drivers/acpi/acpica/evevent.c

// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/******************************************************************************
 *
 * Module Name: evevent - Fixed Event handling and dispatch
 *
 * Copyright (C) 2000 - 2019, Intel Corp.
 *
 *****************************************************************************/

#include <acpi/acpi.h>
#include "accommon.h"
#include "acevents.h"

#define _COMPONENT          ACPI_EVENTS
ACPI_MODULE_NAME("evevent")
#if (!ACPI_REDUCED_HARDWARE)	/* Entire module */
/* Local prototypes */
static acpi_status acpi_ev_fixed_event_initialize(void);

static u32 acpi_ev_fixed_event_dispatch(u32 event);

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_initialize_events
 *
 * PARAMETERS:  None
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Initialize global data structures for ACPI events (Fixed, GPE)
 *
 ******************************************************************************/

acpi_status acpi_ev_initialize_events(void)
{
	acpi_status status;

	ACPI_FUNCTION_TRACE(ev_initialize_events);

	/* If Hardware Reduced flag is set, there are no fixed events */

	if (acpi_gbl_reduced_hardware) {
		return_ACPI_STATUS(AE_OK);
	}

	/*
	 * Initialize the Fixed and General Purpose Events. This is done prior to
	 * enabling SCIs to prevent interrupts from occurring before the handlers
	 * are installed.
	 */
	status = acpi_ev_fixed_event_initialize();
	if (ACPI_FAILURE(status)) {
		ACPI_EXCEPTION((AE_INFO, status,
				"Unable to initialize fixed events"));
		return_ACPI_STATUS(status);
	}

	status = acpi_ev_gpe_initialize();
	if (ACPI_FAILURE(status)) {
		ACPI_EXCEPTION((AE_INFO, status,
				"Unable to initialize general purpose events"));
		return_ACPI_STATUS(status);
	}

	return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_install_xrupt_handlers
 *
 * PARAMETERS:  None
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Install interrupt handlers for the SCI and Global Lock
 *
 ******************************************************************************/

acpi_status acpi_ev_install_xrupt_handlers(void)
{
	acpi_status status;

	ACPI_FUNCTION_TRACE(ev_install_xrupt_handlers);

	/* If Hardware Reduced flag is set, there is no ACPI h/w */

	if (acpi_gbl_reduced_hardware) {
		return_ACPI_STATUS(AE_OK);
	}

	/* Install the SCI handler */

	status = acpi_ev_install_sci_handler();
	if (ACPI_FAILURE(status)) {
		ACPI_EXCEPTION((AE_INFO, status,
				"Unable to install System Control Interrupt handler"));
		return_ACPI_STATUS(status);
	}

	/* Install the handler for the Global Lock */

	status = acpi_ev_init_global_lock_handler();
	if (ACPI_FAILURE(status)) {
		ACPI_EXCEPTION((AE_INFO, status,
				"Unable to initialize Global Lock handler"));
		return_ACPI_STATUS(status);
	}

	acpi_gbl_events_initialized = TRUE;
	return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_fixed_event_initialize
 *
 * PARAMETERS:  None
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Install the fixed event handlers and disable all fixed events.
 *
 ******************************************************************************/

static acpi_status acpi_ev_fixed_event_initialize(void)
{
	u32 i;
	acpi_status status;

	/*
	 * Initialize the structure that keeps track of fixed event handlers and
	 * enable the fixed events.
	 */
	for (i = 0; i < ACPI_NUM_FIXED_EVENTS; i++) {
		acpi_gbl_fixed_event_handlers[i].handler = NULL;
		acpi_gbl_fixed_event_handlers[i].context = NULL;

		/* Disable the fixed event */

		if (acpi_gbl_fixed_event_info[i].enable_register_id != 0xFF) {
			status =
			    acpi_write_bit_register(acpi_gbl_fixed_event_info
						    [i].enable_register_id,
						    ACPI_DISABLE_EVENT);
			if (ACPI_FAILURE(status)) {
				return (status);
			}
		}
	}

	return (AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_fixed_event_detect
 *
 * PARAMETERS:  None
 *
 * RETURN:      INTERRUPT_HANDLED or INTERRUPT_NOT_HANDLED
 *
 * DESCRIPTION: Checks the PM status register for active fixed events
 *
 ******************************************************************************/

u32 acpi_ev_fixed_event_detect(void)
{
	u32 int_status = ACPI_INTERRUPT_NOT_HANDLED;
	u32 fixed_status;
	u32 fixed_enable;
	u32 i;
	acpi_status status;

	ACPI_FUNCTION_NAME(ev_fixed_event_detect);

	/*
	 * Read the fixed feature status and enable registers, as all the cases
	 * depend on their values. Ignore errors here.
	 */
	status = acpi_hw_register_read(ACPI_REGISTER_PM1_STATUS, &fixed_status);
	status |=
	    acpi_hw_register_read(ACPI_REGISTER_PM1_ENABLE, &fixed_enable);
	if (ACPI_FAILURE(status)) {
		return (int_status);
	}

	ACPI_DEBUG_PRINT((ACPI_DB_INTERRUPTS,
			  "Fixed Event Block: Enable %08X Status %08X\n",
			  fixed_enable, fixed_status));

	/*
	 * Check for all possible Fixed Events and dispatch those that are active
	 */
	for (i = 0; i < ACPI_NUM_FIXED_EVENTS; i++) {

		/* Both the status and enable bits must be on for this event */

		if ((fixed_status & acpi_gbl_fixed_event_info[i].
		     status_bit_mask)
		    && (fixed_enable & acpi_gbl_fixed_event_info[i].
			enable_bit_mask)) {
			/*
			 * Found an active (signalled) event. Invoke global event
			 * handler if present.
			 */
			acpi_fixed_event_count[i]++;
			if (acpi_gbl_global_event_handler) {
				acpi_gbl_global_event_handler
				    (ACPI_EVENT_TYPE_FIXED, NULL, i,
				     acpi_gbl_global_event_handler_context);
			}

			int_status |= acpi_ev_fixed_event_dispatch(i);
		}
	}

	return (int_status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_fixed_event_dispatch
 *
 * PARAMETERS:  event               - Event type
 *
 * RETURN:      INTERRUPT_HANDLED or INTERRUPT_NOT_HANDLED
 *
 * DESCRIPTION: Clears the status bit for the requested event, calls the
 *              handler that previously registered for the event.
 *              NOTE: If there is no handler for the event, the event is
 *              disabled to prevent further interrupts.
 *
 ******************************************************************************/

static u32 acpi_ev_fixed_event_dispatch(u32 event)
{

	ACPI_FUNCTION_ENTRY();

	/* Clear the status bit */

	(void)acpi_write_bit_register(acpi_gbl_fixed_event_info[event].
				      status_register_id, ACPI_CLEAR_STATUS);

	/*
	 * Make sure that a handler exists. If not, report an error
	 * and disable the event to prevent further interrupts.
	 */
	if (!acpi_gbl_fixed_event_handlers[event].handler) {
		(void)acpi_write_bit_register(acpi_gbl_fixed_event_info[event].
					      enable_register_id,
					      ACPI_DISABLE_EVENT);

		ACPI_ERROR((AE_INFO,
			    "No installed handler for fixed event - %s (%u), disabling",
			    acpi_ut_get_event_name(event), event));

		return (ACPI_INTERRUPT_NOT_HANDLED);
	}

	/* Invoke the Fixed Event handler */

	return ((acpi_gbl_fixed_event_handlers[event].
		 handler) (acpi_gbl_fixed_event_handlers[event].context));
}

#endif				/* !ACPI_REDUCED_HARDWARE */