/*

    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 (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 "../../video/ataricommon/SDL_atarimxalloc_c.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 unsigned 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);

/* 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"));

	}

	/* 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)

{

	long snd_format;

	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;

	void *buffer;

	/* 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 */

	buffer = SDL_MintAudio_audiobuf[SDL_MintAudio_numbuf];

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

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

	}

	/* 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;

	}

	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]));

	SDL_MintAudio_CheckFpu();

	/* Setup audio hardware */

	Mint_InitAudio(this, spec);

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

}

static void Mint_GsxbInterrupt(void)

{

	Uint8 *newbuf;

	if (SDL_MintAudio_mutex)

		return;

	SDL_MintAudio_mutex=1;

	SDL_MintAudio_numbuf ^= 1;

	SDL_MintAudio_Callback();

	newbuf = SDL_MintAudio_audiobuf[SDL_MintAudio_numbuf];

	Setbuffer(0, newbuf, newbuf + SDL_MintAudio_audiosize);

	SDL_MintAudio_mutex=0;

}

static void Mint_GsxbNullInterrupt(void)

{

}