drivers/input/touchscreen/tsc2007_core.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * drivers/input/touchscreen/tsc2007.c
  *
  * Copyright (c) 2008 MtekVision Co., Ltd.
  *	Kwangwoo Lee <kwlee@mtekvision.com>
  *
  * Using code from:
  *  - ads7846.c
  *	Copyright (c) 2005 David Brownell
  *	Copyright (c) 2006 Nokia Corporation
  *  - corgi_ts.c
  *	Copyright (C) 2004-2005 Richard Purdie
  *  - omap_ts.[hc], ads7846.h, ts_osk.c
  *	Copyright (C) 2002 MontaVista Software
  *	Copyright (C) 2004 Texas Instruments
  *	Copyright (C) 2005 Dirk Behme
  */

 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/input.h>
 #include <linux/interrupt.h>
 #include <linux/i2c.h>
 #include <linux/of_device.h>
 #include <linux/of_gpio.h>
 #include <linux/platform_data/tsc2007.h>
 #include "tsc2007.h"

 int tsc2007_xfer(struct tsc2007 *tsc, u8 cmd)
 {
 	s32 data;
 	u16 val;

 	data = i2c_smbus_read_word_data(tsc->client, cmd);
 	if (data < 0) {
 		dev_err(&tsc->client->dev, "i2c io error: %d\n", data);
 		return data;
 	}

 	/* The protocol and raw data format from i2c interface:
 	 * S Addr Wr [A] Comm [A] S Addr Rd [A] [DataLow] A [DataHigh] NA P
 	 * Where DataLow has [D11-D4], DataHigh has [D3-D0 << 4 | Dummy 4bit].
 	 */
 	val = swab16(data) >> 4;

 	dev_dbg(&tsc->client->dev, "data: 0x%x, val: 0x%x\n", data, val);

 	return val;
 }

 static void tsc2007_read_values(struct tsc2007 *tsc, struct ts_event *tc)
 {
 	/* y- still on; turn on only y+ (and ADC) */
 	tc->y = tsc2007_xfer(tsc, READ_Y);

 	/* turn y- off, x+ on, then leave in lowpower */
 	tc->x = tsc2007_xfer(tsc, READ_X);

 	/* turn y+ off, x- on; we'll use formula #1 */
 	tc->z1 = tsc2007_xfer(tsc, READ_Z1);
 	tc->z2 = tsc2007_xfer(tsc, READ_Z2);

 	/* Prepare for next touch reading - power down ADC, enable PENIRQ */
 	tsc2007_xfer(tsc, PWRDOWN);
 }

 u32 tsc2007_calculate_resistance(struct tsc2007 *tsc, struct ts_event *tc)
 {
 	u32 rt = 0;

 	/* range filtering */
 	if (tc->x == MAX_12BIT)
 		tc->x = 0;

 	if (likely(tc->x && tc->z1)) {
 		/* compute touch resistance using equation #1 */
 		rt = tc->z2 - tc->z1;
 		rt *= tc->x;
 		rt *= tsc->x_plate_ohms;
 		rt /= tc->z1;
 		rt = (rt + 2047) >> 12;
 	}

 	return rt;
 }

 bool tsc2007_is_pen_down(struct tsc2007 *ts)
 {
 	/*
 	 * NOTE: We can't rely on the pressure to determine the pen down
 	 * state, even though this controller has a pressure sensor.
 	 * The pressure value can fluctuate for quite a while after
 	 * lifting the pen and in some cases may not even settle at the
 	 * expected value.
 	 *
 	 * The only safe way to check for the pen up condition is in the
 	 * work function by reading the pen signal state (it's a GPIO
 	 * and IRQ). Unfortunately such callback is not always available,
 	 * in that case we assume that the pen is down and expect caller
 	 * to fall back on the pressure reading.
 	 */

 	if (!ts->get_pendown_state)
 		return true;

 	return ts->get_pendown_state(&ts->client->dev);
 }

 static irqreturn_t tsc2007_soft_irq(int irq, void *handle)
 {
 	struct tsc2007 *ts = handle;
 	struct input_dev *input = ts->input;
 	struct ts_event tc;
 	u32 rt;

 	while (!ts->stopped && tsc2007_is_pen_down(ts)) {

 		/* pen is down, continue with the measurement */

 		mutex_lock(&ts->mlock);
 		tsc2007_read_values(ts, &tc);
 		mutex_unlock(&ts->mlock);

 		rt = tsc2007_calculate_resistance(ts, &tc);

 		if (!rt && !ts->get_pendown_state) {
 			/*
 			 * If pressure reported is 0 and we don't have
 			 * callback to check pendown state, we have to
 			 * assume that pen was lifted up.
 			 */
 			break;
 		}

 		if (rt <= ts->max_rt) {
 			dev_dbg(&ts->client->dev,
 				"DOWN point(%4d,%4d), resistance (%4u)\n",
 				tc.x, tc.y, rt);

 			rt = ts->max_rt - rt;

 			input_report_key(input, BTN_TOUCH, 1);
 			input_report_abs(input, ABS_X, tc.x);
 			input_report_abs(input, ABS_Y, tc.y);
 			input_report_abs(input, ABS_PRESSURE, rt);

 			input_sync(input);

 		} else {
 			/*
 			 * Sample found inconsistent by debouncing or pressure is
 			 * beyond the maximum. Don't report it to user space,
 			 * repeat at least once more the measurement.
 			 */
 			dev_dbg(&ts->client->dev, "ignored pressure %d\n", rt);
 		}

 		wait_event_timeout(ts->wait, ts->stopped, ts->poll_period);
 	}

 	dev_dbg(&ts->client->dev, "UP\n");

 	input_report_key(input, BTN_TOUCH, 0);
 	input_report_abs(input, ABS_PRESSURE, 0);
 	input_sync(input);

 	if (ts->clear_penirq)
 		ts->clear_penirq();

 	return IRQ_HANDLED;
 }

 static irqreturn_t tsc2007_hard_irq(int irq, void *handle)
 {
 	struct tsc2007 *ts = handle;

 	if (tsc2007_is_pen_down(ts))
 		return IRQ_WAKE_THREAD;

 	if (ts->clear_penirq)
 		ts->clear_penirq();

 	return IRQ_HANDLED;
 }

 static void tsc2007_stop(struct tsc2007 *ts)
 {
 	ts->stopped = true;
 	mb();
 	wake_up(&ts->wait);

 	disable_irq(ts->irq);
 }

 static int tsc2007_open(struct input_dev *input_dev)
 {
 	struct tsc2007 *ts = input_get_drvdata(input_dev);
 	int err;

 	ts->stopped = false;
 	mb();

 	enable_irq(ts->irq);

 	/* Prepare for touch readings - power down ADC and enable PENIRQ */
 	err = tsc2007_xfer(ts, PWRDOWN);
 	if (err < 0) {
 		tsc2007_stop(ts);
 		return err;
 	}

 	return 0;
 }

 static void tsc2007_close(struct input_dev *input_dev)
 {
 	struct tsc2007 *ts = input_get_drvdata(input_dev);

 	tsc2007_stop(ts);
 }

 #ifdef CONFIG_OF
 static int tsc2007_get_pendown_state_gpio(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct tsc2007 *ts = i2c_get_clientdata(client);

 	return !gpio_get_value(ts->gpio);
 }

 static int tsc2007_probe_dt(struct i2c_client *client, struct tsc2007 *ts)
 {
 	struct device_node *np = client->dev.of_node;
 	u32 val32;
 	u64 val64;

 	if (!np) {
 		dev_err(&client->dev, "missing device tree data\n");
 		return -EINVAL;
 	}

 	if (!of_property_read_u32(np, "ti,max-rt", &val32))
 		ts->max_rt = val32;
 	else
 		ts->max_rt = MAX_12BIT;

 	if (!of_property_read_u32(np, "ti,fuzzx", &val32))
 		ts->fuzzx = val32;

 	if (!of_property_read_u32(np, "ti,fuzzy", &val32))
 		ts->fuzzy = val32;

 	if (!of_property_read_u32(np, "ti,fuzzz", &val32))
 		ts->fuzzz = val32;

 	if (!of_property_read_u64(np, "ti,poll-period", &val64))
 		ts->poll_period = msecs_to_jiffies(val64);
 	else
 		ts->poll_period = msecs_to_jiffies(1);

 	if (!of_property_read_u32(np, "ti,x-plate-ohms", &val32)) {
 		ts->x_plate_ohms = val32;
 	} else {
 		dev_err(&client->dev, "missing ti,x-plate-ohms devicetree property.");
 		return -EINVAL;
 	}

 	ts->gpio = of_get_gpio(np, 0);
 	if (gpio_is_valid(ts->gpio))
 		ts->get_pendown_state = tsc2007_get_pendown_state_gpio;
 	else
 		dev_warn(&client->dev,
 			 "GPIO not specified in DT (of_get_gpio returned %d)\n",
 			 ts->gpio);

 	return 0;
 }
 #else
 static int tsc2007_probe_dt(struct i2c_client *client, struct tsc2007 *ts)
 {
 	dev_err(&client->dev, "platform data is required!\n");
 	return -EINVAL;
 }
 #endif

 static int tsc2007_probe_pdev(struct i2c_client *client, struct tsc2007 *ts,
 			      const struct tsc2007_platform_data *pdata,
 			      const struct i2c_device_id *id)
 {
 	ts->model             = pdata->model;
 	ts->x_plate_ohms      = pdata->x_plate_ohms;
 	ts->max_rt            = pdata->max_rt ? : MAX_12BIT;
 	ts->poll_period       = msecs_to_jiffies(pdata->poll_period ? : 1);
 	ts->get_pendown_state = pdata->get_pendown_state;
 	ts->clear_penirq      = pdata->clear_penirq;
 	ts->fuzzx             = pdata->fuzzx;
 	ts->fuzzy             = pdata->fuzzy;
 	ts->fuzzz             = pdata->fuzzz;

 	if (pdata->x_plate_ohms == 0) {
 		dev_err(&client->dev, "x_plate_ohms is not set up in platform data");
 		return -EINVAL;
 	}

 	return 0;
 }

 static void tsc2007_call_exit_platform_hw(void *data)
 {
 	struct device *dev = data;
 	const struct tsc2007_platform_data *pdata = dev_get_platdata(dev);

 	pdata->exit_platform_hw();
 }

 static int tsc2007_probe(struct i2c_client *client,
 			 const struct i2c_device_id *id)
 {
 	const struct tsc2007_platform_data *pdata =
 		dev_get_platdata(&client->dev);
 	struct tsc2007 *ts;
 	struct input_dev *input_dev;
 	int err;

 	if (!i2c_check_functionality(client->adapter,
 				     I2C_FUNC_SMBUS_READ_WORD_DATA))
 		return -EIO;

 	ts = devm_kzalloc(&client->dev, sizeof(struct tsc2007), GFP_KERNEL);
 	if (!ts)
 		return -ENOMEM;

 	if (pdata)
 		err = tsc2007_probe_pdev(client, ts, pdata, id);
 	else
 		err = tsc2007_probe_dt(client, ts);
 	if (err)
 		return err;

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

 	i2c_set_clientdata(client, ts);

 	ts->client = client;
 	ts->irq = client->irq;
 	ts->input = input_dev;

 	init_waitqueue_head(&ts->wait);
 	mutex_init(&ts->mlock);

 	snprintf(ts->phys, sizeof(ts->phys),
 		 "%s/input0", dev_name(&client->dev));

 	input_dev->name = "TSC2007 Touchscreen";
 	input_dev->phys = ts->phys;
 	input_dev->id.bustype = BUS_I2C;

 	input_dev->open = tsc2007_open;
 	input_dev->close = tsc2007_close;

 	input_set_drvdata(input_dev, ts);

 	input_set_capability(input_dev, EV_KEY, BTN_TOUCH);

 	input_set_abs_params(input_dev, ABS_X, 0, MAX_12BIT, ts->fuzzx, 0);
 	input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, ts->fuzzy, 0);
 	input_set_abs_params(input_dev, ABS_PRESSURE, 0, MAX_12BIT,
 			     ts->fuzzz, 0);

 	if (pdata) {
 		if (pdata->exit_platform_hw) {
 			err = devm_add_action(&client->dev,
 					      tsc2007_call_exit_platform_hw,
 					      &client->dev);
 			if (err) {
 				dev_err(&client->dev,
 					"Failed to register exit_platform_hw action, %d\n",
 					err);
 				return err;
 			}
 		}

 		if (pdata->init_platform_hw)
 			pdata->init_platform_hw();
 	}

 	err = devm_request_threaded_irq(&client->dev, ts->irq,
 					tsc2007_hard_irq, tsc2007_soft_irq,
 					IRQF_ONESHOT,
 					client->dev.driver->name, ts);
 	if (err) {
 		dev_err(&client->dev, "Failed to request irq %d: %d\n",
 			ts->irq, err);
 		return err;
 	}

 	tsc2007_stop(ts);

 	/* power down the chip (TSC2007_SETUP does not ACK on I2C) */
 	err = tsc2007_xfer(ts, PWRDOWN);
 	if (err < 0) {
 		dev_err(&client->dev,
 			"Failed to setup chip: %d\n", err);
 		return err;	/* chip does not respond */
 	}

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

 	err =  tsc2007_iio_configure(ts);
 	if (err) {
 		dev_err(&client->dev,
 			"Failed to register with IIO: %d\n", err);
 		return err;
 	}

 	return 0;
 }

 static const struct i2c_device_id tsc2007_idtable[] = {
 	{ "tsc2007", 0 },
 	{ }
 };

 MODULE_DEVICE_TABLE(i2c, tsc2007_idtable);

 #ifdef CONFIG_OF
 static const struct of_device_id tsc2007_of_match[] = {
 	{ .compatible = "ti,tsc2007" },
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, tsc2007_of_match);
 #endif

 static struct i2c_driver tsc2007_driver = {
 	.driver = {
 		.name	= "tsc2007",
 		.of_match_table = of_match_ptr(tsc2007_of_match),
 	},
 	.id_table	= tsc2007_idtable,
 	.probe		= tsc2007_probe,
 };

 module_i2c_driver(tsc2007_driver);

 MODULE_AUTHOR("Kwangwoo Lee <kwlee@mtekvision.com>");
 MODULE_DESCRIPTION("TSC2007 TouchScreen Driver");
 MODULE_LICENSE("GPL");
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* drivers/input/touchscreen/tsc2007.c
	*
	* Copyright (c) 2008 MtekVision Co., Ltd.
	* Kwangwoo Lee <kwlee@mtekvision.com>
	*
	* Using code from:
	* - ads7846.c
	* Copyright (c) 2005 David Brownell
	* Copyright (c) 2006 Nokia Corporation
	* - corgi_ts.c
	* Copyright (C) 2004-2005 Richard Purdie
	* - omap_ts.[hc], ads7846.h, ts_osk.c
	* Copyright (C) 2002 MontaVista Software
	* Copyright (C) 2004 Texas Instruments
	* Copyright (C) 2005 Dirk Behme
	*/

	#include <linux/module.h>
	#include <linux/slab.h>
	#include <linux/input.h>
	#include <linux/interrupt.h>
	#include <linux/i2c.h>
	#include <linux/of_device.h>
	#include <linux/of_gpio.h>
	#include <linux/platform_data/tsc2007.h>
	#include "tsc2007.h"

	int tsc2007_xfer(struct tsc2007 *tsc, u8 cmd)
	{
	s32 data;
	u16 val;

	data = i2c_smbus_read_word_data(tsc->client, cmd);
	if (data < 0) {
	dev_err(&tsc->client->dev, "i2c io error: %d\n", data);
	return data;
	}

	/* The protocol and raw data format from i2c interface:
	* S Addr Wr [A] Comm [A] S Addr Rd [A] [DataLow] A [DataHigh] NA P
	* Where DataLow has [D11-D4], DataHigh has [D3-D0 << 4 \| Dummy 4bit].
	*/
	val = swab16(data) >> 4;

	dev_dbg(&tsc->client->dev, "data: 0x%x, val: 0x%x\n", data, val);

	return val;
	}

	static void tsc2007_read_values(struct tsc2007 tsc, struct ts_event tc)
	{
	/* y- still on; turn on only y+ (and ADC) */
	tc->y = tsc2007_xfer(tsc, READ_Y);

	/* turn y- off, x+ on, then leave in lowpower */
	tc->x = tsc2007_xfer(tsc, READ_X);

	/* turn y+ off, x- on; we'll use formula #1 */
	tc->z1 = tsc2007_xfer(tsc, READ_Z1);
	tc->z2 = tsc2007_xfer(tsc, READ_Z2);

	/* Prepare for next touch reading - power down ADC, enable PENIRQ */
	tsc2007_xfer(tsc, PWRDOWN);
	}

	u32 tsc2007_calculate_resistance(struct tsc2007 tsc, struct ts_event tc)
	{
	u32 rt = 0;

	/* range filtering */
	if (tc->x == MAX_12BIT)
	tc->x = 0;

	if (likely(tc->x && tc->z1)) {
	/* compute touch resistance using equation #1 */
	rt = tc->z2 - tc->z1;
	rt *= tc->x;
	rt *= tsc->x_plate_ohms;
	rt /= tc->z1;
	rt = (rt + 2047) >> 12;
	}

	return rt;
	}

	bool tsc2007_is_pen_down(struct tsc2007 *ts)
	{
	/*
	* NOTE: We can't rely on the pressure to determine the pen down
	* state, even though this controller has a pressure sensor.
	* The pressure value can fluctuate for quite a while after
	* lifting the pen and in some cases may not even settle at the
	* expected value.
	*
	* The only safe way to check for the pen up condition is in the
	* work function by reading the pen signal state (it's a GPIO
	* and IRQ). Unfortunately such callback is not always available,
	* in that case we assume that the pen is down and expect caller
	* to fall back on the pressure reading.
	*/

	if (!ts->get_pendown_state)
	return true;

	return ts->get_pendown_state(&ts->client->dev);
	}

	static irqreturn_t tsc2007_soft_irq(int irq, void *handle)
	{
	struct tsc2007 *ts = handle;
	struct input_dev *input = ts->input;
	struct ts_event tc;
	u32 rt;

	while (!ts->stopped && tsc2007_is_pen_down(ts)) {

	/* pen is down, continue with the measurement */

	mutex_lock(&ts->mlock);
	tsc2007_read_values(ts, &tc);
	mutex_unlock(&ts->mlock);

	rt = tsc2007_calculate_resistance(ts, &tc);

	if (!rt && !ts->get_pendown_state) {
	/*
	* If pressure reported is 0 and we don't have
	* callback to check pendown state, we have to
	* assume that pen was lifted up.
	*/
	break;
	}

	if (rt <= ts->max_rt) {
	dev_dbg(&ts->client->dev,
	"DOWN point(%4d,%4d), resistance (%4u)\n",
	tc.x, tc.y, rt);

	rt = ts->max_rt - rt;

	input_report_key(input, BTN_TOUCH, 1);
	input_report_abs(input, ABS_X, tc.x);
	input_report_abs(input, ABS_Y, tc.y);
	input_report_abs(input, ABS_PRESSURE, rt);

	input_sync(input);

	} else {
	/*
	* Sample found inconsistent by debouncing or pressure is
	* beyond the maximum. Don't report it to user space,
	* repeat at least once more the measurement.
	*/
	dev_dbg(&ts->client->dev, "ignored pressure %d\n", rt);
	}

	wait_event_timeout(ts->wait, ts->stopped, ts->poll_period);
	}

	dev_dbg(&ts->client->dev, "UP\n");

	input_report_key(input, BTN_TOUCH, 0);
	input_report_abs(input, ABS_PRESSURE, 0);
	input_sync(input);

	if (ts->clear_penirq)
	ts->clear_penirq();

	return IRQ_HANDLED;
	}

	static irqreturn_t tsc2007_hard_irq(int irq, void *handle)
	{
	struct tsc2007 *ts = handle;

	if (tsc2007_is_pen_down(ts))
	return IRQ_WAKE_THREAD;

	if (ts->clear_penirq)
	ts->clear_penirq();

	return IRQ_HANDLED;
	}

	static void tsc2007_stop(struct tsc2007 *ts)
	{
	ts->stopped = true;
	mb();
	wake_up(&ts->wait);

	disable_irq(ts->irq);
	}

	static int tsc2007_open(struct input_dev *input_dev)
	{
	struct tsc2007 *ts = input_get_drvdata(input_dev);
	int err;

	ts->stopped = false;
	mb();

	enable_irq(ts->irq);

	/* Prepare for touch readings - power down ADC and enable PENIRQ */
	err = tsc2007_xfer(ts, PWRDOWN);
	if (err < 0) {
	tsc2007_stop(ts);
	return err;
	}

	return 0;
	}

	static void tsc2007_close(struct input_dev *input_dev)
	{
	struct tsc2007 *ts = input_get_drvdata(input_dev);

	tsc2007_stop(ts);
	}

	#ifdef CONFIG_OF
	static int tsc2007_get_pendown_state_gpio(struct device *dev)
	{
	struct i2c_client *client = to_i2c_client(dev);
	struct tsc2007 *ts = i2c_get_clientdata(client);

	return !gpio_get_value(ts->gpio);
	}

	static int tsc2007_probe_dt(struct i2c_client client, struct tsc2007 ts)
	{
	struct device_node *np = client->dev.of_node;
	u32 val32;
	u64 val64;

	if (!np) {
	dev_err(&client->dev, "missing device tree data\n");
	return -EINVAL;
	}

	if (!of_property_read_u32(np, "ti,max-rt", &val32))
	ts->max_rt = val32;
	else
	ts->max_rt = MAX_12BIT;

	if (!of_property_read_u32(np, "ti,fuzzx", &val32))
	ts->fuzzx = val32;

	if (!of_property_read_u32(np, "ti,fuzzy", &val32))
	ts->fuzzy = val32;

	if (!of_property_read_u32(np, "ti,fuzzz", &val32))
	ts->fuzzz = val32;

	if (!of_property_read_u64(np, "ti,poll-period", &val64))
	ts->poll_period = msecs_to_jiffies(val64);
	else
	ts->poll_period = msecs_to_jiffies(1);

	if (!of_property_read_u32(np, "ti,x-plate-ohms", &val32)) {
	ts->x_plate_ohms = val32;
	} else {
	dev_err(&client->dev, "missing ti,x-plate-ohms devicetree property.");
	return -EINVAL;
	}

	ts->gpio = of_get_gpio(np, 0);
	if (gpio_is_valid(ts->gpio))
	ts->get_pendown_state = tsc2007_get_pendown_state_gpio;
	else
	dev_warn(&client->dev,
	"GPIO not specified in DT (of_get_gpio returned %d)\n",
	ts->gpio);

	return 0;
	}
	#else
	static int tsc2007_probe_dt(struct i2c_client client, struct tsc2007 ts)
	{
	dev_err(&client->dev, "platform data is required!\n");
	return -EINVAL;
	}
	#endif

	static int tsc2007_probe_pdev(struct i2c_client client, struct tsc2007 ts,
	const struct tsc2007_platform_data *pdata,
	const struct i2c_device_id *id)
	{
	ts->model = pdata->model;
	ts->x_plate_ohms = pdata->x_plate_ohms;
	ts->max_rt = pdata->max_rt ? : MAX_12BIT;
	ts->poll_period = msecs_to_jiffies(pdata->poll_period ? : 1);
	ts->get_pendown_state = pdata->get_pendown_state;
	ts->clear_penirq = pdata->clear_penirq;
	ts->fuzzx = pdata->fuzzx;
	ts->fuzzy = pdata->fuzzy;
	ts->fuzzz = pdata->fuzzz;

	if (pdata->x_plate_ohms == 0) {
	dev_err(&client->dev, "x_plate_ohms is not set up in platform data");
	return -EINVAL;
	}

	return 0;
	}

	static void tsc2007_call_exit_platform_hw(void *data)
	{
	struct device *dev = data;
	const struct tsc2007_platform_data *pdata = dev_get_platdata(dev);

	pdata->exit_platform_hw();
	}

	static int tsc2007_probe(struct i2c_client *client,
	const struct i2c_device_id *id)
	{
	const struct tsc2007_platform_data *pdata =
	dev_get_platdata(&client->dev);
	struct tsc2007 *ts;
	struct input_dev *input_dev;
	int err;

	if (!i2c_check_functionality(client->adapter,
	I2C_FUNC_SMBUS_READ_WORD_DATA))
	return -EIO;

	ts = devm_kzalloc(&client->dev, sizeof(struct tsc2007), GFP_KERNEL);
	if (!ts)
	return -ENOMEM;

	if (pdata)
	err = tsc2007_probe_pdev(client, ts, pdata, id);
	else
	err = tsc2007_probe_dt(client, ts);
	if (err)
	return err;

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

	i2c_set_clientdata(client, ts);

	ts->client = client;
	ts->irq = client->irq;
	ts->input = input_dev;

	init_waitqueue_head(&ts->wait);
	mutex_init(&ts->mlock);

	snprintf(ts->phys, sizeof(ts->phys),
	"%s/input0", dev_name(&client->dev));

	input_dev->name = "TSC2007 Touchscreen";
	input_dev->phys = ts->phys;
	input_dev->id.bustype = BUS_I2C;

	input_dev->open = tsc2007_open;
	input_dev->close = tsc2007_close;

	input_set_drvdata(input_dev, ts);

	input_set_capability(input_dev, EV_KEY, BTN_TOUCH);

	input_set_abs_params(input_dev, ABS_X, 0, MAX_12BIT, ts->fuzzx, 0);
	input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, ts->fuzzy, 0);
	input_set_abs_params(input_dev, ABS_PRESSURE, 0, MAX_12BIT,
	ts->fuzzz, 0);

	if (pdata) {
	if (pdata->exit_platform_hw) {
	err = devm_add_action(&client->dev,
	tsc2007_call_exit_platform_hw,
	&client->dev);
	if (err) {
	dev_err(&client->dev,
	"Failed to register exit_platform_hw action, %d\n",
	err);
	return err;
	}
	}

	if (pdata->init_platform_hw)
	pdata->init_platform_hw();
	}

	err = devm_request_threaded_irq(&client->dev, ts->irq,
	tsc2007_hard_irq, tsc2007_soft_irq,
	IRQF_ONESHOT,
	client->dev.driver->name, ts);
	if (err) {
	dev_err(&client->dev, "Failed to request irq %d: %d\n",
	ts->irq, err);
	return err;
	}

	tsc2007_stop(ts);

	/* power down the chip (TSC2007_SETUP does not ACK on I2C) */
	err = tsc2007_xfer(ts, PWRDOWN);
	if (err < 0) {
	dev_err(&client->dev,
	"Failed to setup chip: %d\n", err);
	return err; /* chip does not respond */
	}

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

	err = tsc2007_iio_configure(ts);
	if (err) {
	dev_err(&client->dev,
	"Failed to register with IIO: %d\n", err);
	return err;
	}

	return 0;
	}

	static const struct i2c_device_id tsc2007_idtable[] = {
	{ "tsc2007", 0 },
	{ }
	};

	MODULE_DEVICE_TABLE(i2c, tsc2007_idtable);

	#ifdef CONFIG_OF
	static const struct of_device_id tsc2007_of_match[] = {
	{ .compatible = "ti,tsc2007" },
	{ /* sentinel */ }
	};
	MODULE_DEVICE_TABLE(of, tsc2007_of_match);
	#endif

	static struct i2c_driver tsc2007_driver = {
	.driver = {
	.name = "tsc2007",
	.of_match_table = of_match_ptr(tsc2007_of_match),
	},
	.id_table = tsc2007_idtable,
	.probe = tsc2007_probe,
	};

	module_i2c_driver(tsc2007_driver);

	MODULE_AUTHOR("Kwangwoo Lee <kwlee@mtekvision.com>");
	MODULE_DESCRIPTION("TSC2007 TouchScreen Driver");
	MODULE_LICENSE("GPL");