xref: /linux/drivers/input/touchscreen/stmfts.c (revision 995832b2cebe6969d1b42635db698803ee31294d)
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/gpio/consumer.h>
9 #include <linux/i2c.h>
10 #include <linux/input/mt.h>
11 #include <linux/input/touchscreen.h>
12 #include <linux/interrupt.h>
13 #include <linux/irq.h>
14 #include <linux/leds.h>
15 #include <linux/module.h>
16 #include <linux/pm_runtime.h>
17 #include <linux/regulator/consumer.h>
18 
19 /* I2C commands */
20 #define STMFTS_READ_INFO			0x80
21 #define STMFTS_READ_STATUS			0x84
22 #define STMFTS_READ_ONE_EVENT			0x85
23 #define STMFTS_READ_ALL_EVENT			0x86
24 #define STMFTS_LATEST_EVENT			0x87
25 #define STMFTS_SLEEP_IN				0x90
26 #define STMFTS_SLEEP_OUT			0x91
27 #define STMFTS_MS_MT_SENSE_OFF			0x92
28 #define STMFTS_MS_MT_SENSE_ON			0x93
29 #define STMFTS_SS_HOVER_SENSE_OFF		0x94
30 #define STMFTS_SS_HOVER_SENSE_ON		0x95
31 #define STMFTS_MS_KEY_SENSE_OFF			0x9a
32 #define STMFTS_MS_KEY_SENSE_ON			0x9b
33 #define STMFTS_SYSTEM_RESET			0xa0
34 #define STMFTS_CLEAR_EVENT_STACK		0xa1
35 #define STMFTS_FULL_FORCE_CALIBRATION		0xa2
36 #define STMFTS_MS_CX_TUNING			0xa3
37 #define STMFTS_SS_CX_TUNING			0xa4
38 
39 /* events */
40 #define STMFTS_EV_NO_EVENT			0x00
41 #define STMFTS_EV_MULTI_TOUCH_DETECTED		0x02
42 #define STMFTS_EV_MULTI_TOUCH_ENTER		0x03
43 #define STMFTS_EV_MULTI_TOUCH_LEAVE		0x04
44 #define STMFTS_EV_MULTI_TOUCH_MOTION		0x05
45 #define STMFTS_EV_HOVER_ENTER			0x07
46 #define STMFTS_EV_HOVER_LEAVE			0x08
47 #define STMFTS_EV_HOVER_MOTION			0x09
48 #define STMFTS_EV_KEY_STATUS			0x0e
49 #define STMFTS_EV_ERROR				0x0f
50 #define STMFTS_EV_CONTROLLER_READY		0x10
51 #define STMFTS_EV_SLEEP_OUT_CONTROLLER_READY	0x11
52 #define STMFTS_EV_STATUS			0x16
53 #define STMFTS_EV_DEBUG				0xdb
54 
55 /* multi touch related event masks */
56 #define STMFTS_MASK_EVENT_ID			0x0f
57 #define STMFTS_MASK_TOUCH_ID			0xf0
58 #define STMFTS_MASK_LEFT_EVENT			0x0f
59 #define STMFTS_MASK_X_MSB			0x0f
60 #define STMFTS_MASK_Y_LSB			0xf0
61 
62 /* key related event masks */
63 #define STMFTS_MASK_KEY_NO_TOUCH		0x00
64 #define STMFTS_MASK_KEY_MENU			0x01
65 #define STMFTS_MASK_KEY_BACK			0x02
66 
67 #define STMFTS_EVENT_SIZE	8
68 #define STMFTS_STACK_DEPTH	32
69 #define STMFTS_DATA_MAX_SIZE	(STMFTS_EVENT_SIZE * STMFTS_STACK_DEPTH)
70 #define STMFTS_MAX_FINGERS	10
71 #define STMFTS_DEV_NAME		"stmfts"
72 
73 static const struct regulator_bulk_data stmfts_supplies[] = {
74 	{ .supply = "vdd" },
75 	{ .supply = "avdd" },
76 };
77 
78 struct stmfts_data {
79 	struct i2c_client *client;
80 	struct input_dev *input;
81 	struct gpio_desc *reset_gpio;
82 	struct led_classdev led_cdev;
83 	struct mutex mutex;
84 
85 	struct touchscreen_properties prop;
86 
87 	struct regulator_bulk_data *supplies;
88 
89 	/*
90 	 * Presence of ledvdd will be used also to check
91 	 * whether the LED is supported.
92 	 */
93 	struct regulator *ledvdd;
94 
95 	u16 chip_id;
96 	u8 chip_ver;
97 	u16 fw_ver;
98 	u8 config_id;
99 	u8 config_ver;
100 
101 	u8 data[STMFTS_DATA_MAX_SIZE];
102 
103 	struct completion cmd_done;
104 
105 	bool use_key;
106 	bool led_status;
107 	bool hover_enabled;
108 	bool running;
109 };
110 
111 static int stmfts_brightness_set(struct led_classdev *led_cdev,
112 				 enum led_brightness value)
113 {
114 	struct stmfts_data *sdata = container_of(led_cdev,
115 					struct stmfts_data, led_cdev);
116 	int err;
117 
118 	if (value != sdata->led_status && sdata->ledvdd) {
119 		if (!value) {
120 			regulator_disable(sdata->ledvdd);
121 		} else {
122 			err = regulator_enable(sdata->ledvdd);
123 			if (err) {
124 				dev_warn(&sdata->client->dev,
125 					 "failed to enable ledvdd regulator: %d\n",
126 					 err);
127 				return err;
128 			}
129 		}
130 		sdata->led_status = value;
131 	}
132 
133 	return 0;
134 }
135 
136 static enum led_brightness stmfts_brightness_get(struct led_classdev *led_cdev)
137 {
138 	struct stmfts_data *sdata = container_of(led_cdev,
139 						struct stmfts_data, led_cdev);
140 
141 	return !!regulator_is_enabled(sdata->ledvdd);
142 }
143 
144 /*
145  * We can't simply use i2c_smbus_read_i2c_block_data because we
146  * need to read 256 bytes, which exceeds the 255-byte SMBus block limit.
147  */
148 static int stmfts_read_events(struct stmfts_data *sdata)
149 {
150 	u8 cmd = STMFTS_READ_ALL_EVENT;
151 	struct i2c_msg msgs[2] = {
152 		{
153 			.addr	= sdata->client->addr,
154 			.len	= 1,
155 			.buf	= &cmd,
156 		},
157 		{
158 			.addr	= sdata->client->addr,
159 			.flags	= I2C_M_RD,
160 			.len	= STMFTS_DATA_MAX_SIZE,
161 			.buf	= sdata->data,
162 		},
163 	};
164 	int ret;
165 
166 	ret = i2c_transfer(sdata->client->adapter, msgs, ARRAY_SIZE(msgs));
167 	if (ret < 0)
168 		return ret;
169 
170 	return ret == ARRAY_SIZE(msgs) ? 0 : -EIO;
171 }
172 
173 static void stmfts_report_contact_event(struct stmfts_data *sdata,
174 					const u8 event[])
175 {
176 	u8 slot_id = (event[0] & STMFTS_MASK_TOUCH_ID) >> 4;
177 	u16 x = event[1] | ((event[2] & STMFTS_MASK_X_MSB) << 8);
178 	u16 y = (event[2] >> 4) | (event[3] << 4);
179 	u8 maj = event[4];
180 	u8 min = event[5];
181 	u8 orientation = event[6];
182 	u8 area = event[7];
183 
184 	input_mt_slot(sdata->input, slot_id);
185 
186 	input_mt_report_slot_state(sdata->input, MT_TOOL_FINGER, true);
187 	input_report_abs(sdata->input, ABS_MT_POSITION_X, x);
188 	input_report_abs(sdata->input, ABS_MT_POSITION_Y, y);
189 	input_report_abs(sdata->input, ABS_MT_TOUCH_MAJOR, maj);
190 	input_report_abs(sdata->input, ABS_MT_TOUCH_MINOR, min);
191 	input_report_abs(sdata->input, ABS_MT_PRESSURE, area);
192 	input_report_abs(sdata->input, ABS_MT_ORIENTATION, orientation);
193 
194 	input_sync(sdata->input);
195 }
196 
197 static void stmfts_report_contact_release(struct stmfts_data *sdata,
198 					  const u8 event[])
199 {
200 	u8 slot_id = (event[0] & STMFTS_MASK_TOUCH_ID) >> 4;
201 
202 	input_mt_slot(sdata->input, slot_id);
203 	input_mt_report_slot_inactive(sdata->input);
204 
205 	input_sync(sdata->input);
206 }
207 
208 static void stmfts_report_hover_event(struct stmfts_data *sdata,
209 				      const u8 event[])
210 {
211 	u16 x = (event[2] << 4) | (event[4] >> 4);
212 	u16 y = (event[3] << 4) | (event[4] & STMFTS_MASK_Y_LSB);
213 	u8 z = event[5];
214 
215 	input_report_abs(sdata->input, ABS_X, x);
216 	input_report_abs(sdata->input, ABS_Y, y);
217 	input_report_abs(sdata->input, ABS_DISTANCE, z);
218 
219 	input_sync(sdata->input);
220 }
221 
222 static void stmfts_report_key_event(struct stmfts_data *sdata, const u8 event[])
223 {
224 	switch (event[2]) {
225 	case 0:
226 		input_report_key(sdata->input, KEY_BACK, 0);
227 		input_report_key(sdata->input, KEY_MENU, 0);
228 		break;
229 
230 	case STMFTS_MASK_KEY_BACK:
231 		input_report_key(sdata->input, KEY_BACK, 1);
232 		break;
233 
234 	case STMFTS_MASK_KEY_MENU:
235 		input_report_key(sdata->input, KEY_MENU, 1);
236 		break;
237 
238 	default:
239 		dev_warn(&sdata->client->dev,
240 			 "unknown key event: %#02x\n", event[2]);
241 		break;
242 	}
243 
244 	input_sync(sdata->input);
245 }
246 
247 static void stmfts_parse_events(struct stmfts_data *sdata)
248 {
249 	int i;
250 
251 	for (i = 0; i < STMFTS_STACK_DEPTH; i++) {
252 		u8 *event = &sdata->data[i * STMFTS_EVENT_SIZE];
253 
254 		switch (event[0]) {
255 		case STMFTS_EV_CONTROLLER_READY:
256 		case STMFTS_EV_SLEEP_OUT_CONTROLLER_READY:
257 		case STMFTS_EV_STATUS:
258 			complete(&sdata->cmd_done);
259 			fallthrough;
260 
261 		case STMFTS_EV_NO_EVENT:
262 		case STMFTS_EV_DEBUG:
263 			return;
264 		}
265 
266 		switch (event[0] & STMFTS_MASK_EVENT_ID) {
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 	guard(mutex)(&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 	return IRQ_HANDLED;
315 }
316 
317 static int stmfts_command(struct stmfts_data *sdata, const u8 cmd)
318 {
319 	int err;
320 
321 	reinit_completion(&sdata->cmd_done);
322 
323 	err = i2c_smbus_write_byte(sdata->client, cmd);
324 	if (err)
325 		return err;
326 
327 	if (!wait_for_completion_timeout(&sdata->cmd_done,
328 					 msecs_to_jiffies(1000)))
329 		return -ETIMEDOUT;
330 
331 	return 0;
332 }
333 
334 static int stmfts_input_open(struct input_dev *dev)
335 {
336 	struct stmfts_data *sdata = input_get_drvdata(dev);
337 	int err;
338 
339 	err = pm_runtime_resume_and_get(&sdata->client->dev);
340 	if (err)
341 		return err;
342 
343 	err = i2c_smbus_write_byte(sdata->client, STMFTS_MS_MT_SENSE_ON);
344 	if (err) {
345 		pm_runtime_put_sync(&sdata->client->dev);
346 		return err;
347 	}
348 
349 	scoped_guard(mutex, &sdata->mutex) {
350 		sdata->running = true;
351 
352 		if (sdata->hover_enabled) {
353 			err = i2c_smbus_write_byte(sdata->client,
354 						   STMFTS_SS_HOVER_SENSE_ON);
355 			if (err)
356 				dev_warn(&sdata->client->dev,
357 					 "failed to enable hover\n");
358 		}
359 	}
360 
361 	if (sdata->use_key) {
362 		err = i2c_smbus_write_byte(sdata->client,
363 					   STMFTS_MS_KEY_SENSE_ON);
364 		if (err)
365 			/* I can still use only the touch screen */
366 			dev_warn(&sdata->client->dev,
367 				 "failed to enable touchkey\n");
368 	}
369 
370 	return 0;
371 }
372 
373 static void stmfts_input_close(struct input_dev *dev)
374 {
375 	struct stmfts_data *sdata = input_get_drvdata(dev);
376 	int err;
377 
378 	err = i2c_smbus_write_byte(sdata->client, STMFTS_MS_MT_SENSE_OFF);
379 	if (err)
380 		dev_warn(&sdata->client->dev,
381 			 "failed to disable touchscreen: %d\n", err);
382 
383 	scoped_guard(mutex, &sdata->mutex) {
384 		sdata->running = false;
385 
386 		if (sdata->hover_enabled) {
387 			err = i2c_smbus_write_byte(sdata->client,
388 						   STMFTS_SS_HOVER_SENSE_OFF);
389 			if (err)
390 				dev_warn(&sdata->client->dev,
391 					 "failed to disable hover: %d\n", err);
392 		}
393 	}
394 
395 	if (sdata->use_key) {
396 		err = i2c_smbus_write_byte(sdata->client,
397 					   STMFTS_MS_KEY_SENSE_OFF);
398 		if (err)
399 			dev_warn(&sdata->client->dev,
400 				 "failed to disable touchkey: %d\n", err);
401 	}
402 
403 	pm_runtime_put_sync(&sdata->client->dev);
404 }
405 
406 static ssize_t stmfts_sysfs_chip_id(struct device *dev,
407 				    struct device_attribute *attr, char *buf)
408 {
409 	struct stmfts_data *sdata = dev_get_drvdata(dev);
410 
411 	return sysfs_emit(buf, "%#x\n", sdata->chip_id);
412 }
413 
414 static ssize_t stmfts_sysfs_chip_version(struct device *dev,
415 					 struct device_attribute *attr,
416 					 char *buf)
417 {
418 	struct stmfts_data *sdata = dev_get_drvdata(dev);
419 
420 	return sysfs_emit(buf, "%u\n", sdata->chip_ver);
421 }
422 
423 static ssize_t stmfts_sysfs_fw_ver(struct device *dev,
424 				   struct device_attribute *attr, char *buf)
425 {
426 	struct stmfts_data *sdata = dev_get_drvdata(dev);
427 
428 	return sysfs_emit(buf, "%u\n", sdata->fw_ver);
429 }
430 
431 static ssize_t stmfts_sysfs_config_id(struct device *dev,
432 				      struct device_attribute *attr, char *buf)
433 {
434 	struct stmfts_data *sdata = dev_get_drvdata(dev);
435 
436 	return sysfs_emit(buf, "%#x\n", sdata->config_id);
437 }
438 
439 static ssize_t stmfts_sysfs_config_version(struct device *dev,
440 					   struct device_attribute *attr,
441 					   char *buf)
442 {
443 	struct stmfts_data *sdata = dev_get_drvdata(dev);
444 
445 	return sysfs_emit(buf, "%u\n", sdata->config_ver);
446 }
447 
448 static ssize_t stmfts_sysfs_read_status(struct device *dev,
449 					struct device_attribute *attr,
450 					char *buf)
451 {
452 	struct stmfts_data *sdata = dev_get_drvdata(dev);
453 	u8 status[4];
454 	int err;
455 
456 	err = i2c_smbus_read_i2c_block_data(sdata->client, STMFTS_READ_STATUS,
457 					    sizeof(status), status);
458 	if (err)
459 		return err;
460 
461 	return sysfs_emit(buf, "%#02x\n", status[0]);
462 }
463 
464 static ssize_t stmfts_sysfs_hover_enable_read(struct device *dev,
465 					      struct device_attribute *attr,
466 					      char *buf)
467 {
468 	struct stmfts_data *sdata = dev_get_drvdata(dev);
469 
470 	return sysfs_emit(buf, "%u\n", sdata->hover_enabled);
471 }
472 
473 static ssize_t stmfts_sysfs_hover_enable_write(struct device *dev,
474 					       struct device_attribute *attr,
475 					       const char *buf, size_t len)
476 {
477 	struct stmfts_data *sdata = dev_get_drvdata(dev);
478 	unsigned long value;
479 	bool hover;
480 	int err;
481 
482 	if (kstrtoul(buf, 0, &value))
483 		return -EINVAL;
484 
485 	hover = !!value;
486 
487 	guard(mutex)(&sdata->mutex);
488 
489 	if (hover != sdata->hover_enabled) {
490 		if (sdata->running) {
491 			err = i2c_smbus_write_byte(sdata->client,
492 						   value ? STMFTS_SS_HOVER_SENSE_ON :
493 							   STMFTS_SS_HOVER_SENSE_OFF);
494 			if (err)
495 				return err;
496 		}
497 
498 		sdata->hover_enabled = hover;
499 	}
500 
501 	return len;
502 }
503 
504 static DEVICE_ATTR(chip_id, 0444, stmfts_sysfs_chip_id, NULL);
505 static DEVICE_ATTR(chip_version, 0444, stmfts_sysfs_chip_version, NULL);
506 static DEVICE_ATTR(fw_ver, 0444, stmfts_sysfs_fw_ver, NULL);
507 static DEVICE_ATTR(config_id, 0444, stmfts_sysfs_config_id, NULL);
508 static DEVICE_ATTR(config_version, 0444, stmfts_sysfs_config_version, NULL);
509 static DEVICE_ATTR(status, 0444, stmfts_sysfs_read_status, NULL);
510 static DEVICE_ATTR(hover_enable, 0644, stmfts_sysfs_hover_enable_read,
511 					stmfts_sysfs_hover_enable_write);
512 
513 static struct attribute *stmfts_sysfs_attrs[] = {
514 	&dev_attr_chip_id.attr,
515 	&dev_attr_chip_version.attr,
516 	&dev_attr_fw_ver.attr,
517 	&dev_attr_config_id.attr,
518 	&dev_attr_config_version.attr,
519 	&dev_attr_status.attr,
520 	&dev_attr_hover_enable.attr,
521 	NULL
522 };
523 ATTRIBUTE_GROUPS(stmfts_sysfs);
524 
525 static int stmfts_read_system_info(struct stmfts_data *sdata)
526 {
527 	int err;
528 	u8 reg[8];
529 
530 	err = i2c_smbus_read_i2c_block_data(sdata->client, STMFTS_READ_INFO,
531 					    sizeof(reg), reg);
532 	if (err < 0)
533 		return err;
534 	if (err != sizeof(reg))
535 		return -EIO;
536 
537 	sdata->chip_id = be16_to_cpup((__be16 *)&reg[6]);
538 	sdata->chip_ver = reg[0];
539 	sdata->fw_ver = be16_to_cpup((__be16 *)&reg[2]);
540 	sdata->config_id = reg[4];
541 	sdata->config_ver = reg[5];
542 
543 	return 0;
544 }
545 
546 static void stmfts_reset(struct stmfts_data *sdata)
547 {
548 	gpiod_set_value_cansleep(sdata->reset_gpio, 1);
549 	msleep(20);
550 
551 	gpiod_set_value_cansleep(sdata->reset_gpio, 0);
552 	msleep(50);
553 }
554 
555 static int stmfts_configure(struct stmfts_data *sdata)
556 {
557 	int err;
558 
559 	err = stmfts_command(sdata, STMFTS_SYSTEM_RESET);
560 	if (err)
561 		return err;
562 
563 	err = stmfts_command(sdata, STMFTS_SLEEP_OUT);
564 	if (err)
565 		return err;
566 
567 	/* optional tuning */
568 	err = stmfts_command(sdata, STMFTS_MS_CX_TUNING);
569 	if (err)
570 		dev_warn(&sdata->client->dev,
571 			 "failed to perform mutual auto tune: %d\n", err);
572 
573 	/* optional tuning */
574 	err = stmfts_command(sdata, STMFTS_SS_CX_TUNING);
575 	if (err)
576 		dev_warn(&sdata->client->dev,
577 			 "failed to perform self auto tune: %d\n", err);
578 
579 	err = stmfts_command(sdata, STMFTS_FULL_FORCE_CALIBRATION);
580 	if (err)
581 		return err;
582 
583 	return 0;
584 }
585 
586 static int stmfts_power_on(struct stmfts_data *sdata)
587 {
588 	int err;
589 
590 	err = regulator_bulk_enable(ARRAY_SIZE(stmfts_supplies),
591 				    sdata->supplies);
592 	if (err)
593 		return err;
594 
595 	/*
596 	 * The datasheet does not specify the power on time, but considering
597 	 * that the reset time is < 10ms, I sleep 20ms to be sure
598 	 */
599 	msleep(20);
600 
601 	if (sdata->reset_gpio)
602 		stmfts_reset(sdata);
603 
604 	err = stmfts_read_system_info(sdata);
605 	if (err)
606 		goto err_disable_regulators;
607 
608 	enable_irq(sdata->client->irq);
609 
610 	msleep(50);
611 
612 	err = stmfts_configure(sdata);
613 	if (err)
614 		goto err_disable_irq;
615 
616 	/*
617 	 * At this point no one is using the touchscreen
618 	 * and I don't really care about the return value
619 	 */
620 	(void)i2c_smbus_write_byte(sdata->client, STMFTS_SLEEP_IN);
621 
622 	return 0;
623 
624 err_disable_irq:
625 	disable_irq(sdata->client->irq);
626 err_disable_regulators:
627 	regulator_bulk_disable(ARRAY_SIZE(stmfts_supplies), sdata->supplies);
628 	return err;
629 }
630 
631 static void stmfts_power_off(void *data)
632 {
633 	struct stmfts_data *sdata = data;
634 
635 	disable_irq(sdata->client->irq);
636 
637 	if (sdata->reset_gpio)
638 		gpiod_set_value_cansleep(sdata->reset_gpio, 1);
639 
640 	regulator_bulk_disable(ARRAY_SIZE(stmfts_supplies), sdata->supplies);
641 }
642 
643 static int stmfts_enable_led(struct stmfts_data *sdata)
644 {
645 	int err;
646 
647 	/* get the regulator for powering the leds on */
648 	sdata->ledvdd = devm_regulator_get(&sdata->client->dev, "ledvdd");
649 	if (IS_ERR(sdata->ledvdd))
650 		return PTR_ERR(sdata->ledvdd);
651 
652 	sdata->led_cdev.name = STMFTS_DEV_NAME;
653 	sdata->led_cdev.max_brightness = LED_ON;
654 	sdata->led_cdev.brightness = LED_OFF;
655 	sdata->led_cdev.brightness_set_blocking = stmfts_brightness_set;
656 	sdata->led_cdev.brightness_get = stmfts_brightness_get;
657 
658 	err = devm_led_classdev_register(&sdata->client->dev, &sdata->led_cdev);
659 	if (err) {
660 		devm_regulator_put(sdata->ledvdd);
661 		return err;
662 	}
663 
664 	return 0;
665 }
666 
667 static int stmfts_probe(struct i2c_client *client)
668 {
669 	struct device *dev = &client->dev;
670 	int err;
671 	struct stmfts_data *sdata;
672 
673 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
674 						I2C_FUNC_SMBUS_BYTE_DATA |
675 						I2C_FUNC_SMBUS_I2C_BLOCK))
676 		return -ENODEV;
677 
678 	sdata = devm_kzalloc(dev, sizeof(*sdata), GFP_KERNEL);
679 	if (!sdata)
680 		return -ENOMEM;
681 
682 	i2c_set_clientdata(client, sdata);
683 
684 	sdata->client = client;
685 	mutex_init(&sdata->mutex);
686 	init_completion(&sdata->cmd_done);
687 
688 	err = devm_regulator_bulk_get_const(dev,
689 					    ARRAY_SIZE(stmfts_supplies),
690 					    stmfts_supplies,
691 					    &sdata->supplies);
692 	if (err)
693 		return err;
694 
695 	sdata->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
696 	if (IS_ERR(sdata->reset_gpio))
697 		return dev_err_probe(dev, PTR_ERR(sdata->reset_gpio),
698 				     "Failed to get GPIO 'reset'\n");
699 
700 	sdata->input = devm_input_allocate_device(dev);
701 	if (!sdata->input)
702 		return -ENOMEM;
703 
704 	sdata->input->name = STMFTS_DEV_NAME;
705 	sdata->input->id.bustype = BUS_I2C;
706 	sdata->input->open = stmfts_input_open;
707 	sdata->input->close = stmfts_input_close;
708 
709 	input_set_capability(sdata->input, EV_ABS, ABS_MT_POSITION_X);
710 	input_set_capability(sdata->input, EV_ABS, ABS_MT_POSITION_Y);
711 	touchscreen_parse_properties(sdata->input, true, &sdata->prop);
712 
713 	input_set_abs_params(sdata->input, ABS_MT_TOUCH_MAJOR, 0, 255, 0, 0);
714 	input_set_abs_params(sdata->input, ABS_MT_TOUCH_MINOR, 0, 255, 0, 0);
715 	input_set_abs_params(sdata->input, ABS_MT_ORIENTATION, 0, 255, 0, 0);
716 	input_set_abs_params(sdata->input, ABS_MT_PRESSURE, 0, 255, 0, 0);
717 	input_set_abs_params(sdata->input, ABS_DISTANCE, 0, 255, 0, 0);
718 
719 	sdata->use_key = device_property_read_bool(dev, "touch-key-connected");
720 	if (sdata->use_key) {
721 		input_set_capability(sdata->input, EV_KEY, KEY_MENU);
722 		input_set_capability(sdata->input, EV_KEY, KEY_BACK);
723 	}
724 
725 	err = input_mt_init_slots(sdata->input,
726 				  STMFTS_MAX_FINGERS, INPUT_MT_DIRECT);
727 	if (err)
728 		return err;
729 
730 	input_set_drvdata(sdata->input, sdata);
731 
732 	/*
733 	 * stmfts_power_on expects interrupt to be disabled, but
734 	 * at this point the device is still off and I do not trust
735 	 * the status of the irq line that can generate some spurious
736 	 * interrupts. To be on the safe side it's better to not enable
737 	 * the interrupts during their request.
738 	 */
739 	err = devm_request_threaded_irq(dev, client->irq,
740 					NULL, stmfts_irq_handler,
741 					IRQF_ONESHOT | IRQF_NO_AUTOEN,
742 					"stmfts_irq", sdata);
743 	if (err)
744 		return err;
745 
746 	dev_dbg(dev, "initializing ST-Microelectronics FTS...\n");
747 
748 	err = stmfts_power_on(sdata);
749 	if (err)
750 		return err;
751 
752 	err = devm_add_action_or_reset(dev, stmfts_power_off, sdata);
753 	if (err)
754 		return err;
755 
756 	err = input_register_device(sdata->input);
757 	if (err)
758 		return err;
759 
760 	if (sdata->use_key) {
761 		err = stmfts_enable_led(sdata);
762 		if (err) {
763 			/*
764 			 * Even if the LEDs have failed to be initialized and
765 			 * used in the driver, I can still use the device even
766 			 * without LEDs. The ledvdd regulator pointer will be
767 			 * used as a flag.
768 			 */
769 			dev_warn(dev, "unable to use touchkey leds\n");
770 			sdata->ledvdd = NULL;
771 		}
772 	}
773 
774 	pm_runtime_enable(dev);
775 	device_enable_async_suspend(dev);
776 
777 	return 0;
778 }
779 
780 static void stmfts_remove(struct i2c_client *client)
781 {
782 	pm_runtime_disable(&client->dev);
783 }
784 
785 static int stmfts_runtime_suspend(struct device *dev)
786 {
787 	struct stmfts_data *sdata = dev_get_drvdata(dev);
788 	int ret;
789 
790 	ret = i2c_smbus_write_byte(sdata->client, STMFTS_SLEEP_IN);
791 	if (ret)
792 		dev_warn(dev, "failed to suspend device: %d\n", ret);
793 
794 	return ret;
795 }
796 
797 static int stmfts_runtime_resume(struct device *dev)
798 {
799 	struct stmfts_data *sdata = dev_get_drvdata(dev);
800 	struct i2c_client *client = sdata->client;
801 	int ret;
802 
803 	ret = i2c_smbus_write_byte(client, STMFTS_SLEEP_OUT);
804 	if (ret)
805 		dev_err(dev, "failed to resume device: %d\n", ret);
806 
807 	return ret;
808 }
809 
810 static int stmfts_suspend(struct device *dev)
811 {
812 	struct stmfts_data *sdata = dev_get_drvdata(dev);
813 
814 	stmfts_power_off(sdata);
815 
816 	return 0;
817 }
818 
819 static int stmfts_resume(struct device *dev)
820 {
821 	struct stmfts_data *sdata = dev_get_drvdata(dev);
822 
823 	return stmfts_power_on(sdata);
824 }
825 
826 static const struct dev_pm_ops stmfts_pm_ops = {
827 	SYSTEM_SLEEP_PM_OPS(stmfts_suspend, stmfts_resume)
828 	RUNTIME_PM_OPS(stmfts_runtime_suspend, stmfts_runtime_resume, NULL)
829 };
830 
831 #ifdef CONFIG_OF
832 static const struct of_device_id stmfts_of_match[] = {
833 	{ .compatible = "st,stmfts", },
834 	{ },
835 };
836 MODULE_DEVICE_TABLE(of, stmfts_of_match);
837 #endif
838 
839 static const struct i2c_device_id stmfts_id[] = {
840 	{ .name = "stmfts" },
841 	{ }
842 };
843 MODULE_DEVICE_TABLE(i2c, stmfts_id);
844 
845 static struct i2c_driver stmfts_driver = {
846 	.driver = {
847 		.name = STMFTS_DEV_NAME,
848 		.dev_groups = stmfts_sysfs_groups,
849 		.of_match_table = of_match_ptr(stmfts_of_match),
850 		.pm = pm_ptr(&stmfts_pm_ops),
851 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
852 	},
853 	.probe = stmfts_probe,
854 	.remove = stmfts_remove,
855 	.id_table = stmfts_id,
856 };
857 
858 module_i2c_driver(stmfts_driver);
859 
860 MODULE_AUTHOR("Andi Shyti <andi.shyti@samsung.com>");
861 MODULE_DESCRIPTION("STMicroelectronics FTS Touch Screen");
862 MODULE_LICENSE("GPL");
863