/****************************************************************************** * * 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); } }