src/audio/mint/SDL_mintaudio_mcsn.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 (MacSound compatible driver)

	Patrice Mandin
*/

#include <support.h>

/* 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_mcsn.h"

/*--- Defines ---*/

#define MINT_AUDIO_DRIVER_NAME "mint_mcsn"

/* Debug print info */
#define DEBUG_NAME "audio:mcsn: "
#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_mcsn_t *cookie_mcsn;

/*--- 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)
{
    unsigned long dummy;
    const char *envr = SDL_getenv ("SDL_AUDIODRIVER");

    SDL_MintAudio_mint_present = (Getcookie (C_MiNT, &dummy) == C_FOUND);

    /* We can't use XBIOS in interrupt with Magic, don't know about thread */
    if (Getcookie (C_MagX, &dummy) == C_FOUND) {
        return (0);
    }

    /* 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;
    }

    /* Check if we have 16 bits audio */
    if ((cookie_snd & SND_16BIT) == 0) {
        DEBUG_PRINT ((DEBUG_NAME "no 16 bits sound\n"));
        return (0);
    }

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

    /* Check if interrupt at end of replay */
    if (cookie_mcsn->pint == 0) {
        DEBUG_PRINT ((DEBUG_NAME "no interrupt at end of replay\n"));
        return (0);
    }

    /* Check if audio is lockable */
    if (Locksnd () != 1) {
        DEBUG_PRINT ((DEBUG_NAME "audio locked by other application\n"));
        return (0);
    }

    Unlocksnd ();

    DEBUG_PRINT ((DEBUG_NAME "MCSN 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_MCSN_bootstrap = {
    MINT_AUDIO_DRIVER_NAME, "MiNT MCSN audio driver",
    Audio_Available, Audio_CreateDevice
};

static void
Mint_LockAudio (_THIS)
{
    /* Stop replay */
    Buffoper (0);
}

static void
Mint_UnlockAudio (_THIS)
{
    /* Restart replay */
    Buffoper (SB_PLA_ENA | SB_PLA_RPT);
}

static void
Mint_CloseAudio (_THIS)
{
    /* Stop replay */
    SDL_MintAudio_WaitThread ();
    Buffoper (0);

    if (!SDL_MintAudio_mint_present) {
        /* Uninstall interrupt */
        Jdisint (MFP_DMASOUND);
    }

    /* 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;
    }

    /* Unlock sound system */
    Unlocksnd ();
}

static int
Mint_CheckAudio (_THIS, SDL_AudioSpec * spec)
{
    int i;
    unsigned long masterclock, masterprediv;

    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;
    switch (cookie_mcsn->play) {
    case MCSN_ST:
        spec->channels = 1;
        spec->format = 8;       /* FIXME: is it signed or unsigned ? */
        SDL_MintAudio_AddFrequency (this, 12500, 0, 0, -1);
        break;
    case MCSN_TT:              /* Also STE, Mega STE */
        spec->format = AUDIO_S8;
        masterclock = MASTERCLOCK_STE;
        masterprediv = MASTERPREDIV_STE;
        if ((cookie_mch >> 16) == MCH_TT) {
            masterclock = MASTERCLOCK_TT;
            masterprediv = MASTERPREDIV_TT;
        }
        for (i = 0; i < 4; i++) {
            SDL_MintAudio_AddFrequency (this,
                                        masterclock / (masterprediv *
                                                       (1 << i)),
                                        masterclock, 3 - i, -1);
        }
        break;
    case MCSN_FALCON:          /* Also Mac */
        for (i = 1; i < 12; i++) {
            /* Remove unusable Falcon codec predivisors */
            if ((i == 6) || (i == 8) || (i == 10)) {
                continue;
            }
            SDL_MintAudio_AddFrequency (this,
                                        MASTERCLOCK_FALCON1 /
                                        (MASTERPREDIV_FALCON * (i + 1)),
                                        CLK25M, i + 1, -1);
        }
        if (cookie_mcsn->res1 != 0) {
            for (i = 1; i < 4; i++) {
                SDL_MintAudio_AddFrequency (this,
                                            (cookie_mcsn->res1) /
                                            (MASTERPREDIV_FALCON *
                                             (1 << i)), CLKEXT,
                                            (1 << i) - 1, -1);
            }
        }
        spec->format |= 0x8000; /* Audio is always signed */
        if ((spec->format & 0x00ff) == 16) {
            spec->format |= 0x1000;     /* Audio is always big endian */
            spec->channels = 2; /* 16 bits always stereo */
        }
        break;
    }

#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)
{
    int channels_mode, prediv, dmaclock;
    void *buffer;

    /* Stop currently playing sound */
    SDL_MintAudio_quit_thread = SDL_FALSE;
    SDL_MintAudio_thread_finished = SDL_TRUE;
    SDL_MintAudio_WaitThread ();
    Buffoper (0);

    /* Set replay tracks */
    Settracks (0, 0);
    Setmontracks (0);

    /* Select replay format */
    channels_mode = STEREO16;
    switch (spec->format & 0xff) {
    case 8:
        if (spec->channels == 2) {
            channels_mode = STEREO8;
        } else {
            channels_mode = MONO8;
        }
        break;
    }
    if (Setmode (channels_mode) < 0) {
        DEBUG_PRINT ((DEBUG_NAME "Setmode() failed\n"));
    }

    dmaclock = MINTAUDIO_frequencies[MINTAUDIO_numfreq].masterclock;
    prediv = MINTAUDIO_frequencies[MINTAUDIO_numfreq].predivisor;
    switch (cookie_mcsn->play) {
    case MCSN_TT:
        Devconnect (DMAPLAY, DAC, CLK25M, CLKOLD, 1);
        Soundcmd (SETPRESCALE, prediv);
        DEBUG_PRINT ((DEBUG_NAME "STE/TT prescaler selected\n"));
        break;
    case MCSN_FALCON:
        Devconnect (DMAPLAY, DAC, dmaclock, prediv, 1);
        DEBUG_PRINT ((DEBUG_NAME "Falcon prescaler selected\n"));
        break;
    }

    /* Set buffer */
    buffer = SDL_MintAudio_audiobuf[SDL_MintAudio_numbuf];
    if (Setbuffer (0, buffer, buffer + spec->size) < 0) {
        DEBUG_PRINT ((DEBUG_NAME "Setbuffer() failed\n"));
    }

    if (SDL_MintAudio_mint_present) {
        SDL_MintAudio_thread_pid = tfork (SDL_MintAudio_Thread, 0);
    } else {
        /* Install interrupt */
        Jdisint (MFP_DMASOUND);
        Xbtimer (XB_TIMERA, 8, 1, SDL_MintAudio_XbiosInterrupt);
        Jenabint (MFP_DMASOUND);

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

    /* Go */
    Buffoper (SB_PLA_ENA | SB_PLA_RPT);
    DEBUG_PRINT ((DEBUG_NAME "hardware initialized\n"));
}

static int
Mint_OpenAudio (_THIS, SDL_AudioSpec * spec)
{
    /* Lock sound system */
    if (Locksnd () != 1) {
        SDL_SetError ("Mint_OpenAudio: Audio system already in use");
        return (-1);
    }

    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 SDL threaded audio */
}

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