summaryrefslogtreecommitdiffstats
path: root/kernel/drivers/media/pci/cx18/cx18-mailbox.c
blob: 1f8aa9a749a1ed57e3a3e4e73fa379b165007c93 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
/*
 *  cx18 mailbox functions
 *
 *  Copyright (C) 2007  Hans Verkuil <hverkuil@xs4all.nl>
 *  Copyright (C) 2008  Andy Walls <awalls@md.metrocast.net>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
 *  02111-1307  USA
 */

#include <stdarg.h>

#include "cx18-driver.h"
#include "cx18-io.h"
#include "cx18-scb.h"
#include "cx18-irq.h"
#include "cx18-mailbox.h"
#include "cx18-queue.h"
#include "cx18-streams.h"
#include "cx18-alsa-pcm.h" /* FIXME make configurable */

static const char *rpu_str[] = { "APU", "CPU", "EPU", "HPU" };

#define API_FAST (1 << 2) /* Short timeout */
#define API_SLOW (1 << 3) /* Additional 300ms timeout */

struct cx18_api_info {
	u32 cmd;
	u8 flags;		/* Flags, see above */
	u8 rpu;			/* Processing unit */
	const char *name; 	/* The name of the command */
};

#define API_ENTRY(rpu, x, f) { (x), (f), (rpu), #x }

static const struct cx18_api_info api_info[] = {
	/* MPEG encoder API */
	API_ENTRY(CPU, CX18_CPU_SET_CHANNEL_TYPE,		0),
	API_ENTRY(CPU, CX18_EPU_DEBUG, 				0),
	API_ENTRY(CPU, CX18_CREATE_TASK, 			0),
	API_ENTRY(CPU, CX18_DESTROY_TASK, 			0),
	API_ENTRY(CPU, CX18_CPU_CAPTURE_START,                  API_SLOW),
	API_ENTRY(CPU, CX18_CPU_CAPTURE_STOP,                   API_SLOW),
	API_ENTRY(CPU, CX18_CPU_CAPTURE_PAUSE,                  0),
	API_ENTRY(CPU, CX18_CPU_CAPTURE_RESUME,                 0),
	API_ENTRY(CPU, CX18_CPU_SET_CHANNEL_TYPE,               0),
	API_ENTRY(CPU, CX18_CPU_SET_STREAM_OUTPUT_TYPE,         0),
	API_ENTRY(CPU, CX18_CPU_SET_VIDEO_IN,                   0),
	API_ENTRY(CPU, CX18_CPU_SET_VIDEO_RATE,                 0),
	API_ENTRY(CPU, CX18_CPU_SET_VIDEO_RESOLUTION,           0),
	API_ENTRY(CPU, CX18_CPU_SET_FILTER_PARAM,               0),
	API_ENTRY(CPU, CX18_CPU_SET_SPATIAL_FILTER_TYPE,        0),
	API_ENTRY(CPU, CX18_CPU_SET_MEDIAN_CORING,              0),
	API_ENTRY(CPU, CX18_CPU_SET_INDEXTABLE,                 0),
	API_ENTRY(CPU, CX18_CPU_SET_AUDIO_PARAMETERS,           0),
	API_ENTRY(CPU, CX18_CPU_SET_VIDEO_MUTE,                 0),
	API_ENTRY(CPU, CX18_CPU_SET_AUDIO_MUTE,                 0),
	API_ENTRY(CPU, CX18_CPU_SET_MISC_PARAMETERS,            0),
	API_ENTRY(CPU, CX18_CPU_SET_RAW_VBI_PARAM,              API_SLOW),
	API_ENTRY(CPU, CX18_CPU_SET_CAPTURE_LINE_NO,            0),
	API_ENTRY(CPU, CX18_CPU_SET_COPYRIGHT,                  0),
	API_ENTRY(CPU, CX18_CPU_SET_AUDIO_PID,                  0),
	API_ENTRY(CPU, CX18_CPU_SET_VIDEO_PID,                  0),
	API_ENTRY(CPU, CX18_CPU_SET_VER_CROP_LINE,              0),
	API_ENTRY(CPU, CX18_CPU_SET_GOP_STRUCTURE,              0),
	API_ENTRY(CPU, CX18_CPU_SET_SCENE_CHANGE_DETECTION,     0),
	API_ENTRY(CPU, CX18_CPU_SET_ASPECT_RATIO,               0),
	API_ENTRY(CPU, CX18_CPU_SET_SKIP_INPUT_FRAME,           0),
	API_ENTRY(CPU, CX18_CPU_SET_SLICED_VBI_PARAM,           0),
	API_ENTRY(CPU, CX18_CPU_SET_USERDATA_PLACE_HOLDER,      0),
	API_ENTRY(CPU, CX18_CPU_GET_ENC_PTS,                    0),
	API_ENTRY(CPU, CX18_CPU_SET_VFC_PARAM,                  0),
	API_ENTRY(CPU, CX18_CPU_DE_SET_MDL_ACK,			0),
	API_ENTRY(CPU, CX18_CPU_DE_SET_MDL,			API_FAST),
	API_ENTRY(CPU, CX18_CPU_DE_RELEASE_MDL,			API_SLOW),
	API_ENTRY(APU, CX18_APU_START,				0),
	API_ENTRY(APU, CX18_APU_STOP,				0),
	API_ENTRY(APU, CX18_APU_RESETAI,			0),
	API_ENTRY(CPU, CX18_CPU_DEBUG_PEEK32,			0),
	API_ENTRY(0, 0,						0),
};

static const struct cx18_api_info *find_api_info(u32 cmd)
{
	int i;

	for (i = 0; api_info[i].cmd; i++)
		if (api_info[i].cmd == cmd)
			return &api_info[i];
	return NULL;
}

/* Call with buf of n*11+1 bytes */
static char *u32arr2hex(u32 data[], int n, char *buf)
{
	char *p;
	int i;

	for (i = 0, p = buf; i < n; i++, p += 11) {
		/* kernel snprintf() appends '\0' always */
		snprintf(p, 12, " %#010x", data[i]);
	}
	*p = '\0';
	return buf;
}

static void dump_mb(struct cx18 *cx, struct cx18_mailbox *mb, char *name)
{
	char argstr[MAX_MB_ARGUMENTS*11+1];

	if (!(cx18_debug & CX18_DBGFLG_API))
		return;

	CX18_DEBUG_API("%s: req %#010x ack %#010x cmd %#010x err %#010x args%s"
		       "\n", name, mb->request, mb->ack, mb->cmd, mb->error,
		       u32arr2hex(mb->args, MAX_MB_ARGUMENTS, argstr));
}


/*
 * Functions that run in a work_queue work handling context
 */

static void cx18_mdl_send_to_dvb(struct cx18_stream *s, struct cx18_mdl *mdl)
{
	struct cx18_buffer *buf;

	if (s->dvb == NULL || !s->dvb->enabled || mdl->bytesused == 0)
		return;

	/* We ignore mdl and buf readpos accounting here - it doesn't matter */

	/* The likely case */
	if (list_is_singular(&mdl->buf_list)) {
		buf = list_first_entry(&mdl->buf_list, struct cx18_buffer,
				       list);
		if (buf->bytesused)
			dvb_dmx_swfilter(&s->dvb->demux,
					 buf->buf, buf->bytesused);
		return;
	}

	list_for_each_entry(buf, &mdl->buf_list, list) {
		if (buf->bytesused == 0)
			break;
		dvb_dmx_swfilter(&s->dvb->demux, buf->buf, buf->bytesused);
	}
}

static void cx18_mdl_send_to_videobuf(struct cx18_stream *s,
	struct cx18_mdl *mdl)
{
	struct cx18_videobuf_buffer *vb_buf;
	struct cx18_buffer *buf;
	u8 *p;
	u32 offset = 0;
	int dispatch = 0;

	if (mdl->bytesused == 0)
		return;

	/* Acquire a videobuf buffer, clone to and and release it */
	spin_lock(&s->vb_lock);
	if (list_empty(&s->vb_capture))
		goto out;

	vb_buf = list_first_entry(&s->vb_capture, struct cx18_videobuf_buffer,
		vb.queue);

	p = videobuf_to_vmalloc(&vb_buf->vb);
	if (!p)
		goto out;

	offset = vb_buf->bytes_used;
	list_for_each_entry(buf, &mdl->buf_list, list) {
		if (buf->bytesused == 0)
			break;

		if ((offset + buf->bytesused) <= vb_buf->vb.bsize) {
			memcpy(p + offset, buf->buf, buf->bytesused);
			offset += buf->bytesused;
			vb_buf->bytes_used += buf->bytesused;
		}
	}

	/* If we've filled the buffer as per the callers res then dispatch it */
	if (vb_buf->bytes_used >= s->vb_bytes_per_frame) {
		dispatch = 1;
		vb_buf->bytes_used = 0;
	}

	if (dispatch) {
		v4l2_get_timestamp(&vb_buf->vb.ts);
		list_del(&vb_buf->vb.queue);
		vb_buf->vb.state = VIDEOBUF_DONE;
		wake_up(&vb_buf->vb.done);
	}

	mod_timer(&s->vb_timeout, msecs_to_jiffies(2000) + jiffies);

out:
	spin_unlock(&s->vb_lock);
}

static void cx18_mdl_send_to_alsa(struct cx18 *cx, struct cx18_stream *s,
				  struct cx18_mdl *mdl)
{
	struct cx18_buffer *buf;

	if (mdl->bytesused == 0)
		return;

	/* We ignore mdl and buf readpos accounting here - it doesn't matter */

	/* The likely case */
	if (list_is_singular(&mdl->buf_list)) {
		buf = list_first_entry(&mdl->buf_list, struct cx18_buffer,
				       list);
		if (buf->bytesused)
			cx->pcm_announce_callback(cx->alsa, buf->buf,
						  buf->bytesused);
		return;
	}

	list_for_each_entry(buf, &mdl->buf_list, list) {
		if (buf->bytesused == 0)
			break;
		cx->pcm_announce_callback(cx->alsa, buf->buf, buf->bytesused);
	}
}

static void epu_dma_done(struct cx18 *cx, struct cx18_in_work_order *order)
{
	u32 handle, mdl_ack_count, id;
	struct cx18_mailbox *mb;
	struct cx18_mdl_ack *mdl_ack;
	struct cx18_stream *s;
	struct cx18_mdl *mdl;
	int i;

	mb = &order->mb;
	handle = mb->args[0];
	s = cx18_handle_to_stream(cx, handle);

	if (s == NULL) {
		CX18_WARN("Got DMA done notification for unknown/inactive"
			  " handle %d, %s mailbox seq no %d\n", handle,
			  (order->flags & CX18_F_EWO_MB_STALE_UPON_RECEIPT) ?
			  "stale" : "good", mb->request);
		return;
	}

	mdl_ack_count = mb->args[2];
	mdl_ack = order->mdl_ack;
	for (i = 0; i < mdl_ack_count; i++, mdl_ack++) {
		id = mdl_ack->id;
		/*
		 * Simple integrity check for processing a stale (and possibly
		 * inconsistent mailbox): make sure the MDL id is in the
		 * valid range for the stream.
		 *
		 * We go through the trouble of dealing with stale mailboxes
		 * because most of the time, the mailbox data is still valid and
		 * unchanged (and in practice the firmware ping-pongs the
		 * two mdl_ack buffers so mdl_acks are not stale).
		 *
		 * There are occasions when we get a half changed mailbox,
		 * which this check catches for a handle & id mismatch.  If the
		 * handle and id do correspond, the worst case is that we
		 * completely lost the old MDL, but pick up the new MDL
		 * early (but the new mdl_ack is guaranteed to be good in this
		 * case as the firmware wouldn't point us to a new mdl_ack until
		 * it's filled in).
		 *
		 * cx18_queue_get_mdl() will detect the lost MDLs
		 * and send them back to q_free for fw rotation eventually.
		 */
		if ((order->flags & CX18_F_EWO_MB_STALE_UPON_RECEIPT) &&
		    !(id >= s->mdl_base_idx &&
		      id < (s->mdl_base_idx + s->buffers))) {
			CX18_WARN("Fell behind! Ignoring stale mailbox with "
				  " inconsistent data. Lost MDL for mailbox "
				  "seq no %d\n", mb->request);
			break;
		}
		mdl = cx18_queue_get_mdl(s, id, mdl_ack->data_used);

		CX18_DEBUG_HI_DMA("DMA DONE for %s (MDL %d)\n", s->name, id);
		if (mdl == NULL) {
			CX18_WARN("Could not find MDL %d for stream %s\n",
				  id, s->name);
			continue;
		}

		CX18_DEBUG_HI_DMA("%s recv bytesused = %d\n",
				  s->name, mdl->bytesused);

		if (s->type == CX18_ENC_STREAM_TYPE_TS) {
			cx18_mdl_send_to_dvb(s, mdl);
			cx18_enqueue(s, mdl, &s->q_free);
		} else if (s->type == CX18_ENC_STREAM_TYPE_PCM) {
			/* Pass the data to cx18-alsa */
			if (cx->pcm_announce_callback != NULL) {
				cx18_mdl_send_to_alsa(cx, s, mdl);
				cx18_enqueue(s, mdl, &s->q_free);
			} else {
				cx18_enqueue(s, mdl, &s->q_full);
			}
		} else if (s->type == CX18_ENC_STREAM_TYPE_YUV) {
			cx18_mdl_send_to_videobuf(s, mdl);
			cx18_enqueue(s, mdl, &s->q_free);
		} else {
			cx18_enqueue(s, mdl, &s->q_full);
			if (s->type == CX18_ENC_STREAM_TYPE_IDX)
				cx18_stream_rotate_idx_mdls(cx);
		}
	}
	/* Put as many MDLs as possible back into fw use */
	cx18_stream_load_fw_queue(s);

	wake_up(&cx->dma_waitq);
	if (s->id != -1)
		wake_up(&s->waitq);
}

static void epu_debug(struct cx18 *cx, struct cx18_in_work_order *order)
{
	char *p;
	char *str = order->str;

	CX18_DEBUG_INFO("%x %s\n", order->mb.args[0], str);
	p = strchr(str, '.');
	if (!test_bit(CX18_F_I_LOADED_FW, &cx->i_flags) && p && p > str)
		CX18_INFO("FW version: %s\n", p - 1);
}

static void epu_cmd(struct cx18 *cx, struct cx18_in_work_order *order)
{
	switch (order->rpu) {
	case CPU:
	{
		switch (order->mb.cmd) {
		case CX18_EPU_DMA_DONE:
			epu_dma_done(cx, order);
			break;
		case CX18_EPU_DEBUG:
			epu_debug(cx, order);
			break;
		default:
			CX18_WARN("Unknown CPU to EPU mailbox command %#0x\n",
				  order->mb.cmd);
			break;
		}
		break;
	}
	case APU:
		CX18_WARN("Unknown APU to EPU mailbox command %#0x\n",
			  order->mb.cmd);
		break;
	default:
		break;
	}
}

static
void free_in_work_order(struct cx18 *cx, struct cx18_in_work_order *order)
{
	atomic_set(&order->pending, 0);
}

void cx18_in_work_handler(struct work_struct *work)
{
	struct cx18_in_work_order *order =
			container_of(work, struct cx18_in_work_order, work);
	struct cx18 *cx = order->cx;
	epu_cmd(cx, order);
	free_in_work_order(cx, order);
}


/*
 * Functions that run in an interrupt handling context
 */

static void mb_ack_irq(struct cx18 *cx, struct cx18_in_work_order *order)
{
	struct cx18_mailbox __iomem *ack_mb;
	u32 ack_irq, req;

	switch (order->rpu) {
	case APU:
		ack_irq = IRQ_EPU_TO_APU_ACK;
		ack_mb = &cx->scb->apu2epu_mb;
		break;
	case CPU:
		ack_irq = IRQ_EPU_TO_CPU_ACK;
		ack_mb = &cx->scb->cpu2epu_mb;
		break;
	default:
		CX18_WARN("Unhandled RPU (%d) for command %x ack\n",
			  order->rpu, order->mb.cmd);
		return;
	}

	req = order->mb.request;
	/* Don't ack if the RPU has gotten impatient and timed us out */
	if (req != cx18_readl(cx, &ack_mb->request) ||
	    req == cx18_readl(cx, &ack_mb->ack)) {
		CX18_DEBUG_WARN("Possibly falling behind: %s self-ack'ed our "
				"incoming %s to EPU mailbox (sequence no. %u) "
				"while processing\n",
				rpu_str[order->rpu], rpu_str[order->rpu], req);
		order->flags |= CX18_F_EWO_MB_STALE_WHILE_PROC;
		return;
	}
	cx18_writel(cx, req, &ack_mb->ack);
	cx18_write_reg_expect(cx, ack_irq, SW2_INT_SET, ack_irq, ack_irq);
	return;
}

static int epu_dma_done_irq(struct cx18 *cx, struct cx18_in_work_order *order)
{
	u32 handle, mdl_ack_offset, mdl_ack_count;
	struct cx18_mailbox *mb;
	int i;

	mb = &order->mb;
	handle = mb->args[0];
	mdl_ack_offset = mb->args[1];
	mdl_ack_count = mb->args[2];

	if (handle == CX18_INVALID_TASK_HANDLE ||
	    mdl_ack_count == 0 || mdl_ack_count > CX18_MAX_MDL_ACKS) {
		if ((order->flags & CX18_F_EWO_MB_STALE) == 0)
			mb_ack_irq(cx, order);
		return -1;
	}

	for (i = 0; i < sizeof(struct cx18_mdl_ack) * mdl_ack_count; i += sizeof(u32))
		((u32 *)order->mdl_ack)[i / sizeof(u32)] =
			cx18_readl(cx, cx->enc_mem + mdl_ack_offset + i);

	if ((order->flags & CX18_F_EWO_MB_STALE) == 0)
		mb_ack_irq(cx, order);
	return 1;
}

static
int epu_debug_irq(struct cx18 *cx, struct cx18_in_work_order *order)
{
	u32 str_offset;
	char *str = order->str;

	str[0] = '\0';
	str_offset = order->mb.args[1];
	if (str_offset) {
		cx18_setup_page(cx, str_offset);
		cx18_memcpy_fromio(cx, str, cx->enc_mem + str_offset, 252);
		str[252] = '\0';
		cx18_setup_page(cx, SCB_OFFSET);
	}

	if ((order->flags & CX18_F_EWO_MB_STALE) == 0)
		mb_ack_irq(cx, order);

	return str_offset ? 1 : 0;
}

static inline
int epu_cmd_irq(struct cx18 *cx, struct cx18_in_work_order *order)
{
	int ret = -1;

	switch (order->rpu) {
	case CPU:
	{
		switch (order->mb.cmd) {
		case CX18_EPU_DMA_DONE:
			ret = epu_dma_done_irq(cx, order);
			break;
		case CX18_EPU_DEBUG:
			ret = epu_debug_irq(cx, order);
			break;
		default:
			CX18_WARN("Unknown CPU to EPU mailbox command %#0x\n",
				  order->mb.cmd);
			break;
		}
		break;
	}
	case APU:
		CX18_WARN("Unknown APU to EPU mailbox command %#0x\n",
			  order->mb.cmd);
		break;
	default:
		break;
	}
	return ret;
}

static inline
struct cx18_in_work_order *alloc_in_work_order_irq(struct cx18 *cx)
{
	int i;
	struct cx18_in_work_order *order = NULL;

	for (i = 0; i < CX18_MAX_IN_WORK_ORDERS; i++) {
		/*
		 * We only need "pending" atomic to inspect its contents,
		 * and need not do a check and set because:
		 * 1. Any work handler thread only clears "pending" and only
		 * on one, particular work order at a time, per handler thread.
		 * 2. "pending" is only set here, and we're serialized because
		 * we're called in an IRQ handler context.
		 */
		if (atomic_read(&cx->in_work_order[i].pending) == 0) {
			order = &cx->in_work_order[i];
			atomic_set(&order->pending, 1);
			break;
		}
	}
	return order;
}

void cx18_api_epu_cmd_irq(struct cx18 *cx, int rpu)
{
	struct cx18_mailbox __iomem *mb;
	struct cx18_mailbox *order_mb;
	struct cx18_in_work_order *order;
	int submit;
	int i;

	switch (rpu) {
	case CPU:
		mb = &cx->scb->cpu2epu_mb;
		break;
	case APU:
		mb = &cx->scb->apu2epu_mb;
		break;
	default:
		return;
	}

	order = alloc_in_work_order_irq(cx);
	if (order == NULL) {
		CX18_WARN("Unable to find blank work order form to schedule "
			  "incoming mailbox command processing\n");
		return;
	}

	order->flags = 0;
	order->rpu = rpu;
	order_mb = &order->mb;

	/* mb->cmd and mb->args[0] through mb->args[2] */
	for (i = 0; i < 4; i++)
		(&order_mb->cmd)[i] = cx18_readl(cx, &mb->cmd + i);

	/* mb->request and mb->ack.  N.B. we want to read mb->ack last */
	for (i = 0; i < 2; i++)
		(&order_mb->request)[i] = cx18_readl(cx, &mb->request + i);

	if (order_mb->request == order_mb->ack) {
		CX18_DEBUG_WARN("Possibly falling behind: %s self-ack'ed our "
				"incoming %s to EPU mailbox (sequence no. %u)"
				"\n",
				rpu_str[rpu], rpu_str[rpu], order_mb->request);
		if (cx18_debug & CX18_DBGFLG_WARN)
			dump_mb(cx, order_mb, "incoming");
		order->flags = CX18_F_EWO_MB_STALE_UPON_RECEIPT;
	}

	/*
	 * Individual EPU command processing is responsible for ack-ing
	 * a non-stale mailbox as soon as possible
	 */
	submit = epu_cmd_irq(cx, order);
	if (submit > 0) {
		queue_work(cx->in_work_queue, &order->work);
	}
}


/*
 * Functions called from a non-interrupt, non work_queue context
 */

static int cx18_api_call(struct cx18 *cx, u32 cmd, int args, u32 data[])
{
	const struct cx18_api_info *info = find_api_info(cmd);
	u32 irq, req, ack, err;
	struct cx18_mailbox __iomem *mb;
	wait_queue_head_t *waitq;
	struct mutex *mb_lock;
	unsigned long int t0, timeout, ret;
	int i;
	char argstr[MAX_MB_ARGUMENTS*11+1];
	DEFINE_WAIT(w);

	if (info == NULL) {
		CX18_WARN("unknown cmd %x\n", cmd);
		return -EINVAL;
	}

	if (cx18_debug & CX18_DBGFLG_API) { /* only call u32arr2hex if needed */
		if (cmd == CX18_CPU_DE_SET_MDL) {
			if (cx18_debug & CX18_DBGFLG_HIGHVOL)
				CX18_DEBUG_HI_API("%s\tcmd %#010x args%s\n",
						info->name, cmd,
						u32arr2hex(data, args, argstr));
		} else
			CX18_DEBUG_API("%s\tcmd %#010x args%s\n",
				       info->name, cmd,
				       u32arr2hex(data, args, argstr));
	}

	switch (info->rpu) {
	case APU:
		waitq = &cx->mb_apu_waitq;
		mb_lock = &cx->epu2apu_mb_lock;
		irq = IRQ_EPU_TO_APU;
		mb = &cx->scb->epu2apu_mb;
		break;
	case CPU:
		waitq = &cx->mb_cpu_waitq;
		mb_lock = &cx->epu2cpu_mb_lock;
		irq = IRQ_EPU_TO_CPU;
		mb = &cx->scb->epu2cpu_mb;
		break;
	default:
		CX18_WARN("Unknown RPU (%d) for API call\n", info->rpu);
		return -EINVAL;
	}

	mutex_lock(mb_lock);
	/*
	 * Wait for an in-use mailbox to complete
	 *
	 * If the XPU is responding with Ack's, the mailbox shouldn't be in
	 * a busy state, since we serialize access to it on our end.
	 *
	 * If the wait for ack after sending a previous command was interrupted
	 * by a signal, we may get here and find a busy mailbox.  After waiting,
	 * mark it "not busy" from our end, if the XPU hasn't ack'ed it still.
	 */
	req = cx18_readl(cx, &mb->request);
	timeout = msecs_to_jiffies(10);
	ret = wait_event_timeout(*waitq,
				 (ack = cx18_readl(cx, &mb->ack)) == req,
				 timeout);
	if (req != ack) {
		/* waited long enough, make the mbox "not busy" from our end */
		cx18_writel(cx, req, &mb->ack);
		CX18_ERR("mbox was found stuck busy when setting up for %s; "
			 "clearing busy and trying to proceed\n", info->name);
	} else if (ret != timeout)
		CX18_DEBUG_API("waited %u msecs for busy mbox to be acked\n",
			       jiffies_to_msecs(timeout-ret));

	/* Build the outgoing mailbox */
	req = ((req & 0xfffffffe) == 0xfffffffe) ? 1 : req + 1;

	cx18_writel(cx, cmd, &mb->cmd);
	for (i = 0; i < args; i++)
		cx18_writel(cx, data[i], &mb->args[i]);
	cx18_writel(cx, 0, &mb->error);
	cx18_writel(cx, req, &mb->request);
	cx18_writel(cx, req - 1, &mb->ack); /* ensure ack & req are distinct */

	/*
	 * Notify the XPU and wait for it to send an Ack back
	 */
	timeout = msecs_to_jiffies((info->flags & API_FAST) ? 10 : 20);

	CX18_DEBUG_HI_IRQ("sending interrupt SW1: %x to send %s\n",
			  irq, info->name);

	/* So we don't miss the wakeup, prepare to wait before notifying fw */
	prepare_to_wait(waitq, &w, TASK_UNINTERRUPTIBLE);
	cx18_write_reg_expect(cx, irq, SW1_INT_SET, irq, irq);

	t0 = jiffies;
	ack = cx18_readl(cx, &mb->ack);
	if (ack != req) {
		schedule_timeout(timeout);
		ret = jiffies - t0;
		ack = cx18_readl(cx, &mb->ack);
	} else {
		ret = jiffies - t0;
	}

	finish_wait(waitq, &w);

	if (req != ack) {
		mutex_unlock(mb_lock);
		if (ret >= timeout) {
			/* Timed out */
			CX18_DEBUG_WARN("sending %s timed out waiting %d msecs "
					"for RPU acknowledgement\n",
					info->name, jiffies_to_msecs(ret));
		} else {
			CX18_DEBUG_WARN("woken up before mailbox ack was ready "
					"after submitting %s to RPU.  only "
					"waited %d msecs on req %u but awakened"
					" with unmatched ack %u\n",
					info->name,
					jiffies_to_msecs(ret),
					req, ack);
		}
		return -EINVAL;
	}

	if (ret >= timeout)
		CX18_DEBUG_WARN("failed to be awakened upon RPU acknowledgment "
				"sending %s; timed out waiting %d msecs\n",
				info->name, jiffies_to_msecs(ret));
	else
		CX18_DEBUG_HI_API("waited %u msecs for %s to be acked\n",
				  jiffies_to_msecs(ret), info->name);

	/* Collect data returned by the XPU */
	for (i = 0; i < MAX_MB_ARGUMENTS; i++)
		data[i] = cx18_readl(cx, &mb->args[i]);
	err = cx18_readl(cx, &mb->error);
	mutex_unlock(mb_lock);

	/*
	 * Wait for XPU to perform extra actions for the caller in some cases.
	 * e.g. CX18_CPU_DE_RELEASE_MDL will cause the CPU to send all MDLs
	 * back in a burst shortly thereafter
	 */
	if (info->flags & API_SLOW)
		cx18_msleep_timeout(300, 0);

	if (err)
		CX18_DEBUG_API("mailbox error %08x for command %s\n", err,
				info->name);
	return err ? -EIO : 0;
}

int cx18_api(struct cx18 *cx, u32 cmd, int args, u32 data[])
{
	return cx18_api_call(cx, cmd, args, data);
}

static int cx18_set_filter_param(struct cx18_stream *s)
{
	struct cx18 *cx = s->cx;
	u32 mode;
	int ret;

	mode = (cx->filter_mode & 1) ? 2 : (cx->spatial_strength ? 1 : 0);
	ret = cx18_vapi(cx, CX18_CPU_SET_FILTER_PARAM, 4,
			s->handle, 1, mode, cx->spatial_strength);
	mode = (cx->filter_mode & 2) ? 2 : (cx->temporal_strength ? 1 : 0);
	ret = ret ? ret : cx18_vapi(cx, CX18_CPU_SET_FILTER_PARAM, 4,
			s->handle, 0, mode, cx->temporal_strength);
	ret = ret ? ret : cx18_vapi(cx, CX18_CPU_SET_FILTER_PARAM, 4,
			s->handle, 2, cx->filter_mode >> 2, 0);
	return ret;
}

int cx18_api_func(void *priv, u32 cmd, int in, int out,
		u32 data[CX2341X_MBOX_MAX_DATA])
{
	struct cx18_stream *s = priv;
	struct cx18 *cx = s->cx;

	switch (cmd) {
	case CX2341X_ENC_SET_OUTPUT_PORT:
		return 0;
	case CX2341X_ENC_SET_FRAME_RATE:
		return cx18_vapi(cx, CX18_CPU_SET_VIDEO_IN, 6,
				s->handle, 0, 0, 0, 0, data[0]);
	case CX2341X_ENC_SET_FRAME_SIZE:
		return cx18_vapi(cx, CX18_CPU_SET_VIDEO_RESOLUTION, 3,
				s->handle, data[1], data[0]);
	case CX2341X_ENC_SET_STREAM_TYPE:
		return cx18_vapi(cx, CX18_CPU_SET_STREAM_OUTPUT_TYPE, 2,
				s->handle, data[0]);
	case CX2341X_ENC_SET_ASPECT_RATIO:
		return cx18_vapi(cx, CX18_CPU_SET_ASPECT_RATIO, 2,
				s->handle, data[0]);

	case CX2341X_ENC_SET_GOP_PROPERTIES:
		return cx18_vapi(cx, CX18_CPU_SET_GOP_STRUCTURE, 3,
				s->handle, data[0], data[1]);
	case CX2341X_ENC_SET_GOP_CLOSURE:
		return 0;
	case CX2341X_ENC_SET_AUDIO_PROPERTIES:
		return cx18_vapi(cx, CX18_CPU_SET_AUDIO_PARAMETERS, 2,
				s->handle, data[0]);
	case CX2341X_ENC_MUTE_AUDIO:
		return cx18_vapi(cx, CX18_CPU_SET_AUDIO_MUTE, 2,
				s->handle, data[0]);
	case CX2341X_ENC_SET_BIT_RATE:
		return cx18_vapi(cx, CX18_CPU_SET_VIDEO_RATE, 5,
				s->handle, data[0], data[1], data[2], data[3]);
	case CX2341X_ENC_MUTE_VIDEO:
		return cx18_vapi(cx, CX18_CPU_SET_VIDEO_MUTE, 2,
				s->handle, data[0]);
	case CX2341X_ENC_SET_FRAME_DROP_RATE:
		return cx18_vapi(cx, CX18_CPU_SET_SKIP_INPUT_FRAME, 2,
				s->handle, data[0]);
	case CX2341X_ENC_MISC:
		return cx18_vapi(cx, CX18_CPU_SET_MISC_PARAMETERS, 4,
				s->handle, data[0], data[1], data[2]);
	case CX2341X_ENC_SET_DNR_FILTER_MODE:
		cx->filter_mode = (data[0] & 3) | (data[1] << 2);
		return cx18_set_filter_param(s);
	case CX2341X_ENC_SET_DNR_FILTER_PROPS:
		cx->spatial_strength = data[0];
		cx->temporal_strength = data[1];
		return cx18_set_filter_param(s);
	case CX2341X_ENC_SET_SPATIAL_FILTER_TYPE:
		return cx18_vapi(cx, CX18_CPU_SET_SPATIAL_FILTER_TYPE, 3,
				s->handle, data[0], data[1]);
	case CX2341X_ENC_SET_CORING_LEVELS:
		return cx18_vapi(cx, CX18_CPU_SET_MEDIAN_CORING, 5,
				s->handle, data[0], data[1], data[2], data[3]);
	}
	CX18_WARN("Unknown cmd %x\n", cmd);
	return 0;
}

int cx18_vapi_result(struct cx18 *cx, u32 data[MAX_MB_ARGUMENTS],
		u32 cmd, int args, ...)
{
	va_list ap;
	int i;

	va_start(ap, args);
	for (i = 0; i < args; i++)
		data[i] = va_arg(ap, u32);
	va_end(ap);
	return cx18_api(cx, cmd, args, data);
}

int cx18_vapi(struct cx18 *cx, u32 cmd, int args, ...)
{
	u32 data[MAX_MB_ARGUMENTS];
	va_list ap;
	int i;

	if (cx == NULL) {
		CX18_ERR("cx == NULL (cmd=%x)\n", cmd);
		return 0;
	}
	if (args > MAX_MB_ARGUMENTS) {
		CX18_ERR("args too big (cmd=%x)\n", cmd);
		args = MAX_MB_ARGUMENTS;
	}
	va_start(ap, args);
	for (i = 0; i < args; i++)
		data[i] = va_arg(ap, u32);
	va_end(ap);
	return cx18_api(cx, cmd, args, data);
}