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CLK/Storage/Disk/Controller/DiskController.cpp

116 lines
3.1 KiB
C++

//
// DiskController.cpp
// Clock Signal
//
// Created by Thomas Harte on 14/07/2016.
// Copyright 2016 Thomas Harte. All rights reserved.
//
#include "DiskController.hpp"
#include "../../../NumberTheory/Factors.hpp"
using namespace Storage::Disk;
Controller::Controller(Cycles clock_rate) :
clock_rate_multiplier_(128000000 / clock_rate.as_int()),
clock_rate_(clock_rate.as_int() * clock_rate_multiplier_),
empty_drive_(new Drive(clock_rate.as_int(), 1, 1)) {
// seed this class with a PLL, any PLL, so that it's safe to assume non-nullptr later
Time one(1);
set_expected_bit_length(one);
set_drive(empty_drive_);
}
void Controller::set_component_prefers_clocking(ClockingHint::Source *component, ClockingHint::Preference clocking) {
update_clocking_observer();
}
ClockingHint::Preference Controller::preferred_clocking() {
return (!drive_ || (drive_->preferred_clocking() == ClockingHint::Preference::None)) ? ClockingHint::Preference::None : ClockingHint::Preference::RealTime;
}
void Controller::run_for(const Cycles cycles) {
if(drive_) drive_->run_for(cycles);
}
Drive &Controller::get_drive() {
return *drive_.get();
}
// MARK: - Drive::EventDelegate
void Controller::process_event(const Drive::Event &event) {
switch(event.type) {
case Track::Event::FluxTransition: pll_->add_pulse(); break;
case Track::Event::IndexHole: process_index_hole(); break;
}
}
void Controller::advance(const Cycles cycles) {
if(is_reading_) pll_->run_for(Cycles(cycles.as_int() * clock_rate_multiplier_));
}
void Controller::process_write_completed() {
// Provided for subclasses to override.
}
// MARK: - PLL control and delegate
void Controller::set_expected_bit_length(Time bit_length) {
bit_length_ = bit_length;
bit_length_.simplify();
Time cycles_per_bit = Storage::Time(clock_rate_) * bit_length;
cycles_per_bit.simplify();
// this conversion doesn't need to be exact because there's a lot of variation to be taken
// account of in rotation speed, air turbulence, etc, so a direct conversion will do
int clocks_per_bit = cycles_per_bit.get<int>();
pll_.reset(new DigitalPhaseLockedLoop(clocks_per_bit, 3));
pll_->set_delegate(this);
}
void Controller::digital_phase_locked_loop_output_bit(int value) {
if(is_reading_) process_input_bit(value);
}
void Controller::set_drive(std::shared_ptr<Drive> drive) {
if(drive_ != drive) {
ClockingHint::Preference former_prefernece = preferred_clocking();
// invalidate_track();
if(drive_) {
drive_->set_event_delegate(nullptr);
drive_->set_clocking_hint_observer(nullptr);
}
drive_ = drive;
if(drive_) {
drive_->set_event_delegate(this);
drive_->set_clocking_hint_observer(this);
} else {
drive_ = empty_drive_;
}
if(preferred_clocking() != former_prefernece) {
update_clocking_observer();
}
}
}
void Controller::begin_writing(bool clamp_to_index_hole) {
is_reading_ = false;
get_drive().begin_writing(bit_length_, clamp_to_index_hole);
}
void Controller::end_writing() {
if(!is_reading_) {
is_reading_ = true;
get_drive().end_writing();
}
}
bool Controller::is_reading() {
return is_reading_;
}