[PATCH v4] Input: add support for the Samsung S6SY761 touchscreen

[PATCH v4] Input: add support for the Samsung S6SY761 touchscreen

[Andi Shyti]

The S6SY761 touchscreen is a capicitive multi-touch controller
for mobile use. It's connected with i2c at the address 0x48.

This commit provides a basic version of the driver which can
handle only initialization, touch events and power states.

The controller is controlled by a firmware which, in the version
I currently have, doesn't provide all the possible
functionalities mentioned in the datasheet.

Signed-off-by: Andi Shyti <andi.shyti@samsung.com>
---
Hi,

sorry for the mix-up of the previous patch. This one should be
fine. Here's the changelog:

v3 - v4
 - fixed a mismatch on the module name

v2 - v3
 - added security check on an unsigned value which can (unlikely)
   get a "negative" value

 - in the probe function the interrupt is requested after the
   input device registration in order to avoid checking in the
   interrupt handler whether the input device has been registered

 - removed the 'prev_pm_state' variable. Its original meaning
   was to restore the state of the device when coming back from
   sleep mode, but because I removed in patch v2 the low power
   mode, now the device works only in two modes and therefore
   'prev_pm_state' is not required any longer.

v1 - v2
 - remove the low power functionality as it doesn't bring any
   benefit
 - use get_unaligned_be16 instead of the form 'a << 8 | b'
 - use max_t instead of '? :'
 - use managed 'devm_device_add_group()'

Thanks,
Andi

 .../bindings/input/touchscreen/samsung,s6sy761.txt |  34 ++
 drivers/input/touchscreen/Kconfig                  |  11 +
 drivers/input/touchscreen/Makefile                 |   1 +
 drivers/input/touchscreen/s6sy761.c                | 556 +++++++++++++++++++++
 4 files changed, 602 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/input/touchscreen/samsung,s6sy761.txt
 create mode 100644 drivers/input/touchscreen/s6sy761.c

diff --git a/Documentation/devicetree/bindings/input/touchscreen/samsung,s6sy761.txt b/Documentation/devicetree/bindings/input/touchscreen/samsung,s6sy761.txt
new file mode 100644
index 000000000000..d9b7c2ff611e
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/touchscreen/samsung,s6sy761.txt
@@ -0,0 +1,34 @@
+* Samsung S6SY761 touchscreen controller
+
+Required properties:
+- compatible		: must be "samsung,s6sy761"
+- reg			: I2C slave address, (e.g. 0x48)
+- interrupt-parent	: the phandle to the interrupt controller which provides
+			  the interrupt
+- interrupts		: interrupt specification
+- avdd-supply		: analogic power supply
+- vdd-supply		: power supply
+
+Optional properties:
+- touchscreen-size-x	: see touchscreen.txt. This property is embedded in the
+			  device. If defined it forces a different x resolution.
+- touchscreen-size-y	: see touchscreen.txt. This property is embedded in the
+			  device. If defined it forces a different y resolution.
+
+Example:
+
+i2c@00000000 {
+
+	/* ... */
+
+	touchscreen@48 {
+		compatible = "samsung,s6sy761";
+		reg = <0x48>;
+		interrupt-parent = <&gpa1>;
+		interrupts = <1 IRQ_TYPE_NONE>;
+		avdd-supply = <&ldo30_reg>;
+		vdd-supply = <&ldo31_reg>;
+		touchscreen-size-x = <4096>;
+		touchscreen-size-y = <4096>;
+	};
+};
diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 176b1a74b2b7..c903db4cf7b2 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -383,6 +383,17 @@ config TOUCHSCREEN_S3C2410
 	  To compile this driver as a module, choose M here: the
 	  module will be called s3c2410_ts.
 
+config TOUCHSCREEN_S6SY761
+	tristate "Samsung S6SY761 Touchscreen driver"
+	depends on I2C
+	help
+	  Say Y if you have the Samsung S6SY761 driver
+
+	  If unsure, say N
+
+	  To compile this driver as module, choose M here: the
+	  module will be called s6sy761.
+
 config TOUCHSCREEN_GUNZE
 	tristate "Gunze AHL-51S touchscreen"
 	select SERIO
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 6badce87037b..4f63439211fd 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -64,6 +64,7 @@ obj-$(CONFIG_TOUCHSCREEN_PENMOUNT)	+= penmount.o
 obj-$(CONFIG_TOUCHSCREEN_PIXCIR)	+= pixcir_i2c_ts.o
 obj-$(CONFIG_TOUCHSCREEN_RM_TS)		+= raydium_i2c_ts.o
 obj-$(CONFIG_TOUCHSCREEN_S3C2410)	+= s3c2410_ts.o
+obj-$(CONFIG_TOUCHSCREEN_S6SY761)	+= s6sy761.o
 obj-$(CONFIG_TOUCHSCREEN_SILEAD)	+= silead.o
 obj-$(CONFIG_TOUCHSCREEN_SIS_I2C)	+= sis_i2c.o
 obj-$(CONFIG_TOUCHSCREEN_ST1232)	+= st1232.o
diff --git a/drivers/input/touchscreen/s6sy761.c b/drivers/input/touchscreen/s6sy761.c
new file mode 100644
index 000000000000..953b0fba7039
--- /dev/null
+++ b/drivers/input/touchscreen/s6sy761.c
@@ -0,0 +1,556 @@
+/*
+ * 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.
+ *
+ * Samsung S6SY761 Touchscreen device driver
+ */
+
+#include <asm/unaligned.h>
+#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/module.h>
+#include <linux/pm_runtime.h>
+#include <linux/regulator/consumer.h>
+
+/* commands */
+#define S6SY761_SENSE_ON		0x10
+#define S6SY761_SENSE_OFF		0x11
+#define S6SY761_TOUCH_FUNCTION		0x30 /* R/W for get/set */
+#define S6SY761_FIRMWARE_INTEGRITY	0x21
+#define S6SY761_PANEL_ID		0x23
+#define S6SY761_DEVICE_ID		0x52
+#define S6SY761_BOOT_STATUS		0x55
+#define S6SY761_READ_ONE_EVENT		0x60
+#define S6SY761_READ_ALL_EVENT		0x61
+#define S6SY761_CLEAR_EVENT_STACK	0x62
+#define S6SY761_APPLICATION_MODE	0xe4
+#define S6SY761_TS_STATUS		0xaf
+
+/* events */
+#define S6SY761_EVENT_INFO		0x02
+#define S6SY761_EVENT_VENDOR_INFO	0x07
+
+/* info */
+#define S6SY761_INFO_BOOT_COMPLETE	0x00
+
+/* firmware status */
+#define S6SY761_FW_OK			0x80
+
+/*
+ * the functionalities are put as a reference
+ * as in the device I am using none of them
+ * works therefore not used in this driver yet.
+ */
+/* touchscreen functionalities */
+#define S6SY761_MASK_TOUCH		BIT(0)
+#define S6SY761_MASK_HOVER		BIT(1)
+#define S6SY761_MASK_COVER		BIT(2)
+#define S6SY761_MASK_GLOVE		BIT(3)
+#define S6SY761_MASK_STYLUS		BIT(4)
+#define S6SY761_MASK_PALM		BIT(5)
+#define S6SY761_MASK_WET		BIT(6)
+#define S6SY761_MASK_PROXIMITY		BIT(7)
+
+/* event id */
+#define S6SY761_EVENT_ID_COORDINATE	0x00
+#define S6SY761_EVENT_ID_STATUS		0x01
+
+/* event register masks */
+#define S6SY761_MASK_TOUCH_STATE	0xc0 /* byte 0 */
+#define S6SY761_MASK_TID		0x3c
+#define S6SY761_MASK_EID		0x03
+#define S6SY761_MASK_X			0xf0 /* byte 3 */
+#define S6SY761_MASK_Y			0x0f
+#define S6SY761_MASK_Z			0x3f /* byte 6 */
+#define S6SY761_MASK_LEFT_EVENTS	0x3f /* byte 7 */
+#define S6SY761_MASK_TOUCH_TYPE		0xc0 /* MSB in byte 6, LSB in byte 7 */
+
+/* event touch state values */
+#define S6SY761_TS_NONE			0x00
+#define S6SY761_TS_PRESS		0x01
+#define S6SY761_TS_MOVE			0x02
+#define S6SY761_TS_RELEASE		0x03
+
+/* application modes */
+#define S6SY761_APP_NORMAL		0x0
+#define S6SY761_APP_LOW_POWER		0x1
+#define S6SY761_APP_TEST		0x2
+#define S6SY761_APP_FLASH		0x3
+#define S6SY761_APP_SLEEP		0x4
+
+#define S6SY761_EVENT_SIZE	8
+#define S6SY761_EVENT_COUNT	32
+#define S6SY761_ALL_EVENT	(S6SY761_EVENT_SIZE * S6SY761_EVENT_COUNT)
+#define S6SY761_DEVID_SIZE	3
+#define S6SY761_PANEL_ID_SIZE	11
+#define S6SY761_TS_STATUS_SIZE	5
+#define S6SY761_MAX_FINGERS	10
+
+#define S6SY761_DEV_NAME	"s6sy761"
+
+enum s6sy761_regulators {
+	S6SY761_REGULATOR_VDD,
+	S6SY761_REGULATOR_AVDD,
+};
+
+struct s6sy761_data {
+	struct i2c_client *client;
+	struct regulator_bulk_data regulators[2];
+	struct input_dev *input;
+	struct touchscreen_properties prop;
+	struct mutex mutex;
+
+	u8 data[S6SY761_ALL_EVENT];
+
+	u16 devid;
+	u8 tx_channel;
+};
+
+
+/*
+ * We can't simply use i2c_smbus_read_i2c_block_data because we
+ * need to read more than 255 bytes
+ */
+static int s6sy761_read_events(struct s6sy761_data *sdata, u16 left_event)
+{
+	u8 cmd = S6SY761_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	= left_event,
+			.buf	= sdata->data + S6SY761_EVENT_COUNT,
+		},
+	};
+	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 s6sy761_report_coordinates(struct s6sy761_data *sdata, u8 *event)
+{
+	u8 tid;
+	u8 major = event[4];
+	u8 minor = event[5];
+	u8 z = event[6] & S6SY761_MASK_Z;
+	u16 x = (event[1] << 3) | ((event[3] & S6SY761_MASK_X) >> 4);
+	u16 y = (event[2] << 3) | (event[3] & S6SY761_MASK_Y);
+
+	if (unlikely(!(event[0] & S6SY761_MASK_TID)))
+		return;
+
+	tid = ((event[0] & S6SY761_MASK_TID) >> 2) - 1;
+
+	input_mt_slot(sdata->input, tid);
+
+	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, major);
+	input_report_abs(sdata->input, ABS_MT_TOUCH_MINOR, minor);
+	input_report_abs(sdata->input, ABS_MT_PRESSURE, z);
+
+	input_sync(sdata->input);
+}
+
+static void s6sy761_report_release(struct s6sy761_data *sdata, u8 *event)
+{
+	u8 tid = ((event[0] & S6SY761_MASK_TID) >> 2) - 1;
+
+	input_mt_slot(sdata->input, tid);
+	input_mt_report_slot_state(sdata->input, MT_TOOL_FINGER, false);
+
+	input_sync(sdata->input);
+}
+
+static void s6sy761_handle_coordinates(struct s6sy761_data *sdata, u8 *event)
+{
+	u8 touch_state = (event[0] & S6SY761_MASK_TOUCH_STATE) >> 6;
+
+	switch (touch_state) {
+
+	case S6SY761_TS_NONE:
+		break;
+	case S6SY761_TS_RELEASE:
+		s6sy761_report_release(sdata, event);
+		break;
+	case S6SY761_TS_PRESS:
+	case S6SY761_TS_MOVE:
+		s6sy761_report_coordinates(sdata, event);
+		break;
+	}
+}
+
+static void s6sy761_handle_events(struct s6sy761_data *sdata, u8 left_event)
+{
+	int i;
+
+	for (i = 0; i < left_event; i++) {
+		u8 *event = &sdata->data[i * S6SY761_EVENT_SIZE];
+		u8 event_id = event[0] & S6SY761_MASK_EID;
+
+		if (!event[0])
+			return;
+
+		switch (event_id) {
+
+		case S6SY761_EVENT_ID_COORDINATE:
+			s6sy761_handle_coordinates(sdata, event);
+			break;
+
+		case S6SY761_EVENT_ID_STATUS:
+			break;
+
+		default:
+			break;
+		}
+	}
+}
+
+static irqreturn_t s6sy761_irq_handler(int irq, void *dev)
+{
+	struct s6sy761_data *sdata = dev;
+	int ret;
+	u8 left_event;
+
+	mutex_lock(&sdata->mutex);
+	ret = i2c_smbus_read_i2c_block_data(sdata->client,
+					    S6SY761_READ_ONE_EVENT,
+					    S6SY761_EVENT_SIZE,
+					    sdata->data);
+	if (ret < 0) {
+		dev_err(&sdata->client->dev, "failed to read events\n");
+		goto out;
+	}
+
+	if (!sdata->data[0])
+		goto out;
+
+	left_event = sdata->data[7] & S6SY761_MASK_LEFT_EVENTS;
+	if (unlikely(left_event > S6SY761_EVENT_COUNT - 1))
+		goto out;
+
+	if (left_event) {
+		ret = s6sy761_read_events(sdata,
+					  left_event * S6SY761_EVENT_COUNT);
+		if (ret < 0) {
+			dev_err(&sdata->client->dev, "failed to read events\n");
+			goto out;
+		}
+	}
+
+	s6sy761_handle_events(sdata, left_event +  1);
+
+	i2c_smbus_write_byte(sdata->client, S6SY761_CLEAR_EVENT_STACK);
+
+out:
+	mutex_unlock(&sdata->mutex);
+	return IRQ_HANDLED;
+}
+
+static int s6sy761_input_open(struct input_dev *dev)
+{
+	struct s6sy761_data *sdata = input_get_drvdata(dev);
+
+	return i2c_smbus_write_byte(sdata->client, S6SY761_SENSE_ON);
+}
+
+static void s6sy761_input_close(struct input_dev *dev)
+{
+	struct s6sy761_data *sdata = input_get_drvdata(dev);
+	int ret;
+
+	ret = i2c_smbus_write_byte(sdata->client, S6SY761_SENSE_OFF);
+	if (ret)
+		dev_err(&sdata->client->dev, "failed to turn off sensing\n");
+}
+
+static ssize_t s6sy761_sysfs_devid(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct s6sy761_data *sdata = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%#x\n", sdata->devid);
+}
+
+static DEVICE_ATTR(devid, 0444, s6sy761_sysfs_devid, NULL);
+
+static struct attribute *s6sy761_sysfs_attrs[] = {
+	&dev_attr_devid.attr,
+	NULL
+};
+
+static struct attribute_group s6sy761_attribute_group = {
+	.attrs = s6sy761_sysfs_attrs
+};
+
+static int s6sy761_hw_init(struct s6sy761_data *sdata)
+{
+	u8 buffer[S6SY761_PANEL_ID_SIZE]; /* larger read size */
+	u8 event;
+	int ret;
+
+	ret = regulator_bulk_enable(ARRAY_SIZE(sdata->regulators),
+				    sdata->regulators);
+	if (ret)
+		return ret;
+
+	msleep(140);
+
+	ret = i2c_smbus_read_i2c_block_data(sdata->client,
+					    S6SY761_READ_ONE_EVENT,
+					    S6SY761_EVENT_SIZE,
+					    buffer);
+	if (ret < 0)
+		return ret;
+
+	event = (buffer[0] >> 2) & 0xf;
+
+	if ((event != S6SY761_EVENT_INFO &&
+		event != S6SY761_EVENT_VENDOR_INFO) ||
+		buffer[1] != S6SY761_INFO_BOOT_COMPLETE)
+		return -ENODEV;
+
+	ret = i2c_smbus_read_i2c_block_data(sdata->client,
+					    S6SY761_DEVICE_ID,
+					    S6SY761_DEVID_SIZE,
+					    buffer);
+	if (ret < 0)
+		return ret;
+
+	sdata->devid = get_unaligned_be16(buffer + 1);
+
+	ret = i2c_smbus_read_i2c_block_data(sdata->client,
+					    S6SY761_PANEL_ID,
+					    S6SY761_PANEL_ID_SIZE,
+					    buffer);
+	if (ret < 0)
+		return ret;
+
+	/* the user hasn't specified the touchscreen resolution */
+	if (!sdata->prop.max_x)
+		sdata->prop.max_x = get_unaligned_be16(buffer);
+
+	if (!sdata->prop.max_y)
+		sdata->prop.max_y = get_unaligned_be16(buffer + 2);
+
+	/* check if both max_x and max_y have a value */
+	if (!sdata->prop.max_x || !sdata->prop.max_y)
+		return -EINVAL;
+
+	/* if no tx channels defined, at least keep one */
+	sdata->tx_channel = max_t(u8, buffer[8], 1);
+
+	ret = i2c_smbus_read_byte_data(sdata->client,
+				       S6SY761_FIRMWARE_INTEGRITY);
+	if (ret < 0)
+		return ret;
+	else if (ret != S6SY761_FW_OK)
+		return -ENODEV;
+
+	ret = i2c_smbus_read_byte_data(sdata->client, S6SY761_BOOT_STATUS);
+	if (ret < 0)
+		return ret;
+
+	ret = i2c_smbus_read_i2c_block_data(sdata->client,
+					    S6SY761_TS_STATUS,
+					    S6SY761_TS_STATUS_SIZE,
+					    buffer);
+	if (ret < 0)
+		return ret;
+
+	ret = i2c_smbus_write_word_data(sdata->client,
+					S6SY761_TOUCH_FUNCTION,
+					S6SY761_MASK_TOUCH);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static void s6sy761_power_off(void *data)
+{
+	struct s6sy761_data *sdata = data;
+
+	disable_irq(sdata->client->irq);
+	regulator_bulk_disable(ARRAY_SIZE(sdata->regulators),
+						sdata->regulators);
+}
+
+static int s6sy761_probe(struct i2c_client *client,
+			const struct i2c_device_id *id)
+{
+	struct s6sy761_data *sdata;
+	int err;
+
+	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);
+
+	sdata->regulators[S6SY761_REGULATOR_VDD].supply = "vdd";
+	sdata->regulators[S6SY761_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, s6sy761_power_off, sdata);
+	if (err)
+		return err;
+
+	err = s6sy761_hw_init(sdata);
+	if (err)
+		return err;
+
+	sdata->input = devm_input_allocate_device(&client->dev);
+	if (!sdata->input)
+		return -ENOMEM;
+
+	sdata->input->name = S6SY761_DEV_NAME;
+	sdata->input->id.bustype = BUS_I2C;
+	sdata->input->open = s6sy761_input_open;
+	sdata->input->close = s6sy761_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);
+	/* the pressure is represented in 6 bits */
+	input_set_abs_params(sdata->input, ABS_MT_PRESSURE, 0, 255, 0, 0);
+
+	err = input_mt_init_slots(sdata->input,
+				  sdata->tx_channel,
+				  INPUT_MT_DIRECT);
+	if (err)
+		return err;
+
+	input_set_drvdata(sdata->input, sdata);
+
+	err = input_register_device(sdata->input);
+	if (err)
+		return err;
+
+	err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
+					s6sy761_irq_handler,
+					IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+					"s6sy761_irq", sdata);
+	if (err)
+		return err;
+
+	err = devm_device_add_group(&client->dev, &s6sy761_attribute_group);
+	if (err)
+		return err;
+
+	pm_runtime_enable(&client->dev);
+
+	return 0;
+}
+
+static int s6sy761_remove(struct i2c_client *client)
+{
+	pm_runtime_disable(&client->dev);
+
+	return 0;
+}
+
+static int __maybe_unused s6sy761_runtime_suspend(struct device *dev)
+{
+	struct s6sy761_data *sdata = dev_get_drvdata(dev);
+
+	return i2c_smbus_write_byte_data(sdata->client,
+				S6SY761_APPLICATION_MODE, S6SY761_APP_SLEEP);
+}
+
+static int __maybe_unused s6sy761_runtime_resume(struct device *dev)
+{
+	struct s6sy761_data *sdata = dev_get_drvdata(dev);
+
+	return i2c_smbus_write_byte_data(sdata->client,
+				S6SY761_APPLICATION_MODE, S6SY761_APP_NORMAL);
+}
+
+static int __maybe_unused s6sy761_suspend(struct device *dev)
+{
+	struct s6sy761_data *sdata = dev_get_drvdata(dev);
+
+	s6sy761_power_off(sdata);
+
+	return 0;
+}
+
+static int __maybe_unused s6sy761_resume(struct device *dev)
+{
+	struct s6sy761_data *sdata = dev_get_drvdata(dev);
+
+	enable_irq(sdata->client->irq);
+
+	return s6sy761_hw_init(sdata);
+}
+
+static const struct dev_pm_ops s6sy761_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(s6sy761_suspend, s6sy761_resume)
+	SET_RUNTIME_PM_OPS(s6sy761_runtime_suspend,
+				s6sy761_runtime_resume, NULL)
+};
+
+#ifdef CONFIG_OF
+static const struct of_device_id s6sy761_of_match[] = {
+	{ .compatible = "samsung,s6sy761", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, s6sy761_of_match);
+#endif
+
+static const struct i2c_device_id s6sy761_id[] = {
+	{ "s6sy761", 0 },
+	{ },
+};
+MODULE_DEVICE_TABLE(i2c, s6sy761_id);
+
+static struct i2c_driver s6sy761_driver = {
+	.driver = {
+		.name = S6SY761_DEV_NAME,
+		.of_match_table = of_match_ptr(s6sy761_of_match),
+		.pm = &s6sy761_pm_ops,
+	},
+	.probe = s6sy761_probe,
+	.remove = s6sy761_remove,
+	.id_table = s6sy761_id,
+};
+
+module_i2c_driver(s6sy761_driver);
+
+MODULE_AUTHOR("Andi Shyti <andi.shyti@samsung.com>");
+MODULE_DESCRIPTION("Samsung S6SY761 Touch Screen");
+MODULE_LICENSE("GPL v2");
-- 
2.14.1

Re: [PATCH v4] Input: add support for the Samsung S6SY761 touchscreen

[Rob Herring]

On Tue, Sep 26, 2017 at 03:31:35PM +0900, Andi Shyti wrote:
> The S6SY761 touchscreen is a capicitive multi-touch controller
> for mobile use. It's connected with i2c at the address 0x48.
> 
> This commit provides a basic version of the driver which can
> handle only initialization, touch events and power states.
> 
> The controller is controlled by a firmware which, in the version
> I currently have, doesn't provide all the possible
> functionalities mentioned in the datasheet.
> 
> Signed-off-by: Andi Shyti <andi.shyti@samsung.com>
> ---
> Hi,
> 
> sorry for the mix-up of the previous patch. This one should be
> fine. Here's the changelog:
> 
> v3 - v4
>  - fixed a mismatch on the module name
> 
> v2 - v3
>  - added security check on an unsigned value which can (unlikely)
>    get a "negative" value
> 
>  - in the probe function the interrupt is requested after the
>    input device registration in order to avoid checking in the
>    interrupt handler whether the input device has been registered
> 
>  - removed the 'prev_pm_state' variable. Its original meaning
>    was to restore the state of the device when coming back from
>    sleep mode, but because I removed in patch v2 the low power
>    mode, now the device works only in two modes and therefore
>    'prev_pm_state' is not required any longer.
> 
> v1 - v2
>  - remove the low power functionality as it doesn't bring any
>    benefit
>  - use get_unaligned_be16 instead of the form 'a << 8 | b'
>  - use max_t instead of '? :'
>  - use managed 'devm_device_add_group()'
> 
> Thanks,
> Andi
> 
>  .../bindings/input/touchscreen/samsung,s6sy761.txt |  34 ++

In the future, a separate patch for bindings please.

Otherwise,

Acked-by: Rob Herring <robh@kernel.org>

>  drivers/input/touchscreen/Kconfig                  |  11 +
>  drivers/input/touchscreen/Makefile                 |   1 +
>  drivers/input/touchscreen/s6sy761.c                | 556 +++++++++++++++++++++
>  4 files changed, 602 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/input/touchscreen/samsung,s6sy761.txt
>  create mode 100644 drivers/input/touchscreen/s6sy761.c

Re: [PATCH v4] Input: add support for the Samsung S6SY761 touchscreen

[Dmitry Torokhov]

Hi Andi,

On Tue, Sep 26, 2017 at 03:31:35PM +0900, Andi Shyti wrote:
> The S6SY761 touchscreen is a capicitive multi-touch controller
> for mobile use. It's connected with i2c at the address 0x48.
> 
> This commit provides a basic version of the driver which can
> handle only initialization, touch events and power states.
> 
> The controller is controlled by a firmware which, in the version
> I currently have, doesn't provide all the possible
> functionalities mentioned in the datasheet.
> 
> Signed-off-by: Andi Shyti <andi.shyti@samsung.com>
> ---
> Hi,
> 
> sorry for the mix-up of the previous patch. This one should be
> fine. Here's the changelog:
> 
> v3 - v4
>  - fixed a mismatch on the module name
> 
> v2 - v3
>  - added security check on an unsigned value which can (unlikely)
>    get a "negative" value
> 
>  - in the probe function the interrupt is requested after the
>    input device registration in order to avoid checking in the
>    interrupt handler whether the input device has been registered
> 
>  - removed the 'prev_pm_state' variable. Its original meaning
>    was to restore the state of the device when coming back from
>    sleep mode, but because I removed in patch v2 the low power
>    mode, now the device works only in two modes and therefore
>    'prev_pm_state' is not required any longer.
> 
> v1 - v2
>  - remove the low power functionality as it doesn't bring any
>    benefit
>  - use get_unaligned_be16 instead of the form 'a << 8 | b'
>  - use max_t instead of '? :'
>  - use managed 'devm_device_add_group()'
> 
> Thanks,
> Andi
> 
>  .../bindings/input/touchscreen/samsung,s6sy761.txt |  34 ++
>  drivers/input/touchscreen/Kconfig                  |  11 +
>  drivers/input/touchscreen/Makefile                 |   1 +
>  drivers/input/touchscreen/s6sy761.c                | 556 +++++++++++++++++++++
>  4 files changed, 602 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/input/touchscreen/samsung,s6sy761.txt
>  create mode 100644 drivers/input/touchscreen/s6sy761.c
> 
> diff --git a/Documentation/devicetree/bindings/input/touchscreen/samsung,s6sy761.txt b/Documentation/devicetree/bindings/input/touchscreen/samsung,s6sy761.txt
> new file mode 100644
> index 000000000000..d9b7c2ff611e
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/input/touchscreen/samsung,s6sy761.txt
> @@ -0,0 +1,34 @@
> +* Samsung S6SY761 touchscreen controller
> +
> +Required properties:
> +- compatible		: must be "samsung,s6sy761"
> +- reg			: I2C slave address, (e.g. 0x48)
> +- interrupt-parent	: the phandle to the interrupt controller which provides
> +			  the interrupt
> +- interrupts		: interrupt specification
> +- avdd-supply		: analogic power supply
> +- vdd-supply		: power supply
> +
> +Optional properties:
> +- touchscreen-size-x	: see touchscreen.txt. This property is embedded in the
> +			  device. If defined it forces a different x resolution.
> +- touchscreen-size-y	: see touchscreen.txt. This property is embedded in the
> +			  device. If defined it forces a different y resolution.
> +
> +Example:
> +
> +i2c@00000000 {
> +
> +	/* ... */
> +
> +	touchscreen@48 {
> +		compatible = "samsung,s6sy761";
> +		reg = <0x48>;
> +		interrupt-parent = <&gpa1>;
> +		interrupts = <1 IRQ_TYPE_NONE>;
> +		avdd-supply = <&ldo30_reg>;
> +		vdd-supply = <&ldo31_reg>;
> +		touchscreen-size-x = <4096>;
> +		touchscreen-size-y = <4096>;
> +	};
> +};
> diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
> index 176b1a74b2b7..c903db4cf7b2 100644
> --- a/drivers/input/touchscreen/Kconfig
> +++ b/drivers/input/touchscreen/Kconfig
> @@ -383,6 +383,17 @@ config TOUCHSCREEN_S3C2410
>  	  To compile this driver as a module, choose M here: the
>  	  module will be called s3c2410_ts.
>  
> +config TOUCHSCREEN_S6SY761
> +	tristate "Samsung S6SY761 Touchscreen driver"
> +	depends on I2C
> +	help
> +	  Say Y if you have the Samsung S6SY761 driver
> +
> +	  If unsure, say N
> +
> +	  To compile this driver as module, choose M here: the
> +	  module will be called s6sy761.
> +
>  config TOUCHSCREEN_GUNZE
>  	tristate "Gunze AHL-51S touchscreen"
>  	select SERIO
> diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
> index 6badce87037b..4f63439211fd 100644
> --- a/drivers/input/touchscreen/Makefile
> +++ b/drivers/input/touchscreen/Makefile
> @@ -64,6 +64,7 @@ obj-$(CONFIG_TOUCHSCREEN_PENMOUNT)	+= penmount.o
>  obj-$(CONFIG_TOUCHSCREEN_PIXCIR)	+= pixcir_i2c_ts.o
>  obj-$(CONFIG_TOUCHSCREEN_RM_TS)		+= raydium_i2c_ts.o
>  obj-$(CONFIG_TOUCHSCREEN_S3C2410)	+= s3c2410_ts.o
> +obj-$(CONFIG_TOUCHSCREEN_S6SY761)	+= s6sy761.o
>  obj-$(CONFIG_TOUCHSCREEN_SILEAD)	+= silead.o
>  obj-$(CONFIG_TOUCHSCREEN_SIS_I2C)	+= sis_i2c.o
>  obj-$(CONFIG_TOUCHSCREEN_ST1232)	+= st1232.o
> diff --git a/drivers/input/touchscreen/s6sy761.c b/drivers/input/touchscreen/s6sy761.c
> new file mode 100644
> index 000000000000..953b0fba7039
> --- /dev/null
> +++ b/drivers/input/touchscreen/s6sy761.c
> @@ -0,0 +1,556 @@
> +/*
> + * 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.
> + *
> + * Samsung S6SY761 Touchscreen device driver
> + */
> +
> +#include <asm/unaligned.h>
> +#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/module.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/regulator/consumer.h>
> +
> +/* commands */
> +#define S6SY761_SENSE_ON		0x10
> +#define S6SY761_SENSE_OFF		0x11
> +#define S6SY761_TOUCH_FUNCTION		0x30 /* R/W for get/set */
> +#define S6SY761_FIRMWARE_INTEGRITY	0x21
> +#define S6SY761_PANEL_ID		0x23
> +#define S6SY761_DEVICE_ID		0x52
> +#define S6SY761_BOOT_STATUS		0x55
> +#define S6SY761_READ_ONE_EVENT		0x60
> +#define S6SY761_READ_ALL_EVENT		0x61
> +#define S6SY761_CLEAR_EVENT_STACK	0x62
> +#define S6SY761_APPLICATION_MODE	0xe4
> +#define S6SY761_TS_STATUS		0xaf
> +
> +/* events */
> +#define S6SY761_EVENT_INFO		0x02
> +#define S6SY761_EVENT_VENDOR_INFO	0x07
> +
> +/* info */
> +#define S6SY761_INFO_BOOT_COMPLETE	0x00
> +
> +/* firmware status */
> +#define S6SY761_FW_OK			0x80
> +
> +/*
> + * the functionalities are put as a reference
> + * as in the device I am using none of them
> + * works therefore not used in this driver yet.
> + */
> +/* touchscreen functionalities */
> +#define S6SY761_MASK_TOUCH		BIT(0)
> +#define S6SY761_MASK_HOVER		BIT(1)
> +#define S6SY761_MASK_COVER		BIT(2)
> +#define S6SY761_MASK_GLOVE		BIT(3)
> +#define S6SY761_MASK_STYLUS		BIT(4)
> +#define S6SY761_MASK_PALM		BIT(5)
> +#define S6SY761_MASK_WET		BIT(6)
> +#define S6SY761_MASK_PROXIMITY		BIT(7)
> +
> +/* event id */
> +#define S6SY761_EVENT_ID_COORDINATE	0x00
> +#define S6SY761_EVENT_ID_STATUS		0x01
> +
> +/* event register masks */
> +#define S6SY761_MASK_TOUCH_STATE	0xc0 /* byte 0 */
> +#define S6SY761_MASK_TID		0x3c
> +#define S6SY761_MASK_EID		0x03
> +#define S6SY761_MASK_X			0xf0 /* byte 3 */
> +#define S6SY761_MASK_Y			0x0f
> +#define S6SY761_MASK_Z			0x3f /* byte 6 */
> +#define S6SY761_MASK_LEFT_EVENTS	0x3f /* byte 7 */
> +#define S6SY761_MASK_TOUCH_TYPE		0xc0 /* MSB in byte 6, LSB in byte 7 */
> +
> +/* event touch state values */
> +#define S6SY761_TS_NONE			0x00
> +#define S6SY761_TS_PRESS		0x01
> +#define S6SY761_TS_MOVE			0x02
> +#define S6SY761_TS_RELEASE		0x03
> +
> +/* application modes */
> +#define S6SY761_APP_NORMAL		0x0
> +#define S6SY761_APP_LOW_POWER		0x1
> +#define S6SY761_APP_TEST		0x2
> +#define S6SY761_APP_FLASH		0x3
> +#define S6SY761_APP_SLEEP		0x4
> +
> +#define S6SY761_EVENT_SIZE	8
> +#define S6SY761_EVENT_COUNT	32
> +#define S6SY761_ALL_EVENT	(S6SY761_EVENT_SIZE * S6SY761_EVENT_COUNT)
> +#define S6SY761_DEVID_SIZE	3
> +#define S6SY761_PANEL_ID_SIZE	11
> +#define S6SY761_TS_STATUS_SIZE	5
> +#define S6SY761_MAX_FINGERS	10
> +
> +#define S6SY761_DEV_NAME	"s6sy761"
> +
> +enum s6sy761_regulators {
> +	S6SY761_REGULATOR_VDD,
> +	S6SY761_REGULATOR_AVDD,
> +};
> +
> +struct s6sy761_data {
> +	struct i2c_client *client;
> +	struct regulator_bulk_data regulators[2];
> +	struct input_dev *input;
> +	struct touchscreen_properties prop;
> +	struct mutex mutex;
> +
> +	u8 data[S6SY761_ALL_EVENT];
> +
> +	u16 devid;
> +	u8 tx_channel;
> +};
> +
> +
> +/*
> + * We can't simply use i2c_smbus_read_i2c_block_data because we
> + * need to read more than 255 bytes
> + */
> +static int s6sy761_read_events(struct s6sy761_data *sdata, u16 left_event)

Can we call it n_events instead of left_event? left_event makes me think
there is also right_event and possibly middle_event.

> +{
> +	u8 cmd = S6SY761_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	= left_event,
> +			.buf	= sdata->data + S6SY761_EVENT_COUNT,

Are you sure it is S6SY761_EVENT_COUNT and not S6SY761_EVENT_SIZE? I;d
expect you want to "move" one event within the buffer?

> +		},
> +	};
> +	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 s6sy761_report_coordinates(struct s6sy761_data *sdata, u8 *event)
> +{
> +	u8 tid;
> +	u8 major = event[4];
> +	u8 minor = event[5];
> +	u8 z = event[6] & S6SY761_MASK_Z;
> +	u16 x = (event[1] << 3) | ((event[3] & S6SY761_MASK_X) >> 4);
> +	u16 y = (event[2] << 3) | (event[3] & S6SY761_MASK_Y);
> +
> +	if (unlikely(!(event[0] & S6SY761_MASK_TID)))
> +		return;
> +
> +	tid = ((event[0] & S6SY761_MASK_TID) >> 2) - 1;
> +
> +	input_mt_slot(sdata->input, tid);
> +
> +	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, major);
> +	input_report_abs(sdata->input, ABS_MT_TOUCH_MINOR, minor);
> +	input_report_abs(sdata->input, ABS_MT_PRESSURE, z);
> +
> +	input_sync(sdata->input);
> +}
> +
> +static void s6sy761_report_release(struct s6sy761_data *sdata, u8 *event)
> +{
> +	u8 tid = ((event[0] & S6SY761_MASK_TID) >> 2) - 1;

You need the same check here:

	if (unlikely(!(event[0] & S6SY761_MASK_TID)))
		return;

or move it in s6sy761_handle_coordinates() and pass tid into
s6sy761_report_coordinates() and s6sy761_report_release().

> +
> +	input_mt_slot(sdata->input, tid);
> +	input_mt_report_slot_state(sdata->input, MT_TOOL_FINGER, false);
> +
> +	input_sync(sdata->input);
> +}
> +
> +static void s6sy761_handle_coordinates(struct s6sy761_data *sdata, u8 *event)
> +{
> +	u8 touch_state = (event[0] & S6SY761_MASK_TOUCH_STATE) >> 6;
> +
> +	switch (touch_state) {
> +
> +	case S6SY761_TS_NONE:
> +		break;
> +	case S6SY761_TS_RELEASE:
> +		s6sy761_report_release(sdata, event);
> +		break;
> +	case S6SY761_TS_PRESS:
> +	case S6SY761_TS_MOVE:
> +		s6sy761_report_coordinates(sdata, event);
> +		break;
> +	}
> +}
> +
> +static void s6sy761_handle_events(struct s6sy761_data *sdata, u8 left_event)

n_events here please.

> +{
> +	int i;
> +
> +	for (i = 0; i < left_event; i++) {
> +		u8 *event = &sdata->data[i * S6SY761_EVENT_SIZE];
> +		u8 event_id = event[0] & S6SY761_MASK_EID;
> +
> +		if (!event[0])
> +			return;
> +
> +		switch (event_id) {
> +
> +		case S6SY761_EVENT_ID_COORDINATE:
> +			s6sy761_handle_coordinates(sdata, event);
> +			break;
> +
> +		case S6SY761_EVENT_ID_STATUS:
> +			break;
> +
> +		default:
> +			break;
> +		}
> +	}
> +}
> +
> +static irqreturn_t s6sy761_irq_handler(int irq, void *dev)
> +{
> +	struct s6sy761_data *sdata = dev;
> +	int ret;
> +	u8 left_event;

n_events.

> +
> +	mutex_lock(&sdata->mutex);

I do not see why you need this mutex. It is only taken in the interrupt
and we will not schedule multiple threads servicing this interrupt
simultaneously.

> +	ret = i2c_smbus_read_i2c_block_data(sdata->client,
> +					    S6SY761_READ_ONE_EVENT,
> +					    S6SY761_EVENT_SIZE,
> +					    sdata->data);
> +	if (ret < 0) {
> +		dev_err(&sdata->client->dev, "failed to read events\n");
> +		goto out;
> +	}
> +
> +	if (!sdata->data[0])
> +		goto out;
> +
> +	left_event = sdata->data[7] & S6SY761_MASK_LEFT_EVENTS;
> +	if (unlikely(left_event > S6SY761_EVENT_COUNT - 1))
> +		goto out;
> +
> +	if (left_event) {
> +		ret = s6sy761_read_events(sdata,
> +					  left_event * S6SY761_EVENT_COUNT);

I am sure you meant S6SY761_EVENT_SIZE here. But I'd prefer if
s6sy761_read_events() accepted count and converted it to length
internally.

> +		if (ret < 0) {
> +			dev_err(&sdata->client->dev, "failed to read events\n");
> +			goto out;
> +		}
> +	}
> +
> +	s6sy761_handle_events(sdata, left_event +  1);



> +
> +	i2c_smbus_write_byte(sdata->client, S6SY761_CLEAR_EVENT_STACK);
> +
> +out:
> +	mutex_unlock(&sdata->mutex);
> +	return IRQ_HANDLED;
> +}
> +
> +static int s6sy761_input_open(struct input_dev *dev)
> +{
> +	struct s6sy761_data *sdata = input_get_drvdata(dev);
> +
> +	return i2c_smbus_write_byte(sdata->client, S6SY761_SENSE_ON);
> +}
> +
> +static void s6sy761_input_close(struct input_dev *dev)
> +{
> +	struct s6sy761_data *sdata = input_get_drvdata(dev);
> +	int ret;
> +
> +	ret = i2c_smbus_write_byte(sdata->client, S6SY761_SENSE_OFF);
> +	if (ret)
> +		dev_err(&sdata->client->dev, "failed to turn off sensing\n");
> +}
> +
> +static ssize_t s6sy761_sysfs_devid(struct device *dev,
> +				struct device_attribute *attr, char *buf)
> +{
> +	struct s6sy761_data *sdata = dev_get_drvdata(dev);
> +
> +	return sprintf(buf, "%#x\n", sdata->devid);
> +}
> +
> +static DEVICE_ATTR(devid, 0444, s6sy761_sysfs_devid, NULL);
> +
> +static struct attribute *s6sy761_sysfs_attrs[] = {
> +	&dev_attr_devid.attr,
> +	NULL
> +};
> +
> +static struct attribute_group s6sy761_attribute_group = {
> +	.attrs = s6sy761_sysfs_attrs
> +};
> +
> +static int s6sy761_hw_init(struct s6sy761_data *sdata)
> +{
> +	u8 buffer[S6SY761_PANEL_ID_SIZE]; /* larger read size */
> +	u8 event;
> +	int ret;
> +
> +	ret = regulator_bulk_enable(ARRAY_SIZE(sdata->regulators),
> +				    sdata->regulators);
> +	if (ret)
> +		return ret;
> +
> +	msleep(140);
> +
> +	ret = i2c_smbus_read_i2c_block_data(sdata->client,
> +					    S6SY761_READ_ONE_EVENT,
> +					    S6SY761_EVENT_SIZE,
> +					    buffer);
> +	if (ret < 0)
> +		return ret;
> +
> +	event = (buffer[0] >> 2) & 0xf;
> +
> +	if ((event != S6SY761_EVENT_INFO &&
> +		event != S6SY761_EVENT_VENDOR_INFO) ||
> +		buffer[1] != S6SY761_INFO_BOOT_COMPLETE)
> +		return -ENODEV;
> +
> +	ret = i2c_smbus_read_i2c_block_data(sdata->client,
> +					    S6SY761_DEVICE_ID,
> +					    S6SY761_DEVID_SIZE,
> +					    buffer);
> +	if (ret < 0)
> +		return ret;
> +
> +	sdata->devid = get_unaligned_be16(buffer + 1);
> +
> +	ret = i2c_smbus_read_i2c_block_data(sdata->client,
> +					    S6SY761_PANEL_ID,
> +					    S6SY761_PANEL_ID_SIZE,
> +					    buffer);
> +	if (ret < 0)
> +		return ret;
> +
> +	/* the user hasn't specified the touchscreen resolution */
> +	if (!sdata->prop.max_x)
> +		sdata->prop.max_x = get_unaligned_be16(buffer);
> +
> +	if (!sdata->prop.max_y)
> +		sdata->prop.max_y = get_unaligned_be16(buffer + 2);
> +
> +	/* check if both max_x and max_y have a value */
> +	if (!sdata->prop.max_x || !sdata->prop.max_y)
> +		return -EINVAL;
> +
> +	/* if no tx channels defined, at least keep one */
> +	sdata->tx_channel = max_t(u8, buffer[8], 1);
> +
> +	ret = i2c_smbus_read_byte_data(sdata->client,
> +				       S6SY761_FIRMWARE_INTEGRITY);
> +	if (ret < 0)
> +		return ret;
> +	else if (ret != S6SY761_FW_OK)
> +		return -ENODEV;
> +
> +	ret = i2c_smbus_read_byte_data(sdata->client, S6SY761_BOOT_STATUS);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = i2c_smbus_read_i2c_block_data(sdata->client,
> +					    S6SY761_TS_STATUS,
> +					    S6SY761_TS_STATUS_SIZE,
> +					    buffer);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = i2c_smbus_write_word_data(sdata->client,
> +					S6SY761_TOUCH_FUNCTION,
> +					S6SY761_MASK_TOUCH);
> +	if (ret)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +static void s6sy761_power_off(void *data)
> +{
> +	struct s6sy761_data *sdata = data;
> +
> +	disable_irq(sdata->client->irq);
> +	regulator_bulk_disable(ARRAY_SIZE(sdata->regulators),
> +						sdata->regulators);
> +}
> +
> +static int s6sy761_probe(struct i2c_client *client,
> +			const struct i2c_device_id *id)
> +{
> +	struct s6sy761_data *sdata;
> +	int err;
> +
> +	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);
> +
> +	sdata->regulators[S6SY761_REGULATOR_VDD].supply = "vdd";
> +	sdata->regulators[S6SY761_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, s6sy761_power_off, sdata);
> +	if (err)
> +		return err;
> +
> +	err = s6sy761_hw_init(sdata);
> +	if (err)
> +		return err;
> +
> +	sdata->input = devm_input_allocate_device(&client->dev);
> +	if (!sdata->input)
> +		return -ENOMEM;
> +
> +	sdata->input->name = S6SY761_DEV_NAME;
> +	sdata->input->id.bustype = BUS_I2C;
> +	sdata->input->open = s6sy761_input_open;
> +	sdata->input->close = s6sy761_input_close;
> +
> +	touchscreen_parse_properties(sdata->input, true, &sdata->prop);

You want to move touchscreen_parse_properties() below
input_set_abs_params. It needs capabilities set up to parse DT properly.
If you don not know the default range, just use input_set_capability():

	input_set_capability(sdata->input, EV_ABS, ABS_MT_POSITION_X);
	input_set_capability(sdata->input, EV_ABS, ABS_MT_POSITION_Y);
	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);
	/* the pressure is represented in 6 bits */ 
	input_set_abs_params(sdata->input, ABS_MT_PRESSURE, 0, 255, 0,
0);

	touchscreen_parse_properties(sdata->input, true, &sdata->prop);

It will adjust the max values (and fuzz) on axes as needed.

> +
> +	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);
> +	/* the pressure is represented in 6 bits */
> +	input_set_abs_params(sdata->input, ABS_MT_PRESSURE, 0, 255, 0, 0);
> +
> +	err = input_mt_init_slots(sdata->input,
> +				  sdata->tx_channel,
> +				  INPUT_MT_DIRECT);
> +	if (err)
> +		return err;
> +
> +	input_set_drvdata(sdata->input, sdata);
> +
> +	err = input_register_device(sdata->input);
> +	if (err)
> +		return err;
> +
> +	err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
> +					s6sy761_irq_handler,
> +					IRQF_TRIGGER_LOW | IRQF_ONESHOT,
> +					"s6sy761_irq", sdata);
> +	if (err)
> +		return err;
> +
> +	err = devm_device_add_group(&client->dev, &s6sy761_attribute_group);
> +	if (err)
> +		return err;
> +
> +	pm_runtime_enable(&client->dev);
> +
> +	return 0;
> +}
> +
> +static int s6sy761_remove(struct i2c_client *client)
> +{
> +	pm_runtime_disable(&client->dev);
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused s6sy761_runtime_suspend(struct device *dev)
> +{
> +	struct s6sy761_data *sdata = dev_get_drvdata(dev);
> +
> +	return i2c_smbus_write_byte_data(sdata->client,
> +				S6SY761_APPLICATION_MODE, S6SY761_APP_SLEEP);
> +}
> +
> +static int __maybe_unused s6sy761_runtime_resume(struct device *dev)
> +{
> +	struct s6sy761_data *sdata = dev_get_drvdata(dev);
> +
> +	return i2c_smbus_write_byte_data(sdata->client,
> +				S6SY761_APPLICATION_MODE, S6SY761_APP_NORMAL);
> +}
> +
> +static int __maybe_unused s6sy761_suspend(struct device *dev)
> +{
> +	struct s6sy761_data *sdata = dev_get_drvdata(dev);
> +
> +	s6sy761_power_off(sdata);
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused s6sy761_resume(struct device *dev)
> +{
> +	struct s6sy761_data *sdata = dev_get_drvdata(dev);
> +
> +	enable_irq(sdata->client->irq);
> +
> +	return s6sy761_hw_init(sdata);
> +}
> +
> +static const struct dev_pm_ops s6sy761_pm_ops = {
> +	SET_SYSTEM_SLEEP_PM_OPS(s6sy761_suspend, s6sy761_resume)
> +	SET_RUNTIME_PM_OPS(s6sy761_runtime_suspend,
> +				s6sy761_runtime_resume, NULL)
> +};
> +
> +#ifdef CONFIG_OF
> +static const struct of_device_id s6sy761_of_match[] = {
> +	{ .compatible = "samsung,s6sy761", },
> +	{ },
> +};
> +MODULE_DEVICE_TABLE(of, s6sy761_of_match);
> +#endif
> +
> +static const struct i2c_device_id s6sy761_id[] = {
> +	{ "s6sy761", 0 },
> +	{ },
> +};
> +MODULE_DEVICE_TABLE(i2c, s6sy761_id);
> +
> +static struct i2c_driver s6sy761_driver = {
> +	.driver = {
> +		.name = S6SY761_DEV_NAME,
> +		.of_match_table = of_match_ptr(s6sy761_of_match),
> +		.pm = &s6sy761_pm_ops,
> +	},
> +	.probe = s6sy761_probe,
> +	.remove = s6sy761_remove,
> +	.id_table = s6sy761_id,
> +};
> +
> +module_i2c_driver(s6sy761_driver);
> +
> +MODULE_AUTHOR("Andi Shyti <andi.shyti@samsung.com>");
> +MODULE_DESCRIPTION("Samsung S6SY761 Touch Screen");
> +MODULE_LICENSE("GPL v2");
> -- 
> 2.14.1
> 

Thanks.

-- 
Dmitry