/*
   * Copyright (C) 2012 Simon Budig, <simon.budig@kernelconcepts.de>

   * Daniel Wagener <daniel.wagener@kernelconcepts.de> (M09 firmware support)

   * Lothar Waßmann <LW@KARO-electronics.de> (DT support)

   *
   * 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.
   *
   * You should have received a copy of the GNU General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   */
  
  /*
   * This is a driver for the EDT "Polytouch" family of touch controllers
   * based on the FocalTech FT5x06 line of chips.
   *
   * Development of this driver has been sponsored by Glyn:
   *    http://www.glyn.com/Products/Displays
   */
  
  #include <linux/module.h>
  #include <linux/ratelimit.h>
  #include <linux/interrupt.h>
  #include <linux/input.h>
  #include <linux/i2c.h>
  #include <linux/uaccess.h>
  #include <linux/delay.h>
  #include <linux/debugfs.h>
  #include <linux/slab.h>
  #include <linux/gpio.h>

  #include <linux/of_gpio.h>

  #include <linux/input/mt.h>
  #include <linux/input/edt-ft5x06.h>
  
  #define MAX_SUPPORT_POINTS		5
  
  #define WORK_REGISTER_THRESHOLD		0x00
  #define WORK_REGISTER_REPORT_RATE	0x08
  #define WORK_REGISTER_GAIN		0x30
  #define WORK_REGISTER_OFFSET		0x31
  #define WORK_REGISTER_NUM_X		0x33
  #define WORK_REGISTER_NUM_Y		0x34

  #define M09_REGISTER_THRESHOLD		0x80
  #define M09_REGISTER_GAIN		0x92
  #define M09_REGISTER_OFFSET		0x93
  #define M09_REGISTER_NUM_X		0x94
  #define M09_REGISTER_NUM_Y		0x95
  
  #define NO_REGISTER			0xff

  #define WORK_REGISTER_OPMODE		0x3c
  #define FACTORY_REGISTER_OPMODE		0x01
  
  #define TOUCH_EVENT_DOWN		0x00
  #define TOUCH_EVENT_UP			0x01
  #define TOUCH_EVENT_ON			0x02
  #define TOUCH_EVENT_RESERVED		0x03
  
  #define EDT_NAME_LEN			23
  #define EDT_SWITCH_MODE_RETRIES		10
  #define EDT_SWITCH_MODE_DELAY		5 /* msec */
  #define EDT_RAW_DATA_RETRIES		100
  #define EDT_RAW_DATA_DELAY		1 /* msec */

  enum edt_ver {
  	M06,
  	M09,
  };
  
  struct edt_reg_addr {
  	int reg_threshold;
  	int reg_report_rate;
  	int reg_gain;
  	int reg_offset;
  	int reg_num_x;
  	int reg_num_y;
  };

  struct edt_ft5x06_ts_data {
  	struct i2c_client *client;
  	struct input_dev *input;
  	u16 num_x;
  	u16 num_y;

  	int reset_pin;
  	int irq_pin;
  	int wake_pin;

  #if defined(CONFIG_DEBUG_FS)
  	struct dentry *debug_dir;
  	u8 *raw_buffer;
  	size_t raw_bufsize;
  #endif
  
  	struct mutex mutex;
  	bool factory_mode;
  	int threshold;
  	int gain;
  	int offset;
  	int report_rate;
  
  	char name[EDT_NAME_LEN];

  
  	struct edt_reg_addr reg_addr;
  	enum edt_ver version;

  };
  
  static int edt_ft5x06_ts_readwrite(struct i2c_client *client,
  				   u16 wr_len, u8 *wr_buf,
  				   u16 rd_len, u8 *rd_buf)
  {
  	struct i2c_msg wrmsg[2];
  	int i = 0;
  	int ret;
  
  	if (wr_len) {
  		wrmsg[i].addr  = client->addr;
  		wrmsg[i].flags = 0;
  		wrmsg[i].len = wr_len;
  		wrmsg[i].buf = wr_buf;
  		i++;
  	}
  	if (rd_len) {
  		wrmsg[i].addr  = client->addr;
  		wrmsg[i].flags = I2C_M_RD;
  		wrmsg[i].len = rd_len;
  		wrmsg[i].buf = rd_buf;
  		i++;
  	}
  
  	ret = i2c_transfer(client->adapter, wrmsg, i);
  	if (ret < 0)
  		return ret;
  	if (ret != i)
  		return -EIO;
  
  	return 0;
  }
  
  static bool edt_ft5x06_ts_check_crc(struct edt_ft5x06_ts_data *tsdata,
  				    u8 *buf, int buflen)
  {
  	int i;
  	u8 crc = 0;
  
  	for (i = 0; i < buflen - 1; i++)
  		crc ^= buf[i];
  
  	if (crc != buf[buflen-1]) {
  		dev_err_ratelimited(&tsdata->client->dev,
  				    "crc error: 0x%02x expected, got 0x%02x
  ",
  				    crc, buf[buflen-1]);
  		return false;
  	}
  
  	return true;
  }
  
  static irqreturn_t edt_ft5x06_ts_isr(int irq, void *dev_id)
  {
  	struct edt_ft5x06_ts_data *tsdata = dev_id;
  	struct device *dev = &tsdata->client->dev;

  	u8 cmd;
  	u8 rdbuf[29];

  	int i, type, x, y, id;

  	int offset, tplen, datalen;

  	int error;

  	switch (tsdata->version) {
  	case M06:
  		cmd = 0xf9; /* tell the controller to send touch data */
  		offset = 5; /* where the actual touch data starts */
  		tplen = 4;  /* data comes in so called frames */
  		datalen = 26; /* how much bytes to listen for */
  		break;
  
  	case M09:
  		cmd = 0x02;
  		offset = 1;
  		tplen = 6;
  		datalen = 29;
  		break;
  
  	default:
  		goto out;
  	}

  	memset(rdbuf, 0, sizeof(rdbuf));
  
  	error = edt_ft5x06_ts_readwrite(tsdata->client,
  					sizeof(cmd), &cmd,

  					datalen, rdbuf);

  	if (error) {
  		dev_err_ratelimited(dev, "Unable to fetch data, error: %d
  ",
  				    error);
  		goto out;
  	}

  	/* M09 does not send header or CRC */
  	if (tsdata->version == M06) {
  		if (rdbuf[0] != 0xaa || rdbuf[1] != 0xaa ||
  			rdbuf[2] != datalen) {
  			dev_err_ratelimited(dev,
  					"Unexpected header: %02x%02x%02x!
  ",
  					rdbuf[0], rdbuf[1], rdbuf[2]);
  			goto out;
  		}

  		if (!edt_ft5x06_ts_check_crc(tsdata, rdbuf, datalen))
  			goto out;
  	}

  
  	for (i = 0; i < MAX_SUPPORT_POINTS; i++) {

  		u8 *buf = &rdbuf[i * tplen + offset];

  		bool down;
  
  		type = buf[0] >> 6;
  		/* ignore Reserved events */
  		if (type == TOUCH_EVENT_RESERVED)
  			continue;

  		/* M06 sometimes sends bogus coordinates in TOUCH_DOWN */
  		if (tsdata->version == M06 && type == TOUCH_EVENT_DOWN)

  			continue;

  		x = ((buf[0] << 8) | buf[1]) & 0x0fff;
  		y = ((buf[2] << 8) | buf[3]) & 0x0fff;
  		id = (buf[2] >> 4) & 0x0f;

  		down = type != TOUCH_EVENT_UP;

  
  		input_mt_slot(tsdata->input, id);
  		input_mt_report_slot_state(tsdata->input, MT_TOOL_FINGER, down);
  
  		if (!down)
  			continue;
  
  		input_report_abs(tsdata->input, ABS_MT_POSITION_X, x);
  		input_report_abs(tsdata->input, ABS_MT_POSITION_Y, y);
  	}
  
  	input_mt_report_pointer_emulation(tsdata->input, true);
  	input_sync(tsdata->input);
  
  out:
  	return IRQ_HANDLED;
  }
  
  static int edt_ft5x06_register_write(struct edt_ft5x06_ts_data *tsdata,
  				     u8 addr, u8 value)
  {
  	u8 wrbuf[4];

  	switch (tsdata->version) {
  	case M06:
  		wrbuf[0] = tsdata->factory_mode ? 0xf3 : 0xfc;
  		wrbuf[1] = tsdata->factory_mode ? addr & 0x7f : addr & 0x3f;
  		wrbuf[1] = tsdata->factory_mode ? addr & 0x7f : addr & 0x3f;
  		wrbuf[2] = value;
  		wrbuf[3] = wrbuf[0] ^ wrbuf[1] ^ wrbuf[2];
  		return edt_ft5x06_ts_readwrite(tsdata->client, 4,
  					wrbuf, 0, NULL);
  	case M09:
  		wrbuf[0] = addr;
  		wrbuf[1] = value;

  		return edt_ft5x06_ts_readwrite(tsdata->client, 2,

  					wrbuf, 0, NULL);
  
  	default:
  		return -EINVAL;
  	}

  }
  
  static int edt_ft5x06_register_read(struct edt_ft5x06_ts_data *tsdata,
  				    u8 addr)
  {
  	u8 wrbuf[2], rdbuf[2];
  	int error;

  	switch (tsdata->version) {
  	case M06:
  		wrbuf[0] = tsdata->factory_mode ? 0xf3 : 0xfc;
  		wrbuf[1] = tsdata->factory_mode ? addr & 0x7f : addr & 0x3f;
  		wrbuf[1] |= tsdata->factory_mode ? 0x80 : 0x40;

  		error = edt_ft5x06_ts_readwrite(tsdata->client, 2, wrbuf, 2,
  						rdbuf);
  		if (error)
  			return error;

  		if ((wrbuf[0] ^ wrbuf[1] ^ rdbuf[0]) != rdbuf[1]) {
  			dev_err(&tsdata->client->dev,
  				"crc error: 0x%02x expected, got 0x%02x
  ",
  				wrbuf[0] ^ wrbuf[1] ^ rdbuf[0],
  				rdbuf[1]);
  			return -EIO;
  		}
  		break;
  
  	case M09:
  		wrbuf[0] = addr;
  		error = edt_ft5x06_ts_readwrite(tsdata->client, 1,
  						wrbuf, 1, rdbuf);
  		if (error)
  			return error;
  		break;
  
  	default:
  		return -EINVAL;

  	}
  
  	return rdbuf[0];
  }
  
  struct edt_ft5x06_attribute {
  	struct device_attribute dattr;
  	size_t field_offset;
  	u8 limit_low;
  	u8 limit_high;

  	u8 addr_m06;
  	u8 addr_m09;

  };

  #define EDT_ATTR(_field, _mode, _addr_m06, _addr_m09,			\
  		_limit_low, _limit_high)				\

  	struct edt_ft5x06_attribute edt_ft5x06_attr_##_field = {	\
  		.dattr = __ATTR(_field, _mode,				\
  				edt_ft5x06_setting_show,		\
  				edt_ft5x06_setting_store),		\

  		.field_offset = offsetof(struct edt_ft5x06_ts_data, _field), \
  		.addr_m06 = _addr_m06,					\
  		.addr_m09 = _addr_m09,					\

  		.limit_low = _limit_low,				\
  		.limit_high = _limit_high,				\

  	}
  
  static ssize_t edt_ft5x06_setting_show(struct device *dev,
  				       struct device_attribute *dattr,
  				       char *buf)
  {
  	struct i2c_client *client = to_i2c_client(dev);
  	struct edt_ft5x06_ts_data *tsdata = i2c_get_clientdata(client);
  	struct edt_ft5x06_attribute *attr =
  			container_of(dattr, struct edt_ft5x06_attribute, dattr);

  	u8 *field = (u8 *)tsdata + attr->field_offset;

  	int val;
  	size_t count = 0;
  	int error = 0;

  	u8 addr;

  
  	mutex_lock(&tsdata->mutex);
  
  	if (tsdata->factory_mode) {
  		error = -EIO;
  		goto out;
  	}

  	switch (tsdata->version) {
  	case M06:
  		addr = attr->addr_m06;
  		break;
  
  	case M09:
  		addr = attr->addr_m09;
  		break;
  
  	default:
  		error = -ENODEV;

  		goto out;
  	}

  	if (addr != NO_REGISTER) {
  		val = edt_ft5x06_register_read(tsdata, addr);
  		if (val < 0) {
  			error = val;
  			dev_err(&tsdata->client->dev,
  				"Failed to fetch attribute %s, error %d
  ",
  				dattr->attr.name, error);
  			goto out;
  		}
  	} else {
  		val = *field;
  	}

  	if (val != *field) {
  		dev_warn(&tsdata->client->dev,
  			 "%s: read (%d) and stored value (%d) differ
  ",
  			 dattr->attr.name, val, *field);
  		*field = val;
  	}
  
  	count = scnprintf(buf, PAGE_SIZE, "%d
  ", val);
  out:
  	mutex_unlock(&tsdata->mutex);
  	return error ?: count;
  }
  
  static ssize_t edt_ft5x06_setting_store(struct device *dev,
  					struct device_attribute *dattr,
  					const char *buf, size_t count)
  {
  	struct i2c_client *client = to_i2c_client(dev);
  	struct edt_ft5x06_ts_data *tsdata = i2c_get_clientdata(client);
  	struct edt_ft5x06_attribute *attr =
  			container_of(dattr, struct edt_ft5x06_attribute, dattr);

  	u8 *field = (u8 *)tsdata + attr->field_offset;

  	unsigned int val;
  	int error;

  	u8 addr;

  
  	mutex_lock(&tsdata->mutex);
  
  	if (tsdata->factory_mode) {
  		error = -EIO;
  		goto out;
  	}
  
  	error = kstrtouint(buf, 0, &val);
  	if (error)
  		goto out;
  
  	if (val < attr->limit_low || val > attr->limit_high) {
  		error = -ERANGE;
  		goto out;
  	}

  	switch (tsdata->version) {
  	case M06:
  		addr = attr->addr_m06;
  		break;
  
  	case M09:
  		addr = attr->addr_m09;
  		break;
  
  	default:
  		error = -ENODEV;

  		goto out;
  	}

  	if (addr != NO_REGISTER) {
  		error = edt_ft5x06_register_write(tsdata, addr, val);
  		if (error) {
  			dev_err(&tsdata->client->dev,
  				"Failed to update attribute %s, error: %d
  ",
  				dattr->attr.name, error);
  			goto out;
  		}
  	}

  	*field = val;
  
  out:
  	mutex_unlock(&tsdata->mutex);
  	return error ?: count;
  }

  static EDT_ATTR(gain, S_IWUSR | S_IRUGO, WORK_REGISTER_GAIN,
  		M09_REGISTER_GAIN, 0, 31);
  static EDT_ATTR(offset, S_IWUSR | S_IRUGO, WORK_REGISTER_OFFSET,
  		M09_REGISTER_OFFSET, 0, 31);
  static EDT_ATTR(threshold, S_IWUSR | S_IRUGO, WORK_REGISTER_THRESHOLD,
  		M09_REGISTER_THRESHOLD, 20, 80);
  static EDT_ATTR(report_rate, S_IWUSR | S_IRUGO, WORK_REGISTER_REPORT_RATE,
  		NO_REGISTER, 3, 14);

  
  static struct attribute *edt_ft5x06_attrs[] = {
  	&edt_ft5x06_attr_gain.dattr.attr,
  	&edt_ft5x06_attr_offset.dattr.attr,
  	&edt_ft5x06_attr_threshold.dattr.attr,
  	&edt_ft5x06_attr_report_rate.dattr.attr,
  	NULL
  };
  
  static const struct attribute_group edt_ft5x06_attr_group = {
  	.attrs = edt_ft5x06_attrs,
  };
  
  #ifdef CONFIG_DEBUG_FS
  static int edt_ft5x06_factory_mode(struct edt_ft5x06_ts_data *tsdata)
  {
  	struct i2c_client *client = tsdata->client;
  	int retries = EDT_SWITCH_MODE_RETRIES;
  	int ret;
  	int error;
  
  	disable_irq(client->irq);
  
  	if (!tsdata->raw_buffer) {
  		tsdata->raw_bufsize = tsdata->num_x * tsdata->num_y *
  				      sizeof(u16);
  		tsdata->raw_buffer = kzalloc(tsdata->raw_bufsize, GFP_KERNEL);
  		if (!tsdata->raw_buffer) {
  			error = -ENOMEM;
  			goto err_out;
  		}
  	}
  
  	/* mode register is 0x3c when in the work mode */

  	if (tsdata->version == M09)
  		goto m09_out;

  	error = edt_ft5x06_register_write(tsdata, WORK_REGISTER_OPMODE, 0x03);
  	if (error) {
  		dev_err(&client->dev,
  			"failed to switch to factory mode, error %d
  ", error);
  		goto err_out;
  	}
  
  	tsdata->factory_mode = true;
  	do {
  		mdelay(EDT_SWITCH_MODE_DELAY);
  		/* mode register is 0x01 when in factory mode */
  		ret = edt_ft5x06_register_read(tsdata, FACTORY_REGISTER_OPMODE);
  		if (ret == 0x03)
  			break;
  	} while (--retries > 0);
  
  	if (retries == 0) {
  		dev_err(&client->dev, "not in factory mode after %dms.
  ",
  			EDT_SWITCH_MODE_RETRIES * EDT_SWITCH_MODE_DELAY);
  		error = -EIO;
  		goto err_out;
  	}
  
  	return 0;
  
  err_out:
  	kfree(tsdata->raw_buffer);
  	tsdata->raw_buffer = NULL;
  	tsdata->factory_mode = false;
  	enable_irq(client->irq);
  
  	return error;

  
  m09_out:
  	dev_err(&client->dev, "No factory mode support for M09
  ");
  	return -EINVAL;

  }
  
  static int edt_ft5x06_work_mode(struct edt_ft5x06_ts_data *tsdata)
  {
  	struct i2c_client *client = tsdata->client;
  	int retries = EDT_SWITCH_MODE_RETRIES;

  	struct edt_reg_addr *reg_addr = &tsdata->reg_addr;

  	int ret;
  	int error;
  
  	/* mode register is 0x01 when in the factory mode */
  	error = edt_ft5x06_register_write(tsdata, FACTORY_REGISTER_OPMODE, 0x1);
  	if (error) {
  		dev_err(&client->dev,
  			"failed to switch to work mode, error: %d
  ", error);
  		return error;
  	}
  
  	tsdata->factory_mode = false;
  
  	do {
  		mdelay(EDT_SWITCH_MODE_DELAY);
  		/* mode register is 0x01 when in factory mode */
  		ret = edt_ft5x06_register_read(tsdata, WORK_REGISTER_OPMODE);
  		if (ret == 0x01)
  			break;
  	} while (--retries > 0);
  
  	if (retries == 0) {
  		dev_err(&client->dev, "not in work mode after %dms.
  ",
  			EDT_SWITCH_MODE_RETRIES * EDT_SWITCH_MODE_DELAY);
  		tsdata->factory_mode = true;
  		return -EIO;
  	}

  	kfree(tsdata->raw_buffer);

  	tsdata->raw_buffer = NULL;
  
  	/* restore parameters */

  	edt_ft5x06_register_write(tsdata, reg_addr->reg_threshold,

  				  tsdata->threshold);

  	edt_ft5x06_register_write(tsdata, reg_addr->reg_gain,

  				  tsdata->gain);

  	edt_ft5x06_register_write(tsdata, reg_addr->reg_offset,

  				  tsdata->offset);

  	if (reg_addr->reg_report_rate)
  		edt_ft5x06_register_write(tsdata, reg_addr->reg_report_rate,

  				  tsdata->report_rate);
  
  	enable_irq(client->irq);
  
  	return 0;
  }
  
  static int edt_ft5x06_debugfs_mode_get(void *data, u64 *mode)
  {
  	struct edt_ft5x06_ts_data *tsdata = data;
  
  	*mode = tsdata->factory_mode;
  
  	return 0;
  };
  
  static int edt_ft5x06_debugfs_mode_set(void *data, u64 mode)
  {
  	struct edt_ft5x06_ts_data *tsdata = data;
  	int retval = 0;
  
  	if (mode > 1)
  		return -ERANGE;
  
  	mutex_lock(&tsdata->mutex);
  
  	if (mode != tsdata->factory_mode) {
  		retval = mode ? edt_ft5x06_factory_mode(tsdata) :

  				edt_ft5x06_work_mode(tsdata);

  	}
  
  	mutex_unlock(&tsdata->mutex);
  
  	return retval;
  };
  
  DEFINE_SIMPLE_ATTRIBUTE(debugfs_mode_fops, edt_ft5x06_debugfs_mode_get,
  			edt_ft5x06_debugfs_mode_set, "%llu
  ");

  static ssize_t edt_ft5x06_debugfs_raw_data_read(struct file *file,
  				char __user *buf, size_t count, loff_t *off)
  {
  	struct edt_ft5x06_ts_data *tsdata = file->private_data;
  	struct i2c_client *client = tsdata->client;
  	int retries  = EDT_RAW_DATA_RETRIES;
  	int val, i, error;
  	size_t read = 0;
  	int colbytes;
  	char wrbuf[3];
  	u8 *rdbuf;
  
  	if (*off < 0 || *off >= tsdata->raw_bufsize)
  		return 0;
  
  	mutex_lock(&tsdata->mutex);
  
  	if (!tsdata->factory_mode || !tsdata->raw_buffer) {
  		error = -EIO;
  		goto out;
  	}
  
  	error = edt_ft5x06_register_write(tsdata, 0x08, 0x01);
  	if (error) {
  		dev_dbg(&client->dev,
  			"failed to write 0x08 register, error %d
  ", error);
  		goto out;
  	}
  
  	do {
  		msleep(EDT_RAW_DATA_DELAY);
  		val = edt_ft5x06_register_read(tsdata, 0x08);
  		if (val < 1)
  			break;
  	} while (--retries > 0);
  
  	if (val < 0) {
  		error = val;
  		dev_dbg(&client->dev,
  			"failed to read 0x08 register, error %d
  ", error);
  		goto out;
  	}
  
  	if (retries == 0) {
  		dev_dbg(&client->dev,
  			"timed out waiting for register to settle
  ");
  		error = -ETIMEDOUT;
  		goto out;
  	}
  
  	rdbuf = tsdata->raw_buffer;
  	colbytes = tsdata->num_y * sizeof(u16);
  
  	wrbuf[0] = 0xf5;
  	wrbuf[1] = 0x0e;
  	for (i = 0; i < tsdata->num_x; i++) {
  		wrbuf[2] = i;  /* column index */
  		error = edt_ft5x06_ts_readwrite(tsdata->client,
  						sizeof(wrbuf), wrbuf,
  						colbytes, rdbuf);
  		if (error)
  			goto out;
  
  		rdbuf += colbytes;
  	}
  
  	read = min_t(size_t, count, tsdata->raw_bufsize - *off);

  	if (copy_to_user(buf, tsdata->raw_buffer + *off, read)) {
  		error = -EFAULT;
  		goto out;
  	}
  
  	*off += read;

  out:
  	mutex_unlock(&tsdata->mutex);
  	return error ?: read;
  };

  static const struct file_operations debugfs_raw_data_fops = {

  	.open = simple_open,

  	.read = edt_ft5x06_debugfs_raw_data_read,
  };

  static void

  edt_ft5x06_ts_prepare_debugfs(struct edt_ft5x06_ts_data *tsdata,
  			      const char *debugfs_name)
  {
  	tsdata->debug_dir = debugfs_create_dir(debugfs_name, NULL);
  	if (!tsdata->debug_dir)
  		return;
  
  	debugfs_create_u16("num_x", S_IRUSR, tsdata->debug_dir, &tsdata->num_x);
  	debugfs_create_u16("num_y", S_IRUSR, tsdata->debug_dir, &tsdata->num_y);
  
  	debugfs_create_file("mode", S_IRUSR | S_IWUSR,
  			    tsdata->debug_dir, tsdata, &debugfs_mode_fops);
  	debugfs_create_file("raw_data", S_IRUSR,
  			    tsdata->debug_dir, tsdata, &debugfs_raw_data_fops);
  }

  static void

  edt_ft5x06_ts_teardown_debugfs(struct edt_ft5x06_ts_data *tsdata)
  {
  	if (tsdata->debug_dir)
  		debugfs_remove_recursive(tsdata->debug_dir);

  	kfree(tsdata->raw_buffer);

  }
  
  #else
  
  static inline void
  edt_ft5x06_ts_prepare_debugfs(struct edt_ft5x06_ts_data *tsdata,
  			      const char *debugfs_name)
  {
  }
  
  static inline void
  edt_ft5x06_ts_teardown_debugfs(struct edt_ft5x06_ts_data *tsdata)
  {
  }
  
  #endif /* CONFIG_DEBUGFS */

  static int edt_ft5x06_ts_reset(struct i2c_client *client,

  			struct edt_ft5x06_ts_data *tsdata)

  {
  	int error;

  	if (gpio_is_valid(tsdata->wake_pin)) {
  		error = devm_gpio_request_one(&client->dev,
  					tsdata->wake_pin, GPIOF_OUT_INIT_LOW,
  					"edt-ft5x06 wake");
  		if (error) {
  			dev_err(&client->dev,
  				"Failed to request GPIO %d as wake pin, error %d
  ",
  				tsdata->wake_pin, error);
  			return error;
  		}

  		msleep(5);

  		gpio_set_value(tsdata->wake_pin, 1);
  	}
  	if (gpio_is_valid(tsdata->reset_pin)) {

  		/* this pulls reset down, enabling the low active reset */

  		error = devm_gpio_request_one(&client->dev,
  					tsdata->reset_pin, GPIOF_OUT_INIT_LOW,
  					"edt-ft5x06 reset");

  		if (error) {
  			dev_err(&client->dev,
  				"Failed to request GPIO %d as reset pin, error %d
  ",

  				tsdata->reset_pin, error);

  			return error;
  		}

  		msleep(5);

  		gpio_set_value(tsdata->reset_pin, 1);

  		msleep(300);

  	}
  
  	return 0;
  }

  static int edt_ft5x06_ts_identify(struct i2c_client *client,

  					struct edt_ft5x06_ts_data *tsdata,
  					char *fw_version)

  {
  	u8 rdbuf[EDT_NAME_LEN];
  	char *p;
  	int error;

  	char *model_name = tsdata->name;

  	/* see what we find if we assume it is a M06 *
  	 * if we get less than EDT_NAME_LEN, we don't want
  	 * to have garbage in there
  	 */
  	memset(rdbuf, 0, sizeof(rdbuf));

  	error = edt_ft5x06_ts_readwrite(client, 1, "\xbb",
  					EDT_NAME_LEN - 1, rdbuf);
  	if (error)
  		return error;

  	/* if we find something consistent, stay with that assumption
  	 * at least M09 won't send 3 bytes here
  	 */
  	if (!(strnicmp(rdbuf + 1, "EP0", 3))) {
  		tsdata->version = M06;
  
  		/* remove last '$' end marker */
  		rdbuf[EDT_NAME_LEN - 1] = '\0';
  		if (rdbuf[EDT_NAME_LEN - 2] == '$')
  			rdbuf[EDT_NAME_LEN - 2] = '\0';
  
  		/* look for Model/Version separator */
  		p = strchr(rdbuf, '*');
  		if (p)
  			*p++ = '\0';
  		strlcpy(model_name, rdbuf + 1, EDT_NAME_LEN);
  		strlcpy(fw_version, p ? p : "", EDT_NAME_LEN);
  	} else {
  		/* since there are only two versions around (M06, M09) */
  		tsdata->version = M09;
  
  		error = edt_ft5x06_ts_readwrite(client, 1, "\xA6",
  						2, rdbuf);
  		if (error)
  			return error;

  		strlcpy(fw_version, rdbuf, 2);

  		error = edt_ft5x06_ts_readwrite(client, 1, "\xA8",
  						1, rdbuf);
  		if (error)
  			return error;
  
  		snprintf(model_name, EDT_NAME_LEN, "EP0%i%i0M09",
  			rdbuf[0] >> 4, rdbuf[0] & 0x0F);
  	}

  
  	return 0;
  }
  
  #define EDT_ATTR_CHECKSET(name, reg) \
  	if (pdata->name >= edt_ft5x06_attr_##name.limit_low &&		\
  	    pdata->name <= edt_ft5x06_attr_##name.limit_high)		\
  		edt_ft5x06_register_write(tsdata, reg, pdata->name)

  #define EDT_GET_PROP(name, reg) {				\
  	u32 val;						\
  	if (of_property_read_u32(np, #name, &val) == 0)		\
  		edt_ft5x06_register_write(tsdata, reg, val);	\
  }
  
  static void edt_ft5x06_ts_get_dt_defaults(struct device_node *np,
  					struct edt_ft5x06_ts_data *tsdata)
  {

  	struct edt_reg_addr *reg_addr = &tsdata->reg_addr;
  
  	EDT_GET_PROP(threshold, reg_addr->reg_threshold);
  	EDT_GET_PROP(gain, reg_addr->reg_gain);
  	EDT_GET_PROP(offset, reg_addr->reg_offset);

  }

  static void

  edt_ft5x06_ts_get_defaults(struct edt_ft5x06_ts_data *tsdata,
  			   const struct edt_ft5x06_platform_data *pdata)
  {

  	struct edt_reg_addr *reg_addr = &tsdata->reg_addr;

  	if (!pdata->use_parameters)
  		return;
  
  	/* pick up defaults from the platform data */

  	EDT_ATTR_CHECKSET(threshold, reg_addr->reg_threshold);
  	EDT_ATTR_CHECKSET(gain, reg_addr->reg_gain);
  	EDT_ATTR_CHECKSET(offset, reg_addr->reg_offset);
  	if (reg_addr->reg_report_rate != NO_REGISTER)
  		EDT_ATTR_CHECKSET(report_rate, reg_addr->reg_report_rate);

  }

  static void

  edt_ft5x06_ts_get_parameters(struct edt_ft5x06_ts_data *tsdata)
  {

  	struct edt_reg_addr *reg_addr = &tsdata->reg_addr;

  	tsdata->threshold = edt_ft5x06_register_read(tsdata,

  						     reg_addr->reg_threshold);
  	tsdata->gain = edt_ft5x06_register_read(tsdata, reg_addr->reg_gain);
  	tsdata->offset = edt_ft5x06_register_read(tsdata, reg_addr->reg_offset);
  	if (reg_addr->reg_report_rate != NO_REGISTER)
  		tsdata->report_rate = edt_ft5x06_register_read(tsdata,
  						reg_addr->reg_report_rate);
  	tsdata->num_x = edt_ft5x06_register_read(tsdata, reg_addr->reg_num_x);
  	tsdata->num_y = edt_ft5x06_register_read(tsdata, reg_addr->reg_num_y);
  }
  
  static void
  edt_ft5x06_ts_set_regs(struct edt_ft5x06_ts_data *tsdata)
  {
  	struct edt_reg_addr *reg_addr = &tsdata->reg_addr;
  
  	switch (tsdata->version) {
  	case M06:
  		reg_addr->reg_threshold = WORK_REGISTER_THRESHOLD;
  		reg_addr->reg_report_rate = WORK_REGISTER_REPORT_RATE;
  		reg_addr->reg_gain = WORK_REGISTER_GAIN;
  		reg_addr->reg_offset = WORK_REGISTER_OFFSET;
  		reg_addr->reg_num_x = WORK_REGISTER_NUM_X;
  		reg_addr->reg_num_y = WORK_REGISTER_NUM_Y;
  		break;
  
  	case M09:
  		reg_addr->reg_threshold = M09_REGISTER_THRESHOLD;
  		reg_addr->reg_gain = M09_REGISTER_GAIN;
  		reg_addr->reg_offset = M09_REGISTER_OFFSET;
  		reg_addr->reg_num_x = M09_REGISTER_NUM_X;
  		reg_addr->reg_num_y = M09_REGISTER_NUM_Y;
  		break;
  	}

  }

  #ifdef CONFIG_OF
  static int edt_ft5x06_i2c_ts_probe_dt(struct device *dev,
  				struct edt_ft5x06_ts_data *tsdata)
  {
  	struct device_node *np = dev->of_node;
  
  	/*
  	 * irq_pin is not needed for DT setup.
  	 * irq is associated via 'interrupts' property in DT
  	 */
  	tsdata->irq_pin = -EINVAL;
  	tsdata->reset_pin = of_get_named_gpio(np, "reset-gpios", 0);
  	tsdata->wake_pin = of_get_named_gpio(np, "wake-gpios", 0);
  
  	return 0;
  }
  #else
  static inline int edt_ft5x06_i2c_ts_probe_dt(struct device *dev,
  					struct edt_ft5x06_ts_data *tsdata)
  {
  	return -ENODEV;
  }
  #endif

  static int edt_ft5x06_ts_probe(struct i2c_client *client,

  					 const struct i2c_device_id *id)
  {
  	const struct edt_ft5x06_platform_data *pdata =

  						dev_get_platdata(&client->dev);

  	struct edt_ft5x06_ts_data *tsdata;
  	struct input_dev *input;
  	int error;
  	char fw_version[EDT_NAME_LEN];

  	unsigned int max_x, max_y;

  
  	dev_dbg(&client->dev, "probing for EDT FT5x06 I2C
  ");

  	tsdata = devm_kzalloc(&client->dev, sizeof(*tsdata), GFP_KERNEL);
  	if (!tsdata) {
  		dev_err(&client->dev, "failed to allocate driver data.
  ");
  		return -ENOMEM;
  	}

  	if (!pdata) {

  		error = edt_ft5x06_i2c_ts_probe_dt(&client->dev, tsdata);
  		if (error) {
  			dev_err(&client->dev,
  				"DT probe failed and no platform data present
  ");
  			return error;
  		}
  	} else {
  		tsdata->reset_pin = pdata->reset_pin;
  		tsdata->irq_pin = pdata->irq_pin;
  		tsdata->wake_pin = -EINVAL;

  	}

  	error = edt_ft5x06_ts_reset(client, tsdata);

  	if (error)
  		return error;

  	if (gpio_is_valid(tsdata->irq_pin)) {
  		error = devm_gpio_request_one(&client->dev, tsdata->irq_pin,
  					GPIOF_IN, "edt-ft5x06 irq");

  		if (error) {
  			dev_err(&client->dev,
  				"Failed to request GPIO %d, error %d
  ",

  				tsdata->irq_pin, error);

  			return error;
  		}
  	}

  	input = devm_input_allocate_device(&client->dev);
  	if (!input) {
  		dev_err(&client->dev, "failed to allocate input device.
  ");
  		return -ENOMEM;

  	}
  
  	mutex_init(&tsdata->mutex);
  	tsdata->client = client;
  	tsdata->input = input;
  	tsdata->factory_mode = false;

  	error = edt_ft5x06_ts_identify(client, tsdata, fw_version);

  	if (error) {
  		dev_err(&client->dev, "touchscreen probe failed
  ");

  		return error;

  	}

  	edt_ft5x06_ts_set_regs(tsdata);

  	if (!pdata)
  		edt_ft5x06_ts_get_dt_defaults(client->dev.of_node, tsdata);
  	else
  		edt_ft5x06_ts_get_defaults(tsdata, pdata);

  	edt_ft5x06_ts_get_parameters(tsdata);
  
  	dev_dbg(&client->dev,
  		"Model \"%s\", Rev. \"%s\", %dx%d sensors
  ",
  		tsdata->name, fw_version, tsdata->num_x, tsdata->num_y);
  
  	input->name = tsdata->name;
  	input->id.bustype = BUS_I2C;
  	input->dev.parent = &client->dev;
  
  	__set_bit(EV_SYN, input->evbit);
  	__set_bit(EV_KEY, input->evbit);
  	__set_bit(EV_ABS, input->evbit);
  	__set_bit(BTN_TOUCH, input->keybit);

  
  	if ( of_property_read_u32(client->dev.of_node, "touchscreen-size-x", &max_x) == 0 ) {
  		input_set_abs_params(input, ABS_X, 0, max_x - 1, 0, 0);
  		input_set_abs_params(input, ABS_MT_POSITION_X,
  				     0, max_x - 1, 0, 0);
  	} else {
  		input_set_abs_params(input, ABS_X, 0, tsdata->num_x * 64 - 1, 0, 0);
  		input_set_abs_params(input, ABS_MT_POSITION_X,
  				     0, tsdata->num_x * 64 - 1, 0, 0);
  	}
  	if ( of_property_read_u32(client->dev.of_node, "touchscreen-size-y", &max_y) == 0 ) {
  		input_set_abs_params(input, ABS_Y, 0, max_y - 1, 0, 0);
  		input_set_abs_params(input, ABS_MT_POSITION_Y,
  				     0, max_y - 1, 0, 0);
  	} else {
  		input_set_abs_params(input, ABS_Y, 0, tsdata->num_y * 64 - 1, 0, 0);
  		input_set_abs_params(input, ABS_MT_POSITION_Y,
  				     0, tsdata->num_y * 64 - 1, 0, 0);
  	}

  	error = input_mt_init_slots(input, MAX_SUPPORT_POINTS, 0);

  	if (error) {
  		dev_err(&client->dev, "Unable to init MT slots.
  ");

  		return error;

  	}
  
  	input_set_drvdata(input, tsdata);
  	i2c_set_clientdata(client, tsdata);

  	error = devm_request_threaded_irq(&client->dev, client->irq, NULL,
  					edt_ft5x06_ts_isr,
  					IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
  					client->name, tsdata);

  	if (error) {
  		dev_err(&client->dev, "Unable to request touchscreen IRQ.
  ");

  		return error;

  	}
  
  	error = sysfs_create_group(&client->dev.kobj, &edt_ft5x06_attr_group);
  	if (error)

  		return error;

  
  	error = input_register_device(input);

  	if (error)
  		goto err_remove_attrs;

  
  	edt_ft5x06_ts_prepare_debugfs(tsdata, dev_driver_string(&client->dev));
  	device_init_wakeup(&client->dev, 1);
  
  	dev_dbg(&client->dev,

  		"EDT FT5x06 initialized: IRQ %d, WAKE pin %d, Reset pin %d.
  ",
  		client->irq, tsdata->wake_pin, tsdata->reset_pin);

  
  	return 0;

  
  err_remove_attrs:
  	sysfs_remove_group(&client->dev.kobj, &edt_ft5x06_attr_group);
  	return error;

  }

  static int edt_ft5x06_ts_remove(struct i2c_client *client)

  {

  	struct edt_ft5x06_ts_data *tsdata = i2c_get_clientdata(client);
  
  	edt_ft5x06_ts_teardown_debugfs(tsdata);
  	sysfs_remove_group(&client->dev.kobj, &edt_ft5x06_attr_group);

  	return 0;
  }
  
  #ifdef CONFIG_PM_SLEEP
  static int edt_ft5x06_ts_suspend(struct device *dev)
  {
  	struct i2c_client *client = to_i2c_client(dev);
  
  	if (device_may_wakeup(dev))
  		enable_irq_wake(client->irq);
  
  	return 0;
  }
  
  static int edt_ft5x06_ts_resume(struct device *dev)
  {
  	struct i2c_client *client = to_i2c_client(dev);
  
  	if (device_may_wakeup(dev))
  		disable_irq_wake(client->irq);
  
  	return 0;
  }
  #endif
  
  static SIMPLE_DEV_PM_OPS(edt_ft5x06_ts_pm_ops,
  			 edt_ft5x06_ts_suspend, edt_ft5x06_ts_resume);
  
  static const struct i2c_device_id edt_ft5x06_ts_id[] = {

  	{ "edt-ft5x06", 0, },
  	{ /* sentinel */ }

  };
  MODULE_DEVICE_TABLE(i2c, edt_ft5x06_ts_id);

  #ifdef CONFIG_OF
  static const struct of_device_id edt_ft5x06_of_match[] = {
  	{ .compatible = "edt,edt-ft5206", },
  	{ .compatible = "edt,edt-ft5306", },
  	{ .compatible = "edt,edt-ft5406", },
  	{ /* sentinel */ }
  };
  MODULE_DEVICE_TABLE(of, edt_ft5x06_of_match);
  #endif

  static struct i2c_driver edt_ft5x06_ts_driver = {
  	.driver = {
  		.owner = THIS_MODULE,
  		.name = "edt_ft5x06",

  		.of_match_table = of_match_ptr(edt_ft5x06_of_match),

  		.pm = &edt_ft5x06_ts_pm_ops,
  	},
  	.id_table = edt_ft5x06_ts_id,
  	.probe    = edt_ft5x06_ts_probe,

  	.remove   = edt_ft5x06_ts_remove,

  };
  
  module_i2c_driver(edt_ft5x06_ts_driver);

  MODULE_ALIAS("i2c:edt-ft5206");
  MODULE_ALIAS("i2c:edt-ft5306");
  MODULE_ALIAS("i2c:edt-ft5406");

  MODULE_AUTHOR("Simon Budig <simon.budig@kernelconcepts.de>");
  MODULE_DESCRIPTION("EDT FT5x06 I2C Touchscreen Driver");
  MODULE_LICENSE("GPL");