xref: /openbmc/linux/sound/pci/mixart/mixart_core.c (revision 12eb4683)
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 
26 #include <asm/io.h>
27 #include <sound/core.h>
28 #include "mixart.h"
29 #include "mixart_hwdep.h"
30 #include "mixart_core.h"
31 
32 
33 #define MSG_TIMEOUT_JIFFIES         (400 * HZ) / 1000 /* 400 ms */
34 
35 #define MSG_DESCRIPTOR_SIZE         0x24
36 #define MSG_HEADER_SIZE             (MSG_DESCRIPTOR_SIZE + 4)
37 
38 #define MSG_DEFAULT_SIZE            512
39 
40 #define MSG_TYPE_MASK               0x00000003    /* mask for following types */
41 #define MSG_TYPE_NOTIFY             0             /* embedded -> driver (only notification, do not get_msg() !) */
42 #define MSG_TYPE_COMMAND            1             /* driver <-> embedded (a command has no answer) */
43 #define MSG_TYPE_REQUEST            2             /* driver -> embedded (request will get an answer back) */
44 #define MSG_TYPE_ANSWER             3             /* embedded -> driver */
45 #define MSG_CANCEL_NOTIFY_MASK      0x80000000    /* this bit is set for a notification that has been canceled */
46 
47 
48 static int retrieve_msg_frame(struct mixart_mgr *mgr, u32 *msg_frame)
49 {
50 	/* read the message frame fifo */
51 	u32 headptr, tailptr;
52 
53 	tailptr = readl_be(MIXART_MEM(mgr, MSG_OUTBOUND_POST_TAIL));
54 	headptr = readl_be(MIXART_MEM(mgr, MSG_OUTBOUND_POST_HEAD));
55 
56 	if (tailptr == headptr)
57 		return 0; /* no message posted */
58 
59 	if (tailptr < MSG_OUTBOUND_POST_STACK)
60 		return 0; /* error */
61 	if (tailptr >= MSG_OUTBOUND_POST_STACK + MSG_BOUND_STACK_SIZE)
62 		return 0; /* error */
63 
64 	*msg_frame = readl_be(MIXART_MEM(mgr, tailptr));
65 
66 	/* increment the tail index */
67 	tailptr += 4;
68 	if( tailptr >= (MSG_OUTBOUND_POST_STACK+MSG_BOUND_STACK_SIZE) )
69 		tailptr = MSG_OUTBOUND_POST_STACK;
70 	writel_be(tailptr, MIXART_MEM(mgr, MSG_OUTBOUND_POST_TAIL));
71 
72 	return 1;
73 }
74 
75 static int get_msg(struct mixart_mgr *mgr, struct mixart_msg *resp,
76 		   u32 msg_frame_address )
77 {
78 	unsigned long flags;
79 	u32  headptr;
80 	u32  size;
81 	int  err;
82 #ifndef __BIG_ENDIAN
83 	unsigned int i;
84 #endif
85 
86 	spin_lock_irqsave(&mgr->msg_lock, flags);
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 		snd_printk(KERN_ERR "problem with response size = %d\n", size);
98 		goto _clean_exit;
99 	}
100 	size -= MSG_DESCRIPTOR_SIZE;
101 
102 	memcpy_fromio(resp->data, MIXART_MEM(mgr, msg_frame_address + MSG_HEADER_SIZE ), size);
103 	resp->size = size;
104 
105 	/* swap if necessary */
106 #ifndef __BIG_ENDIAN
107 	size /= 4; /* u32 size */
108 	for(i=0; i < size; i++) {
109 		((u32*)resp->data)[i] = be32_to_cpu(((u32*)resp->data)[i]);
110 	}
111 #endif
112 
113 	/*
114 	 * free message frame address
115 	 */
116 	headptr = readl_be(MIXART_MEM(mgr, MSG_OUTBOUND_FREE_HEAD));
117 
118 	if( (headptr < MSG_OUTBOUND_FREE_STACK) || ( headptr >= (MSG_OUTBOUND_FREE_STACK+MSG_BOUND_STACK_SIZE))) {
119 		err = -EINVAL;
120 		goto _clean_exit;
121 	}
122 
123 	/* give address back to outbound fifo */
124 	writel_be(msg_frame_address, MIXART_MEM(mgr, headptr));
125 
126 	/* increment the outbound free head */
127 	headptr += 4;
128 	if( headptr >= (MSG_OUTBOUND_FREE_STACK+MSG_BOUND_STACK_SIZE) )
129 		headptr = MSG_OUTBOUND_FREE_STACK;
130 
131 	writel_be(headptr, MIXART_MEM(mgr, MSG_OUTBOUND_FREE_HEAD));
132 
133  _clean_exit:
134 	spin_unlock_irqrestore(&mgr->msg_lock, flags);
135 
136 	return err;
137 }
138 
139 
140 /*
141  * send a message to miXart. return: the msg_frame used for this message
142  */
143 /* call with mgr->msg_lock held! */
144 static int send_msg( struct mixart_mgr *mgr,
145 		     struct mixart_msg *msg,
146 		     int max_answersize,
147 		     int mark_pending,
148 		     u32 *msg_event)
149 {
150 	u32 headptr, tailptr;
151 	u32 msg_frame_address;
152 	int err, i;
153 
154 	if (snd_BUG_ON(msg->size % 4))
155 		return -EINVAL;
156 
157 	err = 0;
158 
159 	/* get message frame address */
160 	tailptr = readl_be(MIXART_MEM(mgr, MSG_INBOUND_FREE_TAIL));
161 	headptr = readl_be(MIXART_MEM(mgr, MSG_INBOUND_FREE_HEAD));
162 
163 	if (tailptr == headptr) {
164 		snd_printk(KERN_ERR "error: no message frame available\n");
165 		return -EBUSY;
166 	}
167 
168 	if( (tailptr < MSG_INBOUND_FREE_STACK) || (tailptr >= (MSG_INBOUND_FREE_STACK+MSG_BOUND_STACK_SIZE))) {
169 		return -EINVAL;
170 	}
171 
172 	msg_frame_address = readl_be(MIXART_MEM(mgr, tailptr));
173 	writel(0, MIXART_MEM(mgr, tailptr)); /* set address to zero on this fifo position */
174 
175 	/* increment the inbound free tail */
176 	tailptr += 4;
177 	if( tailptr >= (MSG_INBOUND_FREE_STACK+MSG_BOUND_STACK_SIZE) )
178 		tailptr = MSG_INBOUND_FREE_STACK;
179 
180 	writel_be(tailptr, MIXART_MEM(mgr, MSG_INBOUND_FREE_TAIL));
181 
182 	/* TODO : use memcpy_toio() with intermediate buffer to copy the message */
183 
184 	/* copy message descriptor to card memory */
185 	writel_be( msg->size + MSG_DESCRIPTOR_SIZE,      MIXART_MEM(mgr, msg_frame_address) );      /* size of descriptor + request */
186 	writel_be( msg->message_id ,                     MIXART_MEM(mgr, msg_frame_address + 4) );  /* dwMessageID */
187 	writel_be( msg->uid.object_id,                   MIXART_MEM(mgr, msg_frame_address + 8) );  /* uidDest */
188 	writel_be( msg->uid.desc,                        MIXART_MEM(mgr, msg_frame_address + 12) ); /* */
189 	writel_be( MSG_DESCRIPTOR_SIZE,                  MIXART_MEM(mgr, msg_frame_address + 16) ); /* SizeHeader */
190 	writel_be( MSG_DESCRIPTOR_SIZE,                  MIXART_MEM(mgr, msg_frame_address + 20) ); /* OffsetDLL_T16 */
191 	writel_be( msg->size,                            MIXART_MEM(mgr, msg_frame_address + 24) ); /* SizeDLL_T16 */
192 	writel_be( MSG_DESCRIPTOR_SIZE,                  MIXART_MEM(mgr, msg_frame_address + 28) ); /* OffsetDLL_DRV */
193 	writel_be( 0,                                    MIXART_MEM(mgr, msg_frame_address + 32) ); /* SizeDLL_DRV */
194 	writel_be( MSG_DESCRIPTOR_SIZE + max_answersize, MIXART_MEM(mgr, msg_frame_address + 36) ); /* dwExpectedAnswerSize */
195 
196 	/* copy message data to card memory */
197 	for( i=0; i < msg->size; i+=4 ) {
198 		writel_be( *(u32*)(msg->data + i), MIXART_MEM(mgr, MSG_HEADER_SIZE + msg_frame_address + i)  );
199 	}
200 
201 	if( mark_pending ) {
202 		if( *msg_event ) {
203 			/* the pending event is the notification we wait for ! */
204 			mgr->pending_event = *msg_event;
205 		}
206 		else {
207 			/* the pending event is the answer we wait for (same address than the request)! */
208 			mgr->pending_event = msg_frame_address;
209 
210 			/* copy address back to caller */
211 			*msg_event = msg_frame_address;
212 		}
213 	}
214 
215 	/* mark the frame as a request (will have an answer) */
216 	msg_frame_address |= MSG_TYPE_REQUEST;
217 
218 	/* post the frame */
219 	headptr = readl_be(MIXART_MEM(mgr, MSG_INBOUND_POST_HEAD));
220 
221 	if( (headptr < MSG_INBOUND_POST_STACK) || (headptr >= (MSG_INBOUND_POST_STACK+MSG_BOUND_STACK_SIZE))) {
222 		return -EINVAL;
223 	}
224 
225 	writel_be(msg_frame_address, MIXART_MEM(mgr, headptr));
226 
227 	/* increment the inbound post head */
228 	headptr += 4;
229 	if( headptr >= (MSG_INBOUND_POST_STACK+MSG_BOUND_STACK_SIZE) )
230 		headptr = MSG_INBOUND_POST_STACK;
231 
232 	writel_be(headptr, MIXART_MEM(mgr, MSG_INBOUND_POST_HEAD));
233 
234 	return 0;
235 }
236 
237 
238 int snd_mixart_send_msg(struct mixart_mgr *mgr, struct mixart_msg *request, int max_resp_size, void *resp_data)
239 {
240 	struct mixart_msg resp;
241 	u32 msg_frame = 0; /* set to 0, so it's no notification to wait for, but the answer */
242 	int err;
243 	wait_queue_t wait;
244 	long timeout;
245 
246 	mutex_lock(&mgr->msg_mutex);
247 
248 	init_waitqueue_entry(&wait, current);
249 
250 	spin_lock_irq(&mgr->msg_lock);
251 	/* send the message */
252 	err = send_msg(mgr, request, max_resp_size, 1, &msg_frame);  /* send and mark the answer pending */
253 	if (err) {
254 		spin_unlock_irq(&mgr->msg_lock);
255 		mutex_unlock(&mgr->msg_mutex);
256 		return err;
257 	}
258 
259 	set_current_state(TASK_UNINTERRUPTIBLE);
260 	add_wait_queue(&mgr->msg_sleep, &wait);
261 	spin_unlock_irq(&mgr->msg_lock);
262 	timeout = schedule_timeout(MSG_TIMEOUT_JIFFIES);
263 	remove_wait_queue(&mgr->msg_sleep, &wait);
264 
265 	if (! timeout) {
266 		/* error - no ack */
267 		mutex_unlock(&mgr->msg_mutex);
268 		snd_printk(KERN_ERR "error: no response on msg %x\n", msg_frame);
269 		return -EIO;
270 	}
271 
272 	/* retrieve the answer into the same struct mixart_msg */
273 	resp.message_id = 0;
274 	resp.uid = (struct mixart_uid){0,0};
275 	resp.data = resp_data;
276 	resp.size = max_resp_size;
277 
278 	err = get_msg(mgr, &resp, msg_frame);
279 
280 	if( request->message_id != resp.message_id )
281 		snd_printk(KERN_ERR "RESPONSE ERROR!\n");
282 
283 	mutex_unlock(&mgr->msg_mutex);
284 	return err;
285 }
286 
287 
288 int snd_mixart_send_msg_wait_notif(struct mixart_mgr *mgr,
289 				   struct mixart_msg *request, u32 notif_event)
290 {
291 	int err;
292 	wait_queue_t wait;
293 	long timeout;
294 
295 	if (snd_BUG_ON(!notif_event))
296 		return -EINVAL;
297 	if (snd_BUG_ON((notif_event & MSG_TYPE_MASK) != MSG_TYPE_NOTIFY))
298 		return -EINVAL;
299 	if (snd_BUG_ON(notif_event & MSG_CANCEL_NOTIFY_MASK))
300 		return -EINVAL;
301 
302 	mutex_lock(&mgr->msg_mutex);
303 
304 	init_waitqueue_entry(&wait, current);
305 
306 	spin_lock_irq(&mgr->msg_lock);
307 	/* send the message */
308 	err = send_msg(mgr, request, MSG_DEFAULT_SIZE, 1, &notif_event);  /* send and mark the notification event pending */
309 	if(err) {
310 		spin_unlock_irq(&mgr->msg_lock);
311 		mutex_unlock(&mgr->msg_mutex);
312 		return err;
313 	}
314 
315 	set_current_state(TASK_UNINTERRUPTIBLE);
316 	add_wait_queue(&mgr->msg_sleep, &wait);
317 	spin_unlock_irq(&mgr->msg_lock);
318 	timeout = schedule_timeout(MSG_TIMEOUT_JIFFIES);
319 	remove_wait_queue(&mgr->msg_sleep, &wait);
320 
321 	if (! timeout) {
322 		/* error - no ack */
323 		mutex_unlock(&mgr->msg_mutex);
324 		snd_printk(KERN_ERR "error: notification %x not received\n", notif_event);
325 		return -EIO;
326 	}
327 
328 	mutex_unlock(&mgr->msg_mutex);
329 	return 0;
330 }
331 
332 
333 int snd_mixart_send_msg_nonblock(struct mixart_mgr *mgr, struct mixart_msg *request)
334 {
335 	u32 message_frame;
336 	unsigned long flags;
337 	int err;
338 
339 	/* just send the message (do not mark it as a pending one) */
340 	spin_lock_irqsave(&mgr->msg_lock, flags);
341 	err = send_msg(mgr, request, MSG_DEFAULT_SIZE, 0, &message_frame);
342 	spin_unlock_irqrestore(&mgr->msg_lock, flags);
343 
344 	/* the answer will be handled by snd_struct mixart_msgasklet()  */
345 	atomic_inc(&mgr->msg_processed);
346 
347 	return err;
348 }
349 
350 
351 /* common buffer of tasklet and interrupt to send/receive messages */
352 static u32 mixart_msg_data[MSG_DEFAULT_SIZE / 4];
353 
354 
355 void snd_mixart_msg_tasklet(unsigned long arg)
356 {
357 	struct mixart_mgr *mgr = ( struct mixart_mgr*)(arg);
358 	struct mixart_msg resp;
359 	u32 msg, addr, type;
360 	int err;
361 
362 	spin_lock(&mgr->lock);
363 
364 	while (mgr->msg_fifo_readptr != mgr->msg_fifo_writeptr) {
365 		msg = mgr->msg_fifo[mgr->msg_fifo_readptr];
366 		mgr->msg_fifo_readptr++;
367 		mgr->msg_fifo_readptr %= MSG_FIFO_SIZE;
368 
369 		/* process the message ... */
370 		addr = msg & ~MSG_TYPE_MASK;
371 		type = msg & MSG_TYPE_MASK;
372 
373 		switch (type) {
374 		case MSG_TYPE_ANSWER:
375 			/* answer to a message on that we did not wait for (send_msg_nonblock) */
376 			resp.message_id = 0;
377 			resp.data = mixart_msg_data;
378 			resp.size = sizeof(mixart_msg_data);
379 			err = get_msg(mgr, &resp, addr);
380 			if( err < 0 ) {
381 				snd_printk(KERN_ERR "tasklet: error(%d) reading mf %x\n", err, msg);
382 				break;
383 			}
384 
385 			switch(resp.message_id) {
386 			case MSG_STREAM_START_INPUT_STAGE_PACKET:
387 			case MSG_STREAM_START_OUTPUT_STAGE_PACKET:
388 			case MSG_STREAM_STOP_INPUT_STAGE_PACKET:
389 			case MSG_STREAM_STOP_OUTPUT_STAGE_PACKET:
390 				if(mixart_msg_data[0])
391 					snd_printk(KERN_ERR "tasklet : error MSG_STREAM_ST***_***PUT_STAGE_PACKET status=%x\n", mixart_msg_data[0]);
392 				break;
393 			default:
394 				snd_printdd("tasklet received mf(%x) : msg_id(%x) uid(%x, %x) size(%zd)\n",
395 					   msg, resp.message_id, resp.uid.object_id, resp.uid.desc, resp.size);
396 				break;
397 			}
398 			break;
399  		case MSG_TYPE_NOTIFY:
400 			/* msg contains no address ! do not get_msg() ! */
401 		case MSG_TYPE_COMMAND:
402 			/* get_msg() necessary */
403 		default:
404 			snd_printk(KERN_ERR "tasklet doesn't know what to do with message %x\n", msg);
405 		} /* switch type */
406 
407 		/* decrement counter */
408 		atomic_dec(&mgr->msg_processed);
409 
410 	} /* while there is a msg in fifo */
411 
412 	spin_unlock(&mgr->lock);
413 }
414 
415 
416 irqreturn_t snd_mixart_interrupt(int irq, void *dev_id)
417 {
418 	struct mixart_mgr *mgr = dev_id;
419 	int err;
420 	struct mixart_msg resp;
421 
422 	u32 msg;
423 	u32 it_reg;
424 
425 	spin_lock(&mgr->lock);
426 
427 	it_reg = readl_le(MIXART_REG(mgr, MIXART_PCI_OMISR_OFFSET));
428 	if( !(it_reg & MIXART_OIDI) ) {
429 		/* this device did not cause the interrupt */
430 		spin_unlock(&mgr->lock);
431 		return IRQ_NONE;
432 	}
433 
434 	/* mask all interrupts */
435 	writel_le(MIXART_HOST_ALL_INTERRUPT_MASKED, MIXART_REG(mgr, MIXART_PCI_OMIMR_OFFSET));
436 
437 	/* outdoorbell register clear */
438 	it_reg = readl(MIXART_REG(mgr, MIXART_PCI_ODBR_OFFSET));
439 	writel(it_reg, MIXART_REG(mgr, MIXART_PCI_ODBR_OFFSET));
440 
441 	/* clear interrupt */
442 	writel_le( MIXART_OIDI, MIXART_REG(mgr, MIXART_PCI_OMISR_OFFSET) );
443 
444 	/* process interrupt */
445 	while (retrieve_msg_frame(mgr, &msg)) {
446 
447 		switch (msg & MSG_TYPE_MASK) {
448 		case MSG_TYPE_COMMAND:
449 			resp.message_id = 0;
450 			resp.data = mixart_msg_data;
451 			resp.size = sizeof(mixart_msg_data);
452 			err = get_msg(mgr, &resp, msg & ~MSG_TYPE_MASK);
453 			if( err < 0 ) {
454 				snd_printk(KERN_ERR "interrupt: error(%d) reading mf %x\n", err, msg);
455 				break;
456 			}
457 
458 			if(resp.message_id == MSG_SERVICES_TIMER_NOTIFY) {
459 				int i;
460 				struct mixart_timer_notify *notify;
461 				notify = (struct mixart_timer_notify *)mixart_msg_data;
462 
463 				for(i=0; i<notify->stream_count; i++) {
464 
465 					u32 buffer_id = notify->streams[i].buffer_id;
466 					unsigned int chip_number =  (buffer_id & MIXART_NOTIFY_CARD_MASK) >> MIXART_NOTIFY_CARD_OFFSET; /* card0 to 3 */
467 					unsigned int pcm_number  =  (buffer_id & MIXART_NOTIFY_PCM_MASK ) >> MIXART_NOTIFY_PCM_OFFSET;  /* pcm0 to 3  */
468 					unsigned int sub_number  =   buffer_id & MIXART_NOTIFY_SUBS_MASK;             /* 0 to MIXART_PLAYBACK_STREAMS */
469 					unsigned int is_capture  = ((buffer_id & MIXART_NOTIFY_CAPT_MASK) != 0);      /* playback == 0 / capture == 1 */
470 
471 					struct snd_mixart *chip  = mgr->chip[chip_number];
472 					struct mixart_stream *stream;
473 
474 					if ((chip_number >= mgr->num_cards) || (pcm_number >= MIXART_PCM_TOTAL) || (sub_number >= MIXART_PLAYBACK_STREAMS)) {
475 						snd_printk(KERN_ERR "error MSG_SERVICES_TIMER_NOTIFY buffer_id (%x) pos(%d)\n",
476 							   buffer_id, notify->streams[i].sample_pos_low_part);
477 						break;
478 					}
479 
480 					if (is_capture)
481 						stream = &chip->capture_stream[pcm_number];
482 					else
483 						stream = &chip->playback_stream[pcm_number][sub_number];
484 
485 					if (stream->substream && (stream->status == MIXART_STREAM_STATUS_RUNNING)) {
486 						struct snd_pcm_runtime *runtime = stream->substream->runtime;
487 						int elapsed = 0;
488 						u64 sample_count = ((u64)notify->streams[i].sample_pos_high_part) << 32;
489 						sample_count |= notify->streams[i].sample_pos_low_part;
490 
491 						while (1) {
492 							u64 new_elapse_pos = stream->abs_period_elapsed +  runtime->period_size;
493 
494 							if (new_elapse_pos > sample_count) {
495 								break; /* while */
496 							}
497 							else {
498 								elapsed = 1;
499 								stream->buf_periods++;
500 								if (stream->buf_periods >= runtime->periods)
501 									stream->buf_periods = 0;
502 
503 								stream->abs_period_elapsed = new_elapse_pos;
504 							}
505 						}
506 						stream->buf_period_frag = (u32)( sample_count - stream->abs_period_elapsed );
507 
508 						if(elapsed) {
509 							spin_unlock(&mgr->lock);
510 							snd_pcm_period_elapsed(stream->substream);
511 							spin_lock(&mgr->lock);
512 						}
513 					}
514 				}
515 				break;
516 			}
517 			if(resp.message_id == MSG_SERVICES_REPORT_TRACES) {
518 				if(resp.size > 1) {
519 #ifndef __BIG_ENDIAN
520 					/* Traces are text: the swapped msg_data has to be swapped back ! */
521 					int i;
522 					for(i=0; i<(resp.size/4); i++) {
523 						(mixart_msg_data)[i] = cpu_to_be32((mixart_msg_data)[i]);
524 					}
525 #endif
526 					((char*)mixart_msg_data)[resp.size - 1] = 0;
527 					snd_printdd("MIXART TRACE : %s\n", (char*)mixart_msg_data);
528 				}
529 				break;
530 			}
531 
532 			snd_printdd("command %x not handled\n", resp.message_id);
533 			break;
534 
535 		case MSG_TYPE_NOTIFY:
536 			if(msg & MSG_CANCEL_NOTIFY_MASK) {
537 				msg &= ~MSG_CANCEL_NOTIFY_MASK;
538 				snd_printk(KERN_ERR "canceled notification %x !\n", msg);
539 			}
540 			/* no break, continue ! */
541 		case MSG_TYPE_ANSWER:
542 			/* answer or notification to a message we are waiting for*/
543 			spin_lock(&mgr->msg_lock);
544 			if( (msg & ~MSG_TYPE_MASK) == mgr->pending_event ) {
545 				wake_up(&mgr->msg_sleep);
546 				mgr->pending_event = 0;
547 			}
548 			/* answer to a message we did't want to wait for */
549 			else {
550 				mgr->msg_fifo[mgr->msg_fifo_writeptr] = msg;
551 				mgr->msg_fifo_writeptr++;
552 				mgr->msg_fifo_writeptr %= MSG_FIFO_SIZE;
553 				tasklet_schedule(&mgr->msg_taskq);
554 			}
555 			spin_unlock(&mgr->msg_lock);
556 			break;
557 		case MSG_TYPE_REQUEST:
558 		default:
559 			snd_printdd("interrupt received request %x\n", msg);
560 			/* TODO : are there things to do here ? */
561 			break;
562 		} /* switch on msg type */
563 	} /* while there are msgs */
564 
565 	/* allow interrupt again */
566 	writel_le( MIXART_ALLOW_OUTBOUND_DOORBELL, MIXART_REG( mgr, MIXART_PCI_OMIMR_OFFSET));
567 
568 	spin_unlock(&mgr->lock);
569 
570 	return IRQ_HANDLED;
571 }
572 
573 
574 void snd_mixart_init_mailbox(struct mixart_mgr *mgr)
575 {
576 	writel( 0, MIXART_MEM( mgr, MSG_HOST_RSC_PROTECTION ) );
577 	writel( 0, MIXART_MEM( mgr, MSG_AGENT_RSC_PROTECTION ) );
578 
579 	/* allow outbound messagebox to generate interrupts */
580 	if(mgr->irq >= 0) {
581 		writel_le( MIXART_ALLOW_OUTBOUND_DOORBELL, MIXART_REG( mgr, MIXART_PCI_OMIMR_OFFSET));
582 	}
583 	return;
584 }
585 
586 void snd_mixart_exit_mailbox(struct mixart_mgr *mgr)
587 {
588 	/* no more interrupts on outbound messagebox */
589 	writel_le( MIXART_HOST_ALL_INTERRUPT_MASKED, MIXART_REG( mgr, MIXART_PCI_OMIMR_OFFSET));
590 	return;
591 }
592 
593 void snd_mixart_reset_board(struct mixart_mgr *mgr)
594 {
595 	/* reset miXart */
596 	writel_be( 1, MIXART_REG(mgr, MIXART_BA1_BRUTAL_RESET_OFFSET) );
597 	return;
598 }
599