/*
   * HID driver for Nintendo Wiimote extension devices
   * Copyright (c) 2011 David Herrmann
   */
  
  /*
   * 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/atomic.h>
  #include <linux/module.h>
  #include <linux/spinlock.h>
  #include <linux/workqueue.h>
  #include "hid-wiimote.h"
  
  struct wiimote_ext {
  	struct wiimote_data *wdata;
  	struct work_struct worker;

  	struct input_dev *input;
  	struct input_dev *mp_input;

  
  	atomic_t opened;
  	atomic_t mp_opened;
  	bool plugged;

  	bool mp_plugged;

  	bool motionp;
  	__u8 ext_type;

  	__u16 calib[4][3];

  };
  
  enum wiiext_type {
  	WIIEXT_NONE,		/* placeholder */
  	WIIEXT_CLASSIC,		/* Nintendo classic controller */
  	WIIEXT_NUNCHUCK,	/* Nintendo nunchuck controller */

  	WIIEXT_BALANCE_BOARD,	/* Nintendo balance board controller */

  };

  enum wiiext_keys {
  	WIIEXT_KEY_C,
  	WIIEXT_KEY_Z,

  	WIIEXT_KEY_A,
  	WIIEXT_KEY_B,
  	WIIEXT_KEY_X,
  	WIIEXT_KEY_Y,
  	WIIEXT_KEY_ZL,
  	WIIEXT_KEY_ZR,
  	WIIEXT_KEY_PLUS,
  	WIIEXT_KEY_MINUS,
  	WIIEXT_KEY_HOME,
  	WIIEXT_KEY_LEFT,
  	WIIEXT_KEY_RIGHT,
  	WIIEXT_KEY_UP,
  	WIIEXT_KEY_DOWN,
  	WIIEXT_KEY_LT,
  	WIIEXT_KEY_RT,

  	WIIEXT_KEY_COUNT
  };
  
  static __u16 wiiext_keymap[] = {
  	BTN_C,		/* WIIEXT_KEY_C */
  	BTN_Z,		/* WIIEXT_KEY_Z */

  	BTN_A,		/* WIIEXT_KEY_A */
  	BTN_B,		/* WIIEXT_KEY_B */
  	BTN_X,		/* WIIEXT_KEY_X */
  	BTN_Y,		/* WIIEXT_KEY_Y */
  	BTN_TL2,	/* WIIEXT_KEY_ZL */
  	BTN_TR2,	/* WIIEXT_KEY_ZR */
  	KEY_NEXT,	/* WIIEXT_KEY_PLUS */
  	KEY_PREVIOUS,	/* WIIEXT_KEY_MINUS */
  	BTN_MODE,	/* WIIEXT_KEY_HOME */
  	KEY_LEFT,	/* WIIEXT_KEY_LEFT */
  	KEY_RIGHT,	/* WIIEXT_KEY_RIGHT */
  	KEY_UP,		/* WIIEXT_KEY_UP */
  	KEY_DOWN,	/* WIIEXT_KEY_DOWN */
  	BTN_TL,		/* WIIEXT_KEY_LT */
  	BTN_TR,		/* WIIEXT_KEY_RT */

  };

  /* disable all extensions */

  static void ext_disable(struct wiimote_ext *ext)
  {
  	unsigned long flags;

  	__u8 wmem = 0x55;
  
  	if (!wiimote_cmd_acquire(ext->wdata)) {
  		wiimote_cmd_write(ext->wdata, 0xa400f0, &wmem, sizeof(wmem));
  		wiimote_cmd_release(ext->wdata);
  	}

  
  	spin_lock_irqsave(&ext->wdata->state.lock, flags);
  	ext->motionp = false;
  	ext->ext_type = WIIEXT_NONE;

  	wiiproto_req_drm(ext->wdata, WIIPROTO_REQ_NULL);

  	spin_unlock_irqrestore(&ext->wdata->state.lock, flags);
  }
  
  static bool motionp_read(struct wiimote_ext *ext)
  {

  	__u8 rmem[2], wmem;
  	ssize_t ret;
  	bool avail = false;

  	if (!atomic_read(&ext->mp_opened))
  		return false;

  	if (wiimote_cmd_acquire(ext->wdata))
  		return false;
  
  	/* initialize motion plus */
  	wmem = 0x55;
  	ret = wiimote_cmd_write(ext->wdata, 0xa600f0, &wmem, sizeof(wmem));
  	if (ret)
  		goto error;
  
  	/* read motion plus ID */
  	ret = wiimote_cmd_read(ext->wdata, 0xa600fe, rmem, 2);
  	if (ret == 2 || rmem[1] == 0x5)
  		avail = true;
  
  error:
  	wiimote_cmd_release(ext->wdata);
  	return avail;

  }
  
  static __u8 ext_read(struct wiimote_ext *ext)
  {

  	ssize_t ret;

  	__u8 buf[24], i, j, offs = 0;

  	__u8 rmem[2], wmem;
  	__u8 type = WIIEXT_NONE;

  	if (!ext->plugged || !atomic_read(&ext->opened))

  		return WIIEXT_NONE;
  
  	if (wiimote_cmd_acquire(ext->wdata))
  		return WIIEXT_NONE;
  
  	/* initialize extension */
  	wmem = 0x55;
  	ret = wiimote_cmd_write(ext->wdata, 0xa400f0, &wmem, sizeof(wmem));
  	if (!ret) {
  		/* disable encryption */
  		wmem = 0x0;
  		wiimote_cmd_write(ext->wdata, 0xa400fb, &wmem, sizeof(wmem));
  	}
  
  	/* read extension ID */
  	ret = wiimote_cmd_read(ext->wdata, 0xa400fe, rmem, 2);
  	if (ret == 2) {
  		if (rmem[0] == 0 && rmem[1] == 0)
  			type = WIIEXT_NUNCHUCK;
  		else if (rmem[0] == 0x01 && rmem[1] == 0x01)
  			type = WIIEXT_CLASSIC;

  		else if (rmem[0] == 0x04 && rmem[1] == 0x02)
  			type = WIIEXT_BALANCE_BOARD;

  	}

  	/* get balance board calibration data */
  	if (type == WIIEXT_BALANCE_BOARD) {
  		ret = wiimote_cmd_read(ext->wdata, 0xa40024, buf, 12);
  		ret += wiimote_cmd_read(ext->wdata, 0xa40024 + 12,
  					buf + 12, 12);
  
  		if (ret != 24) {
  			type = WIIEXT_NONE;
  		} else {
  			for (i = 0; i < 3; i++) {
  				for (j = 0; j < 4; j++) {
  					ext->calib[j][i] = buf[offs];
  					ext->calib[j][i] <<= 8;
  					ext->calib[j][i] |= buf[offs + 1];
  					offs += 2;
  				}
  			}
  		}
  	}

  	wiimote_cmd_release(ext->wdata);
  
  	return type;

  }
  
  static void ext_enable(struct wiimote_ext *ext, bool motionp, __u8 ext_type)
  {
  	unsigned long flags;

  	__u8 wmem;
  	int ret;
  
  	if (motionp) {
  		if (wiimote_cmd_acquire(ext->wdata))
  			return;
  
  		if (ext_type == WIIEXT_CLASSIC)
  			wmem = 0x07;
  		else if (ext_type == WIIEXT_NUNCHUCK)
  			wmem = 0x05;
  		else
  			wmem = 0x04;
  
  		ret = wiimote_cmd_write(ext->wdata, 0xa600fe, &wmem, sizeof(wmem));
  		wiimote_cmd_release(ext->wdata);
  		if (ret)
  			return;
  	}

  
  	spin_lock_irqsave(&ext->wdata->state.lock, flags);
  	ext->motionp = motionp;
  	ext->ext_type = ext_type;

  	wiiproto_req_drm(ext->wdata, WIIPROTO_REQ_NULL);

  	spin_unlock_irqrestore(&ext->wdata->state.lock, flags);
  }

  static void wiiext_worker(struct work_struct *work)
  {
  	struct wiimote_ext *ext = container_of(work, struct wiimote_ext,
  									worker);

  	bool motionp;
  	__u8 ext_type;
  
  	ext_disable(ext);
  	motionp = motionp_read(ext);
  	ext_type = ext_read(ext);
  	ext_enable(ext, motionp, ext_type);

  }
  
  /* schedule work only once, otherwise mark for reschedule */
  static void wiiext_schedule(struct wiimote_ext *ext)
  {

  	schedule_work(&ext->worker);

  }
  
  /*
   * Reacts on extension port events
   * Whenever the driver gets an event from the wiimote that an extension has been
   * plugged or unplugged, this funtion shall be called. It checks what extensions
   * are connected and initializes and activates them.
   * This can be called in atomic context. The initialization is done in a
   * separate worker thread. The state.lock spinlock must be held by the caller.
   */
  void wiiext_event(struct wiimote_data *wdata, bool plugged)
  {
  	if (!wdata->ext)
  		return;
  
  	if (wdata->ext->plugged == plugged)
  		return;
  
  	wdata->ext->plugged = plugged;

  
  	if (!plugged)
  		wdata->ext->mp_plugged = false;

  	/*
  	 * We need to call wiiext_schedule(wdata->ext) here, however, the
  	 * extension initialization logic is not fully understood and so
  	 * automatic initialization is not supported, yet.
  	 */
  }
  
  /*
   * Returns true if the current DRM mode should contain extension data and false
   * if there is no interest in extension data.
   * All supported extensions send 6 byte extension data so any DRM that contains
   * extension bytes is fine.
   * The caller must hold the state.lock spinlock.
   */
  bool wiiext_active(struct wiimote_data *wdata)
  {
  	if (!wdata->ext)
  		return false;
  
  	return wdata->ext->motionp || wdata->ext->ext_type;
  }

  static void handler_motionp(struct wiimote_ext *ext, const __u8 *payload)
  {

  	__s32 x, y, z;
  	bool plugged;
  
  	/*        |   8    7    6    5    4    3 |  2  |  1  |
  	 *   -----+------------------------------+-----+-----+
  	 *    1   |               Yaw Speed <7:0>            |
  	 *    2   |              Roll Speed <7:0>            |
  	 *    3   |             Pitch Speed <7:0>            |
  	 *   -----+------------------------------+-----+-----+
  	 *    4   |       Yaw Speed <13:8>       | Yaw |Pitch|
  	 *   -----+------------------------------+-----+-----+
  	 *    5   |      Roll Speed <13:8>       |Roll | Ext |
  	 *   -----+------------------------------+-----+-----+
  	 *    6   |     Pitch Speed <13:8>       |  1  |  0  |
  	 *   -----+------------------------------+-----+-----+
  	 * The single bits Yaw, Roll, Pitch in the lower right corner specify
  	 * whether the wiimote is rotating fast (0) or slow (1). Speed for slow
  	 * roation is 440 deg/s and for fast rotation 2000 deg/s. To get a
  	 * linear scale we multiply by 2000/440 = ~4.5454 which is 18 for fast
  	 * and 9 for slow.
  	 * If the wiimote is not rotating the sensor reports 2^13 = 8192.
  	 * Ext specifies whether an extension is connected to the motionp.
  	 */
  
  	x = payload[0];
  	y = payload[1];
  	z = payload[2];
  
  	x |= (((__u16)payload[3]) << 6) & 0xff00;
  	y |= (((__u16)payload[4]) << 6) & 0xff00;
  	z |= (((__u16)payload[5]) << 6) & 0xff00;
  
  	x -= 8192;
  	y -= 8192;
  	z -= 8192;
  
  	if (!(payload[3] & 0x02))
  		x *= 18;
  	else
  		x *= 9;
  	if (!(payload[4] & 0x02))
  		y *= 18;
  	else
  		y *= 9;
  	if (!(payload[3] & 0x01))
  		z *= 18;
  	else
  		z *= 9;
  
  	input_report_abs(ext->mp_input, ABS_RX, x);
  	input_report_abs(ext->mp_input, ABS_RY, y);
  	input_report_abs(ext->mp_input, ABS_RZ, z);
  	input_sync(ext->mp_input);
  
  	plugged = payload[5] & 0x01;
  	if (plugged != ext->mp_plugged)
  		ext->mp_plugged = plugged;

  }
  
  static void handler_nunchuck(struct wiimote_ext *ext, const __u8 *payload)
  {

  	__s16 x, y, z, bx, by;
  
  	/*   Byte |   8    7 |  6    5 |  4    3 |  2 |  1  |
  	 *   -----+----------+---------+---------+----+-----+
  	 *    1   |              Button X <7:0>             |
  	 *    2   |              Button Y <7:0>             |
  	 *   -----+----------+---------+---------+----+-----+
  	 *    3   |               Speed X <9:2>             |
  	 *    4   |               Speed Y <9:2>             |
  	 *    5   |               Speed Z <9:2>             |
  	 *   -----+----------+---------+---------+----+-----+
  	 *    6   | Z <1:0>  | Y <1:0> | X <1:0> | BC | BZ  |
  	 *   -----+----------+---------+---------+----+-----+
  	 * Button X/Y is the analog stick. Speed X, Y and Z are the
  	 * accelerometer data in the same format as the wiimote's accelerometer.
  	 * The 6th byte contains the LSBs of the accelerometer data.
  	 * BC and BZ are the C and Z buttons: 0 means pressed
  	 *
  	 * If reported interleaved with motionp, then the layout changes. The
  	 * 5th and 6th byte changes to:
  	 *   -----+-----------------------------------+-----+
  	 *    5   |            Speed Z <9:3>          | EXT |
  	 *   -----+--------+-----+-----+----+----+----+-----+
  	 *    6   |Z <2:1> |Y <1>|X <1>| BC | BZ | 0  |  0  |
  	 *   -----+--------+-----+-----+----+----+----+-----+
  	 * All three accelerometer values lose their LSB. The other data is
  	 * still available but slightly moved.
  	 *
  	 * Center data for button values is 128. Center value for accelerometer
  	 * values it 512 / 0x200
  	 */
  
  	bx = payload[0];
  	by = payload[1];
  	bx -= 128;
  	by -= 128;
  
  	x = payload[2] << 2;
  	y = payload[3] << 2;
  	z = payload[4] << 2;
  
  	if (ext->motionp) {
  		x |= (payload[5] >> 3) & 0x02;
  		y |= (payload[5] >> 4) & 0x02;
  		z &= ~0x4;
  		z |= (payload[5] >> 5) & 0x06;
  	} else {
  		x |= (payload[5] >> 2) & 0x03;
  		y |= (payload[5] >> 4) & 0x03;
  		z |= (payload[5] >> 6) & 0x03;
  	}
  
  	x -= 0x200;
  	y -= 0x200;
  	z -= 0x200;
  
  	input_report_abs(ext->input, ABS_HAT0X, bx);
  	input_report_abs(ext->input, ABS_HAT0Y, by);
  
  	input_report_abs(ext->input, ABS_RX, x);
  	input_report_abs(ext->input, ABS_RY, y);
  	input_report_abs(ext->input, ABS_RZ, z);
  
  	if (ext->motionp) {
  		input_report_key(ext->input,

  			wiiext_keymap[WIIEXT_KEY_Z], !(payload[5] & 0x04));

  		input_report_key(ext->input,

  			wiiext_keymap[WIIEXT_KEY_C], !(payload[5] & 0x08));

  	} else {
  		input_report_key(ext->input,

  			wiiext_keymap[WIIEXT_KEY_Z], !(payload[5] & 0x01));

  		input_report_key(ext->input,

  			wiiext_keymap[WIIEXT_KEY_C], !(payload[5] & 0x02));

  	}
  
  	input_sync(ext->input);

  }
  
  static void handler_classic(struct wiimote_ext *ext, const __u8 *payload)
  {

  	__s8 rx, ry, lx, ly, lt, rt;
  
  	/*   Byte |  8  |  7  |  6  |  5  |  4  |  3  |  2  |  1  |
  	 *   -----+-----+-----+-----+-----+-----+-----+-----+-----+
  	 *    1   | RX <5:4>  |              LX <5:0>             |
  	 *    2   | RX <3:2>  |              LY <5:0>             |
  	 *   -----+-----+-----+-----+-----------------------------+
  	 *    3   |RX<1>| LT <5:4>  |         RY <5:1>            |
  	 *   -----+-----+-----------+-----------------------------+
  	 *    4   |     LT <3:1>    |         RT <5:1>            |
  	 *   -----+-----+-----+-----+-----+-----+-----+-----+-----+
  	 *    5   | BDR | BDD | BLT | B-  | BH  | B+  | BRT |  1  |
  	 *   -----+-----+-----+-----+-----+-----+-----+-----+-----+
  	 *    6   | BZL | BB  | BY  | BA  | BX  | BZR | BDL | BDU |
  	 *   -----+-----+-----+-----+-----+-----+-----+-----+-----+
  	 * All buttons are 0 if pressed
  	 * RX and RY are right analog stick
  	 * LX and LY are left analog stick
  	 * LT is left trigger, RT is right trigger
  	 * BLT is 0 if left trigger is fully pressed
  	 * BRT is 0 if right trigger is fully pressed
  	 * BDR, BDD, BDL, BDU form the D-Pad with right, down, left, up buttons
  	 * BZL is left Z button and BZR is right Z button
  	 * B-, BH, B+ are +, HOME and - buttons
  	 * BB, BY, BA, BX are A, B, X, Y buttons
  	 * LSB of RX, RY, LT, and RT are not transmitted and always 0.
  	 *
  	 * With motionp enabled it changes slightly to this:
  	 *   Byte |  8  |  7  |  6  |  5  |  4  |  3  |  2  |  1  |
  	 *   -----+-----+-----+-----+-----+-----+-----+-----+-----+
  	 *    1   | RX <4:3>  |          LX <5:1>           | BDU |
  	 *    2   | RX <2:1>  |          LY <5:1>           | BDL |
  	 *   -----+-----+-----+-----+-----------------------+-----+
  	 *    3   |RX<0>| LT <4:3>  |         RY <4:0>            |
  	 *   -----+-----+-----------+-----------------------------+
  	 *    4   |     LT <2:0>    |         RT <4:0>            |
  	 *   -----+-----+-----+-----+-----+-----+-----+-----+-----+
  	 *    5   | BDR | BDD | BLT | B-  | BH  | B+  | BRT | EXT |
  	 *   -----+-----+-----+-----+-----+-----+-----+-----+-----+
  	 *    6   | BZL | BB  | BY  | BA  | BX  | BZR |  0  |  0  |
  	 *   -----+-----+-----+-----+-----+-----+-----+-----+-----+
  	 * Only the LSBs of LX and LY are lost. BDU and BDL are moved, the rest
  	 * is the same as before.
  	 */
  
  	if (ext->motionp) {
  		lx = payload[0] & 0x3e;
  		ly = payload[0] & 0x3e;
  	} else {
  		lx = payload[0] & 0x3f;
  		ly = payload[0] & 0x3f;
  	}
  
  	rx = (payload[0] >> 3) & 0x14;
  	rx |= (payload[1] >> 5) & 0x06;
  	rx |= (payload[2] >> 7) & 0x01;
  	ry = payload[2] & 0x1f;
  
  	rt = payload[3] & 0x1f;
  	lt = (payload[2] >> 2) & 0x18;
  	lt |= (payload[3] >> 5) & 0x07;
  
  	rx <<= 1;
  	ry <<= 1;
  	rt <<= 1;
  	lt <<= 1;
  
  	input_report_abs(ext->input, ABS_HAT1X, lx - 0x20);
  	input_report_abs(ext->input, ABS_HAT1Y, ly - 0x20);
  	input_report_abs(ext->input, ABS_HAT2X, rx - 0x20);
  	input_report_abs(ext->input, ABS_HAT2Y, ry - 0x20);
  	input_report_abs(ext->input, ABS_HAT3X, rt - 0x20);
  	input_report_abs(ext->input, ABS_HAT3Y, lt - 0x20);
  
  	input_report_key(ext->input, wiiext_keymap[WIIEXT_KEY_RIGHT],
  							!!(payload[4] & 0x80));
  	input_report_key(ext->input, wiiext_keymap[WIIEXT_KEY_DOWN],
  							!!(payload[4] & 0x40));
  	input_report_key(ext->input, wiiext_keymap[WIIEXT_KEY_LT],
  							!!(payload[4] & 0x20));
  	input_report_key(ext->input, wiiext_keymap[WIIEXT_KEY_MINUS],
  							!!(payload[4] & 0x10));
  	input_report_key(ext->input, wiiext_keymap[WIIEXT_KEY_HOME],
  							!!(payload[4] & 0x08));
  	input_report_key(ext->input, wiiext_keymap[WIIEXT_KEY_PLUS],
  							!!(payload[4] & 0x04));
  	input_report_key(ext->input, wiiext_keymap[WIIEXT_KEY_RT],
  							!!(payload[4] & 0x02));
  	input_report_key(ext->input, wiiext_keymap[WIIEXT_KEY_ZL],
  							!!(payload[5] & 0x80));
  	input_report_key(ext->input, wiiext_keymap[WIIEXT_KEY_B],
  							!!(payload[5] & 0x40));
  	input_report_key(ext->input, wiiext_keymap[WIIEXT_KEY_Y],
  							!!(payload[5] & 0x20));
  	input_report_key(ext->input, wiiext_keymap[WIIEXT_KEY_A],
  							!!(payload[5] & 0x10));
  	input_report_key(ext->input, wiiext_keymap[WIIEXT_KEY_X],
  							!!(payload[5] & 0x08));
  	input_report_key(ext->input, wiiext_keymap[WIIEXT_KEY_ZR],
  							!!(payload[5] & 0x04));
  
  	if (ext->motionp) {
  		input_report_key(ext->input, wiiext_keymap[WIIEXT_KEY_UP],
  							!!(payload[0] & 0x01));
  		input_report_key(ext->input, wiiext_keymap[WIIEXT_KEY_LEFT],
  							!!(payload[1] & 0x01));
  	} else {
  		input_report_key(ext->input, wiiext_keymap[WIIEXT_KEY_UP],
  							!!(payload[5] & 0x01));
  		input_report_key(ext->input, wiiext_keymap[WIIEXT_KEY_LEFT],
  							!!(payload[5] & 0x02));
  	}
  
  	input_sync(ext->input);

  }

  static void handler_balance_board(struct wiimote_ext *ext, const __u8 *payload)
  {

  	__s32 val[4], tmp;
  	unsigned int i;

  
  	/*   Byte |  8  7  6  5  4  3  2  1  |
  	 *   -----+--------------------------+
  	 *    1   |    Top Right <15:8>      |
  	 *    2   |    Top Right  <7:0>      |
  	 *   -----+--------------------------+
  	 *    3   | Bottom Right <15:8>      |
  	 *    4   | Bottom Right  <7:0>      |
  	 *   -----+--------------------------+
  	 *    5   |     Top Left <15:8>      |
  	 *    6   |     Top Left  <7:0>      |
  	 *   -----+--------------------------+
  	 *    7   |  Bottom Left <15:8>      |
  	 *    8   |  Bottom Left  <7:0>      |
  	 *   -----+--------------------------+
  	 *
  	 * These values represent the weight-measurements of the Wii-balance
  	 * board with 16bit precision.
  	 *
  	 * The balance-board is never reported interleaved with motionp.
  	 */
  
  	val[0] = payload[0];
  	val[0] <<= 8;
  	val[0] |= payload[1];
  
  	val[1] = payload[2];
  	val[1] <<= 8;
  	val[1] |= payload[3];
  
  	val[2] = payload[4];
  	val[2] <<= 8;
  	val[2] |= payload[5];
  
  	val[3] = payload[6];
  	val[3] <<= 8;
  	val[3] |= payload[7];

  	/* apply calibration data */
  	for (i = 0; i < 4; i++) {
  		if (val[i] < ext->calib[i][1]) {
  			tmp = val[i] - ext->calib[i][0];
  			tmp *= 1700;
  			tmp /= ext->calib[i][1] - ext->calib[i][0];
  		} else {
  			tmp = val[i] - ext->calib[i][1];
  			tmp *= 1700;

  			tmp /= ext->calib[i][2] - ext->calib[i][1];
  			tmp += 1700;

  		}
  		val[i] = tmp;
  	}

  	input_report_abs(ext->input, ABS_HAT0X, val[0]);
  	input_report_abs(ext->input, ABS_HAT0Y, val[1]);
  	input_report_abs(ext->input, ABS_HAT1X, val[2]);
  	input_report_abs(ext->input, ABS_HAT1Y, val[3]);
  
  	input_sync(ext->input);
  }

  /* call this with state.lock spinlock held */
  void wiiext_handle(struct wiimote_data *wdata, const __u8 *payload)
  {
  	struct wiimote_ext *ext = wdata->ext;
  
  	if (!ext)
  		return;
  
  	if (ext->motionp && (payload[5] & 0x02)) {
  		handler_motionp(ext, payload);
  	} else if (ext->ext_type == WIIEXT_NUNCHUCK) {
  		handler_nunchuck(ext, payload);
  	} else if (ext->ext_type == WIIEXT_CLASSIC) {
  		handler_classic(ext, payload);

  	} else if (ext->ext_type == WIIEXT_BALANCE_BOARD) {
  		handler_balance_board(ext, payload);

  	}
  }

  static ssize_t wiiext_show(struct device *dev, struct device_attribute *attr,
  								char *buf)
  {
  	struct wiimote_data *wdata = dev_to_wii(dev);
  	__u8 type = WIIEXT_NONE;
  	bool motionp = false;
  	unsigned long flags;
  
  	spin_lock_irqsave(&wdata->state.lock, flags);
  	if (wdata->ext) {
  		motionp = wdata->ext->motionp;
  		type = wdata->ext->ext_type;
  	}
  	spin_unlock_irqrestore(&wdata->state.lock, flags);
  
  	if (type == WIIEXT_NUNCHUCK) {
  		if (motionp)
  			return sprintf(buf, "motionp+nunchuck
  ");
  		else
  			return sprintf(buf, "nunchuck
  ");
  	} else if (type == WIIEXT_CLASSIC) {
  		if (motionp)
  			return sprintf(buf, "motionp+classic
  ");
  		else
  			return sprintf(buf, "classic
  ");

  	} else if (type == WIIEXT_BALANCE_BOARD) {
  		if (motionp)
  			return sprintf(buf, "motionp+balanceboard
  ");
  		else
  			return sprintf(buf, "balanceboard
  ");

  	} else {
  		if (motionp)
  			return sprintf(buf, "motionp
  ");
  		else
  			return sprintf(buf, "none
  ");
  	}
  }
  
  static DEVICE_ATTR(extension, S_IRUGO, wiiext_show, NULL);

  static int wiiext_input_open(struct input_dev *dev)
  {
  	struct wiimote_ext *ext = input_get_drvdata(dev);
  	int ret;
  
  	ret = hid_hw_open(ext->wdata->hdev);
  	if (ret)
  		return ret;
  
  	atomic_inc(&ext->opened);
  	wiiext_schedule(ext);
  
  	return 0;
  }
  
  static void wiiext_input_close(struct input_dev *dev)
  {
  	struct wiimote_ext *ext = input_get_drvdata(dev);
  
  	atomic_dec(&ext->opened);
  	wiiext_schedule(ext);
  	hid_hw_close(ext->wdata->hdev);
  }
  
  static int wiiext_mp_open(struct input_dev *dev)
  {
  	struct wiimote_ext *ext = input_get_drvdata(dev);
  	int ret;
  
  	ret = hid_hw_open(ext->wdata->hdev);
  	if (ret)
  		return ret;
  
  	atomic_inc(&ext->mp_opened);
  	wiiext_schedule(ext);
  
  	return 0;
  }
  
  static void wiiext_mp_close(struct input_dev *dev)
  {
  	struct wiimote_ext *ext = input_get_drvdata(dev);
  
  	atomic_dec(&ext->mp_opened);
  	wiiext_schedule(ext);
  	hid_hw_close(ext->wdata->hdev);
  }

  /* Initializes the extension driver of a wiimote */
  int wiiext_init(struct wiimote_data *wdata)
  {
  	struct wiimote_ext *ext;
  	unsigned long flags;

  	int ret, i;

  
  	ext = kzalloc(sizeof(*ext), GFP_KERNEL);
  	if (!ext)
  		return -ENOMEM;
  
  	ext->wdata = wdata;
  	INIT_WORK(&ext->worker, wiiext_worker);

  	ext->input = input_allocate_device();
  	if (!ext->input) {
  		ret = -ENOMEM;
  		goto err_input;
  	}
  
  	input_set_drvdata(ext->input, ext);
  	ext->input->open = wiiext_input_open;
  	ext->input->close = wiiext_input_close;
  	ext->input->dev.parent = &wdata->hdev->dev;
  	ext->input->id.bustype = wdata->hdev->bus;
  	ext->input->id.vendor = wdata->hdev->vendor;
  	ext->input->id.product = wdata->hdev->product;
  	ext->input->id.version = wdata->hdev->version;
  	ext->input->name = WIIMOTE_NAME " Extension";

  	set_bit(EV_KEY, ext->input->evbit);
  	for (i = 0; i < WIIEXT_KEY_COUNT; ++i)
  		set_bit(wiiext_keymap[i], ext->input->keybit);
  
  	set_bit(EV_ABS, ext->input->evbit);
  	set_bit(ABS_HAT0X, ext->input->absbit);
  	set_bit(ABS_HAT0Y, ext->input->absbit);

  	set_bit(ABS_HAT1X, ext->input->absbit);
  	set_bit(ABS_HAT1Y, ext->input->absbit);
  	set_bit(ABS_HAT2X, ext->input->absbit);
  	set_bit(ABS_HAT2Y, ext->input->absbit);
  	set_bit(ABS_HAT3X, ext->input->absbit);
  	set_bit(ABS_HAT3Y, ext->input->absbit);

  	input_set_abs_params(ext->input, ABS_HAT0X, -120, 120, 2, 4);
  	input_set_abs_params(ext->input, ABS_HAT0Y, -120, 120, 2, 4);

  	input_set_abs_params(ext->input, ABS_HAT1X, -30, 30, 1, 1);
  	input_set_abs_params(ext->input, ABS_HAT1Y, -30, 30, 1, 1);
  	input_set_abs_params(ext->input, ABS_HAT2X, -30, 30, 1, 1);
  	input_set_abs_params(ext->input, ABS_HAT2Y, -30, 30, 1, 1);
  	input_set_abs_params(ext->input, ABS_HAT3X, -30, 30, 1, 1);
  	input_set_abs_params(ext->input, ABS_HAT3Y, -30, 30, 1, 1);

  	set_bit(ABS_RX, ext->input->absbit);
  	set_bit(ABS_RY, ext->input->absbit);
  	set_bit(ABS_RZ, ext->input->absbit);
  	input_set_abs_params(ext->input, ABS_RX, -500, 500, 2, 4);
  	input_set_abs_params(ext->input, ABS_RY, -500, 500, 2, 4);
  	input_set_abs_params(ext->input, ABS_RZ, -500, 500, 2, 4);

  	ret = input_register_device(ext->input);
  	if (ret) {
  		input_free_device(ext->input);
  		goto err_input;
  	}
  
  	ext->mp_input = input_allocate_device();
  	if (!ext->mp_input) {
  		ret = -ENOMEM;
  		goto err_mp;
  	}
  
  	input_set_drvdata(ext->mp_input, ext);
  	ext->mp_input->open = wiiext_mp_open;
  	ext->mp_input->close = wiiext_mp_close;
  	ext->mp_input->dev.parent = &wdata->hdev->dev;
  	ext->mp_input->id.bustype = wdata->hdev->bus;
  	ext->mp_input->id.vendor = wdata->hdev->vendor;
  	ext->mp_input->id.product = wdata->hdev->product;
  	ext->mp_input->id.version = wdata->hdev->version;
  	ext->mp_input->name = WIIMOTE_NAME " Motion+";

  	set_bit(EV_ABS, ext->mp_input->evbit);
  	set_bit(ABS_RX, ext->mp_input->absbit);
  	set_bit(ABS_RY, ext->mp_input->absbit);
  	set_bit(ABS_RZ, ext->mp_input->absbit);
  	input_set_abs_params(ext->mp_input, ABS_RX, -160000, 160000, 4, 8);
  	input_set_abs_params(ext->mp_input, ABS_RY, -160000, 160000, 4, 8);
  	input_set_abs_params(ext->mp_input, ABS_RZ, -160000, 160000, 4, 8);

  	ret = input_register_device(ext->mp_input);
  	if (ret) {
  		input_free_device(ext->mp_input);
  		goto err_mp;
  	}

  	ret = device_create_file(&wdata->hdev->dev, &dev_attr_extension);
  	if (ret)

  		goto err_dev;

  	spin_lock_irqsave(&wdata->state.lock, flags);
  	wdata->ext = ext;
  	spin_unlock_irqrestore(&wdata->state.lock, flags);
  
  	return 0;

  err_dev:
  	input_unregister_device(ext->mp_input);
  err_mp:
  	input_unregister_device(ext->input);
  err_input:

  	kfree(ext);
  	return ret;

  }
  
  /* Deinitializes the extension driver of a wiimote */
  void wiiext_deinit(struct wiimote_data *wdata)
  {
  	struct wiimote_ext *ext = wdata->ext;
  	unsigned long flags;
  
  	if (!ext)
  		return;
  
  	/*
  	 * We first unset wdata->ext to avoid further input from the wiimote
  	 * core. The worker thread does not access this pointer so it is not
  	 * affected by this.
  	 * We kill the worker after this so it does not get respawned during
  	 * deinitialization.
  	 */
  
  	spin_lock_irqsave(&wdata->state.lock, flags);
  	wdata->ext = NULL;
  	spin_unlock_irqrestore(&wdata->state.lock, flags);

  	device_remove_file(&wdata->hdev->dev, &dev_attr_extension);

  	input_unregister_device(ext->mp_input);
  	input_unregister_device(ext->input);

  	cancel_work_sync(&ext->worker);
  	kfree(ext);
  }