input/mouse/hgpk.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * OLPC HGPK (XO-1) touchpad PS/2 mouse driver
0004  *
0005  * Copyright (c) 2006-2008 One Laptop Per Child
0006  * Authors:
0007  *   Zephaniah E. Hull
0008  *   Andres Salomon <dilinger@debian.org>
0009  *
0010  * This driver is partly based on the ALPS driver, which is:
0011  *
0012  * Copyright (c) 2003 Neil Brown <neilb@cse.unsw.edu.au>
0013  * Copyright (c) 2003-2005 Peter Osterlund <petero2@telia.com>
0014  * Copyright (c) 2004 Dmitry Torokhov <dtor@mail.ru>
0015  * Copyright (c) 2005 Vojtech Pavlik <vojtech@suse.cz>
0016  */
0017
0018 /*
0019  * The spec from ALPS is available from
0020  * <http://wiki.laptop.org/go/Touch_Pad/Tablet>.  It refers to this
0021  * device as HGPK (Hybrid GS, PT, and Keymatrix).
0022  *
0023  * The earliest versions of the device had simultaneous reporting; that
0024  * was removed.  After that, the device used the Advanced Mode GS/PT streaming
0025  * stuff.  That turned out to be too buggy to support, so we've finally
0026  * switched to Mouse Mode (which utilizes only the center 1/3 of the touchpad).
0027  */
0028
0029 #define DEBUG
0030 #include <linux/slab.h>
0031 #include <linux/input.h>
0032 #include <linux/module.h>
0033 #include <linux/serio.h>
0034 #include <linux/libps2.h>
0035 #include <linux/delay.h>
0036 #include <asm/olpc.h>
0037
0038 #include "psmouse.h"
0039 #include "hgpk.h"
0040
0041 #define ILLEGAL_XY 999999
0042
0043 static bool tpdebug;
0044 module_param(tpdebug, bool, 0644);
0045 MODULE_PARM_DESC(tpdebug, "enable debugging, dumping packets to KERN_DEBUG.");
0046
0047 static int recalib_delta = 100;
0048 module_param(recalib_delta, int, 0644);
0049 MODULE_PARM_DESC(recalib_delta,
0050     "packets containing a delta this large will be discarded, and a "
0051     "recalibration may be scheduled.");
0052
0053 static int jumpy_delay = 20;
0054 module_param(jumpy_delay, int, 0644);
0055 MODULE_PARM_DESC(jumpy_delay,
0056     "delay (ms) before recal after jumpiness detected");
0057
0058 static int spew_delay = 1;
0059 module_param(spew_delay, int, 0644);
0060 MODULE_PARM_DESC(spew_delay,
0061     "delay (ms) before recal after packet spew detected");
0062
0063 static int recal_guard_time;
0064 module_param(recal_guard_time, int, 0644);
0065 MODULE_PARM_DESC(recal_guard_time,
0066     "interval (ms) during which recal will be restarted if packet received");
0067
0068 static int post_interrupt_delay = 40;
0069 module_param(post_interrupt_delay, int, 0644);
0070 MODULE_PARM_DESC(post_interrupt_delay,
0071     "delay (ms) before recal after recal interrupt detected");
0072
0073 static bool autorecal = true;
0074 module_param(autorecal, bool, 0644);
0075 MODULE_PARM_DESC(autorecal, "enable recalibration in the driver");
0076
0077 static char hgpk_mode_name[16];
0078 module_param_string(hgpk_mode, hgpk_mode_name, sizeof(hgpk_mode_name), 0644);
0079 MODULE_PARM_DESC(hgpk_mode,
0080     "default hgpk mode: mouse, glidesensor or pentablet");
0081
0082 static int hgpk_default_mode = HGPK_MODE_MOUSE;
0083
0084 static const char * const hgpk_mode_names[] = {
0085     [HGPK_MODE_MOUSE] = "Mouse",
0086     [HGPK_MODE_GLIDESENSOR] = "GlideSensor",
0087     [HGPK_MODE_PENTABLET] = "PenTablet",
0088 };
0089
0090 static int hgpk_mode_from_name(const char *buf, int len)
0091 {
0092     int i;
0093
0094     for (i = 0; i < ARRAY_SIZE(hgpk_mode_names); i++) {
0095         const char *name = hgpk_mode_names[i];
0096         if (strlen(name) == len && !strncasecmp(name, buf, len))
0097             return i;
0098     }
0099
0100     return HGPK_MODE_INVALID;
0101 }
0102
0103 /*
0104  * see if new value is within 20% of half of old value
0105  */
0106 static int approx_half(int curr, int prev)
0107 {
0108     int belowhalf, abovehalf;
0109
0110     if (curr < 5 || prev < 5)
0111         return 0;
0112
0113     belowhalf = (prev * 8) / 20;
0114     abovehalf = (prev * 12) / 20;
0115
0116     return belowhalf < curr && curr <= abovehalf;
0117 }
0118
0119 /*
0120  * Throw out oddly large delta packets, and any that immediately follow whose
0121  * values are each approximately half of the previous.  It seems that the ALPS
0122  * firmware emits errant packets, and they get averaged out slowly.
0123  */
0124 static int hgpk_discard_decay_hack(struct psmouse *psmouse, int x, int y)
0125 {
0126     struct hgpk_data *priv = psmouse->private;
0127     int avx, avy;
0128     bool do_recal = false;
0129
0130     avx = abs(x);
0131     avy = abs(y);
0132
0133     /* discard if too big, or half that but > 4 times the prev delta */
0134     if (avx > recalib_delta ||
0135         (avx > recalib_delta / 2 && ((avx / 4) > priv->xlast))) {
0136         psmouse_warn(psmouse, "detected %dpx jump in x\n", x);
0137         priv->xbigj = avx;
0138     } else if (approx_half(avx, priv->xbigj)) {
0139         psmouse_warn(psmouse, "detected secondary %dpx jump in x\n", x);
0140         priv->xbigj = avx;
0141         priv->xsaw_secondary++;
0142     } else {
0143         if (priv->xbigj && priv->xsaw_secondary > 1)
0144             do_recal = true;
0145         priv->xbigj = 0;
0146         priv->xsaw_secondary = 0;
0147     }
0148
0149     if (avy > recalib_delta ||
0150         (avy > recalib_delta / 2 && ((avy / 4) > priv->ylast))) {
0151         psmouse_warn(psmouse, "detected %dpx jump in y\n", y);
0152         priv->ybigj = avy;
0153     } else if (approx_half(avy, priv->ybigj)) {
0154         psmouse_warn(psmouse, "detected secondary %dpx jump in y\n", y);
0155         priv->ybigj = avy;
0156         priv->ysaw_secondary++;
0157     } else {
0158         if (priv->ybigj && priv->ysaw_secondary > 1)
0159             do_recal = true;
0160         priv->ybigj = 0;
0161         priv->ysaw_secondary = 0;
0162     }
0163
0164     priv->xlast = avx;
0165     priv->ylast = avy;
0166
0167     if (do_recal && jumpy_delay) {
0168         psmouse_warn(psmouse, "scheduling recalibration\n");
0169         psmouse_queue_work(psmouse, &priv->recalib_wq,
0170                 msecs_to_jiffies(jumpy_delay));
0171     }
0172
0173     return priv->xbigj || priv->ybigj;
0174 }
0175
0176 static void hgpk_reset_spew_detection(struct hgpk_data *priv)
0177 {
0178     priv->spew_count = 0;
0179     priv->dupe_count = 0;
0180     priv->x_tally = 0;
0181     priv->y_tally = 0;
0182     priv->spew_flag = NO_SPEW;
0183 }
0184
0185 static void hgpk_reset_hack_state(struct psmouse *psmouse)
0186 {
0187     struct hgpk_data *priv = psmouse->private;
0188
0189     priv->abs_x = priv->abs_y = -1;
0190     priv->xlast = priv->ylast = ILLEGAL_XY;
0191     priv->xbigj = priv->ybigj = 0;
0192     priv->xsaw_secondary = priv->ysaw_secondary = 0;
0193     hgpk_reset_spew_detection(priv);
0194 }
0195
0196 /*
0197  * We have no idea why this particular hardware bug occurs.  The touchpad
0198  * will randomly start spewing packets without anything touching the
0199  * pad.  This wouldn't necessarily be bad, but it's indicative of a
0200  * severely miscalibrated pad; attempting to use the touchpad while it's
0201  * spewing means the cursor will jump all over the place, and act "drunk".
0202  *
0203  * The packets that are spewed tend to all have deltas between -2 and 2, and
0204  * the cursor will move around without really going very far.  It will
0205  * tend to end up in the same location; if we tally up the changes over
0206  * 100 packets, we end up w/ a final delta of close to 0.  This happens
0207  * pretty regularly when the touchpad is spewing, and is pretty hard to
0208  * manually trigger (at least for *my* fingers).  So, it makes a perfect
0209  * scheme for detecting spews.
0210  */
0211 static void hgpk_spewing_hack(struct psmouse *psmouse,
0212                   int l, int r, int x, int y)
0213 {
0214     struct hgpk_data *priv = psmouse->private;
0215
0216     /* ignore button press packets; many in a row could trigger
0217      * a false-positive! */
0218     if (l || r)
0219         return;
0220
0221     /* don't track spew if the workaround feature has been turned off */
0222     if (!spew_delay)
0223         return;
0224
0225     if (abs(x) > 3 || abs(y) > 3) {
0226         /* no spew, or spew ended */
0227         hgpk_reset_spew_detection(priv);
0228         return;
0229     }
0230
0231     /* Keep a tally of the overall delta to the cursor position caused by
0232      * the spew */
0233     priv->x_tally += x;
0234     priv->y_tally += y;
0235
0236     switch (priv->spew_flag) {
0237     case NO_SPEW:
0238         /* we're not spewing, but this packet might be the start */
0239         priv->spew_flag = MAYBE_SPEWING;
0240
0241         fallthrough;
0242
0243     case MAYBE_SPEWING:
0244         priv->spew_count++;
0245
0246         if (priv->spew_count < SPEW_WATCH_COUNT)
0247             break;
0248
0249         /* excessive spew detected, request recalibration */
0250         priv->spew_flag = SPEW_DETECTED;
0251
0252         fallthrough;
0253
0254     case SPEW_DETECTED:
0255         /* only recalibrate when the overall delta to the cursor
0256          * is really small. if the spew is causing significant cursor
0257          * movement, it is probably a case of the user moving the
0258          * cursor very slowly across the screen. */
0259         if (abs(priv->x_tally) < 3 && abs(priv->y_tally) < 3) {
0260             psmouse_warn(psmouse, "packet spew detected (%d,%d)\n",
0261                      priv->x_tally, priv->y_tally);
0262             priv->spew_flag = RECALIBRATING;
0263             psmouse_queue_work(psmouse, &priv->recalib_wq,
0264                        msecs_to_jiffies(spew_delay));
0265         }
0266
0267         break;
0268     case RECALIBRATING:
0269         /* we already detected a spew and requested a recalibration,
0270          * just wait for the queue to kick into action. */
0271         break;
0272     }
0273 }
0274
0275 /*
0276  * HGPK Mouse Mode format (standard mouse format, sans middle button)
0277  *
0278  * byte 0:  y-over  x-over  y-neg   x-neg   1   0   swr swl
0279  * byte 1:  x7  x6  x5  x4  x3  x2  x1  x0
0280  * byte 2:  y7  y6  y5  y4  y3  y2  y1  y0
0281  *
0282  * swr/swl are the left/right buttons.
0283  * x-neg/y-neg are the x and y delta negative bits
0284  * x-over/y-over are the x and y overflow bits
0285  *
0286  * ---
0287  *
0288  * HGPK Advanced Mode - single-mode format
0289  *
0290  * byte 0(PT):  1    1    0    0    1    1     1     1
0291  * byte 0(GS):  1    1    1    1    1    1     1     1
0292  * byte 1:      0   x6   x5   x4   x3   x2    x1    x0
0293  * byte 2(PT):  0    0   x9   x8   x7    ? pt-dsw    0
0294  * byte 2(GS):  0  x10   x9   x8   x7    ? gs-dsw pt-dsw
0295  * byte 3:      0   y9   y8   y7    1    0   swr   swl
0296  * byte 4:      0   y6   y5   y4   y3   y2    y1    y0
0297  * byte 5:      0   z6   z5   z4   z3   z2    z1    z0
0298  *
0299  * ?'s are not defined in the protocol spec, may vary between models.
0300  *
0301  * swr/swl are the left/right buttons.
0302  *
0303  * pt-dsw/gs-dsw indicate that the pt/gs sensor is detecting a
0304  * pen/finger
0305  */
0306 static bool hgpk_is_byte_valid(struct psmouse *psmouse, unsigned char *packet)
0307 {
0308     struct hgpk_data *priv = psmouse->private;
0309     int pktcnt = psmouse->pktcnt;
0310     bool valid;
0311
0312     switch (priv->mode) {
0313     case HGPK_MODE_MOUSE:
0314         valid = (packet[0] & 0x0C) == 0x08;
0315         break;
0316
0317     case HGPK_MODE_GLIDESENSOR:
0318         valid = pktcnt == 1 ?
0319             packet[0] == HGPK_GS : !(packet[pktcnt - 1] & 0x80);
0320         break;
0321
0322     case HGPK_MODE_PENTABLET:
0323         valid = pktcnt == 1 ?
0324             packet[0] == HGPK_PT : !(packet[pktcnt - 1] & 0x80);
0325         break;
0326
0327     default:
0328         valid = false;
0329         break;
0330     }
0331
0332     if (!valid)
0333         psmouse_dbg(psmouse,
0334                 "bad data, mode %d (%d) %*ph\n",
0335                 priv->mode, pktcnt, 6, psmouse->packet);
0336
0337     return valid;
0338 }
0339
0340 static void hgpk_process_advanced_packet(struct psmouse *psmouse)
0341 {
0342     struct hgpk_data *priv = psmouse->private;
0343     struct input_dev *idev = psmouse->dev;
0344     unsigned char *packet = psmouse->packet;
0345     int down = !!(packet[2] & 2);
0346     int left = !!(packet[3] & 1);
0347     int right = !!(packet[3] & 2);
0348     int x = packet[1] | ((packet[2] & 0x78) << 4);
0349     int y = packet[4] | ((packet[3] & 0x70) << 3);
0350
0351     if (priv->mode == HGPK_MODE_GLIDESENSOR) {
0352         int pt_down = !!(packet[2] & 1);
0353         int finger_down = !!(packet[2] & 2);
0354         int z = packet[5];
0355
0356         input_report_abs(idev, ABS_PRESSURE, z);
0357         if (tpdebug)
0358             psmouse_dbg(psmouse, "pd=%d fd=%d z=%d",
0359                     pt_down, finger_down, z);
0360     } else {
0361         /*
0362          * PenTablet mode does not report pressure, so we don't
0363          * report it here
0364          */
0365         if (tpdebug)
0366             psmouse_dbg(psmouse, "pd=%d ", down);
0367     }
0368
0369     if (tpdebug)
0370         psmouse_dbg(psmouse, "l=%d r=%d x=%d y=%d\n",
0371                 left, right, x, y);
0372
0373     input_report_key(idev, BTN_TOUCH, down);
0374     input_report_key(idev, BTN_LEFT, left);
0375     input_report_key(idev, BTN_RIGHT, right);
0376
0377     /*
0378      * If this packet says that the finger was removed, reset our position
0379      * tracking so that we don't erroneously detect a jump on next press.
0380      */
0381     if (!down) {
0382         hgpk_reset_hack_state(psmouse);
0383         goto done;
0384     }
0385
0386     /*
0387      * Weed out duplicate packets (we get quite a few, and they mess up
0388      * our jump detection)
0389      */
0390     if (x == priv->abs_x && y == priv->abs_y) {
0391         if (++priv->dupe_count > SPEW_WATCH_COUNT) {
0392             if (tpdebug)
0393                 psmouse_dbg(psmouse, "hard spew detected\n");
0394             priv->spew_flag = RECALIBRATING;
0395             psmouse_queue_work(psmouse, &priv->recalib_wq,
0396                        msecs_to_jiffies(spew_delay));
0397         }
0398         goto done;
0399     }
0400
0401     /* not a duplicate, continue with position reporting */
0402     priv->dupe_count = 0;
0403
0404     /* Don't apply hacks in PT mode, it seems reliable */
0405     if (priv->mode != HGPK_MODE_PENTABLET && priv->abs_x != -1) {
0406         int x_diff = priv->abs_x - x;
0407         int y_diff = priv->abs_y - y;
0408         if (hgpk_discard_decay_hack(psmouse, x_diff, y_diff)) {
0409             if (tpdebug)
0410                 psmouse_dbg(psmouse, "discarding\n");
0411             goto done;
0412         }
0413         hgpk_spewing_hack(psmouse, left, right, x_diff, y_diff);
0414     }
0415
0416     input_report_abs(idev, ABS_X, x);
0417     input_report_abs(idev, ABS_Y, y);
0418     priv->abs_x = x;
0419     priv->abs_y = y;
0420
0421 done:
0422     input_sync(idev);
0423 }
0424
0425 static void hgpk_process_simple_packet(struct psmouse *psmouse)
0426 {
0427     struct input_dev *dev = psmouse->dev;
0428     unsigned char *packet = psmouse->packet;
0429     int left = packet[0] & 1;
0430     int right = (packet[0] >> 1) & 1;
0431     int x = packet[1] - ((packet[0] << 4) & 0x100);
0432     int y = ((packet[0] << 3) & 0x100) - packet[2];
0433
0434     if (packet[0] & 0xc0)
0435         psmouse_dbg(psmouse,
0436                 "overflow -- 0x%02x 0x%02x 0x%02x\n",
0437                 packet[0], packet[1], packet[2]);
0438
0439     if (hgpk_discard_decay_hack(psmouse, x, y)) {
0440         if (tpdebug)
0441             psmouse_dbg(psmouse, "discarding\n");
0442         return;
0443     }
0444
0445     hgpk_spewing_hack(psmouse, left, right, x, y);
0446
0447     if (tpdebug)
0448         psmouse_dbg(psmouse, "l=%d r=%d x=%d y=%d\n",
0449                 left, right, x, y);
0450
0451     input_report_key(dev, BTN_LEFT, left);
0452     input_report_key(dev, BTN_RIGHT, right);
0453
0454     input_report_rel(dev, REL_X, x);
0455     input_report_rel(dev, REL_Y, y);
0456
0457     input_sync(dev);
0458 }
0459
0460 static psmouse_ret_t hgpk_process_byte(struct psmouse *psmouse)
0461 {
0462     struct hgpk_data *priv = psmouse->private;
0463
0464     if (!hgpk_is_byte_valid(psmouse, psmouse->packet))
0465         return PSMOUSE_BAD_DATA;
0466
0467     if (psmouse->pktcnt >= psmouse->pktsize) {
0468         if (priv->mode == HGPK_MODE_MOUSE)
0469             hgpk_process_simple_packet(psmouse);
0470         else
0471             hgpk_process_advanced_packet(psmouse);
0472         return PSMOUSE_FULL_PACKET;
0473     }
0474
0475     if (priv->recalib_window) {
0476         if (time_before(jiffies, priv->recalib_window)) {
0477             /*
0478              * ugh, got a packet inside our recalibration
0479              * window, schedule another recalibration.
0480              */
0481             psmouse_dbg(psmouse,
0482                     "packet inside calibration window, queueing another recalibration\n");
0483             psmouse_queue_work(psmouse, &priv->recalib_wq,
0484                     msecs_to_jiffies(post_interrupt_delay));
0485         }
0486         priv->recalib_window = 0;
0487     }
0488
0489     return PSMOUSE_GOOD_DATA;
0490 }
0491
0492 static int hgpk_select_mode(struct psmouse *psmouse)
0493 {
0494     struct ps2dev *ps2dev = &psmouse->ps2dev;
0495     struct hgpk_data *priv = psmouse->private;
0496     int i;
0497     int cmd;
0498
0499     /*
0500      * 4 disables to enable advanced mode
0501      * then 3 0xf2 bytes as the preamble for GS/PT selection
0502      */
0503     const int advanced_init[] = {
0504         PSMOUSE_CMD_DISABLE, PSMOUSE_CMD_DISABLE,
0505         PSMOUSE_CMD_DISABLE, PSMOUSE_CMD_DISABLE,
0506         0xf2, 0xf2, 0xf2,
0507     };
0508
0509     switch (priv->mode) {
0510     case HGPK_MODE_MOUSE:
0511         psmouse->pktsize = 3;
0512         break;
0513
0514     case HGPK_MODE_GLIDESENSOR:
0515     case HGPK_MODE_PENTABLET:
0516         psmouse->pktsize = 6;
0517
0518         /* Switch to 'Advanced mode.', four disables in a row. */
0519         for (i = 0; i < ARRAY_SIZE(advanced_init); i++)
0520             if (ps2_command(ps2dev, NULL, advanced_init[i]))
0521                 return -EIO;
0522
0523         /* select between GlideSensor (mouse) or PenTablet */
0524         cmd = priv->mode == HGPK_MODE_GLIDESENSOR ?
0525             PSMOUSE_CMD_SETSCALE11 : PSMOUSE_CMD_SETSCALE21;
0526
0527         if (ps2_command(ps2dev, NULL, cmd))
0528             return -EIO;
0529         break;
0530
0531     default:
0532         return -EINVAL;
0533     }
0534
0535     return 0;
0536 }
0537
0538 static void hgpk_setup_input_device(struct input_dev *input,
0539                     struct input_dev *old_input,
0540                     enum hgpk_mode mode)
0541 {
0542     if (old_input) {
0543         input->name = old_input->name;
0544         input->phys = old_input->phys;
0545         input->id = old_input->id;
0546         input->dev.parent = old_input->dev.parent;
0547     }
0548
0549     memset(input->evbit, 0, sizeof(input->evbit));
0550     memset(input->relbit, 0, sizeof(input->relbit));
0551     memset(input->keybit, 0, sizeof(input->keybit));
0552
0553     /* All modes report left and right buttons */
0554     __set_bit(EV_KEY, input->evbit);
0555     __set_bit(BTN_LEFT, input->keybit);
0556     __set_bit(BTN_RIGHT, input->keybit);
0557
0558     switch (mode) {
0559     case HGPK_MODE_MOUSE:
0560         __set_bit(EV_REL, input->evbit);
0561         __set_bit(REL_X, input->relbit);
0562         __set_bit(REL_Y, input->relbit);
0563         break;
0564
0565     case HGPK_MODE_GLIDESENSOR:
0566         __set_bit(BTN_TOUCH, input->keybit);
0567         __set_bit(BTN_TOOL_FINGER, input->keybit);
0568
0569         __set_bit(EV_ABS, input->evbit);
0570
0571         /* GlideSensor has pressure sensor, PenTablet does not */
0572         input_set_abs_params(input, ABS_PRESSURE, 0, 15, 0, 0);
0573
0574         /* From device specs */
0575         input_set_abs_params(input, ABS_X, 0, 399, 0, 0);
0576         input_set_abs_params(input, ABS_Y, 0, 290, 0, 0);
0577
0578         /* Calculated by hand based on usable size (52mm x 38mm) */
0579         input_abs_set_res(input, ABS_X, 8);
0580         input_abs_set_res(input, ABS_Y, 8);
0581         break;
0582
0583     case HGPK_MODE_PENTABLET:
0584         __set_bit(BTN_TOUCH, input->keybit);
0585         __set_bit(BTN_TOOL_FINGER, input->keybit);
0586
0587         __set_bit(EV_ABS, input->evbit);
0588
0589         /* From device specs */
0590         input_set_abs_params(input, ABS_X, 0, 999, 0, 0);
0591         input_set_abs_params(input, ABS_Y, 5, 239, 0, 0);
0592
0593         /* Calculated by hand based on usable size (156mm x 38mm) */
0594         input_abs_set_res(input, ABS_X, 6);
0595         input_abs_set_res(input, ABS_Y, 8);
0596         break;
0597
0598     default:
0599         BUG();
0600     }
0601 }
0602
0603 static int hgpk_reset_device(struct psmouse *psmouse, bool recalibrate)
0604 {
0605     int err;
0606
0607     psmouse_reset(psmouse);
0608
0609     if (recalibrate) {
0610         struct ps2dev *ps2dev = &psmouse->ps2dev;
0611
0612         /* send the recalibrate request */
0613         if (ps2_command(ps2dev, NULL, 0xf5) ||
0614             ps2_command(ps2dev, NULL, 0xf5) ||
0615             ps2_command(ps2dev, NULL, 0xe6) ||
0616             ps2_command(ps2dev, NULL, 0xf5)) {
0617             return -1;
0618         }
0619
0620         /* according to ALPS, 150mS is required for recalibration */
0621         msleep(150);
0622     }
0623
0624     err = hgpk_select_mode(psmouse);
0625     if (err) {
0626         psmouse_err(psmouse, "failed to select mode\n");
0627         return err;
0628     }
0629
0630     hgpk_reset_hack_state(psmouse);
0631
0632     return 0;
0633 }
0634
0635 static int hgpk_force_recalibrate(struct psmouse *psmouse)
0636 {
0637     struct hgpk_data *priv = psmouse->private;
0638     int err;
0639
0640     /* C-series touchpads added the recalibrate command */
0641     if (psmouse->model < HGPK_MODEL_C)
0642         return 0;
0643
0644     if (!autorecal) {
0645         psmouse_dbg(psmouse, "recalibration disabled, ignoring\n");
0646         return 0;
0647     }
0648
0649     psmouse_dbg(psmouse, "recalibrating touchpad..\n");
0650
0651     /* we don't want to race with the irq handler, nor with resyncs */
0652     psmouse_set_state(psmouse, PSMOUSE_INITIALIZING);
0653
0654     /* start by resetting the device */
0655     err = hgpk_reset_device(psmouse, true);
0656     if (err)
0657         return err;
0658
0659     /*
0660      * XXX: If a finger is down during this delay, recalibration will
0661      * detect capacitance incorrectly.  This is a hardware bug, and
0662      * we don't have a good way to deal with it.  The 2s window stuff
0663      * (below) is our best option for now.
0664      */
0665     if (psmouse_activate(psmouse))
0666         return -1;
0667
0668     if (tpdebug)
0669         psmouse_dbg(psmouse, "touchpad reactivated\n");
0670
0671     /*
0672      * If we get packets right away after recalibrating, it's likely
0673      * that a finger was on the touchpad.  If so, it's probably
0674      * miscalibrated, so we optionally schedule another.
0675      */
0676     if (recal_guard_time)
0677         priv->recalib_window = jiffies +
0678             msecs_to_jiffies(recal_guard_time);
0679
0680     return 0;
0681 }
0682
0683 /*
0684  * This puts the touchpad in a power saving mode; according to ALPS, current
0685  * consumption goes down to 50uA after running this.  To turn power back on,
0686  * we drive MS-DAT low.  Measuring with a 1mA resolution ammeter says that
0687  * the current on the SUS_3.3V rail drops from 3mA or 4mA to 0 when we do this.
0688  *
0689  * We have no formal spec that details this operation -- the low-power
0690  * sequence came from a long-lost email trail.
0691  */
0692 static int hgpk_toggle_powersave(struct psmouse *psmouse, int enable)
0693 {
0694     struct ps2dev *ps2dev = &psmouse->ps2dev;
0695     int timeo;
0696     int err;
0697
0698     /* Added on D-series touchpads */
0699     if (psmouse->model < HGPK_MODEL_D)
0700         return 0;
0701
0702     if (enable) {
0703         psmouse_set_state(psmouse, PSMOUSE_INITIALIZING);
0704
0705         /*
0706          * Sending a byte will drive MS-DAT low; this will wake up
0707          * the controller.  Once we get an ACK back from it, it
0708          * means we can continue with the touchpad re-init.  ALPS
0709          * tells us that 1s should be long enough, so set that as
0710          * the upper bound. (in practice, it takes about 3 loops.)
0711          */
0712         for (timeo = 20; timeo > 0; timeo--) {
0713             if (!ps2_sendbyte(ps2dev, PSMOUSE_CMD_DISABLE, 20))
0714                 break;
0715             msleep(25);
0716         }
0717
0718         err = hgpk_reset_device(psmouse, false);
0719         if (err) {
0720             psmouse_err(psmouse, "Failed to reset device!\n");
0721             return err;
0722         }
0723
0724         /* should be all set, enable the touchpad */
0725         psmouse_activate(psmouse);
0726         psmouse_dbg(psmouse, "Touchpad powered up.\n");
0727     } else {
0728         psmouse_dbg(psmouse, "Powering off touchpad.\n");
0729
0730         if (ps2_command(ps2dev, NULL, 0xec) ||
0731             ps2_command(ps2dev, NULL, 0xec) ||
0732             ps2_command(ps2dev, NULL, 0xea)) {
0733             return -1;
0734         }
0735
0736         psmouse_set_state(psmouse, PSMOUSE_IGNORE);
0737
0738         /* probably won't see an ACK, the touchpad will be off */
0739         ps2_sendbyte(ps2dev, 0xec, 20);
0740     }
0741
0742     return 0;
0743 }
0744
0745 static int hgpk_poll(struct psmouse *psmouse)
0746 {
0747     /* We can't poll, so always return failure. */
0748     return -1;
0749 }
0750
0751 static int hgpk_reconnect(struct psmouse *psmouse)
0752 {
0753     struct hgpk_data *priv = psmouse->private;
0754
0755     /*
0756      * During suspend/resume the ps2 rails remain powered.  We don't want
0757      * to do a reset because it's flush data out of buffers; however,
0758      * earlier prototypes (B1) had some brokenness that required a reset.
0759      */
0760     if (olpc_board_at_least(olpc_board(0xb2)))
0761         if (psmouse->ps2dev.serio->dev.power.power_state.event !=
0762                 PM_EVENT_ON)
0763             return 0;
0764
0765     priv->powered = 1;
0766     return hgpk_reset_device(psmouse, false);
0767 }
0768
0769 static ssize_t hgpk_show_powered(struct psmouse *psmouse, void *data, char *buf)
0770 {
0771     struct hgpk_data *priv = psmouse->private;
0772
0773     return sprintf(buf, "%d\n", priv->powered);
0774 }
0775
0776 static ssize_t hgpk_set_powered(struct psmouse *psmouse, void *data,
0777                 const char *buf, size_t count)
0778 {
0779     struct hgpk_data *priv = psmouse->private;
0780     unsigned int value;
0781     int err;
0782
0783     err = kstrtouint(buf, 10, &value);
0784     if (err)
0785         return err;
0786
0787     if (value > 1)
0788         return -EINVAL;
0789
0790     if (value != priv->powered) {
0791         /*
0792          * hgpk_toggle_power will deal w/ state so
0793          * we're not racing w/ irq
0794          */
0795         err = hgpk_toggle_powersave(psmouse, value);
0796         if (!err)
0797             priv->powered = value;
0798     }
0799
0800     return err ? err : count;
0801 }
0802
0803 __PSMOUSE_DEFINE_ATTR(powered, S_IWUSR | S_IRUGO, NULL,
0804               hgpk_show_powered, hgpk_set_powered, false);
0805
0806 static ssize_t attr_show_mode(struct psmouse *psmouse, void *data, char *buf)
0807 {
0808     struct hgpk_data *priv = psmouse->private;
0809
0810     return sprintf(buf, "%s\n", hgpk_mode_names[priv->mode]);
0811 }
0812
0813 static ssize_t attr_set_mode(struct psmouse *psmouse, void *data,
0814                  const char *buf, size_t len)
0815 {
0816     struct hgpk_data *priv = psmouse->private;
0817     enum hgpk_mode old_mode = priv->mode;
0818     enum hgpk_mode new_mode = hgpk_mode_from_name(buf, len);
0819     struct input_dev *old_dev = psmouse->dev;
0820     struct input_dev *new_dev;
0821     int err;
0822
0823     if (new_mode == HGPK_MODE_INVALID)
0824         return -EINVAL;
0825
0826     if (old_mode == new_mode)
0827         return len;
0828
0829     new_dev = input_allocate_device();
0830     if (!new_dev)
0831         return -ENOMEM;
0832
0833     psmouse_set_state(psmouse, PSMOUSE_INITIALIZING);
0834
0835     /* Switch device into the new mode */
0836     priv->mode = new_mode;
0837     err = hgpk_reset_device(psmouse, false);
0838     if (err)
0839         goto err_try_restore;
0840
0841     hgpk_setup_input_device(new_dev, old_dev, new_mode);
0842
0843     psmouse_set_state(psmouse, PSMOUSE_CMD_MODE);
0844
0845     err = input_register_device(new_dev);
0846     if (err)
0847         goto err_try_restore;
0848
0849     psmouse->dev = new_dev;
0850     input_unregister_device(old_dev);
0851
0852     return len;
0853
0854 err_try_restore:
0855     input_free_device(new_dev);
0856     priv->mode = old_mode;
0857     hgpk_reset_device(psmouse, false);
0858
0859     return err;
0860 }
0861
0862 PSMOUSE_DEFINE_ATTR(hgpk_mode, S_IWUSR | S_IRUGO, NULL,
0863             attr_show_mode, attr_set_mode);
0864
0865 static ssize_t hgpk_trigger_recal_show(struct psmouse *psmouse,
0866         void *data, char *buf)
0867 {
0868     return -EINVAL;
0869 }
0870
0871 static ssize_t hgpk_trigger_recal(struct psmouse *psmouse, void *data,
0872                 const char *buf, size_t count)
0873 {
0874     struct hgpk_data *priv = psmouse->private;
0875     unsigned int value;
0876     int err;
0877
0878     err = kstrtouint(buf, 10, &value);
0879     if (err)
0880         return err;
0881
0882     if (value != 1)
0883         return -EINVAL;
0884
0885     /*
0886      * We queue work instead of doing recalibration right here
0887      * to avoid adding locking to to hgpk_force_recalibrate()
0888      * since workqueue provides serialization.
0889      */
0890     psmouse_queue_work(psmouse, &priv->recalib_wq, 0);
0891     return count;
0892 }
0893
0894 __PSMOUSE_DEFINE_ATTR(recalibrate, S_IWUSR | S_IRUGO, NULL,
0895               hgpk_trigger_recal_show, hgpk_trigger_recal, false);
0896
0897 static void hgpk_disconnect(struct psmouse *psmouse)
0898 {
0899     struct hgpk_data *priv = psmouse->private;
0900
0901     device_remove_file(&psmouse->ps2dev.serio->dev,
0902                &psmouse_attr_powered.dattr);
0903     device_remove_file(&psmouse->ps2dev.serio->dev,
0904                &psmouse_attr_hgpk_mode.dattr);
0905
0906     if (psmouse->model >= HGPK_MODEL_C)
0907         device_remove_file(&psmouse->ps2dev.serio->dev,
0908                    &psmouse_attr_recalibrate.dattr);
0909
0910     psmouse_reset(psmouse);
0911     kfree(priv);
0912 }
0913
0914 static void hgpk_recalib_work(struct work_struct *work)
0915 {
0916     struct delayed_work *w = to_delayed_work(work);
0917     struct hgpk_data *priv = container_of(w, struct hgpk_data, recalib_wq);
0918     struct psmouse *psmouse = priv->psmouse;
0919
0920     if (hgpk_force_recalibrate(psmouse))
0921         psmouse_err(psmouse, "recalibration failed!\n");
0922 }
0923
0924 static int hgpk_register(struct psmouse *psmouse)
0925 {
0926     struct hgpk_data *priv = psmouse->private;
0927     int err;
0928
0929     /* register handlers */
0930     psmouse->protocol_handler = hgpk_process_byte;
0931     psmouse->poll = hgpk_poll;
0932     psmouse->disconnect = hgpk_disconnect;
0933     psmouse->reconnect = hgpk_reconnect;
0934
0935     /* Disable the idle resync. */
0936     psmouse->resync_time = 0;
0937     /* Reset after a lot of bad bytes. */
0938     psmouse->resetafter = 1024;
0939
0940     hgpk_setup_input_device(psmouse->dev, NULL, priv->mode);
0941
0942     err = device_create_file(&psmouse->ps2dev.serio->dev,
0943                  &psmouse_attr_powered.dattr);
0944     if (err) {
0945         psmouse_err(psmouse, "Failed creating 'powered' sysfs node\n");
0946         return err;
0947     }
0948
0949     err = device_create_file(&psmouse->ps2dev.serio->dev,
0950                  &psmouse_attr_hgpk_mode.dattr);
0951     if (err) {
0952         psmouse_err(psmouse,
0953                 "Failed creating 'hgpk_mode' sysfs node\n");
0954         goto err_remove_powered;
0955     }
0956
0957     /* C-series touchpads added the recalibrate command */
0958     if (psmouse->model >= HGPK_MODEL_C) {
0959         err = device_create_file(&psmouse->ps2dev.serio->dev,
0960                      &psmouse_attr_recalibrate.dattr);
0961         if (err) {
0962             psmouse_err(psmouse,
0963                     "Failed creating 'recalibrate' sysfs node\n");
0964             goto err_remove_mode;
0965         }
0966     }
0967
0968     return 0;
0969
0970 err_remove_mode:
0971     device_remove_file(&psmouse->ps2dev.serio->dev,
0972                &psmouse_attr_hgpk_mode.dattr);
0973 err_remove_powered:
0974     device_remove_file(&psmouse->ps2dev.serio->dev,
0975                &psmouse_attr_powered.dattr);
0976     return err;
0977 }
0978
0979 int hgpk_init(struct psmouse *psmouse)
0980 {
0981     struct hgpk_data *priv;
0982     int err;
0983
0984     priv = kzalloc(sizeof(struct hgpk_data), GFP_KERNEL);
0985     if (!priv) {
0986         err = -ENOMEM;
0987         goto alloc_fail;
0988     }
0989
0990     psmouse->private = priv;
0991
0992     priv->psmouse = psmouse;
0993     priv->powered = true;
0994     priv->mode = hgpk_default_mode;
0995     INIT_DELAYED_WORK(&priv->recalib_wq, hgpk_recalib_work);
0996
0997     err = hgpk_reset_device(psmouse, false);
0998     if (err)
0999         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 }