xref: /openbmc/linux/drivers/input/mouse/appletouch.c (revision b8bb76713ec50df2f11efee386e16f93d51e1076)
1 /*
2  * Apple USB Touchpad (for post-February 2005 PowerBooks and MacBooks) driver
3  *
4  * Copyright (C) 2001-2004 Greg Kroah-Hartman (greg@kroah.com)
5  * Copyright (C) 2005-2008 Johannes Berg (johannes@sipsolutions.net)
6  * Copyright (C) 2005-2008 Stelian Pop (stelian@popies.net)
7  * Copyright (C) 2005      Frank Arnold (frank@scirocco-5v-turbo.de)
8  * Copyright (C) 2005      Peter Osterlund (petero2@telia.com)
9  * Copyright (C) 2005      Michael Hanselmann (linux-kernel@hansmi.ch)
10  * Copyright (C) 2006      Nicolas Boichat (nicolas@boichat.ch)
11  * Copyright (C) 2007-2008 Sven Anders (anders@anduras.de)
12  *
13  * Thanks to Alex Harper <basilisk@foobox.net> for his inputs.
14  *
15  * This program is free software; you can redistribute it and/or modify
16  * it under the terms of the GNU General Public License as published by
17  * the Free Software Foundation; either version 2 of the License, or
18  * (at your option) any later version.
19  *
20  * This program is distributed in the hope that it will be useful,
21  * but WITHOUT ANY WARRANTY; without even the implied warranty of
22  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
23  * GNU General Public License for more details.
24  *
25  * You should have received a copy of the GNU General Public License
26  * along with this program; if not, write to the Free Software
27  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
28  *
29  */
30 
31 #include <linux/kernel.h>
32 #include <linux/errno.h>
33 #include <linux/init.h>
34 #include <linux/slab.h>
35 #include <linux/module.h>
36 #include <linux/usb/input.h>
37 
38 /*
39  * Note: We try to keep the touchpad aspect ratio while still doing only
40  * simple arithmetics:
41  *	0 <= x <= (xsensors - 1) * xfact
42  *	0 <= y <= (ysensors - 1) * yfact
43  */
44 struct atp_info {
45 	int xsensors;				/* number of X sensors */
46 	int xsensors_17;			/* 17" models have more sensors */
47 	int ysensors;				/* number of Y sensors */
48 	int xfact;				/* X multiplication factor */
49 	int yfact;				/* Y multiplication factor */
50 	int datalen;				/* size of USB transfers */
51 	void (*callback)(struct urb *);		/* callback function */
52 };
53 
54 static void atp_complete_geyser_1_2(struct urb *urb);
55 static void atp_complete_geyser_3_4(struct urb *urb);
56 
57 static const struct atp_info fountain_info = {
58 	.xsensors	= 16,
59 	.xsensors_17	= 26,
60 	.ysensors	= 16,
61 	.xfact		= 64,
62 	.yfact		= 43,
63 	.datalen	= 81,
64 	.callback	= atp_complete_geyser_1_2,
65 };
66 
67 static const struct atp_info geyser1_info = {
68 	.xsensors	= 16,
69 	.xsensors_17	= 26,
70 	.ysensors	= 16,
71 	.xfact		= 64,
72 	.yfact		= 43,
73 	.datalen	= 81,
74 	.callback	= atp_complete_geyser_1_2,
75 };
76 
77 static const struct atp_info geyser2_info = {
78 	.xsensors	= 15,
79 	.xsensors_17	= 20,
80 	.ysensors	= 9,
81 	.xfact		= 64,
82 	.yfact		= 43,
83 	.datalen	= 64,
84 	.callback	= atp_complete_geyser_1_2,
85 };
86 
87 static const struct atp_info geyser3_info = {
88 	.xsensors	= 20,
89 	.ysensors	= 10,
90 	.xfact		= 64,
91 	.yfact		= 64,
92 	.datalen	= 64,
93 	.callback	= atp_complete_geyser_3_4,
94 };
95 
96 static const struct atp_info geyser4_info = {
97 	.xsensors	= 20,
98 	.ysensors	= 10,
99 	.xfact		= 64,
100 	.yfact		= 64,
101 	.datalen	= 64,
102 	.callback	= atp_complete_geyser_3_4,
103 };
104 
105 #define ATP_DEVICE(prod, info)					\
106 {								\
107 	.match_flags = USB_DEVICE_ID_MATCH_DEVICE |		\
108 		       USB_DEVICE_ID_MATCH_INT_CLASS |		\
109 		       USB_DEVICE_ID_MATCH_INT_PROTOCOL,	\
110 	.idVendor = 0x05ac, /* Apple */				\
111 	.idProduct = (prod),					\
112 	.bInterfaceClass = 0x03,				\
113 	.bInterfaceProtocol = 0x02,				\
114 	.driver_info = (unsigned long) &info,			\
115 }
116 
117 /*
118  * Table of devices (Product IDs) that work with this driver.
119  * (The names come from Info.plist in AppleUSBTrackpad.kext,
120  *  According to Info.plist Geyser IV is the same as Geyser III.)
121  */
122 
123 static struct usb_device_id atp_table[] = {
124 	/* PowerBooks Feb 2005, iBooks G4 */
125 	ATP_DEVICE(0x020e, fountain_info),	/* FOUNTAIN ANSI */
126 	ATP_DEVICE(0x020f, fountain_info),	/* FOUNTAIN ISO */
127 	ATP_DEVICE(0x030a, fountain_info),	/* FOUNTAIN TP ONLY */
128 	ATP_DEVICE(0x030b, geyser1_info),	/* GEYSER 1 TP ONLY */
129 
130 	/* PowerBooks Oct 2005 */
131 	ATP_DEVICE(0x0214, geyser2_info),	/* GEYSER 2 ANSI */
132 	ATP_DEVICE(0x0215, geyser2_info),	/* GEYSER 2 ISO */
133 	ATP_DEVICE(0x0216, geyser2_info),	/* GEYSER 2 JIS */
134 
135 	/* Core Duo MacBook & MacBook Pro */
136 	ATP_DEVICE(0x0217, geyser3_info),	/* GEYSER 3 ANSI */
137 	ATP_DEVICE(0x0218, geyser3_info),	/* GEYSER 3 ISO */
138 	ATP_DEVICE(0x0219, geyser3_info),	/* GEYSER 3 JIS */
139 
140 	/* Core2 Duo MacBook & MacBook Pro */
141 	ATP_DEVICE(0x021a, geyser4_info),	/* GEYSER 4 ANSI */
142 	ATP_DEVICE(0x021b, geyser4_info),	/* GEYSER 4 ISO */
143 	ATP_DEVICE(0x021c, geyser4_info),	/* GEYSER 4 JIS */
144 
145 	/* Core2 Duo MacBook3,1 */
146 	ATP_DEVICE(0x0229, geyser4_info),	/* GEYSER 4 HF ANSI */
147 	ATP_DEVICE(0x022a, geyser4_info),	/* GEYSER 4 HF ISO */
148 	ATP_DEVICE(0x022b, geyser4_info),	/* GEYSER 4 HF JIS */
149 
150 	/* Terminating entry */
151 	{ }
152 };
153 MODULE_DEVICE_TABLE(usb, atp_table);
154 
155 /* maximum number of sensors */
156 #define ATP_XSENSORS	26
157 #define ATP_YSENSORS	16
158 
159 /* amount of fuzz this touchpad generates */
160 #define ATP_FUZZ	16
161 
162 /* maximum pressure this driver will report */
163 #define ATP_PRESSURE	300
164 
165 /*
166  * Threshold for the touchpad sensors. Any change less than ATP_THRESHOLD is
167  * ignored.
168  */
169 #define ATP_THRESHOLD	 5
170 
171 /* Geyser initialization constants */
172 #define ATP_GEYSER_MODE_READ_REQUEST_ID		1
173 #define ATP_GEYSER_MODE_WRITE_REQUEST_ID	9
174 #define ATP_GEYSER_MODE_REQUEST_VALUE		0x300
175 #define ATP_GEYSER_MODE_REQUEST_INDEX		0
176 #define ATP_GEYSER_MODE_VENDOR_VALUE		0x04
177 
178 /**
179  * enum atp_status_bits - status bit meanings
180  *
181  * These constants represent the meaning of the status bits.
182  * (only Geyser 3/4)
183  *
184  * @ATP_STATUS_BUTTON: The button was pressed
185  * @ATP_STATUS_BASE_UPDATE: Update of the base values (untouched pad)
186  * @ATP_STATUS_FROM_RESET: Reset previously performed
187  */
188 enum atp_status_bits {
189 	ATP_STATUS_BUTTON	= BIT(0),
190 	ATP_STATUS_BASE_UPDATE	= BIT(2),
191 	ATP_STATUS_FROM_RESET	= BIT(4),
192 };
193 
194 /* Structure to hold all of our device specific stuff */
195 struct atp {
196 	char			phys[64];
197 	struct usb_device	*udev;		/* usb device */
198 	struct urb		*urb;		/* usb request block */
199 	u8			*data;		/* transferred data */
200 	struct input_dev	*input;		/* input dev */
201 	const struct atp_info	*info;		/* touchpad model */
202 	bool			open;
203 	bool			valid;		/* are the samples valid? */
204 	bool			size_detect_done;
205 	bool			overflow_warned;
206 	int			x_old;		/* last reported x/y, */
207 	int			y_old;		/* used for smoothing */
208 	signed char		xy_cur[ATP_XSENSORS + ATP_YSENSORS];
209 	signed char		xy_old[ATP_XSENSORS + ATP_YSENSORS];
210 	int			xy_acc[ATP_XSENSORS + ATP_YSENSORS];
211 	int			idlecount;	/* number of empty packets */
212 	struct work_struct	work;
213 };
214 
215 #define dbg_dump(msg, tab) \
216 	if (debug > 1) {						\
217 		int __i;						\
218 		printk(KERN_DEBUG "appletouch: %s", msg);		\
219 		for (__i = 0; __i < ATP_XSENSORS + ATP_YSENSORS; __i++)	\
220 			printk(" %02x", tab[__i]);			\
221 		printk("\n");						\
222 	}
223 
224 #define dprintk(format, a...)						\
225 	do {								\
226 		if (debug)						\
227 			printk(KERN_DEBUG format, ##a);			\
228 	} while (0)
229 
230 MODULE_AUTHOR("Johannes Berg");
231 MODULE_AUTHOR("Stelian Pop");
232 MODULE_AUTHOR("Frank Arnold");
233 MODULE_AUTHOR("Michael Hanselmann");
234 MODULE_AUTHOR("Sven Anders");
235 MODULE_DESCRIPTION("Apple PowerBook and MacBook USB touchpad driver");
236 MODULE_LICENSE("GPL");
237 
238 /*
239  * Make the threshold a module parameter
240  */
241 static int threshold = ATP_THRESHOLD;
242 module_param(threshold, int, 0644);
243 MODULE_PARM_DESC(threshold, "Discard any change in data from a sensor"
244 			    " (the trackpad has many of these sensors)"
245 			    " less than this value.");
246 
247 static int debug;
248 module_param(debug, int, 0644);
249 MODULE_PARM_DESC(debug, "Activate debugging output");
250 
251 /*
252  * By default newer Geyser devices send standard USB HID mouse
253  * packets (Report ID 2). This code changes device mode, so it
254  * sends raw sensor reports (Report ID 5).
255  */
256 static int atp_geyser_init(struct usb_device *udev)
257 {
258 	char data[8];
259 	int size;
260 	int i;
261 
262 	size = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
263 			ATP_GEYSER_MODE_READ_REQUEST_ID,
264 			USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
265 			ATP_GEYSER_MODE_REQUEST_VALUE,
266 			ATP_GEYSER_MODE_REQUEST_INDEX, &data, 8, 5000);
267 
268 	if (size != 8) {
269 		dprintk("atp_geyser_init: read error\n");
270 		for (i = 0; i < 8; i++)
271 			dprintk("appletouch[%d]: %d\n", i, data[i]);
272 
273 		err("Failed to read mode from device.");
274 		return -EIO;
275 	}
276 
277 	/* Apply the mode switch */
278 	data[0] = ATP_GEYSER_MODE_VENDOR_VALUE;
279 
280 	size = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
281 			ATP_GEYSER_MODE_WRITE_REQUEST_ID,
282 			USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
283 			ATP_GEYSER_MODE_REQUEST_VALUE,
284 			ATP_GEYSER_MODE_REQUEST_INDEX, &data, 8, 5000);
285 
286 	if (size != 8) {
287 		dprintk("atp_geyser_init: write error\n");
288 		for (i = 0; i < 8; i++)
289 			dprintk("appletouch[%d]: %d\n", i, data[i]);
290 
291 		err("Failed to request geyser raw mode");
292 		return -EIO;
293 	}
294 	return 0;
295 }
296 
297 /*
298  * Reinitialise the device. This usually stops stream of empty packets
299  * coming from it.
300  */
301 static void atp_reinit(struct work_struct *work)
302 {
303 	struct atp *dev = container_of(work, struct atp, work);
304 	struct usb_device *udev = dev->udev;
305 	int retval;
306 
307 	dprintk("appletouch: putting appletouch to sleep (reinit)\n");
308 	atp_geyser_init(udev);
309 
310 	retval = usb_submit_urb(dev->urb, GFP_ATOMIC);
311 	if (retval)
312 		err("atp_reinit: usb_submit_urb failed with error %d",
313 		    retval);
314 }
315 
316 static int atp_calculate_abs(int *xy_sensors, int nb_sensors, int fact,
317 			     int *z, int *fingers)
318 {
319 	int i;
320 	/* values to calculate mean */
321 	int pcum = 0, psum = 0;
322 	int is_increasing = 0;
323 
324 	*fingers = 0;
325 
326 	for (i = 0; i < nb_sensors; i++) {
327 		if (xy_sensors[i] < threshold) {
328 			if (is_increasing)
329 				is_increasing = 0;
330 
331 			continue;
332 		}
333 
334 		/*
335 		 * Makes the finger detection more versatile.  For example,
336 		 * two fingers with no gap will be detected.  Also, my
337 		 * tests show it less likely to have intermittent loss
338 		 * of multiple finger readings while moving around (scrolling).
339 		 *
340 		 * Changes the multiple finger detection to counting humps on
341 		 * sensors (transitions from nonincreasing to increasing)
342 		 * instead of counting transitions from low sensors (no
343 		 * finger reading) to high sensors (finger above
344 		 * sensor)
345 		 *
346 		 * - Jason Parekh <jasonparekh@gmail.com>
347 		 */
348 		if (i < 1 ||
349 		    (!is_increasing && xy_sensors[i - 1] < xy_sensors[i])) {
350 			(*fingers)++;
351 			is_increasing = 1;
352 		} else if (i > 0 && xy_sensors[i - 1] >= xy_sensors[i]) {
353 			is_increasing = 0;
354 		}
355 
356 		/*
357 		 * Subtracts threshold so a high sensor that just passes the
358 		 * threshold won't skew the calculated absolute coordinate.
359 		 * Fixes an issue where slowly moving the mouse would
360 		 * occasionally jump a number of pixels (slowly moving the
361 		 * finger makes this issue most apparent.)
362 		 */
363 		pcum += (xy_sensors[i] - threshold) * i;
364 		psum += (xy_sensors[i] - threshold);
365 	}
366 
367 	if (psum > 0) {
368 		*z = psum;
369 		return pcum * fact / psum;
370 	}
371 
372 	return 0;
373 }
374 
375 static inline void atp_report_fingers(struct input_dev *input, int fingers)
376 {
377 	input_report_key(input, BTN_TOOL_FINGER, fingers == 1);
378 	input_report_key(input, BTN_TOOL_DOUBLETAP, fingers == 2);
379 	input_report_key(input, BTN_TOOL_TRIPLETAP, fingers > 2);
380 }
381 
382 /* Check URB status and for correct length of data package */
383 
384 #define ATP_URB_STATUS_SUCCESS		0
385 #define ATP_URB_STATUS_ERROR		1
386 #define ATP_URB_STATUS_ERROR_FATAL	2
387 
388 static int atp_status_check(struct urb *urb)
389 {
390 	struct atp *dev = urb->context;
391 
392 	switch (urb->status) {
393 	case 0:
394 		/* success */
395 		break;
396 	case -EOVERFLOW:
397 		if (!dev->overflow_warned) {
398 			printk(KERN_WARNING "appletouch: OVERFLOW with data "
399 				"length %d, actual length is %d\n",
400 				dev->info->datalen, dev->urb->actual_length);
401 			dev->overflow_warned = true;
402 		}
403 	case -ECONNRESET:
404 	case -ENOENT:
405 	case -ESHUTDOWN:
406 		/* This urb is terminated, clean up */
407 		dbg("atp_complete: urb shutting down with status: %d",
408 		    urb->status);
409 		return ATP_URB_STATUS_ERROR_FATAL;
410 
411 	default:
412 		dbg("atp_complete: nonzero urb status received: %d",
413 		    urb->status);
414 		return ATP_URB_STATUS_ERROR;
415 	}
416 
417 	/* drop incomplete datasets */
418 	if (dev->urb->actual_length != dev->info->datalen) {
419 		dprintk("appletouch: incomplete data package"
420 			" (first byte: %d, length: %d).\n",
421 			dev->data[0], dev->urb->actual_length);
422 		return ATP_URB_STATUS_ERROR;
423 	}
424 
425 	return ATP_URB_STATUS_SUCCESS;
426 }
427 
428 static void atp_detect_size(struct atp *dev)
429 {
430 	int i;
431 
432 	/* 17" Powerbooks have extra X sensors */
433 	for (i = dev->info->xsensors; i < ATP_XSENSORS; i++) {
434 		if (dev->xy_cur[i]) {
435 
436 			printk(KERN_INFO "appletouch: 17\" model detected.\n");
437 
438 			input_set_abs_params(dev->input, ABS_X, 0,
439 					     (dev->info->xsensors_17 - 1) *
440 							dev->info->xfact - 1,
441 					     ATP_FUZZ, 0);
442 			break;
443 		}
444 	}
445 }
446 
447 /*
448  * USB interrupt callback functions
449  */
450 
451 /* Interrupt function for older touchpads: FOUNTAIN/GEYSER1/GEYSER2 */
452 
453 static void atp_complete_geyser_1_2(struct urb *urb)
454 {
455 	int x, y, x_z, y_z, x_f, y_f;
456 	int retval, i, j;
457 	int key;
458 	struct atp *dev = urb->context;
459 	int status = atp_status_check(urb);
460 
461 	if (status == ATP_URB_STATUS_ERROR_FATAL)
462 		return;
463 	else if (status == ATP_URB_STATUS_ERROR)
464 		goto exit;
465 
466 	/* reorder the sensors values */
467 	if (dev->info == &geyser2_info) {
468 		memset(dev->xy_cur, 0, sizeof(dev->xy_cur));
469 
470 		/*
471 		 * The values are laid out like this:
472 		 * Y1, Y2, -, Y3, Y4, -, ..., X1, X2, -, X3, X4, -, ...
473 		 * '-' is an unused value.
474 		 */
475 
476 		/* read X values */
477 		for (i = 0, j = 19; i < 20; i += 2, j += 3) {
478 			dev->xy_cur[i] = dev->data[j];
479 			dev->xy_cur[i + 1] = dev->data[j + 1];
480 		}
481 
482 		/* read Y values */
483 		for (i = 0, j = 1; i < 9; i += 2, j += 3) {
484 			dev->xy_cur[ATP_XSENSORS + i] = dev->data[j];
485 			dev->xy_cur[ATP_XSENSORS + i + 1] = dev->data[j + 1];
486 		}
487 	} else {
488 		for (i = 0; i < 8; i++) {
489 			/* X values */
490 			dev->xy_cur[i +  0] = dev->data[5 * i +  2];
491 			dev->xy_cur[i +  8] = dev->data[5 * i +  4];
492 			dev->xy_cur[i + 16] = dev->data[5 * i + 42];
493 			if (i < 2)
494 				dev->xy_cur[i + 24] = dev->data[5 * i + 44];
495 
496 			/* Y values */
497 			dev->xy_cur[ATP_XSENSORS + i] = dev->data[5 * i +  1];
498 			dev->xy_cur[ATP_XSENSORS + i + 8] = dev->data[5 * i + 3];
499 		}
500 	}
501 
502 	dbg_dump("sample", dev->xy_cur);
503 
504 	if (!dev->valid) {
505 		/* first sample */
506 		dev->valid = true;
507 		dev->x_old = dev->y_old = -1;
508 
509 		/* Store first sample */
510 		memcpy(dev->xy_old, dev->xy_cur, sizeof(dev->xy_old));
511 
512 		/* Perform size detection, if not done already */
513 		if (unlikely(!dev->size_detect_done)) {
514 			atp_detect_size(dev);
515 			dev->size_detect_done = 1;
516 			goto exit;
517 		}
518 	}
519 
520 	for (i = 0; i < ATP_XSENSORS + ATP_YSENSORS; i++) {
521 		/* accumulate the change */
522 		signed char change = dev->xy_old[i] - dev->xy_cur[i];
523 		dev->xy_acc[i] -= change;
524 
525 		/* prevent down drifting */
526 		if (dev->xy_acc[i] < 0)
527 			dev->xy_acc[i] = 0;
528 	}
529 
530 	memcpy(dev->xy_old, dev->xy_cur, sizeof(dev->xy_old));
531 
532 	dbg_dump("accumulator", dev->xy_acc);
533 
534 	x = atp_calculate_abs(dev->xy_acc, ATP_XSENSORS,
535 			      dev->info->xfact, &x_z, &x_f);
536 	y = atp_calculate_abs(dev->xy_acc + ATP_XSENSORS, ATP_YSENSORS,
537 			      dev->info->yfact, &y_z, &y_f);
538 	key = dev->data[dev->info->datalen - 1] & ATP_STATUS_BUTTON;
539 
540 	if (x && y) {
541 		if (dev->x_old != -1) {
542 			x = (dev->x_old * 3 + x) >> 2;
543 			y = (dev->y_old * 3 + y) >> 2;
544 			dev->x_old = x;
545 			dev->y_old = y;
546 
547 			if (debug > 1)
548 				printk(KERN_DEBUG "appletouch: "
549 					"X: %3d Y: %3d Xz: %3d Yz: %3d\n",
550 					x, y, x_z, y_z);
551 
552 			input_report_key(dev->input, BTN_TOUCH, 1);
553 			input_report_abs(dev->input, ABS_X, x);
554 			input_report_abs(dev->input, ABS_Y, y);
555 			input_report_abs(dev->input, ABS_PRESSURE,
556 					 min(ATP_PRESSURE, x_z + y_z));
557 			atp_report_fingers(dev->input, max(x_f, y_f));
558 		}
559 		dev->x_old = x;
560 		dev->y_old = y;
561 
562 	} else if (!x && !y) {
563 
564 		dev->x_old = dev->y_old = -1;
565 		input_report_key(dev->input, BTN_TOUCH, 0);
566 		input_report_abs(dev->input, ABS_PRESSURE, 0);
567 		atp_report_fingers(dev->input, 0);
568 
569 		/* reset the accumulator on release */
570 		memset(dev->xy_acc, 0, sizeof(dev->xy_acc));
571 	}
572 
573 	input_report_key(dev->input, BTN_LEFT, key);
574 	input_sync(dev->input);
575 
576  exit:
577 	retval = usb_submit_urb(dev->urb, GFP_ATOMIC);
578 	if (retval)
579 		err("atp_complete: usb_submit_urb failed with result %d",
580 		    retval);
581 }
582 
583 /* Interrupt function for older touchpads: GEYSER3/GEYSER4 */
584 
585 static void atp_complete_geyser_3_4(struct urb *urb)
586 {
587 	int x, y, x_z, y_z, x_f, y_f;
588 	int retval, i, j;
589 	int key;
590 	struct atp *dev = urb->context;
591 	int status = atp_status_check(urb);
592 
593 	if (status == ATP_URB_STATUS_ERROR_FATAL)
594 		return;
595 	else if (status == ATP_URB_STATUS_ERROR)
596 		goto exit;
597 
598 	/* Reorder the sensors values:
599 	 *
600 	 * The values are laid out like this:
601 	 * -, Y1, Y2, -, Y3, Y4, -, ..., -, X1, X2, -, X3, X4, ...
602 	 * '-' is an unused value.
603 	 */
604 
605 	/* read X values */
606 	for (i = 0, j = 19; i < 20; i += 2, j += 3) {
607 		dev->xy_cur[i] = dev->data[j + 1];
608 		dev->xy_cur[i + 1] = dev->data[j + 2];
609 	}
610 	/* read Y values */
611 	for (i = 0, j = 1; i < 9; i += 2, j += 3) {
612 		dev->xy_cur[ATP_XSENSORS + i] = dev->data[j + 1];
613 		dev->xy_cur[ATP_XSENSORS + i + 1] = dev->data[j + 2];
614 	}
615 
616 	dbg_dump("sample", dev->xy_cur);
617 
618 	/* Just update the base values (i.e. touchpad in untouched state) */
619 	if (dev->data[dev->info->datalen - 1] & ATP_STATUS_BASE_UPDATE) {
620 
621 		dprintk(KERN_DEBUG "appletouch: updated base values\n");
622 
623 		memcpy(dev->xy_old, dev->xy_cur, sizeof(dev->xy_old));
624 		goto exit;
625 	}
626 
627 	for (i = 0; i < ATP_XSENSORS + ATP_YSENSORS; i++) {
628 		/* calculate the change */
629 		dev->xy_acc[i] = dev->xy_cur[i] - dev->xy_old[i];
630 
631 		/* this is a round-robin value, so couple with that */
632 		if (dev->xy_acc[i] > 127)
633 			dev->xy_acc[i] -= 256;
634 
635 		if (dev->xy_acc[i] < -127)
636 			dev->xy_acc[i] += 256;
637 
638 		/* prevent down drifting */
639 		if (dev->xy_acc[i] < 0)
640 			dev->xy_acc[i] = 0;
641 	}
642 
643 	dbg_dump("accumulator", dev->xy_acc);
644 
645 	x = atp_calculate_abs(dev->xy_acc, ATP_XSENSORS,
646 			      dev->info->xfact, &x_z, &x_f);
647 	y = atp_calculate_abs(dev->xy_acc + ATP_XSENSORS, ATP_YSENSORS,
648 			      dev->info->yfact, &y_z, &y_f);
649 	key = dev->data[dev->info->datalen - 1] & ATP_STATUS_BUTTON;
650 
651 	if (x && y) {
652 		if (dev->x_old != -1) {
653 			x = (dev->x_old * 3 + x) >> 2;
654 			y = (dev->y_old * 3 + y) >> 2;
655 			dev->x_old = x;
656 			dev->y_old = y;
657 
658 			if (debug > 1)
659 				printk(KERN_DEBUG "appletouch: X: %3d Y: %3d "
660 				       "Xz: %3d Yz: %3d\n",
661 				       x, y, x_z, y_z);
662 
663 			input_report_key(dev->input, BTN_TOUCH, 1);
664 			input_report_abs(dev->input, ABS_X, x);
665 			input_report_abs(dev->input, ABS_Y, y);
666 			input_report_abs(dev->input, ABS_PRESSURE,
667 					 min(ATP_PRESSURE, x_z + y_z));
668 			atp_report_fingers(dev->input, max(x_f, y_f));
669 		}
670 		dev->x_old = x;
671 		dev->y_old = y;
672 
673 	} else if (!x && !y) {
674 
675 		dev->x_old = dev->y_old = -1;
676 		input_report_key(dev->input, BTN_TOUCH, 0);
677 		input_report_abs(dev->input, ABS_PRESSURE, 0);
678 		atp_report_fingers(dev->input, 0);
679 
680 		/* reset the accumulator on release */
681 		memset(dev->xy_acc, 0, sizeof(dev->xy_acc));
682 	}
683 
684 	input_report_key(dev->input, BTN_LEFT, key);
685 	input_sync(dev->input);
686 
687 	/*
688 	 * Geysers 3/4 will continue to send packets continually after
689 	 * the first touch unless reinitialised. Do so if it's been
690 	 * idle for a while in order to avoid waking the kernel up
691 	 * several hundred times a second.
692 	 */
693 
694 	/*
695 	 * Button must not be pressed when entering suspend,
696 	 * otherwise we will never release the button.
697 	 */
698 	if (!x && !y && !key) {
699 		dev->idlecount++;
700 		if (dev->idlecount == 10) {
701 			dev->x_old = dev->y_old = -1;
702 			dev->idlecount = 0;
703 			schedule_work(&dev->work);
704 			/* Don't resubmit urb here, wait for reinit */
705 			return;
706 		}
707 	} else
708 		dev->idlecount = 0;
709 
710  exit:
711 	retval = usb_submit_urb(dev->urb, GFP_ATOMIC);
712 	if (retval)
713 		err("atp_complete: usb_submit_urb failed with result %d",
714 		    retval);
715 }
716 
717 static int atp_open(struct input_dev *input)
718 {
719 	struct atp *dev = input_get_drvdata(input);
720 
721 	if (usb_submit_urb(dev->urb, GFP_ATOMIC))
722 		return -EIO;
723 
724 	dev->open = 1;
725 	return 0;
726 }
727 
728 static void atp_close(struct input_dev *input)
729 {
730 	struct atp *dev = input_get_drvdata(input);
731 
732 	usb_kill_urb(dev->urb);
733 	cancel_work_sync(&dev->work);
734 	dev->open = 0;
735 }
736 
737 static int atp_handle_geyser(struct atp *dev)
738 {
739 	struct usb_device *udev = dev->udev;
740 
741 	if (dev->info != &fountain_info) {
742 		/* switch to raw sensor mode */
743 		if (atp_geyser_init(udev))
744 			return -EIO;
745 
746 		printk(KERN_INFO "appletouch: Geyser mode initialized.\n");
747 	}
748 
749 	return 0;
750 }
751 
752 static int atp_probe(struct usb_interface *iface,
753 		     const struct usb_device_id *id)
754 {
755 	struct atp *dev;
756 	struct input_dev *input_dev;
757 	struct usb_device *udev = interface_to_usbdev(iface);
758 	struct usb_host_interface *iface_desc;
759 	struct usb_endpoint_descriptor *endpoint;
760 	int int_in_endpointAddr = 0;
761 	int i, error = -ENOMEM;
762 	const struct atp_info *info = (const struct atp_info *)id->driver_info;
763 
764 	/* set up the endpoint information */
765 	/* use only the first interrupt-in endpoint */
766 	iface_desc = iface->cur_altsetting;
767 	for (i = 0; i < iface_desc->desc.bNumEndpoints; i++) {
768 		endpoint = &iface_desc->endpoint[i].desc;
769 		if (!int_in_endpointAddr && usb_endpoint_is_int_in(endpoint)) {
770 			/* we found an interrupt in endpoint */
771 			int_in_endpointAddr = endpoint->bEndpointAddress;
772 			break;
773 		}
774 	}
775 	if (!int_in_endpointAddr) {
776 		err("Could not find int-in endpoint");
777 		return -EIO;
778 	}
779 
780 	/* allocate memory for our device state and initialize it */
781 	dev = kzalloc(sizeof(struct atp), GFP_KERNEL);
782 	input_dev = input_allocate_device();
783 	if (!dev || !input_dev) {
784 		err("Out of memory");
785 		goto err_free_devs;
786 	}
787 
788 	dev->udev = udev;
789 	dev->input = input_dev;
790 	dev->info = info;
791 	dev->overflow_warned = false;
792 
793 	dev->urb = usb_alloc_urb(0, GFP_KERNEL);
794 	if (!dev->urb)
795 		goto err_free_devs;
796 
797 	dev->data = usb_buffer_alloc(dev->udev, dev->info->datalen, GFP_KERNEL,
798 				     &dev->urb->transfer_dma);
799 	if (!dev->data)
800 		goto err_free_urb;
801 
802 	usb_fill_int_urb(dev->urb, udev,
803 			 usb_rcvintpipe(udev, int_in_endpointAddr),
804 			 dev->data, dev->info->datalen,
805 			 dev->info->callback, dev, 1);
806 
807 	error = atp_handle_geyser(dev);
808 	if (error)
809 		goto err_free_buffer;
810 
811 	usb_make_path(udev, dev->phys, sizeof(dev->phys));
812 	strlcat(dev->phys, "/input0", sizeof(dev->phys));
813 
814 	input_dev->name = "appletouch";
815 	input_dev->phys = dev->phys;
816 	usb_to_input_id(dev->udev, &input_dev->id);
817 	input_dev->dev.parent = &iface->dev;
818 
819 	input_set_drvdata(input_dev, dev);
820 
821 	input_dev->open = atp_open;
822 	input_dev->close = atp_close;
823 
824 	set_bit(EV_ABS, input_dev->evbit);
825 
826 	input_set_abs_params(input_dev, ABS_X, 0,
827 			     (dev->info->xsensors - 1) * dev->info->xfact - 1,
828 			     ATP_FUZZ, 0);
829 	input_set_abs_params(input_dev, ABS_Y, 0,
830 			     (dev->info->ysensors - 1) * dev->info->yfact - 1,
831 			     ATP_FUZZ, 0);
832 	input_set_abs_params(input_dev, ABS_PRESSURE, 0, ATP_PRESSURE, 0, 0);
833 
834 	set_bit(EV_KEY, input_dev->evbit);
835 	set_bit(BTN_TOUCH, input_dev->keybit);
836 	set_bit(BTN_TOOL_FINGER, input_dev->keybit);
837 	set_bit(BTN_TOOL_DOUBLETAP, input_dev->keybit);
838 	set_bit(BTN_TOOL_TRIPLETAP, input_dev->keybit);
839 	set_bit(BTN_LEFT, input_dev->keybit);
840 
841 	error = input_register_device(dev->input);
842 	if (error)
843 		goto err_free_buffer;
844 
845 	/* save our data pointer in this interface device */
846 	usb_set_intfdata(iface, dev);
847 
848 	INIT_WORK(&dev->work, atp_reinit);
849 
850 	return 0;
851 
852  err_free_buffer:
853 	usb_buffer_free(dev->udev, dev->info->datalen,
854 			dev->data, dev->urb->transfer_dma);
855  err_free_urb:
856 	usb_free_urb(dev->urb);
857  err_free_devs:
858 	usb_set_intfdata(iface, NULL);
859 	kfree(dev);
860 	input_free_device(input_dev);
861 	return error;
862 }
863 
864 static void atp_disconnect(struct usb_interface *iface)
865 {
866 	struct atp *dev = usb_get_intfdata(iface);
867 
868 	usb_set_intfdata(iface, NULL);
869 	if (dev) {
870 		usb_kill_urb(dev->urb);
871 		input_unregister_device(dev->input);
872 		usb_buffer_free(dev->udev, dev->info->datalen,
873 				dev->data, dev->urb->transfer_dma);
874 		usb_free_urb(dev->urb);
875 		kfree(dev);
876 	}
877 	printk(KERN_INFO "input: appletouch disconnected\n");
878 }
879 
880 static int atp_recover(struct atp *dev)
881 {
882 	int error;
883 
884 	error = atp_handle_geyser(dev);
885 	if (error)
886 		return error;
887 
888 	if (dev->open && usb_submit_urb(dev->urb, GFP_ATOMIC))
889 		return -EIO;
890 
891 	return 0;
892 }
893 
894 static int atp_suspend(struct usb_interface *iface, pm_message_t message)
895 {
896 	struct atp *dev = usb_get_intfdata(iface);
897 
898 	usb_kill_urb(dev->urb);
899 	return 0;
900 }
901 
902 static int atp_resume(struct usb_interface *iface)
903 {
904 	struct atp *dev = usb_get_intfdata(iface);
905 
906 	if (dev->open && usb_submit_urb(dev->urb, GFP_ATOMIC))
907 		return -EIO;
908 
909 	return 0;
910 }
911 
912 static int atp_reset_resume(struct usb_interface *iface)
913 {
914 	struct atp *dev = usb_get_intfdata(iface);
915 
916 	return atp_recover(dev);
917 }
918 
919 static struct usb_driver atp_driver = {
920 	.name		= "appletouch",
921 	.probe		= atp_probe,
922 	.disconnect	= atp_disconnect,
923 	.suspend	= atp_suspend,
924 	.resume		= atp_resume,
925 	.reset_resume	= atp_reset_resume,
926 	.id_table	= atp_table,
927 };
928 
929 static int __init atp_init(void)
930 {
931 	return usb_register(&atp_driver);
932 }
933 
934 static void __exit atp_exit(void)
935 {
936 	usb_deregister(&atp_driver);
937 }
938 
939 module_init(atp_init);
940 module_exit(atp_exit);
941