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Diffstat (limited to 'drivers/acpi/hardware/hwacpi.c')
| -rw-r--r-- | drivers/acpi/hardware/hwacpi.c | 230 |
1 files changed, 230 insertions, 0 deletions
diff --git a/drivers/acpi/hardware/hwacpi.c b/drivers/acpi/hardware/hwacpi.c new file mode 100644 index 000000000000..529e922bdc85 --- /dev/null +++ b/drivers/acpi/hardware/hwacpi.c @@ -0,0 +1,230 @@ + +/****************************************************************************** + * + * Module Name: hwacpi - ACPI Hardware Initialization/Mode Interface + * + *****************************************************************************/ + +/* + * Copyright (C) 2000 - 2005, 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_initialize + * + * PARAMETERS: None + * + * RETURN: Status + * + * DESCRIPTION: Initialize and validate various ACPI registers + * + ******************************************************************************/ + +acpi_status +acpi_hw_initialize ( + void) +{ + acpi_status status; + + + ACPI_FUNCTION_TRACE ("hw_initialize"); + + + /* We must have the ACPI tables by the time we get here */ + + if (!acpi_gbl_FADT) { + ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "A FADT is not loaded\n")); + + return_ACPI_STATUS (AE_NO_ACPI_TABLES); + } + + /* Sanity check the FADT for valid values */ + + status = acpi_ut_validate_fadt (); + if (ACPI_FAILURE (status)) { + return_ACPI_STATUS (status); + } + + return_ACPI_STATUS (AE_OK); +} + + +/****************************************************************************** + * + * 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_cmd) { + ACPI_REPORT_ERROR (("No SMI_CMD in FADT, mode transition failed.\n")); + 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_REPORT_ERROR (("No ACPI mode transition supported in this system (enable/disable both zero)\n")); + 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_cmd, + (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_cmd, + (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_REPORT_ERROR (("Could not write mode change, %s\n", acpi_format_exception (status))); + 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_REPORT_ERROR (("Hardware never changed modes\n")); + 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_cmd) { + return_VALUE (ACPI_SYS_MODE_ACPI); + } + + status = acpi_get_register (ACPI_BITREG_SCI_ENABLE, &value, ACPI_MTX_LOCK); + if (ACPI_FAILURE (status)) { + return_VALUE (ACPI_SYS_MODE_LEGACY); + } + + if (value) { + return_VALUE (ACPI_SYS_MODE_ACPI); + } + else { + return_VALUE (ACPI_SYS_MODE_LEGACY); + } +} |