/*
   * Stephen Evanchik <evanchsa@gmail.com>
   *
   * This program is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 as published by
   * the Free Software Foundation.
   *
   * Trademarks are the property of their respective owners.
   */

  #include <linux/slab.h>

  #include <linux/delay.h>
  #include <linux/serio.h>
  #include <linux/module.h>

  #include <linux/input.h>
  #include <linux/libps2.h>
  #include <linux/proc_fs.h>
  #include <asm/uaccess.h>
  #include "psmouse.h"
  #include "trackpoint.h"

  /*

   * Power-on Reset: Resets all trackpoint parameters, including RAM values,
   * to defaults.
   * Returns zero on success, non-zero on failure.
   */
  static int trackpoint_power_on_reset(struct ps2dev *ps2dev)
  {
  	unsigned char results[2];
  	int tries = 0;
  
  	/* Issue POR command, and repeat up to once if 0xFC00 received */
  	do {
  		if (ps2_command(ps2dev, NULL, MAKE_PS2_CMD(0, 0, TP_COMMAND)) ||
  		    ps2_command(ps2dev, results, MAKE_PS2_CMD(0, 2, TP_POR)))
  			return -1;
  	} while (results[0] == 0xFC && results[1] == 0x00 && ++tries < 2);
  
  	/* Check for success response -- 0xAA00 */
  	if (results[0] != 0xAA || results[1] != 0x00)
  		return -1;
  
  	return 0;
  }
  
  /*

   * Device IO: read, write and toggle bit
   */

  static int trackpoint_read(struct ps2dev *ps2dev,
  			   unsigned char loc, unsigned char *results)

  {
  	if (ps2_command(ps2dev, NULL, MAKE_PS2_CMD(0, 0, TP_COMMAND)) ||
  	    ps2_command(ps2dev, results, MAKE_PS2_CMD(0, 1, loc))) {
  		return -1;
  	}
  
  	return 0;
  }

  static int trackpoint_write(struct ps2dev *ps2dev,
  			    unsigned char loc, unsigned char val)

  {
  	if (ps2_command(ps2dev, NULL, MAKE_PS2_CMD(0, 0, TP_COMMAND)) ||
  	    ps2_command(ps2dev, NULL, MAKE_PS2_CMD(0, 0, TP_WRITE_MEM)) ||
  	    ps2_command(ps2dev, NULL, MAKE_PS2_CMD(0, 0, loc)) ||
  	    ps2_command(ps2dev, NULL, MAKE_PS2_CMD(0, 0, val))) {
  		return -1;
  	}
  
  	return 0;
  }

  static int trackpoint_toggle_bit(struct ps2dev *ps2dev,
  				 unsigned char loc, unsigned char mask)

  {
  	/* Bad things will happen if the loc param isn't in this range */
  	if (loc < 0x20 || loc >= 0x2F)
  		return -1;
  
  	if (ps2_command(ps2dev, NULL, MAKE_PS2_CMD(0, 0, TP_COMMAND)) ||
  	    ps2_command(ps2dev, NULL, MAKE_PS2_CMD(0, 0, TP_TOGGLE)) ||
  	    ps2_command(ps2dev, NULL, MAKE_PS2_CMD(0, 0, loc)) ||
  	    ps2_command(ps2dev, NULL, MAKE_PS2_CMD(0, 0, mask))) {
  		return -1;
  	}
  
  	return 0;
  }

  static int trackpoint_update_bit(struct ps2dev *ps2dev, unsigned char loc,
  				 unsigned char mask, unsigned char value)
  {
  	int retval = 0;
  	unsigned char data;
  
  	trackpoint_read(ps2dev, loc, &data);
  	if (((data & mask) == mask) != !!value)
  		retval = trackpoint_toggle_bit(ps2dev, loc, mask);
  
  	return retval;
  }

  /*
   * Trackpoint-specific attributes
   */
  struct trackpoint_attr_data {
  	size_t field_offset;
  	unsigned char command;
  	unsigned char mask;

  	unsigned char inverted;

  	unsigned char power_on_default;

  };

  static ssize_t trackpoint_show_int_attr(struct psmouse *psmouse, void *data, char *buf)
  {
  	struct trackpoint_data *tp = psmouse->private;
  	struct trackpoint_attr_data *attr = data;

  	unsigned char value = *(unsigned char *)((char *)tp + attr->field_offset);
  
  	if (attr->inverted)
  		value = !value;

  	return sprintf(buf, "%u
  ", value);

  }

  static ssize_t trackpoint_set_int_attr(struct psmouse *psmouse, void *data,
  					const char *buf, size_t count)
  {
  	struct trackpoint_data *tp = psmouse->private;
  	struct trackpoint_attr_data *attr = data;
  	unsigned char *field = (unsigned char *)((char *)tp + attr->field_offset);

  	unsigned char value;
  	int err;

  	err = kstrtou8(buf, 10, &value);
  	if (err)
  		return err;

  	*field = value;
  	trackpoint_write(&psmouse->ps2dev, attr->command, value);

  	return count;
  }

  #define TRACKPOINT_INT_ATTR(_name, _command, _default)				\

  	static struct trackpoint_attr_data trackpoint_attr_##_name = {		\
  		.field_offset = offsetof(struct trackpoint_data, _name),	\
  		.command = _command,						\

  		.power_on_default = _default,					\

  	};									\
  	PSMOUSE_DEFINE_ATTR(_name, S_IWUSR | S_IRUGO,				\
  			    &trackpoint_attr_##_name,				\
  			    trackpoint_show_int_attr, trackpoint_set_int_attr)
  
  static ssize_t trackpoint_set_bit_attr(struct psmouse *psmouse, void *data,
  					const char *buf, size_t count)
  {
  	struct trackpoint_data *tp = psmouse->private;
  	struct trackpoint_attr_data *attr = data;
  	unsigned char *field = (unsigned char *)((char *)tp + attr->field_offset);

  	unsigned int value;
  	int err;
  
  	err = kstrtouint(buf, 10, &value);
  	if (err)
  		return err;

  	if (value > 1)

  		return -EINVAL;

  	if (attr->inverted)
  		value = !value;

  	if (*field != value) {
  		*field = value;
  		trackpoint_toggle_bit(&psmouse->ps2dev, attr->command, attr->mask);
  	}

  	return count;
  }

  #define TRACKPOINT_BIT_ATTR(_name, _command, _mask, _inv, _default)	\
  static struct trackpoint_attr_data trackpoint_attr_##_name = {		\
  	.field_offset		= offsetof(struct trackpoint_data,	\
  					   _name),			\
  	.command		= _command,				\
  	.mask			= _mask,				\
  	.inverted		= _inv,					\
  	.power_on_default	= _default,				\
  	};								\
  PSMOUSE_DEFINE_ATTR(_name, S_IWUSR | S_IRUGO,				\
  		    &trackpoint_attr_##_name,				\
  		    trackpoint_show_int_attr, trackpoint_set_bit_attr)
  
  #define TRACKPOINT_UPDATE_BIT(_psmouse, _tp, _name)			\
  do {									\
  	struct trackpoint_attr_data *_attr = &trackpoint_attr_##_name;	\
  									\
  	trackpoint_update_bit(&_psmouse->ps2dev,			\
  			_attr->command, _attr->mask, _tp->_name);	\
  } while (0)
  
  #define TRACKPOINT_UPDATE(_power_on, _psmouse, _tp, _name)		\
  do {									\
  	if (!_power_on ||						\
  	    _tp->_name != trackpoint_attr_##_name.power_on_default) {	\
  		if (!trackpoint_attr_##_name.mask)			\
  			trackpoint_write(&_psmouse->ps2dev,		\
  				 trackpoint_attr_##_name.command,	\
  				 _tp->_name);				\
  		else							\
  			TRACKPOINT_UPDATE_BIT(_psmouse, _tp, _name);	\
  	}								\
  } while (0)
  
  #define TRACKPOINT_SET_POWER_ON_DEFAULT(_tp, _name)				\
  	(_tp->_name = trackpoint_attr_##_name.power_on_default)
  
  TRACKPOINT_INT_ATTR(sensitivity, TP_SENS, TP_DEF_SENS);
  TRACKPOINT_INT_ATTR(speed, TP_SPEED, TP_DEF_SPEED);
  TRACKPOINT_INT_ATTR(inertia, TP_INERTIA, TP_DEF_INERTIA);
  TRACKPOINT_INT_ATTR(reach, TP_REACH, TP_DEF_REACH);
  TRACKPOINT_INT_ATTR(draghys, TP_DRAGHYS, TP_DEF_DRAGHYS);
  TRACKPOINT_INT_ATTR(mindrag, TP_MINDRAG, TP_DEF_MINDRAG);
  TRACKPOINT_INT_ATTR(thresh, TP_THRESH, TP_DEF_THRESH);
  TRACKPOINT_INT_ATTR(upthresh, TP_UP_THRESH, TP_DEF_UP_THRESH);
  TRACKPOINT_INT_ATTR(ztime, TP_Z_TIME, TP_DEF_Z_TIME);
  TRACKPOINT_INT_ATTR(jenks, TP_JENKS_CURV, TP_DEF_JENKS_CURV);

  TRACKPOINT_INT_ATTR(drift_time, TP_DRIFT_TIME, TP_DEF_DRIFT_TIME);

  
  TRACKPOINT_BIT_ATTR(press_to_select, TP_TOGGLE_PTSON, TP_MASK_PTSON, 0,
  		    TP_DEF_PTSON);
  TRACKPOINT_BIT_ATTR(skipback, TP_TOGGLE_SKIPBACK, TP_MASK_SKIPBACK, 0,
  		    TP_DEF_SKIPBACK);
  TRACKPOINT_BIT_ATTR(ext_dev, TP_TOGGLE_EXT_DEV, TP_MASK_EXT_DEV, 1,
  		    TP_DEF_EXT_DEV);

  
  static struct attribute *trackpoint_attrs[] = {

  	&psmouse_attr_sensitivity.dattr.attr,
  	&psmouse_attr_speed.dattr.attr,
  	&psmouse_attr_inertia.dattr.attr,
  	&psmouse_attr_reach.dattr.attr,
  	&psmouse_attr_draghys.dattr.attr,
  	&psmouse_attr_mindrag.dattr.attr,
  	&psmouse_attr_thresh.dattr.attr,
  	&psmouse_attr_upthresh.dattr.attr,
  	&psmouse_attr_ztime.dattr.attr,
  	&psmouse_attr_jenks.dattr.attr,

  	&psmouse_attr_drift_time.dattr.attr,

  	&psmouse_attr_press_to_select.dattr.attr,
  	&psmouse_attr_skipback.dattr.attr,
  	&psmouse_attr_ext_dev.dattr.attr,

  	NULL
  };
  
  static struct attribute_group trackpoint_attr_group = {
  	.attrs = trackpoint_attrs,
  };

  static int trackpoint_start_protocol(struct psmouse *psmouse, unsigned char *firmware_id)

  {

  	unsigned char param[2] = { 0 };

  	if (ps2_command(&psmouse->ps2dev, param, MAKE_PS2_CMD(0, 2, TP_READ_ID)))
  		return -1;
  
  	if (param[0] != TP_MAGIC_IDENT)
  		return -1;
  
  	if (firmware_id)
  		*firmware_id = param[1];
  
  	return 0;

  }

  /*
   * Write parameters to trackpad.
   * in_power_on_state: Set to true if TP is in default / power-on state (ex. if
   *		      power-on reset was run). If so, values will only be
   *		      written to TP if they differ from power-on default.
   */
  static int trackpoint_sync(struct psmouse *psmouse, bool in_power_on_state)

  {

  	struct trackpoint_data *tp = psmouse->private;

  	if (!in_power_on_state) {
  		/*
  		 * Disable features that may make device unusable
  		 * with this driver.
  		 */
  		trackpoint_update_bit(&psmouse->ps2dev, TP_TOGGLE_TWOHAND,
  				      TP_MASK_TWOHAND, TP_DEF_TWOHAND);

  		trackpoint_update_bit(&psmouse->ps2dev, TP_TOGGLE_SOURCE_TAG,
  				      TP_MASK_SOURCE_TAG, TP_DEF_SOURCE_TAG);

  		trackpoint_update_bit(&psmouse->ps2dev, TP_TOGGLE_MB,
  				      TP_MASK_MB, TP_DEF_MB);
  	}

  	/*
  	 * These properties can be changed in this driver. Only
  	 * configure them if the values are non-default or if the TP is in
  	 * an unknown state.
  	 */
  	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, sensitivity);
  	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, inertia);
  	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, speed);
  	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, reach);
  	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, draghys);
  	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, mindrag);
  	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, thresh);
  	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, upthresh);
  	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, ztime);
  	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, jenks);

  	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, drift_time);

  
  	/* toggles */
  	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, press_to_select);
  	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, skipback);
  	TRACKPOINT_UPDATE(in_power_on_state, psmouse, tp, ext_dev);

  
  	return 0;
  }
  
  static void trackpoint_defaults(struct trackpoint_data *tp)
  {

  	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, sensitivity);
  	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, speed);
  	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, reach);
  	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, draghys);
  	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, mindrag);
  	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, thresh);
  	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, upthresh);
  	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, ztime);
  	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, jenks);

  	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, drift_time);

  	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, inertia);
  
  	/* toggles */
  	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, press_to_select);
  	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, skipback);
  	TRACKPOINT_SET_POWER_ON_DEFAULT(tp, ext_dev);

  }

  static void trackpoint_disconnect(struct psmouse *psmouse)
  {
  	sysfs_remove_group(&psmouse->ps2dev.serio->dev.kobj, &trackpoint_attr_group);
  
  	kfree(psmouse->private);
  	psmouse->private = NULL;
  }
  
  static int trackpoint_reconnect(struct psmouse *psmouse)
  {

  	int reset_fail;

  	if (trackpoint_start_protocol(psmouse, NULL))
  		return -1;

  	reset_fail = trackpoint_power_on_reset(&psmouse->ps2dev);
  	if (trackpoint_sync(psmouse, !reset_fail))

  		return -1;
  
  	return 0;
  }

  int trackpoint_detect(struct psmouse *psmouse, bool set_properties)

  {

  	struct ps2dev *ps2dev = &psmouse->ps2dev;
  	unsigned char firmware_id;
  	unsigned char button_info;

  	int error;

  	if (trackpoint_start_protocol(psmouse, &firmware_id))

  		return -1;
  
  	if (!set_properties)
  		return 0;

  	if (trackpoint_read(&psmouse->ps2dev, TP_EXT_BTN, &button_info)) {

  		psmouse_warn(psmouse, "failed to get extended button data
  ");

  		button_info = 0;
  	}

  	psmouse->private = kzalloc(sizeof(struct trackpoint_data), GFP_KERNEL);
  	if (!psmouse->private)

  		return -ENOMEM;

  
  	psmouse->vendor = "IBM";
  	psmouse->name = "TrackPoint";

  	psmouse->reconnect = trackpoint_reconnect;

  	psmouse->disconnect = trackpoint_disconnect;

  	if ((button_info & 0x0f) >= 3)
  		__set_bit(BTN_MIDDLE, psmouse->dev->keybit);

  	__set_bit(INPUT_PROP_POINTER, psmouse->dev->propbit);

  	__set_bit(INPUT_PROP_POINTING_STICK, psmouse->dev->propbit);

  	trackpoint_defaults(psmouse->private);

  
  	error = trackpoint_power_on_reset(&psmouse->ps2dev);
  
  	/* Write defaults to TP only if reset fails. */
  	if (error)
  		trackpoint_sync(psmouse, false);

  	error = sysfs_create_group(&ps2dev->serio->dev.kobj, &trackpoint_attr_group);
  	if (error) {

  		psmouse_err(psmouse,
  			    "failed to create sysfs attributes, error: %d
  ",
  			    error);

  		kfree(psmouse->private);
  		psmouse->private = NULL;

  		return -1;
  	}

  	psmouse_info(psmouse,
  		     "IBM TrackPoint firmware: 0x%02x, buttons: %d/%d
  ",
  		     firmware_id,
  		     (button_info & 0xf0) >> 4, button_info & 0x0f);

  
  	return 0;
  }