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
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
|
/*
* userspace interface for pi433 radio module
*
* Pi433 is a 433MHz radio module for the Raspberry Pi.
* It is based on the HopeRf Module RFM69CW. Therefore inside of this
* driver, you'll find an abstraction of the rf69 chip.
*
* If needed, this driver could be extended, to also support other
* devices, basing on HopeRfs rf69.
*
* The driver can also be extended, to support other modules of
* HopeRf with a similar interace - e. g. RFM69HCW, RFM12, RFM95, ...
*
* Copyright (C) 2016 Wolf-Entwicklungen
* Marcus Wolf <linux@wolf-entwicklungen.de>
*
* 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.
*/
#undef DEBUG
#include <linux/init.h>
#include <linux/module.h>
#include <linux/idr.h>
#include <linux/ioctl.h>
#include <linux/uaccess.h>
#include <linux/fs.h>
#include <linux/device.h>
#include <linux/cdev.h>
#include <linux/err.h>
#include <linux/kfifo.h>
#include <linux/errno.h>
#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/gpio/consumer.h>
#include <linux/kthread.h>
#include <linux/wait.h>
#include <linux/spi/spi.h>
#ifdef CONFIG_COMPAT
#include <asm/compat.h>
#endif
#include "pi433_if.h"
#include "rf69.h"
#define N_PI433_MINORS (1U << MINORBITS) /*32*/ /* ... up to 256 */
#define MAX_MSG_SIZE 900 /* min: FIFO_SIZE! */
#define MSG_FIFO_SIZE 65536 /* 65536 = 2^16 */
#define NUM_DIO 2
static dev_t pi433_dev;
static DEFINE_IDR(pi433_idr);
static DEFINE_MUTEX(minor_lock); /* Protect idr accesses */
static struct class *pi433_class; /* mainly for udev to create /dev/pi433 */
/* tx config is instance specific
* so with each open a new tx config struct is needed
*/
/* rx config is device specific
* so we have just one rx config, ebedded in device struct
*/
struct pi433_device {
/* device handling related values */
dev_t devt;
int minor;
struct device *dev;
struct cdev *cdev;
struct spi_device *spi;
unsigned users;
/* irq related values */
struct gpio_desc *gpiod[NUM_DIO];
int irq_num[NUM_DIO];
u8 irq_state[NUM_DIO];
/* tx related values */
STRUCT_KFIFO_REC_1(MSG_FIFO_SIZE) tx_fifo;
struct mutex tx_fifo_lock; // TODO: check, whether necessary or obsolete
struct task_struct *tx_task_struct;
wait_queue_head_t tx_wait_queue;
u8 free_in_fifo;
char buffer[MAX_MSG_SIZE];
/* rx related values */
struct pi433_rx_cfg rx_cfg;
u8 *rx_buffer;
unsigned int rx_buffer_size;
u32 rx_bytes_to_drop;
u32 rx_bytes_dropped;
unsigned int rx_position;
struct mutex rx_lock;
wait_queue_head_t rx_wait_queue;
/* fifo wait queue */
struct task_struct *fifo_task_struct;
wait_queue_head_t fifo_wait_queue;
/* flags */
bool rx_active;
bool tx_active;
bool interrupt_rx_allowed;
};
struct pi433_instance {
struct pi433_device *device;
struct pi433_tx_cfg tx_cfg;
};
/*-------------------------------------------------------------------------*/
/* GPIO interrupt handlers */
static irqreturn_t DIO0_irq_handler(int irq, void *dev_id)
{
struct pi433_device *device = dev_id;
if (device->irq_state[DIO0] == DIO_PACKET_SENT) {
device->free_in_fifo = FIFO_SIZE;
dev_dbg(device->dev, "DIO0 irq: Packet sent\n");
wake_up_interruptible(&device->fifo_wait_queue);
} else if (device->irq_state[DIO0] == DIO_RSSI_DIO0) {
dev_dbg(device->dev, "DIO0 irq: RSSI level over threshold\n");
wake_up_interruptible(&device->rx_wait_queue);
} else if (device->irq_state[DIO0] == DIO_PAYLOAD_READY) {
dev_dbg(device->dev, "DIO0 irq: Payload ready\n");
device->free_in_fifo = 0;
wake_up_interruptible(&device->fifo_wait_queue);
}
return IRQ_HANDLED;
}
static irqreturn_t DIO1_irq_handler(int irq, void *dev_id)
{
struct pi433_device *device = dev_id;
if (device->irq_state[DIO1] == DIO_FIFO_NOT_EMPTY_DIO1) {
device->free_in_fifo = FIFO_SIZE;
} else if (device->irq_state[DIO1] == DIO_FIFO_LEVEL) {
if (device->rx_active)
device->free_in_fifo = FIFO_THRESHOLD - 1;
else
device->free_in_fifo = FIFO_SIZE - FIFO_THRESHOLD - 1;
}
dev_dbg(device->dev,
"DIO1 irq: %d bytes free in fifo\n", device->free_in_fifo);
wake_up_interruptible(&device->fifo_wait_queue);
return IRQ_HANDLED;
}
/*-------------------------------------------------------------------------*/
static int
rf69_set_rx_cfg(struct pi433_device *dev, struct pi433_rx_cfg *rx_cfg)
{
int ret;
int payload_length;
/* receiver config */
ret = rf69_set_frequency(dev->spi, rx_cfg->frequency);
if (ret < 0)
return ret;
ret = rf69_set_bit_rate(dev->spi, rx_cfg->bit_rate);
if (ret < 0)
return ret;
ret = rf69_set_modulation(dev->spi, rx_cfg->modulation);
if (ret < 0)
return ret;
ret = rf69_set_antenna_impedance(dev->spi, rx_cfg->antenna_impedance);
if (ret < 0)
return ret;
ret = rf69_set_rssi_threshold(dev->spi, rx_cfg->rssi_threshold);
if (ret < 0)
return ret;
ret = rf69_set_ook_threshold_dec(dev->spi, rx_cfg->threshold_decrement);
if (ret < 0)
return ret;
ret = rf69_set_bandwidth(dev->spi, rx_cfg->bw_mantisse, rx_cfg->bw_exponent);
if (ret < 0)
return ret;
ret = rf69_set_bandwidth_during_afc(dev->spi, rx_cfg->bw_mantisse, rx_cfg->bw_exponent);
if (ret < 0)
return ret;
ret = rf69_set_dagc(dev->spi, rx_cfg->dagc);
if (ret < 0)
return ret;
dev->rx_bytes_to_drop = rx_cfg->bytes_to_drop;
/* packet config */
/* enable */
if (rx_cfg->enable_sync == OPTION_ON) {
ret = rf69_enable_sync(dev->spi);
if (ret < 0)
return ret;
ret = rf69_set_fifo_fill_condition(dev->spi, afterSyncInterrupt);
if (ret < 0)
return ret;
} else {
ret = rf69_disable_sync(dev->spi);
if (ret < 0)
return ret;
ret = rf69_set_fifo_fill_condition(dev->spi, always);
if (ret < 0)
return ret;
}
if (rx_cfg->enable_length_byte == OPTION_ON) {
ret = rf69_set_packet_format(dev->spi, packetLengthVar);
if (ret < 0)
return ret;
} else {
ret = rf69_set_packet_format(dev->spi, packetLengthFix);
if (ret < 0)
return ret;
}
ret = rf69_set_adressFiltering(dev->spi, rx_cfg->enable_address_filtering);
if (ret < 0)
return ret;
if (rx_cfg->enable_crc == OPTION_ON) {
ret = rf69_enable_crc(dev->spi);
if (ret < 0)
return ret;
} else {
ret = rf69_disable_crc(dev->spi);
if (ret < 0)
return ret;
}
/* lengths */
ret = rf69_set_sync_size(dev->spi, rx_cfg->sync_length);
if (ret < 0)
return ret;
if (rx_cfg->enable_length_byte == OPTION_ON) {
ret = rf69_set_payload_length(dev->spi, 0xff);
if (ret < 0)
return ret;
} else if (rx_cfg->fixed_message_length != 0) {
payload_length = rx_cfg->fixed_message_length;
if (rx_cfg->enable_length_byte == OPTION_ON)
payload_length++;
if (rx_cfg->enable_address_filtering != filteringOff)
payload_length++;
ret = rf69_set_payload_length(dev->spi, payload_length);
if (ret < 0)
return ret;
} else {
ret = rf69_set_payload_length(dev->spi, 0);
if (ret < 0)
return ret;
}
/* values */
if (rx_cfg->enable_sync == OPTION_ON) {
ret = rf69_set_sync_values(dev->spi, rx_cfg->sync_pattern);
if (ret < 0)
return ret;
}
if (rx_cfg->enable_address_filtering != filteringOff) {
ret = rf69_set_node_address(dev->spi, rx_cfg->node_address);
if (ret < 0)
return ret;
ret = rf69_set_broadcast_address(dev->spi, rx_cfg->broadcast_address);
if (ret < 0)
return ret;
}
return 0;
}
static int
rf69_set_tx_cfg(struct pi433_device *dev, struct pi433_tx_cfg *tx_cfg)
{
int ret;
ret = rf69_set_frequency(dev->spi, tx_cfg->frequency);
if (ret < 0)
return ret;
ret = rf69_set_bit_rate(dev->spi, tx_cfg->bit_rate);
if (ret < 0)
return ret;
ret = rf69_set_modulation(dev->spi, tx_cfg->modulation);
if (ret < 0)
return ret;
ret = rf69_set_deviation(dev->spi, tx_cfg->dev_frequency);
if (ret < 0)
return ret;
ret = rf69_set_pa_ramp(dev->spi, tx_cfg->pa_ramp);
if (ret < 0)
return ret;
ret = rf69_set_modulation_shaping(dev->spi, tx_cfg->mod_shaping);
if (ret < 0)
return ret;
ret = rf69_set_tx_start_condition(dev->spi, tx_cfg->tx_start_condition);
if (ret < 0)
return ret;
/* packet format enable */
if (tx_cfg->enable_preamble == OPTION_ON) {
ret = rf69_set_preamble_length(dev->spi, tx_cfg->preamble_length);
if (ret < 0)
return ret;
} else {
ret = rf69_set_preamble_length(dev->spi, 0);
if (ret < 0)
return ret;
}
if (tx_cfg->enable_sync == OPTION_ON) {
ret = rf69_enable_sync(dev->spi);
if (ret < 0)
return ret;
} else {
ret = rf69_disable_sync(dev->spi);
if (ret < 0)
return ret;
}
if (tx_cfg->enable_length_byte == OPTION_ON) {
ret = rf69_set_packet_format(dev->spi, packetLengthVar);
if (ret < 0)
return ret;
} else {
ret = rf69_set_packet_format(dev->spi, packetLengthFix);
if (ret < 0)
return ret;
}
if (tx_cfg->enable_crc == OPTION_ON) {
ret = rf69_enable_crc(dev->spi);
if (ret < 0)
return ret;
} else {
ret = rf69_disable_crc(dev->spi);
if (ret < 0)
return ret;
}
/* configure sync, if enabled */
if (tx_cfg->enable_sync == OPTION_ON) {
ret = rf69_set_sync_size(dev->spi, tx_cfg->sync_length);
if (ret < 0)
return ret;
ret = rf69_set_sync_values(dev->spi, tx_cfg->sync_pattern);
if (ret < 0)
return ret;
}
return 0;
}
/*-------------------------------------------------------------------------*/
static int
pi433_start_rx(struct pi433_device *dev)
{
int retval;
/* return without action, if no pending read request */
if (!dev->rx_active)
return 0;
/* setup for receiving */
retval = rf69_set_rx_cfg(dev, &dev->rx_cfg);
if (retval)
return retval;
/* setup rssi irq */
retval = rf69_set_dio_mapping(dev->spi, DIO0, DIO_RSSI_DIO0);
if (retval < 0)
return retval;
dev->irq_state[DIO0] = DIO_RSSI_DIO0;
irq_set_irq_type(dev->irq_num[DIO0], IRQ_TYPE_EDGE_RISING);
/* setup fifo level interrupt */
retval = rf69_set_fifo_threshold(dev->spi, FIFO_SIZE - FIFO_THRESHOLD);
if (retval < 0)
return retval;
retval = rf69_set_dio_mapping(dev->spi, DIO1, DIO_FIFO_LEVEL);
if (retval < 0)
return retval;
dev->irq_state[DIO1] = DIO_FIFO_LEVEL;
irq_set_irq_type(dev->irq_num[DIO1], IRQ_TYPE_EDGE_RISING);
/* set module to receiving mode */
retval = rf69_set_mode(dev->spi, receive);
if (retval < 0)
return retval;
return 0;
}
/*-------------------------------------------------------------------------*/
static int
pi433_receive(void *data)
{
struct pi433_device *dev = data;
struct spi_device *spi = dev->spi;
int bytes_to_read, bytes_total;
int retval;
dev->interrupt_rx_allowed = false;
/* wait for any tx to finish */
dev_dbg(dev->dev, "rx: going to wait for any tx to finish");
retval = wait_event_interruptible(dev->rx_wait_queue, !dev->tx_active);
if (retval) {
/* wait was interrupted */
dev->interrupt_rx_allowed = true;
wake_up_interruptible(&dev->tx_wait_queue);
return retval;
}
/* prepare status vars */
dev->free_in_fifo = FIFO_SIZE;
dev->rx_position = 0;
dev->rx_bytes_dropped = 0;
/* setup radio module to listen for something "in the air" */
retval = pi433_start_rx(dev);
if (retval)
return retval;
/* now check RSSI, if low wait for getting high (RSSI interrupt) */
while (!rf69_get_flag(dev->spi, rssiExceededThreshold)) {
/* allow tx to interrupt us while waiting for high RSSI */
dev->interrupt_rx_allowed = true;
wake_up_interruptible(&dev->tx_wait_queue);
/* wait for RSSI level to become high */
dev_dbg(dev->dev, "rx: going to wait for high RSSI level");
retval = wait_event_interruptible(dev->rx_wait_queue,
rf69_get_flag(dev->spi,
rssiExceededThreshold));
if (retval) /* wait was interrupted */
goto abort;
dev->interrupt_rx_allowed = false;
/* cross check for ongoing tx */
if (!dev->tx_active)
break;
}
/* configure payload ready irq */
retval = rf69_set_dio_mapping(spi, DIO0, DIO_PAYLOAD_READY);
if (retval < 0)
goto abort;
dev->irq_state[DIO0] = DIO_PAYLOAD_READY;
irq_set_irq_type(dev->irq_num[DIO0], IRQ_TYPE_EDGE_RISING);
/* fixed or unlimited length? */
if (dev->rx_cfg.fixed_message_length != 0) {
if (dev->rx_cfg.fixed_message_length > dev->rx_buffer_size) {
retval = -1;
goto abort;
}
bytes_total = dev->rx_cfg.fixed_message_length;
dev_dbg(dev->dev, "rx: msg len set to %d by fixed length", bytes_total);
} else {
bytes_total = dev->rx_buffer_size;
dev_dbg(dev->dev, "rx: msg len set to %d as requested by read", bytes_total);
}
/* length byte enabled? */
if (dev->rx_cfg.enable_length_byte == OPTION_ON) {
retval = wait_event_interruptible(dev->fifo_wait_queue,
dev->free_in_fifo < FIFO_SIZE);
if (retval) /* wait was interrupted */
goto abort;
rf69_read_fifo(spi, (u8 *)&bytes_total, 1);
if (bytes_total > dev->rx_buffer_size) {
retval = -1;
goto abort;
}
dev->free_in_fifo++;
dev_dbg(dev->dev, "rx: msg len reset to %d due to length byte", bytes_total);
}
/* address byte enabled? */
if (dev->rx_cfg.enable_address_filtering != filteringOff) {
u8 dummy;
bytes_total--;
retval = wait_event_interruptible(dev->fifo_wait_queue,
dev->free_in_fifo < FIFO_SIZE);
if (retval) /* wait was interrupted */
goto abort;
rf69_read_fifo(spi, &dummy, 1);
dev->free_in_fifo++;
dev_dbg(dev->dev, "rx: address byte stripped off");
}
/* get payload */
while (dev->rx_position < bytes_total) {
if (!rf69_get_flag(dev->spi, payloadReady)) {
retval = wait_event_interruptible(dev->fifo_wait_queue,
dev->free_in_fifo < FIFO_SIZE);
if (retval) /* wait was interrupted */
goto abort;
}
/* need to drop bytes or acquire? */
if (dev->rx_bytes_to_drop > dev->rx_bytes_dropped)
bytes_to_read = dev->rx_bytes_to_drop - dev->rx_bytes_dropped;
else
bytes_to_read = bytes_total - dev->rx_position;
/* access the fifo */
if (bytes_to_read > FIFO_SIZE - dev->free_in_fifo)
bytes_to_read = FIFO_SIZE - dev->free_in_fifo;
retval = rf69_read_fifo(spi,
&dev->rx_buffer[dev->rx_position],
bytes_to_read);
if (retval) /* read failed */
goto abort;
dev->free_in_fifo += bytes_to_read;
/* adjust status vars */
if (dev->rx_bytes_to_drop > dev->rx_bytes_dropped)
dev->rx_bytes_dropped += bytes_to_read;
else
dev->rx_position += bytes_to_read;
}
/* rx done, wait was interrupted or error occurred */
abort:
dev->interrupt_rx_allowed = true;
if (rf69_set_mode(dev->spi, standby))
pr_err("rf69_set_mode(): radio module failed to go standby\n");
wake_up_interruptible(&dev->tx_wait_queue);
if (retval)
return retval;
else
return bytes_total;
}
static int
pi433_tx_thread(void *data)
{
struct pi433_device *device = data;
struct spi_device *spi = device->spi;
struct pi433_tx_cfg tx_cfg;
u8 *buffer = device->buffer;
size_t size;
bool rx_interrupted = false;
int position, repetitions;
int retval;
while (1) {
/* wait for fifo to be populated or for request to terminate*/
dev_dbg(device->dev, "thread: going to wait for new messages");
wait_event_interruptible(device->tx_wait_queue,
(!kfifo_is_empty(&device->tx_fifo) ||
kthread_should_stop()));
if (kthread_should_stop())
return 0;
/* get data from fifo in the following order:
* - tx_cfg
* - size of message
* - message
*/
mutex_lock(&device->tx_fifo_lock);
retval = kfifo_out(&device->tx_fifo, &tx_cfg, sizeof(tx_cfg));
if (retval != sizeof(tx_cfg)) {
dev_dbg(device->dev, "reading tx_cfg from fifo failed: got %d byte(s), expected %d", retval, (unsigned int)sizeof(tx_cfg));
mutex_unlock(&device->tx_fifo_lock);
continue;
}
retval = kfifo_out(&device->tx_fifo, &size, sizeof(size_t));
if (retval != sizeof(size_t)) {
dev_dbg(device->dev, "reading msg size from fifo failed: got %d, expected %d", retval, (unsigned int)sizeof(size_t));
mutex_unlock(&device->tx_fifo_lock);
continue;
}
/* use fixed message length, if requested */
if (tx_cfg.fixed_message_length != 0)
size = tx_cfg.fixed_message_length;
/* increase size, if len byte is requested */
if (tx_cfg.enable_length_byte == OPTION_ON)
size++;
/* increase size, if adr byte is requested */
if (tx_cfg.enable_address_byte == OPTION_ON)
size++;
/* prime buffer */
memset(buffer, 0, size);
position = 0;
/* add length byte, if requested */
if (tx_cfg.enable_length_byte == OPTION_ON)
buffer[position++] = size - 1; /* according to spec length byte itself must be excluded from the length calculation */
/* add adr byte, if requested */
if (tx_cfg.enable_address_byte == OPTION_ON)
buffer[position++] = tx_cfg.address_byte;
/* finally get message data from fifo */
retval = kfifo_out(&device->tx_fifo, &buffer[position], sizeof(buffer) - position);
dev_dbg(device->dev, "read %d message byte(s) from fifo queue.", retval);
mutex_unlock(&device->tx_fifo_lock);
/* if rx is active, we need to interrupt the waiting for
* incoming telegrams, to be able to send something.
* We are only allowed, if currently no reception takes
* place otherwise we need to wait for the incoming telegram
* to finish
*/
wait_event_interruptible(device->tx_wait_queue,
!device->rx_active ||
device->interrupt_rx_allowed == true);
/* prevent race conditions
* irq will be reenabled after tx config is set
*/
disable_irq(device->irq_num[DIO0]);
device->tx_active = true;
if (device->rx_active && rx_interrupted == false) {
/* rx is currently waiting for a telegram;
* we need to set the radio module to standby
*/
retval = rf69_set_mode(device->spi, standby);
if (retval < 0)
return retval;
rx_interrupted = true;
}
/* clear fifo, set fifo threshold, set payload length */
retval = rf69_set_mode(spi, standby); /* this clears the fifo */
if (retval < 0)
return retval;
retval = rf69_set_fifo_threshold(spi, FIFO_THRESHOLD);
if (retval < 0)
return retval;
if (tx_cfg.enable_length_byte == OPTION_ON) {
retval = rf69_set_payload_length(spi, size * tx_cfg.repetitions);
if (retval < 0)
return retval;
} else {
retval = rf69_set_payload_length(spi, 0);
if (retval < 0)
return retval;
}
/* configure the rf chip */
retval = rf69_set_tx_cfg(device, &tx_cfg);
if (retval < 0)
return retval;
/* enable fifo level interrupt */
retval = rf69_set_dio_mapping(spi, DIO1, DIO_FIFO_LEVEL);
if (retval < 0)
return retval;
device->irq_state[DIO1] = DIO_FIFO_LEVEL;
irq_set_irq_type(device->irq_num[DIO1], IRQ_TYPE_EDGE_FALLING);
/* enable packet sent interrupt */
retval = rf69_set_dio_mapping(spi, DIO0, DIO_PACKET_SENT);
if (retval < 0)
return retval;
device->irq_state[DIO0] = DIO_PACKET_SENT;
irq_set_irq_type(device->irq_num[DIO0], IRQ_TYPE_EDGE_RISING);
enable_irq(device->irq_num[DIO0]); /* was disabled by rx active check */
/* enable transmission */
retval = rf69_set_mode(spi, transmit);
if (retval < 0)
return retval;
/* transfer this msg (and repetitions) to chip fifo */
device->free_in_fifo = FIFO_SIZE;
position = 0;
repetitions = tx_cfg.repetitions;
while ((repetitions > 0) && (size > position)) {
if ((size - position) > device->free_in_fifo) {
/* msg to big for fifo - take a part */
int temp = device->free_in_fifo;
device->free_in_fifo = 0;
rf69_write_fifo(spi,
&buffer[position],
temp);
position += temp;
} else {
/* msg fits into fifo - take all */
device->free_in_fifo -= size;
repetitions--;
rf69_write_fifo(spi,
&buffer[position],
(size - position));
position = 0; /* reset for next repetition */
}
retval = wait_event_interruptible(device->fifo_wait_queue,
device->free_in_fifo > 0);
if (retval) {
printk("ABORT\n");
goto abort;
}
}
/* we are done. Wait for packet to get sent */
dev_dbg(device->dev, "thread: wait for packet to get sent/fifo to be empty");
wait_event_interruptible(device->fifo_wait_queue,
device->free_in_fifo == FIFO_SIZE ||
kthread_should_stop());
if (kthread_should_stop())
printk("ABORT\n");
/* STOP_TRANSMISSION */
dev_dbg(device->dev, "thread: Packet sent. Set mode to stby.");
retval = rf69_set_mode(spi, standby);
if (retval < 0)
return retval;
/* everything sent? */
if (kfifo_is_empty(&device->tx_fifo)) {
abort:
if (rx_interrupted) {
rx_interrupted = false;
pi433_start_rx(device);
}
device->tx_active = false;
wake_up_interruptible(&device->rx_wait_queue);
}
}
}
/*-------------------------------------------------------------------------*/
static ssize_t
pi433_read(struct file *filp, char __user *buf, size_t size, loff_t *f_pos)
{
struct pi433_instance *instance;
struct pi433_device *device;
int bytes_received;
ssize_t retval;
/* check, whether internal buffer is big enough for requested size */
if (size > MAX_MSG_SIZE)
return -EMSGSIZE;
instance = filp->private_data;
device = instance->device;
/* just one read request at a time */
mutex_lock(&device->rx_lock);
if (device->rx_active) {
mutex_unlock(&device->rx_lock);
return -EAGAIN;
} else {
device->rx_active = true;
mutex_unlock(&device->rx_lock);
}
/* start receiving */
/* will block until something was received*/
device->rx_buffer_size = size;
bytes_received = pi433_receive(device);
/* release rx */
mutex_lock(&device->rx_lock);
device->rx_active = false;
mutex_unlock(&device->rx_lock);
/* if read was successful copy to user space*/
if (bytes_received > 0) {
retval = copy_to_user(buf, device->rx_buffer, bytes_received);
if (retval)
return -EFAULT;
}
return bytes_received;
}
static ssize_t
pi433_write(struct file *filp, const char __user *buf,
size_t count, loff_t *f_pos)
{
struct pi433_instance *instance;
struct pi433_device *device;
int retval;
unsigned int copied;
instance = filp->private_data;
device = instance->device;
/* check, whether internal buffer (tx thread) is big enough for requested size */
if (count > MAX_MSG_SIZE)
return -EMSGSIZE;
/* write the following sequence into fifo:
* - tx_cfg
* - size of message
* - message
*/
mutex_lock(&device->tx_fifo_lock);
retval = kfifo_in(&device->tx_fifo, &instance->tx_cfg, sizeof(instance->tx_cfg));
if (retval != sizeof(instance->tx_cfg))
goto abort;
retval = kfifo_in(&device->tx_fifo, &count, sizeof(size_t));
if (retval != sizeof(size_t))
goto abort;
retval = kfifo_from_user(&device->tx_fifo, buf, count, &copied);
if (retval || copied != count)
goto abort;
mutex_unlock(&device->tx_fifo_lock);
/* start transfer */
wake_up_interruptible(&device->tx_wait_queue);
dev_dbg(device->dev, "write: generated new msg with %d bytes.", copied);
return 0;
abort:
dev_dbg(device->dev, "write to fifo failed: 0x%x", retval);
kfifo_reset(&device->tx_fifo); // TODO: maybe find a solution, not to discard already stored, valid entries
mutex_unlock(&device->tx_fifo_lock);
return -EAGAIN;
}
static long
pi433_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
int retval = 0;
struct pi433_instance *instance;
struct pi433_device *device;
void __user *argp = (void __user *)arg;
/* Check type and command number */
if (_IOC_TYPE(cmd) != PI433_IOC_MAGIC)
return -ENOTTY;
/* TODO? guard against device removal before, or while,
* we issue this ioctl. --> device_get()
*/
instance = filp->private_data;
device = instance->device;
if (device == NULL)
return -ESHUTDOWN;
switch (cmd) {
case PI433_IOC_RD_TX_CFG:
if (copy_to_user(argp, &instance->tx_cfg,
sizeof(struct pi433_tx_cfg)))
return -EFAULT;
break;
case PI433_IOC_WR_TX_CFG:
if (copy_from_user(&instance->tx_cfg, argp,
sizeof(struct pi433_tx_cfg)))
return -EFAULT;
break;
case PI433_IOC_RD_RX_CFG:
if (copy_to_user(argp, &device->rx_cfg,
sizeof(struct pi433_rx_cfg)))
return -EFAULT;
break;
case PI433_IOC_WR_RX_CFG:
mutex_lock(&device->rx_lock);
/* during pendig read request, change of config not allowed */
if (device->rx_active) {
mutex_unlock(&device->rx_lock);
return -EAGAIN;
}
if (copy_from_user(&device->rx_cfg, argp,
sizeof(struct pi433_rx_cfg))) {
mutex_unlock(&device->rx_lock);
return -EFAULT;
}
mutex_unlock(&device->rx_lock);
break;
default:
retval = -EINVAL;
}
return retval;
}
#ifdef CONFIG_COMPAT
static long
pi433_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
return pi433_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
}
#else
#define pi433_compat_ioctl NULL
#endif /* CONFIG_COMPAT */
/*-------------------------------------------------------------------------*/
static int pi433_open(struct inode *inode, struct file *filp)
{
struct pi433_device *device;
struct pi433_instance *instance;
mutex_lock(&minor_lock);
device = idr_find(&pi433_idr, iminor(inode));
mutex_unlock(&minor_lock);
if (!device) {
pr_debug("device: minor %d unknown.\n", iminor(inode));
return -ENODEV;
}
if (!device->rx_buffer) {
device->rx_buffer = kmalloc(MAX_MSG_SIZE, GFP_KERNEL);
if (!device->rx_buffer) {
dev_dbg(device->dev, "open/ENOMEM\n");
return -ENOMEM;
}
}
device->users++;
instance = kzalloc(sizeof(*instance), GFP_KERNEL);
if (!instance) {
kfree(device->rx_buffer);
device->rx_buffer = NULL;
return -ENOMEM;
}
/* setup instance data*/
instance->device = device;
instance->tx_cfg.bit_rate = 4711;
// TODO: fill instance->tx_cfg;
/* instance data as context */
filp->private_data = instance;
nonseekable_open(inode, filp);
return 0;
}
static int pi433_release(struct inode *inode, struct file *filp)
{
struct pi433_instance *instance;
struct pi433_device *device;
instance = filp->private_data;
device = instance->device;
kfree(instance);
filp->private_data = NULL;
/* last close? */
device->users--;
if (!device->users) {
kfree(device->rx_buffer);
device->rx_buffer = NULL;
if (device->spi == NULL)
kfree(device);
}
return 0;
}
/*-------------------------------------------------------------------------*/
static int setup_GPIOs(struct pi433_device *device)
{
char name[5];
int retval;
int i;
const irq_handler_t DIO_irq_handler[NUM_DIO] = {
DIO0_irq_handler,
DIO1_irq_handler
};
for (i = 0; i < NUM_DIO; i++) {
/* "construct" name and get the gpio descriptor */
snprintf(name, sizeof(name), "DIO%d", i);
device->gpiod[i] = gpiod_get(&device->spi->dev, name, 0 /*GPIOD_IN*/);
if (device->gpiod[i] == ERR_PTR(-ENOENT)) {
dev_dbg(&device->spi->dev, "Could not find entry for %s. Ignoring.", name);
continue;
}
if (device->gpiod[i] == ERR_PTR(-EBUSY))
dev_dbg(&device->spi->dev, "%s is busy.", name);
if (IS_ERR(device->gpiod[i])) {
retval = PTR_ERR(device->gpiod[i]);
/* release already allocated gpios */
for (i--; i >= 0; i--) {
free_irq(device->irq_num[i], device);
gpiod_put(device->gpiod[i]);
}
return retval;
}
/* configure the pin */
gpiod_unexport(device->gpiod[i]);
retval = gpiod_direction_input(device->gpiod[i]);
if (retval)
return retval;
/* configure irq */
device->irq_num[i] = gpiod_to_irq(device->gpiod[i]);
if (device->irq_num[i] < 0) {
device->gpiod[i] = ERR_PTR(-EINVAL);//(struct gpio_desc *)device->irq_num[i];
return device->irq_num[i];
}
retval = request_irq(device->irq_num[i],
DIO_irq_handler[i],
0, /* flags */
name,
device);
if (retval)
return retval;
dev_dbg(&device->spi->dev, "%s successfully configured", name);
}
return 0;
}
static void free_GPIOs(struct pi433_device *device)
{
int i;
for (i = 0; i < NUM_DIO; i++) {
/* check if gpiod is valid */
if (IS_ERR(device->gpiod[i]))
continue;
free_irq(device->irq_num[i], device);
gpiod_put(device->gpiod[i]);
}
return;
}
static int pi433_get_minor(struct pi433_device *device)
{
int retval = -ENOMEM;
mutex_lock(&minor_lock);
retval = idr_alloc(&pi433_idr, device, 0, N_PI433_MINORS, GFP_KERNEL);
if (retval >= 0) {
device->minor = retval;
retval = 0;
} else if (retval == -ENOSPC) {
dev_err(&device->spi->dev, "too many pi433 devices\n");
retval = -EINVAL;
}
mutex_unlock(&minor_lock);
return retval;
}
static void pi433_free_minor(struct pi433_device *dev)
{
mutex_lock(&minor_lock);
idr_remove(&pi433_idr, dev->minor);
mutex_unlock(&minor_lock);
}
/*-------------------------------------------------------------------------*/
static const struct file_operations pi433_fops = {
.owner = THIS_MODULE,
/* REVISIT switch to aio primitives, so that userspace
* gets more complete API coverage. It'll simplify things
* too, except for the locking.
*/
.write = pi433_write,
.read = pi433_read,
.unlocked_ioctl = pi433_ioctl,
.compat_ioctl = pi433_compat_ioctl,
.open = pi433_open,
.release = pi433_release,
.llseek = no_llseek,
};
/*-------------------------------------------------------------------------*/
static int pi433_probe(struct spi_device *spi)
{
struct pi433_device *device;
int retval;
/* setup spi parameters */
spi->mode = 0x00;
spi->bits_per_word = 8;
/* spi->max_speed_hz = 10000000; 1MHz already set by device tree overlay */
retval = spi_setup(spi);
if (retval) {
dev_dbg(&spi->dev, "configuration of SPI interface failed!\n");
return retval;
} else {
dev_dbg(&spi->dev,
"spi interface setup: mode 0x%2x, %d bits per word, %dhz max speed",
spi->mode, spi->bits_per_word, spi->max_speed_hz);
}
/* Ping the chip by reading the version register */
retval = spi_w8r8(spi, 0x10);
if (retval < 0)
return retval;
switch (retval) {
case 0x24:
dev_dbg(&spi->dev, "found pi433 (ver. 0x%x)", retval);
break;
default:
dev_dbg(&spi->dev, "unknown chip version: 0x%x", retval);
return -ENODEV;
}
/* Allocate driver data */
device = kzalloc(sizeof(*device), GFP_KERNEL);
if (!device)
return -ENOMEM;
/* Initialize the driver data */
device->spi = spi;
device->rx_active = false;
device->tx_active = false;
device->interrupt_rx_allowed = false;
/* init wait queues */
init_waitqueue_head(&device->tx_wait_queue);
init_waitqueue_head(&device->rx_wait_queue);
init_waitqueue_head(&device->fifo_wait_queue);
/* init fifo */
INIT_KFIFO(device->tx_fifo);
/* init mutexes and locks */
mutex_init(&device->tx_fifo_lock);
mutex_init(&device->rx_lock);
/* setup GPIO (including irq_handler) for the different DIOs */
retval = setup_GPIOs(device);
if (retval) {
dev_dbg(&spi->dev, "setup of GPIOs failed");
goto GPIO_failed;
}
/* setup the radio module */
retval = rf69_set_mode(spi, standby);
if (retval < 0)
goto minor_failed;
retval = rf69_set_data_mode(spi, DATAMODUL_MODE_PACKET);
if (retval < 0)
goto minor_failed;
retval = rf69_enable_amplifier(spi, MASK_PALEVEL_PA0);
if (retval < 0)
goto minor_failed;
retval = rf69_disable_amplifier(spi, MASK_PALEVEL_PA1);
if (retval < 0)
goto minor_failed;
retval = rf69_disable_amplifier(spi, MASK_PALEVEL_PA2);
if (retval < 0)
goto minor_failed;
retval = rf69_set_output_power_level(spi, 13);
if (retval < 0)
goto minor_failed;
retval = rf69_set_antenna_impedance(spi, fiftyOhm);
if (retval < 0)
goto minor_failed;
/* determ minor number */
retval = pi433_get_minor(device);
if (retval) {
dev_dbg(&spi->dev, "get of minor number failed");
goto minor_failed;
}
/* create device */
device->devt = MKDEV(MAJOR(pi433_dev), device->minor);
device->dev = device_create(pi433_class,
&spi->dev,
device->devt,
device,
"pi433.%d",
device->minor);
if (IS_ERR(device->dev)) {
pr_err("pi433: device register failed\n");
retval = PTR_ERR(device->dev);
goto device_create_failed;
} else {
dev_dbg(device->dev,
"created device for major %d, minor %d\n",
MAJOR(pi433_dev),
device->minor);
}
/* start tx thread */
device->tx_task_struct = kthread_run(pi433_tx_thread,
device,
"pi433.%d_tx_task",
device->minor);
if (IS_ERR(device->tx_task_struct)) {
dev_dbg(device->dev, "start of send thread failed");
goto send_thread_failed;
}
/* create cdev */
device->cdev = cdev_alloc();
device->cdev->owner = THIS_MODULE;
cdev_init(device->cdev, &pi433_fops);
retval = cdev_add(device->cdev, device->devt, 1);
if (retval) {
dev_dbg(device->dev, "register of cdev failed");
goto cdev_failed;
}
/* spi setup */
spi_set_drvdata(spi, device);
return 0;
cdev_failed:
kthread_stop(device->tx_task_struct);
send_thread_failed:
device_destroy(pi433_class, device->devt);
device_create_failed:
pi433_free_minor(device);
minor_failed:
free_GPIOs(device);
GPIO_failed:
kfree(device);
return retval;
}
static int pi433_remove(struct spi_device *spi)
{
struct pi433_device *device = spi_get_drvdata(spi);
/* free GPIOs */
free_GPIOs(device);
/* make sure ops on existing fds can abort cleanly */
device->spi = NULL;
kthread_stop(device->tx_task_struct);
device_destroy(pi433_class, device->devt);
cdev_del(device->cdev);
pi433_free_minor(device);
if (device->users == 0)
kfree(device);
return 0;
}
static const struct of_device_id pi433_dt_ids[] = {
{ .compatible = "Smarthome-Wolf,pi433" },
{},
};
MODULE_DEVICE_TABLE(of, pi433_dt_ids);
static struct spi_driver pi433_spi_driver = {
.driver = {
.name = "pi433",
.owner = THIS_MODULE,
.of_match_table = of_match_ptr(pi433_dt_ids),
},
.probe = pi433_probe,
.remove = pi433_remove,
/* NOTE: suspend/resume methods are not necessary here.
* We don't do anything except pass the requests to/from
* the underlying controller. The refrigerator handles
* most issues; the controller driver handles the rest.
*/
};
/*-------------------------------------------------------------------------*/
static int __init pi433_init(void)
{
int status;
/* If MAX_MSG_SIZE is smaller then FIFO_SIZE, the driver won't
* work stable - risk of buffer overflow
*/
if (MAX_MSG_SIZE < FIFO_SIZE)
return -EINVAL;
/* Claim device numbers. Then register a class
* that will key udev/mdev to add/remove /dev nodes. Last, register
* Last, register the driver which manages those device numbers.
*/
status = alloc_chrdev_region(&pi433_dev, 0 /*firstminor*/, N_PI433_MINORS /*count*/, "pi433" /*name*/);
if (status < 0)
return status;
pi433_class = class_create(THIS_MODULE, "pi433");
if (IS_ERR(pi433_class)) {
unregister_chrdev(MAJOR(pi433_dev),
pi433_spi_driver.driver.name);
return PTR_ERR(pi433_class);
}
status = spi_register_driver(&pi433_spi_driver);
if (status < 0) {
class_destroy(pi433_class);
unregister_chrdev(MAJOR(pi433_dev),
pi433_spi_driver.driver.name);
}
return status;
}
module_init(pi433_init);
static void __exit pi433_exit(void)
{
spi_unregister_driver(&pi433_spi_driver);
class_destroy(pi433_class);
unregister_chrdev(MAJOR(pi433_dev), pi433_spi_driver.driver.name);
}
module_exit(pi433_exit);
MODULE_AUTHOR("Marcus Wolf, <linux@wolf-entwicklungen.de>");
MODULE_DESCRIPTION("Driver for Pi433");
MODULE_LICENSE("GPL");
MODULE_ALIAS("spi:pi433");
|