xref: /openbmc/linux/drivers/input/mouse/appletouch.c (revision 9ac8d3fb)
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      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 /* Type of touchpad */
39 enum atp_touchpad_type {
40 	ATP_FOUNTAIN,
41 	ATP_GEYSER1,
42 	ATP_GEYSER2,
43 	ATP_GEYSER3,
44 	ATP_GEYSER4
45 };
46 
47 #define ATP_DEVICE(prod, type)					\
48 {								\
49 	.match_flags = USB_DEVICE_ID_MATCH_DEVICE |		\
50 		       USB_DEVICE_ID_MATCH_INT_CLASS |		\
51 		       USB_DEVICE_ID_MATCH_INT_PROTOCOL,	\
52 	.idVendor = 0x05ac, /* Apple */				\
53 	.idProduct = (prod),					\
54 	.bInterfaceClass = 0x03,				\
55 	.bInterfaceProtocol = 0x02,				\
56 	.driver_info = ATP_ ## type,				\
57 }
58 
59 /*
60  * Table of devices (Product IDs) that work with this driver.
61  * (The names come from Info.plist in AppleUSBTrackpad.kext,
62  *  According to Info.plist Geyser IV is the same as Geyser III.)
63  */
64 
65 static struct usb_device_id atp_table [] = {
66 	/* PowerBooks Feb 2005, iBooks G4 */
67 	ATP_DEVICE(0x020e, FOUNTAIN),	/* FOUNTAIN ANSI */
68 	ATP_DEVICE(0x020f, FOUNTAIN),	/* FOUNTAIN ISO */
69 	ATP_DEVICE(0x030a, FOUNTAIN),	/* FOUNTAIN TP ONLY */
70 	ATP_DEVICE(0x030b, GEYSER1),	/* GEYSER 1 TP ONLY */
71 
72 	/* PowerBooks Oct 2005 */
73 	ATP_DEVICE(0x0214, GEYSER2),	/* GEYSER 2 ANSI */
74 	ATP_DEVICE(0x0215, GEYSER2),	/* GEYSER 2 ISO */
75 	ATP_DEVICE(0x0216, GEYSER2),	/* GEYSER 2 JIS */
76 
77 	/* Core Duo MacBook & MacBook Pro */
78 	ATP_DEVICE(0x0217, GEYSER3),	/* GEYSER 3 ANSI */
79 	ATP_DEVICE(0x0218, GEYSER3),	/* GEYSER 3 ISO */
80 	ATP_DEVICE(0x0219, GEYSER3),	/* GEYSER 3 JIS */
81 
82 	/* Core2 Duo MacBook & MacBook Pro */
83 	ATP_DEVICE(0x021a, GEYSER4),	/* GEYSER 4 ANSI */
84 	ATP_DEVICE(0x021b, GEYSER4),	/* GEYSER 4 ISO */
85 	ATP_DEVICE(0x021c, GEYSER4),	/* GEYSER 4 JIS */
86 
87 	/* Core2 Duo MacBook3,1 */
88 	ATP_DEVICE(0x0229, GEYSER4),	/* GEYSER 4 HF ANSI */
89 	ATP_DEVICE(0x022a, GEYSER4),	/* GEYSER 4 HF ISO */
90 	ATP_DEVICE(0x022b, GEYSER4),	/* GEYSER 4 HF JIS */
91 
92 	/* Terminating entry */
93 	{ }
94 };
95 MODULE_DEVICE_TABLE(usb, atp_table);
96 
97 /*
98  * number of sensors. Note that only 16 instead of 26 X (horizontal)
99  * sensors exist on 12" and 15" PowerBooks. All models have 16 Y
100  * (vertical) sensors.
101  */
102 #define ATP_XSENSORS	26
103 #define ATP_YSENSORS	16
104 
105 /* amount of fuzz this touchpad generates */
106 #define ATP_FUZZ	16
107 
108 /* maximum pressure this driver will report */
109 #define ATP_PRESSURE	300
110 /*
111  * multiplication factor for the X and Y coordinates.
112  * We try to keep the touchpad aspect ratio while still doing only simple
113  * arithmetics.
114  * The factors below give coordinates like:
115  *
116  *      0 <= x <  960 on 12" and 15" Powerbooks
117  *      0 <= x < 1600 on 17" Powerbooks and 17" MacBook Pro
118  *      0 <= x < 1216 on MacBooks and 15" MacBook Pro
119  *
120  *      0 <= y <  646 on all Powerbooks
121  *      0 <= y <  774 on all MacBooks
122  */
123 #define ATP_XFACT	64
124 #define ATP_YFACT	43
125 
126 /*
127  * Threshold for the touchpad sensors. Any change less than ATP_THRESHOLD is
128  * ignored.
129  */
130 #define ATP_THRESHOLD	 5
131 
132 /* Geyser initialization constants */
133 #define ATP_GEYSER_MODE_READ_REQUEST_ID		1
134 #define ATP_GEYSER_MODE_WRITE_REQUEST_ID	9
135 #define ATP_GEYSER_MODE_REQUEST_VALUE		0x300
136 #define ATP_GEYSER_MODE_REQUEST_INDEX		0
137 #define ATP_GEYSER_MODE_VENDOR_VALUE		0x04
138 
139 /**
140  * enum atp_status_bits - status bit meanings
141  *
142  * These constants represent the meaning of the status bits.
143  * (only Geyser 3/4)
144  *
145  * @ATP_STATUS_BUTTON: The button was pressed
146  * @ATP_STATUS_BASE_UPDATE: Update of the base values (untouched pad)
147  * @ATP_STATUS_FROM_RESET: Reset previously performed
148  */
149 enum atp_status_bits {
150 	ATP_STATUS_BUTTON	= BIT(0),
151 	ATP_STATUS_BASE_UPDATE	= BIT(2),
152 	ATP_STATUS_FROM_RESET	= BIT(4),
153 };
154 
155 /* Structure to hold all of our device specific stuff */
156 struct atp {
157 	char			phys[64];
158 	struct usb_device	*udev;		/* usb device */
159 	struct urb		*urb;		/* usb request block */
160 	u8			*data;		/* transferred data */
161 	struct input_dev	*input;		/* input dev */
162 	enum atp_touchpad_type	type;		/* type of touchpad */
163 	bool			open;
164 	bool			valid;		/* are the samples valid? */
165 	bool			size_detect_done;
166 	bool			overflow_warned;
167 	int			x_old;		/* last reported x/y, */
168 	int			y_old;		/* used for smoothing */
169 	signed char		xy_cur[ATP_XSENSORS + ATP_YSENSORS];
170 	signed char		xy_old[ATP_XSENSORS + ATP_YSENSORS];
171 	int			xy_acc[ATP_XSENSORS + ATP_YSENSORS];
172 	int			datalen;	/* size of USB transfer */
173 	int			idlecount;	/* number of empty packets */
174 	struct work_struct	work;
175 };
176 
177 #define dbg_dump(msg, tab) \
178 	if (debug > 1) {						\
179 		int __i;						\
180 		printk(KERN_DEBUG "appletouch: %s", msg);		\
181 		for (__i = 0; __i < ATP_XSENSORS + ATP_YSENSORS; __i++)	\
182 			printk(" %02x", tab[__i]);			\
183 		printk("\n");						\
184 	}
185 
186 #define dprintk(format, a...)						\
187 	do {								\
188 		if (debug)						\
189 			printk(KERN_DEBUG format, ##a);			\
190 	} while (0)
191 
192 MODULE_AUTHOR("Johannes Berg");
193 MODULE_AUTHOR("Stelian Pop");
194 MODULE_AUTHOR("Frank Arnold");
195 MODULE_AUTHOR("Michael Hanselmann");
196 MODULE_AUTHOR("Sven Anders");
197 MODULE_DESCRIPTION("Apple PowerBook and MacBook USB touchpad driver");
198 MODULE_LICENSE("GPL");
199 
200 /*
201  * Make the threshold a module parameter
202  */
203 static int threshold = ATP_THRESHOLD;
204 module_param(threshold, int, 0644);
205 MODULE_PARM_DESC(threshold, "Discard any change in data from a sensor"
206 			    " (the trackpad has many of these sensors)"
207 			    " less than this value.");
208 
209 static int debug;
210 module_param(debug, int, 0644);
211 MODULE_PARM_DESC(debug, "Activate debugging output");
212 
213 /*
214  * By default newer Geyser devices send standard USB HID mouse
215  * packets (Report ID 2). This code changes device mode, so it
216  * sends raw sensor reports (Report ID 5).
217  */
218 static int atp_geyser_init(struct usb_device *udev)
219 {
220 	char data[8];
221 	int size;
222 	int i;
223 
224 	size = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
225 			ATP_GEYSER_MODE_READ_REQUEST_ID,
226 			USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
227 			ATP_GEYSER_MODE_REQUEST_VALUE,
228 			ATP_GEYSER_MODE_REQUEST_INDEX, &data, 8, 5000);
229 
230 	if (size != 8) {
231 		dprintk("atp_geyser_init: read error\n");
232 		for (i = 0; i < 8; i++)
233 			dprintk("appletouch[%d]: %d\n", i, data[i]);
234 
235 		err("Failed to read mode from device.");
236 		return -EIO;
237 	}
238 
239 	/* Apply the mode switch */
240 	data[0] = ATP_GEYSER_MODE_VENDOR_VALUE;
241 
242 	size = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
243 			ATP_GEYSER_MODE_WRITE_REQUEST_ID,
244 			USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
245 			ATP_GEYSER_MODE_REQUEST_VALUE,
246 			ATP_GEYSER_MODE_REQUEST_INDEX, &data, 8, 5000);
247 
248 	if (size != 8) {
249 		dprintk("atp_geyser_init: write error\n");
250 		for (i = 0; i < 8; i++)
251 			dprintk("appletouch[%d]: %d\n", i, data[i]);
252 
253 		err("Failed to request geyser raw mode");
254 		return -EIO;
255 	}
256 	return 0;
257 }
258 
259 /*
260  * Reinitialise the device. This usually stops stream of empty packets
261  * coming from it.
262  */
263 static void atp_reinit(struct work_struct *work)
264 {
265 	struct atp *dev = container_of(work, struct atp, work);
266 	struct usb_device *udev = dev->udev;
267 	int retval;
268 
269 	dprintk("appletouch: putting appletouch to sleep (reinit)\n");
270 	atp_geyser_init(udev);
271 
272 	retval = usb_submit_urb(dev->urb, GFP_ATOMIC);
273 	if (retval)
274 		err("atp_reinit: usb_submit_urb failed with error %d",
275 		    retval);
276 }
277 
278 static int atp_calculate_abs(int *xy_sensors, int nb_sensors, int fact,
279 			     int *z, int *fingers)
280 {
281 	int i;
282 	/* values to calculate mean */
283 	int pcum = 0, psum = 0;
284 	int is_increasing = 0;
285 
286 	*fingers = 0;
287 
288 	for (i = 0; i < nb_sensors; i++) {
289 		if (xy_sensors[i] < threshold) {
290 			if (is_increasing)
291 				is_increasing = 0;
292 
293 			continue;
294 		}
295 
296 		/*
297 		 * Makes the finger detection more versatile.  For example,
298 		 * two fingers with no gap will be detected.  Also, my
299 		 * tests show it less likely to have intermittent loss
300 		 * of multiple finger readings while moving around (scrolling).
301 		 *
302 		 * Changes the multiple finger detection to counting humps on
303 		 * sensors (transitions from nonincreasing to increasing)
304 		 * instead of counting transitions from low sensors (no
305 		 * finger reading) to high sensors (finger above
306 		 * sensor)
307 		 *
308 		 * - Jason Parekh <jasonparekh@gmail.com>
309 		 */
310 		if (i < 1 ||
311 		    (!is_increasing && xy_sensors[i - 1] < xy_sensors[i])) {
312 			(*fingers)++;
313 			is_increasing = 1;
314 		} else if (i > 0 && xy_sensors[i - 1] >= xy_sensors[i]) {
315 			is_increasing = 0;
316 		}
317 
318 		/*
319 		 * Subtracts threshold so a high sensor that just passes the
320 		 * threshold won't skew the calculated absolute coordinate.
321 		 * Fixes an issue where slowly moving the mouse would
322 		 * occasionally jump a number of pixels (slowly moving the
323 		 * finger makes this issue most apparent.)
324 		 */
325 		pcum += (xy_sensors[i] - threshold) * i;
326 		psum += (xy_sensors[i] - threshold);
327 	}
328 
329 	if (psum > 0) {
330 		*z = psum;
331 		return pcum * fact / psum;
332 	}
333 
334 	return 0;
335 }
336 
337 static inline void atp_report_fingers(struct input_dev *input, int fingers)
338 {
339 	input_report_key(input, BTN_TOOL_FINGER, fingers == 1);
340 	input_report_key(input, BTN_TOOL_DOUBLETAP, fingers == 2);
341 	input_report_key(input, BTN_TOOL_TRIPLETAP, fingers > 2);
342 }
343 
344 /* Check URB status and for correct length of data package */
345 
346 #define ATP_URB_STATUS_SUCCESS		0
347 #define ATP_URB_STATUS_ERROR		1
348 #define ATP_URB_STATUS_ERROR_FATAL	2
349 
350 static int atp_status_check(struct urb *urb)
351 {
352 	struct atp *dev = urb->context;
353 
354 	switch (urb->status) {
355 	case 0:
356 		/* success */
357 		break;
358 	case -EOVERFLOW:
359 		if (!dev->overflow_warned) {
360 			printk(KERN_WARNING "appletouch: OVERFLOW with data "
361 				"length %d, actual length is %d\n",
362 				dev->datalen, dev->urb->actual_length);
363 			dev->overflow_warned = true;
364 		}
365 	case -ECONNRESET:
366 	case -ENOENT:
367 	case -ESHUTDOWN:
368 		/* This urb is terminated, clean up */
369 		dbg("atp_complete: urb shutting down with status: %d",
370 		    urb->status);
371 		return ATP_URB_STATUS_ERROR_FATAL;
372 
373 	default:
374 		dbg("atp_complete: nonzero urb status received: %d",
375 		    urb->status);
376 		return ATP_URB_STATUS_ERROR;
377 	}
378 
379 	/* drop incomplete datasets */
380 	if (dev->urb->actual_length != dev->datalen) {
381 		dprintk("appletouch: incomplete data package"
382 			" (first byte: %d, length: %d).\n",
383 			dev->data[0], dev->urb->actual_length);
384 		return ATP_URB_STATUS_ERROR;
385 	}
386 
387 	return ATP_URB_STATUS_SUCCESS;
388 }
389 
390 /*
391  * USB interrupt callback functions
392  */
393 
394 /* Interrupt function for older touchpads: FOUNTAIN/GEYSER1/GEYSER2 */
395 
396 static void atp_complete_geyser_1_2(struct urb *urb)
397 {
398 	int x, y, x_z, y_z, x_f, y_f;
399 	int retval, i, j;
400 	int key;
401 	struct atp *dev = urb->context;
402 	int status = atp_status_check(urb);
403 
404 	if (status == ATP_URB_STATUS_ERROR_FATAL)
405 		return;
406 	else if (status == ATP_URB_STATUS_ERROR)
407 		goto exit;
408 
409 	/* reorder the sensors values */
410 	if (dev->type == ATP_GEYSER2) {
411 		memset(dev->xy_cur, 0, sizeof(dev->xy_cur));
412 
413 		/*
414 		 * The values are laid out like this:
415 		 * Y1, Y2, -, Y3, Y4, -, ..., X1, X2, -, X3, X4, -, ...
416 		 * '-' is an unused value.
417 		 */
418 
419 		/* read X values */
420 		for (i = 0, j = 19; i < 20; i += 2, j += 3) {
421 			dev->xy_cur[i] = dev->data[j];
422 			dev->xy_cur[i + 1] = dev->data[j + 1];
423 		}
424 
425 		/* read Y values */
426 		for (i = 0, j = 1; i < 9; i += 2, j += 3) {
427 			dev->xy_cur[ATP_XSENSORS + i] = dev->data[j];
428 			dev->xy_cur[ATP_XSENSORS + i + 1] = dev->data[j + 1];
429 		}
430 	} else {
431 		for (i = 0; i < 8; i++) {
432 			/* X values */
433 			dev->xy_cur[i +  0] = dev->data[5 * i +  2];
434 			dev->xy_cur[i +  8] = dev->data[5 * i +  4];
435 			dev->xy_cur[i + 16] = dev->data[5 * i + 42];
436 			if (i < 2)
437 				dev->xy_cur[i + 24] = dev->data[5 * i + 44];
438 
439 			/* Y values */
440 			dev->xy_cur[i + 26] = dev->data[5 * i +  1];
441 			dev->xy_cur[i + 34] = dev->data[5 * i +  3];
442 		}
443 	}
444 
445 	dbg_dump("sample", dev->xy_cur);
446 
447 	if (!dev->valid) {
448 		/* first sample */
449 		dev->valid = true;
450 		dev->x_old = dev->y_old = -1;
451 
452 		/* Store first sample */
453 		memcpy(dev->xy_old, dev->xy_cur, sizeof(dev->xy_old));
454 
455 		/* Perform size detection, if not done already */
456 		if (!dev->size_detect_done) {
457 
458 			/* 17" Powerbooks have extra X sensors */
459 			for (i = (dev->type == ATP_GEYSER2 ? 15 : 16);
460 			     i < ATP_XSENSORS; i++) {
461 				if (!dev->xy_cur[i])
462 					continue;
463 
464 				printk(KERN_INFO
465 					"appletouch: 17\" model detected.\n");
466 
467 				if (dev->type == ATP_GEYSER2)
468 					input_set_abs_params(dev->input, ABS_X,
469 							     0,
470 							     (20 - 1) *
471 							     ATP_XFACT - 1,
472 							     ATP_FUZZ, 0);
473 				else
474 					input_set_abs_params(dev->input, ABS_X,
475 							     0,
476 							     (26 - 1) *
477 							     ATP_XFACT - 1,
478 							     ATP_FUZZ, 0);
479 				break;
480 			}
481 
482 			dev->size_detect_done = 1;
483 			goto exit;
484 		}
485 	}
486 
487 	for (i = 0; i < ATP_XSENSORS + ATP_YSENSORS; i++) {
488 		/* accumulate the change */
489 		signed char change = dev->xy_old[i] - dev->xy_cur[i];
490 		dev->xy_acc[i] -= change;
491 
492 		/* prevent down drifting */
493 		if (dev->xy_acc[i] < 0)
494 			dev->xy_acc[i] = 0;
495 	}
496 
497 	memcpy(dev->xy_old, dev->xy_cur, sizeof(dev->xy_old));
498 
499 	dbg_dump("accumulator", dev->xy_acc);
500 
501 	x = atp_calculate_abs(dev->xy_acc, ATP_XSENSORS,
502 			      ATP_XFACT, &x_z, &x_f);
503 	y = atp_calculate_abs(dev->xy_acc + ATP_XSENSORS, ATP_YSENSORS,
504 			      ATP_YFACT, &y_z, &y_f);
505 	key = dev->data[dev->datalen - 1] & ATP_STATUS_BUTTON;
506 
507 	if (x && y) {
508 		if (dev->x_old != -1) {
509 			x = (dev->x_old * 3 + x) >> 2;
510 			y = (dev->y_old * 3 + y) >> 2;
511 			dev->x_old = x;
512 			dev->y_old = y;
513 
514 			if (debug > 1)
515 				printk(KERN_DEBUG "appletouch: "
516 					"X: %3d Y: %3d Xz: %3d Yz: %3d\n",
517 					x, y, x_z, y_z);
518 
519 			input_report_key(dev->input, BTN_TOUCH, 1);
520 			input_report_abs(dev->input, ABS_X, x);
521 			input_report_abs(dev->input, ABS_Y, y);
522 			input_report_abs(dev->input, ABS_PRESSURE,
523 					 min(ATP_PRESSURE, x_z + y_z));
524 			atp_report_fingers(dev->input, max(x_f, y_f));
525 		}
526 		dev->x_old = x;
527 		dev->y_old = y;
528 
529 	} else if (!x && !y) {
530 
531 		dev->x_old = dev->y_old = -1;
532 		input_report_key(dev->input, BTN_TOUCH, 0);
533 		input_report_abs(dev->input, ABS_PRESSURE, 0);
534 		atp_report_fingers(dev->input, 0);
535 
536 		/* reset the accumulator on release */
537 		memset(dev->xy_acc, 0, sizeof(dev->xy_acc));
538 	}
539 
540 	input_report_key(dev->input, BTN_LEFT, key);
541 	input_sync(dev->input);
542 
543  exit:
544 	retval = usb_submit_urb(dev->urb, GFP_ATOMIC);
545 	if (retval)
546 		err("atp_complete: usb_submit_urb failed with result %d",
547 		    retval);
548 }
549 
550 /* Interrupt function for older touchpads: GEYSER3/GEYSER4 */
551 
552 static void atp_complete_geyser_3_4(struct urb *urb)
553 {
554 	int x, y, x_z, y_z, x_f, y_f;
555 	int retval, i, j;
556 	int key;
557 	struct atp *dev = urb->context;
558 	int status = atp_status_check(urb);
559 
560 	if (status == ATP_URB_STATUS_ERROR_FATAL)
561 		return;
562 	else if (status == ATP_URB_STATUS_ERROR)
563 		goto exit;
564 
565 	/* Reorder the sensors values:
566 	 *
567 	 * The values are laid out like this:
568 	 * -, Y1, Y2, -, Y3, Y4, -, ..., -, X1, X2, -, X3, X4, ...
569 	 * '-' is an unused value.
570 	 */
571 
572 	/* read X values */
573 	for (i = 0, j = 19; i < 20; i += 2, j += 3) {
574 		dev->xy_cur[i] = dev->data[j + 1];
575 		dev->xy_cur[i + 1] = dev->data[j + 2];
576 	}
577 	/* read Y values */
578 	for (i = 0, j = 1; i < 9; i += 2, j += 3) {
579 		dev->xy_cur[ATP_XSENSORS + i] = dev->data[j + 1];
580 		dev->xy_cur[ATP_XSENSORS + i + 1] = dev->data[j + 2];
581 	}
582 
583 	dbg_dump("sample", dev->xy_cur);
584 
585 	/* Just update the base values (i.e. touchpad in untouched state) */
586 	if (dev->data[dev->datalen - 1] & ATP_STATUS_BASE_UPDATE) {
587 
588 		dprintk(KERN_DEBUG "appletouch: updated base values\n");
589 
590 		memcpy(dev->xy_old, dev->xy_cur, sizeof(dev->xy_old));
591 		goto exit;
592 	}
593 
594 	for (i = 0; i < ATP_XSENSORS + ATP_YSENSORS; i++) {
595 		/* calculate the change */
596 		dev->xy_acc[i] = dev->xy_cur[i] - dev->xy_old[i];
597 
598 		/* this is a round-robin value, so couple with that */
599 		if (dev->xy_acc[i] > 127)
600 			dev->xy_acc[i] -= 256;
601 
602 		if (dev->xy_acc[i] < -127)
603 			dev->xy_acc[i] += 256;
604 
605 		/* prevent down drifting */
606 		if (dev->xy_acc[i] < 0)
607 			dev->xy_acc[i] = 0;
608 	}
609 
610 	dbg_dump("accumulator", dev->xy_acc);
611 
612 	x = atp_calculate_abs(dev->xy_acc, ATP_XSENSORS,
613 			      ATP_XFACT, &x_z, &x_f);
614 	y = atp_calculate_abs(dev->xy_acc + ATP_XSENSORS, ATP_YSENSORS,
615 			      ATP_YFACT, &y_z, &y_f);
616 	key = dev->data[dev->datalen - 1] & ATP_STATUS_BUTTON;
617 
618 	if (x && y) {
619 		if (dev->x_old != -1) {
620 			x = (dev->x_old * 3 + x) >> 2;
621 			y = (dev->y_old * 3 + y) >> 2;
622 			dev->x_old = x;
623 			dev->y_old = y;
624 
625 			if (debug > 1)
626 				printk(KERN_DEBUG "appletouch: X: %3d Y: %3d "
627 				       "Xz: %3d Yz: %3d\n",
628 				       x, y, x_z, y_z);
629 
630 			input_report_key(dev->input, BTN_TOUCH, 1);
631 			input_report_abs(dev->input, ABS_X, x);
632 			input_report_abs(dev->input, ABS_Y, y);
633 			input_report_abs(dev->input, ABS_PRESSURE,
634 					 min(ATP_PRESSURE, x_z + y_z));
635 			atp_report_fingers(dev->input, max(x_f, y_f));
636 		}
637 		dev->x_old = x;
638 		dev->y_old = y;
639 
640 	} else if (!x && !y) {
641 
642 		dev->x_old = dev->y_old = -1;
643 		input_report_key(dev->input, BTN_TOUCH, 0);
644 		input_report_abs(dev->input, ABS_PRESSURE, 0);
645 		atp_report_fingers(dev->input, 0);
646 
647 		/* reset the accumulator on release */
648 		memset(dev->xy_acc, 0, sizeof(dev->xy_acc));
649 	}
650 
651 	input_report_key(dev->input, BTN_LEFT, key);
652 	input_sync(dev->input);
653 
654 	/*
655 	 * Geysers 3/4 will continue to send packets continually after
656 	 * the first touch unless reinitialised. Do so if it's been
657 	 * idle for a while in order to avoid waking the kernel up
658 	 * several hundred times a second.
659 	 */
660 
661 	/*
662 	 * Button must not be pressed when entering suspend,
663 	 * otherwise we will never release the button.
664 	 */
665 	if (!x && !y && !key) {
666 		dev->idlecount++;
667 		if (dev->idlecount == 10) {
668 			dev->x_old = dev->y_old = -1;
669 			dev->idlecount = 0;
670 			schedule_work(&dev->work);
671 			/* Don't resubmit urb here, wait for reinit */
672 			return;
673 		}
674 	} else
675 		dev->idlecount = 0;
676 
677  exit:
678 	retval = usb_submit_urb(dev->urb, GFP_ATOMIC);
679 	if (retval)
680 		err("atp_complete: usb_submit_urb failed with result %d",
681 		    retval);
682 }
683 
684 static int atp_open(struct input_dev *input)
685 {
686 	struct atp *dev = input_get_drvdata(input);
687 
688 	if (usb_submit_urb(dev->urb, GFP_ATOMIC))
689 		return -EIO;
690 
691 	dev->open = 1;
692 	return 0;
693 }
694 
695 static void atp_close(struct input_dev *input)
696 {
697 	struct atp *dev = input_get_drvdata(input);
698 
699 	usb_kill_urb(dev->urb);
700 	cancel_work_sync(&dev->work);
701 	dev->open = 0;
702 }
703 
704 static int atp_handle_geyser(struct atp *dev)
705 {
706 	struct usb_device *udev = dev->udev;
707 
708 	if (dev->type != ATP_FOUNTAIN) {
709 		/* switch to raw sensor mode */
710 		if (atp_geyser_init(udev))
711 			return -EIO;
712 
713 		printk(KERN_INFO "appletouch: Geyser mode initialized.\n");
714 	}
715 
716 	return 0;
717 }
718 
719 static int atp_probe(struct usb_interface *iface,
720 		     const struct usb_device_id *id)
721 {
722 	struct atp *dev;
723 	struct input_dev *input_dev;
724 	struct usb_device *udev = interface_to_usbdev(iface);
725 	struct usb_host_interface *iface_desc;
726 	struct usb_endpoint_descriptor *endpoint;
727 	int int_in_endpointAddr = 0;
728 	int i, error = -ENOMEM;
729 
730 	/* set up the endpoint information */
731 	/* use only the first interrupt-in endpoint */
732 	iface_desc = iface->cur_altsetting;
733 	for (i = 0; i < iface_desc->desc.bNumEndpoints; i++) {
734 		endpoint = &iface_desc->endpoint[i].desc;
735 		if (!int_in_endpointAddr && usb_endpoint_is_int_in(endpoint)) {
736 			/* we found an interrupt in endpoint */
737 			int_in_endpointAddr = endpoint->bEndpointAddress;
738 			break;
739 		}
740 	}
741 	if (!int_in_endpointAddr) {
742 		err("Could not find int-in endpoint");
743 		return -EIO;
744 	}
745 
746 	/* allocate memory for our device state and initialize it */
747 	dev = kzalloc(sizeof(struct atp), GFP_KERNEL);
748 	input_dev = input_allocate_device();
749 	if (!dev || !input_dev) {
750 		err("Out of memory");
751 		goto err_free_devs;
752 	}
753 
754 	dev->udev = udev;
755 	dev->input = input_dev;
756 	dev->type = id->driver_info;
757 	dev->overflow_warned = false;
758 	if (dev->type == ATP_FOUNTAIN || dev->type == ATP_GEYSER1)
759 		dev->datalen = 81;
760 	else
761 		dev->datalen = 64;
762 
763 	dev->urb = usb_alloc_urb(0, GFP_KERNEL);
764 	if (!dev->urb)
765 		goto err_free_devs;
766 
767 	dev->data = usb_buffer_alloc(dev->udev, dev->datalen, GFP_KERNEL,
768 				     &dev->urb->transfer_dma);
769 	if (!dev->data)
770 		goto err_free_urb;
771 
772 	/* Select the USB complete (callback) function */
773 	if (dev->type == ATP_FOUNTAIN ||
774 	    dev->type == ATP_GEYSER1 ||
775 	    dev->type == ATP_GEYSER2)
776 		usb_fill_int_urb(dev->urb, udev,
777 				 usb_rcvintpipe(udev, int_in_endpointAddr),
778 				 dev->data, dev->datalen,
779 				 atp_complete_geyser_1_2, dev, 1);
780 	else
781 		usb_fill_int_urb(dev->urb, udev,
782 				 usb_rcvintpipe(udev, int_in_endpointAddr),
783 				 dev->data, dev->datalen,
784 				 atp_complete_geyser_3_4, dev, 1);
785 
786 	error = atp_handle_geyser(dev);
787 	if (error)
788 		goto err_free_buffer;
789 
790 	usb_make_path(udev, dev->phys, sizeof(dev->phys));
791 	strlcat(dev->phys, "/input0", sizeof(dev->phys));
792 
793 	input_dev->name = "appletouch";
794 	input_dev->phys = dev->phys;
795 	usb_to_input_id(dev->udev, &input_dev->id);
796 	input_dev->dev.parent = &iface->dev;
797 
798 	input_set_drvdata(input_dev, dev);
799 
800 	input_dev->open = atp_open;
801 	input_dev->close = atp_close;
802 
803 	set_bit(EV_ABS, input_dev->evbit);
804 
805 	if (dev->type == ATP_GEYSER3 || dev->type == ATP_GEYSER4) {
806 		/*
807 		 * MacBook have 20 X sensors, 10 Y sensors
808 		 */
809 		input_set_abs_params(input_dev, ABS_X, 0,
810 				     ((20 - 1) * ATP_XFACT) - 1, ATP_FUZZ, 0);
811 		input_set_abs_params(input_dev, ABS_Y, 0,
812 				     ((10 - 1) * ATP_YFACT) - 1, ATP_FUZZ, 0);
813 	} else if (dev->type == ATP_GEYSER2) {
814 		/*
815 		 * Oct 2005 15" PowerBooks have 15 X sensors, 17" are detected
816 		 * later.
817 		 */
818 		input_set_abs_params(input_dev, ABS_X, 0,
819 				     ((15 - 1) * ATP_XFACT) - 1, ATP_FUZZ, 0);
820 		input_set_abs_params(input_dev, ABS_Y, 0,
821 				     ((9 - 1) * ATP_YFACT) - 1, ATP_FUZZ, 0);
822 	} else {
823 		/*
824 		 * 12" and 15" Powerbooks only have 16 x sensors,
825 		 * 17" models are detected later.
826 		 */
827 		input_set_abs_params(input_dev, ABS_X, 0,
828 				     (16 - 1) * ATP_XFACT - 1,
829 				     ATP_FUZZ, 0);
830 		input_set_abs_params(input_dev, ABS_Y, 0,
831 				     (ATP_YSENSORS - 1) * ATP_YFACT - 1,
832 				     ATP_FUZZ, 0);
833 	}
834 	input_set_abs_params(input_dev, ABS_PRESSURE, 0, ATP_PRESSURE, 0, 0);
835 
836 	set_bit(EV_KEY, input_dev->evbit);
837 	set_bit(BTN_TOUCH, input_dev->keybit);
838 	set_bit(BTN_TOOL_FINGER, input_dev->keybit);
839 	set_bit(BTN_TOOL_DOUBLETAP, input_dev->keybit);
840 	set_bit(BTN_TOOL_TRIPLETAP, input_dev->keybit);
841 	set_bit(BTN_LEFT, input_dev->keybit);
842 
843 	error = input_register_device(dev->input);
844 	if (error)
845 		goto err_free_buffer;
846 
847 	/* save our data pointer in this interface device */
848 	usb_set_intfdata(iface, dev);
849 
850 	INIT_WORK(&dev->work, atp_reinit);
851 
852 	return 0;
853 
854  err_free_buffer:
855 	usb_buffer_free(dev->udev, dev->datalen,
856 			dev->data, dev->urb->transfer_dma);
857  err_free_urb:
858 	usb_free_urb(dev->urb);
859  err_free_devs:
860 	usb_set_intfdata(iface, NULL);
861 	kfree(dev);
862 	input_free_device(input_dev);
863 	return error;
864 }
865 
866 static void atp_disconnect(struct usb_interface *iface)
867 {
868 	struct atp *dev = usb_get_intfdata(iface);
869 
870 	usb_set_intfdata(iface, NULL);
871 	if (dev) {
872 		usb_kill_urb(dev->urb);
873 		input_unregister_device(dev->input);
874 		usb_buffer_free(dev->udev, dev->datalen,
875 				dev->data, dev->urb->transfer_dma);
876 		usb_free_urb(dev->urb);
877 		kfree(dev);
878 	}
879 	printk(KERN_INFO "input: appletouch disconnected\n");
880 }
881 
882 static int atp_recover(struct atp *dev)
883 {
884 	int error;
885 
886 	error = atp_handle_geyser(dev);
887 	if (error)
888 		return error;
889 
890 	if (dev->open && usb_submit_urb(dev->urb, GFP_ATOMIC))
891 		return -EIO;
892 
893 	return 0;
894 }
895 
896 static int atp_suspend(struct usb_interface *iface, pm_message_t message)
897 {
898 	struct atp *dev = usb_get_intfdata(iface);
899 
900 	usb_kill_urb(dev->urb);
901 	return 0;
902 }
903 
904 static int atp_resume(struct usb_interface *iface)
905 {
906 	struct atp *dev = usb_get_intfdata(iface);
907 
908 	if (dev->open && usb_submit_urb(dev->urb, GFP_ATOMIC))
909 		return -EIO;
910 
911 	return 0;
912 }
913 
914 static int atp_reset_resume(struct usb_interface *iface)
915 {
916 	struct atp *dev = usb_get_intfdata(iface);
917 
918 	return atp_recover(dev);
919 }
920 
921 static struct usb_driver atp_driver = {
922 	.name		= "appletouch",
923 	.probe		= atp_probe,
924 	.disconnect	= atp_disconnect,
925 	.suspend	= atp_suspend,
926 	.resume		= atp_resume,
927 	.reset_resume	= atp_reset_resume,
928 	.id_table	= atp_table,
929 };
930 
931 static int __init atp_init(void)
932 {
933 	return usb_register(&atp_driver);
934 }
935 
936 static void __exit atp_exit(void)
937 {
938 	usb_deregister(&atp_driver);
939 }
940 
941 module_init(atp_init);
942 module_exit(atp_exit);
943