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
43static bool tpdebug;
44module_param(tpdebug, bool, 0644);
45MODULE_PARM_DESC(tpdebug, "enable debugging, dumping packets to KERN_DEBUG.");
46
47static int recalib_delta = 100;
48module_param(recalib_delta, int, 0644);
49MODULE_PARM_DESC(recalib_delta,
50 "packets containing a delta this large will be discarded, and a "
51 "recalibration may be scheduled.");
52
53static int jumpy_delay = 20;
54module_param(jumpy_delay, int, 0644);
55MODULE_PARM_DESC(jumpy_delay,
56 "delay (ms) before recal after jumpiness detected");
57
58static int spew_delay = 1;
59module_param(spew_delay, int, 0644);
60MODULE_PARM_DESC(spew_delay,
61 "delay (ms) before recal after packet spew detected");
62
63static int recal_guard_time;
64module_param(recal_guard_time, int, 0644);
65MODULE_PARM_DESC(recal_guard_time,
66 "interval (ms) during which recal will be restarted if packet received");
67
68static int post_interrupt_delay = 40;
69module_param(post_interrupt_delay, int, 0644);
70MODULE_PARM_DESC(post_interrupt_delay,
71 "delay (ms) before recal after recal interrupt detected");
72
73static bool autorecal = true;
74module_param(autorecal, bool, 0644);
75MODULE_PARM_DESC(autorecal, "enable recalibration in the driver");
76
77static char hgpk_mode_name[16];
78module_param_string(hgpk_mode, hgpk_mode_name, sizeof(hgpk_mode_name), 0644);
79MODULE_PARM_DESC(hgpk_mode,
80 "default hgpk mode: mouse, glidesensor or pentablet");
81
82static int hgpk_default_mode = HGPK_MODE_MOUSE;
83
84static const char * const hgpk_mode_names[] = {
85 [HGPK_MODE_MOUSE] = "Mouse",
86 [HGPK_MODE_GLIDESENSOR] = "GlideSensor",
87 [HGPK_MODE_PENTABLET] = "PenTablet",
88};
89
90static 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(s1: name, s2: buf, n: 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 */
106static 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 */
124static 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(curr: avx, prev: 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(curr: avy, prev: 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, work: &priv->recalib_wq,
170 delay: msecs_to_jiffies(m: jumpy_delay));
171 }
172
173 return priv->xbigj || priv->ybigj;
174}
175
176static 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
185static 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 */
211static 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, work: &priv->recalib_wq,
264 delay: msecs_to_jiffies(m: 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 */
306static 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
340static 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(dev: idev, ABS_PRESSURE, value: 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(dev: idev, BTN_TOUCH, value: down);
374 input_report_key(dev: idev, BTN_LEFT, value: left);
375 input_report_key(dev: idev, BTN_RIGHT, value: 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, work: &priv->recalib_wq,
396 delay: msecs_to_jiffies(m: 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: x_diff, y: y_diff)) {
409 if (tpdebug)
410 psmouse_dbg(psmouse, "discarding\n");
411 goto done;
412 }
413 hgpk_spewing_hack(psmouse, l: left, r: right, x: x_diff, y: y_diff);
414 }
415
416 input_report_abs(dev: idev, ABS_X, value: x);
417 input_report_abs(dev: idev, ABS_Y, value: y);
418 priv->abs_x = x;
419 priv->abs_y = y;
420
421done:
422 input_sync(dev: idev);
423}
424
425static 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, l: left, r: 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, value: left);
452 input_report_key(dev, BTN_RIGHT, value: right);
453
454 input_report_rel(dev, REL_X, value: x);
455 input_report_rel(dev, REL_Y, value: y);
456
457 input_sync(dev);
458}
459
460static 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, packet: 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, work: &priv->recalib_wq,
484 delay: msecs_to_jiffies(m: post_interrupt_delay));
485 }
486 priv->recalib_window = 0;
487 }
488
489 return PSMOUSE_GOOD_DATA;
490}
491
492static 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, command: 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, command: cmd))
528 return -EIO;
529 break;
530
531 default:
532 return -EINVAL;
533 }
534
535 return 0;
536}
537
538static 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(dev: input, ABS_PRESSURE, min: 0, max: 15, fuzz: 0, flat: 0);
573
574 /* From device specs */
575 input_set_abs_params(dev: input, ABS_X, min: 0, max: 399, fuzz: 0, flat: 0);
576 input_set_abs_params(dev: input, ABS_Y, min: 0, max: 290, fuzz: 0, flat: 0);
577
578 /* Calculated by hand based on usable size (52mm x 38mm) */
579 input_abs_set_res(dev: input, ABS_X, val: 8);
580 input_abs_set_res(dev: input, ABS_Y, val: 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(dev: input, ABS_X, min: 0, max: 999, fuzz: 0, flat: 0);
591 input_set_abs_params(dev: input, ABS_Y, min: 5, max: 239, fuzz: 0, flat: 0);
592
593 /* Calculated by hand based on usable size (156mm x 38mm) */
594 input_abs_set_res(dev: input, ABS_X, val: 6);
595 input_abs_set_res(dev: input, ABS_Y, val: 8);
596 break;
597
598 default:
599 BUG();
600 }
601}
602
603static 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, command: 0xf5) ||
614 ps2_command(ps2dev, NULL, command: 0xf5) ||
615 ps2_command(ps2dev, NULL, command: 0xe6) ||
616 ps2_command(ps2dev, NULL, command: 0xf5)) {
617 return -1;
618 }
619
620 /* according to ALPS, 150mS is required for recalibration */
621 msleep(msecs: 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
635static 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, new_state: PSMOUSE_INITIALIZING);
653
654 /* start by resetting the device */
655 err = hgpk_reset_device(psmouse, recalibrate: 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(m: 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 */
692static 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, new_state: 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, timeout: 20))
714 break;
715 msleep(msecs: 25);
716 }
717
718 err = hgpk_reset_device(psmouse, recalibrate: 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, command: 0xec) ||
731 ps2_command(ps2dev, NULL, command: 0xec) ||
732 ps2_command(ps2dev, NULL, command: 0xea)) {
733 return -1;
734 }
735
736 psmouse_set_state(psmouse, new_state: PSMOUSE_IGNORE);
737
738 /* probably won't see an ACK, the touchpad will be off */
739 ps2_sendbyte(ps2dev, byte: 0xec, timeout: 20);
740 }
741
742 return 0;
743}
744
745static int hgpk_poll(struct psmouse *psmouse)
746{
747 /* We can't poll, so always return failure. */
748 return -1;
749}
750
751static 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, recalibrate: false);
767}
768
769static 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, fmt: "%d\n", priv->powered);
774}
775
776static 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(s: buf, base: 10, res: &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, enable: 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
806static 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, fmt: "%s\n", hgpk_mode_names[priv->mode]);
811}
812
813static 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, new_state: PSMOUSE_INITIALIZING);
834
835 /* Switch device into the new mode */
836 priv->mode = new_mode;
837 err = hgpk_reset_device(psmouse, recalibrate: false);
838 if (err)
839 goto err_try_restore;
840
841 hgpk_setup_input_device(input: new_dev, old_input: old_dev, mode: new_mode);
842
843 psmouse_set_state(psmouse, new_state: 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
854err_try_restore:
855 input_free_device(dev: new_dev);
856 priv->mode = old_mode;
857 hgpk_reset_device(psmouse, recalibrate: false);
858
859 return err;
860}
861
862PSMOUSE_DEFINE_ATTR(hgpk_mode, S_IWUSR | S_IRUGO, NULL,
863 attr_show_mode, attr_set_mode);
864
865static ssize_t hgpk_trigger_recal_show(struct psmouse *psmouse,
866 void *data, char *buf)
867{
868 return -EINVAL;
869}
870
871static 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(s: buf, base: 10, res: &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 hgpk_force_recalibrate()
888 * since workqueue provides serialization.
889 */
890 psmouse_queue_work(psmouse, work: &priv->recalib_wq, delay: 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
897static void hgpk_disconnect(struct psmouse *psmouse)
898{
899 struct hgpk_data *priv = psmouse->private;
900
901 device_remove_file(dev: &psmouse->ps2dev.serio->dev,
902 attr: &psmouse_attr_powered.dattr);
903 device_remove_file(dev: &psmouse->ps2dev.serio->dev,
904 attr: &psmouse_attr_hgpk_mode.dattr);
905
906 if (psmouse->model >= HGPK_MODEL_C)
907 device_remove_file(dev: &psmouse->ps2dev.serio->dev,
908 attr: &psmouse_attr_recalibrate.dattr);
909
910 psmouse_reset(psmouse);
911 kfree(objp: priv);
912}
913
914static 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
924static 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(input: psmouse->dev, NULL, mode: priv->mode);
941
942 err = device_create_file(device: &psmouse->ps2dev.serio->dev,
943 entry: &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(device: &psmouse->ps2dev.serio->dev,
950 entry: &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(device: &psmouse->ps2dev.serio->dev,
960 entry: &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
970err_remove_mode:
971 device_remove_file(dev: &psmouse->ps2dev.serio->dev,
972 attr: &psmouse_attr_hgpk_mode.dattr);
973err_remove_powered:
974 device_remove_file(dev: &psmouse->ps2dev.serio->dev,
975 attr: &psmouse_attr_powered.dattr);
976 return err;
977}
978
979int hgpk_init(struct psmouse *psmouse)
980{
981 struct hgpk_data *priv;
982 int err;
983
984 priv = kzalloc(sizeof(*priv), 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, recalibrate: 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
1007init_fail:
1008 kfree(objp: priv);
1009alloc_fail:
1010 return err;
1011}
1012
1013static 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
1037int 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
1054void hgpk_module_init(void)
1055{
1056 hgpk_default_mode = hgpk_mode_from_name(buf: hgpk_mode_name,
1057 strlen(hgpk_mode_name));
1058 if (hgpk_default_mode == HGPK_MODE_INVALID) {
1059 hgpk_default_mode = HGPK_MODE_MOUSE;
1060 strscpy(hgpk_mode_name, hgpk_mode_names[HGPK_MODE_MOUSE],
1061 sizeof(hgpk_mode_name));
1062 }
1063}
1064

source code of linux/drivers/input/mouse/hgpk.c