/******************************************************************************
 *
 * Module Name: hwacpi - ACPI Hardware Initialization/Mode Interface
 *              $Revision: 46 $
 *
 *****************************************************************************/

/*
 *  Copyright (C) 2000, 2001 R. Byron Moore
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */


#include "acpi.h"
#include "achware.h"


#define _COMPONENT          ACPI_HARDWARE
	 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 = AE_OK;
	u32                     index;


	FUNCTION_TRACE ("Hw_initialize");


	/* We must have the ACPI tables by the time we get here */

	if (!acpi_gbl_FADT) {
		acpi_gbl_restore_acpi_chipset = FALSE;

		ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "No FADT!\n"));

		return_ACPI_STATUS (AE_NO_ACPI_TABLES);
	}

	/* Identify current ACPI/legacy mode   */

	switch (acpi_gbl_system_flags & SYS_MODES_MASK) {
	case (SYS_MODE_ACPI):

		acpi_gbl_original_mode = SYS_MODE_ACPI;
		ACPI_DEBUG_PRINT ((ACPI_DB_INFO, "System supports ACPI mode only.\n"));
		break;


	case (SYS_MODE_LEGACY):

		acpi_gbl_original_mode = SYS_MODE_LEGACY;
		ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
			"Tables loaded from buffer, hardware assumed to support LEGACY mode only.\n"));
		break;


	case (SYS_MODE_ACPI | SYS_MODE_LEGACY):

		if (acpi_hw_get_mode () == SYS_MODE_ACPI) {
			acpi_gbl_original_mode = SYS_MODE_ACPI;
		}
		else {
			acpi_gbl_original_mode = SYS_MODE_LEGACY;
		}

		ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
			"System supports both ACPI and LEGACY modes.\n"));

		ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
			"System is currently in %s mode.\n",
			(acpi_gbl_original_mode == SYS_MODE_ACPI) ? "ACPI" : "LEGACY"));
		break;
	}


	if (acpi_gbl_system_flags & SYS_MODE_ACPI) {
		/* Target system supports ACPI mode */

		/*
		 * The purpose of this code is to save the initial state
		 * of the ACPI event enable registers. An exit function will be
		 * registered which will restore this state when the application
		 * exits. The exit function will also clear all of the ACPI event
		 * status bits prior to restoring the original mode.
		 *
		 * The location of the PM1a_evt_blk enable registers is defined as the
		 * base of PM1a_evt_blk + DIV_2(PM1a_evt_blk_length). Since the spec further
		 * fully defines the PM1a_evt_blk to be a total of 4 bytes, the offset
		 * for the enable registers is always 2 from the base. It is hard
		 * coded here. If this changes in the spec, this code will need to
		 * be modified. The PM1b_evt_blk behaves as expected.
		 */
		acpi_gbl_pm1_enable_register_save = (u16) acpi_hw_register_read (
				   ACPI_MTX_LOCK, PM1_EN);


		/*
		 * The GPEs behave similarly, except that the length of the register
		 * block is not fixed, so the buffer must be allocated with malloc
		 */
		if (ACPI_VALID_ADDRESS (acpi_gbl_FADT->Xgpe0blk.address) &&
			acpi_gbl_FADT->gpe0blk_len) {
			/* GPE0 specified in FADT  */

			acpi_gbl_gpe0enable_register_save = ACPI_MEM_ALLOCATE (
					   DIV_2 (acpi_gbl_FADT->gpe0blk_len));
			if (!acpi_gbl_gpe0enable_register_save) {
				return_ACPI_STATUS (AE_NO_MEMORY);
			}

			/* Save state of GPE0 enable bits */

			for (index = 0; index < DIV_2 (acpi_gbl_FADT->gpe0blk_len); index++) {
				acpi_gbl_gpe0enable_register_save[index] =
					(u8) acpi_hw_register_read (ACPI_MTX_LOCK, GPE0_EN_BLOCK | index);
			}
		}

		else {
			acpi_gbl_gpe0enable_register_save = NULL;
		}

		if (ACPI_VALID_ADDRESS (acpi_gbl_FADT->Xgpe1_blk.address) &&
			acpi_gbl_FADT->gpe1_blk_len) {
			/* GPE1 defined */

			acpi_gbl_gpe1_enable_register_save = ACPI_MEM_ALLOCATE (
					   DIV_2 (acpi_gbl_FADT->gpe1_blk_len));
			if (!acpi_gbl_gpe1_enable_register_save) {
				return_ACPI_STATUS (AE_NO_MEMORY);
			}

			/* save state of GPE1 enable bits */

			for (index = 0; index < DIV_2 (acpi_gbl_FADT->gpe1_blk_len); index++) {
				acpi_gbl_gpe1_enable_register_save[index] =
					(u8) acpi_hw_register_read (ACPI_MTX_LOCK, GPE1_EN_BLOCK | index);
			}
		}

		else {
			acpi_gbl_gpe1_enable_register_save = NULL;
		}
	}

	return_ACPI_STATUS (status);
}


/******************************************************************************
 *
 * FUNCTION:    Acpi_hw_set_mode
 *
 * PARAMETERS:  Mode            - SYS_MODE_ACPI or SYS_MODE_LEGACY
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Transitions the system into the requested mode or does nothing
 *              if the system is already in that mode.
 *
 ******************************************************************************/

acpi_status
acpi_hw_set_mode (
	u32                     mode)
{

	acpi_status             status = AE_NO_HARDWARE_RESPONSE;


	FUNCTION_TRACE ("Hw_set_mode");


	if (mode == SYS_MODE_ACPI) {
		/* BIOS should have disabled ALL fixed and GP events */

		acpi_os_write_port (acpi_gbl_FADT->smi_cmd, acpi_gbl_FADT->acpi_enable, 8);
		ACPI_DEBUG_PRINT ((ACPI_DB_INFO, "Attempting to enable ACPI mode\n"));
	}

	else if (mode == SYS_MODE_LEGACY) {
		/*
		 * BIOS should clear all fixed status bits and restore fixed event
		 * enable bits to default
		 */
		acpi_os_write_port (acpi_gbl_FADT->smi_cmd, acpi_gbl_FADT->acpi_disable, 8);
		ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
				 "Attempting to enable Legacy (non-ACPI) mode\n"));
	}

	/* Give the platform some time to react */

	acpi_os_stall (20000);

	if (acpi_hw_get_mode () == mode) {
		ACPI_DEBUG_PRINT ((ACPI_DB_INFO, "Mode %X successfully enabled\n", mode));
		status = AE_OK;
	}

	return_ACPI_STATUS (status);
}


/******************************************************************************
 *
 * 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)
{

	FUNCTION_TRACE ("Hw_get_mode");


	if (acpi_hw_register_bit_access (ACPI_READ, ACPI_MTX_LOCK, SCI_EN)) {
		return_VALUE (SYS_MODE_ACPI);
	}
	else {
		return_VALUE (SYS_MODE_LEGACY);
	}
}


/******************************************************************************
 *
 * FUNCTION:    Acpi_hw_get_mode_capabilities
 *
 * PARAMETERS:  none
 *
 * RETURN:      logical OR of SYS_MODE_ACPI and SYS_MODE_LEGACY determined at initial
 *              system state.
 *
 * DESCRIPTION: Returns capablities of system
 *
 ******************************************************************************/

u32
acpi_hw_get_mode_capabilities (void)
{

	FUNCTION_TRACE ("Hw_get_mode_capabilities");


	if (!(acpi_gbl_system_flags & SYS_MODES_MASK)) {
		if (acpi_hw_get_mode () == SYS_MODE_LEGACY) {
			/*
			 * Assume that if this call is being made, Acpi_init has been called
			 * and ACPI support has been established by the presence of the
			 * tables.  Therefore since we're in SYS_MODE_LEGACY, the system
			 * must support both modes
			 */
			acpi_gbl_system_flags |= (SYS_MODE_ACPI | SYS_MODE_LEGACY);
		}

		else {
			/* TBD: [Investigate] !!! this may be unsafe... */
			/*
			 * system is is ACPI mode, so try to switch back to LEGACY to see if
			 * it is supported
			 */
			acpi_hw_set_mode (SYS_MODE_LEGACY);

			if (acpi_hw_get_mode () == SYS_MODE_LEGACY) {
				/* Now in SYS_MODE_LEGACY, so both are supported */

				acpi_gbl_system_flags |= (SYS_MODE_ACPI | SYS_MODE_LEGACY);
				acpi_hw_set_mode (SYS_MODE_ACPI);
			}

			else {
				/* Still in SYS_MODE_ACPI so this must be an ACPI only system */

				acpi_gbl_system_flags |= SYS_MODE_ACPI;
			}
		}
	}

	return_VALUE (acpi_gbl_system_flags & SYS_MODES_MASK);
}