/*
   * Apple USB BCM5974 (Macbook Air and Penryn Macbook Pro) multitouch driver
   *
   * Copyright (C) 2008	   Henrik Rydberg (rydberg@euromail.se)
   * Copyright (C) 2015      John Horan (knasher@gmail.com)
   *
   * The USB initialization and package decoding was made by
   * Scott Shawcroft as part of the touchd user-space driver project:
   * Copyright (C) 2008	   Scott Shawcroft (scott.shawcroft@gmail.com)
   *
   * The BCM5974 driver is based on the appletouch driver:
   * Copyright (C) 2001-2004 Greg Kroah-Hartman (greg@kroah.com)
   * Copyright (C) 2005      Johannes Berg (johannes@sipsolutions.net)
   * Copyright (C) 2005	   Stelian Pop (stelian@popies.net)
   * Copyright (C) 2005	   Frank Arnold (frank@scirocco-5v-turbo.de)
   * Copyright (C) 2005	   Peter Osterlund (petero2@telia.com)
   * Copyright (C) 2005	   Michael Hanselmann (linux-kernel@hansmi.ch)
   * Copyright (C) 2006	   Nicolas Boichat (nicolas@boichat.ch)
   *
   * 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.
   *
   * 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 program; if not, write to the Free Software
   * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
   *
   */
  
  #include <linux/kernel.h>
  #include <linux/errno.h>
  #include <linux/slab.h>
  #include <linux/module.h>
  #include <linux/usb/input.h>
  #include <linux/hid.h>
  #include <linux/mutex.h>
  #include <linux/input/mt.h>
  
  #define USB_VENDOR_ID_APPLE		0x05ac
  
  /* MacbookAir, aka wellspring */
  #define USB_DEVICE_ID_APPLE_WELLSPRING_ANSI	0x0223
  #define USB_DEVICE_ID_APPLE_WELLSPRING_ISO	0x0224
  #define USB_DEVICE_ID_APPLE_WELLSPRING_JIS	0x0225
  /* MacbookProPenryn, aka wellspring2 */
  #define USB_DEVICE_ID_APPLE_WELLSPRING2_ANSI	0x0230
  #define USB_DEVICE_ID_APPLE_WELLSPRING2_ISO	0x0231
  #define USB_DEVICE_ID_APPLE_WELLSPRING2_JIS	0x0232
  /* Macbook5,1 (unibody), aka wellspring3 */
  #define USB_DEVICE_ID_APPLE_WELLSPRING3_ANSI	0x0236
  #define USB_DEVICE_ID_APPLE_WELLSPRING3_ISO	0x0237
  #define USB_DEVICE_ID_APPLE_WELLSPRING3_JIS	0x0238
  /* MacbookAir3,2 (unibody), aka wellspring5 */
  #define USB_DEVICE_ID_APPLE_WELLSPRING4_ANSI	0x023f
  #define USB_DEVICE_ID_APPLE_WELLSPRING4_ISO	0x0240
  #define USB_DEVICE_ID_APPLE_WELLSPRING4_JIS	0x0241
  /* MacbookAir3,1 (unibody), aka wellspring4 */
  #define USB_DEVICE_ID_APPLE_WELLSPRING4A_ANSI	0x0242
  #define USB_DEVICE_ID_APPLE_WELLSPRING4A_ISO	0x0243
  #define USB_DEVICE_ID_APPLE_WELLSPRING4A_JIS	0x0244
  /* Macbook8 (unibody, March 2011) */
  #define USB_DEVICE_ID_APPLE_WELLSPRING5_ANSI	0x0245
  #define USB_DEVICE_ID_APPLE_WELLSPRING5_ISO	0x0246
  #define USB_DEVICE_ID_APPLE_WELLSPRING5_JIS	0x0247
  /* MacbookAir4,1 (unibody, July 2011) */
  #define USB_DEVICE_ID_APPLE_WELLSPRING6A_ANSI	0x0249
  #define USB_DEVICE_ID_APPLE_WELLSPRING6A_ISO	0x024a
  #define USB_DEVICE_ID_APPLE_WELLSPRING6A_JIS	0x024b
  /* MacbookAir4,2 (unibody, July 2011) */
  #define USB_DEVICE_ID_APPLE_WELLSPRING6_ANSI	0x024c
  #define USB_DEVICE_ID_APPLE_WELLSPRING6_ISO	0x024d
  #define USB_DEVICE_ID_APPLE_WELLSPRING6_JIS	0x024e
  /* Macbook8,2 (unibody) */
  #define USB_DEVICE_ID_APPLE_WELLSPRING5A_ANSI	0x0252
  #define USB_DEVICE_ID_APPLE_WELLSPRING5A_ISO	0x0253
  #define USB_DEVICE_ID_APPLE_WELLSPRING5A_JIS	0x0254
  /* MacbookPro10,1 (unibody, June 2012) */
  #define USB_DEVICE_ID_APPLE_WELLSPRING7_ANSI	0x0262
  #define USB_DEVICE_ID_APPLE_WELLSPRING7_ISO	0x0263
  #define USB_DEVICE_ID_APPLE_WELLSPRING7_JIS	0x0264
  /* MacbookPro10,2 (unibody, October 2012) */
  #define USB_DEVICE_ID_APPLE_WELLSPRING7A_ANSI	0x0259
  #define USB_DEVICE_ID_APPLE_WELLSPRING7A_ISO	0x025a
  #define USB_DEVICE_ID_APPLE_WELLSPRING7A_JIS	0x025b
  /* MacbookAir6,2 (unibody, June 2013) */
  #define USB_DEVICE_ID_APPLE_WELLSPRING8_ANSI	0x0290
  #define USB_DEVICE_ID_APPLE_WELLSPRING8_ISO	0x0291
  #define USB_DEVICE_ID_APPLE_WELLSPRING8_JIS	0x0292
  /* MacbookPro12,1 (2015) */
  #define USB_DEVICE_ID_APPLE_WELLSPRING9_ANSI	0x0272
  #define USB_DEVICE_ID_APPLE_WELLSPRING9_ISO	0x0273
  #define USB_DEVICE_ID_APPLE_WELLSPRING9_JIS	0x0274
  
  #define BCM5974_DEVICE(prod) {					\
  	.match_flags = (USB_DEVICE_ID_MATCH_DEVICE |		\
  			USB_DEVICE_ID_MATCH_INT_CLASS |		\
  			USB_DEVICE_ID_MATCH_INT_PROTOCOL),	\
  	.idVendor = USB_VENDOR_ID_APPLE,			\
  	.idProduct = (prod),					\
  	.bInterfaceClass = USB_INTERFACE_CLASS_HID,		\
  	.bInterfaceProtocol = USB_INTERFACE_PROTOCOL_MOUSE	\
  }
  
  /* table of devices that work with this driver */
  static const struct usb_device_id bcm5974_table[] = {
  	/* MacbookAir1.1 */
  	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING_ANSI),
  	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING_ISO),
  	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING_JIS),
  	/* MacbookProPenryn */
  	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING2_ANSI),
  	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING2_ISO),
  	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING2_JIS),
  	/* Macbook5,1 */
  	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING3_ANSI),
  	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING3_ISO),
  	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING3_JIS),
  	/* MacbookAir3,2 */
  	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING4_ANSI),
  	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING4_ISO),
  	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING4_JIS),
  	/* MacbookAir3,1 */
  	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING4A_ANSI),
  	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING4A_ISO),
  	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING4A_JIS),
  	/* MacbookPro8 */
  	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING5_ANSI),
  	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING5_ISO),
  	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING5_JIS),
  	/* MacbookAir4,1 */
  	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING6A_ANSI),
  	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING6A_ISO),
  	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING6A_JIS),
  	/* MacbookAir4,2 */
  	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING6_ANSI),
  	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING6_ISO),
  	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING6_JIS),
  	/* MacbookPro8,2 */
  	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING5A_ANSI),
  	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING5A_ISO),
  	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING5A_JIS),
  	/* MacbookPro10,1 */
  	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING7_ANSI),
  	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING7_ISO),
  	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING7_JIS),
  	/* MacbookPro10,2 */
  	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING7A_ANSI),
  	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING7A_ISO),
  	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING7A_JIS),
  	/* MacbookAir6,2 */
  	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING8_ANSI),
  	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING8_ISO),
  	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING8_JIS),
  	/* MacbookPro12,1 */
  	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING9_ANSI),
  	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING9_ISO),
  	BCM5974_DEVICE(USB_DEVICE_ID_APPLE_WELLSPRING9_JIS),
  	/* Terminating entry */
  	{}
  };
  MODULE_DEVICE_TABLE(usb, bcm5974_table);
  
  MODULE_AUTHOR("Henrik Rydberg");
  MODULE_DESCRIPTION("Apple USB BCM5974 multitouch driver");
  MODULE_LICENSE("GPL");
  
  #define dprintk(level, format, a...)\
  	{ if (debug >= level) printk(KERN_DEBUG format, ##a); }
  
  static int debug = 1;
  module_param(debug, int, 0644);
  MODULE_PARM_DESC(debug, "Activate debugging output");
  
  /* button data structure */
  struct bt_data {
  	u8 unknown1;		/* constant */
  	u8 button;		/* left button */
  	u8 rel_x;		/* relative x coordinate */
  	u8 rel_y;		/* relative y coordinate */
  };
  
  /* trackpad header types */
  enum tp_type {
  	TYPE1,			/* plain trackpad */
  	TYPE2,			/* button integrated in trackpad */
  	TYPE3,			/* additional header fields since June 2013 */
  	TYPE4			/* additional header field for pressure data */
  };
  
  /* trackpad finger data offsets, le16-aligned */
  #define HEADER_TYPE1		(13 * sizeof(__le16))
  #define HEADER_TYPE2		(15 * sizeof(__le16))
  #define HEADER_TYPE3		(19 * sizeof(__le16))
  #define HEADER_TYPE4		(23 * sizeof(__le16))
  
  /* trackpad button data offsets */
  #define BUTTON_TYPE1		0
  #define BUTTON_TYPE2		15
  #define BUTTON_TYPE3		23
  #define BUTTON_TYPE4		31
  
  /* list of device capability bits */
  #define HAS_INTEGRATED_BUTTON	1
  
  /* trackpad finger data block size */
  #define FSIZE_TYPE1		(14 * sizeof(__le16))
  #define FSIZE_TYPE2		(14 * sizeof(__le16))
  #define FSIZE_TYPE3		(14 * sizeof(__le16))
  #define FSIZE_TYPE4		(15 * sizeof(__le16))
  
  /* offset from header to finger struct */
  #define DELTA_TYPE1		(0 * sizeof(__le16))
  #define DELTA_TYPE2		(0 * sizeof(__le16))
  #define DELTA_TYPE3		(0 * sizeof(__le16))
  #define DELTA_TYPE4		(1 * sizeof(__le16))
  
  /* usb control message mode switch data */
  #define USBMSG_TYPE1		8, 0x300, 0, 0, 0x1, 0x8
  #define USBMSG_TYPE2		8, 0x300, 0, 0, 0x1, 0x8
  #define USBMSG_TYPE3		8, 0x300, 0, 0, 0x1, 0x8
  #define USBMSG_TYPE4		2, 0x302, 2, 1, 0x1, 0x0
  
  /* Wellspring initialization constants */
  #define BCM5974_WELLSPRING_MODE_READ_REQUEST_ID		1
  #define BCM5974_WELLSPRING_MODE_WRITE_REQUEST_ID	9
  
  /* trackpad finger structure, le16-aligned */
  struct tp_finger {
  	__le16 origin;		/* zero when switching track finger */
  	__le16 abs_x;		/* absolute x coodinate */
  	__le16 abs_y;		/* absolute y coodinate */
  	__le16 rel_x;		/* relative x coodinate */
  	__le16 rel_y;		/* relative y coodinate */
  	__le16 tool_major;	/* tool area, major axis */
  	__le16 tool_minor;	/* tool area, minor axis */
  	__le16 orientation;	/* 16384 when point, else 15 bit angle */
  	__le16 touch_major;	/* touch area, major axis */
  	__le16 touch_minor;	/* touch area, minor axis */
  	__le16 unused[2];	/* zeros */
  	__le16 pressure;	/* pressure on forcetouch touchpad */
  	__le16 multi;		/* one finger: varies, more fingers: constant */
  } __attribute__((packed,aligned(2)));
  
  /* trackpad finger data size, empirically at least ten fingers */
  #define MAX_FINGERS		16
  #define MAX_FINGER_ORIENTATION	16384
  
  /* device-specific parameters */
  struct bcm5974_param {
  	int snratio;		/* signal-to-noise ratio */
  	int min;		/* device minimum reading */
  	int max;		/* device maximum reading */
  };
  
  /* device-specific configuration */
  struct bcm5974_config {
  	int ansi, iso, jis;	/* the product id of this device */
  	int caps;		/* device capability bitmask */
  	int bt_ep;		/* the endpoint of the button interface */
  	int bt_datalen;		/* data length of the button interface */
  	int tp_ep;		/* the endpoint of the trackpad interface */
  	enum tp_type tp_type;	/* type of trackpad interface */
  	int tp_header;		/* bytes in header block */
  	int tp_datalen;		/* data length of the trackpad interface */
  	int tp_button;		/* offset to button data */
  	int tp_fsize;		/* bytes in single finger block */
  	int tp_delta;		/* offset from header to finger struct */
  	int um_size;		/* usb control message length */
  	int um_req_val;		/* usb control message value */
  	int um_req_idx;		/* usb control message index */
  	int um_switch_idx;	/* usb control message mode switch index */
  	int um_switch_on;	/* usb control message mode switch on */
  	int um_switch_off;	/* usb control message mode switch off */
  	struct bcm5974_param p;	/* finger pressure limits */
  	struct bcm5974_param w;	/* finger width limits */
  	struct bcm5974_param x;	/* horizontal limits */
  	struct bcm5974_param y;	/* vertical limits */
  	struct bcm5974_param o;	/* orientation limits */
  };
  
  /* logical device structure */
  struct bcm5974 {
  	char phys[64];
  	struct usb_device *udev;	/* usb device */
  	struct usb_interface *intf;	/* our interface */
  	struct input_dev *input;	/* input dev */
  	struct bcm5974_config cfg;	/* device configuration */
  	struct mutex pm_mutex;		/* serialize access to open/suspend */
  	int opened;			/* 1: opened, 0: closed */
  	struct urb *bt_urb;		/* button usb request block */
  	struct bt_data *bt_data;	/* button transferred data */
  	struct urb *tp_urb;		/* trackpad usb request block */
  	u8 *tp_data;			/* trackpad transferred data */
  	const struct tp_finger *index[MAX_FINGERS];	/* finger index data */
  	struct input_mt_pos pos[MAX_FINGERS];		/* position array */
  	int slots[MAX_FINGERS];				/* slot assignments */
  };
  
  /* trackpad finger block data, le16-aligned */
  static const struct tp_finger *get_tp_finger(const struct bcm5974 *dev, int i)
  {
  	const struct bcm5974_config *c = &dev->cfg;
  	u8 *f_base = dev->tp_data + c->tp_header + c->tp_delta;
  
  	return (const struct tp_finger *)(f_base + i * c->tp_fsize);
  }
  
  #define DATAFORMAT(type)				\
  	type,						\
  	HEADER_##type,					\
  	HEADER_##type + (MAX_FINGERS) * (FSIZE_##type),	\
  	BUTTON_##type,					\
  	FSIZE_##type,					\
  	DELTA_##type,					\
  	USBMSG_##type
  
  /* logical signal quality */
  #define SN_PRESSURE	45		/* pressure signal-to-noise ratio */
  #define SN_WIDTH	25		/* width signal-to-noise ratio */
  #define SN_COORD	250		/* coordinate signal-to-noise ratio */
  #define SN_ORIENT	10		/* orientation signal-to-noise ratio */
  
  /* device constants */
  static const struct bcm5974_config bcm5974_config_table[] = {
  	{
  		USB_DEVICE_ID_APPLE_WELLSPRING_ANSI,
  		USB_DEVICE_ID_APPLE_WELLSPRING_ISO,
  		USB_DEVICE_ID_APPLE_WELLSPRING_JIS,
  		0,
  		0x84, sizeof(struct bt_data),
  		0x81, DATAFORMAT(TYPE1),
  		{ SN_PRESSURE, 0, 256 },
  		{ SN_WIDTH, 0, 2048 },
  		{ SN_COORD, -4824, 5342 },
  		{ SN_COORD, -172, 5820 },
  		{ SN_ORIENT, -MAX_FINGER_ORIENTATION, MAX_FINGER_ORIENTATION }
  	},
  	{
  		USB_DEVICE_ID_APPLE_WELLSPRING2_ANSI,
  		USB_DEVICE_ID_APPLE_WELLSPRING2_ISO,
  		USB_DEVICE_ID_APPLE_WELLSPRING2_JIS,
  		0,
  		0x84, sizeof(struct bt_data),
  		0x81, DATAFORMAT(TYPE1),
  		{ SN_PRESSURE, 0, 256 },
  		{ SN_WIDTH, 0, 2048 },
  		{ SN_COORD, -4824, 4824 },
  		{ SN_COORD, -172, 4290 },
  		{ SN_ORIENT, -MAX_FINGER_ORIENTATION, MAX_FINGER_ORIENTATION }
  	},
  	{
  		USB_DEVICE_ID_APPLE_WELLSPRING3_ANSI,
  		USB_DEVICE_ID_APPLE_WELLSPRING3_ISO,
  		USB_DEVICE_ID_APPLE_WELLSPRING3_JIS,
  		HAS_INTEGRATED_BUTTON,
  		0x84, sizeof(struct bt_data),
  		0x81, DATAFORMAT(TYPE2),
  		{ SN_PRESSURE, 0, 300 },
  		{ SN_WIDTH, 0, 2048 },
  		{ SN_COORD, -4460, 5166 },
  		{ SN_COORD, -75, 6700 },
  		{ SN_ORIENT, -MAX_FINGER_ORIENTATION, MAX_FINGER_ORIENTATION }
  	},
  	{
  		USB_DEVICE_ID_APPLE_WELLSPRING4_ANSI,
  		USB_DEVICE_ID_APPLE_WELLSPRING4_ISO,
  		USB_DEVICE_ID_APPLE_WELLSPRING4_JIS,
  		HAS_INTEGRATED_BUTTON,
  		0x84, sizeof(struct bt_data),
  		0x81, DATAFORMAT(TYPE2),
  		{ SN_PRESSURE, 0, 300 },
  		{ SN_WIDTH, 0, 2048 },
  		{ SN_COORD, -4620, 5140 },
  		{ SN_COORD, -150, 6600 },
  		{ SN_ORIENT, -MAX_FINGER_ORIENTATION, MAX_FINGER_ORIENTATION }
  	},
  	{
  		USB_DEVICE_ID_APPLE_WELLSPRING4A_ANSI,
  		USB_DEVICE_ID_APPLE_WELLSPRING4A_ISO,
  		USB_DEVICE_ID_APPLE_WELLSPRING4A_JIS,
  		HAS_INTEGRATED_BUTTON,
  		0x84, sizeof(struct bt_data),
  		0x81, DATAFORMAT(TYPE2),
  		{ SN_PRESSURE, 0, 300 },
  		{ SN_WIDTH, 0, 2048 },
  		{ SN_COORD, -4616, 5112 },
  		{ SN_COORD, -142, 5234 },
  		{ SN_ORIENT, -MAX_FINGER_ORIENTATION, MAX_FINGER_ORIENTATION }
  	},
  	{
  		USB_DEVICE_ID_APPLE_WELLSPRING5_ANSI,
  		USB_DEVICE_ID_APPLE_WELLSPRING5_ISO,
  		USB_DEVICE_ID_APPLE_WELLSPRING5_JIS,
  		HAS_INTEGRATED_BUTTON,
  		0x84, sizeof(struct bt_data),
  		0x81, DATAFORMAT(TYPE2),
  		{ SN_PRESSURE, 0, 300 },
  		{ SN_WIDTH, 0, 2048 },
  		{ SN_COORD, -4415, 5050 },
  		{ SN_COORD, -55, 6680 },
  		{ SN_ORIENT, -MAX_FINGER_ORIENTATION, MAX_FINGER_ORIENTATION }
  	},
  	{
  		USB_DEVICE_ID_APPLE_WELLSPRING6_ANSI,
  		USB_DEVICE_ID_APPLE_WELLSPRING6_ISO,
  		USB_DEVICE_ID_APPLE_WELLSPRING6_JIS,
  		HAS_INTEGRATED_BUTTON,
  		0x84, sizeof(struct bt_data),
  		0x81, DATAFORMAT(TYPE2),
  		{ SN_PRESSURE, 0, 300 },
  		{ SN_WIDTH, 0, 2048 },
  		{ SN_COORD, -4620, 5140 },
  		{ SN_COORD, -150, 6600 },
  		{ SN_ORIENT, -MAX_FINGER_ORIENTATION, MAX_FINGER_ORIENTATION }
  	},
  	{
  		USB_DEVICE_ID_APPLE_WELLSPRING5A_ANSI,
  		USB_DEVICE_ID_APPLE_WELLSPRING5A_ISO,
  		USB_DEVICE_ID_APPLE_WELLSPRING5A_JIS,
  		HAS_INTEGRATED_BUTTON,
  		0x84, sizeof(struct bt_data),
  		0x81, DATAFORMAT(TYPE2),
  		{ SN_PRESSURE, 0, 300 },
  		{ SN_WIDTH, 0, 2048 },
  		{ SN_COORD, -4750, 5280 },
  		{ SN_COORD, -150, 6730 },
  		{ SN_ORIENT, -MAX_FINGER_ORIENTATION, MAX_FINGER_ORIENTATION }
  	},
  	{
  		USB_DEVICE_ID_APPLE_WELLSPRING6A_ANSI,
  		USB_DEVICE_ID_APPLE_WELLSPRING6A_ISO,
  		USB_DEVICE_ID_APPLE_WELLSPRING6A_JIS,
  		HAS_INTEGRATED_BUTTON,
  		0x84, sizeof(struct bt_data),
  		0x81, DATAFORMAT(TYPE2),
  		{ SN_PRESSURE, 0, 300 },
  		{ SN_WIDTH, 0, 2048 },
  		{ SN_COORD, -4620, 5140 },
  		{ SN_COORD, -150, 6600 },
  		{ SN_ORIENT, -MAX_FINGER_ORIENTATION, MAX_FINGER_ORIENTATION }
  	},
  	{
  		USB_DEVICE_ID_APPLE_WELLSPRING7_ANSI,
  		USB_DEVICE_ID_APPLE_WELLSPRING7_ISO,
  		USB_DEVICE_ID_APPLE_WELLSPRING7_JIS,
  		HAS_INTEGRATED_BUTTON,
  		0x84, sizeof(struct bt_data),
  		0x81, DATAFORMAT(TYPE2),
  		{ SN_PRESSURE, 0, 300 },
  		{ SN_WIDTH, 0, 2048 },
  		{ SN_COORD, -4750, 5280 },
  		{ SN_COORD, -150, 6730 },
  		{ SN_ORIENT, -MAX_FINGER_ORIENTATION, MAX_FINGER_ORIENTATION }
  	},
  	{
  		USB_DEVICE_ID_APPLE_WELLSPRING7A_ANSI,
  		USB_DEVICE_ID_APPLE_WELLSPRING7A_ISO,
  		USB_DEVICE_ID_APPLE_WELLSPRING7A_JIS,
  		HAS_INTEGRATED_BUTTON,
  		0x84, sizeof(struct bt_data),
  		0x81, DATAFORMAT(TYPE2),
  		{ SN_PRESSURE, 0, 300 },
  		{ SN_WIDTH, 0, 2048 },
  		{ SN_COORD, -4750, 5280 },
  		{ SN_COORD, -150, 6730 },
  		{ SN_ORIENT, -MAX_FINGER_ORIENTATION, MAX_FINGER_ORIENTATION }
  	},
  	{
  		USB_DEVICE_ID_APPLE_WELLSPRING8_ANSI,
  		USB_DEVICE_ID_APPLE_WELLSPRING8_ISO,
  		USB_DEVICE_ID_APPLE_WELLSPRING8_JIS,
  		HAS_INTEGRATED_BUTTON,
  		0, sizeof(struct bt_data),
  		0x83, DATAFORMAT(TYPE3),
  		{ SN_PRESSURE, 0, 300 },
  		{ SN_WIDTH, 0, 2048 },
  		{ SN_COORD, -4620, 5140 },
  		{ SN_COORD, -150, 6600 },
  		{ SN_ORIENT, -MAX_FINGER_ORIENTATION, MAX_FINGER_ORIENTATION }
  	},
  	{
  		USB_DEVICE_ID_APPLE_WELLSPRING9_ANSI,
  		USB_DEVICE_ID_APPLE_WELLSPRING9_ISO,
  		USB_DEVICE_ID_APPLE_WELLSPRING9_JIS,
  		HAS_INTEGRATED_BUTTON,
  		0, sizeof(struct bt_data),
  		0x83, DATAFORMAT(TYPE4),
  		{ SN_PRESSURE, 0, 300 },
  		{ SN_WIDTH, 0, 2048 },
  		{ SN_COORD, -4828, 5345 },
  		{ SN_COORD, -203, 6803 },
  		{ SN_ORIENT, -MAX_FINGER_ORIENTATION, MAX_FINGER_ORIENTATION }
  	},
  	{}
  };
  
  /* return the device-specific configuration by device */
  static const struct bcm5974_config *bcm5974_get_config(struct usb_device *udev)
  {
  	u16 id = le16_to_cpu(udev->descriptor.idProduct);
  	const struct bcm5974_config *cfg;
  
  	for (cfg = bcm5974_config_table; cfg->ansi; ++cfg)
  		if (cfg->ansi == id || cfg->iso == id || cfg->jis == id)
  			return cfg;
  
  	return bcm5974_config_table;
  }
  
  /* convert 16-bit little endian to signed integer */
  static inline int raw2int(__le16 x)
  {
  	return (signed short)le16_to_cpu(x);
  }
  
  static void set_abs(struct input_dev *input, unsigned int code,
  		    const struct bcm5974_param *p)
  {
  	int fuzz = p->snratio ? (p->max - p->min) / p->snratio : 0;
  	input_set_abs_params(input, code, p->min, p->max, fuzz, 0);
  }
  
  /* setup which logical events to report */
  static void setup_events_to_report(struct input_dev *input_dev,
  				   const struct bcm5974_config *cfg)
  {
  	__set_bit(EV_ABS, input_dev->evbit);
  
  	/* for synaptics only */
  	input_set_abs_params(input_dev, ABS_PRESSURE, 0, 256, 5, 0);
  	input_set_abs_params(input_dev, ABS_TOOL_WIDTH, 0, 16, 0, 0);
  
  	/* finger touch area */
  	set_abs(input_dev, ABS_MT_TOUCH_MAJOR, &cfg->w);
  	set_abs(input_dev, ABS_MT_TOUCH_MINOR, &cfg->w);
  	/* finger approach area */
  	set_abs(input_dev, ABS_MT_WIDTH_MAJOR, &cfg->w);
  	set_abs(input_dev, ABS_MT_WIDTH_MINOR, &cfg->w);
  	/* finger orientation */
  	set_abs(input_dev, ABS_MT_ORIENTATION, &cfg->o);
  	/* finger position */
  	set_abs(input_dev, ABS_MT_POSITION_X, &cfg->x);
  	set_abs(input_dev, ABS_MT_POSITION_Y, &cfg->y);
  
  	__set_bit(EV_KEY, input_dev->evbit);
  	__set_bit(BTN_LEFT, input_dev->keybit);
  
  	if (cfg->caps & HAS_INTEGRATED_BUTTON)
  		__set_bit(INPUT_PROP_BUTTONPAD, input_dev->propbit);
  
  	input_mt_init_slots(input_dev, MAX_FINGERS,
  		INPUT_MT_POINTER | INPUT_MT_DROP_UNUSED | INPUT_MT_TRACK);
  }
  
  /* report button data as logical button state */
  static int report_bt_state(struct bcm5974 *dev, int size)
  {
  	if (size != sizeof(struct bt_data))
  		return -EIO;
  
  	dprintk(7,
  		"bcm5974: button data: %x %x %x %x
  ",
  		dev->bt_data->unknown1, dev->bt_data->button,
  		dev->bt_data->rel_x, dev->bt_data->rel_y);
  
  	input_report_key(dev->input, BTN_LEFT, dev->bt_data->button);
  	input_sync(dev->input);
  
  	return 0;
  }
  
  static void report_finger_data(struct input_dev *input, int slot,
  			       const struct input_mt_pos *pos,
  			       const struct tp_finger *f)
  {
  	input_mt_slot(input, slot);
  	input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
  
  	input_report_abs(input, ABS_MT_TOUCH_MAJOR,
  			 raw2int(f->touch_major) << 1);
  	input_report_abs(input, ABS_MT_TOUCH_MINOR,
  			 raw2int(f->touch_minor) << 1);
  	input_report_abs(input, ABS_MT_WIDTH_MAJOR,
  			 raw2int(f->tool_major) << 1);
  	input_report_abs(input, ABS_MT_WIDTH_MINOR,
  			 raw2int(f->tool_minor) << 1);
  	input_report_abs(input, ABS_MT_ORIENTATION,
  			 MAX_FINGER_ORIENTATION - raw2int(f->orientation));
  	input_report_abs(input, ABS_MT_POSITION_X, pos->x);
  	input_report_abs(input, ABS_MT_POSITION_Y, pos->y);
  }
  
  static void report_synaptics_data(struct input_dev *input,
  				  const struct bcm5974_config *cfg,
  				  const struct tp_finger *f, int raw_n)
  {
  	int abs_p = 0, abs_w = 0;
  
  	if (raw_n) {
  		int p = raw2int(f->touch_major);
  		int w = raw2int(f->tool_major);
  		if (p > 0 && raw2int(f->origin)) {
  			abs_p = clamp_val(256 * p / cfg->p.max, 0, 255);
  			abs_w = clamp_val(16 * w / cfg->w.max, 0, 15);
  		}
  	}
  
  	input_report_abs(input, ABS_PRESSURE, abs_p);
  	input_report_abs(input, ABS_TOOL_WIDTH, abs_w);
  }
  
  /* report trackpad data as logical trackpad state */
  static int report_tp_state(struct bcm5974 *dev, int size)
  {
  	const struct bcm5974_config *c = &dev->cfg;
  	const struct tp_finger *f;
  	struct input_dev *input = dev->input;
  	int raw_n, i, n = 0;
  
  	if (size < c->tp_header || (size - c->tp_header) % c->tp_fsize != 0)
  		return -EIO;
  
  	raw_n = (size - c->tp_header) / c->tp_fsize;
  
  	for (i = 0; i < raw_n; i++) {
  		f = get_tp_finger(dev, i);
  		if (raw2int(f->touch_major) == 0)
  			continue;
  		dev->pos[n].x = raw2int(f->abs_x);
  		dev->pos[n].y = c->y.min + c->y.max - raw2int(f->abs_y);
  		dev->index[n++] = f;
  	}
  
  	input_mt_assign_slots(input, dev->slots, dev->pos, n, 0);
  
  	for (i = 0; i < n; i++)
  		report_finger_data(input, dev->slots[i],
  				   &dev->pos[i], dev->index[i]);
  
  	input_mt_sync_frame(input);
  
  	report_synaptics_data(input, c, get_tp_finger(dev, 0), raw_n);
  
  	/* later types report button events via integrated button only */
  	if (c->caps & HAS_INTEGRATED_BUTTON) {
  		int ibt = raw2int(dev->tp_data[c->tp_button]);
  		input_report_key(input, BTN_LEFT, ibt);
  	}
  
  	input_sync(input);
  
  	return 0;
  }
  
  static int bcm5974_wellspring_mode(struct bcm5974 *dev, bool on)
  {
  	const struct bcm5974_config *c = &dev->cfg;
  	int retval = 0, size;
  	char *data;
  
  	/* Type 3 does not require a mode switch */
  	if (dev->cfg.tp_type == TYPE3)
  		return 0;
  
  	data = kmalloc(c->um_size, GFP_KERNEL);
  	if (!data) {
  		dev_err(&dev->intf->dev, "out of memory
  ");
  		retval = -ENOMEM;
  		goto out;
  	}
  
  	/* read configuration */
  	size = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
  			BCM5974_WELLSPRING_MODE_READ_REQUEST_ID,
  			USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
  			c->um_req_val, c->um_req_idx, data, c->um_size, 5000);
  
  	if (size != c->um_size) {
  		dev_err(&dev->intf->dev, "could not read from device
  ");
  		retval = -EIO;
  		goto out;
  	}
  
  	/* apply the mode switch */
  	data[c->um_switch_idx] = on ? c->um_switch_on : c->um_switch_off;
  
  	/* write configuration */
  	size = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
  			BCM5974_WELLSPRING_MODE_WRITE_REQUEST_ID,
  			USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
  			c->um_req_val, c->um_req_idx, data, c->um_size, 5000);
  
  	if (size != c->um_size) {
  		dev_err(&dev->intf->dev, "could not write to device
  ");
  		retval = -EIO;
  		goto out;
  	}
  
  	dprintk(2, "bcm5974: switched to %s mode.
  ",
  		on ? "wellspring" : "normal");
  
   out:
  	kfree(data);
  	return retval;
  }
  
  static void bcm5974_irq_button(struct urb *urb)
  {
  	struct bcm5974 *dev = urb->context;
  	struct usb_interface *intf = dev->intf;
  	int error;
  
  	switch (urb->status) {
  	case 0:
  		break;
  	case -EOVERFLOW:
  	case -ECONNRESET:
  	case -ENOENT:
  	case -ESHUTDOWN:
  		dev_dbg(&intf->dev, "button urb shutting down: %d
  ",
  			urb->status);
  		return;
  	default:
  		dev_dbg(&intf->dev, "button urb status: %d
  ", urb->status);
  		goto exit;
  	}
  
  	if (report_bt_state(dev, dev->bt_urb->actual_length))
  		dprintk(1, "bcm5974: bad button package, length: %d
  ",
  			dev->bt_urb->actual_length);
  
  exit:
  	error = usb_submit_urb(dev->bt_urb, GFP_ATOMIC);
  	if (error)
  		dev_err(&intf->dev, "button urb failed: %d
  ", error);
  }
  
  static void bcm5974_irq_trackpad(struct urb *urb)
  {
  	struct bcm5974 *dev = urb->context;
  	struct usb_interface *intf = dev->intf;
  	int error;
  
  	switch (urb->status) {
  	case 0:
  		break;
  	case -EOVERFLOW:
  	case -ECONNRESET:
  	case -ENOENT:
  	case -ESHUTDOWN:
  		dev_dbg(&intf->dev, "trackpad urb shutting down: %d
  ",
  			urb->status);
  		return;
  	default:
  		dev_dbg(&intf->dev, "trackpad urb status: %d
  ", urb->status);
  		goto exit;
  	}
  
  	/* control response ignored */
  	if (dev->tp_urb->actual_length == 2)
  		goto exit;
  
  	if (report_tp_state(dev, dev->tp_urb->actual_length))
  		dprintk(1, "bcm5974: bad trackpad package, length: %d
  ",
  			dev->tp_urb->actual_length);
  
  exit:
  	error = usb_submit_urb(dev->tp_urb, GFP_ATOMIC);
  	if (error)
  		dev_err(&intf->dev, "trackpad urb failed: %d
  ", error);
  }
  
  /*
   * The Wellspring trackpad, like many recent Apple trackpads, share
   * the usb device with the keyboard. Since keyboards are usually
   * handled by the HID system, the device ends up being handled by two
   * modules. Setting up the device therefore becomes slightly
   * complicated. To enable multitouch features, a mode switch is
   * required, which is usually applied via the control interface of the
   * device.  It can be argued where this switch should take place. In
   * some drivers, like appletouch, the switch is made during
   * probe. However, the hid module may also alter the state of the
   * device, resulting in trackpad malfunction under certain
   * circumstances. To get around this problem, there is at least one
   * example that utilizes the USB_QUIRK_RESET_RESUME quirk in order to
   * receive a reset_resume request rather than the normal resume.
   * Since the implementation of reset_resume is equal to mode switch
   * plus start_traffic, it seems easier to always do the switch when
   * starting traffic on the device.
   */
  static int bcm5974_start_traffic(struct bcm5974 *dev)
  {
  	int error;
  
  	error = bcm5974_wellspring_mode(dev, true);
  	if (error) {
  		dprintk(1, "bcm5974: mode switch failed
  ");
  		goto err_out;
  	}
  
  	if (dev->bt_urb) {
  		error = usb_submit_urb(dev->bt_urb, GFP_KERNEL);
  		if (error)
  			goto err_reset_mode;
  	}
  
  	error = usb_submit_urb(dev->tp_urb, GFP_KERNEL);
  	if (error)
  		goto err_kill_bt;
  
  	return 0;
  
  err_kill_bt:
  	usb_kill_urb(dev->bt_urb);
  err_reset_mode:
  	bcm5974_wellspring_mode(dev, false);
  err_out:
  	return error;
  }
  
  static void bcm5974_pause_traffic(struct bcm5974 *dev)
  {
  	usb_kill_urb(dev->tp_urb);
  	usb_kill_urb(dev->bt_urb);
  	bcm5974_wellspring_mode(dev, false);
  }
  
  /*
   * The code below implements open/close and manual suspend/resume.
   * All functions may be called in random order.
   *
   * Opening a suspended device fails with EACCES - permission denied.
   *
   * Failing a resume leaves the device resumed but closed.
   */
  static int bcm5974_open(struct input_dev *input)
  {
  	struct bcm5974 *dev = input_get_drvdata(input);
  	int error;
  
  	error = usb_autopm_get_interface(dev->intf);
  	if (error)
  		return error;
  
  	mutex_lock(&dev->pm_mutex);
  
  	error = bcm5974_start_traffic(dev);
  	if (!error)
  		dev->opened = 1;
  
  	mutex_unlock(&dev->pm_mutex);
  
  	if (error)
  		usb_autopm_put_interface(dev->intf);
  
  	return error;
  }
  
  static void bcm5974_close(struct input_dev *input)
  {
  	struct bcm5974 *dev = input_get_drvdata(input);
  
  	mutex_lock(&dev->pm_mutex);
  
  	bcm5974_pause_traffic(dev);
  	dev->opened = 0;
  
  	mutex_unlock(&dev->pm_mutex);
  
  	usb_autopm_put_interface(dev->intf);
  }
  
  static int bcm5974_suspend(struct usb_interface *iface, pm_message_t message)
  {
  	struct bcm5974 *dev = usb_get_intfdata(iface);
  
  	mutex_lock(&dev->pm_mutex);
  
  	if (dev->opened)
  		bcm5974_pause_traffic(dev);
  
  	mutex_unlock(&dev->pm_mutex);
  
  	return 0;
  }
  
  static int bcm5974_resume(struct usb_interface *iface)
  {
  	struct bcm5974 *dev = usb_get_intfdata(iface);
  	int error = 0;
  
  	mutex_lock(&dev->pm_mutex);
  
  	if (dev->opened)
  		error = bcm5974_start_traffic(dev);
  
  	mutex_unlock(&dev->pm_mutex);
  
  	return error;
  }
  
  static int bcm5974_probe(struct usb_interface *iface,
  			 const struct usb_device_id *id)
  {
  	struct usb_device *udev = interface_to_usbdev(iface);
  	const struct bcm5974_config *cfg;
  	struct bcm5974 *dev;
  	struct input_dev *input_dev;
  	int error = -ENOMEM;
  
  	/* find the product index */
  	cfg = bcm5974_get_config(udev);
  
  	/* allocate memory for our device state and initialize it */
  	dev = kzalloc(sizeof(struct bcm5974), GFP_KERNEL);
  	input_dev = input_allocate_device();
  	if (!dev || !input_dev) {
  		dev_err(&iface->dev, "out of memory
  ");
  		goto err_free_devs;
  	}
  
  	dev->udev = udev;
  	dev->intf = iface;
  	dev->input = input_dev;
  	dev->cfg = *cfg;
  	mutex_init(&dev->pm_mutex);
  
  	/* setup urbs */
  	if (cfg->tp_type == TYPE1) {
  		dev->bt_urb = usb_alloc_urb(0, GFP_KERNEL);
  		if (!dev->bt_urb)
  			goto err_free_devs;
  	}
  
  	dev->tp_urb = usb_alloc_urb(0, GFP_KERNEL);
  	if (!dev->tp_urb)
  		goto err_free_bt_urb;
  
  	if (dev->bt_urb) {
  		dev->bt_data = usb_alloc_coherent(dev->udev,
  					  dev->cfg.bt_datalen, GFP_KERNEL,
  					  &dev->bt_urb->transfer_dma);
  		if (!dev->bt_data)
  			goto err_free_urb;
  	}
  
  	dev->tp_data = usb_alloc_coherent(dev->udev,
  					  dev->cfg.tp_datalen, GFP_KERNEL,
  					  &dev->tp_urb->transfer_dma);
  	if (!dev->tp_data)
  		goto err_free_bt_buffer;
  
  	if (dev->bt_urb)
  		usb_fill_int_urb(dev->bt_urb, udev,
  				 usb_rcvintpipe(udev, cfg->bt_ep),
  				 dev->bt_data, dev->cfg.bt_datalen,
  				 bcm5974_irq_button, dev, 1);
  
  	usb_fill_int_urb(dev->tp_urb, udev,
  			 usb_rcvintpipe(udev, cfg->tp_ep),
  			 dev->tp_data, dev->cfg.tp_datalen,
  			 bcm5974_irq_trackpad, dev, 1);
  
  	/* create bcm5974 device */
  	usb_make_path(udev, dev->phys, sizeof(dev->phys));
  	strlcat(dev->phys, "/input0", sizeof(dev->phys));
  
  	input_dev->name = "bcm5974";
  	input_dev->phys = dev->phys;
  	usb_to_input_id(dev->udev, &input_dev->id);
  	/* report driver capabilities via the version field */
  	input_dev->id.version = cfg->caps;
  	input_dev->dev.parent = &iface->dev;
  
  	input_set_drvdata(input_dev, dev);
  
  	input_dev->open = bcm5974_open;
  	input_dev->close = bcm5974_close;
  
  	setup_events_to_report(input_dev, cfg);
  
  	error = input_register_device(dev->input);
  	if (error)
  		goto err_free_buffer;
  
  	/* save our data pointer in this interface device */
  	usb_set_intfdata(iface, dev);
  
  	return 0;
  
  err_free_buffer:
  	usb_free_coherent(dev->udev, dev->cfg.tp_datalen,
  		dev->tp_data, dev->tp_urb->transfer_dma);
  err_free_bt_buffer:
  	if (dev->bt_urb)
  		usb_free_coherent(dev->udev, dev->cfg.bt_datalen,
  				  dev->bt_data, dev->bt_urb->transfer_dma);
  err_free_urb:
  	usb_free_urb(dev->tp_urb);
  err_free_bt_urb:
  	usb_free_urb(dev->bt_urb);
  err_free_devs:
  	usb_set_intfdata(iface, NULL);
  	input_free_device(input_dev);
  	kfree(dev);
  	return error;
  }
  
  static void bcm5974_disconnect(struct usb_interface *iface)
  {
  	struct bcm5974 *dev = usb_get_intfdata(iface);
  
  	usb_set_intfdata(iface, NULL);
  
  	input_unregister_device(dev->input);
  	usb_free_coherent(dev->udev, dev->cfg.tp_datalen,
  			  dev->tp_data, dev->tp_urb->transfer_dma);
  	if (dev->bt_urb)
  		usb_free_coherent(dev->udev, dev->cfg.bt_datalen,
  				  dev->bt_data, dev->bt_urb->transfer_dma);
  	usb_free_urb(dev->tp_urb);
  	usb_free_urb(dev->bt_urb);
  	kfree(dev);
  }
  
  static struct usb_driver bcm5974_driver = {
  	.name			= "bcm5974",
  	.probe			= bcm5974_probe,
  	.disconnect		= bcm5974_disconnect,
  	.suspend		= bcm5974_suspend,
  	.resume			= bcm5974_resume,
  	.id_table		= bcm5974_table,
  	.supports_autosuspend	= 1,
  };
  
  module_usb_driver(bcm5974_driver);