xref: /openbmc/linux/sound/pci/mixart/mixart_core.c (revision 6d99a79c)
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 <linux/interrupt.h>
24 #include <linux/mutex.h>
25 #include <linux/pci.h>
26 #include <linux/io.h>
27 
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 	if (tailptr < MSG_OUTBOUND_POST_STACK)
61 		return 0; /* error */
62 	if (tailptr >= MSG_OUTBOUND_POST_STACK + MSG_BOUND_STACK_SIZE)
63 		return 0; /* error */
64 
65 	*msg_frame = readl_be(MIXART_MEM(mgr, tailptr));
66 
67 	/* increment the tail index */
68 	tailptr += 4;
69 	if( tailptr >= (MSG_OUTBOUND_POST_STACK+MSG_BOUND_STACK_SIZE) )
70 		tailptr = MSG_OUTBOUND_POST_STACK;
71 	writel_be(tailptr, MIXART_MEM(mgr, MSG_OUTBOUND_POST_TAIL));
72 
73 	return 1;
74 }
75 
76 static int get_msg(struct mixart_mgr *mgr, struct mixart_msg *resp,
77 		   u32 msg_frame_address )
78 {
79 	u32  headptr;
80 	u32  size;
81 	int  err;
82 #ifndef __BIG_ENDIAN
83 	unsigned int i;
84 #endif
85 
86 	mutex_lock(&mgr->msg_lock);
87 	err = 0;
88 
89 	/* copy message descriptor from miXart to driver */
90 	size                =  readl_be(MIXART_MEM(mgr, msg_frame_address));       /* size of descriptor + response */
91 	resp->message_id    =  readl_be(MIXART_MEM(mgr, msg_frame_address + 4));   /* dwMessageID */
92 	resp->uid.object_id =  readl_be(MIXART_MEM(mgr, msg_frame_address + 8));   /* uidDest */
93 	resp->uid.desc      =  readl_be(MIXART_MEM(mgr, msg_frame_address + 12));  /* */
94 
95 	if( (size < MSG_DESCRIPTOR_SIZE) || (resp->size < (size - MSG_DESCRIPTOR_SIZE))) {
96 		err = -EINVAL;
97 		dev_err(&mgr->pci->dev,
98 			"problem with response size = %d\n", size);
99 		goto _clean_exit;
100 	}
101 	size -= MSG_DESCRIPTOR_SIZE;
102 
103 	memcpy_fromio(resp->data, MIXART_MEM(mgr, msg_frame_address + MSG_HEADER_SIZE ), size);
104 	resp->size = size;
105 
106 	/* swap if necessary */
107 #ifndef __BIG_ENDIAN
108 	size /= 4; /* u32 size */
109 	for(i=0; i < size; i++) {
110 		((u32*)resp->data)[i] = be32_to_cpu(((__be32*)resp->data)[i]);
111 	}
112 #endif
113 
114 	/*
115 	 * free message frame address
116 	 */
117 	headptr = readl_be(MIXART_MEM(mgr, MSG_OUTBOUND_FREE_HEAD));
118 
119 	if( (headptr < MSG_OUTBOUND_FREE_STACK) || ( headptr >= (MSG_OUTBOUND_FREE_STACK+MSG_BOUND_STACK_SIZE))) {
120 		err = -EINVAL;
121 		goto _clean_exit;
122 	}
123 
124 	/* give address back to outbound fifo */
125 	writel_be(msg_frame_address, MIXART_MEM(mgr, headptr));
126 
127 	/* increment the outbound free head */
128 	headptr += 4;
129 	if( headptr >= (MSG_OUTBOUND_FREE_STACK+MSG_BOUND_STACK_SIZE) )
130 		headptr = MSG_OUTBOUND_FREE_STACK;
131 
132 	writel_be(headptr, MIXART_MEM(mgr, MSG_OUTBOUND_FREE_HEAD));
133 
134  _clean_exit:
135 	mutex_unlock(&mgr->msg_lock);
136 
137 	return err;
138 }
139 
140 
141 /*
142  * send a message to miXart. return: the msg_frame used for this message
143  */
144 /* call with mgr->msg_lock held! */
145 static int send_msg( struct mixart_mgr *mgr,
146 		     struct mixart_msg *msg,
147 		     int max_answersize,
148 		     int mark_pending,
149 		     u32 *msg_event)
150 {
151 	u32 headptr, tailptr;
152 	u32 msg_frame_address;
153 	int i;
154 
155 	if (snd_BUG_ON(msg->size % 4))
156 		return -EINVAL;
157 
158 	/* get message frame address */
159 	tailptr = readl_be(MIXART_MEM(mgr, MSG_INBOUND_FREE_TAIL));
160 	headptr = readl_be(MIXART_MEM(mgr, MSG_INBOUND_FREE_HEAD));
161 
162 	if (tailptr == headptr) {
163 		dev_err(&mgr->pci->dev, "error: no message frame available\n");
164 		return -EBUSY;
165 	}
166 
167 	if( (tailptr < MSG_INBOUND_FREE_STACK) || (tailptr >= (MSG_INBOUND_FREE_STACK+MSG_BOUND_STACK_SIZE))) {
168 		return -EINVAL;
169 	}
170 
171 	msg_frame_address = readl_be(MIXART_MEM(mgr, tailptr));
172 	writel(0, MIXART_MEM(mgr, tailptr)); /* set address to zero on this fifo position */
173 
174 	/* increment the inbound free tail */
175 	tailptr += 4;
176 	if( tailptr >= (MSG_INBOUND_FREE_STACK+MSG_BOUND_STACK_SIZE) )
177 		tailptr = MSG_INBOUND_FREE_STACK;
178 
179 	writel_be(tailptr, MIXART_MEM(mgr, MSG_INBOUND_FREE_TAIL));
180 
181 	/* TODO : use memcpy_toio() with intermediate buffer to copy the message */
182 
183 	/* copy message descriptor to card memory */
184 	writel_be( msg->size + MSG_DESCRIPTOR_SIZE,      MIXART_MEM(mgr, msg_frame_address) );      /* size of descriptor + request */
185 	writel_be( msg->message_id ,                     MIXART_MEM(mgr, msg_frame_address + 4) );  /* dwMessageID */
186 	writel_be( msg->uid.object_id,                   MIXART_MEM(mgr, msg_frame_address + 8) );  /* uidDest */
187 	writel_be( msg->uid.desc,                        MIXART_MEM(mgr, msg_frame_address + 12) ); /* */
188 	writel_be( MSG_DESCRIPTOR_SIZE,                  MIXART_MEM(mgr, msg_frame_address + 16) ); /* SizeHeader */
189 	writel_be( MSG_DESCRIPTOR_SIZE,                  MIXART_MEM(mgr, msg_frame_address + 20) ); /* OffsetDLL_T16 */
190 	writel_be( msg->size,                            MIXART_MEM(mgr, msg_frame_address + 24) ); /* SizeDLL_T16 */
191 	writel_be( MSG_DESCRIPTOR_SIZE,                  MIXART_MEM(mgr, msg_frame_address + 28) ); /* OffsetDLL_DRV */
192 	writel_be( 0,                                    MIXART_MEM(mgr, msg_frame_address + 32) ); /* SizeDLL_DRV */
193 	writel_be( MSG_DESCRIPTOR_SIZE + max_answersize, MIXART_MEM(mgr, msg_frame_address + 36) ); /* dwExpectedAnswerSize */
194 
195 	/* copy message data to card memory */
196 	for( i=0; i < msg->size; i+=4 ) {
197 		writel_be( *(u32*)(msg->data + i), MIXART_MEM(mgr, MSG_HEADER_SIZE + msg_frame_address + i)  );
198 	}
199 
200 	if( mark_pending ) {
201 		if( *msg_event ) {
202 			/* the pending event is the notification we wait for ! */
203 			mgr->pending_event = *msg_event;
204 		}
205 		else {
206 			/* the pending event is the answer we wait for (same address than the request)! */
207 			mgr->pending_event = msg_frame_address;
208 
209 			/* copy address back to caller */
210 			*msg_event = msg_frame_address;
211 		}
212 	}
213 
214 	/* mark the frame as a request (will have an answer) */
215 	msg_frame_address |= MSG_TYPE_REQUEST;
216 
217 	/* post the frame */
218 	headptr = readl_be(MIXART_MEM(mgr, MSG_INBOUND_POST_HEAD));
219 
220 	if( (headptr < MSG_INBOUND_POST_STACK) || (headptr >= (MSG_INBOUND_POST_STACK+MSG_BOUND_STACK_SIZE))) {
221 		return -EINVAL;
222 	}
223 
224 	writel_be(msg_frame_address, MIXART_MEM(mgr, headptr));
225 
226 	/* increment the inbound post head */
227 	headptr += 4;
228 	if( headptr >= (MSG_INBOUND_POST_STACK+MSG_BOUND_STACK_SIZE) )
229 		headptr = MSG_INBOUND_POST_STACK;
230 
231 	writel_be(headptr, MIXART_MEM(mgr, MSG_INBOUND_POST_HEAD));
232 
233 	return 0;
234 }
235 
236 
237 int snd_mixart_send_msg(struct mixart_mgr *mgr, struct mixart_msg *request, int max_resp_size, void *resp_data)
238 {
239 	struct mixart_msg resp;
240 	u32 msg_frame = 0; /* set to 0, so it's no notification to wait for, but the answer */
241 	int err;
242 	wait_queue_entry_t wait;
243 	long timeout;
244 
245 	init_waitqueue_entry(&wait, current);
246 
247 	mutex_lock(&mgr->msg_lock);
248 	/* send the message */
249 	err = send_msg(mgr, request, max_resp_size, 1, &msg_frame);  /* send and mark the answer pending */
250 	if (err) {
251 		mutex_unlock(&mgr->msg_lock);
252 		return err;
253 	}
254 
255 	set_current_state(TASK_UNINTERRUPTIBLE);
256 	add_wait_queue(&mgr->msg_sleep, &wait);
257 	mutex_unlock(&mgr->msg_lock);
258 	timeout = schedule_timeout(MSG_TIMEOUT_JIFFIES);
259 	remove_wait_queue(&mgr->msg_sleep, &wait);
260 
261 	if (! timeout) {
262 		/* error - no ack */
263 		dev_err(&mgr->pci->dev,
264 			"error: no response on msg %x\n", msg_frame);
265 		return -EIO;
266 	}
267 
268 	/* retrieve the answer into the same struct mixart_msg */
269 	resp.message_id = 0;
270 	resp.uid = (struct mixart_uid){0,0};
271 	resp.data = resp_data;
272 	resp.size = max_resp_size;
273 
274 	err = get_msg(mgr, &resp, msg_frame);
275 
276 	if( request->message_id != resp.message_id )
277 		dev_err(&mgr->pci->dev, "RESPONSE ERROR!\n");
278 
279 	return err;
280 }
281 
282 
283 int snd_mixart_send_msg_wait_notif(struct mixart_mgr *mgr,
284 				   struct mixart_msg *request, u32 notif_event)
285 {
286 	int err;
287 	wait_queue_entry_t wait;
288 	long timeout;
289 
290 	if (snd_BUG_ON(!notif_event))
291 		return -EINVAL;
292 	if (snd_BUG_ON((notif_event & MSG_TYPE_MASK) != MSG_TYPE_NOTIFY))
293 		return -EINVAL;
294 	if (snd_BUG_ON(notif_event & MSG_CANCEL_NOTIFY_MASK))
295 		return -EINVAL;
296 
297 	init_waitqueue_entry(&wait, current);
298 
299 	mutex_lock(&mgr->msg_lock);
300 	/* send the message */
301 	err = send_msg(mgr, request, MSG_DEFAULT_SIZE, 1, &notif_event);  /* send and mark the notification event pending */
302 	if(err) {
303 		mutex_unlock(&mgr->msg_lock);
304 		return err;
305 	}
306 
307 	set_current_state(TASK_UNINTERRUPTIBLE);
308 	add_wait_queue(&mgr->msg_sleep, &wait);
309 	mutex_unlock(&mgr->msg_lock);
310 	timeout = schedule_timeout(MSG_TIMEOUT_JIFFIES);
311 	remove_wait_queue(&mgr->msg_sleep, &wait);
312 
313 	if (! timeout) {
314 		/* error - no ack */
315 		dev_err(&mgr->pci->dev,
316 			"error: notification %x not received\n", notif_event);
317 		return -EIO;
318 	}
319 
320 	return 0;
321 }
322 
323 
324 int snd_mixart_send_msg_nonblock(struct mixart_mgr *mgr, struct mixart_msg *request)
325 {
326 	u32 message_frame;
327 	int err;
328 
329 	/* just send the message (do not mark it as a pending one) */
330 	mutex_lock(&mgr->msg_lock);
331 	err = send_msg(mgr, request, MSG_DEFAULT_SIZE, 0, &message_frame);
332 	mutex_unlock(&mgr->msg_lock);
333 
334 	/* the answer will be handled by snd_struct mixart_msgasklet()  */
335 	atomic_inc(&mgr->msg_processed);
336 
337 	return err;
338 }
339 
340 
341 /* common buffer of interrupt to send/receive messages */
342 static u32 mixart_msg_data[MSG_DEFAULT_SIZE / 4];
343 
344 
345 static void snd_mixart_process_msg(struct mixart_mgr *mgr)
346 {
347 	struct mixart_msg resp;
348 	u32 msg, addr, type;
349 	int err;
350 
351 	while (mgr->msg_fifo_readptr != mgr->msg_fifo_writeptr) {
352 		msg = mgr->msg_fifo[mgr->msg_fifo_readptr];
353 		mgr->msg_fifo_readptr++;
354 		mgr->msg_fifo_readptr %= MSG_FIFO_SIZE;
355 
356 		/* process the message ... */
357 		addr = msg & ~MSG_TYPE_MASK;
358 		type = msg & MSG_TYPE_MASK;
359 
360 		switch (type) {
361 		case MSG_TYPE_ANSWER:
362 			/* answer to a message on that we did not wait for (send_msg_nonblock) */
363 			resp.message_id = 0;
364 			resp.data = mixart_msg_data;
365 			resp.size = sizeof(mixart_msg_data);
366 			err = get_msg(mgr, &resp, addr);
367 			if( err < 0 ) {
368 				dev_err(&mgr->pci->dev,
369 					"error(%d) reading mf %x\n",
370 					err, msg);
371 				break;
372 			}
373 
374 			switch(resp.message_id) {
375 			case MSG_STREAM_START_INPUT_STAGE_PACKET:
376 			case MSG_STREAM_START_OUTPUT_STAGE_PACKET:
377 			case MSG_STREAM_STOP_INPUT_STAGE_PACKET:
378 			case MSG_STREAM_STOP_OUTPUT_STAGE_PACKET:
379 				if(mixart_msg_data[0])
380 					dev_err(&mgr->pci->dev,
381 						"error MSG_STREAM_ST***_***PUT_STAGE_PACKET status=%x\n",
382 						mixart_msg_data[0]);
383 				break;
384 			default:
385 				dev_dbg(&mgr->pci->dev,
386 					"received mf(%x) : msg_id(%x) uid(%x, %x) size(%zd)\n",
387 					   msg, resp.message_id, resp.uid.object_id, resp.uid.desc, resp.size);
388 				break;
389 			}
390 			break;
391  		case MSG_TYPE_NOTIFY:
392 			/* msg contains no address ! do not get_msg() ! */
393 		case MSG_TYPE_COMMAND:
394 			/* get_msg() necessary */
395 		default:
396 			dev_err(&mgr->pci->dev,
397 				"doesn't know what to do with message %x\n",
398 				msg);
399 		} /* switch type */
400 
401 		/* decrement counter */
402 		atomic_dec(&mgr->msg_processed);
403 
404 	} /* while there is a msg in fifo */
405 }
406 
407 
408 irqreturn_t snd_mixart_interrupt(int irq, void *dev_id)
409 {
410 	struct mixart_mgr *mgr = dev_id;
411 	u32 it_reg;
412 
413 	it_reg = readl_le(MIXART_REG(mgr, MIXART_PCI_OMISR_OFFSET));
414 	if( !(it_reg & MIXART_OIDI) ) {
415 		/* this device did not cause the interrupt */
416 		return IRQ_NONE;
417 	}
418 
419 	/* mask all interrupts */
420 	writel_le(MIXART_HOST_ALL_INTERRUPT_MASKED, MIXART_REG(mgr, MIXART_PCI_OMIMR_OFFSET));
421 
422 	/* outdoorbell register clear */
423 	it_reg = readl(MIXART_REG(mgr, MIXART_PCI_ODBR_OFFSET));
424 	writel(it_reg, MIXART_REG(mgr, MIXART_PCI_ODBR_OFFSET));
425 
426 	/* clear interrupt */
427 	writel_le( MIXART_OIDI, MIXART_REG(mgr, MIXART_PCI_OMISR_OFFSET) );
428 
429 	return IRQ_WAKE_THREAD;
430 }
431 
432 irqreturn_t snd_mixart_threaded_irq(int irq, void *dev_id)
433 {
434 	struct mixart_mgr *mgr = dev_id;
435 	int err;
436 	struct mixart_msg resp;
437 	u32 msg;
438 
439 	mutex_lock(&mgr->lock);
440 	/* process interrupt */
441 	while (retrieve_msg_frame(mgr, &msg)) {
442 
443 		switch (msg & MSG_TYPE_MASK) {
444 		case MSG_TYPE_COMMAND:
445 			resp.message_id = 0;
446 			resp.data = mixart_msg_data;
447 			resp.size = sizeof(mixart_msg_data);
448 			err = get_msg(mgr, &resp, msg & ~MSG_TYPE_MASK);
449 			if( err < 0 ) {
450 				dev_err(&mgr->pci->dev,
451 					"interrupt: error(%d) reading mf %x\n",
452 					err, msg);
453 				break;
454 			}
455 
456 			if(resp.message_id == MSG_SERVICES_TIMER_NOTIFY) {
457 				int i;
458 				struct mixart_timer_notify *notify;
459 				notify = (struct mixart_timer_notify *)mixart_msg_data;
460 
461 				for(i=0; i<notify->stream_count; i++) {
462 
463 					u32 buffer_id = notify->streams[i].buffer_id;
464 					unsigned int chip_number =  (buffer_id & MIXART_NOTIFY_CARD_MASK) >> MIXART_NOTIFY_CARD_OFFSET; /* card0 to 3 */
465 					unsigned int pcm_number  =  (buffer_id & MIXART_NOTIFY_PCM_MASK ) >> MIXART_NOTIFY_PCM_OFFSET;  /* pcm0 to 3  */
466 					unsigned int sub_number  =   buffer_id & MIXART_NOTIFY_SUBS_MASK;             /* 0 to MIXART_PLAYBACK_STREAMS */
467 					unsigned int is_capture  = ((buffer_id & MIXART_NOTIFY_CAPT_MASK) != 0);      /* playback == 0 / capture == 1 */
468 
469 					struct snd_mixart *chip  = mgr->chip[chip_number];
470 					struct mixart_stream *stream;
471 
472 					if ((chip_number >= mgr->num_cards) || (pcm_number >= MIXART_PCM_TOTAL) || (sub_number >= MIXART_PLAYBACK_STREAMS)) {
473 						dev_err(&mgr->pci->dev,
474 							"error MSG_SERVICES_TIMER_NOTIFY buffer_id (%x) pos(%d)\n",
475 							   buffer_id, notify->streams[i].sample_pos_low_part);
476 						break;
477 					}
478 
479 					if (is_capture)
480 						stream = &chip->capture_stream[pcm_number];
481 					else
482 						stream = &chip->playback_stream[pcm_number][sub_number];
483 
484 					if (stream->substream && (stream->status == MIXART_STREAM_STATUS_RUNNING)) {
485 						struct snd_pcm_runtime *runtime = stream->substream->runtime;
486 						int elapsed = 0;
487 						u64 sample_count = ((u64)notify->streams[i].sample_pos_high_part) << 32;
488 						sample_count |= notify->streams[i].sample_pos_low_part;
489 
490 						while (1) {
491 							u64 new_elapse_pos = stream->abs_period_elapsed +  runtime->period_size;
492 
493 							if (new_elapse_pos > sample_count) {
494 								break; /* while */
495 							}
496 							else {
497 								elapsed = 1;
498 								stream->buf_periods++;
499 								if (stream->buf_periods >= runtime->periods)
500 									stream->buf_periods = 0;
501 
502 								stream->abs_period_elapsed = new_elapse_pos;
503 							}
504 						}
505 						stream->buf_period_frag = (u32)( sample_count - stream->abs_period_elapsed );
506 
507 						if(elapsed) {
508 							mutex_unlock(&mgr->lock);
509 							snd_pcm_period_elapsed(stream->substream);
510 							mutex_lock(&mgr->lock);
511 						}
512 					}
513 				}
514 				break;
515 			}
516 			if(resp.message_id == MSG_SERVICES_REPORT_TRACES) {
517 				if(resp.size > 1) {
518 #ifndef __BIG_ENDIAN
519 					/* Traces are text: the swapped msg_data has to be swapped back ! */
520 					int i;
521 					for(i=0; i<(resp.size/4); i++) {
522 						((__be32*)mixart_msg_data)[i] = cpu_to_be32((mixart_msg_data)[i]);
523 					}
524 #endif
525 					((char*)mixart_msg_data)[resp.size - 1] = 0;
526 					dev_dbg(&mgr->pci->dev,
527 						"MIXART TRACE : %s\n",
528 						(char *)mixart_msg_data);
529 				}
530 				break;
531 			}
532 
533 			dev_dbg(&mgr->pci->dev, "command %x not handled\n",
534 				resp.message_id);
535 			break;
536 
537 		case MSG_TYPE_NOTIFY:
538 			if(msg & MSG_CANCEL_NOTIFY_MASK) {
539 				msg &= ~MSG_CANCEL_NOTIFY_MASK;
540 				dev_err(&mgr->pci->dev,
541 					"canceled notification %x !\n", msg);
542 			}
543 			/* fall through */
544 		case MSG_TYPE_ANSWER:
545 			/* answer or notification to a message we are waiting for*/
546 			mutex_lock(&mgr->msg_lock);
547 			if( (msg & ~MSG_TYPE_MASK) == mgr->pending_event ) {
548 				wake_up(&mgr->msg_sleep);
549 				mgr->pending_event = 0;
550 			}
551 			/* answer to a message we did't want to wait for */
552 			else {
553 				mgr->msg_fifo[mgr->msg_fifo_writeptr] = msg;
554 				mgr->msg_fifo_writeptr++;
555 				mgr->msg_fifo_writeptr %= MSG_FIFO_SIZE;
556 				snd_mixart_process_msg(mgr);
557 			}
558 			mutex_unlock(&mgr->msg_lock);
559 			break;
560 		case MSG_TYPE_REQUEST:
561 		default:
562 			dev_dbg(&mgr->pci->dev,
563 				"interrupt received request %x\n", msg);
564 			/* TODO : are there things to do here ? */
565 			break;
566 		} /* switch on msg type */
567 	} /* while there are msgs */
568 
569 	/* allow interrupt again */
570 	writel_le( MIXART_ALLOW_OUTBOUND_DOORBELL, MIXART_REG( mgr, MIXART_PCI_OMIMR_OFFSET));
571 
572 	mutex_unlock(&mgr->lock);
573 
574 	return IRQ_HANDLED;
575 }
576 
577 
578 void snd_mixart_init_mailbox(struct mixart_mgr *mgr)
579 {
580 	writel( 0, MIXART_MEM( mgr, MSG_HOST_RSC_PROTECTION ) );
581 	writel( 0, MIXART_MEM( mgr, MSG_AGENT_RSC_PROTECTION ) );
582 
583 	/* allow outbound messagebox to generate interrupts */
584 	if(mgr->irq >= 0) {
585 		writel_le( MIXART_ALLOW_OUTBOUND_DOORBELL, MIXART_REG( mgr, MIXART_PCI_OMIMR_OFFSET));
586 	}
587 	return;
588 }
589 
590 void snd_mixart_exit_mailbox(struct mixart_mgr *mgr)
591 {
592 	/* no more interrupts on outbound messagebox */
593 	writel_le( MIXART_HOST_ALL_INTERRUPT_MASKED, MIXART_REG( mgr, MIXART_PCI_OMIMR_OFFSET));
594 	return;
595 }
596 
597 void snd_mixart_reset_board(struct mixart_mgr *mgr)
598 {
599 	/* reset miXart */
600 	writel_be( 1, MIXART_REG(mgr, MIXART_BA1_BRUTAL_RESET_OFFSET) );
601 	return;
602 }
603