Merge branch 'simplify-do_wp_page'
[linux-2.6-microblaze.git] / drivers / input / mouse / hgpk.c
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
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  */
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  */
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
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
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  */
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  */
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
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
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
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
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
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
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
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  */
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
745 static int hgpk_poll(struct psmouse *psmouse)
746 {
747         /* We can't poll, so always return failure. */
748         return -1;
749 }
750
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
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
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
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
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
865 static ssize_t hgpk_trigger_recal_show(struct psmouse *psmouse,
866                 void *data, char *buf)
867 {
868         return -EINVAL;
869 }
870
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
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
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
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
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
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
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
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 }