1 /*
2  * Copyright (C) 2012-2013 MundoReader S.L.
3  * Author: Heiko Stuebner <heiko@sntech.de>
4  *
5  * based in parts on Nook zforce driver
6  *
7  * Copyright (C) 2010 Barnes & Noble, Inc.
8  * Author: Pieter Truter<ptruter@intrinsyc.com>
9  *
10  * This software is licensed under the terms of the GNU General Public
11  * License version 2, as published by the Free Software Foundation, and
12  * may be copied, distributed, and modified under those terms.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  * GNU General Public License for more details.
18  */
19 
20 #include <linux/module.h>
21 #include <linux/hrtimer.h>
22 #include <linux/slab.h>
23 #include <linux/input.h>
24 #include <linux/interrupt.h>
25 #include <linux/i2c.h>
26 #include <linux/delay.h>
27 #include <linux/gpio.h>
28 #include <linux/device.h>
29 #include <linux/sysfs.h>
30 #include <linux/input/mt.h>
31 #include <linux/platform_data/zforce_ts.h>
32 
33 #define WAIT_TIMEOUT		msecs_to_jiffies(1000)
34 
35 #define FRAME_START		0xee
36 
37 /* Offsets of the different parts of the payload the controller sends */
38 #define PAYLOAD_HEADER		0
39 #define PAYLOAD_LENGTH		1
40 #define PAYLOAD_BODY		2
41 
42 /* Response offsets */
43 #define RESPONSE_ID		0
44 #define RESPONSE_DATA		1
45 
46 /* Commands */
47 #define COMMAND_DEACTIVATE	0x00
48 #define COMMAND_INITIALIZE	0x01
49 #define COMMAND_RESOLUTION	0x02
50 #define COMMAND_SETCONFIG	0x03
51 #define COMMAND_DATAREQUEST	0x04
52 #define COMMAND_SCANFREQ	0x08
53 #define COMMAND_STATUS		0X1e
54 
55 /*
56  * Responses the controller sends as a result of
57  * command requests
58  */
59 #define RESPONSE_DEACTIVATE	0x00
60 #define RESPONSE_INITIALIZE	0x01
61 #define RESPONSE_RESOLUTION	0x02
62 #define RESPONSE_SETCONFIG	0x03
63 #define RESPONSE_SCANFREQ	0x08
64 #define RESPONSE_STATUS		0X1e
65 
66 /*
67  * Notifications are send by the touch controller without
68  * being requested by the driver and include for example
69  * touch indications
70  */
71 #define NOTIFICATION_TOUCH		0x04
72 #define NOTIFICATION_BOOTCOMPLETE	0x07
73 #define NOTIFICATION_OVERRUN		0x25
74 #define NOTIFICATION_PROXIMITY		0x26
75 #define NOTIFICATION_INVALID_COMMAND	0xfe
76 
77 #define ZFORCE_REPORT_POINTS		2
78 #define ZFORCE_MAX_AREA			0xff
79 
80 #define STATE_DOWN			0
81 #define STATE_MOVE			1
82 #define STATE_UP			2
83 
84 #define SETCONFIG_DUALTOUCH		(1 << 0)
85 
86 struct zforce_point {
87 	int coord_x;
88 	int coord_y;
89 	int state;
90 	int id;
91 	int area_major;
92 	int area_minor;
93 	int orientation;
94 	int pressure;
95 	int prblty;
96 };
97 
98 /*
99  * @client		the i2c_client
100  * @input		the input device
101  * @suspending		in the process of going to suspend (don't emit wakeup
102  *			events for commands executed to suspend the device)
103  * @suspended		device suspended
104  * @access_mutex	serialize i2c-access, to keep multipart reads together
105  * @command_done	completion to wait for the command result
106  * @command_mutex	serialize commands send to the ic
107  * @command_waiting	the id of the command that that is currently waiting
108  *			for a result
109  * @command_result	returned result of the command
110  */
111 struct zforce_ts {
112 	struct i2c_client	*client;
113 	struct input_dev	*input;
114 	const struct zforce_ts_platdata *pdata;
115 	char			phys[32];
116 
117 	bool			suspending;
118 	bool			suspended;
119 	bool			boot_complete;
120 
121 	/* Firmware version information */
122 	u16			version_major;
123 	u16			version_minor;
124 	u16			version_build;
125 	u16			version_rev;
126 
127 	struct mutex		access_mutex;
128 
129 	struct completion	command_done;
130 	struct mutex		command_mutex;
131 	int			command_waiting;
132 	int			command_result;
133 };
134 
135 static int zforce_command(struct zforce_ts *ts, u8 cmd)
136 {
137 	struct i2c_client *client = ts->client;
138 	char buf[3];
139 	int ret;
140 
141 	dev_dbg(&client->dev, "%s: 0x%x\n", __func__, cmd);
142 
143 	buf[0] = FRAME_START;
144 	buf[1] = 1; /* data size, command only */
145 	buf[2] = cmd;
146 
147 	mutex_lock(&ts->access_mutex);
148 	ret = i2c_master_send(client, &buf[0], ARRAY_SIZE(buf));
149 	mutex_unlock(&ts->access_mutex);
150 	if (ret < 0) {
151 		dev_err(&client->dev, "i2c send data request error: %d\n", ret);
152 		return ret;
153 	}
154 
155 	return 0;
156 }
157 
158 static int zforce_send_wait(struct zforce_ts *ts, const char *buf, int len)
159 {
160 	struct i2c_client *client = ts->client;
161 	int ret;
162 
163 	ret = mutex_trylock(&ts->command_mutex);
164 	if (!ret) {
165 		dev_err(&client->dev, "already waiting for a command\n");
166 		return -EBUSY;
167 	}
168 
169 	dev_dbg(&client->dev, "sending %d bytes for command 0x%x\n",
170 		buf[1], buf[2]);
171 
172 	ts->command_waiting = buf[2];
173 
174 	mutex_lock(&ts->access_mutex);
175 	ret = i2c_master_send(client, buf, len);
176 	mutex_unlock(&ts->access_mutex);
177 	if (ret < 0) {
178 		dev_err(&client->dev, "i2c send data request error: %d\n", ret);
179 		goto unlock;
180 	}
181 
182 	dev_dbg(&client->dev, "waiting for result for command 0x%x\n", buf[2]);
183 
184 	if (wait_for_completion_timeout(&ts->command_done, WAIT_TIMEOUT) == 0) {
185 		ret = -ETIME;
186 		goto unlock;
187 	}
188 
189 	ret = ts->command_result;
190 
191 unlock:
192 	mutex_unlock(&ts->command_mutex);
193 	return ret;
194 }
195 
196 static int zforce_command_wait(struct zforce_ts *ts, u8 cmd)
197 {
198 	struct i2c_client *client = ts->client;
199 	char buf[3];
200 	int ret;
201 
202 	dev_dbg(&client->dev, "%s: 0x%x\n", __func__, cmd);
203 
204 	buf[0] = FRAME_START;
205 	buf[1] = 1; /* data size, command only */
206 	buf[2] = cmd;
207 
208 	ret = zforce_send_wait(ts, &buf[0], ARRAY_SIZE(buf));
209 	if (ret < 0) {
210 		dev_err(&client->dev, "i2c send data request error: %d\n", ret);
211 		return ret;
212 	}
213 
214 	return 0;
215 }
216 
217 static int zforce_resolution(struct zforce_ts *ts, u16 x, u16 y)
218 {
219 	struct i2c_client *client = ts->client;
220 	char buf[7] = { FRAME_START, 5, COMMAND_RESOLUTION,
221 			(x & 0xff), ((x >> 8) & 0xff),
222 			(y & 0xff), ((y >> 8) & 0xff) };
223 
224 	dev_dbg(&client->dev, "set resolution to (%d,%d)\n", x, y);
225 
226 	return zforce_send_wait(ts, &buf[0], ARRAY_SIZE(buf));
227 }
228 
229 static int zforce_scan_frequency(struct zforce_ts *ts, u16 idle, u16 finger,
230 				 u16 stylus)
231 {
232 	struct i2c_client *client = ts->client;
233 	char buf[9] = { FRAME_START, 7, COMMAND_SCANFREQ,
234 			(idle & 0xff), ((idle >> 8) & 0xff),
235 			(finger & 0xff), ((finger >> 8) & 0xff),
236 			(stylus & 0xff), ((stylus >> 8) & 0xff) };
237 
238 	dev_dbg(&client->dev, "set scan frequency to (idle: %d, finger: %d, stylus: %d)\n",
239 		idle, finger, stylus);
240 
241 	return zforce_send_wait(ts, &buf[0], ARRAY_SIZE(buf));
242 }
243 
244 static int zforce_setconfig(struct zforce_ts *ts, char b1)
245 {
246 	struct i2c_client *client = ts->client;
247 	char buf[7] = { FRAME_START, 5, COMMAND_SETCONFIG,
248 			b1, 0, 0, 0 };
249 
250 	dev_dbg(&client->dev, "set config to (%d)\n", b1);
251 
252 	return zforce_send_wait(ts, &buf[0], ARRAY_SIZE(buf));
253 }
254 
255 static int zforce_start(struct zforce_ts *ts)
256 {
257 	struct i2c_client *client = ts->client;
258 	const struct zforce_ts_platdata *pdata = dev_get_platdata(&client->dev);
259 	int ret;
260 
261 	dev_dbg(&client->dev, "starting device\n");
262 
263 	ret = zforce_command_wait(ts, COMMAND_INITIALIZE);
264 	if (ret) {
265 		dev_err(&client->dev, "Unable to initialize, %d\n", ret);
266 		return ret;
267 	}
268 
269 	ret = zforce_resolution(ts, pdata->x_max, pdata->y_max);
270 	if (ret) {
271 		dev_err(&client->dev, "Unable to set resolution, %d\n", ret);
272 		goto error;
273 	}
274 
275 	ret = zforce_scan_frequency(ts, 10, 50, 50);
276 	if (ret) {
277 		dev_err(&client->dev, "Unable to set scan frequency, %d\n",
278 			ret);
279 		goto error;
280 	}
281 
282 	ret = zforce_setconfig(ts, SETCONFIG_DUALTOUCH);
283 	if (ret) {
284 		dev_err(&client->dev, "Unable to set config\n");
285 		goto error;
286 	}
287 
288 	/* start sending touch events */
289 	ret = zforce_command(ts, COMMAND_DATAREQUEST);
290 	if (ret) {
291 		dev_err(&client->dev, "Unable to request data\n");
292 		goto error;
293 	}
294 
295 	/*
296 	 * Per NN, initial cal. take max. of 200msec.
297 	 * Allow time to complete this calibration
298 	 */
299 	msleep(200);
300 
301 	return 0;
302 
303 error:
304 	zforce_command_wait(ts, COMMAND_DEACTIVATE);
305 	return ret;
306 }
307 
308 static int zforce_stop(struct zforce_ts *ts)
309 {
310 	struct i2c_client *client = ts->client;
311 	int ret;
312 
313 	dev_dbg(&client->dev, "stopping device\n");
314 
315 	/* Deactivates touch sensing and puts the device into sleep. */
316 	ret = zforce_command_wait(ts, COMMAND_DEACTIVATE);
317 	if (ret != 0) {
318 		dev_err(&client->dev, "could not deactivate device, %d\n",
319 			ret);
320 		return ret;
321 	}
322 
323 	return 0;
324 }
325 
326 static int zforce_touch_event(struct zforce_ts *ts, u8 *payload)
327 {
328 	struct i2c_client *client = ts->client;
329 	const struct zforce_ts_platdata *pdata = dev_get_platdata(&client->dev);
330 	struct zforce_point point;
331 	int count, i, num = 0;
332 
333 	count = payload[0];
334 	if (count > ZFORCE_REPORT_POINTS) {
335 		dev_warn(&client->dev, "to many coordinates %d, expected max %d\n",
336 			 count, ZFORCE_REPORT_POINTS);
337 		count = ZFORCE_REPORT_POINTS;
338 	}
339 
340 	for (i = 0; i < count; i++) {
341 		point.coord_x =
342 			payload[9 * i + 2] << 8 | payload[9 * i + 1];
343 		point.coord_y =
344 			payload[9 * i + 4] << 8 | payload[9 * i + 3];
345 
346 		if (point.coord_x > pdata->x_max ||
347 		    point.coord_y > pdata->y_max) {
348 			dev_warn(&client->dev, "coordinates (%d,%d) invalid\n",
349 				point.coord_x, point.coord_y);
350 			point.coord_x = point.coord_y = 0;
351 		}
352 
353 		point.state = payload[9 * i + 5] & 0x03;
354 		point.id = (payload[9 * i + 5] & 0xfc) >> 2;
355 
356 		/* determine touch major, minor and orientation */
357 		point.area_major = max(payload[9 * i + 6],
358 					  payload[9 * i + 7]);
359 		point.area_minor = min(payload[9 * i + 6],
360 					  payload[9 * i + 7]);
361 		point.orientation = payload[9 * i + 6] > payload[9 * i + 7];
362 
363 		point.pressure = payload[9 * i + 8];
364 		point.prblty = payload[9 * i + 9];
365 
366 		dev_dbg(&client->dev,
367 			"point %d/%d: state %d, id %d, pressure %d, prblty %d, x %d, y %d, amajor %d, aminor %d, ori %d\n",
368 			i, count, point.state, point.id,
369 			point.pressure, point.prblty,
370 			point.coord_x, point.coord_y,
371 			point.area_major, point.area_minor,
372 			point.orientation);
373 
374 		/* the zforce id starts with "1", so needs to be decreased */
375 		input_mt_slot(ts->input, point.id - 1);
376 
377 		input_mt_report_slot_state(ts->input, MT_TOOL_FINGER,
378 						point.state != STATE_UP);
379 
380 		if (point.state != STATE_UP) {
381 			input_report_abs(ts->input, ABS_MT_POSITION_X,
382 					 point.coord_x);
383 			input_report_abs(ts->input, ABS_MT_POSITION_Y,
384 					 point.coord_y);
385 			input_report_abs(ts->input, ABS_MT_TOUCH_MAJOR,
386 					 point.area_major);
387 			input_report_abs(ts->input, ABS_MT_TOUCH_MINOR,
388 					 point.area_minor);
389 			input_report_abs(ts->input, ABS_MT_ORIENTATION,
390 					 point.orientation);
391 			num++;
392 		}
393 	}
394 
395 	input_mt_sync_frame(ts->input);
396 
397 	input_mt_report_finger_count(ts->input, num);
398 
399 	input_sync(ts->input);
400 
401 	return 0;
402 }
403 
404 static int zforce_read_packet(struct zforce_ts *ts, u8 *buf)
405 {
406 	struct i2c_client *client = ts->client;
407 	int ret;
408 
409 	mutex_lock(&ts->access_mutex);
410 
411 	/* read 2 byte message header */
412 	ret = i2c_master_recv(client, buf, 2);
413 	if (ret < 0) {
414 		dev_err(&client->dev, "error reading header: %d\n", ret);
415 		goto unlock;
416 	}
417 
418 	if (buf[PAYLOAD_HEADER] != FRAME_START) {
419 		dev_err(&client->dev, "invalid frame start: %d\n", buf[0]);
420 		ret = -EIO;
421 		goto unlock;
422 	}
423 
424 	if (buf[PAYLOAD_LENGTH] <= 0 || buf[PAYLOAD_LENGTH] > 255) {
425 		dev_err(&client->dev, "invalid payload length: %d\n",
426 			buf[PAYLOAD_LENGTH]);
427 		ret = -EIO;
428 		goto unlock;
429 	}
430 
431 	/* read the message */
432 	ret = i2c_master_recv(client, &buf[PAYLOAD_BODY], buf[PAYLOAD_LENGTH]);
433 	if (ret < 0) {
434 		dev_err(&client->dev, "error reading payload: %d\n", ret);
435 		goto unlock;
436 	}
437 
438 	dev_dbg(&client->dev, "read %d bytes for response command 0x%x\n",
439 		buf[PAYLOAD_LENGTH], buf[PAYLOAD_BODY]);
440 
441 unlock:
442 	mutex_unlock(&ts->access_mutex);
443 	return ret;
444 }
445 
446 static void zforce_complete(struct zforce_ts *ts, int cmd, int result)
447 {
448 	struct i2c_client *client = ts->client;
449 
450 	if (ts->command_waiting == cmd) {
451 		dev_dbg(&client->dev, "completing command 0x%x\n", cmd);
452 		ts->command_result = result;
453 		complete(&ts->command_done);
454 	} else {
455 		dev_dbg(&client->dev, "command %d not for us\n", cmd);
456 	}
457 }
458 
459 static irqreturn_t zforce_irq(int irq, void *dev_id)
460 {
461 	struct zforce_ts *ts = dev_id;
462 	struct i2c_client *client = ts->client;
463 
464 	if (ts->suspended && device_may_wakeup(&client->dev))
465 		pm_wakeup_event(&client->dev, 500);
466 
467 	return IRQ_WAKE_THREAD;
468 }
469 
470 static irqreturn_t zforce_irq_thread(int irq, void *dev_id)
471 {
472 	struct zforce_ts *ts = dev_id;
473 	struct i2c_client *client = ts->client;
474 	const struct zforce_ts_platdata *pdata = dev_get_platdata(&client->dev);
475 	int ret;
476 	u8 payload_buffer[512];
477 	u8 *payload;
478 
479 	/*
480 	 * When still suspended, return.
481 	 * Due to the level-interrupt we will get re-triggered later.
482 	 */
483 	if (ts->suspended) {
484 		msleep(20);
485 		return IRQ_HANDLED;
486 	}
487 
488 	dev_dbg(&client->dev, "handling interrupt\n");
489 
490 	/* Don't emit wakeup events from commands run by zforce_suspend */
491 	if (!ts->suspending && device_may_wakeup(&client->dev))
492 		pm_stay_awake(&client->dev);
493 
494 	while (!gpio_get_value(pdata->gpio_int)) {
495 		ret = zforce_read_packet(ts, payload_buffer);
496 		if (ret < 0) {
497 			dev_err(&client->dev, "could not read packet, ret: %d\n",
498 				ret);
499 			break;
500 		}
501 
502 		payload =  &payload_buffer[PAYLOAD_BODY];
503 
504 		switch (payload[RESPONSE_ID]) {
505 		case NOTIFICATION_TOUCH:
506 			/*
507 			 * Always report touch-events received while
508 			 * suspending, when being a wakeup source
509 			 */
510 			if (ts->suspending && device_may_wakeup(&client->dev))
511 				pm_wakeup_event(&client->dev, 500);
512 			zforce_touch_event(ts, &payload[RESPONSE_DATA]);
513 			break;
514 
515 		case NOTIFICATION_BOOTCOMPLETE:
516 			ts->boot_complete = payload[RESPONSE_DATA];
517 			zforce_complete(ts, payload[RESPONSE_ID], 0);
518 			break;
519 
520 		case RESPONSE_INITIALIZE:
521 		case RESPONSE_DEACTIVATE:
522 		case RESPONSE_SETCONFIG:
523 		case RESPONSE_RESOLUTION:
524 		case RESPONSE_SCANFREQ:
525 			zforce_complete(ts, payload[RESPONSE_ID],
526 					payload[RESPONSE_DATA]);
527 			break;
528 
529 		case RESPONSE_STATUS:
530 			/*
531 			 * Version Payload Results
532 			 * [2:major] [2:minor] [2:build] [2:rev]
533 			 */
534 			ts->version_major = (payload[RESPONSE_DATA + 1] << 8) |
535 						payload[RESPONSE_DATA];
536 			ts->version_minor = (payload[RESPONSE_DATA + 3] << 8) |
537 						payload[RESPONSE_DATA + 2];
538 			ts->version_build = (payload[RESPONSE_DATA + 5] << 8) |
539 						payload[RESPONSE_DATA + 4];
540 			ts->version_rev   = (payload[RESPONSE_DATA + 7] << 8) |
541 						payload[RESPONSE_DATA + 6];
542 			dev_dbg(&ts->client->dev, "Firmware Version %04x:%04x %04x:%04x\n",
543 				ts->version_major, ts->version_minor,
544 				ts->version_build, ts->version_rev);
545 
546 			zforce_complete(ts, payload[RESPONSE_ID], 0);
547 			break;
548 
549 		case NOTIFICATION_INVALID_COMMAND:
550 			dev_err(&ts->client->dev, "invalid command: 0x%x\n",
551 				payload[RESPONSE_DATA]);
552 			break;
553 
554 		default:
555 			dev_err(&ts->client->dev, "unrecognized response id: 0x%x\n",
556 				payload[RESPONSE_ID]);
557 			break;
558 		}
559 	}
560 
561 	if (!ts->suspending && device_may_wakeup(&client->dev))
562 		pm_relax(&client->dev);
563 
564 	dev_dbg(&client->dev, "finished interrupt\n");
565 
566 	return IRQ_HANDLED;
567 }
568 
569 static int zforce_input_open(struct input_dev *dev)
570 {
571 	struct zforce_ts *ts = input_get_drvdata(dev);
572 	int ret;
573 
574 	ret = zforce_start(ts);
575 	if (ret)
576 		return ret;
577 
578 	return 0;
579 }
580 
581 static void zforce_input_close(struct input_dev *dev)
582 {
583 	struct zforce_ts *ts = input_get_drvdata(dev);
584 	struct i2c_client *client = ts->client;
585 	int ret;
586 
587 	ret = zforce_stop(ts);
588 	if (ret)
589 		dev_warn(&client->dev, "stopping zforce failed\n");
590 
591 	return;
592 }
593 
594 #ifdef CONFIG_PM_SLEEP
595 static int zforce_suspend(struct device *dev)
596 {
597 	struct i2c_client *client = to_i2c_client(dev);
598 	struct zforce_ts *ts = i2c_get_clientdata(client);
599 	struct input_dev *input = ts->input;
600 	int ret = 0;
601 
602 	mutex_lock(&input->mutex);
603 	ts->suspending = true;
604 
605 	/*
606 	 * When configured as a wakeup source device should always wake
607 	 * the system, therefore start device if necessary.
608 	 */
609 	if (device_may_wakeup(&client->dev)) {
610 		dev_dbg(&client->dev, "suspend while being a wakeup source\n");
611 
612 		/* Need to start device, if not open, to be a wakeup source. */
613 		if (!input->users) {
614 			ret = zforce_start(ts);
615 			if (ret)
616 				goto unlock;
617 		}
618 
619 		enable_irq_wake(client->irq);
620 	} else if (input->users) {
621 		dev_dbg(&client->dev, "suspend without being a wakeup source\n");
622 
623 		ret = zforce_stop(ts);
624 		if (ret)
625 			goto unlock;
626 
627 		disable_irq(client->irq);
628 	}
629 
630 	ts->suspended = true;
631 
632 unlock:
633 	ts->suspending = false;
634 	mutex_unlock(&input->mutex);
635 
636 	return ret;
637 }
638 
639 static int zforce_resume(struct device *dev)
640 {
641 	struct i2c_client *client = to_i2c_client(dev);
642 	struct zforce_ts *ts = i2c_get_clientdata(client);
643 	struct input_dev *input = ts->input;
644 	int ret = 0;
645 
646 	mutex_lock(&input->mutex);
647 
648 	ts->suspended = false;
649 
650 	if (device_may_wakeup(&client->dev)) {
651 		dev_dbg(&client->dev, "resume from being a wakeup source\n");
652 
653 		disable_irq_wake(client->irq);
654 
655 		/* need to stop device if it was not open on suspend */
656 		if (!input->users) {
657 			ret = zforce_stop(ts);
658 			if (ret)
659 				goto unlock;
660 		}
661 	} else if (input->users) {
662 		dev_dbg(&client->dev, "resume without being a wakeup source\n");
663 
664 		enable_irq(client->irq);
665 
666 		ret = zforce_start(ts);
667 		if (ret < 0)
668 			goto unlock;
669 	}
670 
671 unlock:
672 	mutex_unlock(&input->mutex);
673 
674 	return ret;
675 }
676 #endif
677 
678 static SIMPLE_DEV_PM_OPS(zforce_pm_ops, zforce_suspend, zforce_resume);
679 
680 static void zforce_reset(void *data)
681 {
682 	struct zforce_ts *ts = data;
683 
684 	gpio_set_value(ts->pdata->gpio_rst, 0);
685 }
686 
687 static int zforce_probe(struct i2c_client *client,
688 			const struct i2c_device_id *id)
689 {
690 	const struct zforce_ts_platdata *pdata = dev_get_platdata(&client->dev);
691 	struct zforce_ts *ts;
692 	struct input_dev *input_dev;
693 	int ret;
694 
695 	if (!pdata)
696 		return -EINVAL;
697 
698 	ts = devm_kzalloc(&client->dev, sizeof(struct zforce_ts), GFP_KERNEL);
699 	if (!ts)
700 		return -ENOMEM;
701 
702 	ret = devm_gpio_request_one(&client->dev, pdata->gpio_int, GPIOF_IN,
703 				    "zforce_ts_int");
704 	if (ret) {
705 		dev_err(&client->dev, "request of gpio %d failed, %d\n",
706 			pdata->gpio_int, ret);
707 		return ret;
708 	}
709 
710 	ret = devm_gpio_request_one(&client->dev, pdata->gpio_rst,
711 				    GPIOF_OUT_INIT_LOW, "zforce_ts_rst");
712 	if (ret) {
713 		dev_err(&client->dev, "request of gpio %d failed, %d\n",
714 			pdata->gpio_rst, ret);
715 		return ret;
716 	}
717 
718 	ret = devm_add_action(&client->dev, zforce_reset, ts);
719 	if (ret) {
720 		dev_err(&client->dev, "failed to register reset action, %d\n",
721 			ret);
722 		return ret;
723 	}
724 
725 	snprintf(ts->phys, sizeof(ts->phys),
726 		 "%s/input0", dev_name(&client->dev));
727 
728 	input_dev = devm_input_allocate_device(&client->dev);
729 	if (!input_dev) {
730 		dev_err(&client->dev, "could not allocate input device\n");
731 		return -ENOMEM;
732 	}
733 
734 	mutex_init(&ts->access_mutex);
735 	mutex_init(&ts->command_mutex);
736 
737 	ts->pdata = pdata;
738 	ts->client = client;
739 	ts->input = input_dev;
740 
741 	input_dev->name = "Neonode zForce touchscreen";
742 	input_dev->phys = ts->phys;
743 	input_dev->id.bustype = BUS_I2C;
744 
745 	input_dev->open = zforce_input_open;
746 	input_dev->close = zforce_input_close;
747 
748 	__set_bit(EV_KEY, input_dev->evbit);
749 	__set_bit(EV_SYN, input_dev->evbit);
750 	__set_bit(EV_ABS, input_dev->evbit);
751 
752 	/* For multi touch */
753 	input_set_abs_params(input_dev, ABS_MT_POSITION_X, 0,
754 			     pdata->x_max, 0, 0);
755 	input_set_abs_params(input_dev, ABS_MT_POSITION_Y, 0,
756 			     pdata->y_max, 0, 0);
757 
758 	input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0,
759 			     ZFORCE_MAX_AREA, 0, 0);
760 	input_set_abs_params(input_dev, ABS_MT_TOUCH_MINOR, 0,
761 			     ZFORCE_MAX_AREA, 0, 0);
762 	input_set_abs_params(input_dev, ABS_MT_ORIENTATION, 0, 1, 0, 0);
763 	input_mt_init_slots(input_dev, ZFORCE_REPORT_POINTS, INPUT_MT_DIRECT);
764 
765 	input_set_drvdata(ts->input, ts);
766 
767 	init_completion(&ts->command_done);
768 
769 	/*
770 	 * The zforce pulls the interrupt low when it has data ready.
771 	 * After it is triggered the isr thread runs until all the available
772 	 * packets have been read and the interrupt is high again.
773 	 * Therefore we can trigger the interrupt anytime it is low and do
774 	 * not need to limit it to the interrupt edge.
775 	 */
776 	ret = devm_request_threaded_irq(&client->dev, client->irq,
777 					zforce_irq, zforce_irq_thread,
778 					IRQF_TRIGGER_LOW | IRQF_ONESHOT,
779 					input_dev->name, ts);
780 	if (ret) {
781 		dev_err(&client->dev, "irq %d request failed\n", client->irq);
782 		return ret;
783 	}
784 
785 	i2c_set_clientdata(client, ts);
786 
787 	/* let the controller boot */
788 	gpio_set_value(pdata->gpio_rst, 1);
789 
790 	ts->command_waiting = NOTIFICATION_BOOTCOMPLETE;
791 	if (wait_for_completion_timeout(&ts->command_done, WAIT_TIMEOUT) == 0)
792 		dev_warn(&client->dev, "bootcomplete timed out\n");
793 
794 	/* need to start device to get version information */
795 	ret = zforce_command_wait(ts, COMMAND_INITIALIZE);
796 	if (ret) {
797 		dev_err(&client->dev, "unable to initialize, %d\n", ret);
798 		return ret;
799 	}
800 
801 	/* this gets the firmware version among other informations */
802 	ret = zforce_command_wait(ts, COMMAND_STATUS);
803 	if (ret < 0) {
804 		dev_err(&client->dev, "couldn't get status, %d\n", ret);
805 		zforce_stop(ts);
806 		return ret;
807 	}
808 
809 	/* stop device and put it into sleep until it is opened */
810 	ret = zforce_stop(ts);
811 	if (ret < 0)
812 		return ret;
813 
814 	device_set_wakeup_capable(&client->dev, true);
815 
816 	ret = input_register_device(input_dev);
817 	if (ret) {
818 		dev_err(&client->dev, "could not register input device, %d\n",
819 			ret);
820 		return ret;
821 	}
822 
823 	return 0;
824 }
825 
826 static struct i2c_device_id zforce_idtable[] = {
827 	{ "zforce-ts", 0 },
828 	{ }
829 };
830 MODULE_DEVICE_TABLE(i2c, zforce_idtable);
831 
832 static struct i2c_driver zforce_driver = {
833 	.driver = {
834 		.owner	= THIS_MODULE,
835 		.name	= "zforce-ts",
836 		.pm	= &zforce_pm_ops,
837 	},
838 	.probe		= zforce_probe,
839 	.id_table	= zforce_idtable,
840 };
841 
842 module_i2c_driver(zforce_driver);
843 
844 MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
845 MODULE_DESCRIPTION("zForce TouchScreen Driver");
846 MODULE_LICENSE("GPL");
847