xref: /openbmc/linux/sound/pci/mixart/mixart_core.c (revision 64c70b1c)
1 /*
2  * Driver for Digigram miXart soundcards
3  *
4  * low level interface with interrupt handling and mail box implementation
5  *
6  * Copyright (c) 2003 by Digigram <alsa@digigram.com>
7  *
8  *   This program is free software; you can redistribute it and/or modify
9  *   it under the terms of the GNU General Public License as published by
10  *   the Free Software Foundation; either version 2 of the License, or
11  *   (at your option) any later version.
12  *
13  *   This program is distributed in the hope that it will be useful,
14  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
15  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  *   GNU General Public License for more details.
17  *
18  *   You should have received a copy of the GNU General Public License
19  *   along with this program; if not, write to the Free Software
20  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
21  */
22 
23 #include <sound/driver.h>
24 #include <linux/interrupt.h>
25 #include <linux/mutex.h>
26 
27 #include <asm/io.h>
28 #include <sound/core.h>
29 #include "mixart.h"
30 #include "mixart_hwdep.h"
31 #include "mixart_core.h"
32 
33 
34 #define MSG_TIMEOUT_JIFFIES         (400 * HZ) / 1000 /* 400 ms */
35 
36 #define MSG_DESCRIPTOR_SIZE         0x24
37 #define MSG_HEADER_SIZE             (MSG_DESCRIPTOR_SIZE + 4)
38 
39 #define MSG_DEFAULT_SIZE            512
40 
41 #define MSG_TYPE_MASK               0x00000003    /* mask for following types */
42 #define MSG_TYPE_NOTIFY             0             /* embedded -> driver (only notification, do not get_msg() !) */
43 #define MSG_TYPE_COMMAND            1             /* driver <-> embedded (a command has no answer) */
44 #define MSG_TYPE_REQUEST            2             /* driver -> embedded (request will get an answer back) */
45 #define MSG_TYPE_ANSWER             3             /* embedded -> driver */
46 #define MSG_CANCEL_NOTIFY_MASK      0x80000000    /* this bit is set for a notification that has been canceled */
47 
48 
49 static int retrieve_msg_frame(struct mixart_mgr *mgr, u32 *msg_frame)
50 {
51 	/* read the message frame fifo */
52 	u32 headptr, tailptr;
53 
54 	tailptr = readl_be(MIXART_MEM(mgr, MSG_OUTBOUND_POST_TAIL));
55 	headptr = readl_be(MIXART_MEM(mgr, MSG_OUTBOUND_POST_HEAD));
56 
57 	if (tailptr == headptr)
58 		return 0; /* no message posted */
59 
60 	snd_assert( tailptr >= MSG_OUTBOUND_POST_STACK, return 0); /* error */
61 	snd_assert( tailptr < (MSG_OUTBOUND_POST_STACK+MSG_BOUND_STACK_SIZE), return 0); /* error */
62 
63 	*msg_frame = readl_be(MIXART_MEM(mgr, tailptr));
64 
65 	/* increment the tail index */
66 	tailptr += 4;
67 	if( tailptr >= (MSG_OUTBOUND_POST_STACK+MSG_BOUND_STACK_SIZE) )
68 		tailptr = MSG_OUTBOUND_POST_STACK;
69 	writel_be(tailptr, MIXART_MEM(mgr, MSG_OUTBOUND_POST_TAIL));
70 
71 	return 1;
72 }
73 
74 static int get_msg(struct mixart_mgr *mgr, struct mixart_msg *resp,
75 		   u32 msg_frame_address )
76 {
77 	unsigned long flags;
78 	u32  headptr;
79 	u32  size;
80 	int  err;
81 #ifndef __BIG_ENDIAN
82 	unsigned int i;
83 #endif
84 
85 	spin_lock_irqsave(&mgr->msg_lock, flags);
86 	err = 0;
87 
88 	/* copy message descriptor from miXart to driver */
89 	size                =  readl_be(MIXART_MEM(mgr, msg_frame_address));       /* size of descriptor + response */
90 	resp->message_id    =  readl_be(MIXART_MEM(mgr, msg_frame_address + 4));   /* dwMessageID */
91 	resp->uid.object_id =  readl_be(MIXART_MEM(mgr, msg_frame_address + 8));   /* uidDest */
92 	resp->uid.desc      =  readl_be(MIXART_MEM(mgr, msg_frame_address + 12));  /* */
93 
94 	if( (size < MSG_DESCRIPTOR_SIZE) || (resp->size < (size - MSG_DESCRIPTOR_SIZE))) {
95 		err = -EINVAL;
96 		snd_printk(KERN_ERR "problem with response size = %d\n", size);
97 		goto _clean_exit;
98 	}
99 	size -= MSG_DESCRIPTOR_SIZE;
100 
101 	memcpy_fromio(resp->data, MIXART_MEM(mgr, msg_frame_address + MSG_HEADER_SIZE ), size);
102 	resp->size = size;
103 
104 	/* swap if necessary */
105 #ifndef __BIG_ENDIAN
106 	size /= 4; /* u32 size */
107 	for(i=0; i < size; i++) {
108 		((u32*)resp->data)[i] = be32_to_cpu(((u32*)resp->data)[i]);
109 	}
110 #endif
111 
112 	/*
113 	 * free message frame address
114 	 */
115 	headptr = readl_be(MIXART_MEM(mgr, MSG_OUTBOUND_FREE_HEAD));
116 
117 	if( (headptr < MSG_OUTBOUND_FREE_STACK) || ( headptr >= (MSG_OUTBOUND_FREE_STACK+MSG_BOUND_STACK_SIZE))) {
118 		err = -EINVAL;
119 		goto _clean_exit;
120 	}
121 
122 	/* give address back to outbound fifo */
123 	writel_be(msg_frame_address, MIXART_MEM(mgr, headptr));
124 
125 	/* increment the outbound free head */
126 	headptr += 4;
127 	if( headptr >= (MSG_OUTBOUND_FREE_STACK+MSG_BOUND_STACK_SIZE) )
128 		headptr = MSG_OUTBOUND_FREE_STACK;
129 
130 	writel_be(headptr, MIXART_MEM(mgr, MSG_OUTBOUND_FREE_HEAD));
131 
132  _clean_exit:
133 	spin_unlock_irqrestore(&mgr->msg_lock, flags);
134 
135 	return err;
136 }
137 
138 
139 /*
140  * send a message to miXart. return: the msg_frame used for this message
141  */
142 /* call with mgr->msg_lock held! */
143 static int send_msg( struct mixart_mgr *mgr,
144 		     struct mixart_msg *msg,
145 		     int max_answersize,
146 		     int mark_pending,
147 		     u32 *msg_event)
148 {
149 	u32 headptr, tailptr;
150 	u32 msg_frame_address;
151 	int err, i;
152 
153 	snd_assert(msg->size % 4 == 0, return -EINVAL);
154 
155 	err = 0;
156 
157 	/* get message frame address */
158 	tailptr = readl_be(MIXART_MEM(mgr, MSG_INBOUND_FREE_TAIL));
159 	headptr = readl_be(MIXART_MEM(mgr, MSG_INBOUND_FREE_HEAD));
160 
161 	if (tailptr == headptr) {
162 		snd_printk(KERN_ERR "error: no message frame available\n");
163 		return -EBUSY;
164 	}
165 
166 	if( (tailptr < MSG_INBOUND_FREE_STACK) || (tailptr >= (MSG_INBOUND_FREE_STACK+MSG_BOUND_STACK_SIZE))) {
167 		return -EINVAL;
168 	}
169 
170 	msg_frame_address = readl_be(MIXART_MEM(mgr, tailptr));
171 	writel(0, MIXART_MEM(mgr, tailptr)); /* set address to zero on this fifo position */
172 
173 	/* increment the inbound free tail */
174 	tailptr += 4;
175 	if( tailptr >= (MSG_INBOUND_FREE_STACK+MSG_BOUND_STACK_SIZE) )
176 		tailptr = MSG_INBOUND_FREE_STACK;
177 
178 	writel_be(tailptr, MIXART_MEM(mgr, MSG_INBOUND_FREE_TAIL));
179 
180 	/* TODO : use memcpy_toio() with intermediate buffer to copy the message */
181 
182 	/* copy message descriptor to card memory */
183 	writel_be( msg->size + MSG_DESCRIPTOR_SIZE,      MIXART_MEM(mgr, msg_frame_address) );      /* size of descriptor + request */
184 	writel_be( msg->message_id ,                     MIXART_MEM(mgr, msg_frame_address + 4) );  /* dwMessageID */
185 	writel_be( msg->uid.object_id,                   MIXART_MEM(mgr, msg_frame_address + 8) );  /* uidDest */
186 	writel_be( msg->uid.desc,                        MIXART_MEM(mgr, msg_frame_address + 12) ); /* */
187 	writel_be( MSG_DESCRIPTOR_SIZE,                  MIXART_MEM(mgr, msg_frame_address + 16) ); /* SizeHeader */
188 	writel_be( MSG_DESCRIPTOR_SIZE,                  MIXART_MEM(mgr, msg_frame_address + 20) ); /* OffsetDLL_T16 */
189 	writel_be( msg->size,                            MIXART_MEM(mgr, msg_frame_address + 24) ); /* SizeDLL_T16 */
190 	writel_be( MSG_DESCRIPTOR_SIZE,                  MIXART_MEM(mgr, msg_frame_address + 28) ); /* OffsetDLL_DRV */
191 	writel_be( 0,                                    MIXART_MEM(mgr, msg_frame_address + 32) ); /* SizeDLL_DRV */
192 	writel_be( MSG_DESCRIPTOR_SIZE + max_answersize, MIXART_MEM(mgr, msg_frame_address + 36) ); /* dwExpectedAnswerSize */
193 
194 	/* copy message data to card memory */
195 	for( i=0; i < msg->size; i+=4 ) {
196 		writel_be( *(u32*)(msg->data + i), MIXART_MEM(mgr, MSG_HEADER_SIZE + msg_frame_address + i)  );
197 	}
198 
199 	if( mark_pending ) {
200 		if( *msg_event ) {
201 			/* the pending event is the notification we wait for ! */
202 			mgr->pending_event = *msg_event;
203 		}
204 		else {
205 			/* the pending event is the answer we wait for (same address than the request)! */
206 			mgr->pending_event = msg_frame_address;
207 
208 			/* copy address back to caller */
209 			*msg_event = msg_frame_address;
210 		}
211 	}
212 
213 	/* mark the frame as a request (will have an answer) */
214 	msg_frame_address |= MSG_TYPE_REQUEST;
215 
216 	/* post the frame */
217 	headptr = readl_be(MIXART_MEM(mgr, MSG_INBOUND_POST_HEAD));
218 
219 	if( (headptr < MSG_INBOUND_POST_STACK) || (headptr >= (MSG_INBOUND_POST_STACK+MSG_BOUND_STACK_SIZE))) {
220 		return -EINVAL;
221 	}
222 
223 	writel_be(msg_frame_address, MIXART_MEM(mgr, headptr));
224 
225 	/* increment the inbound post head */
226 	headptr += 4;
227 	if( headptr >= (MSG_INBOUND_POST_STACK+MSG_BOUND_STACK_SIZE) )
228 		headptr = MSG_INBOUND_POST_STACK;
229 
230 	writel_be(headptr, MIXART_MEM(mgr, MSG_INBOUND_POST_HEAD));
231 
232 	return 0;
233 }
234 
235 
236 int snd_mixart_send_msg(struct mixart_mgr *mgr, struct mixart_msg *request, int max_resp_size, void *resp_data)
237 {
238 	struct mixart_msg resp;
239 	u32 msg_frame = 0; /* set to 0, so it's no notification to wait for, but the answer */
240 	int err;
241 	wait_queue_t wait;
242 	long timeout;
243 
244 	mutex_lock(&mgr->msg_mutex);
245 
246 	init_waitqueue_entry(&wait, current);
247 
248 	spin_lock_irq(&mgr->msg_lock);
249 	/* send the message */
250 	err = send_msg(mgr, request, max_resp_size, 1, &msg_frame);  /* send and mark the answer pending */
251 	if (err) {
252 		spin_unlock_irq(&mgr->msg_lock);
253 		mutex_unlock(&mgr->msg_mutex);
254 		return err;
255 	}
256 
257 	set_current_state(TASK_UNINTERRUPTIBLE);
258 	add_wait_queue(&mgr->msg_sleep, &wait);
259 	spin_unlock_irq(&mgr->msg_lock);
260 	timeout = schedule_timeout(MSG_TIMEOUT_JIFFIES);
261 	remove_wait_queue(&mgr->msg_sleep, &wait);
262 
263 	if (! timeout) {
264 		/* error - no ack */
265 		mutex_unlock(&mgr->msg_mutex);
266 		snd_printk(KERN_ERR "error: no reponse on msg %x\n", msg_frame);
267 		return -EIO;
268 	}
269 
270 	/* retrieve the answer into the same struct mixart_msg */
271 	resp.message_id = 0;
272 	resp.uid = (struct mixart_uid){0,0};
273 	resp.data = resp_data;
274 	resp.size = max_resp_size;
275 
276 	err = get_msg(mgr, &resp, msg_frame);
277 
278 	if( request->message_id != resp.message_id )
279 		snd_printk(KERN_ERR "REPONSE ERROR!\n");
280 
281 	mutex_unlock(&mgr->msg_mutex);
282 	return err;
283 }
284 
285 
286 int snd_mixart_send_msg_wait_notif(struct mixart_mgr *mgr,
287 				   struct mixart_msg *request, u32 notif_event)
288 {
289 	int err;
290 	wait_queue_t wait;
291 	long timeout;
292 
293 	snd_assert(notif_event != 0, return -EINVAL);
294 	snd_assert((notif_event & MSG_TYPE_MASK) == MSG_TYPE_NOTIFY, return -EINVAL);
295 	snd_assert((notif_event & MSG_CANCEL_NOTIFY_MASK) == 0, return -EINVAL);
296 
297 	mutex_lock(&mgr->msg_mutex);
298 
299 	init_waitqueue_entry(&wait, current);
300 
301 	spin_lock_irq(&mgr->msg_lock);
302 	/* send the message */
303 	err = send_msg(mgr, request, MSG_DEFAULT_SIZE, 1, &notif_event);  /* send and mark the notification event pending */
304 	if(err) {
305 		spin_unlock_irq(&mgr->msg_lock);
306 		mutex_unlock(&mgr->msg_mutex);
307 		return err;
308 	}
309 
310 	set_current_state(TASK_UNINTERRUPTIBLE);
311 	add_wait_queue(&mgr->msg_sleep, &wait);
312 	spin_unlock_irq(&mgr->msg_lock);
313 	timeout = schedule_timeout(MSG_TIMEOUT_JIFFIES);
314 	remove_wait_queue(&mgr->msg_sleep, &wait);
315 
316 	if (! timeout) {
317 		/* error - no ack */
318 		mutex_unlock(&mgr->msg_mutex);
319 		snd_printk(KERN_ERR "error: notification %x not received\n", notif_event);
320 		return -EIO;
321 	}
322 
323 	mutex_unlock(&mgr->msg_mutex);
324 	return 0;
325 }
326 
327 
328 int snd_mixart_send_msg_nonblock(struct mixart_mgr *mgr, struct mixart_msg *request)
329 {
330 	u32 message_frame;
331 	unsigned long flags;
332 	int err;
333 
334 	/* just send the message (do not mark it as a pending one) */
335 	spin_lock_irqsave(&mgr->msg_lock, flags);
336 	err = send_msg(mgr, request, MSG_DEFAULT_SIZE, 0, &message_frame);
337 	spin_unlock_irqrestore(&mgr->msg_lock, flags);
338 
339 	/* the answer will be handled by snd_struct mixart_msgasklet()  */
340 	atomic_inc(&mgr->msg_processed);
341 
342 	return err;
343 }
344 
345 
346 /* common buffer of tasklet and interrupt to send/receive messages */
347 static u32 mixart_msg_data[MSG_DEFAULT_SIZE / 4];
348 
349 
350 void snd_mixart_msg_tasklet(unsigned long arg)
351 {
352 	struct mixart_mgr *mgr = ( struct mixart_mgr*)(arg);
353 	struct mixart_msg resp;
354 	u32 msg, addr, type;
355 	int err;
356 
357 	spin_lock(&mgr->lock);
358 
359 	while (mgr->msg_fifo_readptr != mgr->msg_fifo_writeptr) {
360 		msg = mgr->msg_fifo[mgr->msg_fifo_readptr];
361 		mgr->msg_fifo_readptr++;
362 		mgr->msg_fifo_readptr %= MSG_FIFO_SIZE;
363 
364 		/* process the message ... */
365 		addr = msg & ~MSG_TYPE_MASK;
366 		type = msg & MSG_TYPE_MASK;
367 
368 		switch (type) {
369 		case MSG_TYPE_ANSWER:
370 			/* answer to a message on that we did not wait for (send_msg_nonblock) */
371 			resp.message_id = 0;
372 			resp.data = mixart_msg_data;
373 			resp.size = sizeof(mixart_msg_data);
374 			err = get_msg(mgr, &resp, addr);
375 			if( err < 0 ) {
376 				snd_printk(KERN_ERR "tasklet: error(%d) reading mf %x\n", err, msg);
377 				break;
378 			}
379 
380 			switch(resp.message_id) {
381 			case MSG_STREAM_START_INPUT_STAGE_PACKET:
382 			case MSG_STREAM_START_OUTPUT_STAGE_PACKET:
383 			case MSG_STREAM_STOP_INPUT_STAGE_PACKET:
384 			case MSG_STREAM_STOP_OUTPUT_STAGE_PACKET:
385 				if(mixart_msg_data[0])
386 					snd_printk(KERN_ERR "tasklet : error MSG_STREAM_ST***_***PUT_STAGE_PACKET status=%x\n", mixart_msg_data[0]);
387 				break;
388 			default:
389 				snd_printdd("tasklet received mf(%x) : msg_id(%x) uid(%x, %x) size(%zd)\n",
390 					   msg, resp.message_id, resp.uid.object_id, resp.uid.desc, resp.size);
391 				break;
392 			}
393 			break;
394  		case MSG_TYPE_NOTIFY:
395 			/* msg contains no address ! do not get_msg() ! */
396 		case MSG_TYPE_COMMAND:
397 			/* get_msg() necessary */
398 		default:
399 			snd_printk(KERN_ERR "tasklet doesn't know what to do with message %x\n", msg);
400 		} /* switch type */
401 
402 		/* decrement counter */
403 		atomic_dec(&mgr->msg_processed);
404 
405 	} /* while there is a msg in fifo */
406 
407 	spin_unlock(&mgr->lock);
408 }
409 
410 
411 irqreturn_t snd_mixart_interrupt(int irq, void *dev_id)
412 {
413 	struct mixart_mgr *mgr = dev_id;
414 	int err;
415 	struct mixart_msg resp;
416 
417 	u32 msg;
418 	u32 it_reg;
419 
420 	spin_lock(&mgr->lock);
421 
422 	it_reg = readl_le(MIXART_REG(mgr, MIXART_PCI_OMISR_OFFSET));
423 	if( !(it_reg & MIXART_OIDI) ) {
424 		/* this device did not cause the interrupt */
425 		spin_unlock(&mgr->lock);
426 		return IRQ_NONE;
427 	}
428 
429 	/* mask all interrupts */
430 	writel_le(MIXART_HOST_ALL_INTERRUPT_MASKED, MIXART_REG(mgr, MIXART_PCI_OMIMR_OFFSET));
431 
432 	/* outdoorbell register clear */
433 	it_reg = readl(MIXART_REG(mgr, MIXART_PCI_ODBR_OFFSET));
434 	writel(it_reg, MIXART_REG(mgr, MIXART_PCI_ODBR_OFFSET));
435 
436 	/* clear interrupt */
437 	writel_le( MIXART_OIDI, MIXART_REG(mgr, MIXART_PCI_OMISR_OFFSET) );
438 
439 	/* process interrupt */
440 	while (retrieve_msg_frame(mgr, &msg)) {
441 
442 		switch (msg & MSG_TYPE_MASK) {
443 		case MSG_TYPE_COMMAND:
444 			resp.message_id = 0;
445 			resp.data = mixart_msg_data;
446 			resp.size = sizeof(mixart_msg_data);
447 			err = get_msg(mgr, &resp, msg & ~MSG_TYPE_MASK);
448 			if( err < 0 ) {
449 				snd_printk(KERN_ERR "interrupt: error(%d) reading mf %x\n", err, msg);
450 				break;
451 			}
452 
453 			if(resp.message_id == MSG_SERVICES_TIMER_NOTIFY) {
454 				int i;
455 				struct mixart_timer_notify *notify;
456 				notify = (struct mixart_timer_notify *)mixart_msg_data;
457 
458 				for(i=0; i<notify->stream_count; i++) {
459 
460 					u32 buffer_id = notify->streams[i].buffer_id;
461 					unsigned int chip_number =  (buffer_id & MIXART_NOTIFY_CARD_MASK) >> MIXART_NOTIFY_CARD_OFFSET; /* card0 to 3 */
462 					unsigned int pcm_number  =  (buffer_id & MIXART_NOTIFY_PCM_MASK ) >> MIXART_NOTIFY_PCM_OFFSET;  /* pcm0 to 3  */
463 					unsigned int sub_number  =   buffer_id & MIXART_NOTIFY_SUBS_MASK;             /* 0 to MIXART_PLAYBACK_STREAMS */
464 					unsigned int is_capture  = ((buffer_id & MIXART_NOTIFY_CAPT_MASK) != 0);      /* playback == 0 / capture == 1 */
465 
466 					struct snd_mixart *chip  = mgr->chip[chip_number];
467 					struct mixart_stream *stream;
468 
469 					if ((chip_number >= mgr->num_cards) || (pcm_number >= MIXART_PCM_TOTAL) || (sub_number >= MIXART_PLAYBACK_STREAMS)) {
470 						snd_printk(KERN_ERR "error MSG_SERVICES_TIMER_NOTIFY buffer_id (%x) pos(%d)\n",
471 							   buffer_id, notify->streams[i].sample_pos_low_part);
472 						break;
473 					}
474 
475 					if (is_capture)
476 						stream = &chip->capture_stream[pcm_number];
477 					else
478 						stream = &chip->playback_stream[pcm_number][sub_number];
479 
480 					if (stream->substream && (stream->status == MIXART_STREAM_STATUS_RUNNING)) {
481 						struct snd_pcm_runtime *runtime = stream->substream->runtime;
482 						int elapsed = 0;
483 						u64 sample_count = ((u64)notify->streams[i].sample_pos_high_part) << 32;
484 						sample_count |= notify->streams[i].sample_pos_low_part;
485 
486 						while (1) {
487 							u64 new_elapse_pos = stream->abs_period_elapsed +  runtime->period_size;
488 
489 							if (new_elapse_pos > sample_count) {
490 								break; /* while */
491 							}
492 							else {
493 								elapsed = 1;
494 								stream->buf_periods++;
495 								if (stream->buf_periods >= runtime->periods)
496 									stream->buf_periods = 0;
497 
498 								stream->abs_period_elapsed = new_elapse_pos;
499 							}
500 						}
501 						stream->buf_period_frag = (u32)( sample_count - stream->abs_period_elapsed );
502 
503 						if(elapsed) {
504 							spin_unlock(&mgr->lock);
505 							snd_pcm_period_elapsed(stream->substream);
506 							spin_lock(&mgr->lock);
507 						}
508 					}
509 				}
510 				break;
511 			}
512 			if(resp.message_id == MSG_SERVICES_REPORT_TRACES) {
513 				if(resp.size > 1) {
514 #ifndef __BIG_ENDIAN
515 					/* Traces are text: the swapped msg_data has to be swapped back ! */
516 					int i;
517 					for(i=0; i<(resp.size/4); i++) {
518 						(mixart_msg_data)[i] = cpu_to_be32((mixart_msg_data)[i]);
519 					}
520 #endif
521 					((char*)mixart_msg_data)[resp.size - 1] = 0;
522 					snd_printdd("MIXART TRACE : %s\n", (char*)mixart_msg_data);
523 				}
524 				break;
525 			}
526 
527 			snd_printdd("command %x not handled\n", resp.message_id);
528 			break;
529 
530 		case MSG_TYPE_NOTIFY:
531 			if(msg & MSG_CANCEL_NOTIFY_MASK) {
532 				msg &= ~MSG_CANCEL_NOTIFY_MASK;
533 				snd_printk(KERN_ERR "canceled notification %x !\n", msg);
534 			}
535 			/* no break, continue ! */
536 		case MSG_TYPE_ANSWER:
537 			/* answer or notification to a message we are waiting for*/
538 			spin_lock(&mgr->msg_lock);
539 			if( (msg & ~MSG_TYPE_MASK) == mgr->pending_event ) {
540 				wake_up(&mgr->msg_sleep);
541 				mgr->pending_event = 0;
542 			}
543 			/* answer to a message we did't want to wait for */
544 			else {
545 				mgr->msg_fifo[mgr->msg_fifo_writeptr] = msg;
546 				mgr->msg_fifo_writeptr++;
547 				mgr->msg_fifo_writeptr %= MSG_FIFO_SIZE;
548 				tasklet_hi_schedule(&mgr->msg_taskq);
549 			}
550 			spin_unlock(&mgr->msg_lock);
551 			break;
552 		case MSG_TYPE_REQUEST:
553 		default:
554 			snd_printdd("interrupt received request %x\n", msg);
555 			/* TODO : are there things to do here ? */
556 			break;
557 		} /* switch on msg type */
558 	} /* while there are msgs */
559 
560 	/* allow interrupt again */
561 	writel_le( MIXART_ALLOW_OUTBOUND_DOORBELL, MIXART_REG( mgr, MIXART_PCI_OMIMR_OFFSET));
562 
563 	spin_unlock(&mgr->lock);
564 
565 	return IRQ_HANDLED;
566 }
567 
568 
569 void snd_mixart_init_mailbox(struct mixart_mgr *mgr)
570 {
571 	writel( 0, MIXART_MEM( mgr, MSG_HOST_RSC_PROTECTION ) );
572 	writel( 0, MIXART_MEM( mgr, MSG_AGENT_RSC_PROTECTION ) );
573 
574 	/* allow outbound messagebox to generate interrupts */
575 	if(mgr->irq >= 0) {
576 		writel_le( MIXART_ALLOW_OUTBOUND_DOORBELL, MIXART_REG( mgr, MIXART_PCI_OMIMR_OFFSET));
577 	}
578 	return;
579 }
580 
581 void snd_mixart_exit_mailbox(struct mixart_mgr *mgr)
582 {
583 	/* no more interrupts on outbound messagebox */
584 	writel_le( MIXART_HOST_ALL_INTERRUPT_MASKED, MIXART_REG( mgr, MIXART_PCI_OMIMR_OFFSET));
585 	return;
586 }
587 
588 void snd_mixart_reset_board(struct mixart_mgr *mgr)
589 {
590 	/* reset miXart */
591 	writel_be( 1, MIXART_REG(mgr, MIXART_BA1_BRUTAL_RESET_OFFSET) );
592 	return;
593 }
594