![Bob Moore](/assets/img/avatar_default.png)
All tool/utility signons. Dual-license module header. Signed-off-by: Bob Moore <robert.moore@intel.com> Signed-off-by: Lv Zheng <lv.zheng@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
669 lines
19 KiB
C
669 lines
19 KiB
C
/*******************************************************************************
|
|
*
|
|
* Module Name: hwregs - Read/write access functions for the various ACPI
|
|
* control and status registers.
|
|
*
|
|
******************************************************************************/
|
|
|
|
/*
|
|
* Copyright (C) 2000 - 2016, 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 "acevents.h"
|
|
|
|
#define _COMPONENT ACPI_HARDWARE
|
|
ACPI_MODULE_NAME("hwregs")
|
|
|
|
#if (!ACPI_REDUCED_HARDWARE)
|
|
/* 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);
|
|
|
|
#endif /* !ACPI_REDUCED_HARDWARE */
|
|
|
|
/******************************************************************************
|
|
*
|
|
* FUNCTION: acpi_hw_validate_register
|
|
*
|
|
* PARAMETERS: reg - GAS register structure
|
|
* max_bit_width - Max bit_width supported (32 or 64)
|
|
* address - Pointer to where the gas->address
|
|
* is returned
|
|
*
|
|
* RETURN: Status
|
|
*
|
|
* DESCRIPTION: Validate the contents of a GAS register. Checks the GAS
|
|
* pointer, Address, space_id, bit_width, and bit_offset.
|
|
*
|
|
******************************************************************************/
|
|
|
|
acpi_status
|
|
acpi_hw_validate_register(struct acpi_generic_address *reg,
|
|
u8 max_bit_width, u64 *address)
|
|
{
|
|
|
|
/* Must have a valid pointer to a GAS structure */
|
|
|
|
if (!reg) {
|
|
return (AE_BAD_PARAMETER);
|
|
}
|
|
|
|
/*
|
|
* Copy the target address. This handles possible alignment issues.
|
|
* Address must not be null. A null address also indicates an optional
|
|
* ACPI register that is not supported, so no error message.
|
|
*/
|
|
ACPI_MOVE_64_TO_64(address, ®->address);
|
|
if (!(*address)) {
|
|
return (AE_BAD_ADDRESS);
|
|
}
|
|
|
|
/* Validate the space_ID */
|
|
|
|
if ((reg->space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY) &&
|
|
(reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO)) {
|
|
ACPI_ERROR((AE_INFO,
|
|
"Unsupported address space: 0x%X", reg->space_id));
|
|
return (AE_SUPPORT);
|
|
}
|
|
|
|
/* Validate the bit_width */
|
|
|
|
if ((reg->bit_width != 8) &&
|
|
(reg->bit_width != 16) &&
|
|
(reg->bit_width != 32) && (reg->bit_width != max_bit_width)) {
|
|
ACPI_ERROR((AE_INFO,
|
|
"Unsupported register bit width: 0x%X",
|
|
reg->bit_width));
|
|
return (AE_SUPPORT);
|
|
}
|
|
|
|
/* Validate the bit_offset. Just a warning for now. */
|
|
|
|
if (reg->bit_offset != 0) {
|
|
ACPI_WARNING((AE_INFO,
|
|
"Unsupported register bit offset: 0x%X",
|
|
reg->bit_offset));
|
|
}
|
|
|
|
return (AE_OK);
|
|
}
|
|
|
|
/******************************************************************************
|
|
*
|
|
* FUNCTION: acpi_hw_read
|
|
*
|
|
* PARAMETERS: value - Where the value is returned
|
|
* reg - GAS register structure
|
|
*
|
|
* RETURN: Status
|
|
*
|
|
* DESCRIPTION: Read from either memory or IO space. This is a 32-bit max
|
|
* version of acpi_read, used internally since the overhead of
|
|
* 64-bit values is not needed.
|
|
*
|
|
* LIMITATIONS: <These limitations also apply to acpi_hw_write>
|
|
* bit_width must be exactly 8, 16, or 32.
|
|
* space_ID must be system_memory or system_IO.
|
|
* bit_offset and access_width are currently ignored, as there has
|
|
* not been a need to implement these.
|
|
*
|
|
******************************************************************************/
|
|
|
|
acpi_status acpi_hw_read(u32 *value, struct acpi_generic_address *reg)
|
|
{
|
|
u64 address;
|
|
u64 value64;
|
|
acpi_status status;
|
|
|
|
ACPI_FUNCTION_NAME(hw_read);
|
|
|
|
/* Validate contents of the GAS register */
|
|
|
|
status = acpi_hw_validate_register(reg, 32, &address);
|
|
if (ACPI_FAILURE(status)) {
|
|
return (status);
|
|
}
|
|
|
|
/* Initialize entire 32-bit return value to zero */
|
|
|
|
*value = 0;
|
|
|
|
/*
|
|
* Two address spaces supported: Memory or IO. PCI_Config is
|
|
* not supported here because the GAS structure is insufficient
|
|
*/
|
|
if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) {
|
|
status = acpi_os_read_memory((acpi_physical_address)
|
|
address, &value64, reg->bit_width);
|
|
|
|
*value = (u32)value64;
|
|
} else { /* ACPI_ADR_SPACE_SYSTEM_IO, validated earlier */
|
|
|
|
status = acpi_hw_read_port((acpi_io_address)
|
|
address, value, reg->bit_width);
|
|
}
|
|
|
|
ACPI_DEBUG_PRINT((ACPI_DB_IO,
|
|
"Read: %8.8X width %2d from %8.8X%8.8X (%s)\n",
|
|
*value, reg->bit_width, ACPI_FORMAT_UINT64(address),
|
|
acpi_ut_get_region_name(reg->space_id)));
|
|
|
|
return (status);
|
|
}
|
|
|
|
/******************************************************************************
|
|
*
|
|
* FUNCTION: acpi_hw_write
|
|
*
|
|
* PARAMETERS: value - Value to be written
|
|
* reg - GAS register structure
|
|
*
|
|
* RETURN: Status
|
|
*
|
|
* DESCRIPTION: Write to either memory or IO space. This is a 32-bit max
|
|
* version of acpi_write, used internally since the overhead of
|
|
* 64-bit values is not needed.
|
|
*
|
|
******************************************************************************/
|
|
|
|
acpi_status acpi_hw_write(u32 value, struct acpi_generic_address *reg)
|
|
{
|
|
u64 address;
|
|
acpi_status status;
|
|
|
|
ACPI_FUNCTION_NAME(hw_write);
|
|
|
|
/* Validate contents of the GAS register */
|
|
|
|
status = acpi_hw_validate_register(reg, 32, &address);
|
|
if (ACPI_FAILURE(status)) {
|
|
return (status);
|
|
}
|
|
|
|
/*
|
|
* Two address spaces supported: Memory or IO. PCI_Config is
|
|
* not supported here because the GAS structure is insufficient
|
|
*/
|
|
if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) {
|
|
status = acpi_os_write_memory((acpi_physical_address)
|
|
address, (u64)value,
|
|
reg->bit_width);
|
|
} else { /* ACPI_ADR_SPACE_SYSTEM_IO, validated earlier */
|
|
|
|
status = acpi_hw_write_port((acpi_io_address)
|
|
address, value, reg->bit_width);
|
|
}
|
|
|
|
ACPI_DEBUG_PRINT((ACPI_DB_IO,
|
|
"Wrote: %8.8X width %2d to %8.8X%8.8X (%s)\n",
|
|
value, reg->bit_width, ACPI_FORMAT_UINT64(address),
|
|
acpi_ut_get_region_name(reg->space_id)));
|
|
|
|
return (status);
|
|
}
|
|
|
|
#if (!ACPI_REDUCED_HARDWARE)
|
|
/*******************************************************************************
|
|
*
|
|
* 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);
|
|
|
|
acpi_os_release_lock(acpi_gbl_hardware_lock, lock_flags);
|
|
|
|
if (ACPI_FAILURE(status)) {
|
|
goto 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);
|
|
|
|
exit:
|
|
return_ACPI_STATUS(status);
|
|
}
|
|
|
|
/*******************************************************************************
|
|
*
|
|
* FUNCTION: acpi_hw_get_bit_register_info
|
|
*
|
|
* 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: 0x%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_hw_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_hw_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_hw_read(&value, &acpi_gbl_FADT.xpm2_control_block);
|
|
break;
|
|
|
|
case ACPI_REGISTER_PM_TIMER: /* 32-bit access */
|
|
|
|
status = acpi_hw_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: 0x%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 each */
|
|
|
|
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_hw_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_hw_write(value, &acpi_gbl_FADT.xpm2_control_block);
|
|
break;
|
|
|
|
case ACPI_REGISTER_PM_TIMER: /* 32-bit access */
|
|
|
|
status = acpi_hw_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: 0x%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_hw_read(&value_a, register_a);
|
|
if (ACPI_FAILURE(status)) {
|
|
return (status);
|
|
}
|
|
|
|
/* Second register is optional */
|
|
|
|
if (register_b->address) {
|
|
status = acpi_hw_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_hw_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_hw_write(value, register_b);
|
|
}
|
|
|
|
return (status);
|
|
}
|
|
|
|
#endif /* !ACPI_REDUCED_HARDWARE */
|