MEMORY:

    status = acpi_os_write_memory((acpi_physical_address) address,

                value, width);

    break;

  case ACPI_ADR_SPACE_SYSTEM_IO:

    status = acpi_os_write_port((acpi_io_address) address,

              value, width);

    break;

  default:

    return (AE_BAD_PARAMETER);

  }

  ACPI_DEBUG_PRINT((ACPI_DB_IO,

        "Wrote: %8.8X width %2d   to %8.8X%8.8X (%s)\n",

        value, width,

        ACPI_FORMAT_UINT64(address),

        acpi_ut_get_region_name(reg->address_space_id)));

  return (status);

}