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Diffstat (limited to 'drivers/acpi/hardware/hwacpi.c')
| -rw-r--r-- | drivers/acpi/hardware/hwacpi.c | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/drivers/acpi/hardware/hwacpi.c b/drivers/acpi/hardware/hwacpi.c new file mode 100644 index 0000000..816894e --- /dev/null +++ b/drivers/acpi/hardware/hwacpi.c @@ -0,0 +1,184 @@ + +/****************************************************************************** + * + * Module Name: hwacpi - ACPI Hardware Initialization/Mode Interface + * + *****************************************************************************/ + +/* + * 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> + +#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); + } +} |
