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 #include <linux/of.h>
33 #include <linux/of_gpio.h>
34 
35 #define WAIT_TIMEOUT		msecs_to_jiffies(1000)
36 
37 #define FRAME_START		0xee
38 #define FRAME_MAXSIZE		257
39 
40 /* Offsets of the different parts of the payload the controller sends */
41 #define PAYLOAD_HEADER		0
42 #define PAYLOAD_LENGTH		1
43 #define PAYLOAD_BODY		2
44 
45 /* Response offsets */
46 #define RESPONSE_ID		0
47 #define RESPONSE_DATA		1
48 
49 /* Commands */
50 #define COMMAND_DEACTIVATE	0x00
51 #define COMMAND_INITIALIZE	0x01
52 #define COMMAND_RESOLUTION	0x02
53 #define COMMAND_SETCONFIG	0x03
54 #define COMMAND_DATAREQUEST	0x04
55 #define COMMAND_SCANFREQ	0x08
56 #define COMMAND_STATUS		0X1e
57 
58 /*
59  * Responses the controller sends as a result of
60  * command requests
61  */
62 #define RESPONSE_DEACTIVATE	0x00
63 #define RESPONSE_INITIALIZE	0x01
64 #define RESPONSE_RESOLUTION	0x02
65 #define RESPONSE_SETCONFIG	0x03
66 #define RESPONSE_SCANFREQ	0x08
67 #define RESPONSE_STATUS		0X1e
68 
69 /*
70  * Notifications are sent by the touch controller without
71  * being requested by the driver and include for example
72  * touch indications
73  */
74 #define NOTIFICATION_TOUCH		0x04
75 #define NOTIFICATION_BOOTCOMPLETE	0x07
76 #define NOTIFICATION_OVERRUN		0x25
77 #define NOTIFICATION_PROXIMITY		0x26
78 #define NOTIFICATION_INVALID_COMMAND	0xfe
79 
80 #define ZFORCE_REPORT_POINTS		2
81 #define ZFORCE_MAX_AREA			0xff
82 
83 #define STATE_DOWN			0
84 #define STATE_MOVE			1
85 #define STATE_UP			2
86 
87 #define SETCONFIG_DUALTOUCH		(1 << 0)
88 
89 struct zforce_point {
90 	int coord_x;
91 	int coord_y;
92 	int state;
93 	int id;
94 	int area_major;
95 	int area_minor;
96 	int orientation;
97 	int pressure;
98 	int prblty;
99 };
100 
101 /*
102  * @client		the i2c_client
103  * @input		the input device
104  * @suspending		in the process of going to suspend (don't emit wakeup
105  *			events for commands executed to suspend the device)
106  * @suspended		device suspended
107  * @access_mutex	serialize i2c-access, to keep multipart reads together
108  * @command_done	completion to wait for the command result
109  * @command_mutex	serialize commands sent to the ic
110  * @command_waiting	the id of the command that is currently waiting
111  *			for a result
112  * @command_result	returned result of the command
113  */
114 struct zforce_ts {
115 	struct i2c_client	*client;
116 	struct input_dev	*input;
117 	const struct zforce_ts_platdata *pdata;
118 	char			phys[32];
119 
120 	bool			suspending;
121 	bool			suspended;
122 	bool			boot_complete;
123 
124 	/* Firmware version information */
125 	u16			version_major;
126 	u16			version_minor;
127 	u16			version_build;
128 	u16			version_rev;
129 
130 	struct mutex		access_mutex;
131 
132 	struct completion	command_done;
133 	struct mutex		command_mutex;
134 	int			command_waiting;
135 	int			command_result;
136 };
137 
138 static int zforce_command(struct zforce_ts *ts, u8 cmd)
139 {
140 	struct i2c_client *client = ts->client;
141 	char buf[3];
142 	int ret;
143 
144 	dev_dbg(&client->dev, "%s: 0x%x\n", __func__, cmd);
145 
146 	buf[0] = FRAME_START;
147 	buf[1] = 1; /* data size, command only */
148 	buf[2] = cmd;
149 
150 	mutex_lock(&ts->access_mutex);
151 	ret = i2c_master_send(client, &buf[0], ARRAY_SIZE(buf));
152 	mutex_unlock(&ts->access_mutex);
153 	if (ret < 0) {
154 		dev_err(&client->dev, "i2c send data request error: %d\n", ret);
155 		return ret;
156 	}
157 
158 	return 0;
159 }
160 
161 static int zforce_send_wait(struct zforce_ts *ts, const char *buf, int len)
162 {
163 	struct i2c_client *client = ts->client;
164 	int ret;
165 
166 	ret = mutex_trylock(&ts->command_mutex);
167 	if (!ret) {
168 		dev_err(&client->dev, "already waiting for a command\n");
169 		return -EBUSY;
170 	}
171 
172 	dev_dbg(&client->dev, "sending %d bytes for command 0x%x\n",
173 		buf[1], buf[2]);
174 
175 	ts->command_waiting = buf[2];
176 
177 	mutex_lock(&ts->access_mutex);
178 	ret = i2c_master_send(client, buf, len);
179 	mutex_unlock(&ts->access_mutex);
180 	if (ret < 0) {
181 		dev_err(&client->dev, "i2c send data request error: %d\n", ret);
182 		goto unlock;
183 	}
184 
185 	dev_dbg(&client->dev, "waiting for result for command 0x%x\n", buf[2]);
186 
187 	if (wait_for_completion_timeout(&ts->command_done, WAIT_TIMEOUT) == 0) {
188 		ret = -ETIME;
189 		goto unlock;
190 	}
191 
192 	ret = ts->command_result;
193 
194 unlock:
195 	mutex_unlock(&ts->command_mutex);
196 	return ret;
197 }
198 
199 static int zforce_command_wait(struct zforce_ts *ts, u8 cmd)
200 {
201 	struct i2c_client *client = ts->client;
202 	char buf[3];
203 	int ret;
204 
205 	dev_dbg(&client->dev, "%s: 0x%x\n", __func__, cmd);
206 
207 	buf[0] = FRAME_START;
208 	buf[1] = 1; /* data size, command only */
209 	buf[2] = cmd;
210 
211 	ret = zforce_send_wait(ts, &buf[0], ARRAY_SIZE(buf));
212 	if (ret < 0) {
213 		dev_err(&client->dev, "i2c send data request error: %d\n", ret);
214 		return ret;
215 	}
216 
217 	return 0;
218 }
219 
220 static int zforce_resolution(struct zforce_ts *ts, u16 x, u16 y)
221 {
222 	struct i2c_client *client = ts->client;
223 	char buf[7] = { FRAME_START, 5, COMMAND_RESOLUTION,
224 			(x & 0xff), ((x >> 8) & 0xff),
225 			(y & 0xff), ((y >> 8) & 0xff) };
226 
227 	dev_dbg(&client->dev, "set resolution to (%d,%d)\n", x, y);
228 
229 	return zforce_send_wait(ts, &buf[0], ARRAY_SIZE(buf));
230 }
231 
232 static int zforce_scan_frequency(struct zforce_ts *ts, u16 idle, u16 finger,
233 				 u16 stylus)
234 {
235 	struct i2c_client *client = ts->client;
236 	char buf[9] = { FRAME_START, 7, COMMAND_SCANFREQ,
237 			(idle & 0xff), ((idle >> 8) & 0xff),
238 			(finger & 0xff), ((finger >> 8) & 0xff),
239 			(stylus & 0xff), ((stylus >> 8) & 0xff) };
240 
241 	dev_dbg(&client->dev,
242 		"set scan frequency to (idle: %d, finger: %d, stylus: %d)\n",
243 		idle, finger, stylus);
244 
245 	return zforce_send_wait(ts, &buf[0], ARRAY_SIZE(buf));
246 }
247 
248 static int zforce_setconfig(struct zforce_ts *ts, char b1)
249 {
250 	struct i2c_client *client = ts->client;
251 	char buf[7] = { FRAME_START, 5, COMMAND_SETCONFIG,
252 			b1, 0, 0, 0 };
253 
254 	dev_dbg(&client->dev, "set config to (%d)\n", b1);
255 
256 	return zforce_send_wait(ts, &buf[0], ARRAY_SIZE(buf));
257 }
258 
259 static int zforce_start(struct zforce_ts *ts)
260 {
261 	struct i2c_client *client = ts->client;
262 	const struct zforce_ts_platdata *pdata = ts->pdata;
263 	int ret;
264 
265 	dev_dbg(&client->dev, "starting device\n");
266 
267 	ret = zforce_command_wait(ts, COMMAND_INITIALIZE);
268 	if (ret) {
269 		dev_err(&client->dev, "Unable to initialize, %d\n", ret);
270 		return ret;
271 	}
272 
273 	ret = zforce_resolution(ts, pdata->x_max, pdata->y_max);
274 	if (ret) {
275 		dev_err(&client->dev, "Unable to set resolution, %d\n", ret);
276 		goto error;
277 	}
278 
279 	ret = zforce_scan_frequency(ts, 10, 50, 50);
280 	if (ret) {
281 		dev_err(&client->dev, "Unable to set scan frequency, %d\n",
282 			ret);
283 		goto error;
284 	}
285 
286 	ret = zforce_setconfig(ts, SETCONFIG_DUALTOUCH);
287 	if (ret) {
288 		dev_err(&client->dev, "Unable to set config\n");
289 		goto error;
290 	}
291 
292 	/* start sending touch events */
293 	ret = zforce_command(ts, COMMAND_DATAREQUEST);
294 	if (ret) {
295 		dev_err(&client->dev, "Unable to request data\n");
296 		goto error;
297 	}
298 
299 	/*
300 	 * Per NN, initial cal. take max. of 200msec.
301 	 * Allow time to complete this calibration
302 	 */
303 	msleep(200);
304 
305 	return 0;
306 
307 error:
308 	zforce_command_wait(ts, COMMAND_DEACTIVATE);
309 	return ret;
310 }
311 
312 static int zforce_stop(struct zforce_ts *ts)
313 {
314 	struct i2c_client *client = ts->client;
315 	int ret;
316 
317 	dev_dbg(&client->dev, "stopping device\n");
318 
319 	/* Deactivates touch sensing and puts the device into sleep. */
320 	ret = zforce_command_wait(ts, COMMAND_DEACTIVATE);
321 	if (ret != 0) {
322 		dev_err(&client->dev, "could not deactivate device, %d\n",
323 			ret);
324 		return ret;
325 	}
326 
327 	return 0;
328 }
329 
330 static int zforce_touch_event(struct zforce_ts *ts, u8 *payload)
331 {
332 	struct i2c_client *client = ts->client;
333 	const struct zforce_ts_platdata *pdata = ts->pdata;
334 	struct zforce_point point;
335 	int count, i, num = 0;
336 
337 	count = payload[0];
338 	if (count > ZFORCE_REPORT_POINTS) {
339 		dev_warn(&client->dev,
340 			 "too many coordinates %d, expected max %d\n",
341 			 count, ZFORCE_REPORT_POINTS);
342 		count = ZFORCE_REPORT_POINTS;
343 	}
344 
345 	for (i = 0; i < count; i++) {
346 		point.coord_x =
347 			payload[9 * i + 2] << 8 | payload[9 * i + 1];
348 		point.coord_y =
349 			payload[9 * i + 4] << 8 | payload[9 * i + 3];
350 
351 		if (point.coord_x > pdata->x_max ||
352 		    point.coord_y > pdata->y_max) {
353 			dev_warn(&client->dev, "coordinates (%d,%d) invalid\n",
354 				point.coord_x, point.coord_y);
355 			point.coord_x = point.coord_y = 0;
356 		}
357 
358 		point.state = payload[9 * i + 5] & 0x03;
359 		point.id = (payload[9 * i + 5] & 0xfc) >> 2;
360 
361 		/* determine touch major, minor and orientation */
362 		point.area_major = max(payload[9 * i + 6],
363 					  payload[9 * i + 7]);
364 		point.area_minor = min(payload[9 * i + 6],
365 					  payload[9 * i + 7]);
366 		point.orientation = payload[9 * i + 6] > payload[9 * i + 7];
367 
368 		point.pressure = payload[9 * i + 8];
369 		point.prblty = payload[9 * i + 9];
370 
371 		dev_dbg(&client->dev,
372 			"point %d/%d: state %d, id %d, pressure %d, prblty %d, x %d, y %d, amajor %d, aminor %d, ori %d\n",
373 			i, count, point.state, point.id,
374 			point.pressure, point.prblty,
375 			point.coord_x, point.coord_y,
376 			point.area_major, point.area_minor,
377 			point.orientation);
378 
379 		/* the zforce id starts with "1", so needs to be decreased */
380 		input_mt_slot(ts->input, point.id - 1);
381 
382 		input_mt_report_slot_state(ts->input, MT_TOOL_FINGER,
383 						point.state != STATE_UP);
384 
385 		if (point.state != STATE_UP) {
386 			input_report_abs(ts->input, ABS_MT_POSITION_X,
387 					 point.coord_x);
388 			input_report_abs(ts->input, ABS_MT_POSITION_Y,
389 					 point.coord_y);
390 			input_report_abs(ts->input, ABS_MT_TOUCH_MAJOR,
391 					 point.area_major);
392 			input_report_abs(ts->input, ABS_MT_TOUCH_MINOR,
393 					 point.area_minor);
394 			input_report_abs(ts->input, ABS_MT_ORIENTATION,
395 					 point.orientation);
396 			num++;
397 		}
398 	}
399 
400 	input_mt_sync_frame(ts->input);
401 
402 	input_mt_report_finger_count(ts->input, num);
403 
404 	input_sync(ts->input);
405 
406 	return 0;
407 }
408 
409 static int zforce_read_packet(struct zforce_ts *ts, u8 *buf)
410 {
411 	struct i2c_client *client = ts->client;
412 	int ret;
413 
414 	mutex_lock(&ts->access_mutex);
415 
416 	/* read 2 byte message header */
417 	ret = i2c_master_recv(client, buf, 2);
418 	if (ret < 0) {
419 		dev_err(&client->dev, "error reading header: %d\n", ret);
420 		goto unlock;
421 	}
422 
423 	if (buf[PAYLOAD_HEADER] != FRAME_START) {
424 		dev_err(&client->dev, "invalid frame start: %d\n", buf[0]);
425 		ret = -EIO;
426 		goto unlock;
427 	}
428 
429 	if (buf[PAYLOAD_LENGTH] == 0) {
430 		dev_err(&client->dev, "invalid payload length: %d\n",
431 			buf[PAYLOAD_LENGTH]);
432 		ret = -EIO;
433 		goto unlock;
434 	}
435 
436 	/* read the message */
437 	ret = i2c_master_recv(client, &buf[PAYLOAD_BODY], buf[PAYLOAD_LENGTH]);
438 	if (ret < 0) {
439 		dev_err(&client->dev, "error reading payload: %d\n", ret);
440 		goto unlock;
441 	}
442 
443 	dev_dbg(&client->dev, "read %d bytes for response command 0x%x\n",
444 		buf[PAYLOAD_LENGTH], buf[PAYLOAD_BODY]);
445 
446 unlock:
447 	mutex_unlock(&ts->access_mutex);
448 	return ret;
449 }
450 
451 static void zforce_complete(struct zforce_ts *ts, int cmd, int result)
452 {
453 	struct i2c_client *client = ts->client;
454 
455 	if (ts->command_waiting == cmd) {
456 		dev_dbg(&client->dev, "completing command 0x%x\n", cmd);
457 		ts->command_result = result;
458 		complete(&ts->command_done);
459 	} else {
460 		dev_dbg(&client->dev, "command %d not for us\n", cmd);
461 	}
462 }
463 
464 static irqreturn_t zforce_irq(int irq, void *dev_id)
465 {
466 	struct zforce_ts *ts = dev_id;
467 	struct i2c_client *client = ts->client;
468 
469 	if (ts->suspended && device_may_wakeup(&client->dev))
470 		pm_wakeup_event(&client->dev, 500);
471 
472 	return IRQ_WAKE_THREAD;
473 }
474 
475 static irqreturn_t zforce_irq_thread(int irq, void *dev_id)
476 {
477 	struct zforce_ts *ts = dev_id;
478 	struct i2c_client *client = ts->client;
479 	const struct zforce_ts_platdata *pdata = ts->pdata;
480 	int ret;
481 	u8 payload_buffer[FRAME_MAXSIZE];
482 	u8 *payload;
483 
484 	/*
485 	 * When still suspended, return.
486 	 * Due to the level-interrupt we will get re-triggered later.
487 	 */
488 	if (ts->suspended) {
489 		msleep(20);
490 		return IRQ_HANDLED;
491 	}
492 
493 	dev_dbg(&client->dev, "handling interrupt\n");
494 
495 	/* Don't emit wakeup events from commands run by zforce_suspend */
496 	if (!ts->suspending && device_may_wakeup(&client->dev))
497 		pm_stay_awake(&client->dev);
498 
499 	while (!gpio_get_value(pdata->gpio_int)) {
500 		ret = zforce_read_packet(ts, payload_buffer);
501 		if (ret < 0) {
502 			dev_err(&client->dev,
503 				"could not read packet, ret: %d\n", ret);
504 			break;
505 		}
506 
507 		payload =  &payload_buffer[PAYLOAD_BODY];
508 
509 		switch (payload[RESPONSE_ID]) {
510 		case NOTIFICATION_TOUCH:
511 			/*
512 			 * Always report touch-events received while
513 			 * suspending, when being a wakeup source
514 			 */
515 			if (ts->suspending && device_may_wakeup(&client->dev))
516 				pm_wakeup_event(&client->dev, 500);
517 			zforce_touch_event(ts, &payload[RESPONSE_DATA]);
518 			break;
519 
520 		case NOTIFICATION_BOOTCOMPLETE:
521 			ts->boot_complete = payload[RESPONSE_DATA];
522 			zforce_complete(ts, payload[RESPONSE_ID], 0);
523 			break;
524 
525 		case RESPONSE_INITIALIZE:
526 		case RESPONSE_DEACTIVATE:
527 		case RESPONSE_SETCONFIG:
528 		case RESPONSE_RESOLUTION:
529 		case RESPONSE_SCANFREQ:
530 			zforce_complete(ts, payload[RESPONSE_ID],
531 					payload[RESPONSE_DATA]);
532 			break;
533 
534 		case RESPONSE_STATUS:
535 			/*
536 			 * Version Payload Results
537 			 * [2:major] [2:minor] [2:build] [2:rev]
538 			 */
539 			ts->version_major = (payload[RESPONSE_DATA + 1] << 8) |
540 						payload[RESPONSE_DATA];
541 			ts->version_minor = (payload[RESPONSE_DATA + 3] << 8) |
542 						payload[RESPONSE_DATA + 2];
543 			ts->version_build = (payload[RESPONSE_DATA + 5] << 8) |
544 						payload[RESPONSE_DATA + 4];
545 			ts->version_rev   = (payload[RESPONSE_DATA + 7] << 8) |
546 						payload[RESPONSE_DATA + 6];
547 			dev_dbg(&ts->client->dev,
548 				"Firmware Version %04x:%04x %04x:%04x\n",
549 				ts->version_major, ts->version_minor,
550 				ts->version_build, ts->version_rev);
551 
552 			zforce_complete(ts, payload[RESPONSE_ID], 0);
553 			break;
554 
555 		case NOTIFICATION_INVALID_COMMAND:
556 			dev_err(&ts->client->dev, "invalid command: 0x%x\n",
557 				payload[RESPONSE_DATA]);
558 			break;
559 
560 		default:
561 			dev_err(&ts->client->dev,
562 				"unrecognized response id: 0x%x\n",
563 				payload[RESPONSE_ID]);
564 			break;
565 		}
566 	}
567 
568 	if (!ts->suspending && device_may_wakeup(&client->dev))
569 		pm_relax(&client->dev);
570 
571 	dev_dbg(&client->dev, "finished interrupt\n");
572 
573 	return IRQ_HANDLED;
574 }
575 
576 static int zforce_input_open(struct input_dev *dev)
577 {
578 	struct zforce_ts *ts = input_get_drvdata(dev);
579 	int ret;
580 
581 	ret = zforce_start(ts);
582 	if (ret)
583 		return ret;
584 
585 	return 0;
586 }
587 
588 static void zforce_input_close(struct input_dev *dev)
589 {
590 	struct zforce_ts *ts = input_get_drvdata(dev);
591 	struct i2c_client *client = ts->client;
592 	int ret;
593 
594 	ret = zforce_stop(ts);
595 	if (ret)
596 		dev_warn(&client->dev, "stopping zforce failed\n");
597 
598 	return;
599 }
600 
601 #ifdef CONFIG_PM_SLEEP
602 static int zforce_suspend(struct device *dev)
603 {
604 	struct i2c_client *client = to_i2c_client(dev);
605 	struct zforce_ts *ts = i2c_get_clientdata(client);
606 	struct input_dev *input = ts->input;
607 	int ret = 0;
608 
609 	mutex_lock(&input->mutex);
610 	ts->suspending = true;
611 
612 	/*
613 	 * When configured as a wakeup source device should always wake
614 	 * the system, therefore start device if necessary.
615 	 */
616 	if (device_may_wakeup(&client->dev)) {
617 		dev_dbg(&client->dev, "suspend while being a wakeup source\n");
618 
619 		/* Need to start device, if not open, to be a wakeup source. */
620 		if (!input->users) {
621 			ret = zforce_start(ts);
622 			if (ret)
623 				goto unlock;
624 		}
625 
626 		enable_irq_wake(client->irq);
627 	} else if (input->users) {
628 		dev_dbg(&client->dev,
629 			"suspend without being a wakeup source\n");
630 
631 		ret = zforce_stop(ts);
632 		if (ret)
633 			goto unlock;
634 
635 		disable_irq(client->irq);
636 	}
637 
638 	ts->suspended = true;
639 
640 unlock:
641 	ts->suspending = false;
642 	mutex_unlock(&input->mutex);
643 
644 	return ret;
645 }
646 
647 static int zforce_resume(struct device *dev)
648 {
649 	struct i2c_client *client = to_i2c_client(dev);
650 	struct zforce_ts *ts = i2c_get_clientdata(client);
651 	struct input_dev *input = ts->input;
652 	int ret = 0;
653 
654 	mutex_lock(&input->mutex);
655 
656 	ts->suspended = false;
657 
658 	if (device_may_wakeup(&client->dev)) {
659 		dev_dbg(&client->dev, "resume from being a wakeup source\n");
660 
661 		disable_irq_wake(client->irq);
662 
663 		/* need to stop device if it was not open on suspend */
664 		if (!input->users) {
665 			ret = zforce_stop(ts);
666 			if (ret)
667 				goto unlock;
668 		}
669 	} else if (input->users) {
670 		dev_dbg(&client->dev, "resume without being a wakeup source\n");
671 
672 		enable_irq(client->irq);
673 
674 		ret = zforce_start(ts);
675 		if (ret < 0)
676 			goto unlock;
677 	}
678 
679 unlock:
680 	mutex_unlock(&input->mutex);
681 
682 	return ret;
683 }
684 #endif
685 
686 static SIMPLE_DEV_PM_OPS(zforce_pm_ops, zforce_suspend, zforce_resume);
687 
688 static void zforce_reset(void *data)
689 {
690 	struct zforce_ts *ts = data;
691 
692 	gpio_set_value(ts->pdata->gpio_rst, 0);
693 }
694 
695 static struct zforce_ts_platdata *zforce_parse_dt(struct device *dev)
696 {
697 	struct zforce_ts_platdata *pdata;
698 	struct device_node *np = dev->of_node;
699 
700 	if (!np)
701 		return ERR_PTR(-ENOENT);
702 
703 	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
704 	if (!pdata) {
705 		dev_err(dev, "failed to allocate platform data\n");
706 		return ERR_PTR(-ENOMEM);
707 	}
708 
709 	pdata->gpio_int = of_get_gpio(np, 0);
710 	if (!gpio_is_valid(pdata->gpio_int)) {
711 		dev_err(dev, "failed to get interrupt gpio\n");
712 		return ERR_PTR(-EINVAL);
713 	}
714 
715 	pdata->gpio_rst = of_get_gpio(np, 1);
716 	if (!gpio_is_valid(pdata->gpio_rst)) {
717 		dev_err(dev, "failed to get reset gpio\n");
718 		return ERR_PTR(-EINVAL);
719 	}
720 
721 	if (of_property_read_u32(np, "x-size", &pdata->x_max)) {
722 		dev_err(dev, "failed to get x-size property\n");
723 		return ERR_PTR(-EINVAL);
724 	}
725 
726 	if (of_property_read_u32(np, "y-size", &pdata->y_max)) {
727 		dev_err(dev, "failed to get y-size property\n");
728 		return ERR_PTR(-EINVAL);
729 	}
730 
731 	return pdata;
732 }
733 
734 static int zforce_probe(struct i2c_client *client,
735 			const struct i2c_device_id *id)
736 {
737 	const struct zforce_ts_platdata *pdata = dev_get_platdata(&client->dev);
738 	struct zforce_ts *ts;
739 	struct input_dev *input_dev;
740 	int ret;
741 
742 	if (!pdata) {
743 		pdata = zforce_parse_dt(&client->dev);
744 		if (IS_ERR(pdata))
745 			return PTR_ERR(pdata);
746 	}
747 
748 	ts = devm_kzalloc(&client->dev, sizeof(struct zforce_ts), GFP_KERNEL);
749 	if (!ts)
750 		return -ENOMEM;
751 
752 	ret = devm_gpio_request_one(&client->dev, pdata->gpio_int, GPIOF_IN,
753 				    "zforce_ts_int");
754 	if (ret) {
755 		dev_err(&client->dev, "request of gpio %d failed, %d\n",
756 			pdata->gpio_int, ret);
757 		return ret;
758 	}
759 
760 	ret = devm_gpio_request_one(&client->dev, pdata->gpio_rst,
761 				    GPIOF_OUT_INIT_LOW, "zforce_ts_rst");
762 	if (ret) {
763 		dev_err(&client->dev, "request of gpio %d failed, %d\n",
764 			pdata->gpio_rst, ret);
765 		return ret;
766 	}
767 
768 	ret = devm_add_action(&client->dev, zforce_reset, ts);
769 	if (ret) {
770 		dev_err(&client->dev, "failed to register reset action, %d\n",
771 			ret);
772 		return ret;
773 	}
774 
775 	snprintf(ts->phys, sizeof(ts->phys),
776 		 "%s/input0", dev_name(&client->dev));
777 
778 	input_dev = devm_input_allocate_device(&client->dev);
779 	if (!input_dev) {
780 		dev_err(&client->dev, "could not allocate input device\n");
781 		return -ENOMEM;
782 	}
783 
784 	mutex_init(&ts->access_mutex);
785 	mutex_init(&ts->command_mutex);
786 
787 	ts->pdata = pdata;
788 	ts->client = client;
789 	ts->input = input_dev;
790 
791 	input_dev->name = "Neonode zForce touchscreen";
792 	input_dev->phys = ts->phys;
793 	input_dev->id.bustype = BUS_I2C;
794 
795 	input_dev->open = zforce_input_open;
796 	input_dev->close = zforce_input_close;
797 
798 	__set_bit(EV_KEY, input_dev->evbit);
799 	__set_bit(EV_SYN, input_dev->evbit);
800 	__set_bit(EV_ABS, input_dev->evbit);
801 
802 	/* For multi touch */
803 	input_set_abs_params(input_dev, ABS_MT_POSITION_X, 0,
804 			     pdata->x_max, 0, 0);
805 	input_set_abs_params(input_dev, ABS_MT_POSITION_Y, 0,
806 			     pdata->y_max, 0, 0);
807 
808 	input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0,
809 			     ZFORCE_MAX_AREA, 0, 0);
810 	input_set_abs_params(input_dev, ABS_MT_TOUCH_MINOR, 0,
811 			     ZFORCE_MAX_AREA, 0, 0);
812 	input_set_abs_params(input_dev, ABS_MT_ORIENTATION, 0, 1, 0, 0);
813 	input_mt_init_slots(input_dev, ZFORCE_REPORT_POINTS, INPUT_MT_DIRECT);
814 
815 	input_set_drvdata(ts->input, ts);
816 
817 	init_completion(&ts->command_done);
818 
819 	/*
820 	 * The zforce pulls the interrupt low when it has data ready.
821 	 * After it is triggered the isr thread runs until all the available
822 	 * packets have been read and the interrupt is high again.
823 	 * Therefore we can trigger the interrupt anytime it is low and do
824 	 * not need to limit it to the interrupt edge.
825 	 */
826 	ret = devm_request_threaded_irq(&client->dev, client->irq,
827 					zforce_irq, zforce_irq_thread,
828 					IRQF_TRIGGER_LOW | IRQF_ONESHOT,
829 					input_dev->name, ts);
830 	if (ret) {
831 		dev_err(&client->dev, "irq %d request failed\n", client->irq);
832 		return ret;
833 	}
834 
835 	i2c_set_clientdata(client, ts);
836 
837 	/* let the controller boot */
838 	gpio_set_value(pdata->gpio_rst, 1);
839 
840 	ts->command_waiting = NOTIFICATION_BOOTCOMPLETE;
841 	if (wait_for_completion_timeout(&ts->command_done, WAIT_TIMEOUT) == 0)
842 		dev_warn(&client->dev, "bootcomplete timed out\n");
843 
844 	/* need to start device to get version information */
845 	ret = zforce_command_wait(ts, COMMAND_INITIALIZE);
846 	if (ret) {
847 		dev_err(&client->dev, "unable to initialize, %d\n", ret);
848 		return ret;
849 	}
850 
851 	/* this gets the firmware version among other information */
852 	ret = zforce_command_wait(ts, COMMAND_STATUS);
853 	if (ret < 0) {
854 		dev_err(&client->dev, "couldn't get status, %d\n", ret);
855 		zforce_stop(ts);
856 		return ret;
857 	}
858 
859 	/* stop device and put it into sleep until it is opened */
860 	ret = zforce_stop(ts);
861 	if (ret < 0)
862 		return ret;
863 
864 	device_set_wakeup_capable(&client->dev, true);
865 
866 	ret = input_register_device(input_dev);
867 	if (ret) {
868 		dev_err(&client->dev, "could not register input device, %d\n",
869 			ret);
870 		return ret;
871 	}
872 
873 	return 0;
874 }
875 
876 static struct i2c_device_id zforce_idtable[] = {
877 	{ "zforce-ts", 0 },
878 	{ }
879 };
880 MODULE_DEVICE_TABLE(i2c, zforce_idtable);
881 
882 #ifdef CONFIG_OF
883 static const struct of_device_id zforce_dt_idtable[] = {
884 	{ .compatible = "neonode,zforce" },
885 	{},
886 };
887 MODULE_DEVICE_TABLE(of, zforce_dt_idtable);
888 #endif
889 
890 static struct i2c_driver zforce_driver = {
891 	.driver = {
892 		.owner	= THIS_MODULE,
893 		.name	= "zforce-ts",
894 		.pm	= &zforce_pm_ops,
895 		.of_match_table	= of_match_ptr(zforce_dt_idtable),
896 	},
897 	.probe		= zforce_probe,
898 	.id_table	= zforce_idtable,
899 };
900 
901 module_i2c_driver(zforce_driver);
902 
903 MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
904 MODULE_DESCRIPTION("zForce TouchScreen Driver");
905 MODULE_LICENSE("GPL");
906