/******************************************************************************
*
* Module Name: hwacpi - ACPI Hardware Initialization/Mode Interface
*
*****************************************************************************/
/*
* Copyright (C) 2000 - 2007, 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 <acpi/acpi.h>
#define _COMPONENT ACPI_HARDWARE
ACPI_MODULE_NAME("hwacpi")
/******************************************************************************
*
* FUNCTION: acpi_hw_set_mode
*
* PARAMETERS: Mode - SYS_MODE_ACPI or SYS_MODE_LEGACY
*
* RETURN: Status
*
* DESCRIPTION: Transitions the system into the requested mode.
*
******************************************************************************/
acpi_status acpi_hw_set_mode(u32 mode)
{
acpi_status status;
u32 retry;
ACPI_FUNCTION_TRACE(hw_set_mode);
/*
* ACPI 2.0 clarified that if SMI_CMD in FADT is zero,
* system does not support mode transition.
*/
if (!acpi_gbl_FADT.smi_command) {
ACPI_ERROR((AE_INFO,
"No SMI_CMD in FADT, mode transition failed"));
return_ACPI_STATUS(AE_NO_HARDWARE_RESPONSE);
}
/*
* ACPI 2.0 clarified the meaning of ACPI_ENABLE and ACPI_DISABLE
* in FADT: If it is zero, enabling or disabling is not supported.
* As old systems may have used zero for mode transition,
* we make sure both the numbers are zero to determine these
* transitions are not supported.
*/
if (!acpi_gbl_FADT.acpi_enable && !acpi_gbl_FADT.acpi_disable) {
ACPI_ERROR((AE_INFO,
"No ACPI mode transition supported in this system (enable/disable both zero)"));
return_ACPI_STATUS(AE_OK);
}
switch (mode) {
case ACPI_SYS_MODE_ACPI:
/* BIOS should have disabled ALL fixed and GP events */
status = acpi_os_write_port(acpi_gbl_FADT.smi_command,
(u32) acpi_gbl_FADT.acpi_enable, 8);
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Attempting to enable ACPI mode\n"));
break;
case ACPI_SYS_MODE_LEGACY:
/*
* BIOS should clear all fixed status bits and restore fixed event
* enable bits to default
*/
status = acpi_os_write_port(acpi_gbl_FADT.smi_command,
(u32) acpi_gbl_FADT.acpi_disable,
8);
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Attempting to enable Legacy (non-ACPI) mode\n"));
break;
default:
return_ACPI_STATUS(AE_BAD_PARAMETER);
}
if (ACPI_FAILURE(status)) {
ACPI_EXCEPTION((AE_INFO, status,
"Could not write ACPI mode change"));
return_ACPI_STATUS(status);
}
/*
* Some hardware takes a LONG time to switch modes. Give them 3 sec to
* do so, but allow faster systems to proceed more quickly.
*/
retry = 3000;
while (retry) {
if (acpi_hw_get_mode() == mode) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Mode %X successfully enabled\n",
mode));
return_ACPI_STATUS(AE_OK);
}
acpi_os_stall(1000);
retry--;
}
ACPI_ERROR((AE_INFO, "Hardware did not change modes"));
return_ACPI_STATUS(AE_NO_HARDWARE_RESPONSE);
}
/*******************************************************************************
*
* FUNCTION: acpi_hw_get_mode
*
* PARAMETERS: none
*
* RETURN: SYS_MODE_ACPI or SYS_MODE_LEGACY
*
* DESCRIPTION: Return current operating state of system. Determined by
* querying the SCI_EN bit.
*
******************************************************************************/
u32 acpi_hw_get_mode(void)
{
acpi_status status;
u32 value;
ACPI_FUNCTION_TRACE(hw_get_mode);
/*
* ACPI 2.0 clarified that if SMI_CMD in FADT is zero,
* system does not support mode transition.
*/
if (!acpi_gbl_FADT.smi_command) {
return_UINT32(ACPI_SYS_MODE_ACPI);
}
status = acpi_get_register(ACPI_BITREG_SCI_ENABLE, &value);
if (ACPI_FAILURE(status)) {
return_UINT32(ACPI_SYS_MODE_LEGACY);
}
if (value) {
return_UINT32(ACPI_SYS_MODE_ACPI);
} else {
return_UINT32(ACPI_SYS_MODE_LEGACY);
}
}
