mips_common/Timer.cc

/*
 * Copyright (c) 2008-2014, Pedigree Developers
 *
 * Please see the CONTRIB file in the root of the source tree for a full
 * list of contributors.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include "Timer.h"
#include "../core/processor/mips32/InterruptManager.h"
#include "pedigree/kernel/Log.h"
#include "pedigree/kernel/compiler.h"
#include "pedigree/kernel/machine/Machine.h"
#include "pedigree/kernel/processor/InterruptManager.h"
#include "pedigree/kernel/processor/Processor.h"

CountCompareTimer CountCompareTimer::m_Instance;

bool CountCompareTimer::registerHandler(TimerHandler *handler)
{
    if (UNLIKELY(handler == 0 && m_Handler != 0))
        return false;

    m_Handler = handler;
    return true;
}

bool CountCompareTimer::initialise()
{
    // Allocate the Interrupt.
    MIPS32InterruptManager &IntManager =
        static_cast<MIPS32InterruptManager &>(InterruptManager::instance());
    if (IntManager.registerExternalInterruptHandler(7, this) == false)
        return false;

    Processor::setInterrupts(true);

    uint32_t bleh;
    asm volatile("mfc0 %0, $12, 1" : "=r"(bleh));
    NOTICE("Bleh: " << Hex << bleh);

    // Unmask our interrupt vector.
    uint32_t sr;
    asm volatile("mfc0 %0, $12;nop" : "=r"(sr));
    //  NOTICE(Hex << sr);
    //  Processor::breakpoint();
    sr |= (0x80 << 8);  // Enable external interrupt 0 - first two bits are
                        // software ints.
    asm volatile("mtc0 %0, $12;nop" : : "r"(sr));

    // Set up the compare register.
    asm volatile("mtc0 %0, $11; nop" : : "r"(m_Compare));
    // Zero the count register.
    asm volatile("mtc0 $zero, $9; nop");

    return true;
}
void CountCompareTimer::uninitialise()
{
}

CountCompareTimer::CountCompareTimer() : m_Handler(0), m_Compare(0x10000)
{
}

void CountCompareTimer::interrupt(size_t interruptNumber, InterruptState &state)
{
    // Set up the compare register.
    m_Compare += 0x10000;
    asm volatile("mtc0 %0, $11; nop" : : "r"(m_Compare));

    //  Processor::breakpoint();

    // Read count - are we about to overlap?
    uint32_t count;
    asm volatile("mfc0 %0, $9; nop" : "=r"(count));

    if (count > m_Compare)
    {
        asm volatile("mtc0 %0, $9; nop" : : "r"(m_Compare - 0x10000));
    }

    // TODO: Delta is wrong
    if (LIKELY(m_Handler != 0))
        m_Handler->timer(0, state);
}