drivers/input/touchscreen/tsc2007.c - kernel/msm-4.9 - Gitiles

 /*
  * 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
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License version 2 as
  *  published by the Free Software Foundation.
  */

 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/input.h>
 #include <linux/interrupt.h>
 #include <linux/i2c.h>
 #include <linux/i2c/tsc2007.h>

 #define TS_POLL_DELAY			1 /* ms delay between samples */
 #define TS_POLL_PERIOD			1 /* ms delay between samples */

 #define TSC2007_MEASURE_TEMP0		(0x0 << 4)
 #define TSC2007_MEASURE_AUX		(0x2 << 4)
 #define TSC2007_MEASURE_TEMP1		(0x4 << 4)
 #define TSC2007_ACTIVATE_XN		(0x8 << 4)
 #define TSC2007_ACTIVATE_YN		(0x9 << 4)
 #define TSC2007_ACTIVATE_YP_XN		(0xa << 4)
 #define TSC2007_SETUP			(0xb << 4)
 #define TSC2007_MEASURE_X		(0xc << 4)
 #define TSC2007_MEASURE_Y		(0xd << 4)
 #define TSC2007_MEASURE_Z1		(0xe << 4)
 #define TSC2007_MEASURE_Z2		(0xf << 4)

 #define TSC2007_POWER_OFF_IRQ_EN	(0x0 << 2)
 #define TSC2007_ADC_ON_IRQ_DIS0		(0x1 << 2)
 #define TSC2007_ADC_OFF_IRQ_EN		(0x2 << 2)
 #define TSC2007_ADC_ON_IRQ_DIS1		(0x3 << 2)

 #define TSC2007_12BIT			(0x0 << 1)
 #define TSC2007_8BIT			(0x1 << 1)

 #define	MAX_12BIT			((1 << 12) - 1)

 #define ADC_ON_12BIT	(TSC2007_12BIT | TSC2007_ADC_ON_IRQ_DIS0)

 #define READ_Y		(ADC_ON_12BIT | TSC2007_MEASURE_Y)
 #define READ_Z1		(ADC_ON_12BIT | TSC2007_MEASURE_Z1)
 #define READ_Z2		(ADC_ON_12BIT | TSC2007_MEASURE_Z2)
 #define READ_X		(ADC_ON_12BIT | TSC2007_MEASURE_X)
 #define PWRDOWN		(TSC2007_12BIT | TSC2007_POWER_OFF_IRQ_EN)

 struct ts_event {
 	u16	x;
 	u16	y;
 	u16	z1, z2;
 };

 struct tsc2007 {
 	struct input_dev	*input;
 	char			phys[32];
 	struct delayed_work	work;

 	struct i2c_client	*client;

 	u16			model;
 	u16			x_plate_ohms;

 	bool			pendown;
 	int			irq;

 	int			(*get_pendown_state)(void);
 	void			(*clear_penirq)(void);
 };

 static inline 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);
 }

 static u32 tsc2007_calculate_pressure(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 pressure 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;
 }

 static void tsc2007_send_up_event(struct tsc2007 *tsc)
 {
 	struct input_dev *input = tsc->input;

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

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

 static void tsc2007_work(struct work_struct *work)
 {
 	struct tsc2007 *ts =
 		container_of(to_delayed_work(work), struct tsc2007, work);
 	struct ts_event tc;
 	u32 rt;

 	/*
 	 * 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 have rely on the pressure anyway.
 	 */
 	if (ts->get_pendown_state) {
 		if (unlikely(!ts->get_pendown_state())) {
 			tsc2007_send_up_event(ts);
 			ts->pendown = false;
 			goto out;
 		}

 		dev_dbg(&ts->client->dev, "pen is still down\n");
 	}

 	tsc2007_read_values(ts, &tc);

 	rt = tsc2007_calculate_pressure(ts, &tc);
 	if (rt > MAX_12BIT) {
 		/*
 		 * 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);
 		goto out;

 	}

 	if (rt) {
 		struct input_dev *input = ts->input;

 		if (!ts->pendown) {
 			dev_dbg(&ts->client->dev, "DOWN\n");

 			input_report_key(input, BTN_TOUCH, 1);
 			ts->pendown = true;
 		}

 		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);

 		dev_dbg(&ts->client->dev, "point(%4d,%4d), pressure (%4u)\n",
 			tc.x, tc.y, rt);

 	} else if (!ts->get_pendown_state && ts->pendown) {
 		/*
 		 * We don't have callback to check pendown state, so we
 		 * have to assume that since pressure reported is 0 the
 		 * pen was lifted up.
 		 */
 		tsc2007_send_up_event(ts);
 		ts->pendown = false;
 	}

  out:
 	if (ts->pendown)
 		schedule_delayed_work(&ts->work,
 				      msecs_to_jiffies(TS_POLL_PERIOD));
 	else
 		enable_irq(ts->irq);
 }

 static irqreturn_t tsc2007_irq(int irq, void *handle)
 {
 	struct tsc2007 *ts = handle;

 	if (!ts->get_pendown_state || likely(ts->get_pendown_state())) {
 		disable_irq_nosync(ts->irq);
 		schedule_delayed_work(&ts->work,
 				      msecs_to_jiffies(TS_POLL_DELAY));
 	}

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

 	return IRQ_HANDLED;
 }

 static void tsc2007_free_irq(struct tsc2007 *ts)
 {
 	free_irq(ts->irq, ts);
 	if (cancel_delayed_work_sync(&ts->work)) {
 		/*
 		 * Work was pending, therefore we need to enable
 		 * IRQ here to balance the disable_irq() done in the
 		 * interrupt handler.
 		 */
 		enable_irq(ts->irq);
 	}
 }

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

 	if (!pdata) {
 		dev_err(&client->dev, "platform data is required!\n");
 		return -EINVAL;
 	}

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

 	ts = kzalloc(sizeof(struct tsc2007), GFP_KERNEL);
 	input_dev = input_allocate_device();
 	if (!ts || !input_dev) {
 		err = -ENOMEM;
 		goto err_free_mem;
 	}

 	ts->client = client;
 	ts->irq = client->irq;
 	ts->input = input_dev;
 	INIT_DELAYED_WORK(&ts->work, tsc2007_work);

 	ts->model             = pdata->model;
 	ts->x_plate_ohms      = pdata->x_plate_ohms;
 	ts->get_pendown_state = pdata->get_pendown_state;
 	ts->clear_penirq      = pdata->clear_penirq;

 	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->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
 	input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);

 	input_set_abs_params(input_dev, ABS_X, 0, MAX_12BIT, 0, 0);
 	input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, 0, 0);
 	input_set_abs_params(input_dev, ABS_PRESSURE, 0, MAX_12BIT, 0, 0);

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

 	err = request_irq(ts->irq, tsc2007_irq, 0,
 			client->dev.driver->name, ts);
 	if (err < 0) {
 		dev_err(&client->dev, "irq %d busy?\n", ts->irq);
 		goto err_free_mem;
 	}

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

 	err = input_register_device(input_dev);
 	if (err)
 		goto err_free_irq;

 	i2c_set_clientdata(client, ts);

 	return 0;

  err_free_irq:
 	tsc2007_free_irq(ts);
 	if (pdata->exit_platform_hw)
 		pdata->exit_platform_hw();
  err_free_mem:
 	input_free_device(input_dev);
 	kfree(ts);
 	return err;
 }

 static int __devexit tsc2007_remove(struct i2c_client *client)
 {
 	struct tsc2007	*ts = i2c_get_clientdata(client);
 	struct tsc2007_platform_data *pdata = client->dev.platform_data;

 	i2c_set_clientdata(client, NULL);

 	tsc2007_free_irq(ts);

 	if (pdata->exit_platform_hw)
 		pdata->exit_platform_hw();

 	input_unregister_device(ts->input);
 	kfree(ts);

 	return 0;
 }

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

 MODULE_DEVICE_TABLE(i2c, tsc2007_idtable);

 static struct i2c_driver tsc2007_driver = {
 	.driver = {
 		.owner	= THIS_MODULE,
 		.name	= "tsc2007"
 	},
 	.id_table	= tsc2007_idtable,
 	.probe		= tsc2007_probe,
 	.remove		= __devexit_p(tsc2007_remove),
 };

 static int __init tsc2007_init(void)
 {
 	return i2c_add_driver(&tsc2007_driver);
 }

 static void __exit tsc2007_exit(void)
 {
 	i2c_del_driver(&tsc2007_driver);
 }

 module_init(tsc2007_init);
 module_exit(tsc2007_exit);

 MODULE_AUTHOR("Kwangwoo Lee <kwlee@mtekvision.com>");
 MODULE_DESCRIPTION("TSC2007 TouchScreen Driver");
 MODULE_LICENSE("GPL");
	/*
	* 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
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*/

	#include <linux/module.h>
	#include <linux/slab.h>
	#include <linux/input.h>
	#include <linux/interrupt.h>
	#include <linux/i2c.h>
	#include <linux/i2c/tsc2007.h>

	#define TS_POLL_DELAY 1 /* ms delay between samples */
	#define TS_POLL_PERIOD 1 /* ms delay between samples */

	#define TSC2007_MEASURE_TEMP0 (0x0 << 4)
	#define TSC2007_MEASURE_AUX (0x2 << 4)
	#define TSC2007_MEASURE_TEMP1 (0x4 << 4)
	#define TSC2007_ACTIVATE_XN (0x8 << 4)
	#define TSC2007_ACTIVATE_YN (0x9 << 4)
	#define TSC2007_ACTIVATE_YP_XN (0xa << 4)
	#define TSC2007_SETUP (0xb << 4)
	#define TSC2007_MEASURE_X (0xc << 4)
	#define TSC2007_MEASURE_Y (0xd << 4)
	#define TSC2007_MEASURE_Z1 (0xe << 4)
	#define TSC2007_MEASURE_Z2 (0xf << 4)

	#define TSC2007_POWER_OFF_IRQ_EN (0x0 << 2)
	#define TSC2007_ADC_ON_IRQ_DIS0 (0x1 << 2)
	#define TSC2007_ADC_OFF_IRQ_EN (0x2 << 2)
	#define TSC2007_ADC_ON_IRQ_DIS1 (0x3 << 2)

	#define TSC2007_12BIT (0x0 << 1)
	#define TSC2007_8BIT (0x1 << 1)

	#define MAX_12BIT ((1 << 12) - 1)

	#define ADC_ON_12BIT (TSC2007_12BIT \| TSC2007_ADC_ON_IRQ_DIS0)

	#define READ_Y (ADC_ON_12BIT \| TSC2007_MEASURE_Y)
	#define READ_Z1 (ADC_ON_12BIT \| TSC2007_MEASURE_Z1)
	#define READ_Z2 (ADC_ON_12BIT \| TSC2007_MEASURE_Z2)
	#define READ_X (ADC_ON_12BIT \| TSC2007_MEASURE_X)
	#define PWRDOWN (TSC2007_12BIT \| TSC2007_POWER_OFF_IRQ_EN)

	struct ts_event {
	u16 x;
	u16 y;
	u16 z1, z2;
	};

	struct tsc2007 {
	struct input_dev *input;
	char phys[32];
	struct delayed_work work;

	struct i2c_client *client;

	u16 model;
	u16 x_plate_ohms;

	bool pendown;
	int irq;

	int (*get_pendown_state)(void);
	void (*clear_penirq)(void);
	};

	static inline 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);
	}

	static u32 tsc2007_calculate_pressure(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 pressure 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;
	}

	static void tsc2007_send_up_event(struct tsc2007 *tsc)
	{
	struct input_dev *input = tsc->input;

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

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

	static void tsc2007_work(struct work_struct *work)
	{
	struct tsc2007 *ts =
	container_of(to_delayed_work(work), struct tsc2007, work);
	struct ts_event tc;
	u32 rt;

	/*
	* 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 have rely on the pressure anyway.
	*/
	if (ts->get_pendown_state) {
	if (unlikely(!ts->get_pendown_state())) {
	tsc2007_send_up_event(ts);
	ts->pendown = false;
	goto out;
	}

	dev_dbg(&ts->client->dev, "pen is still down\n");
	}

	tsc2007_read_values(ts, &tc);

	rt = tsc2007_calculate_pressure(ts, &tc);
	if (rt > MAX_12BIT) {
	/*
	* 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);
	goto out;

	}

	if (rt) {
	struct input_dev *input = ts->input;

	if (!ts->pendown) {
	dev_dbg(&ts->client->dev, "DOWN\n");

	input_report_key(input, BTN_TOUCH, 1);
	ts->pendown = true;
	}

	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);

	dev_dbg(&ts->client->dev, "point(%4d,%4d), pressure (%4u)\n",
	tc.x, tc.y, rt);

	} else if (!ts->get_pendown_state && ts->pendown) {
	/*
	* We don't have callback to check pendown state, so we
	* have to assume that since pressure reported is 0 the
	* pen was lifted up.
	*/
	tsc2007_send_up_event(ts);
	ts->pendown = false;
	}

	out:
	if (ts->pendown)
	schedule_delayed_work(&ts->work,
	msecs_to_jiffies(TS_POLL_PERIOD));
	else
	enable_irq(ts->irq);
	}

	static irqreturn_t tsc2007_irq(int irq, void *handle)
	{
	struct tsc2007 *ts = handle;

	if (!ts->get_pendown_state \|\| likely(ts->get_pendown_state())) {
	disable_irq_nosync(ts->irq);
	schedule_delayed_work(&ts->work,
	msecs_to_jiffies(TS_POLL_DELAY));
	}

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

	return IRQ_HANDLED;
	}

	static void tsc2007_free_irq(struct tsc2007 *ts)
	{
	free_irq(ts->irq, ts);
	if (cancel_delayed_work_sync(&ts->work)) {
	/*
	* Work was pending, therefore we need to enable
	* IRQ here to balance the disable_irq() done in the
	* interrupt handler.
	*/
	enable_irq(ts->irq);
	}
	}

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

	if (!pdata) {
	dev_err(&client->dev, "platform data is required!\n");
	return -EINVAL;
	}

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

	ts = kzalloc(sizeof(struct tsc2007), GFP_KERNEL);
	input_dev = input_allocate_device();
	if (!ts \|\| !input_dev) {
	err = -ENOMEM;
	goto err_free_mem;
	}

	ts->client = client;
	ts->irq = client->irq;
	ts->input = input_dev;
	INIT_DELAYED_WORK(&ts->work, tsc2007_work);

	ts->model = pdata->model;
	ts->x_plate_ohms = pdata->x_plate_ohms;
	ts->get_pendown_state = pdata->get_pendown_state;
	ts->clear_penirq = pdata->clear_penirq;

	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->evbit[0] = BIT_MASK(EV_KEY) \| BIT_MASK(EV_ABS);
	input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);

	input_set_abs_params(input_dev, ABS_X, 0, MAX_12BIT, 0, 0);
	input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, 0, 0);
	input_set_abs_params(input_dev, ABS_PRESSURE, 0, MAX_12BIT, 0, 0);

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

	err = request_irq(ts->irq, tsc2007_irq, 0,
	client->dev.driver->name, ts);
	if (err < 0) {
	dev_err(&client->dev, "irq %d busy?\n", ts->irq);
	goto err_free_mem;
	}

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

	err = input_register_device(input_dev);
	if (err)
	goto err_free_irq;

	i2c_set_clientdata(client, ts);

	return 0;

	err_free_irq:
	tsc2007_free_irq(ts);
	if (pdata->exit_platform_hw)
	pdata->exit_platform_hw();
	err_free_mem:
	input_free_device(input_dev);
	kfree(ts);
	return err;
	}

	static int __devexit tsc2007_remove(struct i2c_client *client)
	{
	struct tsc2007 *ts = i2c_get_clientdata(client);
	struct tsc2007_platform_data *pdata = client->dev.platform_data;

	i2c_set_clientdata(client, NULL);

	tsc2007_free_irq(ts);

	if (pdata->exit_platform_hw)
	pdata->exit_platform_hw();

	input_unregister_device(ts->input);
	kfree(ts);

	return 0;
	}

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

	MODULE_DEVICE_TABLE(i2c, tsc2007_idtable);

	static struct i2c_driver tsc2007_driver = {
	.driver = {
	.owner = THIS_MODULE,
	.name = "tsc2007"
	},
	.id_table = tsc2007_idtable,
	.probe = tsc2007_probe,
	.remove = __devexit_p(tsc2007_remove),
	};

	static int __init tsc2007_init(void)
	{
	return i2c_add_driver(&tsc2007_driver);
	}

	static void __exit tsc2007_exit(void)
	{
	i2c_del_driver(&tsc2007_driver);
	}

	module_init(tsc2007_init);
	module_exit(tsc2007_exit);

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