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 * Copyright 2005 Develer S.r.l. (http://www.develer.com/)
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 *
 *
 * \author Bernie Innocenti <bernie@codewiz.org>
 *
 * \brief Low-level timer module for Qt emulator (implementation).
 */
#include <cfg/compiler.h> /* hptime.t */

// Qt headers
#include <QtCore/QDateTime>
#include <QtCore/QTimer>

#if CONFIG_KERN_IRQ
#include <kern/irq.h>
#endif


// The user interrupt server routine
void timer_isr(void);


/**
 * Singleton class for Qt-based hardware timer emulation.
 */
class EmulTimer : public QObject
{
private:
	Q_OBJECT;

	/// System timer (counts ms since application startup)
	QTime system_time;

	/// The 1ms "hardware" tick counter.
	QTimer timer;

	/**
	 * We deliberately don't use RAII because the real hardware
	 * we're simulating needs to be initialized manually.
	 */
	bool initialized;

	/// Private ctor (singleton)
	EmulTimer() : initialized(false) { }

public:
	/// Return singleton instance
	static EmulTimer &instance()
	{
		static EmulTimer et;
		return et;
	}

	/// Start timer emulator.
	void init()
	{
		// Timer initialized twice?
		ASSERT(!initialized);

		// Record initial time
		system_time.start();

		#if CONFIG_KERN_IRQ
			irq_register(SIGALRM, timer_isr);
		#endif

		// Activate timer interrupt
		connect(&timer, SIGNAL(timeout()), SLOT(timerInterrupt()));
		timer.start(1000 / TIMER_TICKS_PER_SEC);

		initialized = true;
	}

	void cleanup()
	{
		// Timer cleaned twice?
		ASSERT(initialized);

		timer.stop();
		timer.disconnect();

		initialized = false;
	}

	/// Return current time in high-precision format.
	hptime_t hpread()
	{
		ASSERT(initialized);
		return system_time.elapsed();
	}

public slots:
	void timerInterrupt(void)
	{
		// Just call user interrupt server, timer restarts automatically.
		#if CONFIG_KERN_IRQ
			irq_entry(SIGALRM);
		#else
			timer_isr();
		#endif
	}

};

#include "timer_qt_moc.cpp"


/// HW dependent timer initialization.
static void timer_hw_init(void)
{
	EmulTimer::instance().init();
}

static void timer_hw_cleanup(void)
{
	EmulTimer::instance().cleanup();
}

INLINE hptime_t timer_hw_hpread(void)
{
	return EmulTimer::instance().hpread();
}

/** Not needed, timer IRQ handler called only for timer source */
#define timer_hw_triggered() (true)