1 /*
2  *  linux/sound/oss/dmasound/dmasound_core.c
3  *
4  *
5  *  OSS/Free compatible Atari TT/Falcon and Amiga DMA sound driver for
6  *  Linux/m68k
7  *  Extended to support Power Macintosh for Linux/ppc by Paul Mackerras
8  *
9  *  (c) 1995 by Michael Schlueter & Michael Marte
10  *
11  *  Michael Schlueter (michael@duck.syd.de) did the basic structure of the VFS
12  *  interface and the u-law to signed byte conversion.
13  *
14  *  Michael Marte (marte@informatik.uni-muenchen.de) did the sound queue,
15  *  /dev/mixer, /dev/sndstat and complemented the VFS interface. He would like
16  *  to thank:
17  *    - Michael Schlueter for initial ideas and documentation on the MFP and
18  *	the DMA sound hardware.
19  *    - Therapy? for their CD 'Troublegum' which really made me rock.
20  *
21  *  /dev/sndstat is based on code by Hannu Savolainen, the author of the
22  *  VoxWare family of drivers.
23  *
24  *  This file is subject to the terms and conditions of the GNU General Public
25  *  License.  See the file COPYING in the main directory of this archive
26  *  for more details.
27  *
28  *  History:
29  *
30  *	1995/8/25	First release
31  *
32  *	1995/9/02	Roman Hodek:
33  *			  - Fixed atari_stram_alloc() call, the timer
34  *			    programming and several race conditions
35  *	1995/9/14	Roman Hodek:
36  *			  - After some discussion with Michael Schlueter,
37  *			    revised the interrupt disabling
38  *			  - Slightly speeded up U8->S8 translation by using
39  *			    long operations where possible
40  *			  - Added 4:3 interpolation for /dev/audio
41  *
42  *	1995/9/20	Torsten Scherer:
43  *			  - Fixed a bug in sq_write and changed /dev/audio
44  *			    converting to play at 12517Hz instead of 6258Hz.
45  *
46  *	1995/9/23	Torsten Scherer:
47  *			  - Changed sq_interrupt() and sq_play() to pre-program
48  *			    the DMA for another frame while there's still one
49  *			    running. This allows the IRQ response to be
50  *			    arbitrarily delayed and playing will still continue.
51  *
52  *	1995/10/14	Guenther Kelleter, Torsten Scherer:
53  *			  - Better support for Falcon audio (the Falcon doesn't
54  *			    raise an IRQ at the end of a frame, but at the
55  *			    beginning instead!). uses 'if (codec_dma)' in lots
56  *			    of places to simply switch between Falcon and TT
57  *			    code.
58  *
59  *	1995/11/06	Torsten Scherer:
60  *			  - Started introducing a hardware abstraction scheme
61  *			    (may perhaps also serve for Amigas?)
62  *			  - Can now play samples at almost all frequencies by
63  *			    means of a more generalized expand routine
64  *			  - Takes a good deal of care to cut data only at
65  *			    sample sizes
66  *			  - Buffer size is now a kernel runtime option
67  *			  - Implemented fsync() & several minor improvements
68  *			Guenther Kelleter:
69  *			  - Useful hints and bug fixes
70  *			  - Cross-checked it for Falcons
71  *
72  *	1996/3/9	Geert Uytterhoeven:
73  *			  - Support added for Amiga, A-law, 16-bit little
74  *			    endian.
75  *			  - Unification to drivers/sound/dmasound.c.
76  *
77  *	1996/4/6	Martin Mitchell:
78  *			  - Updated to 1.3 kernel.
79  *
80  *	1996/6/13       Topi Kanerva:
81  *			  - Fixed things that were broken (mainly the amiga
82  *			    14-bit routines)
83  *			  - /dev/sndstat shows now the real hardware frequency
84  *			  - The lowpass filter is disabled by default now
85  *
86  *	1996/9/25	Geert Uytterhoeven:
87  *			  - Modularization
88  *
89  *	1998/6/10	Andreas Schwab:
90  *			  - Converted to use sound_core
91  *
92  *	1999/12/28	Richard Zidlicky:
93  *			  - Added support for Q40
94  *
95  *	2000/2/27	Geert Uytterhoeven:
96  *			  - Clean up and split the code into 4 parts:
97  *			      o dmasound_core: machine-independent code
98  *			      o dmasound_atari: Atari TT and Falcon support
99  *			      o dmasound_awacs: Apple PowerMac support
100  *			      o dmasound_paula: Amiga support
101  *
102  *	2000/3/25	Geert Uytterhoeven:
103  *			  - Integration of dmasound_q40
104  *			  - Small clean ups
105  *
106  *	2001/01/26 [1.0] Iain Sandoe
107  *			  - make /dev/sndstat show revision & edition info.
108  *			  - since dmasound.mach.sq_setup() can fail on pmac
109  *			    its type has been changed to int and the returns
110  *			    are checked.
111  *		   [1.1]  - stop missing translations from being called.
112  *	2001/02/08 [1.2]  - remove unused translation tables & move machine-
113  *			    specific tables to low-level.
114  *			  - return correct info. for SNDCTL_DSP_GETFMTS.
115  *		   [1.3]  - implement SNDCTL_DSP_GETCAPS fully.
116  *		   [1.4]  - make /dev/sndstat text length usage deterministic.
117  *			  - make /dev/sndstat call to low-level
118  *			    dmasound.mach.state_info() pass max space to ll driver.
119  *			  - tidy startup banners and output info.
120  *		   [1.5]  - tidy up a little (removed some unused #defines in
121  *			    dmasound.h)
122  *			  - fix up HAS_RECORD conditionalisation.
123  *			  - add record code in places it is missing...
124  *			  - change buf-sizes to bytes to allow < 1kb for pmac
125  *			    if user param entry is < 256 the value is taken to
126  *			    be in kb > 256 is taken to be in bytes.
127  *			  - make default buff/frag params conditional on
128  *			    machine to allow smaller values for pmac.
129  *			  - made the ioctls, read & write comply with the OSS
130  *			    rules on setting params.
131  *			  - added parsing of _setup() params for record.
132  *	2001/04/04 [1.6]  - fix bug where sample rates higher than maximum were
133  *			    being reported as OK.
134  *			  - fix open() to return -EBUSY as per OSS doc. when
135  *			    audio is in use - this is independent of O_NOBLOCK.
136  *			  - fix bug where SNDCTL_DSP_POST was blocking.
137  */
138 
139  /* Record capability notes 30/01/2001:
140   * At present these observations apply only to pmac LL driver (the only one
141   * that can do record, at present).  However, if other LL drivers for machines
142   * with record are added they may apply.
143   *
144   * The fragment parameters for the record and play channels are separate.
145   * However, if the driver is opened O_RDWR there is no way (in the current OSS
146   * API) to specify their values independently for the record and playback
147   * channels.  Since the only common factor between the input & output is the
148   * sample rate (on pmac) it should be possible to open /dev/dspX O_WRONLY and
149   * /dev/dspY O_RDONLY.  The input & output channels could then have different
150   * characteristics (other than the first that sets sample rate claiming the
151   * right to set it for ever).  As it stands, the format, channels, number of
152   * bits & sample rate are assumed to be common.  In the future perhaps these
153   * should be the responsibility of the LL driver - and then if a card really
154   * does not share items between record & playback they can be specified
155   * separately.
156 */
157 
158 /* Thread-safeness of shared_resources notes: 31/01/2001
159  * If the user opens O_RDWR and then splits record & play between two threads
160  * both of which inherit the fd - and then starts changing things from both
161  * - we will have difficulty telling.
162  *
163  * It's bad application coding - but ...
164  * TODO: think about how to sort this out... without bogging everything down in
165  * semaphores.
166  *
167  * Similarly, the OSS spec says "all changes to parameters must be between
168  * open() and the first read() or write(). - and a bit later on (by
169  * implication) "between SNDCTL_DSP_RESET and the first read() or write() after
170  * it".  If the app is multi-threaded and this rule is broken between threads
171  * we will have trouble spotting it - and the fault will be rather obscure :-(
172  *
173  * We will try and put out at least a kmsg if we see it happen... but I think
174  * it will be quite hard to trap it with an -EXXX return... because we can't
175  * see the fault until after the damage is done.
176 */
177 
178 #include <linux/module.h>
179 #include <linux/slab.h>
180 #include <linux/sound.h>
181 #include <linux/init.h>
182 #include <linux/soundcard.h>
183 #include <linux/poll.h>
184 #include <linux/smp_lock.h>
185 
186 #include <asm/uaccess.h>
187 
188 #include "dmasound.h"
189 
190 #define DMASOUND_CORE_REVISION 1
191 #define DMASOUND_CORE_EDITION 6
192 
193     /*
194      *  Declarations
195      */
196 
197 int dmasound_catchRadius = 0;
198 module_param(dmasound_catchRadius, int, 0);
199 
200 static unsigned int numWriteBufs = DEFAULT_N_BUFFERS;
201 module_param(numWriteBufs, int, 0);
202 static unsigned int writeBufSize = DEFAULT_BUFF_SIZE ;	/* in bytes */
203 module_param(writeBufSize, int, 0);
204 
205 MODULE_LICENSE("GPL");
206 
207 #ifdef MODULE
208 static int sq_unit = -1;
209 static int mixer_unit = -1;
210 static int state_unit = -1;
211 static int irq_installed;
212 #endif /* MODULE */
213 
214 /* software implemented recording volume! */
215 uint software_input_volume = SW_INPUT_VOLUME_SCALE * SW_INPUT_VOLUME_DEFAULT;
216 EXPORT_SYMBOL(software_input_volume);
217 
218 /* control over who can modify resources shared between play/record */
219 static mode_t shared_resource_owner;
220 static int shared_resources_initialised;
221 
222     /*
223      *  Mid level stuff
224      */
225 
226 struct sound_settings dmasound = { .lock = SPIN_LOCK_UNLOCKED };
227 
228 static inline void sound_silence(void)
229 {
230 	dmasound.mach.silence(); /* _MUST_ stop DMA */
231 }
232 
233 static inline int sound_set_format(int format)
234 {
235 	return dmasound.mach.setFormat(format);
236 }
237 
238 
239 static int sound_set_speed(int speed)
240 {
241 	if (speed < 0)
242 		return dmasound.soft.speed;
243 
244 	/* trap out-of-range speed settings.
245 	   at present we allow (arbitrarily) low rates - using soft
246 	   up-conversion - but we can't allow > max because there is
247 	   no soft down-conversion.
248 	*/
249 	if (dmasound.mach.max_dsp_speed &&
250 	   (speed > dmasound.mach.max_dsp_speed))
251 		speed = dmasound.mach.max_dsp_speed ;
252 
253 	dmasound.soft.speed = speed;
254 
255 	if (dmasound.minDev == SND_DEV_DSP)
256 		dmasound.dsp.speed = dmasound.soft.speed;
257 
258 	return dmasound.soft.speed;
259 }
260 
261 static int sound_set_stereo(int stereo)
262 {
263 	if (stereo < 0)
264 		return dmasound.soft.stereo;
265 
266 	stereo = !!stereo;    /* should be 0 or 1 now */
267 
268 	dmasound.soft.stereo = stereo;
269 	if (dmasound.minDev == SND_DEV_DSP)
270 		dmasound.dsp.stereo = stereo;
271 
272 	return stereo;
273 }
274 
275 static ssize_t sound_copy_translate(TRANS *trans, const u_char __user *userPtr,
276 				    size_t userCount, u_char frame[],
277 				    ssize_t *frameUsed, ssize_t frameLeft)
278 {
279 	ssize_t (*ct_func)(const u_char __user *, size_t, u_char *, ssize_t *, ssize_t);
280 
281 	switch (dmasound.soft.format) {
282 	    case AFMT_MU_LAW:
283 		ct_func = trans->ct_ulaw;
284 		break;
285 	    case AFMT_A_LAW:
286 		ct_func = trans->ct_alaw;
287 		break;
288 	    case AFMT_S8:
289 		ct_func = trans->ct_s8;
290 		break;
291 	    case AFMT_U8:
292 		ct_func = trans->ct_u8;
293 		break;
294 	    case AFMT_S16_BE:
295 		ct_func = trans->ct_s16be;
296 		break;
297 	    case AFMT_U16_BE:
298 		ct_func = trans->ct_u16be;
299 		break;
300 	    case AFMT_S16_LE:
301 		ct_func = trans->ct_s16le;
302 		break;
303 	    case AFMT_U16_LE:
304 		ct_func = trans->ct_u16le;
305 		break;
306 	    default:
307 		return 0;
308 	}
309 	/* if the user has requested a non-existent translation don't try
310 	   to call it but just return 0 bytes moved
311 	*/
312 	if (ct_func)
313 		return ct_func(userPtr, userCount, frame, frameUsed, frameLeft);
314 	return 0;
315 }
316 
317     /*
318      *  /dev/mixer abstraction
319      */
320 
321 static struct {
322     int busy;
323     int modify_counter;
324 } mixer;
325 
326 static int mixer_open(struct inode *inode, struct file *file)
327 {
328 	if (!try_module_get(dmasound.mach.owner))
329 		return -ENODEV;
330 	mixer.busy = 1;
331 	return 0;
332 }
333 
334 static int mixer_release(struct inode *inode, struct file *file)
335 {
336 	lock_kernel();
337 	mixer.busy = 0;
338 	module_put(dmasound.mach.owner);
339 	unlock_kernel();
340 	return 0;
341 }
342 static int mixer_ioctl(struct inode *inode, struct file *file, u_int cmd,
343 		       u_long arg)
344 {
345 	if (_SIOC_DIR(cmd) & _SIOC_WRITE)
346 	    mixer.modify_counter++;
347 	switch (cmd) {
348 	    case OSS_GETVERSION:
349 		return IOCTL_OUT(arg, SOUND_VERSION);
350 	    case SOUND_MIXER_INFO:
351 		{
352 		    mixer_info info;
353 		    memset(&info, 0, sizeof(info));
354 		    strlcpy(info.id, dmasound.mach.name2, sizeof(info.id));
355 		    strlcpy(info.name, dmasound.mach.name2, sizeof(info.name));
356 		    info.modify_counter = mixer.modify_counter;
357 		    if (copy_to_user((void __user *)arg, &info, sizeof(info)))
358 			    return -EFAULT;
359 		    return 0;
360 		}
361 	}
362 	if (dmasound.mach.mixer_ioctl)
363 	    return dmasound.mach.mixer_ioctl(cmd, arg);
364 	return -EINVAL;
365 }
366 
367 static const struct file_operations mixer_fops =
368 {
369 	.owner		= THIS_MODULE,
370 	.llseek		= no_llseek,
371 	.ioctl		= mixer_ioctl,
372 	.open		= mixer_open,
373 	.release	= mixer_release,
374 };
375 
376 static void mixer_init(void)
377 {
378 #ifndef MODULE
379 	int mixer_unit;
380 #endif
381 	mixer_unit = register_sound_mixer(&mixer_fops, -1);
382 	if (mixer_unit < 0)
383 		return;
384 
385 	mixer.busy = 0;
386 	dmasound.treble = 0;
387 	dmasound.bass = 0;
388 	if (dmasound.mach.mixer_init)
389 	    dmasound.mach.mixer_init();
390 }
391 
392 
393     /*
394      *  Sound queue stuff, the heart of the driver
395      */
396 
397 struct sound_queue dmasound_write_sq;
398 static void sq_reset_output(void) ;
399 
400 static int sq_allocate_buffers(struct sound_queue *sq, int num, int size)
401 {
402 	int i;
403 
404 	if (sq->buffers)
405 		return 0;
406 	sq->numBufs = num;
407 	sq->bufSize = size;
408 	sq->buffers = kmalloc (num * sizeof(char *), GFP_KERNEL);
409 	if (!sq->buffers)
410 		return -ENOMEM;
411 	for (i = 0; i < num; i++) {
412 		sq->buffers[i] = dmasound.mach.dma_alloc(size, GFP_KERNEL);
413 		if (!sq->buffers[i]) {
414 			while (i--)
415 				dmasound.mach.dma_free(sq->buffers[i], size);
416 			kfree(sq->buffers);
417 			sq->buffers = NULL;
418 			return -ENOMEM;
419 		}
420 	}
421 	return 0;
422 }
423 
424 static void sq_release_buffers(struct sound_queue *sq)
425 {
426 	int i;
427 
428 	if (sq->buffers) {
429 		for (i = 0; i < sq->numBufs; i++)
430 			dmasound.mach.dma_free(sq->buffers[i], sq->bufSize);
431 		kfree(sq->buffers);
432 		sq->buffers = NULL;
433 	}
434 }
435 
436 
437 static int sq_setup(struct sound_queue *sq)
438 {
439 	int (*setup_func)(void) = NULL;
440 	int hard_frame ;
441 
442 	if (sq->locked) { /* are we already set? - and not changeable */
443 #ifdef DEBUG_DMASOUND
444 printk("dmasound_core: tried to sq_setup a locked queue\n") ;
445 #endif
446 		return -EINVAL ;
447 	}
448 	sq->locked = 1 ; /* don't think we have a race prob. here _check_ */
449 
450 	/* make sure that the parameters are set up
451 	   This should have been done already...
452 	*/
453 
454 	dmasound.mach.init();
455 
456 	/* OK.  If the user has set fragment parameters explicitly, then we
457 	   should leave them alone... as long as they are valid.
458 	   Invalid user fragment params can occur if we allow the whole buffer
459 	   to be used when the user requests the fragments sizes (with no soft
460 	   x-lation) and then the user subsequently sets a soft x-lation that
461 	   requires increased internal buffering.
462 
463 	   Othwerwise (if the user did not set them) OSS says that we should
464 	   select frag params on the basis of 0.5 s output & 0.1 s input
465 	   latency. (TODO.  For now we will copy in the defaults.)
466 	*/
467 
468 	if (sq->user_frags <= 0) {
469 		sq->max_count = sq->numBufs ;
470 		sq->max_active = sq->numBufs ;
471 		sq->block_size = sq->bufSize;
472 		/* set up the user info */
473 		sq->user_frags = sq->numBufs ;
474 		sq->user_frag_size = sq->bufSize ;
475 		sq->user_frag_size *=
476 			(dmasound.soft.size * (dmasound.soft.stereo+1) ) ;
477 		sq->user_frag_size /=
478 			(dmasound.hard.size * (dmasound.hard.stereo+1) ) ;
479 	} else {
480 		/* work out requested block size */
481 		sq->block_size = sq->user_frag_size ;
482 		sq->block_size *=
483 			(dmasound.hard.size * (dmasound.hard.stereo+1) ) ;
484 		sq->block_size /=
485 			(dmasound.soft.size * (dmasound.soft.stereo+1) ) ;
486 		/* the user wants to write frag-size chunks */
487 		sq->block_size *= dmasound.hard.speed ;
488 		sq->block_size /= dmasound.soft.speed ;
489 		/* this only works for size values which are powers of 2 */
490 		hard_frame =
491 			(dmasound.hard.size * (dmasound.hard.stereo+1))/8 ;
492 		sq->block_size +=  (hard_frame - 1) ;
493 		sq->block_size &= ~(hard_frame - 1) ; /* make sure we are aligned */
494 		/* let's just check for obvious mistakes */
495 		if ( sq->block_size <= 0 || sq->block_size > sq->bufSize) {
496 #ifdef DEBUG_DMASOUND
497 printk("dmasound_core: invalid frag size (user set %d)\n", sq->user_frag_size) ;
498 #endif
499 			sq->block_size = sq->bufSize ;
500 		}
501 		if ( sq->user_frags <= sq->numBufs ) {
502 			sq->max_count = sq->user_frags ;
503 			/* if user has set max_active - then use it */
504 			sq->max_active = (sq->max_active <= sq->max_count) ?
505 				sq->max_active : sq->max_count ;
506 		} else {
507 #ifdef DEBUG_DMASOUND
508 printk("dmasound_core: invalid frag count (user set %d)\n", sq->user_frags) ;
509 #endif
510 			sq->max_count =
511 			sq->max_active = sq->numBufs ;
512 		}
513 	}
514 	sq->front = sq->count = sq->rear_size = 0;
515 	sq->syncing = 0;
516 	sq->active = 0;
517 
518 	if (sq == &write_sq) {
519 	    sq->rear = -1;
520 	    setup_func = dmasound.mach.write_sq_setup;
521 	}
522 	if (setup_func)
523 	    return setup_func();
524 	return 0 ;
525 }
526 
527 static inline void sq_play(void)
528 {
529 	dmasound.mach.play();
530 }
531 
532 static ssize_t sq_write(struct file *file, const char __user *src, size_t uLeft,
533 			loff_t *ppos)
534 {
535 	ssize_t uWritten = 0;
536 	u_char *dest;
537 	ssize_t uUsed = 0, bUsed, bLeft;
538 	unsigned long flags ;
539 
540 	/* ++TeSche: Is something like this necessary?
541 	 * Hey, that's an honest question! Or does any other part of the
542 	 * filesystem already checks this situation? I really don't know.
543 	 */
544 	if (uLeft == 0)
545 		return 0;
546 
547 	/* implement any changes we have made to the soft/hard params.
548 	   this is not satisfactory really, all we have done up to now is to
549 	   say what we would like - there hasn't been any real checking of capability
550 	*/
551 
552 	if (shared_resources_initialised == 0) {
553 		dmasound.mach.init() ;
554 		shared_resources_initialised = 1 ;
555 	}
556 
557 	/* set up the sq if it is not already done. This may seem a dumb place
558 	   to do it - but it is what OSS requires.  It means that write() can
559 	   return memory allocation errors.  To avoid this possibility use the
560 	   GETBLKSIZE or GETOSPACE ioctls (after you've fiddled with all the
561 	   params you want to change) - these ioctls also force the setup.
562 	*/
563 
564 	if (write_sq.locked == 0) {
565 		if ((uWritten = sq_setup(&write_sq)) < 0) return uWritten ;
566 		uWritten = 0 ;
567 	}
568 
569 /* FIXME: I think that this may be the wrong behaviour when we get strapped
570 	for time and the cpu is close to being (or actually) behind in sending data.
571 	- because we've lost the time that the N samples, already in the buffer,
572 	would have given us to get here with the next lot from the user.
573 */
574 	/* The interrupt doesn't start to play the last, incomplete frame.
575 	 * Thus we can append to it without disabling the interrupts! (Note
576 	 * also that write_sq.rear isn't affected by the interrupt.)
577 	 */
578 
579 	/* as of 1.6 this behaviour changes if SNDCTL_DSP_POST has been issued:
580 	   this will mimic the behaviour of syncing and allow the sq_play() to
581 	   queue a partial fragment.  Since sq_play() may/will be called from
582 	   the IRQ handler - at least on Pmac we have to deal with it.
583 	   The strategy - possibly not optimum - is to kill _POST status if we
584 	   get here.  This seems, at least, reasonable - in the sense that POST
585 	   is supposed to indicate that we might not write before the queue
586 	   is drained - and if we get here in time then it does not apply.
587 	*/
588 
589 	spin_lock_irqsave(&dmasound.lock, flags);
590 	write_sq.syncing &= ~2 ; /* take out POST status */
591 	spin_unlock_irqrestore(&dmasound.lock, flags);
592 
593 	if (write_sq.count > 0 &&
594 	    (bLeft = write_sq.block_size-write_sq.rear_size) > 0) {
595 		dest = write_sq.buffers[write_sq.rear];
596 		bUsed = write_sq.rear_size;
597 		uUsed = sound_copy_translate(dmasound.trans_write, src, uLeft,
598 					     dest, &bUsed, bLeft);
599 		if (uUsed <= 0)
600 			return uUsed;
601 		src += uUsed;
602 		uWritten += uUsed;
603 		uLeft = (uUsed <= uLeft) ? (uLeft - uUsed) : 0 ; /* paranoia */
604 		write_sq.rear_size = bUsed;
605 	}
606 
607 	while (uLeft) {
608 		while (write_sq.count >= write_sq.max_active) {
609 			sq_play();
610 			if (write_sq.open_mode & O_NONBLOCK)
611 				return uWritten > 0 ? uWritten : -EAGAIN;
612 			SLEEP(write_sq.action_queue);
613 			if (signal_pending(current))
614 				return uWritten > 0 ? uWritten : -EINTR;
615 		}
616 
617 		/* Here, we can avoid disabling the interrupt by first
618 		 * copying and translating the data, and then updating
619 		 * the write_sq variables. Until this is done, the interrupt
620 		 * won't see the new frame and we can work on it
621 		 * undisturbed.
622 		 */
623 
624 		dest = write_sq.buffers[(write_sq.rear+1) % write_sq.max_count];
625 		bUsed = 0;
626 		bLeft = write_sq.block_size;
627 		uUsed = sound_copy_translate(dmasound.trans_write, src, uLeft,
628 					     dest, &bUsed, bLeft);
629 		if (uUsed <= 0)
630 			break;
631 		src += uUsed;
632 		uWritten += uUsed;
633 		uLeft = (uUsed <= uLeft) ? (uLeft - uUsed) : 0 ; /* paranoia */
634 		if (bUsed) {
635 			write_sq.rear = (write_sq.rear+1) % write_sq.max_count;
636 			write_sq.rear_size = bUsed;
637 			write_sq.count++;
638 		}
639 	} /* uUsed may have been 0 */
640 
641 	sq_play();
642 
643 	return uUsed < 0? uUsed: uWritten;
644 }
645 
646 static unsigned int sq_poll(struct file *file, struct poll_table_struct *wait)
647 {
648 	unsigned int mask = 0;
649 	int retVal;
650 
651 	if (write_sq.locked == 0) {
652 		if ((retVal = sq_setup(&write_sq)) < 0)
653 			return retVal;
654 		return 0;
655 	}
656 	if (file->f_mode & FMODE_WRITE )
657 		poll_wait(file, &write_sq.action_queue, wait);
658 	if (file->f_mode & FMODE_WRITE)
659 		if (write_sq.count < write_sq.max_active || write_sq.block_size - write_sq.rear_size > 0)
660 			mask |= POLLOUT | POLLWRNORM;
661 	return mask;
662 
663 }
664 
665 static inline void sq_init_waitqueue(struct sound_queue *sq)
666 {
667 	init_waitqueue_head(&sq->action_queue);
668 	init_waitqueue_head(&sq->open_queue);
669 	init_waitqueue_head(&sq->sync_queue);
670 	sq->busy = 0;
671 }
672 
673 #if 0 /* blocking open() */
674 static inline void sq_wake_up(struct sound_queue *sq, struct file *file,
675 			      mode_t mode)
676 {
677 	if (file->f_mode & mode) {
678 		sq->busy = 0; /* CHECK: IS THIS OK??? */
679 		WAKE_UP(sq->open_queue);
680 	}
681 }
682 #endif
683 
684 static int sq_open2(struct sound_queue *sq, struct file *file, mode_t mode,
685 		    int numbufs, int bufsize)
686 {
687 	int rc = 0;
688 
689 	if (file->f_mode & mode) {
690 		if (sq->busy) {
691 #if 0 /* blocking open() */
692 			rc = -EBUSY;
693 			if (file->f_flags & O_NONBLOCK)
694 				return rc;
695 			rc = -EINTR;
696 			while (sq->busy) {
697 				SLEEP(sq->open_queue);
698 				if (signal_pending(current))
699 					return rc;
700 			}
701 			rc = 0;
702 #else
703 			/* OSS manual says we will return EBUSY regardless
704 			   of O_NOBLOCK.
705 			*/
706 			return -EBUSY ;
707 #endif
708 		}
709 		sq->busy = 1; /* Let's play spot-the-race-condition */
710 
711 		/* allocate the default number & size of buffers.
712 		   (i.e. specified in _setup() or as module params)
713 		   can't be changed at the moment - but _could_ be perhaps
714 		   in the setfragments ioctl.
715 		*/
716 		if (( rc = sq_allocate_buffers(sq, numbufs, bufsize))) {
717 #if 0 /* blocking open() */
718 			sq_wake_up(sq, file, mode);
719 #else
720 			sq->busy = 0 ;
721 #endif
722 			return rc;
723 		}
724 
725 		sq->open_mode = file->f_mode;
726 	}
727 	return rc;
728 }
729 
730 #define write_sq_init_waitqueue()	sq_init_waitqueue(&write_sq)
731 #if 0 /* blocking open() */
732 #define write_sq_wake_up(file)		sq_wake_up(&write_sq, file, FMODE_WRITE)
733 #endif
734 #define write_sq_release_buffers()	sq_release_buffers(&write_sq)
735 #define write_sq_open(file)	\
736 	sq_open2(&write_sq, file, FMODE_WRITE, numWriteBufs, writeBufSize )
737 
738 static int sq_open(struct inode *inode, struct file *file)
739 {
740 	int rc;
741 
742 	if (!try_module_get(dmasound.mach.owner))
743 		return -ENODEV;
744 
745 	rc = write_sq_open(file); /* checks the f_mode */
746 	if (rc)
747 		goto out;
748 	if (file->f_mode & FMODE_READ) {
749 		/* TODO: if O_RDWR, release any resources grabbed by write part */
750 		rc = -ENXIO ; /* I think this is what is required by open(2) */
751 		goto out;
752 	}
753 
754 	if (dmasound.mach.sq_open)
755 	    dmasound.mach.sq_open(file->f_mode);
756 
757 	/* CHECK whether this is sensible - in the case that dsp0 could be opened
758 	  O_RDONLY and dsp1 could be opened O_WRONLY
759 	*/
760 
761 	dmasound.minDev = iminor(inode) & 0x0f;
762 
763 	/* OK. - we should make some attempt at consistency. At least the H'ware
764 	   options should be set with a valid mode.  We will make it that the LL
765 	   driver must supply defaults for hard & soft params.
766 	*/
767 
768 	if (shared_resource_owner == 0) {
769 		/* you can make this AFMT_U8/mono/8K if you want to mimic old
770 		   OSS behaviour - while we still have soft translations ;-) */
771 		dmasound.soft = dmasound.mach.default_soft ;
772 		dmasound.dsp = dmasound.mach.default_soft ;
773 		dmasound.hard = dmasound.mach.default_hard ;
774 	}
775 
776 #ifndef DMASOUND_STRICT_OSS_COMPLIANCE
777 	/* none of the current LL drivers can actually do this "native" at the moment
778 	   OSS does not really require us to supply /dev/audio if we can't do it.
779 	*/
780 	if (dmasound.minDev == SND_DEV_AUDIO) {
781 		sound_set_speed(8000);
782 		sound_set_stereo(0);
783 		sound_set_format(AFMT_MU_LAW);
784 	}
785 #endif
786 
787 	return 0;
788  out:
789 	module_put(dmasound.mach.owner);
790 	return rc;
791 }
792 
793 static void sq_reset_output(void)
794 {
795 	sound_silence(); /* this _must_ stop DMA, we might be about to lose the buffers */
796 	write_sq.active = 0;
797 	write_sq.count = 0;
798 	write_sq.rear_size = 0;
799 	/* write_sq.front = (write_sq.rear+1) % write_sq.max_count;*/
800 	write_sq.front = 0 ;
801 	write_sq.rear = -1 ; /* same as for set-up */
802 
803 	/* OK - we can unlock the parameters and fragment settings */
804 	write_sq.locked = 0 ;
805 	write_sq.user_frags = 0 ;
806 	write_sq.user_frag_size = 0 ;
807 }
808 
809 static void sq_reset(void)
810 {
811 	sq_reset_output() ;
812 	/* we could consider resetting the shared_resources_owner here... but I
813 	   think it is probably still rather non-obvious to application writer
814 	*/
815 
816 	/* we release everything else though */
817 	shared_resources_initialised = 0 ;
818 }
819 
820 static int sq_fsync(struct file *filp, struct dentry *dentry)
821 {
822 	int rc = 0;
823 	int timeout = 5;
824 
825 	write_sq.syncing |= 1;
826 	sq_play();	/* there may be an incomplete frame waiting */
827 
828 	while (write_sq.active) {
829 		SLEEP(write_sq.sync_queue);
830 		if (signal_pending(current)) {
831 			/* While waiting for audio output to drain, an
832 			 * interrupt occurred.  Stop audio output immediately
833 			 * and clear the queue. */
834 			sq_reset_output();
835 			rc = -EINTR;
836 			break;
837 		}
838 		if (!--timeout) {
839 			printk(KERN_WARNING "dmasound: Timeout draining output\n");
840 			sq_reset_output();
841 			rc = -EIO;
842 			break;
843 		}
844 	}
845 
846 	/* flag no sync regardless of whether we had a DSP_POST or not */
847 	write_sq.syncing = 0 ;
848 	return rc;
849 }
850 
851 static int sq_release(struct inode *inode, struct file *file)
852 {
853 	int rc = 0;
854 
855 	lock_kernel();
856 
857 	if (file->f_mode & FMODE_WRITE) {
858 		if (write_sq.busy)
859 			rc = sq_fsync(file, file->f_path.dentry);
860 
861 		sq_reset_output() ; /* make sure dma is stopped and all is quiet */
862 		write_sq_release_buffers();
863 		write_sq.busy = 0;
864 	}
865 
866 	if (file->f_mode & shared_resource_owner) { /* it's us that has them */
867 		shared_resource_owner = 0 ;
868 		shared_resources_initialised = 0 ;
869 		dmasound.hard = dmasound.mach.default_hard ;
870 	}
871 
872 	module_put(dmasound.mach.owner);
873 
874 #if 0 /* blocking open() */
875 	/* Wake up a process waiting for the queue being released.
876 	 * Note: There may be several processes waiting for a call
877 	 * to open() returning. */
878 
879 	/* Iain: hmm I don't understand this next comment ... */
880 	/* There is probably a DOS atack here. They change the mode flag. */
881 	/* XXX add check here,*/
882 	read_sq_wake_up(file); /* checks f_mode */
883 	write_sq_wake_up(file); /* checks f_mode */
884 #endif /* blocking open() */
885 
886 	unlock_kernel();
887 
888 	return rc;
889 }
890 
891 /* here we see if we have a right to modify format, channels, size and so on
892    if no-one else has claimed it already then we do...
893 
894    TODO: We might change this to mask O_RDWR such that only one or the other channel
895    is the owner - if we have problems.
896 */
897 
898 static int shared_resources_are_mine(mode_t md)
899 {
900 	if (shared_resource_owner)
901 		return (shared_resource_owner & md ) ;
902 	else {
903 		shared_resource_owner = md ;
904 		return 1 ;
905 	}
906 }
907 
908 /* if either queue is locked we must deny the right to change shared params
909 */
910 
911 static int queues_are_quiescent(void)
912 {
913 	if (write_sq.locked)
914 		return 0 ;
915 	return 1 ;
916 }
917 
918 /* check and set a queue's fragments per user's wishes...
919    we will check against the pre-defined literals and the actual sizes.
920    This is a bit fraught - because soft translations can mess with our
921    buffer requirements *after* this call - OSS says "call setfrags first"
922 */
923 
924 /* It is possible to replace all the -EINVAL returns with an override that
925    just puts the allowable value in.  This may be what many OSS apps require
926 */
927 
928 static int set_queue_frags(struct sound_queue *sq, int bufs, int size)
929 {
930 	if (sq->locked) {
931 #ifdef DEBUG_DMASOUND
932 printk("dmasound_core: tried to set_queue_frags on a locked queue\n") ;
933 #endif
934 		return -EINVAL ;
935 	}
936 
937 	if ((size < MIN_FRAG_SIZE) || (size > MAX_FRAG_SIZE))
938 		return -EINVAL ;
939 	size = (1<<size) ; /* now in bytes */
940 	if (size > sq->bufSize)
941 		return -EINVAL ; /* this might still not work */
942 
943 	if (bufs <= 0)
944 		return -EINVAL ;
945 	if (bufs > sq->numBufs) /* the user is allowed say "don't care" with 0x7fff */
946 		bufs = sq->numBufs ;
947 
948 	/* there is, currently, no way to specify max_active separately
949 	   from max_count.  This could be a LL driver issue - I guess
950 	   if there is a requirement for these values to be different then
951 	  we will have to pass that info. up to this level.
952 	*/
953 	sq->user_frags =
954 	sq->max_active = bufs ;
955 	sq->user_frag_size = size ;
956 
957 	return 0 ;
958 }
959 
960 static int sq_ioctl(struct inode *inode, struct file *file, u_int cmd,
961 		    u_long arg)
962 {
963 	int val, result;
964 	u_long fmt;
965 	int data;
966 	int size, nbufs;
967 	audio_buf_info info;
968 
969 	switch (cmd) {
970 	case SNDCTL_DSP_RESET:
971 		sq_reset();
972 		return 0;
973 		break ;
974 	case SNDCTL_DSP_GETFMTS:
975 		fmt = dmasound.mach.hardware_afmts ; /* this is what OSS says.. */
976 		return IOCTL_OUT(arg, fmt);
977 		break ;
978 	case SNDCTL_DSP_GETBLKSIZE:
979 		/* this should tell the caller about bytes that the app can
980 		   read/write - the app doesn't care about our internal buffers.
981 		   We force sq_setup() here as per OSS 1.1 (which should
982 		   compute the values necessary).
983 		   Since there is no mechanism to specify read/write separately, for
984 		   fds opened O_RDWR, the write_sq values will, arbitrarily, overwrite
985 		   the read_sq ones.
986 		*/
987 		size = 0 ;
988 		if (file->f_mode & FMODE_WRITE) {
989 			if ( !write_sq.locked )
990 				sq_setup(&write_sq) ;
991 			size = write_sq.user_frag_size ;
992 		}
993 		return IOCTL_OUT(arg, size);
994 		break ;
995 	case SNDCTL_DSP_POST:
996 		/* all we are going to do is to tell the LL that any
997 		   partial frags can be queued for output.
998 		   The LL will have to clear this flag when last output
999 		   is queued.
1000 		*/
1001 		write_sq.syncing |= 0x2 ;
1002 		sq_play() ;
1003 		return 0 ;
1004 	case SNDCTL_DSP_SYNC:
1005 		/* This call, effectively, has the same behaviour as SNDCTL_DSP_RESET
1006 		   except that it waits for output to finish before resetting
1007 		   everything - read, however, is killed imediately.
1008 		*/
1009 		result = 0 ;
1010 		if (file->f_mode & FMODE_WRITE) {
1011 			result = sq_fsync(file, file->f_path.dentry);
1012 			sq_reset_output() ;
1013 		}
1014 		/* if we are the shared resource owner then release them */
1015 		if (file->f_mode & shared_resource_owner)
1016 			shared_resources_initialised = 0 ;
1017 		return result ;
1018 		break ;
1019 	case SOUND_PCM_READ_RATE:
1020 		return IOCTL_OUT(arg, dmasound.soft.speed);
1021 	case SNDCTL_DSP_SPEED:
1022 		/* changing this on the fly will have weird effects on the sound.
1023 		   Where there are rate conversions implemented in soft form - it
1024 		   will cause the _ctx_xxx() functions to be substituted.
1025 		   However, there doesn't appear to be any reason to dis-allow it from
1026 		   a driver pov.
1027 		*/
1028 		if (shared_resources_are_mine(file->f_mode)) {
1029 			IOCTL_IN(arg, data);
1030 			data = sound_set_speed(data) ;
1031 			shared_resources_initialised = 0 ;
1032 			return IOCTL_OUT(arg, data);
1033 		} else
1034 			return -EINVAL ;
1035 		break ;
1036 	/* OSS says these next 4 actions are undefined when the device is
1037 	   busy/active - we will just return -EINVAL.
1038 	   To be allowed to change one - (a) you have to own the right
1039 	    (b) the queue(s) must be quiescent
1040 	*/
1041 	case SNDCTL_DSP_STEREO:
1042 		if (shared_resources_are_mine(file->f_mode) &&
1043 		    queues_are_quiescent()) {
1044 			IOCTL_IN(arg, data);
1045 			shared_resources_initialised = 0 ;
1046 			return IOCTL_OUT(arg, sound_set_stereo(data));
1047 		} else
1048 			return -EINVAL ;
1049 		break ;
1050 	case SOUND_PCM_WRITE_CHANNELS:
1051 		if (shared_resources_are_mine(file->f_mode) &&
1052 		    queues_are_quiescent()) {
1053 			IOCTL_IN(arg, data);
1054 			/* the user might ask for 20 channels, we will return 1 or 2 */
1055 			shared_resources_initialised = 0 ;
1056 			return IOCTL_OUT(arg, sound_set_stereo(data-1)+1);
1057 		} else
1058 			return -EINVAL ;
1059 		break ;
1060 	case SNDCTL_DSP_SETFMT:
1061 		if (shared_resources_are_mine(file->f_mode) &&
1062 		    queues_are_quiescent()) {
1063 		    	int format;
1064 			IOCTL_IN(arg, data);
1065 			shared_resources_initialised = 0 ;
1066 			format = sound_set_format(data);
1067 			result = IOCTL_OUT(arg, format);
1068 			if (result < 0)
1069 				return result;
1070 			if (format != data && data != AFMT_QUERY)
1071 				return -EINVAL;
1072 			return 0;
1073 		} else
1074 			return -EINVAL ;
1075 	case SNDCTL_DSP_SUBDIVIDE:
1076 		return -EINVAL ;
1077 	case SNDCTL_DSP_SETFRAGMENT:
1078 		/* we can do this independently for the two queues - with the
1079 		   proviso that for fds opened O_RDWR we cannot separate the
1080 		   actions and both queues will be set per the last call.
1081 		   NOTE: this does *NOT* actually set the queue up - merely
1082 		   registers our intentions.
1083 		*/
1084 		IOCTL_IN(arg, data);
1085 		result = 0 ;
1086 		nbufs = (data >> 16) & 0x7fff ; /* 0x7fff is 'use maximum' */
1087 		size = data & 0xffff;
1088 		if (file->f_mode & FMODE_WRITE) {
1089 			result = set_queue_frags(&write_sq, nbufs, size) ;
1090 			if (result)
1091 				return result ;
1092 		}
1093 		/* NOTE: this return value is irrelevant - OSS specifically says that
1094 		   the value is 'random' and that the user _must_ check the actual
1095 		   frags values using SNDCTL_DSP_GETBLKSIZE or similar */
1096 		return IOCTL_OUT(arg, data);
1097 		break ;
1098 	case SNDCTL_DSP_GETOSPACE:
1099 		/*
1100 		*/
1101 		if (file->f_mode & FMODE_WRITE) {
1102 			if ( !write_sq.locked )
1103 				sq_setup(&write_sq) ;
1104 			info.fragments = write_sq.max_active - write_sq.count;
1105 			info.fragstotal = write_sq.max_active;
1106 			info.fragsize = write_sq.user_frag_size;
1107 			info.bytes = info.fragments * info.fragsize;
1108 			if (copy_to_user((void __user *)arg, &info, sizeof(info)))
1109 				return -EFAULT;
1110 			return 0;
1111 		} else
1112 			return -EINVAL ;
1113 		break ;
1114 	case SNDCTL_DSP_GETCAPS:
1115 		val = dmasound.mach.capabilities & 0xffffff00;
1116 		return IOCTL_OUT(arg,val);
1117 
1118 	default:
1119 		return mixer_ioctl(inode, file, cmd, arg);
1120 	}
1121 	return -EINVAL;
1122 }
1123 
1124 static const struct file_operations sq_fops =
1125 {
1126 	.owner		= THIS_MODULE,
1127 	.llseek		= no_llseek,
1128 	.write		= sq_write,
1129 	.poll		= sq_poll,
1130 	.ioctl		= sq_ioctl,
1131 	.open		= sq_open,
1132 	.release	= sq_release,
1133 };
1134 
1135 static int sq_init(void)
1136 {
1137 	const struct file_operations *fops = &sq_fops;
1138 #ifndef MODULE
1139 	int sq_unit;
1140 #endif
1141 
1142 	sq_unit = register_sound_dsp(fops, -1);
1143 	if (sq_unit < 0) {
1144 		printk(KERN_ERR "dmasound_core: couldn't register fops\n") ;
1145 		return sq_unit ;
1146 	}
1147 
1148 	write_sq_init_waitqueue();
1149 
1150 	/* These parameters will be restored for every clean open()
1151 	 * in the case of multiple open()s (e.g. dsp0 & dsp1) they
1152 	 * will be set so long as the shared resources have no owner.
1153 	 */
1154 
1155 	if (shared_resource_owner == 0) {
1156 		dmasound.soft = dmasound.mach.default_soft ;
1157 		dmasound.hard = dmasound.mach.default_hard ;
1158 		dmasound.dsp = dmasound.mach.default_soft ;
1159 		shared_resources_initialised = 0 ;
1160 	}
1161 	return 0 ;
1162 }
1163 
1164 
1165     /*
1166      *  /dev/sndstat
1167      */
1168 
1169 /* we allow more space for record-enabled because there are extra output lines.
1170    the number here must include the amount we are prepared to give to the low-level
1171    driver.
1172 */
1173 
1174 #define STAT_BUFF_LEN 768
1175 
1176 /* this is how much space we will allow the low-level driver to use
1177    in the stat buffer.  Currently, 2 * (80 character line + <NL>).
1178    We do not police this (it is up to the ll driver to be honest).
1179 */
1180 
1181 #define LOW_LEVEL_STAT_ALLOC 162
1182 
1183 static struct {
1184     int busy;
1185     char buf[STAT_BUFF_LEN];	/* state.buf should not overflow! */
1186     int len, ptr;
1187 } state;
1188 
1189 /* publish this function for use by low-level code, if required */
1190 
1191 char *get_afmt_string(int afmt)
1192 {
1193         switch(afmt) {
1194             case AFMT_MU_LAW:
1195                 return "mu-law";
1196                 break;
1197             case AFMT_A_LAW:
1198                 return "A-law";
1199                 break;
1200             case AFMT_U8:
1201                 return "unsigned 8 bit";
1202                 break;
1203             case AFMT_S8:
1204                 return "signed 8 bit";
1205                 break;
1206             case AFMT_S16_BE:
1207                 return "signed 16 bit BE";
1208                 break;
1209             case AFMT_U16_BE:
1210                 return "unsigned 16 bit BE";
1211                 break;
1212             case AFMT_S16_LE:
1213                 return "signed 16 bit LE";
1214                 break;
1215             case AFMT_U16_LE:
1216                 return "unsigned 16 bit LE";
1217                 break;
1218 	    case 0:
1219 		return "format not set" ;
1220 		break ;
1221             default:
1222                 break ;
1223         }
1224         return "ERROR: Unsupported AFMT_XXXX code" ;
1225 }
1226 
1227 static int state_open(struct inode *inode, struct file *file)
1228 {
1229 	char *buffer = state.buf;
1230 	int len = 0;
1231 
1232 	if (state.busy)
1233 		return -EBUSY;
1234 
1235 	if (!try_module_get(dmasound.mach.owner))
1236 		return -ENODEV;
1237 	state.ptr = 0;
1238 	state.busy = 1;
1239 
1240 	len += sprintf(buffer+len, "%sDMA sound driver rev %03d :\n",
1241 		dmasound.mach.name, (DMASOUND_CORE_REVISION<<4) +
1242 		((dmasound.mach.version>>8) & 0x0f));
1243 	len += sprintf(buffer+len,
1244 		"Core driver edition %02d.%02d : %s driver edition %02d.%02d\n",
1245 		DMASOUND_CORE_REVISION, DMASOUND_CORE_EDITION, dmasound.mach.name2,
1246 		(dmasound.mach.version >> 8), (dmasound.mach.version & 0xff)) ;
1247 
1248 	/* call the low-level module to fill in any stat info. that it has
1249 	   if present.  Maximum buffer usage is specified.
1250 	*/
1251 
1252 	if (dmasound.mach.state_info)
1253 		len += dmasound.mach.state_info(buffer+len,
1254 			(size_t) LOW_LEVEL_STAT_ALLOC) ;
1255 
1256 	/* make usage of the state buffer as deterministic as poss.
1257 	   exceptional conditions could cause overrun - and this is flagged as
1258 	   a kernel error.
1259 	*/
1260 
1261 	/* formats and settings */
1262 
1263 	len += sprintf(buffer+len,"\t\t === Formats & settings ===\n") ;
1264 	len += sprintf(buffer+len,"Parameter %20s%20s\n","soft","hard") ;
1265 	len += sprintf(buffer+len,"Format   :%20s%20s\n",
1266 		get_afmt_string(dmasound.soft.format),
1267 		get_afmt_string(dmasound.hard.format));
1268 
1269 	len += sprintf(buffer+len,"Samp Rate:%14d s/sec%14d s/sec\n",
1270 		       dmasound.soft.speed, dmasound.hard.speed);
1271 
1272 	len += sprintf(buffer+len,"Channels :%20s%20s\n",
1273 		       dmasound.soft.stereo ? "stereo" : "mono",
1274 		       dmasound.hard.stereo ? "stereo" : "mono" );
1275 
1276 	/* sound queue status */
1277 
1278 	len += sprintf(buffer+len,"\t\t === Sound Queue status ===\n");
1279 	len += sprintf(buffer+len,"Allocated:%8s%6s\n","Buffers","Size") ;
1280 	len += sprintf(buffer+len,"%9s:%8d%6d\n",
1281 		"write", write_sq.numBufs, write_sq.bufSize) ;
1282 	len += sprintf(buffer+len,
1283 		"Current  : MaxFrg FragSiz MaxAct Frnt Rear "
1284 		"Cnt RrSize A B S L  xruns\n") ;
1285 	len += sprintf(buffer+len,"%9s:%7d%8d%7d%5d%5d%4d%7d%2d%2d%2d%2d%7d\n",
1286 		"write", write_sq.max_count, write_sq.block_size,
1287 		write_sq.max_active, write_sq.front, write_sq.rear,
1288 		write_sq.count, write_sq.rear_size, write_sq.active,
1289 		write_sq.busy, write_sq.syncing, write_sq.locked, write_sq.xruns) ;
1290 #ifdef DEBUG_DMASOUND
1291 printk("dmasound: stat buffer used %d bytes\n", len) ;
1292 #endif
1293 
1294 	if (len >= STAT_BUFF_LEN)
1295 		printk(KERN_ERR "dmasound_core: stat buffer overflowed!\n");
1296 
1297 	state.len = len;
1298 	return 0;
1299 }
1300 
1301 static int state_release(struct inode *inode, struct file *file)
1302 {
1303 	lock_kernel();
1304 	state.busy = 0;
1305 	module_put(dmasound.mach.owner);
1306 	unlock_kernel();
1307 	return 0;
1308 }
1309 
1310 static ssize_t state_read(struct file *file, char __user *buf, size_t count,
1311 			  loff_t *ppos)
1312 {
1313 	int n = state.len - state.ptr;
1314 	if (n > count)
1315 		n = count;
1316 	if (n <= 0)
1317 		return 0;
1318 	if (copy_to_user(buf, &state.buf[state.ptr], n))
1319 		return -EFAULT;
1320 	state.ptr += n;
1321 	return n;
1322 }
1323 
1324 static const struct file_operations state_fops = {
1325 	.owner		= THIS_MODULE,
1326 	.llseek		= no_llseek,
1327 	.read		= state_read,
1328 	.open		= state_open,
1329 	.release	= state_release,
1330 };
1331 
1332 static int state_init(void)
1333 {
1334 #ifndef MODULE
1335 	int state_unit;
1336 #endif
1337 	state_unit = register_sound_special(&state_fops, SND_DEV_STATUS);
1338 	if (state_unit < 0)
1339 		return state_unit ;
1340 	state.busy = 0;
1341 	return 0 ;
1342 }
1343 
1344 
1345     /*
1346      *  Config & Setup
1347      *
1348      *  This function is called by _one_ chipset-specific driver
1349      */
1350 
1351 int dmasound_init(void)
1352 {
1353 	int res ;
1354 #ifdef MODULE
1355 	if (irq_installed)
1356 		return -EBUSY;
1357 #endif
1358 
1359 	/* Set up sound queue, /dev/audio and /dev/dsp. */
1360 
1361 	/* Set default settings. */
1362 	if ((res = sq_init()) < 0)
1363 		return res ;
1364 
1365 	/* Set up /dev/sndstat. */
1366 	if ((res = state_init()) < 0)
1367 		return res ;
1368 
1369 	/* Set up /dev/mixer. */
1370 	mixer_init();
1371 
1372 	if (!dmasound.mach.irqinit()) {
1373 		printk(KERN_ERR "DMA sound driver: Interrupt initialization failed\n");
1374 		return -ENODEV;
1375 	}
1376 #ifdef MODULE
1377 	irq_installed = 1;
1378 #endif
1379 
1380 	printk(KERN_INFO "%s DMA sound driver rev %03d installed\n",
1381 		dmasound.mach.name, (DMASOUND_CORE_REVISION<<4) +
1382 		((dmasound.mach.version>>8) & 0x0f));
1383 	printk(KERN_INFO
1384 		"Core driver edition %02d.%02d : %s driver edition %02d.%02d\n",
1385 		DMASOUND_CORE_REVISION, DMASOUND_CORE_EDITION, dmasound.mach.name2,
1386 		(dmasound.mach.version >> 8), (dmasound.mach.version & 0xff)) ;
1387 	printk(KERN_INFO "Write will use %4d fragments of %7d bytes as default\n",
1388 		numWriteBufs, writeBufSize) ;
1389 	return 0;
1390 }
1391 
1392 #ifdef MODULE
1393 
1394 void dmasound_deinit(void)
1395 {
1396 	if (irq_installed) {
1397 		sound_silence();
1398 		dmasound.mach.irqcleanup();
1399 		irq_installed = 0;
1400 	}
1401 
1402 	write_sq_release_buffers();
1403 
1404 	if (mixer_unit >= 0)
1405 		unregister_sound_mixer(mixer_unit);
1406 	if (state_unit >= 0)
1407 		unregister_sound_special(state_unit);
1408 	if (sq_unit >= 0)
1409 		unregister_sound_dsp(sq_unit);
1410 }
1411 
1412 #else /* !MODULE */
1413 
1414 static int dmasound_setup(char *str)
1415 {
1416 	int ints[6], size;
1417 
1418 	str = get_options(str, ARRAY_SIZE(ints), ints);
1419 
1420 	/* check the bootstrap parameter for "dmasound=" */
1421 
1422 	/* FIXME: other than in the most naive of cases there is no sense in these
1423 	 *	  buffers being other than powers of two.  This is not checked yet.
1424 	 */
1425 
1426 	switch (ints[0]) {
1427 	case 3:
1428 		if ((ints[3] < 0) || (ints[3] > MAX_CATCH_RADIUS))
1429 			printk("dmasound_setup: invalid catch radius, using default = %d\n", catchRadius);
1430 		else
1431 			catchRadius = ints[3];
1432 		/* fall through */
1433 	case 2:
1434 		if (ints[1] < MIN_BUFFERS)
1435 			printk("dmasound_setup: invalid number of buffers, using default = %d\n", numWriteBufs);
1436 		else
1437 			numWriteBufs = ints[1];
1438 		/* fall through */
1439 	case 1:
1440 		if ((size = ints[2]) < 256) /* check for small buffer specs */
1441 			size <<= 10 ;
1442                 if (size < MIN_BUFSIZE || size > MAX_BUFSIZE)
1443                         printk("dmasound_setup: invalid write buffer size, using default = %d\n", writeBufSize);
1444                 else
1445                         writeBufSize = size;
1446 	case 0:
1447 		break;
1448 	default:
1449 		printk("dmasound_setup: invalid number of arguments\n");
1450 		return 0;
1451 	}
1452 	return 1;
1453 }
1454 
1455 __setup("dmasound=", dmasound_setup);
1456 
1457 #endif /* !MODULE */
1458 
1459     /*
1460      *  Conversion tables
1461      */
1462 
1463 #ifdef HAS_8BIT_TABLES
1464 /* 8 bit mu-law */
1465 
1466 char dmasound_ulaw2dma8[] = {
1467 	-126,	-122,	-118,	-114,	-110,	-106,	-102,	-98,
1468 	-94,	-90,	-86,	-82,	-78,	-74,	-70,	-66,
1469 	-63,	-61,	-59,	-57,	-55,	-53,	-51,	-49,
1470 	-47,	-45,	-43,	-41,	-39,	-37,	-35,	-33,
1471 	-31,	-30,	-29,	-28,	-27,	-26,	-25,	-24,
1472 	-23,	-22,	-21,	-20,	-19,	-18,	-17,	-16,
1473 	-16,	-15,	-15,	-14,	-14,	-13,	-13,	-12,
1474 	-12,	-11,	-11,	-10,	-10,	-9,	-9,	-8,
1475 	-8,	-8,	-7,	-7,	-7,	-7,	-6,	-6,
1476 	-6,	-6,	-5,	-5,	-5,	-5,	-4,	-4,
1477 	-4,	-4,	-4,	-4,	-3,	-3,	-3,	-3,
1478 	-3,	-3,	-3,	-3,	-2,	-2,	-2,	-2,
1479 	-2,	-2,	-2,	-2,	-2,	-2,	-2,	-2,
1480 	-1,	-1,	-1,	-1,	-1,	-1,	-1,	-1,
1481 	-1,	-1,	-1,	-1,	-1,	-1,	-1,	-1,
1482 	-1,	-1,	-1,	-1,	-1,	-1,	-1,	0,
1483 	125,	121,	117,	113,	109,	105,	101,	97,
1484 	93,	89,	85,	81,	77,	73,	69,	65,
1485 	62,	60,	58,	56,	54,	52,	50,	48,
1486 	46,	44,	42,	40,	38,	36,	34,	32,
1487 	30,	29,	28,	27,	26,	25,	24,	23,
1488 	22,	21,	20,	19,	18,	17,	16,	15,
1489 	15,	14,	14,	13,	13,	12,	12,	11,
1490 	11,	10,	10,	9,	9,	8,	8,	7,
1491 	7,	7,	6,	6,	6,	6,	5,	5,
1492 	5,	5,	4,	4,	4,	4,	3,	3,
1493 	3,	3,	3,	3,	2,	2,	2,	2,
1494 	2,	2,	2,	2,	1,	1,	1,	1,
1495 	1,	1,	1,	1,	1,	1,	1,	1,
1496 	0,	0,	0,	0,	0,	0,	0,	0,
1497 	0,	0,	0,	0,	0,	0,	0,	0,
1498 	0,	0,	0,	0,	0,	0,	0,	0
1499 };
1500 
1501 /* 8 bit A-law */
1502 
1503 char dmasound_alaw2dma8[] = {
1504 	-22,	-21,	-24,	-23,	-18,	-17,	-20,	-19,
1505 	-30,	-29,	-32,	-31,	-26,	-25,	-28,	-27,
1506 	-11,	-11,	-12,	-12,	-9,	-9,	-10,	-10,
1507 	-15,	-15,	-16,	-16,	-13,	-13,	-14,	-14,
1508 	-86,	-82,	-94,	-90,	-70,	-66,	-78,	-74,
1509 	-118,	-114,	-126,	-122,	-102,	-98,	-110,	-106,
1510 	-43,	-41,	-47,	-45,	-35,	-33,	-39,	-37,
1511 	-59,	-57,	-63,	-61,	-51,	-49,	-55,	-53,
1512 	-2,	-2,	-2,	-2,	-2,	-2,	-2,	-2,
1513 	-2,	-2,	-2,	-2,	-2,	-2,	-2,	-2,
1514 	-1,	-1,	-1,	-1,	-1,	-1,	-1,	-1,
1515 	-1,	-1,	-1,	-1,	-1,	-1,	-1,	-1,
1516 	-6,	-6,	-6,	-6,	-5,	-5,	-5,	-5,
1517 	-8,	-8,	-8,	-8,	-7,	-7,	-7,	-7,
1518 	-3,	-3,	-3,	-3,	-3,	-3,	-3,	-3,
1519 	-4,	-4,	-4,	-4,	-4,	-4,	-4,	-4,
1520 	21,	20,	23,	22,	17,	16,	19,	18,
1521 	29,	28,	31,	30,	25,	24,	27,	26,
1522 	10,	10,	11,	11,	8,	8,	9,	9,
1523 	14,	14,	15,	15,	12,	12,	13,	13,
1524 	86,	82,	94,	90,	70,	66,	78,	74,
1525 	118,	114,	126,	122,	102,	98,	110,	106,
1526 	43,	41,	47,	45,	35,	33,	39,	37,
1527 	59,	57,	63,	61,	51,	49,	55,	53,
1528 	1,	1,	1,	1,	1,	1,	1,	1,
1529 	1,	1,	1,	1,	1,	1,	1,	1,
1530 	0,	0,	0,	0,	0,	0,	0,	0,
1531 	0,	0,	0,	0,	0,	0,	0,	0,
1532 	5,	5,	5,	5,	4,	4,	4,	4,
1533 	7,	7,	7,	7,	6,	6,	6,	6,
1534 	2,	2,	2,	2,	2,	2,	2,	2,
1535 	3,	3,	3,	3,	3,	3,	3,	3
1536 };
1537 #endif /* HAS_8BIT_TABLES */
1538 
1539     /*
1540      *  Visible symbols for modules
1541      */
1542 
1543 EXPORT_SYMBOL(dmasound);
1544 EXPORT_SYMBOL(dmasound_init);
1545 #ifdef MODULE
1546 EXPORT_SYMBOL(dmasound_deinit);
1547 #endif
1548 EXPORT_SYMBOL(dmasound_write_sq);
1549 EXPORT_SYMBOL(dmasound_catchRadius);
1550 #ifdef HAS_8BIT_TABLES
1551 EXPORT_SYMBOL(dmasound_ulaw2dma8);
1552 EXPORT_SYMBOL(dmasound_alaw2dma8);
1553 #endif
1554 EXPORT_SYMBOL(get_afmt_string) ;
1555