/*

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

*/

/*

MiNT audio driver

using XBIOS functions (Falcon)

Patrice Mandin

*/

#include <stdlib.h>

#include <stdio.h>

#include <string.h>

/* Mint includes */

#include <mint/osbind.h>

#include <mint/falcon.h>

#include <mint/cookie.h>

#include "SDL_endian.h"

#include "SDL_audio.h"

#include "SDL_audio_c.h"

#include "SDL_audiomem.h"

#include "SDL_sysaudio.h"

#include "SDL_atarimxalloc_c.h"

#include "SDL_mintaudio.h"

/*--- Defines ---*/

#define MINT_AUDIO_DRIVER_NAME "mint_xbios"

/* Debug print info */

#define DEBUG_NAME "audio:xbios: "

#if 0

#define DEBUG_PRINT(what) \

{ \

printf what; \

}

#else

#define DEBUG_PRINT(what)

#endif

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

static unsigned long cookie_snd;

/*--- 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 = getenv("SDL_AUDIODRIVER");

/* Check if user asked a different audio driver */

if ((envr) && (strcmp(envr, MINT_AUDIO_DRIVER_NAME)!=0)) {

DEBUG_PRINT((DEBUG_NAME "user asked a different audio driver\n"));

return(0);

}

/* 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);

}

/* 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 "XBIOS audio available!\n"));

return(1);

}

static void Audio_DeleteDevice(SDL_AudioDevice *device)

{

free(device->hidden);

free(device);

}

static SDL_AudioDevice *Audio_CreateDevice(int devindex)

{

SDL_AudioDevice *this;

/* Initialize all variables that we clean on shutdown */

this = (SDL_AudioDevice *)malloc(sizeof(SDL_AudioDevice));

if ( this ) {

memset(this, 0, (sizeof *this));

this->hidden = (struct SDL_PrivateAudioData *)

malloc((sizeof *this->hidden));

}

if ( (this == NULL) || (this->hidden == NULL) ) {

SDL_OutOfMemory();

if ( this ) {

free(this);

}

return(0);

}

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_XBIOS_bootstrap = {

MINT_AUDIO_DRIVER_NAME, "MiNT XBIOS 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 */

Buffoper(0);

/* 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;

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));

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 */

}

/* FIXME: check for an external clock */

MINTAUDIO_sfreq=1;

MINTAUDIO_nfreq=12;

for (i=MINTAUDIO_sfreq;i<MINTAUDIO_nfreq;i++) {

MINTAUDIO_hardfreq[i]=MASTERCLOCK_FALCON1/(MASTERPREDIV_FALCON*(i+1));

DEBUG_PRINT((DEBUG_NAME "calc:freq(%d)=%lu\n", i, MINTAUDIO_hardfreq[i]));

}

MINTAUDIO_numfreq=SDL_MintAudio_SearchFrequency(this, 1, spec->freq);

spec->freq=MINTAUDIO_hardfreq[MINTAUDIO_numfreq];

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;

void *buffer;

/* Stop currently playing sound */

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"));

}

/* FIXME: select an external clock */

Devconnect(DMAPLAY, DAC, CLK25M, MINTAUDIO_numfreq, 1);

DEBUG_PRINT((DEBUG_NAME "25.175 MHz clock selected, prescaler %d\n", MINTAUDIO_numfreq));

/* Set buffer */

buffer = SDL_MintAudio_audiobuf[SDL_MintAudio_numbuf];

if (Setbuffer(0, buffer, buffer + spec->size)<0) {

DEBUG_PRINT((DEBUG_NAME "Setbuffer() failed\n"));

}

/* 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;

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 */

}