drivers/input/mouse/appletouch.c - kernel/msm-4.19 - Gitiles

 /*
  * Apple USB Touchpad (for post-February 2005 PowerBooks and MacBooks) 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)
  *
  * Thanks to Alex Harper <basilisk@foobox.net> for his inputs.
  *
  * 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>

 /* Apple has powerbooks which have the keyboard with different Product IDs */
 #define APPLE_VENDOR_ID		0x05AC

 /* These names come from Info.plist in AppleUSBTrackpad.kext */
 #define FOUNTAIN_ANSI_PRODUCT_ID	0x020E
 #define FOUNTAIN_ISO_PRODUCT_ID		0x020F

 #define FOUNTAIN_TP_ONLY_PRODUCT_ID	0x030A

 #define GEYSER1_TP_ONLY_PRODUCT_ID	0x030B

 #define GEYSER_ANSI_PRODUCT_ID		0x0214
 #define GEYSER_ISO_PRODUCT_ID		0x0215
 #define GEYSER_JIS_PRODUCT_ID		0x0216

 /* MacBook devices */
 #define GEYSER3_ANSI_PRODUCT_ID		0x0217
 #define GEYSER3_ISO_PRODUCT_ID		0x0218
 #define GEYSER3_JIS_PRODUCT_ID		0x0219

 /*
  * Geyser IV: same as Geyser III according to Info.plist in AppleUSBTrackpad.kext
  * -> same IOClass (AppleUSBGrIIITrackpad), same acceleration tables
  */
 #define GEYSER4_ANSI_PRODUCT_ID	0x021A
 #define GEYSER4_ISO_PRODUCT_ID	0x021B
 #define GEYSER4_JIS_PRODUCT_ID	0x021C

 #define ATP_DEVICE(prod)					\
 	.match_flags = USB_DEVICE_ID_MATCH_DEVICE |		\
 		       USB_DEVICE_ID_MATCH_INT_CLASS |		\
 		       USB_DEVICE_ID_MATCH_INT_PROTOCOL,	\
 	.idVendor = APPLE_VENDOR_ID,				\
 	.idProduct = (prod),					\
 	.bInterfaceClass = 0x03,				\
 	.bInterfaceProtocol = 0x02

 /* table of devices that work with this driver */
 static struct usb_device_id atp_table [] = {
 	{ ATP_DEVICE(FOUNTAIN_ANSI_PRODUCT_ID) },
 	{ ATP_DEVICE(FOUNTAIN_ISO_PRODUCT_ID) },
 	{ ATP_DEVICE(FOUNTAIN_TP_ONLY_PRODUCT_ID) },
 	{ ATP_DEVICE(GEYSER1_TP_ONLY_PRODUCT_ID) },

 	/* PowerBooks Oct 2005 */
 	{ ATP_DEVICE(GEYSER_ANSI_PRODUCT_ID) },
 	{ ATP_DEVICE(GEYSER_ISO_PRODUCT_ID) },
 	{ ATP_DEVICE(GEYSER_JIS_PRODUCT_ID) },

 	/* Core Duo MacBook & MacBook Pro */
 	{ ATP_DEVICE(GEYSER3_ANSI_PRODUCT_ID) },
 	{ ATP_DEVICE(GEYSER3_ISO_PRODUCT_ID) },
 	{ ATP_DEVICE(GEYSER3_JIS_PRODUCT_ID) },

 	/* Core2 Duo MacBook & MacBook Pro */
 	{ ATP_DEVICE(GEYSER4_ANSI_PRODUCT_ID) },
 	{ ATP_DEVICE(GEYSER4_ISO_PRODUCT_ID) },
 	{ ATP_DEVICE(GEYSER4_JIS_PRODUCT_ID) },

 	/* Terminating entry */
 	{ }
 };
 MODULE_DEVICE_TABLE (usb, atp_table);

 /*
  * number of sensors. Note that only 16 instead of 26 X (horizontal)
  * sensors exist on 12" and 15" PowerBooks. All models have 16 Y
  * (vertical) sensors.
  */
 #define ATP_XSENSORS	26
 #define ATP_YSENSORS	16

 /* amount of fuzz this touchpad generates */
 #define ATP_FUZZ	16

 /* maximum pressure this driver will report */
 #define ATP_PRESSURE	300
 /*
  * multiplication factor for the X and Y coordinates.
  * We try to keep the touchpad aspect ratio while still doing only simple
  * arithmetics.
  * The factors below give coordinates like:
  *	0 <= x <  960 on 12" and 15" Powerbooks
  *	0 <= x < 1600 on 17" Powerbooks
  *	0 <= y <  646
  */
 #define ATP_XFACT	64
 #define ATP_YFACT	43

 /*
  * Threshold for the touchpad sensors. Any change less than ATP_THRESHOLD is
  * ignored.
  */
 #define ATP_THRESHOLD	 5

 /* MacBook Pro (Geyser 3 & 4) initialization constants */
 #define ATP_GEYSER3_MODE_READ_REQUEST_ID 1
 #define ATP_GEYSER3_MODE_WRITE_REQUEST_ID 9
 #define ATP_GEYSER3_MODE_REQUEST_VALUE 0x300
 #define ATP_GEYSER3_MODE_REQUEST_INDEX 0
 #define ATP_GEYSER3_MODE_VENDOR_VALUE 0x04

 /* Structure to hold all of our device specific stuff */
 struct atp {
 	char			phys[64];
 	struct usb_device *	udev;		/* usb device */
 	struct urb *		urb;		/* usb request block */
 	signed char *		data;		/* transferred data */
 	int			open;		/* non-zero if opened */
 	struct input_dev	*input;		/* input dev */
 	int			valid;		/* are the sensors valid ? */
 	int			x_old;		/* last reported x/y, */
 	int			y_old;		/* used for smoothing */
 						/* current value of the sensors */
 	signed char		xy_cur[ATP_XSENSORS + ATP_YSENSORS];
 						/* last value of the sensors */
 	signed char		xy_old[ATP_XSENSORS + ATP_YSENSORS];
 						/* accumulated sensors */
 	int			xy_acc[ATP_XSENSORS + ATP_YSENSORS];
 	int			overflowwarn;	/* overflow warning printed? */
 	int			datalen;	/* size of an USB urb transfer */
 	int			idlecount;      /* number of empty packets */
 	struct work_struct      work;
 };

 #define dbg_dump(msg, tab) \
 	if (debug > 1) {						\
 		int i;							\
 		printk("appletouch: %s %lld", msg, (long long)jiffies); \
 		for (i = 0; i < ATP_XSENSORS + ATP_YSENSORS; i++)	\
 			printk(" %02x", tab[i]);			\
 		printk("\n");						\
 	}

 #define dprintk(format, a...)						\
 	do {								\
 		if (debug) printk(format, ##a);				\
 	} while (0)

 MODULE_AUTHOR("Johannes Berg, Stelian Pop, Frank Arnold, Michael Hanselmann");
 MODULE_DESCRIPTION("Apple PowerBooks USB touchpad driver");
 MODULE_LICENSE("GPL");

 /*
  * Make the threshold a module parameter
  */
 static int threshold = ATP_THRESHOLD;
 module_param(threshold, int, 0644);
 MODULE_PARM_DESC(threshold, "Discards any change in data from a sensor (trackpad has hundreds of these sensors) less than this value");

 static int debug = 1;
 module_param(debug, int, 0644);
 MODULE_PARM_DESC(debug, "Activate debugging output");

 /* Checks if the device a Geyser 2 (ANSI, ISO, JIS) */
 static inline int atp_is_geyser_2(struct atp *dev)
 {
 	u16 productId = le16_to_cpu(dev->udev->descriptor.idProduct);

 	return (productId == GEYSER_ANSI_PRODUCT_ID) ||
 		(productId == GEYSER_ISO_PRODUCT_ID) ||
 		(productId == GEYSER_JIS_PRODUCT_ID);
 }

 static inline int atp_is_geyser_3(struct atp *dev)
 {
 	u16 productId = le16_to_cpu(dev->udev->descriptor.idProduct);

 	return (productId == GEYSER3_ANSI_PRODUCT_ID) ||
 		(productId == GEYSER3_ISO_PRODUCT_ID) ||
 		(productId == GEYSER3_JIS_PRODUCT_ID) ||
 		(productId == GEYSER4_ANSI_PRODUCT_ID) ||
 		(productId == GEYSER4_ISO_PRODUCT_ID) ||
 		(productId == GEYSER4_JIS_PRODUCT_ID);
 }

 /*
  * By default Geyser 3 device sends standard USB HID mouse
  * packets (Report ID 2). This code changes device mode, so it
  * sends raw sensor reports (Report ID 5).
  */
 static int atp_geyser3_init(struct usb_device *udev)
 {
 	char data[8];
 	int size;

 	size = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
 			ATP_GEYSER3_MODE_READ_REQUEST_ID,
 			USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 			ATP_GEYSER3_MODE_REQUEST_VALUE,
 			ATP_GEYSER3_MODE_REQUEST_INDEX, &data, 8, 5000);

 	if (size != 8) {
 		err("Could not do mode read request from device"
 		    " (Geyser 3 mode)");
 		return -EIO;
 	}

 	/* Apply the mode switch */
 	data[0] = ATP_GEYSER3_MODE_VENDOR_VALUE;

 	size = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
 			ATP_GEYSER3_MODE_WRITE_REQUEST_ID,
 			USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 			ATP_GEYSER3_MODE_REQUEST_VALUE,
 			ATP_GEYSER3_MODE_REQUEST_INDEX, &data, 8, 5000);

 	if (size != 8) {
 		err("Could not do mode write request to device"
 		    " (Geyser 3 mode)");
 		return -EIO;
 	}
 	return 0;
 }

 /* Reinitialise the device if it's a geyser 3 */
 static void atp_reinit(struct work_struct *work)
 {
 	struct atp *dev = container_of(work, struct atp, work);
 	struct usb_device *udev = dev->udev;

 	dev->idlecount = 0;
 	atp_geyser3_init(udev);
 }

 static int atp_calculate_abs(int *xy_sensors, int nb_sensors, int fact,
 			     int *z, int *fingers)
 {
 	int i;
 	/* values to calculate mean */
 	int pcum = 0, psum = 0;
 	int is_increasing = 0;

 	*fingers = 0;

 	for (i = 0; i < nb_sensors; i++) {
 		if (xy_sensors[i] < threshold) {
 			if (is_increasing)
 				is_increasing = 0;

 			continue;
 		}

 		/*
 		 * Makes the finger detection more versatile.  For example,
 		 * two fingers with no gap will be detected.  Also, my
 		 * tests show it less likely to have intermittent loss
 		 * of multiple finger readings while moving around (scrolling).
 		 *
 		 * Changes the multiple finger detection to counting humps on
 		 * sensors (transitions from nonincreasing to increasing)
 		 * instead of counting transitions from low sensors (no
 		 * finger reading) to high sensors (finger above
 		 * sensor)
 		 *
 		 * - Jason Parekh <jasonparekh@gmail.com>
 		 */
 		if (i < 1 || (!is_increasing && xy_sensors[i - 1] < xy_sensors[i])) {
 			(*fingers)++;
 			is_increasing = 1;
 		} else if (i > 0 && xy_sensors[i - 1] >= xy_sensors[i]) {
 			is_increasing = 0;
 		}

 		/*
 		 * Subtracts threshold so a high sensor that just passes the threshold
 		 * won't skew the calculated absolute coordinate.  Fixes an issue
 		 * where slowly moving the mouse would occassionaly jump a number of
 		 * pixels (let me restate--slowly moving the mouse makes this issue
 		 * most apparent).
 		 */
 		pcum += (xy_sensors[i] - threshold) * i;
 		psum += (xy_sensors[i] - threshold);
 	}

 	if (psum > 0) {
 		*z = psum;
 		return pcum * fact / psum;
 	}

 	return 0;
 }

 static inline void atp_report_fingers(struct input_dev *input, int fingers)
 {
 	input_report_key(input, BTN_TOOL_FINGER, fingers == 1);
 	input_report_key(input, BTN_TOOL_DOUBLETAP, fingers == 2);
 	input_report_key(input, BTN_TOOL_TRIPLETAP, fingers > 2);
 }

 static void atp_complete(struct urb* urb)
 {
 	int x, y, x_z, y_z, x_f, y_f;
 	int retval, i, j;
 	int key;
 	struct atp *dev = urb->context;

 	switch (urb->status) {
 	case 0:
 		/* success */
 		break;
 	case -EOVERFLOW:
 		if(!dev->overflowwarn) {
 			printk("appletouch: OVERFLOW with data "
 				"length %d, actual length is %d\n",
 				dev->datalen, dev->urb->actual_length);
 			dev->overflowwarn = 1;
 		}
 	case -ECONNRESET:
 	case -ENOENT:
 	case -ESHUTDOWN:
 		/* This urb is terminated, clean up */
 		dbg("%s - urb shutting down with status: %d",
 		    __FUNCTION__, urb->status);
 		return;
 	default:
 		dbg("%s - nonzero urb status received: %d",
 		    __FUNCTION__, urb->status);
 		goto exit;
 	}

 	/* drop incomplete datasets */
 	if (dev->urb->actual_length != dev->datalen) {
 		dprintk("appletouch: incomplete data package"
 			" (first byte: %d, length: %d).\n",
 			dev->data[0], dev->urb->actual_length);
 		goto exit;
 	}

 	/* reorder the sensors values */
 	if (atp_is_geyser_3(dev)) {
 		memset(dev->xy_cur, 0, sizeof(dev->xy_cur));

 		/*
 		 * The values are laid out like this:
 		 * -, Y1, Y2, -, Y3, Y4, -, ..., -, X1, X2, -, X3, X4, ...
 		 * '-' is an unused value.
 		 */

 		/* read X values */
 		for (i = 0, j = 19; i < 20; i += 2, j += 3) {
 			dev->xy_cur[i] = dev->data[j + 1];
 			dev->xy_cur[i + 1] = dev->data[j + 2];
 		}
 		/* read Y values */
 		for (i = 0, j = 1; i < 9; i += 2, j += 3) {
 			dev->xy_cur[ATP_XSENSORS + i] = dev->data[j + 1];
 			dev->xy_cur[ATP_XSENSORS + i + 1] = dev->data[j + 2];
 		}
 	} else if (atp_is_geyser_2(dev)) {
 		memset(dev->xy_cur, 0, sizeof(dev->xy_cur));

 		/*
 		 * The values are laid out like this:
 		 * Y1, Y2, -, Y3, Y4, -, ..., X1, X2, -, X3, X4, -, ...
 		 * '-' is an unused value.
 		 */

 		/* read X values */
 		for (i = 0, j = 19; i < 20; i += 2, j += 3) {
 			dev->xy_cur[i] = dev->data[j];
 			dev->xy_cur[i + 1] = dev->data[j + 1];
 		}

 		/* read Y values */
 		for (i = 0, j = 1; i < 9; i += 2, j += 3) {
 			dev->xy_cur[ATP_XSENSORS + i] = dev->data[j];
 			dev->xy_cur[ATP_XSENSORS + i + 1] = dev->data[j + 1];
 		}
 	} else {
 		for (i = 0; i < 8; i++) {
 			/* X values */
 			dev->xy_cur[i     ] = dev->data[5 * i +  2];
 			dev->xy_cur[i +  8] = dev->data[5 * i +  4];
 			dev->xy_cur[i + 16] = dev->data[5 * i + 42];
 			if (i < 2)
 				dev->xy_cur[i + 24] = dev->data[5 * i + 44];

 			/* Y values */
 			dev->xy_cur[i + 26] = dev->data[5 * i +  1];
 			dev->xy_cur[i + 34] = dev->data[5 * i +  3];
 		}
 	}

 	dbg_dump("sample", dev->xy_cur);

 	if (!dev->valid) {
 		/* first sample */
 		dev->valid = 1;
 		dev->x_old = dev->y_old = -1;
 		memcpy(dev->xy_old, dev->xy_cur, sizeof(dev->xy_old));

 		if (atp_is_geyser_3(dev)) /* No 17" Macbooks (yet) */
 			goto exit;

 		/* 17" Powerbooks have extra X sensors */
 		for (i = (atp_is_geyser_2(dev)?15:16); i < ATP_XSENSORS; i++) {
 			if (!dev->xy_cur[i]) continue;

 			printk("appletouch: 17\" model detected.\n");
 			if(atp_is_geyser_2(dev))
 				input_set_abs_params(dev->input, ABS_X, 0,
 						     (20 - 1) *
 						     ATP_XFACT - 1,
 						     ATP_FUZZ, 0);
 			else
 				input_set_abs_params(dev->input, ABS_X, 0,
 						     (ATP_XSENSORS - 1) *
 						     ATP_XFACT - 1,
 						     ATP_FUZZ, 0);

 			break;
 		}

 		goto exit;
 	}

 	for (i = 0; i < ATP_XSENSORS + ATP_YSENSORS; i++) {
 		/* accumulate the change */
 		signed char change = dev->xy_old[i] - dev->xy_cur[i];
 		dev->xy_acc[i] -= change;

 		/* prevent down drifting */
 		if (dev->xy_acc[i] < 0)
 			dev->xy_acc[i] = 0;
 	}

 	memcpy(dev->xy_old, dev->xy_cur, sizeof(dev->xy_old));

 	dbg_dump("accumulator", dev->xy_acc);

 	x = atp_calculate_abs(dev->xy_acc, ATP_XSENSORS,
 			      ATP_XFACT, &x_z, &x_f);
 	y = atp_calculate_abs(dev->xy_acc + ATP_XSENSORS, ATP_YSENSORS,
 			      ATP_YFACT, &y_z, &y_f);
 	key = dev->data[dev->datalen - 1] & 1;

 	if (x && y) {
 		if (dev->x_old != -1) {
 			x = (dev->x_old * 3 + x) >> 2;
 			y = (dev->y_old * 3 + y) >> 2;
 			dev->x_old = x;
 			dev->y_old = y;

 			if (debug > 1)
 				printk("appletouch: X: %3d Y: %3d "
 				       "Xz: %3d Yz: %3d\n",
 				       x, y, x_z, y_z);

 			input_report_key(dev->input, BTN_TOUCH, 1);
 			input_report_abs(dev->input, ABS_X, x);
 			input_report_abs(dev->input, ABS_Y, y);
 			input_report_abs(dev->input, ABS_PRESSURE,
 					 min(ATP_PRESSURE, x_z + y_z));
 			atp_report_fingers(dev->input, max(x_f, y_f));
 		}
 		dev->x_old = x;
 		dev->y_old = y;

 	} else if (!x && !y) {

 		dev->x_old = dev->y_old = -1;
 		input_report_key(dev->input, BTN_TOUCH, 0);
 		input_report_abs(dev->input, ABS_PRESSURE, 0);
 		atp_report_fingers(dev->input, 0);

 		/* reset the accumulator on release */
 		memset(dev->xy_acc, 0, sizeof(dev->xy_acc));

 		/* Geyser 3 will continue to send packets continually after
 		   the first touch unless reinitialised. Do so if it's been
 		   idle for a while in order to avoid waking the kernel up
 		   several hundred times a second */
 		if (!key && atp_is_geyser_3(dev)) {
 			dev->idlecount++;
 			if (dev->idlecount == 10) {
 				dev->valid = 0;
 				schedule_work(&dev->work);
 			}
 		}
 	}

 	input_report_key(dev->input, BTN_LEFT, key);
 	input_sync(dev->input);

 exit:
 	retval = usb_submit_urb(dev->urb, GFP_ATOMIC);
 	if (retval) {
 		err("%s - usb_submit_urb failed with result %d",
 		    __FUNCTION__, retval);
 	}
 }

 static int atp_open(struct input_dev *input)
 {
 	struct atp *dev = input_get_drvdata(input);

 	if (usb_submit_urb(dev->urb, GFP_ATOMIC))
 		return -EIO;

 	dev->open = 1;
 	return 0;
 }

 static void atp_close(struct input_dev *input)
 {
 	struct atp *dev = input_get_drvdata(input);

 	usb_kill_urb(dev->urb);
 	cancel_work_sync(&dev->work);
 	dev->open = 0;
 }

 static int atp_probe(struct usb_interface *iface, const struct usb_device_id *id)
 {
 	struct atp *dev;
 	struct input_dev *input_dev;
 	struct usb_device *udev = interface_to_usbdev(iface);
 	struct usb_host_interface *iface_desc;
 	struct usb_endpoint_descriptor *endpoint;
 	int int_in_endpointAddr = 0;
 	int i, error = -ENOMEM;

 	/* set up the endpoint information */
 	/* use only the first interrupt-in endpoint */
 	iface_desc = iface->cur_altsetting;
 	for (i = 0; i < iface_desc->desc.bNumEndpoints; i++) {
 		endpoint = &iface_desc->endpoint[i].desc;
 		if (!int_in_endpointAddr && usb_endpoint_is_int_in(endpoint)) {
 			/* we found an interrupt in endpoint */
 			int_in_endpointAddr = endpoint->bEndpointAddress;
 			break;
 		}
 	}
 	if (!int_in_endpointAddr) {
 		err("Could not find int-in endpoint");
 		return -EIO;
 	}

 	/* allocate memory for our device state and initialize it */
 	dev = kzalloc(sizeof(struct atp), GFP_KERNEL);
 	input_dev = input_allocate_device();
 	if (!dev || !input_dev) {
 		err("Out of memory");
 		goto err_free_devs;
 	}

 	dev->udev = udev;
 	dev->input = input_dev;
 	dev->overflowwarn = 0;
 	if (atp_is_geyser_3(dev))
 		dev->datalen = 64;
 	else if (atp_is_geyser_2(dev))
 		dev->datalen = 64;
 	else
 		dev->datalen = 81;

 	if (atp_is_geyser_3(dev)) {
 		/* switch to raw sensor mode */
 		if (atp_geyser3_init(udev))
 			goto err_free_devs;

 		printk("appletouch Geyser 3 inited.\n");
 	}

 	dev->urb = usb_alloc_urb(0, GFP_KERNEL);
 	if (!dev->urb)
 		goto err_free_devs;

 	dev->data = usb_buffer_alloc(dev->udev, dev->datalen, GFP_KERNEL,
 				     &dev->urb->transfer_dma);
 	if (!dev->data)
 		goto err_free_urb;

 	usb_fill_int_urb(dev->urb, udev,
 			 usb_rcvintpipe(udev, int_in_endpointAddr),
 			 dev->data, dev->datalen, atp_complete, dev, 1);

 	usb_make_path(udev, dev->phys, sizeof(dev->phys));
 	strlcat(dev->phys, "/input0", sizeof(dev->phys));

 	input_dev->name = "appletouch";
 	input_dev->phys = dev->phys;
 	usb_to_input_id(dev->udev, &input_dev->id);
 	input_dev->dev.parent = &iface->dev;

 	input_set_drvdata(input_dev, dev);

 	input_dev->open = atp_open;
 	input_dev->close = atp_close;

 	set_bit(EV_ABS, input_dev->evbit);

 	if (atp_is_geyser_3(dev)) {
 		/*
 		 * MacBook have 20 X sensors, 10 Y sensors
 		 */
 		input_set_abs_params(input_dev, ABS_X, 0,
 				     ((20 - 1) * ATP_XFACT) - 1, ATP_FUZZ, 0);
 		input_set_abs_params(input_dev, ABS_Y, 0,
 				     ((10 - 1) * ATP_YFACT) - 1, ATP_FUZZ, 0);
 	} else if (atp_is_geyser_2(dev)) {
 		/*
 		 * Oct 2005 15" PowerBooks have 15 X sensors, 17" are detected
 		 * later.
 		 */
 		input_set_abs_params(input_dev, ABS_X, 0,
 				     ((15 - 1) * ATP_XFACT) - 1, ATP_FUZZ, 0);
 		input_set_abs_params(input_dev, ABS_Y, 0,
 				     ((9 - 1) * ATP_YFACT) - 1, ATP_FUZZ, 0);
 	} else {
 		/*
 		 * 12" and 15" Powerbooks only have 16 x sensors,
 		 * 17" models are detected later.
 		 */
 		input_set_abs_params(input_dev, ABS_X, 0,
 				     (16 - 1) * ATP_XFACT - 1, ATP_FUZZ, 0);
 		input_set_abs_params(input_dev, ABS_Y, 0,
 				     (ATP_YSENSORS - 1) * ATP_YFACT - 1, ATP_FUZZ, 0);
 	}
 	input_set_abs_params(input_dev, ABS_PRESSURE, 0, ATP_PRESSURE, 0, 0);

 	set_bit(EV_KEY, input_dev->evbit);
 	set_bit(BTN_TOUCH, input_dev->keybit);
 	set_bit(BTN_TOOL_FINGER, input_dev->keybit);
 	set_bit(BTN_TOOL_DOUBLETAP, input_dev->keybit);
 	set_bit(BTN_TOOL_TRIPLETAP, input_dev->keybit);
 	set_bit(BTN_LEFT, input_dev->keybit);

 	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);

 	INIT_WORK(&dev->work, atp_reinit);

 	return 0;

  err_free_buffer:
 	usb_buffer_free(dev->udev, dev->datalen,
 			dev->data, dev->urb->transfer_dma);
  err_free_urb:
 	usb_free_urb(dev->urb);
  err_free_devs:
 	usb_set_intfdata(iface, NULL);
 	kfree(dev);
 	input_free_device(input_dev);
 	return error;
 }

 static void atp_disconnect(struct usb_interface *iface)
 {
 	struct atp *dev = usb_get_intfdata(iface);

 	usb_set_intfdata(iface, NULL);
 	if (dev) {
 		usb_kill_urb(dev->urb);
 		input_unregister_device(dev->input);
 		usb_buffer_free(dev->udev, dev->datalen,
 				dev->data, dev->urb->transfer_dma);
 		usb_free_urb(dev->urb);
 		kfree(dev);
 	}
 	printk(KERN_INFO "input: appletouch disconnected\n");
 }

 static int atp_suspend(struct usb_interface *iface, pm_message_t message)
 {
 	struct atp *dev = usb_get_intfdata(iface);

 	usb_kill_urb(dev->urb);
 	dev->valid = 0;

 	return 0;
 }

 static int atp_resume(struct usb_interface *iface)
 {
 	struct atp *dev = usb_get_intfdata(iface);

 	if (dev->open && usb_submit_urb(dev->urb, GFP_ATOMIC))
 		return -EIO;

 	return 0;
 }

 static struct usb_driver atp_driver = {
 	.name		= "appletouch",
 	.probe		= atp_probe,
 	.disconnect	= atp_disconnect,
 	.suspend	= atp_suspend,
 	.resume		= atp_resume,
 	.id_table	= atp_table,
 };

 static int __init atp_init(void)
 {
 	return usb_register(&atp_driver);
 }

 static void __exit atp_exit(void)
 {
 	usb_deregister(&atp_driver);
 }

 module_init(atp_init);
 module_exit(atp_exit);
	/*
	* Apple USB Touchpad (for post-February 2005 PowerBooks and MacBooks) 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)
	*
	* Thanks to Alex Harper <basilisk@foobox.net> for his inputs.
	*
	* 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>

	/* Apple has powerbooks which have the keyboard with different Product IDs */
	#define APPLE_VENDOR_ID 0x05AC

	/* These names come from Info.plist in AppleUSBTrackpad.kext */
	#define FOUNTAIN_ANSI_PRODUCT_ID 0x020E
	#define FOUNTAIN_ISO_PRODUCT_ID 0x020F

	#define FOUNTAIN_TP_ONLY_PRODUCT_ID 0x030A

	#define GEYSER1_TP_ONLY_PRODUCT_ID 0x030B

	#define GEYSER_ANSI_PRODUCT_ID 0x0214
	#define GEYSER_ISO_PRODUCT_ID 0x0215
	#define GEYSER_JIS_PRODUCT_ID 0x0216

	/* MacBook devices */
	#define GEYSER3_ANSI_PRODUCT_ID 0x0217
	#define GEYSER3_ISO_PRODUCT_ID 0x0218
	#define GEYSER3_JIS_PRODUCT_ID 0x0219

	/*
	* Geyser IV: same as Geyser III according to Info.plist in AppleUSBTrackpad.kext
	* -> same IOClass (AppleUSBGrIIITrackpad), same acceleration tables
	*/
	#define GEYSER4_ANSI_PRODUCT_ID 0x021A
	#define GEYSER4_ISO_PRODUCT_ID 0x021B
	#define GEYSER4_JIS_PRODUCT_ID 0x021C

	#define ATP_DEVICE(prod) \
	.match_flags = USB_DEVICE_ID_MATCH_DEVICE \| \
	USB_DEVICE_ID_MATCH_INT_CLASS \| \
	USB_DEVICE_ID_MATCH_INT_PROTOCOL, \
	.idVendor = APPLE_VENDOR_ID, \
	.idProduct = (prod), \
	.bInterfaceClass = 0x03, \
	.bInterfaceProtocol = 0x02

	/* table of devices that work with this driver */
	static struct usb_device_id atp_table [] = {
	{ ATP_DEVICE(FOUNTAIN_ANSI_PRODUCT_ID) },
	{ ATP_DEVICE(FOUNTAIN_ISO_PRODUCT_ID) },
	{ ATP_DEVICE(FOUNTAIN_TP_ONLY_PRODUCT_ID) },
	{ ATP_DEVICE(GEYSER1_TP_ONLY_PRODUCT_ID) },

	/* PowerBooks Oct 2005 */
	{ ATP_DEVICE(GEYSER_ANSI_PRODUCT_ID) },
	{ ATP_DEVICE(GEYSER_ISO_PRODUCT_ID) },
	{ ATP_DEVICE(GEYSER_JIS_PRODUCT_ID) },

	/* Core Duo MacBook & MacBook Pro */
	{ ATP_DEVICE(GEYSER3_ANSI_PRODUCT_ID) },
	{ ATP_DEVICE(GEYSER3_ISO_PRODUCT_ID) },
	{ ATP_DEVICE(GEYSER3_JIS_PRODUCT_ID) },

	/* Core2 Duo MacBook & MacBook Pro */
	{ ATP_DEVICE(GEYSER4_ANSI_PRODUCT_ID) },
	{ ATP_DEVICE(GEYSER4_ISO_PRODUCT_ID) },
	{ ATP_DEVICE(GEYSER4_JIS_PRODUCT_ID) },

	/* Terminating entry */
	{ }
	};
	MODULE_DEVICE_TABLE (usb, atp_table);

	/*
	* number of sensors. Note that only 16 instead of 26 X (horizontal)
	* sensors exist on 12" and 15" PowerBooks. All models have 16 Y
	* (vertical) sensors.
	*/
	#define ATP_XSENSORS 26
	#define ATP_YSENSORS 16

	/* amount of fuzz this touchpad generates */
	#define ATP_FUZZ 16

	/* maximum pressure this driver will report */
	#define ATP_PRESSURE 300
	/*
	* multiplication factor for the X and Y coordinates.
	* We try to keep the touchpad aspect ratio while still doing only simple
	* arithmetics.
	* The factors below give coordinates like:
	* 0 <= x < 960 on 12" and 15" Powerbooks
	* 0 <= x < 1600 on 17" Powerbooks
	* 0 <= y < 646
	*/
	#define ATP_XFACT 64
	#define ATP_YFACT 43

	/*
	* Threshold for the touchpad sensors. Any change less than ATP_THRESHOLD is
	* ignored.
	*/
	#define ATP_THRESHOLD 5

	/* MacBook Pro (Geyser 3 & 4) initialization constants */
	#define ATP_GEYSER3_MODE_READ_REQUEST_ID 1
	#define ATP_GEYSER3_MODE_WRITE_REQUEST_ID 9
	#define ATP_GEYSER3_MODE_REQUEST_VALUE 0x300
	#define ATP_GEYSER3_MODE_REQUEST_INDEX 0
	#define ATP_GEYSER3_MODE_VENDOR_VALUE 0x04

	/* Structure to hold all of our device specific stuff */
	struct atp {
	char phys[64];
	struct usb_device * udev; /* usb device */
	struct urb * urb; /* usb request block */
	signed char * data; /* transferred data */
	int open; /* non-zero if opened */
	struct input_dev input; / input dev */
	int valid; /* are the sensors valid ? */
	int x_old; /* last reported x/y, */
	int y_old; /* used for smoothing */
	/* current value of the sensors */
	signed char xy_cur[ATP_XSENSORS + ATP_YSENSORS];
	/* last value of the sensors */
	signed char xy_old[ATP_XSENSORS + ATP_YSENSORS];
	/* accumulated sensors */
	int xy_acc[ATP_XSENSORS + ATP_YSENSORS];
	int overflowwarn; /* overflow warning printed? */
	int datalen; /* size of an USB urb transfer */
	int idlecount; /* number of empty packets */
	struct work_struct work;
	};

	#define dbg_dump(msg, tab) \
	if (debug > 1) { \
	int i; \
	printk("appletouch: %s %lld", msg, (long long)jiffies); \
	for (i = 0; i < ATP_XSENSORS + ATP_YSENSORS; i++) \
	printk(" %02x", tab[i]); \
	printk("\n"); \
	}

	#define dprintk(format, a...) \
	do { \
	if (debug) printk(format, ##a); \
	} while (0)

	MODULE_AUTHOR("Johannes Berg, Stelian Pop, Frank Arnold, Michael Hanselmann");
	MODULE_DESCRIPTION("Apple PowerBooks USB touchpad driver");
	MODULE_LICENSE("GPL");

	/*
	* Make the threshold a module parameter
	*/
	static int threshold = ATP_THRESHOLD;
	module_param(threshold, int, 0644);
	MODULE_PARM_DESC(threshold, "Discards any change in data from a sensor (trackpad has hundreds of these sensors) less than this value");

	static int debug = 1;
	module_param(debug, int, 0644);
	MODULE_PARM_DESC(debug, "Activate debugging output");

	/* Checks if the device a Geyser 2 (ANSI, ISO, JIS) */
	static inline int atp_is_geyser_2(struct atp *dev)
	{
	u16 productId = le16_to_cpu(dev->udev->descriptor.idProduct);

	return (productId == GEYSER_ANSI_PRODUCT_ID) \|\|
	(productId == GEYSER_ISO_PRODUCT_ID) \|\|
	(productId == GEYSER_JIS_PRODUCT_ID);
	}

	static inline int atp_is_geyser_3(struct atp *dev)
	{
	u16 productId = le16_to_cpu(dev->udev->descriptor.idProduct);

	return (productId == GEYSER3_ANSI_PRODUCT_ID) \|\|
	(productId == GEYSER3_ISO_PRODUCT_ID) \|\|
	(productId == GEYSER3_JIS_PRODUCT_ID) \|\|
	(productId == GEYSER4_ANSI_PRODUCT_ID) \|\|
	(productId == GEYSER4_ISO_PRODUCT_ID) \|\|
	(productId == GEYSER4_JIS_PRODUCT_ID);
	}

	/*
	* By default Geyser 3 device sends standard USB HID mouse
	* packets (Report ID 2). This code changes device mode, so it
	* sends raw sensor reports (Report ID 5).
	*/
	static int atp_geyser3_init(struct usb_device *udev)
	{
	char data[8];
	int size;

	size = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
	ATP_GEYSER3_MODE_READ_REQUEST_ID,
	USB_DIR_IN \| USB_TYPE_CLASS \| USB_RECIP_INTERFACE,
	ATP_GEYSER3_MODE_REQUEST_VALUE,
	ATP_GEYSER3_MODE_REQUEST_INDEX, &data, 8, 5000);

	if (size != 8) {
	err("Could not do mode read request from device"
	" (Geyser 3 mode)");
	return -EIO;
	}

	/* Apply the mode switch */
	data[0] = ATP_GEYSER3_MODE_VENDOR_VALUE;

	size = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
	ATP_GEYSER3_MODE_WRITE_REQUEST_ID,
	USB_DIR_OUT \| USB_TYPE_CLASS \| USB_RECIP_INTERFACE,
	ATP_GEYSER3_MODE_REQUEST_VALUE,
	ATP_GEYSER3_MODE_REQUEST_INDEX, &data, 8, 5000);

	if (size != 8) {
	err("Could not do mode write request to device"
	" (Geyser 3 mode)");
	return -EIO;
	}
	return 0;
	}

	/* Reinitialise the device if it's a geyser 3 */
	static void atp_reinit(struct work_struct *work)
	{
	struct atp *dev = container_of(work, struct atp, work);
	struct usb_device *udev = dev->udev;

	dev->idlecount = 0;
	atp_geyser3_init(udev);
	}

	static int atp_calculate_abs(int *xy_sensors, int nb_sensors, int fact,
	int z, int fingers)
	{
	int i;
	/* values to calculate mean */
	int pcum = 0, psum = 0;
	int is_increasing = 0;

	*fingers = 0;

	for (i = 0; i < nb_sensors; i++) {
	if (xy_sensors[i] < threshold) {
	if (is_increasing)
	is_increasing = 0;

	continue;
	}

	/*
	* Makes the finger detection more versatile. For example,
	* two fingers with no gap will be detected. Also, my
	* tests show it less likely to have intermittent loss
	* of multiple finger readings while moving around (scrolling).
	*
	* Changes the multiple finger detection to counting humps on
	* sensors (transitions from nonincreasing to increasing)
	* instead of counting transitions from low sensors (no
	* finger reading) to high sensors (finger above
	* sensor)
	*
	* - Jason Parekh <jasonparekh@gmail.com>
	*/
	if (i < 1 \|\| (!is_increasing && xy_sensors[i - 1] < xy_sensors[i])) {
	(*fingers)++;
	is_increasing = 1;
	} else if (i > 0 && xy_sensors[i - 1] >= xy_sensors[i]) {
	is_increasing = 0;
	}

	/*
	* Subtracts threshold so a high sensor that just passes the threshold
	* won't skew the calculated absolute coordinate. Fixes an issue
	* where slowly moving the mouse would occassionaly jump a number of
	* pixels (let me restate--slowly moving the mouse makes this issue
	* most apparent).
	*/
	pcum += (xy_sensors[i] - threshold) * i;
	psum += (xy_sensors[i] - threshold);
	}

	if (psum > 0) {
	*z = psum;
	return pcum * fact / psum;
	}

	return 0;
	}

	static inline void atp_report_fingers(struct input_dev *input, int fingers)
	{
	input_report_key(input, BTN_TOOL_FINGER, fingers == 1);
	input_report_key(input, BTN_TOOL_DOUBLETAP, fingers == 2);
	input_report_key(input, BTN_TOOL_TRIPLETAP, fingers > 2);
	}

	static void atp_complete(struct urb* urb)
	{
	int x, y, x_z, y_z, x_f, y_f;
	int retval, i, j;
	int key;
	struct atp *dev = urb->context;

	switch (urb->status) {
	case 0:
	/* success */
	break;
	case -EOVERFLOW:
	if(!dev->overflowwarn) {
	printk("appletouch: OVERFLOW with data "
	"length %d, actual length is %d\n",
	dev->datalen, dev->urb->actual_length);
	dev->overflowwarn = 1;
	}
	case -ECONNRESET:
	case -ENOENT:
	case -ESHUTDOWN:
	/* This urb is terminated, clean up */
	dbg("%s - urb shutting down with status: %d",
	__FUNCTION__, urb->status);
	return;
	default:
	dbg("%s - nonzero urb status received: %d",
	__FUNCTION__, urb->status);
	goto exit;
	}

	/* drop incomplete datasets */
	if (dev->urb->actual_length != dev->datalen) {
	dprintk("appletouch: incomplete data package"
	" (first byte: %d, length: %d).\n",
	dev->data[0], dev->urb->actual_length);
	goto exit;
	}

	/* reorder the sensors values */
	if (atp_is_geyser_3(dev)) {
	memset(dev->xy_cur, 0, sizeof(dev->xy_cur));

	/*
	* The values are laid out like this:
	* -, Y1, Y2, -, Y3, Y4, -, ..., -, X1, X2, -, X3, X4, ...
	* '-' is an unused value.
	*/

	/* read X values */
	for (i = 0, j = 19; i < 20; i += 2, j += 3) {
	dev->xy_cur[i] = dev->data[j + 1];
	dev->xy_cur[i + 1] = dev->data[j + 2];
	}
	/* read Y values */
	for (i = 0, j = 1; i < 9; i += 2, j += 3) {
	dev->xy_cur[ATP_XSENSORS + i] = dev->data[j + 1];
	dev->xy_cur[ATP_XSENSORS + i + 1] = dev->data[j + 2];
	}
	} else if (atp_is_geyser_2(dev)) {
	memset(dev->xy_cur, 0, sizeof(dev->xy_cur));

	/*
	* The values are laid out like this:
	* Y1, Y2, -, Y3, Y4, -, ..., X1, X2, -, X3, X4, -, ...
	* '-' is an unused value.
	*/

	/* read X values */
	for (i = 0, j = 19; i < 20; i += 2, j += 3) {
	dev->xy_cur[i] = dev->data[j];
	dev->xy_cur[i + 1] = dev->data[j + 1];
	}

	/* read Y values */
	for (i = 0, j = 1; i < 9; i += 2, j += 3) {
	dev->xy_cur[ATP_XSENSORS + i] = dev->data[j];
	dev->xy_cur[ATP_XSENSORS + i + 1] = dev->data[j + 1];
	}
	} else {
	for (i = 0; i < 8; i++) {
	/* X values */
	dev->xy_cur[i ] = dev->data[5 * i + 2];
	dev->xy_cur[i + 8] = dev->data[5 * i + 4];
	dev->xy_cur[i + 16] = dev->data[5 * i + 42];
	if (i < 2)
	dev->xy_cur[i + 24] = dev->data[5 * i + 44];

	/* Y values */
	dev->xy_cur[i + 26] = dev->data[5 * i + 1];
	dev->xy_cur[i + 34] = dev->data[5 * i + 3];
	}
	}

	dbg_dump("sample", dev->xy_cur);

	if (!dev->valid) {
	/* first sample */
	dev->valid = 1;
	dev->x_old = dev->y_old = -1;
	memcpy(dev->xy_old, dev->xy_cur, sizeof(dev->xy_old));

	if (atp_is_geyser_3(dev)) /* No 17" Macbooks (yet) */
	goto exit;

	/* 17" Powerbooks have extra X sensors */
	for (i = (atp_is_geyser_2(dev)?15:16); i < ATP_XSENSORS; i++) {
	if (!dev->xy_cur[i]) continue;

	printk("appletouch: 17\" model detected.\n");
	if(atp_is_geyser_2(dev))
	input_set_abs_params(dev->input, ABS_X, 0,
	(20 - 1) *
	ATP_XFACT - 1,
	ATP_FUZZ, 0);
	else
	input_set_abs_params(dev->input, ABS_X, 0,
	(ATP_XSENSORS - 1) *
	ATP_XFACT - 1,
	ATP_FUZZ, 0);

	break;
	}

	goto exit;
	}

	for (i = 0; i < ATP_XSENSORS + ATP_YSENSORS; i++) {
	/* accumulate the change */
	signed char change = dev->xy_old[i] - dev->xy_cur[i];
	dev->xy_acc[i] -= change;

	/* prevent down drifting */
	if (dev->xy_acc[i] < 0)
	dev->xy_acc[i] = 0;
	}

	memcpy(dev->xy_old, dev->xy_cur, sizeof(dev->xy_old));

	dbg_dump("accumulator", dev->xy_acc);

	x = atp_calculate_abs(dev->xy_acc, ATP_XSENSORS,
	ATP_XFACT, &x_z, &x_f);
	y = atp_calculate_abs(dev->xy_acc + ATP_XSENSORS, ATP_YSENSORS,
	ATP_YFACT, &y_z, &y_f);
	key = dev->data[dev->datalen - 1] & 1;

	if (x && y) {
	if (dev->x_old != -1) {
	x = (dev->x_old * 3 + x) >> 2;
	y = (dev->y_old * 3 + y) >> 2;
	dev->x_old = x;
	dev->y_old = y;

	if (debug > 1)
	printk("appletouch: X: %3d Y: %3d "
	"Xz: %3d Yz: %3d\n",
	x, y, x_z, y_z);

	input_report_key(dev->input, BTN_TOUCH, 1);
	input_report_abs(dev->input, ABS_X, x);
	input_report_abs(dev->input, ABS_Y, y);
	input_report_abs(dev->input, ABS_PRESSURE,
	min(ATP_PRESSURE, x_z + y_z));
	atp_report_fingers(dev->input, max(x_f, y_f));
	}
	dev->x_old = x;
	dev->y_old = y;

	} else if (!x && !y) {

	dev->x_old = dev->y_old = -1;
	input_report_key(dev->input, BTN_TOUCH, 0);
	input_report_abs(dev->input, ABS_PRESSURE, 0);
	atp_report_fingers(dev->input, 0);

	/* reset the accumulator on release */
	memset(dev->xy_acc, 0, sizeof(dev->xy_acc));

	/* Geyser 3 will continue to send packets continually after
	the first touch unless reinitialised. Do so if it's been
	idle for a while in order to avoid waking the kernel up
	several hundred times a second */
	if (!key && atp_is_geyser_3(dev)) {
	dev->idlecount++;
	if (dev->idlecount == 10) {
	dev->valid = 0;
	schedule_work(&dev->work);
	}
	}
	}

	input_report_key(dev->input, BTN_LEFT, key);
	input_sync(dev->input);

	exit:
	retval = usb_submit_urb(dev->urb, GFP_ATOMIC);
	if (retval) {
	err("%s - usb_submit_urb failed with result %d",
	__FUNCTION__, retval);
	}
	}

	static int atp_open(struct input_dev *input)
	{
	struct atp *dev = input_get_drvdata(input);

	if (usb_submit_urb(dev->urb, GFP_ATOMIC))
	return -EIO;

	dev->open = 1;
	return 0;
	}

	static void atp_close(struct input_dev *input)
	{
	struct atp *dev = input_get_drvdata(input);

	usb_kill_urb(dev->urb);
	cancel_work_sync(&dev->work);
	dev->open = 0;
	}

	static int atp_probe(struct usb_interface iface, const struct usb_device_id id)
	{
	struct atp *dev;
	struct input_dev *input_dev;
	struct usb_device *udev = interface_to_usbdev(iface);
	struct usb_host_interface *iface_desc;
	struct usb_endpoint_descriptor *endpoint;
	int int_in_endpointAddr = 0;
	int i, error = -ENOMEM;

	/* set up the endpoint information */
	/* use only the first interrupt-in endpoint */
	iface_desc = iface->cur_altsetting;
	for (i = 0; i < iface_desc->desc.bNumEndpoints; i++) {
	endpoint = &iface_desc->endpoint[i].desc;
	if (!int_in_endpointAddr && usb_endpoint_is_int_in(endpoint)) {
	/* we found an interrupt in endpoint */
	int_in_endpointAddr = endpoint->bEndpointAddress;
	break;
	}
	}
	if (!int_in_endpointAddr) {
	err("Could not find int-in endpoint");
	return -EIO;
	}

	/* allocate memory for our device state and initialize it */
	dev = kzalloc(sizeof(struct atp), GFP_KERNEL);
	input_dev = input_allocate_device();
	if (!dev \|\| !input_dev) {
	err("Out of memory");
	goto err_free_devs;
	}

	dev->udev = udev;
	dev->input = input_dev;
	dev->overflowwarn = 0;
	if (atp_is_geyser_3(dev))
	dev->datalen = 64;
	else if (atp_is_geyser_2(dev))
	dev->datalen = 64;
	else
	dev->datalen = 81;

	if (atp_is_geyser_3(dev)) {
	/* switch to raw sensor mode */
	if (atp_geyser3_init(udev))
	goto err_free_devs;

	printk("appletouch Geyser 3 inited.\n");
	}

	dev->urb = usb_alloc_urb(0, GFP_KERNEL);
	if (!dev->urb)
	goto err_free_devs;

	dev->data = usb_buffer_alloc(dev->udev, dev->datalen, GFP_KERNEL,
	&dev->urb->transfer_dma);
	if (!dev->data)
	goto err_free_urb;

	usb_fill_int_urb(dev->urb, udev,
	usb_rcvintpipe(udev, int_in_endpointAddr),
	dev->data, dev->datalen, atp_complete, dev, 1);

	usb_make_path(udev, dev->phys, sizeof(dev->phys));
	strlcat(dev->phys, "/input0", sizeof(dev->phys));

	input_dev->name = "appletouch";
	input_dev->phys = dev->phys;
	usb_to_input_id(dev->udev, &input_dev->id);
	input_dev->dev.parent = &iface->dev;

	input_set_drvdata(input_dev, dev);

	input_dev->open = atp_open;
	input_dev->close = atp_close;

	set_bit(EV_ABS, input_dev->evbit);

	if (atp_is_geyser_3(dev)) {
	/*
	* MacBook have 20 X sensors, 10 Y sensors
	*/
	input_set_abs_params(input_dev, ABS_X, 0,
	((20 - 1) * ATP_XFACT) - 1, ATP_FUZZ, 0);
	input_set_abs_params(input_dev, ABS_Y, 0,
	((10 - 1) * ATP_YFACT) - 1, ATP_FUZZ, 0);
	} else if (atp_is_geyser_2(dev)) {
	/*
	* Oct 2005 15" PowerBooks have 15 X sensors, 17" are detected
	* later.
	*/
	input_set_abs_params(input_dev, ABS_X, 0,
	((15 - 1) * ATP_XFACT) - 1, ATP_FUZZ, 0);
	input_set_abs_params(input_dev, ABS_Y, 0,
	((9 - 1) * ATP_YFACT) - 1, ATP_FUZZ, 0);
	} else {
	/*
	* 12" and 15" Powerbooks only have 16 x sensors,
	* 17" models are detected later.
	*/
	input_set_abs_params(input_dev, ABS_X, 0,
	(16 - 1) * ATP_XFACT - 1, ATP_FUZZ, 0);
	input_set_abs_params(input_dev, ABS_Y, 0,
	(ATP_YSENSORS - 1) * ATP_YFACT - 1, ATP_FUZZ, 0);
	}
	input_set_abs_params(input_dev, ABS_PRESSURE, 0, ATP_PRESSURE, 0, 0);

	set_bit(EV_KEY, input_dev->evbit);
	set_bit(BTN_TOUCH, input_dev->keybit);
	set_bit(BTN_TOOL_FINGER, input_dev->keybit);
	set_bit(BTN_TOOL_DOUBLETAP, input_dev->keybit);
	set_bit(BTN_TOOL_TRIPLETAP, input_dev->keybit);
	set_bit(BTN_LEFT, input_dev->keybit);

	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);

	INIT_WORK(&dev->work, atp_reinit);

	return 0;

	err_free_buffer:
	usb_buffer_free(dev->udev, dev->datalen,
	dev->data, dev->urb->transfer_dma);
	err_free_urb:
	usb_free_urb(dev->urb);
	err_free_devs:
	usb_set_intfdata(iface, NULL);
	kfree(dev);
	input_free_device(input_dev);
	return error;
	}

	static void atp_disconnect(struct usb_interface *iface)
	{
	struct atp *dev = usb_get_intfdata(iface);

	usb_set_intfdata(iface, NULL);
	if (dev) {
	usb_kill_urb(dev->urb);
	input_unregister_device(dev->input);
	usb_buffer_free(dev->udev, dev->datalen,
	dev->data, dev->urb->transfer_dma);
	usb_free_urb(dev->urb);
	kfree(dev);
	}
	printk(KERN_INFO "input: appletouch disconnected\n");
	}

	static int atp_suspend(struct usb_interface *iface, pm_message_t message)
	{
	struct atp *dev = usb_get_intfdata(iface);

	usb_kill_urb(dev->urb);
	dev->valid = 0;

	return 0;
	}

	static int atp_resume(struct usb_interface *iface)
	{
	struct atp *dev = usb_get_intfdata(iface);

	if (dev->open && usb_submit_urb(dev->urb, GFP_ATOMIC))
	return -EIO;

	return 0;
	}

	static struct usb_driver atp_driver = {
	.name = "appletouch",
	.probe = atp_probe,
	.disconnect = atp_disconnect,
	.suspend = atp_suspend,
	.resume = atp_resume,
	.id_table = atp_table,
	};

	static int __init atp_init(void)
	{
	return usb_register(&atp_driver);
	}

	static void __exit atp_exit(void)
	{
	usb_deregister(&atp_driver);
	}

	module_init(atp_init);
	module_exit(atp_exit);