xref: /openbmc/linux/drivers/input/mouse/appletouch.c (revision 8fdff1dc)
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 usb_interface	*intf;		/* usb interface */
199 	struct urb		*urb;		/* usb request block */
200 	u8			*data;		/* transferred data */
201 	struct input_dev	*input;		/* input dev */
202 	const struct atp_info	*info;		/* touchpad model */
203 	bool			open;
204 	bool			valid;		/* are the samples valid? */
205 	bool			size_detect_done;
206 	bool			overflow_warned;
207 	int			x_old;		/* last reported x/y, */
208 	int			y_old;		/* used for smoothing */
209 	signed char		xy_cur[ATP_XSENSORS + ATP_YSENSORS];
210 	signed char		xy_old[ATP_XSENSORS + ATP_YSENSORS];
211 	int			xy_acc[ATP_XSENSORS + ATP_YSENSORS];
212 	int			idlecount;	/* number of empty packets */
213 	struct work_struct	work;
214 };
215 
216 #define dbg_dump(msg, tab) \
217 	if (debug > 1) {						\
218 		int __i;						\
219 		printk(KERN_DEBUG "appletouch: %s", msg);		\
220 		for (__i = 0; __i < ATP_XSENSORS + ATP_YSENSORS; __i++)	\
221 			printk(" %02x", tab[__i]);			\
222 		printk("\n");						\
223 	}
224 
225 #define dprintk(format, a...)						\
226 	do {								\
227 		if (debug)						\
228 			printk(KERN_DEBUG format, ##a);			\
229 	} while (0)
230 
231 MODULE_AUTHOR("Johannes Berg");
232 MODULE_AUTHOR("Stelian Pop");
233 MODULE_AUTHOR("Frank Arnold");
234 MODULE_AUTHOR("Michael Hanselmann");
235 MODULE_AUTHOR("Sven Anders");
236 MODULE_DESCRIPTION("Apple PowerBook and MacBook USB touchpad driver");
237 MODULE_LICENSE("GPL");
238 
239 /*
240  * Make the threshold a module parameter
241  */
242 static int threshold = ATP_THRESHOLD;
243 module_param(threshold, int, 0644);
244 MODULE_PARM_DESC(threshold, "Discard any change in data from a sensor"
245 			    " (the trackpad has many of these sensors)"
246 			    " less than this value.");
247 
248 static int debug;
249 module_param(debug, int, 0644);
250 MODULE_PARM_DESC(debug, "Activate debugging output");
251 
252 /*
253  * By default newer Geyser devices send standard USB HID mouse
254  * packets (Report ID 2). This code changes device mode, so it
255  * sends raw sensor reports (Report ID 5).
256  */
257 static int atp_geyser_init(struct atp *dev)
258 {
259 	struct usb_device *udev = dev->udev;
260 	char *data;
261 	int size;
262 	int i;
263 	int ret;
264 
265 	data = kmalloc(8, GFP_KERNEL);
266 	if (!data) {
267 		dev_err(&dev->intf->dev, "Out of memory\n");
268 		return -ENOMEM;
269 	}
270 
271 	size = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
272 			ATP_GEYSER_MODE_READ_REQUEST_ID,
273 			USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
274 			ATP_GEYSER_MODE_REQUEST_VALUE,
275 			ATP_GEYSER_MODE_REQUEST_INDEX, data, 8, 5000);
276 
277 	if (size != 8) {
278 		dprintk("atp_geyser_init: read error\n");
279 		for (i = 0; i < 8; i++)
280 			dprintk("appletouch[%d]: %d\n", i, data[i]);
281 
282 		dev_err(&dev->intf->dev, "Failed to read mode from device.\n");
283 		ret = -EIO;
284 		goto out_free;
285 	}
286 
287 	/* Apply the mode switch */
288 	data[0] = ATP_GEYSER_MODE_VENDOR_VALUE;
289 
290 	size = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
291 			ATP_GEYSER_MODE_WRITE_REQUEST_ID,
292 			USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
293 			ATP_GEYSER_MODE_REQUEST_VALUE,
294 			ATP_GEYSER_MODE_REQUEST_INDEX, data, 8, 5000);
295 
296 	if (size != 8) {
297 		dprintk("atp_geyser_init: write error\n");
298 		for (i = 0; i < 8; i++)
299 			dprintk("appletouch[%d]: %d\n", i, data[i]);
300 
301 		dev_err(&dev->intf->dev, "Failed to request geyser raw mode\n");
302 		ret = -EIO;
303 		goto out_free;
304 	}
305 	ret = 0;
306 out_free:
307 	kfree(data);
308 	return ret;
309 }
310 
311 /*
312  * Reinitialise the device. This usually stops stream of empty packets
313  * coming from it.
314  */
315 static void atp_reinit(struct work_struct *work)
316 {
317 	struct atp *dev = container_of(work, struct atp, work);
318 	int retval;
319 
320 	dprintk("appletouch: putting appletouch to sleep (reinit)\n");
321 	atp_geyser_init(dev);
322 
323 	retval = usb_submit_urb(dev->urb, GFP_ATOMIC);
324 	if (retval)
325 		dev_err(&dev->intf->dev,
326 			"atp_reinit: usb_submit_urb failed with error %d\n",
327 			retval);
328 }
329 
330 static int atp_calculate_abs(int *xy_sensors, int nb_sensors, int fact,
331 			     int *z, int *fingers)
332 {
333 	int i;
334 	/* values to calculate mean */
335 	int pcum = 0, psum = 0;
336 	int is_increasing = 0;
337 
338 	*fingers = 0;
339 
340 	for (i = 0; i < nb_sensors; i++) {
341 		if (xy_sensors[i] < threshold) {
342 			if (is_increasing)
343 				is_increasing = 0;
344 
345 			continue;
346 		}
347 
348 		/*
349 		 * Makes the finger detection more versatile.  For example,
350 		 * two fingers with no gap will be detected.  Also, my
351 		 * tests show it less likely to have intermittent loss
352 		 * of multiple finger readings while moving around (scrolling).
353 		 *
354 		 * Changes the multiple finger detection to counting humps on
355 		 * sensors (transitions from nonincreasing to increasing)
356 		 * instead of counting transitions from low sensors (no
357 		 * finger reading) to high sensors (finger above
358 		 * sensor)
359 		 *
360 		 * - Jason Parekh <jasonparekh@gmail.com>
361 		 */
362 		if (i < 1 ||
363 		    (!is_increasing && xy_sensors[i - 1] < xy_sensors[i])) {
364 			(*fingers)++;
365 			is_increasing = 1;
366 		} else if (i > 0 && (xy_sensors[i - 1] - xy_sensors[i] > threshold)) {
367 			is_increasing = 0;
368 		}
369 
370 		/*
371 		 * Subtracts threshold so a high sensor that just passes the
372 		 * threshold won't skew the calculated absolute coordinate.
373 		 * Fixes an issue where slowly moving the mouse would
374 		 * occasionally jump a number of pixels (slowly moving the
375 		 * finger makes this issue most apparent.)
376 		 */
377 		pcum += (xy_sensors[i] - threshold) * i;
378 		psum += (xy_sensors[i] - threshold);
379 	}
380 
381 	if (psum > 0) {
382 		*z = psum;
383 		return pcum * fact / psum;
384 	}
385 
386 	return 0;
387 }
388 
389 static inline void atp_report_fingers(struct input_dev *input, int fingers)
390 {
391 	input_report_key(input, BTN_TOOL_FINGER, fingers == 1);
392 	input_report_key(input, BTN_TOOL_DOUBLETAP, fingers == 2);
393 	input_report_key(input, BTN_TOOL_TRIPLETAP, fingers > 2);
394 }
395 
396 /* Check URB status and for correct length of data package */
397 
398 #define ATP_URB_STATUS_SUCCESS		0
399 #define ATP_URB_STATUS_ERROR		1
400 #define ATP_URB_STATUS_ERROR_FATAL	2
401 
402 static int atp_status_check(struct urb *urb)
403 {
404 	struct atp *dev = urb->context;
405 	struct usb_interface *intf = dev->intf;
406 
407 	switch (urb->status) {
408 	case 0:
409 		/* success */
410 		break;
411 	case -EOVERFLOW:
412 		if (!dev->overflow_warned) {
413 			dev_warn(&intf->dev,
414 				"appletouch: OVERFLOW with data length %d, actual length is %d\n",
415 				dev->info->datalen, dev->urb->actual_length);
416 			dev->overflow_warned = true;
417 		}
418 	case -ECONNRESET:
419 	case -ENOENT:
420 	case -ESHUTDOWN:
421 		/* This urb is terminated, clean up */
422 		dev_dbg(&intf->dev,
423 			"atp_complete: urb shutting down with status: %d\n",
424 			urb->status);
425 		return ATP_URB_STATUS_ERROR_FATAL;
426 
427 	default:
428 		dev_dbg(&intf->dev,
429 			"atp_complete: nonzero urb status received: %d\n",
430 			urb->status);
431 		return ATP_URB_STATUS_ERROR;
432 	}
433 
434 	/* drop incomplete datasets */
435 	if (dev->urb->actual_length != dev->info->datalen) {
436 		dprintk("appletouch: incomplete data package"
437 			" (first byte: %d, length: %d).\n",
438 			dev->data[0], dev->urb->actual_length);
439 		return ATP_URB_STATUS_ERROR;
440 	}
441 
442 	return ATP_URB_STATUS_SUCCESS;
443 }
444 
445 static void atp_detect_size(struct atp *dev)
446 {
447 	int i;
448 
449 	/* 17" Powerbooks have extra X sensors */
450 	for (i = dev->info->xsensors; i < ATP_XSENSORS; i++) {
451 		if (dev->xy_cur[i]) {
452 
453 			dev_info(&dev->intf->dev,
454 				"appletouch: 17\" model detected.\n");
455 
456 			input_set_abs_params(dev->input, ABS_X, 0,
457 					     (dev->info->xsensors_17 - 1) *
458 							dev->info->xfact - 1,
459 					     ATP_FUZZ, 0);
460 			break;
461 		}
462 	}
463 }
464 
465 /*
466  * USB interrupt callback functions
467  */
468 
469 /* Interrupt function for older touchpads: FOUNTAIN/GEYSER1/GEYSER2 */
470 
471 static void atp_complete_geyser_1_2(struct urb *urb)
472 {
473 	int x, y, x_z, y_z, x_f, y_f;
474 	int retval, i, j;
475 	int key;
476 	struct atp *dev = urb->context;
477 	int status = atp_status_check(urb);
478 
479 	if (status == ATP_URB_STATUS_ERROR_FATAL)
480 		return;
481 	else if (status == ATP_URB_STATUS_ERROR)
482 		goto exit;
483 
484 	/* reorder the sensors values */
485 	if (dev->info == &geyser2_info) {
486 		memset(dev->xy_cur, 0, sizeof(dev->xy_cur));
487 
488 		/*
489 		 * The values are laid out like this:
490 		 * Y1, Y2, -, Y3, Y4, -, ..., X1, X2, -, X3, X4, -, ...
491 		 * '-' is an unused value.
492 		 */
493 
494 		/* read X values */
495 		for (i = 0, j = 19; i < 20; i += 2, j += 3) {
496 			dev->xy_cur[i] = dev->data[j];
497 			dev->xy_cur[i + 1] = dev->data[j + 1];
498 		}
499 
500 		/* read Y values */
501 		for (i = 0, j = 1; i < 9; i += 2, j += 3) {
502 			dev->xy_cur[ATP_XSENSORS + i] = dev->data[j];
503 			dev->xy_cur[ATP_XSENSORS + i + 1] = dev->data[j + 1];
504 		}
505 	} else {
506 		for (i = 0; i < 8; i++) {
507 			/* X values */
508 			dev->xy_cur[i +  0] = dev->data[5 * i +  2];
509 			dev->xy_cur[i +  8] = dev->data[5 * i +  4];
510 			dev->xy_cur[i + 16] = dev->data[5 * i + 42];
511 			if (i < 2)
512 				dev->xy_cur[i + 24] = dev->data[5 * i + 44];
513 
514 			/* Y values */
515 			dev->xy_cur[ATP_XSENSORS + i] = dev->data[5 * i +  1];
516 			dev->xy_cur[ATP_XSENSORS + i + 8] = dev->data[5 * i + 3];
517 		}
518 	}
519 
520 	dbg_dump("sample", dev->xy_cur);
521 
522 	if (!dev->valid) {
523 		/* first sample */
524 		dev->valid = true;
525 		dev->x_old = dev->y_old = -1;
526 
527 		/* Store first sample */
528 		memcpy(dev->xy_old, dev->xy_cur, sizeof(dev->xy_old));
529 
530 		/* Perform size detection, if not done already */
531 		if (unlikely(!dev->size_detect_done)) {
532 			atp_detect_size(dev);
533 			dev->size_detect_done = 1;
534 			goto exit;
535 		}
536 	}
537 
538 	for (i = 0; i < ATP_XSENSORS + ATP_YSENSORS; i++) {
539 		/* accumulate the change */
540 		signed char change = dev->xy_old[i] - dev->xy_cur[i];
541 		dev->xy_acc[i] -= change;
542 
543 		/* prevent down drifting */
544 		if (dev->xy_acc[i] < 0)
545 			dev->xy_acc[i] = 0;
546 	}
547 
548 	memcpy(dev->xy_old, dev->xy_cur, sizeof(dev->xy_old));
549 
550 	dbg_dump("accumulator", dev->xy_acc);
551 
552 	x = atp_calculate_abs(dev->xy_acc, ATP_XSENSORS,
553 			      dev->info->xfact, &x_z, &x_f);
554 	y = atp_calculate_abs(dev->xy_acc + ATP_XSENSORS, ATP_YSENSORS,
555 			      dev->info->yfact, &y_z, &y_f);
556 	key = dev->data[dev->info->datalen - 1] & ATP_STATUS_BUTTON;
557 
558 	if (x && y) {
559 		if (dev->x_old != -1) {
560 			x = (dev->x_old * 3 + x) >> 2;
561 			y = (dev->y_old * 3 + y) >> 2;
562 			dev->x_old = x;
563 			dev->y_old = y;
564 
565 			if (debug > 1)
566 				printk(KERN_DEBUG "appletouch: "
567 					"X: %3d Y: %3d Xz: %3d Yz: %3d\n",
568 					x, y, x_z, y_z);
569 
570 			input_report_key(dev->input, BTN_TOUCH, 1);
571 			input_report_abs(dev->input, ABS_X, x);
572 			input_report_abs(dev->input, ABS_Y, y);
573 			input_report_abs(dev->input, ABS_PRESSURE,
574 					 min(ATP_PRESSURE, x_z + y_z));
575 			atp_report_fingers(dev->input, max(x_f, y_f));
576 		}
577 		dev->x_old = x;
578 		dev->y_old = y;
579 
580 	} else if (!x && !y) {
581 
582 		dev->x_old = dev->y_old = -1;
583 		input_report_key(dev->input, BTN_TOUCH, 0);
584 		input_report_abs(dev->input, ABS_PRESSURE, 0);
585 		atp_report_fingers(dev->input, 0);
586 
587 		/* reset the accumulator on release */
588 		memset(dev->xy_acc, 0, sizeof(dev->xy_acc));
589 	}
590 
591 	input_report_key(dev->input, BTN_LEFT, key);
592 	input_sync(dev->input);
593 
594  exit:
595 	retval = usb_submit_urb(dev->urb, GFP_ATOMIC);
596 	if (retval)
597 		dev_err(&dev->intf->dev,
598 			"atp_complete: usb_submit_urb failed with result %d\n",
599 			retval);
600 }
601 
602 /* Interrupt function for older touchpads: GEYSER3/GEYSER4 */
603 
604 static void atp_complete_geyser_3_4(struct urb *urb)
605 {
606 	int x, y, x_z, y_z, x_f, y_f;
607 	int retval, i, j;
608 	int key;
609 	struct atp *dev = urb->context;
610 	int status = atp_status_check(urb);
611 
612 	if (status == ATP_URB_STATUS_ERROR_FATAL)
613 		return;
614 	else if (status == ATP_URB_STATUS_ERROR)
615 		goto exit;
616 
617 	/* Reorder the sensors values:
618 	 *
619 	 * The values are laid out like this:
620 	 * -, Y1, Y2, -, Y3, Y4, -, ..., -, X1, X2, -, X3, X4, ...
621 	 * '-' is an unused value.
622 	 */
623 
624 	/* read X values */
625 	for (i = 0, j = 19; i < 20; i += 2, j += 3) {
626 		dev->xy_cur[i] = dev->data[j + 1];
627 		dev->xy_cur[i + 1] = dev->data[j + 2];
628 	}
629 	/* read Y values */
630 	for (i = 0, j = 1; i < 9; i += 2, j += 3) {
631 		dev->xy_cur[ATP_XSENSORS + i] = dev->data[j + 1];
632 		dev->xy_cur[ATP_XSENSORS + i + 1] = dev->data[j + 2];
633 	}
634 
635 	dbg_dump("sample", dev->xy_cur);
636 
637 	/* Just update the base values (i.e. touchpad in untouched state) */
638 	if (dev->data[dev->info->datalen - 1] & ATP_STATUS_BASE_UPDATE) {
639 
640 		dprintk("appletouch: updated base values\n");
641 
642 		memcpy(dev->xy_old, dev->xy_cur, sizeof(dev->xy_old));
643 		goto exit;
644 	}
645 
646 	for (i = 0; i < ATP_XSENSORS + ATP_YSENSORS; i++) {
647 		/* calculate the change */
648 		dev->xy_acc[i] = dev->xy_cur[i] - dev->xy_old[i];
649 
650 		/* this is a round-robin value, so couple with that */
651 		if (dev->xy_acc[i] > 127)
652 			dev->xy_acc[i] -= 256;
653 
654 		if (dev->xy_acc[i] < -127)
655 			dev->xy_acc[i] += 256;
656 
657 		/* prevent down drifting */
658 		if (dev->xy_acc[i] < 0)
659 			dev->xy_acc[i] = 0;
660 	}
661 
662 	dbg_dump("accumulator", dev->xy_acc);
663 
664 	x = atp_calculate_abs(dev->xy_acc, ATP_XSENSORS,
665 			      dev->info->xfact, &x_z, &x_f);
666 	y = atp_calculate_abs(dev->xy_acc + ATP_XSENSORS, ATP_YSENSORS,
667 			      dev->info->yfact, &y_z, &y_f);
668 	key = dev->data[dev->info->datalen - 1] & ATP_STATUS_BUTTON;
669 
670 	if (x && y) {
671 		if (dev->x_old != -1) {
672 			x = (dev->x_old * 3 + x) >> 2;
673 			y = (dev->y_old * 3 + y) >> 2;
674 			dev->x_old = x;
675 			dev->y_old = y;
676 
677 			if (debug > 1)
678 				printk(KERN_DEBUG "appletouch: X: %3d Y: %3d "
679 				       "Xz: %3d Yz: %3d\n",
680 				       x, y, x_z, y_z);
681 
682 			input_report_key(dev->input, BTN_TOUCH, 1);
683 			input_report_abs(dev->input, ABS_X, x);
684 			input_report_abs(dev->input, ABS_Y, y);
685 			input_report_abs(dev->input, ABS_PRESSURE,
686 					 min(ATP_PRESSURE, x_z + y_z));
687 			atp_report_fingers(dev->input, max(x_f, y_f));
688 		}
689 		dev->x_old = x;
690 		dev->y_old = y;
691 
692 	} else if (!x && !y) {
693 
694 		dev->x_old = dev->y_old = -1;
695 		input_report_key(dev->input, BTN_TOUCH, 0);
696 		input_report_abs(dev->input, ABS_PRESSURE, 0);
697 		atp_report_fingers(dev->input, 0);
698 
699 		/* reset the accumulator on release */
700 		memset(dev->xy_acc, 0, sizeof(dev->xy_acc));
701 	}
702 
703 	input_report_key(dev->input, BTN_LEFT, key);
704 	input_sync(dev->input);
705 
706 	/*
707 	 * Geysers 3/4 will continue to send packets continually after
708 	 * the first touch unless reinitialised. Do so if it's been
709 	 * idle for a while in order to avoid waking the kernel up
710 	 * several hundred times a second.
711 	 */
712 
713 	/*
714 	 * Button must not be pressed when entering suspend,
715 	 * otherwise we will never release the button.
716 	 */
717 	if (!x && !y && !key) {
718 		dev->idlecount++;
719 		if (dev->idlecount == 10) {
720 			dev->x_old = dev->y_old = -1;
721 			dev->idlecount = 0;
722 			schedule_work(&dev->work);
723 			/* Don't resubmit urb here, wait for reinit */
724 			return;
725 		}
726 	} else
727 		dev->idlecount = 0;
728 
729  exit:
730 	retval = usb_submit_urb(dev->urb, GFP_ATOMIC);
731 	if (retval)
732 		dev_err(&dev->intf->dev,
733 			"atp_complete: usb_submit_urb failed with result %d\n",
734 			retval);
735 }
736 
737 static int atp_open(struct input_dev *input)
738 {
739 	struct atp *dev = input_get_drvdata(input);
740 
741 	if (usb_submit_urb(dev->urb, GFP_ATOMIC))
742 		return -EIO;
743 
744 	dev->open = 1;
745 	return 0;
746 }
747 
748 static void atp_close(struct input_dev *input)
749 {
750 	struct atp *dev = input_get_drvdata(input);
751 
752 	usb_kill_urb(dev->urb);
753 	cancel_work_sync(&dev->work);
754 	dev->open = 0;
755 }
756 
757 static int atp_handle_geyser(struct atp *dev)
758 {
759 	if (dev->info != &fountain_info) {
760 		/* switch to raw sensor mode */
761 		if (atp_geyser_init(dev))
762 			return -EIO;
763 
764 		dev_info(&dev->intf->dev, "Geyser mode initialized.\n");
765 	}
766 
767 	return 0;
768 }
769 
770 static int atp_probe(struct usb_interface *iface,
771 		     const struct usb_device_id *id)
772 {
773 	struct atp *dev;
774 	struct input_dev *input_dev;
775 	struct usb_device *udev = interface_to_usbdev(iface);
776 	struct usb_host_interface *iface_desc;
777 	struct usb_endpoint_descriptor *endpoint;
778 	int int_in_endpointAddr = 0;
779 	int i, error = -ENOMEM;
780 	const struct atp_info *info = (const struct atp_info *)id->driver_info;
781 
782 	/* set up the endpoint information */
783 	/* use only the first interrupt-in endpoint */
784 	iface_desc = iface->cur_altsetting;
785 	for (i = 0; i < iface_desc->desc.bNumEndpoints; i++) {
786 		endpoint = &iface_desc->endpoint[i].desc;
787 		if (!int_in_endpointAddr && usb_endpoint_is_int_in(endpoint)) {
788 			/* we found an interrupt in endpoint */
789 			int_in_endpointAddr = endpoint->bEndpointAddress;
790 			break;
791 		}
792 	}
793 	if (!int_in_endpointAddr) {
794 		dev_err(&iface->dev, "Could not find int-in endpoint\n");
795 		return -EIO;
796 	}
797 
798 	/* allocate memory for our device state and initialize it */
799 	dev = kzalloc(sizeof(struct atp), GFP_KERNEL);
800 	input_dev = input_allocate_device();
801 	if (!dev || !input_dev) {
802 		dev_err(&iface->dev, "Out of memory\n");
803 		goto err_free_devs;
804 	}
805 
806 	dev->udev = udev;
807 	dev->intf = iface;
808 	dev->input = input_dev;
809 	dev->info = info;
810 	dev->overflow_warned = false;
811 
812 	dev->urb = usb_alloc_urb(0, GFP_KERNEL);
813 	if (!dev->urb)
814 		goto err_free_devs;
815 
816 	dev->data = usb_alloc_coherent(dev->udev, dev->info->datalen, GFP_KERNEL,
817 				       &dev->urb->transfer_dma);
818 	if (!dev->data)
819 		goto err_free_urb;
820 
821 	usb_fill_int_urb(dev->urb, udev,
822 			 usb_rcvintpipe(udev, int_in_endpointAddr),
823 			 dev->data, dev->info->datalen,
824 			 dev->info->callback, dev, 1);
825 
826 	error = atp_handle_geyser(dev);
827 	if (error)
828 		goto err_free_buffer;
829 
830 	usb_make_path(udev, dev->phys, sizeof(dev->phys));
831 	strlcat(dev->phys, "/input0", sizeof(dev->phys));
832 
833 	input_dev->name = "appletouch";
834 	input_dev->phys = dev->phys;
835 	usb_to_input_id(dev->udev, &input_dev->id);
836 	input_dev->dev.parent = &iface->dev;
837 
838 	input_set_drvdata(input_dev, dev);
839 
840 	input_dev->open = atp_open;
841 	input_dev->close = atp_close;
842 
843 	set_bit(EV_ABS, input_dev->evbit);
844 
845 	input_set_abs_params(input_dev, ABS_X, 0,
846 			     (dev->info->xsensors - 1) * dev->info->xfact - 1,
847 			     ATP_FUZZ, 0);
848 	input_set_abs_params(input_dev, ABS_Y, 0,
849 			     (dev->info->ysensors - 1) * dev->info->yfact - 1,
850 			     ATP_FUZZ, 0);
851 	input_set_abs_params(input_dev, ABS_PRESSURE, 0, ATP_PRESSURE, 0, 0);
852 
853 	set_bit(EV_KEY, input_dev->evbit);
854 	set_bit(BTN_TOUCH, input_dev->keybit);
855 	set_bit(BTN_TOOL_FINGER, input_dev->keybit);
856 	set_bit(BTN_TOOL_DOUBLETAP, input_dev->keybit);
857 	set_bit(BTN_TOOL_TRIPLETAP, input_dev->keybit);
858 	set_bit(BTN_LEFT, input_dev->keybit);
859 
860 	error = input_register_device(dev->input);
861 	if (error)
862 		goto err_free_buffer;
863 
864 	/* save our data pointer in this interface device */
865 	usb_set_intfdata(iface, dev);
866 
867 	INIT_WORK(&dev->work, atp_reinit);
868 
869 	return 0;
870 
871  err_free_buffer:
872 	usb_free_coherent(dev->udev, dev->info->datalen,
873 			  dev->data, dev->urb->transfer_dma);
874  err_free_urb:
875 	usb_free_urb(dev->urb);
876  err_free_devs:
877 	usb_set_intfdata(iface, NULL);
878 	kfree(dev);
879 	input_free_device(input_dev);
880 	return error;
881 }
882 
883 static void atp_disconnect(struct usb_interface *iface)
884 {
885 	struct atp *dev = usb_get_intfdata(iface);
886 
887 	usb_set_intfdata(iface, NULL);
888 	if (dev) {
889 		usb_kill_urb(dev->urb);
890 		input_unregister_device(dev->input);
891 		usb_free_coherent(dev->udev, dev->info->datalen,
892 				  dev->data, dev->urb->transfer_dma);
893 		usb_free_urb(dev->urb);
894 		kfree(dev);
895 	}
896 	dev_info(&iface->dev, "input: appletouch disconnected\n");
897 }
898 
899 static int atp_recover(struct atp *dev)
900 {
901 	int error;
902 
903 	error = atp_handle_geyser(dev);
904 	if (error)
905 		return error;
906 
907 	if (dev->open && usb_submit_urb(dev->urb, GFP_ATOMIC))
908 		return -EIO;
909 
910 	return 0;
911 }
912 
913 static int atp_suspend(struct usb_interface *iface, pm_message_t message)
914 {
915 	struct atp *dev = usb_get_intfdata(iface);
916 
917 	usb_kill_urb(dev->urb);
918 	return 0;
919 }
920 
921 static int atp_resume(struct usb_interface *iface)
922 {
923 	struct atp *dev = usb_get_intfdata(iface);
924 
925 	if (dev->open && usb_submit_urb(dev->urb, GFP_ATOMIC))
926 		return -EIO;
927 
928 	return 0;
929 }
930 
931 static int atp_reset_resume(struct usb_interface *iface)
932 {
933 	struct atp *dev = usb_get_intfdata(iface);
934 
935 	return atp_recover(dev);
936 }
937 
938 static struct usb_driver atp_driver = {
939 	.name		= "appletouch",
940 	.probe		= atp_probe,
941 	.disconnect	= atp_disconnect,
942 	.suspend	= atp_suspend,
943 	.resume		= atp_resume,
944 	.reset_resume	= atp_reset_resume,
945 	.id_table	= atp_table,
946 };
947 
948 module_usb_driver(atp_driver);
949