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/mutex.h>
185 #include <linux/sched/signal.h>
186 
187 #include <linux/uaccess.h>
188 
189 #include "dmasound.h"
190 
191 #define DMASOUND_CORE_REVISION 1
192 #define DMASOUND_CORE_EDITION 6
193 
194     /*
195      *  Declarations
196      */
197 
198 static DEFINE_MUTEX(dmasound_core_mutex);
199 int dmasound_catchRadius = 0;
200 module_param(dmasound_catchRadius, int, 0);
201 
202 static unsigned int numWriteBufs = DEFAULT_N_BUFFERS;
203 module_param(numWriteBufs, int, 0);
204 static unsigned int writeBufSize = DEFAULT_BUFF_SIZE ;	/* in bytes */
205 module_param(writeBufSize, int, 0);
206 
207 MODULE_LICENSE("GPL");
208 
209 #ifdef MODULE
210 static int sq_unit = -1;
211 static int mixer_unit = -1;
212 static int state_unit = -1;
213 static int irq_installed;
214 #endif /* MODULE */
215 
216 /* control over who can modify resources shared between play/record */
217 static fmode_t shared_resource_owner;
218 static int shared_resources_initialised;
219 
220     /*
221      *  Mid level stuff
222      */
223 
224 struct sound_settings dmasound = {
225 	.lock = __SPIN_LOCK_UNLOCKED(dmasound.lock)
226 };
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 	mutex_lock(&dmasound_core_mutex);
329 	if (!try_module_get(dmasound.mach.owner)) {
330 		mutex_unlock(&dmasound_core_mutex);
331 		return -ENODEV;
332 	}
333 	mixer.busy = 1;
334 	mutex_unlock(&dmasound_core_mutex);
335 	return 0;
336 }
337 
338 static int mixer_release(struct inode *inode, struct file *file)
339 {
340 	mutex_lock(&dmasound_core_mutex);
341 	mixer.busy = 0;
342 	module_put(dmasound.mach.owner);
343 	mutex_unlock(&dmasound_core_mutex);
344 	return 0;
345 }
346 
347 static int mixer_ioctl(struct file *file, u_int cmd, u_long arg)
348 {
349 	if (_SIOC_DIR(cmd) & _SIOC_WRITE)
350 	    mixer.modify_counter++;
351 	switch (cmd) {
352 	    case OSS_GETVERSION:
353 		return IOCTL_OUT(arg, SOUND_VERSION);
354 	    case SOUND_MIXER_INFO:
355 		{
356 		    mixer_info info;
357 		    memset(&info, 0, sizeof(info));
358 		    strlcpy(info.id, dmasound.mach.name2, sizeof(info.id));
359 		    strlcpy(info.name, dmasound.mach.name2, sizeof(info.name));
360 		    info.modify_counter = mixer.modify_counter;
361 		    if (copy_to_user((void __user *)arg, &info, sizeof(info)))
362 			    return -EFAULT;
363 		    return 0;
364 		}
365 	}
366 	if (dmasound.mach.mixer_ioctl)
367 	    return dmasound.mach.mixer_ioctl(cmd, arg);
368 	return -EINVAL;
369 }
370 
371 static long mixer_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
372 {
373 	int ret;
374 
375 	mutex_lock(&dmasound_core_mutex);
376 	ret = mixer_ioctl(file, cmd, arg);
377 	mutex_unlock(&dmasound_core_mutex);
378 
379 	return ret;
380 }
381 
382 static const struct file_operations mixer_fops =
383 {
384 	.owner		= THIS_MODULE,
385 	.llseek		= no_llseek,
386 	.unlocked_ioctl	= mixer_unlocked_ioctl,
387 	.open		= mixer_open,
388 	.release	= mixer_release,
389 };
390 
391 static void mixer_init(void)
392 {
393 #ifndef MODULE
394 	int mixer_unit;
395 #endif
396 	mixer_unit = register_sound_mixer(&mixer_fops, -1);
397 	if (mixer_unit < 0)
398 		return;
399 
400 	mixer.busy = 0;
401 	dmasound.treble = 0;
402 	dmasound.bass = 0;
403 	if (dmasound.mach.mixer_init)
404 	    dmasound.mach.mixer_init();
405 }
406 
407 
408     /*
409      *  Sound queue stuff, the heart of the driver
410      */
411 
412 struct sound_queue dmasound_write_sq;
413 static void sq_reset_output(void) ;
414 
415 static int sq_allocate_buffers(struct sound_queue *sq, int num, int size)
416 {
417 	int i;
418 
419 	if (sq->buffers)
420 		return 0;
421 	sq->numBufs = num;
422 	sq->bufSize = size;
423 	sq->buffers = kmalloc_array (num, sizeof(char *), GFP_KERNEL);
424 	if (!sq->buffers)
425 		return -ENOMEM;
426 	for (i = 0; i < num; i++) {
427 		sq->buffers[i] = dmasound.mach.dma_alloc(size, GFP_KERNEL);
428 		if (!sq->buffers[i]) {
429 			while (i--)
430 				dmasound.mach.dma_free(sq->buffers[i], size);
431 			kfree(sq->buffers);
432 			sq->buffers = NULL;
433 			return -ENOMEM;
434 		}
435 	}
436 	return 0;
437 }
438 
439 static void sq_release_buffers(struct sound_queue *sq)
440 {
441 	int i;
442 
443 	if (sq->buffers) {
444 		for (i = 0; i < sq->numBufs; i++)
445 			dmasound.mach.dma_free(sq->buffers[i], sq->bufSize);
446 		kfree(sq->buffers);
447 		sq->buffers = NULL;
448 	}
449 }
450 
451 
452 static int sq_setup(struct sound_queue *sq)
453 {
454 	int (*setup_func)(void) = NULL;
455 	int hard_frame ;
456 
457 	if (sq->locked) { /* are we already set? - and not changeable */
458 #ifdef DEBUG_DMASOUND
459 printk("dmasound_core: tried to sq_setup a locked queue\n") ;
460 #endif
461 		return -EINVAL ;
462 	}
463 	sq->locked = 1 ; /* don't think we have a race prob. here _check_ */
464 
465 	/* make sure that the parameters are set up
466 	   This should have been done already...
467 	*/
468 
469 	dmasound.mach.init();
470 
471 	/* OK.  If the user has set fragment parameters explicitly, then we
472 	   should leave them alone... as long as they are valid.
473 	   Invalid user fragment params can occur if we allow the whole buffer
474 	   to be used when the user requests the fragments sizes (with no soft
475 	   x-lation) and then the user subsequently sets a soft x-lation that
476 	   requires increased internal buffering.
477 
478 	   Othwerwise (if the user did not set them) OSS says that we should
479 	   select frag params on the basis of 0.5 s output & 0.1 s input
480 	   latency. (TODO.  For now we will copy in the defaults.)
481 	*/
482 
483 	if (sq->user_frags <= 0) {
484 		sq->max_count = sq->numBufs ;
485 		sq->max_active = sq->numBufs ;
486 		sq->block_size = sq->bufSize;
487 		/* set up the user info */
488 		sq->user_frags = sq->numBufs ;
489 		sq->user_frag_size = sq->bufSize ;
490 		sq->user_frag_size *=
491 			(dmasound.soft.size * (dmasound.soft.stereo+1) ) ;
492 		sq->user_frag_size /=
493 			(dmasound.hard.size * (dmasound.hard.stereo+1) ) ;
494 	} else {
495 		/* work out requested block size */
496 		sq->block_size = sq->user_frag_size ;
497 		sq->block_size *=
498 			(dmasound.hard.size * (dmasound.hard.stereo+1) ) ;
499 		sq->block_size /=
500 			(dmasound.soft.size * (dmasound.soft.stereo+1) ) ;
501 		/* the user wants to write frag-size chunks */
502 		sq->block_size *= dmasound.hard.speed ;
503 		sq->block_size /= dmasound.soft.speed ;
504 		/* this only works for size values which are powers of 2 */
505 		hard_frame =
506 			(dmasound.hard.size * (dmasound.hard.stereo+1))/8 ;
507 		sq->block_size +=  (hard_frame - 1) ;
508 		sq->block_size &= ~(hard_frame - 1) ; /* make sure we are aligned */
509 		/* let's just check for obvious mistakes */
510 		if ( sq->block_size <= 0 || sq->block_size > sq->bufSize) {
511 #ifdef DEBUG_DMASOUND
512 printk("dmasound_core: invalid frag size (user set %d)\n", sq->user_frag_size) ;
513 #endif
514 			sq->block_size = sq->bufSize ;
515 		}
516 		if ( sq->user_frags <= sq->numBufs ) {
517 			sq->max_count = sq->user_frags ;
518 			/* if user has set max_active - then use it */
519 			sq->max_active = (sq->max_active <= sq->max_count) ?
520 				sq->max_active : sq->max_count ;
521 		} else {
522 #ifdef DEBUG_DMASOUND
523 printk("dmasound_core: invalid frag count (user set %d)\n", sq->user_frags) ;
524 #endif
525 			sq->max_count =
526 			sq->max_active = sq->numBufs ;
527 		}
528 	}
529 	sq->front = sq->count = sq->rear_size = 0;
530 	sq->syncing = 0;
531 	sq->active = 0;
532 
533 	if (sq == &write_sq) {
534 	    sq->rear = -1;
535 	    setup_func = dmasound.mach.write_sq_setup;
536 	}
537 	if (setup_func)
538 	    return setup_func();
539 	return 0 ;
540 }
541 
542 static inline void sq_play(void)
543 {
544 	dmasound.mach.play();
545 }
546 
547 static ssize_t sq_write(struct file *file, const char __user *src, size_t uLeft,
548 			loff_t *ppos)
549 {
550 	ssize_t uWritten = 0;
551 	u_char *dest;
552 	ssize_t uUsed = 0, bUsed, bLeft;
553 	unsigned long flags ;
554 
555 	/* ++TeSche: Is something like this necessary?
556 	 * Hey, that's an honest question! Or does any other part of the
557 	 * filesystem already checks this situation? I really don't know.
558 	 */
559 	if (uLeft == 0)
560 		return 0;
561 
562 	/* implement any changes we have made to the soft/hard params.
563 	   this is not satisfactory really, all we have done up to now is to
564 	   say what we would like - there hasn't been any real checking of capability
565 	*/
566 
567 	if (shared_resources_initialised == 0) {
568 		dmasound.mach.init() ;
569 		shared_resources_initialised = 1 ;
570 	}
571 
572 	/* set up the sq if it is not already done. This may seem a dumb place
573 	   to do it - but it is what OSS requires.  It means that write() can
574 	   return memory allocation errors.  To avoid this possibility use the
575 	   GETBLKSIZE or GETOSPACE ioctls (after you've fiddled with all the
576 	   params you want to change) - these ioctls also force the setup.
577 	*/
578 
579 	if (write_sq.locked == 0) {
580 		if ((uWritten = sq_setup(&write_sq)) < 0) return uWritten ;
581 		uWritten = 0 ;
582 	}
583 
584 /* FIXME: I think that this may be the wrong behaviour when we get strapped
585 	for time and the cpu is close to being (or actually) behind in sending data.
586 	- because we've lost the time that the N samples, already in the buffer,
587 	would have given us to get here with the next lot from the user.
588 */
589 	/* The interrupt doesn't start to play the last, incomplete frame.
590 	 * Thus we can append to it without disabling the interrupts! (Note
591 	 * also that write_sq.rear isn't affected by the interrupt.)
592 	 */
593 
594 	/* as of 1.6 this behaviour changes if SNDCTL_DSP_POST has been issued:
595 	   this will mimic the behaviour of syncing and allow the sq_play() to
596 	   queue a partial fragment.  Since sq_play() may/will be called from
597 	   the IRQ handler - at least on Pmac we have to deal with it.
598 	   The strategy - possibly not optimum - is to kill _POST status if we
599 	   get here.  This seems, at least, reasonable - in the sense that POST
600 	   is supposed to indicate that we might not write before the queue
601 	   is drained - and if we get here in time then it does not apply.
602 	*/
603 
604 	spin_lock_irqsave(&dmasound.lock, flags);
605 	write_sq.syncing &= ~2 ; /* take out POST status */
606 	spin_unlock_irqrestore(&dmasound.lock, flags);
607 
608 	if (write_sq.count > 0 &&
609 	    (bLeft = write_sq.block_size-write_sq.rear_size) > 0) {
610 		dest = write_sq.buffers[write_sq.rear];
611 		bUsed = write_sq.rear_size;
612 		uUsed = sound_copy_translate(dmasound.trans_write, src, uLeft,
613 					     dest, &bUsed, bLeft);
614 		if (uUsed <= 0)
615 			return uUsed;
616 		src += uUsed;
617 		uWritten += uUsed;
618 		uLeft = (uUsed <= uLeft) ? (uLeft - uUsed) : 0 ; /* paranoia */
619 		write_sq.rear_size = bUsed;
620 	}
621 
622 	while (uLeft) {
623 		DEFINE_WAIT(wait);
624 
625 		while (write_sq.count >= write_sq.max_active) {
626 			prepare_to_wait(&write_sq.action_queue, &wait, TASK_INTERRUPTIBLE);
627 			sq_play();
628 			if (write_sq.non_blocking) {
629 				finish_wait(&write_sq.action_queue, &wait);
630 				return uWritten > 0 ? uWritten : -EAGAIN;
631 			}
632 			if (write_sq.count < write_sq.max_active)
633 				break;
634 
635 			schedule_timeout(HZ);
636 			if (signal_pending(current)) {
637 				finish_wait(&write_sq.action_queue, &wait);
638 				return uWritten > 0 ? uWritten : -EINTR;
639 			}
640 		}
641 
642 		finish_wait(&write_sq.action_queue, &wait);
643 
644 		/* Here, we can avoid disabling the interrupt by first
645 		 * copying and translating the data, and then updating
646 		 * the write_sq variables. Until this is done, the interrupt
647 		 * won't see the new frame and we can work on it
648 		 * undisturbed.
649 		 */
650 
651 		dest = write_sq.buffers[(write_sq.rear+1) % write_sq.max_count];
652 		bUsed = 0;
653 		bLeft = write_sq.block_size;
654 		uUsed = sound_copy_translate(dmasound.trans_write, src, uLeft,
655 					     dest, &bUsed, bLeft);
656 		if (uUsed <= 0)
657 			break;
658 		src += uUsed;
659 		uWritten += uUsed;
660 		uLeft = (uUsed <= uLeft) ? (uLeft - uUsed) : 0 ; /* paranoia */
661 		if (bUsed) {
662 			write_sq.rear = (write_sq.rear+1) % write_sq.max_count;
663 			write_sq.rear_size = bUsed;
664 			write_sq.count++;
665 		}
666 	} /* uUsed may have been 0 */
667 
668 	sq_play();
669 
670 	return uUsed < 0? uUsed: uWritten;
671 }
672 
673 static __poll_t sq_poll(struct file *file, struct poll_table_struct *wait)
674 {
675 	__poll_t mask = 0;
676 	int retVal;
677 
678 	if (write_sq.locked == 0) {
679 		if ((retVal = sq_setup(&write_sq)) < 0)
680 			return retVal;
681 		return 0;
682 	}
683 	if (file->f_mode & FMODE_WRITE )
684 		poll_wait(file, &write_sq.action_queue, wait);
685 	if (file->f_mode & FMODE_WRITE)
686 		if (write_sq.count < write_sq.max_active || write_sq.block_size - write_sq.rear_size > 0)
687 			mask |= EPOLLOUT | EPOLLWRNORM;
688 	return mask;
689 
690 }
691 
692 static inline void sq_init_waitqueue(struct sound_queue *sq)
693 {
694 	init_waitqueue_head(&sq->action_queue);
695 	init_waitqueue_head(&sq->open_queue);
696 	init_waitqueue_head(&sq->sync_queue);
697 	sq->busy = 0;
698 }
699 
700 #if 0 /* blocking open() */
701 static inline void sq_wake_up(struct sound_queue *sq, struct file *file,
702 			      fmode_t mode)
703 {
704 	if (file->f_mode & mode) {
705 		sq->busy = 0; /* CHECK: IS THIS OK??? */
706 		WAKE_UP(sq->open_queue);
707 	}
708 }
709 #endif
710 
711 static int sq_open2(struct sound_queue *sq, struct file *file, fmode_t mode,
712 		    int numbufs, int bufsize)
713 {
714 	int rc = 0;
715 
716 	if (file->f_mode & mode) {
717 		if (sq->busy) {
718 #if 0 /* blocking open() */
719 			rc = -EBUSY;
720 			if (file->f_flags & O_NONBLOCK)
721 				return rc;
722 			rc = -EINTR;
723 			if (wait_event_interruptible(sq->open_queue, !sq->busy))
724 				return rc;
725 			rc = 0;
726 #else
727 			/* OSS manual says we will return EBUSY regardless
728 			   of O_NOBLOCK.
729 			*/
730 			return -EBUSY ;
731 #endif
732 		}
733 		sq->busy = 1; /* Let's play spot-the-race-condition */
734 
735 		/* allocate the default number & size of buffers.
736 		   (i.e. specified in _setup() or as module params)
737 		   can't be changed at the moment - but _could_ be perhaps
738 		   in the setfragments ioctl.
739 		*/
740 		if (( rc = sq_allocate_buffers(sq, numbufs, bufsize))) {
741 #if 0 /* blocking open() */
742 			sq_wake_up(sq, file, mode);
743 #else
744 			sq->busy = 0 ;
745 #endif
746 			return rc;
747 		}
748 
749 		sq->non_blocking = file->f_flags & O_NONBLOCK;
750 	}
751 	return rc;
752 }
753 
754 #define write_sq_init_waitqueue()	sq_init_waitqueue(&write_sq)
755 #if 0 /* blocking open() */
756 #define write_sq_wake_up(file)		sq_wake_up(&write_sq, file, FMODE_WRITE)
757 #endif
758 #define write_sq_release_buffers()	sq_release_buffers(&write_sq)
759 #define write_sq_open(file)	\
760 	sq_open2(&write_sq, file, FMODE_WRITE, numWriteBufs, writeBufSize )
761 
762 static int sq_open(struct inode *inode, struct file *file)
763 {
764 	int rc;
765 
766 	mutex_lock(&dmasound_core_mutex);
767 	if (!try_module_get(dmasound.mach.owner)) {
768 		mutex_unlock(&dmasound_core_mutex);
769 		return -ENODEV;
770 	}
771 
772 	rc = write_sq_open(file); /* checks the f_mode */
773 	if (rc)
774 		goto out;
775 	if (file->f_mode & FMODE_READ) {
776 		/* TODO: if O_RDWR, release any resources grabbed by write part */
777 		rc = -ENXIO ; /* I think this is what is required by open(2) */
778 		goto out;
779 	}
780 
781 	if (dmasound.mach.sq_open)
782 	    dmasound.mach.sq_open(file->f_mode);
783 
784 	/* CHECK whether this is sensible - in the case that dsp0 could be opened
785 	  O_RDONLY and dsp1 could be opened O_WRONLY
786 	*/
787 
788 	dmasound.minDev = iminor(inode) & 0x0f;
789 
790 	/* OK. - we should make some attempt at consistency. At least the H'ware
791 	   options should be set with a valid mode.  We will make it that the LL
792 	   driver must supply defaults for hard & soft params.
793 	*/
794 
795 	if (shared_resource_owner == 0) {
796 		/* you can make this AFMT_U8/mono/8K if you want to mimic old
797 		   OSS behaviour - while we still have soft translations ;-) */
798 		dmasound.soft = dmasound.mach.default_soft ;
799 		dmasound.dsp = dmasound.mach.default_soft ;
800 		dmasound.hard = dmasound.mach.default_hard ;
801 	}
802 
803 #ifndef DMASOUND_STRICT_OSS_COMPLIANCE
804 	/* none of the current LL drivers can actually do this "native" at the moment
805 	   OSS does not really require us to supply /dev/audio if we can't do it.
806 	*/
807 	if (dmasound.minDev == SND_DEV_AUDIO) {
808 		sound_set_speed(8000);
809 		sound_set_stereo(0);
810 		sound_set_format(AFMT_MU_LAW);
811 	}
812 #endif
813 	mutex_unlock(&dmasound_core_mutex);
814 	return 0;
815  out:
816 	module_put(dmasound.mach.owner);
817 	mutex_unlock(&dmasound_core_mutex);
818 	return rc;
819 }
820 
821 static void sq_reset_output(void)
822 {
823 	sound_silence(); /* this _must_ stop DMA, we might be about to lose the buffers */
824 	write_sq.active = 0;
825 	write_sq.count = 0;
826 	write_sq.rear_size = 0;
827 	/* write_sq.front = (write_sq.rear+1) % write_sq.max_count;*/
828 	write_sq.front = 0 ;
829 	write_sq.rear = -1 ; /* same as for set-up */
830 
831 	/* OK - we can unlock the parameters and fragment settings */
832 	write_sq.locked = 0 ;
833 	write_sq.user_frags = 0 ;
834 	write_sq.user_frag_size = 0 ;
835 }
836 
837 static void sq_reset(void)
838 {
839 	sq_reset_output() ;
840 	/* we could consider resetting the shared_resources_owner here... but I
841 	   think it is probably still rather non-obvious to application writer
842 	*/
843 
844 	/* we release everything else though */
845 	shared_resources_initialised = 0 ;
846 }
847 
848 static int sq_fsync(void)
849 {
850 	int rc = 0;
851 	int timeout = 5;
852 
853 	write_sq.syncing |= 1;
854 	sq_play();	/* there may be an incomplete frame waiting */
855 
856 	while (write_sq.active) {
857 		wait_event_interruptible_timeout(write_sq.sync_queue,
858 						 !write_sq.active, HZ);
859 		if (signal_pending(current)) {
860 			/* While waiting for audio output to drain, an
861 			 * interrupt occurred.  Stop audio output immediately
862 			 * and clear the queue. */
863 			sq_reset_output();
864 			rc = -EINTR;
865 			break;
866 		}
867 		if (!--timeout) {
868 			printk(KERN_WARNING "dmasound: Timeout draining output\n");
869 			sq_reset_output();
870 			rc = -EIO;
871 			break;
872 		}
873 	}
874 
875 	/* flag no sync regardless of whether we had a DSP_POST or not */
876 	write_sq.syncing = 0 ;
877 	return rc;
878 }
879 
880 static int sq_release(struct inode *inode, struct file *file)
881 {
882 	int rc = 0;
883 
884 	mutex_lock(&dmasound_core_mutex);
885 
886 	if (file->f_mode & FMODE_WRITE) {
887 		if (write_sq.busy)
888 			rc = sq_fsync();
889 
890 		sq_reset_output() ; /* make sure dma is stopped and all is quiet */
891 		write_sq_release_buffers();
892 		write_sq.busy = 0;
893 	}
894 
895 	if (file->f_mode & shared_resource_owner) { /* it's us that has them */
896 		shared_resource_owner = 0 ;
897 		shared_resources_initialised = 0 ;
898 		dmasound.hard = dmasound.mach.default_hard ;
899 	}
900 
901 	module_put(dmasound.mach.owner);
902 
903 #if 0 /* blocking open() */
904 	/* Wake up a process waiting for the queue being released.
905 	 * Note: There may be several processes waiting for a call
906 	 * to open() returning. */
907 
908 	/* Iain: hmm I don't understand this next comment ... */
909 	/* There is probably a DOS atack here. They change the mode flag. */
910 	/* XXX add check here,*/
911 	read_sq_wake_up(file); /* checks f_mode */
912 	write_sq_wake_up(file); /* checks f_mode */
913 #endif /* blocking open() */
914 
915 	mutex_unlock(&dmasound_core_mutex);
916 
917 	return rc;
918 }
919 
920 /* here we see if we have a right to modify format, channels, size and so on
921    if no-one else has claimed it already then we do...
922 
923    TODO: We might change this to mask O_RDWR such that only one or the other channel
924    is the owner - if we have problems.
925 */
926 
927 static int shared_resources_are_mine(fmode_t md)
928 {
929 	if (shared_resource_owner)
930 		return (shared_resource_owner & md) != 0;
931 	else {
932 		shared_resource_owner = md ;
933 		return 1 ;
934 	}
935 }
936 
937 /* if either queue is locked we must deny the right to change shared params
938 */
939 
940 static int queues_are_quiescent(void)
941 {
942 	if (write_sq.locked)
943 		return 0 ;
944 	return 1 ;
945 }
946 
947 /* check and set a queue's fragments per user's wishes...
948    we will check against the pre-defined literals and the actual sizes.
949    This is a bit fraught - because soft translations can mess with our
950    buffer requirements *after* this call - OSS says "call setfrags first"
951 */
952 
953 /* It is possible to replace all the -EINVAL returns with an override that
954    just puts the allowable value in.  This may be what many OSS apps require
955 */
956 
957 static int set_queue_frags(struct sound_queue *sq, int bufs, int size)
958 {
959 	if (sq->locked) {
960 #ifdef DEBUG_DMASOUND
961 printk("dmasound_core: tried to set_queue_frags on a locked queue\n") ;
962 #endif
963 		return -EINVAL ;
964 	}
965 
966 	if ((size < MIN_FRAG_SIZE) || (size > MAX_FRAG_SIZE))
967 		return -EINVAL ;
968 	size = (1<<size) ; /* now in bytes */
969 	if (size > sq->bufSize)
970 		return -EINVAL ; /* this might still not work */
971 
972 	if (bufs <= 0)
973 		return -EINVAL ;
974 	if (bufs > sq->numBufs) /* the user is allowed say "don't care" with 0x7fff */
975 		bufs = sq->numBufs ;
976 
977 	/* there is, currently, no way to specify max_active separately
978 	   from max_count.  This could be a LL driver issue - I guess
979 	   if there is a requirement for these values to be different then
980 	  we will have to pass that info. up to this level.
981 	*/
982 	sq->user_frags =
983 	sq->max_active = bufs ;
984 	sq->user_frag_size = size ;
985 
986 	return 0 ;
987 }
988 
989 static int sq_ioctl(struct file *file, u_int cmd, u_long arg)
990 {
991 	int val, result;
992 	u_long fmt;
993 	int data;
994 	int size, nbufs;
995 	audio_buf_info info;
996 
997 	switch (cmd) {
998 	case SNDCTL_DSP_RESET:
999 		sq_reset();
1000 		return 0;
1001 		break ;
1002 	case SNDCTL_DSP_GETFMTS:
1003 		fmt = dmasound.mach.hardware_afmts ; /* this is what OSS says.. */
1004 		return IOCTL_OUT(arg, fmt);
1005 		break ;
1006 	case SNDCTL_DSP_GETBLKSIZE:
1007 		/* this should tell the caller about bytes that the app can
1008 		   read/write - the app doesn't care about our internal buffers.
1009 		   We force sq_setup() here as per OSS 1.1 (which should
1010 		   compute the values necessary).
1011 		   Since there is no mechanism to specify read/write separately, for
1012 		   fds opened O_RDWR, the write_sq values will, arbitrarily, overwrite
1013 		   the read_sq ones.
1014 		*/
1015 		size = 0 ;
1016 		if (file->f_mode & FMODE_WRITE) {
1017 			if ( !write_sq.locked )
1018 				sq_setup(&write_sq) ;
1019 			size = write_sq.user_frag_size ;
1020 		}
1021 		return IOCTL_OUT(arg, size);
1022 		break ;
1023 	case SNDCTL_DSP_POST:
1024 		/* all we are going to do is to tell the LL that any
1025 		   partial frags can be queued for output.
1026 		   The LL will have to clear this flag when last output
1027 		   is queued.
1028 		*/
1029 		write_sq.syncing |= 0x2 ;
1030 		sq_play() ;
1031 		return 0 ;
1032 	case SNDCTL_DSP_SYNC:
1033 		/* This call, effectively, has the same behaviour as SNDCTL_DSP_RESET
1034 		   except that it waits for output to finish before resetting
1035 		   everything - read, however, is killed immediately.
1036 		*/
1037 		result = 0 ;
1038 		if (file->f_mode & FMODE_WRITE) {
1039 			result = sq_fsync();
1040 			sq_reset_output() ;
1041 		}
1042 		/* if we are the shared resource owner then release them */
1043 		if (file->f_mode & shared_resource_owner)
1044 			shared_resources_initialised = 0 ;
1045 		return result ;
1046 		break ;
1047 	case SOUND_PCM_READ_RATE:
1048 		return IOCTL_OUT(arg, dmasound.soft.speed);
1049 	case SNDCTL_DSP_SPEED:
1050 		/* changing this on the fly will have weird effects on the sound.
1051 		   Where there are rate conversions implemented in soft form - it
1052 		   will cause the _ctx_xxx() functions to be substituted.
1053 		   However, there doesn't appear to be any reason to dis-allow it from
1054 		   a driver pov.
1055 		*/
1056 		if (shared_resources_are_mine(file->f_mode)) {
1057 			IOCTL_IN(arg, data);
1058 			data = sound_set_speed(data) ;
1059 			shared_resources_initialised = 0 ;
1060 			return IOCTL_OUT(arg, data);
1061 		} else
1062 			return -EINVAL ;
1063 		break ;
1064 	/* OSS says these next 4 actions are undefined when the device is
1065 	   busy/active - we will just return -EINVAL.
1066 	   To be allowed to change one - (a) you have to own the right
1067 	    (b) the queue(s) must be quiescent
1068 	*/
1069 	case SNDCTL_DSP_STEREO:
1070 		if (shared_resources_are_mine(file->f_mode) &&
1071 		    queues_are_quiescent()) {
1072 			IOCTL_IN(arg, data);
1073 			shared_resources_initialised = 0 ;
1074 			return IOCTL_OUT(arg, sound_set_stereo(data));
1075 		} else
1076 			return -EINVAL ;
1077 		break ;
1078 	case SOUND_PCM_WRITE_CHANNELS:
1079 		if (shared_resources_are_mine(file->f_mode) &&
1080 		    queues_are_quiescent()) {
1081 			IOCTL_IN(arg, data);
1082 			/* the user might ask for 20 channels, we will return 1 or 2 */
1083 			shared_resources_initialised = 0 ;
1084 			return IOCTL_OUT(arg, sound_set_stereo(data-1)+1);
1085 		} else
1086 			return -EINVAL ;
1087 		break ;
1088 	case SNDCTL_DSP_SETFMT:
1089 		if (shared_resources_are_mine(file->f_mode) &&
1090 		    queues_are_quiescent()) {
1091 		    	int format;
1092 			IOCTL_IN(arg, data);
1093 			shared_resources_initialised = 0 ;
1094 			format = sound_set_format(data);
1095 			result = IOCTL_OUT(arg, format);
1096 			if (result < 0)
1097 				return result;
1098 			if (format != data && data != AFMT_QUERY)
1099 				return -EINVAL;
1100 			return 0;
1101 		} else
1102 			return -EINVAL ;
1103 	case SNDCTL_DSP_SUBDIVIDE:
1104 		return -EINVAL ;
1105 	case SNDCTL_DSP_SETFRAGMENT:
1106 		/* we can do this independently for the two queues - with the
1107 		   proviso that for fds opened O_RDWR we cannot separate the
1108 		   actions and both queues will be set per the last call.
1109 		   NOTE: this does *NOT* actually set the queue up - merely
1110 		   registers our intentions.
1111 		*/
1112 		IOCTL_IN(arg, data);
1113 		result = 0 ;
1114 		nbufs = (data >> 16) & 0x7fff ; /* 0x7fff is 'use maximum' */
1115 		size = data & 0xffff;
1116 		if (file->f_mode & FMODE_WRITE) {
1117 			result = set_queue_frags(&write_sq, nbufs, size) ;
1118 			if (result)
1119 				return result ;
1120 		}
1121 		/* NOTE: this return value is irrelevant - OSS specifically says that
1122 		   the value is 'random' and that the user _must_ check the actual
1123 		   frags values using SNDCTL_DSP_GETBLKSIZE or similar */
1124 		return IOCTL_OUT(arg, data);
1125 		break ;
1126 	case SNDCTL_DSP_GETOSPACE:
1127 		/*
1128 		*/
1129 		if (file->f_mode & FMODE_WRITE) {
1130 			if ( !write_sq.locked )
1131 				sq_setup(&write_sq) ;
1132 			info.fragments = write_sq.max_active - write_sq.count;
1133 			info.fragstotal = write_sq.max_active;
1134 			info.fragsize = write_sq.user_frag_size;
1135 			info.bytes = info.fragments * info.fragsize;
1136 			if (copy_to_user((void __user *)arg, &info, sizeof(info)))
1137 				return -EFAULT;
1138 			return 0;
1139 		} else
1140 			return -EINVAL ;
1141 		break ;
1142 	case SNDCTL_DSP_GETCAPS:
1143 		val = dmasound.mach.capabilities & 0xffffff00;
1144 		return IOCTL_OUT(arg,val);
1145 
1146 	default:
1147 		return mixer_ioctl(file, cmd, arg);
1148 	}
1149 	return -EINVAL;
1150 }
1151 
1152 static long sq_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
1153 {
1154 	int ret;
1155 
1156 	mutex_lock(&dmasound_core_mutex);
1157 	ret = sq_ioctl(file, cmd, arg);
1158 	mutex_unlock(&dmasound_core_mutex);
1159 
1160 	return ret;
1161 }
1162 
1163 static const struct file_operations sq_fops =
1164 {
1165 	.owner		= THIS_MODULE,
1166 	.llseek		= no_llseek,
1167 	.write		= sq_write,
1168 	.poll		= sq_poll,
1169 	.unlocked_ioctl	= sq_unlocked_ioctl,
1170 	.open		= sq_open,
1171 	.release	= sq_release,
1172 };
1173 
1174 static int sq_init(void)
1175 {
1176 	const struct file_operations *fops = &sq_fops;
1177 #ifndef MODULE
1178 	int sq_unit;
1179 #endif
1180 
1181 	sq_unit = register_sound_dsp(fops, -1);
1182 	if (sq_unit < 0) {
1183 		printk(KERN_ERR "dmasound_core: couldn't register fops\n") ;
1184 		return sq_unit ;
1185 	}
1186 
1187 	write_sq_init_waitqueue();
1188 
1189 	/* These parameters will be restored for every clean open()
1190 	 * in the case of multiple open()s (e.g. dsp0 & dsp1) they
1191 	 * will be set so long as the shared resources have no owner.
1192 	 */
1193 
1194 	if (shared_resource_owner == 0) {
1195 		dmasound.soft = dmasound.mach.default_soft ;
1196 		dmasound.hard = dmasound.mach.default_hard ;
1197 		dmasound.dsp = dmasound.mach.default_soft ;
1198 		shared_resources_initialised = 0 ;
1199 	}
1200 	return 0 ;
1201 }
1202 
1203 
1204     /*
1205      *  /dev/sndstat
1206      */
1207 
1208 /* we allow more space for record-enabled because there are extra output lines.
1209    the number here must include the amount we are prepared to give to the low-level
1210    driver.
1211 */
1212 
1213 #define STAT_BUFF_LEN 768
1214 
1215 /* this is how much space we will allow the low-level driver to use
1216    in the stat buffer.  Currently, 2 * (80 character line + <NL>).
1217    We do not police this (it is up to the ll driver to be honest).
1218 */
1219 
1220 #define LOW_LEVEL_STAT_ALLOC 162
1221 
1222 static struct {
1223     int busy;
1224     char buf[STAT_BUFF_LEN];	/* state.buf should not overflow! */
1225     int len, ptr;
1226 } state;
1227 
1228 /* publish this function for use by low-level code, if required */
1229 
1230 static char *get_afmt_string(int afmt)
1231 {
1232         switch(afmt) {
1233             case AFMT_MU_LAW:
1234                 return "mu-law";
1235                 break;
1236             case AFMT_A_LAW:
1237                 return "A-law";
1238                 break;
1239             case AFMT_U8:
1240                 return "unsigned 8 bit";
1241                 break;
1242             case AFMT_S8:
1243                 return "signed 8 bit";
1244                 break;
1245             case AFMT_S16_BE:
1246                 return "signed 16 bit BE";
1247                 break;
1248             case AFMT_U16_BE:
1249                 return "unsigned 16 bit BE";
1250                 break;
1251             case AFMT_S16_LE:
1252                 return "signed 16 bit LE";
1253                 break;
1254             case AFMT_U16_LE:
1255                 return "unsigned 16 bit LE";
1256                 break;
1257 	    case 0:
1258 		return "format not set" ;
1259 		break ;
1260             default:
1261                 break ;
1262         }
1263         return "ERROR: Unsupported AFMT_XXXX code" ;
1264 }
1265 
1266 static int state_open(struct inode *inode, struct file *file)
1267 {
1268 	char *buffer = state.buf;
1269 	int len = 0;
1270 	int ret;
1271 
1272 	mutex_lock(&dmasound_core_mutex);
1273 	ret = -EBUSY;
1274 	if (state.busy)
1275 		goto out;
1276 
1277 	ret = -ENODEV;
1278 	if (!try_module_get(dmasound.mach.owner))
1279 		goto out;
1280 
1281 	state.ptr = 0;
1282 	state.busy = 1;
1283 
1284 	len += sprintf(buffer+len, "%sDMA sound driver rev %03d :\n",
1285 		dmasound.mach.name, (DMASOUND_CORE_REVISION<<4) +
1286 		((dmasound.mach.version>>8) & 0x0f));
1287 	len += sprintf(buffer+len,
1288 		"Core driver edition %02d.%02d : %s driver edition %02d.%02d\n",
1289 		DMASOUND_CORE_REVISION, DMASOUND_CORE_EDITION, dmasound.mach.name2,
1290 		(dmasound.mach.version >> 8), (dmasound.mach.version & 0xff)) ;
1291 
1292 	/* call the low-level module to fill in any stat info. that it has
1293 	   if present.  Maximum buffer usage is specified.
1294 	*/
1295 
1296 	if (dmasound.mach.state_info)
1297 		len += dmasound.mach.state_info(buffer+len,
1298 			(size_t) LOW_LEVEL_STAT_ALLOC) ;
1299 
1300 	/* make usage of the state buffer as deterministic as poss.
1301 	   exceptional conditions could cause overrun - and this is flagged as
1302 	   a kernel error.
1303 	*/
1304 
1305 	/* formats and settings */
1306 
1307 	len += sprintf(buffer+len,"\t\t === Formats & settings ===\n") ;
1308 	len += sprintf(buffer+len,"Parameter %20s%20s\n","soft","hard") ;
1309 	len += sprintf(buffer+len,"Format   :%20s%20s\n",
1310 		get_afmt_string(dmasound.soft.format),
1311 		get_afmt_string(dmasound.hard.format));
1312 
1313 	len += sprintf(buffer+len,"Samp Rate:%14d s/sec%14d s/sec\n",
1314 		       dmasound.soft.speed, dmasound.hard.speed);
1315 
1316 	len += sprintf(buffer+len,"Channels :%20s%20s\n",
1317 		       dmasound.soft.stereo ? "stereo" : "mono",
1318 		       dmasound.hard.stereo ? "stereo" : "mono" );
1319 
1320 	/* sound queue status */
1321 
1322 	len += sprintf(buffer+len,"\t\t === Sound Queue status ===\n");
1323 	len += sprintf(buffer+len,"Allocated:%8s%6s\n","Buffers","Size") ;
1324 	len += sprintf(buffer+len,"%9s:%8d%6d\n",
1325 		"write", write_sq.numBufs, write_sq.bufSize) ;
1326 	len += sprintf(buffer+len,
1327 		"Current  : MaxFrg FragSiz MaxAct Frnt Rear "
1328 		"Cnt RrSize A B S L  xruns\n") ;
1329 	len += sprintf(buffer+len,"%9s:%7d%8d%7d%5d%5d%4d%7d%2d%2d%2d%2d%7d\n",
1330 		"write", write_sq.max_count, write_sq.block_size,
1331 		write_sq.max_active, write_sq.front, write_sq.rear,
1332 		write_sq.count, write_sq.rear_size, write_sq.active,
1333 		write_sq.busy, write_sq.syncing, write_sq.locked, write_sq.xruns) ;
1334 #ifdef DEBUG_DMASOUND
1335 printk("dmasound: stat buffer used %d bytes\n", len) ;
1336 #endif
1337 
1338 	if (len >= STAT_BUFF_LEN)
1339 		printk(KERN_ERR "dmasound_core: stat buffer overflowed!\n");
1340 
1341 	state.len = len;
1342 	ret = 0;
1343 out:
1344 	mutex_unlock(&dmasound_core_mutex);
1345 	return ret;
1346 }
1347 
1348 static int state_release(struct inode *inode, struct file *file)
1349 {
1350 	mutex_lock(&dmasound_core_mutex);
1351 	state.busy = 0;
1352 	module_put(dmasound.mach.owner);
1353 	mutex_unlock(&dmasound_core_mutex);
1354 	return 0;
1355 }
1356 
1357 static ssize_t state_read(struct file *file, char __user *buf, size_t count,
1358 			  loff_t *ppos)
1359 {
1360 	int n = state.len - state.ptr;
1361 	if (n > count)
1362 		n = count;
1363 	if (n <= 0)
1364 		return 0;
1365 	if (copy_to_user(buf, &state.buf[state.ptr], n))
1366 		return -EFAULT;
1367 	state.ptr += n;
1368 	return n;
1369 }
1370 
1371 static const struct file_operations state_fops = {
1372 	.owner		= THIS_MODULE,
1373 	.llseek		= no_llseek,
1374 	.read		= state_read,
1375 	.open		= state_open,
1376 	.release	= state_release,
1377 };
1378 
1379 static int state_init(void)
1380 {
1381 #ifndef MODULE
1382 	int state_unit;
1383 #endif
1384 	state_unit = register_sound_special(&state_fops, SND_DEV_STATUS);
1385 	if (state_unit < 0)
1386 		return state_unit ;
1387 	state.busy = 0;
1388 	return 0 ;
1389 }
1390 
1391 
1392     /*
1393      *  Config & Setup
1394      *
1395      *  This function is called by _one_ chipset-specific driver
1396      */
1397 
1398 int dmasound_init(void)
1399 {
1400 	int res ;
1401 #ifdef MODULE
1402 	if (irq_installed)
1403 		return -EBUSY;
1404 #endif
1405 
1406 	/* Set up sound queue, /dev/audio and /dev/dsp. */
1407 
1408 	/* Set default settings. */
1409 	if ((res = sq_init()) < 0)
1410 		return res ;
1411 
1412 	/* Set up /dev/sndstat. */
1413 	if ((res = state_init()) < 0)
1414 		return res ;
1415 
1416 	/* Set up /dev/mixer. */
1417 	mixer_init();
1418 
1419 	if (!dmasound.mach.irqinit()) {
1420 		printk(KERN_ERR "DMA sound driver: Interrupt initialization failed\n");
1421 		return -ENODEV;
1422 	}
1423 #ifdef MODULE
1424 	irq_installed = 1;
1425 #endif
1426 
1427 	printk(KERN_INFO "%s DMA sound driver rev %03d installed\n",
1428 		dmasound.mach.name, (DMASOUND_CORE_REVISION<<4) +
1429 		((dmasound.mach.version>>8) & 0x0f));
1430 	printk(KERN_INFO
1431 		"Core driver edition %02d.%02d : %s driver edition %02d.%02d\n",
1432 		DMASOUND_CORE_REVISION, DMASOUND_CORE_EDITION, dmasound.mach.name2,
1433 		(dmasound.mach.version >> 8), (dmasound.mach.version & 0xff)) ;
1434 	printk(KERN_INFO "Write will use %4d fragments of %7d bytes as default\n",
1435 		numWriteBufs, writeBufSize) ;
1436 	return 0;
1437 }
1438 
1439 #ifdef MODULE
1440 
1441 void dmasound_deinit(void)
1442 {
1443 	if (irq_installed) {
1444 		sound_silence();
1445 		dmasound.mach.irqcleanup();
1446 		irq_installed = 0;
1447 	}
1448 
1449 	write_sq_release_buffers();
1450 
1451 	if (mixer_unit >= 0)
1452 		unregister_sound_mixer(mixer_unit);
1453 	if (state_unit >= 0)
1454 		unregister_sound_special(state_unit);
1455 	if (sq_unit >= 0)
1456 		unregister_sound_dsp(sq_unit);
1457 }
1458 
1459 #else /* !MODULE */
1460 
1461 static int dmasound_setup(char *str)
1462 {
1463 	int ints[6], size;
1464 
1465 	str = get_options(str, ARRAY_SIZE(ints), ints);
1466 
1467 	/* check the bootstrap parameter for "dmasound=" */
1468 
1469 	/* FIXME: other than in the most naive of cases there is no sense in these
1470 	 *	  buffers being other than powers of two.  This is not checked yet.
1471 	 */
1472 
1473 	switch (ints[0]) {
1474 	case 3:
1475 		if ((ints[3] < 0) || (ints[3] > MAX_CATCH_RADIUS))
1476 			printk("dmasound_setup: invalid catch radius, using default = %d\n", catchRadius);
1477 		else
1478 			catchRadius = ints[3];
1479 		/* fall through */
1480 	case 2:
1481 		if (ints[1] < MIN_BUFFERS)
1482 			printk("dmasound_setup: invalid number of buffers, using default = %d\n", numWriteBufs);
1483 		else
1484 			numWriteBufs = ints[1];
1485 		/* fall through */
1486 	case 1:
1487 		if ((size = ints[2]) < 256) /* check for small buffer specs */
1488 			size <<= 10 ;
1489                 if (size < MIN_BUFSIZE || size > MAX_BUFSIZE)
1490                         printk("dmasound_setup: invalid write buffer size, using default = %d\n", writeBufSize);
1491                 else
1492                         writeBufSize = size;
1493 	case 0:
1494 		break;
1495 	default:
1496 		printk("dmasound_setup: invalid number of arguments\n");
1497 		return 0;
1498 	}
1499 	return 1;
1500 }
1501 
1502 __setup("dmasound=", dmasound_setup);
1503 
1504 #endif /* !MODULE */
1505 
1506     /*
1507      *  Conversion tables
1508      */
1509 
1510 #ifdef HAS_8BIT_TABLES
1511 /* 8 bit mu-law */
1512 
1513 char dmasound_ulaw2dma8[] = {
1514 	-126,	-122,	-118,	-114,	-110,	-106,	-102,	-98,
1515 	-94,	-90,	-86,	-82,	-78,	-74,	-70,	-66,
1516 	-63,	-61,	-59,	-57,	-55,	-53,	-51,	-49,
1517 	-47,	-45,	-43,	-41,	-39,	-37,	-35,	-33,
1518 	-31,	-30,	-29,	-28,	-27,	-26,	-25,	-24,
1519 	-23,	-22,	-21,	-20,	-19,	-18,	-17,	-16,
1520 	-16,	-15,	-15,	-14,	-14,	-13,	-13,	-12,
1521 	-12,	-11,	-11,	-10,	-10,	-9,	-9,	-8,
1522 	-8,	-8,	-7,	-7,	-7,	-7,	-6,	-6,
1523 	-6,	-6,	-5,	-5,	-5,	-5,	-4,	-4,
1524 	-4,	-4,	-4,	-4,	-3,	-3,	-3,	-3,
1525 	-3,	-3,	-3,	-3,	-2,	-2,	-2,	-2,
1526 	-2,	-2,	-2,	-2,	-2,	-2,	-2,	-2,
1527 	-1,	-1,	-1,	-1,	-1,	-1,	-1,	-1,
1528 	-1,	-1,	-1,	-1,	-1,	-1,	-1,	-1,
1529 	-1,	-1,	-1,	-1,	-1,	-1,	-1,	0,
1530 	125,	121,	117,	113,	109,	105,	101,	97,
1531 	93,	89,	85,	81,	77,	73,	69,	65,
1532 	62,	60,	58,	56,	54,	52,	50,	48,
1533 	46,	44,	42,	40,	38,	36,	34,	32,
1534 	30,	29,	28,	27,	26,	25,	24,	23,
1535 	22,	21,	20,	19,	18,	17,	16,	15,
1536 	15,	14,	14,	13,	13,	12,	12,	11,
1537 	11,	10,	10,	9,	9,	8,	8,	7,
1538 	7,	7,	6,	6,	6,	6,	5,	5,
1539 	5,	5,	4,	4,	4,	4,	3,	3,
1540 	3,	3,	3,	3,	2,	2,	2,	2,
1541 	2,	2,	2,	2,	1,	1,	1,	1,
1542 	1,	1,	1,	1,	1,	1,	1,	1,
1543 	0,	0,	0,	0,	0,	0,	0,	0,
1544 	0,	0,	0,	0,	0,	0,	0,	0,
1545 	0,	0,	0,	0,	0,	0,	0,	0
1546 };
1547 
1548 /* 8 bit A-law */
1549 
1550 char dmasound_alaw2dma8[] = {
1551 	-22,	-21,	-24,	-23,	-18,	-17,	-20,	-19,
1552 	-30,	-29,	-32,	-31,	-26,	-25,	-28,	-27,
1553 	-11,	-11,	-12,	-12,	-9,	-9,	-10,	-10,
1554 	-15,	-15,	-16,	-16,	-13,	-13,	-14,	-14,
1555 	-86,	-82,	-94,	-90,	-70,	-66,	-78,	-74,
1556 	-118,	-114,	-126,	-122,	-102,	-98,	-110,	-106,
1557 	-43,	-41,	-47,	-45,	-35,	-33,	-39,	-37,
1558 	-59,	-57,	-63,	-61,	-51,	-49,	-55,	-53,
1559 	-2,	-2,	-2,	-2,	-2,	-2,	-2,	-2,
1560 	-2,	-2,	-2,	-2,	-2,	-2,	-2,	-2,
1561 	-1,	-1,	-1,	-1,	-1,	-1,	-1,	-1,
1562 	-1,	-1,	-1,	-1,	-1,	-1,	-1,	-1,
1563 	-6,	-6,	-6,	-6,	-5,	-5,	-5,	-5,
1564 	-8,	-8,	-8,	-8,	-7,	-7,	-7,	-7,
1565 	-3,	-3,	-3,	-3,	-3,	-3,	-3,	-3,
1566 	-4,	-4,	-4,	-4,	-4,	-4,	-4,	-4,
1567 	21,	20,	23,	22,	17,	16,	19,	18,
1568 	29,	28,	31,	30,	25,	24,	27,	26,
1569 	10,	10,	11,	11,	8,	8,	9,	9,
1570 	14,	14,	15,	15,	12,	12,	13,	13,
1571 	86,	82,	94,	90,	70,	66,	78,	74,
1572 	118,	114,	126,	122,	102,	98,	110,	106,
1573 	43,	41,	47,	45,	35,	33,	39,	37,
1574 	59,	57,	63,	61,	51,	49,	55,	53,
1575 	1,	1,	1,	1,	1,	1,	1,	1,
1576 	1,	1,	1,	1,	1,	1,	1,	1,
1577 	0,	0,	0,	0,	0,	0,	0,	0,
1578 	0,	0,	0,	0,	0,	0,	0,	0,
1579 	5,	5,	5,	5,	4,	4,	4,	4,
1580 	7,	7,	7,	7,	6,	6,	6,	6,
1581 	2,	2,	2,	2,	2,	2,	2,	2,
1582 	3,	3,	3,	3,	3,	3,	3,	3
1583 };
1584 #endif /* HAS_8BIT_TABLES */
1585 
1586     /*
1587      *  Visible symbols for modules
1588      */
1589 
1590 EXPORT_SYMBOL(dmasound);
1591 EXPORT_SYMBOL(dmasound_init);
1592 #ifdef MODULE
1593 EXPORT_SYMBOL(dmasound_deinit);
1594 #endif
1595 EXPORT_SYMBOL(dmasound_write_sq);
1596 EXPORT_SYMBOL(dmasound_catchRadius);
1597 #ifdef HAS_8BIT_TABLES
1598 EXPORT_SYMBOL(dmasound_ulaw2dma8);
1599 EXPORT_SYMBOL(dmasound_alaw2dma8);
1600 #endif
1601