1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * OLPC HGPK (XO-1) touchpad PS/2 mouse driver
4  *
5  * Copyright (c) 2006-2008 One Laptop Per Child
6  * Authors:
7  *   Zephaniah E. Hull
8  *   Andres Salomon <dilinger@debian.org>
9  *
10  * This driver is partly based on the ALPS driver, which is:
11  *
12  * Copyright (c) 2003 Neil Brown <neilb@cse.unsw.edu.au>
13  * Copyright (c) 2003-2005 Peter Osterlund <petero2@telia.com>
14  * Copyright (c) 2004 Dmitry Torokhov <dtor@mail.ru>
15  * Copyright (c) 2005 Vojtech Pavlik <vojtech@suse.cz>
16  */
17 
18 /*
19  * The spec from ALPS is available from
20  * <http://wiki.laptop.org/go/Touch_Pad/Tablet>.  It refers to this
21  * device as HGPK (Hybrid GS, PT, and Keymatrix).
22  *
23  * The earliest versions of the device had simultaneous reporting; that
24  * was removed.  After that, the device used the Advanced Mode GS/PT streaming
25  * stuff.  That turned out to be too buggy to support, so we've finally
26  * switched to Mouse Mode (which utilizes only the center 1/3 of the touchpad).
27  */
28 
29 #define DEBUG
30 #include <linux/slab.h>
31 #include <linux/input.h>
32 #include <linux/module.h>
33 #include <linux/serio.h>
34 #include <linux/libps2.h>
35 #include <linux/delay.h>
36 #include <asm/olpc.h>
37 
38 #include "psmouse.h"
39 #include "hgpk.h"
40 
41 #define ILLEGAL_XY 999999
42 
43 static bool tpdebug;
44 module_param(tpdebug, bool, 0644);
45 MODULE_PARM_DESC(tpdebug, "enable debugging, dumping packets to KERN_DEBUG.");
46 
47 static int recalib_delta = 100;
48 module_param(recalib_delta, int, 0644);
49 MODULE_PARM_DESC(recalib_delta,
50 	"packets containing a delta this large will be discarded, and a "
51 	"recalibration may be scheduled.");
52 
53 static int jumpy_delay = 20;
54 module_param(jumpy_delay, int, 0644);
55 MODULE_PARM_DESC(jumpy_delay,
56 	"delay (ms) before recal after jumpiness detected");
57 
58 static int spew_delay = 1;
59 module_param(spew_delay, int, 0644);
60 MODULE_PARM_DESC(spew_delay,
61 	"delay (ms) before recal after packet spew detected");
62 
63 static int recal_guard_time;
64 module_param(recal_guard_time, int, 0644);
65 MODULE_PARM_DESC(recal_guard_time,
66 	"interval (ms) during which recal will be restarted if packet received");
67 
68 static int post_interrupt_delay = 40;
69 module_param(post_interrupt_delay, int, 0644);
70 MODULE_PARM_DESC(post_interrupt_delay,
71 	"delay (ms) before recal after recal interrupt detected");
72 
73 static bool autorecal = true;
74 module_param(autorecal, bool, 0644);
75 MODULE_PARM_DESC(autorecal, "enable recalibration in the driver");
76 
77 static char hgpk_mode_name[16];
78 module_param_string(hgpk_mode, hgpk_mode_name, sizeof(hgpk_mode_name), 0644);
79 MODULE_PARM_DESC(hgpk_mode,
80 	"default hgpk mode: mouse, glidesensor or pentablet");
81 
82 static int hgpk_default_mode = HGPK_MODE_MOUSE;
83 
84 static const char * const hgpk_mode_names[] = {
85 	[HGPK_MODE_MOUSE] = "Mouse",
86 	[HGPK_MODE_GLIDESENSOR] = "GlideSensor",
87 	[HGPK_MODE_PENTABLET] = "PenTablet",
88 };
89 
hgpk_mode_from_name(const char * buf,int len)90 static int hgpk_mode_from_name(const char *buf, int len)
91 {
92 	int i;
93 
94 	for (i = 0; i < ARRAY_SIZE(hgpk_mode_names); i++) {
95 		const char *name = hgpk_mode_names[i];
96 		if (strlen(name) == len && !strncasecmp(name, buf, len))
97 			return i;
98 	}
99 
100 	return HGPK_MODE_INVALID;
101 }
102 
103 /*
104  * see if new value is within 20% of half of old value
105  */
approx_half(int curr,int prev)106 static int approx_half(int curr, int prev)
107 {
108 	int belowhalf, abovehalf;
109 
110 	if (curr < 5 || prev < 5)
111 		return 0;
112 
113 	belowhalf = (prev * 8) / 20;
114 	abovehalf = (prev * 12) / 20;
115 
116 	return belowhalf < curr && curr <= abovehalf;
117 }
118 
119 /*
120  * Throw out oddly large delta packets, and any that immediately follow whose
121  * values are each approximately half of the previous.  It seems that the ALPS
122  * firmware emits errant packets, and they get averaged out slowly.
123  */
hgpk_discard_decay_hack(struct psmouse * psmouse,int x,int y)124 static int hgpk_discard_decay_hack(struct psmouse *psmouse, int x, int y)
125 {
126 	struct hgpk_data *priv = psmouse->private;
127 	int avx, avy;
128 	bool do_recal = false;
129 
130 	avx = abs(x);
131 	avy = abs(y);
132 
133 	/* discard if too big, or half that but > 4 times the prev delta */
134 	if (avx > recalib_delta ||
135 		(avx > recalib_delta / 2 && ((avx / 4) > priv->xlast))) {
136 		psmouse_warn(psmouse, "detected %dpx jump in x\n", x);
137 		priv->xbigj = avx;
138 	} else if (approx_half(avx, priv->xbigj)) {
139 		psmouse_warn(psmouse, "detected secondary %dpx jump in x\n", x);
140 		priv->xbigj = avx;
141 		priv->xsaw_secondary++;
142 	} else {
143 		if (priv->xbigj && priv->xsaw_secondary > 1)
144 			do_recal = true;
145 		priv->xbigj = 0;
146 		priv->xsaw_secondary = 0;
147 	}
148 
149 	if (avy > recalib_delta ||
150 		(avy > recalib_delta / 2 && ((avy / 4) > priv->ylast))) {
151 		psmouse_warn(psmouse, "detected %dpx jump in y\n", y);
152 		priv->ybigj = avy;
153 	} else if (approx_half(avy, priv->ybigj)) {
154 		psmouse_warn(psmouse, "detected secondary %dpx jump in y\n", y);
155 		priv->ybigj = avy;
156 		priv->ysaw_secondary++;
157 	} else {
158 		if (priv->ybigj && priv->ysaw_secondary > 1)
159 			do_recal = true;
160 		priv->ybigj = 0;
161 		priv->ysaw_secondary = 0;
162 	}
163 
164 	priv->xlast = avx;
165 	priv->ylast = avy;
166 
167 	if (do_recal && jumpy_delay) {
168 		psmouse_warn(psmouse, "scheduling recalibration\n");
169 		psmouse_queue_work(psmouse, &priv->recalib_wq,
170 				msecs_to_jiffies(jumpy_delay));
171 	}
172 
173 	return priv->xbigj || priv->ybigj;
174 }
175 
hgpk_reset_spew_detection(struct hgpk_data * priv)176 static void hgpk_reset_spew_detection(struct hgpk_data *priv)
177 {
178 	priv->spew_count = 0;
179 	priv->dupe_count = 0;
180 	priv->x_tally = 0;
181 	priv->y_tally = 0;
182 	priv->spew_flag = NO_SPEW;
183 }
184 
hgpk_reset_hack_state(struct psmouse * psmouse)185 static void hgpk_reset_hack_state(struct psmouse *psmouse)
186 {
187 	struct hgpk_data *priv = psmouse->private;
188 
189 	priv->abs_x = priv->abs_y = -1;
190 	priv->xlast = priv->ylast = ILLEGAL_XY;
191 	priv->xbigj = priv->ybigj = 0;
192 	priv->xsaw_secondary = priv->ysaw_secondary = 0;
193 	hgpk_reset_spew_detection(priv);
194 }
195 
196 /*
197  * We have no idea why this particular hardware bug occurs.  The touchpad
198  * will randomly start spewing packets without anything touching the
199  * pad.  This wouldn't necessarily be bad, but it's indicative of a
200  * severely miscalibrated pad; attempting to use the touchpad while it's
201  * spewing means the cursor will jump all over the place, and act "drunk".
202  *
203  * The packets that are spewed tend to all have deltas between -2 and 2, and
204  * the cursor will move around without really going very far.  It will
205  * tend to end up in the same location; if we tally up the changes over
206  * 100 packets, we end up w/ a final delta of close to 0.  This happens
207  * pretty regularly when the touchpad is spewing, and is pretty hard to
208  * manually trigger (at least for *my* fingers).  So, it makes a perfect
209  * scheme for detecting spews.
210  */
hgpk_spewing_hack(struct psmouse * psmouse,int l,int r,int x,int y)211 static void hgpk_spewing_hack(struct psmouse *psmouse,
212 			      int l, int r, int x, int y)
213 {
214 	struct hgpk_data *priv = psmouse->private;
215 
216 	/* ignore button press packets; many in a row could trigger
217 	 * a false-positive! */
218 	if (l || r)
219 		return;
220 
221 	/* don't track spew if the workaround feature has been turned off */
222 	if (!spew_delay)
223 		return;
224 
225 	if (abs(x) > 3 || abs(y) > 3) {
226 		/* no spew, or spew ended */
227 		hgpk_reset_spew_detection(priv);
228 		return;
229 	}
230 
231 	/* Keep a tally of the overall delta to the cursor position caused by
232 	 * the spew */
233 	priv->x_tally += x;
234 	priv->y_tally += y;
235 
236 	switch (priv->spew_flag) {
237 	case NO_SPEW:
238 		/* we're not spewing, but this packet might be the start */
239 		priv->spew_flag = MAYBE_SPEWING;
240 
241 		fallthrough;
242 
243 	case MAYBE_SPEWING:
244 		priv->spew_count++;
245 
246 		if (priv->spew_count < SPEW_WATCH_COUNT)
247 			break;
248 
249 		/* excessive spew detected, request recalibration */
250 		priv->spew_flag = SPEW_DETECTED;
251 
252 		fallthrough;
253 
254 	case SPEW_DETECTED:
255 		/* only recalibrate when the overall delta to the cursor
256 		 * is really small. if the spew is causing significant cursor
257 		 * movement, it is probably a case of the user moving the
258 		 * cursor very slowly across the screen. */
259 		if (abs(priv->x_tally) < 3 && abs(priv->y_tally) < 3) {
260 			psmouse_warn(psmouse, "packet spew detected (%d,%d)\n",
261 				     priv->x_tally, priv->y_tally);
262 			priv->spew_flag = RECALIBRATING;
263 			psmouse_queue_work(psmouse, &priv->recalib_wq,
264 					   msecs_to_jiffies(spew_delay));
265 		}
266 
267 		break;
268 	case RECALIBRATING:
269 		/* we already detected a spew and requested a recalibration,
270 		 * just wait for the queue to kick into action. */
271 		break;
272 	}
273 }
274 
275 /*
276  * HGPK Mouse Mode format (standard mouse format, sans middle button)
277  *
278  * byte 0:	y-over	x-over	y-neg	x-neg	1	0	swr	swl
279  * byte 1:	x7	x6	x5	x4	x3	x2	x1	x0
280  * byte 2:	y7	y6	y5	y4	y3	y2	y1	y0
281  *
282  * swr/swl are the left/right buttons.
283  * x-neg/y-neg are the x and y delta negative bits
284  * x-over/y-over are the x and y overflow bits
285  *
286  * ---
287  *
288  * HGPK Advanced Mode - single-mode format
289  *
290  * byte 0(PT):  1    1    0    0    1    1     1     1
291  * byte 0(GS):  1    1    1    1    1    1     1     1
292  * byte 1:      0   x6   x5   x4   x3   x2    x1    x0
293  * byte 2(PT):  0    0   x9   x8   x7    ? pt-dsw    0
294  * byte 2(GS):  0  x10   x9   x8   x7    ? gs-dsw pt-dsw
295  * byte 3:      0   y9   y8   y7    1    0   swr   swl
296  * byte 4:      0   y6   y5   y4   y3   y2    y1    y0
297  * byte 5:      0   z6   z5   z4   z3   z2    z1    z0
298  *
299  * ?'s are not defined in the protocol spec, may vary between models.
300  *
301  * swr/swl are the left/right buttons.
302  *
303  * pt-dsw/gs-dsw indicate that the pt/gs sensor is detecting a
304  * pen/finger
305  */
hgpk_is_byte_valid(struct psmouse * psmouse,unsigned char * packet)306 static bool hgpk_is_byte_valid(struct psmouse *psmouse, unsigned char *packet)
307 {
308 	struct hgpk_data *priv = psmouse->private;
309 	int pktcnt = psmouse->pktcnt;
310 	bool valid;
311 
312 	switch (priv->mode) {
313 	case HGPK_MODE_MOUSE:
314 		valid = (packet[0] & 0x0C) == 0x08;
315 		break;
316 
317 	case HGPK_MODE_GLIDESENSOR:
318 		valid = pktcnt == 1 ?
319 			packet[0] == HGPK_GS : !(packet[pktcnt - 1] & 0x80);
320 		break;
321 
322 	case HGPK_MODE_PENTABLET:
323 		valid = pktcnt == 1 ?
324 			packet[0] == HGPK_PT : !(packet[pktcnt - 1] & 0x80);
325 		break;
326 
327 	default:
328 		valid = false;
329 		break;
330 	}
331 
332 	if (!valid)
333 		psmouse_dbg(psmouse,
334 			    "bad data, mode %d (%d) %*ph\n",
335 			    priv->mode, pktcnt, 6, psmouse->packet);
336 
337 	return valid;
338 }
339 
hgpk_process_advanced_packet(struct psmouse * psmouse)340 static void hgpk_process_advanced_packet(struct psmouse *psmouse)
341 {
342 	struct hgpk_data *priv = psmouse->private;
343 	struct input_dev *idev = psmouse->dev;
344 	unsigned char *packet = psmouse->packet;
345 	int down = !!(packet[2] & 2);
346 	int left = !!(packet[3] & 1);
347 	int right = !!(packet[3] & 2);
348 	int x = packet[1] | ((packet[2] & 0x78) << 4);
349 	int y = packet[4] | ((packet[3] & 0x70) << 3);
350 
351 	if (priv->mode == HGPK_MODE_GLIDESENSOR) {
352 		int pt_down = !!(packet[2] & 1);
353 		int finger_down = !!(packet[2] & 2);
354 		int z = packet[5];
355 
356 		input_report_abs(idev, ABS_PRESSURE, z);
357 		if (tpdebug)
358 			psmouse_dbg(psmouse, "pd=%d fd=%d z=%d",
359 				    pt_down, finger_down, z);
360 	} else {
361 		/*
362 		 * PenTablet mode does not report pressure, so we don't
363 		 * report it here
364 		 */
365 		if (tpdebug)
366 			psmouse_dbg(psmouse, "pd=%d ", down);
367 	}
368 
369 	if (tpdebug)
370 		psmouse_dbg(psmouse, "l=%d r=%d x=%d y=%d\n",
371 			    left, right, x, y);
372 
373 	input_report_key(idev, BTN_TOUCH, down);
374 	input_report_key(idev, BTN_LEFT, left);
375 	input_report_key(idev, BTN_RIGHT, right);
376 
377 	/*
378 	 * If this packet says that the finger was removed, reset our position
379 	 * tracking so that we don't erroneously detect a jump on next press.
380 	 */
381 	if (!down) {
382 		hgpk_reset_hack_state(psmouse);
383 		goto done;
384 	}
385 
386 	/*
387 	 * Weed out duplicate packets (we get quite a few, and they mess up
388 	 * our jump detection)
389 	 */
390 	if (x == priv->abs_x && y == priv->abs_y) {
391 		if (++priv->dupe_count > SPEW_WATCH_COUNT) {
392 			if (tpdebug)
393 				psmouse_dbg(psmouse, "hard spew detected\n");
394 			priv->spew_flag = RECALIBRATING;
395 			psmouse_queue_work(psmouse, &priv->recalib_wq,
396 					   msecs_to_jiffies(spew_delay));
397 		}
398 		goto done;
399 	}
400 
401 	/* not a duplicate, continue with position reporting */
402 	priv->dupe_count = 0;
403 
404 	/* Don't apply hacks in PT mode, it seems reliable */
405 	if (priv->mode != HGPK_MODE_PENTABLET && priv->abs_x != -1) {
406 		int x_diff = priv->abs_x - x;
407 		int y_diff = priv->abs_y - y;
408 		if (hgpk_discard_decay_hack(psmouse, x_diff, y_diff)) {
409 			if (tpdebug)
410 				psmouse_dbg(psmouse, "discarding\n");
411 			goto done;
412 		}
413 		hgpk_spewing_hack(psmouse, left, right, x_diff, y_diff);
414 	}
415 
416 	input_report_abs(idev, ABS_X, x);
417 	input_report_abs(idev, ABS_Y, y);
418 	priv->abs_x = x;
419 	priv->abs_y = y;
420 
421 done:
422 	input_sync(idev);
423 }
424 
hgpk_process_simple_packet(struct psmouse * psmouse)425 static void hgpk_process_simple_packet(struct psmouse *psmouse)
426 {
427 	struct input_dev *dev = psmouse->dev;
428 	unsigned char *packet = psmouse->packet;
429 	int left = packet[0] & 1;
430 	int right = (packet[0] >> 1) & 1;
431 	int x = packet[1] - ((packet[0] << 4) & 0x100);
432 	int y = ((packet[0] << 3) & 0x100) - packet[2];
433 
434 	if (packet[0] & 0xc0)
435 		psmouse_dbg(psmouse,
436 			    "overflow -- 0x%02x 0x%02x 0x%02x\n",
437 			    packet[0], packet[1], packet[2]);
438 
439 	if (hgpk_discard_decay_hack(psmouse, x, y)) {
440 		if (tpdebug)
441 			psmouse_dbg(psmouse, "discarding\n");
442 		return;
443 	}
444 
445 	hgpk_spewing_hack(psmouse, left, right, x, y);
446 
447 	if (tpdebug)
448 		psmouse_dbg(psmouse, "l=%d r=%d x=%d y=%d\n",
449 			    left, right, x, y);
450 
451 	input_report_key(dev, BTN_LEFT, left);
452 	input_report_key(dev, BTN_RIGHT, right);
453 
454 	input_report_rel(dev, REL_X, x);
455 	input_report_rel(dev, REL_Y, y);
456 
457 	input_sync(dev);
458 }
459 
hgpk_process_byte(struct psmouse * psmouse)460 static psmouse_ret_t hgpk_process_byte(struct psmouse *psmouse)
461 {
462 	struct hgpk_data *priv = psmouse->private;
463 
464 	if (!hgpk_is_byte_valid(psmouse, psmouse->packet))
465 		return PSMOUSE_BAD_DATA;
466 
467 	if (psmouse->pktcnt >= psmouse->pktsize) {
468 		if (priv->mode == HGPK_MODE_MOUSE)
469 			hgpk_process_simple_packet(psmouse);
470 		else
471 			hgpk_process_advanced_packet(psmouse);
472 		return PSMOUSE_FULL_PACKET;
473 	}
474 
475 	if (priv->recalib_window) {
476 		if (time_before(jiffies, priv->recalib_window)) {
477 			/*
478 			 * ugh, got a packet inside our recalibration
479 			 * window, schedule another recalibration.
480 			 */
481 			psmouse_dbg(psmouse,
482 				    "packet inside calibration window, queueing another recalibration\n");
483 			psmouse_queue_work(psmouse, &priv->recalib_wq,
484 					msecs_to_jiffies(post_interrupt_delay));
485 		}
486 		priv->recalib_window = 0;
487 	}
488 
489 	return PSMOUSE_GOOD_DATA;
490 }
491 
hgpk_select_mode(struct psmouse * psmouse)492 static int hgpk_select_mode(struct psmouse *psmouse)
493 {
494 	struct ps2dev *ps2dev = &psmouse->ps2dev;
495 	struct hgpk_data *priv = psmouse->private;
496 	int i;
497 	int cmd;
498 
499 	/*
500 	 * 4 disables to enable advanced mode
501 	 * then 3 0xf2 bytes as the preamble for GS/PT selection
502 	 */
503 	const int advanced_init[] = {
504 		PSMOUSE_CMD_DISABLE, PSMOUSE_CMD_DISABLE,
505 		PSMOUSE_CMD_DISABLE, PSMOUSE_CMD_DISABLE,
506 		0xf2, 0xf2, 0xf2,
507 	};
508 
509 	switch (priv->mode) {
510 	case HGPK_MODE_MOUSE:
511 		psmouse->pktsize = 3;
512 		break;
513 
514 	case HGPK_MODE_GLIDESENSOR:
515 	case HGPK_MODE_PENTABLET:
516 		psmouse->pktsize = 6;
517 
518 		/* Switch to 'Advanced mode.', four disables in a row. */
519 		for (i = 0; i < ARRAY_SIZE(advanced_init); i++)
520 			if (ps2_command(ps2dev, NULL, advanced_init[i]))
521 				return -EIO;
522 
523 		/* select between GlideSensor (mouse) or PenTablet */
524 		cmd = priv->mode == HGPK_MODE_GLIDESENSOR ?
525 			PSMOUSE_CMD_SETSCALE11 : PSMOUSE_CMD_SETSCALE21;
526 
527 		if (ps2_command(ps2dev, NULL, cmd))
528 			return -EIO;
529 		break;
530 
531 	default:
532 		return -EINVAL;
533 	}
534 
535 	return 0;
536 }
537 
hgpk_setup_input_device(struct input_dev * input,struct input_dev * old_input,enum hgpk_mode mode)538 static void hgpk_setup_input_device(struct input_dev *input,
539 				    struct input_dev *old_input,
540 				    enum hgpk_mode mode)
541 {
542 	if (old_input) {
543 		input->name = old_input->name;
544 		input->phys = old_input->phys;
545 		input->id = old_input->id;
546 		input->dev.parent = old_input->dev.parent;
547 	}
548 
549 	memset(input->evbit, 0, sizeof(input->evbit));
550 	memset(input->relbit, 0, sizeof(input->relbit));
551 	memset(input->keybit, 0, sizeof(input->keybit));
552 
553 	/* All modes report left and right buttons */
554 	__set_bit(EV_KEY, input->evbit);
555 	__set_bit(BTN_LEFT, input->keybit);
556 	__set_bit(BTN_RIGHT, input->keybit);
557 
558 	switch (mode) {
559 	case HGPK_MODE_MOUSE:
560 		__set_bit(EV_REL, input->evbit);
561 		__set_bit(REL_X, input->relbit);
562 		__set_bit(REL_Y, input->relbit);
563 		break;
564 
565 	case HGPK_MODE_GLIDESENSOR:
566 		__set_bit(BTN_TOUCH, input->keybit);
567 		__set_bit(BTN_TOOL_FINGER, input->keybit);
568 
569 		__set_bit(EV_ABS, input->evbit);
570 
571 		/* GlideSensor has pressure sensor, PenTablet does not */
572 		input_set_abs_params(input, ABS_PRESSURE, 0, 15, 0, 0);
573 
574 		/* From device specs */
575 		input_set_abs_params(input, ABS_X, 0, 399, 0, 0);
576 		input_set_abs_params(input, ABS_Y, 0, 290, 0, 0);
577 
578 		/* Calculated by hand based on usable size (52mm x 38mm) */
579 		input_abs_set_res(input, ABS_X, 8);
580 		input_abs_set_res(input, ABS_Y, 8);
581 		break;
582 
583 	case HGPK_MODE_PENTABLET:
584 		__set_bit(BTN_TOUCH, input->keybit);
585 		__set_bit(BTN_TOOL_FINGER, input->keybit);
586 
587 		__set_bit(EV_ABS, input->evbit);
588 
589 		/* From device specs */
590 		input_set_abs_params(input, ABS_X, 0, 999, 0, 0);
591 		input_set_abs_params(input, ABS_Y, 5, 239, 0, 0);
592 
593 		/* Calculated by hand based on usable size (156mm x 38mm) */
594 		input_abs_set_res(input, ABS_X, 6);
595 		input_abs_set_res(input, ABS_Y, 8);
596 		break;
597 
598 	default:
599 		BUG();
600 	}
601 }
602 
hgpk_reset_device(struct psmouse * psmouse,bool recalibrate)603 static int hgpk_reset_device(struct psmouse *psmouse, bool recalibrate)
604 {
605 	int err;
606 
607 	psmouse_reset(psmouse);
608 
609 	if (recalibrate) {
610 		struct ps2dev *ps2dev = &psmouse->ps2dev;
611 
612 		/* send the recalibrate request */
613 		if (ps2_command(ps2dev, NULL, 0xf5) ||
614 		    ps2_command(ps2dev, NULL, 0xf5) ||
615 		    ps2_command(ps2dev, NULL, 0xe6) ||
616 		    ps2_command(ps2dev, NULL, 0xf5)) {
617 			return -1;
618 		}
619 
620 		/* according to ALPS, 150mS is required for recalibration */
621 		msleep(150);
622 	}
623 
624 	err = hgpk_select_mode(psmouse);
625 	if (err) {
626 		psmouse_err(psmouse, "failed to select mode\n");
627 		return err;
628 	}
629 
630 	hgpk_reset_hack_state(psmouse);
631 
632 	return 0;
633 }
634 
hgpk_force_recalibrate(struct psmouse * psmouse)635 static int hgpk_force_recalibrate(struct psmouse *psmouse)
636 {
637 	struct hgpk_data *priv = psmouse->private;
638 	int err;
639 
640 	/* C-series touchpads added the recalibrate command */
641 	if (psmouse->model < HGPK_MODEL_C)
642 		return 0;
643 
644 	if (!autorecal) {
645 		psmouse_dbg(psmouse, "recalibration disabled, ignoring\n");
646 		return 0;
647 	}
648 
649 	psmouse_dbg(psmouse, "recalibrating touchpad..\n");
650 
651 	/* we don't want to race with the irq handler, nor with resyncs */
652 	psmouse_set_state(psmouse, PSMOUSE_INITIALIZING);
653 
654 	/* start by resetting the device */
655 	err = hgpk_reset_device(psmouse, true);
656 	if (err)
657 		return err;
658 
659 	/*
660 	 * XXX: If a finger is down during this delay, recalibration will
661 	 * detect capacitance incorrectly.  This is a hardware bug, and
662 	 * we don't have a good way to deal with it.  The 2s window stuff
663 	 * (below) is our best option for now.
664 	 */
665 	if (psmouse_activate(psmouse))
666 		return -1;
667 
668 	if (tpdebug)
669 		psmouse_dbg(psmouse, "touchpad reactivated\n");
670 
671 	/*
672 	 * If we get packets right away after recalibrating, it's likely
673 	 * that a finger was on the touchpad.  If so, it's probably
674 	 * miscalibrated, so we optionally schedule another.
675 	 */
676 	if (recal_guard_time)
677 		priv->recalib_window = jiffies +
678 			msecs_to_jiffies(recal_guard_time);
679 
680 	return 0;
681 }
682 
683 /*
684  * This puts the touchpad in a power saving mode; according to ALPS, current
685  * consumption goes down to 50uA after running this.  To turn power back on,
686  * we drive MS-DAT low.  Measuring with a 1mA resolution ammeter says that
687  * the current on the SUS_3.3V rail drops from 3mA or 4mA to 0 when we do this.
688  *
689  * We have no formal spec that details this operation -- the low-power
690  * sequence came from a long-lost email trail.
691  */
hgpk_toggle_powersave(struct psmouse * psmouse,int enable)692 static int hgpk_toggle_powersave(struct psmouse *psmouse, int enable)
693 {
694 	struct ps2dev *ps2dev = &psmouse->ps2dev;
695 	int timeo;
696 	int err;
697 
698 	/* Added on D-series touchpads */
699 	if (psmouse->model < HGPK_MODEL_D)
700 		return 0;
701 
702 	if (enable) {
703 		psmouse_set_state(psmouse, PSMOUSE_INITIALIZING);
704 
705 		/*
706 		 * Sending a byte will drive MS-DAT low; this will wake up
707 		 * the controller.  Once we get an ACK back from it, it
708 		 * means we can continue with the touchpad re-init.  ALPS
709 		 * tells us that 1s should be long enough, so set that as
710 		 * the upper bound. (in practice, it takes about 3 loops.)
711 		 */
712 		for (timeo = 20; timeo > 0; timeo--) {
713 			if (!ps2_sendbyte(ps2dev, PSMOUSE_CMD_DISABLE, 20))
714 				break;
715 			msleep(25);
716 		}
717 
718 		err = hgpk_reset_device(psmouse, false);
719 		if (err) {
720 			psmouse_err(psmouse, "Failed to reset device!\n");
721 			return err;
722 		}
723 
724 		/* should be all set, enable the touchpad */
725 		psmouse_activate(psmouse);
726 		psmouse_dbg(psmouse, "Touchpad powered up.\n");
727 	} else {
728 		psmouse_dbg(psmouse, "Powering off touchpad.\n");
729 
730 		if (ps2_command(ps2dev, NULL, 0xec) ||
731 		    ps2_command(ps2dev, NULL, 0xec) ||
732 		    ps2_command(ps2dev, NULL, 0xea)) {
733 			return -1;
734 		}
735 
736 		psmouse_set_state(psmouse, PSMOUSE_IGNORE);
737 
738 		/* probably won't see an ACK, the touchpad will be off */
739 		ps2_sendbyte(ps2dev, 0xec, 20);
740 	}
741 
742 	return 0;
743 }
744 
hgpk_poll(struct psmouse * psmouse)745 static int hgpk_poll(struct psmouse *psmouse)
746 {
747 	/* We can't poll, so always return failure. */
748 	return -1;
749 }
750 
hgpk_reconnect(struct psmouse * psmouse)751 static int hgpk_reconnect(struct psmouse *psmouse)
752 {
753 	struct hgpk_data *priv = psmouse->private;
754 
755 	/*
756 	 * During suspend/resume the ps2 rails remain powered.  We don't want
757 	 * to do a reset because it's flush data out of buffers; however,
758 	 * earlier prototypes (B1) had some brokenness that required a reset.
759 	 */
760 	if (olpc_board_at_least(olpc_board(0xb2)))
761 		if (psmouse->ps2dev.serio->dev.power.power_state.event !=
762 				PM_EVENT_ON)
763 			return 0;
764 
765 	priv->powered = 1;
766 	return hgpk_reset_device(psmouse, false);
767 }
768 
hgpk_show_powered(struct psmouse * psmouse,void * data,char * buf)769 static ssize_t hgpk_show_powered(struct psmouse *psmouse, void *data, char *buf)
770 {
771 	struct hgpk_data *priv = psmouse->private;
772 
773 	return sprintf(buf, "%d\n", priv->powered);
774 }
775 
hgpk_set_powered(struct psmouse * psmouse,void * data,const char * buf,size_t count)776 static ssize_t hgpk_set_powered(struct psmouse *psmouse, void *data,
777 				const char *buf, size_t count)
778 {
779 	struct hgpk_data *priv = psmouse->private;
780 	unsigned int value;
781 	int err;
782 
783 	err = kstrtouint(buf, 10, &value);
784 	if (err)
785 		return err;
786 
787 	if (value > 1)
788 		return -EINVAL;
789 
790 	if (value != priv->powered) {
791 		/*
792 		 * hgpk_toggle_power will deal w/ state so
793 		 * we're not racing w/ irq
794 		 */
795 		err = hgpk_toggle_powersave(psmouse, value);
796 		if (!err)
797 			priv->powered = value;
798 	}
799 
800 	return err ? err : count;
801 }
802 
803 __PSMOUSE_DEFINE_ATTR(powered, S_IWUSR | S_IRUGO, NULL,
804 		      hgpk_show_powered, hgpk_set_powered, false);
805 
attr_show_mode(struct psmouse * psmouse,void * data,char * buf)806 static ssize_t attr_show_mode(struct psmouse *psmouse, void *data, char *buf)
807 {
808 	struct hgpk_data *priv = psmouse->private;
809 
810 	return sprintf(buf, "%s\n", hgpk_mode_names[priv->mode]);
811 }
812 
attr_set_mode(struct psmouse * psmouse,void * data,const char * buf,size_t len)813 static ssize_t attr_set_mode(struct psmouse *psmouse, void *data,
814 			     const char *buf, size_t len)
815 {
816 	struct hgpk_data *priv = psmouse->private;
817 	enum hgpk_mode old_mode = priv->mode;
818 	enum hgpk_mode new_mode = hgpk_mode_from_name(buf, len);
819 	struct input_dev *old_dev = psmouse->dev;
820 	struct input_dev *new_dev;
821 	int err;
822 
823 	if (new_mode == HGPK_MODE_INVALID)
824 		return -EINVAL;
825 
826 	if (old_mode == new_mode)
827 		return len;
828 
829 	new_dev = input_allocate_device();
830 	if (!new_dev)
831 		return -ENOMEM;
832 
833 	psmouse_set_state(psmouse, PSMOUSE_INITIALIZING);
834 
835 	/* Switch device into the new mode */
836 	priv->mode = new_mode;
837 	err = hgpk_reset_device(psmouse, false);
838 	if (err)
839 		goto err_try_restore;
840 
841 	hgpk_setup_input_device(new_dev, old_dev, new_mode);
842 
843 	psmouse_set_state(psmouse, PSMOUSE_CMD_MODE);
844 
845 	err = input_register_device(new_dev);
846 	if (err)
847 		goto err_try_restore;
848 
849 	psmouse->dev = new_dev;
850 	input_unregister_device(old_dev);
851 
852 	return len;
853 
854 err_try_restore:
855 	input_free_device(new_dev);
856 	priv->mode = old_mode;
857 	hgpk_reset_device(psmouse, false);
858 
859 	return err;
860 }
861 
862 PSMOUSE_DEFINE_ATTR(hgpk_mode, S_IWUSR | S_IRUGO, NULL,
863 		    attr_show_mode, attr_set_mode);
864 
hgpk_trigger_recal_show(struct psmouse * psmouse,void * data,char * buf)865 static ssize_t hgpk_trigger_recal_show(struct psmouse *psmouse,
866 		void *data, char *buf)
867 {
868 	return -EINVAL;
869 }
870 
hgpk_trigger_recal(struct psmouse * psmouse,void * data,const char * buf,size_t count)871 static ssize_t hgpk_trigger_recal(struct psmouse *psmouse, void *data,
872 				const char *buf, size_t count)
873 {
874 	struct hgpk_data *priv = psmouse->private;
875 	unsigned int value;
876 	int err;
877 
878 	err = kstrtouint(buf, 10, &value);
879 	if (err)
880 		return err;
881 
882 	if (value != 1)
883 		return -EINVAL;
884 
885 	/*
886 	 * We queue work instead of doing recalibration right here
887 	 * to avoid adding locking to to hgpk_force_recalibrate()
888 	 * since workqueue provides serialization.
889 	 */
890 	psmouse_queue_work(psmouse, &priv->recalib_wq, 0);
891 	return count;
892 }
893 
894 __PSMOUSE_DEFINE_ATTR(recalibrate, S_IWUSR | S_IRUGO, NULL,
895 		      hgpk_trigger_recal_show, hgpk_trigger_recal, false);
896 
hgpk_disconnect(struct psmouse * psmouse)897 static void hgpk_disconnect(struct psmouse *psmouse)
898 {
899 	struct hgpk_data *priv = psmouse->private;
900 
901 	device_remove_file(&psmouse->ps2dev.serio->dev,
902 			   &psmouse_attr_powered.dattr);
903 	device_remove_file(&psmouse->ps2dev.serio->dev,
904 			   &psmouse_attr_hgpk_mode.dattr);
905 
906 	if (psmouse->model >= HGPK_MODEL_C)
907 		device_remove_file(&psmouse->ps2dev.serio->dev,
908 				   &psmouse_attr_recalibrate.dattr);
909 
910 	psmouse_reset(psmouse);
911 	kfree(priv);
912 }
913 
hgpk_recalib_work(struct work_struct * work)914 static void hgpk_recalib_work(struct work_struct *work)
915 {
916 	struct delayed_work *w = to_delayed_work(work);
917 	struct hgpk_data *priv = container_of(w, struct hgpk_data, recalib_wq);
918 	struct psmouse *psmouse = priv->psmouse;
919 
920 	if (hgpk_force_recalibrate(psmouse))
921 		psmouse_err(psmouse, "recalibration failed!\n");
922 }
923 
hgpk_register(struct psmouse * psmouse)924 static int hgpk_register(struct psmouse *psmouse)
925 {
926 	struct hgpk_data *priv = psmouse->private;
927 	int err;
928 
929 	/* register handlers */
930 	psmouse->protocol_handler = hgpk_process_byte;
931 	psmouse->poll = hgpk_poll;
932 	psmouse->disconnect = hgpk_disconnect;
933 	psmouse->reconnect = hgpk_reconnect;
934 
935 	/* Disable the idle resync. */
936 	psmouse->resync_time = 0;
937 	/* Reset after a lot of bad bytes. */
938 	psmouse->resetafter = 1024;
939 
940 	hgpk_setup_input_device(psmouse->dev, NULL, priv->mode);
941 
942 	err = device_create_file(&psmouse->ps2dev.serio->dev,
943 				 &psmouse_attr_powered.dattr);
944 	if (err) {
945 		psmouse_err(psmouse, "Failed creating 'powered' sysfs node\n");
946 		return err;
947 	}
948 
949 	err = device_create_file(&psmouse->ps2dev.serio->dev,
950 				 &psmouse_attr_hgpk_mode.dattr);
951 	if (err) {
952 		psmouse_err(psmouse,
953 			    "Failed creating 'hgpk_mode' sysfs node\n");
954 		goto err_remove_powered;
955 	}
956 
957 	/* C-series touchpads added the recalibrate command */
958 	if (psmouse->model >= HGPK_MODEL_C) {
959 		err = device_create_file(&psmouse->ps2dev.serio->dev,
960 					 &psmouse_attr_recalibrate.dattr);
961 		if (err) {
962 			psmouse_err(psmouse,
963 				    "Failed creating 'recalibrate' sysfs node\n");
964 			goto err_remove_mode;
965 		}
966 	}
967 
968 	return 0;
969 
970 err_remove_mode:
971 	device_remove_file(&psmouse->ps2dev.serio->dev,
972 			   &psmouse_attr_hgpk_mode.dattr);
973 err_remove_powered:
974 	device_remove_file(&psmouse->ps2dev.serio->dev,
975 			   &psmouse_attr_powered.dattr);
976 	return err;
977 }
978 
hgpk_init(struct psmouse * psmouse)979 int hgpk_init(struct psmouse *psmouse)
980 {
981 	struct hgpk_data *priv;
982 	int err;
983 
984 	priv = kzalloc(sizeof(struct hgpk_data), GFP_KERNEL);
985 	if (!priv) {
986 		err = -ENOMEM;
987 		goto alloc_fail;
988 	}
989 
990 	psmouse->private = priv;
991 
992 	priv->psmouse = psmouse;
993 	priv->powered = true;
994 	priv->mode = hgpk_default_mode;
995 	INIT_DELAYED_WORK(&priv->recalib_wq, hgpk_recalib_work);
996 
997 	err = hgpk_reset_device(psmouse, false);
998 	if (err)
999 		goto init_fail;
1000 
1001 	err = hgpk_register(psmouse);
1002 	if (err)
1003 		goto init_fail;
1004 
1005 	return 0;
1006 
1007 init_fail:
1008 	kfree(priv);
1009 alloc_fail:
1010 	return err;
1011 }
1012 
hgpk_get_model(struct psmouse * psmouse)1013 static enum hgpk_model_t hgpk_get_model(struct psmouse *psmouse)
1014 {
1015 	struct ps2dev *ps2dev = &psmouse->ps2dev;
1016 	unsigned char param[3];
1017 
1018 	/* E7, E7, E7, E9 gets us a 3 byte identifier */
1019 	if (ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE21) ||
1020 	    ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE21) ||
1021 	    ps2_command(ps2dev,  NULL, PSMOUSE_CMD_SETSCALE21) ||
1022 	    ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO)) {
1023 		return -EIO;
1024 	}
1025 
1026 	psmouse_dbg(psmouse, "ID: %*ph\n", 3, param);
1027 
1028 	/* HGPK signature: 0x67, 0x00, 0x<model> */
1029 	if (param[0] != 0x67 || param[1] != 0x00)
1030 		return -ENODEV;
1031 
1032 	psmouse_info(psmouse, "OLPC touchpad revision 0x%x\n", param[2]);
1033 
1034 	return param[2];
1035 }
1036 
hgpk_detect(struct psmouse * psmouse,bool set_properties)1037 int hgpk_detect(struct psmouse *psmouse, bool set_properties)
1038 {
1039 	int version;
1040 
1041 	version = hgpk_get_model(psmouse);
1042 	if (version < 0)
1043 		return version;
1044 
1045 	if (set_properties) {
1046 		psmouse->vendor = "ALPS";
1047 		psmouse->name = "HGPK";
1048 		psmouse->model = version;
1049 	}
1050 
1051 	return 0;
1052 }
1053 
hgpk_module_init(void)1054 void hgpk_module_init(void)
1055 {
1056 	hgpk_default_mode = hgpk_mode_from_name(hgpk_mode_name,
1057 						strlen(hgpk_mode_name));
1058 	if (hgpk_default_mode == HGPK_MODE_INVALID) {
1059 		hgpk_default_mode = HGPK_MODE_MOUSE;
1060 		strlcpy(hgpk_mode_name, hgpk_mode_names[HGPK_MODE_MOUSE],
1061 			sizeof(hgpk_mode_name));
1062 	}
1063 }
1064