1 // SPDX-License-Identifier: GPL-2.0
2 // STMicroelectronics FTS Touchscreen device driver
3 //
4 // Copyright (c) 2017 Samsung Electronics Co., Ltd.
5 // Copyright (c) 2017 Andi Shyti <andi@etezian.org>
6 
7 #include <linux/delay.h>
8 #include <linux/i2c.h>
9 #include <linux/input/mt.h>
10 #include <linux/input/touchscreen.h>
11 #include <linux/interrupt.h>
12 #include <linux/irq.h>
13 #include <linux/leds.h>
14 #include <linux/module.h>
15 #include <linux/pm_runtime.h>
16 #include <linux/regulator/consumer.h>
17 
18 /* I2C commands */
19 #define STMFTS_READ_INFO			0x80
20 #define STMFTS_READ_STATUS			0x84
21 #define STMFTS_READ_ONE_EVENT			0x85
22 #define STMFTS_READ_ALL_EVENT			0x86
23 #define STMFTS_LATEST_EVENT			0x87
24 #define STMFTS_SLEEP_IN				0x90
25 #define STMFTS_SLEEP_OUT			0x91
26 #define STMFTS_MS_MT_SENSE_OFF			0x92
27 #define STMFTS_MS_MT_SENSE_ON			0x93
28 #define STMFTS_SS_HOVER_SENSE_OFF		0x94
29 #define STMFTS_SS_HOVER_SENSE_ON		0x95
30 #define STMFTS_MS_KEY_SENSE_OFF			0x9a
31 #define STMFTS_MS_KEY_SENSE_ON			0x9b
32 #define STMFTS_SYSTEM_RESET			0xa0
33 #define STMFTS_CLEAR_EVENT_STACK		0xa1
34 #define STMFTS_FULL_FORCE_CALIBRATION		0xa2
35 #define STMFTS_MS_CX_TUNING			0xa3
36 #define STMFTS_SS_CX_TUNING			0xa4
37 
38 /* events */
39 #define STMFTS_EV_NO_EVENT			0x00
40 #define STMFTS_EV_MULTI_TOUCH_DETECTED		0x02
41 #define STMFTS_EV_MULTI_TOUCH_ENTER		0x03
42 #define STMFTS_EV_MULTI_TOUCH_LEAVE		0x04
43 #define STMFTS_EV_MULTI_TOUCH_MOTION		0x05
44 #define STMFTS_EV_HOVER_ENTER			0x07
45 #define STMFTS_EV_HOVER_LEAVE			0x08
46 #define STMFTS_EV_HOVER_MOTION			0x09
47 #define STMFTS_EV_KEY_STATUS			0x0e
48 #define STMFTS_EV_ERROR				0x0f
49 #define STMFTS_EV_CONTROLLER_READY		0x10
50 #define STMFTS_EV_SLEEP_OUT_CONTROLLER_READY	0x11
51 #define STMFTS_EV_STATUS			0x16
52 #define STMFTS_EV_DEBUG				0xdb
53 
54 /* multi touch related event masks */
55 #define STMFTS_MASK_EVENT_ID			0x0f
56 #define STMFTS_MASK_TOUCH_ID			0xf0
57 #define STMFTS_MASK_LEFT_EVENT			0x0f
58 #define STMFTS_MASK_X_MSB			0x0f
59 #define STMFTS_MASK_Y_LSB			0xf0
60 
61 /* key related event masks */
62 #define STMFTS_MASK_KEY_NO_TOUCH		0x00
63 #define STMFTS_MASK_KEY_MENU			0x01
64 #define STMFTS_MASK_KEY_BACK			0x02
65 
66 #define STMFTS_EVENT_SIZE	8
67 #define STMFTS_STACK_DEPTH	32
68 #define STMFTS_DATA_MAX_SIZE	(STMFTS_EVENT_SIZE * STMFTS_STACK_DEPTH)
69 #define STMFTS_MAX_FINGERS	10
70 #define STMFTS_DEV_NAME		"stmfts"
71 
72 enum stmfts_regulators {
73 	STMFTS_REGULATOR_VDD,
74 	STMFTS_REGULATOR_AVDD,
75 };
76 
77 struct stmfts_data {
78 	struct i2c_client *client;
79 	struct input_dev *input;
80 	struct led_classdev led_cdev;
81 	struct mutex mutex;
82 
83 	struct touchscreen_properties prop;
84 
85 	struct regulator_bulk_data regulators[2];
86 
87 	/*
88 	 * Presence of ledvdd will be used also to check
89 	 * whether the LED is supported.
90 	 */
91 	struct regulator *ledvdd;
92 
93 	u16 chip_id;
94 	u8 chip_ver;
95 	u16 fw_ver;
96 	u8 config_id;
97 	u8 config_ver;
98 
99 	u8 data[STMFTS_DATA_MAX_SIZE];
100 
101 	struct completion cmd_done;
102 
103 	bool use_key;
104 	bool led_status;
105 	bool hover_enabled;
106 	bool running;
107 };
108 
109 static int stmfts_brightness_set(struct led_classdev *led_cdev,
110 					enum led_brightness value)
111 {
112 	struct stmfts_data *sdata = container_of(led_cdev,
113 					struct stmfts_data, led_cdev);
114 	int err;
115 
116 	if (value != sdata->led_status && sdata->ledvdd) {
117 		if (!value) {
118 			regulator_disable(sdata->ledvdd);
119 		} else {
120 			err = regulator_enable(sdata->ledvdd);
121 			if (err) {
122 				dev_warn(&sdata->client->dev,
123 					 "failed to disable ledvdd regulator: %d\n",
124 					 err);
125 				return err;
126 			}
127 		}
128 		sdata->led_status = value;
129 	}
130 
131 	return 0;
132 }
133 
134 static enum led_brightness stmfts_brightness_get(struct led_classdev *led_cdev)
135 {
136 	struct stmfts_data *sdata = container_of(led_cdev,
137 						struct stmfts_data, led_cdev);
138 
139 	return !!regulator_is_enabled(sdata->ledvdd);
140 }
141 
142 /*
143  * We can't simply use i2c_smbus_read_i2c_block_data because we
144  * need to read more than 255 bytes (
145  */
146 static int stmfts_read_events(struct stmfts_data *sdata)
147 {
148 	u8 cmd = STMFTS_READ_ALL_EVENT;
149 	struct i2c_msg msgs[2] = {
150 		{
151 			.addr	= sdata->client->addr,
152 			.len	= 1,
153 			.buf	= &cmd,
154 		},
155 		{
156 			.addr	= sdata->client->addr,
157 			.flags	= I2C_M_RD,
158 			.len	= STMFTS_DATA_MAX_SIZE,
159 			.buf	= sdata->data,
160 		},
161 	};
162 	int ret;
163 
164 	ret = i2c_transfer(sdata->client->adapter, msgs, ARRAY_SIZE(msgs));
165 	if (ret < 0)
166 		return ret;
167 
168 	return ret == ARRAY_SIZE(msgs) ? 0 : -EIO;
169 }
170 
171 static void stmfts_report_contact_event(struct stmfts_data *sdata,
172 					const u8 event[])
173 {
174 	u8 slot_id = (event[0] & STMFTS_MASK_TOUCH_ID) >> 4;
175 	u16 x = event[1] | ((event[2] & STMFTS_MASK_X_MSB) << 8);
176 	u16 y = (event[2] >> 4) | (event[3] << 4);
177 	u8 maj = event[4];
178 	u8 min = event[5];
179 	u8 orientation = event[6];
180 	u8 area = event[7];
181 
182 	input_mt_slot(sdata->input, slot_id);
183 
184 	input_mt_report_slot_state(sdata->input, MT_TOOL_FINGER, true);
185 	input_report_abs(sdata->input, ABS_MT_POSITION_X, x);
186 	input_report_abs(sdata->input, ABS_MT_POSITION_Y, y);
187 	input_report_abs(sdata->input, ABS_MT_TOUCH_MAJOR, maj);
188 	input_report_abs(sdata->input, ABS_MT_TOUCH_MINOR, min);
189 	input_report_abs(sdata->input, ABS_MT_PRESSURE, area);
190 	input_report_abs(sdata->input, ABS_MT_ORIENTATION, orientation);
191 
192 	input_sync(sdata->input);
193 }
194 
195 static void stmfts_report_contact_release(struct stmfts_data *sdata,
196 					  const u8 event[])
197 {
198 	u8 slot_id = (event[0] & STMFTS_MASK_TOUCH_ID) >> 4;
199 
200 	input_mt_slot(sdata->input, slot_id);
201 	input_mt_report_slot_inactive(sdata->input);
202 
203 	input_sync(sdata->input);
204 }
205 
206 static void stmfts_report_hover_event(struct stmfts_data *sdata,
207 				      const u8 event[])
208 {
209 	u16 x = (event[2] << 4) | (event[4] >> 4);
210 	u16 y = (event[3] << 4) | (event[4] & STMFTS_MASK_Y_LSB);
211 	u8 z = event[5];
212 
213 	input_report_abs(sdata->input, ABS_X, x);
214 	input_report_abs(sdata->input, ABS_Y, y);
215 	input_report_abs(sdata->input, ABS_DISTANCE, z);
216 
217 	input_sync(sdata->input);
218 }
219 
220 static void stmfts_report_key_event(struct stmfts_data *sdata, const u8 event[])
221 {
222 	switch (event[2]) {
223 	case 0:
224 		input_report_key(sdata->input, KEY_BACK, 0);
225 		input_report_key(sdata->input, KEY_MENU, 0);
226 		break;
227 
228 	case STMFTS_MASK_KEY_BACK:
229 		input_report_key(sdata->input, KEY_BACK, 1);
230 		break;
231 
232 	case STMFTS_MASK_KEY_MENU:
233 		input_report_key(sdata->input, KEY_MENU, 1);
234 		break;
235 
236 	default:
237 		dev_warn(&sdata->client->dev,
238 			 "unknown key event: %#02x\n", event[2]);
239 		break;
240 	}
241 
242 	input_sync(sdata->input);
243 }
244 
245 static void stmfts_parse_events(struct stmfts_data *sdata)
246 {
247 	int i;
248 
249 	for (i = 0; i < STMFTS_STACK_DEPTH; i++) {
250 		u8 *event = &sdata->data[i * STMFTS_EVENT_SIZE];
251 
252 		switch (event[0]) {
253 
254 		case STMFTS_EV_CONTROLLER_READY:
255 		case STMFTS_EV_SLEEP_OUT_CONTROLLER_READY:
256 		case STMFTS_EV_STATUS:
257 			complete(&sdata->cmd_done);
258 			fallthrough;
259 
260 		case STMFTS_EV_NO_EVENT:
261 		case STMFTS_EV_DEBUG:
262 			return;
263 		}
264 
265 		switch (event[0] & STMFTS_MASK_EVENT_ID) {
266 
267 		case STMFTS_EV_MULTI_TOUCH_ENTER:
268 		case STMFTS_EV_MULTI_TOUCH_MOTION:
269 			stmfts_report_contact_event(sdata, event);
270 			break;
271 
272 		case STMFTS_EV_MULTI_TOUCH_LEAVE:
273 			stmfts_report_contact_release(sdata, event);
274 			break;
275 
276 		case STMFTS_EV_HOVER_ENTER:
277 		case STMFTS_EV_HOVER_LEAVE:
278 		case STMFTS_EV_HOVER_MOTION:
279 			stmfts_report_hover_event(sdata, event);
280 			break;
281 
282 		case STMFTS_EV_KEY_STATUS:
283 			stmfts_report_key_event(sdata, event);
284 			break;
285 
286 		case STMFTS_EV_ERROR:
287 			dev_warn(&sdata->client->dev,
288 					"error code: 0x%x%x%x%x%x%x",
289 					event[6], event[5], event[4],
290 					event[3], event[2], event[1]);
291 			break;
292 
293 		default:
294 			dev_err(&sdata->client->dev,
295 				"unknown event %#02x\n", event[0]);
296 		}
297 	}
298 }
299 
300 static irqreturn_t stmfts_irq_handler(int irq, void *dev)
301 {
302 	struct stmfts_data *sdata = dev;
303 	int err;
304 
305 	mutex_lock(&sdata->mutex);
306 
307 	err = stmfts_read_events(sdata);
308 	if (unlikely(err))
309 		dev_err(&sdata->client->dev,
310 			"failed to read events: %d\n", err);
311 	else
312 		stmfts_parse_events(sdata);
313 
314 	mutex_unlock(&sdata->mutex);
315 	return IRQ_HANDLED;
316 }
317 
318 static int stmfts_command(struct stmfts_data *sdata, const u8 cmd)
319 {
320 	int err;
321 
322 	reinit_completion(&sdata->cmd_done);
323 
324 	err = i2c_smbus_write_byte(sdata->client, cmd);
325 	if (err)
326 		return err;
327 
328 	if (!wait_for_completion_timeout(&sdata->cmd_done,
329 					 msecs_to_jiffies(1000)))
330 		return -ETIMEDOUT;
331 
332 	return 0;
333 }
334 
335 static int stmfts_input_open(struct input_dev *dev)
336 {
337 	struct stmfts_data *sdata = input_get_drvdata(dev);
338 	int err;
339 
340 	err = pm_runtime_resume_and_get(&sdata->client->dev);
341 	if (err)
342 		return err;
343 
344 	err = i2c_smbus_write_byte(sdata->client, STMFTS_MS_MT_SENSE_ON);
345 	if (err) {
346 		pm_runtime_put_sync(&sdata->client->dev);
347 		return err;
348 	}
349 
350 	mutex_lock(&sdata->mutex);
351 	sdata->running = true;
352 
353 	if (sdata->hover_enabled) {
354 		err = i2c_smbus_write_byte(sdata->client,
355 					   STMFTS_SS_HOVER_SENSE_ON);
356 		if (err)
357 			dev_warn(&sdata->client->dev,
358 				 "failed to enable hover\n");
359 	}
360 	mutex_unlock(&sdata->mutex);
361 
362 	if (sdata->use_key) {
363 		err = i2c_smbus_write_byte(sdata->client,
364 					   STMFTS_MS_KEY_SENSE_ON);
365 		if (err)
366 			/* I can still use only the touch screen */
367 			dev_warn(&sdata->client->dev,
368 				 "failed to enable touchkey\n");
369 	}
370 
371 	return 0;
372 }
373 
374 static void stmfts_input_close(struct input_dev *dev)
375 {
376 	struct stmfts_data *sdata = input_get_drvdata(dev);
377 	int err;
378 
379 	err = i2c_smbus_write_byte(sdata->client, STMFTS_MS_MT_SENSE_OFF);
380 	if (err)
381 		dev_warn(&sdata->client->dev,
382 			 "failed to disable touchscreen: %d\n", err);
383 
384 	mutex_lock(&sdata->mutex);
385 
386 	sdata->running = false;
387 
388 	if (sdata->hover_enabled) {
389 		err = i2c_smbus_write_byte(sdata->client,
390 					   STMFTS_SS_HOVER_SENSE_OFF);
391 		if (err)
392 			dev_warn(&sdata->client->dev,
393 				 "failed to disable hover: %d\n", err);
394 	}
395 	mutex_unlock(&sdata->mutex);
396 
397 	if (sdata->use_key) {
398 		err = i2c_smbus_write_byte(sdata->client,
399 					   STMFTS_MS_KEY_SENSE_OFF);
400 		if (err)
401 			dev_warn(&sdata->client->dev,
402 				 "failed to disable touchkey: %d\n", err);
403 	}
404 
405 	pm_runtime_put_sync(&sdata->client->dev);
406 }
407 
408 static ssize_t stmfts_sysfs_chip_id(struct device *dev,
409 				struct device_attribute *attr, char *buf)
410 {
411 	struct stmfts_data *sdata = dev_get_drvdata(dev);
412 
413 	return sprintf(buf, "%#x\n", sdata->chip_id);
414 }
415 
416 static ssize_t stmfts_sysfs_chip_version(struct device *dev,
417 				struct device_attribute *attr, char *buf)
418 {
419 	struct stmfts_data *sdata = dev_get_drvdata(dev);
420 
421 	return sprintf(buf, "%u\n", sdata->chip_ver);
422 }
423 
424 static ssize_t stmfts_sysfs_fw_ver(struct device *dev,
425 				struct device_attribute *attr, char *buf)
426 {
427 	struct stmfts_data *sdata = dev_get_drvdata(dev);
428 
429 	return sprintf(buf, "%u\n", sdata->fw_ver);
430 }
431 
432 static ssize_t stmfts_sysfs_config_id(struct device *dev,
433 				struct device_attribute *attr, char *buf)
434 {
435 	struct stmfts_data *sdata = dev_get_drvdata(dev);
436 
437 	return sprintf(buf, "%#x\n", sdata->config_id);
438 }
439 
440 static ssize_t stmfts_sysfs_config_version(struct device *dev,
441 				struct device_attribute *attr, char *buf)
442 {
443 	struct stmfts_data *sdata = dev_get_drvdata(dev);
444 
445 	return sprintf(buf, "%u\n", sdata->config_ver);
446 }
447 
448 static ssize_t stmfts_sysfs_read_status(struct device *dev,
449 				struct device_attribute *attr, char *buf)
450 {
451 	struct stmfts_data *sdata = dev_get_drvdata(dev);
452 	u8 status[4];
453 	int err;
454 
455 	err = i2c_smbus_read_i2c_block_data(sdata->client, STMFTS_READ_STATUS,
456 					    sizeof(status), status);
457 	if (err)
458 		return err;
459 
460 	return sprintf(buf, "%#02x\n", status[0]);
461 }
462 
463 static ssize_t stmfts_sysfs_hover_enable_read(struct device *dev,
464 				struct device_attribute *attr, char *buf)
465 {
466 	struct stmfts_data *sdata = dev_get_drvdata(dev);
467 
468 	return sprintf(buf, "%u\n", sdata->hover_enabled);
469 }
470 
471 static ssize_t stmfts_sysfs_hover_enable_write(struct device *dev,
472 				struct device_attribute *attr,
473 				const char *buf, size_t len)
474 {
475 	struct stmfts_data *sdata = dev_get_drvdata(dev);
476 	unsigned long value;
477 	int err = 0;
478 
479 	if (kstrtoul(buf, 0, &value))
480 		return -EINVAL;
481 
482 	mutex_lock(&sdata->mutex);
483 
484 	if (value && sdata->hover_enabled)
485 		goto out;
486 
487 	if (sdata->running)
488 		err = i2c_smbus_write_byte(sdata->client,
489 					   value ? STMFTS_SS_HOVER_SENSE_ON :
490 						   STMFTS_SS_HOVER_SENSE_OFF);
491 
492 	if (!err)
493 		sdata->hover_enabled = !!value;
494 
495 out:
496 	mutex_unlock(&sdata->mutex);
497 
498 	return len;
499 }
500 
501 static DEVICE_ATTR(chip_id, 0444, stmfts_sysfs_chip_id, NULL);
502 static DEVICE_ATTR(chip_version, 0444, stmfts_sysfs_chip_version, NULL);
503 static DEVICE_ATTR(fw_ver, 0444, stmfts_sysfs_fw_ver, NULL);
504 static DEVICE_ATTR(config_id, 0444, stmfts_sysfs_config_id, NULL);
505 static DEVICE_ATTR(config_version, 0444, stmfts_sysfs_config_version, NULL);
506 static DEVICE_ATTR(status, 0444, stmfts_sysfs_read_status, NULL);
507 static DEVICE_ATTR(hover_enable, 0644, stmfts_sysfs_hover_enable_read,
508 					stmfts_sysfs_hover_enable_write);
509 
510 static struct attribute *stmfts_sysfs_attrs[] = {
511 	&dev_attr_chip_id.attr,
512 	&dev_attr_chip_version.attr,
513 	&dev_attr_fw_ver.attr,
514 	&dev_attr_config_id.attr,
515 	&dev_attr_config_version.attr,
516 	&dev_attr_status.attr,
517 	&dev_attr_hover_enable.attr,
518 	NULL
519 };
520 
521 static struct attribute_group stmfts_attribute_group = {
522 	.attrs = stmfts_sysfs_attrs
523 };
524 
525 static int stmfts_power_on(struct stmfts_data *sdata)
526 {
527 	int err;
528 	u8 reg[8];
529 
530 	err = regulator_bulk_enable(ARRAY_SIZE(sdata->regulators),
531 				    sdata->regulators);
532 	if (err)
533 		return err;
534 
535 	/*
536 	 * The datasheet does not specify the power on time, but considering
537 	 * that the reset time is < 10ms, I sleep 20ms to be sure
538 	 */
539 	msleep(20);
540 
541 	err = i2c_smbus_read_i2c_block_data(sdata->client, STMFTS_READ_INFO,
542 					    sizeof(reg), reg);
543 	if (err < 0)
544 		return err;
545 	if (err != sizeof(reg))
546 		return -EIO;
547 
548 	sdata->chip_id = be16_to_cpup((__be16 *)&reg[6]);
549 	sdata->chip_ver = reg[0];
550 	sdata->fw_ver = be16_to_cpup((__be16 *)&reg[2]);
551 	sdata->config_id = reg[4];
552 	sdata->config_ver = reg[5];
553 
554 	enable_irq(sdata->client->irq);
555 
556 	msleep(50);
557 
558 	err = stmfts_command(sdata, STMFTS_SYSTEM_RESET);
559 	if (err)
560 		return err;
561 
562 	err = stmfts_command(sdata, STMFTS_SLEEP_OUT);
563 	if (err)
564 		return err;
565 
566 	/* optional tuning */
567 	err = stmfts_command(sdata, STMFTS_MS_CX_TUNING);
568 	if (err)
569 		dev_warn(&sdata->client->dev,
570 			 "failed to perform mutual auto tune: %d\n", err);
571 
572 	/* optional tuning */
573 	err = stmfts_command(sdata, STMFTS_SS_CX_TUNING);
574 	if (err)
575 		dev_warn(&sdata->client->dev,
576 			 "failed to perform self auto tune: %d\n", err);
577 
578 	err = stmfts_command(sdata, STMFTS_FULL_FORCE_CALIBRATION);
579 	if (err)
580 		return err;
581 
582 	/*
583 	 * At this point no one is using the touchscreen
584 	 * and I don't really care about the return value
585 	 */
586 	(void) i2c_smbus_write_byte(sdata->client, STMFTS_SLEEP_IN);
587 
588 	return 0;
589 }
590 
591 static void stmfts_power_off(void *data)
592 {
593 	struct stmfts_data *sdata = data;
594 
595 	disable_irq(sdata->client->irq);
596 	regulator_bulk_disable(ARRAY_SIZE(sdata->regulators),
597 						sdata->regulators);
598 }
599 
600 /* This function is void because I don't want to prevent using the touch key
601  * only because the LEDs don't get registered
602  */
603 static int stmfts_enable_led(struct stmfts_data *sdata)
604 {
605 	int err;
606 
607 	/* get the regulator for powering the leds on */
608 	sdata->ledvdd = devm_regulator_get(&sdata->client->dev, "ledvdd");
609 	if (IS_ERR(sdata->ledvdd))
610 		return PTR_ERR(sdata->ledvdd);
611 
612 	sdata->led_cdev.name = STMFTS_DEV_NAME;
613 	sdata->led_cdev.max_brightness = LED_ON;
614 	sdata->led_cdev.brightness = LED_OFF;
615 	sdata->led_cdev.brightness_set_blocking = stmfts_brightness_set;
616 	sdata->led_cdev.brightness_get = stmfts_brightness_get;
617 
618 	err = devm_led_classdev_register(&sdata->client->dev, &sdata->led_cdev);
619 	if (err) {
620 		devm_regulator_put(sdata->ledvdd);
621 		return err;
622 	}
623 
624 	return 0;
625 }
626 
627 static int stmfts_probe(struct i2c_client *client)
628 {
629 	int err;
630 	struct stmfts_data *sdata;
631 
632 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
633 						I2C_FUNC_SMBUS_BYTE_DATA |
634 						I2C_FUNC_SMBUS_I2C_BLOCK))
635 		return -ENODEV;
636 
637 	sdata = devm_kzalloc(&client->dev, sizeof(*sdata), GFP_KERNEL);
638 	if (!sdata)
639 		return -ENOMEM;
640 
641 	i2c_set_clientdata(client, sdata);
642 
643 	sdata->client = client;
644 	mutex_init(&sdata->mutex);
645 	init_completion(&sdata->cmd_done);
646 
647 	sdata->regulators[STMFTS_REGULATOR_VDD].supply = "vdd";
648 	sdata->regulators[STMFTS_REGULATOR_AVDD].supply = "avdd";
649 	err = devm_regulator_bulk_get(&client->dev,
650 				      ARRAY_SIZE(sdata->regulators),
651 				      sdata->regulators);
652 	if (err)
653 		return err;
654 
655 	sdata->input = devm_input_allocate_device(&client->dev);
656 	if (!sdata->input)
657 		return -ENOMEM;
658 
659 	sdata->input->name = STMFTS_DEV_NAME;
660 	sdata->input->id.bustype = BUS_I2C;
661 	sdata->input->open = stmfts_input_open;
662 	sdata->input->close = stmfts_input_close;
663 
664 	input_set_capability(sdata->input, EV_ABS, ABS_MT_POSITION_X);
665 	input_set_capability(sdata->input, EV_ABS, ABS_MT_POSITION_Y);
666 	touchscreen_parse_properties(sdata->input, true, &sdata->prop);
667 
668 	input_set_abs_params(sdata->input, ABS_MT_TOUCH_MAJOR, 0, 255, 0, 0);
669 	input_set_abs_params(sdata->input, ABS_MT_TOUCH_MINOR, 0, 255, 0, 0);
670 	input_set_abs_params(sdata->input, ABS_MT_ORIENTATION, 0, 255, 0, 0);
671 	input_set_abs_params(sdata->input, ABS_MT_PRESSURE, 0, 255, 0, 0);
672 	input_set_abs_params(sdata->input, ABS_DISTANCE, 0, 255, 0, 0);
673 
674 	sdata->use_key = device_property_read_bool(&client->dev,
675 						   "touch-key-connected");
676 	if (sdata->use_key) {
677 		input_set_capability(sdata->input, EV_KEY, KEY_MENU);
678 		input_set_capability(sdata->input, EV_KEY, KEY_BACK);
679 	}
680 
681 	err = input_mt_init_slots(sdata->input,
682 				  STMFTS_MAX_FINGERS, INPUT_MT_DIRECT);
683 	if (err)
684 		return err;
685 
686 	input_set_drvdata(sdata->input, sdata);
687 
688 	/*
689 	 * stmfts_power_on expects interrupt to be disabled, but
690 	 * at this point the device is still off and I do not trust
691 	 * the status of the irq line that can generate some spurious
692 	 * interrupts. To be on the safe side it's better to not enable
693 	 * the interrupts during their request.
694 	 */
695 	err = devm_request_threaded_irq(&client->dev, client->irq,
696 					NULL, stmfts_irq_handler,
697 					IRQF_ONESHOT | IRQF_NO_AUTOEN,
698 					"stmfts_irq", sdata);
699 	if (err)
700 		return err;
701 
702 	dev_dbg(&client->dev, "initializing ST-Microelectronics FTS...\n");
703 
704 	err = stmfts_power_on(sdata);
705 	if (err)
706 		return err;
707 
708 	err = devm_add_action_or_reset(&client->dev, stmfts_power_off, sdata);
709 	if (err)
710 		return err;
711 
712 	err = input_register_device(sdata->input);
713 	if (err)
714 		return err;
715 
716 	if (sdata->use_key) {
717 		err = stmfts_enable_led(sdata);
718 		if (err) {
719 			/*
720 			 * Even if the LEDs have failed to be initialized and
721 			 * used in the driver, I can still use the device even
722 			 * without LEDs. The ledvdd regulator pointer will be
723 			 * used as a flag.
724 			 */
725 			dev_warn(&client->dev, "unable to use touchkey leds\n");
726 			sdata->ledvdd = NULL;
727 		}
728 	}
729 
730 	err = devm_device_add_group(&client->dev, &stmfts_attribute_group);
731 	if (err)
732 		return err;
733 
734 	pm_runtime_enable(&client->dev);
735 	device_enable_async_suspend(&client->dev);
736 
737 	return 0;
738 }
739 
740 static void stmfts_remove(struct i2c_client *client)
741 {
742 	pm_runtime_disable(&client->dev);
743 }
744 
745 static int stmfts_runtime_suspend(struct device *dev)
746 {
747 	struct stmfts_data *sdata = dev_get_drvdata(dev);
748 	int ret;
749 
750 	ret = i2c_smbus_write_byte(sdata->client, STMFTS_SLEEP_IN);
751 	if (ret)
752 		dev_warn(dev, "failed to suspend device: %d\n", ret);
753 
754 	return ret;
755 }
756 
757 static int stmfts_runtime_resume(struct device *dev)
758 {
759 	struct stmfts_data *sdata = dev_get_drvdata(dev);
760 	int ret;
761 
762 	ret = i2c_smbus_write_byte(sdata->client, STMFTS_SLEEP_OUT);
763 	if (ret)
764 		dev_err(dev, "failed to resume device: %d\n", ret);
765 
766 	return ret;
767 }
768 
769 static int stmfts_suspend(struct device *dev)
770 {
771 	struct stmfts_data *sdata = dev_get_drvdata(dev);
772 
773 	stmfts_power_off(sdata);
774 
775 	return 0;
776 }
777 
778 static int stmfts_resume(struct device *dev)
779 {
780 	struct stmfts_data *sdata = dev_get_drvdata(dev);
781 
782 	return stmfts_power_on(sdata);
783 }
784 
785 static const struct dev_pm_ops stmfts_pm_ops = {
786 	SYSTEM_SLEEP_PM_OPS(stmfts_suspend, stmfts_resume)
787 	RUNTIME_PM_OPS(stmfts_runtime_suspend, stmfts_runtime_resume, NULL)
788 };
789 
790 #ifdef CONFIG_OF
791 static const struct of_device_id stmfts_of_match[] = {
792 	{ .compatible = "st,stmfts", },
793 	{ },
794 };
795 MODULE_DEVICE_TABLE(of, stmfts_of_match);
796 #endif
797 
798 static const struct i2c_device_id stmfts_id[] = {
799 	{ "stmfts", 0 },
800 	{ },
801 };
802 MODULE_DEVICE_TABLE(i2c, stmfts_id);
803 
804 static struct i2c_driver stmfts_driver = {
805 	.driver = {
806 		.name = STMFTS_DEV_NAME,
807 		.of_match_table = of_match_ptr(stmfts_of_match),
808 		.pm = pm_ptr(&stmfts_pm_ops),
809 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
810 	},
811 	.probe = stmfts_probe,
812 	.remove = stmfts_remove,
813 	.id_table = stmfts_id,
814 };
815 
816 module_i2c_driver(stmfts_driver);
817 
818 MODULE_AUTHOR("Andi Shyti <andi.shyti@samsung.com>");
819 MODULE_DESCRIPTION("STMicroelectronics FTS Touch Screen");
820 MODULE_LICENSE("GPL v2");
821