drivers/input/touchscreen/exc3000.c - third_party/kernel - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Driver for I2C connected EETI EXC3000 multiple touch controller
  *
  * Copyright (C) 2017 Ahmet Inan <inan@distec.de>
  *
  * minimal implementation based on egalax_ts.c and egalax_i2c.c
  */

 #include <linux/bitops.h>
 #include <linux/delay.h>
 #include <linux/device.h>
 #include <linux/gpio/consumer.h>
 #include <linux/i2c.h>
 #include <linux/input.h>
 #include <linux/input/mt.h>
 #include <linux/input/touchscreen.h>
 #include <linux/interrupt.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/sizes.h>
 #include <linux/timer.h>
 #include <asm/unaligned.h>

 #define EXC3000_NUM_SLOTS		10
 #define EXC3000_SLOTS_PER_FRAME		5
 #define EXC3000_LEN_FRAME		66
 #define EXC3000_LEN_POINT		10

 #define EXC3000_LEN_MODEL_NAME		16
 #define EXC3000_LEN_FW_VERSION		16

 #define EXC3000_MT1_EVENT		0x06
 #define EXC3000_MT2_EVENT		0x18

 #define EXC3000_TIMEOUT_MS		100

 #define EXC3000_RESET_MS		10
 #define EXC3000_READY_MS		100

 static const struct i2c_device_id exc3000_id[];

 struct eeti_dev_info {
 	const char *name;
 	int max_xy;
 };

 enum eeti_dev_id {
 	EETI_EXC3000,
 	EETI_EXC80H60,
 	EETI_EXC80H84,
 };

 static struct eeti_dev_info exc3000_info[] = {
 	[EETI_EXC3000] = {
 		.name = "EETI EXC3000 Touch Screen",
 		.max_xy = SZ_4K - 1,
 	},
 	[EETI_EXC80H60] = {
 		.name = "EETI EXC80H60 Touch Screen",
 		.max_xy = SZ_16K - 1,
 	},
 	[EETI_EXC80H84] = {
 		.name = "EETI EXC80H84 Touch Screen",
 		.max_xy = SZ_16K - 1,
 	},
 };

 struct exc3000_data {
 	struct i2c_client *client;
 	const struct eeti_dev_info *info;
 	struct input_dev *input;
 	struct touchscreen_properties prop;
 	struct gpio_desc *reset;
 	struct timer_list timer;
 	u8 buf[2 * EXC3000_LEN_FRAME];
 	struct completion wait_event;
 	struct mutex query_lock;
 	int query_result;
 	char model[EXC3000_LEN_MODEL_NAME];
 	char fw_version[EXC3000_LEN_FW_VERSION];
 };

 static void exc3000_report_slots(struct input_dev *input,
 				 struct touchscreen_properties *prop,
 				 const u8 *buf, int num)
 {
 	for (; num--; buf += EXC3000_LEN_POINT) {
 		if (buf[0] & BIT(0)) {
 			input_mt_slot(input, buf[1]);
 			input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
 			touchscreen_report_pos(input, prop,
 					       get_unaligned_le16(buf + 2),
 					       get_unaligned_le16(buf + 4),
 					       true);
 		}
 	}
 }

 static void exc3000_timer(struct timer_list *t)
 {
 	struct exc3000_data *data = from_timer(data, t, timer);

 	input_mt_sync_frame(data->input);
 	input_sync(data->input);
 }

 static int exc3000_read_frame(struct exc3000_data *data, u8 *buf)
 {
 	struct i2c_client *client = data->client;
 	u8 expected_event = EXC3000_MT1_EVENT;
 	int ret;

 	if (data->info->max_xy == SZ_16K - 1)
 		expected_event = EXC3000_MT2_EVENT;

 	ret = i2c_master_send(client, "'", 2);
 	if (ret < 0)
 		return ret;

 	if (ret != 2)
 		return -EIO;

 	ret = i2c_master_recv(client, buf, EXC3000_LEN_FRAME);
 	if (ret < 0)
 		return ret;

 	if (ret != EXC3000_LEN_FRAME)
 		return -EIO;

 	if (get_unaligned_le16(buf) != EXC3000_LEN_FRAME)
 		return -EINVAL;

 	if (buf[2] != expected_event)
 		return -EINVAL;

 	return 0;
 }

 static int exc3000_read_data(struct exc3000_data *data,
 			     u8 *buf, int *n_slots)
 {
 	int error;

 	error = exc3000_read_frame(data, buf);
 	if (error)
 		return error;

 	*n_slots = buf[3];
 	if (!*n_slots || *n_slots > EXC3000_NUM_SLOTS)
 		return -EINVAL;

 	if (*n_slots > EXC3000_SLOTS_PER_FRAME) {
 		/* Read 2nd frame to get the rest of the contacts. */
 		error = exc3000_read_frame(data, buf + EXC3000_LEN_FRAME);
 		if (error)
 			return error;

 		/* 2nd chunk must have number of contacts set to 0. */
 		if (buf[EXC3000_LEN_FRAME + 3] != 0)
 			return -EINVAL;
 	}

 	return 0;
 }

 static int exc3000_query_interrupt(struct exc3000_data *data)
 {
 	u8 *buf = data->buf;
 	int error;

 	error = i2c_master_recv(data->client, buf, EXC3000_LEN_FRAME);
 	if (error < 0)
 		return error;

 	if (buf[0] != 'B')
 		return -EPROTO;

 	if (buf[4] == 'E')
 		strlcpy(data->model, buf + 5, sizeof(data->model));
 	else if (buf[4] == 'D')
 		strlcpy(data->fw_version, buf + 5, sizeof(data->fw_version));
 	else
 		return -EPROTO;

 	return 0;
 }

 static irqreturn_t exc3000_interrupt(int irq, void *dev_id)
 {
 	struct exc3000_data *data = dev_id;
 	struct input_dev *input = data->input;
 	u8 *buf = data->buf;
 	int slots, total_slots;
 	int error;

 	if (mutex_is_locked(&data->query_lock)) {
 		data->query_result = exc3000_query_interrupt(data);
 		complete(&data->wait_event);
 		goto out;
 	}

 	error = exc3000_read_data(data, buf, &total_slots);
 	if (error) {
 		/* Schedule a timer to release "stuck" contacts */
 		mod_timer(&data->timer,
 			  jiffies + msecs_to_jiffies(EXC3000_TIMEOUT_MS));
 		goto out;
 	}

 	/*
 	 * We read full state successfully, no contacts will be "stuck".
 	 */
 	del_timer_sync(&data->timer);

 	while (total_slots > 0) {
 		slots = min(total_slots, EXC3000_SLOTS_PER_FRAME);
 		exc3000_report_slots(input, &data->prop, buf + 4, slots);
 		total_slots -= slots;
 		buf += EXC3000_LEN_FRAME;
 	}

 	input_mt_sync_frame(input);
 	input_sync(input);

 out:
 	return IRQ_HANDLED;
 }

 static ssize_t fw_version_show(struct device *dev,
 			       struct device_attribute *attr, char *buf)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct exc3000_data *data = i2c_get_clientdata(client);
 	static const u8 request[68] = {
 		0x67, 0x00, 0x42, 0x00, 0x03, 0x01, 'D', 0x00
 	};
 	int error;

 	mutex_lock(&data->query_lock);

 	data->query_result = -ETIMEDOUT;
 	reinit_completion(&data->wait_event);

 	error = i2c_master_send(client, request, sizeof(request));
 	if (error < 0) {
 		mutex_unlock(&data->query_lock);
 		return error;
 	}

 	wait_for_completion_interruptible_timeout(&data->wait_event, 1 * HZ);
 	mutex_unlock(&data->query_lock);

 	if (data->query_result < 0)
 		return data->query_result;

 	return sprintf(buf, "%s\n", data->fw_version);
 }
 static DEVICE_ATTR_RO(fw_version);

 static ssize_t exc3000_get_model(struct exc3000_data *data)
 {
 	static const u8 request[68] = {
 		0x67, 0x00, 0x42, 0x00, 0x03, 0x01, 'E', 0x00
 	};
 	struct i2c_client *client = data->client;
 	int error;

 	mutex_lock(&data->query_lock);
 	data->query_result = -ETIMEDOUT;
 	reinit_completion(&data->wait_event);

 	error = i2c_master_send(client, request, sizeof(request));
 	if (error < 0) {
 		mutex_unlock(&data->query_lock);
 		return error;
 	}

 	wait_for_completion_interruptible_timeout(&data->wait_event, 1 * HZ);
 	mutex_unlock(&data->query_lock);

 	return data->query_result;
 }

 static ssize_t model_show(struct device *dev,
 			  struct device_attribute *attr, char *buf)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct exc3000_data *data = i2c_get_clientdata(client);
 	int error;

 	error = exc3000_get_model(data);
 	if (error < 0)
 		return error;

 	return sprintf(buf, "%s\n", data->model);
 }
 static DEVICE_ATTR_RO(model);

 static struct attribute *sysfs_attrs[] = {
 	&dev_attr_fw_version.attr,
 	&dev_attr_model.attr,
 	NULL
 };

 static struct attribute_group exc3000_attribute_group = {
 	.attrs = sysfs_attrs
 };

 static int exc3000_probe(struct i2c_client *client)
 {
 	struct exc3000_data *data;
 	struct input_dev *input;
 	int error, max_xy, retry;

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

 	data->client = client;
 	data->info = device_get_match_data(&client->dev);
 	if (!data->info) {
 		enum eeti_dev_id eeti_dev_id =
 			i2c_match_id(exc3000_id, client)->driver_data;
 		data->info = &exc3000_info[eeti_dev_id];
 	}
 	timer_setup(&data->timer, exc3000_timer, 0);
 	init_completion(&data->wait_event);
 	mutex_init(&data->query_lock);

 	data->reset = devm_gpiod_get_optional(&client->dev, "reset",
 					      GPIOD_OUT_HIGH);
 	if (IS_ERR(data->reset))
 		return PTR_ERR(data->reset);

 	if (data->reset) {
 		msleep(EXC3000_RESET_MS);
 		gpiod_set_value_cansleep(data->reset, 0);
 		msleep(EXC3000_READY_MS);
 	}

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

 	data->input = input;
 	input_set_drvdata(input, data);

 	input->name = data->info->name;
 	input->id.bustype = BUS_I2C;

 	max_xy = data->info->max_xy;
 	input_set_abs_params(input, ABS_MT_POSITION_X, 0, max_xy, 0, 0);
 	input_set_abs_params(input, ABS_MT_POSITION_Y, 0, max_xy, 0, 0);

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

 	error = input_mt_init_slots(input, EXC3000_NUM_SLOTS,
 				    INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
 	if (error)
 		return error;

 	error = input_register_device(input);
 	if (error)
 		return error;

 	error = devm_request_threaded_irq(&client->dev, client->irq,
 					  NULL, exc3000_interrupt, IRQF_ONESHOT,
 					  client->name, data);
 	if (error)
 		return error;

 	/*
 	 * I²C does not have built-in recovery, so retry on failure. This
 	 * ensures, that the device probe will not fail for temporary issues
 	 * on the bus.  This is not needed for the sysfs calls (userspace
 	 * will receive the error code and can start another query) and
 	 * cannot be done for touch events (but that only means loosing one
 	 * or two touch events anyways).
 	 */
 	for (retry = 0; retry < 3; retry++) {
 		error = exc3000_get_model(data);
 		if (!error)
 			break;
 		dev_warn(&client->dev, "Retry %d get EETI EXC3000 model: %d\n",
 			 retry + 1, error);
 	}

 	if (error)
 		return error;

 	dev_dbg(&client->dev, "TS Model: %s", data->model);

 	i2c_set_clientdata(client, data);

 	error = devm_device_add_group(&client->dev, &exc3000_attribute_group);
 	if (error)
 		return error;

 	return 0;
 }

 static const struct i2c_device_id exc3000_id[] = {
 	{ "exc3000", EETI_EXC3000 },
 	{ "exc80h60", EETI_EXC80H60 },
 	{ "exc80h84", EETI_EXC80H84 },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, exc3000_id);

 #ifdef CONFIG_OF
 static const struct of_device_id exc3000_of_match[] = {
 	{ .compatible = "eeti,exc3000", .data = &exc3000_info[EETI_EXC3000] },
 	{ .compatible = "eeti,exc80h60", .data = &exc3000_info[EETI_EXC80H60] },
 	{ .compatible = "eeti,exc80h84", .data = &exc3000_info[EETI_EXC80H84] },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, exc3000_of_match);
 #endif

 static struct i2c_driver exc3000_driver = {
 	.driver = {
 		.name	= "exc3000",
 		.of_match_table = of_match_ptr(exc3000_of_match),
 	},
 	.id_table	= exc3000_id,
 	.probe_new	= exc3000_probe,
 };

 module_i2c_driver(exc3000_driver);

 MODULE_AUTHOR("Ahmet Inan <inan@distec.de>");
 MODULE_DESCRIPTION("I2C connected EETI EXC3000 multiple touch controller driver");
 MODULE_LICENSE("GPL v2");
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* Driver for I2C connected EETI EXC3000 multiple touch controller
	*
	* Copyright (C) 2017 Ahmet Inan <inan@distec.de>
	*
	* minimal implementation based on egalax_ts.c and egalax_i2c.c
	*/

	#include <linux/bitops.h>
	#include <linux/delay.h>
	#include <linux/device.h>
	#include <linux/gpio/consumer.h>
	#include <linux/i2c.h>
	#include <linux/input.h>
	#include <linux/input/mt.h>
	#include <linux/input/touchscreen.h>
	#include <linux/interrupt.h>
	#include <linux/module.h>
	#include <linux/of.h>
	#include <linux/sizes.h>
	#include <linux/timer.h>
	#include <asm/unaligned.h>

	#define EXC3000_NUM_SLOTS 10
	#define EXC3000_SLOTS_PER_FRAME 5
	#define EXC3000_LEN_FRAME 66
	#define EXC3000_LEN_POINT 10

	#define EXC3000_LEN_MODEL_NAME 16
	#define EXC3000_LEN_FW_VERSION 16

	#define EXC3000_MT1_EVENT 0x06
	#define EXC3000_MT2_EVENT 0x18

	#define EXC3000_TIMEOUT_MS 100

	#define EXC3000_RESET_MS 10
	#define EXC3000_READY_MS 100

	static const struct i2c_device_id exc3000_id[];

	struct eeti_dev_info {
	const char *name;
	int max_xy;
	};

	enum eeti_dev_id {
	EETI_EXC3000,
	EETI_EXC80H60,
	EETI_EXC80H84,
	};

	static struct eeti_dev_info exc3000_info[] = {
	[EETI_EXC3000] = {
	.name = "EETI EXC3000 Touch Screen",
	.max_xy = SZ_4K - 1,
	},
	[EETI_EXC80H60] = {
	.name = "EETI EXC80H60 Touch Screen",
	.max_xy = SZ_16K - 1,
	},
	[EETI_EXC80H84] = {
	.name = "EETI EXC80H84 Touch Screen",
	.max_xy = SZ_16K - 1,
	},
	};

	struct exc3000_data {
	struct i2c_client *client;
	const struct eeti_dev_info *info;
	struct input_dev *input;
	struct touchscreen_properties prop;
	struct gpio_desc *reset;
	struct timer_list timer;
	u8 buf[2 * EXC3000_LEN_FRAME];
	struct completion wait_event;
	struct mutex query_lock;
	int query_result;
	char model[EXC3000_LEN_MODEL_NAME];
	char fw_version[EXC3000_LEN_FW_VERSION];
	};

	static void exc3000_report_slots(struct input_dev *input,
	struct touchscreen_properties *prop,
	const u8 *buf, int num)
	{
	for (; num--; buf += EXC3000_LEN_POINT) {
	if (buf[0] & BIT(0)) {
	input_mt_slot(input, buf[1]);
	input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
	touchscreen_report_pos(input, prop,
	get_unaligned_le16(buf + 2),
	get_unaligned_le16(buf + 4),
	true);
	}
	}
	}

	static void exc3000_timer(struct timer_list *t)
	{
	struct exc3000_data *data = from_timer(data, t, timer);

	input_mt_sync_frame(data->input);
	input_sync(data->input);
	}

	static int exc3000_read_frame(struct exc3000_data data, u8 buf)
	{
	struct i2c_client *client = data->client;
	u8 expected_event = EXC3000_MT1_EVENT;
	int ret;

	if (data->info->max_xy == SZ_16K - 1)
	expected_event = EXC3000_MT2_EVENT;

	ret = i2c_master_send(client, "'", 2);
	if (ret < 0)
	return ret;

	if (ret != 2)
	return -EIO;

	ret = i2c_master_recv(client, buf, EXC3000_LEN_FRAME);
	if (ret < 0)
	return ret;

	if (ret != EXC3000_LEN_FRAME)
	return -EIO;

	if (get_unaligned_le16(buf) != EXC3000_LEN_FRAME)
	return -EINVAL;

	if (buf[2] != expected_event)
	return -EINVAL;

	return 0;
	}

	static int exc3000_read_data(struct exc3000_data *data,
	u8 buf, int n_slots)
	{
	int error;

	error = exc3000_read_frame(data, buf);
	if (error)
	return error;

	*n_slots = buf[3];
	if (!n_slots \|\| n_slots > EXC3000_NUM_SLOTS)
	return -EINVAL;

	if (*n_slots > EXC3000_SLOTS_PER_FRAME) {
	/* Read 2nd frame to get the rest of the contacts. */
	error = exc3000_read_frame(data, buf + EXC3000_LEN_FRAME);
	if (error)
	return error;

	/* 2nd chunk must have number of contacts set to 0. */
	if (buf[EXC3000_LEN_FRAME + 3] != 0)
	return -EINVAL;
	}

	return 0;
	}

	static int exc3000_query_interrupt(struct exc3000_data *data)
	{
	u8 *buf = data->buf;
	int error;

	error = i2c_master_recv(data->client, buf, EXC3000_LEN_FRAME);
	if (error < 0)
	return error;

	if (buf[0] != 'B')
	return -EPROTO;

	if (buf[4] == 'E')
	strlcpy(data->model, buf + 5, sizeof(data->model));
	else if (buf[4] == 'D')
	strlcpy(data->fw_version, buf + 5, sizeof(data->fw_version));
	else
	return -EPROTO;

	return 0;
	}

	static irqreturn_t exc3000_interrupt(int irq, void *dev_id)
	{
	struct exc3000_data *data = dev_id;
	struct input_dev *input = data->input;
	u8 *buf = data->buf;
	int slots, total_slots;
	int error;

	if (mutex_is_locked(&data->query_lock)) {
	data->query_result = exc3000_query_interrupt(data);
	complete(&data->wait_event);
	goto out;
	}

	error = exc3000_read_data(data, buf, &total_slots);
	if (error) {
	/* Schedule a timer to release "stuck" contacts */
	mod_timer(&data->timer,
	jiffies + msecs_to_jiffies(EXC3000_TIMEOUT_MS));
	goto out;
	}

	/*
	* We read full state successfully, no contacts will be "stuck".
	*/
	del_timer_sync(&data->timer);

	while (total_slots > 0) {
	slots = min(total_slots, EXC3000_SLOTS_PER_FRAME);
	exc3000_report_slots(input, &data->prop, buf + 4, slots);
	total_slots -= slots;
	buf += EXC3000_LEN_FRAME;
	}

	input_mt_sync_frame(input);
	input_sync(input);

	out:
	return IRQ_HANDLED;
	}

	static ssize_t fw_version_show(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct i2c_client *client = to_i2c_client(dev);
	struct exc3000_data *data = i2c_get_clientdata(client);
	static const u8 request[68] = {
	0x67, 0x00, 0x42, 0x00, 0x03, 0x01, 'D', 0x00
	};
	int error;

	mutex_lock(&data->query_lock);

	data->query_result = -ETIMEDOUT;
	reinit_completion(&data->wait_event);

	error = i2c_master_send(client, request, sizeof(request));
	if (error < 0) {
	mutex_unlock(&data->query_lock);
	return error;
	}

	wait_for_completion_interruptible_timeout(&data->wait_event, 1 * HZ);
	mutex_unlock(&data->query_lock);

	if (data->query_result < 0)
	return data->query_result;

	return sprintf(buf, "%s\n", data->fw_version);
	}
	static DEVICE_ATTR_RO(fw_version);

	static ssize_t exc3000_get_model(struct exc3000_data *data)
	{
	static const u8 request[68] = {
	0x67, 0x00, 0x42, 0x00, 0x03, 0x01, 'E', 0x00
	};
	struct i2c_client *client = data->client;
	int error;

	mutex_lock(&data->query_lock);
	data->query_result = -ETIMEDOUT;
	reinit_completion(&data->wait_event);

	error = i2c_master_send(client, request, sizeof(request));
	if (error < 0) {
	mutex_unlock(&data->query_lock);
	return error;
	}

	wait_for_completion_interruptible_timeout(&data->wait_event, 1 * HZ);
	mutex_unlock(&data->query_lock);

	return data->query_result;
	}

	static ssize_t model_show(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct i2c_client *client = to_i2c_client(dev);
	struct exc3000_data *data = i2c_get_clientdata(client);
	int error;

	error = exc3000_get_model(data);
	if (error < 0)
	return error;

	return sprintf(buf, "%s\n", data->model);
	}
	static DEVICE_ATTR_RO(model);

	static struct attribute *sysfs_attrs[] = {
	&dev_attr_fw_version.attr,
	&dev_attr_model.attr,
	NULL
	};

	static struct attribute_group exc3000_attribute_group = {
	.attrs = sysfs_attrs
	};

	static int exc3000_probe(struct i2c_client *client)
	{
	struct exc3000_data *data;
	struct input_dev *input;
	int error, max_xy, retry;

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

	data->client = client;
	data->info = device_get_match_data(&client->dev);
	if (!data->info) {
	enum eeti_dev_id eeti_dev_id =
	i2c_match_id(exc3000_id, client)->driver_data;
	data->info = &exc3000_info[eeti_dev_id];
	}
	timer_setup(&data->timer, exc3000_timer, 0);
	init_completion(&data->wait_event);
	mutex_init(&data->query_lock);

	data->reset = devm_gpiod_get_optional(&client->dev, "reset",
	GPIOD_OUT_HIGH);
	if (IS_ERR(data->reset))
	return PTR_ERR(data->reset);

	if (data->reset) {
	msleep(EXC3000_RESET_MS);
	gpiod_set_value_cansleep(data->reset, 0);
	msleep(EXC3000_READY_MS);
	}

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

	data->input = input;
	input_set_drvdata(input, data);

	input->name = data->info->name;
	input->id.bustype = BUS_I2C;

	max_xy = data->info->max_xy;
	input_set_abs_params(input, ABS_MT_POSITION_X, 0, max_xy, 0, 0);
	input_set_abs_params(input, ABS_MT_POSITION_Y, 0, max_xy, 0, 0);

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

	error = input_mt_init_slots(input, EXC3000_NUM_SLOTS,
	INPUT_MT_DIRECT \| INPUT_MT_DROP_UNUSED);
	if (error)
	return error;

	error = input_register_device(input);
	if (error)
	return error;

	error = devm_request_threaded_irq(&client->dev, client->irq,
	NULL, exc3000_interrupt, IRQF_ONESHOT,
	client->name, data);
	if (error)
	return error;

	/*
	* I²C does not have built-in recovery, so retry on failure. This
	* ensures, that the device probe will not fail for temporary issues
	* on the bus. This is not needed for the sysfs calls (userspace
	* will receive the error code and can start another query) and
	* cannot be done for touch events (but that only means loosing one
	* or two touch events anyways).
	*/
	for (retry = 0; retry < 3; retry++) {
	error = exc3000_get_model(data);
	if (!error)
	break;
	dev_warn(&client->dev, "Retry %d get EETI EXC3000 model: %d\n",
	retry + 1, error);
	}

	if (error)
	return error;

	dev_dbg(&client->dev, "TS Model: %s", data->model);

	i2c_set_clientdata(client, data);

	error = devm_device_add_group(&client->dev, &exc3000_attribute_group);
	if (error)
	return error;

	return 0;
	}

	static const struct i2c_device_id exc3000_id[] = {
	{ "exc3000", EETI_EXC3000 },
	{ "exc80h60", EETI_EXC80H60 },
	{ "exc80h84", EETI_EXC80H84 },
	{ }
	};
	MODULE_DEVICE_TABLE(i2c, exc3000_id);

	#ifdef CONFIG_OF
	static const struct of_device_id exc3000_of_match[] = {
	{ .compatible = "eeti,exc3000", .data = &exc3000_info[EETI_EXC3000] },
	{ .compatible = "eeti,exc80h60", .data = &exc3000_info[EETI_EXC80H60] },
	{ .compatible = "eeti,exc80h84", .data = &exc3000_info[EETI_EXC80H84] },
	{ }
	};
	MODULE_DEVICE_TABLE(of, exc3000_of_match);
	#endif

	static struct i2c_driver exc3000_driver = {
	.driver = {
	.name = "exc3000",
	.of_match_table = of_match_ptr(exc3000_of_match),
	},
	.id_table = exc3000_id,
	.probe_new = exc3000_probe,
	};

	module_i2c_driver(exc3000_driver);

	MODULE_AUTHOR("Ahmet Inan <inan@distec.de>");
	MODULE_DESCRIPTION("I2C connected EETI EXC3000 multiple touch controller driver");
	MODULE_LICENSE("GPL v2");