50 lines
1.7 KiB
C
50 lines
1.7 KiB
C
/* -*- Mode: C; c-basic-offset: 3 -*-
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*
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* timer.c - Interfaces for the various timers available on PC hardware.
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*
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* This file is part of Metalkit, a simple collection of modules for
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* writing software that runs on the bare metal. Get the latest code
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* at http://svn.navi.cx/misc/trunk/metalkit/
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*
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* Copyright (c) 2008-2009 Micah Dowty
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*
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* Permission is hereby granted, free of charge, to any person
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* obtaining a copy of this software and associated documentation
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* files (the "Software"), to deal in the Software without
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* restriction, including without limitation the rights to use,
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* copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the
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* Software is furnished to do so, subject to the following
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* conditions:
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*
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* The above copyright notice and this permission notice shall be
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* included in all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
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* OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
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* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
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* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
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* OTHER DEALINGS IN THE SOFTWARE.
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*/
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#include "timer.h"
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#include "io.h"
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/*
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* Timer_InitPIT --
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*
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* Set up PIT channel 0 in rate timer mode, with the provided
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* divisor. It will trigger IRQ 0 at (PIT_HZ / divisor) Hz.
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*/
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fastcall void
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Timer_InitPIT(uint16 divisor)
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{
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IO_Out8(0x43, 0x34);
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IO_Out8(0x40, divisor & 0xFF);
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IO_Out8(0x40, divisor >> 8);
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}
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