summaryrefslogtreecommitdiffstats
path: root/drivers/input/touchscreen/zforce_ts.c
blob: 5230519b0f749d2c874f507aae1a026f966ad684 (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
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2012-2013 MundoReader S.L.
 * Author: Heiko Stuebner <heiko@sntech.de>
 *
 * based in parts on Nook zforce driver
 *
 * Copyright (C) 2010 Barnes & Noble, Inc.
 * Author: Pieter Truter<ptruter@intrinsyc.com>
 */

#include <linux/module.h>
#include <linux/hrtimer.h>
#include <linux/slab.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/i2c.h>
#include <linux/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/device.h>
#include <linux/sysfs.h>
#include <linux/input/mt.h>
#include <linux/platform_data/zforce_ts.h>
#include <linux/regulator/consumer.h>
#include <linux/of.h>

#define WAIT_TIMEOUT		msecs_to_jiffies(1000)

#define FRAME_START		0xee
#define FRAME_MAXSIZE		257

/* Offsets of the different parts of the payload the controller sends */
#define PAYLOAD_HEADER		0
#define PAYLOAD_LENGTH		1
#define PAYLOAD_BODY		2

/* Response offsets */
#define RESPONSE_ID		0
#define RESPONSE_DATA		1

/* Commands */
#define COMMAND_DEACTIVATE	0x00
#define COMMAND_INITIALIZE	0x01
#define COMMAND_RESOLUTION	0x02
#define COMMAND_SETCONFIG	0x03
#define COMMAND_DATAREQUEST	0x04
#define COMMAND_SCANFREQ	0x08
#define COMMAND_STATUS		0X1e

/*
 * Responses the controller sends as a result of
 * command requests
 */
#define RESPONSE_DEACTIVATE	0x00
#define RESPONSE_INITIALIZE	0x01
#define RESPONSE_RESOLUTION	0x02
#define RESPONSE_SETCONFIG	0x03
#define RESPONSE_SCANFREQ	0x08
#define RESPONSE_STATUS		0X1e

/*
 * Notifications are sent by the touch controller without
 * being requested by the driver and include for example
 * touch indications
 */
#define NOTIFICATION_TOUCH		0x04
#define NOTIFICATION_BOOTCOMPLETE	0x07
#define NOTIFICATION_OVERRUN		0x25
#define NOTIFICATION_PROXIMITY		0x26
#define NOTIFICATION_INVALID_COMMAND	0xfe

#define ZFORCE_REPORT_POINTS		2
#define ZFORCE_MAX_AREA			0xff

#define STATE_DOWN			0
#define STATE_MOVE			1
#define STATE_UP			2

#define SETCONFIG_DUALTOUCH		(1 << 0)

struct zforce_point {
	int coord_x;
	int coord_y;
	int state;
	int id;
	int area_major;
	int area_minor;
	int orientation;
	int pressure;
	int prblty;
};

/*
 * @client		the i2c_client
 * @input		the input device
 * @suspending		in the process of going to suspend (don't emit wakeup
 *			events for commands executed to suspend the device)
 * @suspended		device suspended
 * @access_mutex	serialize i2c-access, to keep multipart reads together
 * @command_done	completion to wait for the command result
 * @command_mutex	serialize commands sent to the ic
 * @command_waiting	the id of the command that is currently waiting
 *			for a result
 * @command_result	returned result of the command
 */
struct zforce_ts {
	struct i2c_client	*client;
	struct input_dev	*input;
	const struct zforce_ts_platdata *pdata;
	char			phys[32];

	struct regulator	*reg_vdd;

	struct gpio_desc	*gpio_int;
	struct gpio_desc	*gpio_rst;

	bool			suspending;
	bool			suspended;
	bool			boot_complete;

	/* Firmware version information */
	u16			version_major;
	u16			version_minor;
	u16			version_build;
	u16			version_rev;

	struct mutex		access_mutex;

	struct completion	command_done;
	struct mutex		command_mutex;
	int			command_waiting;
	int			command_result;
};

static int zforce_command(struct zforce_ts *ts, u8 cmd)
{
	struct i2c_client *client = ts->client;
	char buf[3];
	int ret;

	dev_dbg(&client->dev, "%s: 0x%x\n", __func__, cmd);

	buf[0] = FRAME_START;
	buf[1] = 1; /* data size, command only */
	buf[2] = cmd;

	mutex_lock(&ts->access_mutex);
	ret = i2c_master_send(client, &buf[0], ARRAY_SIZE(buf));
	mutex_unlock(&ts->access_mutex);
	if (ret < 0) {
		dev_err(&client->dev, "i2c send data request error: %d\n", ret);
		return ret;
	}

	return 0;
}

static void zforce_reset_assert(struct zforce_ts *ts)
{
	gpiod_set_value_cansleep(ts->gpio_rst, 1);
}

static void zforce_reset_deassert(struct zforce_ts *ts)
{
	gpiod_set_value_cansleep(ts->gpio_rst, 0);
}

static int zforce_send_wait(struct zforce_ts *ts, const char *buf, int len)
{
	struct i2c_client *client = ts->client;
	int ret;

	ret = mutex_trylock(&ts->command_mutex);
	if (!ret) {
		dev_err(&client->dev, "already waiting for a command\n");
		return -EBUSY;
	}

	dev_dbg(&client->dev, "sending %d bytes for command 0x%x\n",
		buf[1], buf[2]);

	ts->command_waiting = buf[2];

	mutex_lock(&ts->access_mutex);
	ret = i2c_master_send(client, buf, len);
	mutex_unlock(&ts->access_mutex);
	if (ret < 0) {
		dev_err(&client->dev, "i2c send data request error: %d\n", ret);
		goto unlock;
	}

	dev_dbg(&client->dev, "waiting for result for command 0x%x\n", buf[2]);

	if (wait_for_completion_timeout(&ts->command_done, WAIT_TIMEOUT) == 0) {
		ret = -ETIME;
		goto unlock;
	}

	ret = ts->command_result;

unlock:
	mutex_unlock(&ts->command_mutex);
	return ret;
}

static int zforce_command_wait(struct zforce_ts *ts, u8 cmd)
{
	struct i2c_client *client = ts->client;
	char buf[3];
	int ret;

	dev_dbg(&client->dev, "%s: 0x%x\n", __func__, cmd);

	buf[0] = FRAME_START;
	buf[1] = 1; /* data size, command only */
	buf[2] = cmd;

	ret = zforce_send_wait(ts, &buf[0], ARRAY_SIZE(buf));
	if (ret < 0) {
		dev_err(&client->dev, "i2c send data request error: %d\n", ret);
		return ret;
	}

	return 0;
}

static int zforce_resolution(struct zforce_ts *ts, u16 x, u16 y)
{
	struct i2c_client *client = ts->client;
	char buf[7] = { FRAME_START, 5, COMMAND_RESOLUTION,
			(x & 0xff), ((x >> 8) & 0xff),
			(y & 0xff), ((y >> 8) & 0xff) };

	dev_dbg(&client->dev, "set resolution to (%d,%d)\n", x, y);

	return zforce_send_wait(ts, &buf[0], ARRAY_SIZE(buf));
}

static int zforce_scan_frequency(struct zforce_ts *ts, u16 idle, u16 finger,
				 u16 stylus)
{
	struct i2c_client *client = ts->client;
	char buf[9] = { FRAME_START, 7, COMMAND_SCANFREQ,
			(idle & 0xff), ((idle >> 8) & 0xff),
			(finger & 0xff), ((finger >> 8) & 0xff),
			(stylus & 0xff), ((stylus >> 8) & 0xff) };

	dev_dbg(&client->dev,
		"set scan frequency to (idle: %d, finger: %d, stylus: %d)\n",
		idle, finger, stylus);

	return zforce_send_wait(ts, &buf[0], ARRAY_SIZE(buf));
}

static int zforce_setconfig(struct zforce_ts *ts, char b1)
{
	struct i2c_client *client = ts->client;
	char buf[7] = { FRAME_START, 5, COMMAND_SETCONFIG,
			b1, 0, 0, 0 };

	dev_dbg(&client->dev, "set config to (%d)\n", b1);

	return zforce_send_wait(ts, &buf[0], ARRAY_SIZE(buf));
}

static int zforce_start(struct zforce_ts *ts)
{
	struct i2c_client *client = ts->client;
	const struct zforce_ts_platdata *pdata = ts->pdata;
	int ret;

	dev_dbg(&client->dev, "starting device\n");

	ret = zforce_command_wait(ts, COMMAND_INITIALIZE);
	if (ret) {
		dev_err(&client->dev, "Unable to initialize, %d\n", ret);
		return ret;
	}

	ret = zforce_resolution(ts, pdata->x_max, pdata->y_max);
	if (ret) {
		dev_err(&client->dev, "Unable to set resolution, %d\n", ret);
		goto error;
	}

	ret = zforce_scan_frequency(ts, 10, 50, 50);
	if (ret) {
		dev_err(&client->dev, "Unable to set scan frequency, %d\n",
			ret);
		goto error;
	}

	ret = zforce_setconfig(ts, SETCONFIG_DUALTOUCH);
	if (ret) {
		dev_err(&client->dev, "Unable to set config\n");
		goto error;
	}

	/* start sending touch events */
	ret = zforce_command(ts, COMMAND_DATAREQUEST);
	if (ret) {
		dev_err(&client->dev, "Unable to request data\n");
		goto error;
	}

	/*
	 * Per NN, initial cal. take max. of 200msec.
	 * Allow time to complete this calibration
	 */
	msleep(200);

	return 0;

error:
	zforce_command_wait(ts, COMMAND_DEACTIVATE);
	return ret;
}

static int zforce_stop(struct zforce_ts *ts)
{
	struct i2c_client *client = ts->client;
	int ret;

	dev_dbg(&client->dev, "stopping device\n");

	/* Deactivates touch sensing and puts the device into sleep. */
	ret = zforce_command_wait(ts, COMMAND_DEACTIVATE);
	if (ret != 0) {
		dev_err(&client->dev, "could not deactivate device, %d\n",
			ret);
		return ret;
	}

	return 0;
}

static int zforce_touch_event(struct zforce_ts *ts, u8 *payload)
{
	struct i2c_client *client = ts->client;
	const struct zforce_ts_platdata *pdata = ts->pdata;
	struct zforce_point point;
	int count, i, num = 0;

	count = payload[0];
	if (count > ZFORCE_REPORT_POINTS) {
		dev_warn(&client->dev,
			 "too many coordinates %d, expected max %d\n",
			 count, ZFORCE_REPORT_POINTS);
		count = ZFORCE_REPORT_POINTS;
	}

	for (i = 0; i < count; i++) {
		point.coord_x =
			payload[9 * i + 2] << 8 | payload[9 * i + 1];
		point.coord_y =
			payload[9 * i + 4] << 8 | payload[9 * i + 3];

		if (point.coord_x > pdata->x_max ||
		    point.coord_y > pdata->y_max) {
			dev_warn(&client->dev, "coordinates (%d,%d) invalid\n",
				point.coord_x, point.coord_y);
			point.coord_x = point.coord_y = 0;
		}

		point.state = payload[9 * i + 5] & 0x0f;
		point.id = (payload[9 * i + 5] & 0xf0) >> 4;

		/* determine touch major, minor and orientation */
		point.area_major = max(payload[9 * i + 6],
					  payload[9 * i + 7]);
		point.area_minor = min(payload[9 * i + 6],
					  payload[9 * i + 7]);
		point.orientation = payload[9 * i + 6] > payload[9 * i + 7];

		point.pressure = payload[9 * i + 8];
		point.prblty = payload[9 * i + 9];

		dev_dbg(&client->dev,
			"point %d/%d: state %d, id %d, pressure %d, prblty %d, x %d, y %d, amajor %d, aminor %d, ori %d\n",
			i, count, point.state, point.id,
			point.pressure, point.prblty,
			point.coord_x, point.coord_y,
			point.area_major, point.area_minor,
			point.orientation);

		/* the zforce id starts with "1", so needs to be decreased */
		input_mt_slot(ts->input, point.id - 1);

		input_mt_report_slot_state(ts->input, MT_TOOL_FINGER,
						point.state != STATE_UP);

		if (point.state != STATE_UP) {
			input_report_abs(ts->input, ABS_MT_POSITION_X,
					 point.coord_x);
			input_report_abs(ts->input, ABS_MT_POSITION_Y,
					 point.coord_y);
			input_report_abs(ts->input, ABS_MT_TOUCH_MAJOR,
					 point.area_major);
			input_report_abs(ts->input, ABS_MT_TOUCH_MINOR,
					 point.area_minor);
			input_report_abs(ts->input, ABS_MT_ORIENTATION,
					 point.orientation);
			num++;
		}
	}

	input_mt_sync_frame(ts->input);

	input_mt_report_finger_count(ts->input, num);

	input_sync(ts->input);

	return 0;
}

static int zforce_read_packet(struct zforce_ts *ts, u8 *buf)
{
	struct i2c_client *client = ts->client;
	int ret;

	mutex_lock(&ts->access_mutex);

	/* read 2 byte message header */
	ret = i2c_master_recv(client, buf, 2);
	if (ret < 0) {
		dev_err(&client->dev, "error reading header: %d\n", ret);
		goto unlock;
	}

	if (buf[PAYLOAD_HEADER] != FRAME_START) {
		dev_err(&client->dev, "invalid frame start: %d\n", buf[0]);
		ret = -EIO;
		goto unlock;
	}

	if (buf[PAYLOAD_LENGTH] == 0) {
		dev_err(&client->dev, "invalid payload length: %d\n",
			buf[PAYLOAD_LENGTH]);
		ret = -EIO;
		goto unlock;
	}

	/* read the message */
	ret = i2c_master_recv(client, &buf[PAYLOAD_BODY], buf[PAYLOAD_LENGTH]);
	if (ret < 0) {
		dev_err(&client->dev, "error reading payload: %d\n", ret);
		goto unlock;
	}

	dev_dbg(&client->dev, "read %d bytes for response command 0x%x\n",
		buf[PAYLOAD_LENGTH], buf[PAYLOAD_BODY]);

unlock:
	mutex_unlock(&ts->access_mutex);
	return ret;
}

static void zforce_complete(struct zforce_ts *ts, int cmd, int result)
{
	struct i2c_client *client = ts->client;

	if (ts->command_waiting == cmd) {
		dev_dbg(&client->dev, "completing command 0x%x\n", cmd);
		ts->command_result = result;
		complete(&ts->command_done);
	} else {
		dev_dbg(&client->dev, "command %d not for us\n", cmd);
	}
}

static irqreturn_t zforce_irq(int irq, void *dev_id)
{
	struct zforce_ts *ts = dev_id;
	struct i2c_client *client = ts->client;

	if (ts->suspended && device_may_wakeup(&client->dev))
		pm_wakeup_event(&client->dev, 500);

	return IRQ_WAKE_THREAD;
}

static irqreturn_t zforce_irq_thread(int irq, void *dev_id)
{
	struct zforce_ts *ts = dev_id;
	struct i2c_client *client = ts->client;
	int ret;
	u8 payload_buffer[FRAME_MAXSIZE];
	u8 *payload;

	/*
	 * When still suspended, return.
	 * Due to the level-interrupt we will get re-triggered later.
	 */
	if (ts->suspended) {
		msleep(20);
		return IRQ_HANDLED;
	}

	dev_dbg(&client->dev, "handling interrupt\n");

	/* Don't emit wakeup events from commands run by zforce_suspend */
	if (!ts->suspending && device_may_wakeup(&client->dev))
		pm_stay_awake(&client->dev);

	/*
	 * Run at least once and exit the loop if
	 * - the optional interrupt GPIO isn't specified
	 *   (there is only one packet read per ISR invocation, then)
	 * or
	 * - the GPIO isn't active any more
	 *   (packet read until the level GPIO indicates that there is
	 *    no IRQ any more)
	 */
	do {
		ret = zforce_read_packet(ts, payload_buffer);
		if (ret < 0) {
			dev_err(&client->dev,
				"could not read packet, ret: %d\n", ret);
			break;
		}

		payload =  &payload_buffer[PAYLOAD_BODY];

		switch (payload[RESPONSE_ID]) {
		case NOTIFICATION_TOUCH:
			/*
			 * Always report touch-events received while
			 * suspending, when being a wakeup source
			 */
			if (ts->suspending && device_may_wakeup(&client->dev))
				pm_wakeup_event(&client->dev, 500);
			zforce_touch_event(ts, &payload[RESPONSE_DATA]);
			break;

		case NOTIFICATION_BOOTCOMPLETE:
			ts->boot_complete = payload[RESPONSE_DATA];
			zforce_complete(ts, payload[RESPONSE_ID], 0);
			break;

		case RESPONSE_INITIALIZE:
		case RESPONSE_DEACTIVATE:
		case RESPONSE_SETCONFIG:
		case RESPONSE_RESOLUTION:
		case RESPONSE_SCANFREQ:
			zforce_complete(ts, payload[RESPONSE_ID],
					payload[RESPONSE_DATA]);
			break;

		case RESPONSE_STATUS:
			/*
			 * Version Payload Results
			 * [2:major] [2:minor] [2:build] [2:rev]
			 */
			ts->version_major = (payload[RESPONSE_DATA + 1] << 8) |
						payload[RESPONSE_DATA];
			ts->version_minor = (payload[RESPONSE_DATA + 3] << 8) |
						payload[RESPONSE_DATA + 2];
			ts->version_build = (payload[RESPONSE_DATA + 5] << 8) |
						payload[RESPONSE_DATA + 4];
			ts->version_rev   = (payload[RESPONSE_DATA + 7] << 8) |
						payload[RESPONSE_DATA + 6];
			dev_dbg(&ts->client->dev,
				"Firmware Version %04x:%04x %04x:%04x\n",
				ts->version_major, ts->version_minor,
				ts->version_build, ts->version_rev);

			zforce_complete(ts, payload[RESPONSE_ID], 0);
			break;

		case NOTIFICATION_INVALID_COMMAND:
			dev_err(&ts->client->dev, "invalid command: 0x%x\n",
				payload[RESPONSE_DATA]);
			break;

		default:
			dev_err(&ts->client->dev,
				"unrecognized response id: 0x%x\n",
				payload[RESPONSE_ID]);
			break;
		}
	} while (gpiod_get_value_cansleep(ts->gpio_int));

	if (!ts->suspending && device_may_wakeup(&client->dev))
		pm_relax(&client->dev);

	dev_dbg(&client->dev, "finished interrupt\n");

	return IRQ_HANDLED;
}

static int zforce_input_open(struct input_dev *dev)
{
	struct zforce_ts *ts = input_get_drvdata(dev);

	return zforce_start(ts);
}

static void zforce_input_close(struct input_dev *dev)
{
	struct zforce_ts *ts = input_get_drvdata(dev);
	struct i2c_client *client = ts->client;
	int ret;

	ret = zforce_stop(ts);
	if (ret)
		dev_warn(&client->dev, "stopping zforce failed\n");

	return;
}

static int __maybe_unused zforce_suspend(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct zforce_ts *ts = i2c_get_clientdata(client);
	struct input_dev *input = ts->input;
	int ret = 0;

	mutex_lock(&input->mutex);
	ts->suspending = true;

	/*
	 * When configured as a wakeup source device should always wake
	 * the system, therefore start device if necessary.
	 */
	if (device_may_wakeup(&client->dev)) {
		dev_dbg(&client->dev, "suspend while being a wakeup source\n");

		/* Need to start device, if not open, to be a wakeup source. */
		if (!input->users) {
			ret = zforce_start(ts);
			if (ret)
				goto unlock;
		}

		enable_irq_wake(client->irq);
	} else if (input->users) {
		dev_dbg(&client->dev,
			"suspend without being a wakeup source\n");

		ret = zforce_stop(ts);
		if (ret)
			goto unlock;

		disable_irq(client->irq);
	}

	ts->suspended = true;

unlock:
	ts->suspending = false;
	mutex_unlock(&input->mutex);

	return ret;
}

static int __maybe_unused zforce_resume(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct zforce_ts *ts = i2c_get_clientdata(client);
	struct input_dev *input = ts->input;
	int ret = 0;

	mutex_lock(&input->mutex);

	ts->suspended = false;

	if (device_may_wakeup(&client->dev)) {
		dev_dbg(&client->dev, "resume from being a wakeup source\n");

		disable_irq_wake(client->irq);

		/* need to stop device if it was not open on suspend */
		if (!input->users) {
			ret = zforce_stop(ts);
			if (ret)
				goto unlock;
		}
	} else if (input->users) {
		dev_dbg(&client->dev, "resume without being a wakeup source\n");

		enable_irq(client->irq);

		ret = zforce_start(ts);
		if (ret < 0)
			goto unlock;
	}

unlock:
	mutex_unlock(&input->mutex);

	return ret;
}

static SIMPLE_DEV_PM_OPS(zforce_pm_ops, zforce_suspend, zforce_resume);

static void zforce_reset(void *data)
{
	struct zforce_ts *ts = data;

	zforce_reset_assert(ts);

	udelay(10);

	if (!IS_ERR(ts->reg_vdd))
		regulator_disable(ts->reg_vdd);
}

static struct zforce_ts_platdata *zforce_parse_dt(struct device *dev)
{
	struct zforce_ts_platdata *pdata;
	struct device_node *np = dev->of_node;

	if (!np)
		return ERR_PTR(-ENOENT);

	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
	if (!pdata) {
		dev_err(dev, "failed to allocate platform data\n");
		return ERR_PTR(-ENOMEM);
	}

	if (of_property_read_u32(np, "x-size", &pdata->x_max)) {
		dev_err(dev, "failed to get x-size property\n");
		return ERR_PTR(-EINVAL);
	}

	if (of_property_read_u32(np, "y-size", &pdata->y_max)) {
		dev_err(dev, "failed to get y-size property\n");
		return ERR_PTR(-EINVAL);
	}

	return pdata;
}

static int zforce_probe(struct i2c_client *client,
			const struct i2c_device_id *id)
{
	const struct zforce_ts_platdata *pdata = dev_get_platdata(&client->dev);
	struct zforce_ts *ts;
	struct input_dev *input_dev;
	int ret;

	if (!pdata) {
		pdata = zforce_parse_dt(&client->dev);
		if (IS_ERR(pdata))
			return PTR_ERR(pdata);
	}

	ts = devm_kzalloc(&client->dev, sizeof(struct zforce_ts), GFP_KERNEL);
	if (!ts)
		return -ENOMEM;

	ts->gpio_rst = devm_gpiod_get_optional(&client->dev, "reset",
					       GPIOD_OUT_HIGH);
	if (IS_ERR(ts->gpio_rst)) {
		ret = PTR_ERR(ts->gpio_rst);
		dev_err(&client->dev,
			"failed to request reset GPIO: %d\n", ret);
		return ret;
	}

	if (ts->gpio_rst) {
		ts->gpio_int = devm_gpiod_get_optional(&client->dev, "irq",
						       GPIOD_IN);
		if (IS_ERR(ts->gpio_int)) {
			ret = PTR_ERR(ts->gpio_int);
			dev_err(&client->dev,
				"failed to request interrupt GPIO: %d\n", ret);
			return ret;
		}
	} else {
		/*
		 * Deprecated GPIO handling for compatibility
		 * with legacy binding.
		 */

		/* INT GPIO */
		ts->gpio_int = devm_gpiod_get_index(&client->dev, NULL, 0,
						    GPIOD_IN);
		if (IS_ERR(ts->gpio_int)) {
			ret = PTR_ERR(ts->gpio_int);
			dev_err(&client->dev,
				"failed to request interrupt GPIO: %d\n", ret);
			return ret;
		}

		/* RST GPIO */
		ts->gpio_rst = devm_gpiod_get_index(&client->dev, NULL, 1,
					    GPIOD_OUT_HIGH);
		if (IS_ERR(ts->gpio_rst)) {
			ret = PTR_ERR(ts->gpio_rst);
			dev_err(&client->dev,
				"failed to request reset GPIO: %d\n", ret);
			return ret;
		}
	}

	ts->reg_vdd = devm_regulator_get_optional(&client->dev, "vdd");
	if (IS_ERR(ts->reg_vdd)) {
		ret = PTR_ERR(ts->reg_vdd);
		if (ret == -EPROBE_DEFER)
			return ret;
	} else {
		ret = regulator_enable(ts->reg_vdd);
		if (ret)
			return ret;

		/*
		 * according to datasheet add 100us grace time after regular
		 * regulator enable delay.
		 */
		udelay(100);
	}

	ret = devm_add_action(&client->dev, zforce_reset, ts);
	if (ret) {
		dev_err(&client->dev, "failed to register reset action, %d\n",
			ret);

		/* hereafter the regulator will be disabled by the action */
		if (!IS_ERR(ts->reg_vdd))
			regulator_disable(ts->reg_vdd);

		return ret;
	}

	snprintf(ts->phys, sizeof(ts->phys),
		 "%s/input0", dev_name(&client->dev));

	input_dev = devm_input_allocate_device(&client->dev);
	if (!input_dev) {
		dev_err(&client->dev, "could not allocate input device\n");
		return -ENOMEM;
	}

	mutex_init(&ts->access_mutex);
	mutex_init(&ts->command_mutex);

	ts->pdata = pdata;
	ts->client = client;
	ts->input = input_dev;

	input_dev->name = "Neonode zForce touchscreen";
	input_dev->phys = ts->phys;
	input_dev->id.bustype = BUS_I2C;

	input_dev->open = zforce_input_open;
	input_dev->close = zforce_input_close;

	__set_bit(EV_KEY, input_dev->evbit);
	__set_bit(EV_SYN, input_dev->evbit);
	__set_bit(EV_ABS, input_dev->evbit);

	/* For multi touch */
	input_set_abs_params(input_dev, ABS_MT_POSITION_X, 0,
			     pdata->x_max, 0, 0);
	input_set_abs_params(input_dev, ABS_MT_POSITION_Y, 0,
			     pdata->y_max, 0, 0);

	input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0,
			     ZFORCE_MAX_AREA, 0, 0);
	input_set_abs_params(input_dev, ABS_MT_TOUCH_MINOR, 0,
			     ZFORCE_MAX_AREA, 0, 0);
	input_set_abs_params(input_dev, ABS_MT_ORIENTATION, 0, 1, 0, 0);
	input_mt_init_slots(input_dev, ZFORCE_REPORT_POINTS, INPUT_MT_DIRECT);

	input_set_drvdata(ts->input, ts);

	init_completion(&ts->command_done);

	/*
	 * The zforce pulls the interrupt low when it has data ready.
	 * After it is triggered the isr thread runs until all the available
	 * packets have been read and the interrupt is high again.
	 * Therefore we can trigger the interrupt anytime it is low and do
	 * not need to limit it to the interrupt edge.
	 */
	ret = devm_request_threaded_irq(&client->dev, client->irq,
					zforce_irq, zforce_irq_thread,
					IRQF_TRIGGER_LOW | IRQF_ONESHOT,
					input_dev->name, ts);
	if (ret) {
		dev_err(&client->dev, "irq %d request failed\n", client->irq);
		return ret;
	}

	i2c_set_clientdata(client, ts);

	/* let the controller boot */
	zforce_reset_deassert(ts);

	ts->command_waiting = NOTIFICATION_BOOTCOMPLETE;
	if (wait_for_completion_timeout(&ts->command_done, WAIT_TIMEOUT) == 0)
		dev_warn(&client->dev, "bootcomplete timed out\n");

	/* need to start device to get version information */
	ret = zforce_command_wait(ts, COMMAND_INITIALIZE);
	if (ret) {
		dev_err(&client->dev, "unable to initialize, %d\n", ret);
		return ret;
	}

	/* this gets the firmware version among other information */
	ret = zforce_command_wait(ts, COMMAND_STATUS);
	if (ret < 0) {
		dev_err(&client->dev, "couldn't get status, %d\n", ret);
		zforce_stop(ts);
		return ret;
	}

	/* stop device and put it into sleep until it is opened */
	ret = zforce_stop(ts);
	if (ret < 0)
		return ret;

	device_set_wakeup_capable(&client->dev, true);

	ret = input_register_device(input_dev);
	if (ret) {
		dev_err(&client->dev, "could not register input device, %d\n",
			ret);
		return ret;
	}

	return 0;
}

static struct i2c_device_id zforce_idtable[] = {
	{ "zforce-ts", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, zforce_idtable);

#ifdef CONFIG_OF
static const struct of_device_id zforce_dt_idtable[] = {
	{ .compatible = "neonode,zforce" },
	{},
};
MODULE_DEVICE_TABLE(of, zforce_dt_idtable);
#endif

static struct i2c_driver zforce_driver = {
	.driver = {
		.name	= "zforce-ts",
		.pm	= &zforce_pm_ops,
		.of_match_table	= of_match_ptr(zforce_dt_idtable),
	},
	.probe		= zforce_probe,
	.id_table	= zforce_idtable,
};

module_i2c_driver(zforce_driver);

MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
MODULE_DESCRIPTION("zForce TouchScreen Driver");
MODULE_LICENSE("GPL");