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1 /*
2     SDL - Simple DirectMedia Layer
3     Copyright (C) 1997-2004 Sam Lantinga
4 
5     This library is free software; you can redistribute it and/or
6     modify it under the terms of the GNU Library General Public
7     License as published by the Free Software Foundation; either
8     version 2 of the License, or (at your option) any later version.
9 
10     This library is distributed in the hope that it will be useful,
11     but WITHOUT ANY WARRANTY; without even the implied warranty of
12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13     Library General Public License for more details.
14 
15     You should have received a copy of the GNU Library General Public
16     License along with this library; if not, write to the Free
17     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
18 
19     Sam Lantinga
20     slouken@libsdl.org
21 */
22 #include "SDL_config.h"
23 
24 /*
25 	MiNT audio driver
26 	using XBIOS functions (GSXB compatible driver)
27 
28 	Patrice Mandin
29 */
30 
31 /* Mint includes */
32 #include <mint/osbind.h>
33 #include <mint/falcon.h>
34 #include <mint/cookie.h>
35 
36 #include "SDL_audio.h"
37 #include "../SDL_audio_c.h"
38 #include "../SDL_sysaudio.h"
39 
40 #include "../../video/ataricommon/SDL_atarimxalloc_c.h"
41 
42 #include "SDL_mintaudio.h"
43 #include "SDL_mintaudio_gsxb.h"
44 
45 /*--- Defines ---*/
46 
47 #define MINT_AUDIO_DRIVER_NAME "mint_gsxb"
48 
49 /* Debug print info */
50 #define DEBUG_NAME "audio:gsxb: "
51 #if 0
52 #define DEBUG_PRINT(what) \
53 	{ \
54 		printf what; \
55 	}
56 #else
57 #define DEBUG_PRINT(what)
58 #endif
59 
60 /*--- Static variables ---*/
61 
62 static unsigned long cookie_snd, cookie_gsxb;
63 
64 /*--- Audio driver functions ---*/
65 
66 static void Mint_CloseAudio(_THIS);
67 static int Mint_OpenAudio(_THIS, SDL_AudioSpec *spec);
68 static void Mint_LockAudio(_THIS);
69 static void Mint_UnlockAudio(_THIS);
70 
71 /* To check/init hardware audio */
72 static int Mint_CheckAudio(_THIS, SDL_AudioSpec *spec);
73 static void Mint_InitAudio(_THIS, SDL_AudioSpec *spec);
74 
75 /* GSXB callbacks */
76 static void Mint_GsxbInterrupt(void);
77 static void Mint_GsxbNullInterrupt(void);
78 
79 /*--- Audio driver bootstrap functions ---*/
80 
Audio_Available(void)81 static int Audio_Available(void)
82 {
83 	const char *envr = SDL_getenv("SDL_AUDIODRIVER");
84 
85 	/* Check if user asked a different audio driver */
86 	if ((envr) && (SDL_strcmp(envr, MINT_AUDIO_DRIVER_NAME)!=0)) {
87 		DEBUG_PRINT((DEBUG_NAME "user asked a different audio driver\n"));
88 		return(0);
89 	}
90 
91 	/* Cookie _SND present ? if not, assume ST machine */
92 	if (Getcookie(C__SND, &cookie_snd) == C_NOTFOUND) {
93 		cookie_snd = SND_PSG;
94 	}
95 
96 	/* Check if we have 16 bits audio */
97 	if ((cookie_snd & SND_16BIT)==0) {
98 		DEBUG_PRINT((DEBUG_NAME "no 16 bits sound\n"));
99 	    return(0);
100 	}
101 
102 	/* Cookie GSXB present ? */
103 	cookie_gsxb = (Getcookie(C_GSXB, &cookie_gsxb) == C_FOUND);
104 
105 	/* Is it GSXB ? */
106 	if (((cookie_snd & SND_GSXB)==0) || (cookie_gsxb==0)) {
107 		DEBUG_PRINT((DEBUG_NAME "no GSXB audio\n"));
108 		return(0);
109 	}
110 
111 	/* Check if audio is lockable */
112 	if (Locksnd()!=1) {
113 		DEBUG_PRINT((DEBUG_NAME "audio locked by other application\n"));
114 		return(0);
115 	}
116 
117 	Unlocksnd();
118 
119 	DEBUG_PRINT((DEBUG_NAME "GSXB audio available!\n"));
120 	return(1);
121 }
122 
Audio_DeleteDevice(SDL_AudioDevice * device)123 static void Audio_DeleteDevice(SDL_AudioDevice *device)
124 {
125     SDL_free(device->hidden);
126     SDL_free(device);
127 }
128 
Audio_CreateDevice(int devindex)129 static SDL_AudioDevice *Audio_CreateDevice(int devindex)
130 {
131 	SDL_AudioDevice *this;
132 
133 	/* Initialize all variables that we clean on shutdown */
134 	this = (SDL_AudioDevice *)SDL_malloc(sizeof(SDL_AudioDevice));
135     if ( this ) {
136         SDL_memset(this, 0, (sizeof *this));
137         this->hidden = (struct SDL_PrivateAudioData *)
138                 SDL_malloc((sizeof *this->hidden));
139     }
140     if ( (this == NULL) || (this->hidden == NULL) ) {
141         SDL_OutOfMemory();
142         if ( this ) {
143             SDL_free(this);
144         }
145         return(0);
146     }
147     SDL_memset(this->hidden, 0, (sizeof *this->hidden));
148 
149     /* Set the function pointers */
150     this->OpenAudio   = Mint_OpenAudio;
151     this->CloseAudio  = Mint_CloseAudio;
152     this->LockAudio   = Mint_LockAudio;
153     this->UnlockAudio = Mint_UnlockAudio;
154     this->free        = Audio_DeleteDevice;
155 
156     return this;
157 }
158 
159 AudioBootStrap MINTAUDIO_GSXB_bootstrap = {
160 	MINT_AUDIO_DRIVER_NAME, "MiNT GSXB audio driver",
161 	Audio_Available, Audio_CreateDevice
162 };
163 
Mint_LockAudio(_THIS)164 static void Mint_LockAudio(_THIS)
165 {
166 	/* Stop replay */
167 	Buffoper(0);
168 }
169 
Mint_UnlockAudio(_THIS)170 static void Mint_UnlockAudio(_THIS)
171 {
172 	/* Restart replay */
173 	Buffoper(SB_PLA_ENA|SB_PLA_RPT);
174 }
175 
Mint_CloseAudio(_THIS)176 static void Mint_CloseAudio(_THIS)
177 {
178 	/* Stop replay */
179 	Buffoper(0);
180 
181 	/* Uninstall interrupt */
182 	if (NSetinterrupt(2, SI_NONE, Mint_GsxbNullInterrupt)<0) {
183 		DEBUG_PRINT((DEBUG_NAME "NSetinterrupt() failed in close\n"));
184 	}
185 
186 	/* Wait if currently playing sound */
187 	while (SDL_MintAudio_mutex != 0) {
188 	}
189 
190 	/* Clear buffers */
191 	if (SDL_MintAudio_audiobuf[0]) {
192 		Mfree(SDL_MintAudio_audiobuf[0]);
193 		SDL_MintAudio_audiobuf[0] = SDL_MintAudio_audiobuf[1] = NULL;
194 	}
195 
196 	/* Unlock sound system */
197 	Unlocksnd();
198 }
199 
Mint_CheckAudio(_THIS,SDL_AudioSpec * spec)200 static int Mint_CheckAudio(_THIS, SDL_AudioSpec *spec)
201 {
202 	long snd_format;
203 	int i, resolution, format_signed, format_bigendian;
204     Uint16 test_format = SDL_FirstAudioFormat(spec->format);
205     int valid_datatype = 0;
206 
207 	resolution = spec->format & 0x00ff;
208 	format_signed = ((spec->format & 0x8000)!=0);
209 	format_bigendian = ((spec->format & 0x1000)!=0);
210 
211 	DEBUG_PRINT((DEBUG_NAME "asked: %d bits, ",spec->format & 0x00ff));
212 	DEBUG_PRINT(("signed=%d, ", ((spec->format & 0x8000)!=0)));
213 	DEBUG_PRINT(("big endian=%d, ", ((spec->format & 0x1000)!=0)));
214 	DEBUG_PRINT(("channels=%d, ", spec->channels));
215 	DEBUG_PRINT(("freq=%d\n", spec->freq));
216 
217     if (spec->channels > 2) {
218         spec->channels = 2;  /* no more than stereo! */
219     }
220 
221     while ((!valid_datatype) && (test_format)) {
222         /* Check formats available */
223         snd_format = Sndstatus(SND_QUERYFORMATS);
224         spec->format = test_format;
225         resolution = spec->format & 0xff;
226         format_signed = (spec->format & (1<<15));
227         format_bigendian = (spec->format & (1<<12));
228         switch (test_format) {
229             case AUDIO_U8:
230             case AUDIO_S8:
231                 if (snd_format & SND_FORMAT8) {
232                     valid_datatype = 1;
233                     snd_format = Sndstatus(SND_QUERY8BIT);
234                 }
235                 break;
236 
237             case AUDIO_U16LSB:
238             case AUDIO_S16LSB:
239             case AUDIO_U16MSB:
240             case AUDIO_S16MSB:
241                 if (snd_format & SND_FORMAT16) {
242                     valid_datatype = 1;
243                     snd_format = Sndstatus(SND_QUERY16BIT);
244                 }
245                 break;
246 
247             default:
248                 test_format = SDL_NextAudioFormat();
249                 break;
250         }
251     }
252 
253     if (!valid_datatype) {
254         SDL_SetError("Unsupported audio format");
255         return (-1);
256     }
257 
258 	/* Check signed/unsigned format */
259 	if (format_signed) {
260 		if (snd_format & SND_FORMATSIGNED) {
261 			/* Ok */
262 		} else if (snd_format & SND_FORMATUNSIGNED) {
263 			/* Give unsigned format */
264 			spec->format = spec->format & (~0x8000);
265 		}
266 	} else {
267 		if (snd_format & SND_FORMATUNSIGNED) {
268 			/* Ok */
269 		} else if (snd_format & SND_FORMATSIGNED) {
270 			/* Give signed format */
271 			spec->format |= 0x8000;
272 		}
273 	}
274 
275 	if (format_bigendian) {
276 		if (snd_format & SND_FORMATBIGENDIAN) {
277 			/* Ok */
278 		} else if (snd_format & SND_FORMATLITTLEENDIAN) {
279 			/* Give little endian format */
280 			spec->format = spec->format & (~0x1000);
281 		}
282 	} else {
283 		if (snd_format & SND_FORMATLITTLEENDIAN) {
284 			/* Ok */
285 		} else if (snd_format & SND_FORMATBIGENDIAN) {
286 			/* Give big endian format */
287 			spec->format |= 0x1000;
288 		}
289 	}
290 
291 	/* Calculate and select the closest frequency */
292 	MINTAUDIO_freqcount=0;
293 	for (i=1;i<4;i++) {
294 		SDL_MintAudio_AddFrequency(this,
295 			MASTERCLOCK_44K/(MASTERPREDIV_MILAN*(1<<i)), MASTERCLOCK_44K,
296 			(1<<i)-1, -1);
297 	}
298 
299 #if 1
300 	for (i=0; i<MINTAUDIO_freqcount; i++) {
301 		DEBUG_PRINT((DEBUG_NAME "freq %d: %lu Hz, clock %lu, prediv %d\n",
302 			i, MINTAUDIO_frequencies[i].frequency, MINTAUDIO_frequencies[i].masterclock,
303 			MINTAUDIO_frequencies[i].predivisor
304 		));
305 	}
306 #endif
307 
308 	MINTAUDIO_numfreq=SDL_MintAudio_SearchFrequency(this, spec->freq);
309 	spec->freq=MINTAUDIO_frequencies[MINTAUDIO_numfreq].frequency;
310 
311 	DEBUG_PRINT((DEBUG_NAME "obtained: %d bits, ",spec->format & 0x00ff));
312 	DEBUG_PRINT(("signed=%d, ", ((spec->format & 0x8000)!=0)));
313 	DEBUG_PRINT(("big endian=%d, ", ((spec->format & 0x1000)!=0)));
314 	DEBUG_PRINT(("channels=%d, ", spec->channels));
315 	DEBUG_PRINT(("freq=%d\n", spec->freq));
316 
317 	return 0;
318 }
319 
Mint_InitAudio(_THIS,SDL_AudioSpec * spec)320 static void Mint_InitAudio(_THIS, SDL_AudioSpec *spec)
321 {
322 	int channels_mode, prediv;
323 	void *buffer;
324 
325 	/* Stop currently playing sound */
326 	Buffoper(0);
327 
328 	/* Set replay tracks */
329 	Settracks(0,0);
330 	Setmontracks(0);
331 
332 	/* Select replay format */
333 	switch (spec->format & 0xff) {
334 		case 8:
335 			if (spec->channels==2) {
336 				channels_mode=STEREO8;
337 			} else {
338 				channels_mode=MONO8;
339 			}
340 			break;
341 		case 16:
342 			if (spec->channels==2) {
343 				channels_mode=STEREO16;
344 			} else {
345 				channels_mode=MONO16;
346 			}
347 			break;
348 		default:
349 			channels_mode=STEREO16;
350 			break;
351 	}
352 	if (Setmode(channels_mode)<0) {
353 		DEBUG_PRINT((DEBUG_NAME "Setmode() failed\n"));
354 	}
355 
356 	prediv = MINTAUDIO_frequencies[MINTAUDIO_numfreq].predivisor;
357 	Devconnect(DMAPLAY, DAC, CLKEXT, prediv, 1);
358 
359 	/* Set buffer */
360 	buffer = SDL_MintAudio_audiobuf[SDL_MintAudio_numbuf];
361 	if (Setbuffer(0, buffer, buffer + spec->size)<0) {
362 		DEBUG_PRINT((DEBUG_NAME "Setbuffer() failed\n"));
363 	}
364 
365 	/* Install interrupt */
366 	if (NSetinterrupt(2, SI_PLAY, Mint_GsxbInterrupt)<0) {
367 		DEBUG_PRINT((DEBUG_NAME "NSetinterrupt() failed\n"));
368 	}
369 
370 	/* Go */
371 	Buffoper(SB_PLA_ENA|SB_PLA_RPT);
372 	DEBUG_PRINT((DEBUG_NAME "hardware initialized\n"));
373 }
374 
Mint_OpenAudio(_THIS,SDL_AudioSpec * spec)375 static int Mint_OpenAudio(_THIS, SDL_AudioSpec *spec)
376 {
377 	/* Lock sound system */
378 	if (Locksnd()!=1) {
379    	    SDL_SetError("Mint_OpenAudio: Audio system already in use");
380         return(-1);
381 	}
382 
383 	SDL_MintAudio_device = this;
384 
385 	/* Check audio capabilities */
386 	if (Mint_CheckAudio(this, spec)==-1) {
387 		return -1;
388 	}
389 
390 	SDL_CalculateAudioSpec(spec);
391 
392 	/* Allocate memory for audio buffers in DMA-able RAM */
393 	DEBUG_PRINT((DEBUG_NAME "buffer size=%d\n", spec->size));
394 
395 	SDL_MintAudio_audiobuf[0] = Atari_SysMalloc(spec->size *2, MX_STRAM);
396 	if (SDL_MintAudio_audiobuf[0]==NULL) {
397 		SDL_SetError("MINT_OpenAudio: Not enough memory for audio buffer");
398 		return (-1);
399 	}
400 	SDL_MintAudio_audiobuf[1] = SDL_MintAudio_audiobuf[0] + spec->size ;
401 	SDL_MintAudio_numbuf=0;
402 	SDL_memset(SDL_MintAudio_audiobuf[0], spec->silence, spec->size *2);
403 	SDL_MintAudio_audiosize = spec->size;
404 	SDL_MintAudio_mutex = 0;
405 
406 	DEBUG_PRINT((DEBUG_NAME "buffer 0 at 0x%08x\n", SDL_MintAudio_audiobuf[0]));
407 	DEBUG_PRINT((DEBUG_NAME "buffer 1 at 0x%08x\n", SDL_MintAudio_audiobuf[1]));
408 
409 	SDL_MintAudio_CheckFpu();
410 
411 	/* Setup audio hardware */
412 	Mint_InitAudio(this, spec);
413 
414     return(1);	/* We don't use threaded audio */
415 }
416 
Mint_GsxbInterrupt(void)417 static void Mint_GsxbInterrupt(void)
418 {
419 	Uint8 *newbuf;
420 
421 	if (SDL_MintAudio_mutex)
422 		return;
423 
424 	SDL_MintAudio_mutex=1;
425 
426 	SDL_MintAudio_numbuf ^= 1;
427 	SDL_MintAudio_Callback();
428 	newbuf = SDL_MintAudio_audiobuf[SDL_MintAudio_numbuf];
429 	Setbuffer(0, newbuf, newbuf + SDL_MintAudio_audiosize);
430 
431 	SDL_MintAudio_mutex=0;
432 }
433 
Mint_GsxbNullInterrupt(void)434 static void Mint_GsxbNullInterrupt(void)
435 {
436 }
437