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path: root/drivers/acpi/hardware/hwacpi.c
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Diffstat (limited to 'drivers/acpi/hardware/hwacpi.c')
-rw-r--r--drivers/acpi/hardware/hwacpi.c230
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diff --git a/drivers/acpi/hardware/hwacpi.c b/drivers/acpi/hardware/hwacpi.c
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index 000000000000..529e922bdc85
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+++ b/drivers/acpi/hardware/hwacpi.c
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+
+/******************************************************************************
+ *
+ * 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);
+ }
+}