/*
 * 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\n",
                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 (c->tp_type == TYPE3)
                return 0;

        data = kmalloc(c->um_size, GFP_KERNEL);
        if (!data) {
                dev_err(&dev->intf->dev, "out of memory\n");
                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\n");
                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\n");
                retval = -EIO;
                goto out;
        }

        dprintk(2, "bcm5974: switched to %s mode.\n",
                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\n",
                        urb->status);
                return;
        default:
                dev_dbg(&intf->dev, "button urb status: %d\n", urb->status);
                goto exit;
        }

        if (report_bt_state(dev, dev->bt_urb->actual_length))
                dprintk(1, "bcm5974: bad button package, length: %d\n",
                        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\n", 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\n",
                        urb->status);
                return;
        default:
                dev_dbg(&intf->dev, "trackpad urb status: %d\n", 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\n",
                        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\n", 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\n");
                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\n");
                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);