drivers/input/touchscreen/bu21013_ts.c - third_party/dump-capture-kernel - Git at Google

 /*
  * Copyright (C) ST-Ericsson SA 2010
  * Author: Naveen Kumar G <naveen.gaddipati@stericsson.com> for ST-Ericsson
  * License terms:GNU General Public License (GPL) version 2
  */

 #include <linux/kernel.h>
 #include <linux/delay.h>
 #include <linux/interrupt.h>
 #include <linux/i2c.h>
 #include <linux/workqueue.h>
 #include <linux/input.h>
 #include <linux/input/bu21013.h>
 #include <linux/slab.h>
 #include <linux/regulator/consumer.h>
 #include <linux/module.h>
 #include <linux/gpio.h>
 #include <linux/of.h>
 #include <linux/of_gpio.h>

 #define PEN_DOWN_INTR	0
 #define MAX_FINGERS	2
 #define RESET_DELAY	30
 #define PENUP_TIMEOUT	(10)
 #define DELTA_MIN	16
 #define MASK_BITS	0x03
 #define SHIFT_8		8
 #define SHIFT_2		2
 #define LENGTH_OF_BUFFER	11
 #define I2C_RETRY_COUNT	5

 #define BU21013_SENSORS_BTN_0_7_REG	0x70
 #define BU21013_SENSORS_BTN_8_15_REG	0x71
 #define BU21013_SENSORS_BTN_16_23_REG	0x72
 #define BU21013_X1_POS_MSB_REG		0x73
 #define BU21013_X1_POS_LSB_REG		0x74
 #define BU21013_Y1_POS_MSB_REG		0x75
 #define BU21013_Y1_POS_LSB_REG		0x76
 #define BU21013_X2_POS_MSB_REG		0x77
 #define BU21013_X2_POS_LSB_REG		0x78
 #define BU21013_Y2_POS_MSB_REG		0x79
 #define BU21013_Y2_POS_LSB_REG		0x7A
 #define BU21013_INT_CLR_REG		0xE8
 #define BU21013_INT_MODE_REG		0xE9
 #define BU21013_GAIN_REG		0xEA
 #define BU21013_OFFSET_MODE_REG		0xEB
 #define BU21013_XY_EDGE_REG		0xEC
 #define BU21013_RESET_REG		0xED
 #define BU21013_CALIB_REG		0xEE
 #define BU21013_DONE_REG		0xEF
 #define BU21013_SENSOR_0_7_REG		0xF0
 #define BU21013_SENSOR_8_15_REG		0xF1
 #define BU21013_SENSOR_16_23_REG	0xF2
 #define BU21013_POS_MODE1_REG		0xF3
 #define BU21013_POS_MODE2_REG		0xF4
 #define BU21013_CLK_MODE_REG		0xF5
 #define BU21013_IDLE_REG		0xFA
 #define BU21013_FILTER_REG		0xFB
 #define BU21013_TH_ON_REG		0xFC
 #define BU21013_TH_OFF_REG		0xFD


 #define BU21013_RESET_ENABLE		0x01

 #define BU21013_SENSORS_EN_0_7		0x3F
 #define BU21013_SENSORS_EN_8_15		0xFC
 #define BU21013_SENSORS_EN_16_23	0x1F

 #define BU21013_POS_MODE1_0		0x02
 #define BU21013_POS_MODE1_1		0x04
 #define BU21013_POS_MODE1_2		0x08

 #define BU21013_POS_MODE2_ZERO		0x01
 #define BU21013_POS_MODE2_AVG1		0x02
 #define BU21013_POS_MODE2_AVG2		0x04
 #define BU21013_POS_MODE2_EN_XY		0x08
 #define BU21013_POS_MODE2_EN_RAW	0x10
 #define BU21013_POS_MODE2_MULTI		0x80

 #define BU21013_CLK_MODE_DIV		0x01
 #define BU21013_CLK_MODE_EXT		0x02
 #define BU21013_CLK_MODE_CALIB		0x80

 #define BU21013_IDLET_0			0x01
 #define BU21013_IDLET_1			0x02
 #define BU21013_IDLET_2			0x04
 #define BU21013_IDLET_3			0x08
 #define BU21013_IDLE_INTERMIT_EN	0x10

 #define BU21013_DELTA_0_6	0x7F
 #define BU21013_FILTER_EN	0x80

 #define BU21013_INT_MODE_LEVEL	0x00
 #define BU21013_INT_MODE_EDGE	0x01

 #define BU21013_GAIN_0		0x01
 #define BU21013_GAIN_1		0x02
 #define BU21013_GAIN_2		0x04

 #define BU21013_OFFSET_MODE_DEFAULT	0x00
 #define BU21013_OFFSET_MODE_MOVE	0x01
 #define BU21013_OFFSET_MODE_DISABLE	0x02

 #define BU21013_TH_ON_0		0x01
 #define BU21013_TH_ON_1		0x02
 #define BU21013_TH_ON_2		0x04
 #define BU21013_TH_ON_3		0x08
 #define BU21013_TH_ON_4		0x10
 #define BU21013_TH_ON_5		0x20
 #define BU21013_TH_ON_6		0x40
 #define BU21013_TH_ON_7		0x80
 #define BU21013_TH_ON_MAX	0xFF

 #define BU21013_TH_OFF_0	0x01
 #define BU21013_TH_OFF_1	0x02
 #define BU21013_TH_OFF_2	0x04
 #define BU21013_TH_OFF_3	0x08
 #define BU21013_TH_OFF_4	0x10
 #define BU21013_TH_OFF_5	0x20
 #define BU21013_TH_OFF_6	0x40
 #define BU21013_TH_OFF_7	0x80
 #define BU21013_TH_OFF_MAX	0xFF

 #define BU21013_X_EDGE_0	0x01
 #define BU21013_X_EDGE_1	0x02
 #define BU21013_X_EDGE_2	0x04
 #define BU21013_X_EDGE_3	0x08
 #define BU21013_Y_EDGE_0	0x10
 #define BU21013_Y_EDGE_1	0x20
 #define BU21013_Y_EDGE_2	0x40
 #define BU21013_Y_EDGE_3	0x80

 #define BU21013_DONE	0x01
 #define BU21013_NUMBER_OF_X_SENSORS	(6)
 #define BU21013_NUMBER_OF_Y_SENSORS	(11)

 #define DRIVER_TP	"bu21013_tp"

 /**
  * struct bu21013_ts_data - touch panel data structure
  * @client: pointer to the i2c client
  * @wait: variable to wait_queue_head_t structure
  * @touch_stopped: touch stop flag
  * @chip: pointer to the touch panel controller
  * @in_dev: pointer to the input device structure
  * @intr_pin: interrupt pin value
  * @regulator: pointer to the Regulator used for touch screen
  *
  * Touch panel device data structure
  */
 struct bu21013_ts_data {
 	struct i2c_client *client;
 	wait_queue_head_t wait;
 	const struct bu21013_platform_device *chip;
 	struct input_dev *in_dev;
 	struct regulator *regulator;
 	unsigned int irq;
 	unsigned int intr_pin;
 	bool touch_stopped;
 };

 /**
  * bu21013_read_block_data(): read the touch co-ordinates
  * @data: bu21013_ts_data structure pointer
  * @buf: byte pointer
  *
  * Read the touch co-ordinates using i2c read block into buffer
  * and returns integer.
  */
 static int bu21013_read_block_data(struct bu21013_ts_data *data, u8 *buf)
 {
 	int ret, i;

 	for (i = 0; i < I2C_RETRY_COUNT; i++) {
 		ret = i2c_smbus_read_i2c_block_data
 			(data->client, BU21013_SENSORS_BTN_0_7_REG,
 				LENGTH_OF_BUFFER, buf);
 		if (ret == LENGTH_OF_BUFFER)
 			return 0;
 	}
 	return -EINVAL;
 }

 /**
  * bu21013_do_touch_report(): Get the touch co-ordinates
  * @data: bu21013_ts_data structure pointer
  *
  * Get the touch co-ordinates from touch sensor registers and writes
  * into device structure and returns integer.
  */
 static int bu21013_do_touch_report(struct bu21013_ts_data *data)
 {
 	u8	buf[LENGTH_OF_BUFFER];
 	unsigned int pos_x[2], pos_y[2];
 	bool	has_x_sensors, has_y_sensors;
 	int	finger_down_count = 0;
 	int	i;

 	if (data == NULL)
 		return -EINVAL;

 	if (bu21013_read_block_data(data, buf) < 0)
 		return -EINVAL;

 	has_x_sensors = hweight32(buf[0] & BU21013_SENSORS_EN_0_7);
 	has_y_sensors = hweight32(((buf[1] & BU21013_SENSORS_EN_8_15) |
 		((buf[2] & BU21013_SENSORS_EN_16_23) << SHIFT_8)) >> SHIFT_2);
 	if (!has_x_sensors || !has_y_sensors)
 		return 0;

 	for (i = 0; i < MAX_FINGERS; i++) {
 		const u8 *p = &buf[4 * i + 3];
 		unsigned int x = p[0] << SHIFT_2 | (p[1] & MASK_BITS);
 		unsigned int y = p[2] << SHIFT_2 | (p[3] & MASK_BITS);
 		if (x == 0 || y == 0)
 			continue;
 		pos_x[finger_down_count] = x;
 		pos_y[finger_down_count] = y;
 		finger_down_count++;
 	}

 	if (finger_down_count) {
 		if (finger_down_count == 2 &&
 		    (abs(pos_x[0] - pos_x[1]) < DELTA_MIN ||
 		     abs(pos_y[0] - pos_y[1]) < DELTA_MIN)) {
 			return 0;
 		}

 		for (i = 0; i < finger_down_count; i++) {
 			if (data->chip->x_flip)
 				pos_x[i] = data->chip->touch_x_max - pos_x[i];
 			if (data->chip->y_flip)
 				pos_y[i] = data->chip->touch_y_max - pos_y[i];

 			input_report_abs(data->in_dev,
 					 ABS_MT_POSITION_X, pos_x[i]);
 			input_report_abs(data->in_dev,
 					 ABS_MT_POSITION_Y, pos_y[i]);
 			input_mt_sync(data->in_dev);
 		}
 	} else
 		input_mt_sync(data->in_dev);

 	input_sync(data->in_dev);

 	return 0;
 }
 /**
  * bu21013_gpio_irq() - gpio thread function for touch interrupt
  * @irq: irq value
  * @device_data: void pointer
  *
  * This gpio thread function for touch interrupt
  * and returns irqreturn_t.
  */
 static irqreturn_t bu21013_gpio_irq(int irq, void *device_data)
 {
 	struct bu21013_ts_data *data = device_data;
 	struct i2c_client *i2c = data->client;
 	int retval;

 	do {
 		retval = bu21013_do_touch_report(data);
 		if (retval < 0) {
 			dev_err(&i2c->dev, "bu21013_do_touch_report failed\n");
 			return IRQ_NONE;
 		}

 		data->intr_pin = gpio_get_value(data->chip->touch_pin);
 		if (data->intr_pin == PEN_DOWN_INTR)
 			wait_event_timeout(data->wait, data->touch_stopped,
 					   msecs_to_jiffies(2));
 	} while (!data->intr_pin && !data->touch_stopped);

 	return IRQ_HANDLED;
 }

 /**
  * bu21013_init_chip() - power on sequence for the bu21013 controller
  * @data: device structure pointer
  *
  * This function is used to power on
  * the bu21013 controller and returns integer.
  */
 static int bu21013_init_chip(struct bu21013_ts_data *data)
 {
 	int retval;
 	struct i2c_client *i2c = data->client;

 	retval = i2c_smbus_write_byte_data(i2c, BU21013_RESET_REG,
 					BU21013_RESET_ENABLE);
 	if (retval < 0) {
 		dev_err(&i2c->dev, "BU21013_RESET reg write failed\n");
 		return retval;
 	}
 	msleep(RESET_DELAY);

 	retval = i2c_smbus_write_byte_data(i2c, BU21013_SENSOR_0_7_REG,
 					BU21013_SENSORS_EN_0_7);
 	if (retval < 0) {
 		dev_err(&i2c->dev, "BU21013_SENSOR_0_7 reg write failed\n");
 		return retval;
 	}

 	retval = i2c_smbus_write_byte_data(i2c, BU21013_SENSOR_8_15_REG,
 						BU21013_SENSORS_EN_8_15);
 	if (retval < 0) {
 		dev_err(&i2c->dev, "BU21013_SENSOR_8_15 reg write failed\n");
 		return retval;
 	}

 	retval = i2c_smbus_write_byte_data(i2c, BU21013_SENSOR_16_23_REG,
 						BU21013_SENSORS_EN_16_23);
 	if (retval < 0) {
 		dev_err(&i2c->dev, "BU21013_SENSOR_16_23 reg write failed\n");
 		return retval;
 	}

 	retval = i2c_smbus_write_byte_data(i2c, BU21013_POS_MODE1_REG,
 				(BU21013_POS_MODE1_0 | BU21013_POS_MODE1_1));
 	if (retval < 0) {
 		dev_err(&i2c->dev, "BU21013_POS_MODE1 reg write failed\n");
 		return retval;
 	}

 	retval = i2c_smbus_write_byte_data(i2c, BU21013_POS_MODE2_REG,
 			(BU21013_POS_MODE2_ZERO | BU21013_POS_MODE2_AVG1 |
 			BU21013_POS_MODE2_AVG2 | BU21013_POS_MODE2_EN_RAW |
 			BU21013_POS_MODE2_MULTI));
 	if (retval < 0) {
 		dev_err(&i2c->dev, "BU21013_POS_MODE2 reg write failed\n");
 		return retval;
 	}

 	if (data->chip->ext_clk)
 		retval = i2c_smbus_write_byte_data(i2c, BU21013_CLK_MODE_REG,
 			(BU21013_CLK_MODE_EXT | BU21013_CLK_MODE_CALIB));
 	else
 		retval = i2c_smbus_write_byte_data(i2c, BU21013_CLK_MODE_REG,
 			(BU21013_CLK_MODE_DIV | BU21013_CLK_MODE_CALIB));
 	if (retval < 0) {
 		dev_err(&i2c->dev, "BU21013_CLK_MODE reg write failed\n");
 		return retval;
 	}

 	retval = i2c_smbus_write_byte_data(i2c, BU21013_IDLE_REG,
 				(BU21013_IDLET_0 | BU21013_IDLE_INTERMIT_EN));
 	if (retval < 0) {
 		dev_err(&i2c->dev, "BU21013_IDLE reg write failed\n");
 		return retval;
 	}

 	retval = i2c_smbus_write_byte_data(i2c, BU21013_INT_MODE_REG,
 						BU21013_INT_MODE_LEVEL);
 	if (retval < 0) {
 		dev_err(&i2c->dev, "BU21013_INT_MODE reg write failed\n");
 		return retval;
 	}

 	retval = i2c_smbus_write_byte_data(i2c, BU21013_FILTER_REG,
 						(BU21013_DELTA_0_6 |
 							BU21013_FILTER_EN));
 	if (retval < 0) {
 		dev_err(&i2c->dev, "BU21013_FILTER reg write failed\n");
 		return retval;
 	}

 	retval = i2c_smbus_write_byte_data(i2c, BU21013_TH_ON_REG,
 					BU21013_TH_ON_5);
 	if (retval < 0) {
 		dev_err(&i2c->dev, "BU21013_TH_ON reg write failed\n");
 		return retval;
 	}

 	retval = i2c_smbus_write_byte_data(i2c, BU21013_TH_OFF_REG,
 				BU21013_TH_OFF_4 | BU21013_TH_OFF_3);
 	if (retval < 0) {
 		dev_err(&i2c->dev, "BU21013_TH_OFF reg write failed\n");
 		return retval;
 	}

 	retval = i2c_smbus_write_byte_data(i2c, BU21013_GAIN_REG,
 					(BU21013_GAIN_0 | BU21013_GAIN_1));
 	if (retval < 0) {
 		dev_err(&i2c->dev, "BU21013_GAIN reg write failed\n");
 		return retval;
 	}

 	retval = i2c_smbus_write_byte_data(i2c, BU21013_OFFSET_MODE_REG,
 					BU21013_OFFSET_MODE_DEFAULT);
 	if (retval < 0) {
 		dev_err(&i2c->dev, "BU21013_OFFSET_MODE reg write failed\n");
 		return retval;
 	}

 	retval = i2c_smbus_write_byte_data(i2c, BU21013_XY_EDGE_REG,
 				(BU21013_X_EDGE_0 | BU21013_X_EDGE_2 |
 				BU21013_Y_EDGE_1 | BU21013_Y_EDGE_3));
 	if (retval < 0) {
 		dev_err(&i2c->dev, "BU21013_XY_EDGE reg write failed\n");
 		return retval;
 	}

 	retval = i2c_smbus_write_byte_data(i2c, BU21013_DONE_REG,
 							BU21013_DONE);
 	if (retval < 0) {
 		dev_err(&i2c->dev, "BU21013_REG_DONE reg write failed\n");
 		return retval;
 	}

 	return 0;
 }

 /**
  * bu21013_free_irq() - frees IRQ registered for touchscreen
  * @bu21013_data: device structure pointer
  *
  * This function signals interrupt thread to stop processing and
  * frees interrupt.
  */
 static void bu21013_free_irq(struct bu21013_ts_data *bu21013_data)
 {
 	bu21013_data->touch_stopped = true;
 	wake_up(&bu21013_data->wait);
 	free_irq(bu21013_data->irq, bu21013_data);
 }

 /**
  * bu21013_cs_disable() - deconfigures the touch panel controller
  * @bu21013_data: device structure pointer
  *
  * This function is used to deconfigure the chip selection
  * for touch panel controller.
  */
 static void bu21013_cs_disable(struct bu21013_ts_data *bu21013_data)
 {
 	int error;

 	error = gpio_direction_output(bu21013_data->chip->cs_pin, 0);
 	if (error < 0)
 		dev_warn(&bu21013_data->client->dev,
 			 "%s: gpio direction failed, error: %d\n",
 			 __func__, error);
 	else
 		gpio_set_value(bu21013_data->chip->cs_pin, 0);

 	gpio_free(bu21013_data->chip->cs_pin);
 }

 #ifdef CONFIG_OF
 static const struct bu21013_platform_device *
 bu21013_parse_dt(struct device *dev)
 {
 	struct device_node *np = dev->of_node;
 	struct bu21013_platform_device *pdata;

 	if (!np) {
 		dev_err(dev, "no device tree or platform data\n");
 		return ERR_PTR(-EINVAL);
 	}

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

 	pdata->y_flip = pdata->x_flip = false;

 	pdata->x_flip = of_property_read_bool(np, "rohm,flip-x");
 	pdata->y_flip = of_property_read_bool(np, "rohm,flip-y");

 	of_property_read_u32(np, "rohm,touch-max-x", &pdata->touch_x_max);
 	of_property_read_u32(np, "rohm,touch-max-y", &pdata->touch_y_max);

 	pdata->touch_pin = of_get_named_gpio(np, "touch-gpio", 0);
 	pdata->cs_pin = of_get_named_gpio(np, "reset-gpio", 0);

 	pdata->ext_clk = false;

 	return pdata;
 }
 #else
 static inline const struct bu21013_platform_device *
 bu21013_parse_dt(struct device *dev)
 {
 	dev_err(dev, "no platform data available\n");
 	return ERR_PTR(-EINVAL);
 }
 #endif

 /**
  * bu21013_probe() - initializes the i2c-client touchscreen driver
  * @client: i2c client structure pointer
  * @id: i2c device id pointer
  *
  * This function used to initializes the i2c-client touchscreen
  * driver and returns integer.
  */
 static int bu21013_probe(struct i2c_client *client,
 			 const struct i2c_device_id *id)
 {
 	const struct bu21013_platform_device *pdata =
 					dev_get_platdata(&client->dev);
 	struct bu21013_ts_data *bu21013_data;
 	struct input_dev *in_dev;
 	int error;

 	if (!i2c_check_functionality(client->adapter,
 					I2C_FUNC_SMBUS_BYTE_DATA)) {
 		dev_err(&client->dev, "i2c smbus byte data not supported\n");
 		return -EIO;
 	}

 	if (!pdata) {
 		pdata = bu21013_parse_dt(&client->dev);
 		if (IS_ERR(pdata))
 			return PTR_ERR(pdata);
 	}

 	if (!gpio_is_valid(pdata->touch_pin)) {
 		dev_err(&client->dev, "invalid touch_pin supplied\n");
 		return -EINVAL;
 	}

 	bu21013_data = kzalloc(sizeof(struct bu21013_ts_data), GFP_KERNEL);
 	in_dev = input_allocate_device();
 	if (!bu21013_data || !in_dev) {
 		dev_err(&client->dev, "device memory alloc failed\n");
 		error = -ENOMEM;
 		goto err_free_mem;
 	}

 	bu21013_data->in_dev = in_dev;
 	bu21013_data->chip = pdata;
 	bu21013_data->client = client;
 	bu21013_data->irq = gpio_to_irq(pdata->touch_pin);

 	bu21013_data->regulator = regulator_get(&client->dev, "avdd");
 	if (IS_ERR(bu21013_data->regulator)) {
 		dev_err(&client->dev, "regulator_get failed\n");
 		error = PTR_ERR(bu21013_data->regulator);
 		goto err_free_mem;
 	}

 	error = regulator_enable(bu21013_data->regulator);
 	if (error < 0) {
 		dev_err(&client->dev, "regulator enable failed\n");
 		goto err_put_regulator;
 	}

 	bu21013_data->touch_stopped = false;
 	init_waitqueue_head(&bu21013_data->wait);

 	/* configure the gpio pins */
 	error = gpio_request_one(pdata->cs_pin, GPIOF_OUT_INIT_HIGH,
 				 "touchp_reset");
 	if (error < 0) {
 		dev_err(&client->dev, "Unable to request gpio reset_pin\n");
 		goto err_disable_regulator;
 	}

 	/* configure the touch panel controller */
 	error = bu21013_init_chip(bu21013_data);
 	if (error) {
 		dev_err(&client->dev, "error in bu21013 config\n");
 		goto err_cs_disable;
 	}

 	/* register the device to input subsystem */
 	in_dev->name = DRIVER_TP;
 	in_dev->id.bustype = BUS_I2C;
 	in_dev->dev.parent = &client->dev;

 	__set_bit(EV_SYN, in_dev->evbit);
 	__set_bit(EV_KEY, in_dev->evbit);
 	__set_bit(EV_ABS, in_dev->evbit);

 	input_set_abs_params(in_dev, ABS_MT_POSITION_X, 0,
 						pdata->touch_x_max, 0, 0);
 	input_set_abs_params(in_dev, ABS_MT_POSITION_Y, 0,
 						pdata->touch_y_max, 0, 0);
 	input_set_drvdata(in_dev, bu21013_data);

 	error = request_threaded_irq(bu21013_data->irq, NULL, bu21013_gpio_irq,
 				     IRQF_TRIGGER_FALLING | IRQF_SHARED |
 					IRQF_ONESHOT,
 				     DRIVER_TP, bu21013_data);
 	if (error) {
 		dev_err(&client->dev, "request irq %d failed\n",
 			bu21013_data->irq);
 		goto err_cs_disable;
 	}

 	error = input_register_device(in_dev);
 	if (error) {
 		dev_err(&client->dev, "failed to register input device\n");
 		goto err_free_irq;
 	}

 	device_init_wakeup(&client->dev, pdata->wakeup);
 	i2c_set_clientdata(client, bu21013_data);

 	return 0;

 err_free_irq:
 	bu21013_free_irq(bu21013_data);
 err_cs_disable:
 	bu21013_cs_disable(bu21013_data);
 err_disable_regulator:
 	regulator_disable(bu21013_data->regulator);
 err_put_regulator:
 	regulator_put(bu21013_data->regulator);
 err_free_mem:
 	input_free_device(in_dev);
 	kfree(bu21013_data);

 	return error;
 }
 /**
  * bu21013_remove() - removes the i2c-client touchscreen driver
  * @client: i2c client structure pointer
  *
  * This function uses to remove the i2c-client
  * touchscreen driver and returns integer.
  */
 static int bu21013_remove(struct i2c_client *client)
 {
 	struct bu21013_ts_data *bu21013_data = i2c_get_clientdata(client);

 	bu21013_free_irq(bu21013_data);

 	bu21013_cs_disable(bu21013_data);

 	input_unregister_device(bu21013_data->in_dev);

 	regulator_disable(bu21013_data->regulator);
 	regulator_put(bu21013_data->regulator);

 	kfree(bu21013_data);

 	return 0;
 }

 #ifdef CONFIG_PM
 /**
  * bu21013_suspend() - suspend the touch screen controller
  * @dev: pointer to device structure
  *
  * This function is used to suspend the
  * touch panel controller and returns integer
  */
 static int bu21013_suspend(struct device *dev)
 {
 	struct bu21013_ts_data *bu21013_data = dev_get_drvdata(dev);
 	struct i2c_client *client = bu21013_data->client;

 	bu21013_data->touch_stopped = true;
 	if (device_may_wakeup(&client->dev))
 		enable_irq_wake(bu21013_data->irq);
 	else
 		disable_irq(bu21013_data->irq);

 	regulator_disable(bu21013_data->regulator);

 	return 0;
 }

 /**
  * bu21013_resume() - resume the touch screen controller
  * @dev: pointer to device structure
  *
  * This function is used to resume the touch panel
  * controller and returns integer.
  */
 static int bu21013_resume(struct device *dev)
 {
 	struct bu21013_ts_data *bu21013_data = dev_get_drvdata(dev);
 	struct i2c_client *client = bu21013_data->client;
 	int retval;

 	retval = regulator_enable(bu21013_data->regulator);
 	if (retval < 0) {
 		dev_err(&client->dev, "bu21013 regulator enable failed\n");
 		return retval;
 	}

 	retval = bu21013_init_chip(bu21013_data);
 	if (retval < 0) {
 		dev_err(&client->dev, "bu21013 controller config failed\n");
 		return retval;
 	}

 	bu21013_data->touch_stopped = false;

 	if (device_may_wakeup(&client->dev))
 		disable_irq_wake(bu21013_data->irq);
 	else
 		enable_irq(bu21013_data->irq);

 	return 0;
 }

 static const struct dev_pm_ops bu21013_dev_pm_ops = {
 	.suspend = bu21013_suspend,
 	.resume  = bu21013_resume,
 };
 #endif

 static const struct i2c_device_id bu21013_id[] = {
 	{ DRIVER_TP, 0 },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, bu21013_id);

 static struct i2c_driver bu21013_driver = {
 	.driver	= {
 		.name	=	DRIVER_TP,
 #ifdef CONFIG_PM
 		.pm	=	&bu21013_dev_pm_ops,
 #endif
 	},
 	.probe		=	bu21013_probe,
 	.remove		=	bu21013_remove,
 	.id_table	=	bu21013_id,
 };

 module_i2c_driver(bu21013_driver);

 MODULE_LICENSE("GPL v2");
 MODULE_AUTHOR("Naveen Kumar G <naveen.gaddipati@stericsson.com>");
 MODULE_DESCRIPTION("bu21013 touch screen controller driver");
	/*
	* Copyright (C) ST-Ericsson SA 2010
	* Author: Naveen Kumar G <naveen.gaddipati@stericsson.com> for ST-Ericsson
	* License terms:GNU General Public License (GPL) version 2
	*/

	#include <linux/kernel.h>
	#include <linux/delay.h>
	#include <linux/interrupt.h>
	#include <linux/i2c.h>
	#include <linux/workqueue.h>
	#include <linux/input.h>
	#include <linux/input/bu21013.h>
	#include <linux/slab.h>
	#include <linux/regulator/consumer.h>
	#include <linux/module.h>
	#include <linux/gpio.h>
	#include <linux/of.h>
	#include <linux/of_gpio.h>

	#define PEN_DOWN_INTR 0
	#define MAX_FINGERS 2
	#define RESET_DELAY 30
	#define PENUP_TIMEOUT (10)
	#define DELTA_MIN 16
	#define MASK_BITS 0x03
	#define SHIFT_8 8
	#define SHIFT_2 2
	#define LENGTH_OF_BUFFER 11
	#define I2C_RETRY_COUNT 5

	#define BU21013_SENSORS_BTN_0_7_REG 0x70
	#define BU21013_SENSORS_BTN_8_15_REG 0x71
	#define BU21013_SENSORS_BTN_16_23_REG 0x72
	#define BU21013_X1_POS_MSB_REG 0x73
	#define BU21013_X1_POS_LSB_REG 0x74
	#define BU21013_Y1_POS_MSB_REG 0x75
	#define BU21013_Y1_POS_LSB_REG 0x76
	#define BU21013_X2_POS_MSB_REG 0x77
	#define BU21013_X2_POS_LSB_REG 0x78
	#define BU21013_Y2_POS_MSB_REG 0x79
	#define BU21013_Y2_POS_LSB_REG 0x7A
	#define BU21013_INT_CLR_REG 0xE8
	#define BU21013_INT_MODE_REG 0xE9
	#define BU21013_GAIN_REG 0xEA
	#define BU21013_OFFSET_MODE_REG 0xEB
	#define BU21013_XY_EDGE_REG 0xEC
	#define BU21013_RESET_REG 0xED
	#define BU21013_CALIB_REG 0xEE
	#define BU21013_DONE_REG 0xEF
	#define BU21013_SENSOR_0_7_REG 0xF0
	#define BU21013_SENSOR_8_15_REG 0xF1
	#define BU21013_SENSOR_16_23_REG 0xF2
	#define BU21013_POS_MODE1_REG 0xF3
	#define BU21013_POS_MODE2_REG 0xF4
	#define BU21013_CLK_MODE_REG 0xF5
	#define BU21013_IDLE_REG 0xFA
	#define BU21013_FILTER_REG 0xFB
	#define BU21013_TH_ON_REG 0xFC
	#define BU21013_TH_OFF_REG 0xFD


	#define BU21013_RESET_ENABLE 0x01

	#define BU21013_SENSORS_EN_0_7 0x3F
	#define BU21013_SENSORS_EN_8_15 0xFC
	#define BU21013_SENSORS_EN_16_23 0x1F

	#define BU21013_POS_MODE1_0 0x02
	#define BU21013_POS_MODE1_1 0x04
	#define BU21013_POS_MODE1_2 0x08

	#define BU21013_POS_MODE2_ZERO 0x01
	#define BU21013_POS_MODE2_AVG1 0x02
	#define BU21013_POS_MODE2_AVG2 0x04
	#define BU21013_POS_MODE2_EN_XY 0x08
	#define BU21013_POS_MODE2_EN_RAW 0x10
	#define BU21013_POS_MODE2_MULTI 0x80

	#define BU21013_CLK_MODE_DIV 0x01
	#define BU21013_CLK_MODE_EXT 0x02
	#define BU21013_CLK_MODE_CALIB 0x80

	#define BU21013_IDLET_0 0x01
	#define BU21013_IDLET_1 0x02
	#define BU21013_IDLET_2 0x04
	#define BU21013_IDLET_3 0x08
	#define BU21013_IDLE_INTERMIT_EN 0x10

	#define BU21013_DELTA_0_6 0x7F
	#define BU21013_FILTER_EN 0x80

	#define BU21013_INT_MODE_LEVEL 0x00
	#define BU21013_INT_MODE_EDGE 0x01

	#define BU21013_GAIN_0 0x01
	#define BU21013_GAIN_1 0x02
	#define BU21013_GAIN_2 0x04

	#define BU21013_OFFSET_MODE_DEFAULT 0x00
	#define BU21013_OFFSET_MODE_MOVE 0x01
	#define BU21013_OFFSET_MODE_DISABLE 0x02

	#define BU21013_TH_ON_0 0x01
	#define BU21013_TH_ON_1 0x02
	#define BU21013_TH_ON_2 0x04
	#define BU21013_TH_ON_3 0x08
	#define BU21013_TH_ON_4 0x10
	#define BU21013_TH_ON_5 0x20
	#define BU21013_TH_ON_6 0x40
	#define BU21013_TH_ON_7 0x80
	#define BU21013_TH_ON_MAX 0xFF

	#define BU21013_TH_OFF_0 0x01
	#define BU21013_TH_OFF_1 0x02
	#define BU21013_TH_OFF_2 0x04
	#define BU21013_TH_OFF_3 0x08
	#define BU21013_TH_OFF_4 0x10
	#define BU21013_TH_OFF_5 0x20
	#define BU21013_TH_OFF_6 0x40
	#define BU21013_TH_OFF_7 0x80
	#define BU21013_TH_OFF_MAX 0xFF

	#define BU21013_X_EDGE_0 0x01
	#define BU21013_X_EDGE_1 0x02
	#define BU21013_X_EDGE_2 0x04
	#define BU21013_X_EDGE_3 0x08
	#define BU21013_Y_EDGE_0 0x10
	#define BU21013_Y_EDGE_1 0x20
	#define BU21013_Y_EDGE_2 0x40
	#define BU21013_Y_EDGE_3 0x80

	#define BU21013_DONE 0x01
	#define BU21013_NUMBER_OF_X_SENSORS (6)
	#define BU21013_NUMBER_OF_Y_SENSORS (11)

	#define DRIVER_TP "bu21013_tp"

	/**
	* struct bu21013_ts_data - touch panel data structure
	* @client: pointer to the i2c client
	* @wait: variable to wait_queue_head_t structure
	* @touch_stopped: touch stop flag
	* @chip: pointer to the touch panel controller
	* @in_dev: pointer to the input device structure
	* @intr_pin: interrupt pin value
	* @regulator: pointer to the Regulator used for touch screen
	*
	* Touch panel device data structure
	*/
	struct bu21013_ts_data {
	struct i2c_client *client;
	wait_queue_head_t wait;
	const struct bu21013_platform_device *chip;
	struct input_dev *in_dev;
	struct regulator *regulator;
	unsigned int irq;
	unsigned int intr_pin;
	bool touch_stopped;
	};

	/**
	* bu21013_read_block_data(): read the touch co-ordinates
	* @data: bu21013_ts_data structure pointer
	* @buf: byte pointer
	*
	* Read the touch co-ordinates using i2c read block into buffer
	* and returns integer.
	*/
	static int bu21013_read_block_data(struct bu21013_ts_data data, u8 buf)
	{
	int ret, i;

	for (i = 0; i < I2C_RETRY_COUNT; i++) {
	ret = i2c_smbus_read_i2c_block_data
	(data->client, BU21013_SENSORS_BTN_0_7_REG,
	LENGTH_OF_BUFFER, buf);
	if (ret == LENGTH_OF_BUFFER)
	return 0;
	}
	return -EINVAL;
	}

	/**
	* bu21013_do_touch_report(): Get the touch co-ordinates
	* @data: bu21013_ts_data structure pointer
	*
	* Get the touch co-ordinates from touch sensor registers and writes
	* into device structure and returns integer.
	*/
	static int bu21013_do_touch_report(struct bu21013_ts_data *data)
	{
	u8 buf[LENGTH_OF_BUFFER];
	unsigned int pos_x[2], pos_y[2];
	bool has_x_sensors, has_y_sensors;
	int finger_down_count = 0;
	int i;

	if (data == NULL)
	return -EINVAL;

	if (bu21013_read_block_data(data, buf) < 0)
	return -EINVAL;

	has_x_sensors = hweight32(buf[0] & BU21013_SENSORS_EN_0_7);
	has_y_sensors = hweight32(((buf[1] & BU21013_SENSORS_EN_8_15) \|
	((buf[2] & BU21013_SENSORS_EN_16_23) << SHIFT_8)) >> SHIFT_2);
	if (!has_x_sensors \|\| !has_y_sensors)
	return 0;

	for (i = 0; i < MAX_FINGERS; i++) {
	const u8 p = &buf[4 i + 3];
	unsigned int x = p[0] << SHIFT_2 \| (p[1] & MASK_BITS);
	unsigned int y = p[2] << SHIFT_2 \| (p[3] & MASK_BITS);
	if (x == 0 \|\| y == 0)
	continue;
	pos_x[finger_down_count] = x;
	pos_y[finger_down_count] = y;
	finger_down_count++;
	}

	if (finger_down_count) {
	if (finger_down_count == 2 &&
	(abs(pos_x[0] - pos_x[1]) < DELTA_MIN \|\|
	abs(pos_y[0] - pos_y[1]) < DELTA_MIN)) {
	return 0;
	}

	for (i = 0; i < finger_down_count; i++) {
	if (data->chip->x_flip)
	pos_x[i] = data->chip->touch_x_max - pos_x[i];
	if (data->chip->y_flip)
	pos_y[i] = data->chip->touch_y_max - pos_y[i];

	input_report_abs(data->in_dev,
	ABS_MT_POSITION_X, pos_x[i]);
	input_report_abs(data->in_dev,
	ABS_MT_POSITION_Y, pos_y[i]);
	input_mt_sync(data->in_dev);
	}
	} else
	input_mt_sync(data->in_dev);

	input_sync(data->in_dev);

	return 0;
	}
	/**
	* bu21013_gpio_irq() - gpio thread function for touch interrupt
	* @irq: irq value
	* @device_data: void pointer
	*
	* This gpio thread function for touch interrupt
	* and returns irqreturn_t.
	*/
	static irqreturn_t bu21013_gpio_irq(int irq, void *device_data)
	{
	struct bu21013_ts_data *data = device_data;
	struct i2c_client *i2c = data->client;
	int retval;

	do {
	retval = bu21013_do_touch_report(data);
	if (retval < 0) {
	dev_err(&i2c->dev, "bu21013_do_touch_report failed\n");
	return IRQ_NONE;
	}

	data->intr_pin = gpio_get_value(data->chip->touch_pin);
	if (data->intr_pin == PEN_DOWN_INTR)
	wait_event_timeout(data->wait, data->touch_stopped,
	msecs_to_jiffies(2));
	} while (!data->intr_pin && !data->touch_stopped);

	return IRQ_HANDLED;
	}

	/**
	* bu21013_init_chip() - power on sequence for the bu21013 controller
	* @data: device structure pointer
	*
	* This function is used to power on
	* the bu21013 controller and returns integer.
	*/
	static int bu21013_init_chip(struct bu21013_ts_data *data)
	{
	int retval;
	struct i2c_client *i2c = data->client;

	retval = i2c_smbus_write_byte_data(i2c, BU21013_RESET_REG,
	BU21013_RESET_ENABLE);
	if (retval < 0) {
	dev_err(&i2c->dev, "BU21013_RESET reg write failed\n");
	return retval;
	}
	msleep(RESET_DELAY);

	retval = i2c_smbus_write_byte_data(i2c, BU21013_SENSOR_0_7_REG,
	BU21013_SENSORS_EN_0_7);
	if (retval < 0) {
	dev_err(&i2c->dev, "BU21013_SENSOR_0_7 reg write failed\n");
	return retval;
	}

	retval = i2c_smbus_write_byte_data(i2c, BU21013_SENSOR_8_15_REG,
	BU21013_SENSORS_EN_8_15);
	if (retval < 0) {
	dev_err(&i2c->dev, "BU21013_SENSOR_8_15 reg write failed\n");
	return retval;
	}

	retval = i2c_smbus_write_byte_data(i2c, BU21013_SENSOR_16_23_REG,
	BU21013_SENSORS_EN_16_23);
	if (retval < 0) {
	dev_err(&i2c->dev, "BU21013_SENSOR_16_23 reg write failed\n");
	return retval;
	}

	retval = i2c_smbus_write_byte_data(i2c, BU21013_POS_MODE1_REG,
	(BU21013_POS_MODE1_0 \| BU21013_POS_MODE1_1));
	if (retval < 0) {
	dev_err(&i2c->dev, "BU21013_POS_MODE1 reg write failed\n");
	return retval;
	}

	retval = i2c_smbus_write_byte_data(i2c, BU21013_POS_MODE2_REG,
	(BU21013_POS_MODE2_ZERO \| BU21013_POS_MODE2_AVG1 \|
	BU21013_POS_MODE2_AVG2 \| BU21013_POS_MODE2_EN_RAW \|
	BU21013_POS_MODE2_MULTI));
	if (retval < 0) {
	dev_err(&i2c->dev, "BU21013_POS_MODE2 reg write failed\n");
	return retval;
	}

	if (data->chip->ext_clk)
	retval = i2c_smbus_write_byte_data(i2c, BU21013_CLK_MODE_REG,
	(BU21013_CLK_MODE_EXT \| BU21013_CLK_MODE_CALIB));
	else
	retval = i2c_smbus_write_byte_data(i2c, BU21013_CLK_MODE_REG,
	(BU21013_CLK_MODE_DIV \| BU21013_CLK_MODE_CALIB));
	if (retval < 0) {
	dev_err(&i2c->dev, "BU21013_CLK_MODE reg write failed\n");
	return retval;
	}

	retval = i2c_smbus_write_byte_data(i2c, BU21013_IDLE_REG,
	(BU21013_IDLET_0 \| BU21013_IDLE_INTERMIT_EN));
	if (retval < 0) {
	dev_err(&i2c->dev, "BU21013_IDLE reg write failed\n");
	return retval;
	}

	retval = i2c_smbus_write_byte_data(i2c, BU21013_INT_MODE_REG,
	BU21013_INT_MODE_LEVEL);
	if (retval < 0) {
	dev_err(&i2c->dev, "BU21013_INT_MODE reg write failed\n");
	return retval;
	}

	retval = i2c_smbus_write_byte_data(i2c, BU21013_FILTER_REG,
	(BU21013_DELTA_0_6 \|
	BU21013_FILTER_EN));
	if (retval < 0) {
	dev_err(&i2c->dev, "BU21013_FILTER reg write failed\n");
	return retval;
	}

	retval = i2c_smbus_write_byte_data(i2c, BU21013_TH_ON_REG,
	BU21013_TH_ON_5);
	if (retval < 0) {
	dev_err(&i2c->dev, "BU21013_TH_ON reg write failed\n");
	return retval;
	}

	retval = i2c_smbus_write_byte_data(i2c, BU21013_TH_OFF_REG,
	BU21013_TH_OFF_4 \| BU21013_TH_OFF_3);
	if (retval < 0) {
	dev_err(&i2c->dev, "BU21013_TH_OFF reg write failed\n");
	return retval;
	}

	retval = i2c_smbus_write_byte_data(i2c, BU21013_GAIN_REG,
	(BU21013_GAIN_0 \| BU21013_GAIN_1));
	if (retval < 0) {
	dev_err(&i2c->dev, "BU21013_GAIN reg write failed\n");
	return retval;
	}

	retval = i2c_smbus_write_byte_data(i2c, BU21013_OFFSET_MODE_REG,
	BU21013_OFFSET_MODE_DEFAULT);
	if (retval < 0) {
	dev_err(&i2c->dev, "BU21013_OFFSET_MODE reg write failed\n");
	return retval;
	}

	retval = i2c_smbus_write_byte_data(i2c, BU21013_XY_EDGE_REG,
	(BU21013_X_EDGE_0 \| BU21013_X_EDGE_2 \|
	BU21013_Y_EDGE_1 \| BU21013_Y_EDGE_3));
	if (retval < 0) {
	dev_err(&i2c->dev, "BU21013_XY_EDGE reg write failed\n");
	return retval;
	}

	retval = i2c_smbus_write_byte_data(i2c, BU21013_DONE_REG,
	BU21013_DONE);
	if (retval < 0) {
	dev_err(&i2c->dev, "BU21013_REG_DONE reg write failed\n");
	return retval;
	}

	return 0;
	}

	/**
	* bu21013_free_irq() - frees IRQ registered for touchscreen
	* @bu21013_data: device structure pointer
	*
	* This function signals interrupt thread to stop processing and
	* frees interrupt.
	*/
	static void bu21013_free_irq(struct bu21013_ts_data *bu21013_data)
	{
	bu21013_data->touch_stopped = true;
	wake_up(&bu21013_data->wait);
	free_irq(bu21013_data->irq, bu21013_data);
	}

	/**
	* bu21013_cs_disable() - deconfigures the touch panel controller
	* @bu21013_data: device structure pointer
	*
	* This function is used to deconfigure the chip selection
	* for touch panel controller.
	*/
	static void bu21013_cs_disable(struct bu21013_ts_data *bu21013_data)
	{
	int error;

	error = gpio_direction_output(bu21013_data->chip->cs_pin, 0);
	if (error < 0)
	dev_warn(&bu21013_data->client->dev,
	"%s: gpio direction failed, error: %d\n",
	__func__, error);
	else
	gpio_set_value(bu21013_data->chip->cs_pin, 0);

	gpio_free(bu21013_data->chip->cs_pin);
	}

	#ifdef CONFIG_OF
	static const struct bu21013_platform_device *
	bu21013_parse_dt(struct device *dev)
	{
	struct device_node *np = dev->of_node;
	struct bu21013_platform_device *pdata;

	if (!np) {
	dev_err(dev, "no device tree or platform data\n");
	return ERR_PTR(-EINVAL);
	}

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

	pdata->y_flip = pdata->x_flip = false;

	pdata->x_flip = of_property_read_bool(np, "rohm,flip-x");
	pdata->y_flip = of_property_read_bool(np, "rohm,flip-y");

	of_property_read_u32(np, "rohm,touch-max-x", &pdata->touch_x_max);
	of_property_read_u32(np, "rohm,touch-max-y", &pdata->touch_y_max);

	pdata->touch_pin = of_get_named_gpio(np, "touch-gpio", 0);
	pdata->cs_pin = of_get_named_gpio(np, "reset-gpio", 0);

	pdata->ext_clk = false;

	return pdata;
	}
	#else
	static inline const struct bu21013_platform_device *
	bu21013_parse_dt(struct device *dev)
	{
	dev_err(dev, "no platform data available\n");
	return ERR_PTR(-EINVAL);
	}
	#endif

	/**
	* bu21013_probe() - initializes the i2c-client touchscreen driver
	* @client: i2c client structure pointer
	* @id: i2c device id pointer
	*
	* This function used to initializes the i2c-client touchscreen
	* driver and returns integer.
	*/
	static int bu21013_probe(struct i2c_client *client,
	const struct i2c_device_id *id)
	{
	const struct bu21013_platform_device *pdata =
	dev_get_platdata(&client->dev);
	struct bu21013_ts_data *bu21013_data;
	struct input_dev *in_dev;
	int error;

	if (!i2c_check_functionality(client->adapter,
	I2C_FUNC_SMBUS_BYTE_DATA)) {
	dev_err(&client->dev, "i2c smbus byte data not supported\n");
	return -EIO;
	}

	if (!pdata) {
	pdata = bu21013_parse_dt(&client->dev);
	if (IS_ERR(pdata))
	return PTR_ERR(pdata);
	}

	if (!gpio_is_valid(pdata->touch_pin)) {
	dev_err(&client->dev, "invalid touch_pin supplied\n");
	return -EINVAL;
	}

	bu21013_data = kzalloc(sizeof(struct bu21013_ts_data), GFP_KERNEL);
	in_dev = input_allocate_device();
	if (!bu21013_data \|\| !in_dev) {
	dev_err(&client->dev, "device memory alloc failed\n");
	error = -ENOMEM;
	goto err_free_mem;
	}

	bu21013_data->in_dev = in_dev;
	bu21013_data->chip = pdata;
	bu21013_data->client = client;
	bu21013_data->irq = gpio_to_irq(pdata->touch_pin);

	bu21013_data->regulator = regulator_get(&client->dev, "avdd");
	if (IS_ERR(bu21013_data->regulator)) {
	dev_err(&client->dev, "regulator_get failed\n");
	error = PTR_ERR(bu21013_data->regulator);
	goto err_free_mem;
	}

	error = regulator_enable(bu21013_data->regulator);
	if (error < 0) {
	dev_err(&client->dev, "regulator enable failed\n");
	goto err_put_regulator;
	}

	bu21013_data->touch_stopped = false;
	init_waitqueue_head(&bu21013_data->wait);

	/* configure the gpio pins */
	error = gpio_request_one(pdata->cs_pin, GPIOF_OUT_INIT_HIGH,
	"touchp_reset");
	if (error < 0) {
	dev_err(&client->dev, "Unable to request gpio reset_pin\n");
	goto err_disable_regulator;
	}

	/* configure the touch panel controller */
	error = bu21013_init_chip(bu21013_data);
	if (error) {
	dev_err(&client->dev, "error in bu21013 config\n");
	goto err_cs_disable;
	}

	/* register the device to input subsystem */
	in_dev->name = DRIVER_TP;
	in_dev->id.bustype = BUS_I2C;
	in_dev->dev.parent = &client->dev;

	__set_bit(EV_SYN, in_dev->evbit);
	__set_bit(EV_KEY, in_dev->evbit);
	__set_bit(EV_ABS, in_dev->evbit);

	input_set_abs_params(in_dev, ABS_MT_POSITION_X, 0,
	pdata->touch_x_max, 0, 0);
	input_set_abs_params(in_dev, ABS_MT_POSITION_Y, 0,
	pdata->touch_y_max, 0, 0);
	input_set_drvdata(in_dev, bu21013_data);

	error = request_threaded_irq(bu21013_data->irq, NULL, bu21013_gpio_irq,
	IRQF_TRIGGER_FALLING \| IRQF_SHARED \|
	IRQF_ONESHOT,
	DRIVER_TP, bu21013_data);
	if (error) {
	dev_err(&client->dev, "request irq %d failed\n",
	bu21013_data->irq);
	goto err_cs_disable;
	}

	error = input_register_device(in_dev);
	if (error) {
	dev_err(&client->dev, "failed to register input device\n");
	goto err_free_irq;
	}

	device_init_wakeup(&client->dev, pdata->wakeup);
	i2c_set_clientdata(client, bu21013_data);

	return 0;

	err_free_irq:
	bu21013_free_irq(bu21013_data);
	err_cs_disable:
	bu21013_cs_disable(bu21013_data);
	err_disable_regulator:
	regulator_disable(bu21013_data->regulator);
	err_put_regulator:
	regulator_put(bu21013_data->regulator);
	err_free_mem:
	input_free_device(in_dev);
	kfree(bu21013_data);

	return error;
	}
	/**
	* bu21013_remove() - removes the i2c-client touchscreen driver
	* @client: i2c client structure pointer
	*
	* This function uses to remove the i2c-client
	* touchscreen driver and returns integer.
	*/
	static int bu21013_remove(struct i2c_client *client)
	{
	struct bu21013_ts_data *bu21013_data = i2c_get_clientdata(client);

	bu21013_free_irq(bu21013_data);

	bu21013_cs_disable(bu21013_data);

	input_unregister_device(bu21013_data->in_dev);

	regulator_disable(bu21013_data->regulator);
	regulator_put(bu21013_data->regulator);

	kfree(bu21013_data);

	return 0;
	}

	#ifdef CONFIG_PM
	/**
	* bu21013_suspend() - suspend the touch screen controller
	* @dev: pointer to device structure
	*
	* This function is used to suspend the
	* touch panel controller and returns integer
	*/
	static int bu21013_suspend(struct device *dev)
	{
	struct bu21013_ts_data *bu21013_data = dev_get_drvdata(dev);
	struct i2c_client *client = bu21013_data->client;

	bu21013_data->touch_stopped = true;
	if (device_may_wakeup(&client->dev))
	enable_irq_wake(bu21013_data->irq);
	else
	disable_irq(bu21013_data->irq);

	regulator_disable(bu21013_data->regulator);

	return 0;
	}

	/**
	* bu21013_resume() - resume the touch screen controller
	* @dev: pointer to device structure
	*
	* This function is used to resume the touch panel
	* controller and returns integer.
	*/
	static int bu21013_resume(struct device *dev)
	{
	struct bu21013_ts_data *bu21013_data = dev_get_drvdata(dev);
	struct i2c_client *client = bu21013_data->client;
	int retval;

	retval = regulator_enable(bu21013_data->regulator);
	if (retval < 0) {
	dev_err(&client->dev, "bu21013 regulator enable failed\n");
	return retval;
	}

	retval = bu21013_init_chip(bu21013_data);
	if (retval < 0) {
	dev_err(&client->dev, "bu21013 controller config failed\n");
	return retval;
	}

	bu21013_data->touch_stopped = false;

	if (device_may_wakeup(&client->dev))
	disable_irq_wake(bu21013_data->irq);
	else
	enable_irq(bu21013_data->irq);

	return 0;
	}

	static const struct dev_pm_ops bu21013_dev_pm_ops = {
	.suspend = bu21013_suspend,
	.resume = bu21013_resume,
	};
	#endif

	static const struct i2c_device_id bu21013_id[] = {
	{ DRIVER_TP, 0 },
	{ }
	};
	MODULE_DEVICE_TABLE(i2c, bu21013_id);

	static struct i2c_driver bu21013_driver = {
	.driver = {
	.name = DRIVER_TP,
	#ifdef CONFIG_PM
	.pm = &bu21013_dev_pm_ops,
	#endif
	},
	.probe = bu21013_probe,
	.remove = bu21013_remove,
	.id_table = bu21013_id,
	};

	module_i2c_driver(bu21013_driver);

	MODULE_LICENSE("GPL v2");
	MODULE_AUTHOR("Naveen Kumar G <naveen.gaddipati@stericsson.com>");
	MODULE_DESCRIPTION("bu21013 touch screen controller driver");