Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input

Pull more input updates from Dmitry Torokhov:
 "Two new drivers for touchscreen controllers:

   - Silead touchscreen controllers
   - SiS 9200 family touchscreen controllers

  and a few driver fixes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: silead - remove some dead code
  Input: sis-i2c - select CONFIG_CRC_ITU_T
  Input: add driver for SiS 9200 family I2C touchscreen controllers
  Input: ili210x - fix permissions on "calibrate" attribute
  Input: elan_i2c - properly wake up touchpad on ASUS laptops
  Input: add driver for Silead touchscreens
  Input: elantech - fix debug dump of the current packet
  Input: rotary_encoder - support binary encoding of states
  Input: xpad - power off wireless 360 controllers on suspend
  Input: i8042 - break load dependency between atkbd/psmouse and i8042
  Input: synaptics-rmi4 - do not check for NULL when calling of_node_put()
  Input: cros_ec_keyb - cleanup use of dev

5 files changed, 1006 insertions, 1 deletions

diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index ee02dc7..2fb1f43 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -1059,6 +1059,31 @@ config TOUCHSCREEN_RM_TS
 	  To compile this driver as a module, choose M here: the
 	  module will be called raydium_i2c_ts.
 
+config TOUCHSCREEN_SILEAD
+	tristate "Silead I2C touchscreen"
+	depends on I2C
+	help
+	  Say Y here if you have the Silead touchscreen connected to
+	  your system.
+
+	  If unsure, say N.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called silead.
+
+config TOUCHSCREEN_SIS_I2C
+	tristate "SiS 9200 family I2C touchscreen"
+	depends on I2C
+	select CRC_ITU_T
+	depends on GPIOLIB || COMPILE_TEST
+	help
+	  This enables support for SiS 9200 family over I2C based touchscreens.
+
+	  If unsure, say N.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called sis_i2c.
+
 config TOUCHSCREEN_ST1232
 	tristate "Sitronix ST1232 touchscreen controllers"
 	depends on I2C
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 3315882..b4373d6 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -64,6 +64,8 @@ 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-$(CONFIG_TOUCHSCREEN_SILEAD)	+= silead.o
+obj-$(CONFIG_TOUCHSCREEN_SIS_I2C)	+= sis_i2c.o
 obj-$(CONFIG_TOUCHSCREEN_ST1232)	+= st1232.o
 obj-$(CONFIG_TOUCHSCREEN_STMPE)		+= stmpe-ts.o
 obj-$(CONFIG_TOUCHSCREEN_SUN4I)		+= sun4i-ts.o
diff --git a/drivers/input/touchscreen/ili210x.c b/drivers/input/touchscreen/ili210x.c
index ddf694b..fe4848b 100644
--- a/drivers/input/touchscreen/ili210x.c
+++ b/drivers/input/touchscreen/ili210x.c
@@ -169,7 +169,7 @@ static ssize_t ili210x_calibrate(struct device *dev,
 
 	return count;
 }
-static DEVICE_ATTR(calibrate, 0644, NULL, ili210x_calibrate);
+static DEVICE_ATTR(calibrate, S_IWUSR, NULL, ili210x_calibrate);
 
 static struct attribute *ili210x_attributes[] = {
 	&dev_attr_calibrate.attr,
diff --git a/drivers/input/touchscreen/silead.c b/drivers/input/touchscreen/silead.c
new file mode 100644
index 0000000..7379fe1
--- /dev/null
+++ b/drivers/input/touchscreen/silead.c
@@ -0,0 +1,565 @@
+/* -------------------------------------------------------------------------
+ * Copyright (C) 2014-2015, Intel Corporation
+ *
+ * Derived from:
+ *  gslX68X.c
+ *  Copyright (C) 2010-2015, Shanghai Sileadinc Co.Ltd
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ * -------------------------------------------------------------------------
+ */
+
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/acpi.h>
+#include <linux/interrupt.h>
+#include <linux/gpio/consumer.h>
+#include <linux/delay.h>
+#include <linux/firmware.h>
+#include <linux/input.h>
+#include <linux/input/mt.h>
+#include <linux/input/touchscreen.h>
+#include <linux/pm.h>
+#include <linux/irq.h>
+
+#include <asm/unaligned.h>
+
+#define SILEAD_TS_NAME		"silead_ts"
+
+#define SILEAD_REG_RESET	0xE0
+#define SILEAD_REG_DATA		0x80
+#define SILEAD_REG_TOUCH_NR	0x80
+#define SILEAD_REG_POWER	0xBC
+#define SILEAD_REG_CLOCK	0xE4
+#define SILEAD_REG_STATUS	0xB0
+#define SILEAD_REG_ID		0xFC
+#define SILEAD_REG_MEM_CHECK	0xB0
+
+#define SILEAD_STATUS_OK	0x5A5A5A5A
+#define SILEAD_TS_DATA_LEN	44
+#define SILEAD_CLOCK		0x04
+
+#define SILEAD_CMD_RESET	0x88
+#define SILEAD_CMD_START	0x00
+
+#define SILEAD_POINT_DATA_LEN	0x04
+#define SILEAD_POINT_Y_OFF      0x00
+#define SILEAD_POINT_Y_MSB_OFF	0x01
+#define SILEAD_POINT_X_OFF	0x02
+#define SILEAD_POINT_X_MSB_OFF	0x03
+#define SILEAD_TOUCH_ID_MASK	0xF0
+
+#define SILEAD_CMD_SLEEP_MIN	10000
+#define SILEAD_CMD_SLEEP_MAX	20000
+#define SILEAD_POWER_SLEEP	20
+#define SILEAD_STARTUP_SLEEP	30
+
+#define SILEAD_MAX_FINGERS	10
+
+enum silead_ts_power {
+	SILEAD_POWER_ON  = 1,
+	SILEAD_POWER_OFF = 0
+};
+
+struct silead_ts_data {
+	struct i2c_client *client;
+	struct gpio_desc *gpio_power;
+	struct input_dev *input;
+	char fw_name[64];
+	struct touchscreen_properties prop;
+	u32 max_fingers;
+	u32 chip_id;
+	struct input_mt_pos pos[SILEAD_MAX_FINGERS];
+	int slots[SILEAD_MAX_FINGERS];
+	int id[SILEAD_MAX_FINGERS];
+};
+
+struct silead_fw_data {
+	u32 offset;
+	u32 val;
+};
+
+static int silead_ts_request_input_dev(struct silead_ts_data *data)
+{
+	struct device *dev = &data->client->dev;
+	int error;
+
+	data->input = devm_input_allocate_device(dev);
+	if (!data->input) {
+		dev_err(dev,
+			"Failed to allocate input device\n");
+		return -ENOMEM;
+	}
+
+	input_set_abs_params(data->input, ABS_MT_POSITION_X, 0, 4095, 0, 0);
+	input_set_abs_params(data->input, ABS_MT_POSITION_Y, 0, 4095, 0, 0);
+	touchscreen_parse_properties(data->input, true, &data->prop);
+
+	input_mt_init_slots(data->input, data->max_fingers,
+			    INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED |
+			    INPUT_MT_TRACK);
+
+	data->input->name = SILEAD_TS_NAME;
+	data->input->phys = "input/ts";
+	data->input->id.bustype = BUS_I2C;
+
+	error = input_register_device(data->input);
+	if (error) {
+		dev_err(dev, "Failed to register input device: %d\n", error);
+		return error;
+	}
+
+	return 0;
+}
+
+static void silead_ts_set_power(struct i2c_client *client,
+				enum silead_ts_power state)
+{
+	struct silead_ts_data *data = i2c_get_clientdata(client);
+
+	if (data->gpio_power) {
+		gpiod_set_value_cansleep(data->gpio_power, state);
+		msleep(SILEAD_POWER_SLEEP);
+	}
+}
+
+static void silead_ts_read_data(struct i2c_client *client)
+{
+	struct silead_ts_data *data = i2c_get_clientdata(client);
+	struct input_dev *input = data->input;
+	struct device *dev = &client->dev;
+	u8 *bufp, buf[SILEAD_TS_DATA_LEN];
+	int touch_nr, error, i;
+
+	error = i2c_smbus_read_i2c_block_data(client, SILEAD_REG_DATA,
+					      SILEAD_TS_DATA_LEN, buf);
+	if (error < 0) {
+		dev_err(dev, "Data read error %d\n", error);
+		return;
+	}
+
+	touch_nr = buf[0];
+	if (touch_nr > data->max_fingers) {
+		dev_warn(dev, "More touches reported then supported %d > %d\n",
+			 touch_nr, data->max_fingers);
+		touch_nr = data->max_fingers;
+	}
+
+	bufp = buf + SILEAD_POINT_DATA_LEN;
+	for (i = 0; i < touch_nr; i++, bufp += SILEAD_POINT_DATA_LEN) {
+		/* Bits 4-7 are the touch id */
+		data->id[i] = (bufp[SILEAD_POINT_X_MSB_OFF] &
+			       SILEAD_TOUCH_ID_MASK) >> 4;
+		touchscreen_set_mt_pos(&data->pos[i], &data->prop,
+			get_unaligned_le16(&bufp[SILEAD_POINT_X_OFF]) & 0xfff,
+			get_unaligned_le16(&bufp[SILEAD_POINT_Y_OFF]) & 0xfff);
+	}
+
+	input_mt_assign_slots(input, data->slots, data->pos, touch_nr, 0);
+
+	for (i = 0; i < touch_nr; i++) {
+		input_mt_slot(input, data->slots[i]);
+		input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
+		input_report_abs(input, ABS_MT_POSITION_X, data->pos[i].x);
+		input_report_abs(input, ABS_MT_POSITION_Y, data->pos[i].y);
+
+		dev_dbg(dev, "x=%d y=%d hw_id=%d sw_id=%d\n", data->pos[i].x,
+			data->pos[i].y, data->id[i], data->slots[i]);
+	}
+
+	input_mt_sync_frame(input);
+	input_sync(input);
+}
+
+static int silead_ts_init(struct i2c_client *client)
+{
+	struct silead_ts_data *data = i2c_get_clientdata(client);
+	int error;
+
+	error = i2c_smbus_write_byte_data(client, SILEAD_REG_RESET,
+					  SILEAD_CMD_RESET);
+	if (error)
+		goto i2c_write_err;
+	usleep_range(SILEAD_CMD_SLEEP_MIN, SILEAD_CMD_SLEEP_MAX);
+
+	error = i2c_smbus_write_byte_data(client, SILEAD_REG_TOUCH_NR,
+					data->max_fingers);
+	if (error)
+		goto i2c_write_err;
+	usleep_range(SILEAD_CMD_SLEEP_MIN, SILEAD_CMD_SLEEP_MAX);
+
+	error = i2c_smbus_write_byte_data(client, SILEAD_REG_CLOCK,
+					  SILEAD_CLOCK);
+	if (error)
+		goto i2c_write_err;
+	usleep_range(SILEAD_CMD_SLEEP_MIN, SILEAD_CMD_SLEEP_MAX);
+
+	error = i2c_smbus_write_byte_data(client, SILEAD_REG_RESET,
+					  SILEAD_CMD_START);
+	if (error)
+		goto i2c_write_err;
+	usleep_range(SILEAD_CMD_SLEEP_MIN, SILEAD_CMD_SLEEP_MAX);
+
+	return 0;
+
+i2c_write_err:
+	dev_err(&client->dev, "Registers clear error %d\n", error);
+	return error;
+}
+
+static int silead_ts_reset(struct i2c_client *client)
+{
+	int error;
+
+	error = i2c_smbus_write_byte_data(client, SILEAD_REG_RESET,
+					  SILEAD_CMD_RESET);
+	if (error)
+		goto i2c_write_err;
+	usleep_range(SILEAD_CMD_SLEEP_MIN, SILEAD_CMD_SLEEP_MAX);
+
+	error = i2c_smbus_write_byte_data(client, SILEAD_REG_CLOCK,
+					  SILEAD_CLOCK);
+	if (error)
+		goto i2c_write_err;
+	usleep_range(SILEAD_CMD_SLEEP_MIN, SILEAD_CMD_SLEEP_MAX);
+
+	error = i2c_smbus_write_byte_data(client, SILEAD_REG_POWER,
+					  SILEAD_CMD_START);
+	if (error)
+		goto i2c_write_err;
+	usleep_range(SILEAD_CMD_SLEEP_MIN, SILEAD_CMD_SLEEP_MAX);
+
+	return 0;
+
+i2c_write_err:
+	dev_err(&client->dev, "Chip reset error %d\n", error);
+	return error;
+}
+
+static int silead_ts_startup(struct i2c_client *client)
+{
+	int error;
+
+	error = i2c_smbus_write_byte_data(client, SILEAD_REG_RESET, 0x00);
+	if (error) {
+		dev_err(&client->dev, "Startup error %d\n", error);
+		return error;
+	}
+
+	msleep(SILEAD_STARTUP_SLEEP);
+
+	return 0;
+}
+
+static int silead_ts_load_fw(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct silead_ts_data *data = i2c_get_clientdata(client);
+	unsigned int fw_size, i;
+	const struct firmware *fw;
+	struct silead_fw_data *fw_data;
+	int error;
+
+	dev_dbg(dev, "Firmware file name: %s", data->fw_name);
+
+	error = request_firmware(&fw, data->fw_name, dev);
+	if (error) {
+		dev_err(dev, "Firmware request error %d\n", error);
+		return error;
+	}
+
+	fw_size = fw->size / sizeof(*fw_data);
+	fw_data = (struct silead_fw_data *)fw->data;
+
+	for (i = 0; i < fw_size; i++) {
+		error = i2c_smbus_write_i2c_block_data(client,
+						       fw_data[i].offset,
+						       4,
+						       (u8 *)&fw_data[i].val);
+		if (error) {
+			dev_err(dev, "Firmware load error %d\n", error);
+			break;
+		}
+	}
+
+	release_firmware(fw);
+	return error ?: 0;
+}
+
+static u32 silead_ts_get_status(struct i2c_client *client)
+{
+	int error;
+	__le32 status;
+
+	error = i2c_smbus_read_i2c_block_data(client, SILEAD_REG_STATUS,
+					      sizeof(status), (u8 *)&status);
+	if (error < 0) {
+		dev_err(&client->dev, "Status read error %d\n", error);
+		return error;
+	}
+
+	return le32_to_cpu(status);
+}
+
+static int silead_ts_get_id(struct i2c_client *client)
+{
+	struct silead_ts_data *data = i2c_get_clientdata(client);
+	__le32 chip_id;
+	int error;
+
+	error = i2c_smbus_read_i2c_block_data(client, SILEAD_REG_ID,
+					      sizeof(chip_id), (u8 *)&chip_id);
+	if (error < 0) {
+		dev_err(&client->dev, "Chip ID read error %d\n", error);
+		return error;
+	}
+
+	data->chip_id = le32_to_cpu(chip_id);
+	dev_info(&client->dev, "Silead chip ID: 0x%8X", data->chip_id);
+
+	return 0;
+}
+
+static int silead_ts_setup(struct i2c_client *client)
+{
+	int error;
+	u32 status;
+
+	silead_ts_set_power(client, SILEAD_POWER_OFF);
+	silead_ts_set_power(client, SILEAD_POWER_ON);
+
+	error = silead_ts_get_id(client);
+	if (error)
+		return error;
+
+	error = silead_ts_init(client);
+	if (error)
+		return error;
+
+	error = silead_ts_reset(client);
+	if (error)
+		return error;
+
+	error = silead_ts_load_fw(client);
+	if (error)
+		return error;
+
+	error = silead_ts_startup(client);
+	if (error)
+		return error;
+
+	status = silead_ts_get_status(client);
+	if (status != SILEAD_STATUS_OK) {
+		dev_err(&client->dev,
+			"Initialization error, status: 0x%X\n", status);
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static irqreturn_t silead_ts_threaded_irq_handler(int irq, void *id)
+{
+	struct silead_ts_data *data = id;
+	struct i2c_client *client = data->client;
+
+	silead_ts_read_data(client);
+
+	return IRQ_HANDLED;
+}
+
+static void silead_ts_read_props(struct i2c_client *client)
+{
+	struct silead_ts_data *data = i2c_get_clientdata(client);
+	struct device *dev = &client->dev;
+	const char *str;
+	int error;
+
+	error = device_property_read_u32(dev, "silead,max-fingers",
+					 &data->max_fingers);
+	if (error) {
+		dev_dbg(dev, "Max fingers read error %d\n", error);
+		data->max_fingers = 5; /* Most devices handle up-to 5 fingers */
+	}
+
+	error = device_property_read_string(dev, "touchscreen-fw-name", &str);
+	if (!error)
+		snprintf(data->fw_name, sizeof(data->fw_name), "%s", str);
+	else
+		dev_dbg(dev, "Firmware file name read error. Using default.");
+}
+
+#ifdef CONFIG_ACPI
+static int silead_ts_set_default_fw_name(struct silead_ts_data *data,
+					 const struct i2c_device_id *id)
+{
+	const struct acpi_device_id *acpi_id;
+	struct device *dev = &data->client->dev;
+	int i;
+
+	if (ACPI_HANDLE(dev)) {
+		acpi_id = acpi_match_device(dev->driver->acpi_match_table, dev);
+		if (!acpi_id)
+			return -ENODEV;
+
+		snprintf(data->fw_name, sizeof(data->fw_name), "%s.fw",
+			acpi_id->id);
+
+		for (i = 0; i < strlen(data->fw_name); i++)
+			data->fw_name[i] = tolower(data->fw_name[i]);
+	} else {
+		snprintf(data->fw_name, sizeof(data->fw_name), "%s.fw",
+			id->name);
+	}
+
+	return 0;
+}
+#else
+static int silead_ts_set_default_fw_name(struct silead_ts_data *data,
+					 const struct i2c_device_id *id)
+{
+	snprintf(data->fw_name, sizeof(data->fw_name), "%s.fw", id->name);
+	return 0;
+}
+#endif
+
+static int silead_ts_probe(struct i2c_client *client,
+			   const struct i2c_device_id *id)
+{
+	struct silead_ts_data *data;
+	struct device *dev = &client->dev;
+	int error;
+
+	if (!i2c_check_functionality(client->adapter,
+				     I2C_FUNC_I2C |
+				     I2C_FUNC_SMBUS_READ_I2C_BLOCK |
+				     I2C_FUNC_SMBUS_WRITE_I2C_BLOCK)) {
+		dev_err(dev, "I2C functionality check failed\n");
+		return -ENXIO;
+	}
+
+	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	i2c_set_clientdata(client, data);
+	data->client = client;
+
+	error = silead_ts_set_default_fw_name(data, id);
+	if (error)
+		return error;
+
+	silead_ts_read_props(client);
+
+	/* We must have the IRQ provided by DT or ACPI subsytem */
+	if (client->irq <= 0)
+		return -ENODEV;
+
+	/* Power GPIO pin */
+	data->gpio_power = gpiod_get_optional(dev, "power", GPIOD_OUT_LOW);
+	if (IS_ERR(data->gpio_power)) {
+		if (PTR_ERR(data->gpio_power) != -EPROBE_DEFER)
+			dev_err(dev, "Shutdown GPIO request failed\n");
+		return PTR_ERR(data->gpio_power);
+	}
+
+	error = silead_ts_setup(client);
+	if (error)
+		return error;
+
+	error = silead_ts_request_input_dev(data);
+	if (error)
+		return error;
+
+	error = devm_request_threaded_irq(dev, client->irq,
+					  NULL, silead_ts_threaded_irq_handler,
+					  IRQF_ONESHOT, client->name, data);
+	if (error) {
+		if (error != -EPROBE_DEFER)
+			dev_err(dev, "IRQ request failed %d\n", error);
+		return error;
+	}
+
+	return 0;
+}
+
+static int __maybe_unused silead_ts_suspend(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+
+	silead_ts_set_power(client, SILEAD_POWER_OFF);
+	return 0;
+}
+
+static int __maybe_unused silead_ts_resume(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	int error, status;
+
+	silead_ts_set_power(client, SILEAD_POWER_ON);
+
+	error = silead_ts_reset(client);
+	if (error)
+		return error;
+
+	error = silead_ts_startup(client);
+	if (error)
+		return error;
+
+	status = silead_ts_get_status(client);
+	if (status != SILEAD_STATUS_OK) {
+		dev_err(dev, "Resume error, status: 0x%02x\n", status);
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(silead_ts_pm, silead_ts_suspend, silead_ts_resume);
+
+static const struct i2c_device_id silead_ts_id[] = {
+	{ "gsl1680", 0 },
+	{ "gsl1688", 0 },
+	{ "gsl3670", 0 },
+	{ "gsl3675", 0 },
+	{ "gsl3692", 0 },
+	{ "mssl1680", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, silead_ts_id);
+
+#ifdef CONFIG_ACPI
+static const struct acpi_device_id silead_ts_acpi_match[] = {
+	{ "GSL1680", 0 },
+	{ "GSL1688", 0 },
+	{ "GSL3670", 0 },
+	{ "GSL3675", 0 },
+	{ "GSL3692", 0 },
+	{ "MSSL1680", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(acpi, silead_ts_acpi_match);
+#endif
+
+static struct i2c_driver silead_ts_driver = {
+	.probe = silead_ts_probe,
+	.id_table = silead_ts_id,
+	.driver = {
+		.name = SILEAD_TS_NAME,
+		.acpi_match_table = ACPI_PTR(silead_ts_acpi_match),
+		.pm = &silead_ts_pm,
+	},
+};
+module_i2c_driver(silead_ts_driver);
+
+MODULE_AUTHOR("Robert Dolca <robert.dolca@intel.com>");
+MODULE_DESCRIPTION("Silead I2C touchscreen driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/input/touchscreen/sis_i2c.c b/drivers/input/touchscreen/sis_i2c.c
new file mode 100644
index 0000000..8d93f8c
--- /dev/null
+++ b/drivers/input/touchscreen/sis_i2c.c
@@ -0,0 +1,413 @@
+/*
+ * Touch Screen driver for SiS 9200 family I2C Touch panels
+ *
+ * Copyright (C) 2015 SiS, Inc.
+ * Copyright (C) 2016 Nextfour Group
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/crc-itu-t.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/input.h>
+#include <linux/input/mt.h>
+#include <linux/interrupt.h>
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <asm/unaligned.h>
+
+#define SIS_I2C_NAME		"sis_i2c_ts"
+
+/*
+ * The I2C packet format:
+ * le16		byte count
+ * u8		Report ID
+ * <contact data - variable length>
+ * u8		Number of contacts
+ * le16		Scan Time (optional)
+ * le16		CRC
+ *
+ * One touch point information consists of 6+ bytes, the order is:
+ * u8		contact state
+ * u8		finger id
+ * le16		x axis
+ * le16		y axis
+ * u8		contact width (optional)
+ * u8		contact height (optional)
+ * u8		pressure (optional)
+ *
+ * Maximum amount of data transmitted in one shot is 64 bytes, if controller
+ * needs to report more contacts than fit in one packet it will send true
+ * number of contacts in first packet and 0 as number of contacts in second
+ * packet.
+ */
+
+#define SIS_MAX_PACKET_SIZE		64
+
+#define SIS_PKT_LEN_OFFSET		0
+#define SIS_PKT_REPORT_OFFSET		2 /* Report ID/type */
+#define SIS_PKT_CONTACT_OFFSET		3 /* First contact */
+
+#define SIS_SCAN_TIME_LEN		2
+
+/* Supported report types */
+#define SIS_ALL_IN_ONE_PACKAGE		0x10
+#define SIS_PKT_IS_TOUCH(x)		(((x) & 0x0f) == 0x01)
+#define SIS_PKT_IS_HIDI2C(x)		(((x) & 0x0f) == 0x06)
+
+/* Contact properties within report */
+#define SIS_PKT_HAS_AREA(x)		((x) & BIT(4))
+#define SIS_PKT_HAS_PRESSURE(x)		((x) & BIT(5))
+#define SIS_PKT_HAS_SCANTIME(x)		((x) & BIT(6))
+
+/* Contact size */
+#define SIS_BASE_LEN_PER_CONTACT	6
+#define SIS_AREA_LEN_PER_CONTACT	2
+#define SIS_PRESSURE_LEN_PER_CONTACT	1
+
+/* Offsets within contact data */
+#define SIS_CONTACT_STATUS_OFFSET	0
+#define SIS_CONTACT_ID_OFFSET		1 /* Contact ID */
+#define SIS_CONTACT_X_OFFSET		2
+#define SIS_CONTACT_Y_OFFSET		4
+#define SIS_CONTACT_WIDTH_OFFSET	6
+#define SIS_CONTACT_HEIGHT_OFFSET	7
+#define SIS_CONTACT_PRESSURE_OFFSET(id)	(SIS_PKT_HAS_AREA(id) ? 8 : 6)
+
+/* Individual contact state */
+#define SIS_STATUS_UP			0x0
+#define SIS_STATUS_DOWN			0x3
+
+/* Touchscreen parameters */
+#define SIS_MAX_FINGERS			10
+#define SIS_MAX_X			4095
+#define SIS_MAX_Y			4095
+#define SIS_MAX_PRESSURE		255
+
+/* Resolution diagonal */
+#define SIS_AREA_LENGTH_LONGER		5792
+/*((SIS_MAX_X^2) + (SIS_MAX_Y^2))^0.5*/
+#define SIS_AREA_LENGTH_SHORT		5792
+#define SIS_AREA_UNIT			(5792 / 32)
+
+struct sis_ts_data {
+	struct i2c_client *client;
+	struct input_dev *input;
+
+	struct gpio_desc *attn_gpio;
+	struct gpio_desc *reset_gpio;
+
+	u8 packet[SIS_MAX_PACKET_SIZE];
+};
+
+static int sis_read_packet(struct i2c_client *client, u8 *buf,
+			   unsigned int *num_contacts,
+			   unsigned int *contact_size)
+{
+	int count_idx;
+	int ret;
+	u16 len;
+	u16 crc, pkg_crc;
+	u8 report_id;
+
+	ret = i2c_master_recv(client, buf, SIS_MAX_PACKET_SIZE);
+	if (ret <= 0)
+		return -EIO;
+
+	len = get_unaligned_le16(&buf[SIS_PKT_LEN_OFFSET]);
+	if (len > SIS_MAX_PACKET_SIZE) {
+		dev_err(&client->dev,
+			"%s: invalid packet length (%d vs %d)\n",
+			__func__, len, SIS_MAX_PACKET_SIZE);
+		return -E2BIG;
+	}
+
+	if (len < 10)
+		return -EINVAL;
+
+	report_id = buf[SIS_PKT_REPORT_OFFSET];
+	count_idx  = len - 1;
+	*contact_size = SIS_BASE_LEN_PER_CONTACT;
+
+	if (report_id != SIS_ALL_IN_ONE_PACKAGE) {
+		if (SIS_PKT_IS_TOUCH(report_id)) {
+			/*
+			 * Calculate CRC ignoring packet length
+			 * in the beginning and CRC transmitted
+			 * at the end of the packet.
+			 */
+			crc = crc_itu_t(0, buf + 2, len - 2 - 2);
+			pkg_crc = get_unaligned_le16(&buf[len - 2]);
+
+			if (crc != pkg_crc) {
+				dev_err(&client->dev,
+					"%s: CRC Error (%d vs %d)\n",
+					__func__, crc, pkg_crc);
+				return -EINVAL;
+			}
+
+			count_idx -= 2;
+
+		} else if (!SIS_PKT_IS_HIDI2C(report_id)) {
+			dev_err(&client->dev,
+				"%s: invalid packet ID %#02x\n",
+				__func__, report_id);
+			return -EINVAL;
+		}
+
+		if (SIS_PKT_HAS_SCANTIME(report_id))
+			count_idx -= SIS_SCAN_TIME_LEN;
+
+		if (SIS_PKT_HAS_AREA(report_id))
+			*contact_size += SIS_AREA_LEN_PER_CONTACT;
+		if (SIS_PKT_HAS_PRESSURE(report_id))
+			*contact_size += SIS_PRESSURE_LEN_PER_CONTACT;
+	}
+
+	*num_contacts = buf[count_idx];
+	return 0;
+}
+
+static int sis_ts_report_contact(struct sis_ts_data *ts, const u8 *data, u8 id)
+{
+	struct input_dev *input = ts->input;
+	int slot;
+	u8 status = data[SIS_CONTACT_STATUS_OFFSET];
+	u8 pressure;
+	u8 height, width;
+	u16 x, y;
+
+	if (status != SIS_STATUS_DOWN && status != SIS_STATUS_UP) {
+		dev_err(&ts->client->dev, "Unexpected touch status: %#02x\n",
+			data[SIS_CONTACT_STATUS_OFFSET]);
+		return -EINVAL;
+	}
+
+	slot = input_mt_get_slot_by_key(input, data[SIS_CONTACT_ID_OFFSET]);
+	if (slot < 0)
+		return -ENOENT;
+
+	input_mt_slot(input, slot);
+	input_mt_report_slot_state(input, MT_TOOL_FINGER,
+				   status == SIS_STATUS_DOWN);
+
+	if (status == SIS_STATUS_DOWN) {
+		pressure = height = width = 1;
+		if (id != SIS_ALL_IN_ONE_PACKAGE) {
+			if (SIS_PKT_HAS_AREA(id)) {
+				width = data[SIS_CONTACT_WIDTH_OFFSET];
+				height = data[SIS_CONTACT_HEIGHT_OFFSET];
+			}
+
+			if (SIS_PKT_HAS_PRESSURE(id))
+				pressure =
+					data[SIS_CONTACT_PRESSURE_OFFSET(id)];
+		}
+
+		x = get_unaligned_le16(&data[SIS_CONTACT_X_OFFSET]);
+		y = get_unaligned_le16(&data[SIS_CONTACT_Y_OFFSET]);
+
+		input_report_abs(input, ABS_MT_TOUCH_MAJOR,
+				 width * SIS_AREA_UNIT);
+		input_report_abs(input, ABS_MT_TOUCH_MINOR,
+				 height * SIS_AREA_UNIT);
+		input_report_abs(input, ABS_MT_PRESSURE, pressure);
+		input_report_abs(input, ABS_MT_POSITION_X, x);
+		input_report_abs(input, ABS_MT_POSITION_Y, y);
+	}
+
+	return 0;
+}
+
+static void sis_ts_handle_packet(struct sis_ts_data *ts)
+{
+	const u8 *contact;
+	unsigned int num_to_report = 0;
+	unsigned int num_contacts;
+	unsigned int num_reported;
+	unsigned int contact_size;
+	int error;
+	u8 report_id;
+
+	do {
+		error = sis_read_packet(ts->client, ts->packet,
+					&num_contacts, &contact_size);
+		if (error)
+			break;
+
+		if (num_to_report == 0) {
+			num_to_report = num_contacts;
+		} else if (num_contacts != 0) {
+			dev_err(&ts->client->dev,
+				"%s: nonzero (%d) point count in tail packet\n",
+				__func__, num_contacts);
+			break;
+		}
+
+		report_id = ts->packet[SIS_PKT_REPORT_OFFSET];
+		contact = &ts->packet[SIS_PKT_CONTACT_OFFSET];
+		num_reported = 0;
+
+		while (num_to_report > 0) {
+			error = sis_ts_report_contact(ts, contact, report_id);
+			if (error)
+				break;
+
+			contact += contact_size;
+			num_to_report--;
+			num_reported++;
+
+			if (report_id != SIS_ALL_IN_ONE_PACKAGE &&
+			    num_reported >= 5) {
+				/*
+				 * The remainder of contacts is sent
+				 * in the 2nd packet.
+				 */
+				break;
+			}
+		}
+	} while (num_to_report > 0);
+
+	input_mt_sync_frame(ts->input);
+	input_sync(ts->input);
+}
+
+static irqreturn_t sis_ts_irq_handler(int irq, void *dev_id)
+{
+	struct sis_ts_data *ts = dev_id;
+
+	do {
+		sis_ts_handle_packet(ts);
+	} while (ts->attn_gpio && gpiod_get_value_cansleep(ts->attn_gpio));
+
+	return IRQ_HANDLED;
+}
+
+static void sis_ts_reset(struct sis_ts_data *ts)
+{
+	if (ts->reset_gpio) {
+		/* Get out of reset */
+		usleep_range(1000, 2000);
+		gpiod_set_value(ts->reset_gpio, 1);
+		usleep_range(1000, 2000);
+		gpiod_set_value(ts->reset_gpio, 0);
+		msleep(100);
+	}
+}
+
+static int sis_ts_probe(struct i2c_client *client,
+			const struct i2c_device_id *id)
+{
+	struct sis_ts_data *ts;
+	struct input_dev *input;
+	int error;
+
+	ts = devm_kzalloc(&client->dev, sizeof(*ts), GFP_KERNEL);
+	if (!ts)
+		return -ENOMEM;
+
+	ts->client = client;
+	i2c_set_clientdata(client, ts);
+
+	ts->attn_gpio = devm_gpiod_get_optional(&client->dev,
+						"attn", GPIOD_IN);
+	if (IS_ERR(ts->attn_gpio)) {
+		error = PTR_ERR(ts->attn_gpio);
+		if (error != -EPROBE_DEFER)
+			dev_err(&client->dev,
+				"Failed to get attention GPIO: %d\n", error);
+		return error;
+	}
+
+	ts->reset_gpio = devm_gpiod_get_optional(&client->dev,
+						 "reset", GPIOD_OUT_LOW);
+	if (IS_ERR(ts->reset_gpio)) {
+		error = PTR_ERR(ts->reset_gpio);
+		if (error != -EPROBE_DEFER)
+			dev_err(&client->dev,
+				"Failed to get reset GPIO: %d\n", error);
+		return error;
+	}
+
+	sis_ts_reset(ts);
+
+	ts->input = input = devm_input_allocate_device(&client->dev);
+	if (!input) {
+		dev_err(&client->dev, "Failed to allocate input device\n");
+		return -ENOMEM;
+	}
+
+	input->name = "SiS Touchscreen";
+	input->id.bustype = BUS_I2C;
+
+	input_set_abs_params(input, ABS_MT_POSITION_X, 0, SIS_MAX_X, 0, 0);
+	input_set_abs_params(input, ABS_MT_POSITION_Y, 0, SIS_MAX_Y, 0, 0);
+	input_set_abs_params(input, ABS_MT_PRESSURE, 0, SIS_MAX_PRESSURE, 0, 0);
+	input_set_abs_params(input, ABS_MT_TOUCH_MAJOR,
+			     0, SIS_AREA_LENGTH_LONGER, 0, 0);
+	input_set_abs_params(input, ABS_MT_TOUCH_MINOR,
+			     0, SIS_AREA_LENGTH_SHORT, 0, 0);
+
+	error = input_mt_init_slots(input, SIS_MAX_FINGERS, INPUT_MT_DIRECT);
+	if (error) {
+		dev_err(&client->dev,
+			"Failed to initialize MT slots: %d\n", error);
+		return error;
+	}
+
+	error = devm_request_threaded_irq(&client->dev, client->irq,
+					  NULL, sis_ts_irq_handler,
+					  IRQF_ONESHOT,
+					  client->name, ts);
+	if (error) {
+		dev_err(&client->dev, "Failed to request IRQ: %d\n", error);
+		return error;
+	}
+
+	error = input_register_device(ts->input);
+	if (error) {
+		dev_err(&client->dev,
+			"Failed to register input device: %d\n", error);
+		return error;
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id sis_ts_dt_ids[] = {
+	{ .compatible = "sis,9200-ts" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, sis_ts_dt_ids);
+#endif
+
+static const struct i2c_device_id sis_ts_id[] = {
+	{ SIS_I2C_NAME,	0 },
+	{ "9200-ts",	0 },
+	{ /* sentinel */  }
+};
+MODULE_DEVICE_TABLE(i2c, sis_ts_id);
+
+static struct i2c_driver sis_ts_driver = {
+	.driver = {
+		.name	= SIS_I2C_NAME,
+		.of_match_table = of_match_ptr(sis_ts_dt_ids),
+	},
+	.probe		= sis_ts_probe,
+	.id_table	= sis_ts_id,
+};
+module_i2c_driver(sis_ts_driver);
+
+MODULE_DESCRIPTION("SiS 9200 Family Touchscreen Driver");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Mika Penttilä <mika.penttila@nextfour.com>");