Input: add support for the STMicroelectronics FingerTip touchscreen
authorAndi Shyti <andi.shyti@samsung.com>
Mon, 5 Jun 2017 22:29:18 +0000 (15:29 -0700)
committerDmitry Torokhov <dmitry.torokhov@gmail.com>
Mon, 5 Jun 2017 22:35:34 +0000 (15:35 -0700)
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>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Documentation/devicetree/bindings/input/touchscreen/st,stmfts.txt [new file with mode: 0644]
drivers/input/touchscreen/Kconfig
drivers/input/touchscreen/Makefile
drivers/input/touchscreen/stmfts.c [new file with mode: 0644]

diff --git a/Documentation/devicetree/bindings/input/touchscreen/st,stmfts.txt b/Documentation/devicetree/bindings/input/touchscreen/st,stmfts.txt
new file mode 100644 (file)
index 0000000..9683595
--- /dev/null
@@ -0,0 +1,43 @@
+* ST-Microelectronics FingerTip touchscreen controller
+
+The ST-Microelectronics FingerTip device provides a basic touchscreen
+functionality. Along with it the user can enable the touchkey which can work as
+a basic HOME and BACK key for phones.
+
+The driver supports also hovering as an absolute single touch event with x, y, z
+coordinates.
+
+Required properties:
+- compatible           : must be "st,stmfts"
+- reg                  : I2C slave address, (e.g. 0x49)
+- interrupt-parent     : the phandle to the interrupt controller which provides
+                         the interrupt
+- interrupts           : interrupt specification
+- avdd-supply          : analogic power supply
+- vdd-supply           : power supply
+- touchscreen-size-x   : see touchscreen.txt
+- touchscreen-size-y   : see touchscreen.txt
+
+Optional properties:
+- touch-key-connected  : specifies whether the touchkey feature is connected
+- ledvdd-supply                : power supply to the touch key leds
+
+Example:
+
+i2c@00000000 {
+
+       /* ... */
+
+       touchscreen@49 {
+               compatible = "st,stmfts";
+               reg = <0x49>;
+               interrupt-parent = <&gpa1>;
+               interrupts = <1 IRQ_TYPE_NONE>;
+               touchscreen-size-x = <1599>;
+               touchscreen-size-y = <2559>;
+               touch-key-connected;
+               avdd-supply = <&ldo30_reg>;
+               vdd-supply = <&ldo31_reg>;
+               ledvdd-supply = <&ldo33_reg>;
+       };
+};
index cf26ca49ae6d623d44d68e654c20082e7cf09d9e..64b30fe273fd7ba17312402c0efc9e81b77e94bb 100644 (file)
@@ -1114,6 +1114,17 @@ 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 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
index 18e476948e44e4a44b16acb9e96887ee4a88b606..6badce87037b54bcea7c91f5ddbaebca4c93db58 100644 (file)
@@ -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 (file)
index 0000000..802d0e8
--- /dev/null
@@ -0,0 +1,822 @@
+/*
+ * 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];
+
+       /*
+        * Presence of ledvdd will be used also to check
+        * whether the LED is supported.
+        */
+       struct regulator *ledvdd;
+
+       u16 chip_id;
+       u8 chip_ver;
+       u16 fw_ver;
+       u8 config_id;
+       u8 config_ver;
+
+       u8 data[STMFTS_DATA_MAX_SIZE];
+
+       struct completion cmd_done;
+
+       bool use_key;
+       bool led_status;
+       bool hover_enabled;
+       bool running;
+};
+
+static 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);
+       int err;
+
+       if (value == sdata->led_status || !sdata->ledvdd)
+               return;
+
+       if (!value) {
+               regulator_disable(sdata->ledvdd);
+       } else {
+               err = regulator_enable(sdata->ledvdd);
+               if (err)
+                       dev_warn(&sdata->client->dev,
+                                "failed to disable ledvdd regulator: %d\n",
+                                err);
+       }
+
+       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);
+}
+
+/*
+ * We can't simply use i2c_smbus_read_i2c_block_data because we
+ * need to read more than 255 bytes (
+ */
+static int stmfts_read_events(struct stmfts_data *sdata)
+{
+       u8 cmd = STMFTS_READ_ALL_EVENT;
+       struct i2c_msg msgs[2] = {
+               {
+                       .addr   = sdata->client->addr,
+                       .len    = 1,
+                       .buf    = &cmd,
+               },
+               {
+                       .addr   = sdata->client->addr,
+                       .flags  = I2C_M_RD,
+                       .len    = STMFTS_DATA_MAX_SIZE,
+                       .buf    = sdata->data,
+               },
+       };
+       int ret;
+
+       ret = i2c_transfer(sdata->client->adapter, msgs, ARRAY_SIZE(msgs));
+       if (ret < 0)
+               return ret;
+
+       return ret == ARRAY_SIZE(msgs) ? 0 : -EIO;
+}
+
+static void stmfts_report_contact_event(struct stmfts_data *sdata,
+                                       const u8 event[])
+{
+       u8 slot_id = (event[0] & STMFTS_MASK_TOUCH_ID) >> 4;
+       u16 x = event[1] | ((event[2] & STMFTS_MASK_X_MSB) << 8);
+       u16 y = (event[2] >> 4) | (event[3] << 4);
+       u8 maj = event[4];
+       u8 min = event[5];
+       u8 orientation = event[6];
+       u8 area = event[7];
+
+       input_mt_slot(sdata->input, slot_id);
+
+       input_mt_report_slot_state(sdata->input, MT_TOOL_FINGER, true);
+       input_report_abs(sdata->input, ABS_MT_POSITION_X, x);
+       input_report_abs(sdata->input, ABS_MT_POSITION_Y, y);
+       input_report_abs(sdata->input, ABS_MT_TOUCH_MAJOR, maj);
+       input_report_abs(sdata->input, ABS_MT_TOUCH_MINOR, min);
+       input_report_abs(sdata->input, ABS_MT_PRESSURE, area);
+       input_report_abs(sdata->input, ABS_MT_ORIENTATION, orientation);
+
+       input_sync(sdata->input);
+}
+
+static void stmfts_report_contact_release(struct stmfts_data *sdata,
+                                         const u8 event[])
+{
+       u8 slot_id = (event[0] & STMFTS_MASK_TOUCH_ID) >> 4;
+
+       input_mt_slot(sdata->input, slot_id);
+       input_mt_report_slot_state(sdata->input, MT_TOOL_FINGER, false);
+
+       input_sync(sdata->input);
+}
+
+static void stmfts_report_hover_event(struct stmfts_data *sdata,
+                                     const u8 event[])
+{
+       u16 x = (event[2] << 4) | (event[4] >> 4);
+       u16 y = (event[3] << 4) | (event[4] & STMFTS_MASK_Y_LSB);
+       u8 z = event[5];
+
+       input_report_abs(sdata->input, ABS_X, x);
+       input_report_abs(sdata->input, ABS_Y, y);
+       input_report_abs(sdata->input, ABS_DISTANCE, z);
+
+       input_sync(sdata->input);
+}
+
+static void stmfts_report_key_event(struct stmfts_data *sdata, const u8 event[])
+{
+       switch (event[2]) {
+       case 0:
+               input_report_key(sdata->input, KEY_BACK, 0);
+               input_report_key(sdata->input, KEY_MENU, 0);
+               break;
+
+       case STMFTS_MASK_KEY_BACK:
+               input_report_key(sdata->input, KEY_BACK, 1);
+               break;
+
+       case STMFTS_MASK_KEY_MENU:
+               input_report_key(sdata->input, KEY_MENU, 1);
+               break;
+
+       default:
+               dev_warn(&sdata->client->dev,
+                        "unknown key event: %#02x\n", event[2]);
+               break;
+       }
+
+       input_sync(sdata->input);
+}
+
+static void stmfts_parse_events(struct stmfts_data *sdata)
+{
+       int i;
+
+       for (i = 0; i < STMFTS_STACK_DEPTH; i++) {
+               u8 *event = &sdata->data[i * STMFTS_EVENT_SIZE];
+
+               switch (event[0]) {
+
+               case STMFTS_EV_CONTROLLER_READY:
+               case STMFTS_EV_SLEEP_OUT_CONTROLLER_READY:
+               case STMFTS_EV_STATUS:
+                       complete(&sdata->cmd_done);
+                       /* fall through */
+
+               case STMFTS_EV_NO_EVENT:
+               case STMFTS_EV_DEBUG:
+                       return;
+               }
+
+               switch (event[0] & STMFTS_MASK_EVENT_ID) {
+
+               case STMFTS_EV_MULTI_TOUCH_ENTER:
+               case STMFTS_EV_MULTI_TOUCH_MOTION:
+                       stmfts_report_contact_event(sdata, event);
+                       break;
+
+               case STMFTS_EV_MULTI_TOUCH_LEAVE:
+                       stmfts_report_contact_release(sdata, event);
+                       break;
+
+               case STMFTS_EV_HOVER_ENTER:
+               case STMFTS_EV_HOVER_LEAVE:
+               case STMFTS_EV_HOVER_MOTION:
+                       stmfts_report_hover_event(sdata, event);
+                       break;
+
+               case STMFTS_EV_KEY_STATUS:
+                       stmfts_report_key_event(sdata, event);
+                       break;
+
+               case STMFTS_EV_ERROR:
+                       dev_warn(&sdata->client->dev,
+                                       "error code: 0x%x%x%x%x%x%x",
+                                       event[6], event[5], event[4],
+                                       event[3], event[2], event[1]);
+                       break;
+
+               default:
+                       dev_err(&sdata->client->dev,
+                               "unknown event %#02x\n", event[0]);
+               }
+       }
+}
+
+static irqreturn_t stmfts_irq_handler(int irq, void *dev)
+{
+       struct stmfts_data *sdata = dev;
+       int err;
+
+       mutex_lock(&sdata->mutex);
+
+       err = stmfts_read_events(sdata);
+       if (unlikely(err))
+               dev_err(&sdata->client->dev,
+                       "failed to read events: %d\n", err);
+       else
+               stmfts_parse_events(sdata);
+
+       mutex_unlock(&sdata->mutex);
+       return IRQ_HANDLED;
+}
+
+static int stmfts_command(struct stmfts_data *sdata, const u8 cmd)
+{
+       int err;
+
+       reinit_completion(&sdata->cmd_done);
+
+       err = i2c_smbus_write_byte(sdata->client, cmd);
+       if (err)
+               return err;
+
+       if (!wait_for_completion_timeout(&sdata->cmd_done,
+                                        msecs_to_jiffies(1000)))
+               return -ETIMEDOUT;
+
+       return 0;
+}
+
+static int stmfts_input_open(struct input_dev *dev)
+{
+       struct stmfts_data *sdata = input_get_drvdata(dev);
+       int err;
+
+       err = pm_runtime_get_sync(&sdata->client->dev);
+       if (err < 0)
+               return err;
+
+       err = i2c_smbus_write_byte(sdata->client, STMFTS_MS_MT_SENSE_ON);
+       if (err)
+               return err;
+
+       mutex_lock(&sdata->mutex);
+       sdata->running = true;
+
+       if (sdata->hover_enabled) {
+               err = i2c_smbus_write_byte(sdata->client,
+                                          STMFTS_SS_HOVER_SENSE_ON);
+               if (err)
+                       dev_warn(&sdata->client->dev,
+                                "failed to enable hover\n");
+       }
+       mutex_unlock(&sdata->mutex);
+
+       if (sdata->use_key) {
+               err = i2c_smbus_write_byte(sdata->client,
+                                          STMFTS_MS_KEY_SENSE_ON);
+               if (err)
+                       /* I can still use only the touch screen */
+                       dev_warn(&sdata->client->dev,
+                                "failed to enable touchkey\n");
+       }
+
+       return 0;
+}
+
+static void stmfts_input_close(struct input_dev *dev)
+{
+       struct stmfts_data *sdata = input_get_drvdata(dev);
+       int err;
+
+       err = i2c_smbus_write_byte(sdata->client, STMFTS_MS_MT_SENSE_OFF);
+       if (err)
+               dev_warn(&sdata->client->dev,
+                        "failed to disable touchscreen: %d\n", err);
+
+       mutex_lock(&sdata->mutex);
+
+       sdata->running = false;
+
+       if (sdata->hover_enabled) {
+               err = i2c_smbus_write_byte(sdata->client,
+                                          STMFTS_SS_HOVER_SENSE_OFF);
+               if (err)
+                       dev_warn(&sdata->client->dev,
+                                "failed to disable hover: %d\n", err);
+       }
+       mutex_unlock(&sdata->mutex);
+
+       if (sdata->use_key) {
+               err = i2c_smbus_write_byte(sdata->client,
+                                          STMFTS_MS_KEY_SENSE_OFF);
+               if (err)
+                       dev_warn(&sdata->client->dev,
+                                "failed to disable touchkey: %d\n", err);
+       }
+
+       pm_runtime_put_sync(&sdata->client->dev);
+}
+
+static ssize_t stmfts_sysfs_chip_id(struct device *dev,
+                               struct device_attribute *attr, char *buf)
+{
+       struct stmfts_data *sdata = dev_get_drvdata(dev);
+
+       return sprintf(buf, "%#x\n", sdata->chip_id);
+}
+
+static ssize_t stmfts_sysfs_chip_version(struct device *dev,
+                               struct device_attribute *attr, char *buf)
+{
+       struct stmfts_data *sdata = dev_get_drvdata(dev);
+
+       return sprintf(buf, "%u\n", sdata->chip_ver);
+}
+
+static ssize_t stmfts_sysfs_fw_ver(struct device *dev,
+                               struct device_attribute *attr, char *buf)
+{
+       struct stmfts_data *sdata = dev_get_drvdata(dev);
+
+       return sprintf(buf, "%u\n", sdata->fw_ver);
+}
+
+static ssize_t stmfts_sysfs_config_id(struct device *dev,
+                               struct device_attribute *attr, char *buf)
+{
+       struct stmfts_data *sdata = dev_get_drvdata(dev);
+
+       return sprintf(buf, "%#x\n", sdata->config_id);
+}
+
+static ssize_t stmfts_sysfs_config_version(struct device *dev,
+                               struct device_attribute *attr, char *buf)
+{
+       struct stmfts_data *sdata = dev_get_drvdata(dev);
+
+       return sprintf(buf, "%u\n", sdata->config_ver);
+}
+
+static ssize_t stmfts_sysfs_read_status(struct device *dev,
+                               struct device_attribute *attr, char *buf)
+{
+       struct stmfts_data *sdata = dev_get_drvdata(dev);
+       u8 status[4];
+       int err;
+
+       err = i2c_smbus_read_i2c_block_data(sdata->client, STMFTS_READ_STATUS,
+                                           sizeof(status), status);
+       if (err)
+               return err;
+
+       return sprintf(buf, "%#02x\n", status[0]);
+}
+
+static ssize_t stmfts_sysfs_hover_enable_read(struct device *dev,
+                               struct device_attribute *attr, char *buf)
+{
+       struct stmfts_data *sdata = dev_get_drvdata(dev);
+
+       return sprintf(buf, "%u\n", sdata->hover_enabled);
+}
+
+static ssize_t stmfts_sysfs_hover_enable_write(struct device *dev,
+                               struct device_attribute *attr,
+                               const char *buf, size_t len)
+{
+       struct stmfts_data *sdata = dev_get_drvdata(dev);
+       unsigned long value;
+       int err = 0;
+
+       if (kstrtoul(buf, 0, &value))
+               return -EINVAL;
+
+       mutex_lock(&sdata->mutex);
+
+       if (value & sdata->hover_enabled)
+               goto out;
+
+       if (sdata->running)
+               err = i2c_smbus_write_byte(sdata->client,
+                                          value ? STMFTS_SS_HOVER_SENSE_ON :
+                                                  STMFTS_SS_HOVER_SENSE_OFF);
+
+       if (!err)
+               sdata->hover_enabled = !!value;
+
+out:
+       mutex_unlock(&sdata->mutex);
+
+       return len;
+}
+
+static DEVICE_ATTR(chip_id, 0444, stmfts_sysfs_chip_id, NULL);
+static DEVICE_ATTR(chip_version, 0444, stmfts_sysfs_chip_version, NULL);
+static DEVICE_ATTR(fw_ver, 0444, stmfts_sysfs_fw_ver, NULL);
+static DEVICE_ATTR(config_id, 0444, stmfts_sysfs_config_id, NULL);
+static DEVICE_ATTR(config_version, 0444, stmfts_sysfs_config_version, NULL);
+static DEVICE_ATTR(status, 0444, stmfts_sysfs_read_status, NULL);
+static DEVICE_ATTR(hover_enable, 0644, stmfts_sysfs_hover_enable_read,
+                                       stmfts_sysfs_hover_enable_write);
+
+static struct attribute *stmfts_sysfs_attrs[] = {
+       &dev_attr_chip_id.attr,
+       &dev_attr_chip_version.attr,
+       &dev_attr_fw_ver.attr,
+       &dev_attr_config_id.attr,
+       &dev_attr_config_version.attr,
+       &dev_attr_status.attr,
+       &dev_attr_hover_enable.attr,
+       NULL
+};
+
+static struct attribute_group stmfts_attribute_group = {
+       .attrs = stmfts_sysfs_attrs
+};
+
+static int stmfts_power_on(struct stmfts_data *sdata)
+{
+       int err;
+       u8 reg[8];
+
+       err = regulator_bulk_enable(ARRAY_SIZE(sdata->regulators),
+                                   sdata->regulators);
+       if (err)
+               return err;
+
+       /*
+        * The datasheet does not specify the power on time, but considering
+        * that the reset time is < 10ms, I sleep 20ms to be sure
+        */
+       msleep(20);
+
+       err = i2c_smbus_read_i2c_block_data(sdata->client, STMFTS_READ_INFO,
+                                           sizeof(reg), reg);
+       if (err < 0)
+               return err;
+       if (err != sizeof(reg))
+               return -EIO;
+
+       sdata->chip_id = be16_to_cpup((__be16 *)&reg[6]);
+       sdata->chip_ver = reg[0];
+       sdata->fw_ver = be16_to_cpup((__be16 *)&reg[2]);
+       sdata->config_id = reg[4];
+       sdata->config_ver = reg[5];
+
+       enable_irq(sdata->client->irq);
+
+       msleep(50);
+
+       err = stmfts_command(sdata, STMFTS_SYSTEM_RESET);
+       if (err)
+               return err;
+
+       err = stmfts_command(sdata, STMFTS_SLEEP_OUT);
+       if (err)
+               return err;
+
+       /* optional tuning */
+       err = stmfts_command(sdata, STMFTS_MS_CX_TUNING);
+       if (err)
+               dev_warn(&sdata->client->dev,
+                        "failed to perform mutual auto tune: %d\n", err);
+
+       /* optional tuning */
+       err = stmfts_command(sdata, STMFTS_SS_CX_TUNING);
+       if (err)
+               dev_warn(&sdata->client->dev,
+                        "failed to perform self auto tune: %d\n", err);
+
+       err = stmfts_command(sdata, STMFTS_FULL_FORCE_CALIBRATION);
+       if (err)
+               return err;
+
+       /*
+        * At this point no one is using the touchscreen
+        * and I don't really care about the return value
+        */
+       (void) i2c_smbus_write_byte(sdata->client, STMFTS_SLEEP_IN);
+
+       return 0;
+}
+
+static void stmfts_power_off(void *data)
+{
+       struct stmfts_data *sdata = data;
+
+       disable_irq(sdata->client->irq);
+       regulator_bulk_disable(ARRAY_SIZE(sdata->regulators),
+                                               sdata->regulators);
+}
+
+/* This function is void because I don't want to prevent using the touch key
+ * only because the LEDs don't get registered
+ */
+static int stmfts_enable_led(struct stmfts_data *sdata)
+{
+       int err;
+
+       /* get the regulator for powering the leds on */
+       sdata->ledvdd = devm_regulator_get(&sdata->client->dev, "ledvdd");
+       if (IS_ERR(sdata->ledvdd))
+               return PTR_ERR(sdata->ledvdd);
+
+       sdata->led_cdev.name = STMFTS_DEV_NAME;
+       sdata->led_cdev.max_brightness = LED_ON;
+       sdata->led_cdev.brightness = LED_OFF;
+       sdata->led_cdev.brightness_set = stmfts_brightness_set;
+       sdata->led_cdev.brightness_get = stmfts_brightness_get;
+
+       err = devm_led_classdev_register(&sdata->client->dev, &sdata->led_cdev);
+       if (err) {
+               devm_regulator_put(sdata->ledvdd);
+               return err;
+       }
+
+       return 0;
+}
+
+static int stmfts_probe(struct i2c_client *client,
+                       const struct i2c_device_id *id)
+{
+       int err;
+       struct stmfts_data *sdata;
+
+       if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
+                                               I2C_FUNC_SMBUS_BYTE_DATA |
+                                               I2C_FUNC_SMBUS_I2C_BLOCK))
+               return -ENODEV;
+
+       sdata = devm_kzalloc(&client->dev, sizeof(*sdata), GFP_KERNEL);
+       if (!sdata)
+               return -ENOMEM;
+
+       i2c_set_clientdata(client, sdata);
+
+       sdata->client = client;
+       mutex_init(&sdata->mutex);
+       init_completion(&sdata->cmd_done);
+
+       sdata->regulators[STMFTS_REGULATOR_VDD].supply = "vdd";
+       sdata->regulators[STMFTS_REGULATOR_AVDD].supply = "avdd";
+       err = devm_regulator_bulk_get(&client->dev,
+                                     ARRAY_SIZE(sdata->regulators),
+                                     sdata->regulators);
+       if (err)
+               return err;
+
+       sdata->input = devm_input_allocate_device(&client->dev);
+       if (!sdata->input)
+               return -ENOMEM;
+
+       sdata->input->name = STMFTS_DEV_NAME;
+       sdata->input->id.bustype = BUS_I2C;
+       sdata->input->open = stmfts_input_open;
+       sdata->input->close = stmfts_input_close;
+
+       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);
+
+       sdata->use_key = device_property_read_bool(&client->dev,
+                                                  "touch-key-connected");
+       if (sdata->use_key) {
+               input_set_capability(sdata->input, EV_KEY, KEY_MENU);
+               input_set_capability(sdata->input, EV_KEY, KEY_BACK);
+       }
+
+       err = input_mt_init_slots(sdata->input,
+                                 STMFTS_MAX_FINGERS, INPUT_MT_DIRECT);
+       if (err)
+               return err;
+
+       input_set_drvdata(sdata->input, sdata);
+
+       err = devm_request_threaded_irq(&client->dev, client->irq,
+                                       NULL, stmfts_irq_handler,
+                                       IRQF_ONESHOT,
+                                       "stmfts_irq", sdata);
+       if (err)
+               return err;
+
+       /* stmfts_power_on expects interrupt to be disabled */
+       disable_irq(client->irq);
+
+       dev_dbg(&client->dev, "initializing ST-Microelectronics FTS...\n");
+
+       err = stmfts_power_on(sdata);
+       if (err)
+               return err;
+
+       err = devm_add_action_or_reset(&client->dev, stmfts_power_off, sdata);
+       if (err)
+               return err;
+
+       err = input_register_device(sdata->input);
+       if (err)
+               return err;
+
+       if (sdata->use_key) {
+               err = stmfts_enable_led(sdata);
+               if (err) {
+                       /*
+                        * Even if the LEDs have failed to be initialized and
+                        * used in the driver, I can still use the device even
+                        * without LEDs. The ledvdd regulator pointer will be
+                        * used as a flag.
+                        */
+                       dev_warn(&client->dev, "unable to use touchkey leds\n");
+                       sdata->ledvdd = NULL;
+               }
+       }
+
+       err = 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)
+{
+       struct stmfts_data *sdata = dev_get_drvdata(dev);
+       int ret;
+
+       ret = i2c_smbus_write_byte(sdata->client, STMFTS_SLEEP_IN);
+       if (ret)
+               dev_warn(dev, "failed to suspend device: %d\n", ret);
+
+       return ret;
+}
+
+static int stmfts_runtime_resume(struct device *dev)
+{
+       struct stmfts_data *sdata = dev_get_drvdata(dev);
+       int ret;
+
+       ret = i2c_smbus_write_byte(sdata->client, STMFTS_SLEEP_OUT);
+       if (ret)
+               dev_err(dev, "failed to resume device: %d\n", ret);
+
+       return ret;
+}
+
+static int __maybe_unused stmfts_suspend(struct device *dev)
+{
+       struct stmfts_data *sdata = dev_get_drvdata(dev);
+
+       stmfts_power_off(sdata);
+
+       return 0;
+}
+
+static int __maybe_unused stmfts_resume(struct device *dev)
+{
+       struct stmfts_data *sdata = dev_get_drvdata(dev);
+
+       return stmfts_power_on(sdata);
+}
+
+static const struct dev_pm_ops stmfts_pm_ops = {
+       SET_SYSTEM_SLEEP_PM_OPS(stmfts_suspend, stmfts_resume)
+       SET_RUNTIME_PM_OPS(stmfts_runtime_suspend, stmfts_runtime_resume, NULL)
+};
+
+#ifdef CONFIG_OF
+static const struct of_device_id stmfts_of_match[] = {
+       { .compatible = "st,stmfts", },
+       { },
+};
+MODULE_DEVICE_TABLE(of, stmfts_of_match);
+#endif
+
+static const struct i2c_device_id stmfts_id[] = {
+       { "stmfts", 0 },
+       { },
+};
+MODULE_DEVICE_TABLE(i2c, stmfts_id);
+
+static struct i2c_driver stmfts_driver = {
+       .driver = {
+               .name = STMFTS_DEV_NAME,
+               .of_match_table = of_match_ptr(stmfts_of_match),
+               .pm = &stmfts_pm_ops,
+       },
+       .probe = 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");