drivers/input/touchscreen/chipone_icn8318.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Driver for ChipOne icn8318 i2c touchscreen controller
  *
  * Copyright (c) 2015 Red Hat Inc.
  *
  * Red Hat authors:
  * Hans de Goede <hdegoede@redhat.com>
  */

 #include <linux/gpio/consumer.h>
 #include <linux/interrupt.h>
 #include <linux/i2c.h>
 #include <linux/input.h>
 #include <linux/input/mt.h>
 #include <linux/input/touchscreen.h>
 #include <linux/module.h>
 #include <linux/of.h>

 #define ICN8318_REG_POWER		4
 #define ICN8318_REG_TOUCHDATA		16

 #define ICN8318_POWER_ACTIVE		0
 #define ICN8318_POWER_MONITOR		1
 #define ICN8318_POWER_HIBERNATE		2

 #define ICN8318_MAX_TOUCHES		5

 struct icn8318_touch {
 	__u8 slot;
 	__be16 x;
 	__be16 y;
 	__u8 pressure;	/* Seems more like finger width then pressure really */
 	__u8 event;
 /* The difference between 2 and 3 is unclear */
 #define ICN8318_EVENT_NO_DATA	1 /* No finger seen yet since wakeup */
 #define ICN8318_EVENT_UPDATE1	2 /* New or updated coordinates */
 #define ICN8318_EVENT_UPDATE2	3 /* New or updated coordinates */
 #define ICN8318_EVENT_END	4 /* Finger lifted */
 } __packed;

 struct icn8318_touch_data {
 	__u8 softbutton;
 	__u8 touch_count;
 	struct icn8318_touch touches[ICN8318_MAX_TOUCHES];
 } __packed;

 struct icn8318_data {
 	struct i2c_client *client;
 	struct input_dev *input;
 	struct gpio_desc *wake_gpio;
 	struct touchscreen_properties prop;
 };

 static int icn8318_read_touch_data(struct i2c_client *client,
 				   struct icn8318_touch_data *touch_data)
 {
 	u8 reg = ICN8318_REG_TOUCHDATA;
 	struct i2c_msg msg[2] = {
 		{
 			.addr = client->addr,
 			.len = 1,
 			.buf = &reg
 		},
 		{
 			.addr = client->addr,
 			.flags = I2C_M_RD,
 			.len = sizeof(struct icn8318_touch_data),
 			.buf = (u8 *)touch_data
 		}
 	};

 	return i2c_transfer(client->adapter, msg, 2);
 }

 static inline bool icn8318_touch_active(u8 event)
 {
 	return (event == ICN8318_EVENT_UPDATE1) ||
 	       (event == ICN8318_EVENT_UPDATE2);
 }

 static irqreturn_t icn8318_irq(int irq, void *dev_id)
 {
 	struct icn8318_data *data = dev_id;
 	struct device *dev = &data->client->dev;
 	struct icn8318_touch_data touch_data;
 	int i, ret;

 	ret = icn8318_read_touch_data(data->client, &touch_data);
 	if (ret < 0) {
 		dev_err(dev, "Error reading touch data: %d\n", ret);
 		return IRQ_HANDLED;
 	}

 	if (touch_data.softbutton) {
 		/*
 		 * Other data is invalid when a softbutton is pressed.
 		 * This needs some extra devicetree bindings to map the icn8318
 		 * softbutton codes to evdev codes. Currently no known devices
 		 * use this.
 		 */
 		return IRQ_HANDLED;
 	}

 	if (touch_data.touch_count > ICN8318_MAX_TOUCHES) {
 		dev_warn(dev, "Too much touches %d > %d\n",
 			 touch_data.touch_count, ICN8318_MAX_TOUCHES);
 		touch_data.touch_count = ICN8318_MAX_TOUCHES;
 	}

 	for (i = 0; i < touch_data.touch_count; i++) {
 		struct icn8318_touch *touch = &touch_data.touches[i];
 		bool act = icn8318_touch_active(touch->event);

 		input_mt_slot(data->input, touch->slot);
 		input_mt_report_slot_state(data->input, MT_TOOL_FINGER, act);
 		if (!act)
 			continue;

 		touchscreen_report_pos(data->input, &data->prop,
 				       be16_to_cpu(touch->x),
 				       be16_to_cpu(touch->y), true);
 	}

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

 	return IRQ_HANDLED;
 }

 static int icn8318_start(struct input_dev *dev)
 {
 	struct icn8318_data *data = input_get_drvdata(dev);

 	enable_irq(data->client->irq);
 	gpiod_set_value_cansleep(data->wake_gpio, 1);

 	return 0;
 }

 static void icn8318_stop(struct input_dev *dev)
 {
 	struct icn8318_data *data = input_get_drvdata(dev);

 	disable_irq(data->client->irq);
 	i2c_smbus_write_byte_data(data->client, ICN8318_REG_POWER,
 				  ICN8318_POWER_HIBERNATE);
 	gpiod_set_value_cansleep(data->wake_gpio, 0);
 }

 static int icn8318_suspend(struct device *dev)
 {
 	struct icn8318_data *data = i2c_get_clientdata(to_i2c_client(dev));

 	mutex_lock(&data->input->mutex);
 	if (input_device_enabled(data->input))
 		icn8318_stop(data->input);
 	mutex_unlock(&data->input->mutex);

 	return 0;
 }

 static int icn8318_resume(struct device *dev)
 {
 	struct icn8318_data *data = i2c_get_clientdata(to_i2c_client(dev));

 	mutex_lock(&data->input->mutex);
 	if (input_device_enabled(data->input))
 		icn8318_start(data->input);
 	mutex_unlock(&data->input->mutex);

 	return 0;
 }

 static DEFINE_SIMPLE_DEV_PM_OPS(icn8318_pm_ops, icn8318_suspend, icn8318_resume);

 static int icn8318_probe(struct i2c_client *client)
 {
 	struct device *dev = &client->dev;
 	struct icn8318_data *data;
 	struct input_dev *input;
 	int error;

 	if (!client->irq) {
 		dev_err(dev, "Error no irq specified\n");
 		return -EINVAL;
 	}

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

 	data->wake_gpio = devm_gpiod_get(dev, "wake", GPIOD_OUT_LOW);
 	if (IS_ERR(data->wake_gpio)) {
 		error = PTR_ERR(data->wake_gpio);
 		if (error != -EPROBE_DEFER)
 			dev_err(dev, "Error getting wake gpio: %d\n", error);
 		return error;
 	}

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

 	input->name = client->name;
 	input->id.bustype = BUS_I2C;
 	input->open = icn8318_start;
 	input->close = icn8318_stop;
 	input->dev.parent = dev;

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

 	touchscreen_parse_properties(input, true, &data->prop);
 	if (!input_abs_get_max(input, ABS_MT_POSITION_X) ||
 	    !input_abs_get_max(input, ABS_MT_POSITION_Y)) {
 		dev_err(dev, "Error touchscreen-size-x and/or -y missing\n");
 		return -EINVAL;
 	}

 	error = input_mt_init_slots(input, ICN8318_MAX_TOUCHES,
 				    INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
 	if (error)
 		return error;

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

 	error = devm_request_threaded_irq(dev, client->irq, NULL, icn8318_irq,
 					  IRQF_ONESHOT, client->name, data);
 	if (error) {
 		dev_err(dev, "Error requesting irq: %d\n", error);
 		return error;
 	}

 	/* Stop device till opened */
 	icn8318_stop(data->input);

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

 	i2c_set_clientdata(client, data);

 	return 0;
 }

 static const struct of_device_id icn8318_of_match[] = {
 	{ .compatible = "chipone,icn8318" },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, icn8318_of_match);

 /* This is useless for OF-enabled devices, but it is needed by I2C subsystem */
 static const struct i2c_device_id icn8318_i2c_id[] = {
 	{ },
 };
 MODULE_DEVICE_TABLE(i2c, icn8318_i2c_id);

 static struct i2c_driver icn8318_driver = {
 	.driver = {
 		.name	= "chipone_icn8318",
 		.pm	= pm_sleep_ptr(&icn8318_pm_ops),
 		.of_match_table = icn8318_of_match,
 	},
 	.probe_new = icn8318_probe,
 	.id_table = icn8318_i2c_id,
 };

 module_i2c_driver(icn8318_driver);

 MODULE_DESCRIPTION("ChipOne icn8318 I2C Touchscreen Driver");
 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
 MODULE_LICENSE("GPL");
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* Driver for ChipOne icn8318 i2c touchscreen controller
	*
	* Copyright (c) 2015 Red Hat Inc.
	*
	* Red Hat authors:
	* Hans de Goede <hdegoede@redhat.com>
	*/

	#include <linux/gpio/consumer.h>
	#include <linux/interrupt.h>
	#include <linux/i2c.h>
	#include <linux/input.h>
	#include <linux/input/mt.h>
	#include <linux/input/touchscreen.h>
	#include <linux/module.h>
	#include <linux/of.h>

	#define ICN8318_REG_POWER 4
	#define ICN8318_REG_TOUCHDATA 16

	#define ICN8318_POWER_ACTIVE 0
	#define ICN8318_POWER_MONITOR 1
	#define ICN8318_POWER_HIBERNATE 2

	#define ICN8318_MAX_TOUCHES 5

	struct icn8318_touch {
	__u8 slot;
	__be16 x;
	__be16 y;
	__u8 pressure; /* Seems more like finger width then pressure really */
	__u8 event;
	/* The difference between 2 and 3 is unclear */
	#define ICN8318_EVENT_NO_DATA 1 /* No finger seen yet since wakeup */
	#define ICN8318_EVENT_UPDATE1 2 /* New or updated coordinates */
	#define ICN8318_EVENT_UPDATE2 3 /* New or updated coordinates */
	#define ICN8318_EVENT_END 4 /* Finger lifted */
	} __packed;

	struct icn8318_touch_data {
	__u8 softbutton;
	__u8 touch_count;
	struct icn8318_touch touches[ICN8318_MAX_TOUCHES];
	} __packed;

	struct icn8318_data {
	struct i2c_client *client;
	struct input_dev *input;
	struct gpio_desc *wake_gpio;
	struct touchscreen_properties prop;
	};

	static int icn8318_read_touch_data(struct i2c_client *client,
	struct icn8318_touch_data *touch_data)
	{
	u8 reg = ICN8318_REG_TOUCHDATA;
	struct i2c_msg msg[2] = {
	{
	.addr = client->addr,
	.len = 1,
	.buf = &reg
	},
	{
	.addr = client->addr,
	.flags = I2C_M_RD,
	.len = sizeof(struct icn8318_touch_data),
	.buf = (u8 *)touch_data
	}
	};

	return i2c_transfer(client->adapter, msg, 2);
	}

	static inline bool icn8318_touch_active(u8 event)
	{
	return (event == ICN8318_EVENT_UPDATE1) \|\|
	(event == ICN8318_EVENT_UPDATE2);
	}

	static irqreturn_t icn8318_irq(int irq, void *dev_id)
	{
	struct icn8318_data *data = dev_id;
	struct device *dev = &data->client->dev;
	struct icn8318_touch_data touch_data;
	int i, ret;

	ret = icn8318_read_touch_data(data->client, &touch_data);
	if (ret < 0) {
	dev_err(dev, "Error reading touch data: %d\n", ret);
	return IRQ_HANDLED;
	}

	if (touch_data.softbutton) {
	/*
	* Other data is invalid when a softbutton is pressed.
	* This needs some extra devicetree bindings to map the icn8318
	* softbutton codes to evdev codes. Currently no known devices
	* use this.
	*/
	return IRQ_HANDLED;
	}

	if (touch_data.touch_count > ICN8318_MAX_TOUCHES) {
	dev_warn(dev, "Too much touches %d > %d\n",
	touch_data.touch_count, ICN8318_MAX_TOUCHES);
	touch_data.touch_count = ICN8318_MAX_TOUCHES;
	}

	for (i = 0; i < touch_data.touch_count; i++) {
	struct icn8318_touch *touch = &touch_data.touches[i];
	bool act = icn8318_touch_active(touch->event);

	input_mt_slot(data->input, touch->slot);
	input_mt_report_slot_state(data->input, MT_TOOL_FINGER, act);
	if (!act)
	continue;

	touchscreen_report_pos(data->input, &data->prop,
	be16_to_cpu(touch->x),
	be16_to_cpu(touch->y), true);
	}

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

	return IRQ_HANDLED;
	}

	static int icn8318_start(struct input_dev *dev)
	{
	struct icn8318_data *data = input_get_drvdata(dev);

	enable_irq(data->client->irq);
	gpiod_set_value_cansleep(data->wake_gpio, 1);

	return 0;
	}

	static void icn8318_stop(struct input_dev *dev)
	{
	struct icn8318_data *data = input_get_drvdata(dev);

	disable_irq(data->client->irq);
	i2c_smbus_write_byte_data(data->client, ICN8318_REG_POWER,
	ICN8318_POWER_HIBERNATE);
	gpiod_set_value_cansleep(data->wake_gpio, 0);
	}

	static int icn8318_suspend(struct device *dev)
	{
	struct icn8318_data *data = i2c_get_clientdata(to_i2c_client(dev));

	mutex_lock(&data->input->mutex);
	if (input_device_enabled(data->input))
	icn8318_stop(data->input);
	mutex_unlock(&data->input->mutex);

	return 0;
	}

	static int icn8318_resume(struct device *dev)
	{
	struct icn8318_data *data = i2c_get_clientdata(to_i2c_client(dev));

	mutex_lock(&data->input->mutex);
	if (input_device_enabled(data->input))
	icn8318_start(data->input);
	mutex_unlock(&data->input->mutex);

	return 0;
	}

	static DEFINE_SIMPLE_DEV_PM_OPS(icn8318_pm_ops, icn8318_suspend, icn8318_resume);

	static int icn8318_probe(struct i2c_client *client)
	{
	struct device *dev = &client->dev;
	struct icn8318_data *data;
	struct input_dev *input;
	int error;

	if (!client->irq) {
	dev_err(dev, "Error no irq specified\n");
	return -EINVAL;
	}

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

	data->wake_gpio = devm_gpiod_get(dev, "wake", GPIOD_OUT_LOW);
	if (IS_ERR(data->wake_gpio)) {
	error = PTR_ERR(data->wake_gpio);
	if (error != -EPROBE_DEFER)
	dev_err(dev, "Error getting wake gpio: %d\n", error);
	return error;
	}

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

	input->name = client->name;
	input->id.bustype = BUS_I2C;
	input->open = icn8318_start;
	input->close = icn8318_stop;
	input->dev.parent = dev;

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

	touchscreen_parse_properties(input, true, &data->prop);
	if (!input_abs_get_max(input, ABS_MT_POSITION_X) \|\|
	!input_abs_get_max(input, ABS_MT_POSITION_Y)) {
	dev_err(dev, "Error touchscreen-size-x and/or -y missing\n");
	return -EINVAL;
	}

	error = input_mt_init_slots(input, ICN8318_MAX_TOUCHES,
	INPUT_MT_DIRECT \| INPUT_MT_DROP_UNUSED);
	if (error)
	return error;

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

	error = devm_request_threaded_irq(dev, client->irq, NULL, icn8318_irq,
	IRQF_ONESHOT, client->name, data);
	if (error) {
	dev_err(dev, "Error requesting irq: %d\n", error);
	return error;
	}

	/* Stop device till opened */
	icn8318_stop(data->input);

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

	i2c_set_clientdata(client, data);

	return 0;
	}

	static const struct of_device_id icn8318_of_match[] = {
	{ .compatible = "chipone,icn8318" },
	{ }
	};
	MODULE_DEVICE_TABLE(of, icn8318_of_match);

	/* This is useless for OF-enabled devices, but it is needed by I2C subsystem */
	static const struct i2c_device_id icn8318_i2c_id[] = {
	{ },
	};
	MODULE_DEVICE_TABLE(i2c, icn8318_i2c_id);

	static struct i2c_driver icn8318_driver = {
	.driver = {
	.name = "chipone_icn8318",
	.pm = pm_sleep_ptr(&icn8318_pm_ops),
	.of_match_table = icn8318_of_match,
	},
	.probe_new = icn8318_probe,
	.id_table = icn8318_i2c_id,
	};

	module_i2c_driver(icn8318_driver);

	MODULE_DESCRIPTION("ChipOne icn8318 I2C Touchscreen Driver");
	MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
	MODULE_LICENSE("GPL");