summaryrefslogtreecommitdiffstats
path: root/drivers/input/mouse/hgpk.c
blob: 015509e0b1408f66a2ff048d53be22365e453639 (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
/*
 * OLPC HGPK (XO-1) touchpad PS/2 mouse driver
 *
 * Copyright (c) 2006-2008 One Laptop Per Child
 * Authors:
 *   Zephaniah E. Hull
 *   Andres Salomon <dilinger@debian.org>
 *
 * This driver is partly based on the ALPS driver, which is:
 *
 * Copyright (c) 2003 Neil Brown <neilb@cse.unsw.edu.au>
 * Copyright (c) 2003-2005 Peter Osterlund <petero2@telia.com>
 * Copyright (c) 2004 Dmitry Torokhov <dtor@mail.ru>
 * Copyright (c) 2005 Vojtech Pavlik <vojtech@suse.cz>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

/*
 * The spec from ALPS is available from
 * <http://wiki.laptop.org/go/Touch_Pad/Tablet>.  It refers to this
 * device as HGPK (Hybrid GS, PT, and Keymatrix).
 *
 * The earliest versions of the device had simultaneous reporting; that
 * was removed.  After that, the device used the Advanced Mode GS/PT streaming
 * stuff.  That turned out to be too buggy to support, so we've finally
 * switched to Mouse Mode (which utilizes only the center 1/3 of the touchpad).
 */

#define DEBUG
#include <linux/slab.h>
#include <linux/input.h>
#include <linux/module.h>
#include <linux/serio.h>
#include <linux/libps2.h>
#include <linux/delay.h>
#include <asm/olpc.h>

#include "psmouse.h"
#include "hgpk.h"

#define ILLEGAL_XY 999999

static bool tpdebug;
module_param(tpdebug, bool, 0644);
MODULE_PARM_DESC(tpdebug, "enable debugging, dumping packets to KERN_DEBUG.");

static int recalib_delta = 100;
module_param(recalib_delta, int, 0644);
MODULE_PARM_DESC(recalib_delta,
	"packets containing a delta this large will be discarded, and a "
	"recalibration may be scheduled.");

static int jumpy_delay = 20;
module_param(jumpy_delay, int, 0644);
MODULE_PARM_DESC(jumpy_delay,
	"delay (ms) before recal after jumpiness detected");

static int spew_delay = 1;
module_param(spew_delay, int, 0644);
MODULE_PARM_DESC(spew_delay,
	"delay (ms) before recal after packet spew detected");

static int recal_guard_time;
module_param(recal_guard_time, int, 0644);
MODULE_PARM_DESC(recal_guard_time,
	"interval (ms) during which recal will be restarted if packet received");

static int post_interrupt_delay = 40;
module_param(post_interrupt_delay, int, 0644);
MODULE_PARM_DESC(post_interrupt_delay,
	"delay (ms) before recal after recal interrupt detected");

static bool autorecal = true;
module_param(autorecal, bool, 0644);
MODULE_PARM_DESC(autorecal, "enable recalibration in the driver");

static char hgpk_mode_name[16];
module_param_string(hgpk_mode, hgpk_mode_name, sizeof(hgpk_mode_name), 0644);
MODULE_PARM_DESC(hgpk_mode,
	"default hgpk mode: mouse, glidesensor or pentablet");

static int hgpk_default_mode = HGPK_MODE_MOUSE;

static const char * const hgpk_mode_names[] = {
	[HGPK_MODE_MOUSE] = "Mouse",
	[HGPK_MODE_GLIDESENSOR] = "GlideSensor",
	[HGPK_MODE_PENTABLET] = "PenTablet",
};

static int hgpk_mode_from_name(const char *buf, int len)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(hgpk_mode_names); i++) {
		const char *name = hgpk_mode_names[i];
		if (strlen(name) == len && !strncasecmp(name, buf, len))
			return i;
	}

	return HGPK_MODE_INVALID;
}

/*
 * see if new value is within 20% of half of old value
 */
static int approx_half(int curr, int prev)
{
	int belowhalf, abovehalf;

	if (curr < 5 || prev < 5)
		return 0;

	belowhalf = (prev * 8) / 20;
	abovehalf = (prev * 12) / 20;

	return belowhalf < curr && curr <= abovehalf;
}

/*
 * Throw out oddly large delta packets, and any that immediately follow whose
 * values are each approximately half of the previous.  It seems that the ALPS
 * firmware emits errant packets, and they get averaged out slowly.
 */
static int hgpk_discard_decay_hack(struct psmouse *psmouse, int x, int y)
{
	struct hgpk_data *priv = psmouse->private;
	int avx, avy;
	bool do_recal = false;

	avx = abs(x);
	avy = abs(y);

	/* discard if too big, or half that but > 4 times the prev delta */
	if (avx > recalib_delta ||
		(avx > recalib_delta / 2 && ((avx / 4) > priv->xlast))) {
		psmouse_warn(psmouse, "detected %dpx jump in x\n", x);
		priv->xbigj = avx;
	} else if (approx_half(avx, priv->xbigj)) {
		psmouse_warn(psmouse, "detected secondary %dpx jump in x\n", x);
		priv->xbigj = avx;
		priv->xsaw_secondary++;
	} else {
		if (priv->xbigj && priv->xsaw_secondary > 1)
			do_recal = true;
		priv->xbigj = 0;
		priv->xsaw_secondary = 0;
	}

	if (avy > recalib_delta ||
		(avy > recalib_delta / 2 && ((avy / 4) > priv->ylast))) {
		psmouse_warn(psmouse, "detected %dpx jump in y\n", y);
		priv->ybigj = avy;
	} else if (approx_half(avy, priv->ybigj)) {
		psmouse_warn(psmouse, "detected secondary %dpx jump in y\n", y);
		priv->ybigj = avy;
		priv->ysaw_secondary++;
	} else {
		if (priv->ybigj && priv->ysaw_secondary > 1)
			do_recal = true;
		priv->ybigj = 0;
		priv->ysaw_secondary = 0;
	}

	priv->xlast = avx;
	priv->ylast = avy;

	if (do_recal && jumpy_delay) {
		psmouse_warn(psmouse, "scheduling recalibration\n");
		psmouse_queue_work(psmouse, &priv->recalib_wq,
				msecs_to_jiffies(jumpy_delay));
	}

	return priv->xbigj || priv->ybigj;
}

static void hgpk_reset_spew_detection(struct hgpk_data *priv)
{
	priv->spew_count = 0;
	priv->dupe_count = 0;
	priv->x_tally = 0;
	priv->y_tally = 0;
	priv->spew_flag = NO_SPEW;
}

static void hgpk_reset_hack_state(struct psmouse *psmouse)
{
	struct hgpk_data *priv = psmouse->private;

	priv->abs_x = priv->abs_y = -1;
	priv->xlast = priv->ylast = ILLEGAL_XY;
	priv->xbigj = priv->ybigj = 0;
	priv->xsaw_secondary = priv->ysaw_secondary = 0;
	hgpk_reset_spew_detection(priv);
}

/*
 * We have no idea why this particular hardware bug occurs.  The touchpad
 * will randomly start spewing packets without anything touching the
 * pad.  This wouldn't necessarily be bad, but it's indicative of a
 * severely miscalibrated pad; attempting to use the touchpad while it's
 * spewing means the cursor will jump all over the place, and act "drunk".
 *
 * The packets that are spewed tend to all have deltas between -2 and 2, and
 * the cursor will move around without really going very far.  It will
 * tend to end up in the same location; if we tally up the changes over
 * 100 packets, we end up w/ a final delta of close to 0.  This happens
 * pretty regularly when the touchpad is spewing, and is pretty hard to
 * manually trigger (at least for *my* fingers).  So, it makes a perfect
 * scheme for detecting spews.
 */
static void hgpk_spewing_hack(struct psmouse *psmouse,
			      int l, int r, int x, int y)
{
	struct hgpk_data *priv = psmouse->private;

	/* ignore button press packets; many in a row could trigger
	 * a false-positive! */
	if (l || r)
		return;

	/* don't track spew if the workaround feature has been turned off */
	if (!spew_delay)
		return;

	if (abs(x) > 3 || abs(y) > 3) {
		/* no spew, or spew ended */
		hgpk_reset_spew_detection(priv);
		return;
	}

	/* Keep a tally of the overall delta to the cursor position caused by
	 * the spew */
	priv->x_tally += x;
	priv->y_tally += y;

	switch (priv->spew_flag) {
	case NO_SPEW:
		/* we're not spewing, but this packet might be the start */
		priv->spew_flag = MAYBE_SPEWING;

		/* fall-through */

	case MAYBE_SPEWING:
		priv->spew_count++;

		if (priv->spew_count < SPEW_WATCH_COUNT)
			break;

		/* excessive spew detected, request recalibration */
		priv->spew_flag = SPEW_DETECTED;

		/* fall-through */

	case SPEW_DETECTED:
		/* only recalibrate when the overall delta to the cursor
		 * is really small. if the spew is causing significant cursor
		 * movement, it is probably a case of the user moving the
		 * cursor very slowly across the screen. */
		if (abs(priv->x_tally) < 3 && abs(priv->y_tally) < 3) {
			psmouse_warn(psmouse, "packet spew detected (%d,%d)\n",
				     priv->x_tally, priv->y_tally);
			priv->spew_flag = RECALIBRATING;
			psmouse_queue_work(psmouse, &priv->recalib_wq,
					   msecs_to_jiffies(spew_delay));
		}

		break;
	case RECALIBRATING:
		/* we already detected a spew and requested a recalibration,
		 * just wait for the queue to kick into action. */
		break;
	}
}

/*
 * HGPK Mouse Mode format (standard mouse format, sans middle button)
 *
 * byte 0:	y-over	x-over	y-neg	x-neg	1	0	swr	swl
 * byte 1:	x7	x6	x5	x4	x3	x2	x1	x0
 * byte 2:	y7	y6	y5	y4	y3	y2	y1	y0
 *
 * swr/swl are the left/right buttons.
 * x-neg/y-neg are the x and y delta negative bits
 * x-over/y-over are the x and y overflow bits
 *
 * ---
 *
 * HGPK Advanced Mode - single-mode format
 *
 * byte 0(PT):  1    1    0    0    1    1     1     1
 * byte 0(GS):  1    1    1    1    1    1     1     1
 * byte 1:      0   x6   x5   x4   x3   x2    x1    x0
 * byte 2(PT):  0    0   x9   x8   x7    ? pt-dsw    0
 * byte 2(GS):  0  x10   x9   x8   x7    ? gs-dsw pt-dsw
 * byte 3:      0   y9   y8   y7    1    0   swr   swl
 * byte 4:      0   y6   y5   y4   y3   y2    y1    y0
 * byte 5:      0   z6   z5   z4   z3   z2    z1    z0
 *
 * ?'s are not defined in the protocol spec, may vary between models.
 *
 * swr/swl are the left/right buttons.
 *
 * pt-dsw/gs-dsw indicate that the pt/gs sensor is detecting a
 * pen/finger
 */
static bool hgpk_is_byte_valid(struct psmouse *psmouse, unsigned char *packet)
{
	struct hgpk_data *priv = psmouse->private;
	int pktcnt = psmouse->pktcnt;
	bool valid;

	switch (priv->mode) {
	case HGPK_MODE_MOUSE:
		valid = (packet[0] & 0x0C) == 0x08;
		break;

	case HGPK_MODE_GLIDESENSOR:
		valid = pktcnt == 1 ?
			packet[0] == HGPK_GS : !(packet[pktcnt - 1] & 0x80);
		break;

	case HGPK_MODE_PENTABLET:
		valid = pktcnt == 1 ?
			packet[0] == HGPK_PT : !(packet[pktcnt - 1] & 0x80);
		break;

	default:
		valid = false;
		break;
	}

	if (!valid)
		psmouse_dbg(psmouse,
			    "bad data, mode %d (%d) %*ph\n",
			    priv->mode, pktcnt, 6, psmouse->packet);

	return valid;
}

static void hgpk_process_advanced_packet(struct psmouse *psmouse)
{
	struct hgpk_data *priv = psmouse->private;
	struct input_dev *idev = psmouse->dev;
	unsigned char *packet = psmouse->packet;
	int down = !!(packet[2] & 2);
	int left = !!(packet[3] & 1);
	int right = !!(packet[3] & 2);
	int x = packet[1] | ((packet[2] & 0x78) << 4);
	int y = packet[4] | ((packet[3] & 0x70) << 3);

	if (priv->mode == HGPK_MODE_GLIDESENSOR) {
		int pt_down = !!(packet[2] & 1);
		int finger_down = !!(packet[2] & 2);
		int z = packet[5];

		input_report_abs(idev, ABS_PRESSURE, z);
		if (tpdebug)
			psmouse_dbg(psmouse, "pd=%d fd=%d z=%d",
				    pt_down, finger_down, z);
	} else {
		/*
		 * PenTablet mode does not report pressure, so we don't
		 * report it here
		 */
		if (tpdebug)
			psmouse_dbg(psmouse, "pd=%d ", down);
	}

	if (tpdebug)
		psmouse_dbg(psmouse, "l=%d r=%d x=%d y=%d\n",
			    left, right, x, y);

	input_report_key(idev, BTN_TOUCH, down);
	input_report_key(idev, BTN_LEFT, left);
	input_report_key(idev, BTN_RIGHT, right);

	/*
	 * If this packet says that the finger was removed, reset our position
	 * tracking so that we don't erroneously detect a jump on next press.
	 */
	if (!down) {
		hgpk_reset_hack_state(psmouse);
		goto done;
	}

	/*
	 * Weed out duplicate packets (we get quite a few, and they mess up
	 * our jump detection)
	 */
	if (x == priv->abs_x && y == priv->abs_y) {
		if (++priv->dupe_count > SPEW_WATCH_COUNT) {
			if (tpdebug)
				psmouse_dbg(psmouse, "hard spew detected\n");
			priv->spew_flag = RECALIBRATING;
			psmouse_queue_work(psmouse, &priv->recalib_wq,
					   msecs_to_jiffies(spew_delay));
		}
		goto done;
	}

	/* not a duplicate, continue with position reporting */
	priv->dupe_count = 0;

	/* Don't apply hacks in PT mode, it seems reliable */
	if (priv->mode != HGPK_MODE_PENTABLET && priv->abs_x != -1) {
		int x_diff = priv->abs_x - x;
		int y_diff = priv->abs_y - y;
		if (hgpk_discard_decay_hack(psmouse, x_diff, y_diff)) {
			if (tpdebug)
				psmouse_dbg(psmouse, "discarding\n");
			goto done;
		}
		hgpk_spewing_hack(psmouse, left, right, x_diff, y_diff);
	}

	input_report_abs(idev, ABS_X, x);
	input_report_abs(idev, ABS_Y, y);
	priv->abs_x = x;
	priv->abs_y = y;

done:
	input_sync(idev);
}

static void hgpk_process_simple_packet(struct psmouse *psmouse)
{
	struct input_dev *dev = psmouse->dev;
	unsigned char *packet = psmouse->packet;
	int left = packet[0] & 1;
	int right = (packet[0] >> 1) & 1;
	int x = packet[1] - ((packet[0] << 4) & 0x100);
	int y = ((packet[0] << 3) & 0x100) - packet[2];

	if (packet[0] & 0xc0)
		psmouse_dbg(psmouse,
			    "overflow -- 0x%02x 0x%02x 0x%02x\n",
			    packet[0], packet[1], packet[2]);

	if (hgpk_discard_decay_hack(psmouse, x, y)) {
		if (tpdebug)
			psmouse_dbg(psmouse, "discarding\n");
		return;
	}

	hgpk_spewing_hack(psmouse, left, right, x, y);

	if (tpdebug)
		psmouse_dbg(psmouse, "l=%d r=%d x=%d y=%d\n",
			    left, right, x, y);

	input_report_key(dev, BTN_LEFT, left);
	input_report_key(dev, BTN_RIGHT, right);

	input_report_rel(dev, REL_X, x);
	input_report_rel(dev, REL_Y, y);

	input_sync(dev);
}

static psmouse_ret_t hgpk_process_byte(struct psmouse *psmouse)
{
	struct hgpk_data *priv = psmouse->private;

	if (!hgpk_is_byte_valid(psmouse, psmouse->packet))
		return PSMOUSE_BAD_DATA;

	if (psmouse->pktcnt >= psmouse->pktsize) {
		if (priv->mode == HGPK_MODE_MOUSE)
			hgpk_process_simple_packet(psmouse);
		else
			hgpk_process_advanced_packet(psmouse);
		return PSMOUSE_FULL_PACKET;
	}

	if (priv->recalib_window) {
		if (time_before(jiffies, priv->recalib_window)) {
			/*
			 * ugh, got a packet inside our recalibration
			 * window, schedule another recalibration.
			 */
			psmouse_dbg(psmouse,
				    "packet inside calibration window, queueing another recalibration\n");
			psmouse_queue_work(psmouse, &priv->recalib_wq,
					msecs_to_jiffies(post_interrupt_delay));
		}
		priv->recalib_window = 0;
	}

	return PSMOUSE_GOOD_DATA;
}

static int hgpk_select_mode(struct psmouse *psmouse)
{
	struct ps2dev *ps2dev = &psmouse->ps2dev;
	struct hgpk_data *priv = psmouse->private;
	int i;
	int cmd;

	/*
	 * 4 disables to enable advanced mode
	 * then 3 0xf2 bytes as the preamble for GS/PT selection
	 */
	const int advanced_init[] = {
		PSMOUSE_CMD_DISABLE, PSMOUSE_CMD_DISABLE,
		PSMOUSE_CMD_DISABLE, PSMOUSE_CMD_DISABLE,
		0xf2, 0xf2, 0xf2,
	};

	switch (priv->mode) {
	case HGPK_MODE_MOUSE:
		psmouse->pktsize = 3;
		break;

	case HGPK_MODE_GLIDESENSOR:
	case HGPK_MODE_PENTABLET:
		psmouse->pktsize = 6;

		/* Switch to 'Advanced mode.', four disables in a row. */
		for (i = 0; i < ARRAY_SIZE(advanced_init); i++)
			if (ps2_command(ps2dev, NULL, advanced_init[i]))
				return -EIO;

		/* select between GlideSensor (mouse) or PenTablet */
		cmd = priv->mode == HGPK_MODE_GLIDESENSOR ?
			PSMOUSE_CMD_SETSCALE11 : PSMOUSE_CMD_SETSCALE21;

		if (ps2_command(ps2dev, NULL, cmd))
			return -EIO;
		break;

	default:
		return -EINVAL;
	}

	return 0;
}

static void hgpk_setup_input_device(struct input_dev *input,
				    struct input_dev *old_input,
				    enum hgpk_mode mode)
{
	if (old_input) {
		input->name = old_input->name;
		input->phys = old_input->phys;
		input->id = old_input->id;
		input->dev.parent = old_input->dev.parent;
	}

	memset(input->evbit, 0, sizeof(input->evbit));
	memset(input->relbit, 0, sizeof(input->relbit));
	memset(input->keybit, 0, sizeof(input->keybit));

	/* All modes report left and right buttons */
	__set_bit(EV_KEY, input->evbit);
	__set_bit(BTN_LEFT, input->keybit);
	__set_bit(BTN_RIGHT, input->keybit);

	switch (mode) {
	case HGPK_MODE_MOUSE:
		__set_bit(EV_REL, input->evbit);
		__set_bit(REL_X, input->relbit);
		__set_bit(REL_Y, input->relbit);
		break;

	case HGPK_MODE_GLIDESENSOR:
		__set_bit(BTN_TOUCH, input->keybit);
		__set_bit(BTN_TOOL_FINGER, input->keybit);

		__set_bit(EV_ABS, input->evbit);

		/* GlideSensor has pressure sensor, PenTablet does not */
		input_set_abs_params(input, ABS_PRESSURE, 0, 15, 0, 0);

		/* From device specs */
		input_set_abs_params(input, ABS_X, 0, 399, 0, 0);
		input_set_abs_params(input, ABS_Y, 0, 290, 0, 0);

		/* Calculated by hand based on usable size (52mm x 38mm) */
		input_abs_set_res(input, ABS_X, 8);
		input_abs_set_res(input, ABS_Y, 8);
		break;

	case HGPK_MODE_PENTABLET:
		__set_bit(BTN_TOUCH, input->keybit);
		__set_bit(BTN_TOOL_FINGER, input->keybit);

		__set_bit(EV_ABS, input->evbit);

		/* From device specs */
		input_set_abs_params(input, ABS_X, 0, 999, 0, 0);
		input_set_abs_params(input, ABS_Y, 5, 239, 0, 0);

		/* Calculated by hand based on usable size (156mm x 38mm) */
		input_abs_set_res(input, ABS_X, 6);
		input_abs_set_res(input, ABS_Y, 8);
		break;

	default:
		BUG();
	}
}

static int hgpk_reset_device(struct psmouse *psmouse, bool recalibrate)
{
	int err;

	psmouse_reset(psmouse);

	if (recalibrate) {
		struct ps2dev *ps2dev = &psmouse->ps2dev;

		/* send the recalibrate request */
		if (ps2_command(ps2dev, NULL, 0xf5) ||
		    ps2_command(ps2dev, NULL, 0xf5) ||
		    ps2_command(ps2dev, NULL, 0xe6) ||
		    ps2_command(ps2dev, NULL, 0xf5)) {
			return -1;
		}

		/* according to ALPS, 150mS is required for recalibration */
		msleep(150);
	}

	err = hgpk_select_mode(psmouse);
	if (err) {
		psmouse_err(psmouse, "failed to select mode\n");
		return err;
	}

	hgpk_reset_hack_state(psmouse);

	return 0;
}

static int hgpk_force_recalibrate(struct psmouse *psmouse)
{
	struct hgpk_data *priv = psmouse->private;
	int err;

	/* C-series touchpads added the recalibrate command */
	if (psmouse->model < HGPK_MODEL_C)
		return 0;

	if (!autorecal) {
		psmouse_dbg(psmouse, "recalibration disabled, ignoring\n");
		return 0;
	}

	psmouse_dbg(psmouse, "recalibrating touchpad..\n");

	/* we don't want to race with the irq handler, nor with resyncs */
	psmouse_set_state(psmouse, PSMOUSE_INITIALIZING);

	/* start by resetting the device */
	err = hgpk_reset_device(psmouse, true);
	if (err)
		return err;

	/*
	 * XXX: If a finger is down during this delay, recalibration will
	 * detect capacitance incorrectly.  This is a hardware bug, and
	 * we don't have a good way to deal with it.  The 2s window stuff
	 * (below) is our best option for now.
	 */
	if (psmouse_activate(psmouse))
		return -1;

	if (tpdebug)
		psmouse_dbg(psmouse, "touchpad reactivated\n");

	/*
	 * If we get packets right away after recalibrating, it's likely
	 * that a finger was on the touchpad.  If so, it's probably
	 * miscalibrated, so we optionally schedule another.
	 */
	if (recal_guard_time)
		priv->recalib_window = jiffies +
			msecs_to_jiffies(recal_guard_time);

	return 0;
}

/*
 * This puts the touchpad in a power saving mode; according to ALPS, current
 * consumption goes down to 50uA after running this.  To turn power back on,
 * we drive MS-DAT low.  Measuring with a 1mA resolution ammeter says that
 * the current on the SUS_3.3V rail drops from 3mA or 4mA to 0 when we do this.
 *
 * We have no formal spec that details this operation -- the low-power
 * sequence came from a long-lost email trail.
 */
static int hgpk_toggle_powersave(struct psmouse *psmouse, int enable)
{
	struct ps2dev *ps2dev = &psmouse->ps2dev;
	int timeo;
	int err;

	/* Added on D-series touchpads */
	if (psmouse->model < HGPK_MODEL_D)
		return 0;

	if (enable) {
		psmouse_set_state(psmouse, PSMOUSE_INITIALIZING);

		/*
		 * Sending a byte will drive MS-DAT low; this will wake up
		 * the controller.  Once we get an ACK back from it, it
		 * means we can continue with the touchpad re-init.  ALPS
		 * tells us that 1s should be long enough, so set that as
		 * the upper bound. (in practice, it takes about 3 loops.)
		 */
		for (timeo = 20; timeo > 0; timeo--) {
			if (!ps2_sendbyte(ps2dev, PSMOUSE_CMD_DISABLE, 20))
				break;
			msleep(25);
		}

		err = hgpk_reset_device(psmouse, false);
		if (err) {
			psmouse_err(psmouse, "Failed to reset device!\n");
			return err;
		}

		/* should be all set, enable the touchpad */
		psmouse_activate(psmouse);
		psmouse_dbg(psmouse, "Touchpad powered up.\n");
	} else {
		psmouse_dbg(psmouse, "Powering off touchpad.\n");

		if (ps2_command(ps2dev, NULL, 0xec) ||
		    ps2_command(ps2dev, NULL, 0xec) ||
		    ps2_command(ps2dev, NULL, 0xea)) {
			return -1;
		}

		psmouse_set_state(psmouse, PSMOUSE_IGNORE);

		/* probably won't see an ACK, the touchpad will be off */
		ps2_sendbyte(ps2dev, 0xec, 20);
	}

	return 0;
}

static int hgpk_poll(struct psmouse *psmouse)
{
	/* We can't poll, so always return failure. */
	return -1;
}

static int hgpk_reconnect(struct psmouse *psmouse)
{
	struct hgpk_data *priv = psmouse->private;

	/*
	 * During suspend/resume the ps2 rails remain powered.  We don't want
	 * to do a reset because it's flush data out of buffers; however,
	 * earlier prototypes (B1) had some brokenness that required a reset.
	 */
	if (olpc_board_at_least(olpc_board(0xb2)))
		if (psmouse->ps2dev.serio->dev.power.power_state.event !=
				PM_EVENT_ON)
			return 0;

	priv->powered = 1;
	return hgpk_reset_device(psmouse, false);
}

static ssize_t hgpk_show_powered(struct psmouse *psmouse, void *data, char *buf)
{
	struct hgpk_data *priv = psmouse->private;

	return sprintf(buf, "%d\n", priv->powered);
}

static ssize_t hgpk_set_powered(struct psmouse *psmouse, void *data,
				const char *buf, size_t count)
{
	struct hgpk_data *priv = psmouse->private;
	unsigned int value;
	int err;

	err = kstrtouint(buf, 10, &value);
	if (err)
		return err;

	if (value > 1)
		return -EINVAL;

	if (value != priv->powered) {
		/*
		 * hgpk_toggle_power will deal w/ state so
		 * we're not racing w/ irq
		 */
		err = hgpk_toggle_powersave(psmouse, value);
		if (!err)
			priv->powered = value;
	}

	return err ? err : count;
}

__PSMOUSE_DEFINE_ATTR(powered, S_IWUSR | S_IRUGO, NULL,
		      hgpk_show_powered, hgpk_set_powered, false);

static ssize_t attr_show_mode(struct psmouse *psmouse, void *data, char *buf)
{
	struct hgpk_data *priv = psmouse->private;

	return sprintf(buf, "%s\n", hgpk_mode_names[priv->mode]);
}

static ssize_t attr_set_mode(struct psmouse *psmouse, void *data,
			     const char *buf, size_t len)
{
	struct hgpk_data *priv = psmouse->private;
	enum hgpk_mode old_mode = priv->mode;
	enum hgpk_mode new_mode = hgpk_mode_from_name(buf, len);
	struct input_dev *old_dev = psmouse->dev;
	struct input_dev *new_dev;
	int err;

	if (new_mode == HGPK_MODE_INVALID)
		return -EINVAL;

	if (old_mode == new_mode)
		return len;

	new_dev = input_allocate_device();
	if (!new_dev)
		return -ENOMEM;

	psmouse_set_state(psmouse, PSMOUSE_INITIALIZING);

	/* Switch device into the new mode */
	priv->mode = new_mode;
	err = hgpk_reset_device(psmouse, false);
	if (err)
		goto err_try_restore;

	hgpk_setup_input_device(new_dev, old_dev, new_mode);

	psmouse_set_state(psmouse, PSMOUSE_CMD_MODE);

	err = input_register_device(new_dev);
	if (err)
		goto err_try_restore;

	psmouse->dev = new_dev;
	input_unregister_device(old_dev);

	return len;

err_try_restore:
	input_free_device(new_dev);
	priv->mode = old_mode;
	hgpk_reset_device(psmouse, false);

	return err;
}

PSMOUSE_DEFINE_ATTR(hgpk_mode, S_IWUSR | S_IRUGO, NULL,
		    attr_show_mode, attr_set_mode);

static ssize_t hgpk_trigger_recal_show(struct psmouse *psmouse,
		void *data, char *buf)
{
	return -EINVAL;
}

static ssize_t hgpk_trigger_recal(struct psmouse *psmouse, void *data,
				const char *buf, size_t count)
{
	struct hgpk_data *priv = psmouse->private;
	unsigned int value;
	int err;

	err = kstrtouint(buf, 10, &value);
	if (err)
		return err;

	if (value != 1)
		return -EINVAL;

	/*
	 * We queue work instead of doing recalibration right here
	 * to avoid adding locking to to hgpk_force_recalibrate()
	 * since workqueue provides serialization.
	 */
	psmouse_queue_work(psmouse, &priv->recalib_wq, 0);
	return count;
}

__PSMOUSE_DEFINE_ATTR(recalibrate, S_IWUSR | S_IRUGO, NULL,
		      hgpk_trigger_recal_show, hgpk_trigger_recal, false);

static void hgpk_disconnect(struct psmouse *psmouse)
{
	struct hgpk_data *priv = psmouse->private;

	device_remove_file(&psmouse->ps2dev.serio->dev,
			   &psmouse_attr_powered.dattr);
	device_remove_file(&psmouse->ps2dev.serio->dev,
			   &psmouse_attr_hgpk_mode.dattr);

	if (psmouse->model >= HGPK_MODEL_C)
		device_remove_file(&psmouse->ps2dev.serio->dev,
				   &psmouse_attr_recalibrate.dattr);

	psmouse_reset(psmouse);
	kfree(priv);
}

static void hgpk_recalib_work(struct work_struct *work)
{
	struct delayed_work *w = to_delayed_work(work);
	struct hgpk_data *priv = container_of(w, struct hgpk_data, recalib_wq);
	struct psmouse *psmouse = priv->psmouse;

	if (hgpk_force_recalibrate(psmouse))
		psmouse_err(psmouse, "recalibration failed!\n");
}

static int hgpk_register(struct psmouse *psmouse)
{
	struct hgpk_data *priv = psmouse->private;
	int err;

	/* register handlers */
	psmouse->protocol_handler = hgpk_process_byte;
	psmouse->poll = hgpk_poll;
	psmouse->disconnect = hgpk_disconnect;
	psmouse->reconnect = hgpk_reconnect;

	/* Disable the idle resync. */
	psmouse->resync_time = 0;
	/* Reset after a lot of bad bytes. */
	psmouse->resetafter = 1024;

	hgpk_setup_input_device(psmouse->dev, NULL, priv->mode);

	err = device_create_file(&psmouse->ps2dev.serio->dev,
				 &psmouse_attr_powered.dattr);
	if (err) {
		psmouse_err(psmouse, "Failed creating 'powered' sysfs node\n");
		return err;
	}

	err = device_create_file(&psmouse->ps2dev.serio->dev,
				 &psmouse_attr_hgpk_mode.dattr);
	if (err) {
		psmouse_err(psmouse,
			    "Failed creating 'hgpk_mode' sysfs node\n");
		goto err_remove_powered;
	}

	/* C-series touchpads added the recalibrate command */
	if (psmouse->model >= HGPK_MODEL_C) {
		err = device_create_file(&psmouse->ps2dev.serio->dev,
					 &psmouse_attr_recalibrate.dattr);
		if (err) {
			psmouse_err(psmouse,
				    "Failed creating 'recalibrate' sysfs node\n");
			goto err_remove_mode;
		}
	}

	return 0;

err_remove_mode:
	device_remove_file(&psmouse->ps2dev.serio->dev,
			   &psmouse_attr_hgpk_mode.dattr);
err_remove_powered:
	device_remove_file(&psmouse->ps2dev.serio->dev,
			   &psmouse_attr_powered.dattr);
	return err;
}

int hgpk_init(struct psmouse *psmouse)
{
	struct hgpk_data *priv;
	int err;

	priv = kzalloc(sizeof(struct hgpk_data), GFP_KERNEL);
	if (!priv) {
		err = -ENOMEM;
		goto alloc_fail;
	}

	psmouse->private = priv;

	priv->psmouse = psmouse;
	priv->powered = true;
	priv->mode = hgpk_default_mode;
	INIT_DELAYED_WORK(&priv->recalib_wq, hgpk_recalib_work);

	err = hgpk_reset_device(psmouse, false);
	if (err)
		goto init_fail;

	err = hgpk_register(psmouse);
	if (err)
		goto init_fail;

	return 0;

init_fail:
	kfree(priv);
alloc_fail:
	return err;
}

static enum hgpk_model_t hgpk_get_model(struct psmouse *psmouse)
{
	struct ps2dev *ps2dev = &psmouse->ps2dev;
	unsigned char param[3];

	/* E7, E7, E7, E9 gets us a 3 byte identifier */
	if (ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE21) ||
	    ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE21) ||
	    ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE21) ||
	    ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO)) {
		return -EIO;
	}

	psmouse_dbg(psmouse, "ID: %*ph\n", 3, param);

	/* HGPK signature: 0x67, 0x00, 0x<model> */
	if (param[0] != 0x67 || param[1] != 0x00)
		return -ENODEV;

	psmouse_info(psmouse, "OLPC touchpad revision 0x%x\n", param[2]);

	return param[2];
}

int hgpk_detect(struct psmouse *psmouse, bool set_properties)
{
	int version;

	version = hgpk_get_model(psmouse);
	if (version < 0)
		return version;

	if (set_properties) {
		psmouse->vendor = "ALPS";
		psmouse->name = "HGPK";
		psmouse->model = version;
	}

	return 0;
}

void hgpk_module_init(void)
{
	hgpk_default_mode = hgpk_mode_from_name(hgpk_mode_name,
						strlen(hgpk_mode_name));
	if (hgpk_default_mode == HGPK_MODE_INVALID) {
		hgpk_default_mode = HGPK_MODE_MOUSE;
		strlcpy(hgpk_mode_name, hgpk_mode_names[HGPK_MODE_MOUSE],
			sizeof(hgpk_mode_name));
	}
}