xref: /openbmc/linux/sound/pci/mixart/mixart_core.c (revision 7a010c3c)
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 	err = 0;
74 
75 	/* copy message descriptor from miXart to driver */
76 	size                =  readl_be(MIXART_MEM(mgr, msg_frame_address));       /* size of descriptor + response */
77 	resp->message_id    =  readl_be(MIXART_MEM(mgr, msg_frame_address + 4));   /* dwMessageID */
78 	resp->uid.object_id =  readl_be(MIXART_MEM(mgr, msg_frame_address + 8));   /* uidDest */
79 	resp->uid.desc      =  readl_be(MIXART_MEM(mgr, msg_frame_address + 12));  /* */
80 
81 	if( (size < MSG_DESCRIPTOR_SIZE) || (resp->size < (size - MSG_DESCRIPTOR_SIZE))) {
82 		err = -EINVAL;
83 		dev_err(&mgr->pci->dev,
84 			"problem with response size = %d\n", size);
85 		goto _clean_exit;
86 	}
87 	size -= MSG_DESCRIPTOR_SIZE;
88 
89 	memcpy_fromio(resp->data, MIXART_MEM(mgr, msg_frame_address + MSG_HEADER_SIZE ), size);
90 	resp->size = size;
91 
92 	/* swap if necessary */
93 #ifndef __BIG_ENDIAN
94 	size /= 4; /* u32 size */
95 	for(i=0; i < size; i++) {
96 		((u32*)resp->data)[i] = be32_to_cpu(((__be32*)resp->data)[i]);
97 	}
98 #endif
99 
100 	/*
101 	 * free message frame address
102 	 */
103 	headptr = readl_be(MIXART_MEM(mgr, MSG_OUTBOUND_FREE_HEAD));
104 
105 	if( (headptr < MSG_OUTBOUND_FREE_STACK) || ( headptr >= (MSG_OUTBOUND_FREE_STACK+MSG_BOUND_STACK_SIZE))) {
106 		err = -EINVAL;
107 		goto _clean_exit;
108 	}
109 
110 	/* give address back to outbound fifo */
111 	writel_be(msg_frame_address, MIXART_MEM(mgr, headptr));
112 
113 	/* increment the outbound free head */
114 	headptr += 4;
115 	if( headptr >= (MSG_OUTBOUND_FREE_STACK+MSG_BOUND_STACK_SIZE) )
116 		headptr = MSG_OUTBOUND_FREE_STACK;
117 
118 	writel_be(headptr, MIXART_MEM(mgr, MSG_OUTBOUND_FREE_HEAD));
119 
120  _clean_exit:
121 	return err;
122 }
123 
124 
125 /*
126  * send a message to miXart. return: the msg_frame used for this message
127  */
128 /* call with mgr->msg_lock held! */
129 static int send_msg( struct mixart_mgr *mgr,
130 		     struct mixart_msg *msg,
131 		     int max_answersize,
132 		     int mark_pending,
133 		     u32 *msg_event)
134 {
135 	u32 headptr, tailptr;
136 	u32 msg_frame_address;
137 	int i;
138 
139 	if (snd_BUG_ON(msg->size % 4))
140 		return -EINVAL;
141 
142 	/* get message frame address */
143 	tailptr = readl_be(MIXART_MEM(mgr, MSG_INBOUND_FREE_TAIL));
144 	headptr = readl_be(MIXART_MEM(mgr, MSG_INBOUND_FREE_HEAD));
145 
146 	if (tailptr == headptr) {
147 		dev_err(&mgr->pci->dev, "error: no message frame available\n");
148 		return -EBUSY;
149 	}
150 
151 	if( (tailptr < MSG_INBOUND_FREE_STACK) || (tailptr >= (MSG_INBOUND_FREE_STACK+MSG_BOUND_STACK_SIZE))) {
152 		return -EINVAL;
153 	}
154 
155 	msg_frame_address = readl_be(MIXART_MEM(mgr, tailptr));
156 	writel(0, MIXART_MEM(mgr, tailptr)); /* set address to zero on this fifo position */
157 
158 	/* increment the inbound free tail */
159 	tailptr += 4;
160 	if( tailptr >= (MSG_INBOUND_FREE_STACK+MSG_BOUND_STACK_SIZE) )
161 		tailptr = MSG_INBOUND_FREE_STACK;
162 
163 	writel_be(tailptr, MIXART_MEM(mgr, MSG_INBOUND_FREE_TAIL));
164 
165 	/* TODO : use memcpy_toio() with intermediate buffer to copy the message */
166 
167 	/* copy message descriptor to card memory */
168 	writel_be( msg->size + MSG_DESCRIPTOR_SIZE,      MIXART_MEM(mgr, msg_frame_address) );      /* size of descriptor + request */
169 	writel_be( msg->message_id ,                     MIXART_MEM(mgr, msg_frame_address + 4) );  /* dwMessageID */
170 	writel_be( msg->uid.object_id,                   MIXART_MEM(mgr, msg_frame_address + 8) );  /* uidDest */
171 	writel_be( msg->uid.desc,                        MIXART_MEM(mgr, msg_frame_address + 12) ); /* */
172 	writel_be( MSG_DESCRIPTOR_SIZE,                  MIXART_MEM(mgr, msg_frame_address + 16) ); /* SizeHeader */
173 	writel_be( MSG_DESCRIPTOR_SIZE,                  MIXART_MEM(mgr, msg_frame_address + 20) ); /* OffsetDLL_T16 */
174 	writel_be( msg->size,                            MIXART_MEM(mgr, msg_frame_address + 24) ); /* SizeDLL_T16 */
175 	writel_be( MSG_DESCRIPTOR_SIZE,                  MIXART_MEM(mgr, msg_frame_address + 28) ); /* OffsetDLL_DRV */
176 	writel_be( 0,                                    MIXART_MEM(mgr, msg_frame_address + 32) ); /* SizeDLL_DRV */
177 	writel_be( MSG_DESCRIPTOR_SIZE + max_answersize, MIXART_MEM(mgr, msg_frame_address + 36) ); /* dwExpectedAnswerSize */
178 
179 	/* copy message data to card memory */
180 	for( i=0; i < msg->size; i+=4 ) {
181 		writel_be( *(u32*)(msg->data + i), MIXART_MEM(mgr, MSG_HEADER_SIZE + msg_frame_address + i)  );
182 	}
183 
184 	if( mark_pending ) {
185 		if( *msg_event ) {
186 			/* the pending event is the notification we wait for ! */
187 			mgr->pending_event = *msg_event;
188 		}
189 		else {
190 			/* the pending event is the answer we wait for (same address than the request)! */
191 			mgr->pending_event = msg_frame_address;
192 
193 			/* copy address back to caller */
194 			*msg_event = msg_frame_address;
195 		}
196 	}
197 
198 	/* mark the frame as a request (will have an answer) */
199 	msg_frame_address |= MSG_TYPE_REQUEST;
200 
201 	/* post the frame */
202 	headptr = readl_be(MIXART_MEM(mgr, MSG_INBOUND_POST_HEAD));
203 
204 	if( (headptr < MSG_INBOUND_POST_STACK) || (headptr >= (MSG_INBOUND_POST_STACK+MSG_BOUND_STACK_SIZE))) {
205 		return -EINVAL;
206 	}
207 
208 	writel_be(msg_frame_address, MIXART_MEM(mgr, headptr));
209 
210 	/* increment the inbound post head */
211 	headptr += 4;
212 	if( headptr >= (MSG_INBOUND_POST_STACK+MSG_BOUND_STACK_SIZE) )
213 		headptr = MSG_INBOUND_POST_STACK;
214 
215 	writel_be(headptr, MIXART_MEM(mgr, MSG_INBOUND_POST_HEAD));
216 
217 	return 0;
218 }
219 
220 
221 int snd_mixart_send_msg(struct mixart_mgr *mgr, struct mixart_msg *request, int max_resp_size, void *resp_data)
222 {
223 	struct mixart_msg resp;
224 	u32 msg_frame = 0; /* set to 0, so it's no notification to wait for, but the answer */
225 	int err;
226 	wait_queue_entry_t wait;
227 	long timeout;
228 
229 	init_waitqueue_entry(&wait, current);
230 
231 	mutex_lock(&mgr->msg_lock);
232 	/* send the message */
233 	err = send_msg(mgr, request, max_resp_size, 1, &msg_frame);  /* send and mark the answer pending */
234 	if (err) {
235 		mutex_unlock(&mgr->msg_lock);
236 		return err;
237 	}
238 
239 	set_current_state(TASK_UNINTERRUPTIBLE);
240 	add_wait_queue(&mgr->msg_sleep, &wait);
241 	mutex_unlock(&mgr->msg_lock);
242 	timeout = schedule_timeout(MSG_TIMEOUT_JIFFIES);
243 	remove_wait_queue(&mgr->msg_sleep, &wait);
244 
245 	if (! timeout) {
246 		/* error - no ack */
247 		dev_err(&mgr->pci->dev,
248 			"error: no response on msg %x\n", msg_frame);
249 		return -EIO;
250 	}
251 
252 	/* retrieve the answer into the same struct mixart_msg */
253 	resp.message_id = 0;
254 	resp.uid = (struct mixart_uid){0,0};
255 	resp.data = resp_data;
256 	resp.size = max_resp_size;
257 
258 	mutex_lock(&mgr->msg_lock);
259 	err = get_msg(mgr, &resp, msg_frame);
260 	mutex_unlock(&mgr->msg_lock);
261 
262 	if( request->message_id != resp.message_id )
263 		dev_err(&mgr->pci->dev, "RESPONSE ERROR!\n");
264 
265 	return err;
266 }
267 
268 
269 int snd_mixart_send_msg_wait_notif(struct mixart_mgr *mgr,
270 				   struct mixart_msg *request, u32 notif_event)
271 {
272 	int err;
273 	wait_queue_entry_t wait;
274 	long timeout;
275 
276 	if (snd_BUG_ON(!notif_event))
277 		return -EINVAL;
278 	if (snd_BUG_ON((notif_event & MSG_TYPE_MASK) != MSG_TYPE_NOTIFY))
279 		return -EINVAL;
280 	if (snd_BUG_ON(notif_event & MSG_CANCEL_NOTIFY_MASK))
281 		return -EINVAL;
282 
283 	init_waitqueue_entry(&wait, current);
284 
285 	mutex_lock(&mgr->msg_lock);
286 	/* send the message */
287 	err = send_msg(mgr, request, MSG_DEFAULT_SIZE, 1, &notif_event);  /* send and mark the notification event pending */
288 	if(err) {
289 		mutex_unlock(&mgr->msg_lock);
290 		return err;
291 	}
292 
293 	set_current_state(TASK_UNINTERRUPTIBLE);
294 	add_wait_queue(&mgr->msg_sleep, &wait);
295 	mutex_unlock(&mgr->msg_lock);
296 	timeout = schedule_timeout(MSG_TIMEOUT_JIFFIES);
297 	remove_wait_queue(&mgr->msg_sleep, &wait);
298 
299 	if (! timeout) {
300 		/* error - no ack */
301 		dev_err(&mgr->pci->dev,
302 			"error: notification %x not received\n", notif_event);
303 		return -EIO;
304 	}
305 
306 	return 0;
307 }
308 
309 
310 int snd_mixart_send_msg_nonblock(struct mixart_mgr *mgr, struct mixart_msg *request)
311 {
312 	u32 message_frame;
313 	int err;
314 
315 	/* just send the message (do not mark it as a pending one) */
316 	mutex_lock(&mgr->msg_lock);
317 	err = send_msg(mgr, request, MSG_DEFAULT_SIZE, 0, &message_frame);
318 	mutex_unlock(&mgr->msg_lock);
319 
320 	/* the answer will be handled by snd_struct mixart_msgasklet()  */
321 	atomic_inc(&mgr->msg_processed);
322 
323 	return err;
324 }
325 
326 
327 /* common buffer of interrupt to send/receive messages */
328 static u32 mixart_msg_data[MSG_DEFAULT_SIZE / 4];
329 
330 
331 static void snd_mixart_process_msg(struct mixart_mgr *mgr)
332 {
333 	struct mixart_msg resp;
334 	u32 msg, addr, type;
335 	int err;
336 
337 	while (mgr->msg_fifo_readptr != mgr->msg_fifo_writeptr) {
338 		msg = mgr->msg_fifo[mgr->msg_fifo_readptr];
339 		mgr->msg_fifo_readptr++;
340 		mgr->msg_fifo_readptr %= MSG_FIFO_SIZE;
341 
342 		/* process the message ... */
343 		addr = msg & ~MSG_TYPE_MASK;
344 		type = msg & MSG_TYPE_MASK;
345 
346 		switch (type) {
347 		case MSG_TYPE_ANSWER:
348 			/* answer to a message on that we did not wait for (send_msg_nonblock) */
349 			resp.message_id = 0;
350 			resp.data = mixart_msg_data;
351 			resp.size = sizeof(mixart_msg_data);
352 			err = get_msg(mgr, &resp, addr);
353 			if( err < 0 ) {
354 				dev_err(&mgr->pci->dev,
355 					"error(%d) reading mf %x\n",
356 					err, msg);
357 				break;
358 			}
359 
360 			switch(resp.message_id) {
361 			case MSG_STREAM_START_INPUT_STAGE_PACKET:
362 			case MSG_STREAM_START_OUTPUT_STAGE_PACKET:
363 			case MSG_STREAM_STOP_INPUT_STAGE_PACKET:
364 			case MSG_STREAM_STOP_OUTPUT_STAGE_PACKET:
365 				if(mixart_msg_data[0])
366 					dev_err(&mgr->pci->dev,
367 						"error MSG_STREAM_ST***_***PUT_STAGE_PACKET status=%x\n",
368 						mixart_msg_data[0]);
369 				break;
370 			default:
371 				dev_dbg(&mgr->pci->dev,
372 					"received mf(%x) : msg_id(%x) uid(%x, %x) size(%zd)\n",
373 					   msg, resp.message_id, resp.uid.object_id, resp.uid.desc, resp.size);
374 				break;
375 			}
376 			break;
377  		case MSG_TYPE_NOTIFY:
378 			/* msg contains no address ! do not get_msg() ! */
379 		case MSG_TYPE_COMMAND:
380 			/* get_msg() necessary */
381 		default:
382 			dev_err(&mgr->pci->dev,
383 				"doesn't know what to do with message %x\n",
384 				msg);
385 		} /* switch type */
386 
387 		/* decrement counter */
388 		atomic_dec(&mgr->msg_processed);
389 
390 	} /* while there is a msg in fifo */
391 }
392 
393 
394 irqreturn_t snd_mixart_interrupt(int irq, void *dev_id)
395 {
396 	struct mixart_mgr *mgr = dev_id;
397 	u32 it_reg;
398 
399 	it_reg = readl_le(MIXART_REG(mgr, MIXART_PCI_OMISR_OFFSET));
400 	if( !(it_reg & MIXART_OIDI) ) {
401 		/* this device did not cause the interrupt */
402 		return IRQ_NONE;
403 	}
404 
405 	/* mask all interrupts */
406 	writel_le(MIXART_HOST_ALL_INTERRUPT_MASKED, MIXART_REG(mgr, MIXART_PCI_OMIMR_OFFSET));
407 
408 	/* outdoorbell register clear */
409 	it_reg = readl(MIXART_REG(mgr, MIXART_PCI_ODBR_OFFSET));
410 	writel(it_reg, MIXART_REG(mgr, MIXART_PCI_ODBR_OFFSET));
411 
412 	/* clear interrupt */
413 	writel_le( MIXART_OIDI, MIXART_REG(mgr, MIXART_PCI_OMISR_OFFSET) );
414 
415 	return IRQ_WAKE_THREAD;
416 }
417 
418 irqreturn_t snd_mixart_threaded_irq(int irq, void *dev_id)
419 {
420 	struct mixart_mgr *mgr = dev_id;
421 	int err;
422 	struct mixart_msg resp;
423 	u32 msg;
424 
425 	mutex_lock(&mgr->lock);
426 	/* process interrupt */
427 	while (retrieve_msg_frame(mgr, &msg)) {
428 
429 		switch (msg & MSG_TYPE_MASK) {
430 		case MSG_TYPE_COMMAND:
431 			resp.message_id = 0;
432 			resp.data = mixart_msg_data;
433 			resp.size = sizeof(mixart_msg_data);
434 			err = get_msg(mgr, &resp, msg & ~MSG_TYPE_MASK);
435 			if( err < 0 ) {
436 				dev_err(&mgr->pci->dev,
437 					"interrupt: error(%d) reading mf %x\n",
438 					err, msg);
439 				break;
440 			}
441 
442 			if(resp.message_id == MSG_SERVICES_TIMER_NOTIFY) {
443 				int i;
444 				struct mixart_timer_notify *notify;
445 				notify = (struct mixart_timer_notify *)mixart_msg_data;
446 
447 				for(i=0; i<notify->stream_count; i++) {
448 
449 					u32 buffer_id = notify->streams[i].buffer_id;
450 					unsigned int chip_number =  (buffer_id & MIXART_NOTIFY_CARD_MASK) >> MIXART_NOTIFY_CARD_OFFSET; /* card0 to 3 */
451 					unsigned int pcm_number  =  (buffer_id & MIXART_NOTIFY_PCM_MASK ) >> MIXART_NOTIFY_PCM_OFFSET;  /* pcm0 to 3  */
452 					unsigned int sub_number  =   buffer_id & MIXART_NOTIFY_SUBS_MASK;             /* 0 to MIXART_PLAYBACK_STREAMS */
453 					unsigned int is_capture  = ((buffer_id & MIXART_NOTIFY_CAPT_MASK) != 0);      /* playback == 0 / capture == 1 */
454 
455 					struct snd_mixart *chip  = mgr->chip[chip_number];
456 					struct mixart_stream *stream;
457 
458 					if ((chip_number >= mgr->num_cards) || (pcm_number >= MIXART_PCM_TOTAL) || (sub_number >= MIXART_PLAYBACK_STREAMS)) {
459 						dev_err(&mgr->pci->dev,
460 							"error MSG_SERVICES_TIMER_NOTIFY buffer_id (%x) pos(%d)\n",
461 							   buffer_id, notify->streams[i].sample_pos_low_part);
462 						break;
463 					}
464 
465 					if (is_capture)
466 						stream = &chip->capture_stream[pcm_number];
467 					else
468 						stream = &chip->playback_stream[pcm_number][sub_number];
469 
470 					if (stream->substream && (stream->status == MIXART_STREAM_STATUS_RUNNING)) {
471 						struct snd_pcm_runtime *runtime = stream->substream->runtime;
472 						int elapsed = 0;
473 						u64 sample_count = ((u64)notify->streams[i].sample_pos_high_part) << 32;
474 						sample_count |= notify->streams[i].sample_pos_low_part;
475 
476 						while (1) {
477 							u64 new_elapse_pos = stream->abs_period_elapsed +  runtime->period_size;
478 
479 							if (new_elapse_pos > sample_count) {
480 								break; /* while */
481 							}
482 							else {
483 								elapsed = 1;
484 								stream->buf_periods++;
485 								if (stream->buf_periods >= runtime->periods)
486 									stream->buf_periods = 0;
487 
488 								stream->abs_period_elapsed = new_elapse_pos;
489 							}
490 						}
491 						stream->buf_period_frag = (u32)( sample_count - stream->abs_period_elapsed );
492 
493 						if(elapsed) {
494 							mutex_unlock(&mgr->lock);
495 							snd_pcm_period_elapsed(stream->substream);
496 							mutex_lock(&mgr->lock);
497 						}
498 					}
499 				}
500 				break;
501 			}
502 			if(resp.message_id == MSG_SERVICES_REPORT_TRACES) {
503 				if(resp.size > 1) {
504 #ifndef __BIG_ENDIAN
505 					/* Traces are text: the swapped msg_data has to be swapped back ! */
506 					int i;
507 					for(i=0; i<(resp.size/4); i++) {
508 						((__be32*)mixart_msg_data)[i] = cpu_to_be32((mixart_msg_data)[i]);
509 					}
510 #endif
511 					((char*)mixart_msg_data)[resp.size - 1] = 0;
512 					dev_dbg(&mgr->pci->dev,
513 						"MIXART TRACE : %s\n",
514 						(char *)mixart_msg_data);
515 				}
516 				break;
517 			}
518 
519 			dev_dbg(&mgr->pci->dev, "command %x not handled\n",
520 				resp.message_id);
521 			break;
522 
523 		case MSG_TYPE_NOTIFY:
524 			if(msg & MSG_CANCEL_NOTIFY_MASK) {
525 				msg &= ~MSG_CANCEL_NOTIFY_MASK;
526 				dev_err(&mgr->pci->dev,
527 					"canceled notification %x !\n", msg);
528 			}
529 			fallthrough;
530 		case MSG_TYPE_ANSWER:
531 			/* answer or notification to a message we are waiting for*/
532 			mutex_lock(&mgr->msg_lock);
533 			if( (msg & ~MSG_TYPE_MASK) == mgr->pending_event ) {
534 				wake_up(&mgr->msg_sleep);
535 				mgr->pending_event = 0;
536 			}
537 			/* answer to a message we did't want to wait for */
538 			else {
539 				mgr->msg_fifo[mgr->msg_fifo_writeptr] = msg;
540 				mgr->msg_fifo_writeptr++;
541 				mgr->msg_fifo_writeptr %= MSG_FIFO_SIZE;
542 				snd_mixart_process_msg(mgr);
543 			}
544 			mutex_unlock(&mgr->msg_lock);
545 			break;
546 		case MSG_TYPE_REQUEST:
547 		default:
548 			dev_dbg(&mgr->pci->dev,
549 				"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 	mutex_unlock(&mgr->lock);
559 
560 	return IRQ_HANDLED;
561 }
562 
563 
564 void snd_mixart_init_mailbox(struct mixart_mgr *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(struct mixart_mgr *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(struct mixart_mgr *mgr)
584 {
585 	/* reset miXart */
586 	writel_be( 1, MIXART_REG(mgr, MIXART_BA1_BRUTAL_RESET_OFFSET) );
587 	return;
588 }
589