xref: /linux/sound/pci/mixart/mixart_core.c (revision 03ab8e6297acd1bc0eedaa050e2a1635c576fd11)
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_TYPE_MASK               0x00000003    /* mask for following types */
27 #define MSG_TYPE_NOTIFY             0             /* embedded -> driver (only notification, do not get_msg() !) */
28 #define MSG_TYPE_COMMAND            1             /* driver <-> embedded (a command has no answer) */
29 #define MSG_TYPE_REQUEST            2             /* driver -> embedded (request will get an answer back) */
30 #define MSG_TYPE_ANSWER             3             /* embedded -> driver */
31 #define MSG_CANCEL_NOTIFY_MASK      0x80000000    /* this bit is set for a notification that has been canceled */
32 
33 
retrieve_msg_frame(struct mixart_mgr * mgr,u32 * msg_frame)34 static int retrieve_msg_frame(struct mixart_mgr *mgr, u32 *msg_frame)
35 {
36 	/* read the message frame fifo */
37 	u32 headptr, tailptr;
38 
39 	tailptr = readl_be(MIXART_MEM(mgr, MSG_OUTBOUND_POST_TAIL));
40 	headptr = readl_be(MIXART_MEM(mgr, MSG_OUTBOUND_POST_HEAD));
41 
42 	if (tailptr == headptr)
43 		return 0; /* no message posted */
44 
45 	if (tailptr < MSG_OUTBOUND_POST_STACK)
46 		return 0; /* error */
47 	if (tailptr >= MSG_OUTBOUND_POST_STACK + MSG_BOUND_STACK_SIZE)
48 		return 0; /* error */
49 
50 	*msg_frame = readl_be(MIXART_MEM(mgr, tailptr));
51 
52 	/* increment the tail index */
53 	tailptr += 4;
54 	if( tailptr >= (MSG_OUTBOUND_POST_STACK+MSG_BOUND_STACK_SIZE) )
55 		tailptr = MSG_OUTBOUND_POST_STACK;
56 	writel_be(tailptr, MIXART_MEM(mgr, MSG_OUTBOUND_POST_TAIL));
57 
58 	return 1;
59 }
60 
get_msg(struct mixart_mgr * mgr,struct mixart_msg * resp,u32 msg_frame_address)61 static int get_msg(struct mixart_mgr *mgr, struct mixart_msg *resp,
62 		   u32 msg_frame_address )
63 {
64 	u32  headptr;
65 	u32  size;
66 	int  err;
67 #ifndef __BIG_ENDIAN
68 	unsigned int i;
69 #endif
70 
71 	err = 0;
72 
73 	/* copy message descriptor from miXart to driver */
74 	size                =  readl_be(MIXART_MEM(mgr, msg_frame_address));       /* size of descriptor + response */
75 	resp->message_id    =  readl_be(MIXART_MEM(mgr, msg_frame_address + 4));   /* dwMessageID */
76 	resp->uid.object_id =  readl_be(MIXART_MEM(mgr, msg_frame_address + 8));   /* uidDest */
77 	resp->uid.desc      =  readl_be(MIXART_MEM(mgr, msg_frame_address + 12));  /* */
78 
79 	if( (size < MSG_DESCRIPTOR_SIZE) || (resp->size < (size - MSG_DESCRIPTOR_SIZE))) {
80 		err = -EINVAL;
81 		dev_err(&mgr->pci->dev,
82 			"problem with response size = %d\n", size);
83 		goto _clean_exit;
84 	}
85 	size -= MSG_DESCRIPTOR_SIZE;
86 
87 	memcpy_fromio(resp->data, MIXART_MEM(mgr, msg_frame_address + MSG_HEADER_SIZE ), size);
88 	resp->size = size;
89 
90 	/* swap if necessary */
91 #ifndef __BIG_ENDIAN
92 	size /= 4; /* u32 size */
93 	for(i=0; i < size; i++) {
94 		((u32*)resp->data)[i] = be32_to_cpu(((__be32*)resp->data)[i]);
95 	}
96 #endif
97 
98 	/*
99 	 * free message frame address
100 	 */
101 	headptr = readl_be(MIXART_MEM(mgr, MSG_OUTBOUND_FREE_HEAD));
102 
103 	if( (headptr < MSG_OUTBOUND_FREE_STACK) || ( headptr >= (MSG_OUTBOUND_FREE_STACK+MSG_BOUND_STACK_SIZE))) {
104 		err = -EINVAL;
105 		goto _clean_exit;
106 	}
107 
108 	/* give address back to outbound fifo */
109 	writel_be(msg_frame_address, MIXART_MEM(mgr, headptr));
110 
111 	/* increment the outbound free head */
112 	headptr += 4;
113 	if( headptr >= (MSG_OUTBOUND_FREE_STACK+MSG_BOUND_STACK_SIZE) )
114 		headptr = MSG_OUTBOUND_FREE_STACK;
115 
116 	writel_be(headptr, MIXART_MEM(mgr, MSG_OUTBOUND_FREE_HEAD));
117 
118  _clean_exit:
119 	return err;
120 }
121 
122 
123 /*
124  * send a message to miXart. return: the msg_frame used for this message
125  */
126 /* call with mgr->msg_lock held! */
send_msg(struct mixart_mgr * mgr,struct mixart_msg * msg,int max_answersize,int mark_pending,u32 * msg_event)127 static int send_msg( struct mixart_mgr *mgr,
128 		     struct mixart_msg *msg,
129 		     int max_answersize,
130 		     int mark_pending,
131 		     u32 *msg_event)
132 {
133 	u32 headptr, tailptr;
134 	u32 msg_frame_address;
135 	int i;
136 
137 	if (snd_BUG_ON(msg->size % 4))
138 		return -EINVAL;
139 
140 	/* get message frame address */
141 	tailptr = readl_be(MIXART_MEM(mgr, MSG_INBOUND_FREE_TAIL));
142 	headptr = readl_be(MIXART_MEM(mgr, MSG_INBOUND_FREE_HEAD));
143 
144 	if (tailptr == headptr) {
145 		dev_err(&mgr->pci->dev, "error: no message frame available\n");
146 		return -EBUSY;
147 	}
148 
149 	if( (tailptr < MSG_INBOUND_FREE_STACK) || (tailptr >= (MSG_INBOUND_FREE_STACK+MSG_BOUND_STACK_SIZE))) {
150 		return -EINVAL;
151 	}
152 
153 	msg_frame_address = readl_be(MIXART_MEM(mgr, tailptr));
154 	writel(0, MIXART_MEM(mgr, tailptr)); /* set address to zero on this fifo position */
155 
156 	/* increment the inbound free tail */
157 	tailptr += 4;
158 	if( tailptr >= (MSG_INBOUND_FREE_STACK+MSG_BOUND_STACK_SIZE) )
159 		tailptr = MSG_INBOUND_FREE_STACK;
160 
161 	writel_be(tailptr, MIXART_MEM(mgr, MSG_INBOUND_FREE_TAIL));
162 
163 	/* TODO : use memcpy_toio() with intermediate buffer to copy the message */
164 
165 	/* copy message descriptor to card memory */
166 	writel_be( msg->size + MSG_DESCRIPTOR_SIZE,      MIXART_MEM(mgr, msg_frame_address) );      /* size of descriptor + request */
167 	writel_be( msg->message_id ,                     MIXART_MEM(mgr, msg_frame_address + 4) );  /* dwMessageID */
168 	writel_be( msg->uid.object_id,                   MIXART_MEM(mgr, msg_frame_address + 8) );  /* uidDest */
169 	writel_be( msg->uid.desc,                        MIXART_MEM(mgr, msg_frame_address + 12) ); /* */
170 	writel_be( MSG_DESCRIPTOR_SIZE,                  MIXART_MEM(mgr, msg_frame_address + 16) ); /* SizeHeader */
171 	writel_be( MSG_DESCRIPTOR_SIZE,                  MIXART_MEM(mgr, msg_frame_address + 20) ); /* OffsetDLL_T16 */
172 	writel_be( msg->size,                            MIXART_MEM(mgr, msg_frame_address + 24) ); /* SizeDLL_T16 */
173 	writel_be( MSG_DESCRIPTOR_SIZE,                  MIXART_MEM(mgr, msg_frame_address + 28) ); /* OffsetDLL_DRV */
174 	writel_be( 0,                                    MIXART_MEM(mgr, msg_frame_address + 32) ); /* SizeDLL_DRV */
175 	writel_be( MSG_DESCRIPTOR_SIZE + max_answersize, MIXART_MEM(mgr, msg_frame_address + 36) ); /* dwExpectedAnswerSize */
176 
177 	/* copy message data to card memory */
178 	for( i=0; i < msg->size; i+=4 ) {
179 		writel_be( *(u32*)(msg->data + i), MIXART_MEM(mgr, MSG_HEADER_SIZE + msg_frame_address + i)  );
180 	}
181 
182 	if( mark_pending ) {
183 		if( *msg_event ) {
184 			/* the pending event is the notification we wait for ! */
185 			mgr->pending_event = *msg_event;
186 		}
187 		else {
188 			/* the pending event is the answer we wait for (same address than the request)! */
189 			mgr->pending_event = msg_frame_address;
190 
191 			/* copy address back to caller */
192 			*msg_event = msg_frame_address;
193 		}
194 	}
195 
196 	/* mark the frame as a request (will have an answer) */
197 	msg_frame_address |= MSG_TYPE_REQUEST;
198 
199 	/* post the frame */
200 	headptr = readl_be(MIXART_MEM(mgr, MSG_INBOUND_POST_HEAD));
201 
202 	if( (headptr < MSG_INBOUND_POST_STACK) || (headptr >= (MSG_INBOUND_POST_STACK+MSG_BOUND_STACK_SIZE))) {
203 		return -EINVAL;
204 	}
205 
206 	writel_be(msg_frame_address, MIXART_MEM(mgr, headptr));
207 
208 	/* increment the inbound post head */
209 	headptr += 4;
210 	if( headptr >= (MSG_INBOUND_POST_STACK+MSG_BOUND_STACK_SIZE) )
211 		headptr = MSG_INBOUND_POST_STACK;
212 
213 	writel_be(headptr, MIXART_MEM(mgr, MSG_INBOUND_POST_HEAD));
214 
215 	return 0;
216 }
217 
218 
snd_mixart_send_msg(struct mixart_mgr * mgr,struct mixart_msg * request,int max_resp_size,void * resp_data)219 int snd_mixart_send_msg(struct mixart_mgr *mgr, struct mixart_msg *request, int max_resp_size, void *resp_data)
220 {
221 	struct mixart_msg resp;
222 	u32 msg_frame = 0; /* set to 0, so it's no notification to wait for, but the answer */
223 	int err;
224 	wait_queue_entry_t wait;
225 	long timeout;
226 
227 	init_waitqueue_entry(&wait, current);
228 
229 	mutex_lock(&mgr->msg_lock);
230 	/* send the message */
231 	err = send_msg(mgr, request, max_resp_size, 1, &msg_frame);  /* send and mark the answer pending */
232 	if (err) {
233 		mutex_unlock(&mgr->msg_lock);
234 		return err;
235 	}
236 
237 	set_current_state(TASK_UNINTERRUPTIBLE);
238 	add_wait_queue(&mgr->msg_sleep, &wait);
239 	mutex_unlock(&mgr->msg_lock);
240 	timeout = schedule_timeout(MSG_TIMEOUT_JIFFIES);
241 	remove_wait_queue(&mgr->msg_sleep, &wait);
242 
243 	if (! timeout) {
244 		/* error - no ack */
245 		dev_err(&mgr->pci->dev,
246 			"error: no response on msg %x\n", msg_frame);
247 		return -EIO;
248 	}
249 
250 	/* retrieve the answer into the same struct mixart_msg */
251 	resp.message_id = 0;
252 	resp.uid = (struct mixart_uid){0,0};
253 	resp.data = resp_data;
254 	resp.size = max_resp_size;
255 
256 	mutex_lock(&mgr->msg_lock);
257 	err = get_msg(mgr, &resp, msg_frame);
258 	mutex_unlock(&mgr->msg_lock);
259 
260 	if( request->message_id != resp.message_id )
261 		dev_err(&mgr->pci->dev, "RESPONSE ERROR!\n");
262 
263 	return err;
264 }
265 
266 
snd_mixart_send_msg_wait_notif(struct mixart_mgr * mgr,struct mixart_msg * request,u32 notif_event)267 int snd_mixart_send_msg_wait_notif(struct mixart_mgr *mgr,
268 				   struct mixart_msg *request, u32 notif_event)
269 {
270 	int err;
271 	wait_queue_entry_t wait;
272 	long timeout;
273 
274 	if (snd_BUG_ON(!notif_event))
275 		return -EINVAL;
276 	if (snd_BUG_ON((notif_event & MSG_TYPE_MASK) != MSG_TYPE_NOTIFY))
277 		return -EINVAL;
278 	if (snd_BUG_ON(notif_event & MSG_CANCEL_NOTIFY_MASK))
279 		return -EINVAL;
280 
281 	init_waitqueue_entry(&wait, current);
282 
283 	mutex_lock(&mgr->msg_lock);
284 	/* send the message */
285 	err = send_msg(mgr, request, MSG_DEFAULT_SIZE, 1, &notif_event);  /* send and mark the notification event pending */
286 	if(err) {
287 		mutex_unlock(&mgr->msg_lock);
288 		return err;
289 	}
290 
291 	set_current_state(TASK_UNINTERRUPTIBLE);
292 	add_wait_queue(&mgr->msg_sleep, &wait);
293 	mutex_unlock(&mgr->msg_lock);
294 	timeout = schedule_timeout(MSG_TIMEOUT_JIFFIES);
295 	remove_wait_queue(&mgr->msg_sleep, &wait);
296 
297 	if (! timeout) {
298 		/* error - no ack */
299 		dev_err(&mgr->pci->dev,
300 			"error: notification %x not received\n", notif_event);
301 		return -EIO;
302 	}
303 
304 	return 0;
305 }
306 
307 
snd_mixart_send_msg_nonblock(struct mixart_mgr * mgr,struct mixart_msg * request)308 int snd_mixart_send_msg_nonblock(struct mixart_mgr *mgr, struct mixart_msg *request)
309 {
310 	u32 message_frame;
311 	int err;
312 
313 	/* just send the message (do not mark it as a pending one) */
314 	mutex_lock(&mgr->msg_lock);
315 	err = send_msg(mgr, request, MSG_DEFAULT_SIZE, 0, &message_frame);
316 	mutex_unlock(&mgr->msg_lock);
317 
318 	/* the answer will be handled by snd_struct mixart_msgasklet()  */
319 	atomic_inc(&mgr->msg_processed);
320 
321 	return err;
322 }
323 
324 
325 /* common buffer of interrupt to send/receive messages */
326 static u32 mixart_msg_data[MSG_DEFAULT_SIZE / 4];
327 
328 
snd_mixart_process_msg(struct mixart_mgr * mgr)329 static void snd_mixart_process_msg(struct mixart_mgr *mgr)
330 {
331 	struct mixart_msg resp;
332 	u32 msg, addr, type;
333 	int err;
334 
335 	while (mgr->msg_fifo_readptr != mgr->msg_fifo_writeptr) {
336 		msg = mgr->msg_fifo[mgr->msg_fifo_readptr];
337 		mgr->msg_fifo_readptr++;
338 		mgr->msg_fifo_readptr %= MSG_FIFO_SIZE;
339 
340 		/* process the message ... */
341 		addr = msg & ~MSG_TYPE_MASK;
342 		type = msg & MSG_TYPE_MASK;
343 
344 		switch (type) {
345 		case MSG_TYPE_ANSWER:
346 			/* answer to a message on that we did not wait for (send_msg_nonblock) */
347 			resp.message_id = 0;
348 			resp.data = mixart_msg_data;
349 			resp.size = sizeof(mixart_msg_data);
350 			err = get_msg(mgr, &resp, addr);
351 			if( err < 0 ) {
352 				dev_err(&mgr->pci->dev,
353 					"error(%d) reading mf %x\n",
354 					err, msg);
355 				break;
356 			}
357 
358 			switch(resp.message_id) {
359 			case MSG_STREAM_START_INPUT_STAGE_PACKET:
360 			case MSG_STREAM_START_OUTPUT_STAGE_PACKET:
361 			case MSG_STREAM_STOP_INPUT_STAGE_PACKET:
362 			case MSG_STREAM_STOP_OUTPUT_STAGE_PACKET:
363 				if(mixart_msg_data[0])
364 					dev_err(&mgr->pci->dev,
365 						"error MSG_STREAM_ST***_***PUT_STAGE_PACKET status=%x\n",
366 						mixart_msg_data[0]);
367 				break;
368 			default:
369 				dev_dbg(&mgr->pci->dev,
370 					"received mf(%x) : msg_id(%x) uid(%x, %x) size(%zd)\n",
371 					   msg, resp.message_id, resp.uid.object_id, resp.uid.desc, resp.size);
372 				break;
373 			}
374 			break;
375  		case MSG_TYPE_NOTIFY:
376 			/* msg contains no address ! do not get_msg() ! */
377 		case MSG_TYPE_COMMAND:
378 			/* get_msg() necessary */
379 		default:
380 			dev_err(&mgr->pci->dev,
381 				"doesn't know what to do with message %x\n",
382 				msg);
383 		} /* switch type */
384 
385 		/* decrement counter */
386 		atomic_dec(&mgr->msg_processed);
387 
388 	} /* while there is a msg in fifo */
389 }
390 
391 
snd_mixart_interrupt(int irq,void * dev_id)392 irqreturn_t snd_mixart_interrupt(int irq, void *dev_id)
393 {
394 	struct mixart_mgr *mgr = dev_id;
395 	u32 it_reg;
396 
397 	it_reg = readl_le(MIXART_REG(mgr, MIXART_PCI_OMISR_OFFSET));
398 	if( !(it_reg & MIXART_OIDI) ) {
399 		/* this device did not cause the interrupt */
400 		return IRQ_NONE;
401 	}
402 
403 	/* mask all interrupts */
404 	writel_le(MIXART_HOST_ALL_INTERRUPT_MASKED, MIXART_REG(mgr, MIXART_PCI_OMIMR_OFFSET));
405 
406 	/* outdoorbell register clear */
407 	it_reg = readl(MIXART_REG(mgr, MIXART_PCI_ODBR_OFFSET));
408 	writel(it_reg, MIXART_REG(mgr, MIXART_PCI_ODBR_OFFSET));
409 
410 	/* clear interrupt */
411 	writel_le( MIXART_OIDI, MIXART_REG(mgr, MIXART_PCI_OMISR_OFFSET) );
412 
413 	return IRQ_WAKE_THREAD;
414 }
415 
snd_mixart_threaded_irq(int irq,void * dev_id)416 irqreturn_t snd_mixart_threaded_irq(int irq, void *dev_id)
417 {
418 	struct mixart_mgr *mgr = dev_id;
419 	int err;
420 	struct mixart_msg resp;
421 	u32 msg;
422 
423 	mutex_lock(&mgr->lock);
424 	/* process interrupt */
425 	while (retrieve_msg_frame(mgr, &msg)) {
426 
427 		switch (msg & MSG_TYPE_MASK) {
428 		case MSG_TYPE_COMMAND:
429 			resp.message_id = 0;
430 			resp.data = mixart_msg_data;
431 			resp.size = sizeof(mixart_msg_data);
432 			err = get_msg(mgr, &resp, msg & ~MSG_TYPE_MASK);
433 			if( err < 0 ) {
434 				dev_err(&mgr->pci->dev,
435 					"interrupt: error(%d) reading mf %x\n",
436 					err, msg);
437 				break;
438 			}
439 
440 			if(resp.message_id == MSG_SERVICES_TIMER_NOTIFY) {
441 				int i;
442 				struct mixart_timer_notify *notify;
443 				notify = (struct mixart_timer_notify *)mixart_msg_data;
444 
445 				BUILD_BUG_ON(sizeof(notify) > sizeof(mixart_msg_data));
446 				if (snd_BUG_ON(notify->stream_count > ARRAY_SIZE(notify->streams)))
447 					break;
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 
snd_mixart_init_mailbox(struct mixart_mgr * mgr)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 
snd_mixart_exit_mailbox(struct mixart_mgr * mgr)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 
snd_mixart_reset_board(struct mixart_mgr * mgr)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