xref: /openbmc/linux/sound/pci/mixart/mixart_core.c (revision 1da177e4)
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 <asm/io.h>
26 #include <sound/core.h>
27 #include "mixart.h"
28 #include "mixart_hwdep.h"
29 #include "mixart_core.h"
30 
31 
32 #define MSG_TIMEOUT_JIFFIES         (400 * HZ) / 1000 /* 400 ms */
33 
34 #define MSG_DESCRIPTOR_SIZE         0x24
35 #define MSG_HEADER_SIZE             (MSG_DESCRIPTOR_SIZE + 4)
36 
37 #define MSG_DEFAULT_SIZE            512
38 
39 #define MSG_TYPE_MASK               0x00000003    /* mask for following types */
40 #define MSG_TYPE_NOTIFY             0             /* embedded -> driver (only notification, do not get_msg() !) */
41 #define MSG_TYPE_COMMAND            1             /* driver <-> embedded (a command has no answer) */
42 #define MSG_TYPE_REQUEST            2             /* driver -> embedded (request will get an answer back) */
43 #define MSG_TYPE_ANSWER             3             /* embedded -> driver */
44 #define MSG_CANCEL_NOTIFY_MASK      0x80000000    /* this bit is set for a notification that has been canceled */
45 
46 
47 static int retrieve_msg_frame(mixart_mgr_t *mgr, u32 *msg_frame)
48 {
49 	/* read the message frame fifo */
50 	u32 headptr, tailptr;
51 
52 	tailptr = readl_be(MIXART_MEM(mgr, MSG_OUTBOUND_POST_TAIL));
53 	headptr = readl_be(MIXART_MEM(mgr, MSG_OUTBOUND_POST_HEAD));
54 
55 	if (tailptr == headptr)
56 		return 0; /* no message posted */
57 
58 	snd_assert( tailptr >= MSG_OUTBOUND_POST_STACK, return 0); /* error */
59 	snd_assert( tailptr < (MSG_OUTBOUND_POST_STACK+MSG_BOUND_STACK_SIZE), return 0); /* error */
60 
61 	*msg_frame = readl_be(MIXART_MEM(mgr, tailptr));
62 
63 	/* increment the tail index */
64 	tailptr += 4;
65 	if( tailptr >= (MSG_OUTBOUND_POST_STACK+MSG_BOUND_STACK_SIZE) )
66 		tailptr = MSG_OUTBOUND_POST_STACK;
67 	writel_be(tailptr, MIXART_MEM(mgr, MSG_OUTBOUND_POST_TAIL));
68 
69 	return 1;
70 }
71 
72 static int get_msg(mixart_mgr_t *mgr, mixart_msg_t *resp, u32 msg_frame_address )
73 {
74 	unsigned long flags;
75 	u32  headptr;
76 	u32  size;
77 	int  err;
78 #ifndef __BIG_ENDIAN
79 	unsigned int i;
80 #endif
81 
82 	spin_lock_irqsave(&mgr->msg_lock, flags);
83 	err = 0;
84 
85 	/* copy message descriptor from miXart to driver */
86 	size                =  readl_be(MIXART_MEM(mgr, msg_frame_address));       /* size of descriptor + response */
87 	resp->message_id    =  readl_be(MIXART_MEM(mgr, msg_frame_address + 4));   /* dwMessageID */
88 	resp->uid.object_id =  readl_be(MIXART_MEM(mgr, msg_frame_address + 8));   /* uidDest */
89 	resp->uid.desc      =  readl_be(MIXART_MEM(mgr, msg_frame_address + 12));  /* */
90 
91 	if( (size < MSG_DESCRIPTOR_SIZE) || (resp->size < (size - MSG_DESCRIPTOR_SIZE))) {
92 		err = -EINVAL;
93 		snd_printk(KERN_ERR "problem with response size = %d\n", size);
94 		goto _clean_exit;
95 	}
96 	size -= MSG_DESCRIPTOR_SIZE;
97 
98 	memcpy_fromio(resp->data, MIXART_MEM(mgr, msg_frame_address + MSG_HEADER_SIZE ), size);
99 	resp->size = size;
100 
101 	/* swap if necessary */
102 #ifndef __BIG_ENDIAN
103 	size /= 4; /* u32 size */
104 	for(i=0; i < size; i++) {
105 		((u32*)resp->data)[i] = be32_to_cpu(((u32*)resp->data)[i]);
106 	}
107 #endif
108 
109 	/*
110 	 * free message frame address
111 	 */
112 	headptr = readl_be(MIXART_MEM(mgr, MSG_OUTBOUND_FREE_HEAD));
113 
114 	if( (headptr < MSG_OUTBOUND_FREE_STACK) || ( headptr >= (MSG_OUTBOUND_FREE_STACK+MSG_BOUND_STACK_SIZE))) {
115 		err = -EINVAL;
116 		goto _clean_exit;
117 	}
118 
119 	/* give address back to outbound fifo */
120 	writel_be(msg_frame_address, MIXART_MEM(mgr, headptr));
121 
122 	/* increment the outbound free head */
123 	headptr += 4;
124 	if( headptr >= (MSG_OUTBOUND_FREE_STACK+MSG_BOUND_STACK_SIZE) )
125 		headptr = MSG_OUTBOUND_FREE_STACK;
126 
127 	writel_be(headptr, MIXART_MEM(mgr, MSG_OUTBOUND_FREE_HEAD));
128 
129  _clean_exit:
130 	spin_unlock_irqrestore(&mgr->msg_lock, flags);
131 
132 	return err;
133 }
134 
135 
136 /*
137  * send a message to miXart. return: the msg_frame used for this message
138  */
139 /* call with mgr->msg_lock held! */
140 static int send_msg( mixart_mgr_t *mgr,
141 		     mixart_msg_t *msg,
142 		     int max_answersize,
143 		     int mark_pending,
144 		     u32 *msg_event)
145 {
146 	u32 headptr, tailptr;
147 	u32 msg_frame_address;
148 	int err, i;
149 
150 	snd_assert(msg->size % 4 == 0, return -EINVAL);
151 
152 	err = 0;
153 
154 	/* get message frame address */
155 	tailptr = readl_be(MIXART_MEM(mgr, MSG_INBOUND_FREE_TAIL));
156 	headptr = readl_be(MIXART_MEM(mgr, MSG_INBOUND_FREE_HEAD));
157 
158 	if (tailptr == headptr) {
159 		snd_printk(KERN_ERR "error: no message frame available\n");
160 		return -EBUSY;
161 	}
162 
163 	if( (tailptr < MSG_INBOUND_FREE_STACK) || (tailptr >= (MSG_INBOUND_FREE_STACK+MSG_BOUND_STACK_SIZE))) {
164 		return -EINVAL;
165 	}
166 
167 	msg_frame_address = readl_be(MIXART_MEM(mgr, tailptr));
168 	writel(0, MIXART_MEM(mgr, tailptr)); /* set address to zero on this fifo position */
169 
170 	/* increment the inbound free tail */
171 	tailptr += 4;
172 	if( tailptr >= (MSG_INBOUND_FREE_STACK+MSG_BOUND_STACK_SIZE) )
173 		tailptr = MSG_INBOUND_FREE_STACK;
174 
175 	writel_be(tailptr, MIXART_MEM(mgr, MSG_INBOUND_FREE_TAIL));
176 
177 	/* TODO : use memcpy_toio() with intermediate buffer to copy the message */
178 
179 	/* copy message descriptor to card memory */
180 	writel_be( msg->size + MSG_DESCRIPTOR_SIZE,      MIXART_MEM(mgr, msg_frame_address) );      /* size of descriptor + request */
181 	writel_be( msg->message_id ,                     MIXART_MEM(mgr, msg_frame_address + 4) );  /* dwMessageID */
182 	writel_be( msg->uid.object_id,                   MIXART_MEM(mgr, msg_frame_address + 8) );  /* uidDest */
183 	writel_be( msg->uid.desc,                        MIXART_MEM(mgr, msg_frame_address + 12) ); /* */
184 	writel_be( MSG_DESCRIPTOR_SIZE,                  MIXART_MEM(mgr, msg_frame_address + 16) ); /* SizeHeader */
185 	writel_be( MSG_DESCRIPTOR_SIZE,                  MIXART_MEM(mgr, msg_frame_address + 20) ); /* OffsetDLL_T16 */
186 	writel_be( msg->size,                            MIXART_MEM(mgr, msg_frame_address + 24) ); /* SizeDLL_T16 */
187 	writel_be( MSG_DESCRIPTOR_SIZE,                  MIXART_MEM(mgr, msg_frame_address + 28) ); /* OffsetDLL_DRV */
188 	writel_be( 0,                                    MIXART_MEM(mgr, msg_frame_address + 32) ); /* SizeDLL_DRV */
189 	writel_be( MSG_DESCRIPTOR_SIZE + max_answersize, MIXART_MEM(mgr, msg_frame_address + 36) ); /* dwExpectedAnswerSize */
190 
191 	/* copy message data to card memory */
192 	for( i=0; i < msg->size; i+=4 ) {
193 		writel_be( *(u32*)(msg->data + i), MIXART_MEM(mgr, MSG_HEADER_SIZE + msg_frame_address + i)  );
194 	}
195 
196 	if( mark_pending ) {
197 		if( *msg_event ) {
198 			/* the pending event is the notification we wait for ! */
199 			mgr->pending_event = *msg_event;
200 		}
201 		else {
202 			/* the pending event is the answer we wait for (same address than the request)! */
203 			mgr->pending_event = msg_frame_address;
204 
205 			/* copy address back to caller */
206 			*msg_event = msg_frame_address;
207 		}
208 	}
209 
210 	/* mark the frame as a request (will have an answer) */
211 	msg_frame_address |= MSG_TYPE_REQUEST;
212 
213 	/* post the frame */
214 	headptr = readl_be(MIXART_MEM(mgr, MSG_INBOUND_POST_HEAD));
215 
216 	if( (headptr < MSG_INBOUND_POST_STACK) || (headptr >= (MSG_INBOUND_POST_STACK+MSG_BOUND_STACK_SIZE))) {
217 		return -EINVAL;
218 	}
219 
220 	writel_be(msg_frame_address, MIXART_MEM(mgr, headptr));
221 
222 	/* increment the inbound post head */
223 	headptr += 4;
224 	if( headptr >= (MSG_INBOUND_POST_STACK+MSG_BOUND_STACK_SIZE) )
225 		headptr = MSG_INBOUND_POST_STACK;
226 
227 	writel_be(headptr, MIXART_MEM(mgr, MSG_INBOUND_POST_HEAD));
228 
229 	return 0;
230 }
231 
232 
233 int snd_mixart_send_msg(mixart_mgr_t *mgr, mixart_msg_t *request, int max_resp_size, void *resp_data)
234 {
235 	mixart_msg_t resp;
236 	u32 msg_frame = 0; /* set to 0, so it's no notification to wait for, but the answer */
237 	int err;
238 	wait_queue_t wait;
239 	long timeout;
240 
241 	down(&mgr->msg_mutex);
242 
243 	init_waitqueue_entry(&wait, current);
244 
245 	spin_lock_irq(&mgr->msg_lock);
246 	/* send the message */
247 	err = send_msg(mgr, request, max_resp_size, 1, &msg_frame);  /* send and mark the answer pending */
248 	if (err) {
249 		spin_unlock_irq(&mgr->msg_lock);
250 		up(&mgr->msg_mutex);
251 		return err;
252 	}
253 
254 	set_current_state(TASK_UNINTERRUPTIBLE);
255 	add_wait_queue(&mgr->msg_sleep, &wait);
256 	spin_unlock_irq(&mgr->msg_lock);
257 	timeout = schedule_timeout(MSG_TIMEOUT_JIFFIES);
258 	remove_wait_queue(&mgr->msg_sleep, &wait);
259 
260 	if (! timeout) {
261 		/* error - no ack */
262 		up(&mgr->msg_mutex);
263 		snd_printk(KERN_ERR "error: no reponse on msg %x\n", msg_frame);
264 		return -EIO;
265 	}
266 
267 	/* retrieve the answer into the same mixart_msg_t */
268 	resp.message_id = 0;
269 	resp.uid = (mixart_uid_t){0,0};
270 	resp.data = resp_data;
271 	resp.size = max_resp_size;
272 
273 	err = get_msg(mgr, &resp, msg_frame);
274 
275 	if( request->message_id != resp.message_id )
276 		snd_printk(KERN_ERR "REPONSE ERROR!\n");
277 
278 	up(&mgr->msg_mutex);
279 	return err;
280 }
281 
282 
283 int snd_mixart_send_msg_wait_notif(mixart_mgr_t *mgr, mixart_msg_t *request, u32 notif_event)
284 {
285 	int err;
286 	wait_queue_t wait;
287 	long timeout;
288 
289 	snd_assert(notif_event != 0, return -EINVAL);
290 	snd_assert((notif_event & MSG_TYPE_MASK) == MSG_TYPE_NOTIFY, return -EINVAL);
291 	snd_assert((notif_event & MSG_CANCEL_NOTIFY_MASK) == 0, return -EINVAL);
292 
293 	down(&mgr->msg_mutex);
294 
295 	init_waitqueue_entry(&wait, current);
296 
297 	spin_lock_irq(&mgr->msg_lock);
298 	/* send the message */
299 	err = send_msg(mgr, request, MSG_DEFAULT_SIZE, 1, &notif_event);  /* send and mark the notification event pending */
300 	if(err) {
301 		spin_unlock_irq(&mgr->msg_lock);
302 		up(&mgr->msg_mutex);
303 		return err;
304 	}
305 
306 	set_current_state(TASK_UNINTERRUPTIBLE);
307 	add_wait_queue(&mgr->msg_sleep, &wait);
308 	spin_unlock_irq(&mgr->msg_lock);
309 	timeout = schedule_timeout(MSG_TIMEOUT_JIFFIES);
310 	remove_wait_queue(&mgr->msg_sleep, &wait);
311 
312 	if (! timeout) {
313 		/* error - no ack */
314 		up(&mgr->msg_mutex);
315 		snd_printk(KERN_ERR "error: notification %x not received\n", notif_event);
316 		return -EIO;
317 	}
318 
319 	up(&mgr->msg_mutex);
320 	return 0;
321 }
322 
323 
324 int snd_mixart_send_msg_nonblock(mixart_mgr_t *mgr, mixart_msg_t *request)
325 {
326 	u32 message_frame;
327 	unsigned long flags;
328 	int err;
329 
330 	/* just send the message (do not mark it as a pending one) */
331 	spin_lock_irqsave(&mgr->msg_lock, flags);
332 	err = send_msg(mgr, request, MSG_DEFAULT_SIZE, 0, &message_frame);
333 	spin_unlock_irqrestore(&mgr->msg_lock, flags);
334 
335 	/* the answer will be handled by snd_mixart_msg_tasklet()  */
336 	atomic_inc(&mgr->msg_processed);
337 
338 	return err;
339 }
340 
341 
342 /* common buffer of tasklet and interrupt to send/receive messages */
343 static u32 mixart_msg_data[MSG_DEFAULT_SIZE / 4];
344 
345 
346 void snd_mixart_msg_tasklet( unsigned long arg)
347 {
348 	mixart_mgr_t *mgr = ( mixart_mgr_t*)(arg);
349 	mixart_msg_t resp;
350 	u32 msg, addr, type;
351 	int err;
352 
353 	spin_lock(&mgr->lock);
354 
355 	while (mgr->msg_fifo_readptr != mgr->msg_fifo_writeptr) {
356 		msg = mgr->msg_fifo[mgr->msg_fifo_readptr];
357 		mgr->msg_fifo_readptr++;
358 		mgr->msg_fifo_readptr %= MSG_FIFO_SIZE;
359 
360 		/* process the message ... */
361 		addr = msg & ~MSG_TYPE_MASK;
362 		type = msg & MSG_TYPE_MASK;
363 
364 		switch (type) {
365 		case MSG_TYPE_ANSWER:
366 			/* answer to a message on that we did not wait for (send_msg_nonblock) */
367 			resp.message_id = 0;
368 			resp.data = mixart_msg_data;
369 			resp.size = sizeof(mixart_msg_data);
370 			err = get_msg(mgr, &resp, addr);
371 			if( err < 0 ) {
372 				snd_printk(KERN_ERR "tasklet: error(%d) reading mf %x\n", err, msg);
373 				break;
374 			}
375 
376 			switch(resp.message_id) {
377 			case MSG_STREAM_START_INPUT_STAGE_PACKET:
378 			case MSG_STREAM_START_OUTPUT_STAGE_PACKET:
379 			case MSG_STREAM_STOP_INPUT_STAGE_PACKET:
380 			case MSG_STREAM_STOP_OUTPUT_STAGE_PACKET:
381 				if(mixart_msg_data[0])
382 					snd_printk(KERN_ERR "tasklet : error MSG_STREAM_ST***_***PUT_STAGE_PACKET status=%x\n", mixart_msg_data[0]);
383 				break;
384 			default:
385 				snd_printdd("tasklet received mf(%x) : msg_id(%x) uid(%x, %x) size(%zd)\n",
386 					   msg, resp.message_id, resp.uid.object_id, resp.uid.desc, resp.size);
387 				break;
388 			}
389 			break;
390  		case MSG_TYPE_NOTIFY:
391 			/* msg contains no address ! do not get_msg() ! */
392 		case MSG_TYPE_COMMAND:
393 			/* get_msg() necessary */
394 		default:
395 			snd_printk(KERN_ERR "tasklet doesn't know what to do with message %x\n", msg);
396 		} /* switch type */
397 
398 		/* decrement counter */
399 		atomic_dec(&mgr->msg_processed);
400 
401 	} /* while there is a msg in fifo */
402 
403 	spin_unlock(&mgr->lock);
404 }
405 
406 
407 irqreturn_t snd_mixart_interrupt(int irq, void *dev_id, struct pt_regs *regs)
408 {
409 	mixart_mgr_t *mgr = dev_id;
410 	int err;
411 	mixart_msg_t resp;
412 
413 	u32 msg;
414 	u32 it_reg;
415 
416 	spin_lock(&mgr->lock);
417 
418 	it_reg = readl_le(MIXART_REG(mgr, MIXART_PCI_OMISR_OFFSET));
419 	if( !(it_reg & MIXART_OIDI) ) {
420 		/* this device did not cause the interrupt */
421 		spin_unlock(&mgr->lock);
422 		return IRQ_NONE;
423 	}
424 
425 	/* mask all interrupts */
426 	writel_le(MIXART_HOST_ALL_INTERRUPT_MASKED, MIXART_REG(mgr, MIXART_PCI_OMIMR_OFFSET));
427 
428 	/* outdoorbell register clear */
429 	it_reg = readl(MIXART_REG(mgr, MIXART_PCI_ODBR_OFFSET));
430 	writel(it_reg, MIXART_REG(mgr, MIXART_PCI_ODBR_OFFSET));
431 
432 	/* clear interrupt */
433 	writel_le( MIXART_OIDI, MIXART_REG(mgr, MIXART_PCI_OMISR_OFFSET) );
434 
435 	/* process interrupt */
436 	while (retrieve_msg_frame(mgr, &msg)) {
437 
438 		switch (msg & MSG_TYPE_MASK) {
439 		case MSG_TYPE_COMMAND:
440 			resp.message_id = 0;
441 			resp.data = mixart_msg_data;
442 			resp.size = sizeof(mixart_msg_data);
443 			err = get_msg(mgr, &resp, msg & ~MSG_TYPE_MASK);
444 			if( err < 0 ) {
445 				snd_printk(KERN_ERR "interrupt: error(%d) reading mf %x\n", err, msg);
446 				break;
447 			}
448 
449 			if(resp.message_id == MSG_SERVICES_TIMER_NOTIFY) {
450 				int i;
451 				mixart_timer_notify_t *notify = (mixart_timer_notify_t*)mixart_msg_data;
452 
453 				for(i=0; i<notify->stream_count; i++) {
454 
455 					u32 buffer_id = notify->streams[i].buffer_id;
456 					unsigned int chip_number =  (buffer_id & MIXART_NOTIFY_CARD_MASK) >> MIXART_NOTIFY_CARD_OFFSET; /* card0 to 3 */
457 					unsigned int pcm_number  =  (buffer_id & MIXART_NOTIFY_PCM_MASK ) >> MIXART_NOTIFY_PCM_OFFSET;  /* pcm0 to 3  */
458 					unsigned int sub_number  =   buffer_id & MIXART_NOTIFY_SUBS_MASK;             /* 0 to MIXART_PLAYBACK_STREAMS */
459 					unsigned int is_capture  = ((buffer_id & MIXART_NOTIFY_CAPT_MASK) != 0);      /* playback == 0 / capture == 1 */
460 
461 					mixart_t *chip  = mgr->chip[chip_number];
462 					mixart_stream_t *stream;
463 
464 					if ((chip_number >= mgr->num_cards) || (pcm_number >= MIXART_PCM_TOTAL) || (sub_number >= MIXART_PLAYBACK_STREAMS)) {
465 						snd_printk(KERN_ERR "error MSG_SERVICES_TIMER_NOTIFY buffer_id (%x) pos(%d)\n",
466 							   buffer_id, notify->streams[i].sample_pos_low_part);
467 						break;
468 					}
469 
470 					if (is_capture)
471 						stream = &chip->capture_stream[pcm_number];
472 					else
473 						stream = &chip->playback_stream[pcm_number][sub_number];
474 
475 					if (stream->substream && (stream->status == MIXART_STREAM_STATUS_RUNNING)) {
476 						snd_pcm_runtime_t *runtime = stream->substream->runtime;
477 						int elapsed = 0;
478 						u64 sample_count = ((u64)notify->streams[i].sample_pos_high_part) << 32;
479 						sample_count |= notify->streams[i].sample_pos_low_part;
480 
481 						while (1) {
482 							u64 new_elapse_pos = stream->abs_period_elapsed +  runtime->period_size;
483 
484 							if (new_elapse_pos > sample_count) {
485 								break; /* while */
486 							}
487 							else {
488 								elapsed = 1;
489 								stream->buf_periods++;
490 								if (stream->buf_periods >= runtime->periods)
491 									stream->buf_periods = 0;
492 
493 								stream->abs_period_elapsed = new_elapse_pos;
494 							}
495 						}
496 						stream->buf_period_frag = (u32)( sample_count - stream->abs_period_elapsed );
497 
498 						if(elapsed) {
499 							spin_unlock(&mgr->lock);
500 							snd_pcm_period_elapsed(stream->substream);
501 							spin_lock(&mgr->lock);
502 						}
503 					}
504 				}
505 				break;
506 			}
507 			if(resp.message_id == MSG_SERVICES_REPORT_TRACES) {
508 				if(resp.size > 1) {
509 #ifndef __BIG_ENDIAN
510 					/* Traces are text: the swapped msg_data has to be swapped back ! */
511 					int i;
512 					for(i=0; i<(resp.size/4); i++) {
513 						(mixart_msg_data)[i] = cpu_to_be32((mixart_msg_data)[i]);
514 					}
515 #endif
516 					((char*)mixart_msg_data)[resp.size - 1] = 0;
517 					snd_printdd("MIXART TRACE : %s\n", (char*)mixart_msg_data);
518 				}
519 				break;
520 			}
521 
522 			snd_printdd("command %x not handled\n", resp.message_id);
523 			break;
524 
525 		case MSG_TYPE_NOTIFY:
526 			if(msg & MSG_CANCEL_NOTIFY_MASK) {
527 				msg &= ~MSG_CANCEL_NOTIFY_MASK;
528 				snd_printk(KERN_ERR "canceled notification %x !\n", msg);
529 			}
530 			/* no break, continue ! */
531 		case MSG_TYPE_ANSWER:
532 			/* answer or notification to a message we are waiting for*/
533 			spin_lock(&mgr->msg_lock);
534 			if( (msg & ~MSG_TYPE_MASK) == mgr->pending_event ) {
535 				wake_up(&mgr->msg_sleep);
536 				mgr->pending_event = 0;
537 			}
538 			/* answer to a message we did't want to wait for */
539 			else {
540 				mgr->msg_fifo[mgr->msg_fifo_writeptr] = msg;
541 				mgr->msg_fifo_writeptr++;
542 				mgr->msg_fifo_writeptr %= MSG_FIFO_SIZE;
543 				tasklet_hi_schedule(&mgr->msg_taskq);
544 			}
545 			spin_unlock(&mgr->msg_lock);
546 			break;
547 		case MSG_TYPE_REQUEST:
548 		default:
549 			snd_printdd("interrupt received request %x\n", msg);
550 			/* TODO : are there things to do here ? */
551 			break;
552 		} /* switch on msg type */
553 	} /* while there are msgs */
554 
555 	/* allow interrupt again */
556 	writel_le( MIXART_ALLOW_OUTBOUND_DOORBELL, MIXART_REG( mgr, MIXART_PCI_OMIMR_OFFSET));
557 
558 	spin_unlock(&mgr->lock);
559 
560 	return IRQ_HANDLED;
561 }
562 
563 
564 void snd_mixart_init_mailbox(mixart_mgr_t *mgr)
565 {
566 	writel( 0, MIXART_MEM( mgr, MSG_HOST_RSC_PROTECTION ) );
567 	writel( 0, MIXART_MEM( mgr, MSG_AGENT_RSC_PROTECTION ) );
568 
569 	/* allow outbound messagebox to generate interrupts */
570 	if(mgr->irq >= 0) {
571 		writel_le( MIXART_ALLOW_OUTBOUND_DOORBELL, MIXART_REG( mgr, MIXART_PCI_OMIMR_OFFSET));
572 	}
573 	return;
574 }
575 
576 void snd_mixart_exit_mailbox(mixart_mgr_t *mgr)
577 {
578 	/* no more interrupts on outbound messagebox */
579 	writel_le( MIXART_HOST_ALL_INTERRUPT_MASKED, MIXART_REG( mgr, MIXART_PCI_OMIMR_OFFSET));
580 	return;
581 }
582 
583 void snd_mixart_reset_board(mixart_mgr_t *mgr)
584 {
585 	/* reset miXart */
586 	writel_be( 1, MIXART_REG(mgr, MIXART_BA1_BRUTAL_RESET_OFFSET) );
587 	return;
588 }
589