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speaker.c

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/*!     \file kernel/speaker.c
 *      \brief System speaker driver.
 *      \author Andrea Righi <drizzt@inwind.it>
 *      \date Last update: 2003-11-02
 *      \note Copyright (&copy;) 2003 Andrea Righi
 */

#include <const.h>

#include <arch/i386.h>

#include <kernel/clock.h>

#include <kernel/speaker.h>

//! \brief Start a sound using the speaker.
//! \param frequency The frequency of the sound.
void sound(uint32_t frequency)
{
        dword x, IF;

        if ((frequency<19) || (frequency>22000)) return;

        x = TIMER_FREQ / frequency;

        IF = GET_IF();
        SET_IF(0);

        outportb(0x61, inportb(0x61) | 3);
        outportb(0x43, 0xB6);
        outportb(0x42, x & 0xFF);
        outportb(0x42, x >> 8);

        SET_IF(IF);
}

//! \brief Turn off the speaker.
void nosound()
{
        dword IF;

        IF = GET_IF();
        SET_IF(0);

        outportb(0x61, inportb(0x61) & 0xFC);

        SET_IF(IF);
}

//! \brief Play a system beep.
void beep()
{
        sound(SYSTEM_BEEP_FREQ);
        delay(SYSTEM_BEEP_TIME);
        nosound();
}

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