xref: /openbmc/linux/sound/pci/mixart/mixart_core.c (revision 4eb5928d)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Driver for Digigram miXart soundcards
4  *
5  * low level interface with interrupt handling and mail box implementation
6  *
7  * Copyright (c) 2003 by Digigram <alsa@digigram.com>
8  */
9 
10 #include <linux/interrupt.h>
11 #include <linux/mutex.h>
12 #include <linux/pci.h>
13 #include <linux/io.h>
14 
15 #include <sound/core.h>
16 #include "mixart.h"
17 #include "mixart_hwdep.h"
18 #include "mixart_core.h"
19 
20 
21 #define MSG_TIMEOUT_JIFFIES         (400 * HZ) / 1000 /* 400 ms */
22 
23 #define MSG_DESCRIPTOR_SIZE         0x24
24 #define MSG_HEADER_SIZE             (MSG_DESCRIPTOR_SIZE + 4)
25 
26 #define MSG_DEFAULT_SIZE            512
27 
28 #define MSG_TYPE_MASK               0x00000003    /* mask for following types */
29 #define MSG_TYPE_NOTIFY             0             /* embedded -> driver (only notification, do not get_msg() !) */
30 #define MSG_TYPE_COMMAND            1             /* driver <-> embedded (a command has no answer) */
31 #define MSG_TYPE_REQUEST            2             /* driver -> embedded (request will get an answer back) */
32 #define MSG_TYPE_ANSWER             3             /* embedded -> driver */
33 #define MSG_CANCEL_NOTIFY_MASK      0x80000000    /* this bit is set for a notification that has been canceled */
34 
35 
36 static int retrieve_msg_frame(struct mixart_mgr *mgr, u32 *msg_frame)
37 {
38 	/* read the message frame fifo */
39 	u32 headptr, tailptr;
40 
41 	tailptr = readl_be(MIXART_MEM(mgr, MSG_OUTBOUND_POST_TAIL));
42 	headptr = readl_be(MIXART_MEM(mgr, MSG_OUTBOUND_POST_HEAD));
43 
44 	if (tailptr == headptr)
45 		return 0; /* no message posted */
46 
47 	if (tailptr < MSG_OUTBOUND_POST_STACK)
48 		return 0; /* error */
49 	if (tailptr >= MSG_OUTBOUND_POST_STACK + MSG_BOUND_STACK_SIZE)
50 		return 0; /* error */
51 
52 	*msg_frame = readl_be(MIXART_MEM(mgr, tailptr));
53 
54 	/* increment the tail index */
55 	tailptr += 4;
56 	if( tailptr >= (MSG_OUTBOUND_POST_STACK+MSG_BOUND_STACK_SIZE) )
57 		tailptr = MSG_OUTBOUND_POST_STACK;
58 	writel_be(tailptr, MIXART_MEM(mgr, MSG_OUTBOUND_POST_TAIL));
59 
60 	return 1;
61 }
62 
63 static int get_msg(struct mixart_mgr *mgr, struct mixart_msg *resp,
64 		   u32 msg_frame_address )
65 {
66 	u32  headptr;
67 	u32  size;
68 	int  err;
69 #ifndef __BIG_ENDIAN
70 	unsigned int i;
71 #endif
72 
73 	mutex_lock(&mgr->msg_lock);
74 	err = 0;
75 
76 	/* copy message descriptor from miXart to driver */
77 	size                =  readl_be(MIXART_MEM(mgr, msg_frame_address));       /* size of descriptor + response */
78 	resp->message_id    =  readl_be(MIXART_MEM(mgr, msg_frame_address + 4));   /* dwMessageID */
79 	resp->uid.object_id =  readl_be(MIXART_MEM(mgr, msg_frame_address + 8));   /* uidDest */
80 	resp->uid.desc      =  readl_be(MIXART_MEM(mgr, msg_frame_address + 12));  /* */
81 
82 	if( (size < MSG_DESCRIPTOR_SIZE) || (resp->size < (size - MSG_DESCRIPTOR_SIZE))) {
83 		err = -EINVAL;
84 		dev_err(&mgr->pci->dev,
85 			"problem with response size = %d\n", size);
86 		goto _clean_exit;
87 	}
88 	size -= MSG_DESCRIPTOR_SIZE;
89 
90 	memcpy_fromio(resp->data, MIXART_MEM(mgr, msg_frame_address + MSG_HEADER_SIZE ), size);
91 	resp->size = size;
92 
93 	/* swap if necessary */
94 #ifndef __BIG_ENDIAN
95 	size /= 4; /* u32 size */
96 	for(i=0; i < size; i++) {
97 		((u32*)resp->data)[i] = be32_to_cpu(((__be32*)resp->data)[i]);
98 	}
99 #endif
100 
101 	/*
102 	 * free message frame address
103 	 */
104 	headptr = readl_be(MIXART_MEM(mgr, MSG_OUTBOUND_FREE_HEAD));
105 
106 	if( (headptr < MSG_OUTBOUND_FREE_STACK) || ( headptr >= (MSG_OUTBOUND_FREE_STACK+MSG_BOUND_STACK_SIZE))) {
107 		err = -EINVAL;
108 		goto _clean_exit;
109 	}
110 
111 	/* give address back to outbound fifo */
112 	writel_be(msg_frame_address, MIXART_MEM(mgr, headptr));
113 
114 	/* increment the outbound free head */
115 	headptr += 4;
116 	if( headptr >= (MSG_OUTBOUND_FREE_STACK+MSG_BOUND_STACK_SIZE) )
117 		headptr = MSG_OUTBOUND_FREE_STACK;
118 
119 	writel_be(headptr, MIXART_MEM(mgr, MSG_OUTBOUND_FREE_HEAD));
120 
121  _clean_exit:
122 	mutex_unlock(&mgr->msg_lock);
123 
124 	return err;
125 }
126 
127 
128 /*
129  * send a message to miXart. return: the msg_frame used for this message
130  */
131 /* call with mgr->msg_lock held! */
132 static int send_msg( struct mixart_mgr *mgr,
133 		     struct mixart_msg *msg,
134 		     int max_answersize,
135 		     int mark_pending,
136 		     u32 *msg_event)
137 {
138 	u32 headptr, tailptr;
139 	u32 msg_frame_address;
140 	int i;
141 
142 	if (snd_BUG_ON(msg->size % 4))
143 		return -EINVAL;
144 
145 	/* get message frame address */
146 	tailptr = readl_be(MIXART_MEM(mgr, MSG_INBOUND_FREE_TAIL));
147 	headptr = readl_be(MIXART_MEM(mgr, MSG_INBOUND_FREE_HEAD));
148 
149 	if (tailptr == headptr) {
150 		dev_err(&mgr->pci->dev, "error: no message frame available\n");
151 		return -EBUSY;
152 	}
153 
154 	if( (tailptr < MSG_INBOUND_FREE_STACK) || (tailptr >= (MSG_INBOUND_FREE_STACK+MSG_BOUND_STACK_SIZE))) {
155 		return -EINVAL;
156 	}
157 
158 	msg_frame_address = readl_be(MIXART_MEM(mgr, tailptr));
159 	writel(0, MIXART_MEM(mgr, tailptr)); /* set address to zero on this fifo position */
160 
161 	/* increment the inbound free tail */
162 	tailptr += 4;
163 	if( tailptr >= (MSG_INBOUND_FREE_STACK+MSG_BOUND_STACK_SIZE) )
164 		tailptr = MSG_INBOUND_FREE_STACK;
165 
166 	writel_be(tailptr, MIXART_MEM(mgr, MSG_INBOUND_FREE_TAIL));
167 
168 	/* TODO : use memcpy_toio() with intermediate buffer to copy the message */
169 
170 	/* copy message descriptor to card memory */
171 	writel_be( msg->size + MSG_DESCRIPTOR_SIZE,      MIXART_MEM(mgr, msg_frame_address) );      /* size of descriptor + request */
172 	writel_be( msg->message_id ,                     MIXART_MEM(mgr, msg_frame_address + 4) );  /* dwMessageID */
173 	writel_be( msg->uid.object_id,                   MIXART_MEM(mgr, msg_frame_address + 8) );  /* uidDest */
174 	writel_be( msg->uid.desc,                        MIXART_MEM(mgr, msg_frame_address + 12) ); /* */
175 	writel_be( MSG_DESCRIPTOR_SIZE,                  MIXART_MEM(mgr, msg_frame_address + 16) ); /* SizeHeader */
176 	writel_be( MSG_DESCRIPTOR_SIZE,                  MIXART_MEM(mgr, msg_frame_address + 20) ); /* OffsetDLL_T16 */
177 	writel_be( msg->size,                            MIXART_MEM(mgr, msg_frame_address + 24) ); /* SizeDLL_T16 */
178 	writel_be( MSG_DESCRIPTOR_SIZE,                  MIXART_MEM(mgr, msg_frame_address + 28) ); /* OffsetDLL_DRV */
179 	writel_be( 0,                                    MIXART_MEM(mgr, msg_frame_address + 32) ); /* SizeDLL_DRV */
180 	writel_be( MSG_DESCRIPTOR_SIZE + max_answersize, MIXART_MEM(mgr, msg_frame_address + 36) ); /* dwExpectedAnswerSize */
181 
182 	/* copy message data to card memory */
183 	for( i=0; i < msg->size; i+=4 ) {
184 		writel_be( *(u32*)(msg->data + i), MIXART_MEM(mgr, MSG_HEADER_SIZE + msg_frame_address + i)  );
185 	}
186 
187 	if( mark_pending ) {
188 		if( *msg_event ) {
189 			/* the pending event is the notification we wait for ! */
190 			mgr->pending_event = *msg_event;
191 		}
192 		else {
193 			/* the pending event is the answer we wait for (same address than the request)! */
194 			mgr->pending_event = msg_frame_address;
195 
196 			/* copy address back to caller */
197 			*msg_event = msg_frame_address;
198 		}
199 	}
200 
201 	/* mark the frame as a request (will have an answer) */
202 	msg_frame_address |= MSG_TYPE_REQUEST;
203 
204 	/* post the frame */
205 	headptr = readl_be(MIXART_MEM(mgr, MSG_INBOUND_POST_HEAD));
206 
207 	if( (headptr < MSG_INBOUND_POST_STACK) || (headptr >= (MSG_INBOUND_POST_STACK+MSG_BOUND_STACK_SIZE))) {
208 		return -EINVAL;
209 	}
210 
211 	writel_be(msg_frame_address, MIXART_MEM(mgr, headptr));
212 
213 	/* increment the inbound post head */
214 	headptr += 4;
215 	if( headptr >= (MSG_INBOUND_POST_STACK+MSG_BOUND_STACK_SIZE) )
216 		headptr = MSG_INBOUND_POST_STACK;
217 
218 	writel_be(headptr, MIXART_MEM(mgr, MSG_INBOUND_POST_HEAD));
219 
220 	return 0;
221 }
222 
223 
224 int snd_mixart_send_msg(struct mixart_mgr *mgr, struct mixart_msg *request, int max_resp_size, void *resp_data)
225 {
226 	struct mixart_msg resp;
227 	u32 msg_frame = 0; /* set to 0, so it's no notification to wait for, but the answer */
228 	int err;
229 	wait_queue_entry_t wait;
230 	long timeout;
231 
232 	init_waitqueue_entry(&wait, current);
233 
234 	mutex_lock(&mgr->msg_lock);
235 	/* send the message */
236 	err = send_msg(mgr, request, max_resp_size, 1, &msg_frame);  /* send and mark the answer pending */
237 	if (err) {
238 		mutex_unlock(&mgr->msg_lock);
239 		return err;
240 	}
241 
242 	set_current_state(TASK_UNINTERRUPTIBLE);
243 	add_wait_queue(&mgr->msg_sleep, &wait);
244 	mutex_unlock(&mgr->msg_lock);
245 	timeout = schedule_timeout(MSG_TIMEOUT_JIFFIES);
246 	remove_wait_queue(&mgr->msg_sleep, &wait);
247 
248 	if (! timeout) {
249 		/* error - no ack */
250 		dev_err(&mgr->pci->dev,
251 			"error: no response on msg %x\n", msg_frame);
252 		return -EIO;
253 	}
254 
255 	/* retrieve the answer into the same struct mixart_msg */
256 	resp.message_id = 0;
257 	resp.uid = (struct mixart_uid){0,0};
258 	resp.data = resp_data;
259 	resp.size = max_resp_size;
260 
261 	err = get_msg(mgr, &resp, msg_frame);
262 
263 	if( request->message_id != resp.message_id )
264 		dev_err(&mgr->pci->dev, "RESPONSE ERROR!\n");
265 
266 	return err;
267 }
268 
269 
270 int snd_mixart_send_msg_wait_notif(struct mixart_mgr *mgr,
271 				   struct mixart_msg *request, u32 notif_event)
272 {
273 	int err;
274 	wait_queue_entry_t wait;
275 	long timeout;
276 
277 	if (snd_BUG_ON(!notif_event))
278 		return -EINVAL;
279 	if (snd_BUG_ON((notif_event & MSG_TYPE_MASK) != MSG_TYPE_NOTIFY))
280 		return -EINVAL;
281 	if (snd_BUG_ON(notif_event & MSG_CANCEL_NOTIFY_MASK))
282 		return -EINVAL;
283 
284 	init_waitqueue_entry(&wait, current);
285 
286 	mutex_lock(&mgr->msg_lock);
287 	/* send the message */
288 	err = send_msg(mgr, request, MSG_DEFAULT_SIZE, 1, &notif_event);  /* send and mark the notification event pending */
289 	if(err) {
290 		mutex_unlock(&mgr->msg_lock);
291 		return err;
292 	}
293 
294 	set_current_state(TASK_UNINTERRUPTIBLE);
295 	add_wait_queue(&mgr->msg_sleep, &wait);
296 	mutex_unlock(&mgr->msg_lock);
297 	timeout = schedule_timeout(MSG_TIMEOUT_JIFFIES);
298 	remove_wait_queue(&mgr->msg_sleep, &wait);
299 
300 	if (! timeout) {
301 		/* error - no ack */
302 		dev_err(&mgr->pci->dev,
303 			"error: notification %x not received\n", notif_event);
304 		return -EIO;
305 	}
306 
307 	return 0;
308 }
309 
310 
311 int snd_mixart_send_msg_nonblock(struct mixart_mgr *mgr, struct mixart_msg *request)
312 {
313 	u32 message_frame;
314 	int err;
315 
316 	/* just send the message (do not mark it as a pending one) */
317 	mutex_lock(&mgr->msg_lock);
318 	err = send_msg(mgr, request, MSG_DEFAULT_SIZE, 0, &message_frame);
319 	mutex_unlock(&mgr->msg_lock);
320 
321 	/* the answer will be handled by snd_struct mixart_msgasklet()  */
322 	atomic_inc(&mgr->msg_processed);
323 
324 	return err;
325 }
326 
327 
328 /* common buffer of interrupt to send/receive messages */
329 static u32 mixart_msg_data[MSG_DEFAULT_SIZE / 4];
330 
331 
332 static void snd_mixart_process_msg(struct mixart_mgr *mgr)
333 {
334 	struct mixart_msg resp;
335 	u32 msg, addr, type;
336 	int err;
337 
338 	while (mgr->msg_fifo_readptr != mgr->msg_fifo_writeptr) {
339 		msg = mgr->msg_fifo[mgr->msg_fifo_readptr];
340 		mgr->msg_fifo_readptr++;
341 		mgr->msg_fifo_readptr %= MSG_FIFO_SIZE;
342 
343 		/* process the message ... */
344 		addr = msg & ~MSG_TYPE_MASK;
345 		type = msg & MSG_TYPE_MASK;
346 
347 		switch (type) {
348 		case MSG_TYPE_ANSWER:
349 			/* answer to a message on that we did not wait for (send_msg_nonblock) */
350 			resp.message_id = 0;
351 			resp.data = mixart_msg_data;
352 			resp.size = sizeof(mixart_msg_data);
353 			err = get_msg(mgr, &resp, addr);
354 			if( err < 0 ) {
355 				dev_err(&mgr->pci->dev,
356 					"error(%d) reading mf %x\n",
357 					err, msg);
358 				break;
359 			}
360 
361 			switch(resp.message_id) {
362 			case MSG_STREAM_START_INPUT_STAGE_PACKET:
363 			case MSG_STREAM_START_OUTPUT_STAGE_PACKET:
364 			case MSG_STREAM_STOP_INPUT_STAGE_PACKET:
365 			case MSG_STREAM_STOP_OUTPUT_STAGE_PACKET:
366 				if(mixart_msg_data[0])
367 					dev_err(&mgr->pci->dev,
368 						"error MSG_STREAM_ST***_***PUT_STAGE_PACKET status=%x\n",
369 						mixart_msg_data[0]);
370 				break;
371 			default:
372 				dev_dbg(&mgr->pci->dev,
373 					"received mf(%x) : msg_id(%x) uid(%x, %x) size(%zd)\n",
374 					   msg, resp.message_id, resp.uid.object_id, resp.uid.desc, resp.size);
375 				break;
376 			}
377 			break;
378  		case MSG_TYPE_NOTIFY:
379 			/* msg contains no address ! do not get_msg() ! */
380 		case MSG_TYPE_COMMAND:
381 			/* get_msg() necessary */
382 		default:
383 			dev_err(&mgr->pci->dev,
384 				"doesn't know what to do with message %x\n",
385 				msg);
386 		} /* switch type */
387 
388 		/* decrement counter */
389 		atomic_dec(&mgr->msg_processed);
390 
391 	} /* while there is a msg in fifo */
392 }
393 
394 
395 irqreturn_t snd_mixart_interrupt(int irq, void *dev_id)
396 {
397 	struct mixart_mgr *mgr = dev_id;
398 	u32 it_reg;
399 
400 	it_reg = readl_le(MIXART_REG(mgr, MIXART_PCI_OMISR_OFFSET));
401 	if( !(it_reg & MIXART_OIDI) ) {
402 		/* this device did not cause the interrupt */
403 		return IRQ_NONE;
404 	}
405 
406 	/* mask all interrupts */
407 	writel_le(MIXART_HOST_ALL_INTERRUPT_MASKED, MIXART_REG(mgr, MIXART_PCI_OMIMR_OFFSET));
408 
409 	/* outdoorbell register clear */
410 	it_reg = readl(MIXART_REG(mgr, MIXART_PCI_ODBR_OFFSET));
411 	writel(it_reg, MIXART_REG(mgr, MIXART_PCI_ODBR_OFFSET));
412 
413 	/* clear interrupt */
414 	writel_le( MIXART_OIDI, MIXART_REG(mgr, MIXART_PCI_OMISR_OFFSET) );
415 
416 	return IRQ_WAKE_THREAD;
417 }
418 
419 irqreturn_t snd_mixart_threaded_irq(int irq, void *dev_id)
420 {
421 	struct mixart_mgr *mgr = dev_id;
422 	int err;
423 	struct mixart_msg resp;
424 	u32 msg;
425 
426 	mutex_lock(&mgr->lock);
427 	/* process interrupt */
428 	while (retrieve_msg_frame(mgr, &msg)) {
429 
430 		switch (msg & MSG_TYPE_MASK) {
431 		case MSG_TYPE_COMMAND:
432 			resp.message_id = 0;
433 			resp.data = mixart_msg_data;
434 			resp.size = sizeof(mixart_msg_data);
435 			err = get_msg(mgr, &resp, msg & ~MSG_TYPE_MASK);
436 			if( err < 0 ) {
437 				dev_err(&mgr->pci->dev,
438 					"interrupt: error(%d) reading mf %x\n",
439 					err, msg);
440 				break;
441 			}
442 
443 			if(resp.message_id == MSG_SERVICES_TIMER_NOTIFY) {
444 				int i;
445 				struct mixart_timer_notify *notify;
446 				notify = (struct mixart_timer_notify *)mixart_msg_data;
447 
448 				for(i=0; i<notify->stream_count; i++) {
449 
450 					u32 buffer_id = notify->streams[i].buffer_id;
451 					unsigned int chip_number =  (buffer_id & MIXART_NOTIFY_CARD_MASK) >> MIXART_NOTIFY_CARD_OFFSET; /* card0 to 3 */
452 					unsigned int pcm_number  =  (buffer_id & MIXART_NOTIFY_PCM_MASK ) >> MIXART_NOTIFY_PCM_OFFSET;  /* pcm0 to 3  */
453 					unsigned int sub_number  =   buffer_id & MIXART_NOTIFY_SUBS_MASK;             /* 0 to MIXART_PLAYBACK_STREAMS */
454 					unsigned int is_capture  = ((buffer_id & MIXART_NOTIFY_CAPT_MASK) != 0);      /* playback == 0 / capture == 1 */
455 
456 					struct snd_mixart *chip  = mgr->chip[chip_number];
457 					struct mixart_stream *stream;
458 
459 					if ((chip_number >= mgr->num_cards) || (pcm_number >= MIXART_PCM_TOTAL) || (sub_number >= MIXART_PLAYBACK_STREAMS)) {
460 						dev_err(&mgr->pci->dev,
461 							"error MSG_SERVICES_TIMER_NOTIFY buffer_id (%x) pos(%d)\n",
462 							   buffer_id, notify->streams[i].sample_pos_low_part);
463 						break;
464 					}
465 
466 					if (is_capture)
467 						stream = &chip->capture_stream[pcm_number];
468 					else
469 						stream = &chip->playback_stream[pcm_number][sub_number];
470 
471 					if (stream->substream && (stream->status == MIXART_STREAM_STATUS_RUNNING)) {
472 						struct snd_pcm_runtime *runtime = stream->substream->runtime;
473 						int elapsed = 0;
474 						u64 sample_count = ((u64)notify->streams[i].sample_pos_high_part) << 32;
475 						sample_count |= notify->streams[i].sample_pos_low_part;
476 
477 						while (1) {
478 							u64 new_elapse_pos = stream->abs_period_elapsed +  runtime->period_size;
479 
480 							if (new_elapse_pos > sample_count) {
481 								break; /* while */
482 							}
483 							else {
484 								elapsed = 1;
485 								stream->buf_periods++;
486 								if (stream->buf_periods >= runtime->periods)
487 									stream->buf_periods = 0;
488 
489 								stream->abs_period_elapsed = new_elapse_pos;
490 							}
491 						}
492 						stream->buf_period_frag = (u32)( sample_count - stream->abs_period_elapsed );
493 
494 						if(elapsed) {
495 							mutex_unlock(&mgr->lock);
496 							snd_pcm_period_elapsed(stream->substream);
497 							mutex_lock(&mgr->lock);
498 						}
499 					}
500 				}
501 				break;
502 			}
503 			if(resp.message_id == MSG_SERVICES_REPORT_TRACES) {
504 				if(resp.size > 1) {
505 #ifndef __BIG_ENDIAN
506 					/* Traces are text: the swapped msg_data has to be swapped back ! */
507 					int i;
508 					for(i=0; i<(resp.size/4); i++) {
509 						((__be32*)mixart_msg_data)[i] = cpu_to_be32((mixart_msg_data)[i]);
510 					}
511 #endif
512 					((char*)mixart_msg_data)[resp.size - 1] = 0;
513 					dev_dbg(&mgr->pci->dev,
514 						"MIXART TRACE : %s\n",
515 						(char *)mixart_msg_data);
516 				}
517 				break;
518 			}
519 
520 			dev_dbg(&mgr->pci->dev, "command %x not handled\n",
521 				resp.message_id);
522 			break;
523 
524 		case MSG_TYPE_NOTIFY:
525 			if(msg & MSG_CANCEL_NOTIFY_MASK) {
526 				msg &= ~MSG_CANCEL_NOTIFY_MASK;
527 				dev_err(&mgr->pci->dev,
528 					"canceled notification %x !\n", msg);
529 			}
530 			fallthrough;
531 		case MSG_TYPE_ANSWER:
532 			/* answer or notification to a message we are waiting for*/
533 			mutex_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 				snd_mixart_process_msg(mgr);
544 			}
545 			mutex_unlock(&mgr->msg_lock);
546 			break;
547 		case MSG_TYPE_REQUEST:
548 		default:
549 			dev_dbg(&mgr->pci->dev,
550 				"interrupt received request %x\n", msg);
551 			/* TODO : are there things to do here ? */
552 			break;
553 		} /* switch on msg type */
554 	} /* while there are msgs */
555 
556 	/* allow interrupt again */
557 	writel_le( MIXART_ALLOW_OUTBOUND_DOORBELL, MIXART_REG( mgr, MIXART_PCI_OMIMR_OFFSET));
558 
559 	mutex_unlock(&mgr->lock);
560 
561 	return IRQ_HANDLED;
562 }
563 
564 
565 void snd_mixart_init_mailbox(struct mixart_mgr *mgr)
566 {
567 	writel( 0, MIXART_MEM( mgr, MSG_HOST_RSC_PROTECTION ) );
568 	writel( 0, MIXART_MEM( mgr, MSG_AGENT_RSC_PROTECTION ) );
569 
570 	/* allow outbound messagebox to generate interrupts */
571 	if(mgr->irq >= 0) {
572 		writel_le( MIXART_ALLOW_OUTBOUND_DOORBELL, MIXART_REG( mgr, MIXART_PCI_OMIMR_OFFSET));
573 	}
574 	return;
575 }
576 
577 void snd_mixart_exit_mailbox(struct mixart_mgr *mgr)
578 {
579 	/* no more interrupts on outbound messagebox */
580 	writel_le( MIXART_HOST_ALL_INTERRUPT_MASKED, MIXART_REG( mgr, MIXART_PCI_OMIMR_OFFSET));
581 	return;
582 }
583 
584 void snd_mixart_reset_board(struct mixart_mgr *mgr)
585 {
586 	/* reset miXart */
587 	writel_be( 1, MIXART_REG(mgr, MIXART_BA1_BRUTAL_RESET_OFFSET) );
588 	return;
589 }
590