view src/audio/mint/SDL_mintaudio_dma8.c @ 2938:2929ed239d2a

Adjusted default choice of audio driver. If a driver can definitely see available devices, it is chosen. Otherwise, we'll take the first driver that initializes but saw no devices...this might be because it can't enumerate them, or there really aren't any available. This prevents the dsp driver from hogging control when there are no /dev/dsp* nodes (for example, on a Linux box with ALSA and no OSS emulation).
author Ryan C. Gordon <icculus@icculus.org>
date Thu, 01 Jan 2009 07:54:58 +0000
parents 99210400e8b9
children 1e431c2631ee
line wrap: on
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/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2009 Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Library General Public License for more details.

    You should have received a copy of the GNU Library General Public
    License along with this library; if not, write to the Free
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

    Sam Lantinga
    slouken@libsdl.org
*/
#include "SDL_config.h"

/*
	MiNT audio driver
	using DMA 8bits (hardware access)

	Patrice Mandin
*/

/* Mint includes */
#include <mint/osbind.h>
#include <mint/falcon.h>
#include <mint/cookie.h>

#include "SDL_audio.h"
#include "../SDL_audio_c.h"
#include "../SDL_sysaudio.h"

#include "../../video/ataricommon/SDL_atarimxalloc_c.h"

#include "SDL_mintaudio.h"
#include "SDL_mintaudio_dma8.h"

/*--- Defines ---*/

#define MINT_AUDIO_DRIVER_NAME "mint_dma8"

/* Debug print info */
#define DEBUG_NAME "audio:dma8: "
#if 0
#define DEBUG_PRINT(what) \
	{ \
		printf what; \
	}
#else
#define DEBUG_PRINT(what)
#endif

/*--- Static variables ---*/

static unsigned long cookie_snd, cookie_mch;

static void
MINTDMA8_LockDevice(_THIS)
{
    void *oldpile;

    /* Stop replay */
    oldpile = (void *) Super(0);
    DMAAUDIO_IO.control = 0;
    Super(oldpile);
}

static void
MINTDMA8_UnlockDevice(_THIS)
{
    void *oldpile;

    /* Restart replay */
    oldpile = (void *) Super(0);
    DMAAUDIO_IO.control = 3;
    Super(oldpile);
}

static void
MINTDMA8_CloseDevice(_THIS)
{
    if (this->hidden != NULL) {
        /* Stop replay */
        void *oldpile = (void *) Super(0);

        DMAAUDIO_IO.control = 0;
        Super(oldpile);

        DEBUG_PRINT((DEBUG_NAME "closeaudio: replay stopped\n"));

        /* Disable interrupt */
        Jdisint(MFP_DMASOUND);

        DEBUG_PRINT((DEBUG_NAME "closeaudio: interrupt disabled\n"));

        /* Wait if currently playing sound */
        while (SDL_MintAudio_mutex != 0) {
        }

        DEBUG_PRINT((DEBUG_NAME "closeaudio: no more interrupt running\n"));

        /* Clear buffers */
        if (SDL_MintAudio_audiobuf[0]) {
            Mfree(SDL_MintAudio_audiobuf[0]);
            SDL_MintAudio_audiobuf[0] = SDL_MintAudio_audiobuf[1] = NULL;
        }

        DEBUG_PRINT((DEBUG_NAME "closeaudio: buffers freed\n"));
        SDL_free(this->hidden);
        this->hidden = NULL;
    }
}

static int
MINTDMA8_CheckAudio(_THIS)
{
    int i, masterprediv, sfreq;
    unsigned long masterclock;

    DEBUG_PRINT((DEBUG_NAME "asked: %d bits, ",
                 SDL_AUDIO_BITSIZE(this->spec.format)));
    DEBUG_PRINT(("float=%d, ", SDL_AUDIO_ISFLOAT(this->spec.format)));
    DEBUG_PRINT(("signed=%d, ", SDL_AUDIO_ISSIGNED(this->spec.format)));
    DEBUG_PRINT(("big endian=%d, ",
                 SDL_AUDIO_ISBIGENDIAN(this->spec.format)));
    DEBUG_PRINT(("channels=%d, ", this->spec.channels));
    DEBUG_PRINT(("freq=%d\n", this->spec.freq));

    if (this->spec.channels > 2) {
        this->spec.channels = 2;        /* no more than stereo! */
    }

    /* Check formats available */
    this->spec.format = AUDIO_S8;

    /* Calculate and select the closest frequency */
    sfreq = 0;
    masterclock = MASTERCLOCK_STE;
    masterprediv = MASTERPREDIV_STE;
    switch (cookie_mch >> 16) {
/*
		case MCH_STE:
			masterclock=MASTERCLOCK_STE;
			masterprediv=MASTERPREDIV_STE;
			break;
*/
    case MCH_TT:
        masterclock = MASTERCLOCK_TT;
        masterprediv = MASTERPREDIV_TT;
        break;
    case MCH_F30:
    case MCH_ARANYM:
        masterclock = MASTERCLOCK_FALCON1;
        masterprediv = MASTERPREDIV_FALCON;
        sfreq = 1;
        break;
    }

    MINTAUDIO_freqcount = 0;
    for (i = sfreq; i < 4; i++) {
        SDL_MintAudio_AddFrequency(this,
                                   masterclock / (masterprediv * (1 << i)),
                                   masterclock, i - sfreq, -1);
    }

#if 1
    for (i = 0; i < MINTAUDIO_freqcount; i++) {
        DEBUG_PRINT((DEBUG_NAME "freq %d: %lu Hz, clock %lu, prediv %d\n",
                     i, MINTAUDIO_frequencies[i].frequency,
                     MINTAUDIO_frequencies[i].masterclock,
                     MINTAUDIO_frequencies[i].predivisor));
    }
#endif

    MINTAUDIO_numfreq = SDL_MintAudio_SearchFrequency(this, this->spec.freq);
    this->spec.freq = MINTAUDIO_frequencies[MINTAUDIO_numfreq].frequency;

    DEBUG_PRINT((DEBUG_NAME "obtained: %d bits, ",
                 SDL_AUDIO_BITSIZE(this->spec.format)));
    DEBUG_PRINT(("float=%d, ", SDL_AUDIO_ISFLOAT(this->spec.format)));
    DEBUG_PRINT(("signed=%d, ", SDL_AUDIO_ISSIGNED(this->spec.format)));
    DEBUG_PRINT(("big endian=%d, ",
                 SDL_AUDIO_ISBIGENDIAN(this->spec.format)));
    DEBUG_PRINT(("channels=%d, ", this->spec.channels));
    DEBUG_PRINT(("freq=%d\n", this->spec.freq));

    return 0;
}

static void
MINTDMA8_InitAudio(_THIS)
{
    void *oldpile;
    unsigned long buffer;
    unsigned char mode;

    /* Set replay tracks */
    if (cookie_snd & SND_16BIT) {
        Settracks(0, 0);
        Setmontracks(0);
    }

    oldpile = (void *) Super(0);

    /* Stop currently playing sound */
    DMAAUDIO_IO.control = 0;

    /* Set buffer */
    buffer = (unsigned long) SDL_MintAudio_audiobuf[SDL_MintAudio_numbuf];
    DMAAUDIO_IO.start_high = (buffer >> 16) & 255;
    DMAAUDIO_IO.start_mid = (buffer >> 8) & 255;
    DMAAUDIO_IO.start_low = buffer & 255;

    buffer += SDL_MintAudio_audiosize;
    DMAAUDIO_IO.end_high = (buffer >> 16) & 255;
    DMAAUDIO_IO.end_mid = (buffer >> 8) & 255;
    DMAAUDIO_IO.end_low = buffer & 255;

    mode = 3 - MINTAUDIO_frequencies[MINTAUDIO_numfreq].predivisor;
    if (this->spec.channels == 1) {
        mode |= 1 << 7;
    }
    DMAAUDIO_IO.sound_ctrl = mode;

    /* Set interrupt */
    Jdisint(MFP_DMASOUND);
    Xbtimer(XB_TIMERA, 8, 1, SDL_MintAudio_Dma8Interrupt);
    Jenabint(MFP_DMASOUND);

    if (cookie_snd & SND_16BIT) {
        if (Setinterrupt(SI_TIMERA, SI_PLAY) < 0) {
            DEBUG_PRINT((DEBUG_NAME "Setinterrupt() failed\n"));
        }
    }

    /* Go */
    DMAAUDIO_IO.control = 3;    /* playback + repeat */

    Super(oldpile);
}

static int
MINTDMA8_OpenDevice(_THIS, const char *devname, int iscapture)
{
    SDL_MintAudio_device = this;

    /* Check audio capabilities */
    if (MINTDMA8_CheckAudio(this) == -1) {
        return 0;
    }

    /* Initialize all variables that we clean on shutdown */
    this->hidden = (struct SDL_PrivateAudioData *)
        SDL_malloc((sizeof *this->hidden));
    if (this->hidden == NULL) {
        SDL_OutOfMemory();
        return 0;
    }
    SDL_memset(this->hidden, 0, (sizeof *this->hidden));

    SDL_CalculateAudioSpec(&this->spec);

    /* Allocate memory for audio buffers in DMA-able RAM */
    DEBUG_PRINT((DEBUG_NAME "buffer size=%d\n", this->spec.size));

    SDL_MintAudio_audiobuf[0] =
        Atari_SysMalloc(this->spec.size * 2, MX_STRAM);
    if (SDL_MintAudio_audiobuf[0] == NULL) {
        SDL_free(this->hidden);
        this->hidden = NULL;
        SDL_OutOfMemory();
        return 0;
    }
    SDL_MintAudio_audiobuf[1] = SDL_MintAudio_audiobuf[0] + this->spec.size;
    SDL_MintAudio_numbuf = 0;
    SDL_memset(SDL_MintAudio_audiobuf[0], this->spec.silence,
               this->spec.size * 2);
    SDL_MintAudio_audiosize = this->spec.size;
    SDL_MintAudio_mutex = 0;

    DEBUG_PRINT((DEBUG_NAME "buffer 0 at 0x%08x\n",
                 SDL_MintAudio_audiobuf[0]));
    DEBUG_PRINT((DEBUG_NAME "buffer 1 at 0x%08x\n",
                 SDL_MintAudio_audiobuf[1]));

    SDL_MintAudio_CheckFpu();

    /* Setup audio hardware */
    MINTDMA8_InitAudio(this);

    return 1;                   /* good to go. */
}

static int
MINTDMA8_Init(SDL_AudioDriverImpl * impl)
{
    /* Cookie _MCH present ? if not, assume ST machine */
    if (Getcookie(C__MCH, &cookie_mch) == C_NOTFOUND) {
        cookie_mch = MCH_ST;
    }

    /* Cookie _SND present ? if not, assume ST machine */
    if (Getcookie(C__SND, &cookie_snd) == C_NOTFOUND) {
        cookie_snd = SND_PSG;
    }

    /* Check if we have 8 bits audio */
    if ((cookie_snd & SND_8BIT) == 0) {
        SDL_SetError(DEBUG_NAME "no 8 bits sound");
        return 0;
    }

    /* Check if audio is lockable */
    if (cookie_snd & SND_16BIT) {
        if (Locksnd() != 1) {
            SDL_SetError(DEBUG_NAME "audio locked by other application");
            return 0;
        }

        Unlocksnd();
    }

    DEBUG_PRINT((DEBUG_NAME "8 bits audio available!\n"));

    /* Set the function pointers */
    impl->OpenDevice = MINTDMA8_OpenDevice;
    impl->CloseDevice = MINTDMA8_CloseDevice;
    impl->LockDevice = MINTDMA8_LockDevice;
    impl->UnlockDevice = MINTDMA8_UnlockDevice;
    impl->OnlyHasDefaultOutputDevice = 1;
    impl->ProvidesOwnCallbackThread = 1;
    impl->SkipMixerLock = 1;

    return 2;  /* 2 == definitely has an audio device. */
}

AudioBootStrap MINTAUDIO_DMA8_bootstrap = {
    MINT_AUDIO_DRIVER_NAME, "MiNT DMA 8 bits audio driver", MINTDMA8_Init, 0
};

/* vi: set ts=4 sw=4 expandtab: */