summaryrefslogtreecommitdiffstats
path: root/drivers/input/misc/ad714x.c
blob: 6deecdd3d11bae34af377bcf648d51b689cc054e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
/*
 * AD714X CapTouch Programmable Controller driver supporting AD7142/3/7/8/7A
 *
 * Copyright 2009-2011 Analog Devices Inc.
 *
 * Licensed under the GPL-2 or later.
 */

#include <linux/device.h>
#include <linux/init.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/input/ad714x.h>
#include <linux/module.h>
#include "ad714x.h"

#define AD714X_PWR_CTRL           0x0
#define AD714X_STG_CAL_EN_REG     0x1
#define AD714X_AMB_COMP_CTRL0_REG 0x2
#define AD714X_PARTID_REG         0x17
#define AD7142_PARTID             0xE620
#define AD7143_PARTID             0xE630
#define AD7147_PARTID             0x1470
#define AD7148_PARTID             0x1480
#define AD714X_STAGECFG_REG       0x80
#define AD714X_SYSCFG_REG         0x0

#define STG_LOW_INT_EN_REG     0x5
#define STG_HIGH_INT_EN_REG    0x6
#define STG_COM_INT_EN_REG     0x7
#define STG_LOW_INT_STA_REG    0x8
#define STG_HIGH_INT_STA_REG   0x9
#define STG_COM_INT_STA_REG    0xA

#define CDC_RESULT_S0          0xB
#define CDC_RESULT_S1          0xC
#define CDC_RESULT_S2          0xD
#define CDC_RESULT_S3          0xE
#define CDC_RESULT_S4          0xF
#define CDC_RESULT_S5          0x10
#define CDC_RESULT_S6          0x11
#define CDC_RESULT_S7          0x12
#define CDC_RESULT_S8          0x13
#define CDC_RESULT_S9          0x14
#define CDC_RESULT_S10         0x15
#define CDC_RESULT_S11         0x16

#define STAGE0_AMBIENT		0xF1
#define STAGE1_AMBIENT		0x115
#define STAGE2_AMBIENT		0x139
#define STAGE3_AMBIENT		0x15D
#define STAGE4_AMBIENT		0x181
#define STAGE5_AMBIENT		0x1A5
#define STAGE6_AMBIENT		0x1C9
#define STAGE7_AMBIENT		0x1ED
#define STAGE8_AMBIENT		0x211
#define STAGE9_AMBIENT		0x234
#define STAGE10_AMBIENT		0x259
#define STAGE11_AMBIENT		0x27D

#define PER_STAGE_REG_NUM      36
#define STAGE_CFGREG_NUM       8
#define SYS_CFGREG_NUM         8

/*
 * driver information which will be used to maintain the software flow
 */
enum ad714x_device_state { IDLE, JITTER, ACTIVE, SPACE };

struct ad714x_slider_drv {
	int highest_stage;
	int abs_pos;
	int flt_pos;
	enum ad714x_device_state state;
	struct input_dev *input;
};

struct ad714x_wheel_drv {
	int abs_pos;
	int flt_pos;
	int pre_highest_stage;
	int highest_stage;
	enum ad714x_device_state state;
	struct input_dev *input;
};

struct ad714x_touchpad_drv {
	int x_highest_stage;
	int x_flt_pos;
	int x_abs_pos;
	int y_highest_stage;
	int y_flt_pos;
	int y_abs_pos;
	int left_ep;
	int left_ep_val;
	int right_ep;
	int right_ep_val;
	int top_ep;
	int top_ep_val;
	int bottom_ep;
	int bottom_ep_val;
	enum ad714x_device_state state;
	struct input_dev *input;
};

struct ad714x_button_drv {
	enum ad714x_device_state state;
	/*
	 * Unlike slider/wheel/touchpad, all buttons point to
	 * same input_dev instance
	 */
	struct input_dev *input;
};

struct ad714x_driver_data {
	struct ad714x_slider_drv *slider;
	struct ad714x_wheel_drv *wheel;
	struct ad714x_touchpad_drv *touchpad;
	struct ad714x_button_drv *button;
};

/*
 * information to integrate all things which will be private data
 * of spi/i2c device
 */

static void ad714x_use_com_int(struct ad714x_chip *ad714x,
				int start_stage, int end_stage)
{
	unsigned short data;
	unsigned short mask;

	mask = ((1 << (end_stage + 1)) - 1) - ((1 << start_stage) - 1);

	ad714x->read(ad714x, STG_COM_INT_EN_REG, &data, 1);
	data |= 1 << end_stage;
	ad714x->write(ad714x, STG_COM_INT_EN_REG, data);

	ad714x->read(ad714x, STG_HIGH_INT_EN_REG, &data, 1);
	data &= ~mask;
	ad714x->write(ad714x, STG_HIGH_INT_EN_REG, data);
}

static void ad714x_use_thr_int(struct ad714x_chip *ad714x,
				int start_stage, int end_stage)
{
	unsigned short data;
	unsigned short mask;

	mask = ((1 << (end_stage + 1)) - 1) - ((1 << start_stage) - 1);

	ad714x->read(ad714x, STG_COM_INT_EN_REG, &data, 1);
	data &= ~(1 << end_stage);
	ad714x->write(ad714x, STG_COM_INT_EN_REG, data);

	ad714x->read(ad714x, STG_HIGH_INT_EN_REG, &data, 1);
	data |= mask;
	ad714x->write(ad714x, STG_HIGH_INT_EN_REG, data);
}

static int ad714x_cal_highest_stage(struct ad714x_chip *ad714x,
					int start_stage, int end_stage)
{
	int max_res = 0;
	int max_idx = 0;
	int i;

	for (i = start_stage; i <= end_stage; i++) {
		if (ad714x->sensor_val[i] > max_res) {
			max_res = ad714x->sensor_val[i];
			max_idx = i;
		}
	}

	return max_idx;
}

static int ad714x_cal_abs_pos(struct ad714x_chip *ad714x,
				int start_stage, int end_stage,
				int highest_stage, int max_coord)
{
	int a_param, b_param;

	if (highest_stage == start_stage) {
		a_param = ad714x->sensor_val[start_stage + 1];
		b_param = ad714x->sensor_val[start_stage] +
			ad714x->sensor_val[start_stage + 1];
	} else if (highest_stage == end_stage) {
		a_param = ad714x->sensor_val[end_stage] *
			(end_stage - start_stage) +
			ad714x->sensor_val[end_stage - 1] *
			(end_stage - start_stage - 1);
		b_param = ad714x->sensor_val[end_stage] +
			ad714x->sensor_val[end_stage - 1];
	} else {
		a_param = ad714x->sensor_val[highest_stage] *
			(highest_stage - start_stage) +
			ad714x->sensor_val[highest_stage - 1] *
			(highest_stage - start_stage - 1) +
			ad714x->sensor_val[highest_stage + 1] *
			(highest_stage - start_stage + 1);
		b_param = ad714x->sensor_val[highest_stage] +
			ad714x->sensor_val[highest_stage - 1] +
			ad714x->sensor_val[highest_stage + 1];
	}

	return (max_coord / (end_stage - start_stage)) * a_param / b_param;
}

/*
 * One button can connect to multi positive and negative of CDCs
 * Multi-buttons can connect to same positive/negative of one CDC
 */
static void ad714x_button_state_machine(struct ad714x_chip *ad714x, int idx)
{
	struct ad714x_button_plat *hw = &ad714x->hw->button[idx];
	struct ad714x_button_drv *sw = &ad714x->sw->button[idx];

	switch (sw->state) {
	case IDLE:
		if (((ad714x->h_state & hw->h_mask) == hw->h_mask) &&
		    ((ad714x->l_state & hw->l_mask) == hw->l_mask)) {
			dev_dbg(ad714x->dev, "button %d touched\n", idx);
			input_report_key(sw->input, hw->keycode, 1);
			input_sync(sw->input);
			sw->state = ACTIVE;
		}
		break;

	case ACTIVE:
		if (((ad714x->h_state & hw->h_mask) != hw->h_mask) ||
		    ((ad714x->l_state & hw->l_mask) != hw->l_mask)) {
			dev_dbg(ad714x->dev, "button %d released\n", idx);
			input_report_key(sw->input, hw->keycode, 0);
			input_sync(sw->input);
			sw->state = IDLE;
		}
		break;

	default:
		break;
	}
}

/*
 * The response of a sensor is defined by the absolute number of codes
 * between the current CDC value and the ambient value.
 */
static void ad714x_slider_cal_sensor_val(struct ad714x_chip *ad714x, int idx)
{
	struct ad714x_slider_plat *hw = &ad714x->hw->slider[idx];
	int i;

	ad714x->read(ad714x, CDC_RESULT_S0 + hw->start_stage,
			&ad714x->adc_reg[hw->start_stage],
			hw->end_stage - hw->start_stage + 1);

	for (i = hw->start_stage; i <= hw->end_stage; i++) {
		ad714x->read(ad714x, STAGE0_AMBIENT + i * PER_STAGE_REG_NUM,
				&ad714x->amb_reg[i], 1);

		ad714x->sensor_val[i] =
			abs(ad714x->adc_reg[i] - ad714x->amb_reg[i]);
	}
}

static void ad714x_slider_cal_highest_stage(struct ad714x_chip *ad714x, int idx)
{
	struct ad714x_slider_plat *hw = &ad714x->hw->slider[idx];
	struct ad714x_slider_drv *sw = &ad714x->sw->slider[idx];

	sw->highest_stage = ad714x_cal_highest_stage(ad714x, hw->start_stage,
			hw->end_stage);

	dev_dbg(ad714x->dev, "slider %d highest_stage:%d\n", idx,
		sw->highest_stage);
}

/*
 * The formulae are very straight forward. It uses the sensor with the
 * highest response and the 2 adjacent ones.
 * When Sensor 0 has the highest response, only sensor 0 and sensor 1
 * are used in the calculations. Similarly when the last sensor has the
 * highest response, only the last sensor and the second last sensors
 * are used in the calculations.
 *
 * For i= idx_of_peak_Sensor-1 to i= idx_of_peak_Sensor+1
 *         v += Sensor response(i)*i
 *         w += Sensor response(i)
 * POS=(Number_of_Positions_Wanted/(Number_of_Sensors_Used-1)) *(v/w)
 */
static void ad714x_slider_cal_abs_pos(struct ad714x_chip *ad714x, int idx)
{
	struct ad714x_slider_plat *hw = &ad714x->hw->slider[idx];
	struct ad714x_slider_drv *sw = &ad714x->sw->slider[idx];

	sw->abs_pos = ad714x_cal_abs_pos(ad714x, hw->start_stage, hw->end_stage,
		sw->highest_stage, hw->max_coord);

	dev_dbg(ad714x->dev, "slider %d absolute position:%d\n", idx,
		sw->abs_pos);
}

/*
 * To minimise the Impact of the noise on the algorithm, ADI developed a
 * routine that filters the CDC results after they have been read by the
 * host processor.
 * The filter used is an Infinite Input Response(IIR) filter implemented
 * in firmware and attenuates the noise on the CDC results after they've
 * been read by the host processor.
 * Filtered_CDC_result = (Filtered_CDC_result * (10 - Coefficient) +
 *				Latest_CDC_result * Coefficient)/10
 */
static void ad714x_slider_cal_flt_pos(struct ad714x_chip *ad714x, int idx)
{
	struct ad714x_slider_drv *sw = &ad714x->sw->slider[idx];

	sw->flt_pos = (sw->flt_pos * (10 - 4) +
			sw->abs_pos * 4)/10;

	dev_dbg(ad714x->dev, "slider %d filter position:%d\n", idx,
		sw->flt_pos);
}

static void ad714x_slider_use_com_int(struct ad714x_chip *ad714x, int idx)
{
	struct ad714x_slider_plat *hw = &ad714x->hw->slider[idx];

	ad714x_use_com_int(ad714x, hw->start_stage, hw->end_stage);
}

static void ad714x_slider_use_thr_int(struct ad714x_chip *ad714x, int idx)
{
	struct ad714x_slider_plat *hw = &ad714x->hw->slider[idx];

	ad714x_use_thr_int(ad714x, hw->start_stage, hw->end_stage);
}

static void ad714x_slider_state_machine(struct ad714x_chip *ad714x, int idx)
{
	struct ad714x_slider_plat *hw = &ad714x->hw->slider[idx];
	struct ad714x_slider_drv *sw = &ad714x->sw->slider[idx];
	unsigned short h_state, c_state;
	unsigned short mask;

	mask = ((1 << (hw->end_stage + 1)) - 1) - ((1 << hw->start_stage) - 1);

	h_state = ad714x->h_state & mask;
	c_state = ad714x->c_state & mask;

	switch (sw->state) {
	case IDLE:
		if (h_state) {
			sw->state = JITTER;
			/* In End of Conversion interrupt mode, the AD714X
			 * continuously generates hardware interrupts.
			 */
			ad714x_slider_use_com_int(ad714x, idx);
			dev_dbg(ad714x->dev, "slider %d touched\n", idx);
		}
		break;

	case JITTER:
		if (c_state == mask) {
			ad714x_slider_cal_sensor_val(ad714x, idx);
			ad714x_slider_cal_highest_stage(ad714x, idx);
			ad714x_slider_cal_abs_pos(ad714x, idx);
			sw->flt_pos = sw->abs_pos;
			sw->state = ACTIVE;
		}
		break;

	case ACTIVE:
		if (c_state == mask) {
			if (h_state) {
				ad714x_slider_cal_sensor_val(ad714x, idx);
				ad714x_slider_cal_highest_stage(ad714x, idx);
				ad714x_slider_cal_abs_pos(ad714x, idx);
				ad714x_slider_cal_flt_pos(ad714x, idx);
				input_report_abs(sw->input, ABS_X, sw->flt_pos);
				input_report_key(sw->input, BTN_TOUCH, 1);
			} else {
				/* When the user lifts off the sensor, configure
				 * the AD714X back to threshold interrupt mode.
				 */
				ad714x_slider_use_thr_int(ad714x, idx);
				sw->state = IDLE;
				input_report_key(sw->input, BTN_TOUCH, 0);
				dev_dbg(ad714x->dev, "slider %d released\n",
					idx);
			}
			input_sync(sw->input);
		}
		break;

	default:
		break;
	}
}

/*
 * When the scroll wheel is activated, we compute the absolute position based
 * on the sensor values. To calculate the position, we first determine the
 * sensor that has the greatest response among the 8 sensors that constitutes
 * the scrollwheel. Then we determined the 2 sensors on either sides of the
 * sensor with the highest response and we apply weights to these sensors.
 */
static void ad714x_wheel_cal_highest_stage(struct ad714x_chip *ad714x, int idx)
{
	struct ad714x_wheel_plat *hw = &ad714x->hw->wheel[idx];
	struct ad714x_wheel_drv *sw = &ad714x->sw->wheel[idx];

	sw->pre_highest_stage = sw->highest_stage;
	sw->highest_stage = ad714x_cal_highest_stage(ad714x, hw->start_stage,
			hw->end_stage);

	dev_dbg(ad714x->dev, "wheel %d highest_stage:%d\n", idx,
		sw->highest_stage);
}

static void ad714x_wheel_cal_sensor_val(struct ad714x_chip *ad714x, int idx)
{
	struct ad714x_wheel_plat *hw = &ad714x->hw->wheel[idx];
	int i;

	ad714x->read(ad714x, CDC_RESULT_S0 + hw->start_stage,
			&ad714x->adc_reg[hw->start_stage],
			hw->end_stage - hw->start_stage + 1);

	for (i = hw->start_stage; i <= hw->end_stage; i++) {
		ad714x->read(ad714x, STAGE0_AMBIENT + i * PER_STAGE_REG_NUM,
				&ad714x->amb_reg[i], 1);
		if (ad714x->adc_reg[i] > ad714x->amb_reg[i])
			ad714x->sensor_val[i] =
				ad714x->adc_reg[i] - ad714x->amb_reg[i];
		else
			ad714x->sensor_val[i] = 0;
	}
}

/*
 * When the scroll wheel is activated, we compute the absolute position based
 * on the sensor values. To calculate the position, we first determine the
 * sensor that has the greatest response among the sensors that constitutes
 * the scrollwheel. Then we determined the sensors on either sides of the
 * sensor with the highest response and we apply weights to these sensors. The
 * result of this computation gives us the mean value.
 */

static void ad714x_wheel_cal_abs_pos(struct ad714x_chip *ad714x, int idx)
{
	struct ad714x_wheel_plat *hw = &ad714x->hw->wheel[idx];
	struct ad714x_wheel_drv *sw = &ad714x->sw->wheel[idx];
	int stage_num = hw->end_stage - hw->start_stage + 1;
	int first_before, highest, first_after;
	int a_param, b_param;

	first_before = (sw->highest_stage + stage_num - 1) % stage_num;
	highest = sw->highest_stage;
	first_after = (sw->highest_stage + stage_num + 1) % stage_num;

	a_param = ad714x->sensor_val[highest] *
		(highest - hw->start_stage) +
		ad714x->sensor_val[first_before] *
		(highest - hw->start_stage - 1) +
		ad714x->sensor_val[first_after] *
		(highest - hw->start_stage + 1);
	b_param = ad714x->sensor_val[highest] +
		ad714x->sensor_val[first_before] +
		ad714x->sensor_val[first_after];

	sw->abs_pos = ((hw->max_coord / (hw->end_stage - hw->start_stage)) *
			a_param) / b_param;

	if (sw->abs_pos > hw->max_coord)
		sw->abs_pos = hw->max_coord;
	else if (sw->abs_pos < 0)
		sw->abs_pos = 0;
}

static void ad714x_wheel_cal_flt_pos(struct ad714x_chip *ad714x, int idx)
{
	struct ad714x_wheel_plat *hw = &ad714x->hw->wheel[idx];
	struct ad714x_wheel_drv *sw = &ad714x->sw->wheel[idx];
	if (((sw->pre_highest_stage == hw->end_stage) &&
			(sw->highest_stage == hw->start_stage)) ||
	    ((sw->pre_highest_stage == hw->start_stage) &&
			(sw->highest_stage == hw->end_stage)))
		sw->flt_pos = sw->abs_pos;
	else
		sw->flt_pos = ((sw->flt_pos * 30) + (sw->abs_pos * 71)) / 100;

	if (sw->flt_pos > hw->max_coord)
		sw->flt_pos = hw->max_coord;
}

static void ad714x_wheel_use_com_int(struct ad714x_chip *ad714x, int idx)
{
	struct ad714x_wheel_plat *hw = &ad714x->hw->wheel[idx];

	ad714x_use_com_int(ad714x, hw->start_stage, hw->end_stage);
}

static void ad714x_wheel_use_thr_int(struct ad714x_chip *ad714x, int idx)
{
	struct ad714x_wheel_plat *hw = &ad714x->hw->wheel[idx];

	ad714x_use_thr_int(ad714x, hw->start_stage, hw->end_stage);
}

static void ad714x_wheel_state_machine(struct ad714x_chip *ad714x, int idx)
{
	struct ad714x_wheel_plat *hw = &ad714x->hw->wheel[idx];
	struct ad714x_wheel_drv *sw = &ad714x->sw->wheel[idx];
	unsigned short h_state, c_state;
	unsigned short mask;

	mask = ((1 << (hw->end_stage + 1)) - 1) - ((1 << hw->start_stage) - 1);

	h_state = ad714x->h_state & mask;
	c_state = ad714x->c_state & mask;

	switch (sw->state) {
	case IDLE:
		if (h_state) {
			sw->state = JITTER;
			/* In End of Conversion interrupt mode, the AD714X
			 * continuously generates hardware interrupts.
			 */
			ad714x_wheel_use_com_int(ad714x, idx);
			dev_dbg(ad714x->dev, "wheel %d touched\n", idx);
		}
		break;

	case JITTER:
		if (c_state == mask)	{
			ad714x_wheel_cal_sensor_val(ad714x, idx);
			ad714x_wheel_cal_highest_stage(ad714x, idx);
			ad714x_wheel_cal_abs_pos(ad714x, idx);
			sw->flt_pos = sw->abs_pos;
			sw->state = ACTIVE;
		}
		break;

	case ACTIVE:
		if (c_state == mask) {
			if (h_state) {
				ad714x_wheel_cal_sensor_val(ad714x, idx);
				ad714x_wheel_cal_highest_stage(ad714x, idx);
				ad714x_wheel_cal_abs_pos(ad714x, idx);
				ad714x_wheel_cal_flt_pos(ad714x, idx);
				input_report_abs(sw->input, ABS_WHEEL,
					sw->flt_pos);
				input_report_key(sw->input, BTN_TOUCH, 1);
			} else {
				/* When the user lifts off the sensor, configure
				 * the AD714X back to threshold interrupt mode.
				 */
				ad714x_wheel_use_thr_int(ad714x, idx);
				sw->state = IDLE;
				input_report_key(sw->input, BTN_TOUCH, 0);

				dev_dbg(ad714x->dev, "wheel %d released\n",
					idx);
			}
			input_sync(sw->input);
		}
		break;

	default:
		break;
	}
}

static void touchpad_cal_sensor_val(struct ad714x_chip *ad714x, int idx)
{
	struct ad714x_touchpad_plat *hw = &ad714x->hw->touchpad[idx];
	int i;

	ad714x->read(ad714x, CDC_RESULT_S0 + hw->x_start_stage,
			&ad714x->adc_reg[hw->x_start_stage],
			hw->x_end_stage - hw->x_start_stage + 1);

	for (i = hw->x_start_stage; i <= hw->x_end_stage; i++) {
		ad714x->read(ad714x, STAGE0_AMBIENT + i * PER_STAGE_REG_NUM,
				&ad714x->amb_reg[i], 1);
		if (ad714x->adc_reg[i] > ad714x->amb_reg[i])
			ad714x->sensor_val[i] =
				ad714x->adc_reg[i] - ad714x->amb_reg[i];
		else
			ad714x->sensor_val[i] = 0;
	}
}

static void touchpad_cal_highest_stage(struct ad714x_chip *ad714x, int idx)
{
	struct ad714x_touchpad_plat *hw = &ad714x->hw->touchpad[idx];
	struct ad714x_touchpad_drv *sw = &ad714x->sw->touchpad[idx];

	sw->x_highest_stage = ad714x_cal_highest_stage(ad714x,
		hw->x_start_stage, hw->x_end_stage);
	sw->y_highest_stage = ad714x_cal_highest_stage(ad714x,
		hw->y_start_stage, hw->y_end_stage);

	dev_dbg(ad714x->dev,
		"touchpad %d x_highest_stage:%d, y_highest_stage:%d\n",
		idx, sw->x_highest_stage, sw->y_highest_stage);
}

/*
 * If 2 fingers are touching the sensor then 2 peaks can be observed in the
 * distribution.
 * The arithmetic doesn't support to get absolute coordinates for multi-touch
 * yet.
 */
static int touchpad_check_second_peak(struct ad714x_chip *ad714x, int idx)
{
	struct ad714x_touchpad_plat *hw = &ad714x->hw->touchpad[idx];
	struct ad714x_touchpad_drv *sw = &ad714x->sw->touchpad[idx];
	int i;

	for (i = hw->x_start_stage; i < sw->x_highest_stage; i++) {
		if ((ad714x->sensor_val[i] - ad714x->sensor_val[i + 1])
			> (ad714x->sensor_val[i + 1] / 10))
			return 1;
	}

	for (i = sw->x_highest_stage; i < hw->x_end_stage; i++) {
		if ((ad714x->sensor_val[i + 1] - ad714x->sensor_val[i])
			> (ad714x->sensor_val[i] / 10))
			return 1;
	}

	for (i = hw->y_start_stage; i < sw->y_highest_stage; i++) {
		if ((ad714x->sensor_val[i] - ad714x->sensor_val[i + 1])
			> (ad714x->sensor_val[i + 1] / 10))
			return 1;
	}

	for (i = sw->y_highest_stage; i < hw->y_end_stage; i++) {
		if ((ad714x->sensor_val[i + 1] - ad714x->sensor_val[i])
			> (ad714x->sensor_val[i] / 10))
			return 1;
	}

	return 0;
}

/*
 * If only one finger is used to activate the touch pad then only 1 peak will be
 * registered in the distribution. This peak and the 2 adjacent sensors will be
 * used in the calculation of the absolute position. This will prevent hand
 * shadows to affect the absolute position calculation.
 */
static void touchpad_cal_abs_pos(struct ad714x_chip *ad714x, int idx)
{
	struct ad714x_touchpad_plat *hw = &ad714x->hw->touchpad[idx];
	struct ad714x_touchpad_drv *sw = &ad714x->sw->touchpad[idx];

	sw->x_abs_pos = ad714x_cal_abs_pos(ad714x, hw->x_start_stage,
			hw->x_end_stage, sw->x_highest_stage, hw->x_max_coord);
	sw->y_abs_pos = ad714x_cal_abs_pos(ad714x, hw->y_start_stage,
			hw->y_end_stage, sw->y_highest_stage, hw->y_max_coord);

	dev_dbg(ad714x->dev, "touchpad %d absolute position:(%d, %d)\n", idx,
			sw->x_abs_pos, sw->y_abs_pos);
}

static void touchpad_cal_flt_pos(struct ad714x_chip *ad714x, int idx)
{
	struct ad714x_touchpad_drv *sw = &ad714x->sw->touchpad[idx];

	sw->x_flt_pos = (sw->x_flt_pos * (10 - 4) +
			sw->x_abs_pos * 4)/10;
	sw->y_flt_pos = (sw->y_flt_pos * (10 - 4) +
			sw->y_abs_pos * 4)/10;

	dev_dbg(ad714x->dev, "touchpad %d filter position:(%d, %d)\n",
			idx, sw->x_flt_pos, sw->y_flt_pos);
}

/*
 * To prevent distortion from showing in the absolute position, it is
 * necessary to detect the end points. When endpoints are detected, the
 * driver stops updating the status variables with absolute positions.
 * End points are detected on the 4 edges of the touchpad sensor. The
 * method to detect them is the same for all 4.
 * To detect the end points, the firmware computes the difference in
 * percent between the sensor on the edge and the adjacent one. The
 * difference is calculated in percent in order to make the end point
 * detection independent of the pressure.
 */

#define LEFT_END_POINT_DETECTION_LEVEL                  550
#define RIGHT_END_POINT_DETECTION_LEVEL                 750
#define LEFT_RIGHT_END_POINT_DEAVTIVALION_LEVEL         850
#define TOP_END_POINT_DETECTION_LEVEL                   550
#define BOTTOM_END_POINT_DETECTION_LEVEL                950
#define TOP_BOTTOM_END_POINT_DEAVTIVALION_LEVEL         700
static int touchpad_check_endpoint(struct ad714x_chip *ad714x, int idx)
{
	struct ad714x_touchpad_plat *hw = &ad714x->hw->touchpad[idx];
	struct ad714x_touchpad_drv *sw  = &ad714x->sw->touchpad[idx];
	int percent_sensor_diff;

	/* left endpoint detect */
	percent_sensor_diff = (ad714x->sensor_val[hw->x_start_stage] -
			ad714x->sensor_val[hw->x_start_stage + 1]) * 100 /
			ad714x->sensor_val[hw->x_start_stage + 1];
	if (!sw->left_ep) {
		if (percent_sensor_diff >= LEFT_END_POINT_DETECTION_LEVEL)  {
			sw->left_ep = 1;
			sw->left_ep_val =
				ad714x->sensor_val[hw->x_start_stage + 1];
		}
	} else {
		if ((percent_sensor_diff < LEFT_END_POINT_DETECTION_LEVEL) &&
		    (ad714x->sensor_val[hw->x_start_stage + 1] >
		     LEFT_RIGHT_END_POINT_DEAVTIVALION_LEVEL + sw->left_ep_val))
			sw->left_ep = 0;
	}

	/* right endpoint detect */
	percent_sensor_diff = (ad714x->sensor_val[hw->x_end_stage] -
			ad714x->sensor_val[hw->x_end_stage - 1]) * 100 /
			ad714x->sensor_val[hw->x_end_stage - 1];
	if (!sw->right_ep) {
		if (percent_sensor_diff >= RIGHT_END_POINT_DETECTION_LEVEL)  {
			sw->right_ep = 1;
			sw->right_ep_val =
				ad714x->sensor_val[hw->x_end_stage - 1];
		}
	} else {
		if ((percent_sensor_diff < RIGHT_END_POINT_DETECTION_LEVEL) &&
		(ad714x->sensor_val[hw->x_end_stage - 1] >
		LEFT_RIGHT_END_POINT_DEAVTIVALION_LEVEL + sw->right_ep_val))
			sw->right_ep = 0;
	}

	/* top endpoint detect */
	percent_sensor_diff = (ad714x->sensor_val[hw->y_start_stage] -
			ad714x->sensor_val[hw->y_start_stage + 1]) * 100 /
			ad714x->sensor_val[hw->y_start_stage + 1];
	if (!sw->top_ep) {
		if (percent_sensor_diff >= TOP_END_POINT_DETECTION_LEVEL)  {
			sw->top_ep = 1;
			sw->top_ep_val =
				ad714x->sensor_val[hw->y_start_stage + 1];
		}
	} else {
		if ((percent_sensor_diff < TOP_END_POINT_DETECTION_LEVEL) &&
		(ad714x->sensor_val[hw->y_start_stage + 1] >
		TOP_BOTTOM_END_POINT_DEAVTIVALION_LEVEL + sw->top_ep_val))
			sw->top_ep = 0;
	}

	/* bottom endpoint detect */
	percent_sensor_diff = (ad714x->sensor_val[hw->y_end_stage] -
		ad714x->sensor_val[hw->y_end_stage - 1]) * 100 /
		ad714x->sensor_val[hw->y_end_stage - 1];
	if (!sw->bottom_ep) {
		if (percent_sensor_diff >= BOTTOM_END_POINT_DETECTION_LEVEL)  {
			sw->bottom_ep = 1;
			sw->bottom_ep_val =
				ad714x->sensor_val[hw->y_end_stage - 1];
		}
	} else {
		if ((percent_sensor_diff < BOTTOM_END_POINT_DETECTION_LEVEL) &&
		(ad714x->sensor_val[hw->y_end_stage - 1] >
		 TOP_BOTTOM_END_POINT_DEAVTIVALION_LEVEL + sw->bottom_ep_val))
			sw->bottom_ep = 0;
	}

	return sw->left_ep || sw->right_ep || sw->top_ep || sw->bottom_ep;
}

static void touchpad_use_com_int(struct ad714x_chip *ad714x, int idx)
{
	struct ad714x_touchpad_plat *hw = &ad714x->hw->touchpad[idx];

	ad714x_use_com_int(ad714x, hw->x_start_stage, hw->x_end_stage);
}

static void touchpad_use_thr_int(struct ad714x_chip *ad714x, int idx)
{
	struct ad714x_touchpad_plat *hw = &ad714x->hw->touchpad[idx];

	ad714x_use_thr_int(ad714x, hw->x_start_stage, hw->x_end_stage);
	ad714x_use_thr_int(ad714x, hw->y_start_stage, hw->y_end_stage);
}

static void ad714x_touchpad_state_machine(struct ad714x_chip *ad714x, int idx)
{
	struct ad714x_touchpad_plat *hw = &ad714x->hw->touchpad[idx];
	struct ad714x_touchpad_drv *sw = &ad714x->sw->touchpad[idx];
	unsigned short h_state, c_state;
	unsigned short mask;

	mask = (((1 << (hw->x_end_stage + 1)) - 1) -
		((1 << hw->x_start_stage) - 1)) +
		(((1 << (hw->y_end_stage + 1)) - 1) -
		((1 << hw->y_start_stage) - 1));

	h_state = ad714x->h_state & mask;
	c_state = ad714x->c_state & mask;

	switch (sw->state) {
	case IDLE:
		if (h_state) {
			sw->state = JITTER;
			/* In End of Conversion interrupt mode, the AD714X
			 * continuously generates hardware interrupts.
			 */
			touchpad_use_com_int(ad714x, idx);
			dev_dbg(ad714x->dev, "touchpad %d touched\n", idx);
		}
		break;

	case JITTER:
		if (c_state == mask) {
			touchpad_cal_sensor_val(ad714x, idx);
			touchpad_cal_highest_stage(ad714x, idx);
			if ((!touchpad_check_second_peak(ad714x, idx)) &&
				(!touchpad_check_endpoint(ad714x, idx))) {
				dev_dbg(ad714x->dev,
					"touchpad%d, 2 fingers or endpoint\n",
					idx);
				touchpad_cal_abs_pos(ad714x, idx);
				sw->x_flt_pos = sw->x_abs_pos;
				sw->y_flt_pos = sw->y_abs_pos;
				sw->state = ACTIVE;
			}
		}
		break;

	case ACTIVE:
		if (c_state == mask) {
			if (h_state) {
				touchpad_cal_sensor_val(ad714x, idx);
				touchpad_cal_highest_stage(ad714x, idx);
				if ((!touchpad_check_second_peak(ad714x, idx))
				  && (!touchpad_check_endpoint(ad714x, idx))) {
					touchpad_cal_abs_pos(ad714x, idx);
					touchpad_cal_flt_pos(ad714x, idx);
					input_report_abs(sw->input, ABS_X,
						sw->x_flt_pos);
					input_report_abs(sw->input, ABS_Y,
						sw->y_flt_pos);
					input_report_key(sw->input, BTN_TOUCH,
						1);
				}
			} else {
				/* When the user lifts off the sensor, configure
				 * the AD714X back to threshold interrupt mode.
				 */
				touchpad_use_thr_int(ad714x, idx);
				sw->state = IDLE;
				input_report_key(sw->input, BTN_TOUCH, 0);
				dev_dbg(ad714x->dev, "touchpad %d released\n",
					idx);
			}
			input_sync(sw->input);
		}
		break;

	default:
		break;
	}
}

static int ad714x_hw_detect(struct ad714x_chip *ad714x)
{
	unsigned short data;

	ad714x->read(ad714x, AD714X_PARTID_REG, &data, 1);
	switch (data & 0xFFF0) {
	case AD7142_PARTID:
		ad714x->product = 0x7142;
		ad714x->version = data & 0xF;
		dev_info(ad714x->dev, "found AD7142 captouch, rev:%d\n",
				ad714x->version);
		return 0;

	case AD7143_PARTID:
		ad714x->product = 0x7143;
		ad714x->version = data & 0xF;
		dev_info(ad714x->dev, "found AD7143 captouch, rev:%d\n",
				ad714x->version);
		return 0;

	case AD7147_PARTID:
		ad714x->product = 0x7147;
		ad714x->version = data & 0xF;
		dev_info(ad714x->dev, "found AD7147(A) captouch, rev:%d\n",
				ad714x->version);
		return 0;

	case AD7148_PARTID:
		ad714x->product = 0x7148;
		ad714x->version = data & 0xF;
		dev_info(ad714x->dev, "found AD7148 captouch, rev:%d\n",
				ad714x->version);
		return 0;

	default:
		dev_err(ad714x->dev,
			"fail to detect AD714X captouch, read ID is %04x\n",
			data);
		return -ENODEV;
	}
}

static void ad714x_hw_init(struct ad714x_chip *ad714x)
{
	int i, j;
	unsigned short reg_base;
	unsigned short data;

	/* configuration CDC and interrupts */

	for (i = 0; i < STAGE_NUM; i++) {
		reg_base = AD714X_STAGECFG_REG + i * STAGE_CFGREG_NUM;
		for (j = 0; j < STAGE_CFGREG_NUM; j++)
			ad714x->write(ad714x, reg_base + j,
					ad714x->hw->stage_cfg_reg[i][j]);
	}

	for (i = 0; i < SYS_CFGREG_NUM; i++)
		ad714x->write(ad714x, AD714X_SYSCFG_REG + i,
			ad714x->hw->sys_cfg_reg[i]);
	for (i = 0; i < SYS_CFGREG_NUM; i++)
		ad714x->read(ad714x, AD714X_SYSCFG_REG + i, &data, 1);

	ad714x->write(ad714x, AD714X_STG_CAL_EN_REG, 0xFFF);

	/* clear all interrupts */
	ad714x->read(ad714x, STG_LOW_INT_STA_REG, &ad714x->l_state, 3);
}

static irqreturn_t ad714x_interrupt_thread(int irq, void *data)
{
	struct ad714x_chip *ad714x = data;
	int i;

	mutex_lock(&ad714x->mutex);

	ad714x->read(ad714x, STG_LOW_INT_STA_REG, &ad714x->l_state, 3);

	for (i = 0; i < ad714x->hw->button_num; i++)
		ad714x_button_state_machine(ad714x, i);
	for (i = 0; i < ad714x->hw->slider_num; i++)
		ad714x_slider_state_machine(ad714x, i);
	for (i = 0; i < ad714x->hw->wheel_num; i++)
		ad714x_wheel_state_machine(ad714x, i);
	for (i = 0; i < ad714x->hw->touchpad_num; i++)
		ad714x_touchpad_state_machine(ad714x, i);

	mutex_unlock(&ad714x->mutex);

	return IRQ_HANDLED;
}

#define MAX_DEVICE_NUM 8
struct ad714x_chip *ad714x_probe(struct device *dev, u16 bus_type, int irq,
				 ad714x_read_t read, ad714x_write_t write)
{
	int i, alloc_idx;
	int error;
	struct input_dev *input[MAX_DEVICE_NUM];

	struct ad714x_platform_data *plat_data = dev_get_platdata(dev);
	struct ad714x_chip *ad714x;
	void *drv_mem;
	unsigned long irqflags;

	struct ad714x_button_drv *bt_drv;
	struct ad714x_slider_drv *sd_drv;
	struct ad714x_wheel_drv *wl_drv;
	struct ad714x_touchpad_drv *tp_drv;


	if (irq <= 0) {
		dev_err(dev, "IRQ not configured!\n");
		error = -EINVAL;
		goto err_out;
	}

	if (dev_get_platdata(dev) == NULL) {
		dev_err(dev, "platform data for ad714x doesn't exist\n");
		error = -EINVAL;
		goto err_out;
	}

	ad714x = kzalloc(sizeof(*ad714x) + sizeof(*ad714x->sw) +
			 sizeof(*sd_drv) * plat_data->slider_num +
			 sizeof(*wl_drv) * plat_data->wheel_num +
			 sizeof(*tp_drv) * plat_data->touchpad_num +
			 sizeof(*bt_drv) * plat_data->button_num, GFP_KERNEL);
	if (!ad714x) {
		error = -ENOMEM;
		goto err_out;
	}

	ad714x->hw = plat_data;

	drv_mem = ad714x + 1;
	ad714x->sw = drv_mem;
	drv_mem += sizeof(*ad714x->sw);
	ad714x->sw->slider = sd_drv = drv_mem;
	drv_mem += sizeof(*sd_drv) * ad714x->hw->slider_num;
	ad714x->sw->wheel = wl_drv = drv_mem;
	drv_mem += sizeof(*wl_drv) * ad714x->hw->wheel_num;
	ad714x->sw->touchpad = tp_drv = drv_mem;
	drv_mem += sizeof(*tp_drv) * ad714x->hw->touchpad_num;
	ad714x->sw->button = bt_drv = drv_mem;
	drv_mem += sizeof(*bt_drv) * ad714x->hw->button_num;

	ad714x->read = read;
	ad714x->write = write;
	ad714x->irq = irq;
	ad714x->dev = dev;

	error = ad714x_hw_detect(ad714x);
	if (error)
		goto err_free_mem;

	/* initialize and request sw/hw resources */

	ad714x_hw_init(ad714x);
	mutex_init(&ad714x->mutex);

	/*
	 * Allocate and register AD714X input device
	 */
	alloc_idx = 0;

	/* a slider uses one input_dev instance */
	if (ad714x->hw->slider_num > 0) {
		struct ad714x_slider_plat *sd_plat = ad714x->hw->slider;

		for (i = 0; i < ad714x->hw->slider_num; i++) {
			sd_drv[i].input = input[alloc_idx] = input_allocate_device();
			if (!input[alloc_idx]) {
				error = -ENOMEM;
				goto err_free_dev;
			}

			__set_bit(EV_ABS, input[alloc_idx]->evbit);
			__set_bit(EV_KEY, input[alloc_idx]->evbit);
			__set_bit(ABS_X, input[alloc_idx]->absbit);
			__set_bit(BTN_TOUCH, input[alloc_idx]->keybit);
			input_set_abs_params(input[alloc_idx],
				ABS_X, 0, sd_plat->max_coord, 0, 0);

			input[alloc_idx]->id.bustype = bus_type;
			input[alloc_idx]->id.product = ad714x->product;
			input[alloc_idx]->id.version = ad714x->version;
			input[alloc_idx]->name = "ad714x_captouch_slider";
			input[alloc_idx]->dev.parent = dev;

			error = input_register_device(input[alloc_idx]);
			if (error)
				goto err_free_dev;

			alloc_idx++;
		}
	}

	/* a wheel uses one input_dev instance */
	if (ad714x->hw->wheel_num > 0) {
		struct ad714x_wheel_plat *wl_plat = ad714x->hw->wheel;

		for (i = 0; i < ad714x->hw->wheel_num; i++) {
			wl_drv[i].input = input[alloc_idx] = input_allocate_device();
			if (!input[alloc_idx]) {
				error = -ENOMEM;
				goto err_free_dev;
			}

			__set_bit(EV_KEY, input[alloc_idx]->evbit);
			__set_bit(EV_ABS, input[alloc_idx]->evbit);
			__set_bit(ABS_WHEEL, input[alloc_idx]->absbit);
			__set_bit(BTN_TOUCH, input[alloc_idx]->keybit);
			input_set_abs_params(input[alloc_idx],
				ABS_WHEEL, 0, wl_plat->max_coord, 0, 0);

			input[alloc_idx]->id.bustype = bus_type;
			input[alloc_idx]->id.product = ad714x->product;
			input[alloc_idx]->id.version = ad714x->version;
			input[alloc_idx]->name = "ad714x_captouch_wheel";
			input[alloc_idx]->dev.parent = dev;

			error = input_register_device(input[alloc_idx]);
			if (error)
				goto err_free_dev;

			alloc_idx++;
		}
	}

	/* a touchpad uses one input_dev instance */
	if (ad714x->hw->touchpad_num > 0) {
		struct ad714x_touchpad_plat *tp_plat = ad714x->hw->touchpad;

		for (i = 0; i < ad714x->hw->touchpad_num; i++) {
			tp_drv[i].input = input[alloc_idx] = input_allocate_device();
			if (!input[alloc_idx]) {
				error = -ENOMEM;
				goto err_free_dev;
			}

			__set_bit(EV_ABS, input[alloc_idx]->evbit);
			__set_bit(EV_KEY, input[alloc_idx]->evbit);
			__set_bit(ABS_X, input[alloc_idx]->absbit);
			__set_bit(ABS_Y, input[alloc_idx]->absbit);
			__set_bit(BTN_TOUCH, input[alloc_idx]->keybit);
			input_set_abs_params(input[alloc_idx],
				ABS_X, 0, tp_plat->x_max_coord, 0, 0);
			input_set_abs_params(input[alloc_idx],
				ABS_Y, 0, tp_plat->y_max_coord, 0, 0);

			input[alloc_idx]->id.bustype = bus_type;
			input[alloc_idx]->id.product = ad714x->product;
			input[alloc_idx]->id.version = ad714x->version;
			input[alloc_idx]->name = "ad714x_captouch_pad";
			input[alloc_idx]->dev.parent = dev;

			error = input_register_device(input[alloc_idx]);
			if (error)
				goto err_free_dev;

			alloc_idx++;
		}
	}

	/* all buttons use one input node */
	if (ad714x->hw->button_num > 0) {
		struct ad714x_button_plat *bt_plat = ad714x->hw->button;

		input[alloc_idx] = input_allocate_device();
		if (!input[alloc_idx]) {
			error = -ENOMEM;
			goto err_free_dev;
		}

		__set_bit(EV_KEY, input[alloc_idx]->evbit);
		for (i = 0; i < ad714x->hw->button_num; i++) {
			bt_drv[i].input = input[alloc_idx];
			__set_bit(bt_plat[i].keycode, input[alloc_idx]->keybit);
		}

		input[alloc_idx]->id.bustype = bus_type;
		input[alloc_idx]->id.product = ad714x->product;
		input[alloc_idx]->id.version = ad714x->version;
		input[alloc_idx]->name = "ad714x_captouch_button";
		input[alloc_idx]->dev.parent = dev;

		error = input_register_device(input[alloc_idx]);
		if (error)
			goto err_free_dev;

		alloc_idx++;
	}

	irqflags = plat_data->irqflags ?: IRQF_TRIGGER_FALLING;
	irqflags |= IRQF_ONESHOT;

	error = request_threaded_irq(ad714x->irq, NULL, ad714x_interrupt_thread,
				     irqflags, "ad714x_captouch", ad714x);
	if (error) {
		dev_err(dev, "can't allocate irq %d\n", ad714x->irq);
		goto err_unreg_dev;
	}

	return ad714x;

 err_free_dev:
	dev_err(dev, "failed to setup AD714x input device %i\n", alloc_idx);
	input_free_device(input[alloc_idx]);
 err_unreg_dev:
	while (--alloc_idx >= 0)
		input_unregister_device(input[alloc_idx]);
 err_free_mem:
	kfree(ad714x);
 err_out:
	return ERR_PTR(error);
}
EXPORT_SYMBOL(ad714x_probe);

void ad714x_remove(struct ad714x_chip *ad714x)
{
	struct ad714x_platform_data *hw = ad714x->hw;
	struct ad714x_driver_data *sw = ad714x->sw;
	int i;

	free_irq(ad714x->irq, ad714x);

	/* unregister and free all input devices */

	for (i = 0; i < hw->slider_num; i++)
		input_unregister_device(sw->slider[i].input);

	for (i = 0; i < hw->wheel_num; i++)
		input_unregister_device(sw->wheel[i].input);

	for (i = 0; i < hw->touchpad_num; i++)
		input_unregister_device(sw->touchpad[i].input);

	if (hw->button_num)
		input_unregister_device(sw->button[0].input);

	kfree(ad714x);
}
EXPORT_SYMBOL(ad714x_remove);

#ifdef CONFIG_PM
int ad714x_disable(struct ad714x_chip *ad714x)
{
	unsigned short data;

	dev_dbg(ad714x->dev, "%s enter\n", __func__);

	mutex_lock(&ad714x->mutex);

	data = ad714x->hw->sys_cfg_reg[AD714X_PWR_CTRL] | 0x3;
	ad714x->write(ad714x, AD714X_PWR_CTRL, data);

	mutex_unlock(&ad714x->mutex);

	return 0;
}
EXPORT_SYMBOL(ad714x_disable);

int ad714x_enable(struct ad714x_chip *ad714x)
{
	dev_dbg(ad714x->dev, "%s enter\n", __func__);

	mutex_lock(&ad714x->mutex);

	/* resume to non-shutdown mode */

	ad714x->write(ad714x, AD714X_PWR_CTRL,
			ad714x->hw->sys_cfg_reg[AD714X_PWR_CTRL]);

	/* make sure the interrupt output line is not low level after resume,
	 * otherwise we will get no chance to enter falling-edge irq again
	 */

	ad714x->read(ad714x, STG_LOW_INT_STA_REG, &ad714x->l_state, 3);

	mutex_unlock(&ad714x->mutex);

	return 0;
}
EXPORT_SYMBOL(ad714x_enable);
#endif

MODULE_DESCRIPTION("Analog Devices AD714X Capacitance Touch Sensor Driver");
MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
MODULE_LICENSE("GPL");