drivers/input/touchscreen/stmfts.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 // STMicroelectronics FTS Touchscreen device driver
 //
 // Copyright (c) 2017 Samsung Electronics Co., Ltd.
 // Copyright (c) 2017 Andi Shyti <andi@etezian.org>

 #include <linux/delay.h>
 #include <linux/i2c.h>
 #include <linux/input/mt.h>
 #include <linux/input/touchscreen.h>
 #include <linux/interrupt.h>
 #include <linux/irq.h>
 #include <linux/leds.h>
 #include <linux/module.h>
 #include <linux/pm_runtime.h>
 #include <linux/regulator/consumer.h>

 /* I2C commands */
 #define STMFTS_READ_INFO			0x80
 #define STMFTS_READ_STATUS			0x84
 #define STMFTS_READ_ONE_EVENT			0x85
 #define STMFTS_READ_ALL_EVENT			0x86
 #define STMFTS_LATEST_EVENT			0x87
 #define STMFTS_SLEEP_IN				0x90
 #define STMFTS_SLEEP_OUT			0x91
 #define STMFTS_MS_MT_SENSE_OFF			0x92
 #define STMFTS_MS_MT_SENSE_ON			0x93
 #define STMFTS_SS_HOVER_SENSE_OFF		0x94
 #define STMFTS_SS_HOVER_SENSE_ON		0x95
 #define STMFTS_MS_KEY_SENSE_OFF			0x9a
 #define STMFTS_MS_KEY_SENSE_ON			0x9b
 #define STMFTS_SYSTEM_RESET			0xa0
 #define STMFTS_CLEAR_EVENT_STACK		0xa1
 #define STMFTS_FULL_FORCE_CALIBRATION		0xa2
 #define STMFTS_MS_CX_TUNING			0xa3
 #define STMFTS_SS_CX_TUNING			0xa4

 /* events */
 #define STMFTS_EV_NO_EVENT			0x00
 #define STMFTS_EV_MULTI_TOUCH_DETECTED		0x02
 #define STMFTS_EV_MULTI_TOUCH_ENTER		0x03
 #define STMFTS_EV_MULTI_TOUCH_LEAVE		0x04
 #define STMFTS_EV_MULTI_TOUCH_MOTION		0x05
 #define STMFTS_EV_HOVER_ENTER			0x07
 #define STMFTS_EV_HOVER_LEAVE			0x08
 #define STMFTS_EV_HOVER_MOTION			0x09
 #define STMFTS_EV_KEY_STATUS			0x0e
 #define STMFTS_EV_ERROR				0x0f
 #define STMFTS_EV_CONTROLLER_READY		0x10
 #define STMFTS_EV_SLEEP_OUT_CONTROLLER_READY	0x11
 #define STMFTS_EV_STATUS			0x16
 #define STMFTS_EV_DEBUG				0xdb

 /* multi touch related event masks */
 #define STMFTS_MASK_EVENT_ID			0x0f
 #define STMFTS_MASK_TOUCH_ID			0xf0
 #define STMFTS_MASK_LEFT_EVENT			0x0f
 #define STMFTS_MASK_X_MSB			0x0f
 #define STMFTS_MASK_Y_LSB			0xf0

 /* key related event masks */
 #define STMFTS_MASK_KEY_NO_TOUCH		0x00
 #define STMFTS_MASK_KEY_MENU			0x01
 #define STMFTS_MASK_KEY_BACK			0x02

 #define STMFTS_EVENT_SIZE	8
 #define STMFTS_STACK_DEPTH	32
 #define STMFTS_DATA_MAX_SIZE	(STMFTS_EVENT_SIZE * STMFTS_STACK_DEPTH)
 #define STMFTS_MAX_FINGERS	10
 #define STMFTS_DEV_NAME		"stmfts"

 enum stmfts_regulators {
 	STMFTS_REGULATOR_VDD,
 	STMFTS_REGULATOR_AVDD,
 };

 struct stmfts_data {
 	struct i2c_client *client;
 	struct input_dev *input;
 	struct led_classdev led_cdev;
 	struct mutex mutex;

 	struct touchscreen_properties prop;

 	struct regulator_bulk_data regulators[2];

 	/*
 	 * Presence of ledvdd will be used also to check
 	 * whether the LED is supported.
 	 */
 	struct regulator *ledvdd;

 	u16 chip_id;
 	u8 chip_ver;
 	u16 fw_ver;
 	u8 config_id;
 	u8 config_ver;

 	u8 data[STMFTS_DATA_MAX_SIZE];

 	struct completion cmd_done;

 	bool use_key;
 	bool led_status;
 	bool hover_enabled;
 	bool running;
 };

 static int stmfts_brightness_set(struct led_classdev *led_cdev,
 					enum led_brightness value)
 {
 	struct stmfts_data *sdata = container_of(led_cdev,
 					struct stmfts_data, led_cdev);
 	int err;

 	if (value != sdata->led_status && sdata->ledvdd) {
 		if (!value) {
 			regulator_disable(sdata->ledvdd);
 		} else {
 			err = regulator_enable(sdata->ledvdd);
 			if (err) {
 				dev_warn(&sdata->client->dev,
 					 "failed to disable ledvdd regulator: %d\n",
 					 err);
 				return err;
 			}
 		}
 		sdata->led_status = value;
 	}

 	return 0;
 }

 static enum led_brightness stmfts_brightness_get(struct led_classdev *led_cdev)
 {
 	struct stmfts_data *sdata = container_of(led_cdev,
 						struct stmfts_data, led_cdev);

 	return !!regulator_is_enabled(sdata->ledvdd);
 }

 /*
  * We can't simply use i2c_smbus_read_i2c_block_data because we
  * need to read more than 255 bytes (
  */
 static int stmfts_read_events(struct stmfts_data *sdata)
 {
 	u8 cmd = STMFTS_READ_ALL_EVENT;
 	struct i2c_msg msgs[2] = {
 		{
 			.addr	= sdata->client->addr,
 			.len	= 1,
 			.buf	= &cmd,
 		},
 		{
 			.addr	= sdata->client->addr,
 			.flags	= I2C_M_RD,
 			.len	= STMFTS_DATA_MAX_SIZE,
 			.buf	= sdata->data,
 		},
 	};
 	int ret;

 	ret = i2c_transfer(sdata->client->adapter, msgs, ARRAY_SIZE(msgs));
 	if (ret < 0)
 		return ret;

 	return ret == ARRAY_SIZE(msgs) ? 0 : -EIO;
 }

 static void stmfts_report_contact_event(struct stmfts_data *sdata,
 					const u8 event[])
 {
 	u8 slot_id = (event[0] & STMFTS_MASK_TOUCH_ID) >> 4;
 	u16 x = event[1] | ((event[2] & STMFTS_MASK_X_MSB) << 8);
 	u16 y = (event[2] >> 4) | (event[3] << 4);
 	u8 maj = event[4];
 	u8 min = event[5];
 	u8 orientation = event[6];
 	u8 area = event[7];

 	input_mt_slot(sdata->input, slot_id);

 	input_mt_report_slot_state(sdata->input, MT_TOOL_FINGER, true);
 	input_report_abs(sdata->input, ABS_MT_POSITION_X, x);
 	input_report_abs(sdata->input, ABS_MT_POSITION_Y, y);
 	input_report_abs(sdata->input, ABS_MT_TOUCH_MAJOR, maj);
 	input_report_abs(sdata->input, ABS_MT_TOUCH_MINOR, min);
 	input_report_abs(sdata->input, ABS_MT_PRESSURE, area);
 	input_report_abs(sdata->input, ABS_MT_ORIENTATION, orientation);

 	input_sync(sdata->input);
 }

 static void stmfts_report_contact_release(struct stmfts_data *sdata,
 					  const u8 event[])
 {
 	u8 slot_id = (event[0] & STMFTS_MASK_TOUCH_ID) >> 4;

 	input_mt_slot(sdata->input, slot_id);
 	input_mt_report_slot_inactive(sdata->input);

 	input_sync(sdata->input);
 }

 static void stmfts_report_hover_event(struct stmfts_data *sdata,
 				      const u8 event[])
 {
 	u16 x = (event[2] << 4) | (event[4] >> 4);
 	u16 y = (event[3] << 4) | (event[4] & STMFTS_MASK_Y_LSB);
 	u8 z = event[5];

 	input_report_abs(sdata->input, ABS_X, x);
 	input_report_abs(sdata->input, ABS_Y, y);
 	input_report_abs(sdata->input, ABS_DISTANCE, z);

 	input_sync(sdata->input);
 }

 static void stmfts_report_key_event(struct stmfts_data *sdata, const u8 event[])
 {
 	switch (event[2]) {
 	case 0:
 		input_report_key(sdata->input, KEY_BACK, 0);
 		input_report_key(sdata->input, KEY_MENU, 0);
 		break;

 	case STMFTS_MASK_KEY_BACK:
 		input_report_key(sdata->input, KEY_BACK, 1);
 		break;

 	case STMFTS_MASK_KEY_MENU:
 		input_report_key(sdata->input, KEY_MENU, 1);
 		break;

 	default:
 		dev_warn(&sdata->client->dev,
 			 "unknown key event: %#02x\n", event[2]);
 		break;
 	}

 	input_sync(sdata->input);
 }

 static void stmfts_parse_events(struct stmfts_data *sdata)
 {
 	int i;

 	for (i = 0; i < STMFTS_STACK_DEPTH; i++) {
 		u8 *event = &sdata->data[i * STMFTS_EVENT_SIZE];

 		switch (event[0]) {

 		case STMFTS_EV_CONTROLLER_READY:
 		case STMFTS_EV_SLEEP_OUT_CONTROLLER_READY:
 		case STMFTS_EV_STATUS:
 			complete(&sdata->cmd_done);
 			fallthrough;

 		case STMFTS_EV_NO_EVENT:
 		case STMFTS_EV_DEBUG:
 			return;
 		}

 		switch (event[0] & STMFTS_MASK_EVENT_ID) {

 		case STMFTS_EV_MULTI_TOUCH_ENTER:
 		case STMFTS_EV_MULTI_TOUCH_MOTION:
 			stmfts_report_contact_event(sdata, event);
 			break;

 		case STMFTS_EV_MULTI_TOUCH_LEAVE:
 			stmfts_report_contact_release(sdata, event);
 			break;

 		case STMFTS_EV_HOVER_ENTER:
 		case STMFTS_EV_HOVER_LEAVE:
 		case STMFTS_EV_HOVER_MOTION:
 			stmfts_report_hover_event(sdata, event);
 			break;

 		case STMFTS_EV_KEY_STATUS:
 			stmfts_report_key_event(sdata, event);
 			break;

 		case STMFTS_EV_ERROR:
 			dev_warn(&sdata->client->dev,
 					"error code: 0x%x%x%x%x%x%x",
 					event[6], event[5], event[4],
 					event[3], event[2], event[1]);
 			break;

 		default:
 			dev_err(&sdata->client->dev,
 				"unknown event %#02x\n", event[0]);
 		}
 	}
 }

 static irqreturn_t stmfts_irq_handler(int irq, void *dev)
 {
 	struct stmfts_data *sdata = dev;
 	int err;

 	mutex_lock(&sdata->mutex);

 	err = stmfts_read_events(sdata);
 	if (unlikely(err))
 		dev_err(&sdata->client->dev,
 			"failed to read events: %d\n", err);
 	else
 		stmfts_parse_events(sdata);

 	mutex_unlock(&sdata->mutex);
 	return IRQ_HANDLED;
 }

 static int stmfts_command(struct stmfts_data *sdata, const u8 cmd)
 {
 	int err;

 	reinit_completion(&sdata->cmd_done);

 	err = i2c_smbus_write_byte(sdata->client, cmd);
 	if (err)
 		return err;

 	if (!wait_for_completion_timeout(&sdata->cmd_done,
 					 msecs_to_jiffies(1000)))
 		return -ETIMEDOUT;

 	return 0;
 }

 static int stmfts_input_open(struct input_dev *dev)
 {
 	struct stmfts_data *sdata = input_get_drvdata(dev);
 	int err;

 	err = pm_runtime_get_sync(&sdata->client->dev);
 	if (err < 0)
 		return err;

 	err = i2c_smbus_write_byte(sdata->client, STMFTS_MS_MT_SENSE_ON);
 	if (err)
 		return err;

 	mutex_lock(&sdata->mutex);
 	sdata->running = true;

 	if (sdata->hover_enabled) {
 		err = i2c_smbus_write_byte(sdata->client,
 					   STMFTS_SS_HOVER_SENSE_ON);
 		if (err)
 			dev_warn(&sdata->client->dev,
 				 "failed to enable hover\n");
 	}
 	mutex_unlock(&sdata->mutex);

 	if (sdata->use_key) {
 		err = i2c_smbus_write_byte(sdata->client,
 					   STMFTS_MS_KEY_SENSE_ON);
 		if (err)
 			/* I can still use only the touch screen */
 			dev_warn(&sdata->client->dev,
 				 "failed to enable touchkey\n");
 	}

 	return 0;
 }

 static void stmfts_input_close(struct input_dev *dev)
 {
 	struct stmfts_data *sdata = input_get_drvdata(dev);
 	int err;

 	err = i2c_smbus_write_byte(sdata->client, STMFTS_MS_MT_SENSE_OFF);
 	if (err)
 		dev_warn(&sdata->client->dev,
 			 "failed to disable touchscreen: %d\n", err);

 	mutex_lock(&sdata->mutex);

 	sdata->running = false;

 	if (sdata->hover_enabled) {
 		err = i2c_smbus_write_byte(sdata->client,
 					   STMFTS_SS_HOVER_SENSE_OFF);
 		if (err)
 			dev_warn(&sdata->client->dev,
 				 "failed to disable hover: %d\n", err);
 	}
 	mutex_unlock(&sdata->mutex);

 	if (sdata->use_key) {
 		err = i2c_smbus_write_byte(sdata->client,
 					   STMFTS_MS_KEY_SENSE_OFF);
 		if (err)
 			dev_warn(&sdata->client->dev,
 				 "failed to disable touchkey: %d\n", err);
 	}

 	pm_runtime_put_sync(&sdata->client->dev);
 }

 static ssize_t stmfts_sysfs_chip_id(struct device *dev,
 				struct device_attribute *attr, char *buf)
 {
 	struct stmfts_data *sdata = dev_get_drvdata(dev);

 	return sprintf(buf, "%#x\n", sdata->chip_id);
 }

 static ssize_t stmfts_sysfs_chip_version(struct device *dev,
 				struct device_attribute *attr, char *buf)
 {
 	struct stmfts_data *sdata = dev_get_drvdata(dev);

 	return sprintf(buf, "%u\n", sdata->chip_ver);
 }

 static ssize_t stmfts_sysfs_fw_ver(struct device *dev,
 				struct device_attribute *attr, char *buf)
 {
 	struct stmfts_data *sdata = dev_get_drvdata(dev);

 	return sprintf(buf, "%u\n", sdata->fw_ver);
 }

 static ssize_t stmfts_sysfs_config_id(struct device *dev,
 				struct device_attribute *attr, char *buf)
 {
 	struct stmfts_data *sdata = dev_get_drvdata(dev);

 	return sprintf(buf, "%#x\n", sdata->config_id);
 }

 static ssize_t stmfts_sysfs_config_version(struct device *dev,
 				struct device_attribute *attr, char *buf)
 {
 	struct stmfts_data *sdata = dev_get_drvdata(dev);

 	return sprintf(buf, "%u\n", sdata->config_ver);
 }

 static ssize_t stmfts_sysfs_read_status(struct device *dev,
 				struct device_attribute *attr, char *buf)
 {
 	struct stmfts_data *sdata = dev_get_drvdata(dev);
 	u8 status[4];
 	int err;

 	err = i2c_smbus_read_i2c_block_data(sdata->client, STMFTS_READ_STATUS,
 					    sizeof(status), status);
 	if (err)
 		return err;

 	return sprintf(buf, "%#02x\n", status[0]);
 }

 static ssize_t stmfts_sysfs_hover_enable_read(struct device *dev,
 				struct device_attribute *attr, char *buf)
 {
 	struct stmfts_data *sdata = dev_get_drvdata(dev);

 	return sprintf(buf, "%u\n", sdata->hover_enabled);
 }

 static ssize_t stmfts_sysfs_hover_enable_write(struct device *dev,
 				struct device_attribute *attr,
 				const char *buf, size_t len)
 {
 	struct stmfts_data *sdata = dev_get_drvdata(dev);
 	unsigned long value;
 	int err = 0;

 	if (kstrtoul(buf, 0, &value))
 		return -EINVAL;

 	mutex_lock(&sdata->mutex);

 	if (value & sdata->hover_enabled)
 		goto out;

 	if (sdata->running)
 		err = i2c_smbus_write_byte(sdata->client,
 					   value ? STMFTS_SS_HOVER_SENSE_ON :
 						   STMFTS_SS_HOVER_SENSE_OFF);

 	if (!err)
 		sdata->hover_enabled = !!value;

 out:
 	mutex_unlock(&sdata->mutex);

 	return len;
 }

 static DEVICE_ATTR(chip_id, 0444, stmfts_sysfs_chip_id, NULL);
 static DEVICE_ATTR(chip_version, 0444, stmfts_sysfs_chip_version, NULL);
 static DEVICE_ATTR(fw_ver, 0444, stmfts_sysfs_fw_ver, NULL);
 static DEVICE_ATTR(config_id, 0444, stmfts_sysfs_config_id, NULL);
 static DEVICE_ATTR(config_version, 0444, stmfts_sysfs_config_version, NULL);
 static DEVICE_ATTR(status, 0444, stmfts_sysfs_read_status, NULL);
 static DEVICE_ATTR(hover_enable, 0644, stmfts_sysfs_hover_enable_read,
 					stmfts_sysfs_hover_enable_write);

 static struct attribute *stmfts_sysfs_attrs[] = {
 	&dev_attr_chip_id.attr,
 	&dev_attr_chip_version.attr,
 	&dev_attr_fw_ver.attr,
 	&dev_attr_config_id.attr,
 	&dev_attr_config_version.attr,
 	&dev_attr_status.attr,
 	&dev_attr_hover_enable.attr,
 	NULL
 };

 static struct attribute_group stmfts_attribute_group = {
 	.attrs = stmfts_sysfs_attrs
 };

 static int stmfts_power_on(struct stmfts_data *sdata)
 {
 	int err;
 	u8 reg[8];

 	err = regulator_bulk_enable(ARRAY_SIZE(sdata->regulators),
 				    sdata->regulators);
 	if (err)
 		return err;

 	/*
 	 * The datasheet does not specify the power on time, but considering
 	 * that the reset time is < 10ms, I sleep 20ms to be sure
 	 */
 	msleep(20);

 	err = i2c_smbus_read_i2c_block_data(sdata->client, STMFTS_READ_INFO,
 					    sizeof(reg), reg);
 	if (err < 0)
 		return err;
 	if (err != sizeof(reg))
 		return -EIO;

 	sdata->chip_id = be16_to_cpup((__be16 *)&reg[6]);
 	sdata->chip_ver = reg[0];
 	sdata->fw_ver = be16_to_cpup((__be16 *)&reg[2]);
 	sdata->config_id = reg[4];
 	sdata->config_ver = reg[5];

 	enable_irq(sdata->client->irq);

 	msleep(50);

 	err = stmfts_command(sdata, STMFTS_SYSTEM_RESET);
 	if (err)
 		return err;

 	err = stmfts_command(sdata, STMFTS_SLEEP_OUT);
 	if (err)
 		return err;

 	/* optional tuning */
 	err = stmfts_command(sdata, STMFTS_MS_CX_TUNING);
 	if (err)
 		dev_warn(&sdata->client->dev,
 			 "failed to perform mutual auto tune: %d\n", err);

 	/* optional tuning */
 	err = stmfts_command(sdata, STMFTS_SS_CX_TUNING);
 	if (err)
 		dev_warn(&sdata->client->dev,
 			 "failed to perform self auto tune: %d\n", err);

 	err = stmfts_command(sdata, STMFTS_FULL_FORCE_CALIBRATION);
 	if (err)
 		return err;

 	/*
 	 * At this point no one is using the touchscreen
 	 * and I don't really care about the return value
 	 */
 	(void) i2c_smbus_write_byte(sdata->client, STMFTS_SLEEP_IN);

 	return 0;
 }

 static void stmfts_power_off(void *data)
 {
 	struct stmfts_data *sdata = data;

 	disable_irq(sdata->client->irq);
 	regulator_bulk_disable(ARRAY_SIZE(sdata->regulators),
 						sdata->regulators);
 }

 /* This function is void because I don't want to prevent using the touch key
  * only because the LEDs don't get registered
  */
 static int stmfts_enable_led(struct stmfts_data *sdata)
 {
 	int err;

 	/* get the regulator for powering the leds on */
 	sdata->ledvdd = devm_regulator_get(&sdata->client->dev, "ledvdd");
 	if (IS_ERR(sdata->ledvdd))
 		return PTR_ERR(sdata->ledvdd);

 	sdata->led_cdev.name = STMFTS_DEV_NAME;
 	sdata->led_cdev.max_brightness = LED_ON;
 	sdata->led_cdev.brightness = LED_OFF;
 	sdata->led_cdev.brightness_set_blocking = stmfts_brightness_set;
 	sdata->led_cdev.brightness_get = stmfts_brightness_get;

 	err = devm_led_classdev_register(&sdata->client->dev, &sdata->led_cdev);
 	if (err) {
 		devm_regulator_put(sdata->ledvdd);
 		return err;
 	}

 	return 0;
 }

 static int stmfts_probe(struct i2c_client *client,
 			const struct i2c_device_id *id)
 {
 	int err;
 	struct stmfts_data *sdata;

 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
 						I2C_FUNC_SMBUS_BYTE_DATA |
 						I2C_FUNC_SMBUS_I2C_BLOCK))
 		return -ENODEV;

 	sdata = devm_kzalloc(&client->dev, sizeof(*sdata), GFP_KERNEL);
 	if (!sdata)
 		return -ENOMEM;

 	i2c_set_clientdata(client, sdata);

 	sdata->client = client;
 	mutex_init(&sdata->mutex);
 	init_completion(&sdata->cmd_done);

 	sdata->regulators[STMFTS_REGULATOR_VDD].supply = "vdd";
 	sdata->regulators[STMFTS_REGULATOR_AVDD].supply = "avdd";
 	err = devm_regulator_bulk_get(&client->dev,
 				      ARRAY_SIZE(sdata->regulators),
 				      sdata->regulators);
 	if (err)
 		return err;

 	sdata->input = devm_input_allocate_device(&client->dev);
 	if (!sdata->input)
 		return -ENOMEM;

 	sdata->input->name = STMFTS_DEV_NAME;
 	sdata->input->id.bustype = BUS_I2C;
 	sdata->input->open = stmfts_input_open;
 	sdata->input->close = stmfts_input_close;

 	input_set_capability(sdata->input, EV_ABS, ABS_MT_POSITION_X);
 	input_set_capability(sdata->input, EV_ABS, ABS_MT_POSITION_Y);
 	touchscreen_parse_properties(sdata->input, true, &sdata->prop);

 	input_set_abs_params(sdata->input, ABS_MT_TOUCH_MAJOR, 0, 255, 0, 0);
 	input_set_abs_params(sdata->input, ABS_MT_TOUCH_MINOR, 0, 255, 0, 0);
 	input_set_abs_params(sdata->input, ABS_MT_ORIENTATION, 0, 255, 0, 0);
 	input_set_abs_params(sdata->input, ABS_MT_PRESSURE, 0, 255, 0, 0);
 	input_set_abs_params(sdata->input, ABS_DISTANCE, 0, 255, 0, 0);

 	sdata->use_key = device_property_read_bool(&client->dev,
 						   "touch-key-connected");
 	if (sdata->use_key) {
 		input_set_capability(sdata->input, EV_KEY, KEY_MENU);
 		input_set_capability(sdata->input, EV_KEY, KEY_BACK);
 	}

 	err = input_mt_init_slots(sdata->input,
 				  STMFTS_MAX_FINGERS, INPUT_MT_DIRECT);
 	if (err)
 		return err;

 	input_set_drvdata(sdata->input, sdata);

 	/*
 	 * stmfts_power_on expects interrupt to be disabled, but
 	 * at this point the device is still off and I do not trust
 	 * the status of the irq line that can generate some spurious
 	 * interrupts. To be on the safe side it's better to not enable
 	 * the interrupts during their request.
 	 */
 	irq_set_status_flags(client->irq, IRQ_NOAUTOEN);
 	err = devm_request_threaded_irq(&client->dev, client->irq,
 					NULL, stmfts_irq_handler,
 					IRQF_ONESHOT,
 					"stmfts_irq", sdata);
 	if (err)
 		return err;

 	dev_dbg(&client->dev, "initializing ST-Microelectronics FTS...\n");

 	err = stmfts_power_on(sdata);
 	if (err)
 		return err;

 	err = devm_add_action_or_reset(&client->dev, stmfts_power_off, sdata);
 	if (err)
 		return err;

 	err = input_register_device(sdata->input);
 	if (err)
 		return err;

 	if (sdata->use_key) {
 		err = stmfts_enable_led(sdata);
 		if (err) {
 			/*
 			 * Even if the LEDs have failed to be initialized and
 			 * used in the driver, I can still use the device even
 			 * without LEDs. The ledvdd regulator pointer will be
 			 * used as a flag.
 			 */
 			dev_warn(&client->dev, "unable to use touchkey leds\n");
 			sdata->ledvdd = NULL;
 		}
 	}

 	err = devm_device_add_group(&client->dev, &stmfts_attribute_group);
 	if (err)
 		return err;

 	pm_runtime_enable(&client->dev);
 	device_enable_async_suspend(&client->dev);

 	return 0;
 }

 static int stmfts_remove(struct i2c_client *client)
 {
 	pm_runtime_disable(&client->dev);

 	return 0;
 }

 static int __maybe_unused stmfts_runtime_suspend(struct device *dev)
 {
 	struct stmfts_data *sdata = dev_get_drvdata(dev);
 	int ret;

 	ret = i2c_smbus_write_byte(sdata->client, STMFTS_SLEEP_IN);
 	if (ret)
 		dev_warn(dev, "failed to suspend device: %d\n", ret);

 	return ret;
 }

 static int __maybe_unused stmfts_runtime_resume(struct device *dev)
 {
 	struct stmfts_data *sdata = dev_get_drvdata(dev);
 	int ret;

 	ret = i2c_smbus_write_byte(sdata->client, STMFTS_SLEEP_OUT);
 	if (ret)
 		dev_err(dev, "failed to resume device: %d\n", ret);

 	return ret;
 }

 static int __maybe_unused stmfts_suspend(struct device *dev)
 {
 	struct stmfts_data *sdata = dev_get_drvdata(dev);

 	stmfts_power_off(sdata);

 	return 0;
 }

 static int __maybe_unused stmfts_resume(struct device *dev)
 {
 	struct stmfts_data *sdata = dev_get_drvdata(dev);

 	return stmfts_power_on(sdata);
 }

 static const struct dev_pm_ops stmfts_pm_ops = {
 	SET_SYSTEM_SLEEP_PM_OPS(stmfts_suspend, stmfts_resume)
 	SET_RUNTIME_PM_OPS(stmfts_runtime_suspend, stmfts_runtime_resume, NULL)
 };

 #ifdef CONFIG_OF
 static const struct of_device_id stmfts_of_match[] = {
 	{ .compatible = "st,stmfts", },
 	{ },
 };
 MODULE_DEVICE_TABLE(of, stmfts_of_match);
 #endif

 static const struct i2c_device_id stmfts_id[] = {
 	{ "stmfts", 0 },
 	{ },
 };
 MODULE_DEVICE_TABLE(i2c, stmfts_id);

 static struct i2c_driver stmfts_driver = {
 	.driver = {
 		.name = STMFTS_DEV_NAME,
 		.of_match_table = of_match_ptr(stmfts_of_match),
 		.pm = &stmfts_pm_ops,
 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
 	},
 	.probe = stmfts_probe,
 	.remove = stmfts_remove,
 	.id_table = stmfts_id,
 };

 module_i2c_driver(stmfts_driver);

 MODULE_AUTHOR("Andi Shyti <andi.shyti@samsung.com>");
 MODULE_DESCRIPTION("STMicroelectronics FTS Touch Screen");
 MODULE_LICENSE("GPL v2");
	// SPDX-License-Identifier: GPL-2.0
	// STMicroelectronics FTS Touchscreen device driver
	//
	// Copyright (c) 2017 Samsung Electronics Co., Ltd.
	// Copyright (c) 2017 Andi Shyti <andi@etezian.org>

	#include <linux/delay.h>
	#include <linux/i2c.h>
	#include <linux/input/mt.h>
	#include <linux/input/touchscreen.h>
	#include <linux/interrupt.h>
	#include <linux/irq.h>
	#include <linux/leds.h>
	#include <linux/module.h>
	#include <linux/pm_runtime.h>
	#include <linux/regulator/consumer.h>

	/* I2C commands */
	#define STMFTS_READ_INFO 0x80
	#define STMFTS_READ_STATUS 0x84
	#define STMFTS_READ_ONE_EVENT 0x85
	#define STMFTS_READ_ALL_EVENT 0x86
	#define STMFTS_LATEST_EVENT 0x87
	#define STMFTS_SLEEP_IN 0x90
	#define STMFTS_SLEEP_OUT 0x91
	#define STMFTS_MS_MT_SENSE_OFF 0x92
	#define STMFTS_MS_MT_SENSE_ON 0x93
	#define STMFTS_SS_HOVER_SENSE_OFF 0x94
	#define STMFTS_SS_HOVER_SENSE_ON 0x95
	#define STMFTS_MS_KEY_SENSE_OFF 0x9a
	#define STMFTS_MS_KEY_SENSE_ON 0x9b
	#define STMFTS_SYSTEM_RESET 0xa0
	#define STMFTS_CLEAR_EVENT_STACK 0xa1
	#define STMFTS_FULL_FORCE_CALIBRATION 0xa2
	#define STMFTS_MS_CX_TUNING 0xa3
	#define STMFTS_SS_CX_TUNING 0xa4

	/* events */
	#define STMFTS_EV_NO_EVENT 0x00
	#define STMFTS_EV_MULTI_TOUCH_DETECTED 0x02
	#define STMFTS_EV_MULTI_TOUCH_ENTER 0x03
	#define STMFTS_EV_MULTI_TOUCH_LEAVE 0x04
	#define STMFTS_EV_MULTI_TOUCH_MOTION 0x05
	#define STMFTS_EV_HOVER_ENTER 0x07
	#define STMFTS_EV_HOVER_LEAVE 0x08
	#define STMFTS_EV_HOVER_MOTION 0x09
	#define STMFTS_EV_KEY_STATUS 0x0e
	#define STMFTS_EV_ERROR 0x0f
	#define STMFTS_EV_CONTROLLER_READY 0x10
	#define STMFTS_EV_SLEEP_OUT_CONTROLLER_READY 0x11
	#define STMFTS_EV_STATUS 0x16
	#define STMFTS_EV_DEBUG 0xdb

	/* multi touch related event masks */
	#define STMFTS_MASK_EVENT_ID 0x0f
	#define STMFTS_MASK_TOUCH_ID 0xf0
	#define STMFTS_MASK_LEFT_EVENT 0x0f
	#define STMFTS_MASK_X_MSB 0x0f
	#define STMFTS_MASK_Y_LSB 0xf0

	/* key related event masks */
	#define STMFTS_MASK_KEY_NO_TOUCH 0x00
	#define STMFTS_MASK_KEY_MENU 0x01
	#define STMFTS_MASK_KEY_BACK 0x02

	#define STMFTS_EVENT_SIZE 8
	#define STMFTS_STACK_DEPTH 32
	#define STMFTS_DATA_MAX_SIZE (STMFTS_EVENT_SIZE * STMFTS_STACK_DEPTH)
	#define STMFTS_MAX_FINGERS 10
	#define STMFTS_DEV_NAME "stmfts"

	enum stmfts_regulators {
	STMFTS_REGULATOR_VDD,
	STMFTS_REGULATOR_AVDD,
	};

	struct stmfts_data {
	struct i2c_client *client;
	struct input_dev *input;
	struct led_classdev led_cdev;
	struct mutex mutex;

	struct touchscreen_properties prop;

	struct regulator_bulk_data regulators[2];

	/*
	* Presence of ledvdd will be used also to check
	* whether the LED is supported.
	*/
	struct regulator *ledvdd;

	u16 chip_id;
	u8 chip_ver;
	u16 fw_ver;
	u8 config_id;
	u8 config_ver;

	u8 data[STMFTS_DATA_MAX_SIZE];

	struct completion cmd_done;

	bool use_key;
	bool led_status;
	bool hover_enabled;
	bool running;
	};

	static int stmfts_brightness_set(struct led_classdev *led_cdev,
	enum led_brightness value)
	{
	struct stmfts_data *sdata = container_of(led_cdev,
	struct stmfts_data, led_cdev);
	int err;

	if (value != sdata->led_status && sdata->ledvdd) {
	if (!value) {
	regulator_disable(sdata->ledvdd);
	} else {
	err = regulator_enable(sdata->ledvdd);
	if (err) {
	dev_warn(&sdata->client->dev,
	"failed to disable ledvdd regulator: %d\n",
	err);
	return err;
	}
	}
	sdata->led_status = value;
	}

	return 0;
	}

	static enum led_brightness stmfts_brightness_get(struct led_classdev *led_cdev)
	{
	struct stmfts_data *sdata = container_of(led_cdev,
	struct stmfts_data, led_cdev);

	return !!regulator_is_enabled(sdata->ledvdd);
	}

	/*
	* We can't simply use i2c_smbus_read_i2c_block_data because we
	* need to read more than 255 bytes (
	*/
	static int stmfts_read_events(struct stmfts_data *sdata)
	{
	u8 cmd = STMFTS_READ_ALL_EVENT;
	struct i2c_msg msgs[2] = {
	{
	.addr = sdata->client->addr,
	.len = 1,
	.buf = &cmd,
	},
	{
	.addr = sdata->client->addr,
	.flags = I2C_M_RD,
	.len = STMFTS_DATA_MAX_SIZE,
	.buf = sdata->data,
	},
	};
	int ret;

	ret = i2c_transfer(sdata->client->adapter, msgs, ARRAY_SIZE(msgs));
	if (ret < 0)
	return ret;

	return ret == ARRAY_SIZE(msgs) ? 0 : -EIO;
	}

	static void stmfts_report_contact_event(struct stmfts_data *sdata,
	const u8 event[])
	{
	u8 slot_id = (event[0] & STMFTS_MASK_TOUCH_ID) >> 4;
	u16 x = event[1] \| ((event[2] & STMFTS_MASK_X_MSB) << 8);
	u16 y = (event[2] >> 4) \| (event[3] << 4);
	u8 maj = event[4];
	u8 min = event[5];
	u8 orientation = event[6];
	u8 area = event[7];

	input_mt_slot(sdata->input, slot_id);

	input_mt_report_slot_state(sdata->input, MT_TOOL_FINGER, true);
	input_report_abs(sdata->input, ABS_MT_POSITION_X, x);
	input_report_abs(sdata->input, ABS_MT_POSITION_Y, y);
	input_report_abs(sdata->input, ABS_MT_TOUCH_MAJOR, maj);
	input_report_abs(sdata->input, ABS_MT_TOUCH_MINOR, min);
	input_report_abs(sdata->input, ABS_MT_PRESSURE, area);
	input_report_abs(sdata->input, ABS_MT_ORIENTATION, orientation);

	input_sync(sdata->input);
	}

	static void stmfts_report_contact_release(struct stmfts_data *sdata,
	const u8 event[])
	{
	u8 slot_id = (event[0] & STMFTS_MASK_TOUCH_ID) >> 4;

	input_mt_slot(sdata->input, slot_id);
	input_mt_report_slot_inactive(sdata->input);

	input_sync(sdata->input);
	}

	static void stmfts_report_hover_event(struct stmfts_data *sdata,
	const u8 event[])
	{
	u16 x = (event[2] << 4) \| (event[4] >> 4);
	u16 y = (event[3] << 4) \| (event[4] & STMFTS_MASK_Y_LSB);
	u8 z = event[5];

	input_report_abs(sdata->input, ABS_X, x);
	input_report_abs(sdata->input, ABS_Y, y);
	input_report_abs(sdata->input, ABS_DISTANCE, z);

	input_sync(sdata->input);
	}

	static void stmfts_report_key_event(struct stmfts_data *sdata, const u8 event[])
	{
	switch (event[2]) {
	case 0:
	input_report_key(sdata->input, KEY_BACK, 0);
	input_report_key(sdata->input, KEY_MENU, 0);
	break;

	case STMFTS_MASK_KEY_BACK:
	input_report_key(sdata->input, KEY_BACK, 1);
	break;

	case STMFTS_MASK_KEY_MENU:
	input_report_key(sdata->input, KEY_MENU, 1);
	break;

	default:
	dev_warn(&sdata->client->dev,
	"unknown key event: %#02x\n", event[2]);
	break;
	}

	input_sync(sdata->input);
	}

	static void stmfts_parse_events(struct stmfts_data *sdata)
	{
	int i;

	for (i = 0; i < STMFTS_STACK_DEPTH; i++) {
	u8 event = &sdata->data[i STMFTS_EVENT_SIZE];

	switch (event[0]) {

	case STMFTS_EV_CONTROLLER_READY:
	case STMFTS_EV_SLEEP_OUT_CONTROLLER_READY:
	case STMFTS_EV_STATUS:
	complete(&sdata->cmd_done);
	fallthrough;

	case STMFTS_EV_NO_EVENT:
	case STMFTS_EV_DEBUG:
	return;
	}

	switch (event[0] & STMFTS_MASK_EVENT_ID) {

	case STMFTS_EV_MULTI_TOUCH_ENTER:
	case STMFTS_EV_MULTI_TOUCH_MOTION:
	stmfts_report_contact_event(sdata, event);
	break;

	case STMFTS_EV_MULTI_TOUCH_LEAVE:
	stmfts_report_contact_release(sdata, event);
	break;

	case STMFTS_EV_HOVER_ENTER:
	case STMFTS_EV_HOVER_LEAVE:
	case STMFTS_EV_HOVER_MOTION:
	stmfts_report_hover_event(sdata, event);
	break;

	case STMFTS_EV_KEY_STATUS:
	stmfts_report_key_event(sdata, event);
	break;

	case STMFTS_EV_ERROR:
	dev_warn(&sdata->client->dev,
	"error code: 0x%x%x%x%x%x%x",
	event[6], event[5], event[4],
	event[3], event[2], event[1]);
	break;

	default:
	dev_err(&sdata->client->dev,
	"unknown event %#02x\n", event[0]);
	}
	}
	}

	static irqreturn_t stmfts_irq_handler(int irq, void *dev)
	{
	struct stmfts_data *sdata = dev;
	int err;

	mutex_lock(&sdata->mutex);

	err = stmfts_read_events(sdata);
	if (unlikely(err))
	dev_err(&sdata->client->dev,
	"failed to read events: %d\n", err);
	else
	stmfts_parse_events(sdata);

	mutex_unlock(&sdata->mutex);
	return IRQ_HANDLED;
	}

	static int stmfts_command(struct stmfts_data *sdata, const u8 cmd)
	{
	int err;

	reinit_completion(&sdata->cmd_done);

	err = i2c_smbus_write_byte(sdata->client, cmd);
	if (err)
	return err;

	if (!wait_for_completion_timeout(&sdata->cmd_done,
	msecs_to_jiffies(1000)))
	return -ETIMEDOUT;

	return 0;
	}

	static int stmfts_input_open(struct input_dev *dev)
	{
	struct stmfts_data *sdata = input_get_drvdata(dev);
	int err;

	err = pm_runtime_get_sync(&sdata->client->dev);
	if (err < 0)
	return err;

	err = i2c_smbus_write_byte(sdata->client, STMFTS_MS_MT_SENSE_ON);
	if (err)
	return err;

	mutex_lock(&sdata->mutex);
	sdata->running = true;

	if (sdata->hover_enabled) {
	err = i2c_smbus_write_byte(sdata->client,
	STMFTS_SS_HOVER_SENSE_ON);
	if (err)
	dev_warn(&sdata->client->dev,
	"failed to enable hover\n");
	}
	mutex_unlock(&sdata->mutex);

	if (sdata->use_key) {
	err = i2c_smbus_write_byte(sdata->client,
	STMFTS_MS_KEY_SENSE_ON);
	if (err)
	/* I can still use only the touch screen */
	dev_warn(&sdata->client->dev,
	"failed to enable touchkey\n");
	}

	return 0;
	}

	static void stmfts_input_close(struct input_dev *dev)
	{
	struct stmfts_data *sdata = input_get_drvdata(dev);
	int err;

	err = i2c_smbus_write_byte(sdata->client, STMFTS_MS_MT_SENSE_OFF);
	if (err)
	dev_warn(&sdata->client->dev,
	"failed to disable touchscreen: %d\n", err);

	mutex_lock(&sdata->mutex);

	sdata->running = false;

	if (sdata->hover_enabled) {
	err = i2c_smbus_write_byte(sdata->client,
	STMFTS_SS_HOVER_SENSE_OFF);
	if (err)
	dev_warn(&sdata->client->dev,
	"failed to disable hover: %d\n", err);
	}
	mutex_unlock(&sdata->mutex);

	if (sdata->use_key) {
	err = i2c_smbus_write_byte(sdata->client,
	STMFTS_MS_KEY_SENSE_OFF);
	if (err)
	dev_warn(&sdata->client->dev,
	"failed to disable touchkey: %d\n", err);
	}

	pm_runtime_put_sync(&sdata->client->dev);
	}

	static ssize_t stmfts_sysfs_chip_id(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct stmfts_data *sdata = dev_get_drvdata(dev);

	return sprintf(buf, "%#x\n", sdata->chip_id);
	}

	static ssize_t stmfts_sysfs_chip_version(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct stmfts_data *sdata = dev_get_drvdata(dev);

	return sprintf(buf, "%u\n", sdata->chip_ver);
	}

	static ssize_t stmfts_sysfs_fw_ver(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct stmfts_data *sdata = dev_get_drvdata(dev);

	return sprintf(buf, "%u\n", sdata->fw_ver);
	}

	static ssize_t stmfts_sysfs_config_id(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct stmfts_data *sdata = dev_get_drvdata(dev);

	return sprintf(buf, "%#x\n", sdata->config_id);
	}

	static ssize_t stmfts_sysfs_config_version(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct stmfts_data *sdata = dev_get_drvdata(dev);

	return sprintf(buf, "%u\n", sdata->config_ver);
	}

	static ssize_t stmfts_sysfs_read_status(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct stmfts_data *sdata = dev_get_drvdata(dev);
	u8 status[4];
	int err;

	err = i2c_smbus_read_i2c_block_data(sdata->client, STMFTS_READ_STATUS,
	sizeof(status), status);
	if (err)
	return err;

	return sprintf(buf, "%#02x\n", status[0]);
	}

	static ssize_t stmfts_sysfs_hover_enable_read(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct stmfts_data *sdata = dev_get_drvdata(dev);

	return sprintf(buf, "%u\n", sdata->hover_enabled);
	}

	static ssize_t stmfts_sysfs_hover_enable_write(struct device *dev,
	struct device_attribute *attr,
	const char *buf, size_t len)
	{
	struct stmfts_data *sdata = dev_get_drvdata(dev);
	unsigned long value;
	int err = 0;

	if (kstrtoul(buf, 0, &value))
	return -EINVAL;

	mutex_lock(&sdata->mutex);

	if (value & sdata->hover_enabled)
	goto out;

	if (sdata->running)
	err = i2c_smbus_write_byte(sdata->client,
	value ? STMFTS_SS_HOVER_SENSE_ON :
	STMFTS_SS_HOVER_SENSE_OFF);

	if (!err)
	sdata->hover_enabled = !!value;

	out:
	mutex_unlock(&sdata->mutex);

	return len;
	}

	static DEVICE_ATTR(chip_id, 0444, stmfts_sysfs_chip_id, NULL);
	static DEVICE_ATTR(chip_version, 0444, stmfts_sysfs_chip_version, NULL);
	static DEVICE_ATTR(fw_ver, 0444, stmfts_sysfs_fw_ver, NULL);
	static DEVICE_ATTR(config_id, 0444, stmfts_sysfs_config_id, NULL);
	static DEVICE_ATTR(config_version, 0444, stmfts_sysfs_config_version, NULL);
	static DEVICE_ATTR(status, 0444, stmfts_sysfs_read_status, NULL);
	static DEVICE_ATTR(hover_enable, 0644, stmfts_sysfs_hover_enable_read,
	stmfts_sysfs_hover_enable_write);

	static struct attribute *stmfts_sysfs_attrs[] = {
	&dev_attr_chip_id.attr,
	&dev_attr_chip_version.attr,
	&dev_attr_fw_ver.attr,
	&dev_attr_config_id.attr,
	&dev_attr_config_version.attr,
	&dev_attr_status.attr,
	&dev_attr_hover_enable.attr,
	NULL
	};

	static struct attribute_group stmfts_attribute_group = {
	.attrs = stmfts_sysfs_attrs
	};

	static int stmfts_power_on(struct stmfts_data *sdata)
	{
	int err;
	u8 reg[8];

	err = regulator_bulk_enable(ARRAY_SIZE(sdata->regulators),
	sdata->regulators);
	if (err)
	return err;

	/*
	* The datasheet does not specify the power on time, but considering
	* that the reset time is < 10ms, I sleep 20ms to be sure
	*/
	msleep(20);

	err = i2c_smbus_read_i2c_block_data(sdata->client, STMFTS_READ_INFO,
	sizeof(reg), reg);
	if (err < 0)
	return err;
	if (err != sizeof(reg))
	return -EIO;

	sdata->chip_id = be16_to_cpup((__be16 *)&reg[6]);
	sdata->chip_ver = reg[0];
	sdata->fw_ver = be16_to_cpup((__be16 *)&reg[2]);
	sdata->config_id = reg[4];
	sdata->config_ver = reg[5];

	enable_irq(sdata->client->irq);

	msleep(50);

	err = stmfts_command(sdata, STMFTS_SYSTEM_RESET);
	if (err)
	return err;

	err = stmfts_command(sdata, STMFTS_SLEEP_OUT);
	if (err)
	return err;

	/* optional tuning */
	err = stmfts_command(sdata, STMFTS_MS_CX_TUNING);
	if (err)
	dev_warn(&sdata->client->dev,
	"failed to perform mutual auto tune: %d\n", err);

	/* optional tuning */
	err = stmfts_command(sdata, STMFTS_SS_CX_TUNING);
	if (err)
	dev_warn(&sdata->client->dev,
	"failed to perform self auto tune: %d\n", err);

	err = stmfts_command(sdata, STMFTS_FULL_FORCE_CALIBRATION);
	if (err)
	return err;

	/*
	* At this point no one is using the touchscreen
	* and I don't really care about the return value
	*/
	(void) i2c_smbus_write_byte(sdata->client, STMFTS_SLEEP_IN);

	return 0;
	}

	static void stmfts_power_off(void *data)
	{
	struct stmfts_data *sdata = data;

	disable_irq(sdata->client->irq);
	regulator_bulk_disable(ARRAY_SIZE(sdata->regulators),
	sdata->regulators);
	}

	/* This function is void because I don't want to prevent using the touch key
	* only because the LEDs don't get registered
	*/
	static int stmfts_enable_led(struct stmfts_data *sdata)
	{
	int err;

	/* get the regulator for powering the leds on */
	sdata->ledvdd = devm_regulator_get(&sdata->client->dev, "ledvdd");
	if (IS_ERR(sdata->ledvdd))
	return PTR_ERR(sdata->ledvdd);

	sdata->led_cdev.name = STMFTS_DEV_NAME;
	sdata->led_cdev.max_brightness = LED_ON;
	sdata->led_cdev.brightness = LED_OFF;
	sdata->led_cdev.brightness_set_blocking = stmfts_brightness_set;
	sdata->led_cdev.brightness_get = stmfts_brightness_get;

	err = devm_led_classdev_register(&sdata->client->dev, &sdata->led_cdev);
	if (err) {
	devm_regulator_put(sdata->ledvdd);
	return err;
	}

	return 0;
	}

	static int stmfts_probe(struct i2c_client *client,
	const struct i2c_device_id *id)
	{
	int err;
	struct stmfts_data *sdata;

	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C \|
	I2C_FUNC_SMBUS_BYTE_DATA \|
	I2C_FUNC_SMBUS_I2C_BLOCK))
	return -ENODEV;

	sdata = devm_kzalloc(&client->dev, sizeof(*sdata), GFP_KERNEL);
	if (!sdata)
	return -ENOMEM;

	i2c_set_clientdata(client, sdata);

	sdata->client = client;
	mutex_init(&sdata->mutex);
	init_completion(&sdata->cmd_done);

	sdata->regulators[STMFTS_REGULATOR_VDD].supply = "vdd";
	sdata->regulators[STMFTS_REGULATOR_AVDD].supply = "avdd";
	err = devm_regulator_bulk_get(&client->dev,
	ARRAY_SIZE(sdata->regulators),
	sdata->regulators);
	if (err)
	return err;

	sdata->input = devm_input_allocate_device(&client->dev);
	if (!sdata->input)
	return -ENOMEM;

	sdata->input->name = STMFTS_DEV_NAME;
	sdata->input->id.bustype = BUS_I2C;
	sdata->input->open = stmfts_input_open;
	sdata->input->close = stmfts_input_close;

	input_set_capability(sdata->input, EV_ABS, ABS_MT_POSITION_X);
	input_set_capability(sdata->input, EV_ABS, ABS_MT_POSITION_Y);
	touchscreen_parse_properties(sdata->input, true, &sdata->prop);

	input_set_abs_params(sdata->input, ABS_MT_TOUCH_MAJOR, 0, 255, 0, 0);
	input_set_abs_params(sdata->input, ABS_MT_TOUCH_MINOR, 0, 255, 0, 0);
	input_set_abs_params(sdata->input, ABS_MT_ORIENTATION, 0, 255, 0, 0);
	input_set_abs_params(sdata->input, ABS_MT_PRESSURE, 0, 255, 0, 0);
	input_set_abs_params(sdata->input, ABS_DISTANCE, 0, 255, 0, 0);

	sdata->use_key = device_property_read_bool(&client->dev,
	"touch-key-connected");
	if (sdata->use_key) {
	input_set_capability(sdata->input, EV_KEY, KEY_MENU);
	input_set_capability(sdata->input, EV_KEY, KEY_BACK);
	}

	err = input_mt_init_slots(sdata->input,
	STMFTS_MAX_FINGERS, INPUT_MT_DIRECT);
	if (err)
	return err;

	input_set_drvdata(sdata->input, sdata);

	/*
	* stmfts_power_on expects interrupt to be disabled, but
	* at this point the device is still off and I do not trust
	* the status of the irq line that can generate some spurious
	* interrupts. To be on the safe side it's better to not enable
	* the interrupts during their request.
	*/
	irq_set_status_flags(client->irq, IRQ_NOAUTOEN);
	err = devm_request_threaded_irq(&client->dev, client->irq,
	NULL, stmfts_irq_handler,
	IRQF_ONESHOT,
	"stmfts_irq", sdata);
	if (err)
	return err;

	dev_dbg(&client->dev, "initializing ST-Microelectronics FTS...\n");

	err = stmfts_power_on(sdata);
	if (err)
	return err;

	err = devm_add_action_or_reset(&client->dev, stmfts_power_off, sdata);
	if (err)
	return err;

	err = input_register_device(sdata->input);
	if (err)
	return err;

	if (sdata->use_key) {
	err = stmfts_enable_led(sdata);
	if (err) {
	/*
	* Even if the LEDs have failed to be initialized and
	* used in the driver, I can still use the device even
	* without LEDs. The ledvdd regulator pointer will be
	* used as a flag.
	*/
	dev_warn(&client->dev, "unable to use touchkey leds\n");
	sdata->ledvdd = NULL;
	}
	}

	err = devm_device_add_group(&client->dev, &stmfts_attribute_group);
	if (err)
	return err;

	pm_runtime_enable(&client->dev);
	device_enable_async_suspend(&client->dev);

	return 0;
	}

	static int stmfts_remove(struct i2c_client *client)
	{
	pm_runtime_disable(&client->dev);

	return 0;
	}

	static int __maybe_unused stmfts_runtime_suspend(struct device *dev)
	{
	struct stmfts_data *sdata = dev_get_drvdata(dev);
	int ret;

	ret = i2c_smbus_write_byte(sdata->client, STMFTS_SLEEP_IN);
	if (ret)
	dev_warn(dev, "failed to suspend device: %d\n", ret);

	return ret;
	}

	static int __maybe_unused stmfts_runtime_resume(struct device *dev)
	{
	struct stmfts_data *sdata = dev_get_drvdata(dev);
	int ret;

	ret = i2c_smbus_write_byte(sdata->client, STMFTS_SLEEP_OUT);
	if (ret)
	dev_err(dev, "failed to resume device: %d\n", ret);

	return ret;
	}

	static int __maybe_unused stmfts_suspend(struct device *dev)
	{
	struct stmfts_data *sdata = dev_get_drvdata(dev);

	stmfts_power_off(sdata);

	return 0;
	}

	static int __maybe_unused stmfts_resume(struct device *dev)
	{
	struct stmfts_data *sdata = dev_get_drvdata(dev);

	return stmfts_power_on(sdata);
	}

	static const struct dev_pm_ops stmfts_pm_ops = {
	SET_SYSTEM_SLEEP_PM_OPS(stmfts_suspend, stmfts_resume)
	SET_RUNTIME_PM_OPS(stmfts_runtime_suspend, stmfts_runtime_resume, NULL)
	};

	#ifdef CONFIG_OF
	static const struct of_device_id stmfts_of_match[] = {
	{ .compatible = "st,stmfts", },
	{ },
	};
	MODULE_DEVICE_TABLE(of, stmfts_of_match);
	#endif

	static const struct i2c_device_id stmfts_id[] = {
	{ "stmfts", 0 },
	{ },
	};
	MODULE_DEVICE_TABLE(i2c, stmfts_id);

	static struct i2c_driver stmfts_driver = {
	.driver = {
	.name = STMFTS_DEV_NAME,
	.of_match_table = of_match_ptr(stmfts_of_match),
	.pm = &stmfts_pm_ops,
	.probe_type = PROBE_PREFER_ASYNCHRONOUS,
	},
	.probe = stmfts_probe,
	.remove = stmfts_remove,
	.id_table = stmfts_id,
	};

	module_i2c_driver(stmfts_driver);

	MODULE_AUTHOR("Andi Shyti <andi.shyti@samsung.com>");
	MODULE_DESCRIPTION("STMicroelectronics FTS Touch Screen");
	MODULE_LICENSE("GPL v2");