2 * Apple USB Touchpad (for post-February 2005 PowerBooks and MacBooks) driver
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)
13 * Thanks to Alex Harper <basilisk@foobox.net> for his inputs.
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.
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.
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.
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>
38 /* Type of touchpad */
39 enum atp_touchpad_type {
47 #define ATP_DEVICE(prod, type) \
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, \
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.)
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 */
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 */
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 */
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 */
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 */
92 /* Terminating entry */
95 MODULE_DEVICE_TABLE(usb, atp_table);
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.
102 #define ATP_XSENSORS 26
103 #define ATP_YSENSORS 16
105 /* amount of fuzz this touchpad generates */
108 /* maximum pressure this driver will report */
109 #define ATP_PRESSURE 300
111 * multiplication factor for the X and Y coordinates.
112 * We try to keep the touchpad aspect ratio while still doing only simple
114 * The factors below give coordinates like:
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
120 * 0 <= y < 646 on all Powerbooks
121 * 0 <= y < 774 on all MacBooks
127 * Threshold for the touchpad sensors. Any change less than ATP_THRESHOLD is
130 #define ATP_THRESHOLD 5
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
139 /* Structure to hold all of our device specific stuff */
142 struct usb_device *udev; /* usb device */
143 struct urb *urb; /* usb request block */
144 signed char *data; /* transferred data */
145 struct input_dev *input; /* input dev */
146 enum atp_touchpad_type type; /* type of touchpad */
148 bool valid; /* are the samples valid? */
149 bool size_detect_done;
150 bool overflow_warned;
151 int x_old; /* last reported x/y, */
152 int y_old; /* used for smoothing */
153 signed char xy_cur[ATP_XSENSORS + ATP_YSENSORS];
154 signed char xy_old[ATP_XSENSORS + ATP_YSENSORS];
155 int xy_acc[ATP_XSENSORS + ATP_YSENSORS];
156 int datalen; /* size of USB transfer */
157 int idlecount; /* number of empty packets */
158 struct work_struct work;
161 #define dbg_dump(msg, tab) \
164 printk(KERN_DEBUG "appletouch: %s", msg); \
165 for (__i = 0; __i < ATP_XSENSORS + ATP_YSENSORS; __i++) \
166 printk(" %02x", tab[__i]); \
170 #define dprintk(format, a...) \
173 printk(KERN_DEBUG format, ##a); \
176 MODULE_AUTHOR("Johannes Berg");
177 MODULE_AUTHOR("Stelian Pop");
178 MODULE_AUTHOR("Frank Arnold");
179 MODULE_AUTHOR("Michael Hanselmann");
180 MODULE_AUTHOR("Sven Anders");
181 MODULE_DESCRIPTION("Apple PowerBook and MacBook USB touchpad driver");
182 MODULE_LICENSE("GPL");
185 * Make the threshold a module parameter
187 static int threshold = ATP_THRESHOLD;
188 module_param(threshold, int, 0644);
189 MODULE_PARM_DESC(threshold, "Discard any change in data from a sensor"
190 " (the trackpad has many of these sensors)"
191 " less than this value.");
194 module_param(debug, int, 0644);
195 MODULE_PARM_DESC(debug, "Activate debugging output");
198 * By default newer Geyser devices send standard USB HID mouse
199 * packets (Report ID 2). This code changes device mode, so it
200 * sends raw sensor reports (Report ID 5).
202 static int atp_geyser_init(struct usb_device *udev)
208 size = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
209 ATP_GEYSER_MODE_READ_REQUEST_ID,
210 USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
211 ATP_GEYSER_MODE_REQUEST_VALUE,
212 ATP_GEYSER_MODE_REQUEST_INDEX, &data, 8, 5000);
215 dprintk("atp_geyser_init: read error\n");
216 for (i = 0; i < 8; i++)
217 dprintk("appletouch[%d]: %d\n", i, data[i]);
219 err("Failed to read mode from device.");
223 /* Apply the mode switch */
224 data[0] = ATP_GEYSER_MODE_VENDOR_VALUE;
226 size = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
227 ATP_GEYSER_MODE_WRITE_REQUEST_ID,
228 USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
229 ATP_GEYSER_MODE_REQUEST_VALUE,
230 ATP_GEYSER_MODE_REQUEST_INDEX, &data, 8, 5000);
233 dprintk("atp_geyser_init: write error\n");
234 for (i = 0; i < 8; i++)
235 dprintk("appletouch[%d]: %d\n", i, data[i]);
237 err("Failed to request geyser raw mode");
244 * Reinitialise the device. This usually stops stream of empty packets
247 static void atp_reinit(struct work_struct *work)
249 struct atp *dev = container_of(work, struct atp, work);
250 struct usb_device *udev = dev->udev;
253 dprintk("appletouch: putting appletouch to sleep (reinit)\n");
256 atp_geyser_init(udev);
258 retval = usb_submit_urb(dev->urb, GFP_ATOMIC);
260 err("atp_reinit: usb_submit_urb failed with error %d",
264 static int atp_calculate_abs(int *xy_sensors, int nb_sensors, int fact,
265 int *z, int *fingers)
268 /* values to calculate mean */
269 int pcum = 0, psum = 0;
270 int is_increasing = 0;
274 for (i = 0; i < nb_sensors; i++) {
275 if (xy_sensors[i] < threshold) {
283 * Makes the finger detection more versatile. For example,
284 * two fingers with no gap will be detected. Also, my
285 * tests show it less likely to have intermittent loss
286 * of multiple finger readings while moving around (scrolling).
288 * Changes the multiple finger detection to counting humps on
289 * sensors (transitions from nonincreasing to increasing)
290 * instead of counting transitions from low sensors (no
291 * finger reading) to high sensors (finger above
294 * - Jason Parekh <jasonparekh@gmail.com>
297 (!is_increasing && xy_sensors[i - 1] < xy_sensors[i])) {
300 } else if (i > 0 && xy_sensors[i - 1] >= xy_sensors[i]) {
305 * Subtracts threshold so a high sensor that just passes the
306 * threshold won't skew the calculated absolute coordinate.
307 * Fixes an issue where slowly moving the mouse would
308 * occasionally jump a number of pixels (slowly moving the
309 * finger makes this issue most apparent.)
311 pcum += (xy_sensors[i] - threshold) * i;
312 psum += (xy_sensors[i] - threshold);
317 return pcum * fact / psum;
323 static inline void atp_report_fingers(struct input_dev *input, int fingers)
325 input_report_key(input, BTN_TOOL_FINGER, fingers == 1);
326 input_report_key(input, BTN_TOOL_DOUBLETAP, fingers == 2);
327 input_report_key(input, BTN_TOOL_TRIPLETAP, fingers > 2);
330 static void atp_complete(struct urb *urb)
332 int x, y, x_z, y_z, x_f, y_f;
335 struct atp *dev = urb->context;
337 switch (urb->status) {
342 if (!dev->overflow_warned) {
343 printk(KERN_WARNING "appletouch: OVERFLOW with data "
344 "length %d, actual length is %d\n",
345 dev->datalen, dev->urb->actual_length);
346 dev->overflow_warned = true;
351 /* This urb is terminated, clean up */
352 dbg("atp_complete: urb shutting down with status: %d",
356 dbg("atp_complete: nonzero urb status received: %d",
361 /* drop incomplete datasets */
362 if (dev->urb->actual_length != dev->datalen) {
363 dprintk("appletouch: incomplete data package"
364 " (first byte: %d, length: %d).\n",
365 dev->data[0], dev->urb->actual_length);
369 /* reorder the sensors values */
370 if (dev->type == ATP_GEYSER3 || dev->type == ATP_GEYSER4) {
371 memset(dev->xy_cur, 0, sizeof(dev->xy_cur));
374 * The values are laid out like this:
375 * -, Y1, Y2, -, Y3, Y4, -, ..., -, X1, X2, -, X3, X4, ...
376 * '-' is an unused value.
380 for (i = 0, j = 19; i < 20; i += 2, j += 3) {
381 dev->xy_cur[i] = dev->data[j + 1];
382 dev->xy_cur[i + 1] = dev->data[j + 2];
385 for (i = 0, j = 1; i < 9; i += 2, j += 3) {
386 dev->xy_cur[ATP_XSENSORS + i] = dev->data[j + 1];
387 dev->xy_cur[ATP_XSENSORS + i + 1] = dev->data[j + 2];
389 } else if (dev->type == ATP_GEYSER2) {
390 memset(dev->xy_cur, 0, sizeof(dev->xy_cur));
393 * The values are laid out like this:
394 * Y1, Y2, -, Y3, Y4, -, ..., X1, X2, -, X3, X4, -, ...
395 * '-' is an unused value.
399 for (i = 0, j = 19; i < 20; i += 2, j += 3) {
400 dev->xy_cur[i] = dev->data[j];
401 dev->xy_cur[i + 1] = dev->data[j + 1];
405 for (i = 0, j = 1; i < 9; i += 2, j += 3) {
406 dev->xy_cur[ATP_XSENSORS + i] = dev->data[j];
407 dev->xy_cur[ATP_XSENSORS + i + 1] = dev->data[j + 1];
410 for (i = 0; i < 8; i++) {
412 dev->xy_cur[i + 0] = dev->data[5 * i + 2];
413 dev->xy_cur[i + 8] = dev->data[5 * i + 4];
414 dev->xy_cur[i + 16] = dev->data[5 * i + 42];
416 dev->xy_cur[i + 24] = dev->data[5 * i + 44];
419 dev->xy_cur[i + 26] = dev->data[5 * i + 1];
420 dev->xy_cur[i + 34] = dev->data[5 * i + 3];
424 dbg_dump("sample", dev->xy_cur);
429 dev->x_old = dev->y_old = -1;
430 memcpy(dev->xy_old, dev->xy_cur, sizeof(dev->xy_old));
432 if (dev->size_detect_done ||
433 dev->type == ATP_GEYSER3) /* No 17" Macbooks (yet) */
436 /* 17" Powerbooks have extra X sensors */
437 for (i = (dev->type == ATP_GEYSER2 ? 15 : 16);
438 i < ATP_XSENSORS; i++) {
442 printk(KERN_INFO "appletouch: 17\" model detected.\n");
443 if (dev->type == ATP_GEYSER2)
444 input_set_abs_params(dev->input, ABS_X, 0,
449 input_set_abs_params(dev->input, ABS_X, 0,
456 dev->size_detect_done = 1;
460 for (i = 0; i < ATP_XSENSORS + ATP_YSENSORS; i++) {
461 /* accumulate the change */
462 signed char change = dev->xy_old[i] - dev->xy_cur[i];
463 dev->xy_acc[i] -= change;
465 /* prevent down drifting */
466 if (dev->xy_acc[i] < 0)
470 memcpy(dev->xy_old, dev->xy_cur, sizeof(dev->xy_old));
472 dbg_dump("accumulator", dev->xy_acc);
474 x = atp_calculate_abs(dev->xy_acc, ATP_XSENSORS,
475 ATP_XFACT, &x_z, &x_f);
476 y = atp_calculate_abs(dev->xy_acc + ATP_XSENSORS, ATP_YSENSORS,
477 ATP_YFACT, &y_z, &y_f);
478 key = dev->data[dev->datalen - 1] & 1;
481 if (dev->x_old != -1) {
482 x = (dev->x_old * 3 + x) >> 2;
483 y = (dev->y_old * 3 + y) >> 2;
488 printk(KERN_DEBUG "appletouch: X: %3d Y: %3d "
492 input_report_key(dev->input, BTN_TOUCH, 1);
493 input_report_abs(dev->input, ABS_X, x);
494 input_report_abs(dev->input, ABS_Y, y);
495 input_report_abs(dev->input, ABS_PRESSURE,
496 min(ATP_PRESSURE, x_z + y_z));
497 atp_report_fingers(dev->input, max(x_f, y_f));
502 } else if (!x && !y) {
504 dev->x_old = dev->y_old = -1;
505 input_report_key(dev->input, BTN_TOUCH, 0);
506 input_report_abs(dev->input, ABS_PRESSURE, 0);
507 atp_report_fingers(dev->input, 0);
509 /* reset the accumulator on release */
510 memset(dev->xy_acc, 0, sizeof(dev->xy_acc));
513 input_report_key(dev->input, BTN_LEFT, key);
514 input_sync(dev->input);
517 * Many Geysers will continue to send packets continually after
518 * the first touch unless reinitialised. Do so if it's been
519 * idle for a while in order to avoid waking the kernel up
520 * several hundred times a second. Re-initialization does not
521 * work on Fountain touchpads.
523 if (dev->type != ATP_FOUNTAIN) {
525 * Button must not be pressed when entering suspend,
526 * otherwise we will never release the button.
528 if (!x && !y && !key) {
530 if (dev->idlecount == 10) {
532 schedule_work(&dev->work);
533 /* Don't resubmit urb here, wait for reinit */
541 retval = usb_submit_urb(dev->urb, GFP_ATOMIC);
543 err("atp_complete: usb_submit_urb failed with result %d",
547 static int atp_open(struct input_dev *input)
549 struct atp *dev = input_get_drvdata(input);
551 if (usb_submit_urb(dev->urb, GFP_ATOMIC))
558 static void atp_close(struct input_dev *input)
560 struct atp *dev = input_get_drvdata(input);
562 usb_kill_urb(dev->urb);
563 cancel_work_sync(&dev->work);
567 static int atp_handle_geyser(struct atp *dev)
569 struct usb_device *udev = dev->udev;
571 if (dev->type != ATP_FOUNTAIN) {
572 /* switch to raw sensor mode */
573 if (atp_geyser_init(udev))
576 printk(KERN_INFO "appletouch: Geyser mode initialized.\n");
582 static int atp_probe(struct usb_interface *iface,
583 const struct usb_device_id *id)
586 struct input_dev *input_dev;
587 struct usb_device *udev = interface_to_usbdev(iface);
588 struct usb_host_interface *iface_desc;
589 struct usb_endpoint_descriptor *endpoint;
590 int int_in_endpointAddr = 0;
591 int i, error = -ENOMEM;
593 /* set up the endpoint information */
594 /* use only the first interrupt-in endpoint */
595 iface_desc = iface->cur_altsetting;
596 for (i = 0; i < iface_desc->desc.bNumEndpoints; i++) {
597 endpoint = &iface_desc->endpoint[i].desc;
598 if (!int_in_endpointAddr && usb_endpoint_is_int_in(endpoint)) {
599 /* we found an interrupt in endpoint */
600 int_in_endpointAddr = endpoint->bEndpointAddress;
604 if (!int_in_endpointAddr) {
605 err("Could not find int-in endpoint");
609 /* allocate memory for our device state and initialize it */
610 dev = kzalloc(sizeof(struct atp), GFP_KERNEL);
611 input_dev = input_allocate_device();
612 if (!dev || !input_dev) {
613 err("Out of memory");
618 dev->input = input_dev;
619 dev->type = id->driver_info;
620 dev->overflow_warned = false;
621 if (dev->type == ATP_FOUNTAIN || dev->type == ATP_GEYSER1)
626 dev->urb = usb_alloc_urb(0, GFP_KERNEL);
630 dev->data = usb_buffer_alloc(dev->udev, dev->datalen, GFP_KERNEL,
631 &dev->urb->transfer_dma);
635 usb_fill_int_urb(dev->urb, udev,
636 usb_rcvintpipe(udev, int_in_endpointAddr),
637 dev->data, dev->datalen, atp_complete, dev, 1);
639 error = atp_handle_geyser(dev);
641 goto err_free_buffer;
643 usb_make_path(udev, dev->phys, sizeof(dev->phys));
644 strlcat(dev->phys, "/input0", sizeof(dev->phys));
646 input_dev->name = "appletouch";
647 input_dev->phys = dev->phys;
648 usb_to_input_id(dev->udev, &input_dev->id);
649 input_dev->dev.parent = &iface->dev;
651 input_set_drvdata(input_dev, dev);
653 input_dev->open = atp_open;
654 input_dev->close = atp_close;
656 set_bit(EV_ABS, input_dev->evbit);
658 if (dev->type == ATP_GEYSER3 || dev->type == ATP_GEYSER4) {
660 * MacBook have 20 X sensors, 10 Y sensors
662 input_set_abs_params(input_dev, ABS_X, 0,
663 ((20 - 1) * ATP_XFACT) - 1, ATP_FUZZ, 0);
664 input_set_abs_params(input_dev, ABS_Y, 0,
665 ((10 - 1) * ATP_YFACT) - 1, ATP_FUZZ, 0);
666 } else if (dev->type == ATP_GEYSER2) {
668 * Oct 2005 15" PowerBooks have 15 X sensors, 17" are detected
671 input_set_abs_params(input_dev, ABS_X, 0,
672 ((15 - 1) * ATP_XFACT) - 1, ATP_FUZZ, 0);
673 input_set_abs_params(input_dev, ABS_Y, 0,
674 ((9 - 1) * ATP_YFACT) - 1, ATP_FUZZ, 0);
677 * 12" and 15" Powerbooks only have 16 x sensors,
678 * 17" models are detected later.
680 input_set_abs_params(input_dev, ABS_X, 0,
681 (16 - 1) * ATP_XFACT - 1,
683 input_set_abs_params(input_dev, ABS_Y, 0,
684 (ATP_YSENSORS - 1) * ATP_YFACT - 1,
687 input_set_abs_params(input_dev, ABS_PRESSURE, 0, ATP_PRESSURE, 0, 0);
689 set_bit(EV_KEY, input_dev->evbit);
690 set_bit(BTN_TOUCH, input_dev->keybit);
691 set_bit(BTN_TOOL_FINGER, input_dev->keybit);
692 set_bit(BTN_TOOL_DOUBLETAP, input_dev->keybit);
693 set_bit(BTN_TOOL_TRIPLETAP, input_dev->keybit);
694 set_bit(BTN_LEFT, input_dev->keybit);
696 error = input_register_device(dev->input);
698 goto err_free_buffer;
700 /* save our data pointer in this interface device */
701 usb_set_intfdata(iface, dev);
703 INIT_WORK(&dev->work, atp_reinit);
708 usb_buffer_free(dev->udev, dev->datalen,
709 dev->data, dev->urb->transfer_dma);
711 usb_free_urb(dev->urb);
713 usb_set_intfdata(iface, NULL);
715 input_free_device(input_dev);
719 static void atp_disconnect(struct usb_interface *iface)
721 struct atp *dev = usb_get_intfdata(iface);
723 usb_set_intfdata(iface, NULL);
725 usb_kill_urb(dev->urb);
726 input_unregister_device(dev->input);
727 usb_buffer_free(dev->udev, dev->datalen,
728 dev->data, dev->urb->transfer_dma);
729 usb_free_urb(dev->urb);
732 printk(KERN_INFO "input: appletouch disconnected\n");
735 static int atp_recover(struct atp *dev)
739 error = atp_handle_geyser(dev);
743 if (dev->open && usb_submit_urb(dev->urb, GFP_ATOMIC))
749 static int atp_suspend(struct usb_interface *iface, pm_message_t message)
751 struct atp *dev = usb_get_intfdata(iface);
753 usb_kill_urb(dev->urb);
759 static int atp_resume(struct usb_interface *iface)
761 struct atp *dev = usb_get_intfdata(iface);
763 if (dev->open && usb_submit_urb(dev->urb, GFP_ATOMIC))
769 static int atp_reset_resume(struct usb_interface *iface)
771 struct atp *dev = usb_get_intfdata(iface);
773 return atp_recover(dev);
776 static struct usb_driver atp_driver = {
777 .name = "appletouch",
779 .disconnect = atp_disconnect,
780 .suspend = atp_suspend,
781 .resume = atp_resume,
782 .reset_resume = atp_reset_resume,
783 .id_table = atp_table,
786 static int __init atp_init(void)
788 return usb_register(&atp_driver);
791 static void __exit atp_exit(void)
793 usb_deregister(&atp_driver);
796 module_init(atp_init);
797 module_exit(atp_exit);