/*
 *
 * FocalTech ft5x06 TouchScreen driver.
 *
 * Copyright (c) 2010  Focal tech Ltd.
 * Copyright (c) 2012, The Linux Foundation. All rights reserved.
 *
 * This software is licensed under the terms of the GNU General Public
 * License version 2, as published by the Free Software Foundation, and
 * may be copied, distributed, and modified under those terms.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 */

#include <linux/i2c.h>
#include <linux/input.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/gpio.h>
#include <linux/regulator/consumer.h>
#include <linux/input/ft5x06_ts.h>

#ifdef CONFIG_HAS_EARLYSUSPEND
#include <linux/earlysuspend.h>
/* Early-suspend level */
#define FT5X06_SUSPEND_LEVEL 1
#endif

#define CFG_MAX_TOUCH_POINTS	5

#define FT_STARTUP_DLY		150
#define FT_RESET_DLY		20

#define FT_PRESS		0x7F
#define FT_MAX_ID		0x0F
#define FT_TOUCH_STEP		6
#define FT_TOUCH_X_H_POS	3
#define FT_TOUCH_X_L_POS	4
#define FT_TOUCH_Y_H_POS	5
#define FT_TOUCH_Y_L_POS	6
#define FT_TOUCH_EVENT_POS	3
#define FT_TOUCH_ID_POS		5

#define POINT_READ_BUF	(3 + FT_TOUCH_STEP * CFG_MAX_TOUCH_POINTS)

/*register address*/
#define FT5X06_REG_PMODE	0xA5
#define FT5X06_REG_FW_VER	0xA6
#define FT5X06_REG_POINT_RATE	0x88
#define FT5X06_REG_THGROUP	0x80

/* power register bits*/
#define FT5X06_PMODE_ACTIVE		0x00
#define FT5X06_PMODE_MONITOR		0x01
#define FT5X06_PMODE_STANDBY		0x02
#define FT5X06_PMODE_HIBERNATE		0x03

#define FT5X06_VTG_MIN_UV	2600000
#define FT5X06_VTG_MAX_UV	3300000
#define FT5X06_I2C_VTG_MIN_UV	1800000
#define FT5X06_I2C_VTG_MAX_UV	1800000

struct ts_event {
	u16 x[CFG_MAX_TOUCH_POINTS];	/*x coordinate */
	u16 y[CFG_MAX_TOUCH_POINTS];	/*y coordinate */
	/* touch event: 0 -- down; 1-- contact; 2 -- contact */
	u8 touch_event[CFG_MAX_TOUCH_POINTS];
	u8 finger_id[CFG_MAX_TOUCH_POINTS];	/*touch ID */
	u16 pressure;
	u8 touch_point;
};

struct ft5x06_ts_data {
	struct i2c_client *client;
	struct input_dev *input_dev;
	struct ts_event event;
	const struct ft5x06_ts_platform_data *pdata;
	struct regulator *vdd;
	struct regulator *vcc_i2c;
#ifdef CONFIG_HAS_EARLYSUSPEND
	struct early_suspend early_suspend;
#endif
};

static int ft5x06_i2c_read(struct i2c_client *client, char *writebuf,
			   int writelen, char *readbuf, int readlen)
{
	int ret;

	if (writelen > 0) {
		struct i2c_msg msgs[] = {
			{
				 .addr = client->addr,
				 .flags = 0,
				 .len = writelen,
				 .buf = writebuf,
			 },
			{
				 .addr = client->addr,
				 .flags = I2C_M_RD,
				 .len = readlen,
				 .buf = readbuf,
			 },
		};
		ret = i2c_transfer(client->adapter, msgs, 2);
		if (ret < 0)
			dev_err(&client->dev, "%s: i2c read error.\n",
				__func__);
	} else {
		struct i2c_msg msgs[] = {
			{
				 .addr = client->addr,
				 .flags = I2C_M_RD,
				 .len = readlen,
				 .buf = readbuf,
			 },
		};
		ret = i2c_transfer(client->adapter, msgs, 1);
		if (ret < 0)
			dev_err(&client->dev, "%s:i2c read error.\n", __func__);
	}
	return ret;
}

static int ft5x06_i2c_write(struct i2c_client *client, char *writebuf,
			    int writelen)
{
	int ret;

	struct i2c_msg msgs[] = {
		{
			 .addr = client->addr,
			 .flags = 0,
			 .len = writelen,
			 .buf = writebuf,
		 },
	};
	ret = i2c_transfer(client->adapter, msgs, 1);
	if (ret < 0)
		dev_err(&client->dev, "%s: i2c write error.\n", __func__);

	return ret;
}

static void ft5x06_report_value(struct ft5x06_ts_data *data)
{
	struct ts_event *event = &data->event;
	int i;
	int fingerdown = 0;

	for (i = 0; i < event->touch_point; i++) {
		if (event->touch_event[i] == 0 || event->touch_event[i] == 2) {
			event->pressure = FT_PRESS;
			fingerdown++;
		} else {
			event->pressure = 0;
		}

		input_report_abs(data->input_dev, ABS_MT_POSITION_X,
				 event->x[i]);
		input_report_abs(data->input_dev, ABS_MT_POSITION_Y,
				 event->y[i]);
		input_report_abs(data->input_dev, ABS_MT_PRESSURE,
				 event->pressure);
		input_report_abs(data->input_dev, ABS_MT_TRACKING_ID,
				 event->finger_id[i]);
		input_report_abs(data->input_dev, ABS_MT_TOUCH_MAJOR,
				 event->pressure);
		input_mt_sync(data->input_dev);
	}

	input_report_key(data->input_dev, BTN_TOUCH, !!fingerdown);
	input_sync(data->input_dev);
}

static int ft5x06_handle_touchdata(struct ft5x06_ts_data *data)
{
	struct ts_event *event = &data->event;
	int ret, i;
	u8 buf[POINT_READ_BUF] = { 0 };
	u8 pointid = FT_MAX_ID;

	ret = ft5x06_i2c_read(data->client, buf, 1, buf, POINT_READ_BUF);
	if (ret < 0) {
		dev_err(&data->client->dev, "%s read touchdata failed.\n",
			__func__);
		return ret;
	}
	memset(event, 0, sizeof(struct ts_event));

	event->touch_point = 0;
	for (i = 0; i < CFG_MAX_TOUCH_POINTS; i++) {
		pointid = (buf[FT_TOUCH_ID_POS + FT_TOUCH_STEP * i]) >> 4;
		if (pointid >= FT_MAX_ID)
			break;
		else
			event->touch_point++;
		event->x[i] =
		    (s16) (buf[FT_TOUCH_X_H_POS + FT_TOUCH_STEP * i] & 0x0F) <<
		    8 | (s16) buf[FT_TOUCH_X_L_POS + FT_TOUCH_STEP * i];
		event->y[i] =
		    (s16) (buf[FT_TOUCH_Y_H_POS + FT_TOUCH_STEP * i] & 0x0F) <<
		    8 | (s16) buf[FT_TOUCH_Y_L_POS + FT_TOUCH_STEP * i];
		event->touch_event[i] =
		    buf[FT_TOUCH_EVENT_POS + FT_TOUCH_STEP * i] >> 6;
		event->finger_id[i] =
		    (buf[FT_TOUCH_ID_POS + FT_TOUCH_STEP * i]) >> 4;
	}

	ft5x06_report_value(data);

	return 0;
}

static irqreturn_t ft5x06_ts_interrupt(int irq, void *dev_id)
{
	struct ft5x06_ts_data *data = dev_id;
	int rc;

	rc = ft5x06_handle_touchdata(data);
	if (rc)
		pr_err("%s: handling touchdata failed\n", __func__);

	return IRQ_HANDLED;
}

static int ft5x06_power_on(struct ft5x06_ts_data *data, bool on)
{
	int rc;

	if (!on)
		goto power_off;

	rc = regulator_enable(data->vdd);
	if (rc) {
		dev_err(&data->client->dev,
			"Regulator vdd enable failed rc=%d\n", rc);
		return rc;
	}

	rc = regulator_enable(data->vcc_i2c);
	if (rc) {
		dev_err(&data->client->dev,
			"Regulator vcc_i2c enable failed rc=%d\n", rc);
		regulator_disable(data->vdd);
	}

	return rc;

power_off:
	rc = regulator_disable(data->vdd);
	if (rc) {
		dev_err(&data->client->dev,
			"Regulator vdd disable failed rc=%d\n", rc);
		return rc;
	}

	rc = regulator_disable(data->vcc_i2c);
	if (rc) {
		dev_err(&data->client->dev,
			"Regulator vcc_i2c disable failed rc=%d\n", rc);
		regulator_enable(data->vdd);
	}

	return rc;
}

static int ft5x06_power_init(struct ft5x06_ts_data *data, bool on)
{
	int rc;

	if (!on)
		goto pwr_deinit;

	data->vdd = regulator_get(&data->client->dev, "vdd");
	if (IS_ERR(data->vdd)) {
		rc = PTR_ERR(data->vdd);
		dev_err(&data->client->dev,
			"Regulator get failed vdd rc=%d\n", rc);
		return rc;
	}

	if (regulator_count_voltages(data->vdd) > 0) {
		rc = regulator_set_voltage(data->vdd, FT5X06_VTG_MIN_UV,
					   FT5X06_VTG_MAX_UV);
		if (rc) {
			dev_err(&data->client->dev,
				"Regulator set_vtg failed vdd rc=%d\n", rc);
			goto reg_vdd_put;
		}
	}

	data->vcc_i2c = regulator_get(&data->client->dev, "vcc_i2c");
	if (IS_ERR(data->vcc_i2c)) {
		rc = PTR_ERR(data->vcc_i2c);
		dev_err(&data->client->dev,
			"Regulator get failed vcc_i2c rc=%d\n", rc);
		goto reg_vdd_set_vtg;
	}

	if (regulator_count_voltages(data->vcc_i2c) > 0) {
		rc = regulator_set_voltage(data->vcc_i2c, FT5X06_I2C_VTG_MIN_UV,
					   FT5X06_I2C_VTG_MAX_UV);
		if (rc) {
			dev_err(&data->client->dev,
			"Regulator set_vtg failed vcc_i2c rc=%d\n", rc);
			goto reg_vcc_i2c_put;
		}
	}

	return 0;

reg_vcc_i2c_put:
	regulator_put(data->vcc_i2c);
reg_vdd_set_vtg:
	if (regulator_count_voltages(data->vdd) > 0)
		regulator_set_voltage(data->vdd, 0, FT5X06_VTG_MAX_UV);
reg_vdd_put:
	regulator_put(data->vdd);
	return rc;

pwr_deinit:
	if (regulator_count_voltages(data->vdd) > 0)
		regulator_set_voltage(data->vdd, 0, FT5X06_VTG_MAX_UV);

	regulator_put(data->vdd);

	if (regulator_count_voltages(data->vcc_i2c) > 0)
		regulator_set_voltage(data->vcc_i2c, 0, FT5X06_I2C_VTG_MAX_UV);

	regulator_put(data->vcc_i2c);
	return 0;
}

#ifdef CONFIG_PM
static int ft5x06_ts_suspend(struct device *dev)
{
	struct ft5x06_ts_data *data = dev_get_drvdata(dev);
	char txbuf[2];

	disable_irq(data->client->irq);

	if (gpio_is_valid(data->pdata->reset_gpio)) {
		txbuf[0] = FT5X06_REG_PMODE;
		txbuf[1] = FT5X06_PMODE_HIBERNATE;
		ft5x06_i2c_write(data->client, txbuf, sizeof(txbuf));
	}

	return 0;
}

static int ft5x06_ts_resume(struct device *dev)
{
	struct ft5x06_ts_data *data = dev_get_drvdata(dev);

	if (gpio_is_valid(data->pdata->reset_gpio)) {
		gpio_set_value_cansleep(data->pdata->reset_gpio, 0);
		msleep(FT_RESET_DLY);
		gpio_set_value_cansleep(data->pdata->reset_gpio, 1);
	}
	enable_irq(data->client->irq);

	return 0;
}

#ifdef CONFIG_HAS_EARLYSUSPEND
static void ft5x06_ts_early_suspend(struct early_suspend *handler)
{
	struct ft5x06_ts_data *data = container_of(handler,
						   struct ft5x06_ts_data,
						   early_suspend);

	ft5x06_ts_suspend(&data->client->dev);
}

static void ft5x06_ts_late_resume(struct early_suspend *handler)
{
	struct ft5x06_ts_data *data = container_of(handler,
						   struct ft5x06_ts_data,
						   early_suspend);

	ft5x06_ts_resume(&data->client->dev);
}
#endif

static const struct dev_pm_ops ft5x06_ts_pm_ops = {
#ifndef CONFIG_HAS_EARLYSUSPEND
	.suspend = ft5x06_ts_suspend,
	.resume = ft5x06_ts_resume,
#endif
};
#endif

static int ft5x06_ts_probe(struct i2c_client *client,
			   const struct i2c_device_id *id)
{
	const struct ft5x06_ts_platform_data *pdata = client->dev.platform_data;
	struct ft5x06_ts_data *data;
	struct input_dev *input_dev;
	u8 reg_value;
	u8 reg_addr;
	int err;

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

	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
		dev_err(&client->dev, "I2C not supported\n");
		return -ENODEV;
	}

	data = kzalloc(sizeof(struct ft5x06_ts_data), GFP_KERNEL);
	if (!data) {
		dev_err(&client->dev, "Not enough memory\n");
		return -ENOMEM;
	}

	input_dev = input_allocate_device();
	if (!input_dev) {
		err = -ENOMEM;
		dev_err(&client->dev, "failed to allocate input device\n");
		goto free_mem;
	}

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

	input_dev->name = "ft5x06_ts";
	input_dev->id.bustype = BUS_I2C;
	input_dev->dev.parent = &client->dev;

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

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

	input_set_abs_params(input_dev, ABS_MT_POSITION_X, 0,
			     pdata->x_max, 0, 0);
	input_set_abs_params(input_dev, ABS_MT_POSITION_Y, 0,
			     pdata->y_max, 0, 0);
	input_set_abs_params(input_dev, ABS_MT_TRACKING_ID, 0,
			     CFG_MAX_TOUCH_POINTS, 0, 0);
	input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0, FT_PRESS, 0, 0);
	input_set_abs_params(input_dev, ABS_MT_PRESSURE, 0, FT_PRESS, 0, 0);

	err = input_register_device(input_dev);
	if (err) {
		dev_err(&client->dev, "Input device registration failed\n");
		goto free_inputdev;
	}

	if (pdata->power_init) {
		err = pdata->power_init(true);
		if (err) {
			dev_err(&client->dev, "power init failed");
			goto unreg_inputdev;
		}
	} else {
		err = ft5x06_power_init(data, true);
		if (err) {
			dev_err(&client->dev, "power init failed");
			goto unreg_inputdev;
		}
	}

	if (pdata->power_on) {
		err = pdata->power_on(true);
		if (err) {
			dev_err(&client->dev, "power on failed");
			goto pwr_deinit;
		}
	} else {
		err = ft5x06_power_on(data, true);
		if (err) {
			dev_err(&client->dev, "power on failed");
			goto pwr_deinit;
		}
	}

	if (gpio_is_valid(pdata->irq_gpio)) {
		err = gpio_request(pdata->irq_gpio, "ft5x06_irq_gpio");
		if (err) {
			dev_err(&client->dev, "irq gpio request failed");
			goto pwr_off;
		}
		err = gpio_direction_input(pdata->irq_gpio);
		if (err) {
			dev_err(&client->dev,
				"set_direction for irq gpio failed\n");
			goto free_irq_gpio;
		}
	}

	if (gpio_is_valid(pdata->reset_gpio)) {
		err = gpio_request(pdata->reset_gpio, "ft5x06_reset_gpio");
		if (err) {
			dev_err(&client->dev, "reset gpio request failed");
			goto free_irq_gpio;
		}

		err = gpio_direction_output(pdata->reset_gpio, 0);
		if (err) {
			dev_err(&client->dev,
				"set_direction for reset gpio failed\n");
			goto free_reset_gpio;
		}
		msleep(FT_RESET_DLY);
		gpio_set_value_cansleep(data->pdata->reset_gpio, 1);
	}

	/* make sure CTP already finish startup process */
	msleep(FT_STARTUP_DLY);

	/*get some register information */
	reg_addr = FT5X06_REG_FW_VER;
	err = ft5x06_i2c_read(client, &reg_addr, 1, &reg_value, 1);
	if (err)
		dev_err(&client->dev, "version read failed");

	dev_info(&client->dev, "[FTS] Firmware version = 0x%x\n", reg_value);

	reg_addr = FT5X06_REG_POINT_RATE;
	ft5x06_i2c_read(client, &reg_addr, 1, &reg_value, 1);
	if (err)
		dev_err(&client->dev, "report rate read failed");
	dev_info(&client->dev, "[FTS] report rate is %dHz.\n", reg_value * 10);

	reg_addr = FT5X06_REG_THGROUP;
	err = ft5x06_i2c_read(client, &reg_addr, 1, &reg_value, 1);
	if (err)
		dev_err(&client->dev, "threshold read failed");
	dev_dbg(&client->dev, "[FTS] touch threshold is %d.\n", reg_value * 4);

	err = request_threaded_irq(client->irq, NULL,
				   ft5x06_ts_interrupt, pdata->irqflags,
				   client->dev.driver->name, data);
	if (err) {
		dev_err(&client->dev, "request irq failed\n");
		goto free_reset_gpio;
	}

#ifdef CONFIG_HAS_EARLYSUSPEND
	data->early_suspend.level = EARLY_SUSPEND_LEVEL_BLANK_SCREEN +
	    FT5X06_SUSPEND_LEVEL;
	data->early_suspend.suspend = ft5x06_ts_early_suspend;
	data->early_suspend.resume = ft5x06_ts_late_resume;
	register_early_suspend(&data->early_suspend);
#endif

	return 0;

free_reset_gpio:
	if (gpio_is_valid(pdata->reset_gpio))
		gpio_free(pdata->reset_gpio);
free_irq_gpio:
	if (gpio_is_valid(pdata->irq_gpio))
		gpio_free(pdata->reset_gpio);
pwr_off:
	if (pdata->power_on)
		pdata->power_on(false);
	else
		ft5x06_power_on(data, false);
pwr_deinit:
	if (pdata->power_init)
		pdata->power_init(false);
	else
		ft5x06_power_init(data, false);
unreg_inputdev:
	input_unregister_device(input_dev);
	input_dev = NULL;
free_inputdev:
	input_free_device(input_dev);
free_mem:
	kfree(data);
	return err;
}

static int ft5x06_ts_remove(struct i2c_client *client)
{
	struct ft5x06_ts_data *data = i2c_get_clientdata(client);

#ifdef CONFIG_HAS_EARLYSUSPEND
	unregister_early_suspend(&data->early_suspend);
#endif
	free_irq(client->irq, data);

	if (gpio_is_valid(data->pdata->reset_gpio))
		gpio_free(data->pdata->reset_gpio);

	if (gpio_is_valid(data->pdata->irq_gpio))
		gpio_free(data->pdata->reset_gpio);

	if (data->pdata->power_on)
		data->pdata->power_on(false);
	else
		ft5x06_power_on(data, false);

	if (data->pdata->power_init)
		data->pdata->power_init(false);
	else
		ft5x06_power_init(data, false);

	input_unregister_device(data->input_dev);
	kfree(data);

	return 0;
}

static const struct i2c_device_id ft5x06_ts_id[] = {
	{"ft5x06_ts", 0},
	{},
};

MODULE_DEVICE_TABLE(i2c, ft5x06_ts_id);

static struct i2c_driver ft5x06_ts_driver = {
	.probe = ft5x06_ts_probe,
	.remove = ft5x06_ts_remove,
	.driver = {
		   .name = "ft5x06_ts",
		   .owner = THIS_MODULE,
#ifdef CONFIG_PM
		   .pm = &ft5x06_ts_pm_ops,
#endif
		   },
	.id_table = ft5x06_ts_id,
};

static int __init ft5x06_ts_init(void)
{
	return i2c_add_driver(&ft5x06_ts_driver);
}
module_init(ft5x06_ts_init);

static void __exit ft5x06_ts_exit(void)
{
	i2c_del_driver(&ft5x06_ts_driver);
}
module_exit(ft5x06_ts_exit);

MODULE_DESCRIPTION("FocalTech ft5x06 TouchScreen driver");
MODULE_LICENSE("GPL v2");