189 lines
6.1 KiB
C
189 lines
6.1 KiB
C
|
|
/******************************************************************************
|
|
*
|
|
* Name: hwtimer.c - ACPI Power Management Timer Interface
|
|
*
|
|
*****************************************************************************/
|
|
|
|
/*
|
|
* Copyright (C) 2000 - 2008, Intel Corp.
|
|
* 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>
|
|
#include "accommon.h"
|
|
|
|
#define _COMPONENT ACPI_HARDWARE
|
|
ACPI_MODULE_NAME("hwtimer")
|
|
|
|
/******************************************************************************
|
|
*
|
|
* FUNCTION: acpi_get_timer_resolution
|
|
*
|
|
* PARAMETERS: Resolution - Where the resolution is returned
|
|
*
|
|
* RETURN: Status and timer resolution
|
|
*
|
|
* DESCRIPTION: Obtains resolution of the ACPI PM Timer (24 or 32 bits).
|
|
*
|
|
******************************************************************************/
|
|
acpi_status acpi_get_timer_resolution(u32 * resolution)
|
|
{
|
|
ACPI_FUNCTION_TRACE(acpi_get_timer_resolution);
|
|
|
|
if (!resolution) {
|
|
return_ACPI_STATUS(AE_BAD_PARAMETER);
|
|
}
|
|
|
|
if ((acpi_gbl_FADT.flags & ACPI_FADT_32BIT_TIMER) == 0) {
|
|
*resolution = 24;
|
|
} else {
|
|
*resolution = 32;
|
|
}
|
|
|
|
return_ACPI_STATUS(AE_OK);
|
|
}
|
|
|
|
ACPI_EXPORT_SYMBOL(acpi_get_timer_resolution)
|
|
|
|
/******************************************************************************
|
|
*
|
|
* FUNCTION: acpi_get_timer
|
|
*
|
|
* PARAMETERS: Ticks - Where the timer value is returned
|
|
*
|
|
* RETURN: Status and current timer value (ticks)
|
|
*
|
|
* DESCRIPTION: Obtains current value of ACPI PM Timer (in ticks).
|
|
*
|
|
******************************************************************************/
|
|
acpi_status acpi_get_timer(u32 * ticks)
|
|
{
|
|
acpi_status status;
|
|
|
|
ACPI_FUNCTION_TRACE(acpi_get_timer);
|
|
|
|
if (!ticks) {
|
|
return_ACPI_STATUS(AE_BAD_PARAMETER);
|
|
}
|
|
|
|
status =
|
|
acpi_hw_read(ticks, &acpi_gbl_FADT.xpm_timer_block);
|
|
|
|
return_ACPI_STATUS(status);
|
|
}
|
|
|
|
ACPI_EXPORT_SYMBOL(acpi_get_timer)
|
|
|
|
/******************************************************************************
|
|
*
|
|
* FUNCTION: acpi_get_timer_duration
|
|
*
|
|
* PARAMETERS: start_ticks - Starting timestamp
|
|
* end_ticks - End timestamp
|
|
* time_elapsed - Where the elapsed time is returned
|
|
*
|
|
* RETURN: Status and time_elapsed
|
|
*
|
|
* DESCRIPTION: Computes the time elapsed (in microseconds) between two
|
|
* PM Timer time stamps, taking into account the possibility of
|
|
* rollovers, the timer resolution, and timer frequency.
|
|
*
|
|
* The PM Timer's clock ticks at roughly 3.6 times per
|
|
* _microsecond_, and its clock continues through Cx state
|
|
* transitions (unlike many CPU timestamp counters) -- making it
|
|
* a versatile and accurate timer.
|
|
*
|
|
* Note that this function accommodates only a single timer
|
|
* rollover. Thus for 24-bit timers, this function should only
|
|
* be used for calculating durations less than ~4.6 seconds
|
|
* (~20 minutes for 32-bit timers) -- calculations below:
|
|
*
|
|
* 2**24 Ticks / 3,600,000 Ticks/Sec = 4.66 sec
|
|
* 2**32 Ticks / 3,600,000 Ticks/Sec = 1193 sec or 19.88 minutes
|
|
*
|
|
******************************************************************************/
|
|
acpi_status
|
|
acpi_get_timer_duration(u32 start_ticks, u32 end_ticks, u32 * time_elapsed)
|
|
{
|
|
acpi_status status;
|
|
u32 delta_ticks;
|
|
acpi_integer quotient;
|
|
|
|
ACPI_FUNCTION_TRACE(acpi_get_timer_duration);
|
|
|
|
if (!time_elapsed) {
|
|
return_ACPI_STATUS(AE_BAD_PARAMETER);
|
|
}
|
|
|
|
/*
|
|
* Compute Tick Delta:
|
|
* Handle (max one) timer rollovers on 24-bit versus 32-bit timers.
|
|
*/
|
|
if (start_ticks < end_ticks) {
|
|
delta_ticks = end_ticks - start_ticks;
|
|
} else if (start_ticks > end_ticks) {
|
|
if ((acpi_gbl_FADT.flags & ACPI_FADT_32BIT_TIMER) == 0) {
|
|
|
|
/* 24-bit Timer */
|
|
|
|
delta_ticks =
|
|
(((0x00FFFFFF - start_ticks) +
|
|
end_ticks) & 0x00FFFFFF);
|
|
} else {
|
|
/* 32-bit Timer */
|
|
|
|
delta_ticks = (0xFFFFFFFF - start_ticks) + end_ticks;
|
|
}
|
|
} else { /* start_ticks == end_ticks */
|
|
|
|
*time_elapsed = 0;
|
|
return_ACPI_STATUS(AE_OK);
|
|
}
|
|
|
|
/*
|
|
* Compute Duration (Requires a 64-bit multiply and divide):
|
|
*
|
|
* time_elapsed = (delta_ticks * 1000000) / PM_TIMER_FREQUENCY;
|
|
*/
|
|
status = acpi_ut_short_divide(((u64) delta_ticks) * 1000000,
|
|
PM_TIMER_FREQUENCY, "ient, NULL);
|
|
|
|
*time_elapsed = (u32) quotient;
|
|
return_ACPI_STATUS(status);
|
|
}
|
|
|
|
ACPI_EXPORT_SYMBOL(acpi_get_timer_duration)
|