drivers/input/touchscreen/ak4183.c - nest-cam/v179/linux - Git at Google

 /*
  * drivers/input/touchscreen/ak4183.c
  *
  * Copyright (C) 2004-2009, Ambarella, Inc.
  *	Zhenwu Xue <zwxue@ambarella.com>
  *
  *
  *  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/hrtimer.h>
 #include <linux/slab.h>
 #include <linux/input.h>
 #include <linux/interrupt.h>
 #include <linux/i2c.h>
 #include <linux/i2c/ak4183.h>

 /* ns delay before the first sample */
 #define TS_POLL_DELAY			(10 * 1000)
 /* ns delay between samples */
 #define TS_POLL_PERIOD			(5 * 1000)


 #define AK4183_MEASURE_X		(0xc << 4)
 #define AK4183_MEASURE_Y		(0xd << 4)
 #define AK4183_MEASURE_Z1		(0xe << 4)
 #define AK4183_MEASURE_Z2		(0xf << 4)

 #define AK4183_AUTO_POWER_IRQ_EN	(0x0 << 2)
 #define AK4183_ADC_ON_IRQ_DIS		(0x1 << 2)

 #define AK4183_12BIT			(0x0 << 1)
 #define AK4183_8BIT			(0x1 << 1)

 #define	VAL_12BIT			(1 << 12)
 #define	MAX_12BIT			(VAL_12BIT - 1)

 #define ADC_ON_12BIT			(AK4183_12BIT | AK4183_AUTO_POWER_IRQ_EN)

 #define READ_X				(ADC_ON_12BIT | AK4183_MEASURE_X)
 #define READ_Y				(ADC_ON_12BIT | AK4183_MEASURE_Y)
 #define READ_Z1				(ADC_ON_12BIT | AK4183_MEASURE_Z1)
 #define READ_Z2				(ADC_ON_12BIT | AK4183_MEASURE_Z2)

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

 struct ak4183 {
 	struct input_dev	*input;
 	char			phys[32];
 	struct hrtimer		timer;
 	struct ts_event		tc;

 	struct workqueue_struct *workqueue;
 	struct work_struct	report_worker;

 	struct i2c_client	*client;

 	spinlock_t		lock;

 	u16			model;
 	u16			x_plate_ohms;
 	struct ak4183_fix_data	fix;

 	unsigned		pendown;
 	int			irq;

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

 static inline int ak4183_xfer(struct ak4183 *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 ak4183_send_event(void *tsc)
 {
 	struct ak4183	*ts = tsc;
 	u32		rt;
 	u32		x, y, z1, z2;

 	x = ts->tc.x;
 	y = ts->tc.y;
 	z1 = ts->tc.z1;
 	z2 = ts->tc.z2;

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

 	if (likely(x && z1)) {
 		/* compute touch pressure resistance using equation #1 */
 		rt = z2;
 		rt -= z1;
 		rt *= x;
 		rt *= ts->x_plate_ohms;
 		rt /= z1;
 		rt = (rt + 2047) >> 12;
 	} else
 		rt = 0;

 	/* 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
 	 */
 	if (rt > MAX_12BIT) {
 		dev_dbg(&ts->client->dev, "ignored pressure %d\n", rt);

 		return;
 	}

 	/* NOTE: We can't rely on the pressure to determine the pen down
 	 * state, even 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
 	 * timer by reading the pen signal state (it's a GPIO _and_ IRQ).
 	 */
 	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 = 1;
 		}

 		if (ts->fix.x_rescale) {
 			x = (x > ts->fix.x_min) ? (x - ts->fix.x_min) : 0;
 			x *= VAL_12BIT;
 			x /= (ts->fix.x_max - ts->fix.x_min);
 			if (x >= MAX_12BIT)
 				x = MAX_12BIT;
 		}

 		if (ts->fix.y_rescale) {
 			y = (y > ts->fix.y_min) ? (y - ts->fix.y_min) : 0;
 			y *= VAL_12BIT;
 			y /= (ts->fix.y_max - ts->fix.y_min);
 			if (y >= MAX_12BIT)
 				y = MAX_12BIT;
 		}

 		if (ts->fix.x_invert)
 			x = (MAX_12BIT - x);

 		if (ts->fix.y_invert)
 			y = (MAX_12BIT - y);

 		input_report_abs(input, ABS_X, x);
 		input_report_abs(input, ABS_Y, y);
 		input_report_abs(input, ABS_PRESSURE, rt);

 		input_sync(input);

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

 static int ak4183_read_values(struct ak4183 *tsc)
 {
 	/* y- still on; turn on only y+ (and ADC) */
 	tsc->tc.y = ak4183_xfer(tsc, READ_Y);

 	/* turn y- off, x+ on, then leave in lowpower */
 	tsc->tc.x = ak4183_xfer(tsc, READ_X);

 	/* turn y+ off, x- on; we'll use formula #1 */
 	tsc->tc.z1 = ak4183_xfer(tsc, READ_Z1);
 	tsc->tc.z2 = ak4183_xfer(tsc, READ_Z2);

 	return 0;
 }

 static enum hrtimer_restart ak4183_timer(struct hrtimer *handle)
 {
 	struct ak4183 *ts = container_of(handle, struct ak4183, timer);

 	queue_work(ts->workqueue, &ts->report_worker);

 	return HRTIMER_NORESTART;
 }

 static irqreturn_t ak4183_irq(int irq, void *handle)
 {
 	struct ak4183 *ts = handle;

 	if (likely(ts->get_pendown_state())) {
 		disable_irq_nosync(ts->irq);
 		hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_DELAY),
 			HRTIMER_MODE_REL);
 	}

 	return IRQ_HANDLED;
 }

 static void ak4183_report_worker(struct work_struct *work)
 {
 	struct ak4183 *ts;

 	ts = container_of(work, struct ak4183, report_worker);

 	if (unlikely(!ts->get_pendown_state() && ts->pendown)) {
 		struct input_dev *input = ts->input;

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

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

 		ts->pendown = 0;

 		if (ts->clear_penirq)
 			ts->clear_penirq();
 		enable_irq(ts->irq);
 	} else {
 		/* pen is still down, continue with the measurement */
 		dev_dbg(&ts->client->dev, "pen is still down\n");

 		ak4183_read_values(ts);
 		ak4183_send_event(ts);

 		hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_PERIOD),
 			HRTIMER_MODE_REL);
 	}
 }

 static int ak4183_probe(struct i2c_client *client,
 			const struct i2c_device_id *id)
 {
 	struct ak4183 *ts;
 	struct ak4183_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 ak4183), GFP_KERNEL);
 	input_dev = input_allocate_device();
 	if (!ts || !input_dev) {
 		err = -ENOMEM;
 		goto err_free_mem;
 	}

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

 	ts->input = input_dev;

 	hrtimer_init(&ts->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
 	ts->timer.function = ak4183_timer;

 	spin_lock_init(&ts->lock);

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

 	pdata->init_platform_hw();

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

 	input_dev->name = "AK4183 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);

 	ak4183_read_values(ts);

 	ts->workqueue = create_singlethread_workqueue("ak4183");
 	INIT_WORK(&ts->report_worker, ak4183_report_worker);
 	ts->irq = client->irq;

 	err = request_irq(ts->irq, ak4183_irq, 0,
 			client->dev.driver->name, ts);
 	if (err < 0) {
 		dev_err(&client->dev, "irq %d busy?\n", ts->irq);
 		goto err_free_mem;
 	}

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

 	dev_info(&client->dev, "registered with irq (%d)\n", ts->irq);

 	return 0;

  err_free_irq:
 	free_irq(ts->irq, ts);
 	hrtimer_cancel(&ts->timer);
  err_free_mem:
 	input_free_device(input_dev);
 	kfree(ts);
 	return err;
 }

 static int ak4183_remove(struct i2c_client *client)
 {
 	struct ak4183	*ts = i2c_get_clientdata(client);
 	struct ak4183_platform_data *pdata;

 	pdata = client->dev.platform_data;
 	pdata->exit_platform_hw();

 	destroy_workqueue(ts->workqueue);
 	free_irq(ts->irq, ts);
 	hrtimer_cancel(&ts->timer);
 	input_unregister_device(ts->input);
 	kfree(ts);

 	return 0;
 }

 static struct i2c_device_id ak4183_idtable[] = {
 	{ "ak4183", 0 },
 	{ }
 };

 MODULE_DEVICE_TABLE(i2c, ak4183_idtable);

 static struct i2c_driver ak4183_driver = {
 	.driver = {
 		.owner	= THIS_MODULE,
 		.name	= "ak4183"
 	},
 	.id_table	= ak4183_idtable,
 	.probe		= ak4183_probe,
 	.remove		= ak4183_remove,
 };

 static int __init ak4183_init(void)
 {
 	return i2c_add_driver(&ak4183_driver);
 }

 static void __exit ak4183_exit(void)
 {
 	i2c_del_driver(&ak4183_driver);
 }

 module_init(ak4183_init);
 module_exit(ak4183_exit);

 MODULE_AUTHOR("Zhenwu Xue <zwxue@ambarella.com>");
 MODULE_DESCRIPTION("AK4183 TouchScreen Driver");
 MODULE_LICENSE("GPL");
	/*
	* drivers/input/touchscreen/ak4183.c
	*
	* Copyright (C) 2004-2009, Ambarella, Inc.
	* Zhenwu Xue <zwxue@ambarella.com>
	*
	*
	* 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/hrtimer.h>
	#include <linux/slab.h>
	#include <linux/input.h>
	#include <linux/interrupt.h>
	#include <linux/i2c.h>
	#include <linux/i2c/ak4183.h>

	/* ns delay before the first sample */
	#define TS_POLL_DELAY (10 * 1000)
	/* ns delay between samples */
	#define TS_POLL_PERIOD (5 * 1000)


	#define AK4183_MEASURE_X (0xc << 4)
	#define AK4183_MEASURE_Y (0xd << 4)
	#define AK4183_MEASURE_Z1 (0xe << 4)
	#define AK4183_MEASURE_Z2 (0xf << 4)

	#define AK4183_AUTO_POWER_IRQ_EN (0x0 << 2)
	#define AK4183_ADC_ON_IRQ_DIS (0x1 << 2)

	#define AK4183_12BIT (0x0 << 1)
	#define AK4183_8BIT (0x1 << 1)

	#define VAL_12BIT (1 << 12)
	#define MAX_12BIT (VAL_12BIT - 1)

	#define ADC_ON_12BIT (AK4183_12BIT \| AK4183_AUTO_POWER_IRQ_EN)

	#define READ_X (ADC_ON_12BIT \| AK4183_MEASURE_X)
	#define READ_Y (ADC_ON_12BIT \| AK4183_MEASURE_Y)
	#define READ_Z1 (ADC_ON_12BIT \| AK4183_MEASURE_Z1)
	#define READ_Z2 (ADC_ON_12BIT \| AK4183_MEASURE_Z2)

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

	struct ak4183 {
	struct input_dev *input;
	char phys[32];
	struct hrtimer timer;
	struct ts_event tc;

	struct workqueue_struct *workqueue;
	struct work_struct report_worker;

	struct i2c_client *client;

	spinlock_t lock;

	u16 model;
	u16 x_plate_ohms;
	struct ak4183_fix_data fix;

	unsigned pendown;
	int irq;

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

	static inline int ak4183_xfer(struct ak4183 *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 ak4183_send_event(void *tsc)
	{
	struct ak4183 *ts = tsc;
	u32 rt;
	u32 x, y, z1, z2;

	x = ts->tc.x;
	y = ts->tc.y;
	z1 = ts->tc.z1;
	z2 = ts->tc.z2;

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

	if (likely(x && z1)) {
	/* compute touch pressure resistance using equation #1 */
	rt = z2;
	rt -= z1;
	rt *= x;
	rt *= ts->x_plate_ohms;
	rt /= z1;
	rt = (rt + 2047) >> 12;
	} else
	rt = 0;

	/* 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
	*/
	if (rt > MAX_12BIT) {
	dev_dbg(&ts->client->dev, "ignored pressure %d\n", rt);

	return;
	}

	/* NOTE: We can't rely on the pressure to determine the pen down
	* state, even 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
	* timer by reading the pen signal state (it's a GPIO _and_ IRQ).
	*/
	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 = 1;
	}

	if (ts->fix.x_rescale) {
	x = (x > ts->fix.x_min) ? (x - ts->fix.x_min) : 0;
	x *= VAL_12BIT;
	x /= (ts->fix.x_max - ts->fix.x_min);
	if (x >= MAX_12BIT)
	x = MAX_12BIT;
	}

	if (ts->fix.y_rescale) {
	y = (y > ts->fix.y_min) ? (y - ts->fix.y_min) : 0;
	y *= VAL_12BIT;
	y /= (ts->fix.y_max - ts->fix.y_min);
	if (y >= MAX_12BIT)
	y = MAX_12BIT;
	}

	if (ts->fix.x_invert)
	x = (MAX_12BIT - x);

	if (ts->fix.y_invert)
	y = (MAX_12BIT - y);

	input_report_abs(input, ABS_X, x);
	input_report_abs(input, ABS_Y, y);
	input_report_abs(input, ABS_PRESSURE, rt);

	input_sync(input);

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

	static int ak4183_read_values(struct ak4183 *tsc)
	{
	/* y- still on; turn on only y+ (and ADC) */
	tsc->tc.y = ak4183_xfer(tsc, READ_Y);

	/* turn y- off, x+ on, then leave in lowpower */
	tsc->tc.x = ak4183_xfer(tsc, READ_X);

	/* turn y+ off, x- on; we'll use formula #1 */
	tsc->tc.z1 = ak4183_xfer(tsc, READ_Z1);
	tsc->tc.z2 = ak4183_xfer(tsc, READ_Z2);

	return 0;
	}

	static enum hrtimer_restart ak4183_timer(struct hrtimer *handle)
	{
	struct ak4183 *ts = container_of(handle, struct ak4183, timer);

	queue_work(ts->workqueue, &ts->report_worker);

	return HRTIMER_NORESTART;
	}

	static irqreturn_t ak4183_irq(int irq, void *handle)
	{
	struct ak4183 *ts = handle;

	if (likely(ts->get_pendown_state())) {
	disable_irq_nosync(ts->irq);
	hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_DELAY),
	HRTIMER_MODE_REL);
	}

	return IRQ_HANDLED;
	}

	static void ak4183_report_worker(struct work_struct *work)
	{
	struct ak4183 *ts;

	ts = container_of(work, struct ak4183, report_worker);

	if (unlikely(!ts->get_pendown_state() && ts->pendown)) {
	struct input_dev *input = ts->input;

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

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

	ts->pendown = 0;

	if (ts->clear_penirq)
	ts->clear_penirq();
	enable_irq(ts->irq);
	} else {
	/* pen is still down, continue with the measurement */
	dev_dbg(&ts->client->dev, "pen is still down\n");

	ak4183_read_values(ts);
	ak4183_send_event(ts);

	hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_PERIOD),
	HRTIMER_MODE_REL);
	}
	}

	static int ak4183_probe(struct i2c_client *client,
	const struct i2c_device_id *id)
	{
	struct ak4183 *ts;
	struct ak4183_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 ak4183), GFP_KERNEL);
	input_dev = input_allocate_device();
	if (!ts \|\| !input_dev) {
	err = -ENOMEM;
	goto err_free_mem;
	}

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

	ts->input = input_dev;

	hrtimer_init(&ts->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
	ts->timer.function = ak4183_timer;

	spin_lock_init(&ts->lock);

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

	pdata->init_platform_hw();

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

	input_dev->name = "AK4183 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);

	ak4183_read_values(ts);

	ts->workqueue = create_singlethread_workqueue("ak4183");
	INIT_WORK(&ts->report_worker, ak4183_report_worker);
	ts->irq = client->irq;

	err = request_irq(ts->irq, ak4183_irq, 0,
	client->dev.driver->name, ts);
	if (err < 0) {
	dev_err(&client->dev, "irq %d busy?\n", ts->irq);
	goto err_free_mem;
	}

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

	dev_info(&client->dev, "registered with irq (%d)\n", ts->irq);

	return 0;

	err_free_irq:
	free_irq(ts->irq, ts);
	hrtimer_cancel(&ts->timer);
	err_free_mem:
	input_free_device(input_dev);
	kfree(ts);
	return err;
	}

	static int ak4183_remove(struct i2c_client *client)
	{
	struct ak4183 *ts = i2c_get_clientdata(client);
	struct ak4183_platform_data *pdata;

	pdata = client->dev.platform_data;
	pdata->exit_platform_hw();

	destroy_workqueue(ts->workqueue);
	free_irq(ts->irq, ts);
	hrtimer_cancel(&ts->timer);
	input_unregister_device(ts->input);
	kfree(ts);

	return 0;
	}

	static struct i2c_device_id ak4183_idtable[] = {
	{ "ak4183", 0 },
	{ }
	};

	MODULE_DEVICE_TABLE(i2c, ak4183_idtable);

	static struct i2c_driver ak4183_driver = {
	.driver = {
	.owner = THIS_MODULE,
	.name = "ak4183"
	},
	.id_table = ak4183_idtable,
	.probe = ak4183_probe,
	.remove = ak4183_remove,
	};

	static int __init ak4183_init(void)
	{
	return i2c_add_driver(&ak4183_driver);
	}

	static void __exit ak4183_exit(void)
	{
	i2c_del_driver(&ak4183_driver);
	}

	module_init(ak4183_init);
	module_exit(ak4183_exit);

	MODULE_AUTHOR("Zhenwu Xue <zwxue@ambarella.com>");
	MODULE_DESCRIPTION("AK4183 TouchScreen Driver");
	MODULE_LICENSE("GPL");