src/audio/mint/SDL_mintaudio_stfa.c

/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2004 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 XBIOS functions (STFA driver)

	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_stfa.h"

/*--- Defines ---*/

#define MINT_AUDIO_DRIVER_NAME "mint_stfa"

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

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

static unsigned long cookie_snd, cookie_mch;
static cookie_stfa_t *cookie_stfa;

static const int freqs[16] = {
    4995, 6269, 7493, 8192,
    9830, 10971, 12538, 14985,
    16384, 19819, 21943, 24576,
    30720, 32336, 43885, 49152
};

/*--- Audio driver functions ---*/

static void Mint_CloseAudio (_THIS);
static int Mint_OpenAudio (_THIS, SDL_AudioSpec * spec);
static void Mint_LockAudio (_THIS);
static void Mint_UnlockAudio (_THIS);

/* To check/init hardware audio */
static int Mint_CheckAudio (_THIS, SDL_AudioSpec * spec);
static void Mint_InitAudio (_THIS, SDL_AudioSpec * spec);

/*--- Audio driver bootstrap functions ---*/

static int
Audio_Available (void)
{
    const char *envr = SDL_getenv ("SDL_AUDIODRIVER");

    /* Check if user asked a different audio driver */
    if ((envr) && (SDL_strcmp (envr, MINT_AUDIO_DRIVER_NAME) != 0)) {
        DEBUG_PRINT ((DEBUG_NAME "user asked a different audio driver\n"));
        return (0);
    }

    /* 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;
    }

    /* Cookie STFA present ? */
    if (Getcookie (C_STFA, (long *) &cookie_stfa) != C_FOUND) {
        DEBUG_PRINT ((DEBUG_NAME "no STFA audio\n"));
        return (0);
    }

    SDL_MintAudio_stfa = cookie_stfa;

    DEBUG_PRINT ((DEBUG_NAME "STFA audio available!\n"));
    return (1);
}

static void
Audio_DeleteDevice (SDL_AudioDevice * device)
{
    SDL_free (device->hidden);
    SDL_free (device);
}

static SDL_AudioDevice *
Audio_CreateDevice (int devindex)
{
    SDL_AudioDevice *this;

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

    /* Set the function pointers */
    this->OpenAudio = Mint_OpenAudio;
    this->CloseAudio = Mint_CloseAudio;
    this->LockAudio = Mint_LockAudio;
    this->UnlockAudio = Mint_UnlockAudio;
    this->free = Audio_DeleteDevice;

    return this;
}

AudioBootStrap MINTAUDIO_STFA_bootstrap = {
    MINT_AUDIO_DRIVER_NAME, "MiNT STFA audio driver",
    Audio_Available, Audio_CreateDevice
};

static void
Mint_LockAudio (_THIS)
{
    void *oldpile;

    /* Stop replay */
    oldpile = (void *) Super (0);
    cookie_stfa->sound_enable = STFA_PLAY_DISABLE;
    Super (oldpile);
}

static void
Mint_UnlockAudio (_THIS)
{
    void *oldpile;

    /* Restart replay */
    oldpile = (void *) Super (0);
    cookie_stfa->sound_enable = STFA_PLAY_ENABLE | STFA_PLAY_REPEAT;
    Super (oldpile);
}

static void
Mint_CloseAudio (_THIS)
{
    void *oldpile;

    /* Stop replay */
    oldpile = (void *) Super (0);
    cookie_stfa->sound_enable = STFA_PLAY_DISABLE;
    Super (oldpile);

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

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

static int
Mint_CheckAudio (_THIS, SDL_AudioSpec * spec)
{
    int i;

    DEBUG_PRINT ((DEBUG_NAME "asked: %d bits, ", spec->format & 0x00ff));
    DEBUG_PRINT (("signed=%d, ", ((spec->format & 0x8000) != 0)));
    DEBUG_PRINT (("big endian=%d, ", ((spec->format & 0x1000) != 0)));
    DEBUG_PRINT (("channels=%d, ", spec->channels));
    DEBUG_PRINT (("freq=%d\n", spec->freq));

    /* Check formats available */
    MINTAUDIO_freqcount = 0;
    for (i = 0; i < 16; i++) {
        SDL_MintAudio_AddFrequency (this, freqs[i], 0, i, -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, spec->freq);
    spec->freq = MINTAUDIO_frequencies[MINTAUDIO_numfreq].frequency;

    DEBUG_PRINT ((DEBUG_NAME "obtained: %d bits, ", spec->format & 0x00ff));
    DEBUG_PRINT (("signed=%d, ", ((spec->format & 0x8000) != 0)));
    DEBUG_PRINT (("big endian=%d, ", ((spec->format & 0x1000) != 0)));
    DEBUG_PRINT (("channels=%d, ", spec->channels));
    DEBUG_PRINT (("freq=%d\n", spec->freq));

    return 0;
}

static void
Mint_InitAudio (_THIS, SDL_AudioSpec * spec)
{
    void *buffer;
    void *oldpile;

    buffer = SDL_MintAudio_audiobuf[SDL_MintAudio_numbuf];

    oldpile = (void *) Super (0);

    /* Stop replay */
    cookie_stfa->sound_enable = STFA_PLAY_DISABLE;

    /* Select replay format */
    cookie_stfa->sound_control =
        MINTAUDIO_frequencies[MINTAUDIO_numfreq].predivisor;
    if ((spec->format & 0xff) == 8) {
        cookie_stfa->sound_control |= STFA_FORMAT_8BIT;
    } else {
        cookie_stfa->sound_control |= STFA_FORMAT_16BIT;
    }
    if (spec->channels == 2) {
        cookie_stfa->sound_control |= STFA_FORMAT_STEREO;
    } else {
        cookie_stfa->sound_control |= STFA_FORMAT_MONO;
    }
    if ((spec->format & 0x8000) != 0) {
        cookie_stfa->sound_control |= STFA_FORMAT_SIGNED;
    } else {
        cookie_stfa->sound_control |= STFA_FORMAT_UNSIGNED;
    }
    if ((spec->format & 0x1000) != 0) {
        cookie_stfa->sound_control |= STFA_FORMAT_BIGENDIAN;
    } else {
        cookie_stfa->sound_control |= STFA_FORMAT_LITENDIAN;
    }

    /* Set buffer */
    cookie_stfa->sound_start = (unsigned long) buffer;
    cookie_stfa->sound_end = (unsigned long) (buffer + spec->size);

    /* Set interrupt */
    cookie_stfa->stfa_it = SDL_MintAudio_StfaInterrupt;

    /* Restart replay */
    cookie_stfa->sound_enable = STFA_PLAY_ENABLE | STFA_PLAY_REPEAT;

    Super (oldpile);

    DEBUG_PRINT ((DEBUG_NAME "hardware initialized\n"));
}

static int
Mint_OpenAudio (_THIS, SDL_AudioSpec * spec)
{
    SDL_MintAudio_device = this;

    /* Check audio capabilities */
    if (Mint_CheckAudio (this, spec) == -1) {
        return -1;
    }

    SDL_CalculateAudioSpec (spec);

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

    SDL_MintAudio_audiobuf[0] = Atari_SysMalloc (spec->size * 2, MX_STRAM);
    if (SDL_MintAudio_audiobuf[0] == NULL) {
        SDL_SetError ("MINT_OpenAudio: Not enough memory for audio buffer");
        return (-1);
    }
    SDL_MintAudio_audiobuf[1] = SDL_MintAudio_audiobuf[0] + spec->size;
    SDL_MintAudio_numbuf = 0;
    SDL_memset (SDL_MintAudio_audiobuf[0], spec->silence, spec->size * 2);
    SDL_MintAudio_audiosize = 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]));

    /* Setup audio hardware */
    Mint_InitAudio (this, spec);

    return (1);                 /* We don't use threaded audio */
}

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