drivers/input/touchscreen/msg2638.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Driver for MStar msg2638 touchscreens
  *
  * Copyright (c) 2021 Vincent Knecht <vincent.knecht@mailoo.org>
  *
  * Checksum and IRQ handler based on mstar_drv_common.c and
  * mstar_drv_mutual_fw_control.c
  * Copyright (c) 2006-2012 MStar Semiconductor, Inc.
  *
  * Driver structure based on zinitix.c by Michael Srba <Michael.Srba@seznam.cz>
  */

 #include <linux/delay.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/kernel.h>
 #include <linux/mod_devicetable.h>
 #include <linux/module.h>
 #include <linux/property.h>
 #include <linux/regulator/consumer.h>
 #include <linux/slab.h>

 #define MODE_DATA_RAW			0x5A

 #define MSG2138_MAX_FINGERS		2
 #define MSG2638_MAX_FINGERS		5

 #define MAX_BUTTONS			4

 #define CHIP_ON_DELAY_MS		15
 #define FIRMWARE_ON_DELAY_MS		50
 #define RESET_DELAY_MIN_US		10000
 #define RESET_DELAY_MAX_US		11000

 struct msg_chip_data {
 	irq_handler_t irq_handler;
 	unsigned int max_fingers;
 };

 struct msg2138_packet {
 	u8	xy_hi; /* higher bits of x and y coordinates */
 	u8	x_low;
 	u8	y_low;
 };

 struct msg2138_touch_event {
 	u8	magic;
 	struct	msg2138_packet pkt[MSG2138_MAX_FINGERS];
 	u8	checksum;
 };

 struct msg2638_packet {
 	u8	xy_hi; /* higher bits of x and y coordinates */
 	u8	x_low;
 	u8	y_low;
 	u8	pressure;
 };

 struct msg2638_touch_event {
 	u8	mode;
 	struct	msg2638_packet pkt[MSG2638_MAX_FINGERS];
 	u8	proximity;
 	u8	checksum;
 };

 struct msg2638_ts_data {
 	struct i2c_client *client;
 	struct input_dev *input_dev;
 	struct touchscreen_properties prop;
 	struct regulator_bulk_data supplies[2];
 	struct gpio_desc *reset_gpiod;
 	int max_fingers;
 	u32 keycodes[MAX_BUTTONS];
 	int num_keycodes;
 };

 static u8 msg2638_checksum(u8 *data, u32 length)
 {
 	s32 sum = 0;
 	u32 i;

 	for (i = 0; i < length; i++)
 		sum += data[i];

 	return (u8)((-sum) & 0xFF);
 }

 static void msg2138_report_keys(struct msg2638_ts_data *msg2638, u8 keys)
 {
 	int i;

 	/* keys can be 0x00 or 0xff when all keys have been released */
 	if (keys == 0xff)
 		keys = 0;

 	for (i = 0; i < msg2638->num_keycodes; ++i)
 		input_report_key(msg2638->input_dev, msg2638->keycodes[i],
 				 keys & BIT(i));
 }

 static irqreturn_t msg2138_ts_irq_handler(int irq, void *msg2638_handler)
 {
 	struct msg2638_ts_data *msg2638 = msg2638_handler;
 	struct i2c_client *client = msg2638->client;
 	struct input_dev *input = msg2638->input_dev;
 	struct msg2138_touch_event touch_event;
 	u32 len = sizeof(touch_event);
 	struct i2c_msg msg[] = {
 		{
 			.addr	= client->addr,
 			.flags	= I2C_M_RD,
 			.len	= sizeof(touch_event),
 			.buf	= (u8 *)&touch_event,
 		},
 	};
 	struct msg2138_packet *p0, *p1;
 	u16 x, y, delta_x, delta_y;
 	int ret;

 	ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
 	if (ret != ARRAY_SIZE(msg)) {
 		dev_err(&client->dev,
 			"Failed I2C transfer in irq handler: %d\n",
 			ret < 0 ? ret : -EIO);
 		goto out;
 	}

 	if (msg2638_checksum((u8 *)&touch_event, len - 1) !=
 						touch_event.checksum) {
 		dev_err(&client->dev, "Failed checksum!\n");
 		goto out;
 	}

 	p0 = &touch_event.pkt[0];
 	p1 = &touch_event.pkt[1];

 	/* Ignore non-pressed finger data, but check for key code */
 	if (p0->xy_hi == 0xFF && p0->x_low == 0xFF && p0->y_low == 0xFF) {
 		if (p1->xy_hi == 0xFF && p1->y_low == 0xFF)
 			msg2138_report_keys(msg2638, p1->x_low);
 		goto report;
 	}

 	x = ((p0->xy_hi & 0xF0) << 4) | p0->x_low;
 	y = ((p0->xy_hi & 0x0F) << 8) | p0->y_low;

 	input_mt_slot(input, 0);
 	input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
 	touchscreen_report_pos(input, &msg2638->prop, x, y, true);

 	/* Ignore non-pressed finger data */
 	if (p1->xy_hi == 0xFF && p1->x_low == 0xFF && p1->y_low == 0xFF)
 		goto report;

 	/* Second finger is reported as a delta position */
 	delta_x = ((p1->xy_hi & 0xF0) << 4) | p1->x_low;
 	delta_y = ((p1->xy_hi & 0x0F) << 8) | p1->y_low;

 	/* Ignore second finger if both deltas equal 0 */
 	if (delta_x == 0 && delta_y == 0)
 		goto report;

 	x += delta_x;
 	y += delta_y;

 	input_mt_slot(input, 1);
 	input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
 	touchscreen_report_pos(input, &msg2638->prop, x, y, true);

 report:
 	input_mt_sync_frame(msg2638->input_dev);
 	input_sync(msg2638->input_dev);

 out:
 	return IRQ_HANDLED;
 }

 static irqreturn_t msg2638_ts_irq_handler(int irq, void *msg2638_handler)
 {
 	struct msg2638_ts_data *msg2638 = msg2638_handler;
 	struct i2c_client *client = msg2638->client;
 	struct input_dev *input = msg2638->input_dev;
 	struct msg2638_touch_event touch_event;
 	u32 len = sizeof(touch_event);
 	struct i2c_msg msg[] = {
 		{
 			.addr	= client->addr,
 			.flags	= I2C_M_RD,
 			.len	= sizeof(touch_event),
 			.buf	= (u8 *)&touch_event,
 		},
 	};
 	struct msg2638_packet *p;
 	u16 x, y;
 	int ret;
 	int i;

 	ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
 	if (ret != ARRAY_SIZE(msg)) {
 		dev_err(&client->dev,
 			"Failed I2C transfer in irq handler: %d\n",
 			ret < 0 ? ret : -EIO);
 		goto out;
 	}

 	if (touch_event.mode != MODE_DATA_RAW)
 		goto out;

 	if (msg2638_checksum((u8 *)&touch_event, len - 1) !=
 						touch_event.checksum) {
 		dev_err(&client->dev, "Failed checksum!\n");
 		goto out;
 	}

 	for (i = 0; i < msg2638->max_fingers; i++) {
 		p = &touch_event.pkt[i];

 		/* Ignore non-pressed finger data */
 		if (p->xy_hi == 0xFF && p->x_low == 0xFF && p->y_low == 0xFF)
 			continue;

 		x = (((p->xy_hi & 0xF0) << 4) | p->x_low);
 		y = (((p->xy_hi & 0x0F) << 8) | p->y_low);

 		input_mt_slot(input, i);
 		input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
 		touchscreen_report_pos(input, &msg2638->prop, x, y, true);
 	}

 	input_mt_sync_frame(msg2638->input_dev);
 	input_sync(msg2638->input_dev);

 out:
 	return IRQ_HANDLED;
 }

 static void msg2638_reset(struct msg2638_ts_data *msg2638)
 {
 	gpiod_set_value_cansleep(msg2638->reset_gpiod, 1);
 	usleep_range(RESET_DELAY_MIN_US, RESET_DELAY_MAX_US);
 	gpiod_set_value_cansleep(msg2638->reset_gpiod, 0);
 	msleep(FIRMWARE_ON_DELAY_MS);
 }

 static int msg2638_start(struct msg2638_ts_data *msg2638)
 {
 	int error;

 	error = regulator_bulk_enable(ARRAY_SIZE(msg2638->supplies),
 				      msg2638->supplies);
 	if (error) {
 		dev_err(&msg2638->client->dev,
 			"Failed to enable regulators: %d\n", error);
 		return error;
 	}

 	msleep(CHIP_ON_DELAY_MS);

 	msg2638_reset(msg2638);

 	enable_irq(msg2638->client->irq);

 	return 0;
 }

 static int msg2638_stop(struct msg2638_ts_data *msg2638)
 {
 	int error;

 	disable_irq(msg2638->client->irq);

 	error = regulator_bulk_disable(ARRAY_SIZE(msg2638->supplies),
 				       msg2638->supplies);
 	if (error) {
 		dev_err(&msg2638->client->dev,
 			"Failed to disable regulators: %d\n", error);
 		return error;
 	}

 	return 0;
 }

 static int msg2638_input_open(struct input_dev *dev)
 {
 	struct msg2638_ts_data *msg2638 = input_get_drvdata(dev);

 	return msg2638_start(msg2638);
 }

 static void msg2638_input_close(struct input_dev *dev)
 {
 	struct msg2638_ts_data *msg2638 = input_get_drvdata(dev);

 	msg2638_stop(msg2638);
 }

 static int msg2638_init_input_dev(struct msg2638_ts_data *msg2638)
 {
 	struct device *dev = &msg2638->client->dev;
 	struct input_dev *input_dev;
 	int error;
 	int i;

 	input_dev = devm_input_allocate_device(dev);
 	if (!input_dev) {
 		dev_err(dev, "Failed to allocate input device.\n");
 		return -ENOMEM;
 	}

 	input_set_drvdata(input_dev, msg2638);
 	msg2638->input_dev = input_dev;

 	input_dev->name = "MStar TouchScreen";
 	input_dev->phys = "input/ts";
 	input_dev->id.bustype = BUS_I2C;
 	input_dev->open = msg2638_input_open;
 	input_dev->close = msg2638_input_close;

 	if (msg2638->num_keycodes) {
 		input_dev->keycode = msg2638->keycodes;
 		input_dev->keycodemax = msg2638->num_keycodes;
 		input_dev->keycodesize = sizeof(msg2638->keycodes[0]);
 		for (i = 0; i < msg2638->num_keycodes; i++)
 			input_set_capability(input_dev,
 					     EV_KEY, msg2638->keycodes[i]);
 	}

 	input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_X);
 	input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_Y);

 	touchscreen_parse_properties(input_dev, true, &msg2638->prop);
 	if (!msg2638->prop.max_x || !msg2638->prop.max_y) {
 		dev_err(dev, "touchscreen-size-x and/or touchscreen-size-y not set in properties\n");
 		return -EINVAL;
 	}

 	error = input_mt_init_slots(input_dev, msg2638->max_fingers,
 				    INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
 	if (error) {
 		dev_err(dev, "Failed to initialize MT slots: %d\n", error);
 		return error;
 	}

 	error = input_register_device(input_dev);
 	if (error) {
 		dev_err(dev, "Failed to register input device: %d\n", error);
 		return error;
 	}

 	return 0;
 }

 static int msg2638_ts_probe(struct i2c_client *client)
 {
 	const struct msg_chip_data *chip_data;
 	struct device *dev = &client->dev;
 	struct msg2638_ts_data *msg2638;
 	int error;

 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 		dev_err(dev, "Failed to assert adapter's support for plain I2C.\n");
 		return -ENXIO;
 	}

 	msg2638 = devm_kzalloc(dev, sizeof(*msg2638), GFP_KERNEL);
 	if (!msg2638)
 		return -ENOMEM;

 	msg2638->client = client;
 	i2c_set_clientdata(client, msg2638);

 	chip_data = device_get_match_data(&client->dev);
 	if (!chip_data || !chip_data->max_fingers) {
 		dev_err(dev, "Invalid or missing chip data\n");
 		return -EINVAL;
 	}

 	msg2638->max_fingers = chip_data->max_fingers;

 	msg2638->supplies[0].supply = "vdd";
 	msg2638->supplies[1].supply = "vddio";
 	error = devm_regulator_bulk_get(dev, ARRAY_SIZE(msg2638->supplies),
 					msg2638->supplies);
 	if (error) {
 		dev_err(dev, "Failed to get regulators: %d\n", error);
 		return error;
 	}

 	msg2638->reset_gpiod = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
 	if (IS_ERR(msg2638->reset_gpiod)) {
 		error = PTR_ERR(msg2638->reset_gpiod);
 		dev_err(dev, "Failed to request reset GPIO: %d\n", error);
 		return error;
 	}

 	msg2638->num_keycodes = device_property_count_u32(dev,
 							  "linux,keycodes");
 	if (msg2638->num_keycodes == -EINVAL) {
 		msg2638->num_keycodes = 0;
 	} else if (msg2638->num_keycodes < 0) {
 		dev_err(dev, "Unable to parse linux,keycodes property: %d\n",
 			msg2638->num_keycodes);
 		return msg2638->num_keycodes;
 	} else if (msg2638->num_keycodes > ARRAY_SIZE(msg2638->keycodes)) {
 		dev_warn(dev, "Found %d linux,keycodes but max is %zd, ignoring the rest\n",
 			 msg2638->num_keycodes, ARRAY_SIZE(msg2638->keycodes));
 		msg2638->num_keycodes = ARRAY_SIZE(msg2638->keycodes);
 	}

 	if (msg2638->num_keycodes > 0) {
 		error = device_property_read_u32_array(dev, "linux,keycodes",
 						       msg2638->keycodes,
 						       msg2638->num_keycodes);
 		if (error) {
 			dev_err(dev, "Unable to read linux,keycodes values: %d\n",
 				error);
 			return error;
 		}
 	}

 	error = devm_request_threaded_irq(dev, client->irq,
 					  NULL, chip_data->irq_handler,
 					  IRQF_ONESHOT | IRQF_NO_AUTOEN,
 					  client->name, msg2638);
 	if (error) {
 		dev_err(dev, "Failed to request IRQ: %d\n", error);
 		return error;
 	}

 	error = msg2638_init_input_dev(msg2638);
 	if (error) {
 		dev_err(dev, "Failed to initialize input device: %d\n", error);
 		return error;
 	}

 	return 0;
 }

 static int msg2638_suspend(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct msg2638_ts_data *msg2638 = i2c_get_clientdata(client);

 	mutex_lock(&msg2638->input_dev->mutex);

 	if (input_device_enabled(msg2638->input_dev))
 		msg2638_stop(msg2638);

 	mutex_unlock(&msg2638->input_dev->mutex);

 	return 0;
 }

 static int msg2638_resume(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct msg2638_ts_data *msg2638 = i2c_get_clientdata(client);
 	int ret = 0;

 	mutex_lock(&msg2638->input_dev->mutex);

 	if (input_device_enabled(msg2638->input_dev))
 		ret = msg2638_start(msg2638);

 	mutex_unlock(&msg2638->input_dev->mutex);

 	return ret;
 }

 static DEFINE_SIMPLE_DEV_PM_OPS(msg2638_pm_ops, msg2638_suspend, msg2638_resume);

 static const struct msg_chip_data msg2138_data = {
 	.irq_handler = msg2138_ts_irq_handler,
 	.max_fingers = MSG2138_MAX_FINGERS,
 };

 static const struct msg_chip_data msg2638_data = {
 	.irq_handler = msg2638_ts_irq_handler,
 	.max_fingers = MSG2638_MAX_FINGERS,
 };

 static const struct of_device_id msg2638_of_match[] = {
 	{ .compatible = "mstar,msg2138", .data = &msg2138_data },
 	{ .compatible = "mstar,msg2638", .data = &msg2638_data },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, msg2638_of_match);

 static struct i2c_driver msg2638_ts_driver = {
 	.probe = msg2638_ts_probe,
 	.driver = {
 		.name = "MStar-TS",
 		.pm = pm_sleep_ptr(&msg2638_pm_ops),
 		.of_match_table = msg2638_of_match,
 	},
 };
 module_i2c_driver(msg2638_ts_driver);

 MODULE_AUTHOR("Vincent Knecht <vincent.knecht@mailoo.org>");
 MODULE_DESCRIPTION("MStar MSG2638 touchscreen driver");
 MODULE_LICENSE("GPL v2");
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* Driver for MStar msg2638 touchscreens
	*
	* Copyright (c) 2021 Vincent Knecht <vincent.knecht@mailoo.org>
	*
	* Checksum and IRQ handler based on mstar_drv_common.c and
	* mstar_drv_mutual_fw_control.c
	* Copyright (c) 2006-2012 MStar Semiconductor, Inc.
	*
	* Driver structure based on zinitix.c by Michael Srba <Michael.Srba@seznam.cz>
	*/

	#include <linux/delay.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/kernel.h>
	#include <linux/mod_devicetable.h>
	#include <linux/module.h>
	#include <linux/property.h>
	#include <linux/regulator/consumer.h>
	#include <linux/slab.h>

	#define MODE_DATA_RAW 0x5A

	#define MSG2138_MAX_FINGERS 2
	#define MSG2638_MAX_FINGERS 5

	#define MAX_BUTTONS 4

	#define CHIP_ON_DELAY_MS 15
	#define FIRMWARE_ON_DELAY_MS 50
	#define RESET_DELAY_MIN_US 10000
	#define RESET_DELAY_MAX_US 11000

	struct msg_chip_data {
	irq_handler_t irq_handler;
	unsigned int max_fingers;
	};

	struct msg2138_packet {
	u8 xy_hi; /* higher bits of x and y coordinates */
	u8 x_low;
	u8 y_low;
	};

	struct msg2138_touch_event {
	u8 magic;
	struct msg2138_packet pkt[MSG2138_MAX_FINGERS];
	u8 checksum;
	};

	struct msg2638_packet {
	u8 xy_hi; /* higher bits of x and y coordinates */
	u8 x_low;
	u8 y_low;
	u8 pressure;
	};

	struct msg2638_touch_event {
	u8 mode;
	struct msg2638_packet pkt[MSG2638_MAX_FINGERS];
	u8 proximity;
	u8 checksum;
	};

	struct msg2638_ts_data {
	struct i2c_client *client;
	struct input_dev *input_dev;
	struct touchscreen_properties prop;
	struct regulator_bulk_data supplies[2];
	struct gpio_desc *reset_gpiod;
	int max_fingers;
	u32 keycodes[MAX_BUTTONS];
	int num_keycodes;
	};

	static u8 msg2638_checksum(u8 *data, u32 length)
	{
	s32 sum = 0;
	u32 i;

	for (i = 0; i < length; i++)
	sum += data[i];

	return (u8)((-sum) & 0xFF);
	}

	static void msg2138_report_keys(struct msg2638_ts_data *msg2638, u8 keys)
	{
	int i;

	/* keys can be 0x00 or 0xff when all keys have been released */
	if (keys == 0xff)
	keys = 0;

	for (i = 0; i < msg2638->num_keycodes; ++i)
	input_report_key(msg2638->input_dev, msg2638->keycodes[i],
	keys & BIT(i));
	}

	static irqreturn_t msg2138_ts_irq_handler(int irq, void *msg2638_handler)
	{
	struct msg2638_ts_data *msg2638 = msg2638_handler;
	struct i2c_client *client = msg2638->client;
	struct input_dev *input = msg2638->input_dev;
	struct msg2138_touch_event touch_event;
	u32 len = sizeof(touch_event);
	struct i2c_msg msg[] = {
	{
	.addr = client->addr,
	.flags = I2C_M_RD,
	.len = sizeof(touch_event),
	.buf = (u8 *)&touch_event,
	},
	};
	struct msg2138_packet p0, p1;
	u16 x, y, delta_x, delta_y;
	int ret;

	ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
	if (ret != ARRAY_SIZE(msg)) {
	dev_err(&client->dev,
	"Failed I2C transfer in irq handler: %d\n",
	ret < 0 ? ret : -EIO);
	goto out;
	}

	if (msg2638_checksum((u8 *)&touch_event, len - 1) !=
	touch_event.checksum) {
	dev_err(&client->dev, "Failed checksum!\n");
	goto out;
	}

	p0 = &touch_event.pkt[0];
	p1 = &touch_event.pkt[1];

	/* Ignore non-pressed finger data, but check for key code */
	if (p0->xy_hi == 0xFF && p0->x_low == 0xFF && p0->y_low == 0xFF) {
	if (p1->xy_hi == 0xFF && p1->y_low == 0xFF)
	msg2138_report_keys(msg2638, p1->x_low);
	goto report;
	}

	x = ((p0->xy_hi & 0xF0) << 4) \| p0->x_low;
	y = ((p0->xy_hi & 0x0F) << 8) \| p0->y_low;

	input_mt_slot(input, 0);
	input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
	touchscreen_report_pos(input, &msg2638->prop, x, y, true);

	/* Ignore non-pressed finger data */
	if (p1->xy_hi == 0xFF && p1->x_low == 0xFF && p1->y_low == 0xFF)
	goto report;

	/* Second finger is reported as a delta position */
	delta_x = ((p1->xy_hi & 0xF0) << 4) \| p1->x_low;
	delta_y = ((p1->xy_hi & 0x0F) << 8) \| p1->y_low;

	/* Ignore second finger if both deltas equal 0 */
	if (delta_x == 0 && delta_y == 0)
	goto report;

	x += delta_x;
	y += delta_y;

	input_mt_slot(input, 1);
	input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
	touchscreen_report_pos(input, &msg2638->prop, x, y, true);

	report:
	input_mt_sync_frame(msg2638->input_dev);
	input_sync(msg2638->input_dev);

	out:
	return IRQ_HANDLED;
	}

	static irqreturn_t msg2638_ts_irq_handler(int irq, void *msg2638_handler)
	{
	struct msg2638_ts_data *msg2638 = msg2638_handler;
	struct i2c_client *client = msg2638->client;
	struct input_dev *input = msg2638->input_dev;
	struct msg2638_touch_event touch_event;
	u32 len = sizeof(touch_event);
	struct i2c_msg msg[] = {
	{
	.addr = client->addr,
	.flags = I2C_M_RD,
	.len = sizeof(touch_event),
	.buf = (u8 *)&touch_event,
	},
	};
	struct msg2638_packet *p;
	u16 x, y;
	int ret;
	int i;

	ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
	if (ret != ARRAY_SIZE(msg)) {
	dev_err(&client->dev,
	"Failed I2C transfer in irq handler: %d\n",
	ret < 0 ? ret : -EIO);
	goto out;
	}

	if (touch_event.mode != MODE_DATA_RAW)
	goto out;

	if (msg2638_checksum((u8 *)&touch_event, len - 1) !=
	touch_event.checksum) {
	dev_err(&client->dev, "Failed checksum!\n");
	goto out;
	}

	for (i = 0; i < msg2638->max_fingers; i++) {
	p = &touch_event.pkt[i];

	/* Ignore non-pressed finger data */
	if (p->xy_hi == 0xFF && p->x_low == 0xFF && p->y_low == 0xFF)
	continue;

	x = (((p->xy_hi & 0xF0) << 4) \| p->x_low);
	y = (((p->xy_hi & 0x0F) << 8) \| p->y_low);

	input_mt_slot(input, i);
	input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
	touchscreen_report_pos(input, &msg2638->prop, x, y, true);
	}

	input_mt_sync_frame(msg2638->input_dev);
	input_sync(msg2638->input_dev);

	out:
	return IRQ_HANDLED;
	}

	static void msg2638_reset(struct msg2638_ts_data *msg2638)
	{
	gpiod_set_value_cansleep(msg2638->reset_gpiod, 1);
	usleep_range(RESET_DELAY_MIN_US, RESET_DELAY_MAX_US);
	gpiod_set_value_cansleep(msg2638->reset_gpiod, 0);
	msleep(FIRMWARE_ON_DELAY_MS);
	}

	static int msg2638_start(struct msg2638_ts_data *msg2638)
	{
	int error;

	error = regulator_bulk_enable(ARRAY_SIZE(msg2638->supplies),
	msg2638->supplies);
	if (error) {
	dev_err(&msg2638->client->dev,
	"Failed to enable regulators: %d\n", error);
	return error;
	}

	msleep(CHIP_ON_DELAY_MS);

	msg2638_reset(msg2638);

	enable_irq(msg2638->client->irq);

	return 0;
	}

	static int msg2638_stop(struct msg2638_ts_data *msg2638)
	{
	int error;

	disable_irq(msg2638->client->irq);

	error = regulator_bulk_disable(ARRAY_SIZE(msg2638->supplies),
	msg2638->supplies);
	if (error) {
	dev_err(&msg2638->client->dev,
	"Failed to disable regulators: %d\n", error);
	return error;
	}

	return 0;
	}

	static int msg2638_input_open(struct input_dev *dev)
	{
	struct msg2638_ts_data *msg2638 = input_get_drvdata(dev);

	return msg2638_start(msg2638);
	}

	static void msg2638_input_close(struct input_dev *dev)
	{
	struct msg2638_ts_data *msg2638 = input_get_drvdata(dev);

	msg2638_stop(msg2638);
	}

	static int msg2638_init_input_dev(struct msg2638_ts_data *msg2638)
	{
	struct device *dev = &msg2638->client->dev;
	struct input_dev *input_dev;
	int error;
	int i;

	input_dev = devm_input_allocate_device(dev);
	if (!input_dev) {
	dev_err(dev, "Failed to allocate input device.\n");
	return -ENOMEM;
	}

	input_set_drvdata(input_dev, msg2638);
	msg2638->input_dev = input_dev;

	input_dev->name = "MStar TouchScreen";
	input_dev->phys = "input/ts";
	input_dev->id.bustype = BUS_I2C;
	input_dev->open = msg2638_input_open;
	input_dev->close = msg2638_input_close;

	if (msg2638->num_keycodes) {
	input_dev->keycode = msg2638->keycodes;
	input_dev->keycodemax = msg2638->num_keycodes;
	input_dev->keycodesize = sizeof(msg2638->keycodes[0]);
	for (i = 0; i < msg2638->num_keycodes; i++)
	input_set_capability(input_dev,
	EV_KEY, msg2638->keycodes[i]);
	}

	input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_X);
	input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_Y);

	touchscreen_parse_properties(input_dev, true, &msg2638->prop);
	if (!msg2638->prop.max_x \|\| !msg2638->prop.max_y) {
	dev_err(dev, "touchscreen-size-x and/or touchscreen-size-y not set in properties\n");
	return -EINVAL;
	}

	error = input_mt_init_slots(input_dev, msg2638->max_fingers,
	INPUT_MT_DIRECT \| INPUT_MT_DROP_UNUSED);
	if (error) {
	dev_err(dev, "Failed to initialize MT slots: %d\n", error);
	return error;
	}

	error = input_register_device(input_dev);
	if (error) {
	dev_err(dev, "Failed to register input device: %d\n", error);
	return error;
	}

	return 0;
	}

	static int msg2638_ts_probe(struct i2c_client *client)
	{
	const struct msg_chip_data *chip_data;
	struct device *dev = &client->dev;
	struct msg2638_ts_data *msg2638;
	int error;

	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
	dev_err(dev, "Failed to assert adapter's support for plain I2C.\n");
	return -ENXIO;
	}

	msg2638 = devm_kzalloc(dev, sizeof(*msg2638), GFP_KERNEL);
	if (!msg2638)
	return -ENOMEM;

	msg2638->client = client;
	i2c_set_clientdata(client, msg2638);

	chip_data = device_get_match_data(&client->dev);
	if (!chip_data \|\| !chip_data->max_fingers) {
	dev_err(dev, "Invalid or missing chip data\n");
	return -EINVAL;
	}

	msg2638->max_fingers = chip_data->max_fingers;

	msg2638->supplies[0].supply = "vdd";
	msg2638->supplies[1].supply = "vddio";
	error = devm_regulator_bulk_get(dev, ARRAY_SIZE(msg2638->supplies),
	msg2638->supplies);
	if (error) {
	dev_err(dev, "Failed to get regulators: %d\n", error);
	return error;
	}

	msg2638->reset_gpiod = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
	if (IS_ERR(msg2638->reset_gpiod)) {
	error = PTR_ERR(msg2638->reset_gpiod);
	dev_err(dev, "Failed to request reset GPIO: %d\n", error);
	return error;
	}

	msg2638->num_keycodes = device_property_count_u32(dev,
	"linux,keycodes");
	if (msg2638->num_keycodes == -EINVAL) {
	msg2638->num_keycodes = 0;
	} else if (msg2638->num_keycodes < 0) {
	dev_err(dev, "Unable to parse linux,keycodes property: %d\n",
	msg2638->num_keycodes);
	return msg2638->num_keycodes;
	} else if (msg2638->num_keycodes > ARRAY_SIZE(msg2638->keycodes)) {
	dev_warn(dev, "Found %d linux,keycodes but max is %zd, ignoring the rest\n",
	msg2638->num_keycodes, ARRAY_SIZE(msg2638->keycodes));
	msg2638->num_keycodes = ARRAY_SIZE(msg2638->keycodes);
	}

	if (msg2638->num_keycodes > 0) {
	error = device_property_read_u32_array(dev, "linux,keycodes",
	msg2638->keycodes,
	msg2638->num_keycodes);
	if (error) {
	dev_err(dev, "Unable to read linux,keycodes values: %d\n",
	error);
	return error;
	}
	}

	error = devm_request_threaded_irq(dev, client->irq,
	NULL, chip_data->irq_handler,
	IRQF_ONESHOT \| IRQF_NO_AUTOEN,
	client->name, msg2638);
	if (error) {
	dev_err(dev, "Failed to request IRQ: %d\n", error);
	return error;
	}

	error = msg2638_init_input_dev(msg2638);
	if (error) {
	dev_err(dev, "Failed to initialize input device: %d\n", error);
	return error;
	}

	return 0;
	}

	static int msg2638_suspend(struct device *dev)
	{
	struct i2c_client *client = to_i2c_client(dev);
	struct msg2638_ts_data *msg2638 = i2c_get_clientdata(client);

	mutex_lock(&msg2638->input_dev->mutex);

	if (input_device_enabled(msg2638->input_dev))
	msg2638_stop(msg2638);

	mutex_unlock(&msg2638->input_dev->mutex);

	return 0;
	}

	static int msg2638_resume(struct device *dev)
	{
	struct i2c_client *client = to_i2c_client(dev);
	struct msg2638_ts_data *msg2638 = i2c_get_clientdata(client);
	int ret = 0;

	mutex_lock(&msg2638->input_dev->mutex);

	if (input_device_enabled(msg2638->input_dev))
	ret = msg2638_start(msg2638);

	mutex_unlock(&msg2638->input_dev->mutex);

	return ret;
	}

	static DEFINE_SIMPLE_DEV_PM_OPS(msg2638_pm_ops, msg2638_suspend, msg2638_resume);

	static const struct msg_chip_data msg2138_data = {
	.irq_handler = msg2138_ts_irq_handler,
	.max_fingers = MSG2138_MAX_FINGERS,
	};

	static const struct msg_chip_data msg2638_data = {
	.irq_handler = msg2638_ts_irq_handler,
	.max_fingers = MSG2638_MAX_FINGERS,
	};

	static const struct of_device_id msg2638_of_match[] = {
	{ .compatible = "mstar,msg2138", .data = &msg2138_data },
	{ .compatible = "mstar,msg2638", .data = &msg2638_data },
	{ }
	};
	MODULE_DEVICE_TABLE(of, msg2638_of_match);

	static struct i2c_driver msg2638_ts_driver = {
	.probe = msg2638_ts_probe,
	.driver = {
	.name = "MStar-TS",
	.pm = pm_sleep_ptr(&msg2638_pm_ops),
	.of_match_table = msg2638_of_match,
	},
	};
	module_i2c_driver(msg2638_ts_driver);

	MODULE_AUTHOR("Vincent Knecht <vincent.knecht@mailoo.org>");
	MODULE_DESCRIPTION("MStar MSG2638 touchscreen driver");
	MODULE_LICENSE("GPL v2");