drivers/input/touchscreen/atmel_mxt_ts.c

/*
 * Atmel maXTouch Touchscreen driver
 *
 * Copyright (C) 2010 Samsung Electronics Co.Ltd
 * Author: Joonyoung Shim <jy0922.shim@samsung.com>
 *
 * This program is free software; you can redistribute  it and/or modify it
 * under  the terms of  the GNU General  Public License as published by the
 * Free Software Foundation;  either version 2 of the  License, or (at your
 * option) any later version.
 *
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/firmware.h>
#include <linux/i2c.h>
#include <linux/i2c/atmel_mxt_ts.h>
#include <linux/input/mt.h>
#include <linux/interrupt.h>
#include <linux/slab.h>

/* Version */
#define MXT_VER_20		20
#define MXT_VER_21		21
#define MXT_VER_22		22

/* Slave addresses */
#define MXT_APP_LOW		0x4a
#define MXT_APP_HIGH		0x4b
#define MXT_BOOT_LOW		0x24
#define MXT_BOOT_HIGH		0x25

/* Firmware */
#define MXT_FW_NAME		"maxtouch.fw"

/* Registers */
#define MXT_FAMILY_ID		0x00
#define MXT_VARIANT_ID		0x01
#define MXT_VERSION		0x02
#define MXT_BUILD		0x03
#define MXT_MATRIX_X_SIZE	0x04
#define MXT_MATRIX_Y_SIZE	0x05
#define MXT_OBJECT_NUM		0x06
#define MXT_OBJECT_START	0x07

#define MXT_OBJECT_SIZE		6

/* Object types */
#define MXT_DEBUG_DIAGNOSTIC_T37	37
#define MXT_GEN_MESSAGE_T5		5
#define MXT_GEN_COMMAND_T6		6
#define MXT_GEN_POWER_T7		7
#define MXT_GEN_ACQUIRE_T8		8
#define MXT_GEN_DATASOURCE_T53		53
#define MXT_TOUCH_MULTI_T9		9
#define MXT_TOUCH_KEYARRAY_T15		15
#define MXT_TOUCH_PROXIMITY_T23		23
#define MXT_TOUCH_PROXKEY_T52		52
#define MXT_PROCI_GRIPFACE_T20		20
#define MXT_PROCG_NOISE_T22		22
#define MXT_PROCI_ONETOUCH_T24		24
#define MXT_PROCI_TWOTOUCH_T27		27
#define MXT_PROCI_GRIP_T40		40
#define MXT_PROCI_PALM_T41		41
#define MXT_PROCI_TOUCHSUPPRESSION_T42	42
#define MXT_PROCI_STYLUS_T47		47
#define MXT_PROCG_NOISESUPPRESSION_T48	48
#define MXT_SPT_COMMSCONFIG_T18		18
#define MXT_SPT_GPIOPWM_T19		19
#define MXT_SPT_SELFTEST_T25		25
#define MXT_SPT_CTECONFIG_T28		28
#define MXT_SPT_USERDATA_T38		38
#define MXT_SPT_DIGITIZER_T43		43
#define MXT_SPT_MESSAGECOUNT_T44	44
#define MXT_SPT_CTECONFIG_T46		46

/* MXT_GEN_COMMAND_T6 field */
#define MXT_COMMAND_RESET	0
#define MXT_COMMAND_BACKUPNV	1
#define MXT_COMMAND_CALIBRATE	2
#define MXT_COMMAND_REPORTALL	3
#define MXT_COMMAND_DIAGNOSTIC	5

/* MXT_GEN_POWER_T7 field */
#define MXT_POWER_IDLEACQINT	0
#define MXT_POWER_ACTVACQINT	1
#define MXT_POWER_ACTV2IDLETO	2

/* MXT_GEN_ACQUIRE_T8 field */
#define MXT_ACQUIRE_CHRGTIME	0
#define MXT_ACQUIRE_TCHDRIFT	2
#define MXT_ACQUIRE_DRIFTST	3
#define MXT_ACQUIRE_TCHAUTOCAL	4
#define MXT_ACQUIRE_SYNC	5
#define MXT_ACQUIRE_ATCHCALST	6
#define MXT_ACQUIRE_ATCHCALSTHR	7

/* MXT_TOUCH_MULTI_T9 field */
#define MXT_TOUCH_CTRL		0
#define MXT_TOUCH_XORIGIN	1
#define MXT_TOUCH_YORIGIN	2
#define MXT_TOUCH_XSIZE		3
#define MXT_TOUCH_YSIZE		4
#define MXT_TOUCH_BLEN		6
#define MXT_TOUCH_TCHTHR	7
#define MXT_TOUCH_TCHDI		8
#define MXT_TOUCH_ORIENT	9
#define MXT_TOUCH_MOVHYSTI	11
#define MXT_TOUCH_MOVHYSTN	12
#define MXT_TOUCH_NUMTOUCH	14
#define MXT_TOUCH_MRGHYST	15
#define MXT_TOUCH_MRGTHR	16
#define MXT_TOUCH_AMPHYST	17
#define MXT_TOUCH_XRANGE_LSB	18
#define MXT_TOUCH_XRANGE_MSB	19
#define MXT_TOUCH_YRANGE_LSB	20
#define MXT_TOUCH_YRANGE_MSB	21
#define MXT_TOUCH_XLOCLIP	22
#define MXT_TOUCH_XHICLIP	23
#define MXT_TOUCH_YLOCLIP	24
#define MXT_TOUCH_YHICLIP	25
#define MXT_TOUCH_XEDGECTRL	26
#define MXT_TOUCH_XEDGEDIST	27
#define MXT_TOUCH_YEDGECTRL	28
#define MXT_TOUCH_YEDGEDIST	29
#define MXT_TOUCH_JUMPLIMIT	30

/* MXT_PROCI_GRIPFACE_T20 field */
#define MXT_GRIPFACE_CTRL	0
#define MXT_GRIPFACE_XLOGRIP	1
#define MXT_GRIPFACE_XHIGRIP	2
#define MXT_GRIPFACE_YLOGRIP	3
#define MXT_GRIPFACE_YHIGRIP	4
#define MXT_GRIPFACE_MAXTCHS	5
#define MXT_GRIPFACE_SZTHR1	7
#define MXT_GRIPFACE_SZTHR2	8
#define MXT_GRIPFACE_SHPTHR1	9
#define MXT_GRIPFACE_SHPTHR2	10
#define MXT_GRIPFACE_SUPEXTTO	11

/* MXT_PROCI_NOISE field */
#define MXT_NOISE_CTRL		0
#define MXT_NOISE_OUTFLEN	1
#define MXT_NOISE_GCAFUL_LSB	3
#define MXT_NOISE_GCAFUL_MSB	4
#define MXT_NOISE_GCAFLL_LSB	5
#define MXT_NOISE_GCAFLL_MSB	6
#define MXT_NOISE_ACTVGCAFVALID	7
#define MXT_NOISE_NOISETHR	8
#define MXT_NOISE_FREQHOPSCALE	10
#define MXT_NOISE_FREQ0		11
#define MXT_NOISE_FREQ1		12
#define MXT_NOISE_FREQ2		13
#define MXT_NOISE_FREQ3		14
#define MXT_NOISE_FREQ4		15
#define MXT_NOISE_IDLEGCAFVALID	16

/* MXT_SPT_COMMSCONFIG_T18 */
#define MXT_COMMS_CTRL		0
#define MXT_COMMS_CMD		1

/* MXT_SPT_CTECONFIG_T28 field */
#define MXT_CTE_CTRL		0
#define MXT_CTE_CMD		1
#define MXT_CTE_MODE		2
#define MXT_CTE_IDLEGCAFDEPTH	3
#define MXT_CTE_ACTVGCAFDEPTH	4
#define MXT_CTE_VOLTAGE		5

#define MXT_VOLTAGE_DEFAULT	2700000
#define MXT_VOLTAGE_STEP	10000

/* Define for MXT_GEN_COMMAND_T6 */
#define MXT_BOOT_VALUE		0xa5
#define MXT_BACKUP_VALUE	0x55
#define MXT_BACKUP_TIME		25	/* msec */
#define MXT_RESET_TIME		65	/* msec */

#define MXT_FWRESET_TIME	175	/* msec */

/* Command to unlock bootloader */
#define MXT_UNLOCK_CMD_MSB	0xaa
#define MXT_UNLOCK_CMD_LSB	0xdc

/* Bootloader mode status */
#define MXT_WAITING_BOOTLOAD_CMD	0xc0	/* valid 7 6 bit only */
#define MXT_WAITING_FRAME_DATA	0x80	/* valid 7 6 bit only */
#define MXT_FRAME_CRC_CHECK	0x02
#define MXT_FRAME_CRC_FAIL	0x03
#define MXT_FRAME_CRC_PASS	0x04
#define MXT_APP_CRC_FAIL	0x40	/* valid 7 8 bit only */
#define MXT_BOOT_STATUS_MASK	0x3f

/* Touch status */
#define MXT_SUPPRESS		(1 << 1)
#define MXT_AMP			(1 << 2)
#define MXT_VECTOR		(1 << 3)
#define MXT_MOVE		(1 << 4)
#define MXT_RELEASE		(1 << 5)
#define MXT_PRESS		(1 << 6)
#define MXT_DETECT		(1 << 7)

/* Touch orient bits */
#define MXT_XY_SWITCH		(1 << 0)
#define MXT_X_INVERT		(1 << 1)
#define MXT_Y_INVERT		(1 << 2)

/* Touchscreen absolute values */
#define MXT_MAX_AREA		0xff

#define MXT_MAX_FINGER		10

struct mxt_info {
	u8 family_id;
	u8 variant_id;
	u8 version;
	u8 build;
	u8 matrix_xsize;
	u8 matrix_ysize;
	u8 object_num;
};

struct mxt_object {
	u8 type;
	u16 start_address;
	u8 size;
	u8 instances;
	u8 num_report_ids;

	/* to map object and message */
	u8 max_reportid;
};

struct mxt_message {
	u8 reportid;
	u8 message[7];
};

struct mxt_finger {
	int status;
	int x;
	int y;
	int area;
	int pressure;
};

/* Each client has this additional data */
struct mxt_data {
	struct i2c_client *client;
	struct input_dev *input_dev;
	char phys[64];		/* device physical location */
	const struct mxt_platform_data *pdata;
	struct mxt_object *object_table;
	struct mxt_info info;
	struct mxt_finger finger[MXT_MAX_FINGER];
	unsigned int irq;
	unsigned int max_x;
	unsigned int max_y;
};

static bool mxt_object_readable(unsigned int type)
{
	switch (type) {
	case MXT_GEN_COMMAND_T6:
	case MXT_GEN_POWER_T7:
	case MXT_GEN_ACQUIRE_T8:
	case MXT_GEN_DATASOURCE_T53:
	case MXT_TOUCH_MULTI_T9:
	case MXT_TOUCH_KEYARRAY_T15:
	case MXT_TOUCH_PROXIMITY_T23:
	case MXT_TOUCH_PROXKEY_T52:
	case MXT_PROCI_GRIPFACE_T20:
	case MXT_PROCG_NOISE_T22:
	case MXT_PROCI_ONETOUCH_T24:
	case MXT_PROCI_TWOTOUCH_T27:
	case MXT_PROCI_GRIP_T40:
	case MXT_PROCI_PALM_T41:
	case MXT_PROCI_TOUCHSUPPRESSION_T42:
	case MXT_PROCI_STYLUS_T47:
	case MXT_PROCG_NOISESUPPRESSION_T48:
	case MXT_SPT_COMMSCONFIG_T18:
	case MXT_SPT_GPIOPWM_T19:
	case MXT_SPT_SELFTEST_T25:
	case MXT_SPT_CTECONFIG_T28:
	case MXT_SPT_USERDATA_T38:
	case MXT_SPT_DIGITIZER_T43:
	case MXT_SPT_CTECONFIG_T46:
		return true;
	default:
		return false;
	}
}

static bool mxt_object_writable(unsigned int type)
{
	switch (type) {
	case MXT_GEN_COMMAND_T6:
	case MXT_GEN_POWER_T7:
	case MXT_GEN_ACQUIRE_T8:
	case MXT_TOUCH_MULTI_T9:
	case MXT_TOUCH_KEYARRAY_T15:
	case MXT_TOUCH_PROXIMITY_T23:
	case MXT_TOUCH_PROXKEY_T52:
	case MXT_PROCI_GRIPFACE_T20:
	case MXT_PROCG_NOISE_T22:
	case MXT_PROCI_ONETOUCH_T24:
	case MXT_PROCI_TWOTOUCH_T27:
	case MXT_PROCI_GRIP_T40:
	case MXT_PROCI_PALM_T41:
	case MXT_PROCI_TOUCHSUPPRESSION_T42:
	case MXT_PROCI_STYLUS_T47:
	case MXT_PROCG_NOISESUPPRESSION_T48:
	case MXT_SPT_COMMSCONFIG_T18:
	case MXT_SPT_GPIOPWM_T19:
	case MXT_SPT_SELFTEST_T25:
	case MXT_SPT_CTECONFIG_T28:
	case MXT_SPT_DIGITIZER_T43:
	case MXT_SPT_CTECONFIG_T46:
		return true;
	default:
		return false;
	}
}

static void mxt_dump_message(struct device *dev,
			     struct mxt_message *message)
{
	dev_dbg(dev, "reportid: %u\tmessage: %02x %02x %02x %02x %02x %02x %02x\n",
		message->reportid, message->message[0], message->message[1],
		message->message[2], message->message[3], message->message[4],
		message->message[5], message->message[6]);
}

static int mxt_check_bootloader(struct i2c_client *client,
				     unsigned int state)
{
	u8 val;

recheck:
	if (i2c_master_recv(client, &val, 1) != 1) {
		dev_err(&client->dev, "%s: i2c recv failed\n", __func__);
		return -EIO;
	}

	switch (state) {
	case MXT_WAITING_BOOTLOAD_CMD:
	case MXT_WAITING_FRAME_DATA:
		val &= ~MXT_BOOT_STATUS_MASK;
		break;
	case MXT_FRAME_CRC_PASS:
		if (val == MXT_FRAME_CRC_CHECK)
			goto recheck;
		break;
	default:
		return -EINVAL;
	}

	if (val != state) {
		dev_err(&client->dev, "Unvalid bootloader mode state\n");
		return -EINVAL;
	}

	return 0;
}

static int mxt_unlock_bootloader(struct i2c_client *client)
{
	u8 buf[2];

	buf[0] = MXT_UNLOCK_CMD_LSB;
	buf[1] = MXT_UNLOCK_CMD_MSB;

	if (i2c_master_send(client, buf, 2) != 2) {
		dev_err(&client->dev, "%s: i2c send failed\n", __func__);
		return -EIO;
	}

	return 0;
}

static int mxt_fw_write(struct i2c_client *client,
			     const u8 *data, unsigned int frame_size)
{
	if (i2c_master_send(client, data, frame_size) != frame_size) {
		dev_err(&client->dev, "%s: i2c send failed\n", __func__);
		return -EIO;
	}

	return 0;
}

static int __mxt_read_reg(struct i2c_client *client,
			       u16 reg, u16 len, void *val)
{
	struct i2c_msg xfer[2];
	u8 buf[2];
	int ret;

	buf[0] = reg & 0xff;
	buf[1] = (reg >> 8) & 0xff;

	/* Write register */
	xfer[0].addr = client->addr;
	xfer[0].flags = 0;
	xfer[0].len = 2;
	xfer[0].buf = buf;

	/* Read data */
	xfer[1].addr = client->addr;
	xfer[1].flags = I2C_M_RD;
	xfer[1].len = len;
	xfer[1].buf = val;

	ret = i2c_transfer(client->adapter, xfer, 2);
	if (ret == 2) {
		ret = 0;
	} else {
		if (ret >= 0)
			ret = -EIO;
		dev_err(&client->dev, "%s: i2c transfer failed (%d)\n",
			__func__, ret);
	}

	return ret;
}

static int mxt_read_reg(struct i2c_client *client, u16 reg, u8 *val)
{
	return __mxt_read_reg(client, reg, 1, val);
}

static int mxt_write_reg(struct i2c_client *client, u16 reg, u8 val)
{
	u8 buf[3];
	int ret;

	buf[0] = reg & 0xff;
	buf[1] = (reg >> 8) & 0xff;
	buf[2] = val;

	ret = i2c_master_send(client, buf, 3);
	if (ret == 3) {
		ret = 0;
	} else {
		if (ret >= 0)
			ret = -EIO;
		dev_err(&client->dev, "%s: i2c send failed (%d)\n",
			__func__, ret);
	}

	return ret;
}

static int mxt_read_object_table(struct i2c_client *client,
				      u16 reg, u8 *object_buf)
{
	return __mxt_read_reg(client, reg, MXT_OBJECT_SIZE,
				   object_buf);
}

static struct mxt_object *
mxt_get_object(struct mxt_data *data, u8 type)
{
	struct mxt_object *object;
	int i;

	for (i = 0; i < data->info.object_num; i++) {
		object = data->object_table + i;
		if (object->type == type)
			return object;
	}

	dev_err(&data->client->dev, "Invalid object type\n");
	return NULL;
}

static int mxt_read_message(struct mxt_data *data,
				 struct mxt_message *message)
{
	struct mxt_object *object;
	u16 reg;

	object = mxt_get_object(data, MXT_GEN_MESSAGE_T5);
	if (!object)
		return -EINVAL;

	reg = object->start_address;
	return __mxt_read_reg(data->client, reg,
			sizeof(struct mxt_message), message);
}

static int mxt_write_object(struct mxt_data *data,
				 u8 type, u8 offset, u8 val)
{
	struct mxt_object *object;
	u16 reg;

	object = mxt_get_object(data, type);
	if (!object || offset >= object->size + 1)
		return -EINVAL;

	reg = object->start_address;
	return mxt_write_reg(data->client, reg + offset, val);
}

static void mxt_input_report(struct mxt_data *data, int single_id)
{
	struct mxt_finger *finger = data->finger;
	struct input_dev *input_dev = data->input_dev;
	int status = finger[single_id].status;
	int finger_num = 0;
	int id;

	for (id = 0; id < MXT_MAX_FINGER; id++) {
		if (!finger[id].status)
			continue;

		input_mt_slot(input_dev, id);
		input_mt_report_slot_state(input_dev, MT_TOOL_FINGER,
				finger[id].status != MXT_RELEASE);

		if (finger[id].status != MXT_RELEASE) {
			finger_num++;
			input_report_abs(input_dev, ABS_MT_TOUCH_MAJOR,
					finger[id].area);
			input_report_abs(input_dev, ABS_MT_POSITION_X,
					finger[id].x);
			input_report_abs(input_dev, ABS_MT_POSITION_Y,
					finger[id].y);
			input_report_abs(input_dev, ABS_MT_PRESSURE,
					finger[id].pressure);
		} else {
			finger[id].status = 0;
		}
	}

	input_report_key(input_dev, BTN_TOUCH, finger_num > 0);

	if (status != MXT_RELEASE) {
		input_report_abs(input_dev, ABS_X, finger[single_id].x);
		input_report_abs(input_dev, ABS_Y, finger[single_id].y);
		input_report_abs(input_dev,
				 ABS_PRESSURE, finger[single_id].pressure);
	}

	input_sync(input_dev);
}

static void mxt_input_touchevent(struct mxt_data *data,
				      struct mxt_message *message, int id)
{
	struct mxt_finger *finger = data->finger;
	struct device *dev = &data->client->dev;
	u8 status = message->message[0];
	int x;
	int y;
	int area;
	int pressure;

	/* Check the touch is present on the screen */
	if (!(status & MXT_DETECT)) {
		if (status & MXT_RELEASE) {
			dev_dbg(dev, "[%d] released\n", id);

			finger[id].status = MXT_RELEASE;
			mxt_input_report(data, id);
		}
		return;
	}

	/* Check only AMP detection */
	if (!(status & (MXT_PRESS | MXT_MOVE)))
		return;

	x = (message->message[1] << 4) | ((message->message[3] >> 4) & 0xf);
	y = (message->message[2] << 4) | ((message->message[3] & 0xf));
	if (data->max_x < 1024)
		x = x >> 2;
	if (data->max_y < 1024)
		y = y >> 2;

	area = message->message[4];
	pressure = message->message[5];

	dev_dbg(dev, "[%d] %s x: %d, y: %d, area: %d\n", id,
		status & MXT_MOVE ? "moved" : "pressed",
		x, y, area);

	finger[id].status = status & MXT_MOVE ?
				MXT_MOVE : MXT_PRESS;
	finger[id].x = x;
	finger[id].y = y;
	finger[id].area = area;
	finger[id].pressure = pressure;

	mxt_input_report(data, id);
}

static irqreturn_t mxt_interrupt(int irq, void *dev_id)
{
	struct mxt_data *data = dev_id;
	struct mxt_message message;
	struct mxt_object *object;
	struct device *dev = &data->client->dev;
	int id;
	u8 reportid;
	u8 max_reportid;
	u8 min_reportid;

	do {
		if (mxt_read_message(data, &message)) {
			dev_err(dev, "Failed to read message\n");
			goto end;
		}

		reportid = message.reportid;

		/* whether reportid is thing of MXT_TOUCH_MULTI_T9 */
		object = mxt_get_object(data, MXT_TOUCH_MULTI_T9);
		if (!object)
			goto end;

		max_reportid = object->max_reportid;
		min_reportid = max_reportid - object->num_report_ids + 1;
		id = reportid - min_reportid;

		if (reportid >= min_reportid && reportid <= max_reportid)
			mxt_input_touchevent(data, &message, id);
		else
			mxt_dump_message(dev, &message);
	} while (reportid != 0xff);

end:
	return IRQ_HANDLED;
}

static int mxt_check_reg_init(struct mxt_data *data)
{
	const struct mxt_platform_data *pdata = data->pdata;
	struct mxt_object *object;
	struct device *dev = &data->client->dev;
	int index = 0;
	int i, j, config_offset;

	if (!pdata->config) {
		dev_dbg(dev, "No cfg data defined, skipping reg init\n");
		return 0;
	}

	for (i = 0; i < data->info.object_num; i++) {
		object = data->object_table + i;

		if (!mxt_object_writable(object->type))
			continue;

		for (j = 0;
		     j < (object->size + 1) * (object->instances + 1);
		     j++) {
			config_offset = index + j;
			if (config_offset > pdata->config_length) {
				dev_err(dev, "Not enough config data!\n");
				return -EINVAL;
			}
			mxt_write_object(data, object->type, j,
					 pdata->config[config_offset]);
		}
		index += (object->size + 1) * (object->instances + 1);
	}

	return 0;
}

static int mxt_make_highchg(struct mxt_data *data)
{
	struct device *dev = &data->client->dev;
	struct mxt_message message;
	int count = 10;
	int error;

	/* Read dummy message to make high CHG pin */
	do {
		error = mxt_read_message(data, &message);
		if (error)
			return error;
	} while (message.reportid != 0xff && --count);

	if (!count) {
		dev_err(dev, "CHG pin isn't cleared\n");
		return -EBUSY;
	}

	return 0;
}

static void mxt_handle_pdata(struct mxt_data *data)
{
	const struct mxt_platform_data *pdata = data->pdata;
	u8 voltage;

	/* Set touchscreen lines */
	mxt_write_object(data, MXT_TOUCH_MULTI_T9, MXT_TOUCH_XSIZE,
			pdata->x_line);
	mxt_write_object(data, MXT_TOUCH_MULTI_T9, MXT_TOUCH_YSIZE,
			pdata->y_line);

	/* Set touchscreen orient */
	mxt_write_object(data, MXT_TOUCH_MULTI_T9, MXT_TOUCH_ORIENT,
			pdata->orient);

	/* Set touchscreen burst length */
	mxt_write_object(data, MXT_TOUCH_MULTI_T9,
			MXT_TOUCH_BLEN, pdata->blen);

	/* Set touchscreen threshold */
	mxt_write_object(data, MXT_TOUCH_MULTI_T9,
			MXT_TOUCH_TCHTHR, pdata->threshold);

	/* Set touchscreen resolution */
	mxt_write_object(data, MXT_TOUCH_MULTI_T9,
			MXT_TOUCH_XRANGE_LSB, (pdata->x_size - 1) & 0xff);
	mxt_write_object(data, MXT_TOUCH_MULTI_T9,
			MXT_TOUCH_XRANGE_MSB, (pdata->x_size - 1) >> 8);
	mxt_write_object(data, MXT_TOUCH_MULTI_T9,
			MXT_TOUCH_YRANGE_LSB, (pdata->y_size - 1) & 0xff);
	mxt_write_object(data, MXT_TOUCH_MULTI_T9,
			MXT_TOUCH_YRANGE_MSB, (pdata->y_size - 1) >> 8);

	/* Set touchscreen voltage */
	if (pdata->voltage) {
		if (pdata->voltage < MXT_VOLTAGE_DEFAULT) {
			voltage = (MXT_VOLTAGE_DEFAULT - pdata->voltage) /
				MXT_VOLTAGE_STEP;
			voltage = 0xff - voltage + 1;
		} else
			voltage = (pdata->voltage - MXT_VOLTAGE_DEFAULT) /
				MXT_VOLTAGE_STEP;

		mxt_write_object(data, MXT_SPT_CTECONFIG_T28,
				MXT_CTE_VOLTAGE, voltage);
	}
}

static int mxt_get_info(struct mxt_data *data)
{
	struct i2c_client *client = data->client;
	struct mxt_info *info = &data->info;
	int error;
	u8 val;

	error = mxt_read_reg(client, MXT_FAMILY_ID, &val);
	if (error)
		return error;
	info->family_id = val;

	error = mxt_read_reg(client, MXT_VARIANT_ID, &val);
	if (error)
		return error;
	info->variant_id = val;

	error = mxt_read_reg(client, MXT_VERSION, &val);
	if (error)
		return error;
	info->version = val;

	error = mxt_read_reg(client, MXT_BUILD, &val);
	if (error)
		return error;
	info->build = val;

	error = mxt_read_reg(client, MXT_OBJECT_NUM, &val);
	if (error)
		return error;
	info->object_num = val;

	return 0;
}

static int mxt_get_object_table(struct mxt_data *data)
{
	int error;
	int i;
	u16 reg;
	u8 reportid = 0;
	u8 buf[MXT_OBJECT_SIZE];

	for (i = 0; i < data->info.object_num; i++) {
		struct mxt_object *object = data->object_table + i;

		reg = MXT_OBJECT_START + MXT_OBJECT_SIZE * i;
		error = mxt_read_object_table(data->client, reg, buf);
		if (error)
			return error;

		object->type = buf[0];
		object->start_address = (buf[2] << 8) | buf[1];
		object->size = buf[3];
		object->instances = buf[4];
		object->num_report_ids = buf[5];

		if (object->num_report_ids) {
			reportid += object->num_report_ids *
					(object->instances + 1);
			object->max_reportid = reportid;
		}
	}

	return 0;
}

static int mxt_initialize(struct mxt_data *data)
{
	struct i2c_client *client = data->client;
	struct mxt_info *info = &data->info;
	int error;
	u8 val;

	error = mxt_get_info(data);
	if (error)
		return error;

	data->object_table = kcalloc(info->object_num,
				     sizeof(struct mxt_object),
				     GFP_KERNEL);
	if (!data->object_table) {
		dev_err(&client->dev, "Failed to allocate memory\n");
		return -ENOMEM;
	}

	/* Get object table information */
	error = mxt_get_object_table(data);
	if (error)
		return error;

	/* Check register init values */
	error = mxt_check_reg_init(data);
	if (error)
		return error;

	mxt_handle_pdata(data);

	/* Backup to memory */
	mxt_write_object(data, MXT_GEN_COMMAND_T6,
			MXT_COMMAND_BACKUPNV,
			MXT_BACKUP_VALUE);
	msleep(MXT_BACKUP_TIME);

	/* Soft reset */
	mxt_write_object(data, MXT_GEN_COMMAND_T6,
			MXT_COMMAND_RESET, 1);
	msleep(MXT_RESET_TIME);

	/* Update matrix size at info struct */
	error = mxt_read_reg(client, MXT_MATRIX_X_SIZE, &val);
	if (error)
		return error;
	info->matrix_xsize = val;

	error = mxt_read_reg(client, MXT_MATRIX_Y_SIZE, &val);
	if (error)
		return error;
	info->matrix_ysize = val;

	dev_info(&client->dev,
			"Family ID: %d Variant ID: %d Version: %d Build: %d\n",
			info->family_id, info->variant_id, info->version,
			info->build);

	dev_info(&client->dev,
			"Matrix X Size: %d Matrix Y Size: %d Object Num: %d\n",
			info->matrix_xsize, info->matrix_ysize,
			info->object_num);

	return 0;
}

static void mxt_calc_resolution(struct mxt_data *data)
{
	unsigned int max_x = data->pdata->x_size - 1;
	unsigned int max_y = data->pdata->y_size - 1;

	if (data->pdata->orient & MXT_XY_SWITCH) {
		data->max_x = max_y;
		data->max_y = max_x;
	} else {
		data->max_x = max_x;
		data->max_y = max_y;
	}
}

static ssize_t mxt_show_instance(char *buf, int count,
				 struct mxt_object *object, int instance,
				 const u8 *val)
{
	int i;

	if (object->instances > 0)
		count += scnprintf(buf + count, PAGE_SIZE - count,
				   "Instance %u\n", instance);

	for (i = 0; i < object->size + 1; i++)
		count += scnprintf(buf + count, PAGE_SIZE - count,
				"\t[%2u]: %02x (%d)\n", i, val[i], val[i]);
	count += scnprintf(buf + count, PAGE_SIZE - count, "\n");

	return count;
}

static ssize_t mxt_object_show(struct device *dev,
				    struct device_attribute *attr, char *buf)
{
	struct mxt_data *data = dev_get_drvdata(dev);
	struct mxt_object *object;
	int count = 0;
	int i, j;
	int error;
	u8 *obuf;

	/* Pre-allocate buffer large enough to hold max sized object. */
	obuf = kmalloc(256, GFP_KERNEL);
	if (!obuf)
		return -ENOMEM;

	error = 0;
	for (i = 0; i < data->info.object_num; i++) {
		object = data->object_table + i;

		if (!mxt_object_readable(object->type))
			continue;

		count += scnprintf(buf + count, PAGE_SIZE - count,
				"T%u:\n", object->type);

		for (j = 0; j < object->instances + 1; j++) {
			u16 size = object->size + 1;
			u16 addr = object->start_address + j * size;

			error = __mxt_read_reg(data->client, addr, size, obuf);
			if (error)
				goto done;

			count = mxt_show_instance(buf, count, object, j, obuf);
		}
	}

done:
	kfree(obuf);
	return error ?: count;
}

static int mxt_load_fw(struct device *dev, const char *fn)
{
	struct mxt_data *data = dev_get_drvdata(dev);
	struct i2c_client *client = data->client;
	const struct firmware *fw = NULL;
	unsigned int frame_size;
	unsigned int pos = 0;
	int ret;

	ret = request_firmware(&fw, fn, dev);
	if (ret) {
		dev_err(dev, "Unable to open firmware %s\n", fn);
		return ret;
	}

	/* Change to the bootloader mode */
	mxt_write_object(data, MXT_GEN_COMMAND_T6,
			MXT_COMMAND_RESET, MXT_BOOT_VALUE);
	msleep(MXT_RESET_TIME);

	/* Change to slave address of bootloader */
	if (client->addr == MXT_APP_LOW)
		client->addr = MXT_BOOT_LOW;
	else
		client->addr = MXT_BOOT_HIGH;

	ret = mxt_check_bootloader(client, MXT_WAITING_BOOTLOAD_CMD);
	if (ret)
		goto out;

	/* Unlock bootloader */
	mxt_unlock_bootloader(client);

	while (pos < fw->size) {
		ret = mxt_check_bootloader(client,
						MXT_WAITING_FRAME_DATA);
		if (ret)
			goto out;

		frame_size = ((*(fw->data + pos) << 8) | *(fw->data + pos + 1));

		/* We should add 2 at frame size as the the firmware data is not
		 * included the CRC bytes.
		 */
		frame_size += 2;

		/* Write one frame to device */
		mxt_fw_write(client, fw->data + pos, frame_size);

		ret = mxt_check_bootloader(client,
						MXT_FRAME_CRC_PASS);
		if (ret)
			goto out;

		pos += frame_size;

		dev_dbg(dev, "Updated %d bytes / %zd bytes\n", pos, fw->size);
	}

out:
	release_firmware(fw);

	/* Change to slave address of application */
	if (client->addr == MXT_BOOT_LOW)
		client->addr = MXT_APP_LOW;
	else
		client->addr = MXT_APP_HIGH;

	return ret;
}

static ssize_t mxt_update_fw_store(struct device *dev,
					struct device_attribute *attr,
					const char *buf, size_t count)
{
	struct mxt_data *data = dev_get_drvdata(dev);
	int error;

	disable_irq(data->irq);

	error = mxt_load_fw(dev, MXT_FW_NAME);
	if (error) {
		dev_err(dev, "The firmware update failed(%d)\n", error);
		count = error;
	} else {
		dev_dbg(dev, "The firmware update succeeded\n");

		/* Wait for reset */
		msleep(MXT_FWRESET_TIME);

		kfree(data->object_table);
		data->object_table = NULL;

		mxt_initialize(data);
	}

	enable_irq(data->irq);

	error = mxt_make_highchg(data);
	if (error)
		return error;

	return count;
}

static DEVICE_ATTR(object, S_IRUGO, mxt_object_show, NULL);
static DEVICE_ATTR(update_fw, S_IWUSR, NULL, mxt_update_fw_store);

static struct attribute *mxt_attrs[] = {
	&dev_attr_object.attr,
	&dev_attr_update_fw.attr,
	NULL
};

static const struct attribute_group mxt_attr_group = {
	.attrs = mxt_attrs,
};

static void mxt_start(struct mxt_data *data)
{
	/* Touch enable */
	mxt_write_object(data,
			MXT_TOUCH_MULTI_T9, MXT_TOUCH_CTRL, 0x83);
}

static void mxt_stop(struct mxt_data *data)
{
	/* Touch disable */
	mxt_write_object(data,
			MXT_TOUCH_MULTI_T9, MXT_TOUCH_CTRL, 0);
}

static int mxt_input_open(struct input_dev *dev)
{
	struct mxt_data *data = input_get_drvdata(dev);

	mxt_start(data);

	return 0;
}

static void mxt_input_close(struct input_dev *dev)
{
	struct mxt_data *data = input_get_drvdata(dev);

	mxt_stop(data);
}

static int __devinit mxt_probe(struct i2c_client *client,
		const struct i2c_device_id *id)
{
	const struct mxt_platform_data *pdata = client->dev.platform_data;
	struct mxt_data *data;
	struct input_dev *input_dev;
	int error;

	if (!pdata)
		return -EINVAL;

	data = kzalloc(sizeof(struct mxt_data), GFP_KERNEL);
	input_dev = input_allocate_device();
	if (!data || !input_dev) {
		dev_err(&client->dev, "Failed to allocate memory\n");
		error = -ENOMEM;
		goto err_free_mem;
	}

	input_dev->name = "Atmel maXTouch Touchscreen";
	snprintf(data->phys, sizeof(data->phys), "i2c-%u-%04x/input0",
		 client->adapter->nr, client->addr);
	input_dev->phys = data->phys;

	input_dev->id.bustype = BUS_I2C;
	input_dev->dev.parent = &client->dev;
	input_dev->open = mxt_input_open;
	input_dev->close = mxt_input_close;

	data->client = client;
	data->input_dev = input_dev;
	data->pdata = pdata;
	data->irq = client->irq;

	mxt_calc_resolution(data);

	__set_bit(EV_ABS, input_dev->evbit);
	__set_bit(EV_KEY, input_dev->evbit);
	__set_bit(BTN_TOUCH, input_dev->keybit);

	/* For single touch */
	input_set_abs_params(input_dev, ABS_X,
			     0, data->max_x, 0, 0);
	input_set_abs_params(input_dev, ABS_Y,
			     0, data->max_y, 0, 0);
	input_set_abs_params(input_dev, ABS_PRESSURE,
			     0, 255, 0, 0);

	/* For multi touch */
	error = input_mt_init_slots(input_dev, MXT_MAX_FINGER);
	if (error)
		goto err_free_mem;
	input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR,
			     0, MXT_MAX_AREA, 0, 0);
	input_set_abs_params(input_dev, ABS_MT_POSITION_X,
			     0, data->max_x, 0, 0);
	input_set_abs_params(input_dev, ABS_MT_POSITION_Y,
			     0, data->max_y, 0, 0);
	input_set_abs_params(input_dev, ABS_MT_PRESSURE,
			     0, 255, 0, 0);

	input_set_drvdata(input_dev, data);
	i2c_set_clientdata(client, data);

	error = mxt_initialize(data);
	if (error)
		goto err_free_object;

	error = request_threaded_irq(client->irq, NULL, mxt_interrupt,
			pdata->irqflags, client->name, data);
	if (error) {
		dev_err(&client->dev, "Failed to register interrupt\n");
		goto err_free_object;
	}

	error = mxt_make_highchg(data);
	if (error)
		goto err_free_irq;

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

	error = sysfs_create_group(&client->dev.kobj, &mxt_attr_group);
	if (error)
		dev_warn(&client->dev, "error creating sysfs entries.\n");

	return 0;

err_free_irq:
	free_irq(client->irq, data);
err_free_object:
	kfree(data->object_table);
err_free_mem:
	input_free_device(input_dev);
	kfree(data);
	return error;
}

static int __devexit mxt_remove(struct i2c_client *client)
{
	struct mxt_data *data = i2c_get_clientdata(client);

	sysfs_remove_group(&client->dev.kobj, &mxt_attr_group);
	free_irq(data->irq, data);
	input_unregister_device(data->input_dev);
	kfree(data->object_table);
	kfree(data);

	return 0;
}

#ifdef CONFIG_PM_SLEEP
static int mxt_suspend(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct mxt_data *data = i2c_get_clientdata(client);
	struct input_dev *input_dev = data->input_dev;

	mutex_lock(&input_dev->mutex);

	if (input_dev->users)
		mxt_stop(data);

	mutex_unlock(&input_dev->mutex);

	return 0;
}

static int mxt_resume(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct mxt_data *data = i2c_get_clientdata(client);
	struct input_dev *input_dev = data->input_dev;

	/* Soft reset */
	mxt_write_object(data, MXT_GEN_COMMAND_T6,
			MXT_COMMAND_RESET, 1);

	msleep(MXT_RESET_TIME);

	mutex_lock(&input_dev->mutex);

	if (input_dev->users)
		mxt_start(data);

	mutex_unlock(&input_dev->mutex);

	return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(mxt_pm_ops, mxt_suspend, mxt_resume);

static const struct i2c_device_id mxt_id[] = {
	{ "qt602240_ts", 0 },
	{ "atmel_mxt_ts", 0 },
	{ "mXT224", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, mxt_id);

static struct i2c_driver mxt_driver = {
	.driver = {
		.name	= "atmel_mxt_ts",
		.owner	= THIS_MODULE,
		.pm	= &mxt_pm_ops,
	},
	.probe		= mxt_probe,
	.remove		= __devexit_p(mxt_remove),
	.id_table	= mxt_id,
};

module_i2c_driver(mxt_driver);

/* Module information */
MODULE_AUTHOR("Joonyoung Shim <jy0922.shim@samsung.com>");
MODULE_DESCRIPTION("Atmel maXTouch Touchscreen driver");
MODULE_LICENSE("GPL");