mirror of
https://github.com/RGBCube/serenity
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108 lines
3.4 KiB
C++
108 lines
3.4 KiB
C++
/*
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* Copyright (c) 2020, Liav A. <liavalb@hotmail.co.il>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are met:
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*
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* 1. Redistributions of source code must retain the above copyright notice, this
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* list of conditions and the following disclaimer.
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*
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* 2. Redistributions in binary form must reproduce the above copyright notice,
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* this list of conditions and the following disclaimer in the documentation
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* and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
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* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <Kernel/Arch/i386/CPU.h>
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#include <Kernel/IO.h>
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#include <Kernel/Interrupts/PIC.h>
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#include <Kernel/Scheduler.h>
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#include <Kernel/Thread.h>
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#include <Kernel/Time/PIT.h>
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#include <Kernel/Time/TimeManagement.h>
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#define IRQ_TIMER 0
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namespace Kernel {
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NonnullRefPtr<PIT> PIT::initialize(Function<void(const RegisterState&)> callback)
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{
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return adopt(*new PIT(move(callback)));
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}
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inline static void reset_countdown(u16 timer_reload)
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{
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IO::out8(PIT_CTL, TIMER0_SELECT | WRITE_WORD | MODE_COUNTDOWN);
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IO::out8(TIMER0_CTL, LSB(timer_reload));
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IO::out8(TIMER0_CTL, MSB(timer_reload));
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}
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PIT::PIT(Function<void(const RegisterState&)> callback)
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: HardwareTimer(IRQ_TIMER, move(callback))
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, m_periodic(true)
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{
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IO::out8(PIT_CTL, TIMER0_SELECT | WRITE_WORD | MODE_SQUARE_WAVE);
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klog() << "PIT: " << OPTIMAL_TICKS_PER_SECOND_RATE << " Hz, square wave (" << String::format("%x", BASE_FREQUENCY / OPTIMAL_TICKS_PER_SECOND_RATE) << ")";
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reset_to_default_ticks_per_second();
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enable_irq();
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}
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size_t PIT::ticks_per_second() const
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{
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return m_frequency;
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}
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void PIT::set_periodic()
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{
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// FIXME: Implement it...
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ASSERT_NOT_REACHED();
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}
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void PIT::set_non_periodic()
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{
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// FIXME: Implement it...
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ASSERT_NOT_REACHED();
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}
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void PIT::reset_to_default_ticks_per_second()
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{
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InterruptDisabler disabler;
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bool success = try_to_set_frequency(OPTIMAL_TICKS_PER_SECOND_RATE);
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ASSERT(success);
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}
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bool PIT::try_to_set_frequency(size_t frequency)
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{
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InterruptDisabler disabler;
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if (!is_capable_of_frequency(frequency))
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return false;
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disable_irq();
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size_t reload_value = BASE_FREQUENCY / frequency;
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IO::out8(TIMER0_CTL, LSB(reload_value));
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IO::out8(TIMER0_CTL, MSB(reload_value));
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m_frequency = frequency;
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enable_irq();
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return true;
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}
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bool PIT::is_capable_of_frequency(size_t frequency) const
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{
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ASSERT(frequency != 0);
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return frequency <= BASE_FREQUENCY;
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}
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size_t PIT::calculate_nearest_possible_frequency(size_t frequency) const
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{
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ASSERT(frequency != 0);
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return frequency;
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}
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}
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