linux/drivers/acpi/hardware/hwtimer.c
Robert Moore 44f6c01242 ACPICA 20050408 from Bob Moore
Fixed three cases in the interpreter where an "index"
argument to an ASL function was still (internally) 32
bits instead of the required 64 bits.  This was the Index
argument to the Index, Mid, and Match operators.

The "strupr" function is now permanently local
(acpi_ut_strupr), since this is not a POSIX-defined
function and not present in most kernel-level C
libraries. References to the C library strupr function
have been removed from the headers.

Completed the deployment of static
functions/prototypes. All prototypes with the static
attribute have been moved from the headers to the owning
C file.

ACPICA 20050329 from Bob Moore

An error is now generated if an attempt is made to create
a Buffer Field of length zero (A CreateField with a length
operand of zero.)

The interpreter now issues a warning whenever executable
code at the module level is detected during ACPI table
load. This will give some idea of the prevalence of this
type of code.

Implemented support for references to named objects (other
than control methods) within package objects.

Enhanced package object output for the debug
object. Package objects are now completely dumped, showing
all elements.

Enhanced miscellaneous object output for the debug
object. Any object can now be written to the debug object
(for example, a device object can be written, and the type
of the object will be displayed.)

The "static" qualifier has been added to all local
functions across the core subsystem.

The number of "long" lines (> 80 chars) within the source
has been significantly reduced, by about 1/3.

Cleaned up all header files to ensure that all CA/iASL
functions are prototyped (even static functions) and the
formatting is consistent.

Two new header files have been added, acopcode.h and
acnames.h.

Removed several obsolete functions that were no longer
used.

Signed-off-by: Len Brown <len.brown@intel.com>
2005-07-12 00:08:52 -04:00

203 lines
6.3 KiB
C

/******************************************************************************
*
* Name: hwtimer.c - ACPI Power Management Timer 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 <linux/module.h>
#include <acpi/acpi.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 (0 == acpi_gbl_FADT->tmr_val_ext) {
*resolution = 24;
}
else {
*resolution = 32;
}
return_ACPI_STATUS (AE_OK);
}
/******************************************************************************
*
* 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_low_level_read (32, ticks, &acpi_gbl_FADT->xpm_tmr_blk);
return_ACPI_STATUS (status);
}
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 (0 == acpi_gbl_FADT->tmr_val_ext) {
/* 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, &quotient, NULL);
*time_elapsed = (u32) quotient;
return_ACPI_STATUS (status);
}
EXPORT_SYMBOL(acpi_get_timer_duration);