xref: /freebsd/sys/dev/usb/input/atp.c (revision cc16dea626cf2fc80cde667ac4798065108e596c)
1 /*-
2  * Copyright (c) 2009 Rohit Grover
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/kernel.h>
33 #include <sys/malloc.h>
34 #include <sys/module.h>
35 #include <sys/lock.h>
36 #include <sys/mutex.h>
37 #include <sys/bus.h>
38 #include <sys/conf.h>
39 #include <sys/fcntl.h>
40 #include <sys/file.h>
41 #include <sys/selinfo.h>
42 #include <sys/poll.h>
43 #include <sys/sysctl.h>
44 #include <sys/uio.h>
45 
46 #include <dev/usb/usb.h>
47 #include <dev/usb/usbdi.h>
48 #include <dev/usb/usbdi_util.h>
49 #include <dev/usb/usbhid.h>
50 #include "usbdevs.h"
51 
52 #define USB_DEBUG_VAR atp_debug
53 #include <dev/usb/usb_debug.h>
54 
55 #include <sys/mouse.h>
56 
57 #define ATP_DRIVER_NAME "atp"
58 
59 /*
60  * Driver specific options: the following options may be set by
61  * `options' statements in the kernel configuration file.
62  */
63 
64 /* The multiplier used to translate sensor reported positions to mickeys. */
65 #ifndef ATP_SCALE_FACTOR
66 #define ATP_SCALE_FACTOR 48
67 #endif
68 
69 /*
70  * This is the age (in microseconds) beyond which a touch is
71  * considered to be a slide; and therefore a tap event isn't registered.
72  */
73 #ifndef ATP_TOUCH_TIMEOUT
74 #define ATP_TOUCH_TIMEOUT 125000
75 #endif
76 
77 /*
78  * A double-tap followed by a single-finger slide is treated as a
79  * special gesture. The driver responds to this gesture by assuming a
80  * virtual button-press for the lifetime of the slide. The following
81  * threshold is the maximum time gap (in microseconds) between the two
82  * tap events preceding the slide for such a gesture.
83  */
84 #ifndef ATP_DOUBLE_TAP_N_DRAG_THRESHOLD
85 #define ATP_DOUBLE_TAP_N_DRAG_THRESHOLD 200000
86 #endif
87 
88 /*
89  * The device provides us only with pressure readings from an array of
90  * X and Y sensors; for our algorithms, we need to interpret groups
91  * (typically pairs) of X and Y readings as being related to a single
92  * finger stroke. We can relate X and Y readings based on their times
93  * of incidence. The coincidence window should be at least 10000us
94  * since it is used against values from getmicrotime(), which has a
95  * precision of around 10ms.
96  */
97 #ifndef ATP_COINCIDENCE_THRESHOLD
98 #define ATP_COINCIDENCE_THRESHOLD  40000 /* unit: microseconds */
99 #if ATP_COINCIDENCE_THRESHOLD > 100000
100 #error "ATP_COINCIDENCE_THRESHOLD too large"
101 #endif
102 #endif /* #ifndef ATP_COINCIDENCE_THRESHOLD */
103 
104 /*
105  * The wait duration (in microseconds) after losing a touch contact
106  * before zombied strokes are reaped and turned into button events.
107  */
108 #define ATP_ZOMBIE_STROKE_REAP_WINDOW   50000
109 #if ATP_ZOMBIE_STROKE_REAP_WINDOW > 100000
110 #error "ATP_ZOMBIE_STROKE_REAP_WINDOW too large"
111 #endif
112 
113 /* end of driver specific options */
114 
115 
116 /* Tunables */
117 static SYSCTL_NODE(_hw_usb, OID_AUTO, atp, CTLFLAG_RW, 0, "USB atp");
118 
119 #ifdef USB_DEBUG
120 enum atp_log_level {
121 	ATP_LLEVEL_DISABLED = 0,
122 	ATP_LLEVEL_ERROR,
123 	ATP_LLEVEL_DEBUG,       /* for troubleshooting */
124 	ATP_LLEVEL_INFO,        /* for diagnostics */
125 };
126 static int atp_debug = ATP_LLEVEL_ERROR; /* the default is to only log errors */
127 SYSCTL_INT(_hw_usb_atp, OID_AUTO, debug, CTLFLAG_RW,
128     &atp_debug, ATP_LLEVEL_ERROR, "ATP debug level");
129 #endif /* USB_DEBUG */
130 
131 static u_int atp_touch_timeout = ATP_TOUCH_TIMEOUT;
132 SYSCTL_UINT(_hw_usb_atp, OID_AUTO, touch_timeout, CTLFLAG_RW,
133     &atp_touch_timeout, 125000, "age threshold (in micros) for a touch");
134 
135 static u_int atp_double_tap_threshold = ATP_DOUBLE_TAP_N_DRAG_THRESHOLD;
136 SYSCTL_UINT(_hw_usb_atp, OID_AUTO, double_tap_threshold, CTLFLAG_RW,
137     &atp_double_tap_threshold, ATP_DOUBLE_TAP_N_DRAG_THRESHOLD,
138     "maximum time (in micros) between a double-tap");
139 
140 static u_int atp_mickeys_scale_factor = ATP_SCALE_FACTOR;
141 static int atp_sysctl_scale_factor_handler(SYSCTL_HANDLER_ARGS);
142 SYSCTL_PROC(_hw_usb_atp, OID_AUTO, scale_factor, CTLTYPE_UINT | CTLFLAG_RW,
143     &atp_mickeys_scale_factor, sizeof(atp_mickeys_scale_factor),
144     atp_sysctl_scale_factor_handler, "IU", "movement scale factor");
145 
146 static u_int atp_small_movement_threshold = ATP_SCALE_FACTOR >> 3;
147 SYSCTL_UINT(_hw_usb_atp, OID_AUTO, small_movement, CTLFLAG_RW,
148     &atp_small_movement_threshold, ATP_SCALE_FACTOR >> 3,
149     "the small movement black-hole for filtering noise");
150 /*
151  * The movement threshold for a stroke; this is the maximum difference
152  * in position which will be resolved as a continuation of a stroke
153  * component.
154  */
155 static u_int atp_max_delta_mickeys = ((3 * ATP_SCALE_FACTOR) >> 1);
156 SYSCTL_UINT(_hw_usb_atp, OID_AUTO, max_delta_mickeys, CTLFLAG_RW,
157     &atp_max_delta_mickeys, ((3 * ATP_SCALE_FACTOR) >> 1),
158     "max. mickeys-delta which will match against an existing stroke");
159 /*
160  * Strokes which accumulate at least this amount of absolute movement
161  * from the aggregate of their components are considered as
162  * slides. Unit: mickeys.
163  */
164 static u_int atp_slide_min_movement = (ATP_SCALE_FACTOR >> 3);
165 SYSCTL_UINT(_hw_usb_atp, OID_AUTO, slide_min_movement, CTLFLAG_RW,
166     &atp_slide_min_movement, (ATP_SCALE_FACTOR >> 3),
167     "strokes with at least this amt. of movement are considered slides");
168 
169 /*
170  * The minimum age of a stroke for it to be considered mature; this
171  * helps filter movements (noise) from immature strokes. Units: interrupts.
172  */
173 static u_int atp_stroke_maturity_threshold = 2;
174 SYSCTL_UINT(_hw_usb_atp, OID_AUTO, stroke_maturity_threshold, CTLFLAG_RW,
175     &atp_stroke_maturity_threshold, 2,
176     "the minimum age of a stroke for it to be considered mature");
177 
178 /* Accept pressure readings from sensors only if above this value. */
179 static u_int atp_sensor_noise_threshold = 2;
180 SYSCTL_UINT(_hw_usb_atp, OID_AUTO, sensor_noise_threshold, CTLFLAG_RW,
181     &atp_sensor_noise_threshold, 2,
182     "accept pressure readings from sensors only if above this value");
183 
184 /* Ignore pressure spans with cumulative press. below this value. */
185 static u_int atp_pspan_min_cum_pressure = 10;
186 SYSCTL_UINT(_hw_usb_atp, OID_AUTO, pspan_min_cum_pressure, CTLFLAG_RW,
187     &atp_pspan_min_cum_pressure, 10,
188     "ignore pressure spans with cumulative press. below this value");
189 
190 /* Maximum allowed width for pressure-spans.*/
191 static u_int atp_pspan_max_width = 4;
192 SYSCTL_UINT(_hw_usb_atp, OID_AUTO, pspan_max_width, CTLFLAG_RW,
193     &atp_pspan_max_width, 4,
194     "maximum allowed width (in sensors) for pressure-spans");
195 
196 /* We support three payload protocols */
197 typedef enum {
198 	ATP_PROT_GEYSER1,
199 	ATP_PROT_GEYSER2,
200 	ATP_PROT_GEYSER3,
201 } atp_protocol;
202 
203 /* Define the various flavours of devices supported by this driver. */
204 enum {
205 	ATP_DEV_PARAMS_0,
206 	ATP_DEV_PARAMS_PBOOK,
207 	ATP_DEV_PARAMS_PBOOK_15A,
208 	ATP_DEV_PARAMS_PBOOK_17,
209 	ATP_N_DEV_PARAMS
210 };
211 struct atp_dev_params {
212 	u_int            data_len;   /* for sensor data */
213 	u_int            n_xsensors;
214 	u_int            n_ysensors;
215 	atp_protocol     prot;
216 } atp_dev_params[ATP_N_DEV_PARAMS] = {
217 	[ATP_DEV_PARAMS_0] = {
218 		.data_len   = 64,
219 		.n_xsensors = 20,
220 		.n_ysensors = 10,
221 		.prot       = ATP_PROT_GEYSER3
222 	},
223 	[ATP_DEV_PARAMS_PBOOK] = {
224 		.data_len   = 81,
225 		.n_xsensors = 16,
226 		.n_ysensors = 16,
227 		.prot       = ATP_PROT_GEYSER1
228 	},
229 	[ATP_DEV_PARAMS_PBOOK_15A] = {
230 		.data_len   = 64,
231 		.n_xsensors = 15,
232 		.n_ysensors = 9,
233 		.prot       = ATP_PROT_GEYSER2
234 	},
235 	[ATP_DEV_PARAMS_PBOOK_17] = {
236 		.data_len   = 81,
237 		.n_xsensors = 26,
238 		.n_ysensors = 16,
239 		.prot       = ATP_PROT_GEYSER1
240 	},
241 };
242 
243 static const STRUCT_USB_HOST_ID atp_devs[] = {
244 	/* Core Duo MacBook & MacBook Pro */
245 	{ USB_VPI(USB_VENDOR_APPLE, 0x0217, ATP_DEV_PARAMS_0) },
246 	{ USB_VPI(USB_VENDOR_APPLE, 0x0218, ATP_DEV_PARAMS_0) },
247 	{ USB_VPI(USB_VENDOR_APPLE, 0x0219, ATP_DEV_PARAMS_0) },
248 
249 	/* Core2 Duo MacBook & MacBook Pro */
250 	{ USB_VPI(USB_VENDOR_APPLE, 0x021a, ATP_DEV_PARAMS_0) },
251 	{ USB_VPI(USB_VENDOR_APPLE, 0x021b, ATP_DEV_PARAMS_0) },
252 	{ USB_VPI(USB_VENDOR_APPLE, 0x021c, ATP_DEV_PARAMS_0) },
253 
254 	/* Core2 Duo MacBook3,1 */
255 	{ USB_VPI(USB_VENDOR_APPLE, 0x0229, ATP_DEV_PARAMS_0) },
256 	{ USB_VPI(USB_VENDOR_APPLE, 0x022a, ATP_DEV_PARAMS_0) },
257 	{ USB_VPI(USB_VENDOR_APPLE, 0x022b, ATP_DEV_PARAMS_0) },
258 
259 	/* 12 inch PowerBook and iBook */
260 	{ USB_VPI(USB_VENDOR_APPLE, 0x030a, ATP_DEV_PARAMS_PBOOK) },
261 	{ USB_VPI(USB_VENDOR_APPLE, 0x030b, ATP_DEV_PARAMS_PBOOK) },
262 
263 	/* 15 inch PowerBook */
264 	{ USB_VPI(USB_VENDOR_APPLE, 0x020e, ATP_DEV_PARAMS_PBOOK) },
265 	{ USB_VPI(USB_VENDOR_APPLE, 0x020f, ATP_DEV_PARAMS_PBOOK) },
266 	{ USB_VPI(USB_VENDOR_APPLE, 0x0215, ATP_DEV_PARAMS_PBOOK_15A) },
267 
268 	/* 17 inch PowerBook */
269 	{ USB_VPI(USB_VENDOR_APPLE, 0x020d, ATP_DEV_PARAMS_PBOOK_17) },
270 
271 };
272 
273 /*
274  * The following structure captures the state of a pressure span along
275  * an axis. Each contact with the touchpad results in separate
276  * pressure spans along the two axes.
277  */
278 typedef struct atp_pspan {
279 	u_int width;   /* in units of sensors */
280 	u_int cum;     /* cumulative compression (from all sensors) */
281 	u_int cog;     /* center of gravity */
282 	u_int loc;     /* location (scaled using the mickeys factor) */
283 	boolean_t matched; /* to track pspans as they match against strokes. */
284 } atp_pspan;
285 
286 typedef enum atp_stroke_type {
287 	ATP_STROKE_TOUCH,
288 	ATP_STROKE_SLIDE,
289 } atp_stroke_type;
290 
291 #define ATP_MAX_PSPANS_PER_AXIS 3
292 
293 typedef struct atp_stroke_component {
294 	/* Fields encapsulating the pressure-span. */
295 	u_int loc;              /* location (scaled) */
296 	u_int cum_pressure;     /* cumulative compression */
297 	u_int max_cum_pressure; /* max cumulative compression */
298 	boolean_t matched; /*to track components as they match against pspans.*/
299 
300 	/* Fields containing information about movement. */
301 	int   delta_mickeys;    /* change in location (un-smoothened movement)*/
302 	int   pending;          /* cum. of pending short movements */
303 	int   movement;         /* current smoothened movement */
304 } atp_stroke_component;
305 
306 typedef enum atp_axis {
307 	X = 0,
308 	Y = 1
309 } atp_axis;
310 
311 #define ATP_MAX_STROKES         (2 * ATP_MAX_PSPANS_PER_AXIS)
312 
313 /*
314  * The following structure captures a finger contact with the
315  * touchpad. A stroke comprises two p-span components and some state.
316  */
317 typedef struct atp_stroke {
318 	atp_stroke_type      type;
319 	struct timeval       ctime; /* create time; for coincident siblings. */
320 	u_int                age;   /*
321 				     * Unit: interrupts; we maintain
322 				     * this value in addition to
323 				     * 'ctime' in order to avoid the
324 				     * expensive call to microtime()
325 				     * at every interrupt.
326 				     */
327 
328 	atp_stroke_component components[2];
329 	u_int                velocity_squared; /*
330 						* Average magnitude (squared)
331 						* of recent velocity.
332 						*/
333 	u_int                cum_movement; /* cum. absolute movement so far */
334 
335 	uint32_t             flags;  /* the state of this stroke */
336 #define ATSF_ZOMBIE          0x1
337 } atp_stroke;
338 
339 #define ATP_FIFO_BUF_SIZE        8 /* bytes */
340 #define ATP_FIFO_QUEUE_MAXLEN   50 /* units */
341 
342 enum {
343 	ATP_INTR_DT,
344 	ATP_RESET,
345 	ATP_N_TRANSFER,
346 };
347 
348 struct atp_softc {
349 	device_t               sc_dev;
350 	struct usb_device     *sc_usb_device;
351 #define MODE_LENGTH 8
352 	char                   sc_mode_bytes[MODE_LENGTH]; /* device mode */
353 	struct mtx             sc_mutex; /* for synchronization */
354 	struct usb_xfer       *sc_xfer[ATP_N_TRANSFER];
355 	struct usb_fifo_sc     sc_fifo;
356 
357 	struct atp_dev_params *sc_params;
358 
359 	mousehw_t              sc_hw;
360 	mousemode_t            sc_mode;
361 	u_int                  sc_pollrate;
362 	mousestatus_t          sc_status;
363 	u_int                  sc_state;
364 #define ATP_ENABLED            0x01
365 #define ATP_ZOMBIES_EXIST      0x02
366 #define ATP_DOUBLE_TAP_DRAG    0x04
367 #define ATP_VALID              0x08
368 
369 	u_int                  sc_left_margin;
370 	u_int                  sc_right_margin;
371 
372 	atp_stroke             sc_strokes[ATP_MAX_STROKES];
373 	u_int                  sc_n_strokes;
374 
375 	int8_t                *sensor_data; /* from interrupt packet */
376 	int                   *base_x;      /* base sensor readings */
377 	int                   *base_y;
378 	int                   *cur_x;       /* current sensor readings */
379 	int                   *cur_y;
380 	int                   *pressure_x;  /* computed pressures */
381 	int                   *pressure_y;
382 
383 	u_int                  sc_idlecount; /* preceding idle interrupts */
384 #define ATP_IDLENESS_THRESHOLD 10
385 
386 	struct timeval         sc_reap_time;
387 	struct timeval         sc_reap_ctime; /*ctime of siblings to be reaped*/
388 };
389 
390 /*
391  * The last byte of the sensor data contains status bits; the
392  * following values define the meanings of these bits.
393  */
394 enum atp_status_bits {
395 	ATP_STATUS_BUTTON      = (uint8_t)0x01, /* The button was pressed */
396 	ATP_STATUS_BASE_UPDATE = (uint8_t)0x04, /* Data from an untouched pad.*/
397 };
398 
399 typedef enum interface_mode {
400 	RAW_SENSOR_MODE = (uint8_t)0x04,
401 	HID_MODE        = (uint8_t)0x08
402 } interface_mode;
403 
404 /*
405  * function prototypes
406  */
407 static usb_fifo_cmd_t   atp_start_read;
408 static usb_fifo_cmd_t   atp_stop_read;
409 static usb_fifo_open_t  atp_open;
410 static usb_fifo_close_t atp_close;
411 static usb_fifo_ioctl_t atp_ioctl;
412 
413 static struct usb_fifo_methods atp_fifo_methods = {
414 	.f_open       = &atp_open,
415 	.f_close      = &atp_close,
416 	.f_ioctl      = &atp_ioctl,
417 	.f_start_read = &atp_start_read,
418 	.f_stop_read  = &atp_stop_read,
419 	.basename[0]  = ATP_DRIVER_NAME,
420 };
421 
422 /* device initialization and shutdown */
423 static usb_error_t   atp_req_get_report(struct usb_device *udev, void *data);
424 static int           atp_set_device_mode(device_t dev, interface_mode mode);
425 static void          atp_reset_callback(struct usb_xfer *, usb_error_t);
426 static int           atp_enable(struct atp_softc *sc);
427 static void          atp_disable(struct atp_softc *sc);
428 static int           atp_softc_populate(struct atp_softc *);
429 static void          atp_softc_unpopulate(struct atp_softc *);
430 
431 /* sensor interpretation */
432 static __inline void atp_interpret_sensor_data(const int8_t *, u_int, atp_axis,
433 			 int *, atp_protocol);
434 static __inline void atp_get_pressures(int *, const int *, const int *, int);
435 static void          atp_detect_pspans(int *, u_int, u_int, atp_pspan *,
436 			 u_int *);
437 
438 /* movement detection */
439 static boolean_t     atp_match_stroke_component(atp_stroke_component *,
440                          const atp_pspan *, atp_stroke_type);
441 static void          atp_match_strokes_against_pspans(struct atp_softc *,
442 			 atp_axis, atp_pspan *, u_int, u_int);
443 static boolean_t     atp_update_strokes(struct atp_softc *,
444 			 atp_pspan *, u_int, atp_pspan *, u_int);
445 static __inline void atp_add_stroke(struct atp_softc *, const atp_pspan *,
446 			 const atp_pspan *);
447 static void          atp_add_new_strokes(struct atp_softc *, atp_pspan *,
448 			 u_int, atp_pspan *, u_int);
449 static void          atp_advance_stroke_state(struct atp_softc *,
450 			 atp_stroke *, boolean_t *);
451 static void          atp_terminate_stroke(struct atp_softc *, u_int);
452 static __inline boolean_t atp_stroke_has_small_movement(const atp_stroke *);
453 static __inline void atp_update_pending_mickeys(atp_stroke_component *);
454 static void          atp_compute_smoothening_scale_ratio(atp_stroke *, int *,
455 			 int *);
456 static boolean_t     atp_compute_stroke_movement(atp_stroke *);
457 
458 /* tap detection */
459 static __inline void atp_setup_reap_time(struct atp_softc *, struct timeval *);
460 static void          atp_reap_zombies(struct atp_softc *, u_int *, u_int *);
461 static void          atp_convert_to_slide(struct atp_softc *, atp_stroke *);
462 
463 /* updating fifo */
464 static void          atp_reset_buf(struct atp_softc *sc);
465 static void          atp_add_to_queue(struct atp_softc *, int, int, uint32_t);
466 
467 
468 usb_error_t
469 atp_req_get_report(struct usb_device *udev, void *data)
470 {
471 	struct usb_device_request req;
472 
473 	req.bmRequestType = UT_READ_CLASS_INTERFACE;
474 	req.bRequest = UR_GET_REPORT;
475 	USETW2(req.wValue, (uint8_t)0x03 /* type */, (uint8_t)0x00 /* id */);
476 	USETW(req.wIndex, 0);
477 	USETW(req.wLength, MODE_LENGTH);
478 
479 	return (usbd_do_request(udev, NULL /* mutex */, &req, data));
480 }
481 
482 static int
483 atp_set_device_mode(device_t dev, interface_mode mode)
484 {
485 	struct atp_softc     *sc;
486 	usb_device_request_t  req;
487 	usb_error_t           err;
488 
489 	if ((mode != RAW_SENSOR_MODE) && (mode != HID_MODE))
490 		return (ENXIO);
491 
492 	sc = device_get_softc(dev);
493 
494 	sc->sc_mode_bytes[0] = mode;
495 	req.bmRequestType = UT_WRITE_CLASS_INTERFACE;
496 	req.bRequest = UR_SET_REPORT;
497 	USETW2(req.wValue, (uint8_t)0x03 /* type */, (uint8_t)0x00 /* id */);
498 	USETW(req.wIndex, 0);
499 	USETW(req.wLength, MODE_LENGTH);
500 	err = usbd_do_request(sc->sc_usb_device, NULL, &req, sc->sc_mode_bytes);
501 	if (err != USB_ERR_NORMAL_COMPLETION)
502 		return (ENXIO);
503 
504 	return (0);
505 }
506 
507 void
508 atp_reset_callback(struct usb_xfer *xfer, usb_error_t error)
509 {
510 	usb_device_request_t   req;
511 	struct usb_page_cache *pc;
512 	struct atp_softc      *sc = usbd_xfer_softc(xfer);
513 
514 	switch (USB_GET_STATE(xfer)) {
515 	case USB_ST_SETUP:
516 		sc->sc_mode_bytes[0] = RAW_SENSOR_MODE;
517 		req.bmRequestType = UT_WRITE_CLASS_INTERFACE;
518 		req.bRequest = UR_SET_REPORT;
519 		USETW2(req.wValue,
520 		    (uint8_t)0x03 /* type */, (uint8_t)0x00 /* id */);
521 		USETW(req.wIndex, 0);
522 		USETW(req.wLength, MODE_LENGTH);
523 
524 		pc = usbd_xfer_get_frame(xfer, 0);
525 		usbd_copy_in(pc, 0, &req, sizeof(req));
526 		pc = usbd_xfer_get_frame(xfer, 1);
527 		usbd_copy_in(pc, 0, sc->sc_mode_bytes, MODE_LENGTH);
528 
529 		usbd_xfer_set_frame_len(xfer, 0, sizeof(req));
530 		usbd_xfer_set_frame_len(xfer, 1, MODE_LENGTH);
531 		usbd_xfer_set_frames(xfer, 2);
532 		usbd_transfer_submit(xfer);
533 		break;
534 
535 	case USB_ST_TRANSFERRED:
536 	default:
537 		break;
538 	}
539 }
540 
541 static int
542 atp_enable(struct atp_softc *sc)
543 {
544 	/* Allocate the dynamic buffers */
545 	if (atp_softc_populate(sc) != 0) {
546 		atp_softc_unpopulate(sc);
547 		return (ENOMEM);
548 	}
549 
550 	/* reset status */
551 	memset(sc->sc_strokes, 0, sizeof(sc->sc_strokes));
552 	sc->sc_n_strokes = 0;
553 	memset(&sc->sc_status, 0, sizeof(sc->sc_status));
554 	sc->sc_idlecount = 0;
555 	sc->sc_state |= ATP_ENABLED;
556 
557 	DPRINTFN(ATP_LLEVEL_INFO, "enabled atp\n");
558 	return (0);
559 }
560 
561 static void
562 atp_disable(struct atp_softc *sc)
563 {
564 	atp_softc_unpopulate(sc);
565 
566 	sc->sc_state &= ~(ATP_ENABLED | ATP_VALID);
567 	DPRINTFN(ATP_LLEVEL_INFO, "disabled atp\n");
568 }
569 
570 /* Allocate dynamic memory for some fields in softc. */
571 static int
572 atp_softc_populate(struct atp_softc *sc)
573 {
574 	const struct atp_dev_params *params = sc->sc_params;
575 
576 	if (params == NULL) {
577 		DPRINTF("params uninitialized!\n");
578 		return (ENXIO);
579 	}
580 	if (params->data_len) {
581 		sc->sensor_data = malloc(params->data_len * sizeof(int8_t),
582 		    M_USB, M_WAITOK);
583 		if (sc->sensor_data == NULL) {
584 			DPRINTF("mem for sensor_data\n");
585 			return (ENXIO);
586 		}
587 	}
588 
589 	if (params->n_xsensors != 0) {
590 		sc->base_x = malloc(params->n_xsensors * sizeof(*(sc->base_x)),
591 		    M_USB, M_WAITOK);
592 		if (sc->base_x == NULL) {
593 			DPRINTF("mem for sc->base_x\n");
594 			return (ENXIO);
595 		}
596 
597 		sc->cur_x = malloc(params->n_xsensors * sizeof(*(sc->cur_x)),
598 		    M_USB, M_WAITOK);
599 		if (sc->cur_x == NULL) {
600 			DPRINTF("mem for sc->cur_x\n");
601 			return (ENXIO);
602 		}
603 
604 		sc->pressure_x =
605 			malloc(params->n_xsensors * sizeof(*(sc->pressure_x)),
606 			    M_USB, M_WAITOK);
607 		if (sc->pressure_x == NULL) {
608 			DPRINTF("mem. for pressure_x\n");
609 			return (ENXIO);
610 		}
611 	}
612 
613 	if (params->n_ysensors != 0) {
614 		sc->base_y = malloc(params->n_ysensors * sizeof(*(sc->base_y)),
615 		    M_USB, M_WAITOK);
616 		if (sc->base_y == NULL) {
617 			DPRINTF("mem for base_y\n");
618 			return (ENXIO);
619 		}
620 
621 		sc->cur_y = malloc(params->n_ysensors * sizeof(*(sc->cur_y)),
622 		    M_USB, M_WAITOK);
623 		if (sc->cur_y == NULL) {
624 			DPRINTF("mem for cur_y\n");
625 			return (ENXIO);
626 		}
627 
628 		sc->pressure_y =
629 			malloc(params->n_ysensors * sizeof(*(sc->pressure_y)),
630 			    M_USB, M_WAITOK);
631 		if (sc->pressure_y == NULL) {
632 			DPRINTF("mem. for pressure_y\n");
633 			return (ENXIO);
634 		}
635 	}
636 
637 	return (0);
638 }
639 
640 /* Free dynamic memory allocated for some fields in softc. */
641 static void
642 atp_softc_unpopulate(struct atp_softc *sc)
643 {
644 	const struct atp_dev_params *params = sc->sc_params;
645 
646 	if (params == NULL) {
647 		return;
648 	}
649 	if (params->n_xsensors != 0) {
650 		if (sc->base_x != NULL) {
651 			free(sc->base_x, M_USB);
652 			sc->base_x = NULL;
653 		}
654 
655 		if (sc->cur_x != NULL) {
656 			free(sc->cur_x, M_USB);
657 			sc->cur_x = NULL;
658 		}
659 
660 		if (sc->pressure_x != NULL) {
661 			free(sc->pressure_x, M_USB);
662 			sc->pressure_x = NULL;
663 		}
664 	}
665 	if (params->n_ysensors != 0) {
666 		if (sc->base_y != NULL) {
667 			free(sc->base_y, M_USB);
668 			sc->base_y = NULL;
669 		}
670 
671 		if (sc->cur_y != NULL) {
672 			free(sc->cur_y, M_USB);
673 			sc->cur_y = NULL;
674 		}
675 
676 		if (sc->pressure_y != NULL) {
677 			free(sc->pressure_y, M_USB);
678 			sc->pressure_y = NULL;
679 		}
680 	}
681 	if (sc->sensor_data != NULL) {
682 		free(sc->sensor_data, M_USB);
683 		sc->sensor_data = NULL;
684 	}
685 }
686 
687 /*
688  * Interpret the data from the X and Y pressure sensors. This function
689  * is called separately for the X and Y sensor arrays. The data in the
690  * USB packet is laid out in the following manner:
691  *
692  * sensor_data:
693  *            --,--,Y1,Y2,--,Y3,Y4,--,Y5,...,Y10, ... X1,X2,--,X3,X4
694  *  indices:   0  1  2  3  4  5  6  7  8 ...  15  ... 20 21 22 23 24
695  *
696  * '--' (in the above) indicates that the value is unimportant.
697  *
698  * Information about the above layout was obtained from the
699  * implementation of the AppleTouch driver in Linux.
700  *
701  * parameters:
702  *   sensor_data
703  *       raw sensor data from the USB packet.
704  *   num
705  *       The number of elements in the array 'arr'.
706  *   axis
707  *       Axis of data to fetch
708  *   arr
709  *       The array to be initialized with the readings.
710  *   prot
711  *       The protocol to use to interpret the data
712  */
713 static __inline void
714 atp_interpret_sensor_data(const int8_t *sensor_data, u_int num, atp_axis axis,
715     int	*arr, atp_protocol prot)
716 {
717 	u_int i;
718 	u_int di;   /* index into sensor data */
719 
720 	switch (prot) {
721 	case ATP_PROT_GEYSER1:
722 		/*
723 		 * For Geyser 1, the sensors are laid out in pairs
724 		 * every 5 bytes.
725 		 */
726 		for (i = 0, di = (axis == Y) ? 1 : 2; i < 8; di += 5, i++) {
727 			arr[i] = sensor_data[di];
728 			arr[i+8] = sensor_data[di+2];
729 			if (axis == X && num > 16)
730 				arr[i+16] = sensor_data[di+40];
731 		}
732 
733 		break;
734 	case ATP_PROT_GEYSER2:
735 	case ATP_PROT_GEYSER3:
736 		for (i = 0, di = (axis == Y) ? 2 : 20; i < num; /* empty */ ) {
737 			arr[i++] = sensor_data[di++];
738 			arr[i++] = sensor_data[di++];
739 			di++;
740 		}
741 		break;
742 	}
743 }
744 
745 static __inline void
746 atp_get_pressures(int *p, const int *cur, const int *base, int n)
747 {
748 	int i;
749 
750 	for (i = 0; i < n; i++) {
751 		p[i] = cur[i] - base[i];
752 		if (p[i] > 127)
753 			p[i] -= 256;
754 		if (p[i] < -127)
755 			p[i] += 256;
756 		if (p[i] < 0)
757 			p[i] = 0;
758 
759 		/*
760 		 * Shave off pressures below the noise-pressure
761 		 * threshold; this will reduce the contribution from
762 		 * lower pressure readings.
763 		 */
764 		if ((u_int)p[i] <= atp_sensor_noise_threshold)
765 			p[i] = 0; /* filter away noise */
766 		else
767 			p[i] -= atp_sensor_noise_threshold;
768 	}
769 }
770 
771 static void
772 atp_detect_pspans(int *p, u_int num_sensors,
773     u_int       max_spans, /* max # of pspans permitted */
774     atp_pspan  *spans,     /* finger spans */
775     u_int      *nspans_p)  /* num spans detected */
776 {
777 	u_int i;
778 	int   maxp;             /* max pressure seen within a span */
779 	u_int num_spans = 0;
780 
781 	enum atp_pspan_state {
782 		ATP_PSPAN_INACTIVE,
783 		ATP_PSPAN_INCREASING,
784 		ATP_PSPAN_DECREASING,
785 	} state; /* state of the pressure span */
786 
787 	/*
788 	 * The following is a simple state machine to track
789 	 * the phase of the pressure span.
790 	 */
791 	memset(spans, 0, max_spans * sizeof(atp_pspan));
792 	maxp = 0;
793 	state = ATP_PSPAN_INACTIVE;
794 	for (i = 0; i < num_sensors; i++) {
795 		if (num_spans >= max_spans)
796 			break;
797 
798 		if (p[i] == 0) {
799 			if (state == ATP_PSPAN_INACTIVE) {
800 				/*
801 				 * There is no pressure information for this
802 				 * sensor, and we aren't tracking a finger.
803 				 */
804 				continue;
805 			} else {
806 				state = ATP_PSPAN_INACTIVE;
807 				maxp = 0;
808 				num_spans++;
809 			}
810 		} else {
811 			switch (state) {
812 			case ATP_PSPAN_INACTIVE:
813 				state = ATP_PSPAN_INCREASING;
814 				maxp  = p[i];
815 				break;
816 
817 			case ATP_PSPAN_INCREASING:
818 				if (p[i] > maxp)
819 					maxp = p[i];
820 				else if (p[i] <= (maxp >> 1))
821 					state = ATP_PSPAN_DECREASING;
822 				break;
823 
824 			case ATP_PSPAN_DECREASING:
825 				if (p[i] > p[i - 1]) {
826 					/*
827 					 * This is the beginning of
828 					 * another span; change state
829 					 * to give the appearance that
830 					 * we're starting from an
831 					 * inactive span, and then
832 					 * re-process this reading in
833 					 * the next iteration.
834 					 */
835 					num_spans++;
836 					state = ATP_PSPAN_INACTIVE;
837 					maxp  = 0;
838 					i--;
839 					continue;
840 				}
841 				break;
842 			}
843 
844 			/* Update the finger span with this reading. */
845 			spans[num_spans].width++;
846 			spans[num_spans].cum += p[i];
847 			spans[num_spans].cog += p[i] * (i + 1);
848 		}
849 	}
850 	if (state != ATP_PSPAN_INACTIVE)
851 		num_spans++;    /* close the last finger span */
852 
853 	/* post-process the spans */
854 	for (i = 0; i < num_spans; i++) {
855 		/* filter away unwanted pressure spans */
856 		if ((spans[i].cum < atp_pspan_min_cum_pressure) ||
857 		    (spans[i].width > atp_pspan_max_width)) {
858 			if ((i + 1) < num_spans) {
859 				memcpy(&spans[i], &spans[i + 1],
860 				    (num_spans - i - 1) * sizeof(atp_pspan));
861 				i--;
862 			}
863 			num_spans--;
864 			continue;
865 		}
866 
867 		/* compute this span's representative location */
868 		spans[i].loc = spans[i].cog * atp_mickeys_scale_factor /
869 			spans[i].cum;
870 
871 		spans[i].matched = FALSE; /* not yet matched against a stroke */
872 	}
873 
874 	*nspans_p = num_spans;
875 }
876 
877 /*
878  * Match a pressure-span against a stroke-component. If there is a
879  * match, update the component's state and return TRUE.
880  */
881 static boolean_t
882 atp_match_stroke_component(atp_stroke_component *component,
883     const atp_pspan *pspan, atp_stroke_type stroke_type)
884 {
885 	int   delta_mickeys;
886 	u_int min_pressure;
887 
888 	delta_mickeys = pspan->loc - component->loc;
889 
890 	if ((u_int)abs(delta_mickeys) > atp_max_delta_mickeys)
891 		return (FALSE); /* the finger span is too far out; no match */
892 
893 	component->loc          = pspan->loc;
894 
895 	/*
896 	 * A sudden and significant increase in a pspan's cumulative
897 	 * pressure indicates the incidence of a new finger
898 	 * contact. This usually revises the pspan's
899 	 * centre-of-gravity, and hence the location of any/all
900 	 * matching stroke component(s). But such a change should
901 	 * *not* be interpreted as a movement.
902 	 */
903         if (pspan->cum > ((3 * component->cum_pressure) >> 1))
904 		delta_mickeys = 0;
905 
906 	component->cum_pressure = pspan->cum;
907 	if (pspan->cum > component->max_cum_pressure)
908 		component->max_cum_pressure = pspan->cum;
909 
910 	/*
911 	 * Disregard the component's movement if its cumulative
912 	 * pressure drops below a fraction of the maximum; this
913 	 * fraction is determined based on the stroke's type.
914 	 */
915 	if (stroke_type == ATP_STROKE_TOUCH)
916 		min_pressure = (3 * component->max_cum_pressure) >> 2;
917 	else
918 		min_pressure = component->max_cum_pressure >> 2;
919 	if (component->cum_pressure < min_pressure)
920 		delta_mickeys = 0;
921 
922 	component->delta_mickeys = delta_mickeys;
923 	return (TRUE);
924 }
925 
926 static void
927 atp_match_strokes_against_pspans(struct atp_softc *sc, atp_axis axis,
928     atp_pspan *pspans, u_int n_pspans, u_int repeat_count)
929 {
930 	u_int i, j;
931 	u_int repeat_index = 0;
932 
933 	/* Determine the index of the multi-span. */
934 	if (repeat_count) {
935 		u_int cum = 0;
936 		for (i = 0; i < n_pspans; i++) {
937 			if (pspans[i].cum > cum) {
938 				repeat_index = i;
939 				cum = pspans[i].cum;
940 			}
941 		}
942 	}
943 
944 	for (i = 0; i < sc->sc_n_strokes; i++) {
945 		atp_stroke *stroke  = &sc->sc_strokes[i];
946 		if (stroke->components[axis].matched)
947 			continue; /* skip matched components */
948 
949 		for (j = 0; j < n_pspans; j++) {
950 			if (pspans[j].matched)
951 				continue; /* skip matched pspans */
952 
953 			if (atp_match_stroke_component(
954 				    &stroke->components[axis], &pspans[j],
955 				    stroke->type)) {
956 				/* There is a match. */
957 				stroke->components[axis].matched = TRUE;
958 
959 				/* Take care to repeat at the multi-span. */
960 				if ((repeat_count > 0) && (j == repeat_index))
961 					repeat_count--;
962 				else
963 					pspans[j].matched = TRUE;
964 
965 				break; /* skip to the next stroke */
966 			}
967 		} /* loop over pspans */
968 	} /* loop over strokes */
969 }
970 
971 /*
972  * Update strokes by matching against current pressure-spans.
973  * Return TRUE if any movement is detected.
974  */
975 static boolean_t
976 atp_update_strokes(struct atp_softc *sc, atp_pspan *pspans_x,
977     u_int n_xpspans, atp_pspan *pspans_y, u_int n_ypspans)
978 {
979 	u_int       i, j;
980 	atp_stroke *stroke;
981 	boolean_t   movement = FALSE;
982 	u_int       repeat_count = 0;
983 
984 	/* Reset X and Y components of all strokes as unmatched. */
985 	for (i = 0; i < sc->sc_n_strokes; i++) {
986 		stroke = &sc->sc_strokes[i];
987 		stroke->components[X].matched = FALSE;
988 		stroke->components[Y].matched = FALSE;
989 	}
990 
991 	/*
992 	 * Usually, the X and Y pspans come in pairs (the common case
993 	 * being a single pair). It is possible, however, that
994 	 * multiple contacts resolve to a single pspan along an
995 	 * axis, as illustrated in the following:
996 	 *
997 	 *   F = finger-contact
998 	 *
999 	 *                pspan  pspan
1000 	 *        +-----------------------+
1001 	 *        |         .      .      |
1002 	 *        |         .      .      |
1003 	 *        |         .      .      |
1004 	 *        |         .      .      |
1005 	 *  pspan |.........F......F      |
1006 	 *        |                       |
1007 	 *        |                       |
1008 	 *        |                       |
1009 	 *        +-----------------------+
1010 	 *
1011 	 *
1012 	 * The above case can be detected by a difference in the
1013 	 * number of X and Y pspans. When this happens, X and Y pspans
1014 	 * aren't easy to pair or match against strokes.
1015 	 *
1016 	 * When X and Y pspans differ in number, the axis with the
1017 	 * smaller number of pspans is regarded as having a repeating
1018 	 * pspan (or a multi-pspan)--in the above illustration, the
1019 	 * Y-axis has a repeating pspan. Our approach is to try to
1020 	 * match the multi-pspan repeatedly against strokes. The
1021 	 * difference between the number of X and Y pspans gives us a
1022 	 * crude repeat_count for matching multi-pspans--i.e. the
1023 	 * multi-pspan along the Y axis (above) has a repeat_count of 1.
1024 	 */
1025 	repeat_count = abs(n_xpspans - n_ypspans);
1026 
1027 	atp_match_strokes_against_pspans(sc, X, pspans_x, n_xpspans,
1028 	    (((repeat_count != 0) && ((n_xpspans < n_ypspans))) ?
1029 		repeat_count : 0));
1030 	atp_match_strokes_against_pspans(sc, Y, pspans_y, n_ypspans,
1031 	    (((repeat_count != 0) && (n_ypspans < n_xpspans)) ?
1032 		repeat_count : 0));
1033 
1034 	/* Update the state of strokes based on the above pspan matches. */
1035 	for (i = 0; i < sc->sc_n_strokes; i++) {
1036 		stroke = &sc->sc_strokes[i];
1037 		if (stroke->components[X].matched &&
1038 		    stroke->components[Y].matched) {
1039 			atp_advance_stroke_state(sc, stroke, &movement);
1040 		} else {
1041 			/*
1042 			 * At least one component of this stroke
1043 			 * didn't match against current pspans;
1044 			 * terminate it.
1045 			 */
1046 			atp_terminate_stroke(sc, i);
1047 		}
1048 	}
1049 
1050 	/* Add new strokes for pairs of unmatched pspans */
1051 	for (i = 0; i < n_xpspans; i++) {
1052 		if (pspans_x[i].matched == FALSE) break;
1053 	}
1054 	for (j = 0; j < n_ypspans; j++) {
1055 		if (pspans_y[j].matched == FALSE) break;
1056 	}
1057 	if ((i < n_xpspans) && (j < n_ypspans)) {
1058 #ifdef USB_DEBUG
1059 		if (atp_debug >= ATP_LLEVEL_INFO) {
1060 			printf("unmatched pspans:");
1061 			for (; i < n_xpspans; i++) {
1062 				if (pspans_x[i].matched)
1063 					continue;
1064 				printf(" X:[loc:%u,cum:%u]",
1065 				    pspans_x[i].loc, pspans_x[i].cum);
1066 			}
1067 			for (; j < n_ypspans; j++) {
1068 				if (pspans_y[j].matched)
1069 					continue;
1070 				printf(" Y:[loc:%u,cum:%u]",
1071 				    pspans_y[j].loc, pspans_y[j].cum);
1072 			}
1073 			printf("\n");
1074 		}
1075 #endif /* USB_DEBUG */
1076 		if ((n_xpspans == 1) && (n_ypspans == 1))
1077 			/* The common case of a single pair of new pspans. */
1078 			atp_add_stroke(sc, &pspans_x[0], &pspans_y[0]);
1079 		else
1080 			atp_add_new_strokes(sc,
1081 			    pspans_x, n_xpspans,
1082 			    pspans_y, n_ypspans);
1083 	}
1084 
1085 #ifdef USB_DEBUG
1086 	if (atp_debug >= ATP_LLEVEL_INFO) {
1087 		for (i = 0; i < sc->sc_n_strokes; i++) {
1088 			atp_stroke *stroke = &sc->sc_strokes[i];
1089 
1090 			printf(" %s%clc:%u,dm:%d,pnd:%d,cum:%d,max:%d,mv:%d%c"
1091 			    ",%clc:%u,dm:%d,pnd:%d,cum:%d,max:%d,mv:%d%c",
1092 			    (stroke->flags & ATSF_ZOMBIE) ? "zomb:" : "",
1093 			    (stroke->type == ATP_STROKE_TOUCH) ? '[' : '<',
1094 			    stroke->components[X].loc,
1095 			    stroke->components[X].delta_mickeys,
1096 			    stroke->components[X].pending,
1097 			    stroke->components[X].cum_pressure,
1098 			    stroke->components[X].max_cum_pressure,
1099 			    stroke->components[X].movement,
1100 			    (stroke->type == ATP_STROKE_TOUCH) ? ']' : '>',
1101 			    (stroke->type == ATP_STROKE_TOUCH) ? '[' : '<',
1102 			    stroke->components[Y].loc,
1103 			    stroke->components[Y].delta_mickeys,
1104 			    stroke->components[Y].pending,
1105 			    stroke->components[Y].cum_pressure,
1106 			    stroke->components[Y].max_cum_pressure,
1107 			    stroke->components[Y].movement,
1108 			    (stroke->type == ATP_STROKE_TOUCH) ? ']' : '>');
1109 		}
1110 		if (sc->sc_n_strokes)
1111 			printf("\n");
1112 	}
1113 #endif /* USB_DEBUG */
1114 
1115 	return (movement);
1116 }
1117 
1118 /* Initialize a stroke using a pressure-span. */
1119 static __inline void
1120 atp_add_stroke(struct atp_softc *sc, const atp_pspan *pspan_x,
1121     const atp_pspan *pspan_y)
1122 {
1123 	atp_stroke *stroke;
1124 
1125 	if (sc->sc_n_strokes >= ATP_MAX_STROKES)
1126 		return;
1127 	stroke = &sc->sc_strokes[sc->sc_n_strokes];
1128 
1129 	memset(stroke, 0, sizeof(atp_stroke));
1130 
1131 	/*
1132 	 * Strokes begin as potential touches. If a stroke survives
1133 	 * longer than a threshold, or if it records significant
1134 	 * cumulative movement, then it is considered a 'slide'.
1135 	 */
1136 	stroke->type = ATP_STROKE_TOUCH;
1137 	microtime(&stroke->ctime);
1138 	stroke->age  = 1;       /* Unit: interrupts */
1139 
1140 	stroke->components[X].loc              = pspan_x->loc;
1141 	stroke->components[X].cum_pressure     = pspan_x->cum;
1142 	stroke->components[X].max_cum_pressure = pspan_x->cum;
1143 	stroke->components[X].matched          = TRUE;
1144 
1145 	stroke->components[Y].loc              = pspan_y->loc;
1146 	stroke->components[Y].cum_pressure     = pspan_y->cum;
1147 	stroke->components[Y].max_cum_pressure = pspan_y->cum;
1148 	stroke->components[Y].matched          = TRUE;
1149 
1150 	sc->sc_n_strokes++;
1151 	if (sc->sc_n_strokes > 1) {
1152 		/* Reset double-tap-n-drag if we have more than one strokes. */
1153 		sc->sc_state &= ~ATP_DOUBLE_TAP_DRAG;
1154 	}
1155 
1156 	DPRINTFN(ATP_LLEVEL_INFO, "[%u,%u], time: %u,%ld\n",
1157 	    stroke->components[X].loc,
1158 	    stroke->components[Y].loc,
1159 	    (unsigned int)stroke->ctime.tv_sec,
1160 	    (unsigned long int)stroke->ctime.tv_usec);
1161 }
1162 
1163 static void
1164 atp_add_new_strokes(struct atp_softc *sc, atp_pspan *pspans_x,
1165     u_int n_xpspans, atp_pspan *pspans_y, u_int n_ypspans)
1166 {
1167 	atp_pspan spans[2][ATP_MAX_PSPANS_PER_AXIS];
1168 	u_int nspans[2];
1169 	u_int i;
1170 	u_int j;
1171 
1172 	/* Copy unmatched pspans into the local arrays. */
1173 	for (i = 0, nspans[X] = 0; i < n_xpspans; i++) {
1174 		if (pspans_x[i].matched == FALSE) {
1175 			spans[X][nspans[X]] = pspans_x[i];
1176 			nspans[X]++;
1177 		}
1178 	}
1179 	for (j = 0, nspans[Y] = 0; j < n_ypspans; j++) {
1180 		if (pspans_y[j].matched == FALSE) {
1181 			spans[Y][nspans[Y]] = pspans_y[j];
1182 			nspans[Y]++;
1183 		}
1184 	}
1185 
1186 	if (nspans[X] == nspans[Y]) {
1187 		/* Create new strokes from pairs of unmatched pspans */
1188 		for (i = 0, j = 0; (i < nspans[X]) && (j < nspans[Y]); i++, j++)
1189 			atp_add_stroke(sc, &spans[X][i], &spans[Y][j]);
1190 	} else {
1191 		u_int    cum = 0;
1192 		atp_axis repeat_axis;      /* axis with multi-pspans */
1193 		u_int    repeat_count;     /* repeat count for the multi-pspan*/
1194 		u_int    repeat_index = 0; /* index of the multi-span */
1195 
1196 		repeat_axis  = (nspans[X] > nspans[Y]) ? Y : X;
1197 		repeat_count = abs(nspans[X] - nspans[Y]);
1198 		for (i = 0; i < nspans[repeat_axis]; i++) {
1199 			if (spans[repeat_axis][i].cum > cum) {
1200 				repeat_index = i;
1201 				cum = spans[repeat_axis][i].cum;
1202 			}
1203 		}
1204 
1205 		/* Create new strokes from pairs of unmatched pspans */
1206 		i = 0, j = 0;
1207 		for (; (i < nspans[X]) && (j < nspans[Y]); i++, j++) {
1208 			atp_add_stroke(sc, &spans[X][i], &spans[Y][j]);
1209 
1210 			/* Take care to repeat at the multi-pspan. */
1211 			if (repeat_count > 0) {
1212 				if ((repeat_axis == X) &&
1213 				    (repeat_index == i)) {
1214 					i--; /* counter loop increment */
1215 					repeat_count--;
1216 				} else if ((repeat_axis == Y) &&
1217 				    (repeat_index == j)) {
1218 					j--; /* counter loop increment */
1219 					repeat_count--;
1220 				}
1221 			}
1222 		}
1223 	}
1224 }
1225 
1226 /*
1227  * Advance the state of this stroke--and update the out-parameter
1228  * 'movement' as a side-effect.
1229  */
1230 void
1231 atp_advance_stroke_state(struct atp_softc *sc, atp_stroke *stroke,
1232     boolean_t *movement)
1233 {
1234 	stroke->age++;
1235 	if (stroke->age <= atp_stroke_maturity_threshold) {
1236 		/* Avoid noise from immature strokes. */
1237 		stroke->components[X].delta_mickeys = 0;
1238 		stroke->components[Y].delta_mickeys = 0;
1239 	}
1240 
1241 	/* Revitalize stroke if it had previously been marked as a zombie. */
1242 	if (stroke->flags & ATSF_ZOMBIE)
1243 		stroke->flags &= ~ATSF_ZOMBIE;
1244 
1245 	if (atp_compute_stroke_movement(stroke))
1246 		*movement = TRUE;
1247 
1248 	if (stroke->type != ATP_STROKE_TOUCH)
1249 		return;
1250 
1251 	/* Convert touch strokes to slides upon detecting movement or age. */
1252 	if (stroke->cum_movement >= atp_slide_min_movement) {
1253 		atp_convert_to_slide(sc, stroke);
1254 	} else {
1255 		/* If a touch stroke is found to be older than the
1256 		 * touch-timeout threshold, it should be converted to
1257 		 * a slide; except if there is a co-incident sibling
1258 		 * with a later creation time.
1259 		 *
1260 		 * When multiple fingers make contact with the
1261 		 * touchpad, they are likely to be separated in their
1262 		 * times of incidence.  During a multi-finger tap,
1263 		 * therefore, the last finger to make
1264 		 * contact--i.e. the one with the latest
1265 		 * 'ctime'--should be used to determine how the
1266 		 * touch-siblings get treated; otherwise older
1267 		 * siblings may lapse the touch-timeout and get
1268 		 * converted into slides prematurely.  The following
1269 		 * loop determines if there exists another touch
1270 		 * stroke with a larger 'ctime' than the current
1271 		 * stroke (NOTE: zombies with a larger 'ctime' are
1272 		 * also considered) .
1273 		 */
1274 
1275 		u_int i;
1276 		for (i = 0; i < sc->sc_n_strokes; i++) {
1277 			if ((&sc->sc_strokes[i] == stroke) ||
1278 			    (sc->sc_strokes[i].type != ATP_STROKE_TOUCH))
1279 				continue;
1280 
1281 			if (timevalcmp(&sc->sc_strokes[i].ctime,
1282 				&stroke->ctime, >))
1283 				break;
1284 		}
1285 		if (i == sc->sc_n_strokes) {
1286 			/* Found no other touch stroke with a larger 'ctime'. */
1287 			struct timeval tdiff;
1288 
1289 			/* Compute the stroke's age. */
1290 			getmicrotime(&tdiff);
1291 			if (timevalcmp(&tdiff, &stroke->ctime, >))
1292 				timevalsub(&tdiff, &stroke->ctime);
1293 			else {
1294 				/*
1295 				 * If we are here, it is because getmicrotime
1296 				 * reported the current time as being behind
1297 				 * the stroke's start time; getmicrotime can
1298 				 * be imprecise.
1299 				 */
1300 				tdiff.tv_sec  = 0;
1301 				tdiff.tv_usec = 0;
1302 			}
1303 
1304 			if ((tdiff.tv_sec > (atp_touch_timeout / 1000000)) ||
1305 			    ((tdiff.tv_sec == (atp_touch_timeout / 1000000)) &&
1306 				(tdiff.tv_usec >=
1307 				    (atp_touch_timeout % 1000000))))
1308 				atp_convert_to_slide(sc, stroke);
1309 		}
1310 	}
1311 }
1312 
1313 /* Switch a given touch stroke to being a slide. */
1314 void
1315 atp_convert_to_slide(struct atp_softc *sc, atp_stroke *stroke)
1316 {
1317 	stroke->type = ATP_STROKE_SLIDE;
1318 
1319 	/* Are we at the beginning of a double-click-n-drag? */
1320 	if ((sc->sc_n_strokes == 1) &&
1321 	    ((sc->sc_state & ATP_ZOMBIES_EXIST) == 0) &&
1322 	    timevalcmp(&stroke->ctime, &sc->sc_reap_time, >)) {
1323 		struct timeval delta;
1324 		struct timeval window = {
1325 			atp_double_tap_threshold / 1000000,
1326 			atp_double_tap_threshold % 1000000
1327 		};
1328 
1329 		delta = stroke->ctime;
1330 		timevalsub(&delta, &sc->sc_reap_time);
1331 		if (timevalcmp(&delta, &window, <=))
1332 			sc->sc_state |= ATP_DOUBLE_TAP_DRAG;
1333 	}
1334 }
1335 
1336 /*
1337  * Terminate a stroke. While SLIDE strokes are dropped, TOUCH strokes
1338  * are retained as zombies so as to reap all their siblings together;
1339  * this helps establish the number of fingers involved in the tap.
1340  */
1341 static void
1342 atp_terminate_stroke(struct atp_softc *sc,
1343     u_int index) /* index of the stroke to be terminated */
1344 {
1345 	atp_stroke *s = &sc->sc_strokes[index];
1346 
1347 	if (s->flags & ATSF_ZOMBIE) {
1348 		return;
1349 	}
1350 
1351 	if ((s->type == ATP_STROKE_TOUCH) &&
1352 	    (s->age > atp_stroke_maturity_threshold)) {
1353 		s->flags |= ATSF_ZOMBIE;
1354 
1355 		/* If no zombies exist, then prepare to reap zombies later. */
1356 		if ((sc->sc_state & ATP_ZOMBIES_EXIST) == 0) {
1357 			atp_setup_reap_time(sc, &s->ctime);
1358 			sc->sc_state |= ATP_ZOMBIES_EXIST;
1359 		}
1360 	} else {
1361 		/* Drop this stroke. */
1362 		memcpy(&sc->sc_strokes[index], &sc->sc_strokes[index + 1],
1363 		    (sc->sc_n_strokes - index - 1) * sizeof(atp_stroke));
1364 		sc->sc_n_strokes--;
1365 
1366 		/*
1367 		 * Reset the double-click-n-drag at the termination of
1368 		 * any slide stroke.
1369 		 */
1370 		sc->sc_state &= ~ATP_DOUBLE_TAP_DRAG;
1371 	}
1372 }
1373 
1374 static __inline boolean_t
1375 atp_stroke_has_small_movement(const atp_stroke *stroke)
1376 {
1377 	return (((u_int)abs(stroke->components[X].delta_mickeys) <=
1378 		atp_small_movement_threshold) &&
1379 	    ((u_int)abs(stroke->components[Y].delta_mickeys) <=
1380 		atp_small_movement_threshold));
1381 }
1382 
1383 /*
1384  * Accumulate delta_mickeys into the component's 'pending' bucket; if
1385  * the aggregate exceeds the small_movement_threshold, then retain
1386  * delta_mickeys for later.
1387  */
1388 static __inline void
1389 atp_update_pending_mickeys(atp_stroke_component *component)
1390 {
1391 	component->pending += component->delta_mickeys;
1392 	if ((u_int)abs(component->pending) <= atp_small_movement_threshold)
1393 		component->delta_mickeys = 0;
1394 	else {
1395 		/*
1396 		 * Penalise pending mickeys for having accumulated
1397 		 * over short deltas. This operation has the effect of
1398 		 * scaling down the cumulative contribution of short
1399 		 * movements.
1400 		 */
1401 		component->pending -= (component->delta_mickeys << 1);
1402 	}
1403 }
1404 
1405 
1406 static void
1407 atp_compute_smoothening_scale_ratio(atp_stroke *stroke, int *numerator,
1408     int *denominator)
1409 {
1410 	int   dxdt;
1411 	int   dydt;
1412 	u_int vel_squared; /* Square of the velocity vector's magnitude. */
1413 	u_int vel_squared_smooth;
1414 
1415 	/* Table holding (10 * sqrt(x)) for x between 1 and 256. */
1416 	static uint8_t sqrt_table[256] = {
1417 		10, 14, 17, 20, 22, 24, 26, 28,
1418 		30, 31, 33, 34, 36, 37, 38, 40,
1419 		41, 42, 43, 44, 45, 46, 47, 48,
1420 		50, 50, 51, 52, 53, 54, 55, 56,
1421 		57, 58, 59, 60, 60, 61, 62, 63,
1422 		64, 64, 65, 66, 67, 67, 68, 69,
1423 		70, 70, 71, 72, 72, 73, 74, 74,
1424 		75, 76, 76, 77, 78, 78, 79, 80,
1425 		80, 81, 81, 82, 83, 83, 84, 84,
1426 		85, 86, 86, 87, 87, 88, 88, 89,
1427 		90, 90, 91, 91, 92, 92, 93, 93,
1428 		94, 94, 95, 95, 96, 96, 97, 97,
1429 		98, 98, 99, 100, 100, 100, 101, 101,
1430 		102, 102, 103, 103, 104, 104, 105, 105,
1431 		106, 106, 107, 107, 108, 108, 109, 109,
1432 		110, 110, 110, 111, 111, 112, 112, 113,
1433 		113, 114, 114, 114, 115, 115, 116, 116,
1434 		117, 117, 117, 118, 118, 119, 119, 120,
1435 		120, 120, 121, 121, 122, 122, 122, 123,
1436 		123, 124, 124, 124, 125, 125, 126, 126,
1437 		126, 127, 127, 128, 128, 128, 129, 129,
1438 		130, 130, 130, 131, 131, 131, 132, 132,
1439 		133, 133, 133, 134, 134, 134, 135, 135,
1440 		136, 136, 136, 137, 137, 137, 138, 138,
1441 		138, 139, 139, 140, 140, 140, 141, 141,
1442 		141, 142, 142, 142, 143, 143, 143, 144,
1443 		144, 144, 145, 145, 145, 146, 146, 146,
1444 		147, 147, 147, 148, 148, 148, 149, 149,
1445 		150, 150, 150, 150, 151, 151, 151, 152,
1446 		152, 152, 153, 153, 153, 154, 154, 154,
1447 		155, 155, 155, 156, 156, 156, 157, 157,
1448 		157, 158, 158, 158, 159, 159, 159, 160
1449 	};
1450 	const u_int N = sizeof(sqrt_table) / sizeof(sqrt_table[0]);
1451 
1452 	dxdt = stroke->components[X].delta_mickeys;
1453 	dydt = stroke->components[Y].delta_mickeys;
1454 
1455 	*numerator = 0, *denominator = 0; /* default values. */
1456 
1457 	/* Compute a smoothened magnitude_squared of the stroke's velocity. */
1458 	vel_squared = dxdt * dxdt + dydt * dydt;
1459 	vel_squared_smooth = (3 * stroke->velocity_squared + vel_squared) >> 2;
1460 	stroke->velocity_squared = vel_squared_smooth; /* retained as history */
1461 	if ((vel_squared == 0) || (vel_squared_smooth == 0))
1462 		return; /* returning (numerator == 0) will imply zero movement*/
1463 
1464 	/*
1465 	 * In order to determine the overall movement scale factor,
1466 	 * we're actually interested in the effect of smoothening upon
1467 	 * the *magnitude* of velocity; i.e. we need to compute the
1468 	 * square-root of (vel_squared_smooth / vel_squared) in the
1469 	 * form of a numerator and denominator.
1470 	 */
1471 
1472 	/* Keep within the bounds of the square-root table. */
1473 	while ((vel_squared > N) || (vel_squared_smooth > N)) {
1474 		/* Dividing uniformly by 2 won't disturb the final ratio. */
1475 		vel_squared        >>= 1;
1476 		vel_squared_smooth >>= 1;
1477 	}
1478 
1479 	*numerator   = sqrt_table[vel_squared_smooth - 1];
1480 	*denominator = sqrt_table[vel_squared - 1];
1481 }
1482 
1483 /*
1484  * Compute a smoothened value for the stroke's movement from
1485  * delta_mickeys in the X and Y components.
1486  */
1487 static boolean_t
1488 atp_compute_stroke_movement(atp_stroke *stroke)
1489 {
1490 	int   num;              /* numerator of scale ratio */
1491 	int   denom;            /* denominator of scale ratio */
1492 
1493 	/*
1494 	 * Short movements are added first to the 'pending' bucket,
1495 	 * and then acted upon only when their aggregate exceeds a
1496 	 * threshold. This has the effect of filtering away movement
1497 	 * noise.
1498 	 */
1499 	if (atp_stroke_has_small_movement(stroke)) {
1500 		atp_update_pending_mickeys(&stroke->components[X]);
1501 		atp_update_pending_mickeys(&stroke->components[Y]);
1502 	} else {                /* large movement */
1503 		/* clear away any pending mickeys if there are large movements*/
1504 		stroke->components[X].pending = 0;
1505 		stroke->components[Y].pending = 0;
1506 	}
1507 
1508 	/* Get the scale ratio and smoothen movement. */
1509 	atp_compute_smoothening_scale_ratio(stroke, &num, &denom);
1510 	if ((num == 0) || (denom == 0)) {
1511 		stroke->components[X].movement = 0;
1512 		stroke->components[Y].movement = 0;
1513 		stroke->velocity_squared >>= 1; /* Erode velocity_squared. */
1514 	} else {
1515 		stroke->components[X].movement =
1516 			(stroke->components[X].delta_mickeys * num) / denom;
1517 		stroke->components[Y].movement =
1518 			(stroke->components[Y].delta_mickeys * num) / denom;
1519 
1520 		stroke->cum_movement +=
1521 			abs(stroke->components[X].movement) +
1522 			abs(stroke->components[Y].movement);
1523 	}
1524 
1525 	return ((stroke->components[X].movement != 0) ||
1526 	    (stroke->components[Y].movement != 0));
1527 }
1528 
1529 static __inline void
1530 atp_setup_reap_time(struct atp_softc *sc, struct timeval *tvp)
1531 {
1532 	struct timeval reap_window = {
1533 		ATP_ZOMBIE_STROKE_REAP_WINDOW / 1000000,
1534 		ATP_ZOMBIE_STROKE_REAP_WINDOW % 1000000
1535 	};
1536 
1537 	microtime(&sc->sc_reap_time);
1538 	timevaladd(&sc->sc_reap_time, &reap_window);
1539 
1540 	sc->sc_reap_ctime = *tvp; /* ctime to reap */
1541 }
1542 
1543 static void
1544 atp_reap_zombies(struct atp_softc *sc, u_int *n_reaped, u_int *reaped_xlocs)
1545 {
1546 	u_int       i;
1547 	atp_stroke *stroke;
1548 
1549 	*n_reaped = 0;
1550 	for (i = 0; i < sc->sc_n_strokes; i++) {
1551 		struct timeval  tdiff;
1552 
1553 		stroke = &sc->sc_strokes[i];
1554 
1555 		if ((stroke->flags & ATSF_ZOMBIE) == 0)
1556 			continue;
1557 
1558 		/* Compare this stroke's ctime with the ctime being reaped. */
1559 		if (timevalcmp(&stroke->ctime, &sc->sc_reap_ctime, >=)) {
1560 			tdiff = stroke->ctime;
1561 			timevalsub(&tdiff, &sc->sc_reap_ctime);
1562 		} else {
1563 			tdiff = sc->sc_reap_ctime;
1564 			timevalsub(&tdiff, &stroke->ctime);
1565 		}
1566 
1567 		if ((tdiff.tv_sec > (ATP_COINCIDENCE_THRESHOLD / 1000000)) ||
1568 		    ((tdiff.tv_sec == (ATP_COINCIDENCE_THRESHOLD / 1000000)) &&
1569 		     (tdiff.tv_usec > (ATP_COINCIDENCE_THRESHOLD % 1000000)))) {
1570 			continue; /* Skip non-siblings. */
1571 		}
1572 
1573 		/*
1574 		 * Reap this sibling zombie stroke.
1575 		 */
1576 
1577 		if (reaped_xlocs != NULL)
1578 			reaped_xlocs[*n_reaped] = stroke->components[X].loc;
1579 
1580 		/* Erase the stroke from the sc. */
1581 		memcpy(&stroke[i], &stroke[i + 1],
1582 		    (sc->sc_n_strokes - i - 1) * sizeof(atp_stroke));
1583 		sc->sc_n_strokes--;
1584 
1585 		*n_reaped += 1;
1586 		--i; /* Decr. i to keep it unchanged for the next iteration */
1587 	}
1588 
1589 	DPRINTFN(ATP_LLEVEL_INFO, "reaped %u zombies\n", *n_reaped);
1590 
1591 	/* There could still be zombies remaining in the system. */
1592 	for (i = 0; i < sc->sc_n_strokes; i++) {
1593 		stroke = &sc->sc_strokes[i];
1594 		if (stroke->flags & ATSF_ZOMBIE) {
1595 			DPRINTFN(ATP_LLEVEL_INFO, "zombies remain!\n");
1596 			atp_setup_reap_time(sc, &stroke->ctime);
1597 			return;
1598 		}
1599 	}
1600 
1601 	/* If we reach here, then no more zombies remain. */
1602 	sc->sc_state &= ~ATP_ZOMBIES_EXIST;
1603 }
1604 
1605 
1606 /* Device methods. */
1607 static device_probe_t  atp_probe;
1608 static device_attach_t atp_attach;
1609 static device_detach_t atp_detach;
1610 static usb_callback_t  atp_intr;
1611 
1612 static const struct usb_config atp_config[ATP_N_TRANSFER] = {
1613 	[ATP_INTR_DT] = {
1614 		.type      = UE_INTERRUPT,
1615 		.endpoint  = UE_ADDR_ANY,
1616 		.direction = UE_DIR_IN,
1617 		.flags = {
1618 			.pipe_bof = 1,
1619 			.short_xfer_ok = 1,
1620 		},
1621 		.bufsize   = 0, /* use wMaxPacketSize */
1622 		.callback  = &atp_intr,
1623 	},
1624 	[ATP_RESET] = {
1625 		.type      = UE_CONTROL,
1626 		.endpoint  = 0, /* Control pipe */
1627 		.direction = UE_DIR_ANY,
1628 		.bufsize = sizeof(struct usb_device_request) + MODE_LENGTH,
1629 		.callback  = &atp_reset_callback,
1630 		.interval = 0,  /* no pre-delay */
1631 	},
1632 };
1633 
1634 static int
1635 atp_probe(device_t self)
1636 {
1637 	struct usb_attach_arg *uaa = device_get_ivars(self);
1638 
1639 	if (uaa->usb_mode != USB_MODE_HOST)
1640 		return (ENXIO);
1641 
1642 	if ((uaa->info.bInterfaceClass != UICLASS_HID) ||
1643 	    (uaa->info.bInterfaceProtocol != UIPROTO_MOUSE))
1644 		return (ENXIO);
1645 
1646 	return (usbd_lookup_id_by_uaa(atp_devs, sizeof(atp_devs), uaa));
1647 }
1648 
1649 static int
1650 atp_attach(device_t dev)
1651 {
1652 	struct atp_softc      *sc = device_get_softc(dev);
1653 	struct usb_attach_arg *uaa = device_get_ivars(dev);
1654 	usb_error_t            err;
1655 
1656 	DPRINTFN(ATP_LLEVEL_INFO, "sc=%p\n", sc);
1657 
1658 	sc->sc_dev        = dev;
1659 	sc->sc_usb_device = uaa->device;
1660 
1661 	/*
1662 	 * By default the touchpad behaves like an HID device, sending
1663 	 * packets with reportID = 2. Such reports contain only
1664 	 * limited information--they encode movement deltas and button
1665 	 * events,--but do not include data from the pressure
1666 	 * sensors. The device input mode can be switched from HID
1667 	 * reports to raw sensor data using vendor-specific USB
1668 	 * control commands; but first the mode must be read.
1669 	 */
1670 	err = atp_req_get_report(sc->sc_usb_device, sc->sc_mode_bytes);
1671 	if (err != USB_ERR_NORMAL_COMPLETION) {
1672 		DPRINTF("failed to read device mode (%d)\n", err);
1673 		return (ENXIO);
1674 	}
1675 
1676 	if (atp_set_device_mode(dev, RAW_SENSOR_MODE) != 0) {
1677 		DPRINTF("failed to set mode to 'RAW_SENSOR' (%d)\n", err);
1678 		return (ENXIO);
1679 	}
1680 
1681 	mtx_init(&sc->sc_mutex, "atpmtx", NULL, MTX_DEF | MTX_RECURSE);
1682 
1683 	err = usbd_transfer_setup(uaa->device,
1684 	    &uaa->info.bIfaceIndex, sc->sc_xfer, atp_config,
1685 	    ATP_N_TRANSFER, sc, &sc->sc_mutex);
1686 
1687 	if (err) {
1688 		DPRINTF("error=%s\n", usbd_errstr(err));
1689 		goto detach;
1690 	}
1691 
1692 	if (usb_fifo_attach(sc->sc_usb_device, sc, &sc->sc_mutex,
1693 		&atp_fifo_methods, &sc->sc_fifo,
1694 		device_get_unit(dev), -1, uaa->info.bIfaceIndex,
1695 		UID_ROOT, GID_OPERATOR, 0644)) {
1696 		goto detach;
1697 	}
1698 
1699 	device_set_usb_desc(dev);
1700 
1701 	sc->sc_params           = &atp_dev_params[uaa->driver_info];
1702 
1703 	sc->sc_hw.buttons       = 3;
1704 	sc->sc_hw.iftype        = MOUSE_IF_USB;
1705 	sc->sc_hw.type          = MOUSE_PAD;
1706 	sc->sc_hw.model         = MOUSE_MODEL_GENERIC;
1707 	sc->sc_hw.hwid          = 0;
1708 	sc->sc_mode.protocol    = MOUSE_PROTO_MSC;
1709 	sc->sc_mode.rate        = -1;
1710 	sc->sc_mode.resolution  = MOUSE_RES_UNKNOWN;
1711 	sc->sc_mode.accelfactor = 0;
1712 	sc->sc_mode.level       = 0;
1713 	sc->sc_mode.packetsize  = MOUSE_MSC_PACKETSIZE;
1714 	sc->sc_mode.syncmask[0] = MOUSE_MSC_SYNCMASK;
1715 	sc->sc_mode.syncmask[1] = MOUSE_MSC_SYNC;
1716 
1717 	sc->sc_state            = 0;
1718 
1719 	sc->sc_left_margin  = atp_mickeys_scale_factor;
1720 	sc->sc_right_margin = (sc->sc_params->n_xsensors - 1) *
1721 		atp_mickeys_scale_factor;
1722 
1723 	return (0);
1724 
1725 detach:
1726 	atp_detach(dev);
1727 	return (ENOMEM);
1728 }
1729 
1730 static int
1731 atp_detach(device_t dev)
1732 {
1733 	struct atp_softc *sc;
1734 
1735 	sc = device_get_softc(dev);
1736 	if (sc->sc_state & ATP_ENABLED) {
1737 		mtx_lock(&sc->sc_mutex);
1738 		atp_disable(sc);
1739 		mtx_unlock(&sc->sc_mutex);
1740 	}
1741 
1742 	usb_fifo_detach(&sc->sc_fifo);
1743 
1744 	usbd_transfer_unsetup(sc->sc_xfer, ATP_N_TRANSFER);
1745 
1746 	mtx_destroy(&sc->sc_mutex);
1747 
1748 	return (0);
1749 }
1750 
1751 static void
1752 atp_intr(struct usb_xfer *xfer, usb_error_t error)
1753 {
1754 	struct atp_softc      *sc = usbd_xfer_softc(xfer);
1755 	int                    len;
1756 	struct usb_page_cache *pc;
1757 	uint8_t                status_bits;
1758 	atp_pspan  pspans_x[ATP_MAX_PSPANS_PER_AXIS];
1759 	atp_pspan  pspans_y[ATP_MAX_PSPANS_PER_AXIS];
1760 	u_int      n_xpspans = 0, n_ypspans = 0;
1761 	u_int      reaped_xlocs[ATP_MAX_STROKES];
1762 	u_int      tap_fingers = 0;
1763 
1764 	usbd_xfer_status(xfer, &len, NULL, NULL, NULL);
1765 
1766 	switch (USB_GET_STATE(xfer)) {
1767 	case USB_ST_TRANSFERRED:
1768 		if (len > (int)sc->sc_params->data_len) {
1769 			DPRINTFN(ATP_LLEVEL_ERROR,
1770 			    "truncating large packet from %u to %u bytes\n",
1771 			    len, sc->sc_params->data_len);
1772 			len = sc->sc_params->data_len;
1773 		}
1774 		if (len < (int)sc->sc_params->data_len)
1775 			goto tr_setup;
1776 
1777 		pc = usbd_xfer_get_frame(xfer, 0);
1778 		usbd_copy_out(pc, 0, sc->sensor_data, sc->sc_params->data_len);
1779 
1780 		/* Interpret sensor data */
1781 		atp_interpret_sensor_data(sc->sensor_data,
1782 		    sc->sc_params->n_xsensors, X, sc->cur_x,
1783 		    sc->sc_params->prot);
1784 		atp_interpret_sensor_data(sc->sensor_data,
1785 		    sc->sc_params->n_ysensors, Y,  sc->cur_y,
1786 		    sc->sc_params->prot);
1787 
1788 		/*
1789 		 * If this is the initial update (from an untouched
1790 		 * pad), we should set the base values for the sensor
1791 		 * data; deltas with respect to these base values can
1792 		 * be used as pressure readings subsequently.
1793 		 */
1794 		status_bits = sc->sensor_data[sc->sc_params->data_len - 1];
1795 		if ((sc->sc_params->prot == ATP_PROT_GEYSER3 &&
1796 		    (status_bits & ATP_STATUS_BASE_UPDATE)) ||
1797 		    !(sc->sc_state & ATP_VALID)) {
1798 			memcpy(sc->base_x, sc->cur_x,
1799 			    sc->sc_params->n_xsensors * sizeof(*(sc->base_x)));
1800 			memcpy(sc->base_y, sc->cur_y,
1801 			    sc->sc_params->n_ysensors * sizeof(*(sc->base_y)));
1802 			sc->sc_state |= ATP_VALID;
1803 			goto tr_setup;
1804 		}
1805 
1806 		/* Get pressure readings and detect p-spans for both axes. */
1807 		atp_get_pressures(sc->pressure_x, sc->cur_x, sc->base_x,
1808 		    sc->sc_params->n_xsensors);
1809 		atp_detect_pspans(sc->pressure_x, sc->sc_params->n_xsensors,
1810 		    ATP_MAX_PSPANS_PER_AXIS,
1811 		    pspans_x, &n_xpspans);
1812 		atp_get_pressures(sc->pressure_y, sc->cur_y, sc->base_y,
1813 		    sc->sc_params->n_ysensors);
1814 		atp_detect_pspans(sc->pressure_y, sc->sc_params->n_ysensors,
1815 		    ATP_MAX_PSPANS_PER_AXIS,
1816 		    pspans_y, &n_ypspans);
1817 
1818 		/* Update strokes with new pspans to detect movements. */
1819 		sc->sc_status.flags &= ~MOUSE_POSCHANGED;
1820 		if (atp_update_strokes(sc,
1821 			pspans_x, n_xpspans,
1822 			pspans_y, n_ypspans))
1823 			sc->sc_status.flags |= MOUSE_POSCHANGED;
1824 
1825 		/* Reap zombies if it is time. */
1826 		if (sc->sc_state & ATP_ZOMBIES_EXIST) {
1827 			struct timeval now;
1828 
1829 			getmicrotime(&now);
1830 			if (timevalcmp(&now, &sc->sc_reap_time, >=))
1831 				atp_reap_zombies(sc, &tap_fingers,
1832 				    reaped_xlocs);
1833 		}
1834 
1835 		sc->sc_status.flags &= ~MOUSE_STDBUTTONSCHANGED;
1836 		sc->sc_status.obutton = sc->sc_status.button;
1837 
1838 		/* Get the state of the physical buttton. */
1839 		sc->sc_status.button = (status_bits & ATP_STATUS_BUTTON) ?
1840 			MOUSE_BUTTON1DOWN : 0;
1841 		if (sc->sc_status.button != 0) {
1842 			/* Reset DOUBLE_TAP_N_DRAG if the button is pressed. */
1843 			sc->sc_state &= ~ATP_DOUBLE_TAP_DRAG;
1844 		} else if (sc->sc_state & ATP_DOUBLE_TAP_DRAG) {
1845 			/* Assume a button-press with DOUBLE_TAP_N_DRAG. */
1846 			sc->sc_status.button = MOUSE_BUTTON1DOWN;
1847 		}
1848 
1849 		sc->sc_status.flags |=
1850 			sc->sc_status.button ^ sc->sc_status.obutton;
1851 		if (sc->sc_status.flags & MOUSE_STDBUTTONSCHANGED) {
1852 			DPRINTFN(ATP_LLEVEL_INFO, "button %s\n",
1853 			    ((sc->sc_status.button & MOUSE_BUTTON1DOWN) ?
1854 				"pressed" : "released"));
1855 		} else if ((sc->sc_status.obutton == 0) &&
1856 		    (sc->sc_status.button == 0) &&
1857 		    (tap_fingers != 0)) {
1858 			/* Ignore single-finger taps at the edges. */
1859 			if ((tap_fingers == 1) &&
1860 			    ((reaped_xlocs[0] <= sc->sc_left_margin) ||
1861 				(reaped_xlocs[0] > sc->sc_right_margin))) {
1862 				tap_fingers = 0;
1863 			}
1864 			DPRINTFN(ATP_LLEVEL_INFO,
1865 			    "tap_fingers: %u\n", tap_fingers);
1866 		}
1867 
1868 		if (sc->sc_status.flags &
1869 		    (MOUSE_POSCHANGED | MOUSE_STDBUTTONSCHANGED)) {
1870 			int   dx, dy;
1871 			u_int n_movements;
1872 
1873 			dx = 0, dy = 0, n_movements = 0;
1874 			for (u_int i = 0; i < sc->sc_n_strokes; i++) {
1875 				atp_stroke *stroke = &sc->sc_strokes[i];
1876 
1877 				if ((stroke->components[X].movement) ||
1878 				    (stroke->components[Y].movement)) {
1879 					dx += stroke->components[X].movement;
1880 					dy += stroke->components[Y].movement;
1881 					n_movements++;
1882 				}
1883 			}
1884 			/*
1885 			 * Disregard movement if multiple
1886 			 * strokes record motion.
1887 			 */
1888 			if (n_movements != 1)
1889 				dx = 0, dy = 0;
1890 
1891 			sc->sc_status.dx += dx;
1892 			sc->sc_status.dy += dy;
1893 			atp_add_to_queue(sc, dx, -dy, sc->sc_status.button);
1894 		}
1895 
1896 		if (tap_fingers != 0) {
1897 			/* Add a pair of events (button-down and button-up). */
1898 			switch (tap_fingers) {
1899 			case 1: atp_add_to_queue(sc, 0, 0, MOUSE_BUTTON1DOWN);
1900 				break;
1901 			case 2: atp_add_to_queue(sc, 0, 0, MOUSE_BUTTON2DOWN);
1902 				break;
1903 			case 3: atp_add_to_queue(sc, 0, 0, MOUSE_BUTTON3DOWN);
1904 				break;
1905 			default: break;/* handle taps of only up to 3 fingers */
1906 			}
1907 			atp_add_to_queue(sc, 0, 0, 0); /* button release */
1908 		}
1909 
1910 		/*
1911 		 * The device continues to trigger interrupts at a
1912 		 * fast rate even after touchpad activity has
1913 		 * stopped. Upon detecting that the device has
1914 		 * remained idle beyond a threshold, we reinitialize
1915 		 * it to silence the interrupts.
1916 		 */
1917 		if ((sc->sc_status.flags  == 0) &&
1918 		    (sc->sc_n_strokes     == 0) &&
1919 		    (sc->sc_status.button == 0)) {
1920 			sc->sc_idlecount++;
1921 			if (sc->sc_idlecount >= ATP_IDLENESS_THRESHOLD) {
1922 				DPRINTFN(ATP_LLEVEL_INFO, "idle\n");
1923 
1924 				/*
1925 				 * Use the last frame before we go idle for
1926 				 * calibration on pads which do not send
1927 				 * calibration frames.
1928 				 */
1929 				if (sc->sc_params->prot < ATP_PROT_GEYSER3) {
1930 					memcpy(sc->base_x, sc->cur_x,
1931 					    sc->sc_params->n_xsensors *
1932 					    sizeof(*(sc->base_x)));
1933 					memcpy(sc->base_y, sc->cur_y,
1934 					    sc->sc_params->n_ysensors *
1935 					    sizeof(*(sc->base_y)));
1936 				}
1937 
1938 				sc->sc_idlecount = 0;
1939 				usbd_transfer_start(sc->sc_xfer[ATP_RESET]);
1940 			}
1941 		} else {
1942 			sc->sc_idlecount = 0;
1943 		}
1944 
1945 	case USB_ST_SETUP:
1946 	tr_setup:
1947 		/* check if we can put more data into the FIFO */
1948 		if (usb_fifo_put_bytes_max(
1949 			    sc->sc_fifo.fp[USB_FIFO_RX]) != 0) {
1950 			usbd_xfer_set_frame_len(xfer, 0,
1951 			    sc->sc_params->data_len);
1952 			usbd_transfer_submit(xfer);
1953 		}
1954 		break;
1955 
1956 	default:                        /* Error */
1957 		if (error != USB_ERR_CANCELLED) {
1958 			/* try clear stall first */
1959 			usbd_xfer_set_stall(xfer);
1960 			goto tr_setup;
1961 		}
1962 		break;
1963 	}
1964 
1965 	return;
1966 }
1967 
1968 static void
1969 atp_add_to_queue(struct atp_softc *sc, int dx, int dy, uint32_t buttons_in)
1970 {
1971 	uint32_t buttons_out;
1972 	uint8_t  buf[8];
1973 
1974 	dx = imin(dx,  254); dx = imax(dx, -256);
1975 	dy = imin(dy,  254); dy = imax(dy, -256);
1976 
1977 	buttons_out = MOUSE_MSC_BUTTONS;
1978 	if (buttons_in & MOUSE_BUTTON1DOWN)
1979 		buttons_out &= ~MOUSE_MSC_BUTTON1UP;
1980 	else if (buttons_in & MOUSE_BUTTON2DOWN)
1981 		buttons_out &= ~MOUSE_MSC_BUTTON2UP;
1982 	else if (buttons_in & MOUSE_BUTTON3DOWN)
1983 		buttons_out &= ~MOUSE_MSC_BUTTON3UP;
1984 
1985 	DPRINTFN(ATP_LLEVEL_INFO, "dx=%d, dy=%d, buttons=%x\n",
1986 	    dx, dy, buttons_out);
1987 
1988 	/* Encode the mouse data in standard format; refer to mouse(4) */
1989 	buf[0] = sc->sc_mode.syncmask[1];
1990 	buf[0] |= buttons_out;
1991 	buf[1] = dx >> 1;
1992 	buf[2] = dy >> 1;
1993 	buf[3] = dx - (dx >> 1);
1994 	buf[4] = dy - (dy >> 1);
1995 	/* Encode extra bytes for level 1 */
1996 	if (sc->sc_mode.level == 1) {
1997 		buf[5] = 0;                    /* dz */
1998 		buf[6] = 0;                    /* dz - (dz / 2) */
1999 		buf[7] = MOUSE_SYS_EXTBUTTONS; /* Extra buttons all up. */
2000 	}
2001 
2002 	usb_fifo_put_data_linear(sc->sc_fifo.fp[USB_FIFO_RX], buf,
2003 	    sc->sc_mode.packetsize, 1);
2004 }
2005 
2006 static void
2007 atp_reset_buf(struct atp_softc *sc)
2008 {
2009 	/* reset read queue */
2010 	usb_fifo_reset(sc->sc_fifo.fp[USB_FIFO_RX]);
2011 }
2012 
2013 static void
2014 atp_start_read(struct usb_fifo *fifo)
2015 {
2016 	struct atp_softc *sc = usb_fifo_softc(fifo);
2017 	int rate;
2018 
2019 	/* Check if we should override the default polling interval */
2020 	rate = sc->sc_pollrate;
2021 	/* Range check rate */
2022 	if (rate > 1000)
2023 		rate = 1000;
2024 	/* Check for set rate */
2025 	if ((rate > 0) && (sc->sc_xfer[ATP_INTR_DT] != NULL)) {
2026 		/* Stop current transfer, if any */
2027 		usbd_transfer_stop(sc->sc_xfer[ATP_INTR_DT]);
2028 		/* Set new interval */
2029 		usbd_xfer_set_interval(sc->sc_xfer[ATP_INTR_DT], 1000 / rate);
2030 		/* Only set pollrate once */
2031 		sc->sc_pollrate = 0;
2032 	}
2033 
2034 	usbd_transfer_start(sc->sc_xfer[ATP_INTR_DT]);
2035 }
2036 
2037 static void
2038 atp_stop_read(struct usb_fifo *fifo)
2039 {
2040 	struct atp_softc *sc = usb_fifo_softc(fifo);
2041 
2042 	usbd_transfer_stop(sc->sc_xfer[ATP_INTR_DT]);
2043 }
2044 
2045 
2046 static int
2047 atp_open(struct usb_fifo *fifo, int fflags)
2048 {
2049 	DPRINTFN(ATP_LLEVEL_INFO, "\n");
2050 
2051 	if (fflags & FREAD) {
2052 		struct atp_softc *sc = usb_fifo_softc(fifo);
2053 		int rc;
2054 
2055 		if (sc->sc_state & ATP_ENABLED)
2056 			return (EBUSY);
2057 
2058 		if (usb_fifo_alloc_buffer(fifo,
2059 			ATP_FIFO_BUF_SIZE, ATP_FIFO_QUEUE_MAXLEN)) {
2060 			return (ENOMEM);
2061 		}
2062 
2063 		rc = atp_enable(sc);
2064 		if (rc != 0) {
2065 			usb_fifo_free_buffer(fifo);
2066 			return (rc);
2067 		}
2068 	}
2069 
2070 	return (0);
2071 }
2072 
2073 static void
2074 atp_close(struct usb_fifo *fifo, int fflags)
2075 {
2076 	if (fflags & FREAD) {
2077 		struct atp_softc *sc = usb_fifo_softc(fifo);
2078 
2079 		atp_disable(sc);
2080 		usb_fifo_free_buffer(fifo);
2081 	}
2082 }
2083 
2084 int
2085 atp_ioctl(struct usb_fifo *fifo, u_long cmd, void *addr, int fflags)
2086 {
2087 	struct atp_softc *sc = usb_fifo_softc(fifo);
2088 	mousemode_t mode;
2089 	int error = 0;
2090 
2091 	mtx_lock(&sc->sc_mutex);
2092 
2093 	switch(cmd) {
2094 	case MOUSE_GETHWINFO:
2095 		*(mousehw_t *)addr = sc->sc_hw;
2096 		break;
2097 	case MOUSE_GETMODE:
2098 		*(mousemode_t *)addr = sc->sc_mode;
2099 		break;
2100 	case MOUSE_SETMODE:
2101 		mode = *(mousemode_t *)addr;
2102 
2103 		if (mode.level == -1)
2104 			/* Don't change the current setting */
2105 			;
2106 		else if ((mode.level < 0) || (mode.level > 1)) {
2107 			error = EINVAL;
2108 			goto done;
2109 		}
2110 		sc->sc_mode.level = mode.level;
2111 		sc->sc_pollrate   = mode.rate;
2112 		sc->sc_hw.buttons = 3;
2113 
2114 		if (sc->sc_mode.level == 0) {
2115 			sc->sc_mode.protocol = MOUSE_PROTO_MSC;
2116 			sc->sc_mode.packetsize = MOUSE_MSC_PACKETSIZE;
2117 			sc->sc_mode.syncmask[0] = MOUSE_MSC_SYNCMASK;
2118 			sc->sc_mode.syncmask[1] = MOUSE_MSC_SYNC;
2119 		} else if (sc->sc_mode.level == 1) {
2120 			sc->sc_mode.protocol = MOUSE_PROTO_SYSMOUSE;
2121 			sc->sc_mode.packetsize = MOUSE_SYS_PACKETSIZE;
2122 			sc->sc_mode.syncmask[0] = MOUSE_SYS_SYNCMASK;
2123 			sc->sc_mode.syncmask[1] = MOUSE_SYS_SYNC;
2124 		}
2125 		atp_reset_buf(sc);
2126 		break;
2127 	case MOUSE_GETLEVEL:
2128 		*(int *)addr = sc->sc_mode.level;
2129 		break;
2130 	case MOUSE_SETLEVEL:
2131 		if (*(int *)addr < 0 || *(int *)addr > 1) {
2132 			error = EINVAL;
2133 			goto done;
2134 		}
2135 		sc->sc_mode.level = *(int *)addr;
2136 		sc->sc_hw.buttons = 3;
2137 
2138 		if (sc->sc_mode.level == 0) {
2139 			sc->sc_mode.protocol = MOUSE_PROTO_MSC;
2140 			sc->sc_mode.packetsize = MOUSE_MSC_PACKETSIZE;
2141 			sc->sc_mode.syncmask[0] = MOUSE_MSC_SYNCMASK;
2142 			sc->sc_mode.syncmask[1] = MOUSE_MSC_SYNC;
2143 		} else if (sc->sc_mode.level == 1) {
2144 			sc->sc_mode.protocol = MOUSE_PROTO_SYSMOUSE;
2145 			sc->sc_mode.packetsize = MOUSE_SYS_PACKETSIZE;
2146 			sc->sc_mode.syncmask[0] = MOUSE_SYS_SYNCMASK;
2147 			sc->sc_mode.syncmask[1] = MOUSE_SYS_SYNC;
2148 		}
2149 		atp_reset_buf(sc);
2150 		break;
2151 	case MOUSE_GETSTATUS: {
2152 		mousestatus_t *status = (mousestatus_t *)addr;
2153 
2154 		*status = sc->sc_status;
2155 		sc->sc_status.obutton = sc->sc_status.button;
2156 		sc->sc_status.button  = 0;
2157 		sc->sc_status.dx = 0;
2158 		sc->sc_status.dy = 0;
2159 		sc->sc_status.dz = 0;
2160 
2161 		if (status->dx || status->dy || status->dz)
2162 			status->flags |= MOUSE_POSCHANGED;
2163 		if (status->button != status->obutton)
2164 			status->flags |= MOUSE_BUTTONSCHANGED;
2165 		break;
2166 	}
2167 	default:
2168 		error = ENOTTY;
2169 	}
2170 
2171 done:
2172 	mtx_unlock(&sc->sc_mutex);
2173 	return (error);
2174 }
2175 
2176 static int
2177 atp_sysctl_scale_factor_handler(SYSCTL_HANDLER_ARGS)
2178 {
2179 	int error;
2180 	u_int tmp;
2181 	u_int prev_mickeys_scale_factor;
2182 
2183 	prev_mickeys_scale_factor = atp_mickeys_scale_factor;
2184 
2185 	tmp = atp_mickeys_scale_factor;
2186 	error = sysctl_handle_int(oidp, &tmp, 0, req);
2187 	if (error != 0 || req->newptr == NULL)
2188 		return (error);
2189 
2190 	if (tmp == prev_mickeys_scale_factor)
2191 		return (0);     /* no change */
2192 
2193 	atp_mickeys_scale_factor = tmp;
2194 	DPRINTFN(ATP_LLEVEL_INFO, "%s: resetting mickeys_scale_factor to %u\n",
2195 	    ATP_DRIVER_NAME, tmp);
2196 
2197 	/* Update dependent thresholds. */
2198 	if (atp_small_movement_threshold == (prev_mickeys_scale_factor >> 3))
2199 		atp_small_movement_threshold = atp_mickeys_scale_factor >> 3;
2200 	if (atp_max_delta_mickeys == ((3 * prev_mickeys_scale_factor) >> 1))
2201 		atp_max_delta_mickeys = ((3 * atp_mickeys_scale_factor) >>1);
2202 	if (atp_slide_min_movement == (prev_mickeys_scale_factor >> 3))
2203 		atp_slide_min_movement = atp_mickeys_scale_factor >> 3;
2204 
2205 	return (0);
2206 }
2207 
2208 static device_method_t atp_methods[] = {
2209 	/* Device interface */
2210 	DEVMETHOD(device_probe,  atp_probe),
2211 	DEVMETHOD(device_attach, atp_attach),
2212 	DEVMETHOD(device_detach, atp_detach),
2213 	{ 0, 0 }
2214 };
2215 
2216 static driver_t atp_driver = {
2217 	.name = ATP_DRIVER_NAME,
2218 	.methods = atp_methods,
2219 	.size = sizeof(struct atp_softc)
2220 };
2221 
2222 static devclass_t atp_devclass;
2223 
2224 DRIVER_MODULE(atp, uhub, atp_driver, atp_devclass, NULL, 0);
2225 MODULE_DEPEND(atp, usb, 1, 1, 1);
2226 MODULE_VERSION(atp, 1);
2227