aboutsummaryrefslogtreecommitdiff
path: root/drivers/input/mouse/bcm5974.c
blob: da280189ef07c573e0a2aa05971eb3f8bbba7f64 (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
/*
 * Apple USB BCM5974 (Macbook Air and Penryn Macbook Pro) multitouch driver
 *
 * Copyright (C) 2008	   Henrik Rydberg (rydberg@euromail.se)
 *
 * The USB initialization and package decoding was made by
 * Scott Shawcroft as part of the touchd user-space driver project:
 * Copyright (C) 2008	   Scott Shawcroft (scott.shawcroft@gmail.com)
 *
 * The BCM5974 driver is based on the appletouch driver:
 * Copyright (C) 2001-2004 Greg Kroah-Hartman (greg@kroah.com)
 * Copyright (C) 2005      Johannes Berg (johannes@sipsolutions.net)
 * Copyright (C) 2005	   Stelian Pop (stelian@popies.net)
 * Copyright (C) 2005	   Frank Arnold (frank@scirocco-5v-turbo.de)
 * Copyright (C) 2005	   Peter Osterlund (petero2@telia.com)
 * Copyright (C) 2005	   Michael Hanselmann (linux-kernel@hansmi.ch)
 * Copyright (C) 2006	   Nicolas Boichat (nicolas@boichat.ch)
 *
 * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/usb/input.h>
#include <linux/hid.h>
#include <linux/mutex.h>

#define USB_VENDOR_ID_APPLE		0x05ac

/* MacbookAir, aka wellspring */
#define USB_DEVICE_ID_APPLE_WELLSPRING_ANSI	0x0223
#define USB_DEVICE_ID_APPLE_WELLSPRING_ISO	0x0224
#define USB_DEVICE_ID_APPLE_WELLSPRING_JIS	0x0225
/* MacbookProPenryn, aka wellspring2 */
#define USB_DEVICE_ID_APPLE_WELLSPRING2_ANSI	0x0230
#define USB_DEVICE_ID_APPLE_WELLSPRING2_ISO	0x0231
#define USB_DEVICE_ID_APPLE_WELLSPRING2_JIS	0x0232
/* Macbook5,1 (unibody), aka wellspring3 */
#define USB_DEVICE_ID_APPLE_WELLSPRING3_ANSI	0x0236
#define USB_DEVICE_ID_APPLE_WELLSPRING3_ISO	0x0237
#define USB_DEVICE_ID_APPLE_WELLSPRING3_JIS	0x0238
/* MacbookAir3,2 (unibody), aka wellspring5 */
#define USB_DEVICE_ID_APPLE_WELLSPRING4_ANSI	0x023f
#define USB_DEVICE_ID_APPLE_WELLSPRING4_ISO	0x0240
#define USB_DEVICE_ID_APPLE_WELLSPRING4_JIS	0x0241
/* MacbookAir3,1 (unibody), aka wellspring4 */
#define USB_DEVICE_ID_APPLE_WELLSPRING4A_ANSI	0x0242
#define USB_DEVICE_ID_APPLE_WELLSPRING4A_ISO	0x0243
#define USB_DEVICE_ID_APPLE_WELLSPRING4A_JIS	0x0244
/* Macbook8 (unibody, March 2011) */
#define USB_DEVICE_ID_APPLE_WELLSPRING5_ANSI	0x0245
#define USB_DEVICE_ID_APPLE_WELLSPRING5_ISO	0x0246
#define USB_DEVICE_ID_APPLE_WELLSPRING5_JIS	0x0247
/* MacbookAir4,2 (unibody, July 2011) */
#define USB_DEVICE_ID_APPLE_WELLSPRING6_ANSI	0x024c
#define USB_DEVICE_ID_APPLE_WELLSPRING6_ISO	0x024d
#define USB_DEVICE_ID_APPLE_WELLSPRING6_JIS	0x024e
/* Macbook8,2 (unibody) */
#define USB_DEVICE_ID_APPLE_WELLSPRING5A_ANSI	0x0252
#define USB_DEVICE_ID_APPLE_WELLSPRING5A_ISO	0x0253
#define USB_DEVICE_ID_APPLE_WELLSPRING5A_JIS	0x0254

#define BCM5974_DEVICE(prod) {					\
	.match_flags = (USB_DEVICE_ID_MATCH_DEVICE |		\
			USB_DEVICE_ID_MATCH_INT_CLASS |		\
			USB_DEVICE_ID_MATCH_INT_PROTOCOL),	\
	.idVendor = USB_VENDOR_ID_APPLE,			\
	.idProduct = (prod),					\
	.bInterfaceClass = USB_INTERFACE_CLASS_HID,		\
	.bInterfaceProtocol = USB_INTERFACE_PROTOCOL_MOUSE	\
}

/* table of devices that work with this driver */
static const struct usb_device_id bcm5974_table[] = {
	/* MacbookAir1.1 */
	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING_ANSI),
	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING_ISO),
	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING_JIS),
	/* MacbookProPenryn */
	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING2_ANSI),
	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING2_ISO),
	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING2_JIS),
	/* Macbook5,1 */
	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING3_ANSI),
	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING3_ISO),
	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING3_JIS),
	/* MacbookAir3,2 */
	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING4_ANSI),
	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING4_ISO),
	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING4_JIS),
	/* MacbookAir3,1 */
	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING4A_ANSI),
	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING4A_ISO),
	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING4A_JIS),
	/* MacbookPro8 */
	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING5_ANSI),
	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING5_ISO),
	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING5_JIS),
	/* MacbookAir4,2 */
	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING6_ANSI),
	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING6_ISO),
	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING6_JIS),
	/* MacbookPro8,2 */
	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING5A_ANSI),
	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING5A_ISO),
	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING5A_JIS),
	/* Terminating entry */
	{}
};
MODULE_DEVICE_TABLE(usb, bcm5974_table);

MODULE_AUTHOR("Henrik Rydberg");
MODULE_DESCRIPTION("Apple USB BCM5974 multitouch driver");
MODULE_LICENSE("GPL");

#define dprintk(level, format, a...)\
	{ if (debug >= level) printk(KERN_DEBUG format, ##a); }

static int debug = 1;
module_param(debug, int, 0644);
MODULE_PARM_DESC(debug, "Activate debugging output");

/* button data structure */
struct bt_data {
	u8 unknown1;		/* constant */
	u8 button;		/* left button */
	u8 rel_x;		/* relative x coordinate */
	u8 rel_y;		/* relative y coordinate */
};

/* trackpad header types */
enum tp_type {
	TYPE1,			/* plain trackpad */
	TYPE2			/* button integrated in trackpad */
};

/* trackpad finger data offsets, le16-aligned */
#define FINGER_TYPE1		(13 * sizeof(__le16))
#define FINGER_TYPE2		(15 * sizeof(__le16))

/* trackpad button data offsets */
#define BUTTON_TYPE2		15

/* list of device capability bits */
#define HAS_INTEGRATED_BUTTON	1

/* trackpad finger structure, le16-aligned */
struct tp_finger {
	__le16 origin;		/* zero when switching track finger */
	__le16 abs_x;		/* absolute x coodinate */
	__le16 abs_y;		/* absolute y coodinate */
	__le16 rel_x;		/* relative x coodinate */
	__le16 rel_y;		/* relative y coodinate */
	__le16 size_major;	/* finger size, major axis? */
	__le16 size_minor;	/* finger size, minor axis? */
	__le16 orientation;	/* 16384 when point, else 15 bit angle */
	__le16 force_major;	/* trackpad force, major axis? */
	__le16 force_minor;	/* trackpad force, minor axis? */
	__le16 unused[3];	/* zeros */
	__le16 multi;		/* one finger: varies, more fingers: constant */
} __attribute__((packed,aligned(2)));

/* trackpad finger data size, empirically at least ten fingers */
#define SIZEOF_FINGER		sizeof(struct tp_finger)
#define SIZEOF_ALL_FINGERS	(16 * SIZEOF_FINGER)
#define MAX_FINGER_ORIENTATION	16384

/* device-specific parameters */
struct bcm5974_param {
	int dim;		/* logical dimension */
	int fuzz;		/* logical noise value */
	int devmin;		/* device minimum reading */
	int devmax;		/* device maximum reading */
};

/* device-specific configuration */
struct bcm5974_config {
	int ansi, iso, jis;	/* the product id of this device */
	int caps;		/* device capability bitmask */
	int bt_ep;		/* the endpoint of the button interface */
	int bt_datalen;		/* data length of the button interface */
	int tp_ep;		/* the endpoint of the trackpad interface */
	enum tp_type tp_type;	/* type of trackpad interface */
	int tp_offset;		/* offset to trackpad finger data */
	int tp_datalen;		/* data length of the trackpad interface */
	struct bcm5974_param p;	/* finger pressure limits */
	struct bcm5974_param w;	/* finger width limits */
	struct bcm5974_param x;	/* horizontal limits */
	struct bcm5974_param y;	/* vertical limits */
};

/* logical device structure */
struct bcm5974 {
	char phys[64];
	struct usb_device *udev;	/* usb device */
	struct usb_interface *intf;	/* our interface */
	struct input_dev *input;	/* input dev */
	struct bcm5974_config cfg;	/* device configuration */
	struct mutex pm_mutex;		/* serialize access to open/suspend */
	int opened;			/* 1: opened, 0: closed */
	struct urb *bt_urb;		/* button usb request block */
	struct bt_data *bt_data;	/* button transferred data */
	struct urb *tp_urb;		/* trackpad usb request block */
	u8 *tp_data;			/* trackpad transferred data */
	int fingers;			/* number of fingers on trackpad */
};

/* logical dimensions */
#define DIM_PRESSURE	256		/* maximum finger pressure */
#define DIM_WIDTH	16		/* maximum finger width */
#define DIM_X		1280		/* maximum trackpad x value */
#define DIM_Y		800		/* maximum trackpad y value */

/* logical signal quality */
#define SN_PRESSURE	45		/* pressure signal-to-noise ratio */
#define SN_WIDTH	100		/* width signal-to-noise ratio */
#define SN_COORD	250		/* coordinate signal-to-noise ratio */

/* pressure thresholds */
#define PRESSURE_LOW	(2 * DIM_PRESSURE / SN_PRESSURE)
#define PRESSURE_HIGH	(3 * PRESSURE_LOW)

/* device constants */
static const struct bcm5974_config bcm5974_config_table[] = {
	{
		USB_DEVICE_ID_APPLE_WELLSPRING_ANSI,
		USB_DEVICE_ID_APPLE_WELLSPRING_ISO,
		USB_DEVICE_ID_APPLE_WELLSPRING_JIS,
		0,
		0x84, sizeof(struct bt_data),
		0x81, TYPE1, FINGER_TYPE1, FINGER_TYPE1 + SIZEOF_ALL_FINGERS,
		{ DIM_PRESSURE, DIM_PRESSURE / SN_PRESSURE, 0, 256 },
		{ DIM_WIDTH, DIM_WIDTH / SN_WIDTH, 0, 2048 },
		{ DIM_X, DIM_X / SN_COORD, -4824, 5342 },
		{ DIM_Y, DIM_Y / SN_COORD, -172, 5820 }
	},
	{
		USB_DEVICE_ID_APPLE_WELLSPRING2_ANSI,
		USB_DEVICE_ID_APPLE_WELLSPRING2_ISO,
		USB_DEVICE_ID_APPLE_WELLSPRING2_JIS,
		0,
		0x84, sizeof(struct bt_data),
		0x81, TYPE1, FINGER_TYPE1, FINGER_TYPE1 + SIZEOF_ALL_FINGERS,
		{ DIM_PRESSURE, DIM_PRESSURE / SN_PRESSURE, 0, 256 },
		{ DIM_WIDTH, DIM_WIDTH / SN_WIDTH, 0, 2048 },
		{ DIM_X, DIM_X / SN_COORD, -4824, 4824 },
		{ DIM_Y, DIM_Y / SN_COORD, -172, 4290 }
	},
	{
		USB_DEVICE_ID_APPLE_WELLSPRING3_ANSI,
		USB_DEVICE_ID_APPLE_WELLSPRING3_ISO,
		USB_DEVICE_ID_APPLE_WELLSPRING3_JIS,
		HAS_INTEGRATED_BUTTON,
		0x84, sizeof(struct bt_data),
		0x81, TYPE2, FINGER_TYPE2, FINGER_TYPE2 + SIZEOF_ALL_FINGERS,
		{ DIM_PRESSURE, DIM_PRESSURE / SN_PRESSURE, 0, 300 },
		{ DIM_WIDTH, DIM_WIDTH / SN_WIDTH, 0, 2048 },
		{ DIM_X, DIM_X / SN_COORD, -4460, 5166 },
		{ DIM_Y, DIM_Y / SN_COORD, -75, 6700 }
	},
	{
		USB_DEVICE_ID_APPLE_WELLSPRING4_ANSI,
		USB_DEVICE_ID_APPLE_WELLSPRING4_ISO,
		USB_DEVICE_ID_APPLE_WELLSPRING4_JIS,
		HAS_INTEGRATED_BUTTON,
		0x84, sizeof(struct bt_data),
		0x81, TYPE2, FINGER_TYPE2, FINGER_TYPE2 + SIZEOF_ALL_FINGERS,
		{ DIM_PRESSURE, DIM_PRESSURE / SN_PRESSURE, 0, 300 },
		{ DIM_WIDTH, DIM_WIDTH / SN_WIDTH, 0, 2048 },
		{ DIM_X, DIM_X / SN_COORD, -4620, 5140 },
		{ DIM_Y, DIM_Y / SN_COORD, -150, 6600 }
	},
	{
		USB_DEVICE_ID_APPLE_WELLSPRING4A_ANSI,
		USB_DEVICE_ID_APPLE_WELLSPRING4A_ISO,
		USB_DEVICE_ID_APPLE_WELLSPRING4A_JIS,
		HAS_INTEGRATED_BUTTON,
		0x84, sizeof(struct bt_data),
		0x81, TYPE2, FINGER_TYPE2, FINGER_TYPE2 + SIZEOF_ALL_FINGERS,
		{ DIM_PRESSURE, DIM_PRESSURE / SN_PRESSURE, 0, 300 },
		{ DIM_WIDTH, DIM_WIDTH / SN_WIDTH, 0, 2048 },
		{ DIM_X, DIM_X / SN_COORD, -4616, 5112 },
		{ DIM_Y, DIM_Y / SN_COORD, -142, 5234 }
	},
	{
		USB_DEVICE_ID_APPLE_WELLSPRING5_ANSI,
		USB_DEVICE_ID_APPLE_WELLSPRING5_ISO,
		USB_DEVICE_ID_APPLE_WELLSPRING5_JIS,
		HAS_INTEGRATED_BUTTON,
		0x84, sizeof(struct bt_data),
		0x81, TYPE2, FINGER_TYPE2, FINGER_TYPE2 + SIZEOF_ALL_FINGERS,
		{ DIM_PRESSURE, DIM_PRESSURE / SN_PRESSURE, 0, 300 },
		{ DIM_WIDTH, DIM_WIDTH / SN_WIDTH, 0, 2048 },
		{ DIM_X, DIM_X / SN_COORD, -4415, 5050 },
		{ DIM_Y, DIM_Y / SN_COORD, -55, 6680 }
	},
	{
		USB_DEVICE_ID_APPLE_WELLSPRING6_ANSI,
		USB_DEVICE_ID_APPLE_WELLSPRING6_ISO,
		USB_DEVICE_ID_APPLE_WELLSPRING6_JIS,
		HAS_INTEGRATED_BUTTON,
		0x84, sizeof(struct bt_data),
		0x81, TYPE2, FINGER_TYPE2, FINGER_TYPE2 + SIZEOF_ALL_FINGERS,
		{ DIM_PRESSURE, DIM_PRESSURE / SN_PRESSURE, 0, 300 },
		{ DIM_WIDTH, DIM_WIDTH / SN_WIDTH, 0, 2048 },
		{ DIM_X, DIM_X / SN_COORD, -4620, 5140 },
		{ DIM_Y, DIM_Y / SN_COORD, -150, 6600 }
	},
	{
		USB_DEVICE_ID_APPLE_WELLSPRING5A_ANSI,
		USB_DEVICE_ID_APPLE_WELLSPRING5A_ISO,
		USB_DEVICE_ID_APPLE_WELLSPRING5A_JIS,
		HAS_INTEGRATED_BUTTON,
		0x84, sizeof(struct bt_data),
		0x81, TYPE2, FINGER_TYPE2, FINGER_TYPE2 + SIZEOF_ALL_FINGERS,
		{ DIM_PRESSURE, DIM_PRESSURE / SN_PRESSURE, 0, 300 },
		{ DIM_WIDTH, DIM_WIDTH / SN_WIDTH, 0, 2048 },
		{ DIM_X, DIM_X / SN_COORD, -4750, 5280 },
		{ DIM_Y, DIM_Y / SN_COORD, -150, 6730 }
	},
	{}
};

/* return the device-specific configuration by device */
static const struct bcm5974_config *bcm5974_get_config(struct usb_device *udev)
{
	u16 id = le16_to_cpu(udev->descriptor.idProduct);
	const struct bcm5974_config *cfg;

	for (cfg = bcm5974_config_table; cfg->ansi; ++cfg)
		if (cfg->ansi == id || cfg->iso == id || cfg->jis == id)
			return cfg;

	return bcm5974_config_table;
}

/* convert 16-bit little endian to signed integer */
static inline int raw2int(__le16 x)
{
	return (signed short)le16_to_cpu(x);
}

/* scale device data to logical dimensions (asserts devmin < devmax) */
static inline int int2scale(const struct bcm5974_param *p, int x)
{
	return x * p->dim / (p->devmax - p->devmin);
}

/* all logical value ranges are [0,dim). */
static inline int int2bound(const struct bcm5974_param *p, int x)
{
	int s = int2scale(p, x);

	return clamp_val(s, 0, p->dim - 1);
}

/* setup which logical events to report */
static void setup_events_to_report(struct input_dev *input_dev,
				   const struct bcm5974_config *cfg)
{
	__set_bit(EV_ABS, input_dev->evbit);

	input_set_abs_params(input_dev, ABS_PRESSURE,
				0, cfg->p.dim, cfg->p.fuzz, 0);
	input_set_abs_params(input_dev, ABS_TOOL_WIDTH,
				0, cfg->w.dim, cfg->w.fuzz, 0);
	input_set_abs_params(input_dev, ABS_X,
				0, cfg->x.dim, cfg->x.fuzz, 0);
	input_set_abs_params(input_dev, ABS_Y,
				0, cfg->y.dim, cfg->y.fuzz, 0);

	/* finger touch area */
	input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR,
			     cfg->w.devmin, cfg->w.devmax, 0, 0);
	input_set_abs_params(input_dev, ABS_MT_TOUCH_MINOR,
			     cfg->w.devmin, cfg->w.devmax, 0, 0);
	/* finger approach area */
	input_set_abs_params(input_dev, ABS_MT_WIDTH_MAJOR,
			     cfg->w.devmin, cfg->w.devmax, 0, 0);
	input_set_abs_params(input_dev, ABS_MT_WIDTH_MINOR,
			     cfg->w.devmin, cfg->w.devmax, 0, 0);
	/* finger orientation */
	input_set_abs_params(input_dev, ABS_MT_ORIENTATION,
			     -MAX_FINGER_ORIENTATION,
			     MAX_FINGER_ORIENTATION, 0, 0);
	/* finger position */
	input_set_abs_params(input_dev, ABS_MT_POSITION_X,
			     cfg->x.devmin, cfg->x.devmax, 0, 0);
	input_set_abs_params(input_dev, ABS_MT_POSITION_Y,
			     cfg->y.devmin, cfg->y.devmax, 0, 0);

	__set_bit(EV_KEY, input_dev->evbit);
	__set_bit(BTN_TOUCH, input_dev->keybit);
	__set_bit(BTN_TOOL_FINGER, input_dev->keybit);
	__set_bit(BTN_TOOL_DOUBLETAP, input_dev->keybit);
	__set_bit(BTN_TOOL_TRIPLETAP, input_dev->keybit);
	__set_bit(BTN_TOOL_QUADTAP, input_dev->keybit);
	__set_bit(BTN_LEFT, input_dev->keybit);

	input_set_events_per_packet(input_dev, 60);
}

/* report button data as logical button state */
static int report_bt_state(struct bcm5974 *dev, int size)
{
	if (size != sizeof(struct bt_data))
		return -EIO;

	dprintk(7,
		"bcm5974: button data: %x %x %x %x\n",
		dev->bt_data->unknown1, dev->bt_data->button,
		dev->bt_data->rel_x, dev->bt_data->rel_y);

	input_report_key(dev->input, BTN_LEFT, dev->bt_data->button);
	input_sync(dev->input);

	return 0;
}

static void report_finger_data(struct input_dev *input,
			       const struct bcm5974_config *cfg,
			       const struct tp_finger *f)
{
	input_report_abs(input, ABS_MT_TOUCH_MAJOR,
			 raw2int(f->force_major) << 1);
	input_report_abs(input, ABS_MT_TOUCH_MINOR,
			 raw2int(f->force_minor) << 1);
	input_report_abs(input, ABS_MT_WIDTH_MAJOR,
			 raw2int(f->size_major) << 1);
	input_report_abs(input, ABS_MT_WIDTH_MINOR,
			 raw2int(f->size_minor) << 1);
	input_report_abs(input, ABS_MT_ORIENTATION,
			 MAX_FINGER_ORIENTATION - raw2int(f->orientation));
	input_report_abs(input, ABS_MT_POSITION_X, raw2int(f->abs_x));
	input_report_abs(input, ABS_MT_POSITION_Y,
			 cfg->y.devmin + cfg->y.devmax - raw2int(f->abs_y));
	input_mt_sync(input);
}

/* report trackpad data as logical trackpad state */
static int report_tp_state(struct bcm5974 *dev, int size)
{
	const struct bcm5974_config *c = &dev->cfg;
	const struct tp_finger *f;
	struct input_dev *input = dev->input;
	int raw_p, raw_w, raw_x, raw_y, raw_n, i;
	int ptest, origin, ibt = 0, nmin = 0, nmax = 0;
	int abs_p = 0, abs_w = 0, abs_x = 0, abs_y = 0;

	if (size < c->tp_offset || (size - c->tp_offset) % SIZEOF_FINGER != 0)
		return -EIO;

	/* finger data, le16-aligned */
	f = (const struct tp_finger *)(dev->tp_data + c->tp_offset);
	raw_n = (size - c->tp_offset) / SIZEOF_FINGER;

	/* always track the first finger; when detached, start over */
	if (raw_n) {

		/* report raw trackpad data */
		for (i = 0; i < raw_n; i++)
			report_finger_data(input, c, &f[i]);

		raw_p = raw2int(f->force_major);
		raw_w = raw2int(f->size_major);
		raw_x = raw2int(f->abs_x);
		raw_y = raw2int(f->abs_y);

		dprintk(9,
			"bcm5974: "
			"raw: p: %+05d w: %+05d x: %+05d y: %+05d n: %d\n",
			raw_p, raw_w, raw_x, raw_y, raw_n);

		ptest = int2bound(&c->p, raw_p);
		origin = raw2int(f->origin);

		/* while tracking finger still valid, count all fingers */
		if (ptest > PRESSURE_LOW && origin) {
			abs_p = ptest;
			abs_w = int2bound(&c->w, raw_w);
			abs_x = int2bound(&c->x, raw_x - c->x.devmin);
			abs_y = int2bound(&c->y, c->y.devmax - raw_y);
			while (raw_n--) {
				ptest = int2bound(&c->p,
						  raw2int(f->force_major));
				if (ptest > PRESSURE_LOW)
					nmax++;
				if (ptest > PRESSURE_HIGH)
					nmin++;
				f++;
			}
		}
	}

	/* set the integrated button if applicable */
	if (c->tp_type == TYPE2)
		ibt = raw2int(dev->tp_data[BUTTON_TYPE2]);

	if (dev->fingers < nmin)
		dev->fingers = nmin;
	if (dev->fingers > nmax)
		dev->fingers = nmax;

	input_report_key(input, BTN_TOUCH, dev->fingers > 0);
	input_report_key(input, BTN_TOOL_FINGER, dev->fingers == 1);
	input_report_key(input, BTN_TOOL_DOUBLETAP, dev->fingers == 2);
	input_report_key(input, BTN_TOOL_TRIPLETAP, dev->fingers == 3);
	input_report_key(input, BTN_TOOL_QUADTAP, dev->fingers > 3);

	input_report_abs(input, ABS_PRESSURE, abs_p);
	input_report_abs(input, ABS_TOOL_WIDTH, abs_w);

	if (abs_p) {
		input_report_abs(input, ABS_X, abs_x);
		input_report_abs(input, ABS_Y, abs_y);

		dprintk(8,
			"bcm5974: abs: p: %+05d w: %+05d x: %+05d y: %+05d "
			"nmin: %d nmax: %d n: %d ibt: %d\n", abs_p, abs_w,
			abs_x, abs_y, nmin, nmax, dev->fingers, ibt);

	}

	/* type 2 reports button events via ibt only */
	if (c->tp_type == TYPE2)
		input_report_key(input, BTN_LEFT, ibt);

	input_sync(input);

	return 0;
}

/* Wellspring initialization constants */
#define BCM5974_WELLSPRING_MODE_READ_REQUEST_ID		1
#define BCM5974_WELLSPRING_MODE_WRITE_REQUEST_ID	9
#define BCM5974_WELLSPRING_MODE_REQUEST_VALUE		0x300
#define BCM5974_WELLSPRING_MODE_REQUEST_INDEX		0
#define BCM5974_WELLSPRING_MODE_VENDOR_VALUE		0x01
#define BCM5974_WELLSPRING_MODE_NORMAL_VALUE		0x08

static int bcm5974_wellspring_mode(struct bcm5974 *dev, bool on)
{
	char *data = kmalloc(8, GFP_KERNEL);
	int retval = 0, size;

	if (!data) {
		err("bcm5974: out of memory");
		retval = -ENOMEM;
		goto out;
	}

	/* read configuration */
	size = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
			BCM5974_WELLSPRING_MODE_READ_REQUEST_ID,
			USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
			BCM5974_WELLSPRING_MODE_REQUEST_VALUE,
			BCM5974_WELLSPRING_MODE_REQUEST_INDEX, data, 8, 5000);

	if (size != 8) {
		err("bcm5974: could not read from device");
		retval = -EIO;
		goto out;
	}

	/* apply the mode switch */
	data[0] = on ?
		BCM5974_WELLSPRING_MODE_VENDOR_VALUE :
		BCM5974_WELLSPRING_MODE_NORMAL_VALUE;

	/* write configuration */
	size = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
			BCM5974_WELLSPRING_MODE_WRITE_REQUEST_ID,
			USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
			BCM5974_WELLSPRING_MODE_REQUEST_VALUE,
			BCM5974_WELLSPRING_MODE_REQUEST_INDEX, data, 8, 5000);

	if (size != 8) {
		err("bcm5974: could not write to device");
		retval = -EIO;
		goto out;
	}

	dprintk(2, "bcm5974: switched to %s mode.\n",
		on ? "wellspring" : "normal");

 out:
	kfree(data);
	return retval;
}

static void bcm5974_irq_button(struct urb *urb)
{
	struct bcm5974 *dev = urb->context;
	int error;

	switch (urb->status) {
	case 0:
		break;
	case -EOVERFLOW:
	case -ECONNRESET:
	case -ENOENT:
	case -ESHUTDOWN:
		dbg("bcm5974: button urb shutting down: %d", urb->status);
		return;
	default:
		dbg("bcm5974: button urb status: %d", urb->status);
		goto exit;
	}

	if (report_bt_state(dev, dev->bt_urb->actual_length))
		dprintk(1, "bcm5974: bad button package, length: %d\n",
			dev->bt_urb->actual_length);

exit:
	error = usb_submit_urb(dev->bt_urb, GFP_ATOMIC);
	if (error)
		err("bcm5974: button urb failed: %d", error);
}

static void bcm5974_irq_trackpad(struct urb *urb)
{
	struct bcm5974 *dev = urb->context;
	int error;

	switch (urb->status) {
	case 0:
		break;
	case -EOVERFLOW:
	case -ECONNRESET:
	case -ENOENT:
	case -ESHUTDOWN:
		dbg("bcm5974: trackpad urb shutting down: %d", urb->status);
		return;
	default:
		dbg("bcm5974: trackpad urb status: %d", urb->status);
		goto exit;
	}

	/* control response ignored */
	if (dev->tp_urb->actual_length == 2)
		goto exit;

	if (report_tp_state(dev, dev->tp_urb->actual_length))
		dprintk(1, "bcm5974: bad trackpad package, length: %d\n",
			dev->tp_urb->actual_length);

exit:
	error = usb_submit_urb(dev->tp_urb, GFP_ATOMIC);
	if (error)
		err("bcm5974: trackpad urb failed: %d", error);
}

/*
 * The Wellspring trackpad, like many recent Apple trackpads, share
 * the usb device with the keyboard. Since keyboards are usually
 * handled by the HID system, the device ends up being handled by two
 * modules. Setting up the device therefore becomes slightly
 * complicated. To enable multitouch features, a mode switch is
 * required, which is usually applied via the control interface of the
 * device.  It can be argued where this switch should take place. In
 * some drivers, like appletouch, the switch is made during
 * probe. However, the hid module may also alter the state of the
 * device, resulting in trackpad malfunction under certain
 * circumstances. To get around this problem, there is at least one
 * example that utilizes the USB_QUIRK_RESET_RESUME quirk in order to
 * receive a reset_resume request rather than the normal resume.
 * Since the implementation of reset_resume is equal to mode switch
 * plus start_traffic, it seems easier to always do the switch when
 * starting traffic on the device.
 */
static int bcm5974_start_traffic(struct bcm5974 *dev)
{
	int error;

	error = bcm5974_wellspring_mode(dev, true);
	if (error) {
		dprintk(1, "bcm5974: mode switch failed\n");
		goto err_out;
	}

	error = usb_submit_urb(dev->bt_urb, GFP_KERNEL);
	if (error)
		goto err_reset_mode;

	error = usb_submit_urb(dev->tp_urb, GFP_KERNEL);
	if (error)
		goto err_kill_bt;

	return 0;

err_kill_bt:
	usb_kill_urb(dev->bt_urb);
err_reset_mode:
	bcm5974_wellspring_mode(dev, false);
err_out:
	return error;
}

static void bcm5974_pause_traffic(struct bcm5974 *dev)
{
	usb_kill_urb(dev->tp_urb);
	usb_kill_urb(dev->bt_urb);
	bcm5974_wellspring_mode(dev, false);
}

/*
 * The code below implements open/close and manual suspend/resume.
 * All functions may be called in random order.
 *
 * Opening a suspended device fails with EACCES - permission denied.
 *
 * Failing a resume leaves the device resumed but closed.
 */
static int bcm5974_open(struct input_dev *input)
{
	struct bcm5974 *dev = input_get_drvdata(input);
	int error;

	error = usb_autopm_get_interface(dev->intf);
	if (error)
		return error;

	mutex_lock(&dev->pm_mutex);

	error = bcm5974_start_traffic(dev);
	if (!error)
		dev->opened = 1;

	mutex_unlock(&dev->pm_mutex);

	if (error)
		usb_autopm_put_interface(dev->intf);

	return error;
}

static void bcm5974_close(struct input_dev *input)
{
	struct bcm5974 *dev = input_get_drvdata(input);

	mutex_lock(&dev->pm_mutex);

	bcm5974_pause_traffic(dev);
	dev->opened = 0;

	mutex_unlock(&dev->pm_mutex);

	usb_autopm_put_interface(dev->intf);
}

static int bcm5974_suspend(struct usb_interface *iface, pm_message_t message)
{
	struct bcm5974 *dev = usb_get_intfdata(iface);

	mutex_lock(&dev->pm_mutex);

	if (dev->opened)
		bcm5974_pause_traffic(dev);

	mutex_unlock(&dev->pm_mutex);

	return 0;
}

static int bcm5974_resume(struct usb_interface *iface)
{
	struct bcm5974 *dev = usb_get_intfdata(iface);
	int error = 0;

	mutex_lock(&dev->pm_mutex);

	if (dev->opened)
		error = bcm5974_start_traffic(dev);

	mutex_unlock(&dev->pm_mutex);

	return error;
}

static int bcm5974_probe(struct usb_interface *iface,
			 const struct usb_device_id *id)
{
	struct usb_device *udev = interface_to_usbdev(iface);
	const struct bcm5974_config *cfg;
	struct bcm5974 *dev;
	struct input_dev *input_dev;
	int error = -ENOMEM;

	/* find the product index */
	cfg = bcm5974_get_config(udev);

	/* allocate memory for our device state and initialize it */
	dev = kzalloc(sizeof(struct bcm5974), GFP_KERNEL);
	input_dev = input_allocate_device();
	if (!dev || !input_dev) {
		err("bcm5974: out of memory");
		goto err_free_devs;
	}

	dev->udev = udev;
	dev->intf = iface;
	dev->input = input_dev;
	dev->cfg = *cfg;
	mutex_init(&dev->pm_mutex);

	/* setup urbs */
	dev->bt_urb = usb_alloc_urb(0, GFP_KERNEL);
	if (!dev->bt_urb)
		goto err_free_devs;

	dev->tp_urb = usb_alloc_urb(0, GFP_KERNEL);
	if (!dev->tp_urb)
		goto err_free_bt_urb;

	dev->bt_data = usb_alloc_coherent(dev->udev,
					  dev->cfg.bt_datalen, GFP_KERNEL,
					  &dev->bt_urb->transfer_dma);
	if (!dev->bt_data)
		goto err_free_urb;

	dev->tp_data = usb_alloc_coherent(dev->udev,
					  dev->cfg.tp_datalen, GFP_KERNEL,
					  &dev->tp_urb->transfer_dma);
	if (!dev->tp_data)
		goto err_free_bt_buffer;

	usb_fill_int_urb(dev->bt_urb, udev,
			 usb_rcvintpipe(udev, cfg->bt_ep),
			 dev->bt_data, dev->cfg.bt_datalen,
			 bcm5974_irq_button, dev, 1);

	usb_fill_int_urb(dev->tp_urb, udev,
			 usb_rcvintpipe(udev, cfg->tp_ep),
			 dev->tp_data, dev->cfg.tp_datalen,
			 bcm5974_irq_trackpad, dev, 1);

	/* create bcm5974 device */
	usb_make_path(udev, dev->phys, sizeof(dev->phys));
	strlcat(dev->phys, "/input0", sizeof(dev->phys));

	input_dev->name = "bcm5974";
	input_dev->phys = dev->phys;
	usb_to_input_id(dev->udev, &input_dev->id);
	/* report driver capabilities via the version field */
	input_dev->id.version = cfg->caps;
	input_dev->dev.parent = &iface->dev;

	input_set_drvdata(input_dev, dev);

	input_dev->open = bcm5974_open;
	input_dev->close = bcm5974_close;

	setup_events_to_report(input_dev, cfg);

	error = input_register_device(dev->input);
	if (error)
		goto err_free_buffer;

	/* save our data pointer in this interface device */
	usb_set_intfdata(iface, dev);

	return 0;

err_free_buffer:
	usb_free_coherent(dev->udev, dev->cfg.tp_datalen,
		dev->tp_data, dev->tp_urb->transfer_dma);
err_free_bt_buffer:
	usb_free_coherent(dev->udev, dev->cfg.bt_datalen,
		dev->bt_data, dev->bt_urb->transfer_dma);
err_free_urb:
	usb_free_urb(dev->tp_urb);
err_free_bt_urb:
	usb_free_urb(dev->bt_urb);
err_free_devs:
	usb_set_intfdata(iface, NULL);
	input_free_device(input_dev);
	kfree(dev);
	return error;
}

static void bcm5974_disconnect(struct usb_interface *iface)
{
	struct bcm5974 *dev = usb_get_intfdata(iface);

	usb_set_intfdata(iface, NULL);

	input_unregister_device(dev->input);
	usb_free_coherent(dev->udev, dev->cfg.tp_datalen,
			  dev->tp_data, dev->tp_urb->transfer_dma);
	usb_free_coherent(dev->udev, dev->cfg.bt_datalen,
			  dev->bt_data, dev->bt_urb->transfer_dma);
	usb_free_urb(dev->tp_urb);
	usb_free_urb(dev->bt_urb);
	kfree(dev);
}

static struct usb_driver bcm5974_driver = {
	.name			= "bcm5974",
	.probe			= bcm5974_probe,
	.disconnect		= bcm5974_disconnect,
	.suspend		= bcm5974_suspend,
	.resume			= bcm5974_resume,
	.id_table		= bcm5974_table,
	.supports_autosuspend	= 1,
};

static int __init bcm5974_init(void)
{
	return usb_register(&bcm5974_driver);
}

static void __exit bcm5974_exit(void)
{
	usb_deregister(&bcm5974_driver);
}

module_init(bcm5974_init);
module_exit(bcm5974_exit);