xref: /openbmc/linux/drivers/input/touchscreen/zforce_ts.c (revision bbde9fc1824aab58bc78c084163007dd6c03fe5b)
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/regulator/consumer.h>
33 #include <linux/of.h>
34 #include <linux/of_gpio.h>
35 
36 #define WAIT_TIMEOUT		msecs_to_jiffies(1000)
37 
38 #define FRAME_START		0xee
39 #define FRAME_MAXSIZE		257
40 
41 /* Offsets of the different parts of the payload the controller sends */
42 #define PAYLOAD_HEADER		0
43 #define PAYLOAD_LENGTH		1
44 #define PAYLOAD_BODY		2
45 
46 /* Response offsets */
47 #define RESPONSE_ID		0
48 #define RESPONSE_DATA		1
49 
50 /* Commands */
51 #define COMMAND_DEACTIVATE	0x00
52 #define COMMAND_INITIALIZE	0x01
53 #define COMMAND_RESOLUTION	0x02
54 #define COMMAND_SETCONFIG	0x03
55 #define COMMAND_DATAREQUEST	0x04
56 #define COMMAND_SCANFREQ	0x08
57 #define COMMAND_STATUS		0X1e
58 
59 /*
60  * Responses the controller sends as a result of
61  * command requests
62  */
63 #define RESPONSE_DEACTIVATE	0x00
64 #define RESPONSE_INITIALIZE	0x01
65 #define RESPONSE_RESOLUTION	0x02
66 #define RESPONSE_SETCONFIG	0x03
67 #define RESPONSE_SCANFREQ	0x08
68 #define RESPONSE_STATUS		0X1e
69 
70 /*
71  * Notifications are sent by the touch controller without
72  * being requested by the driver and include for example
73  * touch indications
74  */
75 #define NOTIFICATION_TOUCH		0x04
76 #define NOTIFICATION_BOOTCOMPLETE	0x07
77 #define NOTIFICATION_OVERRUN		0x25
78 #define NOTIFICATION_PROXIMITY		0x26
79 #define NOTIFICATION_INVALID_COMMAND	0xfe
80 
81 #define ZFORCE_REPORT_POINTS		2
82 #define ZFORCE_MAX_AREA			0xff
83 
84 #define STATE_DOWN			0
85 #define STATE_MOVE			1
86 #define STATE_UP			2
87 
88 #define SETCONFIG_DUALTOUCH		(1 << 0)
89 
90 struct zforce_point {
91 	int coord_x;
92 	int coord_y;
93 	int state;
94 	int id;
95 	int area_major;
96 	int area_minor;
97 	int orientation;
98 	int pressure;
99 	int prblty;
100 };
101 
102 /*
103  * @client		the i2c_client
104  * @input		the input device
105  * @suspending		in the process of going to suspend (don't emit wakeup
106  *			events for commands executed to suspend the device)
107  * @suspended		device suspended
108  * @access_mutex	serialize i2c-access, to keep multipart reads together
109  * @command_done	completion to wait for the command result
110  * @command_mutex	serialize commands sent to the ic
111  * @command_waiting	the id of the command that is currently waiting
112  *			for a result
113  * @command_result	returned result of the command
114  */
115 struct zforce_ts {
116 	struct i2c_client	*client;
117 	struct input_dev	*input;
118 	const struct zforce_ts_platdata *pdata;
119 	char			phys[32];
120 
121 	struct regulator	*reg_vdd;
122 
123 	bool			suspending;
124 	bool			suspended;
125 	bool			boot_complete;
126 
127 	/* Firmware version information */
128 	u16			version_major;
129 	u16			version_minor;
130 	u16			version_build;
131 	u16			version_rev;
132 
133 	struct mutex		access_mutex;
134 
135 	struct completion	command_done;
136 	struct mutex		command_mutex;
137 	int			command_waiting;
138 	int			command_result;
139 };
140 
141 static int zforce_command(struct zforce_ts *ts, u8 cmd)
142 {
143 	struct i2c_client *client = ts->client;
144 	char buf[3];
145 	int ret;
146 
147 	dev_dbg(&client->dev, "%s: 0x%x\n", __func__, cmd);
148 
149 	buf[0] = FRAME_START;
150 	buf[1] = 1; /* data size, command only */
151 	buf[2] = cmd;
152 
153 	mutex_lock(&ts->access_mutex);
154 	ret = i2c_master_send(client, &buf[0], ARRAY_SIZE(buf));
155 	mutex_unlock(&ts->access_mutex);
156 	if (ret < 0) {
157 		dev_err(&client->dev, "i2c send data request error: %d\n", ret);
158 		return ret;
159 	}
160 
161 	return 0;
162 }
163 
164 static int zforce_send_wait(struct zforce_ts *ts, const char *buf, int len)
165 {
166 	struct i2c_client *client = ts->client;
167 	int ret;
168 
169 	ret = mutex_trylock(&ts->command_mutex);
170 	if (!ret) {
171 		dev_err(&client->dev, "already waiting for a command\n");
172 		return -EBUSY;
173 	}
174 
175 	dev_dbg(&client->dev, "sending %d bytes for command 0x%x\n",
176 		buf[1], buf[2]);
177 
178 	ts->command_waiting = buf[2];
179 
180 	mutex_lock(&ts->access_mutex);
181 	ret = i2c_master_send(client, buf, len);
182 	mutex_unlock(&ts->access_mutex);
183 	if (ret < 0) {
184 		dev_err(&client->dev, "i2c send data request error: %d\n", ret);
185 		goto unlock;
186 	}
187 
188 	dev_dbg(&client->dev, "waiting for result for command 0x%x\n", buf[2]);
189 
190 	if (wait_for_completion_timeout(&ts->command_done, WAIT_TIMEOUT) == 0) {
191 		ret = -ETIME;
192 		goto unlock;
193 	}
194 
195 	ret = ts->command_result;
196 
197 unlock:
198 	mutex_unlock(&ts->command_mutex);
199 	return ret;
200 }
201 
202 static int zforce_command_wait(struct zforce_ts *ts, u8 cmd)
203 {
204 	struct i2c_client *client = ts->client;
205 	char buf[3];
206 	int ret;
207 
208 	dev_dbg(&client->dev, "%s: 0x%x\n", __func__, cmd);
209 
210 	buf[0] = FRAME_START;
211 	buf[1] = 1; /* data size, command only */
212 	buf[2] = cmd;
213 
214 	ret = zforce_send_wait(ts, &buf[0], ARRAY_SIZE(buf));
215 	if (ret < 0) {
216 		dev_err(&client->dev, "i2c send data request error: %d\n", ret);
217 		return ret;
218 	}
219 
220 	return 0;
221 }
222 
223 static int zforce_resolution(struct zforce_ts *ts, u16 x, u16 y)
224 {
225 	struct i2c_client *client = ts->client;
226 	char buf[7] = { FRAME_START, 5, COMMAND_RESOLUTION,
227 			(x & 0xff), ((x >> 8) & 0xff),
228 			(y & 0xff), ((y >> 8) & 0xff) };
229 
230 	dev_dbg(&client->dev, "set resolution to (%d,%d)\n", x, y);
231 
232 	return zforce_send_wait(ts, &buf[0], ARRAY_SIZE(buf));
233 }
234 
235 static int zforce_scan_frequency(struct zforce_ts *ts, u16 idle, u16 finger,
236 				 u16 stylus)
237 {
238 	struct i2c_client *client = ts->client;
239 	char buf[9] = { FRAME_START, 7, COMMAND_SCANFREQ,
240 			(idle & 0xff), ((idle >> 8) & 0xff),
241 			(finger & 0xff), ((finger >> 8) & 0xff),
242 			(stylus & 0xff), ((stylus >> 8) & 0xff) };
243 
244 	dev_dbg(&client->dev,
245 		"set scan frequency to (idle: %d, finger: %d, stylus: %d)\n",
246 		idle, finger, stylus);
247 
248 	return zforce_send_wait(ts, &buf[0], ARRAY_SIZE(buf));
249 }
250 
251 static int zforce_setconfig(struct zforce_ts *ts, char b1)
252 {
253 	struct i2c_client *client = ts->client;
254 	char buf[7] = { FRAME_START, 5, COMMAND_SETCONFIG,
255 			b1, 0, 0, 0 };
256 
257 	dev_dbg(&client->dev, "set config to (%d)\n", b1);
258 
259 	return zforce_send_wait(ts, &buf[0], ARRAY_SIZE(buf));
260 }
261 
262 static int zforce_start(struct zforce_ts *ts)
263 {
264 	struct i2c_client *client = ts->client;
265 	const struct zforce_ts_platdata *pdata = ts->pdata;
266 	int ret;
267 
268 	dev_dbg(&client->dev, "starting device\n");
269 
270 	ret = zforce_command_wait(ts, COMMAND_INITIALIZE);
271 	if (ret) {
272 		dev_err(&client->dev, "Unable to initialize, %d\n", ret);
273 		return ret;
274 	}
275 
276 	ret = zforce_resolution(ts, pdata->x_max, pdata->y_max);
277 	if (ret) {
278 		dev_err(&client->dev, "Unable to set resolution, %d\n", ret);
279 		goto error;
280 	}
281 
282 	ret = zforce_scan_frequency(ts, 10, 50, 50);
283 	if (ret) {
284 		dev_err(&client->dev, "Unable to set scan frequency, %d\n",
285 			ret);
286 		goto error;
287 	}
288 
289 	ret = zforce_setconfig(ts, SETCONFIG_DUALTOUCH);
290 	if (ret) {
291 		dev_err(&client->dev, "Unable to set config\n");
292 		goto error;
293 	}
294 
295 	/* start sending touch events */
296 	ret = zforce_command(ts, COMMAND_DATAREQUEST);
297 	if (ret) {
298 		dev_err(&client->dev, "Unable to request data\n");
299 		goto error;
300 	}
301 
302 	/*
303 	 * Per NN, initial cal. take max. of 200msec.
304 	 * Allow time to complete this calibration
305 	 */
306 	msleep(200);
307 
308 	return 0;
309 
310 error:
311 	zforce_command_wait(ts, COMMAND_DEACTIVATE);
312 	return ret;
313 }
314 
315 static int zforce_stop(struct zforce_ts *ts)
316 {
317 	struct i2c_client *client = ts->client;
318 	int ret;
319 
320 	dev_dbg(&client->dev, "stopping device\n");
321 
322 	/* Deactivates touch sensing and puts the device into sleep. */
323 	ret = zforce_command_wait(ts, COMMAND_DEACTIVATE);
324 	if (ret != 0) {
325 		dev_err(&client->dev, "could not deactivate device, %d\n",
326 			ret);
327 		return ret;
328 	}
329 
330 	return 0;
331 }
332 
333 static int zforce_touch_event(struct zforce_ts *ts, u8 *payload)
334 {
335 	struct i2c_client *client = ts->client;
336 	const struct zforce_ts_platdata *pdata = ts->pdata;
337 	struct zforce_point point;
338 	int count, i, num = 0;
339 
340 	count = payload[0];
341 	if (count > ZFORCE_REPORT_POINTS) {
342 		dev_warn(&client->dev,
343 			 "too many coordinates %d, expected max %d\n",
344 			 count, ZFORCE_REPORT_POINTS);
345 		count = ZFORCE_REPORT_POINTS;
346 	}
347 
348 	for (i = 0; i < count; i++) {
349 		point.coord_x =
350 			payload[9 * i + 2] << 8 | payload[9 * i + 1];
351 		point.coord_y =
352 			payload[9 * i + 4] << 8 | payload[9 * i + 3];
353 
354 		if (point.coord_x > pdata->x_max ||
355 		    point.coord_y > pdata->y_max) {
356 			dev_warn(&client->dev, "coordinates (%d,%d) invalid\n",
357 				point.coord_x, point.coord_y);
358 			point.coord_x = point.coord_y = 0;
359 		}
360 
361 		point.state = payload[9 * i + 5] & 0x03;
362 		point.id = (payload[9 * i + 5] & 0xfc) >> 2;
363 
364 		/* determine touch major, minor and orientation */
365 		point.area_major = max(payload[9 * i + 6],
366 					  payload[9 * i + 7]);
367 		point.area_minor = min(payload[9 * i + 6],
368 					  payload[9 * i + 7]);
369 		point.orientation = payload[9 * i + 6] > payload[9 * i + 7];
370 
371 		point.pressure = payload[9 * i + 8];
372 		point.prblty = payload[9 * i + 9];
373 
374 		dev_dbg(&client->dev,
375 			"point %d/%d: state %d, id %d, pressure %d, prblty %d, x %d, y %d, amajor %d, aminor %d, ori %d\n",
376 			i, count, point.state, point.id,
377 			point.pressure, point.prblty,
378 			point.coord_x, point.coord_y,
379 			point.area_major, point.area_minor,
380 			point.orientation);
381 
382 		/* the zforce id starts with "1", so needs to be decreased */
383 		input_mt_slot(ts->input, point.id - 1);
384 
385 		input_mt_report_slot_state(ts->input, MT_TOOL_FINGER,
386 						point.state != STATE_UP);
387 
388 		if (point.state != STATE_UP) {
389 			input_report_abs(ts->input, ABS_MT_POSITION_X,
390 					 point.coord_x);
391 			input_report_abs(ts->input, ABS_MT_POSITION_Y,
392 					 point.coord_y);
393 			input_report_abs(ts->input, ABS_MT_TOUCH_MAJOR,
394 					 point.area_major);
395 			input_report_abs(ts->input, ABS_MT_TOUCH_MINOR,
396 					 point.area_minor);
397 			input_report_abs(ts->input, ABS_MT_ORIENTATION,
398 					 point.orientation);
399 			num++;
400 		}
401 	}
402 
403 	input_mt_sync_frame(ts->input);
404 
405 	input_mt_report_finger_count(ts->input, num);
406 
407 	input_sync(ts->input);
408 
409 	return 0;
410 }
411 
412 static int zforce_read_packet(struct zforce_ts *ts, u8 *buf)
413 {
414 	struct i2c_client *client = ts->client;
415 	int ret;
416 
417 	mutex_lock(&ts->access_mutex);
418 
419 	/* read 2 byte message header */
420 	ret = i2c_master_recv(client, buf, 2);
421 	if (ret < 0) {
422 		dev_err(&client->dev, "error reading header: %d\n", ret);
423 		goto unlock;
424 	}
425 
426 	if (buf[PAYLOAD_HEADER] != FRAME_START) {
427 		dev_err(&client->dev, "invalid frame start: %d\n", buf[0]);
428 		ret = -EIO;
429 		goto unlock;
430 	}
431 
432 	if (buf[PAYLOAD_LENGTH] == 0) {
433 		dev_err(&client->dev, "invalid payload length: %d\n",
434 			buf[PAYLOAD_LENGTH]);
435 		ret = -EIO;
436 		goto unlock;
437 	}
438 
439 	/* read the message */
440 	ret = i2c_master_recv(client, &buf[PAYLOAD_BODY], buf[PAYLOAD_LENGTH]);
441 	if (ret < 0) {
442 		dev_err(&client->dev, "error reading payload: %d\n", ret);
443 		goto unlock;
444 	}
445 
446 	dev_dbg(&client->dev, "read %d bytes for response command 0x%x\n",
447 		buf[PAYLOAD_LENGTH], buf[PAYLOAD_BODY]);
448 
449 unlock:
450 	mutex_unlock(&ts->access_mutex);
451 	return ret;
452 }
453 
454 static void zforce_complete(struct zforce_ts *ts, int cmd, int result)
455 {
456 	struct i2c_client *client = ts->client;
457 
458 	if (ts->command_waiting == cmd) {
459 		dev_dbg(&client->dev, "completing command 0x%x\n", cmd);
460 		ts->command_result = result;
461 		complete(&ts->command_done);
462 	} else {
463 		dev_dbg(&client->dev, "command %d not for us\n", cmd);
464 	}
465 }
466 
467 static irqreturn_t zforce_irq(int irq, void *dev_id)
468 {
469 	struct zforce_ts *ts = dev_id;
470 	struct i2c_client *client = ts->client;
471 
472 	if (ts->suspended && device_may_wakeup(&client->dev))
473 		pm_wakeup_event(&client->dev, 500);
474 
475 	return IRQ_WAKE_THREAD;
476 }
477 
478 static irqreturn_t zforce_irq_thread(int irq, void *dev_id)
479 {
480 	struct zforce_ts *ts = dev_id;
481 	struct i2c_client *client = ts->client;
482 	const struct zforce_ts_platdata *pdata = ts->pdata;
483 	int ret;
484 	u8 payload_buffer[FRAME_MAXSIZE];
485 	u8 *payload;
486 
487 	/*
488 	 * When still suspended, return.
489 	 * Due to the level-interrupt we will get re-triggered later.
490 	 */
491 	if (ts->suspended) {
492 		msleep(20);
493 		return IRQ_HANDLED;
494 	}
495 
496 	dev_dbg(&client->dev, "handling interrupt\n");
497 
498 	/* Don't emit wakeup events from commands run by zforce_suspend */
499 	if (!ts->suspending && device_may_wakeup(&client->dev))
500 		pm_stay_awake(&client->dev);
501 
502 	while (!gpio_get_value(pdata->gpio_int)) {
503 		ret = zforce_read_packet(ts, payload_buffer);
504 		if (ret < 0) {
505 			dev_err(&client->dev,
506 				"could not read packet, ret: %d\n", ret);
507 			break;
508 		}
509 
510 		payload =  &payload_buffer[PAYLOAD_BODY];
511 
512 		switch (payload[RESPONSE_ID]) {
513 		case NOTIFICATION_TOUCH:
514 			/*
515 			 * Always report touch-events received while
516 			 * suspending, when being a wakeup source
517 			 */
518 			if (ts->suspending && device_may_wakeup(&client->dev))
519 				pm_wakeup_event(&client->dev, 500);
520 			zforce_touch_event(ts, &payload[RESPONSE_DATA]);
521 			break;
522 
523 		case NOTIFICATION_BOOTCOMPLETE:
524 			ts->boot_complete = payload[RESPONSE_DATA];
525 			zforce_complete(ts, payload[RESPONSE_ID], 0);
526 			break;
527 
528 		case RESPONSE_INITIALIZE:
529 		case RESPONSE_DEACTIVATE:
530 		case RESPONSE_SETCONFIG:
531 		case RESPONSE_RESOLUTION:
532 		case RESPONSE_SCANFREQ:
533 			zforce_complete(ts, payload[RESPONSE_ID],
534 					payload[RESPONSE_DATA]);
535 			break;
536 
537 		case RESPONSE_STATUS:
538 			/*
539 			 * Version Payload Results
540 			 * [2:major] [2:minor] [2:build] [2:rev]
541 			 */
542 			ts->version_major = (payload[RESPONSE_DATA + 1] << 8) |
543 						payload[RESPONSE_DATA];
544 			ts->version_minor = (payload[RESPONSE_DATA + 3] << 8) |
545 						payload[RESPONSE_DATA + 2];
546 			ts->version_build = (payload[RESPONSE_DATA + 5] << 8) |
547 						payload[RESPONSE_DATA + 4];
548 			ts->version_rev   = (payload[RESPONSE_DATA + 7] << 8) |
549 						payload[RESPONSE_DATA + 6];
550 			dev_dbg(&ts->client->dev,
551 				"Firmware Version %04x:%04x %04x:%04x\n",
552 				ts->version_major, ts->version_minor,
553 				ts->version_build, ts->version_rev);
554 
555 			zforce_complete(ts, payload[RESPONSE_ID], 0);
556 			break;
557 
558 		case NOTIFICATION_INVALID_COMMAND:
559 			dev_err(&ts->client->dev, "invalid command: 0x%x\n",
560 				payload[RESPONSE_DATA]);
561 			break;
562 
563 		default:
564 			dev_err(&ts->client->dev,
565 				"unrecognized response id: 0x%x\n",
566 				payload[RESPONSE_ID]);
567 			break;
568 		}
569 	}
570 
571 	if (!ts->suspending && device_may_wakeup(&client->dev))
572 		pm_relax(&client->dev);
573 
574 	dev_dbg(&client->dev, "finished interrupt\n");
575 
576 	return IRQ_HANDLED;
577 }
578 
579 static int zforce_input_open(struct input_dev *dev)
580 {
581 	struct zforce_ts *ts = input_get_drvdata(dev);
582 	int ret;
583 
584 	ret = zforce_start(ts);
585 	if (ret)
586 		return ret;
587 
588 	return 0;
589 }
590 
591 static void zforce_input_close(struct input_dev *dev)
592 {
593 	struct zforce_ts *ts = input_get_drvdata(dev);
594 	struct i2c_client *client = ts->client;
595 	int ret;
596 
597 	ret = zforce_stop(ts);
598 	if (ret)
599 		dev_warn(&client->dev, "stopping zforce failed\n");
600 
601 	return;
602 }
603 
604 static int __maybe_unused zforce_suspend(struct device *dev)
605 {
606 	struct i2c_client *client = to_i2c_client(dev);
607 	struct zforce_ts *ts = i2c_get_clientdata(client);
608 	struct input_dev *input = ts->input;
609 	int ret = 0;
610 
611 	mutex_lock(&input->mutex);
612 	ts->suspending = true;
613 
614 	/*
615 	 * When configured as a wakeup source device should always wake
616 	 * the system, therefore start device if necessary.
617 	 */
618 	if (device_may_wakeup(&client->dev)) {
619 		dev_dbg(&client->dev, "suspend while being a wakeup source\n");
620 
621 		/* Need to start device, if not open, to be a wakeup source. */
622 		if (!input->users) {
623 			ret = zforce_start(ts);
624 			if (ret)
625 				goto unlock;
626 		}
627 
628 		enable_irq_wake(client->irq);
629 	} else if (input->users) {
630 		dev_dbg(&client->dev,
631 			"suspend without being a wakeup source\n");
632 
633 		ret = zforce_stop(ts);
634 		if (ret)
635 			goto unlock;
636 
637 		disable_irq(client->irq);
638 	}
639 
640 	ts->suspended = true;
641 
642 unlock:
643 	ts->suspending = false;
644 	mutex_unlock(&input->mutex);
645 
646 	return ret;
647 }
648 
649 static int __maybe_unused zforce_resume(struct device *dev)
650 {
651 	struct i2c_client *client = to_i2c_client(dev);
652 	struct zforce_ts *ts = i2c_get_clientdata(client);
653 	struct input_dev *input = ts->input;
654 	int ret = 0;
655 
656 	mutex_lock(&input->mutex);
657 
658 	ts->suspended = false;
659 
660 	if (device_may_wakeup(&client->dev)) {
661 		dev_dbg(&client->dev, "resume from being a wakeup source\n");
662 
663 		disable_irq_wake(client->irq);
664 
665 		/* need to stop device if it was not open on suspend */
666 		if (!input->users) {
667 			ret = zforce_stop(ts);
668 			if (ret)
669 				goto unlock;
670 		}
671 	} else if (input->users) {
672 		dev_dbg(&client->dev, "resume without being a wakeup source\n");
673 
674 		enable_irq(client->irq);
675 
676 		ret = zforce_start(ts);
677 		if (ret < 0)
678 			goto unlock;
679 	}
680 
681 unlock:
682 	mutex_unlock(&input->mutex);
683 
684 	return ret;
685 }
686 
687 static SIMPLE_DEV_PM_OPS(zforce_pm_ops, zforce_suspend, zforce_resume);
688 
689 static void zforce_reset(void *data)
690 {
691 	struct zforce_ts *ts = data;
692 
693 	gpio_set_value(ts->pdata->gpio_rst, 0);
694 
695 	udelay(10);
696 
697 	if (!IS_ERR(ts->reg_vdd))
698 		regulator_disable(ts->reg_vdd);
699 }
700 
701 static struct zforce_ts_platdata *zforce_parse_dt(struct device *dev)
702 {
703 	struct zforce_ts_platdata *pdata;
704 	struct device_node *np = dev->of_node;
705 
706 	if (!np)
707 		return ERR_PTR(-ENOENT);
708 
709 	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
710 	if (!pdata) {
711 		dev_err(dev, "failed to allocate platform data\n");
712 		return ERR_PTR(-ENOMEM);
713 	}
714 
715 	pdata->gpio_int = of_get_gpio(np, 0);
716 	if (!gpio_is_valid(pdata->gpio_int)) {
717 		dev_err(dev, "failed to get interrupt gpio\n");
718 		return ERR_PTR(-EINVAL);
719 	}
720 
721 	pdata->gpio_rst = of_get_gpio(np, 1);
722 	if (!gpio_is_valid(pdata->gpio_rst)) {
723 		dev_err(dev, "failed to get reset gpio\n");
724 		return ERR_PTR(-EINVAL);
725 	}
726 
727 	if (of_property_read_u32(np, "x-size", &pdata->x_max)) {
728 		dev_err(dev, "failed to get x-size property\n");
729 		return ERR_PTR(-EINVAL);
730 	}
731 
732 	if (of_property_read_u32(np, "y-size", &pdata->y_max)) {
733 		dev_err(dev, "failed to get y-size property\n");
734 		return ERR_PTR(-EINVAL);
735 	}
736 
737 	return pdata;
738 }
739 
740 static int zforce_probe(struct i2c_client *client,
741 			const struct i2c_device_id *id)
742 {
743 	const struct zforce_ts_platdata *pdata = dev_get_platdata(&client->dev);
744 	struct zforce_ts *ts;
745 	struct input_dev *input_dev;
746 	int ret;
747 
748 	if (!pdata) {
749 		pdata = zforce_parse_dt(&client->dev);
750 		if (IS_ERR(pdata))
751 			return PTR_ERR(pdata);
752 	}
753 
754 	ts = devm_kzalloc(&client->dev, sizeof(struct zforce_ts), GFP_KERNEL);
755 	if (!ts)
756 		return -ENOMEM;
757 
758 	ret = devm_gpio_request_one(&client->dev, pdata->gpio_int, GPIOF_IN,
759 				    "zforce_ts_int");
760 	if (ret) {
761 		dev_err(&client->dev, "request of gpio %d failed, %d\n",
762 			pdata->gpio_int, ret);
763 		return ret;
764 	}
765 
766 	ret = devm_gpio_request_one(&client->dev, pdata->gpio_rst,
767 				    GPIOF_OUT_INIT_LOW, "zforce_ts_rst");
768 	if (ret) {
769 		dev_err(&client->dev, "request of gpio %d failed, %d\n",
770 			pdata->gpio_rst, ret);
771 		return ret;
772 	}
773 
774 	ts->reg_vdd = devm_regulator_get_optional(&client->dev, "vdd");
775 	if (IS_ERR(ts->reg_vdd)) {
776 		ret = PTR_ERR(ts->reg_vdd);
777 		if (ret == -EPROBE_DEFER)
778 			return ret;
779 	} else {
780 		ret = regulator_enable(ts->reg_vdd);
781 		if (ret)
782 			return ret;
783 
784 		/*
785 		 * according to datasheet add 100us grace time after regular
786 		 * regulator enable delay.
787 		 */
788 		udelay(100);
789 	}
790 
791 	ret = devm_add_action(&client->dev, zforce_reset, ts);
792 	if (ret) {
793 		dev_err(&client->dev, "failed to register reset action, %d\n",
794 			ret);
795 
796 		/* hereafter the regulator will be disabled by the action */
797 		if (!IS_ERR(ts->reg_vdd))
798 			regulator_disable(ts->reg_vdd);
799 
800 		return ret;
801 	}
802 
803 	snprintf(ts->phys, sizeof(ts->phys),
804 		 "%s/input0", dev_name(&client->dev));
805 
806 	input_dev = devm_input_allocate_device(&client->dev);
807 	if (!input_dev) {
808 		dev_err(&client->dev, "could not allocate input device\n");
809 		return -ENOMEM;
810 	}
811 
812 	mutex_init(&ts->access_mutex);
813 	mutex_init(&ts->command_mutex);
814 
815 	ts->pdata = pdata;
816 	ts->client = client;
817 	ts->input = input_dev;
818 
819 	input_dev->name = "Neonode zForce touchscreen";
820 	input_dev->phys = ts->phys;
821 	input_dev->id.bustype = BUS_I2C;
822 
823 	input_dev->open = zforce_input_open;
824 	input_dev->close = zforce_input_close;
825 
826 	__set_bit(EV_KEY, input_dev->evbit);
827 	__set_bit(EV_SYN, input_dev->evbit);
828 	__set_bit(EV_ABS, input_dev->evbit);
829 
830 	/* For multi touch */
831 	input_set_abs_params(input_dev, ABS_MT_POSITION_X, 0,
832 			     pdata->x_max, 0, 0);
833 	input_set_abs_params(input_dev, ABS_MT_POSITION_Y, 0,
834 			     pdata->y_max, 0, 0);
835 
836 	input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0,
837 			     ZFORCE_MAX_AREA, 0, 0);
838 	input_set_abs_params(input_dev, ABS_MT_TOUCH_MINOR, 0,
839 			     ZFORCE_MAX_AREA, 0, 0);
840 	input_set_abs_params(input_dev, ABS_MT_ORIENTATION, 0, 1, 0, 0);
841 	input_mt_init_slots(input_dev, ZFORCE_REPORT_POINTS, INPUT_MT_DIRECT);
842 
843 	input_set_drvdata(ts->input, ts);
844 
845 	init_completion(&ts->command_done);
846 
847 	/*
848 	 * The zforce pulls the interrupt low when it has data ready.
849 	 * After it is triggered the isr thread runs until all the available
850 	 * packets have been read and the interrupt is high again.
851 	 * Therefore we can trigger the interrupt anytime it is low and do
852 	 * not need to limit it to the interrupt edge.
853 	 */
854 	ret = devm_request_threaded_irq(&client->dev, client->irq,
855 					zforce_irq, zforce_irq_thread,
856 					IRQF_TRIGGER_LOW | IRQF_ONESHOT,
857 					input_dev->name, ts);
858 	if (ret) {
859 		dev_err(&client->dev, "irq %d request failed\n", client->irq);
860 		return ret;
861 	}
862 
863 	i2c_set_clientdata(client, ts);
864 
865 	/* let the controller boot */
866 	gpio_set_value(pdata->gpio_rst, 1);
867 
868 	ts->command_waiting = NOTIFICATION_BOOTCOMPLETE;
869 	if (wait_for_completion_timeout(&ts->command_done, WAIT_TIMEOUT) == 0)
870 		dev_warn(&client->dev, "bootcomplete timed out\n");
871 
872 	/* need to start device to get version information */
873 	ret = zforce_command_wait(ts, COMMAND_INITIALIZE);
874 	if (ret) {
875 		dev_err(&client->dev, "unable to initialize, %d\n", ret);
876 		return ret;
877 	}
878 
879 	/* this gets the firmware version among other information */
880 	ret = zforce_command_wait(ts, COMMAND_STATUS);
881 	if (ret < 0) {
882 		dev_err(&client->dev, "couldn't get status, %d\n", ret);
883 		zforce_stop(ts);
884 		return ret;
885 	}
886 
887 	/* stop device and put it into sleep until it is opened */
888 	ret = zforce_stop(ts);
889 	if (ret < 0)
890 		return ret;
891 
892 	device_set_wakeup_capable(&client->dev, true);
893 
894 	ret = input_register_device(input_dev);
895 	if (ret) {
896 		dev_err(&client->dev, "could not register input device, %d\n",
897 			ret);
898 		return ret;
899 	}
900 
901 	return 0;
902 }
903 
904 static struct i2c_device_id zforce_idtable[] = {
905 	{ "zforce-ts", 0 },
906 	{ }
907 };
908 MODULE_DEVICE_TABLE(i2c, zforce_idtable);
909 
910 #ifdef CONFIG_OF
911 static const struct of_device_id zforce_dt_idtable[] = {
912 	{ .compatible = "neonode,zforce" },
913 	{},
914 };
915 MODULE_DEVICE_TABLE(of, zforce_dt_idtable);
916 #endif
917 
918 static struct i2c_driver zforce_driver = {
919 	.driver = {
920 		.owner	= THIS_MODULE,
921 		.name	= "zforce-ts",
922 		.pm	= &zforce_pm_ops,
923 		.of_match_table	= of_match_ptr(zforce_dt_idtable),
924 	},
925 	.probe		= zforce_probe,
926 	.id_table	= zforce_idtable,
927 };
928 
929 module_i2c_driver(zforce_driver);
930 
931 MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
932 MODULE_DESCRIPTION("zForce TouchScreen Driver");
933 MODULE_LICENSE("GPL");
934