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/*
* Copyright (c) 2020, Liav A. <liavalb@hotmail.co.il>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/Function.h>
#include <AK/RefCounted.h>
#include <Kernel/Interrupts/IRQHandler.h>
#include <Kernel/Time/TimeManagement.h>
namespace Kernel {
enum class HardwareTimerType {
i8253 = 0x1, /* PIT */
RTC = 0x2, /* Real Time Clock */
HighPrecisionEventTimer = 0x3, /* also known as IA-PC HPET */
LocalAPICTimer = 0x4 /* Local APIC */
};
template<typename InterruptHandlerType>
class HardwareTimer;
class HardwareTimerBase
: public RefCounted<HardwareTimerBase> {
public:
virtual ~HardwareTimerBase() = default;
// We need to create a virtual will_be_destroyed here because we derive
// from RefCounted<HardwareTimerBase> here, which means that RefCounted<>
// will only call will_be_destroyed if we define it here. The derived
// classes then should forward this to e.g. GenericInterruptHandler.
virtual void will_be_destroyed() = 0;
virtual StringView model() const = 0;
virtual HardwareTimerType timer_type() const = 0;
virtual Function<void(const RegisterState&)> set_callback(Function<void(const RegisterState&)>) = 0;
virtual bool is_periodic() const = 0;
virtual bool is_periodic_capable() const = 0;
virtual void set_periodic() = 0;
virtual void set_non_periodic() = 0;
virtual void disable() = 0;
virtual u32 frequency() const = 0;
virtual bool can_query_raw() const { return false; }
virtual u64 current_raw() const { return 0; }
virtual u64 raw_to_ns(u64) const { return 0; }
virtual size_t ticks_per_second() const = 0;
virtual void reset_to_default_ticks_per_second() = 0;
virtual bool try_to_set_frequency(size_t frequency) = 0;
virtual bool is_capable_of_frequency(size_t frequency) const = 0;
virtual size_t calculate_nearest_possible_frequency(size_t frequency) const = 0;
};
template<>
class HardwareTimer<IRQHandler>
: public HardwareTimerBase
, public IRQHandler {
public:
virtual void will_be_destroyed() override
{
IRQHandler::will_be_destroyed();
}
virtual StringView purpose() const override
{
if (TimeManagement::the().is_system_timer(*this))
return "System Timer"sv;
return model();
}
virtual Function<void(const RegisterState&)> set_callback(Function<void(const RegisterState&)> callback) override
{
disable_irq();
auto previous_callback = move(m_callback);
m_callback = move(callback);
enable_irq();
return previous_callback;
}
virtual u32 frequency() const override { return (u32)m_frequency; }
protected:
HardwareTimer(u8 irq_number, Function<void(const RegisterState&)> callback = nullptr)
: IRQHandler(irq_number)
, m_callback(move(callback))
{
}
virtual bool handle_irq(const RegisterState& regs) override
{
// Note: if we have an IRQ on this line, it's going to be the timer always
if (m_callback) {
m_callback(regs);
return true;
}
return false;
}
u64 m_frequency { OPTIMAL_TICKS_PER_SECOND_RATE };
private:
Function<void(const RegisterState&)> m_callback;
};
template<>
class HardwareTimer<GenericInterruptHandler>
: public HardwareTimerBase
, public GenericInterruptHandler {
public:
virtual void will_be_destroyed() override
{
GenericInterruptHandler::will_be_destroyed();
}
virtual StringView purpose() const override
{
return model();
}
virtual Function<void(const RegisterState&)> set_callback(Function<void(const RegisterState&)> callback) override
{
auto previous_callback = move(m_callback);
m_callback = move(callback);
return previous_callback;
}
virtual size_t sharing_devices_count() const override { return 0; }
virtual bool is_shared_handler() const override { return false; }
virtual bool is_sharing_with_others() const override { return false; }
virtual HandlerType type() const override { return HandlerType::IRQHandler; }
virtual StringView controller() const override { return nullptr; }
virtual bool eoi() override;
virtual u32 frequency() const override { return (u32)m_frequency; }
protected:
HardwareTimer(u8 irq_number, Function<void(const RegisterState&)> callback = nullptr)
: GenericInterruptHandler(irq_number)
, m_callback(move(callback))
{
}
virtual bool handle_interrupt(const RegisterState& regs) override
{
// Note: if we have an IRQ on this line, it's going to be the timer always
if (m_callback) {
m_callback(regs);
return true;
}
return false;
}
u64 m_frequency { OPTIMAL_TICKS_PER_SECOND_RATE };
private:
Function<void(const RegisterState&)> m_callback;
};
}
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