/*

SDL - Simple DirectMedia Layer

Copyright (C) 1997-2012 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 (GSXB compatible 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 "SDL_mintaudio.h"

#include "SDL_mintaudio_gsxb.h"

/*--- Defines ---*/

#define MINT_AUDIO_DRIVER_NAME "mint_gsxb"

/* Debug print info */

#define DEBUG_NAME "audio:gsxb: "

#if 0

#define DEBUG_PRINT(what) \

{ \

printf what; \

}

#else

#define DEBUG_PRINT(what)

#endif

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

static long cookie_snd, cookie_gsxb;

/*--- 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);

static void Mint_SwapBuffers(Uint8 *nextbuf, int nextsize);

/* GSXB callbacks */

static void Mint_GsxbInterrupt(void);

static void Mint_GsxbNullInterrupt(void);

/*--- 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 _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 GSXB present ? */

cookie_gsxb = (Getcookie(C_GSXB, &cookie_gsxb) == C_FOUND);

/* Is it GSXB ? */

if (((cookie_snd & SND_GSXB)==0) || (cookie_gsxb==0)) {

DEBUG_PRINT((DEBUG_NAME "no GSXB audio\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 "GSXB 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_GSXB_bootstrap = {

MINT_AUDIO_DRIVER_NAME, "MiNT GSXB 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 */

if (NSetinterrupt(2, SI_NONE, Mint_GsxbNullInterrupt)<0) {

DEBUG_PRINT((DEBUG_NAME "NSetinterrupt() failed in close\n"));

}

SDL_MintAudio_FreeBuffers();

/* Unlock sound system */

Unlocksnd();

}

static int Mint_CheckAudio(_THIS, SDL_AudioSpec *spec)

{

long snd_format = 0;

int i, /*resolution,*/ format_signed, format_bigendian;

Uint16 test_format = SDL_FirstAudioFormat(spec->format);

int valid_datatype = 0;

/*resolution = spec->format & 0x00ff;*/

format_signed = ((spec->format & 0x8000)!=0);

format_bigendian = ((spec->format & 0x1000)!=0);

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));

if (spec->channels > 2) {

spec->channels = 2; /* no more than stereo! */

}

while ((!valid_datatype) && (test_format)) {

/* Check formats available */

snd_format = Sndstatus(SND_QUERYFORMATS);

spec->format = test_format;

/*resolution = spec->format & 0xff;*/

format_signed = (spec->format & (1<<15));

format_bigendian = (spec->format & (1<<12));

switch (test_format) {

case AUDIO_U8:

case AUDIO_S8:

if (snd_format & SND_FORMAT8) {

valid_datatype = 1;

snd_format = Sndstatus(SND_QUERY8BIT);

}

break;

case AUDIO_U16LSB:

case AUDIO_S16LSB:

case AUDIO_U16MSB:

case AUDIO_S16MSB:

if (snd_format & SND_FORMAT16) {

valid_datatype = 1;

snd_format = Sndstatus(SND_QUERY16BIT);

}

break;

default:

test_format = SDL_NextAudioFormat();

break;

}

}

if (!valid_datatype) {

SDL_SetError("Unsupported audio format");

return (-1);

}

/* Check signed/unsigned format */

if (format_signed) {

if (snd_format & SND_FORMATSIGNED) {

/* Ok */

} else if (snd_format & SND_FORMATUNSIGNED) {

/* Give unsigned format */

spec->format = spec->format & (~0x8000);

}

} else {

if (snd_format & SND_FORMATUNSIGNED) {

/* Ok */

} else if (snd_format & SND_FORMATSIGNED) {

/* Give signed format */

spec->format |= 0x8000;

}

}

if (format_bigendian) {

if (snd_format & SND_FORMATBIGENDIAN) {

/* Ok */

} else if (snd_format & SND_FORMATLITTLEENDIAN) {

/* Give little endian format */

spec->format = spec->format & (~0x1000);

}

} else {

if (snd_format & SND_FORMATLITTLEENDIAN) {

/* Ok */

} else if (snd_format & SND_FORMATBIGENDIAN) {

/* Give big endian format */

spec->format |= 0x1000;

}

}

/* Calculate and select the closest frequency */

MINTAUDIO_freqcount=0;

for (i=1;i<4;i++) {

SDL_MintAudio_AddFrequency(this,

MASTERCLOCK_44K/(MASTERPREDIV_MILAN*(1<<i)), MASTERCLOCK_44K,

(1<<i)-1, -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)

{

int channels_mode, prediv;

/* Stop currently playing sound */

Buffoper(0);

/* Set replay tracks */

Settracks(0,0);

Setmontracks(0);

/* Select replay format */

switch (spec->format & 0xff) {

case 8:

if (spec->channels==2) {

channels_mode=STEREO8;

} else {

channels_mode=MONO8;

}

break;

case 16:

if (spec->channels==2) {

channels_mode=STEREO16;

} else {

channels_mode=MONO16;

}

break;

default:

channels_mode=STEREO16;

break;

}

if (Setmode(channels_mode)<0) {

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

}

prediv = MINTAUDIO_frequencies[MINTAUDIO_numfreq].predivisor;

Devconnect(DMAPLAY, DAC, CLKEXT, prediv, 1);

/* Set buffer */

Mint_SwapBuffers(MINTAUDIO_audiobuf[0], MINTAUDIO_audiosize);

/* Install interrupt */

if (NSetinterrupt(2, SI_PLAY, Mint_GsxbInterrupt)<0) {

DEBUG_PRINT((DEBUG_NAME "NSetinterrupt() 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;

}

if (!SDL_MintAudio_InitBuffers(spec)) {

return -1;

}

/* Setup audio hardware */

MINTAUDIO_swapbuf = Mint_SwapBuffers;

Mint_InitAudio(this, spec);

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

}

static void Mint_SwapBuffers(Uint8 *nextbuf, int nextsize)

{

unsigned long buffer = (unsigned long) nextbuf;

Setbuffer(0, buffer, buffer + nextsize);

}

static void Mint_GsxbInterrupt(void)

{

++SDL_MintAudio_num_its;

}

static void Mint_GsxbNullInterrupt(void)

{

}