aboutsummaryrefslogtreecommitdiff
path: root/drivers/media/rc/redrat3.c
blob: 0042367b060cc5b5cf578f1691ce43248a2a4747 (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
/*
 * USB RedRat3 IR Transceiver rc-core driver
 *
 * Copyright (c) 2011 by Jarod Wilson <jarod@redhat.com>
 *  based heavily on the work of Stephen Cox, with additional
 *  help from RedRat Ltd.
 *
 * This driver began life based an an old version of the first-generation
 * lirc_mceusb driver from the lirc 0.7.2 distribution. It was then
 * significantly rewritten by Stephen Cox with the aid of RedRat Ltd's
 * Chris Dodge.
 *
 * The driver was then ported to rc-core and significantly rewritten again,
 * by Jarod, using the in-kernel mceusb driver as a guide, after an initial
 * port effort was started by Stephen.
 *
 * TODO LIST:
 * - fix lirc not showing repeats properly
 * --
 *
 * The RedRat3 is a USB transceiver with both send & receive,
 * with 2 separate sensors available for receive to enable
 * both good long range reception for general use, and good
 * short range reception when required for learning a signal.
 *
 * http://www.redrat.co.uk/
 *
 * It uses its own little protocol to communicate, the required
 * parts of which are embedded within this driver.
 * --
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 */

#include <asm/unaligned.h>
#include <linux/device.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/usb.h>
#include <linux/usb/input.h>
#include <media/rc-core.h>

/* Driver Information */
#define DRIVER_AUTHOR "Jarod Wilson <jarod@redhat.com>"
#define DRIVER_AUTHOR2 "The Dweller, Stephen Cox"
#define DRIVER_DESC "RedRat3 USB IR Transceiver Driver"
#define DRIVER_NAME "redrat3"

/* module parameters */
#ifdef CONFIG_USB_DEBUG
static int debug = 1;
#else
static int debug;
#endif

#define RR3_DEBUG_STANDARD		0x1
#define RR3_DEBUG_FUNCTION_TRACE	0x2

#define rr3_dbg(dev, fmt, ...)					\
	do {							\
		if (debug & RR3_DEBUG_STANDARD)			\
			dev_info(dev, fmt, ## __VA_ARGS__);	\
	} while (0)

#define rr3_ftr(dev, fmt, ...)					\
	do {							\
		if (debug & RR3_DEBUG_FUNCTION_TRACE)		\
			dev_info(dev, fmt, ## __VA_ARGS__);	\
	} while (0)

/* bulk data transfer types */
#define RR3_ERROR		0x01
#define RR3_MOD_SIGNAL_IN	0x20
#define RR3_MOD_SIGNAL_OUT	0x21

/* Get the RR firmware version */
#define RR3_FW_VERSION		0xb1
#define RR3_FW_VERSION_LEN	64
/* Send encoded signal bulk-sent earlier*/
#define RR3_TX_SEND_SIGNAL	0xb3
#define RR3_SET_IR_PARAM	0xb7
#define RR3_GET_IR_PARAM	0xb8
/* Blink the red LED on the device */
#define RR3_BLINK_LED		0xb9
/* Read serial number of device */
#define RR3_READ_SER_NO		0xba
#define RR3_SER_NO_LEN		4
/* Start capture with the RC receiver */
#define RR3_RC_DET_ENABLE	0xbb
/* Stop capture with the RC receiver */
#define RR3_RC_DET_DISABLE	0xbc
/* Return the status of RC detector capture */
#define RR3_RC_DET_STATUS	0xbd
/* Reset redrat */
#define RR3_RESET		0xa0

/* Max number of lengths in the signal. */
#define RR3_IR_IO_MAX_LENGTHS	0x01
/* Periods to measure mod. freq. */
#define RR3_IR_IO_PERIODS_MF	0x02
/* Size of memory for main signal data */
#define RR3_IR_IO_SIG_MEM_SIZE	0x03
/* Delta value when measuring lengths */
#define RR3_IR_IO_LENGTH_FUZZ	0x04
/* Timeout for end of signal detection */
#define RR3_IR_IO_SIG_TIMEOUT	0x05
/* Minumum value for pause recognition. */
#define RR3_IR_IO_MIN_PAUSE	0x06

/* Clock freq. of EZ-USB chip */
#define RR3_CLK			24000000
/* Clock periods per timer count */
#define RR3_CLK_PER_COUNT	12
/* (RR3_CLK / RR3_CLK_PER_COUNT) */
#define RR3_CLK_CONV_FACTOR	2000000
/* USB bulk-in IR data endpoint address */
#define RR3_BULK_IN_EP_ADDR	0x82

/* Size of the fixed-length portion of the signal */
#define RR3_DRIVER_MAXLENS	128
#define RR3_MAX_SIG_SIZE	512
#define RR3_TIME_UNIT		50
#define RR3_END_OF_SIGNAL	0x7f
#define RR3_TX_TRAILER_LEN	2
#define RR3_RX_MIN_TIMEOUT	5
#define RR3_RX_MAX_TIMEOUT	2000

/* The 8051's CPUCS Register address */
#define RR3_CPUCS_REG_ADDR	0x7f92

#define USB_RR3USB_VENDOR_ID	0x112a
#define USB_RR3USB_PRODUCT_ID	0x0001
#define USB_RR3IIUSB_PRODUCT_ID	0x0005

struct redrat3_header {
	__be16 length;
	__be16 transfer_type;
} __packed;

/* sending and receiving irdata */
struct redrat3_irdata {
	struct redrat3_header header;
	__be32 pause;
	__be16 mod_freq_count;
	__be16 num_periods;
	__u8 max_lengths;
	__u8 no_lengths;
	__be16 max_sig_size;
	__be16 sig_size;
	__u8 no_repeats;
	__be16 lens[RR3_DRIVER_MAXLENS]; /* not aligned */
	__u8 sigdata[RR3_MAX_SIG_SIZE];
} __packed;

/* firmware errors */
struct redrat3_error {
	struct redrat3_header header;
	__be16 fw_error;
} __packed;

/* table of devices that work with this driver */
static struct usb_device_id redrat3_dev_table[] = {
	/* Original version of the RedRat3 */
	{USB_DEVICE(USB_RR3USB_VENDOR_ID, USB_RR3USB_PRODUCT_ID)},
	/* Second Version/release of the RedRat3 - RetRat3-II */
	{USB_DEVICE(USB_RR3USB_VENDOR_ID, USB_RR3IIUSB_PRODUCT_ID)},
	{}			/* Terminating entry */
};

/* Structure to hold all of our device specific stuff */
struct redrat3_dev {
	/* core device bits */
	struct rc_dev *rc;
	struct device *dev;

	/* save off the usb device pointer */
	struct usb_device *udev;

	/* the receive endpoint */
	struct usb_endpoint_descriptor *ep_in;
	/* the buffer to receive data */
	void *bulk_in_buf;
	/* urb used to read ir data */
	struct urb *read_urb;

	/* the send endpoint */
	struct usb_endpoint_descriptor *ep_out;

	/* usb dma */
	dma_addr_t dma_in;

	/* rx signal timeout timer */
	struct timer_list rx_timeout;
	u32 hw_timeout;

	/* Is the device currently transmitting?*/
	bool transmitting;

	/* store for current packet */
	struct redrat3_irdata irdata;
	u16 bytes_read;

	u32 carrier;

	char name[64];
	char phys[64];
};

/*
 * redrat3_issue_async
 *
 *  Issues an async read to the ir data in port..
 *  sets the callback to be redrat3_handle_async
 */
static void redrat3_issue_async(struct redrat3_dev *rr3)
{
	int res;

	rr3_ftr(rr3->dev, "Entering %s\n", __func__);

	res = usb_submit_urb(rr3->read_urb, GFP_ATOMIC);
	if (res)
		rr3_dbg(rr3->dev, "%s: receive request FAILED! "
			"(res %d, len %d)\n", __func__, res,
			rr3->read_urb->transfer_buffer_length);
}

static void redrat3_dump_fw_error(struct redrat3_dev *rr3, int code)
{
	if (!rr3->transmitting && (code != 0x40))
		dev_info(rr3->dev, "fw error code 0x%02x: ", code);

	switch (code) {
	case 0x00:
		pr_cont("No Error\n");
		break;

	/* Codes 0x20 through 0x2f are IR Firmware Errors */
	case 0x20:
		pr_cont("Initial signal pulse not long enough "
			"to measure carrier frequency\n");
		break;
	case 0x21:
		pr_cont("Not enough length values allocated for signal\n");
		break;
	case 0x22:
		pr_cont("Not enough memory allocated for signal data\n");
		break;
	case 0x23:
		pr_cont("Too many signal repeats\n");
		break;
	case 0x28:
		pr_cont("Insufficient memory available for IR signal "
			"data memory allocation\n");
		break;
	case 0x29:
		pr_cont("Insufficient memory available "
			"for IrDa signal data memory allocation\n");
		break;

	/* Codes 0x30 through 0x3f are USB Firmware Errors */
	case 0x30:
		pr_cont("Insufficient memory available for bulk "
			"transfer structure\n");
		break;

	/*
	 * Other error codes... These are primarily errors that can occur in
	 * the control messages sent to the redrat
	 */
	case 0x40:
		if (!rr3->transmitting)
			pr_cont("Signal capture has been terminated\n");
		break;
	case 0x41:
		pr_cont("Attempt to set/get and unknown signal I/O "
			"algorithm parameter\n");
		break;
	case 0x42:
		pr_cont("Signal capture already started\n");
		break;

	default:
		pr_cont("Unknown Error\n");
		break;
	}
}

static u32 redrat3_val_to_mod_freq(struct redrat3_irdata *irdata)
{
	u32 mod_freq = 0;
	u16 mod_freq_count = be16_to_cpu(irdata->mod_freq_count);

	if (mod_freq_count != 0)
		mod_freq = (RR3_CLK * be16_to_cpu(irdata->num_periods)) /
			(mod_freq_count * RR3_CLK_PER_COUNT);

	return mod_freq;
}

/* this function scales down the figures for the same result... */
static u32 redrat3_len_to_us(u32 length)
{
	u32 biglen = length * 1000;
	u32 divisor = (RR3_CLK_CONV_FACTOR) / 1000;
	u32 result = (u32) (biglen / divisor);

	/* don't allow zero lengths to go back, breaks lirc */
	return result ? result : 1;
}

/*
 * convert us back into redrat3 lengths
 *
 * length * 1000   length * 1000000
 * ------------- = ---------------- = micro
 * rr3clk / 1000       rr3clk

 * 6 * 2       4 * 3        micro * rr3clk          micro * rr3clk / 1000
 * ----- = 4   ----- = 6    -------------- = len    ---------------------
 *   3           2             1000000                    1000
 */
static u32 redrat3_us_to_len(u32 microsec)
{
	u32 result;
	u32 divisor;

	microsec &= IR_MAX_DURATION;
	divisor = (RR3_CLK_CONV_FACTOR / 1000);
	result = (u32)(microsec * divisor) / 1000;

	/* don't allow zero lengths to go back, breaks lirc */
	return result ? result : 1;
}

/* timer callback to send reset event */
static void redrat3_rx_timeout(unsigned long data)
{
	struct redrat3_dev *rr3 = (struct redrat3_dev *)data;

	rr3_dbg(rr3->dev, "calling ir_raw_event_reset\n");
	ir_raw_event_reset(rr3->rc);
}

static void redrat3_process_ir_data(struct redrat3_dev *rr3)
{
	DEFINE_IR_RAW_EVENT(rawir);
	struct device *dev;
	unsigned i, trailer = 0;
	unsigned sig_size, single_len, offset, val;
	unsigned long delay;
	u32 mod_freq;

	if (!rr3) {
		pr_err("%s called with no context!\n", __func__);
		return;
	}

	rr3_ftr(rr3->dev, "Entered %s\n", __func__);

	dev = rr3->dev;

	/* Make sure we reset the IR kfifo after a bit of inactivity */
	delay = usecs_to_jiffies(rr3->hw_timeout);
	mod_timer(&rr3->rx_timeout, jiffies + delay);

	mod_freq = redrat3_val_to_mod_freq(&rr3->irdata);
	rr3_dbg(dev, "Got mod_freq of %u\n", mod_freq);

	/* process each rr3 encoded byte into an int */
	sig_size = be16_to_cpu(rr3->irdata.sig_size);
	for (i = 0; i < sig_size; i++) {
		offset = rr3->irdata.sigdata[i];
		val = get_unaligned_be16(&rr3->irdata.lens[offset]);
		single_len = redrat3_len_to_us(val);

		/* we should always get pulse/space/pulse/space samples */
		if (i % 2)
			rawir.pulse = false;
		else
			rawir.pulse = true;

		rawir.duration = US_TO_NS(single_len);
		/* Save initial pulse length to fudge trailer */
		if (i == 0)
			trailer = rawir.duration;
		/* cap the value to IR_MAX_DURATION */
		rawir.duration &= IR_MAX_DURATION;

		rr3_dbg(dev, "storing %s with duration %d (i: %d)\n",
			rawir.pulse ? "pulse" : "space", rawir.duration, i);
		ir_raw_event_store_with_filter(rr3->rc, &rawir);
	}

	/* add a trailing space, if need be */
	if (i % 2) {
		rawir.pulse = false;
		/* this duration is made up, and may not be ideal... */
		if (trailer < US_TO_NS(1000))
			rawir.duration = US_TO_NS(2800);
		else
			rawir.duration = trailer;
		rr3_dbg(dev, "storing trailing space with duration %d\n",
			rawir.duration);
		ir_raw_event_store_with_filter(rr3->rc, &rawir);
	}

	rr3_dbg(dev, "calling ir_raw_event_handle\n");
	ir_raw_event_handle(rr3->rc);
}

/* Util fn to send rr3 cmds */
static u8 redrat3_send_cmd(int cmd, struct redrat3_dev *rr3)
{
	struct usb_device *udev;
	u8 *data;
	int res;

	data = kzalloc(sizeof(u8), GFP_KERNEL);
	if (!data)
		return -ENOMEM;

	udev = rr3->udev;
	res = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0), cmd,
			      USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
			      0x0000, 0x0000, data, sizeof(u8), HZ * 10);

	if (res < 0) {
		dev_err(rr3->dev, "%s: Error sending rr3 cmd res %d, data %d",
			__func__, res, *data);
		res = -EIO;
	} else
		res = data[0];

	kfree(data);

	return res;
}

/* Enables the long range detector and starts async receive */
static int redrat3_enable_detector(struct redrat3_dev *rr3)
{
	struct device *dev = rr3->dev;
	u8 ret;

	rr3_ftr(dev, "Entering %s\n", __func__);

	ret = redrat3_send_cmd(RR3_RC_DET_ENABLE, rr3);
	if (ret != 0)
		dev_dbg(dev, "%s: unexpected ret of %d\n",
			__func__, ret);

	ret = redrat3_send_cmd(RR3_RC_DET_STATUS, rr3);
	if (ret != 1) {
		dev_err(dev, "%s: detector status: %d, should be 1\n",
			__func__, ret);
		return -EIO;
	}

	redrat3_issue_async(rr3);

	return 0;
}

static inline void redrat3_delete(struct redrat3_dev *rr3,
				  struct usb_device *udev)
{
	rr3_ftr(rr3->dev, "%s cleaning up\n", __func__);
	usb_kill_urb(rr3->read_urb);

	usb_free_urb(rr3->read_urb);

	usb_free_coherent(udev, le16_to_cpu(rr3->ep_in->wMaxPacketSize),
			  rr3->bulk_in_buf, rr3->dma_in);

	kfree(rr3);
}

static u32 redrat3_get_timeout(struct redrat3_dev *rr3)
{
	__be32 *tmp;
	u32 timeout = MS_TO_US(150); /* a sane default, if things go haywire */
	int len, ret, pipe;

	len = sizeof(*tmp);
	tmp = kzalloc(len, GFP_KERNEL);
	if (!tmp) {
		dev_warn(rr3->dev, "Memory allocation faillure\n");
		return timeout;
	}

	pipe = usb_rcvctrlpipe(rr3->udev, 0);
	ret = usb_control_msg(rr3->udev, pipe, RR3_GET_IR_PARAM,
			      USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
			      RR3_IR_IO_SIG_TIMEOUT, 0, tmp, len, HZ * 5);
	if (ret != len)
		dev_warn(rr3->dev, "Failed to read timeout from hardware\n");
	else {
		timeout = redrat3_len_to_us(be32_to_cpup(tmp));

		rr3_dbg(rr3->dev, "Got timeout of %d ms\n", timeout / 1000);
	}

	kfree(tmp);

	return timeout;
}

static void redrat3_reset(struct redrat3_dev *rr3)
{
	struct usb_device *udev = rr3->udev;
	struct device *dev = rr3->dev;
	int rc, rxpipe, txpipe;
	u8 *val;
	int len = sizeof(u8);

	rr3_ftr(dev, "Entering %s\n", __func__);

	rxpipe = usb_rcvctrlpipe(udev, 0);
	txpipe = usb_sndctrlpipe(udev, 0);

	val = kmalloc(len, GFP_KERNEL);
	if (!val) {
		dev_err(dev, "Memory allocation failure\n");
		return;
	}

	*val = 0x01;
	rc = usb_control_msg(udev, rxpipe, RR3_RESET,
			     USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
			     RR3_CPUCS_REG_ADDR, 0, val, len, HZ * 25);
	rr3_dbg(dev, "reset returned 0x%02x\n", rc);

	*val = 5;
	rc = usb_control_msg(udev, txpipe, RR3_SET_IR_PARAM,
			     USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
			     RR3_IR_IO_LENGTH_FUZZ, 0, val, len, HZ * 25);
	rr3_dbg(dev, "set ir parm len fuzz %d rc 0x%02x\n", *val, rc);

	*val = RR3_DRIVER_MAXLENS;
	rc = usb_control_msg(udev, txpipe, RR3_SET_IR_PARAM,
			     USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
			     RR3_IR_IO_MAX_LENGTHS, 0, val, len, HZ * 25);
	rr3_dbg(dev, "set ir parm max lens %d rc 0x%02x\n", *val, rc);

	kfree(val);
}

static void redrat3_get_firmware_rev(struct redrat3_dev *rr3)
{
	int rc = 0;
	char *buffer;

	rr3_ftr(rr3->dev, "Entering %s\n", __func__);

	buffer = kzalloc(sizeof(char) * (RR3_FW_VERSION_LEN + 1), GFP_KERNEL);
	if (!buffer) {
		dev_err(rr3->dev, "Memory allocation failure\n");
		return;
	}

	rc = usb_control_msg(rr3->udev, usb_rcvctrlpipe(rr3->udev, 0),
			     RR3_FW_VERSION,
			     USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
			     0, 0, buffer, RR3_FW_VERSION_LEN, HZ * 5);

	if (rc >= 0)
		dev_info(rr3->dev, "Firmware rev: %s", buffer);
	else
		dev_err(rr3->dev, "Problem fetching firmware ID\n");

	kfree(buffer);
	rr3_ftr(rr3->dev, "Exiting %s\n", __func__);
}

static void redrat3_read_packet_start(struct redrat3_dev *rr3, unsigned len)
{
	struct redrat3_header *header = rr3->bulk_in_buf;
	unsigned pktlen, pkttype;

	rr3_ftr(rr3->dev, "Entering %s\n", __func__);

	/* grab the Length and type of transfer */
	pktlen = be16_to_cpu(header->length);
	pkttype = be16_to_cpu(header->transfer_type);

	if (pktlen > sizeof(rr3->irdata)) {
		dev_warn(rr3->dev, "packet length %u too large\n", pktlen);
		return;
	}

	switch (pkttype) {
	case RR3_ERROR:
		if (len >= sizeof(struct redrat3_error)) {
			struct redrat3_error *error = rr3->bulk_in_buf;
			unsigned fw_error = be16_to_cpu(error->fw_error);
			redrat3_dump_fw_error(rr3, fw_error);
		}
		break;

	case RR3_MOD_SIGNAL_IN:
		memcpy(&rr3->irdata, rr3->bulk_in_buf, len);
		rr3->bytes_read = len;
		rr3_dbg(rr3->dev, "bytes_read %d, pktlen %d\n",
			rr3->bytes_read, pktlen);
		break;

	default:
		rr3_dbg(rr3->dev, "ignoring packet with type 0x%02x, len of %d, 0x%02x\n",
						pkttype, len, pktlen);
		break;
	}
}

static void redrat3_read_packet_continue(struct redrat3_dev *rr3, unsigned len)
{
	void *irdata = &rr3->irdata;

	rr3_ftr(rr3->dev, "Entering %s\n", __func__);

	if (len + rr3->bytes_read > sizeof(rr3->irdata)) {
		dev_warn(rr3->dev, "too much data for packet\n");
		rr3->bytes_read = 0;
		return;
	}

	memcpy(irdata + rr3->bytes_read, rr3->bulk_in_buf, len);

	rr3->bytes_read += len;
	rr3_dbg(rr3->dev, "bytes_read %d, pktlen %d\n", rr3->bytes_read,
				 be16_to_cpu(rr3->irdata.header.length));
}

/* gather IR data from incoming urb, process it when we have enough */
static int redrat3_get_ir_data(struct redrat3_dev *rr3, unsigned len)
{
	struct device *dev = rr3->dev;
	unsigned pkttype;
	int ret = 0;

	rr3_ftr(dev, "Entering %s\n", __func__);

	if (rr3->bytes_read == 0 && len >= sizeof(struct redrat3_header)) {
		redrat3_read_packet_start(rr3, len);
	} else if (rr3->bytes_read != 0) {
		redrat3_read_packet_continue(rr3, len);
	} else if (rr3->bytes_read == 0) {
		dev_err(dev, "error: no packet data read\n");
		ret = -ENODATA;
		goto out;
	}

	if (rr3->bytes_read < be16_to_cpu(rr3->irdata.header.length))
		/* we're still accumulating data */
		return 0;

	/* if we get here, we've got IR data to decode */
	pkttype = be16_to_cpu(rr3->irdata.header.transfer_type);
	if (pkttype == RR3_MOD_SIGNAL_IN)
		redrat3_process_ir_data(rr3);
	else
		rr3_dbg(dev, "discarding non-signal data packet (type 0x%02x)\n",
								pkttype);

out:
	rr3->bytes_read = 0;
	return ret;
}

/* callback function from USB when async USB request has completed */
static void redrat3_handle_async(struct urb *urb)
{
	struct redrat3_dev *rr3;
	int ret;

	if (!urb)
		return;

	rr3 = urb->context;
	if (!rr3) {
		pr_err("%s called with invalid context!\n", __func__);
		usb_unlink_urb(urb);
		return;
	}

	rr3_ftr(rr3->dev, "Entering %s\n", __func__);

	switch (urb->status) {
	case 0:
		ret = redrat3_get_ir_data(rr3, urb->actual_length);
		if (!ret) {
			/* no error, prepare to read more */
			redrat3_issue_async(rr3);
		}
		break;

	case -ECONNRESET:
	case -ENOENT:
	case -ESHUTDOWN:
		usb_unlink_urb(urb);
		return;

	case -EPIPE:
	default:
		dev_warn(rr3->dev, "Error: urb status = %d\n", urb->status);
		rr3->bytes_read = 0;
		break;
	}
}

static u16 mod_freq_to_val(unsigned int mod_freq)
{
	int mult = 6000000;

	/* Clk used in mod. freq. generation is CLK24/4. */
	return 65536 - (mult / mod_freq);
}

static int redrat3_set_tx_carrier(struct rc_dev *rcdev, u32 carrier)
{
	struct redrat3_dev *rr3 = rcdev->priv;
	struct device *dev = rr3->dev;

	rr3_dbg(dev, "Setting modulation frequency to %u", carrier);
	if (carrier == 0)
		return -EINVAL;

	rr3->carrier = carrier;

	return carrier;
}

static int redrat3_transmit_ir(struct rc_dev *rcdev, unsigned *txbuf,
				unsigned count)
{
	struct redrat3_dev *rr3 = rcdev->priv;
	struct device *dev = rr3->dev;
	struct redrat3_irdata *irdata = NULL;
	int ret, ret_len;
	int lencheck, cur_sample_len, pipe;
	int *sample_lens = NULL;
	u8 curlencheck = 0;
	unsigned i, sendbuf_len;

	rr3_ftr(dev, "Entering %s\n", __func__);

	if (rr3->transmitting) {
		dev_warn(dev, "%s: transmitter already in use\n", __func__);
		return -EAGAIN;
	}

	if (count > RR3_MAX_SIG_SIZE - RR3_TX_TRAILER_LEN)
		return -EINVAL;

	/* rr3 will disable rc detector on transmit */
	rr3->transmitting = true;

	sample_lens = kzalloc(sizeof(int) * RR3_DRIVER_MAXLENS, GFP_KERNEL);
	if (!sample_lens) {
		ret = -ENOMEM;
		goto out;
	}

	irdata = kzalloc(sizeof(*irdata), GFP_KERNEL);
	if (!irdata) {
		ret = -ENOMEM;
		goto out;
	}

	for (i = 0; i < count; i++) {
		cur_sample_len = redrat3_us_to_len(txbuf[i]);
		if (cur_sample_len > 0xffff) {
			dev_warn(dev, "transmit period of %uus truncated to %uus\n",
					txbuf[i], redrat3_len_to_us(0xffff));
			cur_sample_len = 0xffff;
		}
		for (lencheck = 0; lencheck < curlencheck; lencheck++) {
			if (sample_lens[lencheck] == cur_sample_len)
				break;
		}
		if (lencheck == curlencheck) {
			rr3_dbg(dev, "txbuf[%d]=%u, pos %d, enc %u\n",
				i, txbuf[i], curlencheck, cur_sample_len);
			if (curlencheck < RR3_DRIVER_MAXLENS) {
				/* now convert the value to a proper
				 * rr3 value.. */
				sample_lens[curlencheck] = cur_sample_len;
				put_unaligned_be16(cur_sample_len,
						&irdata->lens[curlencheck]);
				curlencheck++;
			} else {
				ret = -EINVAL;
				goto out;
			}
		}
		irdata->sigdata[i] = lencheck;
	}

	irdata->sigdata[count] = RR3_END_OF_SIGNAL;
	irdata->sigdata[count + 1] = RR3_END_OF_SIGNAL;

	sendbuf_len = offsetof(struct redrat3_irdata,
					sigdata[count + RR3_TX_TRAILER_LEN]);
	/* fill in our packet header */
	irdata->header.length = cpu_to_be16(sendbuf_len -
						sizeof(struct redrat3_header));
	irdata->header.transfer_type = cpu_to_be16(RR3_MOD_SIGNAL_OUT);
	irdata->pause = cpu_to_be32(redrat3_len_to_us(100));
	irdata->mod_freq_count = cpu_to_be16(mod_freq_to_val(rr3->carrier));
	irdata->no_lengths = curlencheck;
	irdata->sig_size = cpu_to_be16(count + RR3_TX_TRAILER_LEN);

	pipe = usb_sndbulkpipe(rr3->udev, rr3->ep_out->bEndpointAddress);
	ret = usb_bulk_msg(rr3->udev, pipe, irdata,
			    sendbuf_len, &ret_len, 10 * HZ);
	rr3_dbg(dev, "sent %d bytes, (ret %d)\n", ret_len, ret);

	/* now tell the hardware to transmit what we sent it */
	pipe = usb_rcvctrlpipe(rr3->udev, 0);
	ret = usb_control_msg(rr3->udev, pipe, RR3_TX_SEND_SIGNAL,
			      USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
			      0, 0, irdata, 2, HZ * 10);

	if (ret < 0)
		dev_err(dev, "Error: control msg send failed, rc %d\n", ret);
	else
		ret = count;

out:
	kfree(sample_lens);
	kfree(irdata);

	rr3->transmitting = false;
	/* rr3 re-enables rc detector because it was enabled before */

	return ret;
}

static struct rc_dev *redrat3_init_rc_dev(struct redrat3_dev *rr3)
{
	struct device *dev = rr3->dev;
	struct rc_dev *rc;
	int ret = -ENODEV;
	u16 prod = le16_to_cpu(rr3->udev->descriptor.idProduct);

	rc = rc_allocate_device();
	if (!rc) {
		dev_err(dev, "remote input dev allocation failed\n");
		goto out;
	}

	snprintf(rr3->name, sizeof(rr3->name), "RedRat3%s "
		 "Infrared Remote Transceiver (%04x:%04x)",
		 prod == USB_RR3IIUSB_PRODUCT_ID ? "-II" : "",
		 le16_to_cpu(rr3->udev->descriptor.idVendor), prod);

	usb_make_path(rr3->udev, rr3->phys, sizeof(rr3->phys));

	rc->input_name = rr3->name;
	rc->input_phys = rr3->phys;
	usb_to_input_id(rr3->udev, &rc->input_id);
	rc->dev.parent = dev;
	rc->priv = rr3;
	rc->driver_type = RC_DRIVER_IR_RAW;
	rc->allowed_protos = RC_BIT_ALL;
	rc->timeout = US_TO_NS(2750);
	rc->tx_ir = redrat3_transmit_ir;
	rc->s_tx_carrier = redrat3_set_tx_carrier;
	rc->driver_name = DRIVER_NAME;
	rc->rx_resolution = US_TO_NS(2);
	rc->map_name = RC_MAP_HAUPPAUGE;

	ret = rc_register_device(rc);
	if (ret < 0) {
		dev_err(dev, "remote dev registration failed\n");
		goto out;
	}

	return rc;

out:
	rc_free_device(rc);
	return NULL;
}

static int redrat3_dev_probe(struct usb_interface *intf,
			     const struct usb_device_id *id)
{
	struct usb_device *udev = interface_to_usbdev(intf);
	struct device *dev = &intf->dev;
	struct usb_host_interface *uhi;
	struct redrat3_dev *rr3;
	struct usb_endpoint_descriptor *ep;
	struct usb_endpoint_descriptor *ep_in = NULL;
	struct usb_endpoint_descriptor *ep_out = NULL;
	u8 addr, attrs;
	int pipe, i;
	int retval = -ENOMEM;

	rr3_ftr(dev, "%s called\n", __func__);

	uhi = intf->cur_altsetting;

	/* find our bulk-in and bulk-out endpoints */
	for (i = 0; i < uhi->desc.bNumEndpoints; ++i) {
		ep = &uhi->endpoint[i].desc;
		addr = ep->bEndpointAddress;
		attrs = ep->bmAttributes;

		if ((ep_in == NULL) &&
		    ((addr & USB_ENDPOINT_DIR_MASK) == USB_DIR_IN) &&
		    ((attrs & USB_ENDPOINT_XFERTYPE_MASK) ==
		     USB_ENDPOINT_XFER_BULK)) {
			rr3_dbg(dev, "found bulk-in endpoint at 0x%02x\n",
				ep->bEndpointAddress);
			/* data comes in on 0x82, 0x81 is for other data... */
			if (ep->bEndpointAddress == RR3_BULK_IN_EP_ADDR)
				ep_in = ep;
		}

		if ((ep_out == NULL) &&
		    ((addr & USB_ENDPOINT_DIR_MASK) == USB_DIR_OUT) &&
		    ((attrs & USB_ENDPOINT_XFERTYPE_MASK) ==
		     USB_ENDPOINT_XFER_BULK)) {
			rr3_dbg(dev, "found bulk-out endpoint at 0x%02x\n",
				ep->bEndpointAddress);
			ep_out = ep;
		}
	}

	if (!ep_in || !ep_out) {
		dev_err(dev, "Couldn't find both in and out endpoints\n");
		retval = -ENODEV;
		goto no_endpoints;
	}

	/* allocate memory for our device state and initialize it */
	rr3 = kzalloc(sizeof(*rr3), GFP_KERNEL);
	if (rr3 == NULL) {
		dev_err(dev, "Memory allocation failure\n");
		goto no_endpoints;
	}

	rr3->dev = &intf->dev;

	/* set up bulk-in endpoint */
	rr3->read_urb = usb_alloc_urb(0, GFP_KERNEL);
	if (!rr3->read_urb) {
		dev_err(dev, "Read urb allocation failure\n");
		goto error;
	}

	rr3->ep_in = ep_in;
	rr3->bulk_in_buf = usb_alloc_coherent(udev,
		le16_to_cpu(ep_in->wMaxPacketSize), GFP_ATOMIC, &rr3->dma_in);
	if (!rr3->bulk_in_buf) {
		dev_err(dev, "Read buffer allocation failure\n");
		goto error;
	}

	pipe = usb_rcvbulkpipe(udev, ep_in->bEndpointAddress);
	usb_fill_bulk_urb(rr3->read_urb, udev, pipe, rr3->bulk_in_buf,
		le16_to_cpu(ep_in->wMaxPacketSize), redrat3_handle_async, rr3);

	rr3->ep_out = ep_out;
	rr3->udev = udev;

	redrat3_reset(rr3);
	redrat3_get_firmware_rev(rr3);

	/* might be all we need to do? */
	retval = redrat3_enable_detector(rr3);
	if (retval < 0)
		goto error;

	/* store current hardware timeout, in us, will use for kfifo resets */
	rr3->hw_timeout = redrat3_get_timeout(rr3);

	/* default.. will get overridden by any sends with a freq defined */
	rr3->carrier = 38000;

	rr3->rc = redrat3_init_rc_dev(rr3);
	if (!rr3->rc) {
		retval = -ENOMEM;
		goto error;
	}
	setup_timer(&rr3->rx_timeout, redrat3_rx_timeout, (unsigned long)rr3);

	/* we can register the device now, as it is ready */
	usb_set_intfdata(intf, rr3);

	rr3_ftr(dev, "Exiting %s\n", __func__);
	return 0;

error:
	redrat3_delete(rr3, rr3->udev);

no_endpoints:
	dev_err(dev, "%s: retval = %x", __func__, retval);

	return retval;
}

static void redrat3_dev_disconnect(struct usb_interface *intf)
{
	struct usb_device *udev = interface_to_usbdev(intf);
	struct redrat3_dev *rr3 = usb_get_intfdata(intf);

	rr3_ftr(&intf->dev, "Entering %s\n", __func__);

	if (!rr3)
		return;

	usb_set_intfdata(intf, NULL);
	rc_unregister_device(rr3->rc);
	del_timer_sync(&rr3->rx_timeout);
	redrat3_delete(rr3, udev);

	rr3_ftr(&intf->dev, "RedRat3 IR Transceiver now disconnected\n");
}

static int redrat3_dev_suspend(struct usb_interface *intf, pm_message_t message)
{
	struct redrat3_dev *rr3 = usb_get_intfdata(intf);
	rr3_ftr(rr3->dev, "suspend\n");
	usb_kill_urb(rr3->read_urb);
	return 0;
}

static int redrat3_dev_resume(struct usb_interface *intf)
{
	struct redrat3_dev *rr3 = usb_get_intfdata(intf);
	rr3_ftr(rr3->dev, "resume\n");
	if (usb_submit_urb(rr3->read_urb, GFP_ATOMIC))
		return -EIO;
	return 0;
}

static struct usb_driver redrat3_dev_driver = {
	.name		= DRIVER_NAME,
	.probe		= redrat3_dev_probe,
	.disconnect	= redrat3_dev_disconnect,
	.suspend	= redrat3_dev_suspend,
	.resume		= redrat3_dev_resume,
	.reset_resume	= redrat3_dev_resume,
	.id_table	= redrat3_dev_table
};

module_usb_driver(redrat3_dev_driver);

MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_AUTHOR(DRIVER_AUTHOR2);
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(usb, redrat3_dev_table);

module_param(debug, int, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(debug, "Enable module debug spew. 0 = no debugging (default) "
		 "0x1 = standard debug messages, 0x2 = function tracing debug. "
		 "Flag bits are addative (i.e., 0x3 for both debug types).");