[v3,2/2] Input: add support for the STMicroelectronics FingerTip touchscreen
diff mbox

Message ID 20170327130743.27783-3-andi.shyti@samsung.com
State Under Review
Headers show

Commit Message

Andi Shyti March 27, 2017, 1:07 p.m. UTC
The stmfts (ST-Microelectronics FingerTip S) touchscreen device
is a capacitive multi-touch controller mainly for mobile use.

It's connected through i2c bus at the address 0x49 and it
interfaces with userspace through input event interface.

At the current state it provides a touchscreen multitouch
functionality up to 10 fingers. Each finger is enumerated with a
distinctive id (from 0 to 9).

If enabled the device can support single "touch" hovering, by
providing three coordinates, x, y and distance.

It is possible to select the touchkey functionality which
provides a basic two keys interface for "home" and "back" menu,
typical in mobile phones.

Signed-off-by: Andi Shyti <andi.shyti@samsung.com>
---
 drivers/input/touchscreen/Kconfig  |  12 +
 drivers/input/touchscreen/Makefile |   1 +
 drivers/input/touchscreen/stmfts.c | 805 +++++++++++++++++++++++++++++++++++++
 3 files changed, 818 insertions(+)
 create mode 100644 drivers/input/touchscreen/stmfts.c

Comments

Andi Shyti April 7, 2017, 9:31 a.m. UTC | #1
Hi Dmitry,

just a kind ping, do you have any comment about this?

Thanks,
Andi

On Mon, Mar 27, 2017 at 10:07:43PM +0900, Andi Shyti wrote:
> The stmfts (ST-Microelectronics FingerTip S) touchscreen device
> is a capacitive multi-touch controller mainly for mobile use.
> 
> It's connected through i2c bus at the address 0x49 and it
> interfaces with userspace through input event interface.
> 
> At the current state it provides a touchscreen multitouch
> functionality up to 10 fingers. Each finger is enumerated with a
> distinctive id (from 0 to 9).
> 
> If enabled the device can support single "touch" hovering, by
> providing three coordinates, x, y and distance.
> 
> It is possible to select the touchkey functionality which
> provides a basic two keys interface for "home" and "back" menu,
> typical in mobile phones.
> 
> Signed-off-by: Andi Shyti <andi.shyti@samsung.com>
> ---
>  drivers/input/touchscreen/Kconfig  |  12 +
>  drivers/input/touchscreen/Makefile |   1 +
>  drivers/input/touchscreen/stmfts.c | 805 +++++++++++++++++++++++++++++++++++++
>  3 files changed, 818 insertions(+)
>  create mode 100644 drivers/input/touchscreen/stmfts.c
> 
> diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
> index 33c62e5de4fa..f8631c64290d 100644
> --- a/drivers/input/touchscreen/Kconfig
> +++ b/drivers/input/touchscreen/Kconfig
> @@ -1114,6 +1114,18 @@ config TOUCHSCREEN_ST1232
>  	  To compile this driver as a module, choose M here: the
>  	  module will be called st1232_ts.
>  
> +config TOUCHSCREEN_STMFTS
> +	tristate "STMicroelectronics STMFTS touchscreen"
> +	depends on I2C
> +	depends on INPUT
> +	depends on LEDS_CLASS
> +	help
> +	  Say Y here if you want support for STMicroelectronics
> +	  STMFTS touchscreen.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called stmfts.
> +
>  config TOUCHSCREEN_STMPE
>  	tristate "STMicroelectronics STMPE touchscreens"
>  	depends on MFD_STMPE
> diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
> index 18e476948e44..6badce87037b 100644
> --- a/drivers/input/touchscreen/Makefile
> +++ b/drivers/input/touchscreen/Makefile
> @@ -67,6 +67,7 @@ obj-$(CONFIG_TOUCHSCREEN_S3C2410)	+= s3c2410_ts.o
>  obj-$(CONFIG_TOUCHSCREEN_SILEAD)	+= silead.o
>  obj-$(CONFIG_TOUCHSCREEN_SIS_I2C)	+= sis_i2c.o
>  obj-$(CONFIG_TOUCHSCREEN_ST1232)	+= st1232.o
> +obj-$(CONFIG_TOUCHSCREEN_STMFTS)	+= stmfts.o
>  obj-$(CONFIG_TOUCHSCREEN_STMPE)		+= stmpe-ts.o
>  obj-$(CONFIG_TOUCHSCREEN_SUN4I)		+= sun4i-ts.o
>  obj-$(CONFIG_TOUCHSCREEN_SUR40)		+= sur40.o
> diff --git a/drivers/input/touchscreen/stmfts.c b/drivers/input/touchscreen/stmfts.c
> new file mode 100644
> index 000000000000..2e18b1456f42
> --- /dev/null
> +++ b/drivers/input/touchscreen/stmfts.c
> @@ -0,0 +1,805 @@
> +/*
> + * Copyright (c) 2017 Samsung Electronics Co., Ltd.
> + * Author: Andi Shyti <andi.shyti@samsung.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + * STMicroelectronics FTS Touchscreen device driver
> + */
> +
> +#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];
> +
> +	/* 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 signal;
> +
> +	bool use_key;
> +	bool led_status;
> +	bool hover_enabled;
> +	bool running;
> +};
> +
> +static int stmfts_read_i2c_block_data(struct stmfts_data *sdata)
> +{
> +	struct i2c_msg msgs[2];
> +	u8 cmd = STMFTS_READ_ALL_EVENT;
> +
> +	msgs[0].addr = sdata->client->addr;
> +	msgs[0].flags = 0;
> +	msgs[0].len = 1;
> +	msgs[0].buf = &cmd;
> +
> +	msgs[1].addr = sdata->client->addr;
> +	msgs[1].flags = I2C_M_RD;
> +	msgs[1].len = STMFTS_DATA_MAX_SIZE - STMFTS_EVENT_SIZE;
> +	msgs[1].buf = sdata->data + STMFTS_EVENT_SIZE;
> +
> +	return i2c_transfer(sdata->client->adapter, msgs, ARRAY_SIZE(msgs));
> +}
> +
> +static void 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);
> +
> +	if (value == sdata->led_status || !sdata->ledvdd)
> +		return;
> +
> +	if (!value) {
> +		regulator_disable(sdata->ledvdd);
> +	} else {
> +		int err = regulator_enable(sdata->ledvdd);
> +
> +		if (err)
> +			dev_warn(&sdata->client->dev,
> +				"failed to disable ledvdd regulator\n");
> +	}
> +
> +	sdata->led_status = value;
> +}
> +
> +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);
> +}
> +
> +static void stmfts_parse_event(struct stmfts_data *sdata)
> +{
> +	u8 id, t_id;
> +	u16 x, y, z, maj, min, orientation, area;
> +	u8 *event;
> +	int i;
> +
> +	for (i = 0; i < STMFTS_STACK_DEPTH; i++) {
> +		event = &sdata->data[i*STMFTS_EVENT_SIZE];
> +
> +		id = event[0] & STMFTS_MASK_EVENT_ID;
> +		t_id = (event[0] & STMFTS_MASK_TOUCH_ID) >> 4;
> +
> +		switch (id) {
> +		case STMFTS_EV_NO_EVENT:
> +			return;
> +
> +		case STMFTS_EV_MULTI_TOUCH_ENTER:
> +		case STMFTS_EV_MULTI_TOUCH_LEAVE:
> +		case STMFTS_EV_MULTI_TOUCH_MOTION:
> +			if (id == STMFTS_EV_MULTI_TOUCH_ENTER)
> +				input_mt_report_slot_state(sdata->input,
> +							MT_TOOL_FINGER, true);
> +			else if (id == STMFTS_EV_MULTI_TOUCH_LEAVE)
> +				input_mt_report_slot_state(sdata->input,
> +							MT_TOOL_FINGER, false);
> +
> +			x = event[1] | ((event[2] & STMFTS_MASK_X_MSB) << 8);
> +			y = (event[2] >> 4) | (event[3] << 4);
> +
> +			maj = event[4];
> +			min = event[5];
> +			orientation = event[6];
> +			area = event[7];
> +
> +			input_mt_slot(sdata->input, t_id);
> +			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);
> +
> +			break;
> +
> +		case STMFTS_EV_HOVER_ENTER:
> +		case STMFTS_EV_HOVER_LEAVE:
> +		case STMFTS_EV_HOVER_MOTION:
> +			x = (event[2] << 4) | (event[4] >> 4);
> +			y = (event[3] << 4) | (event[4] & STMFTS_MASK_Y_LSB);
> +			z = event[5];
> +			orientation = event[6] & STMFTS_MASK_Y_LSB;
> +
> +			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);
> +
> +			break;
> +
> +		case STMFTS_EV_KEY_STATUS:
> +			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\n");
> +			}
> +
> +			input_sync(sdata->input);
> +			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 0x%x\n", event[0]);
> +		}
> +	}
> +}
> +
> +static irqreturn_t stmfts_irq_handler(int irq, void *dev)
> +{
> +	struct stmfts_data *sdata = dev;
> +	int ret;
> +
> +	mutex_lock(&sdata->mutex);
> +	ret = i2c_smbus_read_i2c_block_data(sdata->client,
> +						STMFTS_READ_ONE_EVENT,
> +						STMFTS_EVENT_SIZE, sdata->data);
> +
> +	if (ret < 0 || ret != STMFTS_EVENT_SIZE)
> +		goto exit;
> +
> +	switch (sdata->data[0]) {
> +	case STMFTS_EV_CONTROLLER_READY:
> +	case STMFTS_EV_SLEEP_OUT_CONTROLLER_READY:
> +	case STMFTS_EV_STATUS:
> +		complete(&sdata->signal);
> +	case STMFTS_EV_NO_EVENT:
> +	case STMFTS_EV_DEBUG:
> +		break;
> +
> +	default:
> +		if (unlikely(!sdata->input))
> +			goto exit;
> +
> +		ret = stmfts_read_i2c_block_data(sdata);
> +		if (ret < 0)
> +			goto exit;
> +
> +		stmfts_parse_event(sdata);
> +	}
> +
> +exit:
> +	mutex_unlock(&sdata->mutex);
> +	return IRQ_HANDLED;
> +}
> +
> +static int stmfts_write_and_wait(struct stmfts_data *sdata, const u8 cmd)
> +{
> +	int err;
> +
> +	err = i2c_smbus_write_byte(sdata->client, cmd);
> +	if (err)
> +		return err;
> +
> +	err = wait_for_completion_timeout(&sdata->signal,
> +					msecs_to_jiffies(1000));
> +
> +	return !err ? -ETIMEDOUT : 0;
> +}
> +
> +static int stmfts_input_open(struct input_dev *dev)
> +{
> +	int ret;
> +	struct stmfts_data *sdata = input_get_drvdata(dev);
> +
> +	ret = pm_runtime_get_sync(&sdata->client->dev);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = i2c_smbus_write_byte(sdata->client, STMFTS_MS_MT_SENSE_ON);
> +	if (ret)
> +		return ret;
> +
> +	mutex_lock(&sdata->mutex);
> +	sdata->running = true;
> +
> +	if (sdata->hover_enabled) {
> +		ret = i2c_smbus_write_byte(sdata->client,
> +						STMFTS_SS_HOVER_SENSE_ON);
> +		if (ret)
> +			dev_warn(&sdata->client->dev,
> +						"failed to enable hover\n");
> +	}
> +	mutex_unlock(&sdata->mutex);
> +
> +	if (sdata->use_key) {
> +		ret = i2c_smbus_write_byte(sdata->client,
> +						STMFTS_MS_KEY_SENSE_ON);
> +		if (ret)
> +			/* 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)
> +{
> +	int ret;
> +	struct stmfts_data *sdata = input_get_drvdata(dev);
> +
> +	ret = i2c_smbus_write_byte(sdata->client, STMFTS_MS_MT_SENSE_OFF);
> +	if (ret)
> +		dev_warn(&sdata->client->dev,
> +					"failed to disable touchscreen\n");
> +
> +	mutex_lock(&sdata->mutex);
> +	sdata->running = false;
> +
> +	if (sdata->hover_enabled) {
> +		ret = i2c_smbus_write_byte(sdata->client,
> +					STMFTS_SS_HOVER_SENSE_OFF);
> +		if (ret)
> +			dev_warn(&sdata->client->dev,
> +						"failed to disable hover\n");
> +	}
> +	mutex_unlock(&sdata->mutex);
> +
> +	if (sdata->use_key) {
> +		i2c_smbus_write_byte(sdata->client, STMFTS_MS_KEY_SENSE_OFF);
> +		if (ret)
> +			dev_warn(&sdata->client->dev,
> +					"failed to disable touchkey\n");
> +	}
> +
> +	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, "0x%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, "0x%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 ret;
> +
> +	ret = i2c_smbus_read_i2c_block_data(sdata->client,
> +					STMFTS_READ_STATUS, 4, status);
> +
> +	return sprintf(buf, "0x%x\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)
> +{
> +	unsigned long value;
> +	int err;
> +	struct stmfts_data *sdata = dev_get_drvdata(dev);
> +
> +	if (kstrtoul(buf, 0, &value))
> +		return -EINVAL;
> +
> +	mutex_lock(&sdata->mutex);
> +
> +	if (value & sdata->hover_enabled)
> +		goto out;
> +
> +	if (!sdata->running) {
> +		sdata->hover_enabled = !!value;
> +		goto out;
> +	}
> +
> +	if (value) {
> +		err = i2c_smbus_write_byte(sdata->client,
> +						STMFTS_SS_HOVER_SENSE_ON);
> +		sdata->hover_enabled = !err;
> +	} else {
> +		err = i2c_smbus_write_byte(sdata->client,
> +					STMFTS_SS_HOVER_SENSE_OFF);
> +		sdata->hover_enabled = !!err;
> +	}
> +
> +	if (err)
> +		dev_warn(&sdata->client->dev, "failed to %s hover\n",
> +						value ? "enable" : "disable");
> +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, 8, reg);
> +	if (err < 0)
> +		return err;
> +	if (err != 8)
> +		return -EIO;
> +
> +	sdata->chip_id = (reg[6] << 8) | reg[7];
> +	sdata->chip_ver = reg[0];
> +	sdata->fw_ver = (reg[2] << 8) | reg[3];
> +	sdata->config_id = reg[4];
> +	sdata->config_ver = reg[5];
> +
> +	reinit_completion(&sdata->signal);
> +
> +	enable_irq(sdata->client->irq);
> +	err = stmfts_write_and_wait(sdata, STMFTS_SYSTEM_RESET);
> +	if (err)
> +		return err;
> +
> +	err = stmfts_write_and_wait(sdata, STMFTS_SLEEP_OUT);
> +	if (err)
> +		return err;
> +
> +	/* optional tuning */
> +	err = stmfts_write_and_wait(sdata, STMFTS_MS_CX_TUNING);
> +	if (err)
> +		dev_warn(&sdata->client->dev, "failed to perform mutual auto tune\n");
> +
> +	/* optional tuning */
> +	err = stmfts_write_and_wait(sdata, STMFTS_SS_CX_TUNING);
> +	if (err)
> +		dev_warn(&sdata->client->dev, "failed to perform self auto tune\n");
> +
> +	err = stmfts_write_and_wait(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
> +	 */
> +	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 = 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;
> +
> +	if (!client->dev.of_node)
> +		return -ENOENT;
> +
> +	sdata = devm_kzalloc(&client->dev, sizeof(*sdata), GFP_KERNEL);
> +	if (!sdata)
> +		return -ENOMEM;
> +
> +	i2c_set_clientdata(client, sdata);
> +
> +	mutex_init(&sdata->mutex);
> +
> +	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;
> +
> +	err = devm_add_action_or_reset(&client->dev, stmfts_power_off, sdata);
> +	if (err)
> +		return err;
> +
> +	sdata->client = client;
> +
> +	init_completion(&sdata->signal);
> +
> +	/*
> +	 * Do not enable interrupts by default.
> +	 * One possible case when an IRQ can be already rased is e.g. if the
> +	 * regulator is set as always on and the stmfts device sends an IRQ as
> +	 * soon as it gets powered, de-synchronizing the power on sequence.
> +	 * During power on, the device will be reset and all the initialization
> +	 * IRQ will be resent.
> +	 */
> +	irq_set_status_flags(client->irq, IRQ_NOAUTOEN);
> +	err = devm_request_threaded_irq(&client->dev, client->irq,
> +					NULL, stmfts_irq_handler,
> +					IRQF_ONESHOT | IRQF_TRIGGER_LOW,
> +					"stmfts_irq", sdata);
> +	if (err)
> +		return err;
> +
> +	dev_info(&client->dev, "initializing ST-Microelectronics FTS...\n");
> +	err = stmfts_power_on(sdata);
> +	if (err)
> +		return err;
> +
> +	sdata->use_key = of_property_read_bool(client->dev.of_node,
> +						"touch-key-connected");
> +
> +	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;
> +
> +	touchscreen_parse_properties(sdata->input, true, &sdata->prop);
> +
> +	input_set_abs_params(sdata->input, ABS_MT_POSITION_X, 0,
> +						sdata->prop.max_x, 0, 0);
> +	input_set_abs_params(sdata->input, ABS_MT_POSITION_Y, 0,
> +						sdata->prop.max_y, 0, 0);
> +	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);
> +
> +	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);
> +	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 = sysfs_create_group(&sdata->client->dev.kobj,
> +					&stmfts_attribute_group);
> +	if (err)
> +		return err;
> +
> +	pm_runtime_enable(&client->dev);
> +
> +	return 0;
> +}
> +
> +static int stmfts_remove(struct i2c_client *client)
> +{
> +	pm_runtime_disable(&client->dev);
> +	sysfs_remove_group(&client->dev.kobj, &stmfts_attribute_group);
> +
> +	return 0;
> +}
> +
> +static int stmfts_runtime_suspend(struct device *dev)
> +{
> +	int ret;
> +	struct stmfts_data *sdata = dev_get_drvdata(dev);
> +
> +	ret = i2c_smbus_write_byte(sdata->client, STMFTS_SLEEP_IN);
> +	if (ret)
> +		dev_warn(dev, "failed to suspend device\n");
> +
> +	return ret;
> +}
> +
> +static int stmfts_runtime_resume(struct device *dev)
> +{
> +	int ret;
> +	struct stmfts_data *sdata = dev_get_drvdata(dev);
> +
> +	ret = i2c_smbus_write_byte(sdata->client, STMFTS_SLEEP_OUT);
> +	if (ret)
> +		dev_err(dev, "failed to resume device\n");
> +
> +	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)
> +};
> +
> +static const struct of_device_id stmfts_of_match[] = {
> +	{ .compatible = "st,stmfts", },
> +	{ },
> +};
> +MODULE_DEVICE_TABLE(of, stmfts_of_match);
> +
> +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 = 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");
> -- 
> 2.11.0
> 
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Andi Shyti April 17, 2017, 10:39 a.m. UTC | #2
Hi Dmitry,

kindly ping, again. Please let me know if there is something I
can do.

Andi

On Fri, Apr 07, 2017 at 06:31:29PM +0900, Andi Shyti wrote:
> Hi Dmitry,
> 
> just a kind ping, do you have any comment about this?
> 
> Thanks,
> Andi
> 
> On Mon, Mar 27, 2017 at 10:07:43PM +0900, Andi Shyti wrote:
> > The stmfts (ST-Microelectronics FingerTip S) touchscreen device
> > is a capacitive multi-touch controller mainly for mobile use.
> > 
> > It's connected through i2c bus at the address 0x49 and it
> > interfaces with userspace through input event interface.
> > 
> > At the current state it provides a touchscreen multitouch
> > functionality up to 10 fingers. Each finger is enumerated with a
> > distinctive id (from 0 to 9).
> > 
> > If enabled the device can support single "touch" hovering, by
> > providing three coordinates, x, y and distance.
> > 
> > It is possible to select the touchkey functionality which
> > provides a basic two keys interface for "home" and "back" menu,
> > typical in mobile phones.
> > 
> > Signed-off-by: Andi Shyti <andi.shyti@samsung.com>
> > ---
> >  drivers/input/touchscreen/Kconfig  |  12 +
> >  drivers/input/touchscreen/Makefile |   1 +
> >  drivers/input/touchscreen/stmfts.c | 805 +++++++++++++++++++++++++++++++++++++
> >  3 files changed, 818 insertions(+)
> >  create mode 100644 drivers/input/touchscreen/stmfts.c
> > 
> > diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
> > index 33c62e5de4fa..f8631c64290d 100644
> > --- a/drivers/input/touchscreen/Kconfig
> > +++ b/drivers/input/touchscreen/Kconfig
> > @@ -1114,6 +1114,18 @@ config TOUCHSCREEN_ST1232
> >  	  To compile this driver as a module, choose M here: the
> >  	  module will be called st1232_ts.
> >  
> > +config TOUCHSCREEN_STMFTS
> > +	tristate "STMicroelectronics STMFTS touchscreen"
> > +	depends on I2C
> > +	depends on INPUT
> > +	depends on LEDS_CLASS
> > +	help
> > +	  Say Y here if you want support for STMicroelectronics
> > +	  STMFTS touchscreen.
> > +
> > +	  To compile this driver as a module, choose M here: the
> > +	  module will be called stmfts.
> > +
> >  config TOUCHSCREEN_STMPE
> >  	tristate "STMicroelectronics STMPE touchscreens"
> >  	depends on MFD_STMPE
> > diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
> > index 18e476948e44..6badce87037b 100644
> > --- a/drivers/input/touchscreen/Makefile
> > +++ b/drivers/input/touchscreen/Makefile
> > @@ -67,6 +67,7 @@ obj-$(CONFIG_TOUCHSCREEN_S3C2410)	+= s3c2410_ts.o
> >  obj-$(CONFIG_TOUCHSCREEN_SILEAD)	+= silead.o
> >  obj-$(CONFIG_TOUCHSCREEN_SIS_I2C)	+= sis_i2c.o
> >  obj-$(CONFIG_TOUCHSCREEN_ST1232)	+= st1232.o
> > +obj-$(CONFIG_TOUCHSCREEN_STMFTS)	+= stmfts.o
> >  obj-$(CONFIG_TOUCHSCREEN_STMPE)		+= stmpe-ts.o
> >  obj-$(CONFIG_TOUCHSCREEN_SUN4I)		+= sun4i-ts.o
> >  obj-$(CONFIG_TOUCHSCREEN_SUR40)		+= sur40.o
> > diff --git a/drivers/input/touchscreen/stmfts.c b/drivers/input/touchscreen/stmfts.c
> > new file mode 100644
> > index 000000000000..2e18b1456f42
> > --- /dev/null
> > +++ b/drivers/input/touchscreen/stmfts.c
> > @@ -0,0 +1,805 @@
> > +/*
> > + * Copyright (c) 2017 Samsung Electronics Co., Ltd.
> > + * Author: Andi Shyti <andi.shyti@samsung.com>
> > + *
> > + * This program is free software; you can redistribute it and/or modify
> > + * it under the terms of the GNU General Public License version 2 as
> > + * published by the Free Software Foundation.
> > + *
> > + * STMicroelectronics FTS Touchscreen device driver
> > + */
> > +
> > +#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];
> > +
> > +	/* 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 signal;
> > +
> > +	bool use_key;
> > +	bool led_status;
> > +	bool hover_enabled;
> > +	bool running;
> > +};
> > +
> > +static int stmfts_read_i2c_block_data(struct stmfts_data *sdata)
> > +{
> > +	struct i2c_msg msgs[2];
> > +	u8 cmd = STMFTS_READ_ALL_EVENT;
> > +
> > +	msgs[0].addr = sdata->client->addr;
> > +	msgs[0].flags = 0;
> > +	msgs[0].len = 1;
> > +	msgs[0].buf = &cmd;
> > +
> > +	msgs[1].addr = sdata->client->addr;
> > +	msgs[1].flags = I2C_M_RD;
> > +	msgs[1].len = STMFTS_DATA_MAX_SIZE - STMFTS_EVENT_SIZE;
> > +	msgs[1].buf = sdata->data + STMFTS_EVENT_SIZE;
> > +
> > +	return i2c_transfer(sdata->client->adapter, msgs, ARRAY_SIZE(msgs));
> > +}
> > +
> > +static void 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);
> > +
> > +	if (value == sdata->led_status || !sdata->ledvdd)
> > +		return;
> > +
> > +	if (!value) {
> > +		regulator_disable(sdata->ledvdd);
> > +	} else {
> > +		int err = regulator_enable(sdata->ledvdd);
> > +
> > +		if (err)
> > +			dev_warn(&sdata->client->dev,
> > +				"failed to disable ledvdd regulator\n");
> > +	}
> > +
> > +	sdata->led_status = value;
> > +}
> > +
> > +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);
> > +}
> > +
> > +static void stmfts_parse_event(struct stmfts_data *sdata)
> > +{
> > +	u8 id, t_id;
> > +	u16 x, y, z, maj, min, orientation, area;
> > +	u8 *event;
> > +	int i;
> > +
> > +	for (i = 0; i < STMFTS_STACK_DEPTH; i++) {
> > +		event = &sdata->data[i*STMFTS_EVENT_SIZE];
> > +
> > +		id = event[0] & STMFTS_MASK_EVENT_ID;
> > +		t_id = (event[0] & STMFTS_MASK_TOUCH_ID) >> 4;
> > +
> > +		switch (id) {
> > +		case STMFTS_EV_NO_EVENT:
> > +			return;
> > +
> > +		case STMFTS_EV_MULTI_TOUCH_ENTER:
> > +		case STMFTS_EV_MULTI_TOUCH_LEAVE:
> > +		case STMFTS_EV_MULTI_TOUCH_MOTION:
> > +			if (id == STMFTS_EV_MULTI_TOUCH_ENTER)
> > +				input_mt_report_slot_state(sdata->input,
> > +							MT_TOOL_FINGER, true);
> > +			else if (id == STMFTS_EV_MULTI_TOUCH_LEAVE)
> > +				input_mt_report_slot_state(sdata->input,
> > +							MT_TOOL_FINGER, false);
> > +
> > +			x = event[1] | ((event[2] & STMFTS_MASK_X_MSB) << 8);
> > +			y = (event[2] >> 4) | (event[3] << 4);
> > +
> > +			maj = event[4];
> > +			min = event[5];
> > +			orientation = event[6];
> > +			area = event[7];
> > +
> > +			input_mt_slot(sdata->input, t_id);
> > +			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);
> > +
> > +			break;
> > +
> > +		case STMFTS_EV_HOVER_ENTER:
> > +		case STMFTS_EV_HOVER_LEAVE:
> > +		case STMFTS_EV_HOVER_MOTION:
> > +			x = (event[2] << 4) | (event[4] >> 4);
> > +			y = (event[3] << 4) | (event[4] & STMFTS_MASK_Y_LSB);
> > +			z = event[5];
> > +			orientation = event[6] & STMFTS_MASK_Y_LSB;
> > +
> > +			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);
> > +
> > +			break;
> > +
> > +		case STMFTS_EV_KEY_STATUS:
> > +			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\n");
> > +			}
> > +
> > +			input_sync(sdata->input);
> > +			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 0x%x\n", event[0]);
> > +		}
> > +	}
> > +}
> > +
> > +static irqreturn_t stmfts_irq_handler(int irq, void *dev)
> > +{
> > +	struct stmfts_data *sdata = dev;
> > +	int ret;
> > +
> > +	mutex_lock(&sdata->mutex);
> > +	ret = i2c_smbus_read_i2c_block_data(sdata->client,
> > +						STMFTS_READ_ONE_EVENT,
> > +						STMFTS_EVENT_SIZE, sdata->data);
> > +
> > +	if (ret < 0 || ret != STMFTS_EVENT_SIZE)
> > +		goto exit;
> > +
> > +	switch (sdata->data[0]) {
> > +	case STMFTS_EV_CONTROLLER_READY:
> > +	case STMFTS_EV_SLEEP_OUT_CONTROLLER_READY:
> > +	case STMFTS_EV_STATUS:
> > +		complete(&sdata->signal);
> > +	case STMFTS_EV_NO_EVENT:
> > +	case STMFTS_EV_DEBUG:
> > +		break;
> > +
> > +	default:
> > +		if (unlikely(!sdata->input))
> > +			goto exit;
> > +
> > +		ret = stmfts_read_i2c_block_data(sdata);
> > +		if (ret < 0)
> > +			goto exit;
> > +
> > +		stmfts_parse_event(sdata);
> > +	}
> > +
> > +exit:
> > +	mutex_unlock(&sdata->mutex);
> > +	return IRQ_HANDLED;
> > +}
> > +
> > +static int stmfts_write_and_wait(struct stmfts_data *sdata, const u8 cmd)
> > +{
> > +	int err;
> > +
> > +	err = i2c_smbus_write_byte(sdata->client, cmd);
> > +	if (err)
> > +		return err;
> > +
> > +	err = wait_for_completion_timeout(&sdata->signal,
> > +					msecs_to_jiffies(1000));
> > +
> > +	return !err ? -ETIMEDOUT : 0;
> > +}
> > +
> > +static int stmfts_input_open(struct input_dev *dev)
> > +{
> > +	int ret;
> > +	struct stmfts_data *sdata = input_get_drvdata(dev);
> > +
> > +	ret = pm_runtime_get_sync(&sdata->client->dev);
> > +	if (ret < 0)
> > +		return ret;
> > +
> > +	ret = i2c_smbus_write_byte(sdata->client, STMFTS_MS_MT_SENSE_ON);
> > +	if (ret)
> > +		return ret;
> > +
> > +	mutex_lock(&sdata->mutex);
> > +	sdata->running = true;
> > +
> > +	if (sdata->hover_enabled) {
> > +		ret = i2c_smbus_write_byte(sdata->client,
> > +						STMFTS_SS_HOVER_SENSE_ON);
> > +		if (ret)
> > +			dev_warn(&sdata->client->dev,
> > +						"failed to enable hover\n");
> > +	}
> > +	mutex_unlock(&sdata->mutex);
> > +
> > +	if (sdata->use_key) {
> > +		ret = i2c_smbus_write_byte(sdata->client,
> > +						STMFTS_MS_KEY_SENSE_ON);
> > +		if (ret)
> > +			/* 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)
> > +{
> > +	int ret;
> > +	struct stmfts_data *sdata = input_get_drvdata(dev);
> > +
> > +	ret = i2c_smbus_write_byte(sdata->client, STMFTS_MS_MT_SENSE_OFF);
> > +	if (ret)
> > +		dev_warn(&sdata->client->dev,
> > +					"failed to disable touchscreen\n");
> > +
> > +	mutex_lock(&sdata->mutex);
> > +	sdata->running = false;
> > +
> > +	if (sdata->hover_enabled) {
> > +		ret = i2c_smbus_write_byte(sdata->client,
> > +					STMFTS_SS_HOVER_SENSE_OFF);
> > +		if (ret)
> > +			dev_warn(&sdata->client->dev,
> > +						"failed to disable hover\n");
> > +	}
> > +	mutex_unlock(&sdata->mutex);
> > +
> > +	if (sdata->use_key) {
> > +		i2c_smbus_write_byte(sdata->client, STMFTS_MS_KEY_SENSE_OFF);
> > +		if (ret)
> > +			dev_warn(&sdata->client->dev,
> > +					"failed to disable touchkey\n");
> > +	}
> > +
> > +	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, "0x%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, "0x%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 ret;
> > +
> > +	ret = i2c_smbus_read_i2c_block_data(sdata->client,
> > +					STMFTS_READ_STATUS, 4, status);
> > +
> > +	return sprintf(buf, "0x%x\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)
> > +{
> > +	unsigned long value;
> > +	int err;
> > +	struct stmfts_data *sdata = dev_get_drvdata(dev);
> > +
> > +	if (kstrtoul(buf, 0, &value))
> > +		return -EINVAL;
> > +
> > +	mutex_lock(&sdata->mutex);
> > +
> > +	if (value & sdata->hover_enabled)
> > +		goto out;
> > +
> > +	if (!sdata->running) {
> > +		sdata->hover_enabled = !!value;
> > +		goto out;
> > +	}
> > +
> > +	if (value) {
> > +		err = i2c_smbus_write_byte(sdata->client,
> > +						STMFTS_SS_HOVER_SENSE_ON);
> > +		sdata->hover_enabled = !err;
> > +	} else {
> > +		err = i2c_smbus_write_byte(sdata->client,
> > +					STMFTS_SS_HOVER_SENSE_OFF);
> > +		sdata->hover_enabled = !!err;
> > +	}
> > +
> > +	if (err)
> > +		dev_warn(&sdata->client->dev, "failed to %s hover\n",
> > +						value ? "enable" : "disable");
> > +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, 8, reg);
> > +	if (err < 0)
> > +		return err;
> > +	if (err != 8)
> > +		return -EIO;
> > +
> > +	sdata->chip_id = (reg[6] << 8) | reg[7];
> > +	sdata->chip_ver = reg[0];
> > +	sdata->fw_ver = (reg[2] << 8) | reg[3];
> > +	sdata->config_id = reg[4];
> > +	sdata->config_ver = reg[5];
> > +
> > +	reinit_completion(&sdata->signal);
> > +
> > +	enable_irq(sdata->client->irq);
> > +	err = stmfts_write_and_wait(sdata, STMFTS_SYSTEM_RESET);
> > +	if (err)
> > +		return err;
> > +
> > +	err = stmfts_write_and_wait(sdata, STMFTS_SLEEP_OUT);
> > +	if (err)
> > +		return err;
> > +
> > +	/* optional tuning */
> > +	err = stmfts_write_and_wait(sdata, STMFTS_MS_CX_TUNING);
> > +	if (err)
> > +		dev_warn(&sdata->client->dev, "failed to perform mutual auto tune\n");
> > +
> > +	/* optional tuning */
> > +	err = stmfts_write_and_wait(sdata, STMFTS_SS_CX_TUNING);
> > +	if (err)
> > +		dev_warn(&sdata->client->dev, "failed to perform self auto tune\n");
> > +
> > +	err = stmfts_write_and_wait(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
> > +	 */
> > +	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 = 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;
> > +
> > +	if (!client->dev.of_node)
> > +		return -ENOENT;
> > +
> > +	sdata = devm_kzalloc(&client->dev, sizeof(*sdata), GFP_KERNEL);
> > +	if (!sdata)
> > +		return -ENOMEM;
> > +
> > +	i2c_set_clientdata(client, sdata);
> > +
> > +	mutex_init(&sdata->mutex);
> > +
> > +	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;
> > +
> > +	err = devm_add_action_or_reset(&client->dev, stmfts_power_off, sdata);
> > +	if (err)
> > +		return err;
> > +
> > +	sdata->client = client;
> > +
> > +	init_completion(&sdata->signal);
> > +
> > +	/*
> > +	 * Do not enable interrupts by default.
> > +	 * One possible case when an IRQ can be already rased is e.g. if the
> > +	 * regulator is set as always on and the stmfts device sends an IRQ as
> > +	 * soon as it gets powered, de-synchronizing the power on sequence.
> > +	 * During power on, the device will be reset and all the initialization
> > +	 * IRQ will be resent.
> > +	 */
> > +	irq_set_status_flags(client->irq, IRQ_NOAUTOEN);
> > +	err = devm_request_threaded_irq(&client->dev, client->irq,
> > +					NULL, stmfts_irq_handler,
> > +					IRQF_ONESHOT | IRQF_TRIGGER_LOW,
> > +					"stmfts_irq", sdata);
> > +	if (err)
> > +		return err;
> > +
> > +	dev_info(&client->dev, "initializing ST-Microelectronics FTS...\n");
> > +	err = stmfts_power_on(sdata);
> > +	if (err)
> > +		return err;
> > +
> > +	sdata->use_key = of_property_read_bool(client->dev.of_node,
> > +						"touch-key-connected");
> > +
> > +	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;
> > +
> > +	touchscreen_parse_properties(sdata->input, true, &sdata->prop);
> > +
> > +	input_set_abs_params(sdata->input, ABS_MT_POSITION_X, 0,
> > +						sdata->prop.max_x, 0, 0);
> > +	input_set_abs_params(sdata->input, ABS_MT_POSITION_Y, 0,
> > +						sdata->prop.max_y, 0, 0);
> > +	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);
> > +
> > +	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);
> > +	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 = sysfs_create_group(&sdata->client->dev.kobj,
> > +					&stmfts_attribute_group);
> > +	if (err)
> > +		return err;
> > +
> > +	pm_runtime_enable(&client->dev);
> > +
> > +	return 0;
> > +}
> > +
> > +static int stmfts_remove(struct i2c_client *client)
> > +{
> > +	pm_runtime_disable(&client->dev);
> > +	sysfs_remove_group(&client->dev.kobj, &stmfts_attribute_group);
> > +
> > +	return 0;
> > +}
> > +
> > +static int stmfts_runtime_suspend(struct device *dev)
> > +{
> > +	int ret;
> > +	struct stmfts_data *sdata = dev_get_drvdata(dev);
> > +
> > +	ret = i2c_smbus_write_byte(sdata->client, STMFTS_SLEEP_IN);
> > +	if (ret)
> > +		dev_warn(dev, "failed to suspend device\n");
> > +
> > +	return ret;
> > +}
> > +
> > +static int stmfts_runtime_resume(struct device *dev)
> > +{
> > +	int ret;
> > +	struct stmfts_data *sdata = dev_get_drvdata(dev);
> > +
> > +	ret = i2c_smbus_write_byte(sdata->client, STMFTS_SLEEP_OUT);
> > +	if (ret)
> > +		dev_err(dev, "failed to resume device\n");
> > +
> > +	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)
> > +};
> > +
> > +static const struct of_device_id stmfts_of_match[] = {
> > +	{ .compatible = "st,stmfts", },
> > +	{ },
> > +};
> > +MODULE_DEVICE_TABLE(of, stmfts_of_match);
> > +
> > +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 = 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");
> > -- 
> > 2.11.0
> > 
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Andi Shyti April 25, 2017, 2:31 a.m. UTC | #3
Hi Dmitry,

again, kindly ping. This patch has been posted on March 27th and
this is the third time I ask you a feedback about it.

Please let me know,
Andi

On Mon, Mar 27, 2017 at 10:07:43PM +0900, Andi Shyti wrote:
> The stmfts (ST-Microelectronics FingerTip S) touchscreen device
> is a capacitive multi-touch controller mainly for mobile use.
> 
> It's connected through i2c bus at the address 0x49 and it
> interfaces with userspace through input event interface.
> 
> At the current state it provides a touchscreen multitouch
> functionality up to 10 fingers. Each finger is enumerated with a
> distinctive id (from 0 to 9).
> 
> If enabled the device can support single "touch" hovering, by
> providing three coordinates, x, y and distance.
> 
> It is possible to select the touchkey functionality which
> provides a basic two keys interface for "home" and "back" menu,
> typical in mobile phones.
> 
> Signed-off-by: Andi Shyti <andi.shyti@samsung.com>
> ---
>  drivers/input/touchscreen/Kconfig  |  12 +
>  drivers/input/touchscreen/Makefile |   1 +
>  drivers/input/touchscreen/stmfts.c | 805 +++++++++++++++++++++++++++++++++++++
>  3 files changed, 818 insertions(+)
>  create mode 100644 drivers/input/touchscreen/stmfts.c
> 
> diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
> index 33c62e5de4fa..f8631c64290d 100644
> --- a/drivers/input/touchscreen/Kconfig
> +++ b/drivers/input/touchscreen/Kconfig
> @@ -1114,6 +1114,18 @@ config TOUCHSCREEN_ST1232
>  	  To compile this driver as a module, choose M here: the
>  	  module will be called st1232_ts.
>  
> +config TOUCHSCREEN_STMFTS
> +	tristate "STMicroelectronics STMFTS touchscreen"
> +	depends on I2C
> +	depends on INPUT
> +	depends on LEDS_CLASS
> +	help
> +	  Say Y here if you want support for STMicroelectronics
> +	  STMFTS touchscreen.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called stmfts.
> +
>  config TOUCHSCREEN_STMPE
>  	tristate "STMicroelectronics STMPE touchscreens"
>  	depends on MFD_STMPE
> diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
> index 18e476948e44..6badce87037b 100644
> --- a/drivers/input/touchscreen/Makefile
> +++ b/drivers/input/touchscreen/Makefile
> @@ -67,6 +67,7 @@ obj-$(CONFIG_TOUCHSCREEN_S3C2410)	+= s3c2410_ts.o
>  obj-$(CONFIG_TOUCHSCREEN_SILEAD)	+= silead.o
>  obj-$(CONFIG_TOUCHSCREEN_SIS_I2C)	+= sis_i2c.o
>  obj-$(CONFIG_TOUCHSCREEN_ST1232)	+= st1232.o
> +obj-$(CONFIG_TOUCHSCREEN_STMFTS)	+= stmfts.o
>  obj-$(CONFIG_TOUCHSCREEN_STMPE)		+= stmpe-ts.o
>  obj-$(CONFIG_TOUCHSCREEN_SUN4I)		+= sun4i-ts.o
>  obj-$(CONFIG_TOUCHSCREEN_SUR40)		+= sur40.o
> diff --git a/drivers/input/touchscreen/stmfts.c b/drivers/input/touchscreen/stmfts.c
> new file mode 100644
> index 000000000000..2e18b1456f42
> --- /dev/null
> +++ b/drivers/input/touchscreen/stmfts.c
> @@ -0,0 +1,805 @@
> +/*
> + * Copyright (c) 2017 Samsung Electronics Co., Ltd.
> + * Author: Andi Shyti <andi.shyti@samsung.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + * STMicroelectronics FTS Touchscreen device driver
> + */
> +
> +#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];
> +
> +	/* 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 signal;
> +
> +	bool use_key;
> +	bool led_status;
> +	bool hover_enabled;
> +	bool running;
> +};
> +
> +static int stmfts_read_i2c_block_data(struct stmfts_data *sdata)
> +{
> +	struct i2c_msg msgs[2];
> +	u8 cmd = STMFTS_READ_ALL_EVENT;
> +
> +	msgs[0].addr = sdata->client->addr;
> +	msgs[0].flags = 0;
> +	msgs[0].len = 1;
> +	msgs[0].buf = &cmd;
> +
> +	msgs[1].addr = sdata->client->addr;
> +	msgs[1].flags = I2C_M_RD;
> +	msgs[1].len = STMFTS_DATA_MAX_SIZE - STMFTS_EVENT_SIZE;
> +	msgs[1].buf = sdata->data + STMFTS_EVENT_SIZE;
> +
> +	return i2c_transfer(sdata->client->adapter, msgs, ARRAY_SIZE(msgs));
> +}
> +
> +static void 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);
> +
> +	if (value == sdata->led_status || !sdata->ledvdd)
> +		return;
> +
> +	if (!value) {
> +		regulator_disable(sdata->ledvdd);
> +	} else {
> +		int err = regulator_enable(sdata->ledvdd);
> +
> +		if (err)
> +			dev_warn(&sdata->client->dev,
> +				"failed to disable ledvdd regulator\n");
> +	}
> +
> +	sdata->led_status = value;
> +}
> +
> +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);
> +}
> +
> +static void stmfts_parse_event(struct stmfts_data *sdata)
> +{
> +	u8 id, t_id;
> +	u16 x, y, z, maj, min, orientation, area;
> +	u8 *event;
> +	int i;
> +
> +	for (i = 0; i < STMFTS_STACK_DEPTH; i++) {
> +		event = &sdata->data[i*STMFTS_EVENT_SIZE];
> +
> +		id = event[0] & STMFTS_MASK_EVENT_ID;
> +		t_id = (event[0] & STMFTS_MASK_TOUCH_ID) >> 4;
> +
> +		switch (id) {
> +		case STMFTS_EV_NO_EVENT:
> +			return;
> +
> +		case STMFTS_EV_MULTI_TOUCH_ENTER:
> +		case STMFTS_EV_MULTI_TOUCH_LEAVE:
> +		case STMFTS_EV_MULTI_TOUCH_MOTION:
> +			if (id == STMFTS_EV_MULTI_TOUCH_ENTER)
> +				input_mt_report_slot_state(sdata->input,
> +							MT_TOOL_FINGER, true);
> +			else if (id == STMFTS_EV_MULTI_TOUCH_LEAVE)
> +				input_mt_report_slot_state(sdata->input,
> +							MT_TOOL_FINGER, false);
> +
> +			x = event[1] | ((event[2] & STMFTS_MASK_X_MSB) << 8);
> +			y = (event[2] >> 4) | (event[3] << 4);
> +
> +			maj = event[4];
> +			min = event[5];
> +			orientation = event[6];
> +			area = event[7];
> +
> +			input_mt_slot(sdata->input, t_id);
> +			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);
> +
> +			break;
> +
> +		case STMFTS_EV_HOVER_ENTER:
> +		case STMFTS_EV_HOVER_LEAVE:
> +		case STMFTS_EV_HOVER_MOTION:
> +			x = (event[2] << 4) | (event[4] >> 4);
> +			y = (event[3] << 4) | (event[4] & STMFTS_MASK_Y_LSB);
> +			z = event[5];
> +			orientation = event[6] & STMFTS_MASK_Y_LSB;
> +
> +			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);
> +
> +			break;
> +
> +		case STMFTS_EV_KEY_STATUS:
> +			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\n");
> +			}
> +
> +			input_sync(sdata->input);
> +			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 0x%x\n", event[0]);
> +		}
> +	}
> +}
> +
> +static irqreturn_t stmfts_irq_handler(int irq, void *dev)
> +{
> +	struct stmfts_data *sdata = dev;
> +	int ret;
> +
> +	mutex_lock(&sdata->mutex);
> +	ret = i2c_smbus_read_i2c_block_data(sdata->client,
> +						STMFTS_READ_ONE_EVENT,
> +						STMFTS_EVENT_SIZE, sdata->data);
> +
> +	if (ret < 0 || ret != STMFTS_EVENT_SIZE)
> +		goto exit;
> +
> +	switch (sdata->data[0]) {
> +	case STMFTS_EV_CONTROLLER_READY:
> +	case STMFTS_EV_SLEEP_OUT_CONTROLLER_READY:
> +	case STMFTS_EV_STATUS:
> +		complete(&sdata->signal);
> +	case STMFTS_EV_NO_EVENT:
> +	case STMFTS_EV_DEBUG:
> +		break;
> +
> +	default:
> +		if (unlikely(!sdata->input))
> +			goto exit;
> +
> +		ret = stmfts_read_i2c_block_data(sdata);
> +		if (ret < 0)
> +			goto exit;
> +
> +		stmfts_parse_event(sdata);
> +	}
> +
> +exit:
> +	mutex_unlock(&sdata->mutex);
> +	return IRQ_HANDLED;
> +}
> +
> +static int stmfts_write_and_wait(struct stmfts_data *sdata, const u8 cmd)
> +{
> +	int err;
> +
> +	err = i2c_smbus_write_byte(sdata->client, cmd);
> +	if (err)
> +		return err;
> +
> +	err = wait_for_completion_timeout(&sdata->signal,
> +					msecs_to_jiffies(1000));
> +
> +	return !err ? -ETIMEDOUT : 0;
> +}
> +
> +static int stmfts_input_open(struct input_dev *dev)
> +{
> +	int ret;
> +	struct stmfts_data *sdata = input_get_drvdata(dev);
> +
> +	ret = pm_runtime_get_sync(&sdata->client->dev);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = i2c_smbus_write_byte(sdata->client, STMFTS_MS_MT_SENSE_ON);
> +	if (ret)
> +		return ret;
> +
> +	mutex_lock(&sdata->mutex);
> +	sdata->running = true;
> +
> +	if (sdata->hover_enabled) {
> +		ret = i2c_smbus_write_byte(sdata->client,
> +						STMFTS_SS_HOVER_SENSE_ON);
> +		if (ret)
> +			dev_warn(&sdata->client->dev,
> +						"failed to enable hover\n");
> +	}
> +	mutex_unlock(&sdata->mutex);
> +
> +	if (sdata->use_key) {
> +		ret = i2c_smbus_write_byte(sdata->client,
> +						STMFTS_MS_KEY_SENSE_ON);
> +		if (ret)
> +			/* 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)
> +{
> +	int ret;
> +	struct stmfts_data *sdata = input_get_drvdata(dev);
> +
> +	ret = i2c_smbus_write_byte(sdata->client, STMFTS_MS_MT_SENSE_OFF);
> +	if (ret)
> +		dev_warn(&sdata->client->dev,
> +					"failed to disable touchscreen\n");
> +
> +	mutex_lock(&sdata->mutex);
> +	sdata->running = false;
> +
> +	if (sdata->hover_enabled) {
> +		ret = i2c_smbus_write_byte(sdata->client,
> +					STMFTS_SS_HOVER_SENSE_OFF);
> +		if (ret)
> +			dev_warn(&sdata->client->dev,
> +						"failed to disable hover\n");
> +	}
> +	mutex_unlock(&sdata->mutex);
> +
> +	if (sdata->use_key) {
> +		i2c_smbus_write_byte(sdata->client, STMFTS_MS_KEY_SENSE_OFF);
> +		if (ret)
> +			dev_warn(&sdata->client->dev,
> +					"failed to disable touchkey\n");
> +	}
> +
> +	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, "0x%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, "0x%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 ret;
> +
> +	ret = i2c_smbus_read_i2c_block_data(sdata->client,
> +					STMFTS_READ_STATUS, 4, status);
> +
> +	return sprintf(buf, "0x%x\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)
> +{
> +	unsigned long value;
> +	int err;
> +	struct stmfts_data *sdata = dev_get_drvdata(dev);
> +
> +	if (kstrtoul(buf, 0, &value))
> +		return -EINVAL;
> +
> +	mutex_lock(&sdata->mutex);
> +
> +	if (value & sdata->hover_enabled)
> +		goto out;
> +
> +	if (!sdata->running) {
> +		sdata->hover_enabled = !!value;
> +		goto out;
> +	}
> +
> +	if (value) {
> +		err = i2c_smbus_write_byte(sdata->client,
> +						STMFTS_SS_HOVER_SENSE_ON);
> +		sdata->hover_enabled = !err;
> +	} else {
> +		err = i2c_smbus_write_byte(sdata->client,
> +					STMFTS_SS_HOVER_SENSE_OFF);
> +		sdata->hover_enabled = !!err;
> +	}
> +
> +	if (err)
> +		dev_warn(&sdata->client->dev, "failed to %s hover\n",
> +						value ? "enable" : "disable");
> +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, 8, reg);
> +	if (err < 0)
> +		return err;
> +	if (err != 8)
> +		return -EIO;
> +
> +	sdata->chip_id = (reg[6] << 8) | reg[7];
> +	sdata->chip_ver = reg[0];
> +	sdata->fw_ver = (reg[2] << 8) | reg[3];
> +	sdata->config_id = reg[4];
> +	sdata->config_ver = reg[5];
> +
> +	reinit_completion(&sdata->signal);
> +
> +	enable_irq(sdata->client->irq);
> +	err = stmfts_write_and_wait(sdata, STMFTS_SYSTEM_RESET);
> +	if (err)
> +		return err;
> +
> +	err = stmfts_write_and_wait(sdata, STMFTS_SLEEP_OUT);
> +	if (err)
> +		return err;
> +
> +	/* optional tuning */
> +	err = stmfts_write_and_wait(sdata, STMFTS_MS_CX_TUNING);
> +	if (err)
> +		dev_warn(&sdata->client->dev, "failed to perform mutual auto tune\n");
> +
> +	/* optional tuning */
> +	err = stmfts_write_and_wait(sdata, STMFTS_SS_CX_TUNING);
> +	if (err)
> +		dev_warn(&sdata->client->dev, "failed to perform self auto tune\n");
> +
> +	err = stmfts_write_and_wait(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
> +	 */
> +	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 = 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;
> +
> +	if (!client->dev.of_node)
> +		return -ENOENT;
> +
> +	sdata = devm_kzalloc(&client->dev, sizeof(*sdata), GFP_KERNEL);
> +	if (!sdata)
> +		return -ENOMEM;
> +
> +	i2c_set_clientdata(client, sdata);
> +
> +	mutex_init(&sdata->mutex);
> +
> +	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;
> +
> +	err = devm_add_action_or_reset(&client->dev, stmfts_power_off, sdata);
> +	if (err)
> +		return err;
> +
> +	sdata->client = client;
> +
> +	init_completion(&sdata->signal);
> +
> +	/*
> +	 * Do not enable interrupts by default.
> +	 * One possible case when an IRQ can be already rased is e.g. if the
> +	 * regulator is set as always on and the stmfts device sends an IRQ as
> +	 * soon as it gets powered, de-synchronizing the power on sequence.
> +	 * During power on, the device will be reset and all the initialization
> +	 * IRQ will be resent.
> +	 */
> +	irq_set_status_flags(client->irq, IRQ_NOAUTOEN);
> +	err = devm_request_threaded_irq(&client->dev, client->irq,
> +					NULL, stmfts_irq_handler,
> +					IRQF_ONESHOT | IRQF_TRIGGER_LOW,
> +					"stmfts_irq", sdata);
> +	if (err)
> +		return err;
> +
> +	dev_info(&client->dev, "initializing ST-Microelectronics FTS...\n");
> +	err = stmfts_power_on(sdata);
> +	if (err)
> +		return err;
> +
> +	sdata->use_key = of_property_read_bool(client->dev.of_node,
> +						"touch-key-connected");
> +
> +	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;
> +
> +	touchscreen_parse_properties(sdata->input, true, &sdata->prop);
> +
> +	input_set_abs_params(sdata->input, ABS_MT_POSITION_X, 0,
> +						sdata->prop.max_x, 0, 0);
> +	input_set_abs_params(sdata->input, ABS_MT_POSITION_Y, 0,
> +						sdata->prop.max_y, 0, 0);
> +	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);
> +
> +	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);
> +	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 = sysfs_create_group(&sdata->client->dev.kobj,
> +					&stmfts_attribute_group);
> +	if (err)
> +		return err;
> +
> +	pm_runtime_enable(&client->dev);
> +
> +	return 0;
> +}
> +
> +static int stmfts_remove(struct i2c_client *client)
> +{
> +	pm_runtime_disable(&client->dev);
> +	sysfs_remove_group(&client->dev.kobj, &stmfts_attribute_group);
> +
> +	return 0;
> +}
> +
> +static int stmfts_runtime_suspend(struct device *dev)
> +{
> +	int ret;
> +	struct stmfts_data *sdata = dev_get_drvdata(dev);
> +
> +	ret = i2c_smbus_write_byte(sdata->client, STMFTS_SLEEP_IN);
> +	if (ret)
> +		dev_warn(dev, "failed to suspend device\n");
> +
> +	return ret;
> +}
> +
> +static int stmfts_runtime_resume(struct device *dev)
> +{
> +	int ret;
> +	struct stmfts_data *sdata = dev_get_drvdata(dev);
> +
> +	ret = i2c_smbus_write_byte(sdata->client, STMFTS_SLEEP_OUT);
> +	if (ret)
> +		dev_err(dev, "failed to resume device\n");
> +
> +	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)
> +};
> +
> +static const struct of_device_id stmfts_of_match[] = {
> +	{ .compatible = "st,stmfts", },
> +	{ },
> +};
> +MODULE_DEVICE_TABLE(of, stmfts_of_match);
> +
> +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 = 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");
> -- 
> 2.11.0
> 
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Dmitry Torokhov April 27, 2017, 12:39 a.m. UTC | #4
Hi Andi,

Quick question:

On Mon, Mar 27, 2017 at 10:07:43PM +0900, Andi Shyti wrote:
> +static irqreturn_t stmfts_irq_handler(int irq, void *dev)
> +{
> +	struct stmfts_data *sdata = dev;
> +	int ret;
> +
> +	mutex_lock(&sdata->mutex);
> +	ret = i2c_smbus_read_i2c_block_data(sdata->client,
> +						STMFTS_READ_ONE_EVENT,
> +						STMFTS_EVENT_SIZE, sdata->data);
> +
> +	if (ret < 0 || ret != STMFTS_EVENT_SIZE)
> +		goto exit;

Why do we split read into 2 chunks? Can we issue STMFTS_READ_ALL_EVENT
right away instead of reading first event, analyzing it, and then (maybe)
fetching the rest?

Also, why do we use smbus protocol for the first event and i2c for the
rest?

Thanks.
Andi Shyti April 27, 2017, 11:41 p.m. UTC | #5
Hi Dmitry,

On Wed, Apr 26, 2017 at 05:39:18PM -0700, Dmitry Torokhov wrote:
> 
> On Mon, Mar 27, 2017 at 10:07:43PM +0900, Andi Shyti wrote:
> > +static irqreturn_t stmfts_irq_handler(int irq, void *dev)
> > +{
> > +	struct stmfts_data *sdata = dev;
> > +	int ret;
> > +
> > +	mutex_lock(&sdata->mutex);
> > +	ret = i2c_smbus_read_i2c_block_data(sdata->client,
> > +						STMFTS_READ_ONE_EVENT,
> > +						STMFTS_EVENT_SIZE, sdata->data);
> > +
> > +	if (ret < 0 || ret != STMFTS_EVENT_SIZE)
> > +		goto exit;
> 
> Why do we split read into 2 chunks? Can we issue STMFTS_READ_ALL_EVENT
> right away instead of reading first event, analyzing it, and then (maybe)
> fetching the rest?

The reason is that I don't need to read all the events at once
anytime, for example debug events or confirmation events normally
occur with a single event in the fifo. In this case I would read
only 32bytes instead of 256bytes.

Unfortunately there are no other ways to know how many events are
in the queue beforehand.

There are some "magic" commands to figure that out, but this is
specific to the Samsung's version of the stmfts and I don't want
to push it to everyone else.

The difference between this version of the driver and the
previous one is that in this one if I stress-use of the
touchscreen, the throughput is optimised (e.g. if I use more
fingers).
Before I was reading single events at time, establishing for each
read an i2c "handshake", this was de-synchronizing the protocol.

> Also, why do we use smbus protocol for the first event and i2c for the
> rest?

Standing to the datasheet, the device is smbus compatible and it
should use smbus all the time. The problem is that here the
protocol is broken in case I want to read out the full FIFO,
which has a total of 256bytes and I have to force the read by
using the function "stmfts_read_i2c_block_data()".

Personally I don't like these kind of i2c reads, because they
duplicate code, the SMBUS does that already, this is why in the
previous version I was reading the events one by one.

Do you think it is better to make a single read of all the fifo?

Andi
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Dmitry Torokhov April 27, 2017, 11:56 p.m. UTC | #6
On Fri, Apr 28, 2017 at 08:41:56AM +0900, Andi Shyti wrote:
> Hi Dmitry,
> 
> On Wed, Apr 26, 2017 at 05:39:18PM -0700, Dmitry Torokhov wrote:
> > 
> > On Mon, Mar 27, 2017 at 10:07:43PM +0900, Andi Shyti wrote:
> > > +static irqreturn_t stmfts_irq_handler(int irq, void *dev)
> > > +{
> > > +	struct stmfts_data *sdata = dev;
> > > +	int ret;
> > > +
> > > +	mutex_lock(&sdata->mutex);
> > > +	ret = i2c_smbus_read_i2c_block_data(sdata->client,
> > > +						STMFTS_READ_ONE_EVENT,
> > > +						STMFTS_EVENT_SIZE, sdata->data);
> > > +
> > > +	if (ret < 0 || ret != STMFTS_EVENT_SIZE)
> > > +		goto exit;
> > 
> > Why do we split read into 2 chunks? Can we issue STMFTS_READ_ALL_EVENT
> > right away instead of reading first event, analyzing it, and then (maybe)
> > fetching the rest?
> 
> The reason is that I don't need to read all the events at once
> anytime, for example debug events or confirmation events normally
> occur with a single event in the fifo. In this case I would read
> only 32bytes instead of 256bytes.
> 
> Unfortunately there are no other ways to know how many events are
> in the queue beforehand.
> 
> There are some "magic" commands to figure that out, but this is
> specific to the Samsung's version of the stmfts and I don't want
> to push it to everyone else.
> 
> The difference between this version of the driver and the
> previous one is that in this one if I stress-use of the
> touchscreen, the throughput is optimised (e.g. if I use more
> fingers).
> Before I was reading single events at time, establishing for each
> read an i2c "handshake", this was de-synchronizing the protocol.
> 
> > Also, why do we use smbus protocol for the first event and i2c for the
> > rest?
> 
> Standing to the datasheet, the device is smbus compatible and it
> should use smbus all the time. The problem is that here the
> protocol is broken in case I want to read out the full FIFO,
> which has a total of 256bytes and I have to force the read by
> using the function "stmfts_read_i2c_block_data()".
> 
> Personally I don't like these kind of i2c reads, because they
> duplicate code, the SMBUS does that already, this is why in the
> previous version I was reading the events one by one.
> 
> Do you think it is better to make a single read of all the fifo?

It depends on what the common case is. It looks like for touch data you
always do 2 i2c transactions per interrupt. I wonder if doing it once
and paying the price of overhead for debug a nd confirmation events is
not worth it.

Thanks.
Andi Shyti April 28, 2017, 12:07 a.m. UTC | #7
Hi Dmitry,

On Thu, Apr 27, 2017 at 04:56:45PM -0700, Dmitry Torokhov wrote:
> On Fri, Apr 28, 2017 at 08:41:56AM +0900, Andi Shyti wrote:
> > On Wed, Apr 26, 2017 at 05:39:18PM -0700, Dmitry Torokhov wrote:
> > > On Mon, Mar 27, 2017 at 10:07:43PM +0900, Andi Shyti wrote:
> > > > +static irqreturn_t stmfts_irq_handler(int irq, void *dev)
> > > > +{
> > > > +	struct stmfts_data *sdata = dev;
> > > > +	int ret;
> > > > +
> > > > +	mutex_lock(&sdata->mutex);
> > > > +	ret = i2c_smbus_read_i2c_block_data(sdata->client,
> > > > +						STMFTS_READ_ONE_EVENT,
> > > > +						STMFTS_EVENT_SIZE, sdata->data);
> > > > +
> > > > +	if (ret < 0 || ret != STMFTS_EVENT_SIZE)
> > > > +		goto exit;
> > > 
> > > Why do we split read into 2 chunks? Can we issue STMFTS_READ_ALL_EVENT
> > > right away instead of reading first event, analyzing it, and then (maybe)
> > > fetching the rest?
> > 
> > The reason is that I don't need to read all the events at once
> > anytime, for example debug events or confirmation events normally
> > occur with a single event in the fifo. In this case I would read
> > only 32bytes instead of 256bytes.
> > 
> > Unfortunately there are no other ways to know how many events are
> > in the queue beforehand.
> > 
> > There are some "magic" commands to figure that out, but this is
> > specific to the Samsung's version of the stmfts and I don't want
> > to push it to everyone else.
> > 
> > The difference between this version of the driver and the
> > previous one is that in this one if I stress-use of the
> > touchscreen, the throughput is optimised (e.g. if I use more
> > fingers).
> > Before I was reading single events at time, establishing for each
> > read an i2c "handshake", this was de-synchronizing the protocol.
> > 
> > > Also, why do we use smbus protocol for the first event and i2c for the
> > > rest?
> > 
> > Standing to the datasheet, the device is smbus compatible and it
> > should use smbus all the time. The problem is that here the
> > protocol is broken in case I want to read out the full FIFO,
> > which has a total of 256bytes and I have to force the read by
> > using the function "stmfts_read_i2c_block_data()".
> > 
> > Personally I don't like these kind of i2c reads, because they
> > duplicate code, the SMBUS does that already, this is why in the
> > previous version I was reading the events one by one.
> > 
> > Do you think it is better to make a single read of all the fifo?
> 
> It depends on what the common case is. It looks like for touch data you
> always do 2 i2c transactions per interrupt. I wonder if doing it once
> and paying the price of overhead for debug a nd confirmation events is
> not worth it.

makes sense, indeed, because I do it all the time when for touch
events (which are the most) not only when the FIFO is not full.
I will do it this way, then... Thanks!

Andi
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Patch
diff mbox

diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 33c62e5de4fa..f8631c64290d 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -1114,6 +1114,18 @@  config TOUCHSCREEN_ST1232
 	  To compile this driver as a module, choose M here: the
 	  module will be called st1232_ts.
 
+config TOUCHSCREEN_STMFTS
+	tristate "STMicroelectronics STMFTS touchscreen"
+	depends on I2C
+	depends on INPUT
+	depends on LEDS_CLASS
+	help
+	  Say Y here if you want support for STMicroelectronics
+	  STMFTS touchscreen.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called stmfts.
+
 config TOUCHSCREEN_STMPE
 	tristate "STMicroelectronics STMPE touchscreens"
 	depends on MFD_STMPE
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 18e476948e44..6badce87037b 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -67,6 +67,7 @@  obj-$(CONFIG_TOUCHSCREEN_S3C2410)	+= s3c2410_ts.o
 obj-$(CONFIG_TOUCHSCREEN_SILEAD)	+= silead.o
 obj-$(CONFIG_TOUCHSCREEN_SIS_I2C)	+= sis_i2c.o
 obj-$(CONFIG_TOUCHSCREEN_ST1232)	+= st1232.o
+obj-$(CONFIG_TOUCHSCREEN_STMFTS)	+= stmfts.o
 obj-$(CONFIG_TOUCHSCREEN_STMPE)		+= stmpe-ts.o
 obj-$(CONFIG_TOUCHSCREEN_SUN4I)		+= sun4i-ts.o
 obj-$(CONFIG_TOUCHSCREEN_SUR40)		+= sur40.o
diff --git a/drivers/input/touchscreen/stmfts.c b/drivers/input/touchscreen/stmfts.c
new file mode 100644
index 000000000000..2e18b1456f42
--- /dev/null
+++ b/drivers/input/touchscreen/stmfts.c
@@ -0,0 +1,805 @@ 
+/*
+ * Copyright (c) 2017 Samsung Electronics Co., Ltd.
+ * Author: Andi Shyti <andi.shyti@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * STMicroelectronics FTS Touchscreen device driver
+ */
+
+#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];
+
+	/* 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 signal;
+
+	bool use_key;
+	bool led_status;
+	bool hover_enabled;
+	bool running;
+};
+
+static int stmfts_read_i2c_block_data(struct stmfts_data *sdata)
+{
+	struct i2c_msg msgs[2];
+	u8 cmd = STMFTS_READ_ALL_EVENT;
+
+	msgs[0].addr = sdata->client->addr;
+	msgs[0].flags = 0;
+	msgs[0].len = 1;
+	msgs[0].buf = &cmd;
+
+	msgs[1].addr = sdata->client->addr;
+	msgs[1].flags = I2C_M_RD;
+	msgs[1].len = STMFTS_DATA_MAX_SIZE - STMFTS_EVENT_SIZE;
+	msgs[1].buf = sdata->data + STMFTS_EVENT_SIZE;
+
+	return i2c_transfer(sdata->client->adapter, msgs, ARRAY_SIZE(msgs));
+}
+
+static void 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);
+
+	if (value == sdata->led_status || !sdata->ledvdd)
+		return;
+
+	if (!value) {
+		regulator_disable(sdata->ledvdd);
+	} else {
+		int err = regulator_enable(sdata->ledvdd);
+
+		if (err)
+			dev_warn(&sdata->client->dev,
+				"failed to disable ledvdd regulator\n");
+	}
+
+	sdata->led_status = value;
+}
+
+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);
+}
+
+static void stmfts_parse_event(struct stmfts_data *sdata)
+{
+	u8 id, t_id;
+	u16 x, y, z, maj, min, orientation, area;
+	u8 *event;
+	int i;
+
+	for (i = 0; i < STMFTS_STACK_DEPTH; i++) {
+		event = &sdata->data[i*STMFTS_EVENT_SIZE];
+
+		id = event[0] & STMFTS_MASK_EVENT_ID;
+		t_id = (event[0] & STMFTS_MASK_TOUCH_ID) >> 4;
+
+		switch (id) {
+		case STMFTS_EV_NO_EVENT:
+			return;
+
+		case STMFTS_EV_MULTI_TOUCH_ENTER:
+		case STMFTS_EV_MULTI_TOUCH_LEAVE:
+		case STMFTS_EV_MULTI_TOUCH_MOTION:
+			if (id == STMFTS_EV_MULTI_TOUCH_ENTER)
+				input_mt_report_slot_state(sdata->input,
+							MT_TOOL_FINGER, true);
+			else if (id == STMFTS_EV_MULTI_TOUCH_LEAVE)
+				input_mt_report_slot_state(sdata->input,
+							MT_TOOL_FINGER, false);
+
+			x = event[1] | ((event[2] & STMFTS_MASK_X_MSB) << 8);
+			y = (event[2] >> 4) | (event[3] << 4);
+
+			maj = event[4];
+			min = event[5];
+			orientation = event[6];
+			area = event[7];
+
+			input_mt_slot(sdata->input, t_id);
+			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);
+
+			break;
+
+		case STMFTS_EV_HOVER_ENTER:
+		case STMFTS_EV_HOVER_LEAVE:
+		case STMFTS_EV_HOVER_MOTION:
+			x = (event[2] << 4) | (event[4] >> 4);
+			y = (event[3] << 4) | (event[4] & STMFTS_MASK_Y_LSB);
+			z = event[5];
+			orientation = event[6] & STMFTS_MASK_Y_LSB;
+
+			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);
+
+			break;
+
+		case STMFTS_EV_KEY_STATUS:
+			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\n");
+			}
+
+			input_sync(sdata->input);
+			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 0x%x\n", event[0]);
+		}
+	}
+}
+
+static irqreturn_t stmfts_irq_handler(int irq, void *dev)
+{
+	struct stmfts_data *sdata = dev;
+	int ret;
+
+	mutex_lock(&sdata->mutex);
+	ret = i2c_smbus_read_i2c_block_data(sdata->client,
+						STMFTS_READ_ONE_EVENT,
+						STMFTS_EVENT_SIZE, sdata->data);
+
+	if (ret < 0 || ret != STMFTS_EVENT_SIZE)
+		goto exit;
+
+	switch (sdata->data[0]) {
+	case STMFTS_EV_CONTROLLER_READY:
+	case STMFTS_EV_SLEEP_OUT_CONTROLLER_READY:
+	case STMFTS_EV_STATUS:
+		complete(&sdata->signal);
+	case STMFTS_EV_NO_EVENT:
+	case STMFTS_EV_DEBUG:
+		break;
+
+	default:
+		if (unlikely(!sdata->input))
+			goto exit;
+
+		ret = stmfts_read_i2c_block_data(sdata);
+		if (ret < 0)
+			goto exit;
+
+		stmfts_parse_event(sdata);
+	}
+
+exit:
+	mutex_unlock(&sdata->mutex);
+	return IRQ_HANDLED;
+}
+
+static int stmfts_write_and_wait(struct stmfts_data *sdata, const u8 cmd)
+{
+	int err;
+
+	err = i2c_smbus_write_byte(sdata->client, cmd);
+	if (err)
+		return err;
+
+	err = wait_for_completion_timeout(&sdata->signal,
+					msecs_to_jiffies(1000));
+
+	return !err ? -ETIMEDOUT : 0;
+}
+
+static int stmfts_input_open(struct input_dev *dev)
+{
+	int ret;
+	struct stmfts_data *sdata = input_get_drvdata(dev);
+
+	ret = pm_runtime_get_sync(&sdata->client->dev);
+	if (ret < 0)
+		return ret;
+
+	ret = i2c_smbus_write_byte(sdata->client, STMFTS_MS_MT_SENSE_ON);
+	if (ret)
+		return ret;
+
+	mutex_lock(&sdata->mutex);
+	sdata->running = true;
+
+	if (sdata->hover_enabled) {
+		ret = i2c_smbus_write_byte(sdata->client,
+						STMFTS_SS_HOVER_SENSE_ON);
+		if (ret)
+			dev_warn(&sdata->client->dev,
+						"failed to enable hover\n");
+	}
+	mutex_unlock(&sdata->mutex);
+
+	if (sdata->use_key) {
+		ret = i2c_smbus_write_byte(sdata->client,
+						STMFTS_MS_KEY_SENSE_ON);
+		if (ret)
+			/* 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)
+{
+	int ret;
+	struct stmfts_data *sdata = input_get_drvdata(dev);
+
+	ret = i2c_smbus_write_byte(sdata->client, STMFTS_MS_MT_SENSE_OFF);
+	if (ret)
+		dev_warn(&sdata->client->dev,
+					"failed to disable touchscreen\n");
+
+	mutex_lock(&sdata->mutex);
+	sdata->running = false;
+
+	if (sdata->hover_enabled) {
+		ret = i2c_smbus_write_byte(sdata->client,
+					STMFTS_SS_HOVER_SENSE_OFF);
+		if (ret)
+			dev_warn(&sdata->client->dev,
+						"failed to disable hover\n");
+	}
+	mutex_unlock(&sdata->mutex);
+
+	if (sdata->use_key) {
+		i2c_smbus_write_byte(sdata->client, STMFTS_MS_KEY_SENSE_OFF);
+		if (ret)
+			dev_warn(&sdata->client->dev,
+					"failed to disable touchkey\n");
+	}
+
+	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, "0x%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, "0x%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 ret;
+
+	ret = i2c_smbus_read_i2c_block_data(sdata->client,
+					STMFTS_READ_STATUS, 4, status);
+
+	return sprintf(buf, "0x%x\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)
+{
+	unsigned long value;
+	int err;
+	struct stmfts_data *sdata = dev_get_drvdata(dev);
+
+	if (kstrtoul(buf, 0, &value))
+		return -EINVAL;
+
+	mutex_lock(&sdata->mutex);
+
+	if (value & sdata->hover_enabled)
+		goto out;
+
+	if (!sdata->running) {
+		sdata->hover_enabled = !!value;
+		goto out;
+	}
+
+	if (value) {
+		err = i2c_smbus_write_byte(sdata->client,
+						STMFTS_SS_HOVER_SENSE_ON);
+		sdata->hover_enabled = !err;
+	} else {
+		err = i2c_smbus_write_byte(sdata->client,
+					STMFTS_SS_HOVER_SENSE_OFF);
+		sdata->hover_enabled = !!err;
+	}
+
+	if (err)
+		dev_warn(&sdata->client->dev, "failed to %s hover\n",
+						value ? "enable" : "disable");
+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, 8, reg);
+	if (err < 0)
+		return err;
+	if (err != 8)
+		return -EIO;
+
+	sdata->chip_id = (reg[6] << 8) | reg[7];
+	sdata->chip_ver = reg[0];
+	sdata->fw_ver = (reg[2] << 8) | reg[3];
+	sdata->config_id = reg[4];
+	sdata->config_ver = reg[5];
+
+	reinit_completion(&sdata->signal);
+
+	enable_irq(sdata->client->irq);
+	err = stmfts_write_and_wait(sdata, STMFTS_SYSTEM_RESET);
+	if (err)
+		return err;
+
+	err = stmfts_write_and_wait(sdata, STMFTS_SLEEP_OUT);
+	if (err)
+		return err;
+
+	/* optional tuning */
+	err = stmfts_write_and_wait(sdata, STMFTS_MS_CX_TUNING);
+	if (err)
+		dev_warn(&sdata->client->dev, "failed to perform mutual auto tune\n");
+
+	/* optional tuning */
+	err = stmfts_write_and_wait(sdata, STMFTS_SS_CX_TUNING);
+	if (err)
+		dev_warn(&sdata->client->dev, "failed to perform self auto tune\n");
+
+	err = stmfts_write_and_wait(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
+	 */
+	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 = 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;
+
+	if (!client->dev.of_node)
+		return -ENOENT;
+
+	sdata = devm_kzalloc(&client->dev, sizeof(*sdata), GFP_KERNEL);
+	if (!sdata)
+		return -ENOMEM;
+
+	i2c_set_clientdata(client, sdata);
+
+	mutex_init(&sdata->mutex);
+
+	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;
+
+	err = devm_add_action_or_reset(&client->dev, stmfts_power_off, sdata);
+	if (err)
+		return err;
+
+	sdata->client = client;
+
+	init_completion(&sdata->signal);
+
+	/*
+	 * Do not enable interrupts by default.
+	 * One possible case when an IRQ can be already rased is e.g. if the
+	 * regulator is set as always on and the stmfts device sends an IRQ as
+	 * soon as it gets powered, de-synchronizing the power on sequence.
+	 * During power on, the device will be reset and all the initialization
+	 * IRQ will be resent.
+	 */
+	irq_set_status_flags(client->irq, IRQ_NOAUTOEN);
+	err = devm_request_threaded_irq(&client->dev, client->irq,
+					NULL, stmfts_irq_handler,
+					IRQF_ONESHOT | IRQF_TRIGGER_LOW,
+					"stmfts_irq", sdata);
+	if (err)
+		return err;
+
+	dev_info(&client->dev, "initializing ST-Microelectronics FTS...\n");
+	err = stmfts_power_on(sdata);
+	if (err)
+		return err;
+
+	sdata->use_key = of_property_read_bool(client->dev.of_node,
+						"touch-key-connected");
+
+	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;
+
+	touchscreen_parse_properties(sdata->input, true, &sdata->prop);
+
+	input_set_abs_params(sdata->input, ABS_MT_POSITION_X, 0,
+						sdata->prop.max_x, 0, 0);
+	input_set_abs_params(sdata->input, ABS_MT_POSITION_Y, 0,
+						sdata->prop.max_y, 0, 0);
+	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);
+
+	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);
+	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 = sysfs_create_group(&sdata->client->dev.kobj,
+					&stmfts_attribute_group);
+	if (err)
+		return err;
+
+	pm_runtime_enable(&client->dev);
+
+	return 0;
+}
+
+static int stmfts_remove(struct i2c_client *client)
+{
+	pm_runtime_disable(&client->dev);
+	sysfs_remove_group(&client->dev.kobj, &stmfts_attribute_group);
+
+	return 0;
+}
+
+static int stmfts_runtime_suspend(struct device *dev)
+{
+	int ret;
+	struct stmfts_data *sdata = dev_get_drvdata(dev);
+
+	ret = i2c_smbus_write_byte(sdata->client, STMFTS_SLEEP_IN);
+	if (ret)
+		dev_warn(dev, "failed to suspend device\n");
+
+	return ret;
+}
+
+static int stmfts_runtime_resume(struct device *dev)
+{
+	int ret;
+	struct stmfts_data *sdata = dev_get_drvdata(dev);
+
+	ret = i2c_smbus_write_byte(sdata->client, STMFTS_SLEEP_OUT);
+	if (ret)
+		dev_err(dev, "failed to resume device\n");
+
+	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)
+};
+
+static const struct of_device_id stmfts_of_match[] = {
+	{ .compatible = "st,stmfts", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, stmfts_of_match);
+
+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 = 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");