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linux/drivers/acpi/acpica/hwregs.c

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/*******************************************************************************
*
* Module Name: hwregs - Read/write access functions for the various ACPI
* control and status registers.
*
******************************************************************************/
/*
* Copyright (C) 2000 - 2008, Intel Corp.
* 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 <acpi/acpi.h>
#include "accommon.h"
#include "acnamesp.h"
#include "acevents.h"
#define _COMPONENT ACPI_HARDWARE
ACPI_MODULE_NAME("hwregs")
/* Local Prototypes */
static acpi_status
acpi_hw_read_multiple(u32 *value,
struct acpi_generic_address *register_a,
struct acpi_generic_address *register_b);
static acpi_status
acpi_hw_write_multiple(u32 value,
struct acpi_generic_address *register_a,
struct acpi_generic_address *register_b);
/*******************************************************************************
*
* FUNCTION: acpi_hw_clear_acpi_status
*
* PARAMETERS: None
*
* RETURN: Status
*
* DESCRIPTION: Clears all fixed and general purpose status bits
*
******************************************************************************/
acpi_status acpi_hw_clear_acpi_status(void)
{
acpi_status status;
acpi_cpu_flags lock_flags = 0;
ACPI_FUNCTION_TRACE(hw_clear_acpi_status);
ACPI_DEBUG_PRINT((ACPI_DB_IO, "About to write %04X to %8.8X%8.8X\n",
ACPI_BITMASK_ALL_FIXED_STATUS,
ACPI_FORMAT_UINT64(acpi_gbl_xpm1a_status.address)));
lock_flags = acpi_os_acquire_lock(acpi_gbl_hardware_lock);
/* Clear the fixed events in PM1 A/B */
status = acpi_hw_register_write(ACPI_REGISTER_PM1_STATUS,
ACPI_BITMASK_ALL_FIXED_STATUS);
if (ACPI_FAILURE(status)) {
goto unlock_and_exit;
}
/* Clear the GPE Bits in all GPE registers in all GPE blocks */
status = acpi_ev_walk_gpe_list(acpi_hw_clear_gpe_block, NULL);
unlock_and_exit:
acpi_os_release_lock(acpi_gbl_hardware_lock, lock_flags);
return_ACPI_STATUS(status);
}
/*******************************************************************************
*
* 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.
*
******************************************************************************/
struct acpi_bit_register_info *acpi_hw_get_bit_register_info(u32 register_id)
{
ACPI_FUNCTION_ENTRY();
if (register_id > ACPI_BITREG_MAX) {
ACPI_ERROR((AE_INFO, "Invalid BitRegister ID: %X",
register_id));
return (NULL);
}
return (&acpi_gbl_bit_register_info[register_id]);
}
/******************************************************************************
*
* FUNCTION: acpi_hw_write_pm1_control
*
* PARAMETERS: pm1a_control - Value to be written to PM1A control
* pm1b_control - Value to be written to PM1B control
*
* RETURN: Status
*
* DESCRIPTION: Write the PM1 A/B control registers. These registers are
* different than than the PM1 A/B status and enable registers
* in that different values can be written to the A/B registers.
* Most notably, the SLP_TYP bits can be different, as per the
* values returned from the _Sx predefined methods.
*
******************************************************************************/
acpi_status acpi_hw_write_pm1_control(u32 pm1a_control, u32 pm1b_control)
{
acpi_status status;
ACPI_FUNCTION_TRACE(hw_write_pm1_control);
status = acpi_write(pm1a_control, &acpi_gbl_FADT.xpm1a_control_block);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
if (acpi_gbl_FADT.xpm1b_control_block.address) {
status =
acpi_write(pm1b_control,
&acpi_gbl_FADT.xpm1b_control_block);
}
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 value = 0;
acpi_status status;
ACPI_FUNCTION_TRACE(hw_register_read);
switch (register_id) {
case ACPI_REGISTER_PM1_STATUS: /* PM1 A/B: 16-bit access each */
status = acpi_hw_read_multiple(&value,
&acpi_gbl_xpm1a_status,
&acpi_gbl_xpm1b_status);
break;
case ACPI_REGISTER_PM1_ENABLE: /* PM1 A/B: 16-bit access each */
status = acpi_hw_read_multiple(&value,
&acpi_gbl_xpm1a_enable,
&acpi_gbl_xpm1b_enable);
break;
case ACPI_REGISTER_PM1_CONTROL: /* PM1 A/B: 16-bit access each */
status = acpi_hw_read_multiple(&value,
&acpi_gbl_FADT.
xpm1a_control_block,
&acpi_gbl_FADT.
xpm1b_control_block);
/*
* Zero the write-only bits. From the ACPI specification, "Hardware
* Write-Only Bits": "Upon reads to registers with write-only bits,
* software masks out all write-only bits."
*/
value &= ~ACPI_PM1_CONTROL_WRITEONLY_BITS;
break;
case ACPI_REGISTER_PM2_CONTROL: /* 8-bit access */
status = acpi_read(&value, &acpi_gbl_FADT.xpm2_control_block);
break;
case ACPI_REGISTER_PM_TIMER: /* 32-bit access */
status = acpi_read(&value, &acpi_gbl_FADT.xpm_timer_block);
break;
case ACPI_REGISTER_SMI_COMMAND_BLOCK: /* 8-bit access */
status =
acpi_hw_read_port(acpi_gbl_FADT.smi_command, &value, 8);
break;
default:
ACPI_ERROR((AE_INFO, "Unknown Register ID: %X", register_id));
status = AE_BAD_PARAMETER;
break;
}
if (ACPI_SUCCESS(status)) {
*return_value = value;
}
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: /* PM1 A/B: 16-bit access each */
/*
* Handle the "ignored" bit in PM1 Status. According to the ACPI
* specification, ignored bits are to be preserved when writing.
* Normally, this would mean a read/modify/write sequence. However,
* preserving a bit in the status register is different. Writing a
* one clears the status, and writing a zero preserves the status.
* Therefore, we must always write zero to the ignored bit.
*
* This behavior is clarified in the ACPI 4.0 specification.
*/
value &= ~ACPI_PM1_STATUS_PRESERVED_BITS;
status = acpi_hw_write_multiple(value,
&acpi_gbl_xpm1a_status,
&acpi_gbl_xpm1b_status);
break;
case ACPI_REGISTER_PM1_ENABLE: /* PM1 A/B: 16-bit access */
status = acpi_hw_write_multiple(value,
&acpi_gbl_xpm1a_enable,
&acpi_gbl_xpm1b_enable);
break;
case ACPI_REGISTER_PM1_CONTROL: /* PM1 A/B: 16-bit access each */
/*
* Perform a read first to preserve certain bits (per ACPI spec)
* Note: This includes SCI_EN, we never want to change this bit
*/
status = acpi_hw_read_multiple(&read_value,
&acpi_gbl_FADT.
xpm1a_control_block,
&acpi_gbl_FADT.
xpm1b_control_block);
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_write_multiple(value,
&acpi_gbl_FADT.
xpm1a_control_block,
&acpi_gbl_FADT.
xpm1b_control_block);
break;
case ACPI_REGISTER_PM2_CONTROL: /* 8-bit access */
/*
* For control registers, all reserved bits must be preserved,
* as per the ACPI spec.
*/
status =
acpi_read(&read_value, &acpi_gbl_FADT.xpm2_control_block);
if (ACPI_FAILURE(status)) {
goto exit;
}
/* Insert the bits to be preserved */
ACPI_INSERT_BITS(value, ACPI_PM2_CONTROL_PRESERVED_BITS,
read_value);
status = acpi_write(value, &acpi_gbl_FADT.xpm2_control_block);
break;
case ACPI_REGISTER_PM_TIMER: /* 32-bit access */
status = acpi_write(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_hw_write_port(acpi_gbl_FADT.smi_command, value, 8);
break;
default:
ACPI_ERROR((AE_INFO, "Unknown Register ID: %X", register_id));
status = AE_BAD_PARAMETER;
break;
}
exit:
return_ACPI_STATUS(status);
}
/******************************************************************************
*
* FUNCTION: acpi_hw_read_multiple
*
* PARAMETERS: Value - Where the register value is returned
* register_a - First ACPI register (required)
* register_b - Second ACPI register (optional)
*
* RETURN: Status
*
* DESCRIPTION: Read from the specified two-part ACPI register (such as PM1 A/B)
*
******************************************************************************/
static acpi_status
acpi_hw_read_multiple(u32 *value,
struct acpi_generic_address *register_a,
struct acpi_generic_address *register_b)
{
u32 value_a = 0;
u32 value_b = 0;
acpi_status status;
/* The first register is always required */
status = acpi_read(&value_a, register_a);
if (ACPI_FAILURE(status)) {
return (status);
}
/* Second register is optional */
if (register_b->address) {
status = acpi_read(&value_b, register_b);
if (ACPI_FAILURE(status)) {
return (status);
}
}
/*
* OR the two return values together. No shifting or masking is necessary,
* because of how the PM1 registers are defined in the ACPI specification:
*
* "Although the bits can be split between the two register blocks (each
* register block has a unique pointer within the FADT), the bit positions
* are maintained. The register block with unimplemented bits (that is,
* those implemented in the other register block) always returns zeros,
* and writes have no side effects"
*/
*value = (value_a | value_b);
return (AE_OK);
}
/******************************************************************************
*
* FUNCTION: acpi_hw_write_multiple
*
* PARAMETERS: Value - The value to write
* register_a - First ACPI register (required)
* register_b - Second ACPI register (optional)
*
* RETURN: Status
*
* DESCRIPTION: Write to the specified two-part ACPI register (such as PM1 A/B)
*
******************************************************************************/
static acpi_status
acpi_hw_write_multiple(u32 value,
struct acpi_generic_address *register_a,
struct acpi_generic_address *register_b)
{
acpi_status status;
/* The first register is always required */
status = acpi_write(value, register_a);
if (ACPI_FAILURE(status)) {
return (status);
}
/*
* Second register is optional
*
* No bit shifting or clearing is necessary, because of how the PM1
* registers are defined in the ACPI specification:
*
* "Although the bits can be split between the two register blocks (each
* register block has a unique pointer within the FADT), the bit positions
* are maintained. The register block with unimplemented bits (that is,
* those implemented in the other register block) always returns zeros,
* and writes have no side effects"
*/
if (register_b->address) {
status = acpi_write(value, register_b);
}
return (status);
}
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