bcm5974.c

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/*
 * Apple USB BCM5974 (Macbook Air and Penryn Macbook Pro) multitouch driver
 *
 * Copyright (C) 2008      Henrik Rydberg ([email protected])
 *
 * 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 ([email protected])
 *
 * The BCM5974 driver is based on the appletouch driver:
 * Copyright (C) 2001-2004 Greg Kroah-Hartman ([email protected])
 * Copyright (C) 2005      Johannes Berg ([email protected])
 * Copyright (C) 2005      Stelian Pop ([email protected])
 * Copyright (C) 2005      Frank Arnold ([email protected])
 * Copyright (C) 2005      Peter Osterlund ([email protected])
 * Copyright (C) 2005      Michael Hanselmann ([email protected])
 * Copyright (C) 2006      Nicolas Boichat ([email protected])
 *
 * 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/init.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

#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),
    /* 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 */
};

/* trackpad finger data offsets, le16-aligned */
#define FINGER_TYPE1        (13 * sizeof(__le16))
#define FINGER_TYPE2        (15 * sizeof(__le16))

/* trackpad button data offsets */
#define BUTTON_TYPE2        15

/* list of device capability bits */
#define HAS_INTEGRATED_BUTTON   1

/* 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[3];   /* zeros */
    __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 SIZEOF_FINGER       sizeof(struct tp_finger)
#define SIZEOF_ALL_FINGERS  (MAX_FINGERS * SIZEOF_FINGER)
#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_offset;      /* offset to trackpad finger data */
    int tp_datalen;     /* data length of the trackpad interface */
    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 */
};

/* 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, TYPE1, FINGER_TYPE1, FINGER_TYPE1 + SIZEOF_ALL_FINGERS,
        { 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, TYPE1, FINGER_TYPE1, FINGER_TYPE1 + SIZEOF_ALL_FINGERS,
        { 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, TYPE2, FINGER_TYPE2, FINGER_TYPE2 + SIZEOF_ALL_FINGERS,
        { 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, TYPE2, FINGER_TYPE2, FINGER_TYPE2 + SIZEOF_ALL_FINGERS,
        { 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, TYPE2, FINGER_TYPE2, FINGER_TYPE2 + SIZEOF_ALL_FINGERS,
        { 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, TYPE2, FINGER_TYPE2, FINGER_TYPE2 + SIZEOF_ALL_FINGERS,
        { 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, TYPE2, FINGER_TYPE2, FINGER_TYPE2 + SIZEOF_ALL_FINGERS,
        { 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, TYPE2, FINGER_TYPE2, FINGER_TYPE2 + SIZEOF_ALL_FINGERS,
        { 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, TYPE2, FINGER_TYPE2, FINGER_TYPE2 + SIZEOF_ALL_FINGERS,
        { 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, TYPE2, FINGER_TYPE2, FINGER_TYPE2 + SIZEOF_ALL_FINGERS,
        { 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, TYPE2, FINGER_TYPE2, FINGER_TYPE2 + SIZEOF_ALL_FINGERS,
        { SN_PRESSURE, 0, 300 },
        { SN_WIDTH, 0, 2048 },
        { SN_COORD, -4750, 5280 },
        { SN_COORD, -150, 6730 },
        { 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_offset || (size - c->tp_offset) % SIZEOF_FINGER != 0)
        return -EIO;

    /* finger data, le16-aligned */
    f = (const struct tp_finger *)(dev->tp_data + c->tp_offset);
    raw_n = (size - c->tp_offset) / SIZEOF_FINGER;

    for (i = 0; i < raw_n; i++) {
        if (raw2int(f[i].touch_major) == 0)
            continue;
        dev->pos[n].x = raw2int(f[i].abs_x);
        dev->pos[n].y = c->y.min + c->y.max - raw2int(f[i].abs_y);
        dev->index[n++] = &f[i];
    }

    input_mt_assign_slots(input, dev->slots, dev->pos, n);

    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, f, raw_n);

    /* type 2 reports button events via ibt only */
    if (c->tp_type == TYPE2) {
        int ibt = raw2int(dev->tp_data[BUTTON_TYPE2]);
        input_report_key(input, BTN_LEFT, ibt);
    }

    input_sync(input);

    return 0;
}

/* Wellspring initialization constants */
#define BCM5974_WELLSPRING_MODE_READ_REQUEST_ID     1
#define BCM5974_WELLSPRING_MODE_WRITE_REQUEST_ID    9
#define BCM5974_WELLSPRING_MODE_REQUEST_VALUE       0x300
#define BCM5974_WELLSPRING_MODE_REQUEST_INDEX       0
#define BCM5974_WELLSPRING_MODE_VENDOR_VALUE        0x01
#define BCM5974_WELLSPRING_MODE_NORMAL_VALUE        0x08

static int bcm5974_wellspring_mode(struct bcm5974 *dev, bool on)
{
    char *data = kmalloc(8, GFP_KERNEL);
    int retval = 0, size;

    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,
            BCM5974_WELLSPRING_MODE_REQUEST_VALUE,
            BCM5974_WELLSPRING_MODE_REQUEST_INDEX, data, 8, 5000);

    if (size != 8) {
        dev_err(&dev->intf->dev, "could not read from device\n");
        retval = -EIO;
        goto out;
    }

    /* apply the mode switch */
    data[0] = on ?
        BCM5974_WELLSPRING_MODE_VENDOR_VALUE :
        BCM5974_WELLSPRING_MODE_NORMAL_VALUE;

    /* 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,
            BCM5974_WELLSPRING_MODE_REQUEST_VALUE,
            BCM5974_WELLSPRING_MODE_REQUEST_INDEX, data, 8, 5000);

    if (size != 8) {
        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);