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 	if (zforce_setconfig(ts, SETCONFIG_DUALTOUCH)) {
283 		dev_err(&client->dev, "Unable to set config\n");
284 		goto error;
285 	}
286 
287 	/* start sending touch events */
288 	ret = zforce_command(ts, COMMAND_DATAREQUEST);
289 	if (ret) {
290 		dev_err(&client->dev, "Unable to request data\n");
291 		goto error;
292 	}
293 
294 	/*
295 	 * Per NN, initial cal. take max. of 200msec.
296 	 * Allow time to complete this calibration
297 	 */
298 	msleep(200);
299 
300 	return 0;
301 
302 error:
303 	zforce_command_wait(ts, COMMAND_DEACTIVATE);
304 	return ret;
305 }
306 
307 static int zforce_stop(struct zforce_ts *ts)
308 {
309 	struct i2c_client *client = ts->client;
310 	int ret;
311 
312 	dev_dbg(&client->dev, "stopping device\n");
313 
314 	/* Deactivates touch sensing and puts the device into sleep. */
315 	ret = zforce_command_wait(ts, COMMAND_DEACTIVATE);
316 	if (ret != 0) {
317 		dev_err(&client->dev, "could not deactivate device, %d\n",
318 			ret);
319 		return ret;
320 	}
321 
322 	return 0;
323 }
324 
325 static int zforce_touch_event(struct zforce_ts *ts, u8 *payload)
326 {
327 	struct i2c_client *client = ts->client;
328 	const struct zforce_ts_platdata *pdata = dev_get_platdata(&client->dev);
329 	struct zforce_point point;
330 	int count, i, num = 0;
331 
332 	count = payload[0];
333 	if (count > ZFORCE_REPORT_POINTS) {
334 		dev_warn(&client->dev, "to many coordinates %d, expected max %d\n",
335 			 count, ZFORCE_REPORT_POINTS);
336 		count = ZFORCE_REPORT_POINTS;
337 	}
338 
339 	for (i = 0; i < count; i++) {
340 		point.coord_x =
341 			payload[9 * i + 2] << 8 | payload[9 * i + 1];
342 		point.coord_y =
343 			payload[9 * i + 4] << 8 | payload[9 * i + 3];
344 
345 		if (point.coord_x > pdata->x_max ||
346 		    point.coord_y > pdata->y_max) {
347 			dev_warn(&client->dev, "coordinates (%d,%d) invalid\n",
348 				point.coord_x, point.coord_y);
349 			point.coord_x = point.coord_y = 0;
350 		}
351 
352 		point.state = payload[9 * i + 5] & 0x03;
353 		point.id = (payload[9 * i + 5] & 0xfc) >> 2;
354 
355 		/* determine touch major, minor and orientation */
356 		point.area_major = max(payload[9 * i + 6],
357 					  payload[9 * i + 7]);
358 		point.area_minor = min(payload[9 * i + 6],
359 					  payload[9 * i + 7]);
360 		point.orientation = payload[9 * i + 6] > payload[9 * i + 7];
361 
362 		point.pressure = payload[9 * i + 8];
363 		point.prblty = payload[9 * i + 9];
364 
365 		dev_dbg(&client->dev,
366 			"point %d/%d: state %d, id %d, pressure %d, prblty %d, x %d, y %d, amajor %d, aminor %d, ori %d\n",
367 			i, count, point.state, point.id,
368 			point.pressure, point.prblty,
369 			point.coord_x, point.coord_y,
370 			point.area_major, point.area_minor,
371 			point.orientation);
372 
373 		/* the zforce id starts with "1", so needs to be decreased */
374 		input_mt_slot(ts->input, point.id - 1);
375 
376 		input_mt_report_slot_state(ts->input, MT_TOOL_FINGER,
377 						point.state != STATE_UP);
378 
379 		if (point.state != STATE_UP) {
380 			input_report_abs(ts->input, ABS_MT_POSITION_X,
381 					 point.coord_x);
382 			input_report_abs(ts->input, ABS_MT_POSITION_Y,
383 					 point.coord_y);
384 			input_report_abs(ts->input, ABS_MT_TOUCH_MAJOR,
385 					 point.area_major);
386 			input_report_abs(ts->input, ABS_MT_TOUCH_MINOR,
387 					 point.area_minor);
388 			input_report_abs(ts->input, ABS_MT_ORIENTATION,
389 					 point.orientation);
390 			num++;
391 		}
392 	}
393 
394 	input_mt_sync_frame(ts->input);
395 
396 	input_mt_report_finger_count(ts->input, num);
397 
398 	input_sync(ts->input);
399 
400 	return 0;
401 }
402 
403 static int zforce_read_packet(struct zforce_ts *ts, u8 *buf)
404 {
405 	struct i2c_client *client = ts->client;
406 	int ret;
407 
408 	mutex_lock(&ts->access_mutex);
409 
410 	/* read 2 byte message header */
411 	ret = i2c_master_recv(client, buf, 2);
412 	if (ret < 0) {
413 		dev_err(&client->dev, "error reading header: %d\n", ret);
414 		goto unlock;
415 	}
416 
417 	if (buf[PAYLOAD_HEADER] != FRAME_START) {
418 		dev_err(&client->dev, "invalid frame start: %d\n", buf[0]);
419 		ret = -EIO;
420 		goto unlock;
421 	}
422 
423 	if (buf[PAYLOAD_LENGTH] <= 0 || buf[PAYLOAD_LENGTH] > 255) {
424 		dev_err(&client->dev, "invalid payload length: %d\n",
425 			buf[PAYLOAD_LENGTH]);
426 		ret = -EIO;
427 		goto unlock;
428 	}
429 
430 	/* read the message */
431 	ret = i2c_master_recv(client, &buf[PAYLOAD_BODY], buf[PAYLOAD_LENGTH]);
432 	if (ret < 0) {
433 		dev_err(&client->dev, "error reading payload: %d\n", ret);
434 		goto unlock;
435 	}
436 
437 	dev_dbg(&client->dev, "read %d bytes for response command 0x%x\n",
438 		buf[PAYLOAD_LENGTH], buf[PAYLOAD_BODY]);
439 
440 unlock:
441 	mutex_unlock(&ts->access_mutex);
442 	return ret;
443 }
444 
445 static void zforce_complete(struct zforce_ts *ts, int cmd, int result)
446 {
447 	struct i2c_client *client = ts->client;
448 
449 	if (ts->command_waiting == cmd) {
450 		dev_dbg(&client->dev, "completing command 0x%x\n", cmd);
451 		ts->command_result = result;
452 		complete(&ts->command_done);
453 	} else {
454 		dev_dbg(&client->dev, "command %d not for us\n", cmd);
455 	}
456 }
457 
458 static irqreturn_t zforce_interrupt(int irq, void *dev_id)
459 {
460 	struct zforce_ts *ts = dev_id;
461 	struct i2c_client *client = ts->client;
462 	const struct zforce_ts_platdata *pdata = dev_get_platdata(&client->dev);
463 	int ret;
464 	u8 payload_buffer[512];
465 	u8 *payload;
466 
467 	/*
468 	 * When suspended, emit a wakeup signal if necessary and return.
469 	 * Due to the level-interrupt we will get re-triggered later.
470 	 */
471 	if (ts->suspended) {
472 		if (device_may_wakeup(&client->dev))
473 			pm_wakeup_event(&client->dev, 500);
474 		msleep(20);
475 		return IRQ_HANDLED;
476 	}
477 
478 	dev_dbg(&client->dev, "handling interrupt\n");
479 
480 	/* Don't emit wakeup events from commands run by zforce_suspend */
481 	if (!ts->suspending && device_may_wakeup(&client->dev))
482 		pm_stay_awake(&client->dev);
483 
484 	while (!gpio_get_value(pdata->gpio_int)) {
485 		ret = zforce_read_packet(ts, payload_buffer);
486 		if (ret < 0) {
487 			dev_err(&client->dev, "could not read packet, ret: %d\n",
488 				ret);
489 			break;
490 		}
491 
492 		payload =  &payload_buffer[PAYLOAD_BODY];
493 
494 		switch (payload[RESPONSE_ID]) {
495 		case NOTIFICATION_TOUCH:
496 			/*
497 			 * Always report touch-events received while
498 			 * suspending, when being a wakeup source
499 			 */
500 			if (ts->suspending && device_may_wakeup(&client->dev))
501 				pm_wakeup_event(&client->dev, 500);
502 			zforce_touch_event(ts, &payload[RESPONSE_DATA]);
503 			break;
504 
505 		case NOTIFICATION_BOOTCOMPLETE:
506 			ts->boot_complete = payload[RESPONSE_DATA];
507 			zforce_complete(ts, payload[RESPONSE_ID], 0);
508 			break;
509 
510 		case RESPONSE_INITIALIZE:
511 		case RESPONSE_DEACTIVATE:
512 		case RESPONSE_SETCONFIG:
513 		case RESPONSE_RESOLUTION:
514 		case RESPONSE_SCANFREQ:
515 			zforce_complete(ts, payload[RESPONSE_ID],
516 					payload[RESPONSE_DATA]);
517 			break;
518 
519 		case RESPONSE_STATUS:
520 			/*
521 			 * Version Payload Results
522 			 * [2:major] [2:minor] [2:build] [2:rev]
523 			 */
524 			ts->version_major = (payload[RESPONSE_DATA + 1] << 8) |
525 						payload[RESPONSE_DATA];
526 			ts->version_minor = (payload[RESPONSE_DATA + 3] << 8) |
527 						payload[RESPONSE_DATA + 2];
528 			ts->version_build = (payload[RESPONSE_DATA + 5] << 8) |
529 						payload[RESPONSE_DATA + 4];
530 			ts->version_rev   = (payload[RESPONSE_DATA + 7] << 8) |
531 						payload[RESPONSE_DATA + 6];
532 			dev_dbg(&ts->client->dev, "Firmware Version %04x:%04x %04x:%04x\n",
533 				ts->version_major, ts->version_minor,
534 				ts->version_build, ts->version_rev);
535 
536 			zforce_complete(ts, payload[RESPONSE_ID], 0);
537 			break;
538 
539 		case NOTIFICATION_INVALID_COMMAND:
540 			dev_err(&ts->client->dev, "invalid command: 0x%x\n",
541 				payload[RESPONSE_DATA]);
542 			break;
543 
544 		default:
545 			dev_err(&ts->client->dev, "unrecognized response id: 0x%x\n",
546 				payload[RESPONSE_ID]);
547 			break;
548 		}
549 	}
550 
551 	if (!ts->suspending && device_may_wakeup(&client->dev))
552 		pm_relax(&client->dev);
553 
554 	dev_dbg(&client->dev, "finished interrupt\n");
555 
556 	return IRQ_HANDLED;
557 }
558 
559 static int zforce_input_open(struct input_dev *dev)
560 {
561 	struct zforce_ts *ts = input_get_drvdata(dev);
562 	int ret;
563 
564 	ret = zforce_start(ts);
565 	if (ret)
566 		return ret;
567 
568 	return 0;
569 }
570 
571 static void zforce_input_close(struct input_dev *dev)
572 {
573 	struct zforce_ts *ts = input_get_drvdata(dev);
574 	struct i2c_client *client = ts->client;
575 	int ret;
576 
577 	ret = zforce_stop(ts);
578 	if (ret)
579 		dev_warn(&client->dev, "stopping zforce failed\n");
580 
581 	return;
582 }
583 
584 #ifdef CONFIG_PM_SLEEP
585 static int zforce_suspend(struct device *dev)
586 {
587 	struct i2c_client *client = to_i2c_client(dev);
588 	struct zforce_ts *ts = i2c_get_clientdata(client);
589 	struct input_dev *input = ts->input;
590 	int ret = 0;
591 
592 	mutex_lock(&input->mutex);
593 	ts->suspending = true;
594 
595 	/*
596 	 * When configured as a wakeup source device should always wake
597 	 * the system, therefore start device if necessary.
598 	 */
599 	if (device_may_wakeup(&client->dev)) {
600 		dev_dbg(&client->dev, "suspend while being a wakeup source\n");
601 
602 		/* Need to start device, if not open, to be a wakeup source. */
603 		if (!input->users) {
604 			ret = zforce_start(ts);
605 			if (ret)
606 				goto unlock;
607 		}
608 
609 		enable_irq_wake(client->irq);
610 	} else if (input->users) {
611 		dev_dbg(&client->dev, "suspend without being a wakeup source\n");
612 
613 		ret = zforce_stop(ts);
614 		if (ret)
615 			goto unlock;
616 
617 		disable_irq(client->irq);
618 	}
619 
620 	ts->suspended = true;
621 
622 unlock:
623 	ts->suspending = false;
624 	mutex_unlock(&input->mutex);
625 
626 	return ret;
627 }
628 
629 static int zforce_resume(struct device *dev)
630 {
631 	struct i2c_client *client = to_i2c_client(dev);
632 	struct zforce_ts *ts = i2c_get_clientdata(client);
633 	struct input_dev *input = ts->input;
634 	int ret = 0;
635 
636 	mutex_lock(&input->mutex);
637 
638 	ts->suspended = false;
639 
640 	if (device_may_wakeup(&client->dev)) {
641 		dev_dbg(&client->dev, "resume from being a wakeup source\n");
642 
643 		disable_irq_wake(client->irq);
644 
645 		/* need to stop device if it was not open on suspend */
646 		if (!input->users) {
647 			ret = zforce_stop(ts);
648 			if (ret)
649 				goto unlock;
650 		}
651 	} else if (input->users) {
652 		dev_dbg(&client->dev, "resume without being a wakeup source\n");
653 
654 		enable_irq(client->irq);
655 
656 		ret = zforce_start(ts);
657 		if (ret < 0)
658 			goto unlock;
659 	}
660 
661 unlock:
662 	mutex_unlock(&input->mutex);
663 
664 	return ret;
665 }
666 #endif
667 
668 static SIMPLE_DEV_PM_OPS(zforce_pm_ops, zforce_suspend, zforce_resume);
669 
670 static void zforce_reset(void *data)
671 {
672 	struct zforce_ts *ts = data;
673 
674 	gpio_set_value(ts->pdata->gpio_rst, 0);
675 }
676 
677 static int zforce_probe(struct i2c_client *client,
678 			const struct i2c_device_id *id)
679 {
680 	const struct zforce_ts_platdata *pdata = dev_get_platdata(&client->dev);
681 	struct zforce_ts *ts;
682 	struct input_dev *input_dev;
683 	int ret;
684 
685 	if (!pdata)
686 		return -EINVAL;
687 
688 	ts = devm_kzalloc(&client->dev, sizeof(struct zforce_ts), GFP_KERNEL);
689 	if (!ts)
690 		return -ENOMEM;
691 
692 	ret = devm_gpio_request_one(&client->dev, pdata->gpio_int, GPIOF_IN,
693 				    "zforce_ts_int");
694 	if (ret) {
695 		dev_err(&client->dev, "request of gpio %d failed, %d\n",
696 			pdata->gpio_int, ret);
697 		return ret;
698 	}
699 
700 	ret = devm_gpio_request_one(&client->dev, pdata->gpio_rst,
701 				    GPIOF_OUT_INIT_LOW, "zforce_ts_rst");
702 	if (ret) {
703 		dev_err(&client->dev, "request of gpio %d failed, %d\n",
704 			pdata->gpio_rst, ret);
705 		return ret;
706 	}
707 
708 	ret = devm_add_action(&client->dev, zforce_reset, ts);
709 	if (ret) {
710 		dev_err(&client->dev, "failed to register reset action, %d\n",
711 			ret);
712 		return ret;
713 	}
714 
715 	snprintf(ts->phys, sizeof(ts->phys),
716 		 "%s/input0", dev_name(&client->dev));
717 
718 	input_dev = devm_input_allocate_device(&client->dev);
719 	if (!input_dev) {
720 		dev_err(&client->dev, "could not allocate input device\n");
721 		return -ENOMEM;
722 	}
723 
724 	mutex_init(&ts->access_mutex);
725 	mutex_init(&ts->command_mutex);
726 
727 	ts->pdata = pdata;
728 	ts->client = client;
729 	ts->input = input_dev;
730 
731 	input_dev->name = "Neonode zForce touchscreen";
732 	input_dev->phys = ts->phys;
733 	input_dev->id.bustype = BUS_I2C;
734 
735 	input_dev->open = zforce_input_open;
736 	input_dev->close = zforce_input_close;
737 
738 	__set_bit(EV_KEY, input_dev->evbit);
739 	__set_bit(EV_SYN, input_dev->evbit);
740 	__set_bit(EV_ABS, input_dev->evbit);
741 
742 	/* For multi touch */
743 	input_set_abs_params(input_dev, ABS_MT_POSITION_X, 0,
744 			     pdata->x_max, 0, 0);
745 	input_set_abs_params(input_dev, ABS_MT_POSITION_Y, 0,
746 			     pdata->y_max, 0, 0);
747 
748 	input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0,
749 			     ZFORCE_MAX_AREA, 0, 0);
750 	input_set_abs_params(input_dev, ABS_MT_TOUCH_MINOR, 0,
751 			     ZFORCE_MAX_AREA, 0, 0);
752 	input_set_abs_params(input_dev, ABS_MT_ORIENTATION, 0, 1, 0, 0);
753 	input_mt_init_slots(input_dev, ZFORCE_REPORT_POINTS, INPUT_MT_DIRECT);
754 
755 	input_set_drvdata(ts->input, ts);
756 
757 	init_completion(&ts->command_done);
758 
759 	/*
760 	 * The zforce pulls the interrupt low when it has data ready.
761 	 * After it is triggered the isr thread runs until all the available
762 	 * packets have been read and the interrupt is high again.
763 	 * Therefore we can trigger the interrupt anytime it is low and do
764 	 * not need to limit it to the interrupt edge.
765 	 */
766 	ret = devm_request_threaded_irq(&client->dev, client->irq, NULL,
767 					zforce_interrupt,
768 					IRQF_TRIGGER_LOW | IRQF_ONESHOT,
769 					input_dev->name, ts);
770 	if (ret) {
771 		dev_err(&client->dev, "irq %d request failed\n", client->irq);
772 		return ret;
773 	}
774 
775 	i2c_set_clientdata(client, ts);
776 
777 	/* let the controller boot */
778 	gpio_set_value(pdata->gpio_rst, 1);
779 
780 	ts->command_waiting = NOTIFICATION_BOOTCOMPLETE;
781 	if (wait_for_completion_timeout(&ts->command_done, WAIT_TIMEOUT) == 0)
782 		dev_warn(&client->dev, "bootcomplete timed out\n");
783 
784 	/* need to start device to get version information */
785 	ret = zforce_command_wait(ts, COMMAND_INITIALIZE);
786 	if (ret) {
787 		dev_err(&client->dev, "unable to initialize, %d\n", ret);
788 		return ret;
789 	}
790 
791 	/* this gets the firmware version among other informations */
792 	ret = zforce_command_wait(ts, COMMAND_STATUS);
793 	if (ret < 0) {
794 		dev_err(&client->dev, "couldn't get status, %d\n", ret);
795 		zforce_stop(ts);
796 		return ret;
797 	}
798 
799 	/* stop device and put it into sleep until it is opened */
800 	ret = zforce_stop(ts);
801 	if (ret < 0)
802 		return ret;
803 
804 	device_set_wakeup_capable(&client->dev, true);
805 
806 	ret = input_register_device(input_dev);
807 	if (ret) {
808 		dev_err(&client->dev, "could not register input device, %d\n",
809 			ret);
810 		return ret;
811 	}
812 
813 	return 0;
814 }
815 
816 static struct i2c_device_id zforce_idtable[] = {
817 	{ "zforce-ts", 0 },
818 	{ }
819 };
820 MODULE_DEVICE_TABLE(i2c, zforce_idtable);
821 
822 static struct i2c_driver zforce_driver = {
823 	.driver = {
824 		.owner	= THIS_MODULE,
825 		.name	= "zforce-ts",
826 		.pm	= &zforce_pm_ops,
827 	},
828 	.probe		= zforce_probe,
829 	.id_table	= zforce_idtable,
830 };
831 
832 module_i2c_driver(zforce_driver);
833 
834 MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
835 MODULE_DESCRIPTION("zForce TouchScreen Driver");
836 MODULE_LICENSE("GPL");
837