aboutsummaryrefslogtreecommitdiffstats
path: root/target/linux/brcm2708/patches-4.4/0527-Support-for-Blokas-Labs-pisound-board.patch
blob: 44335f1fd245ffab8391f0c13eefaf814ba7cb01 (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
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
From 1c20ff1871ce0edc2d4c71a1eb4591cb4e8912e9 Mon Sep 17 00:00:00 2001
From: gtrainavicius <gtrainavicius@users.noreply.github.com>
Date: Sun, 23 Oct 2016 12:06:53 +0300
Subject: [PATCH] Support for Blokas Labs pisound board

---
 .../devicetree/bindings/vendor-prefixes.txt        |   1 +
 arch/arm/boot/dts/overlays/Makefile                |   1 +
 arch/arm/boot/dts/overlays/README                  |   6 +
 arch/arm/boot/dts/overlays/pisound-overlay.dts     | 114 +++
 arch/arm/configs/bcm2709_defconfig                 |   1 +
 arch/arm/configs/bcmrpi_defconfig                  |   1 +
 sound/soc/bcm/Kconfig                              |   6 +
 sound/soc/bcm/Makefile                             |   2 +
 sound/soc/bcm/pisound.c                            | 987 +++++++++++++++++++++
 9 files changed, 1119 insertions(+)
 create mode 100644 arch/arm/boot/dts/overlays/pisound-overlay.dts
 create mode 100644 sound/soc/bcm/pisound.c

--- a/Documentation/devicetree/bindings/vendor-prefixes.txt
+++ b/Documentation/devicetree/bindings/vendor-prefixes.txt
@@ -33,6 +33,7 @@ auo	AU Optronics Corporation
 avago	Avago Technologies
 avic	Shanghai AVIC Optoelectronics Co., Ltd.
 axis	Axis Communications AB
+blokaslabs	Vilniaus Blokas UAB
 bosch	Bosch Sensortec GmbH
 boundary	Boundary Devices Inc.
 brcm	Broadcom Corporation
--- a/arch/arm/boot/dts/overlays/Makefile
+++ b/arch/arm/boot/dts/overlays/Makefile
@@ -62,6 +62,7 @@ dtbo-$(RPI_DT_OVERLAYS) += pi3-disable-b
 dtbo-$(RPI_DT_OVERLAYS) += pi3-miniuart-bt.dtbo
 dtbo-$(RPI_DT_OVERLAYS) += piscreen.dtbo
 dtbo-$(RPI_DT_OVERLAYS) += piscreen2r.dtbo
+dtbo-$(RPI_DT_OVERLAYS) += pisound.dtbo
 dtbo-$(RPI_DT_OVERLAYS) += pitft22.dtbo
 dtbo-$(RPI_DT_OVERLAYS) += pitft28-capacitive.dtbo
 dtbo-$(RPI_DT_OVERLAYS) += pitft28-resistive.dtbo
--- a/arch/arm/boot/dts/overlays/README
+++ b/arch/arm/boot/dts/overlays/README
@@ -808,6 +808,12 @@ Params: speed                   Display
         xohms                   Touchpanel sensitivity (X-plate resistance)
 
 
+Name:   pisound
+Info:   Configures the Blokas Labs pisound card
+Load:   dtoverlay=pisound
+Params: <None>
+
+
 Name:   pitft22
 Info:   Adafruit PiTFT 2.2" screen
 Load:   dtoverlay=pitft22,<param>=<val>
--- /dev/null
+++ b/arch/arm/boot/dts/overlays/pisound-overlay.dts
@@ -0,0 +1,114 @@
+/*
+ * pisound Linux kernel module.
+ * Copyright (C) 2016  Vilniaus Blokas UAB, http://blokas.io/pisound
+ *
+ * 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; version 2 of the
+ * License.
+ *
+ * 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+/dts-v1/;
+/plugin/;
+
+#include <dt-bindings/gpio/gpio.h>
+
+/ {
+	compatible = "brcm,bcm2708";
+
+	fragment@0 {
+		target = <&sound>;
+		__overlay__ {
+			compatible = "blokaslabs,pisound";
+			i2s-controller = <&i2s>;
+			status = "okay";
+
+			pinctrl-0 = <&pisound_button_pins>;
+
+			osr-gpios =
+				<&gpio 13 GPIO_ACTIVE_HIGH>,
+				<&gpio 26 GPIO_ACTIVE_HIGH>,
+				<&gpio 16 GPIO_ACTIVE_HIGH>;
+
+			reset-gpios =
+				<&gpio 12 GPIO_ACTIVE_HIGH>,
+				<&gpio 24 GPIO_ACTIVE_HIGH>;
+
+			data_available-gpios = <&gpio 25 GPIO_ACTIVE_HIGH>;
+
+			button-gpios = <&gpio 17 GPIO_ACTIVE_LOW>;
+		};
+	};
+
+	fragment@1 {
+		target = <&gpio>;
+		__overlay__ {
+			pinctrl-names = "default";
+			pinctrl-0 = <&pisound_button_pins>;
+
+			pisound_button_pins: pisound_button_pins {
+				brcm,pins = <17>;
+				brcm,function = <0>; // Input
+				brcm,pull = <2>; // Pull-Up
+			};
+		};
+	};
+
+	fragment@2 {
+		target = <&i2s>;
+		__overlay__ {
+			status = "okay";
+		};
+	};
+
+	fragment@3 {
+		target-path = "/";
+		__overlay__ {
+			pcm5102a-codec {
+				#sound-dai-cells = <0>;
+				compatible = "ti,pcm5102a";
+				status = "okay";
+			};
+		};
+	};
+
+	fragment@4 {
+		target = <&spi0>;
+		__overlay__ {
+			status = "okay";
+
+			spidev@0{
+				status = "disabled";
+			};
+
+			spidev@1{
+				status = "okay";
+			};
+		};
+	};
+
+	fragment@5 {
+		target = <&spi0>;
+		__overlay__ {
+			#address-cells = <1>;
+			#size-cells = <0>;
+
+			pisound_spi: pisound_spi@0{
+				compatible = "blokaslabs,pisound-spi";
+				reg = <0>;
+				pinctrl-names = "default";
+				pinctrl-0 = <&spi0_pins>;
+				spi-max-frequency = <1000000>;
+			};
+		};
+	};
+};
--- a/arch/arm/configs/bcm2709_defconfig
+++ b/arch/arm/configs/bcm2709_defconfig
@@ -880,6 +880,7 @@ CONFIG_SND_AUDIOINJECTOR_PI_SOUNDCARD=m
 CONFIG_SND_DIGIDAC1_SOUNDCARD=m
 CONFIG_SND_BCM2708_SOC_DIONAUDIO_LOCO=m
 CONFIG_SND_BCM2708_SOC_ALLO_PIANO_DAC=m
+CONFIG_SND_PISOUND=m
 CONFIG_SND_SOC_ADAU1701=m
 CONFIG_SND_SOC_WM8804_I2C=m
 CONFIG_SND_SIMPLE_CARD=m
--- a/arch/arm/configs/bcmrpi_defconfig
+++ b/arch/arm/configs/bcmrpi_defconfig
@@ -872,6 +872,7 @@ CONFIG_SND_AUDIOINJECTOR_PI_SOUNDCARD=m
 CONFIG_SND_DIGIDAC1_SOUNDCARD=m
 CONFIG_SND_BCM2708_SOC_DIONAUDIO_LOCO=m
 CONFIG_SND_BCM2708_SOC_ALLO_PIANO_DAC=m
+CONFIG_SND_PISOUND=m
 CONFIG_SND_SOC_ADAU1701=m
 CONFIG_SND_SOC_WM8804_I2C=m
 CONFIG_SND_SIMPLE_CARD=m
--- a/sound/soc/bcm/Kconfig
+++ b/sound/soc/bcm/Kconfig
@@ -121,3 +121,9 @@ config SND_BCM2708_SOC_ALLO_PIANO_DAC
 	select SND_SOC_PCM512x_I2C
 	help
 	  Say Y or M if you want to add support for Allo Piano DAC.
+
+config SND_PISOUND
+	tristate "Support for Blokas Labs pisound"
+	depends on SND_BCM2708_SOC_I2S || SND_BCM2835_SOC_I2S
+	help
+	  Say Y or M if you want to add support for Blokas Labs pisound.
--- a/sound/soc/bcm/Makefile
+++ b/sound/soc/bcm/Makefile
@@ -20,6 +20,7 @@ snd-soc-audioinjector-pi-soundcard-objs
 snd-soc-digidac1-soundcard-objs := digidac1-soundcard.o
 snd-soc-dionaudio-loco-objs := dionaudio_loco.o
 snd-soc-allo-piano-dac-objs := allo-piano-dac.o
+snd-soc-pisound-objs := pisound.o
 
 obj-$(CONFIG_SND_BCM2708_SOC_ADAU1977_ADC) += snd-soc-adau1977-adc.o
 obj-$(CONFIG_SND_BCM2708_SOC_HIFIBERRY_DAC) += snd-soc-hifiberry-dac.o
@@ -37,3 +38,4 @@ obj-$(CONFIG_SND_AUDIOINJECTOR_PI_SOUNDC
 obj-$(CONFIG_SND_DIGIDAC1_SOUNDCARD) += snd-soc-digidac1-soundcard.o
 obj-$(CONFIG_SND_BCM2708_SOC_DIONAUDIO_LOCO) += snd-soc-dionaudio-loco.o
 obj-$(CONFIG_SND_BCM2708_SOC_ALLO_PIANO_DAC) += snd-soc-allo-piano-dac.o
+obj-$(CONFIG_SND_PISOUND) += snd-soc-pisound.o
--- /dev/null
+++ b/sound/soc/bcm/pisound.c
@@ -0,0 +1,987 @@
+/*
+ * pisound Linux kernel module.
+ * Copyright (C) 2016  Vilniaus Blokas UAB, http://blokas.io/pisound
+ *
+ * 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; version 2 of the
+ * License.
+ *
+ * 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., 51 Franklin Street, Fifth Floor, Boston,
+ * MA  02110-1301, USA.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/gpio.h>
+#include <linux/kobject.h>
+#include <linux/sysfs.h>
+#include <linux/delay.h>
+#include <linux/spi/spi.h>
+#include <linux/interrupt.h>
+#include <linux/kfifo.h>
+
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/soc.h>
+#include <sound/jack.h>
+#include <sound/rawmidi.h>
+#include <sound/asequencer.h>
+
+static int pisnd_spi_init(struct device *dev);
+static void pisnd_spi_uninit(void);
+
+static void pisnd_spi_send(uint8_t val);
+static uint8_t pisnd_spi_recv(uint8_t *buffer, uint8_t length);
+
+typedef void (*pisnd_spi_recv_cb)(void *data);
+static void pisnd_spi_set_callback(pisnd_spi_recv_cb cb, void *data);
+
+static const char *pisnd_spi_get_serial(void);
+static const char *pisnd_spi_get_id(void);
+static const char *pisnd_spi_get_version(void);
+
+static int pisnd_midi_init(struct snd_card *card);
+static void pisnd_midi_uninit(void);
+
+#define PISOUND_LOG_PREFIX "pisound: "
+
+#ifdef DEBUG
+#	define printd(...) pr_alert(PISOUND_LOG_PREFIX __VA_ARGS__)
+#else
+#	define printd(...) do {} while (0)
+#endif
+
+#define printe(...) pr_err(PISOUND_LOG_PREFIX __VA_ARGS__)
+#define printi(...) pr_info(PISOUND_LOG_PREFIX __VA_ARGS__)
+
+static int pisnd_output_open(struct snd_rawmidi_substream *substream)
+{
+	return 0;
+}
+
+static int pisnd_output_close(struct snd_rawmidi_substream *substream)
+{
+	return 0;
+}
+
+static void pisnd_output_trigger(
+	struct snd_rawmidi_substream *substream,
+	int up
+	)
+{
+	uint8_t data;
+
+	if (!up)
+		return;
+
+	while (snd_rawmidi_transmit_peek(substream, &data, 1)) {
+		pisnd_spi_send(data);
+		snd_rawmidi_transmit_ack(substream, 1);
+	}
+}
+
+static void pisnd_output_drain(struct snd_rawmidi_substream *substream)
+{
+	uint8_t data;
+
+	while (snd_rawmidi_transmit_peek(substream, &data, 1)) {
+		pisnd_spi_send(data);
+
+		snd_rawmidi_transmit_ack(substream, 1);
+	}
+}
+
+static int pisnd_input_open(struct snd_rawmidi_substream *substream)
+{
+	return 0;
+}
+
+static int pisnd_input_close(struct snd_rawmidi_substream *substream)
+{
+	return 0;
+}
+
+static void pisnd_midi_recv_callback(void *substream)
+{
+	uint8_t data[128];
+	uint8_t n = 0;
+
+	while ((n = pisnd_spi_recv(data, sizeof(data)))) {
+		int res = snd_rawmidi_receive(substream, data, n);
+		(void)res;
+		printd("midi recv 0x%02x, res = %d\n", data, res);
+	}
+}
+
+static void pisnd_input_trigger(struct snd_rawmidi_substream *substream, int up)
+{
+	if (up) {
+		pisnd_spi_set_callback(pisnd_midi_recv_callback, substream);
+		pisnd_midi_recv_callback(substream);
+	} else {
+		pisnd_spi_set_callback(NULL, NULL);
+	}
+}
+
+static struct snd_rawmidi *g_rmidi;
+
+static struct snd_rawmidi_ops pisnd_output_ops = {
+	.open = pisnd_output_open,
+	.close = pisnd_output_close,
+	.trigger = pisnd_output_trigger,
+	.drain = pisnd_output_drain,
+};
+
+static struct snd_rawmidi_ops pisnd_input_ops = {
+	.open = pisnd_input_open,
+	.close = pisnd_input_close,
+	.trigger = pisnd_input_trigger,
+};
+
+static void pisnd_get_port_info(
+	struct snd_rawmidi *rmidi,
+	int number,
+	struct snd_seq_port_info *seq_port_info
+	)
+{
+	seq_port_info->type =
+		SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC |
+		SNDRV_SEQ_PORT_TYPE_HARDWARE |
+		SNDRV_SEQ_PORT_TYPE_PORT;
+	seq_port_info->midi_voices = 0;
+}
+
+static struct snd_rawmidi_global_ops pisnd_global_ops = {
+	.get_port_info = pisnd_get_port_info,
+};
+
+static int pisnd_midi_init(struct snd_card *card)
+{
+	int err = snd_rawmidi_new(card, "pisound MIDI", 0, 1, 1, &g_rmidi);
+
+	if (err < 0) {
+		printe("snd_rawmidi_new failed: %d\n", err);
+		return err;
+	}
+
+	strcpy(g_rmidi->name, "pisound MIDI ");
+	strcat(g_rmidi->name, pisnd_spi_get_serial());
+
+	g_rmidi->info_flags =
+		SNDRV_RAWMIDI_INFO_OUTPUT |
+		SNDRV_RAWMIDI_INFO_INPUT |
+		SNDRV_RAWMIDI_INFO_DUPLEX;
+
+	g_rmidi->ops = &pisnd_global_ops;
+
+	g_rmidi->private_data = (void *)0;
+
+	snd_rawmidi_set_ops(
+		g_rmidi,
+		SNDRV_RAWMIDI_STREAM_OUTPUT,
+		&pisnd_output_ops
+		);
+
+	snd_rawmidi_set_ops(
+		g_rmidi,
+		SNDRV_RAWMIDI_STREAM_INPUT,
+		&pisnd_input_ops
+		);
+
+	return 0;
+}
+
+static void pisnd_midi_uninit(void)
+{
+}
+
+static void *g_recvData;
+static pisnd_spi_recv_cb g_recvCallback;
+
+#define FIFO_SIZE 512
+
+static char g_serial_num[11];
+static char g_id[25];
+static char g_version[5];
+
+DEFINE_KFIFO(spi_fifo_in,  uint8_t, FIFO_SIZE);
+DEFINE_KFIFO(spi_fifo_out, uint8_t, FIFO_SIZE);
+
+static struct gpio_desc *data_available;
+static struct gpio_desc *spi_reset;
+
+static struct spi_device *pisnd_spi_device;
+
+static struct workqueue_struct *pisnd_workqueue;
+static struct work_struct pisnd_work_process;
+
+static void pisnd_work_handler(struct work_struct *work);
+
+static uint16_t spi_transfer16(uint16_t val);
+
+static int pisnd_init_workqueues(void)
+{
+	pisnd_workqueue = create_singlethread_workqueue("pisnd_workqueue");
+	INIT_WORK(&pisnd_work_process, pisnd_work_handler);
+
+	return 0;
+}
+
+static void pisnd_uninit_workqueues(void)
+{
+	flush_workqueue(pisnd_workqueue);
+	destroy_workqueue(pisnd_workqueue);
+
+	pisnd_workqueue = NULL;
+}
+
+static bool pisnd_spi_has_more(void)
+{
+	return gpiod_get_value(data_available);
+}
+
+enum task_e {
+	TASK_PROCESS = 0,
+};
+
+static void pisnd_schedule_process(enum task_e task)
+{
+	if (pisnd_spi_device != NULL &&
+		pisnd_workqueue != NULL &&
+		!work_pending(&pisnd_work_process)
+		) {
+		printd("schedule: has more = %d\n", pisnd_spi_has_more());
+		if (task == TASK_PROCESS)
+			queue_work(pisnd_workqueue, &pisnd_work_process);
+	}
+}
+
+static irqreturn_t data_available_interrupt_handler(int irq, void *dev_id)
+{
+	if (irq == gpiod_to_irq(data_available) && pisnd_spi_has_more()) {
+		printd("schedule from irq\n");
+		pisnd_schedule_process(TASK_PROCESS);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static DEFINE_SPINLOCK(spilock);
+static unsigned long spilockflags;
+
+static uint16_t spi_transfer16(uint16_t val)
+{
+	int err;
+	struct spi_transfer transfer;
+	struct spi_message msg;
+	uint8_t txbuf[2];
+	uint8_t rxbuf[2];
+
+	if (!pisnd_spi_device) {
+		printe("pisnd_spi_device null, returning\n");
+		return 0;
+	}
+
+	spi_message_init(&msg);
+
+	memset(&transfer, 0, sizeof(transfer));
+	memset(&rxbuf, 0, sizeof(rxbuf));
+
+	txbuf[0] = val >> 8;
+	txbuf[1] = val & 0xff;
+
+	transfer.tx_buf = &txbuf;
+	transfer.rx_buf = &rxbuf;
+	transfer.len = sizeof(txbuf);
+	transfer.speed_hz = 125000;
+	transfer.delay_usecs = 100;
+	spi_message_add_tail(&transfer, &msg);
+
+	spin_lock_irqsave(&spilock, spilockflags);
+	err = spi_sync(pisnd_spi_device, &msg);
+	spin_unlock_irqrestore(&spilock, spilockflags);
+
+	if (err < 0) {
+		printe("spi_sync error %d\n", err);
+		return 0;
+	}
+
+	printd("received: %02x%02x\n", rxbuf[0], rxbuf[1]);
+	printd("hasMore %d\n", pisnd_spi_has_more());
+
+	return (rxbuf[0] << 8) | rxbuf[1];
+}
+
+static int spi_read_bytes(char *dst, size_t length, uint8_t *bytesRead)
+{
+	uint16_t rx;
+	uint8_t size;
+	uint8_t i;
+
+	memset(dst, 0, length);
+	*bytesRead = 0;
+
+	 rx = spi_transfer16(0);
+	if (!(rx >> 8))
+		return -EINVAL;
+
+	size = rx & 0xff;
+
+	if (size > length)
+		return -EINVAL;
+
+	for (i = 0; i < size; ++i) {
+		rx = spi_transfer16(0);
+		if (!(rx >> 8))
+			return -EINVAL;
+
+		dst[i] = rx & 0xff;
+	}
+
+	*bytesRead = i;
+
+	return 0;
+}
+
+static int spi_device_match(struct device *dev, void *data)
+{
+	struct spi_device *spi = container_of(dev, struct spi_device, dev);
+
+	printd("      %s %s %dkHz %d bits mode=0x%02X\n",
+		spi->modalias, dev_name(dev), spi->max_speed_hz/1000,
+		spi->bits_per_word, spi->mode);
+
+	if (strcmp("pisound-spi", spi->modalias) == 0) {
+		printi("\tFound!\n");
+		return 1;
+	}
+
+	printe("\tNot found!\n");
+	return 0;
+}
+
+static struct spi_device *pisnd_spi_find_device(void)
+{
+	struct device *dev;
+
+	printi("Searching for spi device...\n");
+	dev = bus_find_device(&spi_bus_type, NULL, NULL, spi_device_match);
+	if (dev != NULL)
+		return container_of(dev, struct spi_device, dev);
+	else
+		return NULL;
+}
+
+static void pisnd_work_handler(struct work_struct *work)
+{
+	uint16_t rx;
+	uint16_t tx;
+	uint8_t val;
+
+	if (work == &pisnd_work_process) {
+		if (pisnd_spi_device == NULL)
+			return;
+
+		do {
+			val = 0;
+			tx = 0;
+
+			if (kfifo_get(&spi_fifo_out, &val))
+				tx = 0x0f00 | val;
+
+			rx = spi_transfer16(tx);
+
+			if (rx & 0xff00) {
+				kfifo_put(&spi_fifo_in, rx & 0xff);
+				if (kfifo_len(&spi_fifo_in) > 16
+					&& g_recvCallback)
+					g_recvCallback(g_recvData);
+			}
+		} while (rx != 0
+			|| !kfifo_is_empty(&spi_fifo_out)
+			|| pisnd_spi_has_more()
+			);
+
+		if (!kfifo_is_empty(&spi_fifo_in) && g_recvCallback)
+			g_recvCallback(g_recvData);
+	}
+}
+
+static int pisnd_spi_gpio_init(struct device *dev)
+{
+	spi_reset = gpiod_get_index(dev, "reset", 1, GPIOD_ASIS);
+	data_available = gpiod_get_index(dev, "data_available", 0, GPIOD_ASIS);
+
+	gpiod_direction_output(spi_reset, 1);
+	gpiod_direction_input(data_available);
+
+	/* Reset the slave. */
+	gpiod_set_value(spi_reset, false);
+	mdelay(1);
+	gpiod_set_value(spi_reset, true);
+
+	/* Give time for spi slave to start. */
+	mdelay(64);
+
+	return 0;
+}
+
+static void pisnd_spi_gpio_uninit(void)
+{
+	gpiod_set_value(spi_reset, false);
+	gpiod_put(spi_reset);
+	spi_reset = NULL;
+
+	gpiod_put(data_available);
+	data_available = NULL;
+}
+
+static int pisnd_spi_gpio_irq_init(struct device *dev)
+{
+	return request_irq(
+		gpiod_to_irq(data_available),
+		data_available_interrupt_handler,
+		IRQF_TIMER | IRQF_TRIGGER_RISING,
+		"data_available_int",
+		NULL
+		);
+}
+
+static void pisnd_spi_gpio_irq_uninit(void)
+{
+	free_irq(gpiod_to_irq(data_available), NULL);
+}
+
+static int spi_read_info(void)
+{
+	uint16_t tmp;
+	uint8_t count;
+	uint8_t n;
+	uint8_t i;
+	uint8_t j;
+	char buffer[257];
+	int ret;
+	char *p;
+
+	memset(g_serial_num, 0, sizeof(g_serial_num));
+	memset(g_version, 0, sizeof(g_version));
+	memset(g_id, 0, sizeof(g_id));
+
+	tmp = spi_transfer16(0);
+
+	if (!(tmp >> 8))
+		return -EINVAL;
+
+	 count = tmp & 0xff;
+
+	for (i = 0; i < count; ++i) {
+		memset(buffer, 0, sizeof(buffer));
+		ret = spi_read_bytes(buffer, sizeof(buffer)-1, &n);
+
+		if (ret < 0)
+			return ret;
+
+		switch (i) {
+		case 0:
+			if (n != 2)
+				return -EINVAL;
+
+			snprintf(
+				g_version,
+				sizeof(g_version),
+				"%x.%02x",
+				buffer[0],
+				buffer[1]
+				);
+			break;
+		case 1:
+			if (n >= sizeof(g_serial_num))
+				return -EINVAL;
+
+			memcpy(g_serial_num, buffer, sizeof(g_serial_num));
+			break;
+		case 2:
+			{
+				if (n >= sizeof(g_id))
+					return -EINVAL;
+
+				p = g_id;
+				for (j = 0; j < n; ++j)
+					p += sprintf(p, "%02x", buffer[j]);
+			}
+			break;
+		default:
+			break;
+		}
+	}
+
+	return 0;
+}
+
+static int pisnd_spi_init(struct device *dev)
+{
+	int ret;
+	struct spi_device *spi;
+
+	memset(g_serial_num, 0, sizeof(g_serial_num));
+	memset(g_id, 0, sizeof(g_id));
+	memset(g_version, 0, sizeof(g_version));
+
+	spi = pisnd_spi_find_device();
+
+	if (spi != NULL) {
+		printd("initializing spi!\n");
+		pisnd_spi_device = spi;
+		ret = spi_setup(pisnd_spi_device);
+	} else {
+		printe("SPI device not found, deferring!\n");
+		return -EPROBE_DEFER;
+	}
+
+	ret = pisnd_spi_gpio_init(dev);
+
+	if (ret < 0) {
+		printe("SPI GPIO init failed: %d\n", ret);
+		spi_dev_put(pisnd_spi_device);
+		pisnd_spi_device = NULL;
+		pisnd_spi_gpio_uninit();
+		return ret;
+	}
+
+	ret = spi_read_info();
+
+	if (ret < 0) {
+		printe("Reading card info failed: %d\n", ret);
+		spi_dev_put(pisnd_spi_device);
+		pisnd_spi_device = NULL;
+		pisnd_spi_gpio_uninit();
+		return ret;
+	}
+
+	/* Flash the LEDs. */
+	spi_transfer16(0xf000);
+
+	ret = pisnd_spi_gpio_irq_init(dev);
+	if (ret < 0) {
+		printe("SPI irq request failed: %d\n", ret);
+		spi_dev_put(pisnd_spi_device);
+		pisnd_spi_device = NULL;
+		pisnd_spi_gpio_irq_uninit();
+		pisnd_spi_gpio_uninit();
+	}
+
+	ret = pisnd_init_workqueues();
+	if (ret != 0) {
+		printe("Workqueue initialization failed: %d\n", ret);
+		spi_dev_put(pisnd_spi_device);
+		pisnd_spi_device = NULL;
+		pisnd_spi_gpio_irq_uninit();
+		pisnd_spi_gpio_uninit();
+		pisnd_uninit_workqueues();
+		return ret;
+	}
+
+	if (pisnd_spi_has_more()) {
+		printd("data is available, scheduling from init\n");
+		pisnd_schedule_process(TASK_PROCESS);
+	}
+
+	return 0;
+}
+
+static void pisnd_spi_uninit(void)
+{
+	pisnd_uninit_workqueues();
+
+	spi_dev_put(pisnd_spi_device);
+	pisnd_spi_device = NULL;
+
+	pisnd_spi_gpio_irq_uninit();
+	pisnd_spi_gpio_uninit();
+}
+
+static void pisnd_spi_send(uint8_t val)
+{
+	kfifo_put(&spi_fifo_out, val);
+	printd("schedule from spi_send\n");
+	pisnd_schedule_process(TASK_PROCESS);
+}
+
+static uint8_t pisnd_spi_recv(uint8_t *buffer, uint8_t length)
+{
+	return kfifo_out(&spi_fifo_in, buffer, length);
+}
+
+static void pisnd_spi_set_callback(pisnd_spi_recv_cb cb, void *data)
+{
+	g_recvData = data;
+	g_recvCallback = cb;
+}
+
+static const char *pisnd_spi_get_serial(void)
+{
+	if (strlen(g_serial_num))
+		return g_serial_num;
+
+	return "";
+}
+
+static const char *pisnd_spi_get_id(void)
+{
+	if (strlen(g_id))
+		return g_id;
+
+	return "";
+}
+
+static const char *pisnd_spi_get_version(void)
+{
+	if (strlen(g_version))
+		return g_version;
+
+	return "";
+}
+
+static const struct of_device_id pisound_of_match[] = {
+	{ .compatible = "blokaslabs,pisound", },
+	{ .compatible = "blokaslabs,pisound-spi", },
+	{},
+};
+
+static struct gpio_desc *osr0, *osr1, *osr2;
+static struct gpio_desc *reset;
+static struct gpio_desc *button;
+
+static int pisnd_hw_params(
+	struct snd_pcm_substream *substream,
+	struct snd_pcm_hw_params *params
+	)
+{
+	printd("rate   = %d\n", params_rate(params));
+	printd("ch     = %d\n", params_channels(params));
+	printd("bits   = %u\n",
+		snd_pcm_format_physical_width(params_format(params)));
+	printd("format = %d\n", params_format(params));
+
+	gpiod_set_value(reset, false);
+
+	switch (params_rate(params)) {
+	case 48000:
+		gpiod_set_value(osr0, true);
+		gpiod_set_value(osr1, false);
+		gpiod_set_value(osr2, false);
+		break;
+	case 96000:
+		gpiod_set_value(osr0, true);
+		gpiod_set_value(osr1, true);
+		gpiod_set_value(osr2, false);
+		break;
+	case 192000:
+		gpiod_set_value(osr0, true);
+		gpiod_set_value(osr1, true);
+		gpiod_set_value(osr2, true);
+		break;
+	default:
+		printe("Unsupported rate %u!\n", params_rate(params));
+		return -EINVAL;
+	}
+
+	gpiod_set_value(reset, true);
+
+	return 0;
+}
+
+static unsigned int rates[3] = {
+	48000, 96000, 192000
+};
+
+static struct snd_pcm_hw_constraint_list constraints_rates = {
+	.count = ARRAY_SIZE(rates),
+	.list = rates,
+	.mask = 0,
+};
+
+static unsigned int sample_bits[] = {
+	24, 32
+};
+
+static struct snd_pcm_hw_constraint_list constraints_sample_bits = {
+	.count = ARRAY_SIZE(sample_bits),
+	.list = sample_bits,
+	.mask = 0,
+};
+
+static int pisnd_startup(struct snd_pcm_substream *substream)
+{
+	int err = snd_pcm_hw_constraint_list(
+		substream->runtime,
+		0,
+		SNDRV_PCM_HW_PARAM_RATE,
+		&constraints_rates
+		);
+
+	if (err < 0)
+		return err;
+
+	err = snd_pcm_hw_constraint_list(
+		substream->runtime,
+		0,
+		SNDRV_PCM_HW_PARAM_SAMPLE_BITS,
+		&constraints_sample_bits
+		);
+
+	if (err < 0)
+		return err;
+
+	return 0;
+}
+
+static struct snd_soc_ops pisnd_ops = {
+	.startup = pisnd_startup,
+	.hw_params = pisnd_hw_params,
+};
+
+static struct snd_soc_dai_link pisnd_dai[] = {
+	{
+		.name           = "pisound",
+		.stream_name    = "pisound",
+		.cpu_dai_name   = "bcm2708-i2s.0",
+		.codec_dai_name = "snd-soc-dummy-dai",
+		.platform_name  = "bcm2708-i2s.0",
+		.codec_name     = "snd-soc-dummy",
+		.dai_fmt        =
+			SND_SOC_DAIFMT_I2S |
+			SND_SOC_DAIFMT_NB_NF |
+			SND_SOC_DAIFMT_CBM_CFM,
+		.ops            = &pisnd_ops,
+	},
+};
+
+static int pisnd_card_probe(struct snd_soc_card *card)
+{
+	int err = pisnd_midi_init(card->snd_card);
+
+	if (err < 0)
+		printe("pisnd_midi_init failed: %d\n", err);
+
+	return err;
+}
+
+static int pisnd_card_remove(struct snd_soc_card *card)
+{
+	pisnd_midi_uninit();
+	return 0;
+}
+
+static struct snd_soc_card pisnd_card = {
+	.name         = "pisound",
+	.owner        = THIS_MODULE,
+	.dai_link     = pisnd_dai,
+	.num_links    = ARRAY_SIZE(pisnd_dai),
+	.probe        = pisnd_card_probe,
+	.remove       = pisnd_card_remove,
+};
+
+static int pisnd_init_gpio(struct device *dev)
+{
+	osr0 = gpiod_get_index(dev, "osr", 0, GPIOD_ASIS);
+	osr1 = gpiod_get_index(dev, "osr", 1, GPIOD_ASIS);
+	osr2 = gpiod_get_index(dev, "osr", 2, GPIOD_ASIS);
+
+	reset = gpiod_get_index(dev, "reset", 0, GPIOD_ASIS);
+
+	button = gpiod_get_index(dev, "button", 0, GPIOD_ASIS);
+
+	gpiod_direction_output(osr0,  1);
+	gpiod_direction_output(osr1,  1);
+	gpiod_direction_output(osr2,  1);
+	gpiod_direction_output(reset, 1);
+
+	gpiod_set_value(reset, false);
+	gpiod_set_value(osr0,   true);
+	gpiod_set_value(osr1,  false);
+	gpiod_set_value(osr2,  false);
+	gpiod_set_value(reset,  true);
+
+	gpiod_export(button, false);
+
+	return 0;
+}
+
+static int pisnd_uninit_gpio(void)
+{
+	int i;
+
+	struct gpio_desc **gpios[] = {
+		&osr0, &osr1, &osr2, &reset, &button,
+	};
+
+	gpiod_unexport(button);
+
+	for (i = 0; i < ARRAY_SIZE(gpios); ++i) {
+		if (*gpios[i] == NULL) {
+			printd("weird, GPIO[%d] is NULL already\n", i);
+			continue;
+		}
+
+		gpiod_put(*gpios[i]);
+		*gpios[i] = NULL;
+	}
+
+	return 0;
+}
+
+static struct kobject *pisnd_kobj;
+
+static ssize_t pisnd_serial_show(
+	struct kobject *kobj,
+	struct kobj_attribute *attr,
+	char *buf
+	)
+{
+	return sprintf(buf, "%s\n", pisnd_spi_get_serial());
+}
+
+static ssize_t pisnd_id_show(
+	struct kobject *kobj,
+	struct kobj_attribute *attr,
+	char *buf
+	)
+{
+	return sprintf(buf, "%s\n", pisnd_spi_get_id());
+}
+
+static ssize_t pisnd_version_show(
+	struct kobject *kobj,
+	struct kobj_attribute *attr,
+	char *buf
+	)
+{
+	return sprintf(buf, "%s\n", pisnd_spi_get_version());
+}
+
+static struct kobj_attribute pisnd_serial_attribute =
+	__ATTR(serial, 0644, pisnd_serial_show, NULL);
+static struct kobj_attribute pisnd_id_attribute =
+	__ATTR(id, 0644, pisnd_id_show, NULL);
+static struct kobj_attribute pisnd_version_attribute =
+	__ATTR(version, 0644, pisnd_version_show, NULL);
+
+static struct attribute *attrs[] = {
+	&pisnd_serial_attribute.attr,
+	&pisnd_id_attribute.attr,
+	&pisnd_version_attribute.attr,
+	NULL
+};
+
+static struct attribute_group attr_group = { .attrs = attrs };
+
+static int pisnd_probe(struct platform_device *pdev)
+{
+	int ret = 0;
+	int i;
+
+	ret = pisnd_spi_init(&pdev->dev);
+	if (ret < 0) {
+		printe("pisnd_spi_init failed: %d\n", ret);
+		return ret;
+	}
+
+	printi("Detected pisound card:\n");
+	printi("\tSerial:  %s\n", pisnd_spi_get_serial());
+	printi("\tVersion: %s\n", pisnd_spi_get_version());
+	printi("\tId:      %s\n", pisnd_spi_get_id());
+
+	pisnd_kobj = kobject_create_and_add("pisound", kernel_kobj);
+	if (!pisnd_kobj) {
+		pisnd_spi_uninit();
+		return -ENOMEM;
+	}
+
+	ret = sysfs_create_group(pisnd_kobj, &attr_group);
+	if (ret < 0) {
+		pisnd_spi_uninit();
+		kobject_put(pisnd_kobj);
+		return -ENOMEM;
+	}
+
+	pisnd_init_gpio(&pdev->dev);
+	pisnd_card.dev = &pdev->dev;
+
+	if (pdev->dev.of_node) {
+		struct device_node *i2s_node;
+
+		i2s_node = of_parse_phandle(
+			pdev->dev.of_node,
+			"i2s-controller",
+			0
+			);
+
+		for (i = 0; i < pisnd_card.num_links; ++i) {
+			struct snd_soc_dai_link *dai = &pisnd_dai[i];
+
+			if (i2s_node) {
+				dai->cpu_dai_name = NULL;
+				dai->cpu_of_node = i2s_node;
+				dai->platform_name = NULL;
+				dai->platform_of_node = i2s_node;
+				dai->stream_name = pisnd_spi_get_serial();
+			}
+		}
+	}
+
+	ret = snd_soc_register_card(&pisnd_card);
+
+	if (ret < 0) {
+		printe("snd_soc_register_card() failed: %d\n", ret);
+		pisnd_uninit_gpio();
+		kobject_put(pisnd_kobj);
+		pisnd_spi_uninit();
+	}
+
+	return ret;
+}
+
+static int pisnd_remove(struct platform_device *pdev)
+{
+	if (pisnd_kobj) {
+		kobject_put(pisnd_kobj);
+		pisnd_kobj = NULL;
+	}
+
+	pisnd_spi_uninit();
+
+	/* Turn off */
+	gpiod_set_value(reset, false);
+	pisnd_uninit_gpio();
+
+	return snd_soc_unregister_card(&pisnd_card);
+}
+
+MODULE_DEVICE_TABLE(of, pisound_of_match);
+
+static struct platform_driver pisnd_driver = {
+	.driver = {
+		.name           = "snd-rpi-pisound",
+		.owner          = THIS_MODULE,
+		.of_match_table = pisound_of_match,
+	},
+	.probe              = pisnd_probe,
+	.remove             = pisnd_remove,
+};
+
+module_platform_driver(pisnd_driver);
+
+MODULE_AUTHOR("Giedrius Trainavicius <giedrius@blokas.io>");
+MODULE_DESCRIPTION("ASoC Driver for pisound, http://blokas.io/pisound");
+MODULE_LICENSE("GPL v2");