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  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Copyright (C) 2012-2013 MundoReader S.L.
  4 * Author: Heiko Stuebner <heiko@sntech.de>
  5 *
  6 * based in parts on Nook zforce driver
  7 *
  8 * Copyright (C) 2010 Barnes & Noble, Inc.
  9 * Author: Pieter Truter<ptruter@intrinsyc.com>
 10 */
 11
 12#include <linux/module.h>
 13#include <linux/hrtimer.h>
 14#include <linux/slab.h>
 15#include <linux/input.h>
 16#include <linux/interrupt.h>
 17#include <linux/i2c.h>
 18#include <linux/delay.h>
 19#include <linux/gpio/consumer.h>
 20#include <linux/device.h>
 21#include <linux/sysfs.h>
 22#include <linux/input/mt.h>
 23#include <linux/platform_data/zforce_ts.h>
 24#include <linux/regulator/consumer.h>
 25#include <linux/of.h>
 26
 27#define WAIT_TIMEOUT		msecs_to_jiffies(1000)
 28
 29#define FRAME_START		0xee
 30#define FRAME_MAXSIZE		257
 31
 32/* Offsets of the different parts of the payload the controller sends */
 33#define PAYLOAD_HEADER		0
 34#define PAYLOAD_LENGTH		1
 35#define PAYLOAD_BODY		2
 36
 37/* Response offsets */
 38#define RESPONSE_ID		0
 39#define RESPONSE_DATA		1
 40
 41/* Commands */
 42#define COMMAND_DEACTIVATE	0x00
 43#define COMMAND_INITIALIZE	0x01
 44#define COMMAND_RESOLUTION	0x02
 45#define COMMAND_SETCONFIG	0x03
 46#define COMMAND_DATAREQUEST	0x04
 47#define COMMAND_SCANFREQ	0x08
 48#define COMMAND_STATUS		0X1e
 49
 50/*
 51 * Responses the controller sends as a result of
 52 * command requests
 53 */
 54#define RESPONSE_DEACTIVATE	0x00
 55#define RESPONSE_INITIALIZE	0x01
 56#define RESPONSE_RESOLUTION	0x02
 57#define RESPONSE_SETCONFIG	0x03
 58#define RESPONSE_SCANFREQ	0x08
 59#define RESPONSE_STATUS		0X1e
 60
 61/*
 62 * Notifications are sent by the touch controller without
 63 * being requested by the driver and include for example
 64 * touch indications
 65 */
 66#define NOTIFICATION_TOUCH		0x04
 67#define NOTIFICATION_BOOTCOMPLETE	0x07
 68#define NOTIFICATION_OVERRUN		0x25
 69#define NOTIFICATION_PROXIMITY		0x26
 70#define NOTIFICATION_INVALID_COMMAND	0xfe
 71
 72#define ZFORCE_REPORT_POINTS		2
 73#define ZFORCE_MAX_AREA			0xff
 74
 75#define STATE_DOWN			0
 76#define STATE_MOVE			1
 77#define STATE_UP			2
 78
 79#define SETCONFIG_DUALTOUCH		(1 << 0)
 80
 81struct zforce_point {
 82	int coord_x;
 83	int coord_y;
 84	int state;
 85	int id;
 86	int area_major;
 87	int area_minor;
 88	int orientation;
 89	int pressure;
 90	int prblty;
 91};
 92
 93/*
 94 * @client		the i2c_client
 95 * @input		the input device
 96 * @suspending		in the process of going to suspend (don't emit wakeup
 97 *			events for commands executed to suspend the device)
 98 * @suspended		device suspended
 99 * @access_mutex	serialize i2c-access, to keep multipart reads together
100 * @command_done	completion to wait for the command result
101 * @command_mutex	serialize commands sent to the ic
102 * @command_waiting	the id of the command that is currently waiting
103 *			for a result
104 * @command_result	returned result of the command
105 */
106struct zforce_ts {
107	struct i2c_client	*client;
108	struct input_dev	*input;
109	const struct zforce_ts_platdata *pdata;
110	char			phys[32];
111
112	struct regulator	*reg_vdd;
113
114	struct gpio_desc	*gpio_int;
115	struct gpio_desc	*gpio_rst;
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
135static 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
158static void zforce_reset_assert(struct zforce_ts *ts)
159{
160	gpiod_set_value_cansleep(ts->gpio_rst, 1);
161}
162
163static void zforce_reset_deassert(struct zforce_ts *ts)
164{
165	gpiod_set_value_cansleep(ts->gpio_rst, 0);
166}
167
168static int zforce_send_wait(struct zforce_ts *ts, const char *buf, int len)
169{
170	struct i2c_client *client = ts->client;
171	int ret;
172
173	ret = mutex_trylock(&ts->command_mutex);
174	if (!ret) {
175		dev_err(&client->dev, "already waiting for a command\n");
176		return -EBUSY;
177	}
178
179	dev_dbg(&client->dev, "sending %d bytes for command 0x%x\n",
180		buf[1], buf[2]);
181
182	ts->command_waiting = buf[2];
183
184	mutex_lock(&ts->access_mutex);
185	ret = i2c_master_send(client, buf, len);
186	mutex_unlock(&ts->access_mutex);
187	if (ret < 0) {
188		dev_err(&client->dev, "i2c send data request error: %d\n", ret);
189		goto unlock;
190	}
191
192	dev_dbg(&client->dev, "waiting for result for command 0x%x\n", buf[2]);
193
194	if (wait_for_completion_timeout(&ts->command_done, WAIT_TIMEOUT) == 0) {
195		ret = -ETIME;
196		goto unlock;
197	}
198
199	ret = ts->command_result;
200
201unlock:
202	mutex_unlock(&ts->command_mutex);
203	return ret;
204}
205
206static int zforce_command_wait(struct zforce_ts *ts, u8 cmd)
207{
208	struct i2c_client *client = ts->client;
209	char buf[3];
210	int ret;
211
212	dev_dbg(&client->dev, "%s: 0x%x\n", __func__, cmd);
213
214	buf[0] = FRAME_START;
215	buf[1] = 1; /* data size, command only */
216	buf[2] = cmd;
217
218	ret = zforce_send_wait(ts, &buf[0], ARRAY_SIZE(buf));
219	if (ret < 0) {
220		dev_err(&client->dev, "i2c send data request error: %d\n", ret);
221		return ret;
222	}
223
224	return 0;
225}
226
227static int zforce_resolution(struct zforce_ts *ts, u16 x, u16 y)
228{
229	struct i2c_client *client = ts->client;
230	char buf[7] = { FRAME_START, 5, COMMAND_RESOLUTION,
231			(x & 0xff), ((x >> 8) & 0xff),
232			(y & 0xff), ((y >> 8) & 0xff) };
233
234	dev_dbg(&client->dev, "set resolution to (%d,%d)\n", x, y);
235
236	return zforce_send_wait(ts, &buf[0], ARRAY_SIZE(buf));
237}
238
239static int zforce_scan_frequency(struct zforce_ts *ts, u16 idle, u16 finger,
240				 u16 stylus)
241{
242	struct i2c_client *client = ts->client;
243	char buf[9] = { FRAME_START, 7, COMMAND_SCANFREQ,
244			(idle & 0xff), ((idle >> 8) & 0xff),
245			(finger & 0xff), ((finger >> 8) & 0xff),
246			(stylus & 0xff), ((stylus >> 8) & 0xff) };
247
248	dev_dbg(&client->dev,
249		"set scan frequency to (idle: %d, finger: %d, stylus: %d)\n",
250		idle, finger, stylus);
251
252	return zforce_send_wait(ts, &buf[0], ARRAY_SIZE(buf));
253}
254
255static int zforce_setconfig(struct zforce_ts *ts, char b1)
256{
257	struct i2c_client *client = ts->client;
258	char buf[7] = { FRAME_START, 5, COMMAND_SETCONFIG,
259			b1, 0, 0, 0 };
260
261	dev_dbg(&client->dev, "set config to (%d)\n", b1);
262
263	return zforce_send_wait(ts, &buf[0], ARRAY_SIZE(buf));
264}
265
266static int zforce_start(struct zforce_ts *ts)
267{
268	struct i2c_client *client = ts->client;
269	const struct zforce_ts_platdata *pdata = ts->pdata;
270	int ret;
271
272	dev_dbg(&client->dev, "starting device\n");
273
274	ret = zforce_command_wait(ts, COMMAND_INITIALIZE);
275	if (ret) {
276		dev_err(&client->dev, "Unable to initialize, %d\n", ret);
277		return ret;
278	}
279
280	ret = zforce_resolution(ts, pdata->x_max, pdata->y_max);
281	if (ret) {
282		dev_err(&client->dev, "Unable to set resolution, %d\n", ret);
283		goto error;
284	}
285
286	ret = zforce_scan_frequency(ts, 10, 50, 50);
287	if (ret) {
288		dev_err(&client->dev, "Unable to set scan frequency, %d\n",
289			ret);
290		goto error;
291	}
292
293	ret = zforce_setconfig(ts, SETCONFIG_DUALTOUCH);
294	if (ret) {
295		dev_err(&client->dev, "Unable to set config\n");
296		goto error;
297	}
298
299	/* start sending touch events */
300	ret = zforce_command(ts, COMMAND_DATAREQUEST);
301	if (ret) {
302		dev_err(&client->dev, "Unable to request data\n");
303		goto error;
304	}
305
306	/*
307	 * Per NN, initial cal. take max. of 200msec.
308	 * Allow time to complete this calibration
309	 */
310	msleep(200);
311
312	return 0;
313
314error:
315	zforce_command_wait(ts, COMMAND_DEACTIVATE);
316	return ret;
317}
318
319static int zforce_stop(struct zforce_ts *ts)
320{
321	struct i2c_client *client = ts->client;
322	int ret;
323
324	dev_dbg(&client->dev, "stopping device\n");
325
326	/* Deactivates touch sensing and puts the device into sleep. */
327	ret = zforce_command_wait(ts, COMMAND_DEACTIVATE);
328	if (ret != 0) {
329		dev_err(&client->dev, "could not deactivate device, %d\n",
330			ret);
331		return ret;
332	}
333
334	return 0;
335}
336
337static int zforce_touch_event(struct zforce_ts *ts, u8 *payload)
338{
339	struct i2c_client *client = ts->client;
340	const struct zforce_ts_platdata *pdata = ts->pdata;
341	struct zforce_point point;
342	int count, i, num = 0;
343
344	count = payload[0];
345	if (count > ZFORCE_REPORT_POINTS) {
346		dev_warn(&client->dev,
347			 "too many coordinates %d, expected max %d\n",
348			 count, ZFORCE_REPORT_POINTS);
349		count = ZFORCE_REPORT_POINTS;
350	}
351
352	for (i = 0; i < count; i++) {
353		point.coord_x =
354			payload[9 * i + 2] << 8 | payload[9 * i + 1];
355		point.coord_y =
356			payload[9 * i + 4] << 8 | payload[9 * i + 3];
357
358		if (point.coord_x > pdata->x_max ||
359		    point.coord_y > pdata->y_max) {
360			dev_warn(&client->dev, "coordinates (%d,%d) invalid\n",
361				point.coord_x, point.coord_y);
362			point.coord_x = point.coord_y = 0;
363		}
364
365		point.state = payload[9 * i + 5] & 0x0f;
366		point.id = (payload[9 * i + 5] & 0xf0) >> 4;
367
368		/* determine touch major, minor and orientation */
369		point.area_major = max(payload[9 * i + 6],
370					  payload[9 * i + 7]);
371		point.area_minor = min(payload[9 * i + 6],
372					  payload[9 * i + 7]);
373		point.orientation = payload[9 * i + 6] > payload[9 * i + 7];
374
375		point.pressure = payload[9 * i + 8];
376		point.prblty = payload[9 * i + 9];
377
378		dev_dbg(&client->dev,
379			"point %d/%d: state %d, id %d, pressure %d, prblty %d, x %d, y %d, amajor %d, aminor %d, ori %d\n",
380			i, count, point.state, point.id,
381			point.pressure, point.prblty,
382			point.coord_x, point.coord_y,
383			point.area_major, point.area_minor,
384			point.orientation);
385
386		/* the zforce id starts with "1", so needs to be decreased */
387		input_mt_slot(ts->input, point.id - 1);
388
389		input_mt_report_slot_state(ts->input, MT_TOOL_FINGER,
390						point.state != STATE_UP);
391
392		if (point.state != STATE_UP) {
393			input_report_abs(ts->input, ABS_MT_POSITION_X,
394					 point.coord_x);
395			input_report_abs(ts->input, ABS_MT_POSITION_Y,
396					 point.coord_y);
397			input_report_abs(ts->input, ABS_MT_TOUCH_MAJOR,
398					 point.area_major);
399			input_report_abs(ts->input, ABS_MT_TOUCH_MINOR,
400					 point.area_minor);
401			input_report_abs(ts->input, ABS_MT_ORIENTATION,
402					 point.orientation);
403			num++;
404		}
405	}
406
407	input_mt_sync_frame(ts->input);
408
409	input_mt_report_finger_count(ts->input, num);
410
411	input_sync(ts->input);
412
413	return 0;
414}
415
416static int zforce_read_packet(struct zforce_ts *ts, u8 *buf)
417{
418	struct i2c_client *client = ts->client;
419	int ret;
420
421	mutex_lock(&ts->access_mutex);
422
423	/* read 2 byte message header */
424	ret = i2c_master_recv(client, buf, 2);
425	if (ret < 0) {
426		dev_err(&client->dev, "error reading header: %d\n", ret);
427		goto unlock;
428	}
429
430	if (buf[PAYLOAD_HEADER] != FRAME_START) {
431		dev_err(&client->dev, "invalid frame start: %d\n", buf[0]);
432		ret = -EIO;
433		goto unlock;
434	}
435
436	if (buf[PAYLOAD_LENGTH] == 0) {
437		dev_err(&client->dev, "invalid payload length: %d\n",
438			buf[PAYLOAD_LENGTH]);
439		ret = -EIO;
440		goto unlock;
441	}
442
443	/* read the message */
444	ret = i2c_master_recv(client, &buf[PAYLOAD_BODY], buf[PAYLOAD_LENGTH]);
445	if (ret < 0) {
446		dev_err(&client->dev, "error reading payload: %d\n", ret);
447		goto unlock;
448	}
449
450	dev_dbg(&client->dev, "read %d bytes for response command 0x%x\n",
451		buf[PAYLOAD_LENGTH], buf[PAYLOAD_BODY]);
452
453unlock:
454	mutex_unlock(&ts->access_mutex);
455	return ret;
456}
457
458static void zforce_complete(struct zforce_ts *ts, int cmd, int result)
459{
460	struct i2c_client *client = ts->client;
461
462	if (ts->command_waiting == cmd) {
463		dev_dbg(&client->dev, "completing command 0x%x\n", cmd);
464		ts->command_result = result;
465		complete(&ts->command_done);
466	} else {
467		dev_dbg(&client->dev, "command %d not for us\n", cmd);
468	}
469}
470
471static irqreturn_t zforce_irq(int irq, void *dev_id)
472{
473	struct zforce_ts *ts = dev_id;
474	struct i2c_client *client = ts->client;
475
476	if (ts->suspended && device_may_wakeup(&client->dev))
477		pm_wakeup_event(&client->dev, 500);
478
479	return IRQ_WAKE_THREAD;
480}
481
482static irqreturn_t zforce_irq_thread(int irq, void *dev_id)
483{
484	struct zforce_ts *ts = dev_id;
485	struct i2c_client *client = ts->client;
486	int ret;
487	u8 payload_buffer[FRAME_MAXSIZE];
488	u8 *payload;
489
490	/*
491	 * When still suspended, return.
492	 * Due to the level-interrupt we will get re-triggered later.
493	 */
494	if (ts->suspended) {
495		msleep(20);
496		return IRQ_HANDLED;
497	}
498
499	dev_dbg(&client->dev, "handling interrupt\n");
500
501	/* Don't emit wakeup events from commands run by zforce_suspend */
502	if (!ts->suspending && device_may_wakeup(&client->dev))
503		pm_stay_awake(&client->dev);
504
505	/*
506	 * Run at least once and exit the loop if
507	 * - the optional interrupt GPIO isn't specified
508	 *   (there is only one packet read per ISR invocation, then)
509	 * or
510	 * - the GPIO isn't active any more
511	 *   (packet read until the level GPIO indicates that there is
512	 *    no IRQ any more)
513	 */
514	do {
515		ret = zforce_read_packet(ts, payload_buffer);
516		if (ret < 0) {
517			dev_err(&client->dev,
518				"could not read packet, ret: %d\n", ret);
519			break;
520		}
521
522		payload =  &payload_buffer[PAYLOAD_BODY];
523
524		switch (payload[RESPONSE_ID]) {
525		case NOTIFICATION_TOUCH:
526			/*
527			 * Always report touch-events received while
528			 * suspending, when being a wakeup source
529			 */
530			if (ts->suspending && device_may_wakeup(&client->dev))
531				pm_wakeup_event(&client->dev, 500);
532			zforce_touch_event(ts, &payload[RESPONSE_DATA]);
533			break;
534
535		case NOTIFICATION_BOOTCOMPLETE:
536			ts->boot_complete = payload[RESPONSE_DATA];
537			zforce_complete(ts, payload[RESPONSE_ID], 0);
538			break;
539
540		case RESPONSE_INITIALIZE:
541		case RESPONSE_DEACTIVATE:
542		case RESPONSE_SETCONFIG:
543		case RESPONSE_RESOLUTION:
544		case RESPONSE_SCANFREQ:
545			zforce_complete(ts, payload[RESPONSE_ID],
546					payload[RESPONSE_DATA]);
547			break;
548
549		case RESPONSE_STATUS:
550			/*
551			 * Version Payload Results
552			 * [2:major] [2:minor] [2:build] [2:rev]
553			 */
554			ts->version_major = (payload[RESPONSE_DATA + 1] << 8) |
555						payload[RESPONSE_DATA];
556			ts->version_minor = (payload[RESPONSE_DATA + 3] << 8) |
557						payload[RESPONSE_DATA + 2];
558			ts->version_build = (payload[RESPONSE_DATA + 5] << 8) |
559						payload[RESPONSE_DATA + 4];
560			ts->version_rev   = (payload[RESPONSE_DATA + 7] << 8) |
561						payload[RESPONSE_DATA + 6];
562			dev_dbg(&ts->client->dev,
563				"Firmware Version %04x:%04x %04x:%04x\n",
564				ts->version_major, ts->version_minor,
565				ts->version_build, ts->version_rev);
566
567			zforce_complete(ts, payload[RESPONSE_ID], 0);
568			break;
569
570		case NOTIFICATION_INVALID_COMMAND:
571			dev_err(&ts->client->dev, "invalid command: 0x%x\n",
572				payload[RESPONSE_DATA]);
573			break;
574
575		default:
576			dev_err(&ts->client->dev,
577				"unrecognized response id: 0x%x\n",
578				payload[RESPONSE_ID]);
579			break;
580		}
581	} while (gpiod_get_value_cansleep(ts->gpio_int));
582
583	if (!ts->suspending && device_may_wakeup(&client->dev))
584		pm_relax(&client->dev);
585
586	dev_dbg(&client->dev, "finished interrupt\n");
587
588	return IRQ_HANDLED;
589}
590
591static int zforce_input_open(struct input_dev *dev)
592{
593	struct zforce_ts *ts = input_get_drvdata(dev);
594
595	return zforce_start(ts);
596}
597
598static void zforce_input_close(struct input_dev *dev)
599{
600	struct zforce_ts *ts = input_get_drvdata(dev);
601	struct i2c_client *client = ts->client;
602	int ret;
603
604	ret = zforce_stop(ts);
605	if (ret)
606		dev_warn(&client->dev, "stopping zforce failed\n");
607
608	return;
609}
610
611static int __maybe_unused zforce_suspend(struct device *dev)
612{
613	struct i2c_client *client = to_i2c_client(dev);
614	struct zforce_ts *ts = i2c_get_clientdata(client);
615	struct input_dev *input = ts->input;
616	int ret = 0;
617
618	mutex_lock(&input->mutex);
619	ts->suspending = true;
620
621	/*
622	 * When configured as a wakeup source device should always wake
623	 * the system, therefore start device if necessary.
624	 */
625	if (device_may_wakeup(&client->dev)) {
626		dev_dbg(&client->dev, "suspend while being a wakeup source\n");
627
628		/* Need to start device, if not open, to be a wakeup source. */
629		if (!input_device_enabled(input)) {
630			ret = zforce_start(ts);
631			if (ret)
632				goto unlock;
633		}
634
635		enable_irq_wake(client->irq);
636	} else if (input_device_enabled(input)) {
637		dev_dbg(&client->dev,
638			"suspend without being a wakeup source\n");
639
640		ret = zforce_stop(ts);
641		if (ret)
642			goto unlock;
643
644		disable_irq(client->irq);
645	}
646
647	ts->suspended = true;
648
649unlock:
650	ts->suspending = false;
651	mutex_unlock(&input->mutex);
652
653	return ret;
654}
655
656static int __maybe_unused zforce_resume(struct device *dev)
657{
658	struct i2c_client *client = to_i2c_client(dev);
659	struct zforce_ts *ts = i2c_get_clientdata(client);
660	struct input_dev *input = ts->input;
661	int ret = 0;
662
663	mutex_lock(&input->mutex);
664
665	ts->suspended = false;
666
667	if (device_may_wakeup(&client->dev)) {
668		dev_dbg(&client->dev, "resume from being a wakeup source\n");
669
670		disable_irq_wake(client->irq);
671
672		/* need to stop device if it was not open on suspend */
673		if (!input_device_enabled(input)) {
674			ret = zforce_stop(ts);
675			if (ret)
676				goto unlock;
677		}
678	} else if (input_device_enabled(input)) {
679		dev_dbg(&client->dev, "resume without being a wakeup source\n");
680
681		enable_irq(client->irq);
682
683		ret = zforce_start(ts);
684		if (ret < 0)
685			goto unlock;
686	}
687
688unlock:
689	mutex_unlock(&input->mutex);
690
691	return ret;
692}
693
694static SIMPLE_DEV_PM_OPS(zforce_pm_ops, zforce_suspend, zforce_resume);
695
696static void zforce_reset(void *data)
697{
698	struct zforce_ts *ts = data;
699
700	zforce_reset_assert(ts);
701
702	udelay(10);
703
704	if (!IS_ERR(ts->reg_vdd))
705		regulator_disable(ts->reg_vdd);
706}
707
708static struct zforce_ts_platdata *zforce_parse_dt(struct device *dev)
709{
710	struct zforce_ts_platdata *pdata;
711	struct device_node *np = dev->of_node;
712
713	if (!np)
714		return ERR_PTR(-ENOENT);
715
716	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
717	if (!pdata) {
718		dev_err(dev, "failed to allocate platform data\n");
719		return ERR_PTR(-ENOMEM);
720	}
721
722	if (of_property_read_u32(np, "x-size", &pdata->x_max)) {
723		dev_err(dev, "failed to get x-size property\n");
724		return ERR_PTR(-EINVAL);
725	}
726
727	if (of_property_read_u32(np, "y-size", &pdata->y_max)) {
728		dev_err(dev, "failed to get y-size property\n");
729		return ERR_PTR(-EINVAL);
730	}
731
732	return pdata;
733}
734
735static int zforce_probe(struct i2c_client *client,
736			const struct i2c_device_id *id)
737{
738	const struct zforce_ts_platdata *pdata = dev_get_platdata(&client->dev);
739	struct zforce_ts *ts;
740	struct input_dev *input_dev;
741	int ret;
742
743	if (!pdata) {
744		pdata = zforce_parse_dt(&client->dev);
745		if (IS_ERR(pdata))
746			return PTR_ERR(pdata);
747	}
748
749	ts = devm_kzalloc(&client->dev, sizeof(struct zforce_ts), GFP_KERNEL);
750	if (!ts)
751		return -ENOMEM;
752
753	ts->gpio_rst = devm_gpiod_get_optional(&client->dev, "reset",
754					       GPIOD_OUT_HIGH);
755	if (IS_ERR(ts->gpio_rst)) {
756		ret = PTR_ERR(ts->gpio_rst);
757		dev_err(&client->dev,
758			"failed to request reset GPIO: %d\n", ret);
759		return ret;
760	}
761
762	if (ts->gpio_rst) {
763		ts->gpio_int = devm_gpiod_get_optional(&client->dev, "irq",
764						       GPIOD_IN);
765		if (IS_ERR(ts->gpio_int)) {
766			ret = PTR_ERR(ts->gpio_int);
767			dev_err(&client->dev,
768				"failed to request interrupt GPIO: %d\n", ret);
769			return ret;
770		}
771	} else {
772		/*
773		 * Deprecated GPIO handling for compatibility
774		 * with legacy binding.
775		 */
776
777		/* INT GPIO */
778		ts->gpio_int = devm_gpiod_get_index(&client->dev, NULL, 0,
779						    GPIOD_IN);
780		if (IS_ERR(ts->gpio_int)) {
781			ret = PTR_ERR(ts->gpio_int);
782			dev_err(&client->dev,
783				"failed to request interrupt GPIO: %d\n", ret);
784			return ret;
785		}
786
787		/* RST GPIO */
788		ts->gpio_rst = devm_gpiod_get_index(&client->dev, NULL, 1,
789					    GPIOD_OUT_HIGH);
790		if (IS_ERR(ts->gpio_rst)) {
791			ret = PTR_ERR(ts->gpio_rst);
792			dev_err(&client->dev,
793				"failed to request reset GPIO: %d\n", ret);
794			return ret;
795		}
796	}
797
798	ts->reg_vdd = devm_regulator_get_optional(&client->dev, "vdd");
799	if (IS_ERR(ts->reg_vdd)) {
800		ret = PTR_ERR(ts->reg_vdd);
801		if (ret == -EPROBE_DEFER)
802			return ret;
803	} else {
804		ret = regulator_enable(ts->reg_vdd);
805		if (ret)
806			return ret;
807
808		/*
809		 * according to datasheet add 100us grace time after regular
810		 * regulator enable delay.
811		 */
812		udelay(100);
813	}
814
815	ret = devm_add_action(&client->dev, zforce_reset, ts);
816	if (ret) {
817		dev_err(&client->dev, "failed to register reset action, %d\n",
818			ret);
819
820		/* hereafter the regulator will be disabled by the action */
821		if (!IS_ERR(ts->reg_vdd))
822			regulator_disable(ts->reg_vdd);
823
824		return ret;
825	}
826
827	snprintf(ts->phys, sizeof(ts->phys),
828		 "%s/input0", dev_name(&client->dev));
829
830	input_dev = devm_input_allocate_device(&client->dev);
831	if (!input_dev) {
832		dev_err(&client->dev, "could not allocate input device\n");
833		return -ENOMEM;
834	}
835
836	mutex_init(&ts->access_mutex);
837	mutex_init(&ts->command_mutex);
838
839	ts->pdata = pdata;
840	ts->client = client;
841	ts->input = input_dev;
842
843	input_dev->name = "Neonode zForce touchscreen";
844	input_dev->phys = ts->phys;
845	input_dev->id.bustype = BUS_I2C;
846
847	input_dev->open = zforce_input_open;
848	input_dev->close = zforce_input_close;
849
850	__set_bit(EV_KEY, input_dev->evbit);
851	__set_bit(EV_SYN, input_dev->evbit);
852	__set_bit(EV_ABS, input_dev->evbit);
853
854	/* For multi touch */
855	input_set_abs_params(input_dev, ABS_MT_POSITION_X, 0,
856			     pdata->x_max, 0, 0);
857	input_set_abs_params(input_dev, ABS_MT_POSITION_Y, 0,
858			     pdata->y_max, 0, 0);
859
860	input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0,
861			     ZFORCE_MAX_AREA, 0, 0);
862	input_set_abs_params(input_dev, ABS_MT_TOUCH_MINOR, 0,
863			     ZFORCE_MAX_AREA, 0, 0);
864	input_set_abs_params(input_dev, ABS_MT_ORIENTATION, 0, 1, 0, 0);
865	input_mt_init_slots(input_dev, ZFORCE_REPORT_POINTS, INPUT_MT_DIRECT);
866
867	input_set_drvdata(ts->input, ts);
868
869	init_completion(&ts->command_done);
870
871	/*
872	 * The zforce pulls the interrupt low when it has data ready.
873	 * After it is triggered the isr thread runs until all the available
874	 * packets have been read and the interrupt is high again.
875	 * Therefore we can trigger the interrupt anytime it is low and do
876	 * not need to limit it to the interrupt edge.
877	 */
878	ret = devm_request_threaded_irq(&client->dev, client->irq,
879					zforce_irq, zforce_irq_thread,
880					IRQF_TRIGGER_LOW | IRQF_ONESHOT,
881					input_dev->name, ts);
882	if (ret) {
883		dev_err(&client->dev, "irq %d request failed\n", client->irq);
884		return ret;
885	}
886
887	i2c_set_clientdata(client, ts);
888
889	/* let the controller boot */
890	zforce_reset_deassert(ts);
891
892	ts->command_waiting = NOTIFICATION_BOOTCOMPLETE;
893	if (wait_for_completion_timeout(&ts->command_done, WAIT_TIMEOUT) == 0)
894		dev_warn(&client->dev, "bootcomplete timed out\n");
895
896	/* need to start device to get version information */
897	ret = zforce_command_wait(ts, COMMAND_INITIALIZE);
898	if (ret) {
899		dev_err(&client->dev, "unable to initialize, %d\n", ret);
900		return ret;
901	}
902
903	/* this gets the firmware version among other information */
904	ret = zforce_command_wait(ts, COMMAND_STATUS);
905	if (ret < 0) {
906		dev_err(&client->dev, "couldn't get status, %d\n", ret);
907		zforce_stop(ts);
908		return ret;
909	}
910
911	/* stop device and put it into sleep until it is opened */
912	ret = zforce_stop(ts);
913	if (ret < 0)
914		return ret;
915
916	device_set_wakeup_capable(&client->dev, true);
917
918	ret = input_register_device(input_dev);
919	if (ret) {
920		dev_err(&client->dev, "could not register input device, %d\n",
921			ret);
922		return ret;
923	}
924
925	return 0;
926}
927
928static struct i2c_device_id zforce_idtable[] = {
929	{ "zforce-ts", 0 },
930	{ }
931};
932MODULE_DEVICE_TABLE(i2c, zforce_idtable);
933
934#ifdef CONFIG_OF
935static const struct of_device_id zforce_dt_idtable[] = {
936	{ .compatible = "neonode,zforce" },
937	{},
938};
939MODULE_DEVICE_TABLE(of, zforce_dt_idtable);
940#endif
941
942static struct i2c_driver zforce_driver = {
943	.driver = {
944		.name	= "zforce-ts",
945		.pm	= &zforce_pm_ops,
946		.of_match_table	= of_match_ptr(zforce_dt_idtable),
947	},
948	.probe		= zforce_probe,
949	.id_table	= zforce_idtable,
950};
951
952module_i2c_driver(zforce_driver);
953
954MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
955MODULE_DESCRIPTION("zForce TouchScreen Driver");
956MODULE_LICENSE("GPL");