summaryrefslogtreecommitdiffstats
path: root/drivers/usb/gadget/function/f_uac2.c
blob: d2dc1f00180b7869201afc1dbd82dcd4b126ab16 (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
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
// SPDX-License-Identifier: GPL-2.0+
/*
 * f_uac2.c -- USB Audio Class 2.0 Function
 *
 * Copyright (C) 2011
 *    Yadwinder Singh (yadi.brar01@gmail.com)
 *    Jaswinder Singh (jaswinder.singh@linaro.org)
 */

#include <linux/usb/audio.h>
#include <linux/usb/audio-v2.h>
#include <linux/module.h>

#include "u_audio.h"
#include "u_uac2.h"

/*
 * The driver implements a simple UAC_2 topology.
 * USB-OUT -> IT_1 -> OT_3 -> ALSA_Capture
 * ALSA_Playback -> IT_2 -> OT_4 -> USB-IN
 * Capture and Playback sampling rates are independently
 *  controlled by two clock sources :
 *    CLK_5 := c_srate, and CLK_6 := p_srate
 */
#define USB_OUT_IT_ID	1
#define IO_IN_IT_ID	2
#define IO_OUT_OT_ID	3
#define USB_IN_OT_ID	4
#define USB_OUT_CLK_ID	5
#define USB_IN_CLK_ID	6

#define CONTROL_ABSENT	0
#define CONTROL_RDONLY	1
#define CONTROL_RDWR	3

#define CLK_FREQ_CTRL	0
#define CLK_VLD_CTRL	2

#define COPY_CTRL	0
#define CONN_CTRL	2
#define OVRLD_CTRL	4
#define CLSTR_CTRL	6
#define UNFLW_CTRL	8
#define OVFLW_CTRL	10

struct f_uac2 {
	struct g_audio g_audio;
	u8 ac_intf, as_in_intf, as_out_intf;
	u8 ac_alt, as_in_alt, as_out_alt;	/* needed for get_alt() */
};

static inline struct f_uac2 *func_to_uac2(struct usb_function *f)
{
	return container_of(f, struct f_uac2, g_audio.func);
}

static inline
struct f_uac2_opts *g_audio_to_uac2_opts(struct g_audio *agdev)
{
	return container_of(agdev->func.fi, struct f_uac2_opts, func_inst);
}

/* --------- USB Function Interface ------------- */

enum {
	STR_ASSOC,
	STR_IF_CTRL,
	STR_CLKSRC_IN,
	STR_CLKSRC_OUT,
	STR_USB_IT,
	STR_IO_IT,
	STR_USB_OT,
	STR_IO_OT,
	STR_AS_OUT_ALT0,
	STR_AS_OUT_ALT1,
	STR_AS_IN_ALT0,
	STR_AS_IN_ALT1,
};

static char clksrc_in[8];
static char clksrc_out[8];

static struct usb_string strings_fn[] = {
	[STR_ASSOC].s = "Source/Sink",
	[STR_IF_CTRL].s = "Topology Control",
	[STR_CLKSRC_IN].s = clksrc_in,
	[STR_CLKSRC_OUT].s = clksrc_out,
	[STR_USB_IT].s = "USBH Out",
	[STR_IO_IT].s = "USBD Out",
	[STR_USB_OT].s = "USBH In",
	[STR_IO_OT].s = "USBD In",
	[STR_AS_OUT_ALT0].s = "Playback Inactive",
	[STR_AS_OUT_ALT1].s = "Playback Active",
	[STR_AS_IN_ALT0].s = "Capture Inactive",
	[STR_AS_IN_ALT1].s = "Capture Active",
	{ },
};

static struct usb_gadget_strings str_fn = {
	.language = 0x0409,	/* en-us */
	.strings = strings_fn,
};

static struct usb_gadget_strings *fn_strings[] = {
	&str_fn,
	NULL,
};

static struct usb_interface_assoc_descriptor iad_desc = {
	.bLength = sizeof iad_desc,
	.bDescriptorType = USB_DT_INTERFACE_ASSOCIATION,

	.bFirstInterface = 0,
	.bInterfaceCount = 3,
	.bFunctionClass = USB_CLASS_AUDIO,
	.bFunctionSubClass = UAC2_FUNCTION_SUBCLASS_UNDEFINED,
	.bFunctionProtocol = UAC_VERSION_2,
};

/* Audio Control Interface */
static struct usb_interface_descriptor std_ac_if_desc = {
	.bLength = sizeof std_ac_if_desc,
	.bDescriptorType = USB_DT_INTERFACE,

	.bAlternateSetting = 0,
	.bNumEndpoints = 0,
	.bInterfaceClass = USB_CLASS_AUDIO,
	.bInterfaceSubClass = USB_SUBCLASS_AUDIOCONTROL,
	.bInterfaceProtocol = UAC_VERSION_2,
};

/* Clock source for IN traffic */
static struct uac_clock_source_descriptor in_clk_src_desc = {
	.bLength = sizeof in_clk_src_desc,
	.bDescriptorType = USB_DT_CS_INTERFACE,

	.bDescriptorSubtype = UAC2_CLOCK_SOURCE,
	.bClockID = USB_IN_CLK_ID,
	.bmAttributes = UAC_CLOCK_SOURCE_TYPE_INT_FIXED,
	.bmControls = (CONTROL_RDONLY << CLK_FREQ_CTRL),
	.bAssocTerminal = 0,
};

/* Clock source for OUT traffic */
static struct uac_clock_source_descriptor out_clk_src_desc = {
	.bLength = sizeof out_clk_src_desc,
	.bDescriptorType = USB_DT_CS_INTERFACE,

	.bDescriptorSubtype = UAC2_CLOCK_SOURCE,
	.bClockID = USB_OUT_CLK_ID,
	.bmAttributes = UAC_CLOCK_SOURCE_TYPE_INT_FIXED,
	.bmControls = (CONTROL_RDONLY << CLK_FREQ_CTRL),
	.bAssocTerminal = 0,
};

/* Input Terminal for USB_OUT */
static struct uac2_input_terminal_descriptor usb_out_it_desc = {
	.bLength = sizeof usb_out_it_desc,
	.bDescriptorType = USB_DT_CS_INTERFACE,

	.bDescriptorSubtype = UAC_INPUT_TERMINAL,
	.bTerminalID = USB_OUT_IT_ID,
	.wTerminalType = cpu_to_le16(UAC_TERMINAL_STREAMING),
	.bAssocTerminal = 0,
	.bCSourceID = USB_OUT_CLK_ID,
	.iChannelNames = 0,
	.bmControls = cpu_to_le16(CONTROL_RDWR << COPY_CTRL),
};

/* Input Terminal for I/O-In */
static struct uac2_input_terminal_descriptor io_in_it_desc = {
	.bLength = sizeof io_in_it_desc,
	.bDescriptorType = USB_DT_CS_INTERFACE,

	.bDescriptorSubtype = UAC_INPUT_TERMINAL,
	.bTerminalID = IO_IN_IT_ID,
	.wTerminalType = cpu_to_le16(UAC_INPUT_TERMINAL_UNDEFINED),
	.bAssocTerminal = 0,
	.bCSourceID = USB_IN_CLK_ID,
	.iChannelNames = 0,
	.bmControls = cpu_to_le16(CONTROL_RDWR << COPY_CTRL),
};

/* Ouput Terminal for USB_IN */
static struct uac2_output_terminal_descriptor usb_in_ot_desc = {
	.bLength = sizeof usb_in_ot_desc,
	.bDescriptorType = USB_DT_CS_INTERFACE,

	.bDescriptorSubtype = UAC_OUTPUT_TERMINAL,
	.bTerminalID = USB_IN_OT_ID,
	.wTerminalType = cpu_to_le16(UAC_TERMINAL_STREAMING),
	.bAssocTerminal = 0,
	.bSourceID = IO_IN_IT_ID,
	.bCSourceID = USB_IN_CLK_ID,
	.bmControls = cpu_to_le16(CONTROL_RDWR << COPY_CTRL),
};

/* Ouput Terminal for I/O-Out */
static struct uac2_output_terminal_descriptor io_out_ot_desc = {
	.bLength = sizeof io_out_ot_desc,
	.bDescriptorType = USB_DT_CS_INTERFACE,

	.bDescriptorSubtype = UAC_OUTPUT_TERMINAL,
	.bTerminalID = IO_OUT_OT_ID,
	.wTerminalType = cpu_to_le16(UAC_OUTPUT_TERMINAL_UNDEFINED),
	.bAssocTerminal = 0,
	.bSourceID = USB_OUT_IT_ID,
	.bCSourceID = USB_OUT_CLK_ID,
	.bmControls = cpu_to_le16(CONTROL_RDWR << COPY_CTRL),
};

static struct uac2_ac_header_descriptor ac_hdr_desc = {
	.bLength = sizeof ac_hdr_desc,
	.bDescriptorType = USB_DT_CS_INTERFACE,

	.bDescriptorSubtype = UAC_MS_HEADER,
	.bcdADC = cpu_to_le16(0x200),
	.bCategory = UAC2_FUNCTION_IO_BOX,
	.wTotalLength = cpu_to_le16(sizeof in_clk_src_desc
			+ sizeof out_clk_src_desc + sizeof usb_out_it_desc
			+ sizeof io_in_it_desc + sizeof usb_in_ot_desc
			+ sizeof io_out_ot_desc),
	.bmControls = 0,
};

/* Audio Streaming OUT Interface - Alt0 */
static struct usb_interface_descriptor std_as_out_if0_desc = {
	.bLength = sizeof std_as_out_if0_desc,
	.bDescriptorType = USB_DT_INTERFACE,

	.bAlternateSetting = 0,
	.bNumEndpoints = 0,
	.bInterfaceClass = USB_CLASS_AUDIO,
	.bInterfaceSubClass = USB_SUBCLASS_AUDIOSTREAMING,
	.bInterfaceProtocol = UAC_VERSION_2,
};

/* Audio Streaming OUT Interface - Alt1 */
static struct usb_interface_descriptor std_as_out_if1_desc = {
	.bLength = sizeof std_as_out_if1_desc,
	.bDescriptorType = USB_DT_INTERFACE,

	.bAlternateSetting = 1,
	.bNumEndpoints = 1,
	.bInterfaceClass = USB_CLASS_AUDIO,
	.bInterfaceSubClass = USB_SUBCLASS_AUDIOSTREAMING,
	.bInterfaceProtocol = UAC_VERSION_2,
};

/* Audio Stream OUT Intface Desc */
static struct uac2_as_header_descriptor as_out_hdr_desc = {
	.bLength = sizeof as_out_hdr_desc,
	.bDescriptorType = USB_DT_CS_INTERFACE,

	.bDescriptorSubtype = UAC_AS_GENERAL,
	.bTerminalLink = USB_OUT_IT_ID,
	.bmControls = 0,
	.bFormatType = UAC_FORMAT_TYPE_I,
	.bmFormats = cpu_to_le32(UAC_FORMAT_TYPE_I_PCM),
	.iChannelNames = 0,
};

/* Audio USB_OUT Format */
static struct uac2_format_type_i_descriptor as_out_fmt1_desc = {
	.bLength = sizeof as_out_fmt1_desc,
	.bDescriptorType = USB_DT_CS_INTERFACE,
	.bDescriptorSubtype = UAC_FORMAT_TYPE,
	.bFormatType = UAC_FORMAT_TYPE_I,
};

/* STD AS ISO OUT Endpoint */
static struct usb_endpoint_descriptor fs_epout_desc = {
	.bLength = USB_DT_ENDPOINT_SIZE,
	.bDescriptorType = USB_DT_ENDPOINT,

	.bEndpointAddress = USB_DIR_OUT,
	.bmAttributes = USB_ENDPOINT_XFER_ISOC | USB_ENDPOINT_SYNC_ASYNC,
	.wMaxPacketSize = cpu_to_le16(1023),
	.bInterval = 1,
};

static struct usb_endpoint_descriptor hs_epout_desc = {
	.bLength = USB_DT_ENDPOINT_SIZE,
	.bDescriptorType = USB_DT_ENDPOINT,

	.bmAttributes = USB_ENDPOINT_XFER_ISOC | USB_ENDPOINT_SYNC_ASYNC,
	.wMaxPacketSize = cpu_to_le16(1024),
	.bInterval = 4,
};

/* CS AS ISO OUT Endpoint */
static struct uac2_iso_endpoint_descriptor as_iso_out_desc = {
	.bLength = sizeof as_iso_out_desc,
	.bDescriptorType = USB_DT_CS_ENDPOINT,

	.bDescriptorSubtype = UAC_EP_GENERAL,
	.bmAttributes = 0,
	.bmControls = 0,
	.bLockDelayUnits = 0,
	.wLockDelay = 0,
};

/* Audio Streaming IN Interface - Alt0 */
static struct usb_interface_descriptor std_as_in_if0_desc = {
	.bLength = sizeof std_as_in_if0_desc,
	.bDescriptorType = USB_DT_INTERFACE,

	.bAlternateSetting = 0,
	.bNumEndpoints = 0,
	.bInterfaceClass = USB_CLASS_AUDIO,
	.bInterfaceSubClass = USB_SUBCLASS_AUDIOSTREAMING,
	.bInterfaceProtocol = UAC_VERSION_2,
};

/* Audio Streaming IN Interface - Alt1 */
static struct usb_interface_descriptor std_as_in_if1_desc = {
	.bLength = sizeof std_as_in_if1_desc,
	.bDescriptorType = USB_DT_INTERFACE,

	.bAlternateSetting = 1,
	.bNumEndpoints = 1,
	.bInterfaceClass = USB_CLASS_AUDIO,
	.bInterfaceSubClass = USB_SUBCLASS_AUDIOSTREAMING,
	.bInterfaceProtocol = UAC_VERSION_2,
};

/* Audio Stream IN Intface Desc */
static struct uac2_as_header_descriptor as_in_hdr_desc = {
	.bLength = sizeof as_in_hdr_desc,
	.bDescriptorType = USB_DT_CS_INTERFACE,

	.bDescriptorSubtype = UAC_AS_GENERAL,
	.bTerminalLink = USB_IN_OT_ID,
	.bmControls = 0,
	.bFormatType = UAC_FORMAT_TYPE_I,
	.bmFormats = cpu_to_le32(UAC_FORMAT_TYPE_I_PCM),
	.iChannelNames = 0,
};

/* Audio USB_IN Format */
static struct uac2_format_type_i_descriptor as_in_fmt1_desc = {
	.bLength = sizeof as_in_fmt1_desc,
	.bDescriptorType = USB_DT_CS_INTERFACE,
	.bDescriptorSubtype = UAC_FORMAT_TYPE,
	.bFormatType = UAC_FORMAT_TYPE_I,
};

/* STD AS ISO IN Endpoint */
static struct usb_endpoint_descriptor fs_epin_desc = {
	.bLength = USB_DT_ENDPOINT_SIZE,
	.bDescriptorType = USB_DT_ENDPOINT,

	.bEndpointAddress = USB_DIR_IN,
	.bmAttributes = USB_ENDPOINT_XFER_ISOC | USB_ENDPOINT_SYNC_ASYNC,
	.wMaxPacketSize = cpu_to_le16(1023),
	.bInterval = 1,
};

static struct usb_endpoint_descriptor hs_epin_desc = {
	.bLength = USB_DT_ENDPOINT_SIZE,
	.bDescriptorType = USB_DT_ENDPOINT,

	.bmAttributes = USB_ENDPOINT_XFER_ISOC | USB_ENDPOINT_SYNC_ASYNC,
	.wMaxPacketSize = cpu_to_le16(1024),
	.bInterval = 4,
};

/* CS AS ISO IN Endpoint */
static struct uac2_iso_endpoint_descriptor as_iso_in_desc = {
	.bLength = sizeof as_iso_in_desc,
	.bDescriptorType = USB_DT_CS_ENDPOINT,

	.bDescriptorSubtype = UAC_EP_GENERAL,
	.bmAttributes = 0,
	.bmControls = 0,
	.bLockDelayUnits = 0,
	.wLockDelay = 0,
};

static struct usb_descriptor_header *fs_audio_desc[] = {
	(struct usb_descriptor_header *)&iad_desc,
	(struct usb_descriptor_header *)&std_ac_if_desc,

	(struct usb_descriptor_header *)&ac_hdr_desc,
	(struct usb_descriptor_header *)&in_clk_src_desc,
	(struct usb_descriptor_header *)&out_clk_src_desc,
	(struct usb_descriptor_header *)&usb_out_it_desc,
	(struct usb_descriptor_header *)&io_in_it_desc,
	(struct usb_descriptor_header *)&usb_in_ot_desc,
	(struct usb_descriptor_header *)&io_out_ot_desc,

	(struct usb_descriptor_header *)&std_as_out_if0_desc,
	(struct usb_descriptor_header *)&std_as_out_if1_desc,

	(struct usb_descriptor_header *)&as_out_hdr_desc,
	(struct usb_descriptor_header *)&as_out_fmt1_desc,
	(struct usb_descriptor_header *)&fs_epout_desc,
	(struct usb_descriptor_header *)&as_iso_out_desc,

	(struct usb_descriptor_header *)&std_as_in_if0_desc,
	(struct usb_descriptor_header *)&std_as_in_if1_desc,

	(struct usb_descriptor_header *)&as_in_hdr_desc,
	(struct usb_descriptor_header *)&as_in_fmt1_desc,
	(struct usb_descriptor_header *)&fs_epin_desc,
	(struct usb_descriptor_header *)&as_iso_in_desc,
	NULL,
};

static struct usb_descriptor_header *hs_audio_desc[] = {
	(struct usb_descriptor_header *)&iad_desc,
	(struct usb_descriptor_header *)&std_ac_if_desc,

	(struct usb_descriptor_header *)&ac_hdr_desc,
	(struct usb_descriptor_header *)&in_clk_src_desc,
	(struct usb_descriptor_header *)&out_clk_src_desc,
	(struct usb_descriptor_header *)&usb_out_it_desc,
	(struct usb_descriptor_header *)&io_in_it_desc,
	(struct usb_descriptor_header *)&usb_in_ot_desc,
	(struct usb_descriptor_header *)&io_out_ot_desc,

	(struct usb_descriptor_header *)&std_as_out_if0_desc,
	(struct usb_descriptor_header *)&std_as_out_if1_desc,

	(struct usb_descriptor_header *)&as_out_hdr_desc,
	(struct usb_descriptor_header *)&as_out_fmt1_desc,
	(struct usb_descriptor_header *)&hs_epout_desc,
	(struct usb_descriptor_header *)&as_iso_out_desc,

	(struct usb_descriptor_header *)&std_as_in_if0_desc,
	(struct usb_descriptor_header *)&std_as_in_if1_desc,

	(struct usb_descriptor_header *)&as_in_hdr_desc,
	(struct usb_descriptor_header *)&as_in_fmt1_desc,
	(struct usb_descriptor_header *)&hs_epin_desc,
	(struct usb_descriptor_header *)&as_iso_in_desc,
	NULL,
};

struct cntrl_cur_lay3 {
	__u32	dCUR;
};

struct cntrl_range_lay3 {
	__u16	wNumSubRanges;
	__u32	dMIN;
	__u32	dMAX;
	__u32	dRES;
} __packed;

static void set_ep_max_packet_size(const struct f_uac2_opts *uac2_opts,
	struct usb_endpoint_descriptor *ep_desc,
	unsigned int factor, bool is_playback)
{
	int chmask, srate, ssize;
	u16 max_packet_size;

	if (is_playback) {
		chmask = uac2_opts->p_chmask;
		srate = uac2_opts->p_srate;
		ssize = uac2_opts->p_ssize;
	} else {
		chmask = uac2_opts->c_chmask;
		srate = uac2_opts->c_srate;
		ssize = uac2_opts->c_ssize;
	}

	max_packet_size = num_channels(chmask) * ssize *
		DIV_ROUND_UP(srate, factor / (1 << (ep_desc->bInterval - 1)));
	ep_desc->wMaxPacketSize = cpu_to_le16(min_t(u16, max_packet_size,
				le16_to_cpu(ep_desc->wMaxPacketSize)));
}

static int
afunc_bind(struct usb_configuration *cfg, struct usb_function *fn)
{
	struct f_uac2 *uac2 = func_to_uac2(fn);
	struct g_audio *agdev = func_to_g_audio(fn);
	struct usb_composite_dev *cdev = cfg->cdev;
	struct usb_gadget *gadget = cdev->gadget;
	struct device *dev = &gadget->dev;
	struct f_uac2_opts *uac2_opts;
	struct usb_string *us;
	int ret;

	uac2_opts = container_of(fn->fi, struct f_uac2_opts, func_inst);

	us = usb_gstrings_attach(cdev, fn_strings, ARRAY_SIZE(strings_fn));
	if (IS_ERR(us))
		return PTR_ERR(us);
	iad_desc.iFunction = us[STR_ASSOC].id;
	std_ac_if_desc.iInterface = us[STR_IF_CTRL].id;
	in_clk_src_desc.iClockSource = us[STR_CLKSRC_IN].id;
	out_clk_src_desc.iClockSource = us[STR_CLKSRC_OUT].id;
	usb_out_it_desc.iTerminal = us[STR_USB_IT].id;
	io_in_it_desc.iTerminal = us[STR_IO_IT].id;
	usb_in_ot_desc.iTerminal = us[STR_USB_OT].id;
	io_out_ot_desc.iTerminal = us[STR_IO_OT].id;
	std_as_out_if0_desc.iInterface = us[STR_AS_OUT_ALT0].id;
	std_as_out_if1_desc.iInterface = us[STR_AS_OUT_ALT1].id;
	std_as_in_if0_desc.iInterface = us[STR_AS_IN_ALT0].id;
	std_as_in_if1_desc.iInterface = us[STR_AS_IN_ALT1].id;


	/* Initialize the configurable parameters */
	usb_out_it_desc.bNrChannels = num_channels(uac2_opts->c_chmask);
	usb_out_it_desc.bmChannelConfig = cpu_to_le32(uac2_opts->c_chmask);
	io_in_it_desc.bNrChannels = num_channels(uac2_opts->p_chmask);
	io_in_it_desc.bmChannelConfig = cpu_to_le32(uac2_opts->p_chmask);
	as_out_hdr_desc.bNrChannels = num_channels(uac2_opts->c_chmask);
	as_out_hdr_desc.bmChannelConfig = cpu_to_le32(uac2_opts->c_chmask);
	as_in_hdr_desc.bNrChannels = num_channels(uac2_opts->p_chmask);
	as_in_hdr_desc.bmChannelConfig = cpu_to_le32(uac2_opts->p_chmask);
	as_out_fmt1_desc.bSubslotSize = uac2_opts->c_ssize;
	as_out_fmt1_desc.bBitResolution = uac2_opts->c_ssize * 8;
	as_in_fmt1_desc.bSubslotSize = uac2_opts->p_ssize;
	as_in_fmt1_desc.bBitResolution = uac2_opts->p_ssize * 8;

	snprintf(clksrc_in, sizeof(clksrc_in), "%uHz", uac2_opts->p_srate);
	snprintf(clksrc_out, sizeof(clksrc_out), "%uHz", uac2_opts->c_srate);

	ret = usb_interface_id(cfg, fn);
	if (ret < 0) {
		dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
		return ret;
	}
	iad_desc.bFirstInterface = ret;

	std_ac_if_desc.bInterfaceNumber = ret;
	uac2->ac_intf = ret;
	uac2->ac_alt = 0;

	ret = usb_interface_id(cfg, fn);
	if (ret < 0) {
		dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
		return ret;
	}
	std_as_out_if0_desc.bInterfaceNumber = ret;
	std_as_out_if1_desc.bInterfaceNumber = ret;
	uac2->as_out_intf = ret;
	uac2->as_out_alt = 0;

	ret = usb_interface_id(cfg, fn);
	if (ret < 0) {
		dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
		return ret;
	}
	std_as_in_if0_desc.bInterfaceNumber = ret;
	std_as_in_if1_desc.bInterfaceNumber = ret;
	uac2->as_in_intf = ret;
	uac2->as_in_alt = 0;

	/* Calculate wMaxPacketSize according to audio bandwidth */
	set_ep_max_packet_size(uac2_opts, &fs_epin_desc, 1000, true);
	set_ep_max_packet_size(uac2_opts, &fs_epout_desc, 1000, false);
	set_ep_max_packet_size(uac2_opts, &hs_epin_desc, 8000, true);
	set_ep_max_packet_size(uac2_opts, &hs_epout_desc, 8000, false);

	agdev->out_ep = usb_ep_autoconfig(gadget, &fs_epout_desc);
	if (!agdev->out_ep) {
		dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
		return ret;
	}

	agdev->in_ep = usb_ep_autoconfig(gadget, &fs_epin_desc);
	if (!agdev->in_ep) {
		dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
		return ret;
	}

	agdev->in_ep_maxpsize = max_t(u16,
				le16_to_cpu(fs_epin_desc.wMaxPacketSize),
				le16_to_cpu(hs_epin_desc.wMaxPacketSize));
	agdev->out_ep_maxpsize = max_t(u16,
				le16_to_cpu(fs_epout_desc.wMaxPacketSize),
				le16_to_cpu(hs_epout_desc.wMaxPacketSize));

	hs_epout_desc.bEndpointAddress = fs_epout_desc.bEndpointAddress;
	hs_epin_desc.bEndpointAddress = fs_epin_desc.bEndpointAddress;

	ret = usb_assign_descriptors(fn, fs_audio_desc, hs_audio_desc, NULL,
				     NULL);
	if (ret)
		return ret;

	agdev->gadget = gadget;

	agdev->params.p_chmask = uac2_opts->p_chmask;
	agdev->params.p_srate = uac2_opts->p_srate;
	agdev->params.p_ssize = uac2_opts->p_ssize;
	agdev->params.c_chmask = uac2_opts->c_chmask;
	agdev->params.c_srate = uac2_opts->c_srate;
	agdev->params.c_ssize = uac2_opts->c_ssize;
	agdev->params.req_number = uac2_opts->req_number;
	ret = g_audio_setup(agdev, "UAC2 PCM", "UAC2_Gadget");
	if (ret)
		goto err_free_descs;
	return 0;

err_free_descs:
	usb_free_all_descriptors(fn);
	agdev->gadget = NULL;
	return ret;
}

static int
afunc_set_alt(struct usb_function *fn, unsigned intf, unsigned alt)
{
	struct usb_composite_dev *cdev = fn->config->cdev;
	struct f_uac2 *uac2 = func_to_uac2(fn);
	struct usb_gadget *gadget = cdev->gadget;
	struct device *dev = &gadget->dev;
	int ret = 0;

	/* No i/f has more than 2 alt settings */
	if (alt > 1) {
		dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
		return -EINVAL;
	}

	if (intf == uac2->ac_intf) {
		/* Control I/f has only 1 AltSetting - 0 */
		if (alt) {
			dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
			return -EINVAL;
		}
		return 0;
	}

	if (intf == uac2->as_out_intf) {
		uac2->as_out_alt = alt;

		if (alt)
			ret = u_audio_start_capture(&uac2->g_audio);
		else
			u_audio_stop_capture(&uac2->g_audio);
	} else if (intf == uac2->as_in_intf) {
		uac2->as_in_alt = alt;

		if (alt)
			ret = u_audio_start_playback(&uac2->g_audio);
		else
			u_audio_stop_playback(&uac2->g_audio);
	} else {
		dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
		return -EINVAL;
	}

	return ret;
}

static int
afunc_get_alt(struct usb_function *fn, unsigned intf)
{
	struct f_uac2 *uac2 = func_to_uac2(fn);
	struct g_audio *agdev = func_to_g_audio(fn);

	if (intf == uac2->ac_intf)
		return uac2->ac_alt;
	else if (intf == uac2->as_out_intf)
		return uac2->as_out_alt;
	else if (intf == uac2->as_in_intf)
		return uac2->as_in_alt;
	else
		dev_err(&agdev->gadget->dev,
			"%s:%d Invalid Interface %d!\n",
			__func__, __LINE__, intf);

	return -EINVAL;
}

static void
afunc_disable(struct usb_function *fn)
{
	struct f_uac2 *uac2 = func_to_uac2(fn);

	uac2->as_in_alt = 0;
	uac2->as_out_alt = 0;
	u_audio_stop_capture(&uac2->g_audio);
	u_audio_stop_playback(&uac2->g_audio);
}

static int
in_rq_cur(struct usb_function *fn, const struct usb_ctrlrequest *cr)
{
	struct usb_request *req = fn->config->cdev->req;
	struct g_audio *agdev = func_to_g_audio(fn);
	struct f_uac2_opts *opts;
	u16 w_length = le16_to_cpu(cr->wLength);
	u16 w_index = le16_to_cpu(cr->wIndex);
	u16 w_value = le16_to_cpu(cr->wValue);
	u8 entity_id = (w_index >> 8) & 0xff;
	u8 control_selector = w_value >> 8;
	int value = -EOPNOTSUPP;
	int p_srate, c_srate;

	opts = g_audio_to_uac2_opts(agdev);
	p_srate = opts->p_srate;
	c_srate = opts->c_srate;

	if (control_selector == UAC2_CS_CONTROL_SAM_FREQ) {
		struct cntrl_cur_lay3 c;
		memset(&c, 0, sizeof(struct cntrl_cur_lay3));

		if (entity_id == USB_IN_CLK_ID)
			c.dCUR = p_srate;
		else if (entity_id == USB_OUT_CLK_ID)
			c.dCUR = c_srate;

		value = min_t(unsigned, w_length, sizeof c);
		memcpy(req->buf, &c, value);
	} else if (control_selector == UAC2_CS_CONTROL_CLOCK_VALID) {
		*(u8 *)req->buf = 1;
		value = min_t(unsigned, w_length, 1);
	} else {
		dev_err(&agdev->gadget->dev,
			"%s:%d control_selector=%d TODO!\n",
			__func__, __LINE__, control_selector);
	}

	return value;
}

static int
in_rq_range(struct usb_function *fn, const struct usb_ctrlrequest *cr)
{
	struct usb_request *req = fn->config->cdev->req;
	struct g_audio *agdev = func_to_g_audio(fn);
	struct f_uac2_opts *opts;
	u16 w_length = le16_to_cpu(cr->wLength);
	u16 w_index = le16_to_cpu(cr->wIndex);
	u16 w_value = le16_to_cpu(cr->wValue);
	u8 entity_id = (w_index >> 8) & 0xff;
	u8 control_selector = w_value >> 8;
	struct cntrl_range_lay3 r;
	int value = -EOPNOTSUPP;
	int p_srate, c_srate;

	opts = g_audio_to_uac2_opts(agdev);
	p_srate = opts->p_srate;
	c_srate = opts->c_srate;

	if (control_selector == UAC2_CS_CONTROL_SAM_FREQ) {
		if (entity_id == USB_IN_CLK_ID)
			r.dMIN = p_srate;
		else if (entity_id == USB_OUT_CLK_ID)
			r.dMIN = c_srate;
		else
			return -EOPNOTSUPP;

		r.dMAX = r.dMIN;
		r.dRES = 0;
		r.wNumSubRanges = 1;

		value = min_t(unsigned, w_length, sizeof r);
		memcpy(req->buf, &r, value);
	} else {
		dev_err(&agdev->gadget->dev,
			"%s:%d control_selector=%d TODO!\n",
			__func__, __LINE__, control_selector);
	}

	return value;
}

static int
ac_rq_in(struct usb_function *fn, const struct usb_ctrlrequest *cr)
{
	if (cr->bRequest == UAC2_CS_CUR)
		return in_rq_cur(fn, cr);
	else if (cr->bRequest == UAC2_CS_RANGE)
		return in_rq_range(fn, cr);
	else
		return -EOPNOTSUPP;
}

static int
out_rq_cur(struct usb_function *fn, const struct usb_ctrlrequest *cr)
{
	u16 w_length = le16_to_cpu(cr->wLength);
	u16 w_value = le16_to_cpu(cr->wValue);
	u8 control_selector = w_value >> 8;

	if (control_selector == UAC2_CS_CONTROL_SAM_FREQ)
		return w_length;

	return -EOPNOTSUPP;
}

static int
setup_rq_inf(struct usb_function *fn, const struct usb_ctrlrequest *cr)
{
	struct f_uac2 *uac2 = func_to_uac2(fn);
	struct g_audio *agdev = func_to_g_audio(fn);
	u16 w_index = le16_to_cpu(cr->wIndex);
	u8 intf = w_index & 0xff;

	if (intf != uac2->ac_intf) {
		dev_err(&agdev->gadget->dev,
			"%s:%d Error!\n", __func__, __LINE__);
		return -EOPNOTSUPP;
	}

	if (cr->bRequestType & USB_DIR_IN)
		return ac_rq_in(fn, cr);
	else if (cr->bRequest == UAC2_CS_CUR)
		return out_rq_cur(fn, cr);

	return -EOPNOTSUPP;
}

static int
afunc_setup(struct usb_function *fn, const struct usb_ctrlrequest *cr)
{
	struct usb_composite_dev *cdev = fn->config->cdev;
	struct g_audio *agdev = func_to_g_audio(fn);
	struct usb_request *req = cdev->req;
	u16 w_length = le16_to_cpu(cr->wLength);
	int value = -EOPNOTSUPP;

	/* Only Class specific requests are supposed to reach here */
	if ((cr->bRequestType & USB_TYPE_MASK) != USB_TYPE_CLASS)
		return -EOPNOTSUPP;

	if ((cr->bRequestType & USB_RECIP_MASK) == USB_RECIP_INTERFACE)
		value = setup_rq_inf(fn, cr);
	else
		dev_err(&agdev->gadget->dev, "%s:%d Error!\n",
				__func__, __LINE__);

	if (value >= 0) {
		req->length = value;
		req->zero = value < w_length;
		value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
		if (value < 0) {
			dev_err(&agdev->gadget->dev,
				"%s:%d Error!\n", __func__, __LINE__);
			req->status = 0;
		}
	}

	return value;
}

static inline struct f_uac2_opts *to_f_uac2_opts(struct config_item *item)
{
	return container_of(to_config_group(item), struct f_uac2_opts,
			    func_inst.group);
}

static void f_uac2_attr_release(struct config_item *item)
{
	struct f_uac2_opts *opts = to_f_uac2_opts(item);

	usb_put_function_instance(&opts->func_inst);
}

static struct configfs_item_operations f_uac2_item_ops = {
	.release	= f_uac2_attr_release,
};

#define UAC2_ATTRIBUTE(name)						\
static ssize_t f_uac2_opts_##name##_show(struct config_item *item,	\
					 char *page)			\
{									\
	struct f_uac2_opts *opts = to_f_uac2_opts(item);		\
	int result;							\
									\
	mutex_lock(&opts->lock);					\
	result = sprintf(page, "%u\n", opts->name);			\
	mutex_unlock(&opts->lock);					\
									\
	return result;							\
}									\
									\
static ssize_t f_uac2_opts_##name##_store(struct config_item *item,	\
					  const char *page, size_t len)	\
{									\
	struct f_uac2_opts *opts = to_f_uac2_opts(item);		\
	int ret;							\
	u32 num;							\
									\
	mutex_lock(&opts->lock);					\
	if (opts->refcnt) {						\
		ret = -EBUSY;						\
		goto end;						\
	}								\
									\
	ret = kstrtou32(page, 0, &num);					\
	if (ret)							\
		goto end;						\
									\
	opts->name = num;						\
	ret = len;							\
									\
end:									\
	mutex_unlock(&opts->lock);					\
	return ret;							\
}									\
									\
CONFIGFS_ATTR(f_uac2_opts_, name)

UAC2_ATTRIBUTE(p_chmask);
UAC2_ATTRIBUTE(p_srate);
UAC2_ATTRIBUTE(p_ssize);
UAC2_ATTRIBUTE(c_chmask);
UAC2_ATTRIBUTE(c_srate);
UAC2_ATTRIBUTE(c_ssize);
UAC2_ATTRIBUTE(req_number);

static struct configfs_attribute *f_uac2_attrs[] = {
	&f_uac2_opts_attr_p_chmask,
	&f_uac2_opts_attr_p_srate,
	&f_uac2_opts_attr_p_ssize,
	&f_uac2_opts_attr_c_chmask,
	&f_uac2_opts_attr_c_srate,
	&f_uac2_opts_attr_c_ssize,
	&f_uac2_opts_attr_req_number,
	NULL,
};

static const struct config_item_type f_uac2_func_type = {
	.ct_item_ops	= &f_uac2_item_ops,
	.ct_attrs	= f_uac2_attrs,
	.ct_owner	= THIS_MODULE,
};

static void afunc_free_inst(struct usb_function_instance *f)
{
	struct f_uac2_opts *opts;

	opts = container_of(f, struct f_uac2_opts, func_inst);
	kfree(opts);
}

static struct usb_function_instance *afunc_alloc_inst(void)
{
	struct f_uac2_opts *opts;

	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
	if (!opts)
		return ERR_PTR(-ENOMEM);

	mutex_init(&opts->lock);
	opts->func_inst.free_func_inst = afunc_free_inst;

	config_group_init_type_name(&opts->func_inst.group, "",
				    &f_uac2_func_type);

	opts->p_chmask = UAC2_DEF_PCHMASK;
	opts->p_srate = UAC2_DEF_PSRATE;
	opts->p_ssize = UAC2_DEF_PSSIZE;
	opts->c_chmask = UAC2_DEF_CCHMASK;
	opts->c_srate = UAC2_DEF_CSRATE;
	opts->c_ssize = UAC2_DEF_CSSIZE;
	opts->req_number = UAC2_DEF_REQ_NUM;
	return &opts->func_inst;
}

static void afunc_free(struct usb_function *f)
{
	struct g_audio *agdev;
	struct f_uac2_opts *opts;

	agdev = func_to_g_audio(f);
	opts = container_of(f->fi, struct f_uac2_opts, func_inst);
	kfree(agdev);
	mutex_lock(&opts->lock);
	--opts->refcnt;
	mutex_unlock(&opts->lock);
}

static void afunc_unbind(struct usb_configuration *c, struct usb_function *f)
{
	struct g_audio *agdev = func_to_g_audio(f);

	g_audio_cleanup(agdev);
	usb_free_all_descriptors(f);

	agdev->gadget = NULL;
}

static struct usb_function *afunc_alloc(struct usb_function_instance *fi)
{
	struct f_uac2	*uac2;
	struct f_uac2_opts *opts;

	uac2 = kzalloc(sizeof(*uac2), GFP_KERNEL);
	if (uac2 == NULL)
		return ERR_PTR(-ENOMEM);

	opts = container_of(fi, struct f_uac2_opts, func_inst);
	mutex_lock(&opts->lock);
	++opts->refcnt;
	mutex_unlock(&opts->lock);

	uac2->g_audio.func.name = "uac2_func";
	uac2->g_audio.func.bind = afunc_bind;
	uac2->g_audio.func.unbind = afunc_unbind;
	uac2->g_audio.func.set_alt = afunc_set_alt;
	uac2->g_audio.func.get_alt = afunc_get_alt;
	uac2->g_audio.func.disable = afunc_disable;
	uac2->g_audio.func.setup = afunc_setup;
	uac2->g_audio.func.free_func = afunc_free;

	return &uac2->g_audio.func;
}

DECLARE_USB_FUNCTION_INIT(uac2, afunc_alloc_inst, afunc_alloc);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Yadwinder Singh");
MODULE_AUTHOR("Jaswinder Singh");