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/*
* High-resolution timing routines (PIT reprogramming)
*
* This file is part of the Mateusz' DOS Routines (MDR): http://mdr.osdn.io
* Published under the terms of the MIT License, as stated below.
*
* Copyright (C) 2014-2022 Mateusz Viste
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to
* deal in the Software without restriction, including without limitation the
* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
#ifndef MDR_TIMER_H
#define MDR_TIMER_H
/* reset the timer value, this can be used by the application to make sure
* no timer wrap occurs during critical parts of the code flow */
void timer_reset(void);
/* This routine will stop the fast clock if it is going. It has void return
* value so that it can be an exit procedure. */
void timer_stop(void);
/* This routine will start the fast clock rate by installing the
* handle_clock routine as the interrupt service routine for the clock
* interrupt and then setting the interrupt rate up to its higher speed
* by programming the 8253 timer chip.
* This routine does nothing if the clock rate is already set to
* its higher rate, but then it returns -1 to indicate the error. */
void timer_init(void);
/* This routine will return the present value of the time, which is
* read from the nowtime structure. Interrupts are disabled during this
* time to prevent the clock from changing while it is being read. */
void timer_read(unsigned long *res);
#endif